Browsing by Author "Warnakulasuriya, D.T.D."

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Assessment of Background Frequency of Micronuclei Formation in Two Selected Populations in Sri Lanka.
(In: Proceedings of the International Postgraduate Research Conference 2017 (IPRC – 2017), Faculty of Graduate Studies, University of Kelaniya, Sri Lanka., 2017) Weerakkody, W.A.T.L.; Warnakulasuriya, D.T.D.; Williams, H.S.A.; Dabarera, M.D.; Rathnayake, R.M.N.P.; Rodrigo, B.K.S.K.; Wickremasinghe, A.R.
This study assessed background frequency of micronuclei formation using biodosimetry in persons living in Norochcholai and Ragama in Sri Lanka. Biodosimetry, a technique used to assess exposure to radiation, is considered superior to physical dosimetry. It gives a clearer picture of individual variation of susceptibility to radiation and human risk assessment. This study establishes baseline levels of micronuclei formation in a Sri Lankan population to monitor possible radiation accidents that may occur at a nuclear power plant that was commissioned in nearby India recently. Biodosimetry has been used to detect external and internal exposure to ionising radiations in scenarios of accidental and occupational exposure wherever nuclear power plants are present. 96 healthy individuals from both sexes were selected for the study (in the age range of 20-59 years), comprising 50 from Norochcholai (area closest to the power plant) and 46 (matched for gender, age and life style) from Ragama (as a control). 10ml of venous blood was drawn and the cytokinesis–block micronuclei assay was performed, 1000 binucleate cells were assessed; the median spontaneous micronuclei formation was estimated. Background radiation was measured using an Automess dose rate meter 6150AD. There was no significant difference in the median MN frequency between the two sexes (p= 0.538). There was no significant difference between the median background frequency of micronuclei formation between the two study areas (p=0.539). Significantly higher radiation dose rate (measured by suevey meter) has been shown in Ragama area compared to Norochcholei area (Mann Whitney U= 217.00, p=0.000 ). There was no strong correlation between background radiation and MN frequency in both areas. The MN frequency can be used as a baseline to monitor exposure to radiation in the future. This is important for monitoring radiation hazards and will be useful in case of a nuclear accident.
Assessment of exposure of gas station attendants in Sri Lanka to benzene, toluene and xylenes.
(Amsterdam, Elsevier, 2019) Scheepers, P.T.J.; de Werdt, L.; van Dael, M.; Anzion, R.; Vanoirbeek, J.; Duca, R.C.; Creta, M.; Godderis, L.; Warnakulasuriya, D.T.D.; Devanarayana, N.M.
ABSTRACT:Exposure to benzene, toluene and p-, m-, o-xylene (BTX) was studied in 29 gas station attendants and 16 office workers in Sri Lanka. The aim of this study was to assess the exposure level and identify potential exposure mitigating measures. Pre- and post-shift samples of end-exhaled air were collected and analysed for BTX on a thermal desorption gas chromatography mass spectrometry system (TD-GC-MS). Urine was collected at the same timepoints and analysed for a metabolite of benzene, S-phenyl mercapturic acid (SPMA), using liquid chromatography-mass spectrometry (LC-MS). Environmental exposure was measured by personal air sampling and analysed by gas chromatography flame ionization detection (GC-FID). Median (range) breathing zone air concentrations were 609 (65.1-1960) μg/m3 for benzene and 746 (<5.0-2770) μg/m3 for toluene. Taking into account long working hours, 28% of the measured exposures exceeded the ACGIH threshold limit value (TLV) for an 8-h time-weighted average of 1.6 mg/m3 for benzene. Xylene isomers were not detected. End-exhaled air concentrations were significantly increased for gas station attendants compared to office workers (p < 0.005). The difference was 1-3-fold in pre-shift and 2-5-fold in post-shift samples. The increase from pre-to post-shift amounted to 5-15-fold (p < 0.005). Pre-shift BTX concentrations in end-exhaled air were higher in smokers compared to non-smokers (p < 0.01). Exposure due to self-reported fuel spills was related to enhanced exhaled BTX (p < 0.05). The same was found for sleeping at the location of the gas station between two work-shifts. Benzene in end-exhaled air was moderately associated with benzene in the breathing zone (r = 0.422; p < 0.001). Median creatinine-corrected S-phenyl mercapturic acid (SPMA) was similar in pre- and post-shift (2.40 and 3.02 μg/g) in gas station attendants but increased in office workers (from 0.55 to 1.07 μg/g). In conclusion, working as a gas station attendant leads to inhalation exposure and occasional skin exposure to BTX. Smoking was identified as the most important co-exposure. Besides taking preventive measure to reduce exposure, the reduction of working hours to 40 h per week is expected to decrease benzene levels below the current TLV.
