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Biomedical subjects

S Mendis

Publications and source records attributed to S Mendis.

36 records · Page 2Linked to original sources
PubMed1994

Pentane and isoprene in expired air from humans: gas-chromatographic analysis of single breath.

Both pentane and isoprene are excreted in human breath. Although pentane is considered an index of lipid peroxidation, the significance of isoprene is unknown. Having a similar boiling point, these two hydrocarbons are difficult to separate by gas chromatography. We separated pentane from isoprene on both a Poraplot Q and a Poraplot U column, injecting single-breath samples directly into a gas chromatograph. The breath samples were pressurized to 800 mmHg to increase the amount of sample volume delivered to the column. In a group of 43 healthy volunteers, the concentrations of end-expiratory pentane and isoprene were 0.57 +/- 0.3 and 7.05 +/- 3.53 nmol/L, respectively. There was a significant linear correlation (r = 0.57, P < 0.0001) between age and pentane concentration in expired air; isoprene showed no correlation with age or pentane concentrations. The age-related increase in pentane production suggests that oxidative stress may play a role in the aging process in humans. The method described should allow for rapid, inexpensive, serial measurement of expired pentane and isoprene.

Adult↗
PubMed1993

Effect of drug treatment on electroneurological measures of peripheral nerve function in leprosy patients.

OBJECTIVE: To investigate whether drug treatment improves the electroneurological measures of affected peripheral nerve function in leprosy patients. DESIGN: Clinical status of patients determined on the first visit by an investigator administered, pre-designed questionnaire, followed by measurement of motor conduction velocity (MCV) and distal latency (DL) of ulnar, median, common peroneal and posterior tibial nerves bilaterally in patients referred consecutively from the dermatology unit and leprosy clinic, Teaching Hospital, Galle. MCV and DL measurements were repeated after 6 to 12 months of treatment. SETTING: Department of Physiology, Faculty of Medicine, University of Ruhuna, Galle. SUBJECTS: 24 diagnosed leprosy patients; tuberculoid, lepromatous and borderline in clinical type. INTERVENTIONS: Based on clinical typing. Tuberculoid (paucibacillary) type rifampicin 600 mg monthly and dapsone 100 mg daily for six months. Lepromatous and borderline (multibacillary) type rifampicin 600 mg and clofazimine 300 mg monthly and dapsone 100 mg and clofazimine 50 mg daily for 24 months. RESULTS: DL in all 4 nerves and MCV in 3 nerves tested were significantly different (p > 0.001) to those for the normal population and remained so after 6 to 12 months of treatment. The DL in the ulnar nerve showed significant improvement (p < 0.05) after treatment. When analysed in each patient individually, before and after treatment, the MCV showed an improvement in 48 to 72% of patients and the DL in 41 to 59%, but differences were not significant. CONCLUSIONS: Electroneurological recovery (return to normal state) of the affected peripheral nerves of leprosy patients does not occur after 6 to 12 months of drug treatment. The significant (p < 0.05) improvement (becoming better) of ulnar nerve DL indicates that, if at all, electroneurologically detectable improvement of nerve function occurs in the early stages of nerve damage, and that it may take longer than one year after starting treatment.

Adolescent↗
PubMed1991

Restriction fragment length polymorphisms in the Apo B gene in relation to coronary heart disease in a southern Asian population.

We have examined DNA polymorphisms associated with the apolipoprotein B gene in 95 Sri Lankan males with ischaemic heart disease and 95 matched controls. For polymorphisms detected using the XbaI or MspI enzymes the allele frequency in Sri Lankans contrasted markedly from that in Caucasians. Overall, there was no significant association of any allele studied with coronary disease cases in this sample. There was, however, a significant difference observed between the XbaI allele frequency in normotriglyceridaemic or normocholesterolaemic CHD cases compared with the allele frequency in the controls.

Alleles↗
PubMed1990

Genetic variation in the cholesteryl ester transfer protein and apolipoprotein A-I genes and its relation to coronary heart disease in a Sri Lankan population.

The influence of variation in the genes for cholesteryl ester transfer protein and apolipoprotein A-I was investigated in 95 patients with coronary heart disease and 95 matched control subjects of South East Asian extraction. Restriction fragment length polymorphisms (RFLPs) linked to the cholesteryl ester transfer protein gene TaqIA and TaqIB, and to the apolipoprotein A-I gene SstI, were examined to investigate the extent of genetic variation at these loci. None of the alleles defined by these RFLPs were associated with increased coronary risk. Analysis of the data by division of high density lipoprotein-cholesterol levels into tertiles showed a trend of a higher frequency of B1 allele (presence of the TaqIB site) with reduced high density lipoprotein levels. The B1 allele was more frequent in control subjects, with low high density lipoprotein levels (P less than 0.02), but not in coronary heart disease patients. The differences became significant for both groups (P less than 0.05) when the data of non-smokers were analysed separately.

Apolipoprotein A-I↗
PubMed1990

The effect of daily consumption of coconut fat and soya-bean fat on plasma lipids and lipoproteins of young normolipidaemic men.

