ORCID Profile
0000-0002-5978-6453
Current Organisation
University of Adelaide
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Publisher: AMPCo
Date: 04-1993
Publisher: Proceedings of the National Academy of Sciences
Date: 25-04-1995
Abstract: The human genome contains many repeated DNA sequences that vary in complexity of repeating unit from a single nucleotide to a whole gene. The repeat sequences can be widely dispersed or in simple tandem arrays. Arrays of up to 5 or 6 nt are known as simple tandem repeats, and these are widely dispersed and highly polymorphic. Members of one group of the simple tandem repeats, the trinucleotide repeats, can undergo an increase in copy number by a process of dynamic mutation. Dynamic mutations of the CCG trinucleotide give rise to one group of fragile sites on human chromosomes, the rare folate-sensitive group. One member of this group, the fragile X (FRAXA) is responsible for the most common familial form of mental retardation. Another member of the group FRAXE is responsible for a rarer mild form of mental retardation. Similar mutations of AGC repeats give rise to a number of neurological disorders. The expanded repeats are unstable between generations and somatically. The intergenerational instability gives rise to unusual patterns of inheritance--particularly anticipation, the increasing severity and/or earlier age of onset of the disorder in successive generations. Dynamic mutations have been found only in the human species, and possible reasons for this are considered. The mechanism of dynamic mutation is discussed, and a number of observations of simple tandem repeat mutation that could assist in understanding this phenomenon are commented on.
Publisher: Oxford University Press (OUP)
Date: 30-06-2011
DOI: 10.1093/HMG/DDR292
Publisher: Wiley
Date: 27-06-1997
DOI: 10.1002/(SICI)1096-8628(19970627)70:4<357::AID-AJMG5>3.0.CO;2-Q
Abstract: The diet-induced obesity (DIO) mouse model has been widely used for obesity studies. The effects of storage conditions on the composition of nutrients in high-fat diets (HFDs) and their impact on metabolic homeostasis have not been systemically investigated. In the current study, we tested the effects of HFDs stored under different conditions and found that mice fed a HFD stored in the fridge (HFD
Publisher: Springer Science and Business Media LLC
Date: 04-1992
DOI: 10.1038/NG0492-7
Abstract: Novel agarose-dextran hydrogels were synthesized and their suitability as experimental models of glomerular basement membrane was examined by measuring their Darcy (hydraulic) permeabilities (kappa). Immobilization of large dextran molecules in agarose was achieved by electron beam irradiation. Composite gels were made with agarose volume fractions (phi(a)) of 0.04 or 0.08 and dextran volume fractions (phi(d)) ranging from 0 to 0.02 (fiber volume/gel volume), using either of two dextran molecular weights (500 or 2000). At either agarose concentration and for either size of dextran, kappa decreased markedly as the amount of dextran was increased. Statistically significant deviations from the value of kappa for pure agarose were obtained for remarkably small volume fractions of dextran: phi(d) > or = 0.0003 for phi(a) = 0.04 and phi(d) > or = 0.001 for phi(a) = 0.08. The Darcy permeabilities were much more sensitive to phi(d) than to phi(a), and were as much as 26 times smaller than those of pure agarose. Although phi(d) was an important variable, dextran molecular weight was not. The effects of dextran addition on kappa were described fairly well using simple structural idealizations. At high agarose concentrations, the dextran chains behaved as fine fibers interspersed among coarse agarose fibrils, whereas, at low concentrations, the dextran molecules began to resemble spherical obstacles embedded in agarose gels. The ability to achieve physiologically relevant Darcy permeabilities with these materials (as low as 1.6 nm2) makes them an attractive experimental model for glomerular basement membrane and possibly other extracellular matrices.
Publisher: Springer Science and Business Media LLC
Date: 10-1982
DOI: 10.1038/299797A0
Abstract: The complete nucleotide sequence of two of the human metallothionein gene family has been compared. One is a functional metallothionein-II gene, the other a pseudogene, lacking introns, terminating in a poly(A) tail and flanked by two direct repeats. In addition, we have detected a size polymorphism associated with the processed gene in the population, examined, and we have observed a region of apparent secondary structure homology between of 5' flanking region of the functional metallothionein-II gene and that of a mouse metallothionein-I gene.
Publisher: Bioscientifica
Date: 08-1992
Abstract: The angiotensinogen gene encodes the precursor protein for the potent vasoconstrictor angiotensin II. Although the gene is expressed in several tissues, the liver is the major source of circulating protein. In previous in-vivo studies we have found that a mini-gene containing 750 bp of 5'-flanking sequence is transcribed in a manner which largely parallels the expression of the endogenous gene. In this report, we characterized conserved elements in the promoter region, in order to determine their role in the transcription of the angiotensinogen gene. Constructs fused to the chlor henicol acetyl transferase (CAT) reporter gene were transfected into hepatocarcinoma Hep G2 cells as well as into nonhepatic cell lines. We found that 5'-deletion mutant constructs, containing sequences from +25 to -90 bp and -321 to -750 bp, were each able to activate transcription. These constructs contain the TATA box and core promoter sequences, including an Sp1-binding site, and two glucocorticoid responsive elements respectively. In the non-hepatic cell lines, HeLa and Jeg-3, we found that the constructs were transcribed at a much lower rate when compared with the expression of a plasmid containing the Rous sarcoma virus long terminal repeat fused to the CAT gene. Constructs which included sequence 5' to -244 were oestrogen inducible. An element which is conserved between rodent and human angiotensinogen promoters is contained within a sequence which is oestrogen responsive, while another binds the liver-enriched transcriptional activator hepatocyte nuclear factor 1. However, the role of this transactivator in the transcription of angiotensinogen remains uncertain.
Publisher: Oxford University Press (OUP)
Date: 25-04-2011
DOI: 10.1093/HMG/DDR177
Publisher: Hindawi Limited
Date: 09-2005
DOI: 10.1002/HUMU.20206
Abstract: Pseudoxanthoma elasticum (PXE) is a systemic heritable disorder that affects the elastic tissue in the skin, eye, and cardiovascular system. Mutations in the ABCC6 gene cause PXE. We performed a mutation screen in ABCC6 using haplotype analysis in conjunction with direct sequencing to achieve a mutation detection rate of 97%. This screen consisted of 170 PXE chromosomes in 81 families, and detected 59 distinct mutations (32 missense, eight nonsense, and six likely splice-site point mutations one small insertion and seven small and five large deletions). Forty-three of these mutations are novel variants, which increases the total number of PXE mutations to 121. While most mutations are rare, three nonsense mutations, a splice donor site mutation, and the large deletion comprising exons 23-29 (c.2996_4208del) were identified as relatively frequent PXE mutations at 26%, 5%, 3.5%, 3%, and 11%, respectively. Chromosomal haplotyping with two proximal and two distal polymorphic markers flanking ABCC6 demonstrated that most chromosomes that carry these relatively frequent PXE mutations have related haplotypes specific for these mutations, which suggests that these chromosomes originate from single founder mutations. The types of mutations found support loss-of-function as the molecular mechanism for the PXE phenotype. In 76 of the 81 families, the affected in iduals were either homozygous for the same mutation or compound heterozygous for two mutations. In the remaining five families with one uncovered mutation, affected showed allelic compound heterozygosity for the cosegregating PXE haplotype. This demonstrates pseudo-dominance as the relevant inheritance mechanism, since disease transmission to the next generation always requires one mutant allelic variant from each parent. In contrast to other previous clinical and molecular claims, our results show evidence only for recessive PXE. This has profound consequences for the genetic counseling of families with PXE.
Publisher: Elsevier BV
Date: 08-1997
DOI: 10.1016/S0092-8674(00)80539-5
Abstract: Familial Mediterranean fever (FMF) is a recessively inherited disorder characterized by dramatic episodes of fever and serosal inflammation. This report describes the cloning of the gene likely to cause FMF from a 115-kb candidate interval on chromosome 16p. Three different missense mutations were identified in affected in iduals, but not in normals. Haplotype and mutational analyses disclosed ancestral relationships among carrier chromosomes in populations that have been separated for centuries. The novel gene encodes a 3.7-kb transcript that is almost exclusively expressed in granulocytes. The predicted protein, pyrin, is a member of a family of nuclear factors homologous to the Ro52 autoantigen. The cloning of the FMF gene promises to shed light on the regulation of acute inflammatory responses.
Publisher: Elsevier BV
Date: 08-1991
DOI: 10.1016/0888-7543(91)90197-M
Abstract: Physical mapping of human chromosome 16 has been undertaken using somatic cell hybrid DNAs as templates for polymerase chain reaction (PCR) deletion analysis of sequence tagged sites (STSs). A panel of 29 somatic cell hybrids was analyzed, confirming and refining previous chromosome 16 breakpoint orders and distinguishing between the locations of breakpoints in new hybrids. Ten STS markers were co lified in three multiplex reactions allowing the rapid, simultaneous deletion analysis of nine different loci. The locations of the protamine (PRM1), sialophorin (SPN), complement component receptor 3A (CR3A), NAD(P)H menadione oxidoreductase 1 (NMOR1), and calbindin (CALB2) genes were refined.
Publisher: Springer Science and Business Media LLC
Date: 05-1983
DOI: 10.1038/303300A0
Abstract: The glandular kallikrein gene family comprises 25-30 highly homologous genes that encode specific proteases involved in the processing of biologically active peptides. In the mouse all the members of this family are closely linked on chromosome 7. The 9.5-kilobase nucleotide sequence of a mouse genomic clone contains one complete kallikrein gene (mGK-1), which is expressed in the male mouse submaxillary gland, and the 3' end of another (mGK-2). Differences in the coding potential of these genes and the amino acid sequences of other known kallikreins seem to be functionally related to the substrate specificity of the different enzymes.
Publisher: Elsevier
Date: 2006
Publisher: Oxford University Press (OUP)
Date: 1979
DOI: 10.1093/NAR/7.5.1137
Abstract: The molecular cloning and nucleotide sequence analysis of adult chicken beta globin mRNA is reported. DNA sequences derived from in vitro transcrption of globin mRNA were purified and lified as recombinant DNA using the plasmid pBR322. Sequence analysis of several clones coding for beta globin strongly suggests that transcription errors may be generated near the 5' end of transcripts in vitro by reverse transcription. The complete sequence of the longest beta globin insert containing 51 bases of the 5' untranslated region as well as the complete coding and 3' untranslated regions has been determined.
Publisher: Environmental Health Perspectives
Date: 03-1984
DOI: 10.1289/EHP.8454111
Abstract: Metallothioneins (MTs) are encoded by a multigene family in man. We have isolated those genes and analyzed the structure of some of them. The MT-II variant is encoded by a single functional gene: MT-IIA. The MT-IIB gene is a processed pseudogene derived from a reverse transcript of MT-II mRNA. On the other hand, the MT-I class of variants are encoded by a large number of genes, arranged in tandem. The MT-IIA and the MT-IA genes show a differential response to glucocorticoid hormones and heavy metals, yet they are both expressed in primary human fibroblasts and in HeLa cells. Expression of both of those genes, in high level after transfer on bovine papilloma virus vectors, leads to increased resistance of the host cells to cadmium-induced toxicity.
Publisher: Springer Science and Business Media LLC
Date: 28-06-2007
DOI: 10.1038/NATURE05887
Publisher: Birkhäuser Basel
Date: 1992
Publisher: Bioscientifica
Date: 09-1989
Abstract: We have used a DNA-cellulose competition assay to investigate the binding of thyroid hormone receptors to fragments of the mouse glandular kallikrein genes and the human and rat GH genes. Nuclear extracts from human lymphoblastoid IM-9 cells were incubated with [ 125 I]tri-iodothyronine ([ 125 I]T 3 ) and DNA-cellulose. The ability of cloned gene fragments to compete for radiolabelled receptors bound to DNA-cellulose was compared with that of DNA from pBR322. As previously observed, a 900 bp fragment from the human GH gene showed preferential binding to the thyroid hormone receptor. High-affinity binding was observed with a synthetic fragment of the rat GH gene encompassing positions − 163 to − 192 but not with a similar fragment from positions −224 to −192. Preferential binding was also observed with fragments of the mouse glandular kallikrein gene, mGK-6. Binding to the entire gene and fragments containing 2300 and 776 bp of the promoter region was identical. Detectable but reduced binding was seen with a shorter fragment. These results suggest that the T 3 receptor binds to multiple sites within the first 776 bp of the mGK-6 gene promoter. Potential thyroid hormone response elements can be identified within this region of the gene. In contrast, the kallikrein gene mGK-3, which shows a different response to thyroid hormone from that of mGK-6, showed no significant binding in the comparable promoter region.
