Browsing by Author "Weerasena, J."

Now showing 1 - 2 of 2

Clinical utility of PCR and real time PCR assays for Cytomegalovirus, hepatitis B and hepatitis C infections.
(Sri Lanka Association for the Advancement of Science, 2008) Dassanayake, R.S.; de Silva, P.; Weerasena, J.; Gunawardene, Y.I.N.S.; Manamperi, A.
Molecular Medicine Unit, Faculty of Medicine, University of Kelaniya, Reactivation of cytomegalovirus (CMV), Hepatitis B (HBV) and C (HCV) viruses from the status of latency is seen in immunocompromised individuals and such reactivation is often associated with morbidity and mortality in such individuals. The prevalence of these viral infections in a selected population of patients referred to the Molecular Diagnostic Laboratory at the Durdan's Hospital, Colombo, during the period from August 2007 to May 2008 were studied using qualitative PCR assays. All specimens from patients with suspected clinical diagnoses of either CMV or HBV or HCV infections were analyzed. Of 176 samples analyzed for CMV 78 were positive (37 males, 29 females) and majority of them are patients from a nephrology unit. Out of 40 and 10 samples analyzed from males and females, respectively, 22 and 4 were positive for HBV. Twenty six samples were analyzed for HCV and only 6 were fond to be infected with viruses and all of them were from males. Although PCR detection of these viral DNA/RNA is a sensitive method to detect infection, it lacks specificity for the detection of active viral disease and for monitoring the efficacy of antiviral therapy. Therefore, Real-time PCR (RT-PCR) assays for the detection and quantification of CMV-DNA, HBV-DNA and HCV-RNA were developed using SYBRgreen1 chemistry. The assays developed are capable of detecting viral particles in blood samples and quantifying viral DNA accurately over a broad range of input target copies (102 - 108copies/ml) and therefore, can be used to predict the reactivation of viruses by comparing with published kinetic criteria in clinical guidelines. Post PCR analyses of Real-time PCR products by agarose gel electrophoresis revealed bands having the same intensity for a wide range of target copies (103 -108copies/ml). In contrast, RT-PCR elicited higher cycle threshold for the descending order of concentration of target copies. Therefore, based on these results, it is evident that the intensity of conventional PCR bands should not be used for the assessment of viral reactivation or for monitoring therapeutic intervention and for this purpose RT-PCR is the method of choice
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.