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Biomedical subjects

D J Fernando

Publications and source records attributed to D J Fernando.

At least 19 recordsLinked to original sources

Dengue viral infections.

Dengue viral infections are one of the most important mosquito borne diseases in the world. They may be asymptomatic or may give rise to undifferentiated fever, dengue fever, dengue haemorrhagic fever (DHF), or dengue shock syndrome. Annually, 100 million cases of dengue fever and half a million cases of DHF occur worldwide. Ninety percent of DHF subjects are children less than 15 years of age. At present, dengue is endemic in 112 countries in the world. No vaccine is available for preventing this disease. Early recognition and prompt initiation of appropriate treatment are vital if disease related morbidity and mortality are to be limited. This review outlines aspects of the epidemiology of dengue infections, the dengue virus and its mosquito vector, clinical features and pathogenesis of dengue infections, and the management and control of these infections.

Africa↗

Screening based on risk factors for gestational diabetes in an Asian population.

The results of glucose tolerance testing (OGTT) in 1004 consecutive women were examined with respect to risk factors for gestational diabetes mellitus (GDM). GDM was diagnosed in 41 of 1004 (4.08%) women. GDM was present in 7.8% of women aged over 35 years (compared to 3.1% if less than 35 years), in 8.1% women with a body mass index (BMI) >/=30 (compared to 3.6% if BMI <30) and in 5.2% of women with a family history of diabetes (compared to 3.9% in the absence of family history of diabetes). Past history of macrosomic babies (over 4 kg) was present in 12.1% of GDMs compared to 8.4% of non-diabetic pregnancies (NDP). A history of unexplained perinatal loss was present in 4.8% of GDMs compared to 2.2% of non-diabetic pregnancies (NDP). Thirteen per cent of grandmultiprous women had GDM compared to 3.9% in women with low parity. The proportion of women who had more than one risk factor was 16.7%. A combination of one or all of these risk factors predicted GDM in only 24 of 41 (58.5%) cases. Selective testing on the basis of risk factors using WHO criteria for diagnosis of GDM would miss over 40% of all cases in our population. Hence, this study supports the policy of universal screening for GDM in populations similar to ours.

Journal Article↗

Feasibility of using different approaches for recruiting younger twins to establish a population based twin register in Sri Lanka.

Identifying twins for a population-based register can be achieved through birth records or community surveys. We studied the feasibility and effectiveness of different methods of identifying and recruiting twins to establish a population based register. To trace twins a population survey was carried out using an interviewer administered questionnaire. We also inspected the birth registration certificates at a divisional secretariat reported from a specified hospital between the years of 1985-1997 and compared it to the birth register of this same hospital. To recruit twins a random sample of 75 twin pairs (150 twins) identified at the Divisional Secretariat were contacted through the post and 25 twin pairs (50 twins) were personally visited. The prevalence of twins was 6.5 twins per 1000 people in the area surveyed. The twinning rate at the hospital was 18.92 twins per 1000 births. A discrepancy of 38 multiples births between the hospital labour room records and those registered at the DS was noted. The response from the postal invitation for recruitment was 59% and the response from the personal invitation was 68%. (Difference 9.4% 95% CI; 7.06-11.73). Community survey and systematic inspection of birth records either at the hospital or the birth registration office was an effective method to trace twins. Once traced, personal contact was more effective than the postal invitation for recruitment of younger twins. A cost-effective approach would be to use a postal coverage followed by personal contact for non-responders. The alternative method, community coverage, would have financial implications.

Birth Certificates↗

Glycaemic indices of different varieties of rice grown in Sri Lanka.

