Showing papers by "University of Peradeniya published in 2011"

Medical management of paraquat ingestion

Abstract: Poisoning by paraquat herbicide is a major medical problem in parts of Asia while sporadic cases occur elsewhere. The very high case fatality of paraquat is due to inherent toxicity and lack of effective treatments. We conducted a systematic search for human studies that report toxicokinetics, mechanisms, clinical features, prognosis and treatment. Paraquat is rapidly but incompletely absorbed and then largely eliminated unchanged in urine within 12-24 h. Clinical features are largely due to intracellular effects. Paraquat generates reactive oxygen species which cause cellular damage via lipid peroxidation, activation of NF-κB, mitochondrial damage and apoptosis in many organs. Kinetics of distribution into these target tissues can be described by a two-compartment model. Paraquat is actively taken up against a concentration gradient into lung tissue leading to pneumonitis and lung fibrosis. Paraquat also causes renal and liver injury. Plasma paraquat concentrations, urine and plasma dithionite tests and clinical features provide a good guide to prognosis. Activated charcoal and Fuller's earth are routinely given to minimize further absorption. Gastric lavage should not be performed. Elimination methods such as haemodialysis and haemoperfusion are unlikely to change the clinical course. Immunosuppression with dexamethasone, cyclophosphamide and methylprednisolone is widely practised, but evidence for efficacy is very weak. Antioxidants such as acetylcysteine and salicylate might be beneficial through free radical scavenging, anti-inflammatory and NF-κB inhibitory actions. However, there are no published human trials. The case fatality is very high in all centres despite large variations in treatment.

Chronic kidney diseases of uncertain etiology (CKDue) in Sri Lanka: geographic distribution and environmental implications.

Abstract: The increase in the number of chronic kidney disease (CKD) patients from the north central region of Sri Lanka has become a environmental health issue of national concern. Unlike in other countries where long-standing diabetes and hypertension are the leading causes of renal diseases, the majority of CKD patients from this part of Sri Lanka do not show any identifiable cause. As the disease is restricted to a remarkably specific geographical terrain, particularly in the north central dry zone of the country, multidisciplinary in-depth research studies are required to identify possible etiologies and risk factors. During this study, population screening in the prevalent region and outside the region, analysis of geoenvironmental and biochemical samples were carried out. Population screening that was carried out using a multistage sampling technique indicated that the point prevalence of CKD with uncertain etiology is about 2-3% among those above 18 years of age. Drinking water collected from high-prevalent and non-endemic regions was analyzed for their trace and ultratrace element contents, including the nephrotoxic heavy metals Cd and U using ICP-MS. The results indicate that the affected regions contain moderate to high levels of fluoride. The Cd contents in drinking water, rice from affected regions and urine from symptomatic and non-symptomatic patients were much lower indicating that Cd is not a contributing factor for CKD with uncertain etiology in Sri Lanka. Although no single geochemical parameter could be clearly and directly related to the CKD etiology on the basis of the elements determined during this study, it is very likely that the unique hydrogeochemistry of the drinking water is closely associated with the incidence of the disease.

Altered pairing behaviour and reproductive success in white ibises exposed to environmentally relevant concentrations of methylmercury

Abstract: Methylmercury (MeHg) is the most biologically available and toxic form of mercury, and can act as a powerful teratogen, neurotoxin and endocrine disruptor in vertebrates. However, mechanisms of endocrine impairment and net effects on demography of biota are poorly understood. Here, we report that experimental exposure of an aquatic bird over 3 years to environmentally relevant dietary MeHg concentrations (0.05–0.3 ppm wet weight) resulted in dose-related increases in male–male pairing behaviour (to 55% of males), and decreases in egg productivity (to 30%). Dosed males showed decreased rates of key courtship behaviours, and were approached less by courting females in comparison to control males. Within dosed groups, homosexual males showed a similar reduction when compared with dosed heterosexual males. We found an average 35 per cent decrease in fledgling production in high-dose birds over the study duration. These results are of interest because (i) MeHg exposure is experimentally tied to demographically important reproductive deficits, (ii) these effects were found at low, chronic exposure levels commonly experienced by wildlife, and (iii) effects on reproductive behaviour and sexual preference mediated by endocrine disruption represent a novel and probably under-reported mechanism by which contaminants may influence wild populations of birds.

