Sri Lankan Population Research Articles

Morphometric Analysis of Dry Human Mandibles of Sri Lankans

<strong>Introduction: </strong>Variety of mandibular morphometric measurements determines the population and sex differences of facial skeleton. This study is aimed to determine the mandibular morphometric measurements of Sri Lankan population. <strong></strong><strong></strong> <strong><br /></strong> <strong>Materials and methods: </strong>Thirteen different mandibular measurements were obtained in 75 dry mandibles of which the gender and age were determined referring to the standard literature. Optimum measures were undertaken to reduce the intra and inter observer bias. The data were analysed using Minitab 19 version. Mean ± SD, mean difference and P- value of each morphometric parameter for both sexes were analysed separately by using Minitab 19 version. <strong><br /></strong> <strong>Results and discussion: </strong>The sample consisted of 40 male and 35 female mandibles, age ranging from 60 – 80 years with the mean age of 67.545 ±4.36765. The mean value of each morphometric parameter in males were higher except in the mandibular angle and the height and breadth of the mandibular body. The maximum mandibular length, bigonial width, maximum ramus height, bicondylar breadth, bicoronoid breadth, bimental breadth and mandibular notch depth of males showed statistical significance (P&lt;0.05). The mean values of all the parameters were different from values of the different populations. <strong></strong><strong></strong> <strong><br /></strong> <strong>Conclusions: </strong>Mandibular morphometric characteristics of Sri Lankans showed distinctiveness within the population and a direct relationship with the sex. These findings provide information for objective assessment facial skeletons of Sri Lankans.

Comparison of actual height and estimated height from ulna length in a selected population of Sri Lankan adults

Rationale: Height is an important parameter in assessment of nutritional status. Height is difficult to measure directly in critically ill patients requiring alternative methods for height estimation. One such method used in the Sri Lankan setting is the Malnutrition Universal Screening Tool (MUST) equation (1) for height estimation using ulna length. But data regarding the accuracy of estimating height from ulna length for the Sri Lankan population hasn’t been studied well. The objective of the following study was to evaluate the accuracy of estimated height from ulna length in adults attending the Medical Nutrition clinic in Base Hospital Gampola as a pilot study in order to evaluate the equation for the Sri Lankan population in the future.

Abstract 9415: Body Mass Index, Waist Circumference and Waist-Hip Ratio in South Asians With Acute Coronary Syndrome

Introduction: Acute coronary syndrome (ACS) is the leading cause of death worldwide, even higher in South Asian countries. South Asia shows a higher incidence of ACS and an increasing trend of overweight and obesity. Methods: This cross-sectional descriptive study was conducted at the Teaching Hospital Peradeniya, Sri Lanka, among the patients presenting with ACS. An interviewer-administered structured questionnaire was used to collect data and to take anthropometric measurements. They were analysed to obtain the body mass index (BMI) and the waist-hip ratio. Results: A total of 780 patients with ACS were included in the study with a mean age of 60.8 ± 11.3 years. Among them, 316 (40.5%) were females. The mean BMI of females was 25.2 ± 4.4 kg m -2 which was higher than that of males 23.9 ± 3.8 kg m -2 , showing a statistically significant difference (p=0.003). The prevalence of overweight and obesity was 37.6% and 21.2%, respectively, significantly higher than the normal values for the ordinary Sri Lankan population (p=0.002). In females, the prevalence of obesity (31.2%) was significantly higher than in males (13.5%) (p=0.000). In males, the prevalence of overweight (40.6%) was significantly higher than in females (33.8%) (p=0.000). The mean waist circumference and waist-hip ratio in females were 88.8 ± 13.8 cm and 0.93 ± 0.10, respectively, which were significantly above the cut-off values for the risk of metabolic complications for South Asians 80 cm (p=0.000) and 0.85 (p=0.000). In males, the mean waist circumference was 86.9 ± 12.9 cm, significantly below the cut-off value for the South Asians (p=0.009), and the mean waist-hip ratio was 0.98, significantly above the cut-off point for South Asians (p=0.000). Conclusions: The proportion of overweight and obesity is significantly higher among the South Asians with ACS than the average South Asian population, confirming them as risk factors for cardiovascular diseases. In females, obesity is more associated with the development of ACS than in males. A higher waist circumference and the waist-hip ratio has an excellent predictive value of ACS in females. However, in males, though the waist-hip ratio has an excellent predictive value of ACS, waist circumference shows a negative correlation.