Role of dipsticks in diagnosis of urinary tract infection in children: is it accurate enough
(Sri Lanka College of Paediatricians, 2015) Fernando, C.M.P.; Galappaththi, A.G.A.R.; Punchihewa, P.M.G.; Karunaratne, G.K.D.; Warnakulasuriya, D.T.D.
BACKGROUND:Urinary tract infection (UTI) is a common problem in childhood. Urine culture is the Gold standard for diagnosis. Dipstick tests for leucocyte esterase reaction (LE) and nitrites (N) are bedside tests useful in the diagnosis of UTI. Accuracy of above tests have been extensively investigated in other countries. No published data is available from Sri Lankan children up to date.OBJECTIVES:To study the diagnostic accuracy of dipstick tests in diagnosis of UTI in Sri Lankan children.DESIGN, SETTING AND METHOD:Descriptive, cross sectional study was conducted in a medical ward at Lady Ridgeway Hospital for Children. 300 children less than 12 years, clinically suspected of UTI were recruited. Dipstick tests (LE and N) and urine culture were performed.RESULTS:Of the 300 children, 118 (39.3%) had positive cultures (pure growth of bacteria >105 cfu/ml), 16 (54%) had negative cultures and 20 (6.7%) had mixed growth. Cultures with mixed growths were excluded and remaining 280 were analyzed. Mean age of the participants was 49 months (SD 41.3), 148 (53%) being males.Accuracy of dipsticks tests (LE and N) in detecting UTI was as follows. LE and N in combination had a sensitivity of 97.5%, specificity of 77.2%, positive predictive value (PPV) of 75.6% and negative predictive value (NPV) of 97.6%. LE alone showed a sensitivity of 96.6% specificity of 77.7%, PPV of 76% and NPV of 96.9%. Corresponding values for N alone were 78.8%, of 97.5%, 95.8% and 86.3% respectively.CONCLUSIONS:Leucocyte esterase reaction and nitrite test in combination showed promising results to detect UTI in children. LE was more sensitive and N was more specific.
Ultrasonographic parameters of the liver, spleen and kidneys among a cohort of school children in Sri Lanka
(BioMed Central, 2017) Warnakulasuriya, D.T.D.; Peries, P.P.U.C.; Rathnasekara, Y.A.C.; Jayawardena, K.T.M.; Upasena, A.; Wickremasinghe, A.R.