Publisher: Elsevier BV
Date: 12-1998
DOI: 10.1016/S0168-9525(98)01628-X
Abstract: Rare fragile sites on chromosomes are the archetypal dynamic mutations. They involve large expansions of the microsatellite CCG or AT-rich minisatellites. The mutation process is an increase in repeat-unit number from within a normal range, through a premutation range, up to full mutation where the fragile site is expressed. Full mutations can inactivate genes and are regions of genomic instability. Common fragile sites, in particular, might have a role in oncogensis by facilitating gene inactivation through chromosomal deletion or lification, but this requires further exploration. The mechanisms behind the changes that give rise to the cytogenetic manifestation of chromosomal fragility are now beginning to be understood.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 24-05-1991
DOI: 10.1126/SCIENCE.252.5009.1179
Abstract: DNA sequences have been located at the fragile X site by in situ hybridization and by the mapping of breakpoints in two somatic cell hybrids that were constructed to break at the fragile site. These hybrids were found to have breakpoints in a common 5-kilobase Eco RI restriction fragment. When this fragment was used as a probe on the chromosomal DNA of normal and fragile X genotype in iduals, alterations in the mobility of the sequences detected by the probe were found only in fragile X genotype DNA. These sequences were of an increased size in all fragile X in iduals and varied within families, indicating that the region was unstable. This probe provides a means with which to analyze fragile X pedigrees and is a diagnostic reagent for the fragile X genotype.
Publisher: Elsevier BV
Date: 09-1992
Publisher: Oxford University Press (OUP)
Date: 12-11-2010
DOI: 10.1093/HMG/DDQ495
Publisher: Springer Science and Business Media LLC
Date: 04-1984
DOI: 10.1038/308513A0
Abstract: Deletion experiments have defined two stretches of DNA (genetic elements), lying close to the promoter for a human gene for metallothionein, that separately mediate the induction of the gene by heavy metal ions, particularly cadmium, and by glucocorticoid hormones. The element responsible for induction by cadmium is duplicated, yet a single copy is fully functional the element responsible for induction by glucocorticoid hormones is coincident with the DNA-binding site for the glucocorticoid hormone receptor.
Publisher: Wiley
Date: 1992
Publisher: Oxford University Press (OUP)
Date: 19-04-2018
DOI: 10.1093/HMG/DDY139
Publisher: Humana Press
Date: 2013
Publisher: Springer Science and Business Media LLC
Date: 07-12-2006
Publisher: Elsevier BV
Date: 06-2001
DOI: 10.1016/S0168-9525(01)02303-4
Abstract: Cancer cells commonly exhibit various forms of genetic instability, such as changes in chromosome copy number, translocations and point mutations in particular genes. Although transmissible change seems to be an essential part of the neoplastic process, the extent to which DNA instability is a cause rather than a consequence of cancer is unclear. Chromosomal fragile sites have been proposed to be not only susceptible to DNA instability in cancer cells, but also associated with genes that contribute to the neoplastic process. Mutation at fragile site loci might therefore have a causative role in cancer. Recent studies on one class of human chromosomal fragile sites show that instability at fragile site loci can functionally contribute to tumor cell biology.
Publisher: Wiley
Date: 15-07-1994
Abstract: Fragile X syndrome, one of the most common human genetic diseases, is characterized by a unique genetic mechanism which involves dynamic mutation in a heritable unstable DNA sequence, a p(CCG)n repeat, in the FRAXA locus. It has recently been suggested that a few founder chromosomes are responsible for most fragile X mutations in the Caucasian population. In order to investigate the origin of the fragile X mutations in the Japanese population, we analyzed haplotypes of the FRAXA locus in 40 unrelated fragile X chromosomes and 142 normal X chromosomes in Japanese males, by using two polymorphic AC repeats, FRAXAC1 and FRAXAC2, which flank the fragile site. This analysis provided evidence for founder fragile X chromosomes in the Japanese population, similar to that in Caucasians, although different haplotypes are involved. The distribution of normal allele size of the p(CCG)n repeat among the X chromosomes in the Japanese population is very similar to that reported for Caucasians, except that the most frequent copy number (n = 28) is one copy less than that in Caucasians and that there is an additional peak at 35 copies. There is significant correlation between FRAXAC alleles and the p(CCG)n repeat copy number in non-fragile X chromosomes, however, alleles with more than 31 copies of the p(CCG)n repeat do not segregate with either of the fragile X common FRAXAC haplotypes.
Publisher: Oxford University Press (OUP)
Date: 1987
Abstract: One of the strategies that plants employ to defend themselves against herbivore attack is the induced production of carnivore-attracting volatiles. Using elicitors and inhibitors of different steps of the signal-transduction pathways can improve our understanding of the mechanisms underlying induced plant defenses. For instance, we recently showed that application of jasmonic acid, a key hormone in the octadecanoid pathway involved in herbivore-induced defense, to Brassica oleracea affects gene expression, hormone levels, and volatile emission, as well as oviposition by herbivores and host location behavior by parasitoids. Such defense responses vary with the dose of the elicitor and with time since application. This addendum describes how the use of inhibitors, in addition to the use of elicitors like jasmonic acid, can be applied in bio-assays to investigate the role of signal-transduction pathways involved in induced plant defense. We show how inhibition of different steps of the octadecanoid pathway affects host location behavior by parasitoids.
Publisher: Oxford University Press (OUP)
Date: 13-06-2007
DOI: 10.1093/HMG/DDM138
Abstract: Huntington's disease (HD) is one of nine neurodegenerative disorders caused by expansion of CAG repeats encoding polyglutamine in their respective, otherwise apparently unrelated proteins. Despite these proteins having widespread and overlapping expression patterns in the brain, a specific and unique subset of neurons exhibits particular vulnerability in each disease. It has been hypothesized that perturbation of normal protein function contributes to the specificity of neuronal vulnerability however, the normal biological functions of many of these proteins including the HD gene product, Huntingtin (Htt), are unclear. To explore the roles of Htt, we have used antisense morpholino oligonucleotides to observe the effects of Htt deficiency in early zebrafish development. Knockdown of Htt expression resulted in a variety of developmental defects. Most notably, Htt-deficient zebrafish had hypochromic blood due to decreased hemoglobin production, despite the presence of iron within blood cells. Furthermore, transferrin receptor 1 transcripts were increased, suggesting cellular iron starvation. Provision of iron to the cytoplasm in a bio-available form restored hemoglobin production in Htt-deficient embryos. Since erythroid cells acquire iron via receptor-mediated endocytosis of transferrin, these results suggest a role for Htt in making endocytosed iron accessible for cellular utilization. Iron is required for oxidative energy production, and defects in iron homeostasis and energy metabolism are features of HD pathogenesis that are most pronounced in the major region of neurodegeneration. It is therefore plausible that perturbation of Htt's normal role in the iron pathway (by polyglutamine tract expansion) contributes to HD pathology, and particularly to its neuronal specificity.
Publisher: Oxford University Press (OUP)
Date: 1991
Publisher: Oxford University Press (OUP)
Date: 1991
Publisher: Oxford University Press (OUP)
Date: 1993
DOI: 10.1093/HMG/2.9.1504
Publisher: Springer Science and Business Media LLC
Date: 2000
Abstract: We have recently mapped the genetic defect underlying pseudoxanthoma elasticum (PXE), an inherited disorder characterized by progressive calcification of elastic fibers in skin, eye, and cardiovascular system, to chromosome 16p 13.1. Here we report further data on the fine-mapping and genomic structure of this locus. Haplotype analysis of informative PXE families narrowed the locus to an interval of less than 500 kb located between markers D16B9621 and D16S764. Three overlapping YAC clones were found to cover this region through YAC-STS content mapping. An overlapping BAC contig was then constructed to cover this interval and the surrounding region. About 80% of this chromosomal region has been fully sequenced using the BAC shotgun technique. Gene content and sequence analysis predicted four genes (MRP1, MRP6, PM5, and a novel transcript) and two pseudogenes (ARA and PKDI) within this interval. By screening a somatic cell hybrid panel we were able to precision-map the breakpoint of Cy185 and the starting point of a chromosomal duplication within 20 kb of BAC A962B4. The present data further refine the localization of PXE, provide additional physical cloning resources, and will aid in the eventual identification of the genetic defect causing PXE.
Publisher: BMJ
Date: 03-1995
DOI: 10.1136/JMG.32.3.162
Abstract: Mental impairment and instability of the CCG repeat at FRAXE is described in six kindreds. Cosegregation of FRAXA and FRAXE was found within one of these kindreds. Cytogenetic expression of FRAXE was shown to skip a generation when associated with a reduction in size of the CCG expansion when transmitted through a male however, in general, transmission occurred through females and a copy number increased from one generation to the next. In these respects the behaviour of FRAXE paralleled that of FRAXA. A relationship between FRAXE and non-specific mental impairment is strongly suggested by the occurrence in these families of more mentally impaired male and female carriers, after removal of index cases, than could reasonably be expected by chance.
Publisher: Oxford University Press (OUP)
Date: 1993
DOI: 10.1093/HMG/2.9.1505
Publisher: Oxford University Press (OUP)
Date: 1993
DOI: 10.1093/HMG/2.9.1506
Publisher: Springer Science and Business Media LLC
Date: 26-05-2000
Abstract: We recently published the precise chromosomal localization on chromosome 16p13.1 of the genetic defect underlying pseudoxanthoma elasticum (PXE), an inherited disorder characterized by progressive calcification of elastic fibers in skin, eye, and the cardiovascular system. Here we report the identification of mutations in the gene encoding the transmembrane transporter protein, ABC-C6 (also known as MRP-6), one of the four genes located in the region of linkage, as cause of the disease. Sequence analysis in four independent consanguineous families from Switzerland, Mexico, and South Africa and in one non-consanguineous family from the United States demonstrated several different mis-sense mutations to cosegregate with the disease phenotype. These findings are consistent with the conclusion that PXE is a recessive disorder that displays allelic heterogeneity, which may explain the considerable phenotypic variance characteristic of the disorder.
Publisher: Oxford University Press (OUP)
Date: 21-03-2013
DOI: 10.1093/HMG/DDT130
Publisher: Springer Science and Business Media LLC
Date: 17-09-2004
DOI: 10.1007/S00427-004-0438-9
Abstract: The human fragile X mental retardation syndrome is caused by expansions of a CGG repeat in the FMR1 gene. FXR1 and FXR2 are autosomal paralogs of FMR1. The products of the three genes, FMRP, FXR1P, and FXR2P, respectively, belong to a family of RNA-binding proteins. While the FMR1-related gene family is well described in human, mouse and Drosophila, little is known about zebrafish (Danio rerio) orthologs of these genes. Here we collate the known FMR1-related gene sequences from zebrafish, examine their regions of structural conservation, and define their orthologies with the human genes. We demonstrate that zebrafish possess only three FMR1-related genes, fmr1, fxr1 and fxr2, and these are orthologous to the human FMR1, FXR1 and FXR2 genes respectively. We examine the spatiotemporal pattern of transcription of the zebrafish genes from 0 hours post fertilisation (hpf) until 24 hpf. Expression of fmr1, fxr1 and fxr2 is widespread throughout this time. However, relative to surrounding tissues, expression of fxr2 is raised in adaxial and somitic cells by 12 hpf while fxr1 expression is high in the anterior of the embryo, and is raised in adaxial cells by 12 hpf. Distinct patterns (and levels) of expression are seen for the different genes later in development. At 24 hpf, fxr1 and fxr2 transcripts show complex distribution patterns in somites. The expression of the FMR1-related gene family in zebrafish tissues is broadly consistent with expression in mouse and human, supporting the idea that zebrafish should be an excellent model organism in which to study the functions of the vertebrate FMR1-related gene family.
