ORCID Profile
0000-0002-5479-9650
Current Organisation
University of Sydney
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Publisher: Springer Science and Business Media LLC
Date: 14-03-2018
DOI: 10.1007/S00784-018-2417-Y
Abstract: Periodontopathogens induce immunoinflammatory responses characterized by the release of inflammatory mediators, e.g., interleukin (IL)-1β, IL-6, and IL-8. Ghrelin (GHRL) is an appetite hormone which mediates its effect via the functional receptor GHS-R1a. This study was to examine the effect of an inflammatory insult on GHS-R1a in human periodontal cells. Periodontal ligament (PDL) cells and gingival fibroblasts (HGFs) were exposed to IL-1β in the presence and absence of GHRL. Cells were also pre-incubated with specific inhibitors of NF-κB or MEK1/MEK2 signaling. Gene expression of GHS-R1a and proinflammatory mediators was assessed by real-time PCR, GHS-R1 protein level by immunocytochemistry, and NF-κB nuclear translocation by immunofluorescence. IL-1β increased significantly the GHS-R1a expression in both cell types in a dose-dependent manner. The stimulatory effect of IL-1β involved the NF-κB and MAPK pathways. Exposure of cells to IL-1β also resulted in an increased production of GHS-R1 protein in both cell types. Furthermore, GHRL counteracted significantly the stimulatory actions of IL-1β on IL-6 and IL-8 in PDL cells. This study demonstrates for the first time that IL-1β upregulates the functional ghrelin receptor in periodontal fibroblastic cells. Moreover, these results further support the assumption that the GHRL/GHS-R system exerts anti-inflammatory effects. Therefore, the upregulation of ghrelin receptor in periodontal cells in response to an inflammatory stimulus may represent a negative feedback mechanism to attenuate the initial inflammatory process in periodontal diseases. The anti-inflammatory GHRL/GHS-R system may serve as a promising target for the prevention and therapy of periodontal diseases.
Publisher: Springer Science and Business Media LLC
Date: 18-09-2010
DOI: 10.1007/S10653-010-9339-1
Abstract: The increase in the number of chronic kidney disease (CKD) patients from the north central region of Sri Lanka has become a environmental health issue of national concern. Unlike in other countries where long-standing diabetes and hypertension are the leading causes of renal diseases, the majority of CKD patients from this part of Sri Lanka do not show any identifiable cause. As the disease is restricted to a remarkably specific geographical terrain, particularly in the north central dry zone of the country, multidisciplinary in-depth research studies are required to identify possible etiologies and risk factors. During this study, population screening in the prevalent region and outside the region, analysis of geoenvironmental and biochemical s les were carried out. Population screening that was carried out using a multistage s ling technique indicated that the point prevalence of CKD with uncertain etiology is about 2-3% among those above 18 years of age. Drinking water collected from high-prevalent and non-endemic regions was analyzed for their trace and ultratrace element contents, including the nephrotoxic heavy metals Cd and U using ICP-MS. The results indicate that the affected regions contain moderate to high levels of fluoride. The Cd contents in drinking water, rice from affected regions and urine from symptomatic and non-symptomatic patients were much lower indicating that Cd is not a contributing factor for CKD with uncertain etiology in Sri Lanka. Although no single geochemical parameter could be clearly and directly related to the CKD etiology on the basis of the elements determined during this study, it is very likely that the unique hydrogeochemistry of the drinking water is closely associated with the incidence of the disease.
