ORCID Profile
0000-0001-5256-2097
Current Organisations
Royal College of Pathologists of Australasia
,
Linköpings universitet
,
Linköping University
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Publisher: Informa UK Limited
Date: 1996
DOI: 10.3109/02844319609056404
Abstract: The repair and contraction during connective tissue repair of mesenteric perforations is prolonged in mice compared with rats. In the present study the stimulating effect of transforming growth factor beta 1 (TGF-beta 1) on different aspects of such repair of the mouse mesentery was assessed. The number of closed mesenteric perforations were counted on different days after operation and the free peritoneal cells were counted, the mitotic index was assessed, and actin distribution of fibroblasts around the perforation was studied with laser scanning confocal microscopy. TGF-beta 1 significantly increased the speed of closure and seemed to induce more actin in fibroblasts at the wound margin. It did not significantly influence the mitotic index, but fewer free peritoneal cells were obtained in mice treated with TGF-beta 1. We conclude that TGF-beta 1 is a potent stimulator of connective tissue repair and contraction in mice. The different methods of closure in rats and mice implicate different molecular responses in wounds and further studies on the stimulating effect of TGF-beta 1 may indicate basic fibroblastic cellular mechanisms that are active during contraction in connective tissue repair.
Publisher: Springer Science and Business Media LLC
Date: 09-1998
DOI: 10.1007/S11626-996-0013-Y
Abstract: In this study we assessed the behavior of fibroblasts during contraction of collagen lattices. We applied a new technique for three-dimensional time-lapse studies of movements of living cells using phase-contrast laser scanning microscopy. Five anchored and five floating collagen lattices were studied regarding the activity of cells during a 7-h period of active contraction. Three-dimensional reconstructions of the fibroblasts and their extensions were made from datasets of 16-26 "optical sections" 5 microm apart recorded hourly during the period of measurements. The distance between fibroblast nuclei in the floating lattices decreased by a mean of 6.8 microm, but remained constant in the anchored group. Only minor variations were found in the angle between a line connecting any two nuclei and the tangent of the lattice margin. The lengths of the cellular extensions continuously changed by shortening and extending, and an increasing number of intercellular contacts were established with time. The angle between the extensions and the periphery of the lattice varied continually, and no distinct pattern of arrangement of the extensions was seen. In conclusion, we have shown in living cells in vitro that fibroblasts do not appear to move around within lattices during contraction but rather send out and withdraw cellular extensions continuously. This speaks against cellular locomotion or movement as a main feature of contraction. Time-lapse scanning laser microscopy has also been shown to be a suitable method to study cellular behavior quantitatively in three dimensions during lattice contraction.
Publisher: Springer Science and Business Media LLC
Date: 15-09-2005
DOI: 10.1007/S00441-005-0046-7
Abstract: Tight junctions (TJ) between retinal pigmented epithelial (RPE) and retinal endothelial cells maintain the outer and inner blood-retinal barrier, and the breakdown of these barriers is associated with retinal diseases. Vascular endothelial growth factor (VEGF) increases vascular permeability and is thought to be involved in age-related maculopathy. However, to date, little is known about the effect of VEGF on RPE cell junctions. We have investigated the effect of VEGF on TJ formation by examining two essential proteins, ZO-1alpha(+) and ZO-1alpha(-). Cultured vascular endothelial cells in the presence of 5 ng/ml VEGF significantly down-regulate ZO-1alpha(+) and ZO-1alpha(-) transcripts and proteins with significant loss of their trans-epithelial resistance (TER). Immunoconfocal analysis with an anti-ZO-1 antibody has confirmed the relocation of ZO-1 protein from membrane to cytoplasm. By contrast, in the presence of 5 ng/ml VEGF, cultured RPE cells (ARPE19 and RPE51) significantly up-regulate ZO-1alpha(+) and ZO-1alpha(-) transcripts and proteins resulting in a significant increase in their TER. Subsequent immunoconfocal analysis has demonstrated increased ZO-1 membrane assembly in VEGF-treated RPE cells. Thus, VEGF has a dual capability with respect to the regulation of the expression of some TJ proteins at the transcriptional and post-translational levels depending on cell type.
