摘要:

SummaryThe potential cholestatic effect of amino acids and metabolites of tryptophan were evaluated by use of seven daily intraperitoneal injections to suckling and weanling rat pups. Of the amino acids present in parenteral nutrition solutions, only tryptophan (given at a dose of 4 mM/kg) produced a significant (p<0.01) elevation of serum cholylglycine (12.8 ± 1.0 µM/liter) as determined by radioimmunoassay, compared to 4.9 ± 0.4 µM/liter in salinetreated control animals. Total serum conjugates of cholic acid, as determined by radioimmunoassay, were similarly elevated, as was serum alanine aminotransferase. Tryptophan injection resulted in elevated cholylglycine concentrations only at doses of 3 mM/kg/day or higher. Animals more than 2 weeks old did not demonstrate elevation of serum cholylglycine. Injection of light-exposed tryptophan in suckling animals caused a greater elevation of cholylglycine (39.0 ± 8.6 µM/liter) than freshly prepared tryptophan solutions (p<0.005). Tryptophan and its spontaneous degradation products could contribute to the cholestatic liver changes observed during parenteral nutrition therapy.

ISSN:0031-3998    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

SummaryThe effect of prenatal glucocorticoid treatment on levels of immunoreactive 6-ketoprostaglandin F1α(PGF1α) (the stable metabolite of prostacyclin) was studied in fetal rat lungs. During late gestation (20-22 days), levels of 6-keto-PGF1αpeaked at 21 days in offspring of control mothers. At a maternal dose of 0.2 mg/kg dexamethasone, maximal enhancement of fetal 6-keto-PGF1αlevels occurred at 20 days gestation. At a treatment dose of 0.4 mg/kg, however, dexamethasone increased fetal lung 6-keto-PGF1αconcentrations throughout late gestation. Because maturation of fetal lung is known to be delayed in males relative to females, we also studied the impact of sex of the fetus on levels of 6-keto-PGF1α. Our results showed no statistically significant differences between females and males in any of the treatment groups at an of the gestational ages studied. These results suggest that prenatal dexamethasone enhances endogenous levels of 6-keto-PGF1αin fetal rat lungs. Since prostacyclin may play important roles in fetal lung maturation and neonatal lung function, the effectiveness of prenatal glucocorticoid therapy for accelerating functional maturity of the fetal lung may in part be due to stimulation of prostacyclin synthesis.

ISSN:0031-3998    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

SummaryThe concentrations of iron, copper, zinc, calcium, magnesium, sodium, potassium, protein, carbohydrate, and fat were analyzed in milk from rhesus monkeys (Macaca mulatta) during the course of lactation. Concentrations of iron, copper, zinc, magnesium, sodium, potassium, and protein were higher in milk of early lactation (colostrum) than in mature milk, while concentrations of calcium increased with lactation time. Concentrations of zinc in monkey colostrum and mature milk were similar to that of human milk, while iron, copper, calcium, and protein concentrations were higher than in human milk.

ISSN:0031-3998    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

SummaryTotal intracellular Ca2+and45Ca2+uptake has been studied in blood platelets from subjects with Down's syndrome and matched controls. In Down's subjects, Ca2+levels (85.5 ± 5.9 nmol/10-9platelets) were significantly lower than controls, 174 ± 10.0 nmol/10-9(p<0.0005). A similar reduction was seen in calcium uptake (Down's platelets, 0.79 ± 0.06 nmol/10-9platelets; controls, 1.17 ± 0.07 nmol/10-9platelets,p< 0.005). The low levels of intracellular Ca2+may be related to decreased granular storage of serotonin, and the decreased Ca2+uptake with impaired transport by intracellular Ca2+-accumulating organelles such as the dense tubular system.

ISSN:0031-3998    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

SummaryThe objective of the present report is to demonstrate the use of receiver-operator characteristics (ROC) analysis in the selection of diagnostic tests for iron deficiency in a specific population. Conventional ROC curves were prepared with true positive fraction (TPF) and false positive fraction (FPF) determined by the application of different cut-off points for four indicators of iron status. ROC plots were then transformed into normal deviate scales. The advantages of Gaussian transformation of TPF and FPF when underlying decision functions are normally distributed are: (i) the ROC curve is a straight line; and (ii) the separation between the two distributions and shape of these distributions can be simply quantitated as intercepts and slopes. In the present study, pretreatment hemoglobin concentration was the most robust diagnostic indicator of iron deficiency as operationally defined by a response of hemoglobin to iron treatment. Free erythrocyte protoporphyrin was a more sensitive and specific predictor than either serum ferritin or transferin saturation when a stringent operational definition of iron deficiency was used. These findings illustrate the utility of ROC analysis in discriminating between diagnostic indicators having different degrees of accuracy.

ISSN:0031-3998    

出版商:OVID    

年代:1984

数据来源: OVID