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Biomedical subjects

H J De Silva

Publications and source records attributed to H J De Silva.

15 recordsLinked to original sources
PubMed2006

Toxicity due to organophosphorus compounds: what about chronic exposure?

The inappropriate use of toxic chemicals is common in developing countries, where it leads to excessive exposure and high risks of unintentional poisoning. The risks are particularly high with the pesticides used in agriculture, where poor rural populations live and work in close proximity to these compounds, which are often stored in and around the home. It is estimated that 99% of all deaths from pesticide poisoning occur in developing countries. Whilst the acute toxicity of pesticides has been well documented, there is still relatively little known of the effects on health of chronic pesticide exposure. Organophosphate insecticides have been extensively used in agriculture in developing countries, with little protection for the communities and individuals thus exposed. Given the indisputable chronic exposure of vulnerable groups to organophosphate compounds, including pregnant women, the fetus and young children, the potential for widespread adverse effects is considerable. Thus, whilst there is some evidence that chronic exposure may have adverse effects on health, there is an urgent need for high-quality observational and interventional studies of both occupational and environmental exposure to these compounds.

Animals↗
PubMed2005

Clinical, biochemical and histological characteristics of a Sri Lankan population of non-alcoholic steatohepatitis (NASH) patients.

BACKGROUND: Non-alcoholic steatohepatitis (NASH) is common and can progress to cirrhosis. It has been regarded as a 'disease of affluence' and there are only a few reports from developing countries. OBJECTIVE: To describe the clinical, biochemical, and histological characteristics of a cohort of NASH patients in Sri Lanka, and to determine their short term outcome following modifications of lifestyle. METHOD: Patients who had a liver biopsy for investigation of raised hepatic enzymes were assessed during the period May 1999 - May 2003. Patients who had an alcohol intake of over 40 g/week were excluded. Detailed clinical and biochemical data of patients with histologically confirmed NASH were compiled. Histological grading and staging was done using the Brunt system. The patients were advised on lifestyle modifications and the control of diseases known to be associated with NASH. They were followed up at 3 -monthly intervals. RESULTS: During the study period liver biopsies were performed on 296 patients and 100 ( 35.1%) were diagnosed as having NASH. (Men = 79, Mean age 37.2 years, SD 10.6). Risk factors for NASH included diabetes mellitus (55%), obesity (52%), hyperlipidaemia (54%), a family history of risk factors (66%) and a high dietary fat intake (66%). However, 44.3% of men and 33.3% of women were not overweight. The histological grading and staging of 80 biopsies showed Grade 1 in 31 (38.8%), Grade 2 in 29 (36.3%), Grade 3 in 20 (25%), Stage 1 in 57 (71.3%) Stage 2 in 13 (16.3%), Stage 3 in 2 (2.5%) and Stage 4 in 8 (10%). In 55/91 (60.4%) patients who were followed up for a median of 2.5 years (range 1-4 years) the serum transaminases returned to normal in a median of 7 months (range 3-14 months). CONCLUSION: The clinical, biochemical and histological features of NASH patients in our series are similar to that reported in western countries. However "lean males" accounted for a significant proportion. In the short term a majority of patients showed improvement in serum transaminases with lifestyle modification.

Age Distribution↗
PubMed2002

Effects of carbohydrate meals of varying consistency on gastric myoelectrical activity.