Outcomes of stroke patients undergoing thrombolysis in Sri Lanka; an observational prospective study from a low-middle income country

BackgroundStroke related deaths are relatively higher in low- and middle-income countries where only a fraction of eligible patients undergo thrombolysis. There is also limited evidence on post-thrombolysis outcomes of patients from Asian countries in these income bands.MethodsThis is a single center prospective observational study of a patient cohort with acute ischaemic stroke, undergoing thrombolysis with alteplase (low and standard dose), over a 24-month period in 2019/2020. Modified Rankin scale (mRS) for dependency at 3 months (primary outcome), duration of hospital stay, incidence of symptomatic intracranial haemorrhages and all-cause mortality at 3 months (secondary outcomes) were recorded. Demographic, clinical and treatment related factors associated with these outcomes were explored.ResultsEighty-nine patients (males – 61, 69%, mean age: 60 years ±12.18) were recruited. Time from symptom onset to reperfusion was 174 min ± 56.50. Fifty-one patients were independent according to mRS, 11 (12.4%) patients died, and 11 (12.5%) developed symptomatic intracranial haemorrhages by 3 months. Functional independence at 3 months was independently associated with National Institutes of Health Stroke Scale (NIHSS) on admission (p < 0.05). Thrombolysis with low dose alteplase did not lead to better or worse outcomes compared to standard dose.ConclusionsOn admission NIHSS is predictive of functional independence at 3 months post-thrombolysis. Low dose alteplase may be as efficacious as standard dose alteplase with associated cost savings, but this needs to be confirmed by a prospective clinical trial for the Sri Lankan population.

Relationship between CRP and depression: A genetically sensitive study in Sri Lanka

BackgroundPrevious studies have shown associations between major depression and C-reactive protein (CRP) levels. Few studies have considered the extent to which shared genetic and environmental factors contribute to this association, nor have they considered the relationship outside of European populations. We examined the association between CRP levels and depression and their aetiology in a Sri Lankan population. MethodsData were collected from 2577 twins and 899 singletons in Colombo, Sri Lanka. Depression symptoms were assessed using the revised Beck Depression Inventory (BDI-II). High-sensitive CRP blood levels were assessed using immunoturbidimetry. Linear regressions were performed to test the association between CRP and depression. The heritability of CRP levels was estimated using Structural Equation Modelling. ResultsCRP was significantly associated with BMI (p < 0.01) but not depression (p > 0.05). In males, variance in CRP levels was explained by shared environment (51% 95%CIs: 13–62) and non-shared environment (45% 95%CIs: 36–54). In contrast, in females, CRP variance was explained by genetic (41% 95%CIs: 10–52) and non-shared environment (56% 95%CIs: 47–67). A genetic correlation between CRP and BMI was observed in females only. LimitationsCRP level was based on a single data collection point, longer term data collection would give a more accurate picture of an individual's state of inflammation. ConclusionsThe lack of association between depression and CRP strengthens the hypothesis that inflammation might contribute to the development of some, but not all types of depression. CRP levels were moderated by the environment, suggesting interventions aimed at reducing CRP levels and risk for inflammatory conditions, particularly in males.

GeNuIne (gene-nutrient interactions) Collaboration: towards implementing multi-ethnic population-based nutrigenetic studies of vitamin B12 and D deficiencies and metabolic diseases.

