Publications by authors named "Piumantha Samaranayake"

Background: Histamine (HA), a small molecule that is synthesized from the amino acid histidine, plays an important role in the immune system where it is associated with allergies, inflammation, and T-cell regulation. In the brain, histamine is stored in mast cells and other non-neuronal cells and also acts as a neurotransmitter. The histamine neuron cell bodies are in the tuberomammillary (TM) nucleus of the hypothalamus and these neurons send projections throughout the central nervous system (CNS), in particular to the cerebral cortex, amygdala, basal ganglia, hippocampus, thalamus, retina, and spinal cord.

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Candida albicans is a clinically important human fungal pathogen. We previously identified the presence of cell-associated phytase activity in C. albicans.

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Contaminated sites pose ecological and human-health risks through exposure to contaminated soil and groundwater. Whereas we can readily locate, monitor, and track contaminants in groundwater, it is harder to perform these tasks in the vadose zone. In this study, tree-core samples were collected at a Superfund site to determine if the sample-collection location around a particular tree could reveal the subsurface location, or direction, of soil and soil-gas contaminant plumes.

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The perceived threat to public health from dental unit water line (DUWL) contamination comes from opportunistic and respiratory pathogens such as Legionella spp, Nontuberculous Mycobacteria (NTM) and pseudomonads. These organisms can grow and multiply in the DUWL biofilm to reach infective concentrations, with the potential for inhalation leading to respiratory infections or direct contamination of surgical wounds. In this paper we discuss current legislation and practical methods for delivering water within the DUWL that meets the standards for safety.

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Objective: To determine the effect of glucose, sucrose, and saccharin on growth, adhesion, and biofilm formation of Candida albicans and Candida tropicalis.

Materials And Methods: The growth rates of mono-cultures of planktonic C. albicans and C.

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Androgen deprivation (AD) therapy failure leads to terminal and incurable castration-resistant prostate cancer (CRPC). We show that the redox-protective protein thioredoxin-1 (TRX1) increases with prostate cancer progression and in androgen-deprived CRPC cells, suggesting that CRPC possesses an enhanced dependency on TRX1. TRX1 inhibition via shRNA or a phase I-approved inhibitor, PX-12 (untested in prostate cancer), impedes the growth of CRPC cells to a greater extent than their androgen-dependent counterparts.

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Vapor intrusion (VI) by volatile organic compounds (VOCs) in the built environment presents a threat to human health. Traditional VI assessments are often time-, cost-, and labor-intensive; whereas traditional subsurface methods sample a relatively small volume in the subsurface and are difficult to collect within and near structures. Trees could provide a similar subsurface sample where roots act as the "sampler' and are already onsite.

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The mechanisms that control extracellular serotonin levels in vivo are not well-defined. This shortcoming makes it very challenging to diagnose and treat the many psychiatric disorders in which serotonin is implicated. Fast-scan cyclic voltammetry (FSCV) can measure rapid serotonin release and reuptake events but cannot report critically important ambient serotonin levels.

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We assessed the effects of four different types of tea extracts (green, oolong, black and pu-erh tea) on cellular surface properties (hydrophobicity and auto-aggregation) and the colonization attributes (attachment and biofilm formation) of four strains of and three strains of . The cellular surface properties were determined using spectrophotometry. The colonization activities were quantified using colorimetric viability assays and visualized using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM).

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Candida dubliniensis shares a wide range of phenotypic characteristics with Candida albicans including a common trait called germ tube positivity. Hence, laboratory differentiation of these two species is cumbersome. Duplex PCR analyses for C.

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Purpose Of The Study: There are limited studies on medication errors in South Asian and South East Asian regions. To bridge this gap, we assessed prescribing errors and selected medicine administration errors among inpatients, and the level of acknowledgement of prescribing errors by specialist physicians in a resource-limited hospital setting.

Study Design: The study was conducted in two medical wards of a hospital in Sri Lanka.

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Pathobiology of dental caries is complex. Data from recent molecular microbiologic studies have further redefined the role of the oral microbiome in the etiology of dental caries. This new information challenges the conventional view on the hegemony of classic cariogenic prokaryotes such as Streptococcus mutans in caries etiology, and raises the intriguing possibility of the participation of the eukaryotic oral fungal pathogen Candida in the caries process.