Nutritional and digestive health benefits of seaweed

Abstract: Seaweed is a famous delicacy in some parts of the Asia and also a well-known source of important food hydrocolloids, such as agar, alginates, and carrageenan In addition to the food value of seaweed, several health benefits have also been reported to be present in this valuable food source It is presumed that the unique features of the marine environment, where the seaweeds are grown, are mainly responsible for most of its properties Among the functional effects of the seaweed, nutritional and health-related benefits have been widely studied Compared to the terrestrial plants and animal-based foods, seaweed is rich in some health-promoting molecules and materials such as, dietary fiber, ω-3 fatty acids, essential amino acids, and vitamins A, B, C, and E In this chapter, the nutritive value of seaweed and the functional effects of its soluble fiber are discussed with a special reference to the digestive health promotion of human

Intercountry prevalences and practices of betel-quid use in south, southeast and eastern Asia regions and associated oral preneoplastic disorders: an international collaborative study by Asian betel-quid consortium of south and east Asia.

Abstract: Health risks stemming from betel-quid (BQ) chewing are frequently overlooked by people. Updated epidemiological data on the increased BQ use among Asian populations using comparable data collection methods have not been widely available. To investigate the prevalence, patterns of practice and associated types of oral preneoplastic disorders, an intercountry Asian Betel-quid Consortium study (the ABC study) was conducted for Taiwan, Mainland China, Malaysia, Indonesia, Nepal and Sri Lanka. A random sample of 8,922 subjects was recruited, and the data were analyzed using survey-data modules adjusted for the complex survey design. Chewing rates among men (10.7-43.6) were significantly higher than women (1.8-34.9) in Taiwan, Mainland China, Nepal and Sri Lanka, while women's rates (29.5-46.8) were higher than that for men (9.8-12.0) in Malaysia and Indonesia. An emerging, higher proportion of new-users were identified for Hunan in Mainland China (11.1-24.7), where Hunan chewers have the unique practice of using the dried husk of areca fruit rather than the solid nut universally used by others. Men in the Eastern and South Asian study communities were deemed likely to combine chewing with smoking and drinking (5.6-13.6). Indonesian women who chewed BQ exhibited the highest prevalence of oral lichen planus, oral submucous fibrosis and oral leukoplakia (9.1-17.3). Lower schooling, alcohol drinking and tobacco smoking were identified as being associated with BQ chewing. In conclusion, the ABC study reveals the significant cultural and demographic differences contributing to practice patterns of BQ usage and the great health risks that such practices pose in the Asian region.

Spatial patterns reveal negative density dependence and habitat associations in tropical trees.

Abstract: Understanding how plant species coexist in tropical rainforests is one of the biggest challenges in community ecology. One prominent hypothesis suggests that rare species are at an advantage because trees have lower survival in areas of high conspecific density due to increased attack by natural enemies, a process known as negative density dependence (NDD). A consensus is emerging that NDD is important for plant-species coexistence in tropical forests. Most evidence comes from short-term studies, but testing the prediction that NDD decreases the spatial aggregation of tree populations provides a long-term perspective. While spatial distributions have provided only weak evidence for NDD so far, the opposing effects of environmental heterogeneity might have confounded previous analyses. Here we use a novel statistical technique to control for environmental heterogeneity while testing whether spatial aggregation decreases with tree size in four tropical forests. We provide evidence for NDD in 22% of the 139 tree species analyzed and show that environmental heterogeneity can obscure the spatial signal of NDD. Environmental heterogeneity contributed to aggregation in 84% of species. We conclude that both biotic interactions and environmental heterogeneity play crucial roles in shaping tree dynamics in tropical forests.

