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Biomedical subjects

D de Silva

Publications and source records attributed to D de Silva.

29 records · Page 2Linked to original sources
PubMed1996

A Scottish family with Bazex-Dupré-Christol syndrome: follicular atrophoderma, congenital hypotrichosis, and basal cell carcinoma.

Bazex-Dupre-Christol syndrome (BDCS) is an X linked dominant disorder of the hair follicle characterised by follicular atrophoderma, multiple basal cell carcinomas, hypotrichosis, milia, and localised hypohidrosis. Follicular atrophoderma (FA) are follicular funnel shaped depressions, "ice pick marks", seen most commonly on the dorsum of the hands. We describe the first known Scottish family with this syndrome, five affected members spanning three generations. They have hypohidrosis confined to the face, coarse hair, dry skin, milia, and follicular atrophoderma. All the adults have a history of multiple basal cell carcinomas. None of them has any skeletal feature suggestive of Gorlin's syndrome. The clinical features, skin histology, and scanning electron microscopic (SEM) examination of the hair are described and illustrated. The features are compared with 15 previous reports of BDCS and four reports in which this is a possible diagnosis are also reviewed. BDCS should be considered as a differential diagnosis in patients with early onset or familial basal cell carcinomas.

Adult↗
PubMed1995

Identification of women at high genetic risk of breast cancer through the National Health Service Breast Screening Programme (NHSBSP).

Breast cancer is a multifactorial disease with an inherited predisposition being implicated in around 5% of all cases. Using previous epidemiological data assessing risks for the relatives of women with breast cancer, we have identified 154 women (from a screened population of 35,505) and 289 of their relatives between 50 and 64 years who have more than twice the age related risk of developing breast cancer. This constitutes 1.24% of the breast screening population attending the North East Scotland NHSBSP. For each woman identified to be at high risk, we have found 1.87 female relatives between 50 and 64 years and 1.85 relatives under 50 years also to be at high risk. Around 78% of the women identified with a significant family history of breast or other cancer have attended for counselling about their risks. The breast screening programme can be used to identify women at high risk of breast cancer in order to offer them (and their relatives) access to genetic counselling and appropriate screening.

Adenocarcinoma↗
PubMed1994

Impaired glucose tolerance and diabetes mellitus in a suburban Sri Lankan community.

The prevalence of impaired glucose tolerance and diabetes mellitus was studied in a suburban Sri Lankan community using 1985 WHO criteria. Oral 75 g glucose tolerance tests were performed on 633 subjects aged 30-64 years. The age-standardized prevalence rates for diabetes mellitus were 5.02 (95% CI 3.59-6.43) and impaired glucose tolerance 5.27 (95% CI 3.74-6.78). A total of 21% of diabetic patients were not known to have diabetes and were diagnosed for the first time during the survey. Obesity was more common (P < 0.05) in diabetic patients (21%) when compared to non-diabetic subjects (10.5%). Diabetes mellitus is a common health problem in Sri Lanka, and there is a need for developing national policies for its prevention and control.

Adult↗
PubMed1993

Relationship between iron and phosphate in mammalian ferritins.

The core of mammalian ferritin is known to contain varying amounts of phosphate as well as iron. This study examined the variations in phosphate found in ferritins from horse spleen, rat liver, and bovine liver. The amount of phosphate varied inversely with the amount of iron present in the core. Theoretical extrapolation showed that in the absence of phosphate approximately 4400 atoms of iron could be incorporated into ferritin. Reconstitution of ferritin with iron and ceruloplasmin followed by prolonged incubation with phosphate produced cores similar to native ferritin in terms of iron to phosphate ratios and rates of iron release. However, ferritin reconstituted in the presence of phosphate differed markedly from native ferritins. The data suggest that phosphate is an integral part of mammalian ferritin cores and influences both core formation and the ease by which iron is released from ferritin.

Animals↗
PubMed1993

The prevalence of macrovascular disease and lipid abnormalities amongst diabetic patients in Sri Lanka.

The prevalence of macrovascular disease and hyperlipidaemia was examined in 500 patients with non-insulin-dependent diabetes mellitus attending a diabetic clinic in a Sri Lankan teaching hospital and 250 controls matched for age and gender. Macrovascular disease was assessed using a modified World Health Organisation questionnaire and modified Minnesota coding of electrocardiogram recordings. Twenty-one per cent of diabetic patients and 14.3% of controls had hypercholesterolaemia (P < 0.05). Macrovascular disease was present in 13.4% of diabetic patients and 8.2% of controls. Significant differences were seen in the prevalence of hypertension (15.6% vs 4.8%, P < 0.05), obesity (16.2% vs 9.7%, P < 0.05), peripheral vascular disease (5.6% vs 2%, P < 0.05) and electrocardiographic abnormalities (12% vs 6%, P < 0.05) in diabetic patients when compared to controls. Hyperlipidaemia and macrovascular disease is common in non-insulin-dependent diabetic patients in Sri Lanka and accounts for significant morbidity.

