Browsing by Author "de Silva, D."

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Anxiety and Depression among the patients with Dysphagia following Oral Maxillofacial and Neck surgeries in four selected hospitals in Western Province, Sri Lanka.
(Faculty of Medicine, University of Kelaniya, Sri Lanka, 2021) Fernando, K.; Fernando, R.; de Silva, D.
Introduction: Undiagnosed anxiety and depression are obstacles to effective management of post-operative dysphagia. In Sri Lanka, the prevalence of anxiety and depression among patients with postoperative dysphagia is not known. Objectives: This study aimed at determining the severity and the stage of dysphagia, presence of anxiety and depression, and to identify the association between the severity and the stage of dysphagia with anxiety and depression following Neck, Oral & Maxillo-Facial (OMF) Surgeries. Methods: A cross-sectional study was conducted among 97 participants, with post¬operative dysphagia following OMF and Neck surgeries at four selected hospitals. Oral-motor and cranial nerve examination, the 3 ml water test, Cervical auscultation, Dysphagia Severity Rating Scale and Hospital Anxiety and Depression Scale were used for data collection. Results: Among the participants 51% presented with pharyngeal phase dysphagia and severe dysphagia. Prevalence of depression was 51% and anxiety was 38%, while 35% and 45% were at the borderline range respectively. With the increasement of dysphagia severity, high levels of anxiety and depression were noted. There was a statistically significant association between the severity of anxiety with severity of dysphagia (p< 0.05). Conclusion: Psychological burden is high among the participants with dysphagia following OMF and neck surgeries. Holistic management of dysphagia following OMF and neck surgeries, should include an assessment of the mental state of these patients and the treatment of anxiety and depression if required.
Arterial tortuosity syndrome: 40 new families and literature review
(Nature Publishing Group, 2018) Beyens, A.; Albuisson, J.; Boel, A.; Al-Essa, M.; Al-Manea, W.; Bonnet, D.; Bostan, O.; Boute, O.; Busa, T.; Chanham, ,N.; Cil, E.; Couke, P.J.; Cousin, M.A.; Dasouki, M.; Da Backer, J.; De Paepe, A.; de Schepper, S.; de Silva, D.; Devriendt, K.; De Wandele, I.; Deyle, D.R.; Dietz, H.; Dupuis-Giroid, S.; Fontenot, E.; Fischer-Zirnsak, B.; Gezdirici, A.; Ghoumid, J.; Giuliano, F.; Baena, N; Haider, M.Z.; Hardin, J.S.; Jeunemaitre, X.; Klee, E.W.; Kornak, U.; Landecho, M.F.; Legrand, A.; Loeys, B.; Lyonnet, S.; Michael, H.; Moceri, P.; Mohammed, S.; Muino-Mosquera, L.; Nampoothiri, S.; Picher, K.; Prescott, k.; Rajeb, A.; Ramos-Arroyo, M.; Rossi, M.; Salih, M.; Seidahmed, M.Z.; Schaefer, E.; Steichen-Gersdorf, E.; Temel, S.; Uysal, F.; Vanhomwegen, M.; Van Laer, L.; Van Maldergem, L.; Warner, D.; Willaert, A.; Collins, T.R.; Taylor, A.; Davis, E.C.; Zarate, Y.; Callewaert, B.