Genetics/epigenetics of oral premalignancy: current status and future research.

Abstract: Squamous cell carcinoma (SCC) of the oral and oropharyngeal region is the sixth most common malignancy in the world today. Despite numerous advances in treatment, long-term survival from this disease remains poor. Early detection can decrease both morbidity and mortality associated with this neoplasm. However, screening for potentially malignant disease is typically confounded by difficulty in discriminating between reactive/inflammatory lesions vs those lesions that are premalignant in nature. Furthermore, the histologic diagnosis of dysplasia can be subjective and is thus prone to a considerable range of interpretation. Similarly, no definitive, validated criteria exist for predicting which dysplastic lesions are most likely to progress to cancer over time. Given this state of science, the presence of dysplasia can only be used to indicate that an oral lesion may have an increased risk of malignant transformation. Molecular biomarkers capable of identifying the subset of lesions likely to progress to cancer are required to eliminate this clinical diagnostic dilemma. The purpose of this review is to assess the current state of knowledge regarding genetic/epigenetic alterations observed in oral mucosal premalignancy. In addition, recommendations for future research studies directed at defining the predictive capacity of specific biomarkers in this modeling are presented.

Lotus japonicus nodulation is photomorphogenetically controlled by sensing the red/far red (R/FR) ratio through jasmonic acid (JA) signaling.

Abstract: Light is critical for supplying carbon to the energetically expensive, nitrogen-fixing symbiosis between legumes and rhizobia. Here, we show that phytochrome B (phyB) is part of the monitoring system to detect suboptimal light conditions, which normally suppress Lotus japonicus nodule development after Mesorhizobium loti inoculation. We found that the number of nodules produced by L. japonicus phyB mutants is significantly reduced compared with the number produced of WT Miyakojima MG20. To explore causes other than photoassimilate production, the possibility that local control by the root genotype occurred was investigated by grafting experiments. The results showed that the shoot and not the root genotype is responsible for root nodule formation. To explore systemic control mechanisms exclusive of photoassimilation, we moved WT MG20 plants from white light to conditions that differed in their ratios of low or high red/far red (R/FR) light. In low R/FR light, the number of MG20 root nodules dramatically decreased compared with plants grown in high R/FR, although photoassimilate content was higher for plants grown under low R/FR. Also, the expression of jasmonic acid (JA) -responsive genes decreased in both low R/FR light-grown WT and white light-grown phyB mutant plants, and it correlated with decreased jasmonoyl-isoleucine content in the phyB mutant. Moreover, both infection thread formation and root nodule formation were positively influenced by JA treatment of WT plants grown in low R/FR light and white light-grown phyB mutants. Together, these results indicate that root nodule formation is photomorphogenetically controlled by sensing the R/FR ratio through JA signaling.

Senescent mesenchymal cells accumulate in human fibrosis by a telomere-independent mechanism and ameliorate fibrosis through matrix metalloproteinases.

Abstract: Fibrosis can occur in many organs, where it is a debilitating and preneoplastic condition. The senescence of activated fibroblasts has been proposed to ameliorate fibrosis via the innate immune system but its role in humans has not been investigated. The availability of oral submucous fibrosis (OSMF) biopsies at different stages of disease progression allowed us to test the hypothesis that senescent fibroblasts accumulate with the progression of human fibrosis in vivo, and also to examine the mechanism of senescence. We tested the hypothesis that senescent cells may ameliorate fibrosis by increasing the secretion of matrix metalloproteinases (MMPs). We have used a combination of in situ immunodetection techniques, drug treatments, fluorescence-activated cell sorting and enzyme-linked absorbance assays on tissue samples and fibroblast cultures. We report a novel panning technique, based on fibronectin adhesion rates, to enrich and deplete senescent cells from fibroblast populations. Senescent fibroblasts, as determined by the presence of senescence-associated heterochromatic foci, accumulated with OSMF progression (R(2) = 0.98) and possessed a reduced replicative lifespan in vitro. Unlike wounds, however, OSMF fibroblasts were quiescent in vivo and consistent with this observation, possessed functional telomeres of normal length. Senescence was associated in vivo and in vitro with oxidative damage, DNA damage foci and p16(INK4A) accumulation and required the production of reactive oxygen species (ROS), perhaps from damaged mitochondria, but not the continuous presence of the disease stimulus (areca nut and tobacco), the tissue environment or other cell types. Depletion of OSMF fibroblasts of senescent cells showed that these cells accounted for 25-83 times more MMP-1 and -2 than their pre-senescent counterparts. The results show that the accumulation of senescent fibroblasts in human fibrosis occurs by a telomere-independent mechanism involving ROS and may locally ameliorate the condition by the increased expression of MMPs prior to clearance by the immune system.