BACKGROUND: Liver, spleen and kidney dimensions on ultrasonography vary with the age, weight and ethnicity. Reference standards of these parameters for normal Sri Lankan children are not available. Our aim was to establish normative data for longitudinal length of liver, spleen and kidneys in healthy children. METHOD: Three hundred fifty-seven children, 5-13 years of age were selected from two randomly selected schools in the Gampaha district in the western province of Sri Lanka. A questionnaire was administered to the parents after obtaining informed written consent. Participants were screened for risk factors for organomegaly and were examined by a trained officer. Children with a past history of infective, inflammatory, haematological, malignant, congestive, collagenous or congenital conditions that can affect the size of the organs were excluded as well as those with clinically evident malnutrition, anemia, lymphadenopathy or organomegaly. Ultrasonographic assessment was done using a high resolution real-time scanner with a 3.5 MHz convex transducer by a trained officer. Children with ultrasonographic abnormalities of organs were also excluded from the study and referred for further evaluation. RESULTS: The study comprised 332 children comprising 176 girls (53%). There was a significant difference in the longitudinal dimension of the liver between the two sexes with a higher value recorded among females (Mann Whitney U = 11,830.5, p = 0.037). Body weight was correlated with the dimensions of the liver, the spleen and the kidneys. On multiple regression analysis body weight significantly associated with all the organs. (p < 0.01) Percentile graphs for longitudinal length of liver, spleen, right and left kidneys were formed according to the body weight. CONCLUSION: The organ dimensions showed the highest correlation with body weight. We hope the normal ultrasonographic values of healthy Sri Lankan children will assist in interpretation of sonographic examinations in daily clinical practice.
Ultrasonographic parameters of the liver, spleen and kidneys among a cohort of school children in the Gampaha district
(Sri lanka Medical Association, 2015) Warnakulasuriya, D.T.D.; Peries, P.P.U.C.; Rathnasekara, Y.A.C.; Jayawardena, K.A.T.M.; Upasena, A.P.
INTRODUCTION AND OBJECTIVES: Liver, spleen and kidney dimensions on uitrasonography vary with age, weight and ethnicity. Reference standards for these parameters in normal Sri Lankan children are not available. Our objective was to establish normative data for the longitudinal length of the liver, spleen and kidneys in healthy children living in the Gampaha District. METHOD: A total of 357 children between the ages of 5 to 12 years were selected from two randomly selected schools in the Gampaha District. A questionnaire was administered to the parents after obtaining informed written consent. Participants were screened for risk factors for organomegaly and were examined by a medical officer. Ultrasonographic assessment was done using a high resolution real-time scanner with a 3.5MHz convex transducer by a trained medical officer. Children with abnormalities in the Ultrasonographic appearance of organs were excluded. RESULTS: The study comprised 332 children (176 girls, 53%). There was no difference in organ dimensions between the two genders (p > 0.05). Body weight showed the best correlation with liver, spleen and kidney dimensions. Age significantly correlated with the longitudinal length of the liver and height significantly correlated with spleen length. Percentile graphs for the longitudinal length of the liver, spleen, right and left kidneys were developed in relation to body weight.
Validation of the World Health Organization/ International Society of Hypertension (WHO/ISH) cardiovascular risk predictions in Sri Lankans based on findings from a prospective cohort study
(Public Library of Science, 2021) Thulani, U.B.; Mettananda, K.C.D.; Warnakulasuriya, D.T.D.; Peiris, T.S.G.; Kasturiratne, K.T.A.A.; Ranawaka, U.K.; Chakrewarthy, S.; Dassanayake, A.S.; Kurukulasooriya, S.A.F.; Niriella, M.A.; de Silva, S.T.; Pathmeswaran, A.; Kato, N.; de Silva, H.J.; Wickremasinghe, A.R.