BACKGROUND: There is at present no agreement on the type of test meal to be used when performing EGG. To our knowledge the response of the stomach to high carbohydrate isocaloric meals of different consistencies has not been formally assessed. AIM: To study 1) the effects of high carbohydrate meals of varying consistency on EGG activity; and 2) the effects of increasing the calorie content of a meal without changing its consistency and composition on the postprandial EGG. SUBJECTS: Eighteen healthy volunteers, six males (age: 21-35 year, weight: 45-60 kg) and 12 females in the follicular phase of the menstrual cycle (age: 24-30 years, weight: 45-55 kg). METHODS: Following an overnight fast subjects were given three high carbohydrate, low fat, isocaloric meals (165-170 kcal) of different consistencies (solid, semisolid, liquid), on three separate days in a random order. The liquid and semisolid meals were equal in volume (200 ml) while the volume of the solid meal was smaller. One hour EGG recordings were done in the fasting and fed states in each subject. As a second step, ten of the above volunteers (taken randomly) were given the solid test meal on a separate day after increasing the calorie content of the meal to 350 kcal. RESULTS: The power of the EGG at the dominant frequency significantly increased after solid (175 kcal meal: fasting 49 +/- 12 dB vs. fed 57 +/- 13 dB; p < 0.05, 375 kcal meal: fasting 48.5 +/- 12.9 dB vs fed 58.1 +/- 11.7 dB) and semisolid (fasting 50 +/- 12 dB vs. fed 55 +/- 13; P < 0.05). The increase in power was not significantly different when fed with solids and semisolids. There was no statistically significant change in EGG power during the first 15 or 60 minutes after the liquid meal. Feeding showed no significant effect on the dominant frequency and the percentage of 2-4 cpm waves of the EGG with any of the three types of test meals. CONCLUSIONS: Solid and semisolid meals high in carbohydrate and low in fat are capable of inducing a significant increase in the EGG power in normal subjects. Isocaloric solid and semisolid meals have similar effects on gastric slow wave activity. EGG appears unaffected by the liquid meal. Therefore only an increase in the power of the EGG can be regarded as normal if a high carbohydrate solid or a semisolid meal is given as the test meal when performing an EGG.

Adult↗
PubMed1998

Driving and epilepsy in Sri Lanka.

Regulations regarding driving for patients with epilepsy vary from country to country. They are well implemented in developed countries, but this is not the case in countries such as Sri Lanka. The aims of this study were to study characteristics of a cohort of patients with epilepsy who were driving or riding a vehicle at present, and study the attitudes of a representative sample of doctors, patients with epilepsy and the general population regarding aspects of driving by patients with epilepsy. Patients with epilepsy attending the medical clinics at the Colombo North General Hospital, Ragama, who were driving, were given a questionnaire and interviewed in order to assess their seizure characteristics. Another questionnaire was administered to epileptic patients visiting the clinics, a sample from the general population (relatives visiting in-patients at the University Medical Unit selected randomly), doctors working at the General Hospital in Ragama and the Base Hospital in Negombo, and general practitioners in the Gampaha district, where these two hospitals are situated, which was designed to assess their views regarding driving by persons with epilepsy. Of the patients with epilepsy interviewed 24.8% were presently driving a vehicle, of them 51% were riding a motorcycle. The attitudes of the general public and patients to driving by epileptic patients were at opposite ends of the spectrum; 97% of the general public being opposed to driving by persons with epilepsy, while epileptics themselves being of the view that the rules should be lax. Doctors thought that there should be some regulations against driving by epileptic patients. These facts must be considered when setting implementable regulations regarding driving by epileptics in developing countries.

Accidents, Traffic↗
PubMed1998

The recto-anal inhibitory reflex: abnormal response in diabetics suggests an intrinsic neuroenteropathy.

As electrical stimulation of the rectum has been shown to result in reflex internal sphincter inhibition mediated by intrinsic nerves, we aimed to evaluate the integrity of these nerves in the rectum of diabetic patients. Anal canal pressure, recto-anal inhibitory reflex (RAIR) and continence were evaluated in 30 diabetic patients (male:female 13:17, median age 57 years, range 37-70) and these data were compared with similar data obtained from 22 age- and sex-matched healthy controls (male:female 9:13, median age 51 years, range 19-65 years). Median duration of diabetes was 8 years (range 3-30). Twelve (40%) of the 30 diabetics had impaired continence for gas (n = 12) and liquid faeces (n = 3). None of the controls had incontinence. Median maximum resting anal canal pressure (MRP) was: patients 30 mmHg (range 20-75 mmHg) versus controls 40 mmHg (range 20-105 mmHg, P = 0.61). Median maximum squeeze pressure (MSP) was 65 mmHg (range 30-150 mmHg) in patients versus 84mmHg (range 35-230 mm Hg) in controls (P = 0.59). Median threshold rectal mucosal electrosensation (RMES-T) was 27mA (5-40 mA) in patients versus 13 mA (5-28 mA) in controls (P = 0.03). Maximum tolerable rectal mucosal electrosensation was 40 mA (20-60) in patients versus 20 mA (10-30), in controls (P = 0.042, all comparisons using the Wilcoxon rank test). Recto-anal inhibitory reflex was present in eight, abnormal in five (one incontinent) and absent in 17 (11 incontinent) diabetics, while it was present in 18 and abnormal in four controls (test of proportion, P = 0.031). Blood glucose in diabetics on the day of the procedure was 98 mg/dL (70-165 mg/dL). Rectal mucosal electrosensitivity and RAIR were impaired in significantly more patients with diabetes than controls, implying impairment of intrinsic neuronal function. The recto-anal inhibitory reflex was either impaired or absent in all diabetic patients with incontinence.