Publisher: Elsevier BV
Date: 05-1988
DOI: 10.1016/0968-0004(88)90144-2
Abstract: Recruitment of patients by health professionals is reported as one of the most challenging steps when undertaking studies in primary care settings. Numerous investigations of the barriers to patient recruitment in trials which recruit patients to receive an intervention have been published. However, we are not aware of any studies that have reported on the recruitment barriers as perceived by health professionals to recruiting patients into cluster randomised trials where patients do not directly receive an intervention. This particular subtype of cluster trial is commonly termed a professional-cluster trial. The aim of this study was to investigate factors that contributed to general practitioners recruitment of patients in a professional-cluster trial which evaluated the effectiveness of an intervention to increase general practitioners adherence to a clinical practice guideline for acute low-back pain. General practitioners enrolled in the study were posted a questionnaire, consisting of quantitative items and an open-ended question, to assess possible reasons for poor patient recruitment. Descriptive statistics were used to summarise quantitative items and responses to the open-ended question were coded into categories. Seventy-nine general practitioners completed at least one item (79/94 = 84%), representing 68 practices (85% practice response rate), and 44 provided a response to the open-ended question. General practitioners recalled inviting a median of two patients with acute low-back pain to participate in the trial over a seven-month period they reported that they intended to recruit patients, but forgot to approach patients to participate and they did not perceive that patients had a strong interest or disinterest in participating. Additional open-ended comments were generally consistent with the quantitative data. A number of barriers to the recruitment of patients with acute low-back pain by general practitioners in a professional-cluster trial were identified. These barriers were similar to those that have been identified in the literature surrounding the recruitment of patients in in idual patient randomised trials. To advance the evidence base for patient recruitment strategies in primary care settings, trialists undertaking professional-cluster trials need to develop and evaluate patient recruitment strategies that minimise the efforts required by practice staff to recruit patients, while also meeting privacy and ethical responsibilities and minimising the risk of selection bias.
Publisher: BMJ
Date: 12-1991
Abstract: We report the genetic localisation of the fragile site at Xq27.3 associated with fragile X syndrome. The position of the fragile site within the multipoint linkage map was determined using two polymorphic microsatellite AC repeat markers FRAXAC1 and FRAXAC2. These markers were physically located within 10 kilobases and on either side of the p(CCG)n repeat responsible for the fragile site. FRAXAC1 has five alleles with heterozygosity of 44% and is in strong linkage disequilibrium with FRAXAC2 which has eight alleles and a heterozygosity of 71%. No recombination was observed either between these markers in 40 normal CEPH pedigrees or with the fragile X in affected pedigrees. These markers provide the means for accurate diagnosis of the fragile X genotype in families by rapid polymerase chain reaction analysis and were used to position the fragile X within the multipoint map of the X chromosome to a position 3.7 cM distal to DXS297 and 1.2 cM proximal to DXS296.
Publisher: Springer New York
Date: 2012
Publisher: Oxford University Press (OUP)
Date: 1989
Publisher: Oxford University Press (OUP)
Date: 29-09-2009
DOI: 10.1093/HMG/DDP455
Publisher: Elsevier BV
Date: 06-1991
DOI: 10.1016/0888-7543(91)90313-4
Abstract: Mapping of 33 anonymous DNA probes and 12 genes to the long arm of chromosome 16 was achieved by the use of 14 mouse/human hybrid cell lines and the fragile site FRA16B. Two of the hybrid cell lines contained overlapping interstitial deletions in bands q21 and q22.1. The localization of the 12 genes has been refined. The breakpoints present in the hybrids, in conjunction with the fragile site, can potentially ide the long arm of chromosome 16 into 16 regions. However, this was reduced to 14 regions because in two instances there were no probes or genes that mapped between pairs of breakpoints.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 28-12-2004
DOI: 10.1212/01.WNL.0000147299.80872.D1
Abstract: Background: Most patients with pure nonprogressive congenital cerebellar ataxia have a sporadic form of unknown heredity and etiology. Several small families have been reported with a dominantly inherited nonprogressive congenital ataxia (NPCA). Methods: The authors ascertained and clinically characterized a four-generation pedigree segregating an autosomal dominant type of congenital nonprogressive cerebellar ataxia associated with cognitive impairment. Following the exclusion of several SCA localizations (SCA-1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 17, IOSCA, and DRPLA), a genome-wide linkage study was performed. Results: Examination of the family showed that all affected members had gait ataxia and cognitive disability with variable features of dysarthria, dysmetria, dysdiadochokinesia, nystagmus, dystonic movements, and cerebellar hypoplasia on imaging. Clinical signs of pyramidal tract dysfunction and sensory changes were absent. A genome-wide search in this family detected linkage to chromosome 3p with a maximum two-point lod score of 4.26 at D3S3630. This localization to the pter is distal to D3S1304, as defined by a recombination event. This overlaps with the SCA15 locus, with the critical overlapping region between the microsatellite markers, D3S1304 and D3S1620 (approximately 8 cM). Conclusion: Autosomal dominant congenital nonprogressive cerebellar ataxia with or without cerebellar hypoplasia overlaps with the SCA15 locus on chromosome 3pter.
Publisher: Springer Science and Business Media LLC
Date: 07-2004
DOI: 10.1038/NG0704-667
Publisher: Springer Science and Business Media LLC
Date: 11-08-2001
Abstract: Pseudoxanthoma elasticum (PXE) is an inherited disorder of the elastic tissue with characteristic progressive calcification of elastic fibers in skin, eye, and the cardiovascular system. Recently mutations in the ABCC6 gene, encoding a transmembrane transporter protein, were identified as cause of the disease. Surprisingly, sequence and RFLP analysis for exon 9 with primers corresponding to flanking intronic sequence in diseased and haplotype negative members from all of our families and in a control population revealed either a homozygous or heterozygous state for the Q378X (1132C-->T) nonsense mutation in all in iduals. With the publication of the genomic structure of the PXE locus we had identified the starting point of a large genomic segmental duplication within the locus in the cytogenetic interval defined by the Cy19 and Cy185 somatic cell hybrid breakpoints on chromosome 16p13.1. By means of somatic cell hybrid mapping we located this starting point telomeric to exon 10 of ABCC6. The duplication, however, does not include exon 10, but exons 1-9. These findings suggest that one or several copies of an ABCC6 pseudogene (psiABCC6) lie within this large segmental duplication. At least one copy contains exons 1-9 and maps to the chromosomal interval defined by the Cy163 and Cy11 breakpoints. Either this copy and/or an additional copy of psiABCC6 within Cy19-Cy183 carries the Q378X mutation that masks the correct identification of this nonsense mutation as being causative in pseudoxanthoma elasticum. Long-range PCR of exon 9 starting from sequence outside the genomic replication circumvents interference from the psiABCC6 DNA sequences and demonstrates that the Q378X mutation in the ABCC6 gene is associated with PXE in some families. These findings lead us to propose that gene conversion mechanisms from psiABCC6 to ABCC6 play a functional role in mutations causing PXE.
Publisher: Public Library of Science (PLoS)
Date: 24-08-2015
Publisher: Oxford University Press (OUP)
Date: 12-1992
DOI: 10.1093/HMG/1.9.773
Abstract: Glycerol is accumulated in response to environmental stresses in a erse range of organisms. Understanding of favorable in vivo effects of this solute requires insight into its interactions with biological macromolecules, and one access to this information is the quantification of so-called preferential interactions in glycerol-biopolymer solutions. For model membrane systems, preferential interactions have been discussed, but not directly measured. Hence, we have applied a new differential vapor pressure equipment to quantify the isoosmotic preferential binding parameter, Gamma( micro 1), for systems of unilamellar vesicles of DMPC in aqueous glycerol. It is found that Gamma( micro 1) decreases linearly with the glycerol concentration with a slope of -0.14 +/- 0.014 per molal. This implies that glycerol is preferentially excluded from the membrane-solvent interface. Calorimetric investigations of the same systems showed that the glycerol-DMPC interactions are weakly endothermic, and the temperature of the main phase transition increases slightly (0.16 degrees C per molal) with the glycerol concentration. The results are discussed with respect to a molecular picture which takes into account both the partitioning of glycerol into the membrane and the preferential exclusion from the hydration layer, and it is concluded that the latter effect contributes about four times stronger than the former to the net interaction.
Publisher: Elsevier BV
Date: 04-1988
DOI: 10.1016/0888-7543(88)90008-0
Abstract: We describe here the cloning, restriction mapping, and sequencing of the mouse angiotensinogen gene. The 5' flanking region contains consensus sequences for several hormone-responsive elements and viral-like enhancers within 750 bp of the cap site. The deduced amino acid sequence shows 87% identity with rat angiotensinogen, but there is a discrepancy in the number of cysteine residues in the mature protein among rat (n = 3), human (n = 4), and mouse (n = 4). Because angiotensinogen is homologous to other members of the serine protease inhibitor family, we aligned the putative reactive center of angiotensinogens from various species. This alignment shows that the inhibitor site in human angiotensinogen is different from its rodent counterpart, but the role of this sequence ergence in the pathogenesis of human disease remains to be established.
Publisher: Elsevier BV
Date: 05-1984
DOI: 10.1016/0092-8674(84)90322-2
Abstract: We describe a region of human DNA containing four metallothionein (hMT) genes. One of these genes, hMT-IA, was found to encode a functional protein that confers heavy metal resistance to NIH 3T3 cells after transfer on a bovine papilloma virus-derived vector. This gene is expressed in cultured human cell lines, but at a lower basal level than the hMT-IIA gene it shows a different induction response to heavy metals and glucocorticoids than the hMT-IIA gene. Induction of the human MT family therefore does not represent an equivalent elevation in the level of expression of in idual genes, but is the sum of the differential responses of active members. The differential response is due to functional differences of the respective promoter/regulatory regions of the genes as shown by gene-fusion experiments. While the hMT-IIA promoter is responsive to Cd++, Zn++, and glucocorticoids, the hMT-IA promoter mediates response only to Cd++.
Publisher: Springer Science and Business Media LLC
Date: 2000
Abstract: The molecular basis for the cytogenetic appearance of chromosomal fragile sites is not yet understood. Late replication and further delay of replication at fragile sites expressing alleles has been observed for FRAXA, FRAXE and FRA3B fragile site loci. We analysed the timing of replication at the FRA10B and FRA16B loci to determine whether late replication is a feature which is shared by all fragile sites and, therefore, is a necessary condition for chromosomal fragile site expression. The FRA10B locus was located in a transitional region between early and late zones of replication. Fragile and non-fragile alleles exhibit a similar replication pattern proximal to the repeat but fragile alleles are delayed relative to non-fragile ones on the distal side. Although fragility at FRA10B appears to be caused by expansion of an AT-rich repeat in the region, replication time near the repeat was similar in fragile and non-fragile alleles. The FRA16B locus was late replicating and appeared to replicate even later on fragile chromosomes. While these observations are compatible with the hypothesis that delayed replication may play a role in fragile site expression, they suggest that replication delay may not need to occur at the expanded repeat region itself in order to be permissive for fragility.
Publisher: Wiley
Date: 22-09-2015
DOI: 10.1002/GCC.22286
Abstract: Fragile site FRA16D exhibits DNA instability in cancer, resulting in diminished levels of protein from the WWOX gene that spans it. WWOX suppresses tumor growth by an undefined mechanism. WWOX participates in pathways involving aerobic metabolism and reactive oxygen species. WWOX comprises two WW domains as well as a short-chain dehydrogenase/reductase enzyme. Herein is described an in vivo genetic analysis in Drosophila melanogaster to identify functional interactions between WWOX and metabolic pathways. Altered WWOX levels modulate variable cellular outgrowths caused by genetic deficiencies of components of the mitochondrial respiratory complexes. This modulation requires the enzyme active site of WWOX, and the defective respiratory complex-induced cellular outgrowths are mediated by reactive oxygen species, dependent upon the Akt pathway and sensitive to levels of autophagy and hypoxia-inducible factor. WWOX is known to contribute to homeostasis by regulating the balance between oxidative phosphorylation and glycolysis. Reduction of WWOX levels results in diminished ability to respond to metabolic perturbation of normal cell growth. Thus, the ability of WWOX to facilitate escape from mitochondrial damage-induced glycolysis (Warburg effect) is, therefore, a plausible mechanism for its tumor suppressor activity.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 24-06-1994
Abstract: Fragile sites are chemically induced nonstaining gaps in chromosomes. Different fragile sites vary in frequency in the population and in the chemistry of their induction. DNA sequences encompassing and including the rare, autosomal, folate-sensitive fragile site, FRA16A, were isolated by positional cloning. The molecular basis of FRA16A was found to be expansion of a normally polymorphic p(CCG)n repeat. This repeat was adjacent to a CpG island that was methylated in fragile site-expressing in iduals. The FRA16A locus in in iduals who do not express the fragile site is not a site of DNA methylation (imprinting), which suggests that the methylation associated with fragile sites may be a consequence and not a cause of their genesis.
