Search PubMed⌕ Search

Biomedical subjects

D Shapcott

Publications and source records attributed to D Shapcott.

At least 19 recordsLinked to original sources
PubMed1995

Accumulation of manganese and copper in pallidum of cirrhotic patients: role in the pathogenesis of hepatic encephalopathy?

Concentrations of zinc, copper and manganese were measured by atomic absorption spectrometry in samples of globus pallidus obtained at autopsy from 9 patients with chronic liver disease and an equal number of age-matched controls. Manganese concentrations were significantly increased several fold (p < 0.01) in globus pallidus of liver disease patients accompanied by smaller but significant 2-fold increases of copper. Zinc concentrations, on the other hand, were within normal limits. Increased pallidal manganese offers a cogent explanation for the observed T1-weighted MRI signal hyperintensity in pallidum of cirrhotic patients. Increased copper content in brain suggests the existence of common pathophysiologic mechanisms in inherited (Wilson Disease) and acquired hepatocerebral disorders.

Aged↗
PubMed1992

Graphic summaries of expert knowledge for the medical curriculum: an experiment in second-year nephrology.

This study was conducted to test the effects of Concept Graphics on learning in clinical nephrology. Second-year medical students were exposed to summaries of the major renal pathologies presented as text with, or without Concept Graphics for 30 minutes, followed by a quiz. Concept Graphics summarize diagnoses using icons that are metaphors of objects or processes. Of nine quiz questions, five were classified as correlation questions and four as memorization questions. The experimental group (n = 39) performed better than the controls (n = 33) in answering the correlation questions (p = 0.018). The experimental group mentioned more frequently than the controls two pathogonomic criteria of the nephritic syndrome (p = 0.02). Results of an opinion poll of the students, comparing sources used in their studies of nephrology were treated by correspondence analysis; the Concept Graphics ranked closest to the classification "very useful".

Computer Graphics↗
PubMed1988

Newborn urine screening experience with over one million infants in the Quebec Network of Genetic Medicine.

We screened urine for chemical individuality in over 1 million newborn infants, by various chromatographic (thin-layer), chemical and spectrophotometric methods, 12 procedures in all. The programme is part of the Quebec Network of Genetic Medicine. Voluntary urine screening began in 1971 and has evolved with changes in choice of tests and times of sample collection. Urine samples were collected on filter paper at either 5, 14 or 21 days after birth; results were best with the 21-day test. Compliance is over 94% with the latter and over 98% with requests for repeat samples. Screening is centralized in one laboratory; follow-up diagnosis, counselling and management are done at four regional centres. Incidence of phenotypes ranged from 1:4300 live births (for expressed cystinuria alleles) to 1 per million (for hyperargininaemia). Over 20 inherited Mendelian disorders were identified. 30 patients required aggressive medical management. We show how this programme can be used for neuroblastoma screening.

Chromatography, Thin Layer↗
PubMed1985

The vitamin status of infants in a free living population.

In infancy an adequate intake of vitamins, either from natural sources or as supplements, is of the utmost importance. The vitamin status of 325 infants was studied with regard to their food intake, vitamin supplementation and health from birth to the third birthday. Only data on vitamins A, C, E and folic acid are presented here. The proportion of bottle-fed infants having a serum level of vitamin C less than 0.30 mg/dl was 4.0 times (P less than 0.002), and of vitamin E less than 0.35 mg/dl was 2.2 times (P less than 0.05) higher than that of breast-fed infants. The proportion of infants with folate level less than 6.0 ng/ml was identical in both groups. No infant was observed with a vitamin A serum level less than 40 mcg/dl. The daily food intake of vitamin C less than 80% of RNI was found n 40% of infants at 6 months, in 10% at 12, and in none at 18 months and afterwards. Vitamin A followed a similar trend. 95% of infants had vitamin E and 75% had folate intake less than 80% RNI. Obviously the mean serum levels of vitamins A and C were significantly higher in supplemented infants at 6, 12, 18 and 30 months than in those without supplements. Health indicators, measured by number of self-reported illness related symptoms, differed according to supplementation. These findings indicated that, even if optimal food intake could supply the recommended quantity of vitamins, the risk of marginal deficiency always remained higher in infants without supplementation.

Age Factors↗
PubMed1984

Studies on the role of taurine in Friedreich's ataxia.

New studies were undertaken to verify the previous findings of increased urinary excretion of taurine, in the basal state and after challenge with a taurine load, in Friedreich's disease. Particular attention was paid to possible causes of error such as weight, muscle mass, creatine and creatinine excretion, variability with time and appropriate control groups. Although the overall findings were confirmed, their interpretation is open to question because of all these factors of error. Many possibilities must still be further explored to account for the apparent taurine retention defect observed in many cases of Friedreich's disease.

Adolescent↗
PubMed1984

Zinc and taurine in Friedreich's ataxia.

Zinc and taurine were measured in urine in the fasting state and following a 4mg/kg load of taurine in subjects with Friedreich's Ataxia (FA), and healthy controls (C), and subjects with Duchenne type muscular dystrophy (MD). Of the FA, 25% had increased fasting excretion of zinc, and 50% had increased excretion of zinc following the taurine load. The MD subjects all had increased zinc excretion at all times. The increased zinc excretion did not correlate with increased excretion of taurine. As an index of zinc deficiency, uptake of zinc by erythrocytes was measured in all subjects and in heterozygotes for FA. The pattern of uptake was abnormal for FA and heterozygotes. Hair analysis for zinc showed that 10 of the 12 FA subjects had low values. We conclude that significant abnormalities in zinc metabolism exist in some, but not all cases of FA. The evidence available does not permit definition of the cause of these abnormalities, whether zinc deficiency or abnormal zinc transport is the primary factor.