Gene-nutrient interactions (GeNuIne) collaboration, a large-scale collaborative project, has been initiated to investigate the impact of gene-nutrient interactions on cardiometabolic diseases using population-based studies from ethnically diverse populations. In this project, the relationship between deficiencies of vitamins B12 and D, and metabolic diseases was explored using a nutrigenetic approach. A genetic risk score (GRS) analysis was used to examine the combined effect of several genetic variations that have been shown to be associated with metabolic diseases and vitamin B12 and D deficiencies, respectively. In Sri Lankan, Indonesian and Brazilian populations, those carrying a high B12-GRS had an increased risk of metabolic diseases under the influence of dietary protein, fibre and carbohydrate intakes, respectively; however, in Asian Indians, genetically instrumented metabolic disease risk showed a significant association with low vitamin B12 status. With regards to nutrigenetic studies on vitamin D status, although high metabolic-GRS showed an interaction with dietary carbohydrate intake on vitamin D status, the study in Indonesian women demonstrated a vitamin D GRS-carbohydrate interaction on body fat percentage. In summary, these nutrigenetic studies from multiple ethnic groups have provided evidence for the influence of the dietary factors on the relationship between vitamin B12/D deficiency and metabolic outcomes. Furthermore, these studies highlight the existence of genetic heterogeneity in gene-diet interactions across ethnically diverse populations, which further implicates the significance of personalised dietary approaches for the prevention of these micronutrient deficiencies and metabolic diseases.

Polymorphisms in rs915941 and rs915942: Are they associated with increased risk of G6PD enzyme deficiency in the Sri Lankan population?

The Journal of the National Science Foundation of Sri Lanka publishes the results of research in all aspects of Science and Technology. The journal also has a website at http://www.nsf.gov.lk/. 2020 Impact Factor: 0.515The JNSF provides immediate open access to its content on the principle that making research freely available to the public supports a greater global exchange of knowledge.

Importance of Following Proper Inhalation Techniques and Awareness Regarding Asthma among Clinical Patients

Aims: Asthma is one of the biggest health burdens on the Sri Lankan population. Achievement of treatment goals isdetermined mainlythrough pharmacological management. The main objective of this study was to evaluate the patient inhaler handling techniques and their awareness regarding their disease condition, as well as to find out how an educational intervention effects patients‘ inhaler handling techniques.&#x0D; Study Design: A Prospective cross sectional study used.&#x0D; Place and Duration of Study: National Hospital for Respiratory Diseases, Welisara and Colombo South Teaching Hospital, Kalubowila between June 2017 to August 2017.&#x0D; Methodology: Clinically diagnosed asthma patients were randomly divided into Control and Test groups. Control comprised 94 patients and the test comprised 93 patients. Their baseline knowledge about asthma and inhaler-using technique were assessed in 1st month by using an interviewer-administered questionnaire and checklist respectively. The test group was given both information leaflet and verbal instructions. Again, all the participants were assessed for the inhaler techniques on their next clinic day by using the same questionnaire and the checklist.&#x0D; Results: After the educational intervention, there was a statistically significant improvement in the test group, in the adherence to the nine steps, including critical steps, regarding all 3 device types (PMDI, DPI, and PMDI with Spacer) in the 2nd-month visit. (at P =.05) When considering awareness about asthma in the total population, most participants were knowledgeable regarding asthma.&#x0D; Conclusion: We observed gaps in knowledge between current practice and what is expected in patients with asthma regarding their inhaler therapy. This might be due to the quality of instructions delivered by health care providers being insufficient and them lacking the time to observe patients individually for the inhaler techniques. Awareness regarding asthma and inhalation techniques can be raised by using information leaflets as well as through verbal counseling.

Assessment of the oral cancer control activities through care seeking behavior of hospital attendees and their level of awareness

Oral cancer is the most common cancer among males in the Sri Lankan population. The aim of this study was to assess the health seeking behaviors and associated factors for OPMD.A hospital based descriptive cross-sectional study was conducted among Out Patients Department attendees of the Institute of Oral Health, Maharagama, from July 1, 2018 to December 31, 2019 by administering a questionnaire followed by an intra oral examination.The total number of 110 OPMD/oral cancer patients were identified. Awareness on OPMD was that 40 ​%. Majority were unaware of the danger of areca nut and alcohol use. Out of the identified cases during oral examination, 47.3 ​% were incidental findings while only 7.3 ​% were referred by the General Medical Practitioners (GMP). None were referred by the Primary Health Care (PHC) staff.The level of awareness on OPMD and its risk factors were very low. Incidental findings during the dental screening being the main mode of detection of OPMD, highlights the importance of conducting opportunistic screening at dental settings. Implementation of the Risk Factor Model (RFM) approach for the early detection of oral cancer through PHC staff and GMP is validated to encourage more early referrals.

