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Biomedical subjects

H Baker

Publications and source records attributed to H Baker.

At least 253 records · Page 14Linked to original sources
PubMed1978

Assay for free and total choline activity in biological fluids and tissues of rats and man with Torulopsis pintolopessi.

The sensitive, specific growth response to choline activity of the thermophilic enteric yeast Torulopsis pintolopessi enables estimation of free and bound choline activity in rat and human fluids and tissues- as little as 10 ng/ml of choline is measurable. Unlike other microbial assays, estimation of unbound (free) choline activity is not influenced by methionine or phospholipids. The method also distinguishes differences in choline activity of fluids and tissues from choline-deficient and choline-replete rats. Free and bound choline activity in blood, red blood cells, plasma, and liver from choline-deficient rats were almost 2-fold lower than from choline-supplemented animals. Free and bound choline activity in whole brain from choline-deficient rats were signifigantly higher (more than 2-fold). The application of the T. pintolopessi method in studying choline status in man and reasons for high choline activity in brain of choline-deficient rats are suggested.

Adult↗
PubMed1978

Severe impairment of dietary folate utilization in the elderly.

Absorption of folates, vitamin B6, pantothenate, and riboflavin from a natural food source (yeast) and from synthetic folylmonoglutamate was studied in 24 elderly subjects (age range, 73 to 101 years) and in 12 healthy younger subjects (age range, 24 to 42 years). All subjects absorbed riboflavin, vitamin B6, and pantothenate from yeast. Ingested folypolyglutamates (the preponderant folates in yeast) proved to be a very poor source of folates for the elderly subjects, whereas synthetic folylmonoglutamate served as a good source. In the younger subjects, yeast was a significant folate source. It is suggested that the folate deficits so common in the elderly are caused by impaired ability to obtain folate from ingested foods. The resultant folate deficit may induce changes in the epithelial structure and enzyme secretion of the small bowel, which may further exacerbate folate malabsorption.

Adult↗
PubMed1978

School phobia: classification and treatment.

Ninety-nine cases of school phobia seen at a child guidance clinic over a period of twelve years were divided into acute and chronic groups and investigated in several ways. The results indicate that the children of both groups are more likely to be the eldest or youngest in the family. Acute school phobia is more likely to occur in youngest children with two or fewer siblings, and mothers tend to be older. It is most common in adolescence and seems often to be precipitated by stress. Chronic school phobia is likely to occur in a child from a larger family and with a younger mother. It is more common in social class V and in children of mentally ill parents. Implications for treatment are discussed.

Acute Disease↗
PubMed1978

Rapamycin (AY-22,989), a new antifungal antibiotic. III. In vitro and in vivo evaluation.

The activity of rapamycin, a new anti-Candida antibiotic, was not affected by pH values between 6 and 8; at pH 4, however, activity was abolished. The MIC of rapamycin did not vary drastically with the size of inoculum: a ten-fold dilution of the inoculum reduced the MIC only two-fold. Serum binding was extensive. Serum levels obtained in mice were higher on subcutaneous injection than with oral administration. Dogs absorbed rapamycin after oral administration. Rapamycin cured systemic candidosis in mice: PD50 s.c. was 9.5 mg/kg: PD50 p.o. was 11 mg/kg. In the same experimental infections amphotericin B and nystatin exhibited PD50 values of less than 0.25 mg and greater than 4,000 units/kg respectively. Rapamycin and amphotericin B, administered at 1, 4 and 24 hours after infection, gave approximately the same percent survival after 30 days of observation. When the above treatment was extended by an additional daily treatment for 6 days, rapamycin by the subcutaneous route yielded a higher percentage of survival than either rapamycin or amphotericin B, administered orally, after a 30-day observation period. Vaginal candidosis in female rats was treated efficiently (91% cure) by rapamycin administered orally. No increase of resistance of C. albicans was observed during treatment.

Amphotericin B↗
PubMed1978

Biopterin content of human neuroblastoma cells in culture.

The biopterin (Crithidia activity) content of several cell lines of human neuroblastoma was quantified. Adrenergic cell lines contained markedly higher levels than those found in cholinergic neuroblastoma cells, fibroblast-like cells and glioblastoma cells in culture.

Biopterins↗
PubMed1977

Vitamin levels in low-birth-weight newborn infants and their mothers.

The cord blood of 50 normal-birth-weight neonates (more than 2,500 grams) and 50 low-birth-weight neonates (less than 2,500 grams) and the respective mother's blood were analyzed for folate, vitamin B6, riboflavin, nicotinate, pantothenate, thiamin, biotin, vitamin B12, vitamin A, and beta-carotene concentrations at parturition. No mothers had received supplemental vitamin intake. Except for vitamin A and beta-carotene, maternal vitamin levels were lower than those of neonates in all instances. Vitamin levels in the blood of low-birth-weight neonates were the same of those of normal-birth-weight infants except for significantly lower folate, vitamin B12, and pantothenate levels.

Biotin↗
PubMed1977

The cell content and secretion of water-soluble vitamins by several freshwater algae.

Three green algae, Chlamydomonas reinhardii, Chlorella vulgaris and Scenedesmus obliquus, and one blue-green alga, Anabaena cyclindrica, were grown in chemically defined media. All the algae examined contained folates, beta-carotene and vitamins C and E; several of the B-vitamins and vitamin A were found in varying amounts in some but not in all the algae examined. All the green algae secreted significant amounts of folate and biotin and all but Scenedesmus secreted pantothenate into their growth medium; Anabaena secreted folate and pantothenate.

Chlorophyta↗
PubMed1976

Potentiation of ethanol fatty liver in rats by chronic administration of nicotinic acid.

Two groups of rats were fed isocalorically on alcohol and control semi-liquid diet for 28 days; two other groups had the same diets except for supplementation with nicotinic acid at 50 mg/100 ml of diet, Blood ethanol levels were unaffected by nicotinic acid administration, even though nicotinic acid was well absorbed and stored in the liver. Lipid analyses of liver and plasma after 28 days revealed that nicotinic acid, per se, stimulated fatty infiltration of the liver and this effect was potentiated when given in conjunction with ethanol.

Animals↗
PubMed1976

Effects of a single intoxicating dose of ethanol on the vitamin profile of organelles in rat liver and brain.

The effects of a single, oral, intoxicating dose of ethanol (EtOH, 9 g/kg body weight) on the distribution of water- and fat-soluble vitamins in various subcellular fractions of eight rat livers and eight rat brains was surveyed. Results were compared to eight other rats receiving a similar dose of saline (controls). Both organs showed redistribution of vitamins among the various organelles after EtOH was given. In saline-treated animals the nucleus and cytosol of the liver contained the highest proportion of all vitamins and the microsomes and lysosomes contained the least. As compared to controls, EtHO ingestion generally caused the mitochondria and microsomes to accumulate vitamins, while vitamins in the lysosomes were decreased. A different pattern was seen in the brain after EtOH administration. Except for thiamin and niacin, the whole brain vitamins were higher than those in controls; they were primarily concentrated in the brain nucleus and mitochondria. It was concluded that changes in the organelle vitamin content of the liver were the result of EtOH injury. The simultaneous attempt to repair the injury was manifested by the by the sequestration of vitamins in the organelles of EtOH-treated animals as compared to controls.

Alcoholic Intoxication↗