Publisher: Wiley
Date: 15-04-1992
Abstract: Genomic insert DNAs from 45 probes representing 113.4 kb of the X chromosome were screened for AC dinucleotide repeat sequence. Two new AC repeat sequences were identified with length polymorphism based on variation in repeat copy number. One at DXS237 exhibits 44% heterozygosity and is potentially useful for rapid diagnosis and mapping of X‐linked disorders in Xp22.3. The other, at DXS102 in Xq26, has 71% heterozygosity. This marker will improve accuracy of diagnoses by linkage for families with Börjeson‐Forssman‐Lehmann syndrome. Review of the literature has identified 31 PCR based markers on the X chromosome, with minimum heterozygosity of 50%, applicable to the mapping and diagnosis of X‐linked disorders.
Publisher: Oxford University Press (OUP)
Date: 21-10-2012
DOI: 10.1093/HMG/DDR487
Abstract: Homopolymeric amino acid repeat sequences in proteins are of particular interest due to the discovery that expanded copy numbers of these repeats are the molecular basis for a growing list of human genetic diseases. Repeat copy numbers above a typical normal range of polyglutamine repeats have been found to be the principal pathogenic agents in a number of these diseases, including Huntington's disease. There is emerging evidence that expansions of amino acids encoded by other reading frames of CAG/CUG repeats, including polyalanine and polyleucine, could contribute to toxicity in the 'polyglutamine' diseases. We have therefore used the Drosophila model system to investigate effects of ectopic expression of polyglutamine, polyleucine and polyalanine repeats in vivo to assess their relative toxicities and the common and distinct characteristics of the pathogenesis that they cause. We find that these homopolymeric sequences all exhibit toxicity and are able to form aggregates in Drosophila, although there are marked differences in the degree of toxicity dependent upon the tissue in which they are expressed.
Publisher: Frontiers Media SA
Date: 10-05-2016
Publisher: Oxford University Press (OUP)
Date: 1982
Abstract: From a cDNA clone bank prepared from cadmium-treated HeLa cells, we isolated clones representing mRNAs whose concentration is increased after cadmium induction. Several metallothionein cDNA clones were isolated by cross-hybridization to mouse metallothionein-I cDNA. The nucleotide sequence of one of these clones, containing a nearly full-length cDNA copy of human metallothionein-II mRNA, was determined. The homology between the human and mouse metallothionein sequences is strictly limited to the coding region of the mRNA. Codon usage in metallothionein mRNA is not random. Seventy-nine percent of the codons have G or C residues at the third position, resulting in a GC-rich sequence.
Publisher: Elsevier BV
Date: 02-1999
DOI: 10.1086/302267
Publisher: Wiley
Date: 1985
DOI: 10.1002/J.1460-2075.1985.TB02327.X
Abstract: Here we describe the structure and linkage of genes encoding the alpha and gamma subunits of mouse nerve growth factor (NGF). These genes are members of the highly homologous glandular kallikrein multigene family. Together with the beta subunit, the alpha and gamma proteins constitute the high mol. wt. (7S) form of NGF isolated from mouse submandibular gland. The gamma subunit is an active serine protease and is thought to cleave pro-beta-NGF to generate the mature growth factor. The alpha subunit has no detectable proteolytic activity, but is essential for the stable formation of 7S NGF. Lack of enzyme activity of the alpha subunit can be attributed, at least in part, to the deletion of 15 nucleotides in a highly conserved coding region which is normally involved in the activation of serine proteases from their inactive zymogen form.
Publisher: Informa UK Limited
Date: 02-01-2016
Publisher: Oxford University Press (OUP)
Date: 25-11-1988
Abstract: The mechanisms behind hot flashes in menopausal women are not fully understood. The flashes in women are probably preceded by and actually initiated by a sudden downward shift in the set point for the core body temperature in the thermoregulatory center that is affected by sex steroids, β-endorphins, and other central neurotransmitters. Treatments that influence these factors may be expected to reduce hot flashes. Since therapy with sex steroids for hot flashes has appeared to cause a number of side effects and risks and women with hot flashes and breast cancer as well as men with prostate cancer and hot flashes are prevented from sex steroid therapy there is a great need for alternative therapies. Acupuncture affecting the opioid system has been suggested as an alternative treatment option for hot flashes in menopausal women and castrated men. The heat loss during hot flashes may be mediated by the potent vasodilator and sweat gland activator calcitonin gene-related peptide (CGRP) the concentration of which increases in plasma during flashes in menopausal women and, according to one study, in castrated men with flushes. There is also evidence for connections between the opioid system and the release of CGRP. In this paper we discuss acupuncture as a treatment alternative for hot flashes and the role of CGRP in this context.
Publisher: Wiley
Date: 15-07-1994
Publisher: Oxford University Press (OUP)
Date: 1987
Abstract: Pyrogen reaction is a side effect of intravenous infusion of solution on body sustained ventricular tachycardia is a serious arrhythmia, no relationship between them has been reported before. Two patients with sustained ventricular tachycardia refractory to lidocaine happened to have pyrogen reaction. The sustained ventricular tachycardia was converted to sinus rhythm after the pyrogen reaction. The conversion of sustained ventricular tachycardia might be related to pyrogen reaction. The effects of pyrogen reaction on sustained ventricular tachycardia need further research.
Publisher: Oxford University Press (OUP)
Date: 25-10-2006
DOI: 10.1093/HMG/DDL422
Abstract: Fragile X Syndrome is a leading heritable cause of mental retardation that results from the loss of FMR1 gene function. Studies in mouse and Drosophila model organisms have been critical in understanding many aspects of the loss of function of the FMR1 gene in the human syndrome. Here, we establish that the zebrafish is a useful model organism for the study of the human fragile X syndrome and can be used to examine phenotypes that are difficult or inaccessible to observation in other model organisms. Using morpholino knockdown of the fmr1 gene, we observed abnormal axonal branching of Rohon-Beard and trigeminal ganglion neurons and guidance and defasciculation defects in the lateral longitudinal fasciculus. We demonstrate that this axonal branching defect can be rescued by treatment with MPEP [2-methyl-6-(phenylethynyl) pyridine]. This is consistent with an interaction between mGluR signalling and fmr1 function in neurite morphogenesis. We also describe novel findings of abnormalities in the abundance of trigeminal ganglion neurons and of craniofacial abnormalities apparently due to dysmorphic cartilage formation. These abnormalities may be related to a role for fmr1 in neural crest cell specification and possibly in migration.
Publisher: Cold Spring Harbor Laboratory
Date: 11-1998
DOI: 10.1101/GR.8.11.1172
Abstract: We used a combination of cDNA selection, exon lification, and computational prediction from genomic sequence to isolate transcribed sequences from genomic DNA surrounding the familial Mediterranean fever (FMF) locus. Eighty-seven kb of genomic DNA around D16S3370 , a marker showing a high degree of linkage disequilibrium with FMF, was sequenced to completion, and the sequence annotated. A transcript map reflecting the minimal number of genes encoded within the ∼700 kb of genomic DNA surrounding the FMF locus was assembled. This map consists of 27 genes with discreet messages detectable on Northerns, in addition to three olfactory-receptor genes, a cluster of 18 tRNA genes, and two putative transcriptional units that have typical intron–exon splice junctions yet do not detect messages on Northerns. Four of the transcripts are identical to genes described previously, seven have been independently identified by the French FMF Consortium, and the others are novel. Six related zinc-finger genes, a cluster of tRNAs, and three olfactory receptors account for the majority of transcribed sequences isolated from a 315-kb FMF central region (between D16S468/D16S3070 and cosmid 377A12). Interspersed among them are several genes that may be important in inflammation. This transcript map not only has permitted the identification of the FMF gene ( MEFV ), but also has provided us an opportunity to probe the structural and functional features of this region of chromosome 16.
Publisher: Springer Science and Business Media LLC
Date: 07-1995
DOI: 10.1038/376145A0
Abstract: The fragile site FRA11B has been localized to the p(CCG)n repeat of the CBL2 proto-oncogene. A proportion of Jacobsen (11q-) syndrome patients inherited a chromosome carrying a CBL2 p(CCG)n expansion, which was truncated close to FRA11B. These results have broad implications for the role of p(CCG)n repeat expansion in the aetiology of genetic disease involving chromosome rearrangements.
Publisher: Oxford University Press (OUP)
Date: 1993
Publisher: Oxford University Press (OUP)
Date: 1989
DOI: 10.1093/NAR/17.2.822
Abstract: To describe the epidemiology of litigation against the tobacco industry in the United States during the years 1994-2005 (described as the "third wave" of tobacco litigation). "Epidemiology" refers to the study of the distribution and determinants of disease in populations. We apply the term "epidemiology" to the litigation context for purposes of characterising qualitatively and, to the extent possible, quantitatively the variety of cases litigated against tobacco manufacturers and allied tobacco interests during the third wave and their impact on the tobacco industry. The data for this paper come from legal cases identified in the Tobacco Deposition and Trial Testimony Archive (DATTA) collection (atta), transcripts of testimony and related documents found in DATTA, government-mandated reports filed by tobacco manufacturers with the US Securities and Exchange Commission, investment company reports, reports and analyses published by the news media, a variety of informational documents produced by the Tobacco Control Resource Center at the Northeastern University School of Law, and legal settlement documents provided by the National Association of Attorneys General. The US tobacco industry faced a far greater number of lawsuits, and a greater variety of types of lawsuit, between 1994 and 2005 than it had in previous years. Plaintiffs won 31 (41%) of the 75 cases that were tried to verdict during the years 1995-2005. Seven plaintiffs have been paid awards totalling US$115 million, including interest, following the exhaustion of appeals. Based on an evaluation of litigation brought against US industry leader Philip Morris, the total number of cases pending peaked in 2000, dropping off modestly since then. For ex le, 36 class actions were pending in 2000, while 33 were pending in 2005. In the same time period, in idual actions fell from a total of 3385 to 2863. While the playing field has been levelled to some degree in the tobacco litigation arena with respect to the resources brought to bear by plaintiffs and defendants, tobacco industry defendants continue to employ far greater financial and human resources than their adversaries. The third wave of tobacco litigation has represented a sea change in efforts to hold the tobacco industry in the United States accountable in American courtrooms. While tobacco manufacturers continue to do their utmost to make these cases difficult to pursue, many of the cases that have gone to trial have met with success in recent years, which suggests that plaintiffs' lawyers are now better equipped to persuade juries of the defendants' culpability.
Publisher: Elsevier BV
Date: 06-1995
DOI: 10.1016/0959-437X(95)80046-8
Abstract: Fragile sites on chromosomes have been classified into a number of groups according to their frequency and the conditions required to induce them. A number of the rare folate-sensitive fragile sites have been characterized and shown to be lified methylated CCG trinucleotide repeats. One common fragile site has been partly characterized and appears to be a region of fragility, rather than a single site.