PurposeWe delineate the clinical spectrum and describe the histology in arterial tortuosity syndrome (ATS), a rare connective tissue disorder characterized by tortuosity of the large and medium-sized arteries, caused by mutations in SLC2A10.MethodsWe retrospectively characterized 40 novel ATS families (50 patients) and reviewed the 52 previously reported patients. We performed histology and electron microscopy (EM) on skin and vascular biopsies and evaluated TGF-β signaling with immunohistochemistry for pSMAD2 and CTGF.ResultsStenoses, tortuosity, and aneurysm formation are widespread occurrences. Severe but rare vascular complications include early and aggressive aortic root aneurysms, neonatal intracranial bleeding, ischemic stroke, and gastric perforation. Thus far, no reports unequivocally document vascular dissections or ruptures. Of note, diaphragmatic hernia and infant respiratory distress syndrome (IRDS) are frequently observed. Skin and vascular biopsies show fragmented elastic fibers (EF) and increased collagen deposition. EM of skin EF shows a fragmented elastin core and a peripheral mantle of microfibrils of random directionality. Skin and end-stage diseased vascular tissue do not indicate increased TGF-β signaling.ConclusionOur findings warrant attention for IRDS and diaphragmatic hernia, close monitoring of the aortic root early in life, and extensive vascular imaging afterwards. EM on skin biopsies shows disease-specific abnormalities. In the published version of this paper the author Neus Baena's name was incorrectly given as Neus Baena Diez. This has now been corrected in both the HTML and PDF versions of the paper.(Baena N)Genetics in Medicine 2018; Sep 10
Arterial tortuosity syndrome: A rare inherited form of connective tissue disorder with SLR2A10 gene mutation
(Sri Lanka College of Paediatricians, 2022) Wijesinghe, S.; de Silva, D.; Samarasinghe, D.; Irugalbandara, S.
No abstract available
Association between Mobile Phone Usage and Hearing Sensitivity among Third Year Students; (of) University of Kelaniya, Sri Lanka
(Faculty of Medicine, University of Kelaniya, 2014) Sivaramalingam, V.; de Silva, D.
With advancement of Global System for mobile (GSM) communication, mobile phones (MP) have become an essential communication tool. Mobile networks operate in frequencies which fall in the microwave range of electromagnetic spectrum. The close proximity of a mobile phone antenna, radio frequency electromagnetic radiation can penetrate into organic tissues causing health hazards. In Sri Lanka, the number of MP users is over 20.3 million and the majority of users are young adults. Up to date, no study has been conducted regarding MP usage and its effects on hearing in Sri Lanka. The objective was to determine the association between MP usage and hearing sensitivity among third year students, University of Kelaniya, Sri Lanka. A descriptive cross sectional study was conducted among 223 students who filled a self-administered questionnaire regarding MP usage and hearing related symptoms. All participants underwent otoscopic examination, and a Distortion Product Otoacoustic Emission (DPOAE) screening at 3 kHz, 4 kHz and 5 kHz frequencies. The mean MP usage hour per day was 1.41 hours (SD 1.22) and the mean MP usage duration was 5.57 years (SD 1.72). The majority of students preferred the right ear for MP conversation, while highest prevalence of hearing loss was observed at 4 kHz (5.6%) and 5 kHz (6.7%) in the right ear. There was no significant difference in hearing loss between the ears of the two sides. A significant association between hearing loss and prolonged usage (more than 5.57years) of MP or excessive usage of MP (more than 1.41 hours per day) could not be found. Symptoms such as warmth, tinnitus, need of repetition and muffled sensation were associated with excess usage of MP.
Attitudes towards genetic counselling and testing among medical students and newly qualified doctors
(Sri Lanka Medical Association, 1997) de Silva, D.; Jayasekera, K.M.; Rubasinghe, N.K.; de Silva, D.G.H.
OBJECTIVES: To determine knowledge about four genetic disorders (Down's syndrome (DS), haemophilia (haem), spinal muscular atrophy type 1 (SMA1) and Huntington's disease (HD)), attitudes towards counselling, acceptability of prenatal diagnosis and termination of pregnancies affected with these conditions. DESIGN: Questionnaire survey of a cohort of medical students and newly qualified doctors. SETTING: Faculty of Medicine, University of Ruhuna. RESULTS: 227 completed questionnaires (111 fourth year and 86 final year students, and 30 demonstrators) were analysed. Awareness of DS and haem, was higher than of SMA1 and HD, and was highest among the demonstrators. Over 80 percent of the cohort would not counsel directively about future pregnancies and would discuss the diseases with the family or at risk individuals. Prenatal diagnosis was found acceptable for DS, haem and SMA1 by a majority of the cohort. Attitudes to termination of affected pregnancies varied, 88 percent, 77 percent, 55 percent and 36 percent finding it acceptable for DS, SMA1, haem, and HD respectively, provided legal terminations were available and termination was requested by parents. CONCLUSIONS: This cohort of students and doctors appear to accept the principles of clinical genetics involving non-directive counselling, prenatal diagnosis and in some disorders, termination of pregnancy
Autonomic functions among fuel handlers in the Gampaha District
(Journal of the Ceylon College of Physicians, 2020) Medagoda, K.; Warnakulasuriya, T.; Kottahachchi, D.; Luke, D.; Wadasinghe, D.; Ariyawansha, J.; Rathnayaka, P.; Dissanayake, T.; de Silva, D.; Devanarayana, N.M.