Betel-derived alkaloid up-regulates keratinocyte alphavbeta6 integrin expression and promotes oral submucous fibrosis.

Abstract: Oral submucous fibrosis (OSF) is a premalignant, fibrosing disorder of the mouth, pharynx, and oesophagus, with a malignant transformation rate of 7-13%. OSF is strongly associated with areca (betel) nut chewing and worldwide, over 5 million people are affected. As αvβ6 integrin is capable of promoting both tissue fibrosis and carcinoma invasion, we examined its expression in fibroepithelial hyperplasia and OSF. αvβ6 was markedly up-regulated in OSF, with high expression detected in 22 of 41 cases (p < 0.001). We investigated the functional role of αvβ6 using oral keratinocyte-derived cells genetically modified to express high αvβ6 (VB6), and also NTERT-immortalized oral keratinocytes, which express low αvβ6 (OKF6/TERT-1). VB6 cells showed significant αvβ6-dependent activation of TGF-β1, which induced transdifferentiation of oral fibroblasts into myofibroblasts and resulted in up-regulation of genes associated with tissue fibrosis. These experimental in vitro findings were confirmed using human clinical samples, where we showed that the stroma of OSF contained myofibroblasts and that TGF-β1-dependent Smad signalling was detectable both in keratinocytes and in myofibroblasts. We also found that arecoline, the major alkaloid of areca nuts, up-regulated keratinocyte αvβ6 expression. This was modulated through the M(4) muscarinic acetylcholine receptor and was suppressed by the M(4) antagonist, tropicamide. Arecoline-dependent αvβ6 up-regulation promoted keratinocyte migration and induced invasion, raising the possibility that this mechanism may support malignant transformation. Over 80% of OSF-related oral cancers examined had moderate/high αvβ6 expression. These data suggest that the pathogenesis of OSF may be epithelial-driven and involve arecoline-dependent up-regulation of αvβ6 integrin.

Delayed Psychological Morbidity Associated with Snakebite Envenoming

Abstract: Introduction The psychological impact of snakebite on its victims, especially possible late effects, has not been systematically studied. Objectives To assess delayed somatic symptoms, depressive disorder, post-traumatic stress disorder (PTSD), and impairment in functioning, among snakebite victims. Methods The study had qualitative and quantitative arms. In the quantitative arm, 88 persons who had systemic envenoming following snakebite from the North Central Province of Sri Lanka were randomly identified from an established research database and interviewed 12 to 48 months (mean 30) after the incident. Persons with no history of snakebite, matched for age, sex, geograpical location and occupation, acted as controls. A modified version of the Beck Depression Inventory, Post-Traumatic Stress Symptom Scale, Hopkins Somatic Symptoms Checklist, Sheehan Disability Inventory and a structured questionnaire were administered. In the qualitative arm, focus group discussions among snakebite victims explored common somatic symptoms attributed to envenoming. Results Previous snakebite victims (cases) had more symptoms than controls as measured by the modified Beck Depression Scale (mean 19.1 Vs 14.4; p<0.001) and Hopkins Symptoms Checklist (38.9 vs. 28.2; p<0.001). 48 (54%) cases met criteria for depressive disorder compared to 13 (15%) controls. 19 (21.6%) cases also met criteria for PTSD. 24 (27%) claimed that the snakebite caused a negative change in their employment; nine (10.2%) had stopped working and 15 (17%) claimed residual physical disability. The themes identified in the qualitative arm included blindness, tooth decay, body aches, headaches, tiredness and weakness. Conclusions Snakebite causes significant ongoing psychological morbidity, a complication not previously documented. The economic and social impacts of this problem need further investigation.

