Nilakshi Samaranayake

• MBBS, Dip. Med. Micro, PhD
• Senior Lecturer at University of Colombo

Background: Aging is an irreversible process influenced by both internal (genetic) and external (environmental) factors. These factors contribute to differences in how individuals age. Aging is not just about a decline in physical and mental abilities but involves complex biological mechanisms. Two main theories explain aging: 1. Programmed Theorie...

The human body undergoes various physical, metabolic, and behavioural changes that are governed by circadian rhythms. The Cryptochrome Circadian Regulator (CRY1 and CRY2) genes encode proteins critical for maintaining these rhythms. Increased expression of CRY genes supports circadian rhythm stability, contributing to overall physiological homeosta...

Cutaneous leishmaniasis (CL) is a vector-borne parasitic disease, routinely diagnosed by direct light microscopy. The sensitivity of this method is dependent on the number of parasites present in the lesion. Immunoexpression of CD1a surface antigen by Leishmania amastigotes and its application as a diagnostic tool has been recently demonstrated in...

Phlebotomus argentipes is the predominant sandfly vector of leishmaniasis in the Indian subcontinent. India and Sri Lanka primarily report visceral and cutaneous leishmaniasis caused by Leishmania donovani. We compared Ph. argentipes from two locations, focusing on its morphological, molecular, and salivary protein characteristics. Sandflies were c...

Phlebotomus argentipes is the established vector of leishmaniasis in the Indian sub-continent. Antibodies to sand fly salivary antigens are biomarkers for vector-host exposure in leishmaniasis-endemic regions. Ph. argentipes transmits Leishmania donovani in Sri Lanka, primarily causing cutaneous leishmaniasis (CL). Our study compared the performanc...

Background:Despite established benefits for mental and physical well-being, the precise underlying molecular mechanisms of the effects of meditation remain unclear. This study explored the hypothesis that long-term meditation practice downregulates the expression of genes associated with stress-induced inflammation. The expression of selected infla...

Leishmaniasis in Sri Lanka was first reported in the early 1990s. Cutaneous leishmaniasis (CL) cases have markedly increased in recent years, demanding due attention from health authorities. The spatial distribution of CL is not homogeneous. This case-control study investigated factors that may contribute to this heterogeneous distribution through...

Cutaneous leishmaniasis (CL) in Sri Lanka is caused by Leishmania donovani, a parasite widely known to cause visceral leishmaniasis. Despite the fact that CL is not generally believed to elicit serological immune responses, recent studies show the presence of antibody responses against this atypical form of CL. This study assesses the potential of...

Introduction-Cytokines play a crucial role in the host immune response of cutaneous leishmaniasis (CL), influencing both the disease progression and healing process. Our previous study findings have suggested that TGF-β is significantly higher in patients, particularly in those with persistent and severe lesions. By down-regulating IFN-Ɣ, deacti...

Leishmaniasis, a neglected tropical disease, encompasses a spectrum of clinical conditions and poses a significant risk of infection to over one billion people worldwide. Visceral leishmaniasis (VL) in the Indian sub-continent (ISC), where the causative parasite is Leishmania donovani, is targeted for elimination by 2025, with some countries alread...

Background Treatment responses to cutaneous leishmaniasis (CL) observed in Sri Lanka show variability, ranging from quick healing to delayed or failed responses to routine medication. The determinants of these differences in treatment response are not well defined. This study aimed to identify predictive features of treatment response and outcome i...

Introduction Telomeres are protective end caps of chromosomes which naturally shorten with each cell division and thus with age. Short telomeres have been associated with many age-related diseases. Meditation has come to the fore as a mind–body practice which could influence the telomere dynamics underlying these phenomena. We previously reported m...

Leishmaniasis is a neglected tropical disease caused by protozoan parasites of genus Leishmania, and transmitted by different species of Phlebotomine sand flies. More than 20 species of Leishmania are known to cause disease in humans and other animals. Leishmania donovani species complex is known to have a vast diversity of clinical manifestations...

Many people suffer from stress and anxiety due to complex lifestyles. Stress is one of the main causes of various diseases. In addition, it causes a lower level of consciousness, quality of life, and a higher rate of cellular aging. Meditation becomes a trending topic to overcome these problems. Key terms including “Meditation,” “Mindfulness,” “Qua...

Background The innate immune mediators are likely to influence the clinical phenotype of leishmaniasis by primary responses which limit or facilitate the spread of the parasite, as well as by modulating adaptive immunity. This study investigated the response of key innate immune cells in a focus which regularly reports localised cutaneous leishmani...