INTRODUCTION AND OBJECTIVES: Economic growth of Sri Lanka has increased the number of motor vehicles. Fuel stations employing more fuel handlers have been established to cope with the demand. The long working hours with exposure to hydrocarbon fuels result in adverse health effects and this study was done to assess the cardiovascular autonomic functions (ANF) including heart rate variations (HRV). METHOD: Fifty fuel handlers from the Gampaha district of Sri Lanka (19-65 years; all were males) from 7 fuel stations were recruited using consecutive sampling and compared with 46 age and gender matched individuals without occupational exposure to fuel (controls). Demographic data were collected after obtaining informed written consent and systematic examination was conducted. ANF assessment and HRV assessment were performed using validated protocols. RESULTS: There were no significant differences in age, weight, height or the BMI among the study and the control populations (p>0.05). Both systolic blood pressure (BP) (Mann Whitney U (MW)= 743.5, p=0.003), diastolic BP (MW= 686.5, p=0.001) and Valsalva ratio (MW= 874.00, p=0.043) were significantly higher among the fuel handlers compared to the controls. Rise in DBP in sustained handgrip, a sympathetic parameter was significantly higher among controls (MW= 863.00, p=0.049). Among HRV parameters, standard deviation of RR intervals was higher among the fuel handlers compared to controls (MW=842.QO, p=0.034). Parasympathetic parameters correlated with exposure hours per week (p<0.05). CONCLUSION: Altered sympathetic: parasympathetic balance was observed among the fuel handlers with a parasympathetic predominance suggesting that autonomic functions are affected on expo sure to air pollution and hydrocarbons.
Cardiovascular autonomic functions of gas station attendants in Sri Lanka
(Springer Nature., 2021) Warnakulasuriya, T.; Medagoda, K.; Kottahachchi, D.; Luke, D.; Wadasinghe, D.; de Silva, D.; Ariyawansha, J.; Rathnayaka, P.; Dissanayaka, T.; Fernando, S.; Devanarayana, N.M.
Introduction: Sri Lanka, a middle-income country in South Asia, has seen a rapid expansion in motor vehicles and, associated with this, an increase in demand for fuel. The dispensing of fuel at fuel stations is performed manually by male fuel handlers, who have long working hours. Such workers are exposed to hydrocarbon fuels which are associated with multiple health effects. This study was performed to determine cardiovascular autonomic functions among fuel handlers in a densely populated district of Sri Lanka. Methods: Fuel handlers (n = 50) from the Gampaha district of Sri Lanka, aged between 19 and 65 years, were identified for the study from seven selected fuel stations. Age and gender-matched controls (n = 46) without occupational exposure to fuel were used as controls. All participants were male (females were not employed as fuel handlers). After obtaining written informed consent, demographic data were collected, and general physical examination performed before autonomic function assessment. Non-parametric methods were used for data analysis. Ethical approval was granted by the ethics review committee of the Faculty of Medicine, University of Kelaniya, Sri Lanka. Results: There were no significant differences in weight, height or BMI among the study and the control populations (p[0.05). Both the systolic (SBP) and diastolic (DBP) blood pressures were significantly higher among the fuel handlers compared to controls (SBP, Mann Whitney U = 743.5, p = 0.003) and (DBP, Mann Whitney U = 686.5, p = 0.001). Valsalva ratio was significantly higher among the fuel handlers (Mann Whitney U—874.00, p = 0.043). The rise in DBP during sustained handgrip, a sympathetic parameter, was significantly higher among the controls (Mann Whitney U = 863.00, p = 0.049). Conclusions: Altered sympathetic:parasympathetic balance was observed among the fuel handlers. Monitoring of the health, using personal protective equipment, and curtailing hours of employment per week is recommended for those employed at fuel stations.