An Autopsy Study Conducted in Colombo South of Sri Lanka to Identify Average Sizes of Aortic and Mitral Valves of the Heart

<strong><em>Introduction:</em></strong><em> </em>There was no uniformity in measuring the anthropological measurements of the heart in the literature. It varies from study to study, country to country, region to region within the same country and author to author according to the material and methodology of the study. So measurements of the heart also vary according to the methods used by different authors in their study. The normality standard for organ anthropometric measurements must be established in a specific reference sample for each population, as the normality values may be different under genetic and environmental influences. This study is aimed to determine the average size of mitral and aortic valves of the adult heart in autopsies done in Teaching Hospital, Colombo South of Sri Lanka. Assess the average circumferential length of the mitral and aortic and also determine the relationship with socio-demographic factors such as body weight, sex, and age and body length. <em> </em> <strong><em>Methodology:</em></strong><em> </em>This study was designed as a descriptive cross-sectional study done in fresh formalin unfixed adult hearts recovered from deceased died due to traumatic and unnatural causes. Samples were collected for one-year period between the periods of September 2018 to September 2019. <em> </em> <strong><em>Results:</em></strong><em> </em>Hundred and twenty-two (122) samples (68 males and 54 females) were included in this study among 282 adult hearts collected during this period due to strict inclusion and exclusion criteria. The average circumferential length of the mitral and aortic valves were in cm for male and females 9.49, 8.76 and 7.05, 6.88. <em> </em> <strong><em>Conclusion:</em></strong><em> </em>This pilot study revealed that intermingling findings with western studies and eastern studies. Especially male mitral valve annular circumferences were compatible with western studies and other findings were compatible with eastern studies. A significant association was demonstrated in the circumference of MV with age and body length (p value = 0.029, 0.034). We recommend large scales multi-centered studies to find out the normality standard for heart measurements in Sri Lankan population.

Copy Number Variants Captured by the Array Comparative Genomic Hybridization in a Cohort of Patients Affected with Hereditary Colorectal Cancer in Sri Lanka: The First CNV Analysis Study of the Hereditary Colorectal Cancer in the Sri Lankan Population

Introduction:Hereditary non-polyposis colorectal cancer (HNPCC), is an autosomal dominant disorder characterized by the development of multiple cancer types. Molecular diagnosis of HNPCC requires the precise identification of pathogenic germline variants in DNA mismatch repair (MMR) genes. Next Generation Sequencing (NGS) is now the gold standard test in practice, to identify these variants. However, large genomic rearrangements (LGR) in cancer predisposing genes (CPGs) are missed by NGS. This may lead to underestimation of the frequency of the variants, misleading the genetic diagnosis and delaying intervention in high risk individuals. Hence this study was aimed at identifying the presence of large genomic alterations that could explain the missing heritable risk of colon cancer in affected patients with family history strongly suggestive of hereditary colorectal cancer in Sri Lanka. Methods:A cohort of six patients affected with hereditary colorectal cancer who tested negative for pathogenic variants in next generation sequencing studies was investigated using Sure Print G3 Human CGH 4x180K microarray platform. Agilent Genomic-Workbench-v7.0.4.0 software was used to identify the Copy Number Variants (CNV). Four healthy individuals (>55years) were used as controls. Annotations of the CNV regions which were observed were done using the database of Genomic Variants. Results:We identified 150 CNVs including regions of both genomic gains and losses in the patient cohort. There was no difference in the average number or the average genomic burden of CNVs identified in the patients versus the controls. CNVs were residing on the positions of 1q21.2, 2q37.3, 2p11.2-p11.1, 5q13.2, 6p12.3, 7q31.33, 7p14.1, 14q32.33, 15q11.1-11.2, 16p11.2, 22q11.22, 22q13.1 that were assessed by the array platform used in the study. CNVs in any of the well-known common CPG s or CNVs that reside on or in close proximity to genes corresponding to MMR pathway were not identified. We found several distinct pathways that have previously been identified as having a direct association with the progression of HNPCC. Conclusion:This study shows that CNVs are likely contributors to the colorectal cancer predisposition in a small but significant proportion of patients affected with hereditary colorectal cancer in this cohort. Further studies have to perform to get a better understanding on the contribution of CNVs to the cancer predisposition in this cohort of patients in the Sri Lankan population.

