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Biomedical subjects

G D Barr

Publications and source records attributed to G D Barr.

35 records · Page 2Linked to original sources

Alcohol and the liver. 3. Laboratory aids in the detection of alcohol abuse.

Alcohol abuse is often difficult to diagnose in the early stages in the absence of physical manifestations and where patients are unaware of their alcohol dependence. Many minimise the amount they consume and alcoholism frequently remains undetected even among patients admitted to hospital. This article reviews the metabolic basis of the common biochemical derangements due to alcohol, with particular emphasis on relevant laboratory tests which are available to practising physicians.

Alcoholism↗

Possible ranitidine hepatitis.

A 63-year-old woman developed anicteric hepatitis after two weeks of therapy with ranitidine. Despite continuation of therapy, her symptoms resolved within five days and transaminase levels returned to normal in the next four weeks, at which time use of the drug ceased. The gamma-glutamyl transpeptidase level returned to normal two weeks later. Although liver biopsy and drug rechallenge were not performed, no other cause for the reaction could be found.

Chemical and Drug Induced Liver Injury↗

Temporal changes in medial basal hypothalamic LH-RH correlated with plasma LH during the rat estrous cycle and following electrochemical stimulation of the medial preoptic area in pentobarbital-treated proestrous rats.

In the present studies we have simultaneously measured changes in medial basal hypothalamic (MBH) leutenizing hormone-releasing hormone (LH-RH) and in plasma LH by radioimmunoassay in female rats at various hours during the 4-day estrous cycle and under experimental conditions known to alter pituitary LH secretion. In groups of rats decapitated at 12.00 h and 15.00 h on estrus and diestrus, plasma LH remained at basal levels (5-8 ng/ml) and MBH-LH-RH concentrations showed average steady state concentrations of 2231 +/- 205 pg/mg. On the day of proestrus hourly measurements of MBH-LH-RH between 12.00 h and 21.00 h suggested rhythmic rises and falls in the decapeptide concomitant with rises and falls in plasma LH. In a second group of pentobarbital-anesthetized proestrous rats a significant decline in MBH-LH-RH occurred (to 573 +/- 137 pg/mg) which then remained at low concentrations between 14.00 h and 18.00 h proestrus. Following bilateral preoptic area (MPOA) electrochemical stimulation of pentobarbital-treated proestrous rats, LH was significantly increased by 30 min, peaked between 90-120 min and returned to basal levels by 210 min poststimulation. In the same animals within 15 min poststimulation, MBH-LH-RH increased from the basal concentrations noted after pentobarbital anesthesia to elevated levels comparable to those observed throughout estrus, diestrus and on proestrous morning. Further, as plasma LH rose to peak concentrations and declined to basal plasma values, rhythmic rises and falls in MBH-LH-RH were observed with intervals between pulses of approximately 60 min. Seemingly, hypothalamic LH-RH is released as pulsatile pulses from a releasable pool; this pool is replenished and again LH-RH is discharged in response to constant stimulation by the preoptic brain.

Animals↗

Hemoglobin concentration in white, black, and Oriental children: is there a need for separate criteria in screening for anemia?

The concentration of hemoglobin in blacks was found to be 0.5 to 1.0 g/dl lower than that of income-matched whites in several large surveys. This difference could be a racial characteristic of blacks, or it might be due to a higher frequency of genetic traits such as thalassemia minor and hemoglobinopathies, or to environmental factors such as iron deficiency. To help in making this distinction, we analyzed the data from multiphasic examinations (1973 to 1975) on 1718 white, 741 black, and 315 Oriental healthy, nonindigent children between 5 and 14 years of age. In the entire population, the median hemoglobin concentration averaged 0.5 g/dl lower in blacks than in whites of both sexes (t test, P less than 0.001). The differences still averaged 0.5 g/dl (P less than 0.001) after exclusion of all those with abnormal hemoglobin by electrophoresis (Hgb S and C) and those whose mean corpuscular volume was more than 5% below the normal mean for age (to exclude iron deficiency or thalassemia minor). The data strengthen the impression that blacks normally have a concentration of hemoglobin averaging about 0.5 g/dl less than in whites. If this is the case, about 10% of normal blacks will be mistakenly designated anemic, if the same norms are applied.