The present paper reports the influence on plasma lipids of isoenergetic diets containing 30% of energy as fat, with a polyunsaturated: saturated fat ratio of 4.00 or 0.25, consumed for 8 weeks by twenty-five young normolipidaemic males. Approximately 70% of the fat energy was provided by the test fats: soya-bean fat and coconut fat. During the soya-bean-fat-eating period the total plasma cholesterol level fell significantly compared with baseline values (P less than 0.001) and during the coconut-fat-eating phase total plasma cholesterol level increased significantly compared with the soya-bean-eating period (P less than 0.001). On the soya-bean-fat diet, high-density-lipoprotein (HDL)-cholesterol decreased by 15% (range 6-35%) and plasma triacylglycerols decreased by 25% (range 13-37%). Results of the present study show that even when the proportion of total fat in the diet is low, a high intake of linoleic acid lowers both total plasma cholesterol and HDL-cholesterol, while a high intake of saturated fat elevates both these lipid fractions. Application of regression formulas to the present findings indicates that short-chain saturated fatty acids have a neutral effect on serum cholesterol.

Adult↗
PubMed1990

Tobacco use in a cohort of children in Sri Lanka.

This study designed to examine the smoking behaviour and attitude of children were carried out on 3447, 11 to 18 year old Sri Lankan School children. The prevalence of smoking in urban and rural children are 7.2% and 4.3% respectively. 0.5% of children chew tobacco or use tobacco snuff. Friends smoking behaviour and attitude are the best predictors of smoking in children. The knowledge of health hazards of smoking is poor and is related to smoking behaviour.

Adolescent↗
PubMed1989

Magnesium, zinc, and manganese in atherosclerosis of the aorta.

Atomic absorption spectrometry was used in a quantitative study of zinc, magnesium, and manganese on 71 postmortal human aortas. Samples were obtained from accident victims 35-65 years of age. Fibrous plaques had higher levels of all three elements when compared to normal aortic tissue. The difference was significant for zinc (p less than 0.001) and magnesium (p less than 0.01). The high elemental levels may be both a cause and effect of atherosclerosis or the result of another unknown parameter.

Adult↗
PubMed1989

Colchicine cardiotoxicity following ingestion of Gloriosa superba tubers.

The clinical features of colchicine toxicity in a patient following ingestion of Gloriosa superba tubers are described. Gastroenteritis, acute renal failure, cardiotoxicity and haematological abnormalities were the main toxic manifestations. There was no hypotension and no neurological manifestations. Electrocardiographic changes were noteworthy and have not been reported previously.

Adult↗
PubMedDate not supplied

Neurotoxic envenoming by the Sri Lankan krait (Bungarus ceylonicus) complicated by traditional treatment and a reaction to antivenom.

A 30 year old woman bitten by a large Sri Lankan krait (Bungarus ceylonicus) developed progressive paralytic symptoms within one hour of the bite. After seeking traditional treatment her condition deteriorated and when she arrived at hospital 6 h after the bite she was drowsy, with bilateral ptosis and signs of aspiration pneumonia (a complication of traditional treatment). She developed an anaphylactic reaction after antivenom treatment and, despite treatment, had a cardio-respiratory arrest. She was resuscitated and mechanically ventilated, but remained deeply unconscious until her death 90 h after the bite. B. ceylonicus is endemic in Sri Lanka, is common in some areas, and could be mistaken for the common krait (B. caeruleus). It is doubtful whether any existing antivenom is effective against its venom.

Adult↗
PubMedDate not supplied

Association between hyperhomocysteinaemia and hypertension in Sri Lankans.

This study examined the relationship between homocysteine and its metabolites, and hypertension in a cohort of Sri Lankan patients with essential hypertension. Serum homocysteine, cysteine, cysteinylglycine and glutathione were measured in 86 patients with a diagnosis of essential hypertension and compared with those of an age- and sex-matched control group. Patients with hypertension had significantly higher mean serum concentrations of homocysteine, cysteine and cysteinylglycine. The odds ratio for hypertension for those with a mean serum homocysteine concentration above 18 mumol/l was 2.8. Hyperhomocysteinaemia is a risk factor for hypertension in Sri Lankans and can lead to a threefold increase in risk.

Adult↗
PubMedDate not supplied

Coronary heart disease and coronary risk profile in a primitive population.

A study of coronary heart disease and risk factors was conducted in a total Sri Lankan aboriginal population who face imminent extinction due to developmental programmes in the vicinity of their jungle homelands. Coronary heart disease was not detected among the aborigines. Hypertension was present in 5.7% of males and 1.9% of females. 39% of males smoked. Serum cholesterol, triglyceride and high density lipoprotein cholesterol levels were 5.25 mmol/l (SD 0.45), 1.99 mmol/l (SD 0.92) and 1.2 mmol/l (SD 0.2) respectively. Obesity was not seen and the level of physical activity was high. The rarity of coronary heart disease could be attributed to this favourable coronary risk profile.

Adult↗