Publisher: Wiley
Date: 06-2010
DOI: 10.1002/LARY.20998
Abstract: The aim of this study was to provide a detailed cytological account on the healing tympanic membrane (TM) over 14 days and to complement existing research into TM wound healing. The study is a prospective cohort study of 19 male Sprague-Dawley (Rattus norvegicus) rats. Rat TMs were perforated using a sterile needle and sacrificed at time points during the 14 days following perforation. The healing of the TM resembles cutaneous wound healing except that the TM is unique in the lack of a supportive matrix beneath the regenerating epithelia. This prevents the influx of reparative cells and nutrients and the in growth of the usual fibroblastic reaction. TM wound healing contrasts with cutaneous wound healing in that keratinocytes are the first cells to close the wound and not the last. A keratin scaffold may not be important in the healing process. The malleus plays a crucial role in the healing of the TM and is the site of significant mitotic activity during the healing process. Migration across layers of the TM appears to account for the closure of the perforation.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-1997
DOI: 10.1097/00006534-199706000-00019
Abstract: Texturization of silicone-filled breast implants has been shown to reduce the incidence of capsular contracture. A double-blind clinical study was undertaken to compare this incidence in saline-filled implants with textured or with smooth surfaces. Twenty-one women underwent mammary augmentation with a textured implant in one breast and a smooth implant in the other. The implants were placed subglandularly. All operations were performed by the same surgeon and all follow-up examinations by another. Breast hardness was evaluated 6 months postoperatively with applanation tonometry, using Baker's grading, and after 12 months, now also with a questionnaire concerning the patient's evaluation. Capsular contracture (Baker 3) had occurred in 33 percent of the breasts at the end of the study, and was bilateral in five cases. The incidence of contracture and the patients' views on the results did not differ between textured and smooth prostheses or between right and left breasts. Five patients requested reoperation, two of them because of breast hardness. Texturization of saline-filled implants thus did not reduce the incidence of capsular contracture.
Publisher: Springer Science and Business Media LLC
Date: 08-1997
DOI: 10.1007/S11626-997-0112-4
Abstract: Closure of rat mesenteric perforation is considered to occur by connective tissue contraction, a process that has been shown to be stimulated by transforming growth factor-beta 1. In the present study, we assessed the expression of alpha-smooth muscle actin during closure by quantitative-reverse transcription-polymerase chain reaction and in situ hybridization. The expression of transforming growth factor-beta 1 and transforming growth factor-beta type II receptor was also estimated in mesenteric membranes and free peritoneal cells after wounding. A larger expression of alpha-smooth muscle actin was seen around the wound edges compared to unwounded tissue. Both alpha-smooth muscle actin and transforming growth factor-beta type II receptor were expressed during Days 0, 3, 5, 7, and 10. The expression of alpha-smooth muscle actin on Day 5 was > 100 times higher than on Day 0. Transforming growth factor-beta 1 was expressed in both membranes and free peritoneal cells of unoperated control animals but down-regulated after wounding, a finding that has not been reported previously. It reappeared on Days 7 and 10 in free peritoneal cells but not in perforated membranes. The enhanced expression of alpha-smooth muscle actin and down-regulation of transforming growth factor-beta 1 expression after wounding appears to be important phenomena in tissue contraction and repair.
Publisher: Georg Thieme Verlag KG
Date: 2000
DOI: 10.1055/S-2000-12557
Abstract: Preimplantation embryos generate intercellular junctions during differentiation of the trophectoderm epithelium and the formation of the blastocyst. These membrane complexes comprise gap junctions, adherens junctions, tight junctions, and desmosomes, each performing fundamental roles in cellular communication, adhesion, and differentiation. The mouse embryo has been used as a model for the biogenesis of cell junctions. Their construction is achieved by temporally regulated gene expression programs. Mechanisms of junction membrane assembly include the timing of transcription, translation, and post-translational modifications of specific junctional proteins. Human embryos exhibit similar expression programs, and defects in these programs may contribute to reduced embryo viability.
