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Biomedical subjects

W W Wells

Publications and source records attributed to W W Wells.

At least 73 records · Page 4Linked to original sources

Selectivity of the 2-deoxyglucose transport system in human and guinea pig polymorphonuclear leukocytes.

To determine whether the deleterious action of D-galactose upon phagocyte function could be related to inhibition of glucose uptake, the properties of glucose transport were investigated by following the incorporation of [G-3H]2-deoxyglucose into human and guinea pig polymorphonuclear leukocytes (PMN). Uptake of [G-3H]2-deoxyglucose by guinea pig PMN proceeded in vitro with a Km of 1.8 mM and Vmax of 0.67 nmol/min per 10(6) cells. This system was competitively inhibited by glucose and mannose but was not significantly affected by galactose, fructose, or 3-0-methylglucose. Maximal uptake of 2-deoxyglucose occurred at 41 degrees C, and phosphorylation was necessary for its intracellular concentration. Transport of 2-deoxyglucose, although not altered by uncouplers of oxidative phosphorylation, was sensitive to inhibitors of glycolysis. Preincubation of cells with 2 mM iodoacetate for 30 min significantly reduced the uptake of 2-deoxyglucose and the intracellular levels of adenosine-5'-triphosphate without decreasing cell viability. These results indicated that uptake of 2-deoxyglucose in guinea pig PMN occurred by facilitated diffusion with subsequent phosphorylation. Similar results were obtained with PMN isolated from human peripheral blood.

Adenosine Triphosphate↗

Inhibitory action of galactose on phagocytes from normal and hypergalactosemic chicks.

The inhibitory effect of galactose on phagocyte function was investigated in normal and hypergalactosemic chicks by monitoring the in vitro killing of Escherichia coli by leukocytes and the in vivo clearance of colloidal 125I-labeled bovine serum albumin ([125I]BSA) from the circulation. Elevated levels of galactose (30 mM) significantly impaired the bactericidal activities of leukocytes from both control and hypergalactosemic chicks. However, the latter cells were more susceptible to the galactose-dependent inhibition. Leukocytes from hypergalactosemic chicks displayed near-normal bactericidal activity when assayed in vitro under simulated normal conditions in the absence of galactose. Mean corrected phagocytic indexes, obtained from data on the clearance of colloidal [125I]BSA, were calculated to be 0.358 and 0.299 for control and hypergalactosemic chicks, respectively. Moreover, increased concentrations of galactose significantly impaired the bactericidal activity of circulating leukocytes but did not significantly affect the phagocytic activity of the reticuoendothelial system.

Animals↗

Properties of a bicarbonate-stimulated ATPase from rat uterus.

Crude subcellular fractions from rat uterus contain a HCO-3 -stimulated Mg2+ -ATPase with properties analogous to those previously reported for the enzyme in gastric mucosa, pancreas, salivary gland and liver lyosome. Estradiol-17 beta treatment of ovariectomized rats resulted in an increase in uterine mitochondrial (HCO-3 +Mg2+)-ATPase and Mg2+ -ATPase activity. In an early response (105 min) to estradiol-17 beta treatment of ovariectomized rats, the lysosomal enzyme, beta-N-acetylglucosaminidase increased in the nuclear and mitochondrial fractions and decreased in the microsomal and supernatant fractions.

Adenosine Triphosphatases↗

myo-Inositol metabolism in the neonatal and developing rat fed a myo-inositol-free diet.

Neonatal rats of the Holtzman strain, 6 days of age, were fed a myo-inositol restricted liquid formula by gastric intubation for 10 days, after which they were fed a purified myo-inositol-free diet until they were 72 days old. No differences in weight gain were observed between myo-inositol/100 ml of formula or 150 mg myo-inositol/100 g diet. Most tissues examined from rats fed the myo-inositol deprived formula and diet had lower free myo-inositol levels than the controls with the exception of the liver. Despite reduced free and lipid-bound myo-inositol in the liver, there was no evidence of fatty liver in the young rats at any age. The cerebrum and cerebellum of myo-inositol deprived rats had normal myelination and mitochondriogenesis as judged by the levels of 2',3'-cyclic nucleotide-3'-phosphohydrolase (EC 3.1.4.1) and fumarase (EC 4.2.1.2) activity, respectively.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗

myo-Inositol metabolism during lactation and development in the rat. The prevention of lactation-induced fatty liver by dietary myo-inositol.

Effects of dietary myo-inositol deprivation were examined during prenatal and postnatal development and during lactation in the rat. The deficient diet contained no detectable myo-inositol while the supplemented diet contained 0.5% (w/w) myo-inositol while the supplemented diet ct contained 0.5% (w/w) myo-inositol at the expense of sucrose. Both diets contained 25% casein, adequate amounts of all known vitamins, choline, and essential fatty acids as well as 0.5% (w/w) phthalylsulfathiazole to depress myo-inositol contribution to the diet by microorganisms. Pregnant rats of the Holtzman strain were fed the respective diets during gestation and lactation, and pups were fed the corresponding diet after weaning until 3 months of age. There were no significant differen-es in body weight between experimental groups. Supplementation of the diet with myo-inositol significanly increased the levels of myo-inositol in plasma, liver, kidney, and intestine of pups at all ages examined, and significantly increased the levels of myo-inositol in the milk and mammary tissue during lactation. During lactation, the myo-inositol deprived dams developed severe fatty livers (31% w/w) characterized by diminished phosphatidyl-inositol (50%) and total phospholipid phosphorus (57%) levels as compared with controls. After weaning, the liver lipid content of the myo-inositol deprived dams returned to normal (4.5%). The data suggest that a possible threshold level of free myo-inositol (approximately 0.15 mumoles/g lipid-free tissue) was required to prevent fatty liver in lactating dams under these dietary conditions. Effects of the deficient diet on fertility were also examined. Based on sperm count and production of offspring, there were no differnences between the experimental and control males. Females of both groups showed equal ability to produce offspring.

Amniotic Fluid↗

Inhibitory action of D-galactose on phagocyte metabolism and function.

To account for enhanced susceptibility to infection among galactosemics, the acute effects of D-galactose on metabolic and functional activities of phagocytic cells in vitro were investigated. Human and guinea pig polymorphonuclear leukocytes (PMN) when incubated in medium containing 30 mM galactose displayed substantially less killing of Escherichia coli than when incubated in medium with 5 mM glucose. Impaired bactericidal activity was dependent upon galactose concentration but could be partially averted by supplementing the galactose-containing medium with 15 mM glucose. Phagocytic activities of guinea pig PMN and peritoneal macrophages were assayed by following ingestion of 32P-labeled E. coli and were also depressed by elevated galactose. Galactose was readily epimerized to glucose by resting PMN, and this conversion was stimulated by phagocytosis. Incubation of macrophages in the presence of galactose resulted in depletion of intracellular levels of adenosine 5' -triphosphate as well as other metabolities.

Adenosine Diphosphate↗

Characterization and tissue distribution of 6-O-beta-D-galactopyranosyl myo-inositol in the rat.

A disaccharide was isolated from rat mammary tissue and determined to be 6-O-beta-galactopyranosyl myo-inositol (6-beta-galactinol) on the basis of combined gas-liquid chromatography-mass spectrometry of the permethylated and peracetylated derivatives as well as previously reported chemical and enzymatic evidence. 6-beta-Galactinol, also found in rat milk, increased during lactation, and on the 18th day represented approximately 17% of the total non-lipid neutral myo-inositol. The sugar was absent in all other rat tissues examined, suggesting a unique association with the process of lactation. This novel galactoside of one human subject on the basis of paper and gas-liquid chromatography.

Animals↗