Present and Future Prospects of Seaweeds in Developing Functional Foods

Abstract: There has been a combined effort among scientists to explore and utilize varying food sources to develop functional foods to cater the ever-increasing demand from the consumers, who seek health-promoting roles of dietary compounds. Considering the diversity of biochemicals in seaweeds that are capable of exerting bioactivities, a growing trend is developing across globe to employ seaweeds in functional food development. Proteins, peptides, amino acids, polysaccharides, phenolics, lipids, vitamins, and minerals in seaweeds and their functional properties provide insights into the success of potential functional food products that can be developed utilizing seaweeds. However, several factors need to be taken into consideration in designing seaweed-based functional foods to obtain the market success. This chapter elaborates on the prospects of seaweeds in developing seaweed-based functional food products.

Estimation of Technical Efficiency and It's Determinants in the Tea Small Holding Sector in the Mid Country Wet Zone of Sri Lanka

Abstract: Sri Lanka is the world leader in made tea production and the small holding sector dominates national production by accounting for 60% of the island's tea production. However, given the high cost of production, there is a belief that it is very difficult to increase profitability without increasing costly inputs such as labour. With this background, in this study technical efficiency of the tea small holdings sector in the Mid Country Wet Zone of Sri Lanka was estimated in order to identify the potential to increase production without incurring any additional costs for inputs. The sources of inefficiency and the robustness of measured technical efficiency in various functional specifications was also investigated. The primary data collected during the period September - January 2001 relevant to sixty small holder tea producers in the Mid-country Wet Zone was used for the study. Maximum likelihood estimates of the stochastic frontier model were estimated for green leaf yield as a function of land extent, family labour, hired labour, fertilizer, chemicals, and dolomite, using Cobb- Douglas and translog models. The determinants of technical efficiency such as age of farmer, experience, education, occupation type of crop (VP/Seedling) and type of clone were investigated, following the Battese and Coelli (1995) specification. According to the Cobb-Douglas specification, extent of land, family labour, hired labour, fertilizer and dolomite showed significant effects on yield. The coefficients for land, family labour, hired labour and fertilizer had positive values of 1.11, 0.027, 0.067 0.029 and 0.004 respectively. The mean technical efficiency of the tea small holdings sector in the Mid Country Wet Zone was found to be 64.60 per cent. The result for the inefficiency model indicates that age of farmer, education, occupation, type of crop (VP or seedling) and type of clone have significant effects on efficiency. The coefficients for age, education, occupation and type of crop showed negative values. However contrary to expectations, type of clone and experience showed positive values. The estimation with the translog model yielded different technical efficiencies, which indicates the fact that technical efficiency estimations are highly sensitive to the functional form specified. DOI: http://dx.doi.org/10.4038/sjae.v4i0.3488 SJAE 2002; 4(1): 137-150

Leptospirosis Outbreak in Sri Lanka in 2008: Lessons for Assessing the Global Burden of Disease