Publisher: Wiley
Date: 10-1997
Publisher: Wiley
Date: 1995
DOI: 10.1111/J.1699-0463.1995.TB01124.X
Abstract: Zinc deficiency impairs connective tissue contraction in the perforated rat mesentery model. Since the rat mesentery is almost avascular, free peritoneal macrophages are important for mesenteric repair. Impairment of contraction may thus be caused either by a direct effect of zinc deficiency on tissue cells or by h ered macrophage function. To further elucidate the role of macrophages in tissue contraction, we studied their effect on lattice contraction. A number of typical functions of macrophages in zinc deficiency were also investigated. Lattice contraction was significantly impaired by conditioned medium from zinc‐deficient macrophages. Zinc deficiency did not influence peripheral blood leukocyte number, but postoperatively the number of peritoneal macrophages increased on days 7 and 10. A significant release of lysosomal enzymes from macrophages was recorded during phagocytosis, whilst no difference was observed between controls and zinc‐deficient macrophages. Superoxide anion generation during phagocytosis was not significantly increased in zinc deficiency. Conditioned medium from zinc‐deficient macrophages was shown to impair lattice contraction in vitro and the results are compatible with impaired macrophage function as a cause of decreased connective tissue contraction in vivo.
Publisher: Elsevier BV
Date: 2014
Publisher: Informa UK Limited
Date: 23-04-2012
DOI: 10.3109/03630269.2012.670683
Abstract: The identification of α-thalassemia (α-thal) due to point mutations has been increasing significantly with the advancement of molecular diagnostic tools. We describe here the molecular and cellular characteristics of the thalassemia mutation HBA2:c.94A>C, a novel point mutation affecting the α2-globin gene, causing a mild α-thal phenotype in a male patient of undisclosed ethnicity, investigated for unexplained microcytosis. The detected mutation is located at the penultimate nucleotide (nt) of the first exon which we postulated might affect pre mRNA splicing. While an in silico analysis did not predict any aberrant splice variants, experimental analysis using our in vitro model for gene expression studies showed utilization of a cryptic splice site at codon 15 that resulted in an aberrant splice variant. As a result, a frameshift in the reading frame of the mature mRNA was produced, leading to the formation of a premature termination codon (PTC) between codons 48 and 49 in exon 2. This in turn leads to nonsense mediated mRNA decay (NMD) and the phenotype of α-thal.
Publisher: Oxford University Press (OUP)
Date: 05-2003
Abstract: We investigated gene expression associated with trophectoderm epithelial intercellular junction formation in single human embryos at different stages of cleavage using RT-PCR methods based upon magnetic bead separation of polyA+ RNA. Trophectoderm tight junction (TJ) and desmosome biogenesis contribute to intercellular sealing and tissue integrity, critical for vectorial transport and blastocoel cavity formation. Expression of the various genes throughout human preimplantation development showed differing levels of sensitivity of detection these genes included claudin-1, occludin (TM4+ and TM4 isoforms), ZO-1 (ZO-1alpha+ and ZO-1alpha- isoforms), ZO-2 and JAM (junction adhesion molecule), and the desmosome junction gene, DSC2 (desmocollin 2). Some transcripts appeared to be expressed throughout preimplantation development (claudin-1, JAM, occludin TM4+ and TM4, ZO-1alpha- isoform) while others tended to be expressed preferentially in later cleavage and associated with blastocyst formation (ZO-2, ZO-1alpha+ isoform, DSC-2), illustrating an expression pattern broadly similar to mouse cleavage stages. Human embryo transcript detection was significantly decreased when reverse transcription was performed in solid phase to generate a bead/cDNA transient library rather than after mRNA elution from beads. Transcript detection tended to be positively correlated with embryo morphological grade using the solid phase method. In blastocysts, occludin TM4-, ZO-1alpha+ and DSC2 transcripts were the most susceptible to failure of detection, indicative of low levels of expression which may impact on trophectoderm differentiation competence. Immunoconfocal microscopy analysis of selected adhesion and TJ proteins in human embryos indicated poor membrane assembly compared with mouse blastocysts, which may further affect embryo viability.