Publisher: Oxford University Press (OUP)
Date: 1987
Abstract: The Na(+)/Ca(2+) exchanger (NCX) is a bi-directional regulator of cytosolic Ca(2+), causing Ca(2+) efflux in forward-mode and Ca(2+) influx in reverse-mode. We hypothesized that reverse-mode NCX is a means of Ca(2+) entry in rat aorta (RA) and vena cava (RVC). NCX protein in RA and RVC was confirmed by immunoprecipitation. To assess NCX function, isometric contraction and intracellular Ca(2+) was measured in RA and RVC rings in response to low extracellular Na(+), endothelin-1 (ET-1), and KCl, in the presence or absence of the NCX antagonist KB-R7943. In RVC, low extracellular Na(+) caused vasoconstriction and an increase in intracellular Ca(2+) that was attenuated by 10μM KB-R7943. KB-R7943 (10 μM) attenuated maximal contraction to ET-1 in RVC (53 ± 9% of control), but not RA (91±1% of control). KB-R7943 (10 μM) reduced the maximal contraction to KCl in RA (48 ± 5%) and nearly abolished it in RVC (9 ± 2%), suggesting that voltage-dependent Ca(2+) influx may be inhibited by KB-R7943 as well. However, the L-type Ca(2+) channel inhibitor nifedipine (1 μM) did not alter ET-1-induced contraction. Our findings suggest that reverse-mode NCX is an important mechanism of Ca(2+) influx in RVC but not RA, especially during ET-1-induced contraction. Also, the effects of KB-R7943 on ET-1-induced contraction of RA and RVC are predominantly mediated by reverse-mode NCX inhibition and not due to off-target inhibition of Ca(2+) channels.
Publisher: Elsevier BV
Date: 08-1992
DOI: 10.1016/0888-7543(92)90035-Q
Abstract: A panel of 54 mouse/human somatic cell hybrids, each possessing various portions of chromosome 16, was constructed 46 were constructed from naturally occurring rearrangements of this chromosome, which were ascertained in clinical cytogenetics laboratories, and a further 8 from rearrangements spontaneously arising during tissue culture. By mapping 235 DNA markers to this panel of hybrids, and in relation to four fragile sites and the centromere, a cytogenetic-based physical map of chromosome 16 with an average resolution of 1.6 Mb was generated. Included are 66 DNA markers that have been typed in the CEPH pedigrees, and these will allow the construction of a detailed correlation of the cytogenetic-based physical map and the genetic map of this chromosome. Cosmids from chromosome 16 that have been assembled into contigs by use of repetitive sequence fingerprinting have been mapped to the hybrid panel. Approximately 11% of the euchromatin is now both represented in such contigs and located on the cytogenetic-based physical map. This high-resolution cytogenetic-based physical map of chromosome 16 will provide the basis for the cloning of genetically mapped disease genes, genes disrupted in cytogenetic rearrangements that have produced abnormal phenotypes, and cancer breakpoints.
Publisher: American Chemical Society (ACS)
Date: 10-1987
DOI: 10.1021/BI00395A026
Abstract: Previously, three proteins have been separately identified as the mouse epidermal growth factor binding protein (EGF-BP). We have identified and sequenced the coding regions of three distinct genes encoding these EGF-BPs from the BALB/c strain. The genes are all members of the glandular kallikrein gene family, which encodes a highly homologous group of serine proteases. Expression of the EGF-BP genes was detected in mouse salivary gland only and was at a relatively similar level for each gene. The isolation of three distinct genes from the one mouse strain indicates that the conflicting data previously reported in the literature are not a result of allelic polymorphisms or strain differences.
Publisher: Cold Spring Harbor Laboratory
Date: 1983
DOI: 10.1101/SQB.1983.048.01.046
Abstract: The incidence of esophageal adenocarcinoma (EAC) is rising and the only known precursor of this disease is Barrett's esophagus (BE). EAC mortality remains high, prompting strategies to screen in iduals with gastroesophageal reflux disease (GERD) symptoms to identify BE and conduct surveillance in order to detect neoplasia at a stage that is amenable to cure. The effectiveness of endoscopic eradication therapy has been improving with reduced harms, yet it is unclear which patients will benefit from this procedure. This chapter reviews the evidence supporting surveillance for BE to reduce mortality from EAC and combines these results with economic analyses to identify the optimal means to manage patients with BE with high-grade dysplasia, low-grade dysplasia, or no dysplasia.
Publisher: Informa UK Limited
Date: 06-1986
DOI: 10.1128/MCB.6.6.2149
Abstract: The human metallothionein (MT) IB gene (hMT-IB) is located in a region of human DNA containing at least four tandemly arranged MT genes. As deduced from its sequence, hMT-IB is likely to encode a functional protein. However, the predicted amino acid sequence differed from the hMT-I amino acid sequence in four positions. Most remarkable was the presence of an additional cysteine. Like other MT genes, hMT-IB has at least two copies of the metal-responsive element upstream from the transcription initiation site. These elements probably are responsible for the metal responsiveness of the hMT-IB promoter, leading to inducible expression of fused heterologous genes. Unlike the hMT-IIA and hMT-IA genes described previously, which are expressed in many different cell types, a high level of expression of the endogenous hMT-IB gene could be detected only in human hepatoma and renal carcinoma cell lines. Therefore, this is the first MT gene described which exhibits tissue specificity of expression. This specificity is controlled by a cis-acting mechanism involving methylation, since incubation of nonexpressing cells with an inhibitor of DNA methylation led to activation of the hMT-IB gene. In support of this notion, we found that the 5' flanking region of the hMT-IB gene was highly methylated in HeLa cells, a nonexpressing cell type, but it was not methylated in a hepatoma (expressing) cell line.
Publisher: Wiley
Date: 09-1986
DOI: 10.1002/J.1460-2075.1986.TB04487.X
Abstract: Suppression of plasminogen activator (PA) activity has been invoked as being part of the general anti-inflammatory action of glucocorticoids. Low concentrations of the synthetic glucocorticoid, dexamethasone (Dex), reduce urokinase-type PA mRNA levels in two cell types, namely a human fibrosarcoma line, HT1080, and synovial fibroblast-like cells isolated from human joints. Conversely, metallothionein IIa (MTIIa) mRNA levels in these cells are raised by Dex. These findings, by suggesting that it is possible to suppress urokinase-type PA activity at the level of gene expression, may have therapeutic implications for diseases such as rheumatoid arthritis where proteases may be contributing to the extensive tissue damage and inflammation.
Publisher: Oxford University Press (OUP)
Date: 10-1998
Abstract: Autosomal dominant familial spastic paraplegia (FSP) is a genetically heterogeneous neurodegenerative disorder displaying anticipation for which three loci have been mapped to the chromosomal positions 14q11.2-q24.3 (SPG3), 2p21-p24 (SPG4) and 15q11.1 (SPG6). The repeat expansion detection (RED) method has been used to demonstrate expanded CAG repeats in some FSP families that map to SPG4. We analyzed 20 FSP families, including four for which there is evidence for linkage to SPG4, and found that in most cases the repeat expansion detected by RED is due to non-pathogenic expansions of the chromosome 18q21.1 SEF2-1 or 17q21.3 ERDA1 locus. Polymorphic expansions at SEF2-1 and ERDA1 appear frequent and may confound RED studies in the search for genes causing disorders demonstrating anticipation. In six FSP families, however, CAG repeat expansion was detected in a subset of affected and at-risk in iduals that did not result from expansion of the SEF2-1 and ERDA1 loci. Overall, 11 of 37 (30%) of the FSP patients with a CAG/CTG repeat expansion are unaccounted for by the SEF2-1 and ERDA1 loci, compared with two of 23 (9%) of the unaffected at-risk in iduals and none of 19 controls. In the majority of cases these novel expansions were shorter than those previously reported.
Publisher: Elsevier BV
Date: 05-1993
Abstract: Batten disease, juvenile onset neuronal ceroid lipofuscinosis, is an autosomal recessive neurodegenerative disorder characterized by accumulation of autofluorescent lipopigment in neurons and other cell types. The disease locus (CLN3) has previously been assigned to chromosome 16p. The genetic localization of CLN3 has been refined by analyzing 70 families using a high-resolution map of 15 marker loci encompassing the CLN3 region on 16p. Crossovers in three maternal meioses allowed localization of CLN3 to the interval between D16S297 and D16S57. Within that interval alleles at three highly polymorphic dinucleotide repeat loci (D16S288, D16S298, D16S299) were found to be in strong linkage disequilibrium with CLN3. Analysis of haplotypes suggests that a majority of CLN3 chromosomes have arisen from a single founder mutation.
Publisher: Oxford University Press (OUP)
Date: 06-04-2005
DOI: 10.1093/HMG/DDI144
Abstract: Neither the molecular basis for common fragile site DNA instability nor the contribution of this form of chromosomal instability to cancer is clearly understood. Fragile site FRA16D (16q23.2) is within regions of frequent loss-of-heterozygosity (LOH) in breast and prostate cancers, is associated with homozygous deletions in various adenocarcinomas and t(14 ) chromosomal translocations in multiple myeloma. The FOR (WWOX) gene spans FRA16D and encodes a partner of p53 that also has a role in apoptosis. Previously untested 53 cancer cell lines were screened for deletions within the FOR/WWOX gene. Deletions were detected in Co115, KM12C and KM12SM. Homozygous deletions in these and two previously identified tumour cell lines were intragenic on both alleles, indicating a distinct mutation mechanism from that causing LOH. Identical FRA16D deletions in two cell lines (one derived from the primary carcinoma and the other from a secondary metastasis) demonstrate that FRA16D DNA instability can be an early, transient event. Sequence analysis across one deletion locates one endpoint within a polymorphic AT-dinucleotide repeat and the other adjacent to an AT-rich mini-satellite repeat implicating AT-rich repeats in FRA16D DNA instability. Another deletion is associated with de novo repetition of the 9 bp AT-rich sequence at one of the deletion endpoints. FRA16D deleted cells retain cytogenetic fragile site expression indicating that the deletions are susceptible sites for breakage rather than regions that confer fragility. Most cell lines with FRA16D homozygous deletions also have FRA3B deletions, therefore common fragile sites represent highly susceptible genome-wide targets for a distinct form of mutation.
Publisher: MDPI AG
Date: 29-06-2021
Abstract: It is now more than 20 years since the FRA16D common chromosomal fragile site was characterised and the WWOX gene spanning this site was identified. In this time, much information has been discovered about its contribution to disease however, the normal biological role of WWOX is not yet clear. Experiments leading to the identification of the WWOX gene are recounted, revealing enigmatic relationships between the fragile site, its gene and the encoded protein. We also highlight research mainly using the genetically tractable model organism Drosophila melanogaster that has shed light on the integral role of WWOX in metabolism. In addition to this role, there are some particularly outstanding questions that remain regarding WWOX, its gene and its chromosomal location. This review, therefore, also aims to highlight two unanswered questions. Firstly, what is the biological relationship between the WWOX gene and the FRA16D common chromosomal fragile site that is located within one of its very large introns? Secondly, what is the actual substrate and product of the WWOX enzyme activity? It is likely that understanding the normal role of WWOX and its relationship to chromosomal fragility are necessary in order to understand how the perturbation of these normal roles results in disease.
Publisher: Elsevier BV
Date: 03-1990
DOI: 10.1016/0303-7207(90)90006-T
Abstract: We have used thyroid hormone receptors from two different human cell lines to investigate receptor binding to the promoters of thyroid hormone-responsive genes. Receptors extracted from IM-9 cells or HeLa cells displayed virtually identical affinity and specificity for [125I]triiodothyronine binding. The cells expressed a c-erbA alpha gene in the same relative proportions as the receptor concentrations. Both receptors were bound to DNA-cellulose and could be displaced with increasing concentrations of calf thymus DNA or pBR322 DNA. Relative to pBR322 DNA (designated as 1), binding to the hGH gene promoter was 8.1 +/- 1.1 using the IM-9 cell receptor. With the HeLa cell receptor relative binding was only 1.1 +/- 0.2. Similar relative differences were obtained with the mouse glandular kallikrein gene, mGK-6. In heat stability studies the IM-9 cell receptor was more resistant to heat inactivation than the HeLa receptor. Triiodothyronine receptors with identical hormone binding patterns may require the presence of an unidentified factor(s) which allows correct recognition of regulation sequences within responsive genes.