Abstract: Global leptospirosis disease burden estimates are hampered by the lack of scientifically sound data from countries with probable high endemicity and limited diagnostic capacities. We describe the seroepidemiologic and clinical characteristics of the leptospirosis outbreak in 2008 in Sri Lanka. Definitive/presumptive case definitions proposed by the World Health Organization Leptospirosis Epidemiology Reference Group were used for case confirmation. Of the 404 possible cases, 155 were confirmed to have leptospirosis. Highest titers of patient seum samples reacted with serovars Pyrogenes (28.7%), Hardjo (18.8%), Javanica (11.5%), and Hebdomadis (11.5%). Sequencing of the 16S ribosomal DNA gene identified six infections: five with Leptospira interrogans and one with L. weilli. In this patient population, acute renal failure was the main complication (14.8%), followed by myocarditis (7.1%) and heart failure (3.9%). The case-fatality rate was 1.3%. This report strengthens the urgent need for increasing laboratory diagnostic capabilities to determine the causes of epidemic and endemic infectious diseases in Sri Lanka, a finding relevant to other tropical regions.

Factors controlling fluoride contents of groundwater in north-central and northwestern Sri Lanka

Abstract: Chemical characterization has been made of groundwater bodies at 294 locations in four village districts in north-central and northwestern Sri Lanka, with special focus on fluorine contamination. High fluoride contents in groundwater are becoming a major problem in the dry zone of Sri Lanka, and dental fluorosis and renal failures are widespread. Field measurements of temperature, pH, and electrical conductivity were made during sampling. Chemical analyses of the water samples were later made using atomic absorption spectroscopy, spectrophotometry, and titration. Fluoride concentrations in the study area vary from 0.01 to 4.34 mg/l, and depend on pH and the concentrations of Na, Ca, and HCO3−. Basement rocks including hornblende biotite gneiss, biotite gneiss, and granitic gneiss seem to have contributed to the anomalous concentrations of fluoride in the groundwater. Longer residence time in aquifers within fractured crystalline bedrocks may enhance fluoride levels in the groundwater in these areas. In addition, elevated fluoride concentrations in shallow groundwater in intensive agricultural areas appear to be related to the leaching of fluoride from soils due to successive irrigation.

Pollution of River Mahaweli and farmlands under irrigation by cadmium from agricultural inputs leading to a chronic renal failure epidemic among farmers in NCP, Sri Lanka

Abstract: Chronic renal failure (CRF) associated with elevated dietary cadmium (Cd) among farming communities in the irrigated agricultural area under the River Mahaweli diversion scheme has reached a significantly higher level of 9,000 patients. Cadmium, derived from contaminated phosphate fertilizer, in irrigation water finds its way into reservoirs, and finally to food, causing chronic renal failure among consumers. Water samples of River Mahaweli and its tributaries in the upper catchment were analyzed to assess the total cadmium contamination of river water and the possible source of cadmium. Except a single tributary (Ulapane Stream, 3.9 μg Cd/l), all other tested tributaries carried more than 5 μg Cd/l, the maximum concentration level accepted to be safe in drinking water. Seven medium-sized streams carrying surface runoff from tea estates had 5.1–10 μg Cd/l. Twenty larger tributaries (Oya), where the catchment is under vegetable and home garden cultivation, carried 10.1–15 μg Cd/l. Nine other major tributaries had extremely high levels of Cd, reaching 20 μg Cd/l. Using geographic information system (GIS), the area in the catchment of each tributary was studied. The specific cropping system in each watershed was determined. The total cadmium loading from each crop area was estimated using the rates and types of phosphate fertilizer used by the respective farmers and the amount of cadmium contained in each type of fertilizer used. Eppawala rock phosphate (ERP), which is mostly used in tea estates, caused least pollution. The amount of cadmium in tributaries had a significant positive correlation with the cadmium loading of the cropping system. Dimbula Tea Estate Stream had the lowest Cd loading (495.9 g/ha/year), compared with vegetable-growing areas in Uma Oya catchment with 50,852.5 g Cd/ha/year. Kendall’s τ rank correlation value of total Cd loading from the catchment by phosphate fertilizer used in all crops in the catchment to the Cd content in the tributaries was +0.48. This indicated a major contribution by the cropping system in the upper catchment area of River Mahaweli to the eventual Cd pollution of river water. Low soil pH (4.5–5.2), higher organic matter content (2–3%), and 18–20 cmol/kg cation exchange capacity (CEC) in upcountry soil have a cumulative effect in the easy release of Cd from soil with the heavy surface runoff in the upcountry wet zone. In view of the existing water conveyance system from upcountry to reservoirs in North Central Province (NCP) through diversion of River Mahaweli, in addition to their own nonpoint pollution by triple superphosphate fertilizer (TSP), this demands a change in overall upper catchment management to minimize Cd pollution through agriculture inputs to prevent CRF due to elevated dietary cadmium among NCP farmers.