Validation of the internet addiction test (IAT) to Sinhalese and assessment of internet addiction among school children in Sri Lanka

AimsTo translate Young's Internet Addiction Test (IAT) to Sinhalese and validate for use in a Sri Lankan population. Following validation of the questionnaire, to use the validated questionnaire to assess the prevalence of internet addiction in a school going population in the Western province of Sri Lanka and identify characteristics of those addicted to the internet.BackgroundThe internet is widely used across the world and in Sri Lanka. Though essential for everyday life there are many negative aspects of internet use. Addiction to the internet is one such problem and identified to exist among the general population and students in other countries. The most common tool used to measure internet addiction is Young's internet addiction test. The phenomena of internet addiction has not been scientifically studied in Sri Lanka according to our knowledge.MethodA school-based cross-sectional analytical study conducted in two stages among students aged 15 to 19 years. In stage 1 of the study, 200 students were administered the Sinhalese translation of the IAT and internal consistency and test retest validity assessed. Once validation of the scale was established the translated scale was used on a sample of 2800 students to assess presence of internet addiction.ResultThe Sinhala translation of the Internet addiction test showed good reliability and validity The Chrohnbach's alpha value was 0.78 and Pearson correlation coefficient of 0.85 and therefore suitable to use in a Sinhalese speaking population in Sri Lanka.Internet addiction was identified among the study population. 8% of the entire study sample and 12.6% among those using the internet showed features of internet addiction. The majority of cases of internet addiction identified were mild 8.2% followed by moderate internet addiction in 3.6% and only 0.9 % having severe internet addiction. There were no significant demographic or internet use related features identified among those with internet users and those not addicted to the internet.ConclusionThis study demonstrated that the Sinhala translation of Young's IAT is suitable to assess internet addiction in Sri Lanka. It also identified that there are students in Sri Lanka who are addicted to the internet. This will possibly impact negatively on their lives at a crucial stage of development and have immediate as well as long term detrimental effects. More studies are required to identify characteristics of those who are addicted to the internet and to plan interventions.

Some Anatomical Variations of the Coronary Circulation among Sri Lankan Adults

The coronary circulation has been the centre of focus of many anatomists, pathologists, cardiologists, cardiothoracic surgeons, physiologists and even the general public especially since the introduction of coronary angiography during the 1960's. Though a large number of data regarding the coronary circulation of the Western populations are available, research about coronary circulation of the Sri Lankan population is comparatively rare. This study comprises of data from 150 autopsy specimens of adult Sri Lankans died due to non-cardiac causes. 99.3% had a tricuspid aortic valve while only in 0.7% the aortic valve was bi-cuspid. The incidence of the ectopic origin of the left and the right coronary artery was equal (1.3%), and the posterior sinus was devoid of coronary ostia. A 55.3% of the study population had a single coronary artery ostium for each main coronary artery. The corresponding figure for the left coronary artery was 91.3%. Six percent (06%) of the right coronary ostia were positioned significantly above the sinus while the corresponding figure for the left coronary ostia was higher (17.5%). The average left ventricular wall thickness for males and females were 13mm and 12mm respectively. Significant muscular bridging (in relation to at-least one coronary artery) was found in 19.3% of the study population. The study concludes that variations in the cardiac anatomy are commoner than expected. As per Kitzman chart, cardiac dimensions of the Sri Lankans are somewhat smaller compared to the dimensions of the Western populations.