OBJECTIVE: Varieties of red raw rice are widely believed to have a better nutritional quality. The physiological effects of consuming different varieties of rice may not be so. The glycaemic index has been developed as an indicator of the physiological effect of foods. It is the glycaemic response of a 50 g carbohydrate portion of food expressed as a percentage of that of a standard. The objective of this study was to determine the glycaemic indices of different varieties of rice grown in Sri Lanka. DESIGN: Digestible carbohydrate content of 11 varieties of rice flour and bread were determined. Fasting blood samples followed by half-hourly samples for two hours were drawn after giving portions of either cooked rice or bread containing 50 g carbohydrate each. SETTING: Fibre mill in Gampaha district. SUBJECTS: Twenty-two fibre mill workers aged between 25 and 50 years. MEASUREMENTS: The area under the blood glucose curve (AUC) for varieties of rice for a subject was calculated. Average AUC of 3 values for bread were calculated. Glycaemic index of each variety of rice was determined from the above variables. RESULTS: Glycaemic indices of varieties of rice differ. The glycaemic indices of varieties of red raw rice varied between 56 and 73 and the variety Bg 350 had the lowest glycaemic index. There was no significant difference between mean glycaemic index of varieties of white raw and some varieties of red raw rice (p = 0.2). Parboiled varieties of red raw rice had a significantly lower glycaemic index than white raw rice (p = 0.04) and some of the red raw rice (p = 0.005). CONCLUSIONS: The glycaemic index cannot be predicted from the colour of the rice grain. Red parboiled varieties of rice and Bg 350 can be recommended for patients with diabetes.

Adult↗

Establishing a twin register in Sri Lanka.

Nearly all twin registers are based in developed countries and there is no twin register in the developing world. Our objectives were to initiate the process of establishing a nationwide twin register in Sri Lanka by starting a volunteer register first and working towards a population-based register. Regular newspaper advertisements, feature articles, radio talks, and television programmes were used to publicise a competition for twins, their parents/relatives and friends requesting them to participate by sending in details of twins. The competition ran from 28 March 1997 for a period of 3 months. It offered prizes for three winners selected by drawing lots. Advertisements highlighted the objective of the competition as establishing a twin register for future research and emphasised that informed consent would be obtained for individual research projects. Those who registered comprise 4602 twin pairs (same sex: male--1564, female--1885; different sex--1153), 80 sets of triplets (same sex: male--17, female--31; different sex--42) and two sets of quadruplets (different sex). The oldest twins, triplets, quadruplets are 85, 46, and 5 years old, respectively; 88.0% of twins are less than 30 years old. Although others have previously used media publicity to enrol twins in twin registers, we believe this to be the first time that twins have been enrolled through competition. We have more young twins, and our gender and zygosity proportions after applying Weinburg's rule do not match the proportions expected from a volunteer twin sample. Establishing a twin register for research purposes has proved possible in a developing country.

Adolescent↗

Cross-cultural adaptation and preliminary validation of a zygosity determination questionnaire for twins in Sri Lanka.

We report the process of adaptation into Sinhala of a questionnaire given to mothers of twins to determine zygosity. Adaptation and validation was carried out in three stages. Firstly, we used a nominal group to translate the English version and to assess the extent of agreement (consensus measurement) on the appropriateness of the translation and resolve disagreement (consensus development). Secondly we used a qualitative interview with 25 mothers of twins. The three main stems of the translated questionnaire were used as a semi-structured interview, and the responses noted verbatim. These were categorised and analysed, and the translated full questionnaire was then presented as closed questions with fixed choice responses. The categorised responses generated during the qualitative interview were compared with the responses to the fixed choices in the full questionnaire. The third stage was the appraisal of the questionnaire by 17 bilingual parents of twins. The source and translated version of the questionnaire were given to them at least 3 days apart. The responses were rated and the total scores were computed to determine the zygosity. This step was carried out to measure the validity and reliability of the Sinhala version. A perfect correlation between the original and adapted version was obtained, with a kappa of 1. The results suggest that the Sinhala version of the questionnaire is conceptually equivalent to the original questionnaire. Comparison of the zygosity determination by using this adapted questionnaire with results from analysis of genetic markers on Sri Lankan twins is needed for final validation of the translated questionnaire.

Cross-Cultural Comparison↗

Long-term complications in newly diagnosed Sri Lankan patients with type 2 diabetes mellitus.

