Journal/Magazine Articles
Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/13
This collection contains original research articles, review articles and case reports published in local and international peer reviewed journals by the staff members of the Faculty of Medicine
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Item Evaluation of PCR-ELISA as a tool for monitoring transmission of Wuchereria bancrofti in District of Gampaha, Sri Lanka(Asian Pacific Organization for Cancer Prevention, 2013) Wijegunawardana, A.D.; Gunawardene, N.S.; Hapuarachchi, C.; Manamperi, A.; Gunawardena, K.; Abeyewickreme, W.; Latif, B.OBJECTIVE: To compare Wuchereria bancrofti (W. bancrofti) infection rates of Culex quinquefasciatus, using dissection and PCR-ELISA in two consecutive time periods (from 2007 to 2008 and from 2008 to 2009). METHODS: Mosquitoes were collected in 30 sentinel and 15 non-sentinel sites in 15 Medical Officer of Health areas of Gampaha Districtknown for the presence of W. bancrofti transmission in two consecutive time period of 2007 to 2008 and 2008 to 2009. Captured mosquitoes were dissected to determine the W. bancrofti larvae (L1, L2, L3). PCR was carried out using DNA extracted from mosquito pools (15 body parts/pool) utilizing the primers specific for Wb-SspI repeat. PCR products were analyzed by hybridization ELISA using fluorescein-labeled wild type specific probes. The prevalence of infected/infective mosquitoes in PCR pools (3 pools/site) was estimated using the PoolScreen™ algorithm and a novel probability-based method. RESULTS: Of 45 batches of mosquitoes dissected, W. bancrofti infected mosquitoes were found in 19 and 13 batches, with an infection rate of 13.29% and 3.10% with mean larval density of 8.7 and 1.0 larvae per mosquito for two study periods in the Gampaha District. Total of 405 pools of head, thorax and abdomen were processed by PCR-ELISA for each year. Of these, 51 and 31 pools were positive for W. bancrofti in the two study periods respectively. The association of dissection based prevalence rates with PCR based rates as determined by the Pearson correlation coefficient were 0.176 and 0.890 respectively for the two periods. CONCLUSIONS: Data indicate that PCR-ELISA is more sensitive than the traditional dissection techniques for monitoring transmission intensityItem STR polymorphisms in Sri Lanka: evaluation of forensic utility in identification of individuals and parentage testing(Sri Lanka Medical Association, 2009) Manamperi, A.; Hapuarachchi, C.; Gunawardene, N.S.; Bandara, A.; Dayanath, D.; Abeyewickreme, W.OBJECTIVES: This preliminary study was carried out to determine the allele frequencies and forensic efficiency parameters for the short tandem repeat loci CSF1PO, TPOX, THO1, D16S539, D7S820, D13S317, vWA, FESFPS and F13B in a test sample population of Sri Lankans. DESIGN: Test samples were obtained from 305 non-related individuals originating from all 9 provinces of Sri Lanka. DNA was extracted from whole blood using chelex-100 and amplified by PCR using the GenePrint STR kit and silver stained. Final DNA profiles were analysed for forensic efficiency parameters and paternity indices using PowerStats version 12. Possible divergence from Hardy-Weinberg Equilibrium was tested using the chi-square test and exact test. RESULTS: All common alleles in the allelic ladders were found in the test sample studied. PIC values >0.5 for all 9 STR loci indicate this STR system to be informative and useful for identification purposes. The D13S317, vWA and D7S820 loci were found to be the most polymorphic markers of the system studied. CONCLUSIONS: No deviations from Hardy-Weinberg Equilibrium were found for any of the loci examined. The results indicate that the 9 STR loci system described here is suitable for estimating DNA profile frequencies in human identification and forensic and parentage testing for legal purposes among Sri Lankans.Item Genotyping of Plasmodium vivax infections in Sri Lanka using Pvmsp-3 alpha and Pvcs genes as markers:a preliminary report(Malaysian Society of Parasitology and Tropical Medicine, 2008) Manamperi, A.; Sanath, M.; Fernando, D.; Wickremasinghe, R.; Anura, B.; Hapuarachchi, C.; Abeyewickreme, W.; Wickremasinghe, A.R.Plasmodim vivax malaria accounts for more than 90% of malaria cases in Sri Lanka. There is limited information on the genetic heterogeneity of P. vivax in endemic areas of the country. Here we have assessed the potential of two P. vivax genes as genetic markers for their use in genotyping parasites collected from the field. DNA extracted from Geimsa-stained P. vivax positive slides were genotyped at two polymorphic loci: the P. vivax merozoite surface protein 3- alpha (Pvmsp-3alpha) and circumsporozoite protein (Pvcs). Analysis of these two genetic markers revealed 11 distinguishable variant types from the two genetic markers: 4 for Pvcs and 7 for Pvmsp-3alpha. The results indicate that the P. vivax parasite population is highly diverse in Sri Lanka, despite the low level of transmission.