Cerebrovascular Disorders↗
PubMed1992

Stoichiometry of Fe(II) oxidation during ceruloplasmin-catalyzed loading of ferritin.

Ceruloplasmin catalyzed the incorporation of iron into apoferritin with a stoichiometry of 3.8 Fe(II)/O2. This value remained the same when ferritin containing varying amounts of iron was used. Contrary to the "crystal growth" model for ferritin formation, no iron incorporation into holoferritin was observed in the absence of ceruloplasmin. Fe(II)/O2 ratios close to 2 were obtained for iron incorporation into apo- and holoferritin in Hepes buffer, in the absence of ceruloplasmin, indicating the formation of reduced oxygen species. Sequential loading of ferritin in this buffer resulted in increasing oxidation of the protein as measured by carbonyl formation. Sequential loading of ferritin using ceruloplasmin did not result in protein oxidation and a maximum of about 2300 atoms of iron were incorporated into rat liver ferritin. This corresponded to the maximum amount of iron found in rat liver ferritin in vivo after injection with iron. These results provide evidence for ceruloplasmin as an effective catalyst for the incorporation of iron into both apo- and holoferritin. The possibility that these findings may have physiological significance is discussed.

Animals↗
PubMed1992

In vitro loading of apoferritin.

This study compared the effect of loading apoferritin either with ferrous ammonium sulfate in various buffers or with ceruloplasmin and chelated ferrous iron. It was shown that loading of apoferritin with ferrous ammonium sulfate was dependent on buffer and pH, and was directly related to the rate of iron autoxidation. The ceruloplasmin-dependent loading of apoferritin, however, was unaffected by these factors. Isoelectric focusing and amino acid analysis of the differently loaded ferritins showed that ferrous ammonium sulfate loading of apoferritin resulted in the depletion of the basic amino acids, lysine and histidine, probably as a result of protein oxidation. No significant differences in amino acid composition was noted for ceruloplasmin-loaded ferritin. Furthermore, ferritin loaded with ferrous ammonium sulfate released more iron than either native or ceruloplasmin-loaded ferritin when either paraquat or EDTA was used as an iron mobilizing agent. We suggest that the loading of apoferritin with ferrous ammonium sulfate occurred as a result of iron autoxidation and may result in oxidation of amino acids and loss of integrity of the protein, and that ceruloplasmin may act as a catalyst for the incorporation of iron into apoferritin in a manner more closely related to that occurring in vivo.

Amino Acids↗
PubMed1990

Rotavirus infection in children hospitalised with diarrhoea in Sri Lanka.

Seasonal and clinical aspects of rotavirus-associated diarrhoea in 98 of the 326 children hospitalised for diarrhoea are described. Rotavirus infection was detected (30% overall) throughout the year from May 1980 to April 1981, but the prevalence was higher during the rainy season (40-50%). The age group in which rotavirus was detected most frequently was from 4 months to 2 years (34.6%). Watery diarrhoea and vomiting were significantly commoner in children with rotavirus diarrhoea (75% and 71% respectively) than those with non-rotavirus diarrhoea (54.2% and 60.8% respectively; p less than 0.05). Although about 15% of the children with rotavirus-associated diarrhoea showed blood or mucus in stools, the invasive nature of rotavirus infection cannot be drawn since the study did not include tests to detect other diarrhoeal pathogens.

Age Factors↗
PubMed1989

2,3,7,8, tetrachlorodibenzo-p-dioxin induces oxygen activation associated with cell respiration.

We have investigated the influence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on bioenergetic functions of isolated heart-mitochondria. Electron transfer and energy conservation activities were found to be decreased in the presence of very low amounts of the polychlorinated biphenyl compound (1.5 nmol/mg mitochondrial protein). The effect was greatest when substrates for complex I were used. In this case coupling of oxidative phosphorylation to respiration was drastically diminished, essentially at the expense of state 3 respiration, and P/O values were found around 2 instead of 3. Succinate-related energy conservation remained practically unaffected in the presence of TCDD, suggesting an interference of the toxic compound at coupling site I. SOD plus catalase were found to protect energy-linked respiration from the effect of dioxin indicating the involvement of superoxide radicals and H2O2 in the development of the observed phenomena. The present contribution provides experimental evidence on the formation of these oxygen species in the presence of TCDD. Furthermore, the site of action of TCDD is demonstrated and discussed in relation to the oxygen radical formation observed.

Animals↗