Mycotoxin Detection in Urine Samples from Patients with Chronic Kidney Disease of Uncertain Etiology in Sri Lanka

Abstract: This was a screening study that aimed to determine the presence of nephrotoxic mycotoxins in urine samples from patients with chronic kidney disease of uncertain etiology in the North Central Province of Sri Lanka. The percentage detection of aflatoxins, ochratoxins and fumonisins in 31 patients were 61.29%, 93.5% and 19.4%, respectively. Geometric means of urinary aflatoxins and ochratoxins were 30.93 creatinine and 34.62 ng/g creatinine in chronic kidney disease of uncertain etiology stage 1–2 patients and 84.12 ng/g creatinine and 63.52 ng/g creatinine in unaffected relatives of patients. In chronic kidney disease of uncertain etiology stage 3–5 patients, geometric means of urinary aflatoxins and ochratoxins were 10.40 and 17.08 ng/g creatinine, respectively. Non-affected relatives of patients (n = 6) had comparable levels of these mycotoxins, but healthy Japanese individuals (n = 4) had lower levels than in Sri Lanka. The higher detection rate of urinary ochratoxins in Sri Lankans indicates that exposure is common in the region.

Review of metastasizing (malignant) ameloblastoma (METAM): pattern of metastasis and treatment.

Abstract: Objectives The rare malignant odontogenic tumor, metastasizing (malignant) ameloblastoma (METAM) is reviewed with the aim of analyzing the pattern of disease and treatment of cervical metastasis based, on 2005 World Health Organization classification. Study design A total of 65 cases, including reported cases from 1923 to 2009 compatible with the current classification and a new case are reviewed. Results METAM occurred mostly in lungs (71%), followed by cervical lymph nodes (28%). Female-to-male ratio was 1:1.1. Primary tumor was diagnosed in 28% of cases at ages ≤20 years, and maxilla-to-mandible ratio was 1:5.2. The mean disease-free interval and survival for pulmonary metastasis were 14.37 years and 3 years, respectively, and 12.96 years and 6 years for cervical METAM. Five-year survival rate for cervical metastasis treated purely surgically was 71.43%. Conclusions According to the available literature, neck dissection is the treatment of choice for cervical METAM. Evidence for the role of chemotherapy and radiotherapy is not conclusive.

The prevalence of Early Childhood Caries in 1-2 yrs olds in a semi-urban area of Sri Lanka

Abstract: Background: ECC remains a problem in both developed and developing countries and ECC has been considered to be present in epidemic proportions in the developing countries. The aetiology and associated factors of ECC should be studied adequately to overcome this health hazard. The objective of this study is to determine the prevalence of ECC in 1 to 2 years old children in some selected MOH areas (semi-urban) in the district of Colombo, Sri Lanka. Methods: This study was conducted as a cross sectional study. A total of 422 children aged 1-2 years were selected using systematic sampling technique in Maharagama, Piliyandala, Nugegoda and Boralesgamuwa MOH areas in Colombo district, Western province, Sri Lanka. The pre-test was done initially with 10 children aged 1 1/2 year olds. Prior to the clinical examination of each child, a questionnaire consisting questions regarding tooth brushing, dietary habits, breast and bottle feeding, long term medications(Sweetened medications taken more than 3 months), attending a dental clinic during pregnancy of mother and socio-economical status of the family was administered to mothers of those children. Sterile dental mouth mirrors were used to detect ECC in children. Results: The prevalence of ECC of the whole sample of 410 children aged 1-2 years was 32.19% and the mean dmft was 2.01 and the mean dmfs was 3.83. From the children who had ECC 95% were untreated. There were significant relationships between dmft and long term use of medications (p < 0.000), intake of sugar with milk (p = 0.013), sweet consumption (p = 0.013), employment of mothers (p < 0.000) and visiting a dental clinic during pregnancy (p < 0.000). Conclusions: This study documents high prevalence and severity of ECC among 1-2 years old children in four selected MOH areas of Colombo district and caries in most of the children with ECC (95%) were untreated. Results reveal an urgent need to increase awareness among the public about ECC and institute preventive strategies.