Challenges in recruting older twins for the Sri Lankan twin registry
(Australian Academic Press, 2003) Sumathipala, A.; Sribaddana, S.H.; Abeysingha, N.M.; de Silva, N*.; Fernando, D.J.; Dayaratne, D.A.; de Silva, D.; Warnasuriya, N.D.; Hotopf, M.
The National Twin Registry of Sri Lanka was established in 1997 as a volunteer register. To extend it to a population-based register, we examined the effectiveness of tracing older twins by inspecting birth records and recruiting them by postal invitation and in-person contact. Birth records at a divisional secretariat reported from 2 maternity hospitals between the years of 1954-1970 were scrutinised to identify a random sample of twins. These hospitals had the highest twin delivery rates for the whole country. We identified 620 twins and a questionnaire was mailed to them. Research assistants visited a cohort of non-respondents (71) in the postal survey. These 620 twins were identified after perusing 20700 birth records. The twinning rate was estimated at 29.95 ([620/20700] x 1000) twins per 1000 registered births (CI 27.63-32.27). In the postal survey, 37 (12%) responded and 62 letters were returned (20%). Both twins were still alive in 20 pairs, one was still alive in 15 pairs, and both twins were dead in 2 pairs. During field visits, 42 (59.2%) addresses were located. Information was available on 16 twin pairs. Both twins were alive in 8 pairs, one each in 4 pairs, and both were dead in 4 pairs and at least one twin was traced in 10 pairs (14%). Both the postal and the field survey gave a low yield. This finding is different from tracing younger twins born between 1985-1997 by using the same methods. Migration, urbanization and development in the country might have affected tracing older twins from the birth record addresses, which were decades old.
Characteristic dental pattern with hypodontia and short roots in Fraser Syndrome
(Wiley-Liss, 2020) Kunz, F.; Kayserili, H.; Midro, A.; de Silva, D.; Basnayake, S.; Güven, Y.; Borys, J.; Schanze, D.; Stellzig-Eisenhauer, A.; Bloch-Zupan, A.; Zenker, M.
ABSTRACT:Fraser syndrome (FS) is a rare autosomal recessive multiple congenital malformation syndrome characterized by cryptophthalmos, cutaneous syndactyly, renal agenesis, ambiguous genitalia, and laryngotracheal anomalies. It is caused by biallelic mutations of FRAS1, FREM2, and GRIP1 genes, encoding components of a protein complex that mediates embryonic epithelial-mesenchymal interactions. Anecdotal reports have described abnormal orodental findings in FS, but no study has as yet addressed the orodental findings of FS systematically. We reviewed dental radiographs of 10 unrelated patients with FS of different genetic etiologies. Dental anomalies were present in all patients with FS and included hypodontia, dental crowding, medial diastema, and retained teeth. A very consistent pattern of shortened dental roots of most permanent teeth as well as altered length/width ratio with shortened dental crowns of upper incisors was also identified. These findings suggest that the FRAS1-FREM complex mediates critical mesenchymal-epithelial interactions during dental crown and root development. The orodental findings of FS reported herein represent a previously underestimated manifestation of the disorder with significant impact on orodental health for affected individuals. Integration of dentists and orthodontists into the multidisciplinary team for management of FS is therefore recommended. KEYWORDS: Fraser syndrome; dental roots; hypodontia; orodental health; taurodontism.
Community-based cluster randomised trial of safe storage to reduce pesticide self-poisoning in rural Sri Lanka: study protocol
(BioMed Central, 2011) Pearson, M.; Konradsen, F.; Gunnell, D.; Dawson, A.H.; Pieris, R.; Weerasinghe, M.; Knipe, D.W.; Jayamanne, S.; Metcalfe, C.; Hawton, K.; Wickremasinghe, A.R.; Atapattu, W.; Bandara, P.; de Silva, D.; Ranasinghe, A.; Mohamed, F.; Buckley, N.A.; Gawarammana, I.; Eddleston, M.A.