A nutrigenetic approach to examine the relationship between vitamin B12 status and cardio‐metabolic traits in multiple ethnic groups – findings from the GeNuIne Collaboration

AbstractLow vitamin B12 concentration has been shown to be a risk factor for cardio‐metabolic traits in numerous observational studies; however, the relationship has remained inconsistent. It is possible that certain genotypes jointly contribute to cardio‐metabolic diseases and vitamin B12 deficiency, and these may be modulated by dietary factors. The main objective of this article is to summarise the findings from the GeNuIne (Gene‐Nutrient Interactions) Collaboration on the effect of gene–nutrient interactions on vitamin B12 concentrations and cardio‐metabolic disease risk factors in population‐based studies from different ethnic groups. Interactions between vitamin B12‐related single‐nucleotide polymorphisms (SNPs) and protein energy intake (%) on waist circumference (Pinteration =0.002) and body fat percentage (Pinteraction =0.034) were observed in Sri Lankan and Indonesian populations, respectively. In the study in Brazilian adolescents, the metabolic and vitamin B12‐related SNPs showed a significant interaction with dietary carbohydrate and protein intakes on oxidised low‐density lipoprotein cholesterol and homocysteine concentrations, respectively. In the Asian Indian population, an association between obesity‐related SNPs and vitamin B12 concentrations (p = 0.018) was observed. In summary, these studies in multiple ethnic groups show that the association between genetically low vitamin B12 concentrations and cardio‐metabolic traits may be modified by dietary intake. Further studies utilising larger sample sizes are needed to confirm or refute our findings.

Linear and Volumetric Analysis of Maxillary Sinus Pneumatization in a Sri Lankan Population Using Cone Beam Computer Tomography.

Objective The objectives of this study were to evaluate the linear and volumetric measurements of the maxillary sinus in relation to sex and side on cone beam computer tomographic (CBCT) images in a Sri Lankan population. Methods A total of 20 sets of CBCT images selected from the database at the Division of Oral Medicine and Radiology, Faculty of Dental Sciences, University of Peradeniya, Sri Lanka, were evaluated. Linear measurements were obtained in a craniocaudal (height), anteroposterior (length), and mediolateral (width) dimensions. Volume was computed by using the same data using a computerized 3D modeling software developed for 3D measurements and calculations. Results The maximum mean craniocaudal dimension was at the level of the 1st and the 2nd molar tooth bilaterally. The largest average craniocaudal, mediolateral, and anteroposterior extensions of the maxillary sinus using CBCT were 31.71 ± 5.44 mm, 21.28 ± 5.09 mm, and 32.92 ± 4.31 mm, respectively. The differences between the sides and sex showed no statistical significance (P > 0.05), except for the maximum average value in craniocaudal dimension which showed a statistically significant difference in relation to gender (P = 0.02). Conclusion There is no significant difference in the largest average craniocaudal, mediolateral, and anteroposterior extensions of the maxillary sinus when gender and side were compared. However, the maximum average value in craniocaudal dimension had a statistically significant difference in relation to gender. This study provides valuable knowledge of the anatomical dimensions of the maxillary sinus which may help clinicians in treatment planning.

Validation of the Sinhala translations of the Pelvic Floor Distress Inventory and the Pelvic Floor Impact Questionnaire in a Sri Lankan population.

This study was to translate and validate self-reported questionnaires, the Pelvic Floor Distress Inventory (PFDI-20) and the Pelvic Floor Impact Questionnaire (PFIQ-7) into Sinhala, the language spoken by the majority of Sri Lankans. A total of 270 patients were enrolled in this study. Two groups were selected with pelvic organ prolapse (POP)-cases and without POP-controls in a ratio of 1:2 respectively. Psychometric properties of the questionnaires were assessed using content validity, face validity, convergent validity, construct validity, internal consistency, and reliability. Pelvic Organ Prolapse Quantification (POP-Q) was used as the test to quantify POP. Excellent content validity was demonstrated by a content validity ratio for all items by experts. Face validity was confirmed by non-experts using a five-point Likert scale and Mann-Whitney U test for all items. Internal consistency was found to be high for both questionnaires (Cronbach's alpha >0.8) in all items. Construct validity was assessed by receiver-operating characteristic curves and the area under the curve is above 0.5 in all items in both questionnaires. Convergent validity was assessed using Pearson coefficient correlation, which was above 0.8 for all subscales. Reliability was low for all subscales in the paired t test. The Sinhala versions of PFDI-20 and PFIQ-7 were valid, consistent, responsive, but have low reliability in the Sri Lankan setting.

