Medicine
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This repository contains the published and unpublished research of the Faculty of Medicine by the staff members of the faculty
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Item Mutational analysis of driver and non-driver mutations of Philadelphia chromosome-negative myeloproliferative neoplasms;diagnosis and recent advances in treatment(Science Publications, 2024) Afolabi, B.O.; Riwaz, A.; Weerasena, J.; Williams, S.; Denipitiya, T.; Somawardana, B.; Faizan, M.; Galhena, B.P.Myeloproliferative neoplasms (MPNs) are hematological disorders affecting myeloid stem cells. They are classified as Philadelphia (Ph) chromosome positive-chronic myeloid leukemia, and Ph-negative polycythemia vera, essential thrombocythemia, primary myelofibrosis, chronic neutrophilic leukemia, chronic eosinophilic leukemia, juvenile myelomonocytic leukemia, and MPN unclassifiable. This review is mainly focused on the Ph-negative MPNs namely, PV, ET, and PMF. These affect both males and females with a slight male predominance, with patients mainly presenting in the seventh decade. Patients often present with thrombotic events resulting in complications that lower survival rates. The major driver mutations that have been identified in MPNs are JAK2 Exon 14, JAK2 Exon 12, MPL Exon 10, and CALR Exon 9. The importance of these driver mutations gives due recognition to their inclusion into the 2022 diagnostic criteria of the MPN WHO Classification. However, other non-driver mutations have also been reported, especially in triple-negative cases. These mutations lead to downstream constitutive activation of the JAK/STAT signaling pathway, as well as the MAPK, and PI3K/Akt pathways. Insights into the molecular pathogenesis of MPN and its association with JAK2, CALR, and MPL mutations have identified JAK2 as a rational therapeutic target. Thus, as an approach to MPN therapy, JAK2 inhibitors, such as ruxolitinib, have been shown to effectively inhibit JAK2, and are currently in clinical trials in combination with other drug classes. This review comprehensively examines the molecular markers of the main Ph-negative MPNs, as well as diagnosis and treatment options.Item Validation of fluorescence in situ hybridization (FISH) assay using an analyte-specific reagent in detecting aneuploidies of chromosomes 13, 18, 21, X, and Y in prenatal diagnosis(LIDSEN Publishers, 2023) Ralalage, B.M.S.K.P.; Kaluarachchi, N.; Randunu, M.; Jainulabdeen, M.; Nanthakumar, R.; Viswakula, S.; Galhena, B.P.Fluorescence In-Situ hybridization (FISH) is a sensitive and highly efficient technique commonly used in routine diagnostics. Most of these tests that use analyte-specific reagents are not approved by US Food and Drug Administration (FDA) but are developed by individual test laboratories. There is an emerging demand for prenatal diagnosis of aneuploidies by FISH. Since most of these assays are laboratory-developed tests, it is essential to validate them prior to their use in diagnosis. However, validation procedures of these assays are oversight despite the presence of several validation guidelines. To validate FISH assay using analyte-specific reagents in detecting aneuploidies of chromosomes 13, 18, 21, X, and Y as per American College of Medical Genetics (ACMG) guidelines in 2016. Analyte-specific reagents supplied by Oxford Gene Technologies were used in the validation process using blood and amniotic fluid samples obtained from healthy male and female adults and fetuses respectively. The validation process includes probe localization, evaluation of assay specificity, and establishment of lower cut-off and reportable reference ranges. Probe localization indicated a 100% specificity for all probes tested. Interphase FISH on uncultured amniotic fluid demonstrated significantly high (≥95%) overall disomic signal patterns for all autosomes and sex chromosomes tested. The reportable 95% confidence interval was 94.84, 94.84, 95.24, 94.54, and 94.54 for chromosomes 13, 18, 21, X, and Y respectively. The present study illustrates an experimental design in validating laboratory-developed FISH assay using analytespecific reagents in detecting aneuploidies of chromosomes 13, 18, 21, X, and Y as per ACMG guidelines. Test probes used in the present study are consistent with probe localization characteristics, assay specificity, and reportable reference ranges recommended by ACMG. Therefore, the FISH assay used in the present study could be recommended as a supplementary prenatal diagnostic test that can be carried out along with standard chromosomal analysis.Item