Practice of meditation has been suggested to improve telomere regulation. This case-control study compared the leucocyte telomere length (TL) and expression of hTERT and hTR genes, between thirty long-term, skilled meditators and thirty matched non-meditators. 63.34% of the participants were males and the average age of the meditators was 43.83±9.9...

Cutaneous leishmaniasis (CL) is a notifiable disease in Sri Lanka with increasing case numbers reported from every part of the country. In addition to disease treatment and vector control measures, knowledge and perceptions in a community are key contributors to a successful intervention program. An island-wide survey was carried out to assess the...

Aims: Leishmaniasis includes several clinical forms. While routine diagnosis of cutaneous leishmaniasis (CL) is by microscopy, an antibody response to CL has been reported in several recent studies. This study evaluated anti-leishmanial IgG antibody responses as a biomarker of active leishmaniasis and a measure of exposure to Leishmania. Methods...

Background The innate immune mediators are likely to influence the clinical phenotype of leishmaniasis by primary responses which limit or facilitate the spread of the parasite, as well as by modulating adaptive immunity. This study investigated the response of key innate immune cells in a focus which regularly reports localised cutaneous leishmani...

Meditation involves psychophysical training which can result in a range of benefits including creating a calm mind and increasing self-awareness, relaxation, and tranquility. Increasing evidence, mostly based on short-term focused interventions, suggests that meditation-based activities may also have favorable effects on physical wellbeing includin...

Meditation is being increasingly known as a practice of health promotion which enables the relationship between the human mind and body. A growing body of research suggested that long-term meditation practice has been popularized among multidisciplinary scientific communities due to its wide array of benefits including enhanced telomere maintenance...

Background Meditation-based practices have been suggested to result in many biological benefits which include reduction of attrition of telomeres, the protective nucleotide-protein complexes at termini of eukaryotic chromosomes. This systematic review evaluated the effects of meditation on telomere length (TL) in healthy adults. Methods Randomized...

Introduction Cutaneous leishmaniasis is an endemic vector borne disease in Sri Lanka caused by the protozoan parasite Leishmania donovani. Patients show diversity in the response to treatment which is likely influenced by multiple factors. Our previous analyses have shown that epidemiological (gender, and age) and clinical features (lesion type, si...

Background Leishmaniasis is a neglected tropical vector-borne disease, which is on the rise in Sri Lanka. Spatiotemporal and risk factor analyses are useful for understanding transmission dynamics, spatial clustering and predicting future disease distribution and trends to facilitate effective infection control. Methods The nationwide clinically c...

Background: Meditation based practices have been suggested to result in many biological benefits which include reduction of attrition of telomeres, the protective nucleotide-protein complexes at termini of eukaryotic chromosomes. This systematic review evaluated the effects of meditation on telomere length (TL) in healthy adults. Methods: Randomize...

Background: Studies have reported that meditation aids in reducing the shortening in human telomere lengths (TL), thus delaying the cellular aging process. However, no systematic reviews have been conducted to evaluate this effect using existing research. To address this, we plan to conduct a systematic review to investigate the effects of meditati...

Leishmaniasis, a neglected tropical disease, is on the decline in South Asia. However, cases of cutaneous leishmaniasis have risen in Sri Lanka since 2001, and the lack of in-depth research on its epidemiologic characteristics hampers control efforts. We analyzed data collected from patients with cutaneous leishmaniasis in Sri Lanka during 2001-201...

Leishmaniasis is a neglected tropical disease caused by a protozoan parasite and is endemic in over 98 countries. Caused by over 20 different species of Leishmania parasites, it is transmitted by an equally wide range of sandfly species. This chapter outlines the different aspects of this complex disease including the epidemiology, risk factors, an...

Objective: The data presented herein represents the raw genotype data of a recently conducted larger study which investigated the association of single nucleotide polymorphisms (SNPs) in breast cancer related genes with the risk and clinicopathological profiles of sporadic breast cancer among Sri Lankan women. A case-control study design was adopt...

Objective: A previous study undertaken at our centre to identify common genetic variants associated with sporadic breast cancer in Sri Lankan women showed that the T allele of rs3218550, located in the 3'untranslated region of X-ray repair cross-complementing gene-2 (XRCC2), increased breast cancer risk by 1.5-fold. Dual luciferase reporter assays...

Introduction: Sri Lanka has a predominantly rural population. However, there is a dearth of research on health and socioeconomic issues in this group. Objective: To describe basic socioeconomic characteristics and health profile in a rural population. Methods: A descriptive cross-sectional household survey was conducted in 1950 households in t...

Background: A previous study undertaken by our team to identify common genetic variants associated with sporadic breast cancer in Sri Lankan women showed that the T allele of rs3218550, located in the 3'untranslated region of X-ray repair cross-complementing gene-2 (XRCC2), increased breast cancer risk by 1.5-fold. Dual luciferase reporter assays p...

