University of Colombo e-Repository

UCER (University of Colombo Electronic Repository) is a collection of scientific research publications by researchers at the University of Colombo, Sri Lanka. This e-Repository serves to manage, preserve and make available the academic works of the faculty, postgraduate students, and research groups. The collection includes faculty publications, master's and doctoral theses abstracts. This repository is updated regularly, and new works are added to collections on a continuous basis

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Authors are responsible for obtaining copyright permission from the publisher and submitting the signed declaration to ir@lib.cmb.ac.lk.

Recent Submissions

Knowledge and use of sublingual glyceryl trinitrate in cardiac patients at the cardiology unit of National Hospital of Sri Lanka
(University of Colombo, 2020) Mudunkotuwa, M. C. N. S.; Munsif, J. M. M.; Nanayakkara, A. G. G. S.; Senanayake, N. P.
Introduction: Angina is a common symptom of Ischemic heart disease (IHD) and it is managed with sublingual glyceryl trinitrate(SLGTN). The objective of the study was to assess the knowledge and use of sublingual glyceryl trinitrate in cardiac patients at cardiology wards, National Hospital of Sri Lanka(NHSL). Methods: A descriptive cross sectional study was conducted using convenient sampling of the diagnosed IHD patients at Cardiology Unit, NHSL from 06th to 31st January 2020. Data were collected using a pretested, validated, interviewer administered questionnaire, prepared according to NHS guidelines, and analyzed using SPSS software. The associations between age, gender, education, monthly income and duration of SLGTN use with the knowledge and use of GTN were analyzed. The Chi square test was used to study the significance of the associations. Results: A total of 125 patients were recruited. Among the respondents, 56.2%(n=70) had satisfactory knowledge and 43.8%(n=55) had poor knowledge. Of the patients, 69.1%(n=86) reported proper use and 30.9%(n=39) had improper use. Females had significantly higher knowledge than males (p=0.003). Patients who had not passed GCE(O/L) had higher knowledge than the patients who had passed GCE(O/L); (p=0.001). Of the 51 patients who did not pass GCE(O/L), 70.58% (n=36) had satisfactory knowledge and of the 74 patients who passed GCE (O/L) 47.3%(n=35) had satisfactory knowledge. There was no association between age, monthly income and duration of SLGTN use with the knowledge and use of SLGTN. Conclusions: Overall, our respondents had a satisfactory level of knowledge on use of SLGTN, and constituted a near normal distribution. However, significant number of patients lacked knowledge on some aspects and had poor use. Males had a significantly poor knowledge compared to females. These findings indicate that further education and counseling is needed. As we used convenient sampling our study population/results may not be applicable for entire population.
The Relationship between Knee Osteoarthritis and Ischemic Heart Disease among Patients Attending National Hospital of Sri Lanka
(University of Colombo, 2023) Dehigahawatta, H.D.U.O.; Ratnatunga, S.
Osteoarthritis is a worldwide highly prevalent type of arthritis and the knee is the most commonly affected joint. Moreover, ischemic heart disease (IHD) is a major contributor to disability among other cardiovascular diseases. A growing amount of research indicates that osteoarthritis may be regarded as a cardiovascular risk factor. This study aimed to assess the relationship between knee osteoarthritis and IHD among patients attending the National Hospital of Sri Lanka (NHSL). A case-control study was conducted with 80 patients, aged between 50-75 years in NHSL. Among them, 40 patients who had been diagnosed with previous IHD from Cardiology and Medical clinics were selected as the case group and 40 patients who had not been diagnosed with a previous IHD from Medical clinics were selected as the control group. Diagnosis of knee osteoarthritis and IHD in both case and control groups was established by a valid diagnosis made by a medical professional. An interviewer- administered questionnaire was used to collect the relevant data. Data were analysed using descriptive statistics and Chi-square test. Most of the study population was female (55%) in both cases and controls. The history of knee osteoarthritis in patients with IHD and their controls differ significantly: the percentage of those that had knee osteoarthritis was higher in cases (37.5%) than in controls (15.0%). (OR=3.4; 95% CI 1.156-9.996. p=0.022). There was a statistically significant relationship between knee osteoarthritis and IHD among patients attending NHSL. That means patients with knee osteoarthritis were at a significantly higher risk of getting an IHD.
Molecular docking simulation of Aspergillus flavus AlmA like protein binding with long chain alkanes (C16-C40)
(University of Colombo, 2022) Viswanathan, P.; Perera, M.; Jayasena, J.