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Many tumors sustain elevated levels of reactive oxygen species (ROS), which drive oncogenic signaling. However, ROS can also trigger anti-tumor responses, such as cell death or senescence, through induction of oxidative stress and concomitant DNA damage. To circumvent the adverse consequences of elevated ROS levels, many tumors develop adaptive responses, such as enhanced redox-protective or oxidatively-generated damage repair pathways.

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Purpose: Single port laparoscopic surgery (SPLS) is a technique which is increasing in popularity. The benefit of SPLS in complex Crohn's disease (CD), which includes a significant cohort of young patients sometimes needing multiple operations, has not been comprehensively assessed. This study analyses our early experience with this technique.

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Aims: Research in to lower urinary tract symptoms (LUTS) in women in South Asia is hampered by lack of validated tools. Our aim was to validate the International Consultation on Incontinence Modular Questionnaire on Female Lower Urinary Tract Symptoms (ICIQ-FLUTS) from English to Tamil.

Method: After translation to Tamil, a validation study was carried out among women attending the gynecology clinic at District General Hospital-Mannar.

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The oral ecosystem comprises the oral flora, so-called oral microbiome, the different anatomic microniches of the oral cavity, and its bathing fluid, saliva. The oral microbiome comprises a group of organisms and includes bacteria, archaea, fungi, protozoa, and viruses. The oral microbiome exists suspended in saliva as planktonic phase organisms or attached to oral surfaces as a plaque biofilm.

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Background: Over the next 20 years, oropharyngeal cancers (OPC) will represent the majority of head and neck cancers (HNCs) in the United States. It is estimated that human papillomavirus (HPV) may account for as much as 70% to 80% of OPCs in North America and in certain parts of Europe. It is hence crucial to understand the disease risk factors and natural history of oral HPV infections.

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Background: Rates of violence and abuse perpetrated on people with intellectual and developmental disability (IDD) have been reported to be significantly higher than on individuals without disability. However, rates of sexual violence against people with IDD in some less industrialized countries, such as Sri Lanka, have not been previously reported.

Objectives: To describe characteristics of victims and perpetrators as well as the types of abuse found during medicolegal examinations of patients with IDD.

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Ride-sharing services are transforming urban mobility by providing timely and convenient transportation to anybody, anywhere, and anytime. These services present enormous potential for positive societal impacts with respect to pollution, energy consumption, congestion, etc. Current mathematical models, however, do not fully address the potential of ride-sharing.

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Atlanto-occipital dissociation injury is an important injury in forensic pathology practice. Radiological diagnosis of atlanto-occipital dissociation clinically is assessed by direct measurement of occipito-vertebral skeletal relationships. Different measurements may be used to diagnose atlanto-occipital dissociation, including the basion-dens interval (BDI) and basion-axial interval (BAI).

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The mortality and morbidity of road traffic accidents (RTA) is increasing in the South Asian region, including Sri Lanka. Therefore, the demographic factors, types of vehicles involved, and the severity of injuries sustained in RTA was studied. Age, gender, and details of the incident of all patients admitted to hospital following a RTA, between January 2007 and August 2012, were obtained by interview.

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Candida species are common human commensals and cause either superficial or invasive opportunistic infections. The biofilm form of candida as opposed to its suspended, planktonic form, is predominantly associated with these infections. Alternative or adjunctive therapies are urgently needed to manage Candida infections as the currently available short arsenal of antifungal drugs has been compromised due to their systemic toxicity, cross-reactivity with other drugs, and above all, by the emergence of drug-resistant Candida species due to irrational drug use.

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Background: In Sri Lanka pertussis continues to circulate in the community and cases among adolescents and adults have been reported despite 95% coverage of the four dose pertussis vaccination during early childhood. Waning of immunity following natural infection or immunization may contribute to the persistent circulation. An adolescent booster dose is not included in the national immunization schedule of Sri Lanka, although this is routine practice in many countries.

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