Publisher: Springer Science and Business Media LLC
Date: 13-10-2012
Publisher: Springer Science and Business Media LLC
Date: 09-2011
Publisher: Springer Science and Business Media LLC
Date: 28-06-2012
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.JTEMB.2019.04.019
Abstract: Chronic kidney disease of uncertain etiology (CKDu) in areas in and around Sri Lanka's North Central Province has been identified as a major non-communicable disease due to its high prevalence and the burden on the public health system. Controversial evidence relating to the etiology and risk factors of CKDu has been reported. The most debated is the role of trace elements such as Cd and As in the pathogenesis of CKDu. Urine and hair s les collected from CKDu patients and healthy controls were measured for the concentration of different elements including Cd and As. To assess the possible environmental exposures, drinking water and rice s les collected from the affected areas as well as unaffected areas in the country were analyzed. Transmission electronic microscopic analysis of renal biopsies from CKDu patients was also performed. Analysis of drinking water and rice s les indicated that the levels of all minerals and trace elements analyzed including Cd and As were within the levels recommended by World Health Organization and Sri Lanka drinking water guidelines and did not suggest any form of contamination. Analysis of biological s les, including urine, hair and renal tissue, did not provide evidence to support Cd or As toxicity in CKDu patients. Overall, the observations of this integrated, comprehensive study, which included biological, environmental and pathological investigations, strongly support our previous reports on the absence of Cd and As toxicity in areas with high prevalence of CKDu. Further, these observations do not provide evidence on the involvement of Cd and As in pathogenesis of CKDu in Sri Lanka.
Publisher: Hindawi Limited
Date: 2017
DOI: 10.1155/2017/4916971
Abstract: Ghrelin plays a major role in obesity-related diseases which have been shown to be associated with periodontitis. This study sought to analyze the expression of the functional receptor for ghrelin (GHS-R1a) in periodontal cells and tissues under microbial conditions in vitro and in vivo . The GHS-R1a expression in human periodontal cells challenged with the periodontopathogen Fusobacterium nucleatum , in gingival biopsies from periodontally healthy and diseased in iduals, and from rats with and without ligature-induced periodontitis was analyzed by real-time PCR, immunocytochemistry, and immunofluorescence. F. nucleatum induced an initial upregulation and subsequent downregulation of GHS-R1a in periodontal cells. In rat experimental periodontitis, the GHS-R1a expression at periodontitis sites was increased during the early stage of periodontitis, but significantly reduced afterwards, when compared with healthy sites. In human gingival biopsies, periodontally diseased sites showed a significantly lower GHS-R1a expression than the healthy sites. The expression of the functional ghrelin receptor in periodontal cells and tissues is modulated by periodontal bacteria. Due to the downregulation of the functional ghrelin receptor by long-term exposure to periodontal bacteria, the anti-inflammatory actions of ghrelin may be diminished in chronic periodontal infections, which could lead to an enhanced periodontal inflammation and tissue destruction.
Publisher: Wiley
Date: 28-12-2019
DOI: 10.1111/ODI.13007
Abstract: Biomedical big data amasses from different sources such as electronic health records, health research, wearable devices and social media. Recent advances in data capturing, storage and analysis techniques have facilitated conversion of a wealth of knowledge in biomedical big data into evidence-based actionable plans to enhance population health and well-being. The delay in reaping the benefits of biomedical big data in dentistry is mainly due to the slow adoption of electronic health record systems, unstructured clinical records, tattered communication between data silos and perceiving oral health as a separate entity from general health. Recent recognition of the complex interplay between oral and general health has acknowledged the power of oral health big data to glean new insights on disease prevention and management. This review paper summarizes recent advances, limitations and challenges in biomedical big data in health care with emphasis on oral health and discusses the potential future applications of oral health big data to improve the quality and efficiency of personalized health care.