We screened 597 newly-diagnosed diabetic patients (201 women) mean +/- SD age 42.3 +/- 6.2 years to determine the prevalence of diabetic complications; 22% presented because of symptoms of diabetes, 27% were diagnosed when hyperglycaemia was discovered at a health screening, and 36% were diagnosed while being treated for intercurrent illness. Neuropathy was present in 25.1%, nephropathy in 29%, retinopathy in 15%, coronary vascular disease in 21%, stroke in 5.6%, peripheral vascular disease in 4.8%, hypertension in 23%, obesity in 16%, central obesity in 21.3%, hypercholesterolaemia in 11%, hypertriglyceridaemia in 14%, and low high-density lipoprotein cholesterol in 12%. The prevalence of coronary vascular disease, hypertension, stroke, neuropathy and retinopathy at the time of diagnosis were higher in our patients than in Caucasian and Indo-Asian patients in the UK. Both a genetic predisposition to develop complications, and exposure to a longer duration of asymptomatic hyperglycaemia due to poor access to adequate health care, may contribute to the high frequency of complications at diagnosis. Since complications are already present at diagnosis, there is a case for implementing primary prevention programmes combined with screening for diabetes in high-risk groups.

Adult↗

The prevalence of peripheral neuropathy in newly diagnosed patients with non-insulin-dependent diabetes mellitus.

INTRODUCTION: Neuropathy is considered to be a longterm complication of diabetes. AIMS: To determine the prevalence of peripheral neuropathy in 112 Sri Lankan patients with recently diagnosed non-insulin-dependent diabetes and a control population of 100 people. METHODS: A diagnosis of peripheral neuropathy was made using a clinical symptom score, clinical examination, quantitative sensory testing and electrophysiological studies. RESULTS: 9.8% of diabetic patients at diagnosis had peripheral neuropathy, 2.6% had foot ulcers, 7.1% had signs of neuropathy, abnormal vibration perception threshold and nerve conduction abnormalities and 15.1% had abnormal nerve conduction velocity without signs or symptoms of neuropathy. The peroneal nerve conduction velocity was higher in diabetic patients when compared to controls. There was an inverse correlation between nerve conduction velocity and fasting blood glucose in diabetic patients (p < 0/05). This association was stronger for peroneal nerve conduction velocity (r = -0.73) than for median nerve motor conduction velocity (r = -0.42). CONCLUSIONS: Symptomatic peripheral neuropathy is common among Sri Lankans with newly diagnosed non-insulin-dependent diabetes. This may be due to a later presentation of diabetes or a genetic predisposition.

Adult↗

The prevalence of gestational diabetes in a Sri Lankan antenatal clinic.

INTRODUCTION: Early diagnosis of gestational diabetes mellitus (GDM) is a prerequisite to reducing fetal and neonatal complications of GDM. OBJECTIVES: (a) To ascertain the prevalence of GDM in a Sri Lankan pregnant population. Using the 75 g oral glucose tolerance test (GTT) and WHO criteria. (b) To establish the predictive value of a 50 g glucose challenge test (GCT) compared to the GTT (c) To compare the outcome of pregnancy in GDM with 'non-diabetic pregnancy' (NDP) STUDY DESIGN: Prospective study on a cohort of pregnant women attending antenatal clinics. SETTING: Sri Jayawardenepura General Hospital (SJGH) RESULTS: Of the 721 patients, 131 (18%) had a positive GCT. 40 (5.5%) patients had GDM. If a one-hour GCT of 7.8 mmol/l was considered suspicious of GDM the sensitivity of the glucose challenge test was 63% and the specificity 84%. Statistically significant differences in the prevalence was found when the women were > 35 years [Relative risk (RR) = 3.87 (95% CI-2.06 to 7.27)] or the body mass index > or = 25. (RR = 2.45 (95 CI-1.30 to 4.61) Presence or absence of high parity, family history of diabetes or recurrent abortions had no significant impact on the prevalence of GDM. Mean birth weight was higher (p < 0.05) in GDM (3615 SD 103) than in NDP (2898 SD 143.6). The likelihood of having a caesarean section was higher (p < 0.01, Relative risk (RR) 2.50, 95% CI 1.56-3.95) in GDM when compared to NDP. A higher incidence of hydramnios (p < 0.01 RR 3.41 95% CI 1.44-8.05) was recorded in GDM when compared to NDP. CONCLUSION: The prevalence of GDM in the antenatal clinics at SJGH is 5.5%. Traditional risk factors did not predict GDM. GDM is associated with a higher risk of caesarean section, hydramnios and macrosomia. Hence screening for GDM should be performed in all pregnant women at 24 to 28 weeks of pregnancy using a GCT.

Adult↗