BACKGROUND: The WHO recognises pesticide poisoning to be the single most important means of suicide globally. Pesticide self-poisoning is a major public health and clinical problem in rural Asia, where it has led to case fatality ratios 20-30 times higher than self-poisoning in the developed world. One approach to reducing access to pesticides is for households to store pesticides in lockable "safe-storage" containers. However, before this approach can be promoted, evidence is required on its effectiveness and safety. METHODS/DESIGN: A community-based cluster randomised controlled trial has been set up in 44,000 households in the North Central Province, Sri Lanka. A census is being performed, collecting baseline demographic data, socio-economic status, pesticide usage, self-harm and alcohol. Participating villages are then randomised and eligible households in the intervention arm given a lockable safe storage container for agrochemicals. The primary outcome will be incidence of pesticide self-poisoning over three years amongst individuals aged 14 years and over. 217,944 person years of follow-up are required in each arm to detect a 33% reduction in pesticide self-poisoning with 80% power at the 5% significance level. Secondary outcomes will include the incidence of all pesticide poisoning and total self-harm. DISCUSSION: This paper describes a large effectiveness study of a community intervention to reduce the burden of intentional poisoning in rural Sri Lanka. The study builds on a strong partnership between provincial health services, local and international researchers, and local communities. We discuss issues in relation to randomisation and contamination, engaging control villages, the intervention, and strategies to improve adherence.
A Comparison of the cytotoxic potential of standardized aqueous and ethanolic extracts of a polyherbal mixture comprised of Nigella sativa (seeds), Hemidesmus indicus (roots) and Smilax glabra (rhizome)
(Medknow Publications, 2010) Samarakoon, S.R.; Thabrew, I.; Galhena, P.B.; de Silva, D.; Tennekoon, K.H.
BACKGROUND: A decoction (hot-water extract) comprised of Nigella sativa (seeds), Hemidesmus indicus (roots), and Smilax glabra (rhizome) has been reported to prevent chemically-induced hepatocarcinogenic changes in rats and to exert significant cytotoxic effects on human hepatoma (HepG2) cells. However, the decoction used in previous studies to determine cytotoxicity was not standardized. Further, during preparation of pharmaceuticals for clinical use, it is more convenient to use an ethanolic extract. Therefore this study was carried out to (a) develop standardizedaqueous and ethanolic extracts of the plant mixture (N. sativa, H. indicus, and S. glabra) used in the preparation of the original decoction, and (b) compare the cytotoxic effects of these two extracts by evaluating cytotoxicity to the human hepatoma (HepG2) cell line. METHODS: Aqueous and ethanolic extracts have been standardized by evaluating organoleptic characters, physicochemical properties, qualitative and quantitative analysis of chemical constituents, and analysis of High Performance Liquid Chromatography (HPLC) and Thin Layer Chromatography (TLC) profiles. Cytotoxic potentials of the above standardized extracts were compared by evaluating their effects on the survival and overall cell activity of HepG2 cells by use of the 3-(4, 5-dimethylthiazol-2yl) -2, 5 - biphenyl tetrazolium bromide (MTT) and Sulphorhodamine B (SRB) assays. RESULTS: Results from MTT and SRB assays demonstrated that both extracts exerted strong dose-dependent in vitro cytotoxicity to HepG2 cells. The standardized aqueous extract showed a marginally (though significantly, P<0.05) higher cyotoxic potential than the ethanolic extract. Thymoquinone, an already known cytotoxic compound isolated from N. sativa seeds was only observed in the standardized ethanolic extract. Thus, compounds other than thymoquinone appear to mediate the cytotoxicity of the standardized aqueous extract of this poly-herbal preparation. CONCLUSION: It may be concluded that results obtained in the present study could be used as a diagnostic tool for the correct identification of these aqueous or ethanolic extracts and would be useful for the preparation of a standardized pharmaceutical product that may be used in the future for clinical therapy of hepatocellular carcinoma.