A study of medieval population in Sri Lanka with reference to the literary sources

Much research has been done on the medieval history of Sri Lanka, but not much attention has been paid to comparison of distribution and statistics of contemporary population to the medieval period. Some research is available on Polonnaruwa and the Dambadeniya periods separately at different intervals. Thus, research on the demographic details of Sri Lanka during the medieval period is scarce. Reliable statistics on the population of Sri Lanka date back to around 1871, the period of the British rule. Therefore, it is difficult to comment on the population of Sri Lanka during the historical periods, such as Rajarata, and particularly when the southwestern kingdoms were active from the 13th century to the modern period and the Kandyan period. However, the periodical sources of literary sources such as Poojavaliya, Nikaya Sangrahaya, Rajavaliya, and Dambadeni Asna written in connection with the reign of Parakramabahu the Great in Polonnaruwa (c. 1153-1186) and the reign of Parakramabahu II in Dambadeniya (c. 1236-1270 CE) report some information regarding the population of the country at the same time. This research is being done with the objective of researching whether it is possible to accept those quantities as true and this is a comparative study. This research employs a qualitative data analysis. The findings are based on a comparative analysis of contemporary literary sources written during the research period, comparing the current population figures with those in the literature. An exploration of these sources reveal that Sri Lankan population was larger than the current population between the 12th and 14th centuries. That is, one has to be careful in reaching conclusions as the information related to the medieval period is limited and the sources are often written for other purposes as well. Therefore, more exploratory type of field research- excavations are needed is this area to support the findings in this study and to draw definite conclusions regarding the population in the medieval Sri Lanka.

Geographic origin of Explanatum explanatum (Creplin, 1847) Fukui, 1929 detected from domestic water buffaloes in Sri Lanka.

The adult stage of Explanatum explanatum has economic importance in the production of ruminants, especially water buffaloes. This species has been widely reported in the Indian sub-continent. Recently, molecular analyses to reveal the dispersal route of this species were performed in Bangladesh, Nepal, and India. In the present study, we focused on E. explanatum distributed in Sri Lanka. A total of 52 flukes were collected from water buffaloes in Sri Lanka and identified as E. explanatum based on the internal transcribed spacer 2 (ITS2) region of nuclear ribosomal DNA. Analysis of the mitochondrial NADH dehydrogenase subunit 1 (nad1) gene from DNA samples detected 18 haplotypes, and five of them were identical to those from the Indian E. explanatum. The pairwise fixation index value indicated that the Sri Lankan population had a comparatively closer relationship with the Indian population than with the Bangladeshi or Nepalese populations. The Sri Lankan population showed significantly lower genetic variability than the Indian population, suggesting that the Indian population was the ancestor of the Sri Lankan population. The movement of host ruminants, including water buffaloes, was probably involved in the introduction of the fluke into Sri Lanka. The results of our study provide useful information for elucidating the geographic origin of E. explanatum distributed in the Indian subcontinent.

Molecular analysis of HLA Class I and Class II genes in five different South Indian linguistic groups.

South Indians are a heterogeneous population who speak different languages and differ in their life style and physical appearance. Major population movements, social structure and caste endogamy have influenced the genetic structure of Indian populations. The human leukocyte antigen (HLA) system of populations is highly informative because of the high level of polymorphisms. Knowledge of allele and haplotype frequencies of the HLA system is important in the search for unrelated bone marrow donors. We investigated the distribution of HLA A, B, C, DRB1 and DQB1 loci in five linguistic groups from South India. HLA-A*01:01:01~B*57:01:01:01~C*06:02:01~DRB1*07:01:01~DQB1*03:03:02 was the common haplotype with highest frequency in all the five populations studied. A few relevant haplotypes were identified as most common haplotypes in each linguistic group. Comparison of HLA-A, -B and -DRB1 allele distribution in these five linguistic groups with the other Asian population showed that the South Indian populations were closely related to Sri Lankan populations. A large South Indian donor registry might serve as good source of donors for patients from Sri Lanka and vice versa.

Hand and Handprint Measurements in the Estimation of Stature in a Sri Lankan Population

Hand and Handprint Measurements in the Estimation of Stature in a Sri Lankan Population