Coastal vegetation planting projects for tsunami disaster mitigation: effectiveness evaluation of new establishments

Abstract: Coastal vegetation acts as a natural barrier against extreme natural and anthropogenic activities, protecting infrastructure and human lives Establishment of hard infrastructure for tsunami protection is not feasible in developing countries due to its cost-intensive nature Coastal vegetation can therefore be a feasible alternative for tsunami and general coastal protection in developing countries This study investigates the effectiveness of current coastal vegetation projects and reports a pilot-scale vegetation project, which provides insights into the management and sustainability of such projects Thirty-seven establishments of coastal vegetation for tsunami protection were identified for the study from Hambantota to Colombo along the southern coast in Sri Lanka Evaluation was carried out to assess whether the coastal vegetation establishments fulfilled the planning objectives, such as vegetation alignment to tsunami direction, tree density and tree species, and whether monoculture or mixed species are grown The study also assessed continuous maintenance and awareness about coastal vegetation, community participation and long-term institutional support from government, nongovernment groups, academic institutions, and other institutions within an integrated framework Approximately 50% of the sites were found to be effective in terms of fulfilling the above requirements and had reasonable protection against future tsunami-type events Continuous maintenance is ensured only for 35% of sites with community participation The survey also revealed the importance of adopting scientific and nonscientific methods of vegetation establishment and selecting appropriate species and structure of vegetation strips for tsunami protection It is expected that this will lead to the development of coastal vegetation guidelines for local authorities

Human Parechovirus Infection in Children Hospitalized with Acute Gastroenteritis in Sri Lanka

Abstract: Of 362 fecal specimens collected from infants and children hospitalized with acute gastroenteritis in Sri Lanka from September 2005 to August 2006, 30 (8.3%) were positive for human parechovirus (HPeV). Six different HPeV genotypes, including HPeV1, -3, -4, -5, -10, and -11, were identified, of these, HPeV11 was reported for the first time.

Chlorophyll a : b Ratio Increases Under Low-light in 'Shade-tolerant' Euglena gracilis

Abstract: Shade tolerance is a key adaptive strategy displayed by heliophytic photosynthetic organisms in response to limited light. Although generalized morphological and physiological traits associated with shade tolerance exist, the interest in shade tolerance has been expanding over the past few years due primarily to the controversies that have emerged on classical hypotheses of shade tolerance. In this paper the shade responses of unicellular excavate Euglena gracilis is discussed. Euglena was photoautotrophically grown under three different light intensities; 28, 84 and 210 μmol m -2 s -1 . Results revealed that E. gracilis is a shade tolerant species which exhibits some typical shade tolerant responses such as decrease in growth rate, light saturation point, light compensation point and dark respiration rate, and increased chlorophyll content. Most importantly, it is reported for the first time that the shade tolerance of this organism is also characterized by the increased chlorophyll a:b ratio, contradicting the generally accepted hypothesis of decreased chlorophyll a:b in shade tolerance response. The probable reasons for increased chlorophyll a:b ratio in E. gracilis under shade are also discussed. Key words: Chlorophyll; Fluorescence; Photosynthesis; PSI; PSII. DOI: 10.4038/tar.v22i1.2666 Tropical Agricultural Research Vol. 22 (1): 12-25 (2010)