Adult↗
PubMed1994

Influence of temperance on short-term mortality among alcohol-dependent men in Sri Lanka.

The influence of temperance on short-term mortality was assessed in a group of alcohol-dependent men admitted to a rehabilitation unit in Sri Lanka. Of the 234 men initially admitted to the programme, 188 were followed up for at least 3 years (mean +/- SD 49.5 +/- 12.6 months) or until death. All 188 were totally abstinent from alcohol on leaving the 6 week residential module of the programme. During follow-up, 115 relapsed to continued heavy drinking, whereas 73 remained either totally abstinent or drank infrequently. There were no significant differences in the age, duration of dependence, number of previous interventions, duration of follow-up or smoking habits between the two groups of patients. The overall mortality for the whole sample population was 9.6%. The mortality among those who relapsed to heavy drinking (13.9%) was more than five times that of those who were abstinent or drank infrequently (2.7%) (P < 0.04). Fifteen of the 16 deaths (93.8%) among those who relapsed to heavy drinking were alcohol-related, and included five suicides and accidents whilst under the influence of alcohol. Temperance significantly reduces short-term mortality in alcohol-dependent men when compared to those who relapse to continued heavy drinking. This difference was primarily due to reduction in the risk of alcohol-related deaths.

Adult↗
PubMed1988

Erythema induratum (of Bazin) in a patient with endometrial tuberculosis.

We report erythema induratum in a patient who was found to have active endometrial tuberculosis. This case report emphasizes the importance of an exhaustive search for active tuberculosis in patients with erythema induratum, especially in countries where tuberculosis is prevalent, as the indiscriminate treatment of erythema induratum with steroids may be harmful.

Adult↗
PubMed1987

The treatment of Guillain-Barré syndrome by modified plasma exchange--a cost effective method for developing countries.

Six patients with the Guillain-Barré syndrome were treated by modified plasma exchange. Five of them showed a rapid improvement which was not consistent with the natural history of the disease. The improvement was assessed by monitoring vital capacity and muscle power, grading the ability to perform motor functions and by the duration of the hospital stay. The method of plasma exchange we used was simpler and cheaper than the conventional method. We recommend the use of our method, especially in developing countries with financial constraints and poor facilities.

Adult↗
PubMedDate not supplied

Prevalence of hepatitis C virus markers in Sri Lankan patients with alcoholic cirrhosis.

A high prevalence of antibodies against hepatitis C virus (HCV) has been reported in patients with alcoholic cirrhosis. There are, however, doubts regarding the specificity of the first generation anti-HCV antibody assays used. We prospectively investigated HCV status in 47 Sri Lankan patients with alcoholic cirrhosis. A first generation assay (Ortho HCV enzyme-linked immunosorbent assay [ELISA]) and two second generation tests (Abbott HCV enzyme immunoassay and United Biomedical Incorporated HCV enzyme immunoassay) were used. Positive results were confirmed by the second generation recombinant immunoblot assay (RIBA 2). Of the 47 patients (46 males, mean age 41.7 years), 17 (36.2%) had previously had one or more blood or plasma transfusions. Seven (14.9%) of the samples were positive for anti-HCV antibodies using the Ortho-HCV ELISA, but only one (2.1%) sample was positive when tested with the second generation assays. The positive result was confirmed by RIBA 2. The prevalence of HCV in the patients was low despite many of them being exposed to blood or blood products. Hepatitis C virus, therefore, may not be an important pathogenic factor in alcoholic cirrhosis in Sri Lanka.

Adult↗