Publisher: Elsevier BV
Date: 04-2011
Publisher: Informa UK Limited
Date: 15-11-2010
DOI: 10.3109/03630269.2010.526896
Abstract: Routine hemoglobin (Hb) analyses identified a new β-globin variant in a family from East Timor. The red cell indices were within normal limits for all affected family members. The variant is due to a missense mutation at amino acid codon 80 (AAC>CAC) which results in the substitution of histidine for asparagine.
Publisher: Springer New York
Date: 2001
Publisher: Springer Science and Business Media LLC
Date: 07-12-2011
DOI: 10.1007/S10735-010-9306-2
Abstract: The aim of this study was to provide a transcriptome profile of Keratinocyte Growth Factor (KGF)-1, Fibroblast Growth Factor (FGF) 2 and FGF10 (KGF2) in the healing rat tympanic membrane (TM) over 7 days and an immunohistochemical account over 14 days following perforation. KGF1, FGF2, and FGF10 play important roles in TM wound healing. The tympanic membranes of rats were perforated and sacrificed at time points over a 14-day period following perforation. The normalized signal intensities and immunohistochemical protein expression patterns at each time point for KGF1, FGF2, and FGF10 are presented. The primary role of both KGF1 and FGF2 appeared to be in the proliferation and migration of keratinocytes. Whereas the role of KGF1 appeared to be exclusively concerned with increased proliferation and migration at the perforation site, the continued expression of FGF2, beyond perforation closure, suggested it has an additional role to play. FGF10 (KGF2), whilst possessing the highest sequence homologous to KGF1, has a different role in TM wound healing. The effect of FGF10 on keratinocytes in wound healing appeared to emanate from the connective tissue layer.
Publisher: Informa UK Limited
Date: 06-2012
DOI: 10.3109/03630269.2012.699488
Abstract: In most references, the transcription initiation site for the α2- and α1-globin genes has been described to lie 37 bp upstream of the translation initiation codon, however, a review of data repositories such as GenBank and Ensembl showed a report of the α2-globin transcription initiation site occurring at position -66 relative to the initiation codon. To confirm the occurrence of these isoforms for both the α2- and α1-globin genes and to document their expression levels, we initiated our current investigation. Total RNA from the peripheral blood of 15 healthy volunteers was analyzed using both semi-quantitative-polymerase chain reaction (PCR) and real-time (ReTi-PCR) protocols developed in our laboratory, with primers designed to enable distinction between the α2- and α1-globin transcripts.We observed two distinct PCR products for each of the globin genes. Subsequent DNA sequencing of 11 in idual PCR products revealed that the α2- and α1-globin transcripts are present in both a long and a short isoform, initiating at positions -66 and -37, respectively. The shorter (-37) isoform is expressed approximately 10,000-100,000 times more strongly than the longer isoform, demonstrating differential expression within the healthy population. This study, for the first time, confirms the presence of two isoforms for both the α2- and α1-globin genes with varying transcription levels in healthy in iduals. The short isoform is expressed at significantly higher levels than the longer isoform for both α2 and α1 genes. Therefore, based on our observations, we propose that despite the contribution of the long isoforms to the total α-globin RNA pool, the short isoforms are the main physiological transcripts.
Publisher: Elsevier BV
Date: 10-2013
Publisher: Springer Science and Business Media LLC
Date: 23-10-2010
DOI: 10.1007/S10735-010-9287-1
Abstract: Epidermal Growth Factor (EGF) has been identified as playing a critical role in the wound healing process. The objective of this study is to investigate the role that EGF plays in rat tympanic membrane (TM) wound healing using two techniques, microarray and immunohistochemistry. The tympanic membranes of rats were perforated using a sterile needle and sacrificed at time points during 2 weeks following perforation. The normalized signal intensities at the time points for EGF and associated genes are presented. The rat EGF mRNA did not change significantly between time points. Five associated proteins, including heparin-binding EGF-like growth factor were found to be differentially expressed above a two fold threshold at 12 h following perforation. EGF staining was found at low levels in the uninjured TM. Levels of EGF staining increased at 24 h in the basal keratinocyte layer, became diffusely elevated in the specimen at 36 h, before a second peak in staining of the keratinocyte layer at Day 4. The staining of EGF corresponds to its multiple roles in TM wound healing.