The sick-building syndrome (SBS) is defined as occurrence of a high frequency of irritative symptoms of unclear aetiology which can be divided into mucous membrane symptoms, general symptoms and dry skin. The symptoms are experienced as work-related as they typically grow worse during the workday in the building and disappear after the person has l...

The sick-building syndrome (SBS) is defined as occurrence of a high frequency of irritative symptoms of unclear aetiology which can be divided into mucous membrane symptoms, general symptoms and dry skin. The symptoms are experienced as work-related as they typically grow worse during the workday in the building and disappear after the person has l...

Objective: The data presented herein represents the preliminary results of the functional assays of a recently conducted larger study in which two single nucleotide polymorphisms (SNPs) [XRCC2:rs3218550 and PHB:rs6917] were significantly associated with risk of breast cancer among Sri Lankan postmenopausal women. The rs3218550 T allele and rs6917...

Background Leishmaniasis is a neglected tropical disease with diverse clinical phenotypes, determined by parasite, host and vector interactions. Despite the advances in molecular biology and the availability of more Leishmania genome references in recent years, the association between parasite species and distinct clinical phenotypes remains poorly...

Background: The use of lengthy, detailed, and complex informed consent forms (ICFs) is of paramount concern in biomedical research as it may not truly promote the rights and interests of research participants. The extent of information in ICFs has been the subject of debates for decades; however, no clear guidance is given. Thus, the objective of t...

Background: The use of lengthy, detailed, and complex informed consent forms (ICFs) is of paramount concern in biomedical research as it may not truly promote the rights and interests of research participants. The extent of information in ICFs has been the subject of debates for decades; however, no clear guidance is given. Thus, the objective of...

Purpose: Several single nucleotide polymorphisms (SNPs) have been reported to be associated with clinicopathological profiles in sporadic breast cancer based on studies conducted on major population groups. The knowledge of the effects of these common genetic variants in South Asian populations remains limited. The present study aimed to investiga...

Background: While a range of common genetic variants have been identified to be associated with risk of sporadic breast cancer in several Western studies, little is known about their role in South Asian populations. Our objective was to examine the association between common genetic variants in breast cancer related genes and risk of breast cancer...

Background The outcome of leishmaniasis is an interplay between Leishamania and the host. Identifying contributory host genetic factors is complicated by the variability in phenotype, ethnicity and parasite species. Leishmaniasis is caused exclusively by L. donovani in Sri Lanka with localized cutaneous leishmaniasis (LCL) being the predominant for...

Background Interpopulation differences in drug responses are well documented, and in some cases they correspond to differences in the frequency of associated genetic markers. Understanding the diversity of genetic markers associated with drug response across different global populations is essential to infer population rates of drug response or ris...

Background: The security forces are a high risk group for malaria transmission in Sri Lanka. Interrupting transmission and maintaining surveillance in this group is an important component of elimination efforts. The objective of the study was to develop a prototype educational programme on malaria for security forces serving in endemic areas. Met...

University Research Symposium 2014, University of Colombo

The efficacy of different treatment regimens in clinical syndromes of toxoplasmosis were assessed by conducting a systematic review of published randomized clinical trials through extensive searches in MEDLINE, EMBASE, and SCOPUS with no date limits, as well as manual review of journals. Outcome measures varied depending on the clinical entity of t...

Introduction: The first Sri Lankan Personal Genome (SLPG), the genome of a Sinhalese man, was sequenced in 2010. This enabled identification of single nucleotide polymorphisms (SNPs) prevalent in the Sri Lankan population at genome scale. SNPs are implicated in health and disease, and identifying SNPs unique to the Sri Lankan population would enabl...

To investigate the association between selected single nucleotide polymorphisms (SNPs) in TNF, LTA and SLC11A1 genes and risk of endemic cutaneous leishmaniasis (CL) in Sri Lanka through a case-control disease association study. An anonymized DNA resource representative of the Sri Lankan population was genotyped initially to establish baseline para...

Introduction: Tumour necrosis factor (TNF) α and β are critical mediators of many inflammatory and immune-stimulatory responses. Inherited variability in TNF production due to genetic variants have been implicated in the susceptibility to many infectious and non infectious conditions, including visceral leishmaniasis caused by Leishmania donovani -...

Human cutaneous leishmaniasis (CL) caused by Leishmania donovani, a pathogen more usually associated with visceral leishmaniasis, is now endemic in Sri Lanka. This report details the characteristics of 200 patients with locally acquired CL, who were recruited prospectively for an ongoing study into the genetic susceptibility to CL in Sri Lanka. In...