Apoferritin and Dps as drug delivery vehicles: Some selected examples in oncology(Elsevier Ltd, 2022) Kuruppu, A.I.; Turyanska, L.; Bradshaw, T.D.; Manickam, S.; Galhena, B.P.; Paranagama, P.; de Silva, R.Background: The ideal nanoparticle should be able to encapsulate either pharmaceutical agents or imaging probes so that it could treat or image clinical tumours by targeting the cancer site efficiently. Further, it would be an added advantage if it demonstrates: small size, built in targeting, biocompatibility and biodegradability. Ferritin, which is an endogenous self-assembling protein, stores iron and plays a role in iron homeostasis. When iron atoms are removed apoferritin (AFt) is formed which consists of a hollow shell where it can be used to load guest molecules. Due to its unique architecture, AFt has been investigated as a versatile carrier for tumour theranostic applications. DNA-binding protein from starved cells (Dps), which also belongs to the ferritin family, is a protein found only in prokaryotes. It is used to store iron and protect chromosomes from oxidative damage; because of its architecture, Dps could also be used as a delivery vehicle. Conclusions: Both these nano particles are promising in the field of oncology, especially due to their stability, solubility and biocompatibility features. Further their exterior surface can be modified for better tumour-targeting ability. More studies, are warranted to determine the immunogenicity, biodistribution, and clearance from the body. General perspective: This review discusses a few selected examples of the remarkable in vitro and in vivo studies that have been carried out in the recent past with the use of AFt and Dps in targeting and delivery of various pharmaceutical agents, natural products and imaging probes in the field of oncology.Item Biochemical and histopathological changes in Wistar Rats after consumption of boiled and un-boiled water from high and low disease prevalent areas for Chronic Kidney Disease of Unknown Etiology (CKDu) in North Central Province (NCP) and Its comparison with Low disease prevalent Colombo, Sri Lanka(BioMed Central,, 2020) Thammitiyagodage, M.G.; de Silva, N.R.; Rathnayake, C.; Karunakaran, R.; Wgss, K.; Gunatillka, M.M.; Ekanayaka, N.; Galhena, B.P.; Thabrew, M.I.BACKGROUND: Chronic Kidney Disease of unknown etiology (CKDu) is prevalent in North Central Province (NCP) of Sri Lanka. Consumption of un-boiled dug well water has been identified as one of the causative factors. This in-vivo study was performed to investigate some of the suspected factors associated with the pathogenesis of CKDu mediated via ground water. METHOD: Rats were given water, collected from high and low disease prevalent areas from the NCP of Sri Lanka and the results compared with those obtained from previously identified low disease prevalent area; Colombo. Blood Urea Nitrogen, creatinine, urinary microalbumin:creatinine ratio together with ALT and AST levels were analyzed and results were compared using one-way ANOVA and paired t-Test. Histopathology was analyzed using non-parametric method. RESULTS: Rats that ingested water from New Town Medirigiriya (NTM) from high disease prevalent NCP reported significantly elevated microalbumin:creatinine ratios compared to other water sources after 8 months, whilst boiled water from NTM had been able to significantly reduce it. Histopathological findings after the 14 months experimental period revealed significantly high tubular lesion index in rats that ingested water from NCP compared to Colombo. Rats that ingested water from high disease prevalent Divuldamana (DD) from NCP showed the highest kidney lesion index though the fluoride content was relatively low in this area compared to other water sources from high disease prevalent NCP. Rats that ingested boiled and un-boiled water from NTM also developed severe lesions whilst the group from Colombo reported the lowest. Low disease prevalent area from NCP, Huruluwewa (HW) also reported elevated liver enzymes and altered renal histopathology. Association of Na+:Ca2+ ratio in the disease progression was not reflected by the current study. Compared to Colombo, high fluoride, calcium and sodium contents were observed in water from high disease prevalent areas. All the water samples were negative for heavy metals. CONCLUSIONS: Though Fluoride is a known kidney toxic agent it cannot be the sole reason for CKDu in NCP, Sri Lanka. Various toxic elements present in NCP water may contribute to different grade of kidney and liver lesions in Wistar rats. KEYWORDS: BUN; CKDu; Microalbumin:creatinine; NCP.