Confirmation of mosaic trisomy 22 in an infant with failure to thrive
(Sri Lanka College of Paediatricians, 2018) Dayasiri, K.C.; de Silva, D.; Weerasekara, K.
No Abstract available
Correction:Arterial tortuosity syndrome: 40 new families and literature review
(Nature Publishing Group, 2019) Beyens, A.; Albuisson, J.; Boel, A.; Al-Essa, M.; Al-Manea, W.; Bonnet, D.; Bostan, O.; Boute, O.; Busa, T.; Chanham, N.; Cil, E.; Couke, P.J.; Cousin, M.A.; Dasouki, M.; Da Backer, J.; De Paepe, A.; de Schepper, S.; de Silva, D.; Devriendt, K.; De Wandele, I.; Deyle, D.R.; Dietz, H.; Dupuis-Giroid, S.; Fontenot, E.; Fischer-Zirnsak, B.; Gezdirici, A.; Ghoumid, J.; Giuliano, F.; Baena, N.; Haider, M.Z.; Hardin, J.S.; Jeunemaitre, X.; Klee, E.W.; Kornak, U.; Landecho, M.F.; Legrand, A.; Loeys, B.; Lyonnet, S.; Michael, H.; Moceri, P.; Mohammed, S.; Muino-Mosquera, L.; Nampoothiri, S.; Picher, K.; Prescott, K.; Rajeb, A.; Ramos-Arroyo, M.; Rossi, M.; Salih, M.; Seidahmed, M.Z.; Schaefer, E.; Steichen-Gersdorf, E.; Temel, S.; Uysal, F.; Vanhomwegen, M.; Van Laer, L.; Van Maldergem, L.; Warner, D.; Willaert, A.; Collins, T.R.; Taylor, A.; Davis, E.C.; Zarate, Y.; Callewaert, B.
In the published version of this paper the author Neus Baena's name was incorrectly given as Neus Baena Diez. This has now been corrected in both the HTML and PDF versions of the paper. Erratum for:Arterial tortuosity syndrome: 40 new families and literature review. Beyens A. et al. [Genet Med. 2018;20(10):1236-1245. doi: 10.1038/gim.2017.253] .
Effectiveness of household lockable pesticide storage to reduce pesticide self-poisoning in rural Asia: a community-based, cluster-randomised controlled trial
(London : J. Onwhyn, 2017) Pearson, M.; Metcalfe, C.; Jayamanne, S.; Gunnell, D.; Weerasinghe, M.; Pieris, R.; Priyadarshana, C.; Knipe, D.W.; Hawton, K.; Dawson, A.H.; Bandara, P.; de Silva, D.; Gawarammana, I.; Eddleston, M.; Konradsen, F.
BACKGROUND: Agricultural pesticide self-poisoning is a major public health problem in rural Asia. The use of safer household pesticidestorage has been promoted to prevent deaths, but there is no evidence of effectiveness. We aimed to test the effectiveness of lockablehousehold containers for prevention of pesticide self-poisoning. METHODS: We did a community-based, cluster-randomised controlled trial in a rural area of North Central Province, Sri Lanka. Clusters of households were randomly assigned (1:1), with a sequence computer-generated by a minimisation process, to intervention or usual practice (control) groups. Intervention households that had farmed or had used or stored pesticide in the preceding agricultural season were given a lockable storage container. Further promotion of use of the containers was restricted to community posters and 6-monthly reminders during routine community meetings. The primary outcome was incidence of pesticide self-poisoning in people aged 14 years or older during 3 years of follow-up. Identification of outcome events was done by staff who were unaware of group allocation. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT1146496. FINDINGS: Between Dec 31, 2010, and Feb 2, 2013, we randomly assigned 90 rural villages to the intervention group and 90 to the control group. 27 091 households (114 168 individuals) in the intervention group and 26 291 households (109 693 individuals) in the control group consented to participate. 20 457 household pesticide storage containers were distributed. In individuals aged 14 years or older, 611 cases of pesticide self-poisoning had occurred by 3 years in the intervention group compared with 641 cases in the control group; incidence of pesticide self-poisoning did not differ between groups (293·3 per 100 000 person-years of follow-up in the intervention group vs 318·0 per 100 000 in the control group; rate ratio [RR] 0·93, 95% CI 0·80-1·08; p=0·33). We found no evidence of switching from pesticide self-poisoning to other forms of self-harm, with no significant difference in the number of fatal (82 in the intervention group vs 67 in the control group; RR 1·22, 0·88-1·68]) or non-fatal (1135 vs 1153; RR 0·97, 0·86-1·08) self-harm events involving all methods. INTERPRETATION: We found no evidence that means reduction through improved household pesticide storage reduces pesticide self-poisoning. Other approaches, particularly removal of highly hazardous pesticides from agricultural practice, are likely to be more effective for suicide prevention in rural Asia. FUNDING: Wellcome Trust, with additional support from the American Foundation for Suicide Prevention, Lister Institute of Preventive Medicine, Chief Scientist Office of Scotland, University of Copenhagen, and NHMRC Australia.