Publisher: BMJ
Date: 08-1996
DOI: 10.1136/JMG.33.8.665
Abstract: Forty-four percent of the fibrillin-1 gene (FBN1) from 19 unrelated families with Marfan syndrome was screened for putative mutations by single strand conformational polymorphism (SSCP) analysis. Four novel mutations were identified and characterised in five people, three with classical Marfan syndrome (two from one family, and one from an unrelated family), one with a more severe phenotype, and one with neonatal Marfan syndrome. The base substitutions G2113A, G2132A, T3163G, and G3458A result in amino acid substitutions A705T, C711Y, C1055G, and C1152Y, respectively. C711Y, C1055G, and C1152Y lead to replacement of a cysteine by another amino acid the latter two occur within epidermal growth factor-like motifs in exon 25 and 27, respectively. The A705T mutation occurs at exon 16 adjacent to the GT splice site. The A705T and C711Y mutations, at exon 16 and 17, respectively, are the first documented in the second transforming growth factor-beta 1 binding protein-like motif of FBN1.
Publisher: Elsevier BV
Date: 08-1991
DOI: 10.1016/0140-6736(91)90426-P
Abstract: Fragile X syndrome, associated with the fragile X chromosome, is the most common cause of familial mental retardation. The condition is characterised by a heritable DNA sequence that consists of an abnormal number of CCG repeats, and which is unstable in both mitosis and meiosis. We suggest that such heritable unstable DNA sequences could be present in other parts of the genome and that these might explain a number of genetic events that are not well understood in terms of classic genetic mechanisms. Such poorly explained observations include anticipation, incomplete penetrance, variable expression, and possibly imprinting, variegation, and multifactorial inheritance.
Publisher: Oxford University Press (OUP)
Date: 1991
Publisher: Elsevier BV
Date: 11-1997
DOI: 10.1016/S0968-0004(97)01108-0
Abstract: Increases in repeat-DNA copy number are the molecular basis of a growing list of human genetic diseases, including fragile X syndrome, myotonic dystrophy, Huntington disease and a form of epilepsy. Repeat-DNA sequences undergo a unique process of dynamic mutation, the common properties of which probably reflect common molecular events. This form of mutation is no longer restricted to trinucleotide repeats, because repeats of different length have been found to undergo expansion.
Publisher: Mary Ann Liebert Inc
Date: 1982
Abstract: A previously-cloned cDNA coding for a member of the kallikrein arginyl-esteropeptidase group of serine proteases, (pMK-1), was used as a hybridization probe to identify a second partial cDNA clone (pMK-2) from mouse submaxillary gland. pMK-2 shares more than a 98% nucleotide sequence homology with pMK-1 the 3' untranslated regions are identical and there are only two predicted amino acid changes over the C-terminal 66 amino acids. The site of one change is implicated in determining substrate specificity, while the other may affect the catalytic mechanism. Thus despite the marked similarity of pMK-1 and pMK-2, the differences probably give rise to functionally distinct enzymes and are not simply polymorphic alleles.
Publisher: Hindawi Limited
Date: 1996
DOI: 10.1002/(SICI)1098-1004(1996)8:1<1::AID-HUMU1>3.0.CO;2-G
Abstract: This study aimed to establish a predictive nomogram integrating epidermal growth factor receptor (EGFR) mutation status for 3- and 5-year overall survival (OS) in unresectable/inoperable stage III non-small cell lung cancer (NSCLC) treated with definitive chemoradiotherapy. A total of 533 stage III NSCLC patients receiving chemoradiotherapy from 2013 to 2017 in our institution were included and ided into training and testing sets (2:1). Significant factors impacting OS were identified in the training set and integrated into the nomogram based on Cox proportional hazards regression. The model was subject to bootstrap internal validation and external validation within the testing set and an independent cohort from a phase III trial. The accuracy and discriminative capacity of the model were examined by calibration plots, C-indexes and risk stratifications. The final multivariate model incorporated sex, smoking history, histology (including EGFR mutation status), TNM stage, planning target volume, chemotherapy sequence and radiation pneumonitis grade. The bootstrapped C-indexes in the training set were 0.688, 0.710 for the 3- and 5-year OS. For external validation, C-indexes for 3- and 5-year OS were 0.717, 0.720 in the testing set and 0.744, 0.699 in the external testing cohort, respectively. The calibration plots presented satisfying accuracy. The derivative risk stratification strategy classified patients into distinct survival subgroups successfully and performed better than the traditional TNM staging. The nomogram incorporating EGFR mutation status could facilitate survival prediction and risk stratification for in idual stage III NSCLC, providing information for enhanced immunotherapy decision and future trial design.
Publisher: Bioscientifica
Date: 04-1990
Abstract: Angiotensinogen mRNA is found in many extrahepatic tissues, where it may participate in local angiotensin-generating systems. In this study we explore the feasibility of using anti-sense RNA to decrease angiotensinogen production in rat H4IIEC3 hepatoma cells. An lifiable shuttle vector was modified to allow the production of high levels of stable anti-sense RNA from two regions of the mouse angiotensinogen gene under the control of the inducible sheep metallothionein promoter. Stably transformed, clonal cell lines expressing anti-sense RNA for angiotensinogen were isolated after selection with the aminoglycoside G418. Subsequently, the number of chromosomally integrated copies of the angiotensinogen anti-sense constructs was co lified by methotrexate selection for dihydrofolate reductase activity carried on the shuttle vector. With a 20- to 30-fold induction of the anti-sense RNAs, the target angiotensinogen mRNA level was reduced to 25–30% of control values. The specificity of this effect was confirmed by showing no decrease in either β-tubulin or neomycin phosphotransferase mRNA levels. Using tissue-specific promoters, it should be possible to direct these effects to specific organs in transgenic mice. However, in agreement with results from other groups, our findings suggest that it will not be possible to eradicate completely the target gene product using the anti-sense RNA strategy.
Publisher: Wiley
Date: 11-1989
DOI: 10.1002/J.1460-2075.1989.TB08495.X
Abstract: Angiotensinogen is the precursor of the potent vasoactive peptide angiotensin II, and is therefore an important determinant of blood pressure and electrolyte homeostasis. In order to map the tissue-specific and inducible enhancer elements governing angiotensinogen gene expression in transgenic mice, we constructed minigenes containing either 0.75 kb or 4 kb or 5' flanking DNA from the BALB/c angiotensinogen gene. Sequences necessary and sufficient to mediate induction by glucocorticoids, oestrogen and bacterial endotoxin were contained on the minigene bearing 0.75 kb of DNA upstream of the capsite. This construct was also able to confer tissue specificity in the majority of organs producing angiotensinogen. In the testis and salivary gland, differences between the donor (BALB/c) and recipient (Swiss) strains were responsible for the apparently aberrant expression of the minigene constructs. The genetic lesion responsible for these expression polymorphisms has been characterized using recombinant inbred mice. An EcoRI restriction fragment length polymorphism which co-segregates with the angiotensinogen expression phenotypes into many inbred mouse strains is also described.
Publisher: Cognizant, LLC
Date: 20-12-2013
Publisher: Elsevier BV
Date: 04-1994
Abstract: The efficiency of mapping and diagnosis of X-linked disorders by linkage depends upon the existence of a high-density genetic map of polymerase chain reaction (PCR)-based markers. DXS1120, DXS1122, DXS1123, DXS1124, DXS1125, DXS1126, and DXS1153 were randomly isolated from a flow-sorted lambda bacteriophage library of the human X chromosome. The CCN (N = A or G) repeat within the androgen receptor was also found to be polymorphic and primers were designed for genotyping the CCN polymorphism in addition to the AGC polymorphism. The above markers, together with microsatellite polymorphisms at DXS237 (GMGX9), 5'DYS-II and 3'DYS MS (within the dystrophin locus), DXS538 (XL27B), PGK1P1, DXS300 (VK29AC), DXS294 (VK17AC), and DXS102 (cX38.1AC), were genotyped in the 40 CEPH reference families. One marker, DXS1153, was found to include cryptic alleles that lify only in homozygotes and hemizygotes but not heterozygotes. A PCR-based linkage map was constructed using all of the above markers plus PCR-based markers from the CEPH database and those PCR-based markers previously typed in our laboratory: ALAS2, DXS292 (VK14AC), DXS297 (VK23AC), FRAXAC1, and FRAXAC2. The genetic map of the X chromosome incorporates 62 PCR-based marker loci, integrates the Weissenbach markers, and extends from XG near Xpter to DXS52 near Xqter, a distance of 236 cM.
Publisher: Elsevier BV
Date: 07-1994
Abstract: A high-resolution cytogenetic-based physical map and a genetic linkage map of human chromosome 16 have been developed based on 79 PCR-typable genetic markers and 2 Southern-based RFLP markers. The PCR-based markers were previously characterized polymorphic (AC)n repeats. Two approaches have led to the characterization of 47 highly informative genetic markers spread along chromosome 16, some of which are closely linked to disease loci. In addition, 22 markers (D16S401-423) previously genetically mapped were also physically mapped. Ten markers characterized by other laboratories were physically mapped and genotyped on the CEPH families. These 32 markers were incorporated into the PCR-based map. Seventy-two markers have heterozygosities > 0.50 and 51 of these markers > 0.70. By multipoint linkage analysis a framework genetic map and a comprehensive genetic map were constructed. The length of the sex-averaged framework genetic map is 152.1 cM. The average distance and the median distance between markers on this map are 3.2 and 2.7 cM, respectively, and the largest gap is 15.9 cM. These maps were anchored to the high-resolution cytogenetic map (on average 1.5 Mb per interval). Together these integrated genetic and physical maps of human chromosome 16 provide the basis for the localization and ultimately the isolation of disease genes that map to this chromosome.
Publisher: Elsevier BV
Date: 07-1992
Publisher: Elsevier BV
Date: 2006
Publisher: Springer Science and Business Media LLC
Date: 02-1994
DOI: 10.1038/NG0294-114
Abstract: M-type (KCNQ2/3) K
Publisher: S. Karger AG
Date: 1988
DOI: 10.1159/000132629
Abstract: The amino acid sequence of human prostate-specific antigen (APS) suggests that it is a member of the glandular kallikrein subfamily of serine proteases. In the mouse, the kallikrein-like family is localized in a single locus on chromosome 7, while other serine proteases are distributed over a variety of different chromosomes. To investigate the physical relationship between the human kallikrein genes, we have used in situ hybridization and Southern analysis of a human × mouse somatic cell hybrid panel to map the APS gene to 19q13, concordant with the renal kallikrein KLK 1 gene. This finding indicates that APS is a member of a human kallikrein-like gene family with analogous organization to that of the mouse.
Publisher: Massachusetts Medical Society
Date: 12-12-1991
Publisher: BMJ
Date: 07-1991
DOI: 10.1136/JMG.28.7.448
Abstract: Linkage was shown between the myotonic dystrophy locus (DM) and a highly polymorphic AC repeat marker within the kallikrein (KLK1) locus (Z = 3.00, theta = 0.0). Linkage between KLK1 and the highly polymorphic AC repeat marker within the apolipoprotein C2 (APOC2) locus, which had been established in normal families, was confirmed in myotonic dystrophy families (Z = 4.37, theta = 0.11). These highly polymorphic AC repeat markers flank DM on chromosome 19. The gene order is cen-APOC2 (0.03) DM (0.08) KLK1-qter with recombination frequencies shown in parentheses. Genotypes for the AC repeat markers can be determined simultaneously by multiplex PCR and separation of the two base pair differences between adjacent alleles on sequencing gels. In informative families, this approach provides rapid diagnosis and is more accurate than methods using markers restricted to the proximal side of the myotonic dystrophy gene.
Publisher: Oxford University Press (OUP)
Date: 1994
DOI: 10.1093/HMG/3.1.210
Publisher: Springer Science and Business Media LLC
Date: 06-1994
DOI: 10.1038/NG0694-122
Publisher: Oxford University Press (OUP)
Date: 07-03-2005
DOI: 10.1093/HMG/DDI096
Abstract: A substantial body of evidence supports the identity of polyglutamine as the pathogenic agent in a variety of human neurodegenerative disorders where the mutation is an expanded CAG repeat. However, in apparent contradiction to this, there are several human neurodegenerative diseases (some of which are clinically indistinguishable from the 'polyglutamine' diseases) that are due to expanded repeats that cannot encode polyglutamine. As polyglutamine cannot be the pathogenic agent in these diseases, either the different disorders have distinct pathogenic pathways or some other common agent is toxic in all of the expanded repeat diseases. Recently, evidence has been presented in support of RNA as the pathogenic agent in Fragile X-associated tremor/ataxia syndrome (FXTAS), caused by expanded CGG repeats at the FRAXA locus. A Drosophila model of FXTAS, in which 90 copies of the CGG repeat are expressed in an untranslated region of RNA, exhibits both neurodegeneration and similar molecular pathology to the 'polyglutamine' diseases. We have, therefore, explored the identity of the pathogenic agent, and specifically the role of RNA, in a Drosophila model of the polyglutamine diseases by the expression of various repeat constructs. These include expanded CAA and CAG repeats and an untranslated CAG repeat. Our data support the identity of polyglutamine as the pathogenic agent in the Drosophila models of expanded CAG repeat neurodegenerative diseases.