Child↗
PubMed1984

Influence of exercise training on tissue chromium concentrations in the rat.

This study reports on the effects of exercise training on the chromium concentrations in the heart, liver, kidney, and gastrocnemius muscle of normal Sprague-Dawley rats. A pair-fed (to the trained rats' intake) and a preexperimental group were also studied in order to control food intake and to ascertain any age-related influence on tissue chromium levels, respectively. Four groups of animals were examined: exercise-trained, pair-fed, preexperimental, and sedentary control. Chromium determination was performed by flameless atomic absorption spectrophotometry. The results from this study show that exercise training increases while pair-feeding and normal aging both decrease chromium levels in tissues. It is suggested that the male Sprague-Dawley rat adapts to exercise training by enhancing tissue levels of chromium or by simply maintaining the high levels of the element found at a younger age.

Aging↗
PubMed1983

Nutrient intake patterns and nutritional status with regard to relative weight in early infancy.

To examine whether or not obesity in later life is related to feeding practice in early infancy, daily nutrient intake was studied in relation to relative weight in a cohort of 170 healthy infants from birth to 3 yr of age. Dietary records were made monthly for the first 6 months and at 3-monthly intervals thereafter, always covering the week preceding anthropometric measurements. The frequency distribution of relative weight varied according to age and sex; the infants did not remain in the same relative weight group during the observed period. When comparing the relative weight at 6 and 36 months, the coefficients of correlation were rather weak for both sexes (r = 0.33 and 0.35). There were no significant differences in the history of breast-feeding according to relative weight. The mean energy intake per kg of body weight was always lower in infants with relative weight above 105% of expected weight and fats and carbohydrates were consumed less in the same group. There were no differences in protein intake according to relative weight, although this intake was always higher than the recommended nutrient intake. Daily intake of zinc was comparable in all weight groups. Results indicate that the infants with above-average relative weights did not consume greater quantities of principal nutrients. The results, therefore, do not support the hypothesis that implicates overfeeding in early infancy as a major cause of obesity in later life.

Aging↗
PubMed1983

Maternal cigarette smoking and fetal oxygen transport: a study of P50, 2,3-diphosphoglycerate, total hemoglobin, hematocrit, and type F hemoglobin in fetal blood.

The current study was undertaken to determine whether the O2 carrying capacity of newborns born to mothers who smoke can accommodate to carbon monoxide poisoning to compensate for the potential tissue hypoxia induced by CO. From a cohort of 1,222 women and newborn infants the total hemogloblin concentration, hematocrit, and carboxyhemoglobin (HbCO) were measured and analyzed with regard to the maternal HbCO level and the number of cigarettes smoked per day. Also, for 100 pairs of mothers, of whom 50 were smokers and 50 nonsmokers, and their newborns, measurements were made of the intraerythrocyte concentration of 2,3-diphosphoglycerate (2,3-DPG), the hemoglobin concentration, and the affinity of hemoglobin for oxygen by determination of O2 tension for 50% of Hb-O2 saturation (P50). The results showed no significant relationship between smoking habits of mothers and their levels of hemoglobin, P50, and 2,3-DPG; only the hematocrit was slightly increased in smoking mothers. However, in fetal blood a significant correlation was found between the number of cigarettes smoked per day and levels of hemoglobin, hematocrit, and P50. The P50 decreased in relationship to the increase in maternal HbCO. The P50 change was brought about by an increase in hemoglobin F found in the fetuses of mothers who smoked. Although all these changes were statistically significant, these mechanisms of acclimatization to CO poisoning appeared trivial in magnitude. It is concluded that the human fetus does not have a biologic capacity to accommodate to maternal cigarette smoking, and therefore the fetus is particularly susceptible to the adverse effects of cigarette smoking.

2,3-Diphosphoglycerate↗
PubMed1982

Biochemical indices of nutritional status in maternal, cord, and early neonatal blood.

The nutritional status of 556 infants born in good health was measured by selected biochemical parameters in maternal venous blood, in mixed arteriovenous cord blood at delivery, and in infant's capillary blood collected at 5 days. The determinations indicating nutritional status were: Hb, hematocrit, protein, cholesterol, triglycerides, vitamins A, C, E, and folic acid, iron, calcium and magnesium. In maternal venous blood, a significant number of women were found to be deficient; 3.4% had Hb below 9.5 g/dl; 6.1% had hematocrit less than 30%; 4.0% had total protein below 5.5 g/dl; 7.0% had vitamin C below 0.20 mg/dl; 3.0% were deficient in iron (less than 40 microgram/dl), 3.6% in folic acid (less than 2.0 ng/ml) and 5.2% in calcium (less than 7.5 mg/dl). Significant correlations were more frequent between maternal and cord blood than in other comparisons. An influence of parity and maternal age was more evident for vitamin C in cord blood than in maternal venous blood. Iron in maternal and cord blood decreased in relation to parity.

Adolescent↗
PubMed1980

Hair chromium at delivery in relation to age and number of pregnancies.

To test the hypothesis that chromium deficiency may be cumulative with age and increasing parity, hair chromium levels were measured in 432 women at delivery. Although the levels in general were lower than those found in nonpregnant women there was no correlation between hair chromium level and age or number of pregnancies. Hair zinc levels were also measured to rule out zinc deficiency as a factor.

Aging↗