Emerging issues in genetic testing in Sri Lanka
(Forum for Medical Ethics Society, 2007) de Silva, D.
No Abstract Available
Erythrocyte antioxidant enzymes in patients with cataract
(Institute for Clinical Science., 2006) Chandrasena, L.G.; Chackrewarthy, S.; Perera, P.T.; de Silva, D.
The pathogenesis of cataract has been found to be influenced by a number of factors including oxidative stress. Catalase, glutathione peroxidase (GPX), and superoxide dismutase (SOD) are some of the antioxidant enzymes that protect the body from oxidative damage. The present study investigates the activities of erythrocyte catalase, GPX, and SOD with respect to senile cataract (non-diabetic cataract) and osmotic cataract (diabetic cataract) in a Sri Lankan population. One hundred and two non-diabetic subjects (50 with cataract and 52 non-cataract) and 106 diabetic subjects (56 with cataract and 50 non-cataract) were recruited into the study. Erythrocyte catalase, GPX, and SOD activities were assayed and the data were analysed by t-test (p <0.05 for significance). In the non-diabetic group, significantly low levels of catalase, GPX, and SOD activities were associated with cataract when compared with non-cataract. No significant changes in catalase, GPX, and SOD activities were observed in the diabetic group between cataract and non-cataract. Senile cataract (non-diabetic cataract) was associated with significantly low levels of erythrocyte catalase, GPX, and SOD when compared with osmotic cataract (diabetic cataract). Positive correlations were observed between catalase and SOD (r = 0.75), catalase and GPX (r = 0.63), and SOD and GPX (r = 0.59) in subjects with senile cataracts. Our results indicate that erythrocyte antioxidant enzyme levels are decreased in senile cataract as opposed to osmotic cataract. Assays of these erythrocyte enzyme activities could provide a marker to identify individuals predisposed to senile cataract.
Exploring the genetic basis of 3MC syndrome: Findings in 12 further families:
(Wiley-Blackwell, 2016) Urquhart, J.; Roberts, R.; de Silva, D.; Shalev, S.; Chervinsky, E.; Nampoothiri, S.; Sznajer, Y.; Revencu, N.; Gunasekera, R.; Suri, M.; Ellingford, J.; Williams, S.; Bhaskar, S.; Clayton-Smith, J.
The 3MC syndromes are a group of rare autosomal recessive disorders where the main clinical features are cleft lip and palate, hypertelorism, highly arched eyebrows, caudal appendage, postnatal growth deficiency, and genitourinary tract anomalies. Ophthalmological abnormalities, most notably anterior chamber defects may also be seen. We describe the clinical and molecular findings in 13 individuals with suspected 3MC syndrome from 12 previously unreported families. The exclusion of the MASP1 and COLEC11 Loci in two individuals from different consanguineous families and the absence of mutations in four further individuals sequenced for both genes raises the possibility that that there is further genetic heterogeneity of 3MC syndrome. © 2016 Wiley Periodicals, Inc.
Genetic testing for single gene disorders
(Sri Lanka Medical Association, 2004) de Silva, D.