Publisher: Informa UK Limited
Date: 06-2012
DOI: 10.3109/03630269.2012.717053
Abstract: We describe two frameshift mutations associated with an α-thalassemia (α-thal) phenotype, identified in three unrelated in iduals investigated for persistent microcytosis. The first mutation, HBA2:c.131delT, is located in codon 43, and the second, HBA2:c.143delA, is located in codon 47. Both are due to single base pair deletions that cause a frameshift and a premature termination codon (PTC) at positions 48/49. The presence of a PTC at this position has been documented to result in nonsense mediated mRNA decay that would account for the thalassemic phenotype.
Publisher: Wiley
Date: 10-1996
Publisher: Informa UK Limited
Date: 21-03-2011
DOI: 10.3109/03630269.2011.557462
Abstract: We describe a novel frameshift mutation associated with an α-thalassemia (α-thal) phenotype in a patient of Sudanese origin investigated for persistent microcytosis. In addition to the α(3.7) deletion, a novel mutation on the α2 gene was detected: HBA2:c.323delT. This mutation causes a frameshift at codon 107 of the α2 gene. The result is a disturbed amino acid sequence for the following 24 amino acids, and a premature termination codon at position 132.
Publisher: Informa UK Limited
Date: 1997
DOI: 10.3109/02844319709085476
Abstract: The inhibition of prostaglandin synthesis by diclofenac was studied with regard to effects on connective-tissue contraction and on the chemotaxis of fibroblasts stimulated by platelet-derived growth factor type BB (PDGF-BB). Collagen lattices populated with human fibroblasts responded to diclofenac with significantly increased contraction the peak effect occurred at a dose of 5 micrograms/ml. Using a two-chamber system, PDGF-BB significantly increased the chemotactic activity of fibroblasts, and addition of diclofenac further increased this activity. Higher doses of diclofenac resulted in cell death, which was also reflected in lessened contraction of lattices with 50 micrograms/ml diclofenac, half of the cells were dead. The study showed that inhibition of prostaglandin synthesis by diclofenac increases the contraction of collagen lattices populated with human fibroblasts and increases the chemotactic activity of fibroblasts stimulated with PDGF-BB.
Publisher: SAGE Publications
Date: 22-04-2010
Abstract: Human tympanic membrane cells (hTMCs), harvested from tympanic membrane (TM) explants, were grown in culture and then seeded on membranes prepared from silkworm (Bombyx mori) silk fibroin (BMSF) and on tissue-culture plastic membranes (PET). Fibroin was isolated from silk cast into membranes with a thickness of 10—15 μm. The hTMCs were cultured on both materials for 15 days in a serum-containing culture medium. The cells grown on both substrata were subjected to nuclear staining (DAPI) and counted. Further, the cultures were immunostained for a number of protein markers related to the epithelial/keratinocyte phenotype and cell adhesion complexes. The BMSF membranes supported levels of hTMC growth higher than that observed on the PET membranes. The immunofluorochemical analysis indicated unequivocally that BMSF is a more suitable substratum than PET with respect to the growth patterns, proliferation, and cell—cell contact and adhesion. BMSF appear as a promising substratum in the tissue-engineered constructs for the replacement of TM in case of nonhealing perforations.
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/RD03070
Abstract: During early development, the eutherian mammalian embryo forms a blastocyst comprising an outer trophectoderm epithelium and enclosed inner cell mass (ICM). The short-term goal of blastocyst morphogenesis, including epithelial differentiation and segregation of the ICM, is mainly regulated autonomously and comprises a combination of temporally controlled gene expression, cell polarisation, differentiative cell isions and cell–cell interactions. This aspect of blastocyst biogenesis is reviewed, focusing, in particular, on the maturation and role of cell adhesion systems. Early embryos are also sensitive to their environment, which can affect their developmental potential in erse ways and may lead to long-term consequences relating to fetal or postnatal growth and physiology. Some current concepts of embryo–environment interactions, which may impact on future health, are also reviewed.