Publisher: Oxford University Press (OUP)
Date: 1991
Publisher: Wiley
Date: 06-1987
DOI: 10.1002/J.1460-2075.1987.TB02421.X
Abstract: The expression of many mouse kallikrein genes in the salivary gland is sexually dimorphic and inducible in females by administration of testosterone or thyroxine. Induction is slow (3-7 days) and is accompanied by the non-uniform differentiation of the cell type expressing these genes from striated duct (SD) cells (female) to granular convoluted tubule (GCT) cells (male). One kallikrein gene, mGK-6, is expressed at an apparently constant total level in male and female and is not induced by either hormone. In situ hybridization histochemistry shows that all kallikrein genes analyzed exhibit uniform cellular distribution of expression in the SD cells of the female. The hormonally mediated differentiation of some, but not all, of these cells has different effects on kallikrein gene expression--mGK-6 is repressed while other kallikreins are induced--leading to non-uniform distribution of expression.
Publisher: Wiley
Date: 25-09-1989
DOI: 10.1016/0014-5793(89)81136-6
Abstract: We have recently identified a cis-acting genetic lesion affecting angiotensinogen gene expression in testis and salivary gland. Accordingly, the angiotensinogen gene was assigned to mouse chromosome 8 by screening a series of hybrid cell lines for retention of mouse angiotensinogen sequences by genomic Southern analysis. In AKXD recombinant inbred mice, the angiotensinogen gene is 2.4 +/- 1.8 centiMorgan from Rn7S-8,a 7S RNA gene located on chromosome 8 (Taylor, B.A., personal communication). However, the segregation of salivary and testicular angiotensinogen expression phenotypes into inbred mouse strains was not concordant with the known chromosome 8 proviruses Emv-2, Mtv-21, Xmv-12 or Xmv-26.
Publisher: The Endocrine Society
Date: 10-1987
Abstract: Inhibin is a glycoprotein hormone composed of two nonidentical subunits. It is produced by the ovary and testis and plays a vital role in gonadal function by inhibiting the secretion of FSH. More recently, additional activities associated with inhibin peptides have been identified. Inhibin heterodimers (alpha-beta) are reported to act directly on ovarian granulosa cells and inhibit estrogen production induced by FSH. Furthermore, homodimers of beta-inhibin subunits stimulate the secretion of FSH, an activity that is directly opposite to that of inhibin. Each of these inhibin-related activities are concerned with the hypothalamic-pituitary-gonadal axis. We have investigated further the complexity of inhibin activity by determining whether inhibin genes are expressed in nongonadal tissue. RNA hybridization experiments demonstrate that the alpha-inhibin gene is expressed in the sheep adrenal cortex and hybridization histochemistry shows that this gene is expressed in each of the functional zones within the cortex. Dot blot analysis showed that the level of alpha mRNA within the adrenal is influenced by ACTH, one of the major regulators of adrenal cortex function. These observations imply that there are inhibin-related peptides not directly associated with the gonads. beta-inhibin gene expression was not clearly detected in the adrenal and we conclude that if expression occurs then it does so at extremely low levels.
Publisher: Oxford University Press (OUP)
Date: 1993
DOI: 10.1093/HMG/2.9.1429
Abstract: The trinucleotide repeat sequences which become unstable in fragile X syndrome and myotonic dystrophy are located in the untranslated regions of their respective genes, FMR1 and DM1. This implies that a functional constraint other than coding capacity maintains the presence of the repeats. In the case of fragile X syndrome, sequences adjacent to the repeat are methylated in affected in iduals and the FMR1 gene is transcriptionally inactive. We demonstrate that the fragile X p(CCG)n repeat itself is methylated in vivo and that methylation of this repeat is able to inhibit in vitro binding of a novel, specific nuclear p(CCG)n binding protein (CCG-BP1)--one of at least 10 distinct simple tandem repeat sequence binding proteins (STR-BPs). We describe additional, apparently distinct, binding activities both for the methylated form of the p(CCG)n repeat and for each of the single strands of the repeat.
Publisher: Frontiers Media SA
Date: 2013
Publisher: Wiley
Date: 13-06-2013
DOI: 10.1002/GCC.22078
Abstract: The WWOX gene spans the FRA16D common chromosomal fragile site and is able to suppress tumor growth. FRA16D is a frequent site of DNA instability in cancer resulting in reduced levels of WWOX expression. Altered levels of WWOX have been shown to affect metabolism. Whereas metabolic reprograming of cells from oxidative phosphorylation to aerobic glycolysis is a major hallmark of tumors, the relationship between common chromosomal fragile site genes and altered metabolism has been unclear. Here we report that altering metabolism from glycolysis to oxidative phosphorylation causes stable increase in steady-state levels of transcripts of the WWOX gene. Consistent with this, exposure to hypoxic conditions, in which cells rely on glycolysis, causes a downregulation of WWOX mRNA. The function of WWOX is therefore intimately integrated with metabolism, as WWOX not only contributes to the metabolic state of cells, its transcript levels are also linked to intracellular metabolic state.
Publisher: BMJ
Date: 12-1991
Abstract: The molecular characterisation of the dystrophin gene, mutations in which are responsible for X linked Duchenne and Becker muscular dystrophies, has led to an array of strategies for the diagnosis of affected subjects and carriers. Initially these were based on blotting and hybridisation technologies but have recently been largely superseded by PCR based techniques which afford greater speed and sensitivity. We describe the use of single strand conformation polymorphism to detect heterozygosity in regions of the dystrophin locus which are deleted in affected males, to determine the carrier status of their female relatives.
Publisher: Oxford University Press (OUP)
Date: 10-2001
Abstract: The term 'dynamic mutation' was introduced to distinguish the unique properties of expanding, unstable DNA repeat sequences from other forms of mutation. The past decade has seen dynamic mutations uncovered as the molecular basis for a growing number of human genetic diseases and for all of the characterized 'rare' chromosomal fragile sites. The common properties of the repeats in different diseases and fragile sites have given insight into this unique form of DNA instability. While the dynamic mutation mechanism explains some unusual genetic characteristics, unexpected findings have raised new questions and challenged some assumptions about the pathways that lead from mutation to disease. This review will address the current understanding of the molecular mechanisms involved in the dynamic mutation process and elaborate on the pathogenic pathways that lead from expanded repeats to the diseases with which they are associated.
Publisher: Elsevier BV
Date: 06-1992
DOI: 10.1016/0888-7543(92)90260-Y
Abstract: A cosmid library of human chromosome 16 has been subcloned, and (AC)n microsatellite positive clones have been identified and sequenced. Oligonucleotide primers flanking the repeat were designed and synthesized for (AC)n microsatellites with n greater than 16. These microsatellite loci were then mapped by PCR using a somatic cell hybrid panel of human chromosome 16, and their heterozygosities and allele frequencies determined. Fourteen (AC)n microsatellites were mapped to discrete physical intervals of human chromosome 16 defined by a mouse/human hybrid panel. Nine of these have expected heterozygosities ranging between 0.60 and 0.79, four have expected heterozygosities between 0.02 and 0.49, and one detected three loci where the alleles could not be resolved.
Publisher: Springer Science and Business Media LLC
Date: 20-06-2005
Abstract: Fragile sites are chromosomal structures that have been proposed to have a determining role in cancer-associated DNA instability. The human WWOX gene spans the FRA16D chromosomal fragile site, the common minimal region of homozygous deletion found in adenocarcinomas and three out of five translocation breakpoints in multiple myeloma. Transcripts from the alternatively spliced WWOX gene encode proteins with common N-terminal WW domains and variable homology to the oxidoreductase family of proteins. In this study, the Drosophila orthologue of the WWOX gene was identified and subjected to mutagenesis via homologous recombination. The resultant DmWWOX1 mutants were viable but exhibited an increased sensitivity to ionizing radiation. This radiation sensitivity was rescued by reintroduction and expression of either the wild-type Drosophila or human WWOX genes. Thus, the protective function of DmWWOX in response to irradiation in Drosophila is conserved with human WWOX (hWWOX). This is consistent with a protective role for hWWOX where aberrant expression, as a result of breakage at the associated fragile site, could contribute directly to cancer progression.
Publisher: Springer Science and Business Media LLC
Date: 07-1992
DOI: 10.1038/NG0792-257
Abstract: The mutation responsible for fragile X syndrome and myotonic dystrophy involves the lification of a simple trinucleotide repeat sequence, which increases in successive generations of affected pedigrees accounting for increasing penetrance of both disorders. This common molecular basis suggests that the two diseases may share other genetic features, but whereas myotonic dystrophy exhibits a significant founder chromosome effect, fragile X syndrome apparently has a very high mutation frequency. By haplotype analysis of microsatellite markers which flank the fragile X unstable element, we have uncovered evidence of founder chromosomes of the fragile X 'mutation'. Disorders caused by heritable unstable elements may therefore exhibit common genetic properties including anticipation and founder chromosomes.
Publisher: American Chemical Society (ACS)
Date: 03-05-1988
DOI: 10.1021/BI00409A003
Abstract: Glandular kallikreins are a family of proteases encoded by a variable number of genes in different mammalian species. In all species examined, however, one particular kallikrein is functionally conserved in its capacity to release the vasoactive peptide, Lys-bradykinin, from low molecular weight kininogen. This kallikrein is found in the kidney, pancreas, and salivary gland, showing a unique pattern of tissue-specific expression relative to other members of the family. We have isolated a genomic clone carrying the human renal kallikrein gene and compared the nucleotide sequence of its promoter region with those of the mouse renal kallikrein gene and another mouse kallikrein gene expressed in a distinct cell type. We find four sequence elements conserved between renal kallikrein genes from the two species. We have also shown that the human gene is localized to 19q13, a position analogous to that of the kallikrein gene family on mouse chromosome 7.
Publisher: Elsevier BV
Date: 05-2007
DOI: 10.1016/J.TIG.2007.03.007
Abstract: The generation and analysis of mutants is central to studies of gene function in model organisms. Methods for random mutagenesis in Drosophila melanogaster have been available for many years, but an alternative approach--targeted mutagenesis using homologous recombination--has only recently been developed. This approach has the advantage of specificity, because genes of interest can be altered. One might expect with a gene-targeting approach that the frequency of background mutations would be minimal. Unfortunately, we have found that this is not the case. Although the possibility of background mutations arising during homologous-recombination-based gene targeting has been raised in the literature, it is not routinely taken into account when using this technique. Our experience suggests that it can be a considerable problem but that it has a relatively simple solution.
Publisher: Elsevier BV
Date: 08-1997
Abstract: The G-protein-coupled P2Y purinoceptors mediate a variety of physiological effects in response to extracellular nucleotides. With the recent discovery of several new members from a variety of species, the P2Y purinoceptor family now encompasses types P2Y1 to P2Y6. By fluorescence in situ hybridization and utilization of the National Center for Biotechnology Information (NCBI) database, the human P2Y6 gene was localized to chromosome 11q13.5, between polymorphic markers D11S1314 and D11S916. NCBI database analysis of the remaining human P2Y purinoceptor genes revealed that P2Y2 and P2Y6 mapped to within less than 4 cM, and thus constitute the first described chromosomal clustering of this gene family. Phylogenetic analysis of the P2Y purinoceptor family demonstrated the presence of five evolutionary branches and suggests the occurrence of an ancient gene duplication event.