Publisher: Springer Science and Business Media LLC
Date: 07-05-2011
DOI: 10.1007/S00128-011-0301-4
Abstract: This was a screening study that aimed to determine the presence of nephrotoxic mycotoxins in urine s les from patients with chronic kidney disease of uncertain etiology in the North Central Province of Sri Lanka. The percentage detection of aflatoxins, ochratoxins and fumonisins in 31 patients were 61.29%, 93.5% and 19.4%, respectively. Geometric means of urinary aflatoxins and ochratoxins were 30.93 creatinine and 34.62 ng/g creatinine in chronic kidney disease of uncertain etiology stage 1-2 patients and 84.12 ng/g creatinine and 63.52 ng/g creatinine in unaffected relatives of patients. In chronic kidney disease of uncertain etiology stage 3-5 patients, geometric means of urinary aflatoxins and ochratoxins were 10.40 and 17.08 ng/g creatinine, respectively. Non-affected relatives of patients (n = 6) had comparable levels of these mycotoxins, but healthy Japanese in iduals (n = 4) had lower levels than in Sri Lanka. The higher detection rate of urinary ochratoxins in Sri Lankans indicates that exposure is common in the region.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2010
DOI: 10.1161/STROKEAHA.109.576694
Abstract: Background and Purpose— Genetic factors are important determinants of intracranial aneurysm (IA). Recently, a multinational, genome-wide association study identified 3 loci associated with IA, located on 2q (rs700651), 8q (rs10958409), and 9p (rs1333040 and rs10757278). The aim of this study was to evaluate these associations. Methods— Familial and sporadic cases were investigated. Familial cases, consisting of 96 subjects with IA, and 46 subjects of unknown status from 31 pedigrees were analyzed with the transmission disequilibrium test and linkage analysis. Associations of single-nucleotide polymorphisms (SNPs) with IA were tested in 419 sporadic IA cases and in 408 control subjects. Sequencing of CDKN2A , CDKN2B , and CDKN2BAS revealed additional SNPs, and their associations with IA were also tested. Results— The transmission disequilibrium test revealed associations of 2 SNPs, rs700651 ( P =0.036) and rs1333040 ( P =0.002), with familial IA. Analysis of SNPs in sporadic cases revealed an allelic association of rs1333040 with IA (odds ratio=1.28 95% CI, 1.04–1.57 P =0.02) but failed to show associations of rs10757278 and rs496892 with IA. We sequenced 3 candidate genes CDKN2A , CDKN2B , and CDKN2BAS . All 6 index cases from IA families had the rs1333040-T allele and SNPs (rs10965215, rs10120688, and rs7341791) in CDKN2BAS . None of these SNPs had linkage disequilibrium with rs1333040 and was associated with IA. Conclusions— A region between introns 7 and 15 of CDKN2BAS carrying the rs1333040-T allele may confer risk for IA.
Publisher: Wiley
Date: 08-2019
DOI: 10.1111/EJE.12382
Abstract: Good clinical skills are crucial for all dental practitioners. The transfer of knowledge from didactic lectures to daily clinical application can be challenging for current millennial learners. This study aimed to evaluate the effectiveness of using instructional videos to teach dental local anaesthesia in an undergraduate oral health programme in 2017. The philosophical basis of this study relies on the Advanced Trauma Life Support (ATLS) course which has been proven effective in practical education. Video clips were made in 3 different formats, with the addition of a quiz-embedded version to reinforce learning and revision for practical assessments. All the students agreed that their motivation to watch the videos was to refresh their memories before assessments. 90% of students agreed the videos helped them to learn psychomotor skills that required accuracy. There was a statistically significant correlation between the number of views of the videos on the administration of block injections and the marks received for practical assessment (r = 0.36, P = 0.05), and correlation between participating in online quizzes and theory assessment (r = 0.371, P = 0.044). Videos with narration and background music were found to be popular amongst oral health students. The use of instructional videos has been found effective in complementing the ATLS approach for teaching psychomotor skills in the administration of local anaesthetics by oral health students. Further studies are required to measure the students' retention of knowledge and application of skills on a patient in clinical settings.
Publisher: Elsevier BV
Date: 11-2023
Publisher: Wiley
Date: 2019
DOI: 10.21815/JDE.019.007
Publisher: Springer Science and Business Media LLC
Date: 25-06-2015
Publisher: Wiley
Date: 2016
Publisher: SAGE Publications
Date: 08-2019
Abstract: Increasing attention is being given to the roles of data management and data sharing in the advancement of research. This study was undertaken to explore opinions and past experiences of established dental researchers as related to data sharing and data management. Researchers were recruited from the International Association for Dental Research scientific groups to complete a survey consisting of Likert-type, multiple-choice, and open-ended questions. All 42 respondents indicated that data sharing should be promoted and facilitated, but many indicated reservations or concerns about the proper use of data and the protection of research subjects. Many had used data from data repositories and received requests for data originating from their studies. Opinions varied regarding restrictions such as requirements to share data and the time limits of investigator rights to keep data. Respondents also varied in their methods of data management and storage, with younger respondents and those with higher direct costs of their research tending to use dedicated experts to manage their data. The expressed respondent support for research data sharing, with the noted concerns, complements the idea of developing managed data clearinghouses capable of promoting, managing, and overseeing the data-sharing process. Researchers can use the results of this study to evaluate and improve management and sharing of research data. By encouraging and facilitating the data-sharing process, research can advance more efficiently, and research findings can be implemented into practice more rapidly to improve patient care and the overall oral health of populations.