Publisher: Springer Science and Business Media LLC
Date: 03-1995
DOI: 10.1007/BF02639426
Abstract: myths about sex during pregnancy harming fetus and leading to preterm labor or miscarriage are very strong factors releasing fear and leading to avoidance of sexual contact during gestation. We therefore evaluated the attitude, sexual experiences and changes in sexual function during pregnancy. a cross-sectional study was conducted among 170 pregnant women who were selected using systematic s ling. Data were collected using an interviewer-administered questionnaire. Data was analysed using IBM SPSS® version 22.0. Descriptive statistics, Chi-square test and Cochran´s Q-test were estimated. the mean age of respondents was 27.2 ± 6.2 years. Most of the respondents, 107 (62.7%) had formal education. One-fifth of the respondents, 34 (20.2%) have been married for over 10 years. More than half of them were multiparous, 112 (68.3%) and in the third trimester of pregnancy, 99 (59.6%). Majority of the respondents, 153 (87.9%) thought coitus was safe in pregnancy. More than half 89 (58.2%) had coitus at least thrice a week before pregnancy and 98.8% have engaged in sexual activities during pregnancy. Most of the respondents, 105 (61.1%) enjoyed coitus during pregnancy. The desire for coitus significantly reduced in the third trimester, p=0.001. sexual intercourse during pregnancy was universal and respondents engaged in sexual activities during different stages of pregnancy. Although sexual frequency declined in pregnancy compared to pre-pregnancy period, most of the respondents desired and enjoyed it. We recommend that couples are well educated to understand the normal fluctuations in sexual interest and practices during pregnancy.
Publisher: Informa UK Limited
Date: 1992
DOI: 10.3109/10520299209110051
Abstract: A new double-embedding technique for thin tissue membranes is presented. This technique is useful for thin membranes such as mesenteric membranes from rodents, which usually measure only 10 microns in thickness. Several membranes are fixed and mounted on four needles located at the bottom of a plastic box. The box is filled with agarose at 50 C and then allowed to solidify. The agarose block is then removed, dehydrated in alcohol, cleared with HistoPetrol (isoparaffin hydrocarbons), permeated with paraffin and sectioned. The morphology is comparable to that obtained with methacrylate plastic embedding but is less time-consuming, less hazardous since no plastic hardener and activator are used and makes immunohistochemical studies easier.
Publisher: SAGE Publications
Date: 12-1996
DOI: 10.1016/S0266-7681(96)80196-3
Abstract: The aim of this study was to see if nodular cells in Dupuytren’s disease differed from dermal cells in their contractile capacity and motility. Ten surgical specimens from patients with Dupuytren’s disease and contracture of the finger of more than 45° were harvested and the nodular cells were explanted and cultured. Dermal fibroblasts from the forearm were used as control cells. Both types of cell had the same growth pattern. The morphology on confocal laser scanning microscopy was also similar in both types of cell. Dermal control cells caused significantly more contraction of collagen lattices compared with fibroblasts from nodules of Dupuytren’s contracture. The F-actin content was equal in both groups. Platelet derived growth factor, PDGF-BB (but not PDGF-AA), increased the chemotactic activity of both cell types, but there were no differences between them. The results indicate that at a late state of the disease cells from Dupuytren’s nodules lose their contractile capacity and regain a phenotype resembling that of dermal fibroblasts.