INTRODUCTION AND OBJECTIVES: There are no cardiovascular (CV) risk prediction models for Sri Lankans. Different risk prediction models not validated for Sri Lankans are being used to predict CV risk of Sri Lankans. We validated the WHO/ISH (SEAR-B) risk prediction charts prospectively in a population-based cohort of Sri Lankans. METHOD: We selected 40-64 year-old participants from the Ragama Medical Officer of Health (MOH) area in 2007 by stratified random sampling and followed them up for 10 years. Ten-year risk predictions of a fatal/non-fatal cardiovascular event (CVE) in 2007 were calculated using WHO/ISH (SEAR-B) charts with and without cholesterol. The CVEs that occurred from 2007-2017 were ascertained. Risk predictions in 2007 were validated against observed CVEs in 2017. RESULTS: Of 2517 participants, the mean age was 53.7 year (SD: 6.7) and 1132 (45%) were males. Using WHO/ISH chart with cholesterol, the percentages of subjects with a 10-year CV risk <10%, 10-19%, 20%-29%, 30-39%, ≥40% were 80.7%, 9.9%, 3.8%, 2.5% and 3.1%, respectively. 142 non-fatal and 73 fatal CVEs were observed during follow-up. Among the cohort, 9.4% were predicted of having a CV risk ≥20% and 8.6% CVEs were observed in the risk category. CVEs were within the predictions of WHO/ISH charts with and without cholesterol in both high (≥20%) and low(<20%) risk males, but only in low(<20%) risk females. The predictions of WHO/ISH charts, with-and without-cholesterol were in agreement in 81% of subjects (ĸ = 0.429; p<0.001). CONCLUSIONS: WHO/ISH (SEAR B) risk prediction charts with-and without-cholesterol may be used in Sri Lanka. Risk charts are more predictive in males than in females and for lower-risk categories. The predictions when stratifying into 2 categories, low risk (<20%) and high risk (≥20%), are more appropriate in clinical practice.
Validation of the World Health Organization/ International Society of Hypertension (WHO/ISH) cardiovascular risk predictions in Sri Lankans based on findings from a prospective cohort study
(Ceylon College of Physicians, 2020) Thulani, U.B.; Mettananda, K.C.D.; Warnakulasuriya, D.T.D.; Peiris, T.S.G.; Kasturiratne, K.T.A.A.; Ranawaka, U.K.; Chackrewarthy, S.; Dassanayake, A.S.; Kurukulasooriya, S.A.F.; Niriella, M.A.; de Silva, S.T.; Pathmeswaran, A.P.; Kato, N.; de Silva, H.J.; Wickremasinghe, A.R.
INTRODUCTION AND OBJECTIVES: There are no cardiovascular(CV)-risk prediction models specifically for Sri Lankans. Different risk prediction models not validated among Sri Lankans are being used to predict CV-risk of Sri Lankans. We validated the WHO/ISH (SEAR-B) risk prediction charts prospectively in a population-based cohort of Sri Lankans. METHOD: We selected participants between 40-64 years, by stratified random sampling of the Ragama Medical Officer of Health area in 2007 and followed them up for 10-years. Risk predictions for 10-years were calculated using WHO/ISH (SEAR-B) charts with- and without-cholesterol in 2007. We identified all new-onset cardiovascular events(CVE) from 2007-2017 by interviewing participants and perusing medical-records/death-certificates in 2017. We validated the risk predictions against observed CVEs. RESULTS: Baseline cohort consisted of 2517 participants (males 1132 (45%), mean age 53.7 (SD: 6.7 years). We observed 215 (8.6%) CVEs over 10-years. WHO/ISH (SEAR B) charts with and without-cholesterol predicted 9.3% (235/2517) and 4.2% (106/2517) to be of high CV-risk ≥20%), respectively. Risk predictions of both WHO/ISH (SEAR B) charts with- and without-cholesterol were in agreement in 2033/2517 (80.3%). Risk predictions of WHO/ISH (SEAR B) charts with and with out-cholesterol were in agreement with observed CVE percentages among all except in high risk females predicted by WHO/ISH (SEAR B) chart with-cholesterol (observed risk 15.3% (95% Cl 12.5 - 18.2%) and predicted risk 2::20%). CONCLUSIONS: WHO/ISH (SEAR B) risk charts provide good 10-year CV-risk predictions for Sri Lankans. The predictions of the two charts, with and without-cholesterol, appear to be in agreement but the chart with-cholesterol seems to be more predictive than the chart without-cholesterol. Risk charts are more predictive in males than in females. The predictive accuracy was best when stratified into two categories; low (<20%) and high (≥20%) risk.