Publisher: Wiley
Date: 2014
Abstract: Previous investigations on chronic kidney disease of unknown etiology characterized by tubulointerstitial damages (CKDu) in the North Central Region (NCR) of Sri Lanka have supported the involvement of social, environmental and genetic factors in its pathogenesis. We conducted a social-environmental-and-genetic epidemiology study on a male population in NCR to investigate the genetic and environmental contributors. We recruited 311 case-series patients and 504 control candidates. Of the 504 control candidates, 218 (43%) were eliminated because of the presence of hypertension, proteinuria, high HbA1c, high serum creatinine or high alpha-1 microglobulin in urine. None of 18 metals measured (μg//) in urine, including Cd, As and Pb, showed significantly higher concentrations in cases compared with controls. As speciation results showed that 75-80% of total urinary As was in the form of arsenobetaine, which is non-toxic to humans. None of the metal concentrations in drinking water s les exceeded guideline values. A genome-wide association study (GWAS) was conducted to determine the genetic contributors. The GWAS yielded a genome-wide significant association with CKDu for a single nucleotide polymorphism (SNP rs6066043 p=5.23 × 10(-9) in quantitative trait locus analysis p=3.73 × 10(-9) in dichotomous analysis) in SLC13A3 (sodium-dependent dicarboxylate transporter member 3). The population attributable fraction and odds ratio for this SNP were 50% and 2.13. Genetic susceptibility was identified as the major risk factor for CKDu. However, 43% of the apparently healthy male population suffers from non-communicable diseases, suggesting their possible influence on CKDu progression.
Publisher: Springer Science and Business Media LLC
Date: 18-10-2019
DOI: 10.1038/S41598-019-51448-7
Abstract: Next Generation sequencing has greatly progressed the exploration of the oral microbiome’s role in dental diseases, however, there has been little focus on the effect of s le storage conditions and their interaction with DNA extraction method. Dental plaque s les collected from 20 healthy participants were pooled and stored in either 75% ethanol or Bead solution for up to 6-months at −80 °C, prior to DNA extraction with either QIA (non-bead beating) or PowerSoil (bead-beating) kit, followed by Illumina sequencing of 16S rRNA gene . We found that storage media and not extraction method had the biggest influence on the ersity and abundance of the oral microbiota recovered. S les stored in Bead solution, independent of the extraction kit, retrieved higher ersity (PowerSoil p = 1.64E-07, QIA p = 0.0085) and had dissimilar overall ecologies as indicated by lower level of shared ersity (PowerSoil p = 0.0000237, QIA p = 0.0088). Comparatively, s les stored in Bead solution and extracted with PowerSoil recovered a higher abundance of Streptococcus species. These data indicate that Bead solution can preserve the oral microbiome in dental plaque reliably, for periods of up to 6-months at −80 °C, and is compatible, with either a bead-beating or non-bead beating DNA extraction method.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.JEBDP.2019.05.014
Abstract: The directional and nondirectional associations of periodontitis with chronic kidney disease: A systematic review and meta-analysis of observational studies. Zhao D, Khawaja AT, Jin L, Li K-Y, Tonetti M, Pelekos G. J Perio Res 2018 53(5):682-704. The authors' own institution, University of Hong Kong. Systematic review with meta-analysis of data.
Publisher: Springer Science and Business Media LLC
Date: 10-08-2013
No related grants have been discovered for Shanika Nanayakkara.