Publisher: Informa UK Limited
Date: 25-11-2013
DOI: 10.3109/03630269.2013.858639
Abstract: In this study, we describe the clinical features and provide experimental analyses of a novel point mutation affecting the penultimate nucleotide of the first exon of the HBA2 (HBA2: c.94A > G) gene identified in a 26-year-old female who also carries a heterozygous Hb E (HBB: c.79G > A) variant. The aim of the study was to investigate the impact of this point mutation on the transcriptional activity of the HBA2 gene using a combination of an initial in silico prediction followed by in vitro mutagenesis and transcriptional activity assessment. The analyses revealed that the HBA2: c.94A > G point mutation causes the activation of a cryptic splice site located 49 bp upstream of the exon1-intron1 boundary in both HBA2 long and short isoforms, thus generating a frameshift and a premature termination codon between codons 48 and 49 in the second exon. A rapid degradation of the aberrantly spliced transcripts by the nonsense mediated decay (NMD) surveillance system is highly indicative of an α-thalassemia (α-thal) phenotype. However, the abnormal mRNA may not be entirely degraded since the proband presents a slight splenomegaly that could be the sign of extra vascular hemolysis.
Publisher: Springer Science and Business Media LLC
Date: 07-8017
DOI: 10.1007/BF01986588
Publisher: Wiley
Date: 14-09-2011
DOI: 10.1002/LARY.22150
Abstract: The aim of this study is to elucidate transcriptional changes that occur in response to tympanic membrane (TM) perforation in rats and to infer key genes and molecular events in the healing process. A prospective cohort study of 393 male Sprague-Dawley (Rattus norvegicus) rats. Sprague-Dawley rats were randomly allocated into either control or perforation groups spanning a 7-day time period. Perforation groups consisted of 12-hour, 24-hour, 36-hour, 2-day, 3-day, 4-day, 5-day, six-day, and 7-day time points. The left TMs of all perforation groups were perforated and the RNA extracted at the specified time point postperforation. Subsequent analysis was performed using Agilent's 4 × 44 k whole rat genome arrays (40 in total) to assess wound-healing gene expression over a 7-day time period. Over a 7-day time course and at nine time points that encompassed the wounding and progression of healing, a total of 3,262 genes were differentially expressed. In this study the transcripts most upregulated occurred at 12 hours. These were Stefin A2 (344-fold), Stefin 2 (143-fold), and Natriuretic peptide precursor type B (222-fold). Those most downregulated also occurred at 12 hours. These were alcohol dehydrogenase 7 (13.1-fold) and gamma-butyrobetaine hydroxylase (10.4-fold). Results were validated by quantitative real-time polymerase chain reaction. The findings of this study provide a baseline against which to identify disease-related molecular signatures, biomarkers, and to develop new treatments for TM conditions based on molecular evidence.
Publisher: Elsevier BV
Date: 06-2012
Publisher: Informa UK Limited
Date: 03-10-2011
DOI: 10.3109/03630269.2011.599086
Abstract: The α-thalassemias are a group of disorders occurring as a result of decreased synthesis of α-globin chains, most commonly due to deletions of α-globin genes. Detection of α-thalassemia (α-thal) caused by point mutations has increased during the past few years and more than 70 different point mutations have been reported for the α1- and α2-globin genes. The mutation at the splice donor site of the first intervening sequence [IVS-I-1 (G>A)] of the α2-globin gene, HBA2:c.95+1G>A, is thought to cause a thalassemic phenotype by interfering with and preventing the normal splicing of pre-mRNA. We developed an in vitro expression system to study α-globin gene point mutations at the molecular and cellular levels. The expression vector carrying the HBA2:c.95+1G>A mutation (α2G(IVS-I-1G>A)) was created using site-directed mutagenesis of a wild type (WT) construct of the α2-globin gene (α2G(2034WT)). Gene expression experiments in human bladder carcinoma 5637 cells were carried out using sequence verified WT and mutated clones. Complementary DNA synthesis and polymerase chain reaction (PCR) analysis showed normal α2-globin transcripts from cells transfected with the WT vector, but aberrant transcripts from cells transfected with the mutated vector carrying the splice donor site mutation. In the presence of the G>A mutation, normal splicing does not occur, and a cryptic splice site 49 bp upstream of the normal site is used. The translation of this product produces a premature termination codon, thus resulting in a thalassemic phenotype.
Publisher: Wiley
Date: 07-2007
No related grants have been discovered for Dr. Reza Ghassemifar.