Publisher: Springer Science and Business Media LLC
Date: 08-09-1999
Abstract: Mutations in the brain specific P/Q type Ca2+ channel alpha1 subunit gene, CACNA1A, have been identified in three clinically distinct disorders, viz. episodic ataxia type 2 (EA-2), familial hemiplegic migraine (FHM) and spinocerebellar ataxia 6 (SCA6). For in iduals with EA-2, the mutations described thus far are presumed to result in a truncated protein product. Several different missense mutations have been identified in patients with FHM. At least two of these mutations have been identified on two different chromosome 19p13 haplotypes and thus represent recurrent mutations. In the present study, we have screened several in iduals for mutations in all 47 exons in the CACNA1A gene by single-strand conformation analysis. We have characterised a novel missense mutation, G5260A, in exon 32 in a family segregating for EA-2. The consequence of this mutation is an amino acid substitution at a highly conserved position within the CACNA1A gene. This represents the first point mutation not resulting in a proposed truncated protein. Furthermore, this mutation has been detected in a family member with mild clinical signs including only migraine. Additionally, a second previously identified recurrent muta tion, C2272T, in exon 16 has been discovered in a patient with FHM.
Publisher: Elsevier BV
Date: 03-1994
Abstract: A hn-cDNA (heteronuclear complementary DNA) library was constructed from a mouse/human somatic cell hybrid, CY18, which contains chromosome 16 as the only human chromosome. Hexamer primers constructed from consensus 5' intron splice sequences were used to generate cDNA from the immature unspliced mRNA. The resulting cDNA library was screened with a total human DNA probe to identify potential human clones. Rescreening was necessary, and use of a mouse-derived clone with homology to 7SL RNA proved successful in eliminating the majority of mouse clones. Thirteen clones had open reading frames, and of those, five showed homology to human sequences in GenBank. Two clones had homology to random partially sequenced cDNAs, one clone was likely to be a GRP78 pseudogene, one clone mapped the PHKG2 gene to 16p11.2-16p12.1, and one clone had homology to human S13 ribosomal protein. All clones except the latter were mapped to a high-resolution somatic cell panel. Although isolation of human chromosome 16 genes from this library was successful, it was apparent that cDNA synthesis was initiated at sites other than intron splice sites, presumably by mispairing of the hexamers.
Publisher: Elsevier BV
Date: 09-1991
DOI: 10.1016/0888-7543(91)90103-L
Abstract: We describe a highly polymorphic microsatellite repeat sequence, KLK1 AC, which is located 3' to the human glandular kallikrein gene (KLK1) at 19q13.3-13.4. A multiplex PCR was developed to simultaneously genotype the KLK1 AC repeat length polymorphism and a similar repeat at the adjacent APOC2 locus at 19q13.2. Genotypes from these two loci in the 40 large kindred pedigrees from the Centre d'Etude du Polymorphisme Humain were used in conjunction with the background genetic map to establish a multipoint linkage map. The KLK1 locus was also localized physically using somatic cell hybrid DNA templates for polymerase chain reaction analysis. Both genetic and physical mapping studies are consistent with the assignment cen-APOC2-KLK1-D19522-qter. The linkage map places KLK1 approximately 10 cM distal to APOC2. These markers therefore flank the myotonic dystrophy gene and may be useful for diagnosis.
Publisher: BMJ
Date: 06-1992
DOI: 10.1136/JMG.29.6.368
Abstract: The utility of the pfxa3 probe for direct molecular diagnosis of the fragile X (FRAXA) has been established. This probe detects lification of an unstable DNA element consisting of variable length CCG repeats. The size of the lified fragment is correlated with phenotype and was determined using PstI digested DNA in family members. In 35 families with the fragile X, there was correspondence in 183 cases between the presence of an lified unstable element and the presence of the fragile X chromosome independently determined by cytogenetics, position in the pedigree, or linked DNA markers flanking the fragile X. There was also correspondence in 124 cases between the presence of the normal 1.0 kb PstI fragment and absence of the fragile X chromosome independently determined by linked flanking markers. Six additional families considered to be isolated cases of 'fragile X' had been diagnosed before recognition of FRAXD. The pfxa3 probe confirmed the cytogenetic diagnosis in three families, the other three being rediagnosed as non-fragile X. A further two families had consistent expression of a different folate sensitive fragile site, FRAXE, close to FRAXA but not associated with fragile X syndrome and not detectable with the pfxa3 probe. Subsequent referrals were received from additional family members or from members of new families for whom carrier status had not been predetermined by linked markers. Direct pfxa3 diagnosis for the 135 females within these 222 additional cases was confirmed by dosage analysis with the control probe pS8.(ABSTRACT TRUNCATED AT 250 WORDS)
Publisher: Oxford University Press (OUP)
Date: 1994
Abstract: Autosomal fragile sites, unlike their X-linked counterparts, are not known to be associated with disease. However, one case report has highlighted a possible relationship between the inheritance of a rare folate-sensitive fragile site in band 11q23.3 (FRA11B) and the chromosome 11q23-->qter deletion in Jacobsen (11q-) syndrome. The mother and brother of the reported Jacobsen syndrome child are FRA11B carriers, suggesting that in vivo breakage at the fragile site during early development could have given rise to the chromosome deletion. We have tested this hypothesis by high resolution physical mapping of FRA11B and of the deletion chromosome breakpoint in the Jacobsen syndrome patient. A detailed restriction map of 600 kb of human chromosome band 11q23.3 has been assembled which covers the PBGD, CBL2 and THY1 genes. FISH experiments with YACs and cosmids from this region have localised FRA11B to an interval of approximately 100 kb containing the 5' end of the CBL2 gene, which includes a CCG trinucleotide repeat. This class of repeat is expanded in the four cloned ex les of fragile site and therefore the CBL2 repeat is a candidate for the location of FRA11B. Further, it is shown that the chromosomal deletion breakpoint of the Jacobsen syndrome child maps within the same interval as the fragile site. The breakpoint has apparently been repaired and stabilised by the de novo addition of a telomere. These data are consistent with a role for an inherited fragile site in the aetiology of a chromosome deletion syndrome.
Publisher: Elsevier BV
Date: 06-2000
Publisher: American Association for the Advancement of Science (AAAS)
Date: 03-04-1987
Abstract: There is much speculation about fragile sites on human chromosomes predisposing to specific chromosome rearrangements seen in cancer. Acute myelomonocytic leukemia is characterized by neoplastic chromosome rearrangements involving band 16q22 in patients who carry the rare fragile site at 16q22. This specific leukemic breakpoint is within the metallothionein gene cluster, which is here shown to be proximal to the rare fragile site (FRA16B) and to a common fragile site (FRA16C) in this region. Hence neither of these fragile sites are at the breakpoint in this leukemic chromosomal rearrangement.
Publisher: Massachusetts Medical Society
Date: 21-07-1994
DOI: 10.1056/NEJM199407213310310
Abstract: Occupational therapists have been using group therapy as their preferred treatment modality in mental healthcare since the origin of the profession. In private mental healthcare units, major depressive disorder (MDD) is the most common psychiatric disease. Occupational therapists use in idual and group therapy to treat adult inpatients with MDD. Little is known about the perceptions and experiences of adult inpatients with MDD regarding occupational therapy activity-based groups. To describe the perceptions and experiences of adult psychiatric inpatients with MDD towards occupational therapy activity-based groups. This article reports on the perceptions of adult psychiatric inpatients with MDD, which formed part of a larger study. The study took place at two private general hospitals in Gauteng province, South Africa, each with a psychiatric ward. The researcher used a qualitative explorative descriptive design. Accessible participants were selected using convenience s ling. Only consenting participants took part in the study. Data were collected during focus group discussions. Data were thematically analysed. Participants' perceptions could be placed into one of four themes: (1) experience improved mood, (2) learned coping skills, (3) regained self-esteem and (4) becoming part of the solution to face life challenges. Activities that are unique to occupational therapy profession can benefit inpatients with MDD. This supports the profession's historical beliefs, assumptions and foundations regarding therapeutic use of activities. According to these inpatients, group activities improved their overall mental health.
Publisher: Elsevier BV
Date: 11-1990
DOI: 10.1016/0888-7543(90)90038-V
Abstract: The functional human metallothionein (MT) genes are located on chromosome 16q13. We have physically mapped the functional human MT locus by isolation and restriction digest mapping of cloned DNA. The mapped region contains all sequences on chromosome 16 that hybridize to metallothionein gene probes and comprises 14 tightly linked MT genes, 6 of which have not been previously described. This analysis defines the genetic limits of metallothionein functional ersity in the human genome.
Publisher: Oxford University Press (OUP)
Date: 1997
DOI: 10.1093/NAR/25.1.147
Abstract: Fibrillin is the major component of extracellular microfibrils. Mutations in the fibrillin gene on chromosome 15 (FBN1) were described at first in the heritable connective tissue disorder, Marfan syndrome (MFS). More recently, FBN1 has also been shown to harbor mutations related to a spectrum of conditions phenotypically related to MFS. These mutations are private, essentially missense, generally non-recurrent and widely distributed throughout the gene. To date no clear genotype henotype relationship has been observed excepted for the localization of neonatal mutations in a cluster between exons 24 and 32. The second version of the computerized Marfan database contains 89 entries. The software has been modified to accomodate new functions and routines.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 21-06-1991
Abstract: The sequence of a Pst I restriction fragment was determined that demonstrate instability in fragile X syndrome pedigrees. The region of instability was localized to a trinucleotide repeat p(CCG)n. The sequence flanking this repeat were identical in normal and affected in iduals. The breakpoints in two somatic cell hybrids constructed to break at the fragile site also mapped to this repeat sequence. The repeat exhibits instability both when cloned in a nonhomologous host and after lification by the polymerase chain reaction. These results suggest variation in the trinucleotide repeat copy number as the molecular basis for the instability and possibly the fragile site. This would account for the observed properties of this region in vivo and in vitro.
Publisher: Public Library of Science (PLoS)
Date: 08-06-2012
Publisher: BMJ
Date: 03-1997
DOI: 10.1136/JMG.34.3.213
Abstract: We describe a 5 year old boy with a de novo t(10 ) translocation and optic nerve coloboma-renal disease (ONCR). On the basis of GTG banding analysis of prometaphase chromosomes, the patient's karyotype was interpreted as either 46,XY,t(10 )(q24.3 q12.3) or t(10 ) (q25.2 q14.1). Fluorescence in situ hybridisation (FISH) studies using a YAC clone containing the PAX2 gene and YAC clones adjoining FRA10B at 10q25.2 showed that the 10q breakpoint had occurred just within the PAX2 gene and was proximal to FRA10B. These FISH results suggest that the translocation causes a disruption of the PAX2 gene and leads to ONCR, in agreement with the recent reports of PAX2 mutations in two unrelated families with ONCR. Furthermore, we refined the regional mapping of the human PAX2 gene to the junction of bands 10q24.3 and 10q25.1.
Publisher: SAGE Publications
Date: 16-01-2015
Abstract: The WWOX gene spans the common chromosomal fragile site FRA16D that is located within a massive (780 kb) intron. The WWOX gene is very long, at 1.1 Mb, which may contribute to the very low abundance of the full-length 1.4 kb mRNA. Alternative splicing also accounts for a variety of aberrant transcripts, most of which are devoid of C-terminal sequences required for WWOX to act as an oxidoreductase. The mouse WWOX gene also spans a chromosomal fragile site implying some sort of functional relationship that confers a selective advantage. The encoded protein domains of WWOX are conserved through evolution (between humans and Drosophila melanogaster) and include WW domains, an NAD -binding site, short-chain dehydrogenase/reductase enzyme and nuclear compartmentalization signals. This homology has enabled functional analyses in D. melanogaster that demonstrate roles for WWOX in reactive oxygen species regulation and metabolism. Indeed the human WWOX gene is also responsive to altered metabolism. Cancer cells typically exhibit altered metabolism (Warburg effect). Many cancers exhibit FRA16D DNA instability that results in aberrant WWOX expression and is associated with poor prognosis for these cancers. It is therefore thought that aberrant WWOX expression contributes to the altered metabolism in cancer. In addition, others have found that a specific (low-expression) allele of WWOX genotype contributes to cancer predisposition.
No related grants have been discovered for Robert Ian Richards.