Adolescent↗

Effect of nutritional supplementation in pregnancy. I. Outcome of pregnancy.

Women judged to be at high risk of delivering low-birth-weight infants were assigned to one of three supplements--high-protein beverage, low-protein beverage, or a vitamin-mineral preparation--to determine the effect these nutritional supplements would have on the outcome of pregnancy. In comparing prenatal nutrient intake and the birth weight of their infants, no significant associations were found. However, since the women were well nourished and since the sample size was small, changes in birth weight may have gone undetected. Nevertheless, a trend of increased birth weight with higher protein intake was observed.

Adolescent↗

Effect of nutritional supplementation in pregnancy. II. Effect on diet.

Women judged to be at high risk of delivering low-birth-weight infants were assigned to one of three supplements--high-protein beverage, low-protein beverage, or a vitamin-mineral preparation--to determine: (a) The acceptability of a liquid dietary supplement to pregnant women. (b) The effect of the dietary supplement on diets normally eaten by pregnant women. Acceptance of the high-protein beverage by the women in this study was low. Fifty per cent of the dropouts indicated a dislike for the beverage because of either poor flavor or an inability to tolerate it. The women generally consumed "adequate" diets, although there were variations. Increases in intakes of calories and protein in Group 1 were statistically significant, suggesting the high-protein beverage served as a supplement for both calories and protein; that is, these nutrients were added to the women's existing intake. For the low-protein beverage women (Group 2), statistics revealed the beverage was used as a substitute.

Diet↗

Well-child care by pediatric nurse practitioners in a large group practice. A controlled study in 1,152 preschool children.

A controlled two-year study of the effectiveness of well-child care by pediatric nurse practitioners (PNPs) of 1,152 children, newborns through age 22 months, was made at the Kaiser-Peranente Medical Centers in San Francisco and Oakland, Calif. In this setting of a large, prepaid, group practice health care plan, the PNPs were found to be entirely competent in maintaining the health of their patients, and were generally accepted by the parents. Effects on utilization of medical care facilities were minimal. Costs of well-child care were reduced.

California↗

Standardization of tissue culture conditions for spontaneous thymidine-2-14C incorporation by unstimulated normal human peripheral lymphocytes: circadian rhythm of DNA synthesis.

The rate of DNA synthesis by human lymphocytes was studied in vitro by measuring unstimulated thymidine-2-14C incorporation (spontaneous lymphocyte blastogenesis; SLB). Freezing lymphocytes and extracting DNA after thawing did not alter the radioactive label count rate and was as efficient as extracting DNA immediately after culture. Omission of fetal calf serum also did not alter the rate of DNA synthesis. Standards established as optimal for studies of SLB were: cell concentration, 1.0 times 10(6)/ml/tube; 14C-TdR concentration, 0.4 mjCi/tube; duration of incubation, 8 hr. In sets of identical samples obtained by specimen division, the variation in counts was 6%. To achieve reproducibility of results; it was essential to count the lymphocytes, and then to ensure that each tube contained almost precisely known numbers of cells. Diurnal variations in the rate of DNA synthesis by circulating lymphocytes of healthy men were measured in vitro by SLB at 2-hr intervals for 24 hr. Leukocyte counts, hematocrit, hemoglobin, plasma cortisol, and body temperature were monitored concurrently. The DNA synthesis rate varied in a 24-hr cycle with peaks at 10 A.M. and 11:00 P.M.., depressions at 4 A.M. and 4 P.M. The rate was correlated with body temperature and hematocrit level, and inversely related to the absolute eosinophil count.

Adult↗