Genetic testing for single gene disorders is becoming available in Sri Lanka. While it offers many benefits, there are concerns about psychological and social problems that can be a consequence of such tests. This article aims to review the potential benefits and disadvantages of genetic testing, and recommends mechanisms that would help minimise problems associated with the inappropriate use of genetic tests
Genotype-phenotype correlations emerging from the identification of missense mutations in MBTPS2
(Wiley, 2013) Bornholdt, D.; Atkinson, T.P.; Bouadjar, B.; Catteau, B.; Cox, H.; de Silva, D.; Fischer, J.; Gunasekera, C.N.; Hadj-Rabia, S.; Happle, R.; Holder-Espinasse, M.; Kaminski, E.; Konig, A.; Megarbane, A.; Megarbane, H.; Neidel, U.; Oeffner, F.; Oji, V.; Theos, A.; Traupe, H.; Vahlquist, A.; van Bon, B.W.; Virtanen, M.; Grzeschik, K.H.
Missense mutations affecting membrane-bound transcription factor protease site 2 (MBTPS2) have been associated with Ichthyosis Follicularis with Atrichia and Photophobia (IFAP) syndrome with or without BRESHECK syndrome, with keratosis follicularis spinulosa decalvans, and Olmsted syndrome. This metalloprotease activates, by intramembranous trimming in conjunction with the protease MBTPS1, regulatory factors involved in sterol control of transcription and in cellular stress response. In this study, 11 different MBTPS2 missensemutations detected in patients from 13 unrelated families were correlated with the clinical phenotype, with their effect on cellular growth in media without lipids, and their potential role for sterol control of transcription. Seven variants were novel [c.774C>G (p.I258M); c.758G>C (p.G253A); c.686T>C (p.F229S); c.1427T>C (p.L476S); c.1430A>T (p.D477V); c.1499G>A (p.G500D); c.1538T>C (p.L513P)], four had previously been reported in unrelated sibships [c.261G>A (p.M87I); c.1286G>A (p.R429H); c.1424T>C (p.F475S); c.1523A>G (p.N508S)]. In the enzyme, the mutations cluster in transmembrane domains. Amino-acid exchanges near the active site are more detrimental to functionality of the enzyme and, clinically, associated with more severe phenotypes. In male patients, a genotype-phenotype correlation begins to emerge, linking the site of the mutation in MBTPS2 with the clinical outcome described as IFAP syndrome with or without BRESHECK syndrome, keratosis follicularis spinulosa decalvans, X-linked, Olmsted syndrome, or possibly further X-linked traits with an oculocutaneous component. © 2013 Wiley Periodicals, Inc.
Geo-helminth infections in a rural area of Sri Lanka
(SEAMEO Regional Tropical Medicine and Public Health Project, 2001) Fernando, S.D.; Goonethilleke, H.; Weerasena, K.H.; Kuruppuarachchi, N.D.; Tilakaratne, D.; de Silva, D.; Wickremasinghe, A.R.
School children carry the heaviest burden of morbidity due to intestinal helminth infection. The objective of this investigation was to study geo-helminth infections in 349 school children aged 6 to 13 years living in a rural area of Sri Lanka. Stool samples were examined by direct saline smear in an initial survey to determine the prevalence of intestinal parasitic infections and thereafter the children were followed up over a two year period with cross sectional surveys of stool samples being carried out at yearly intervals. Following collection of a stool sample, all the subjects were treated with mebendazole 500 mg as a single dose. Weights and heights were measured using standardized procedures. 2 ml of venous blood were collected from each subject under aseptic conditions to determine hematological indices. The prevalence of geo-helminth infections was low, and the prevalence declined during the two-year period from 5.4 percent in 1997 to 2.2 percent in 1998 and 2.0 percent in 1999 following yearly mass anti-helminth treatment. The incidence density was 0.021 cases per child year. The reduction in the prevalence from the baseline to the second survey is probably due to the reduction of the reservoir of infection among children as a result of mass treatment at baseline. The prevalence of infection during the second and third surveys were almost the same probably due to infections originating from other segments of the untreated population.