Introduction: AlmA is a bacterial enzyme known to initiate the degradation of long-chain alkanes. Although efficient degradation of alkanes has been observed in fungi, their mechanisms and the enzymes involved are poorly understood. The objective of this study was to identify the binding capability of AlmA like protein in A.flavus using in-silico methods. Methods: A putative AlmA homolog protein sequence similar to the Acinetobacter sp. was identified from Aspergillus flavus and its 3D structure was modelled and validated using bioinformatics techniques. The 3D structures of Alkanes and the cofactors required for AlmA (FAD and NADP), were optimised using Orca Version 4.2.1 and molecules were docked stepwise using AutoDock Vina 1.2.0. The cofactors were initially docked on to the AlmA. The AlmA homolog bound to co-factors were then docked with alkanes (C16-C40). The RMSD value and binding affinity of molecules were evaluated. Hydrophobic interactions and docking site analysis of the A. flavus AlmA like protein and AlmA of Acinetobacter sp. were conducted using Chimera, Protein Ligand Interaction Profiler (PLIP), and ProteinsPlus and results were compared and analysed for ubiquity of similar interactions.
Design and implementation of a novel pharmacogenetic assay for the identification of CYP2D6*10 genetic variant in a cohort of oestrogen receptor positive breast cancer patients
(University of Colombo, 2020) Ranadeva, N.D.K.; Sirisena, N.D.; Wetthasinghe, T.K.; Noordeen, N.; Dissanayake, V.H.W.
Introduction: Tamoxifen is widely used as an adjuvant endocrine therapy in oestrogen receptor (ER) positive premenopausal breast cancer patients. However, in nearly 30% of such patients, pharmacogenomically important variants in the CYP2D6 gene are known to affect tamoxifen metabolism resulting in reduced drug efficacy. CYP2D6*10 variant is reported to be the most common variant found in South Asian populations. This study was undertaken to design and implement a novel pharmacogenetic assay for the identification of CYP2D6*10 gene variant in a Sri Lankan ER positive breast cancer cohort. Methods: A novel single variant tetra-amplification refractory mutation system (T-ARMS) polymerase chain reaction (PCR) assay was designed for the CYP2D6*10:100C>T (rs1065852) variant. The assay was optimized and implemented by genotyping the variant in an existing blood resource obtained from a cohort of breast cancer patients. A total of 70 samples were genotyped. The gel images were interpreted using the following band sizes: Control: 454bp; C allele: 195bp; T allele: 300bp. Genotype frequencies were calculated using the homozygous and heterozygous counts of both alleles. Genotyping results were further validated by Sanger sequencing. Allele frequencies were calculated using the Hardy-Weinberg equation. Results: The desired specific gel bands for the single variant T-ARMS PCR method were obtained after several steps of optimization. Genotype frequency for CYP2D6*10 :rs1065852C>T was: CC - 24.3% (17/70), CT - 75.7% (53/70) and the variant (T) allele frequency was 37.9%. Conclusion: We successfully designed and implemented a novel genotyping assay for CYP2D6*10 variant. The minor allele for the variant was identified in heterozygous (C/T) form in the genotyped cohort. This can be introduced as a low-cost, single step optimized pharmacogenomic assay for the breast cancer patients to predict their response to tamoxifen along with assays for the detection of other CYP2D6 variants that affect tamoxifen metabolism.
Cutaneous leishmaniasis treatment failure to sodium stibogluconate in Southern Sri Lanka
(University of Colombo, 2020) Silva, N.H.; Liyanage, P.L.A.N.; Deerasinghe, T.; Chandrasekara, N.V.; Chellappan, K.; Karunaweera, N.D.
Introduction: Treatment failure (TF) of cutaneous leishmaniasis (CL) to intra-lesional sodium stibogluconate (IL-SSG) in Sri Lanka is threatening disease control. This study was aimed at identifying demographic and clinical factors of CL lesions associated with TF. Methods: A descriptive cohort study was conducted at Base Hospital Tangalle and District General Hospital, Hambantota from April 2016 to October 2018. 201 laboratory-confirmed CL patients were recruited and followed-up weekly till 10 IL-SSG injections or until achieving complete cure, which ever came first. TF was defined as lesions not completely healed after 10 weekly IL-SSG injections, as judged clinically. Results: A large proportion of study subjects (75.1%; 151/201) failed IL-SSG treatment. There were more adults than young patients in the TF group (84% ,127/151 adults aged 21-70 years and 16%, 24/151 young aged 1-20 years). Binary logistic regression analysis showed, factors such as the location of the lesion of the body, its number and the lag period between the disease onset and treatment appear prominent determinants of TF specially in the 1-30 years age group (p values < 0.05). Conclusions: This is the first detailed study on characteristics of leishmaniasis treatment failures and associated demographic and clinical factors in Sri Lanka. Majority of the study population failed treatment with IL-SSG. This stresses the importance of further studies on TF, which may include associated factors related to host, parasitic as well as environment factors to understand the likely mechanisms of TF and combat TF accordingl