摘要:

Water contents of the various body compartments were estimated before and after a 7- to 10-h period of extracorporeal membrane oxygenation in five healthy baboon neonates. Total body water, extracellular water, and plasma volume were estimated simultaneously by antipyrine, bromide, and T-1824 dilution. Volumes of intracellular water, interstitial water, and blood and red cells were calculated from the experimental estimates. Mean preextracorporeal membrane oxygenation estimates of body water volume were in agreement with those previously reported in baboon neonates. During extracorporeal membrane oxygenation, no statistically significant changes occurred in the water content of the various body compartments. This absence of changes was contrasted to the changes demonstrated in human infants and adults undergoing intracardiac surgery with extracorporeal oxygenation and hypothermia and various hypotheses were put forward to explain the different changes observed.

ISSN:0031-3998    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Circulating immune complexes (CIC) have been found to be elevated in individuals with cystic fibrosis (CF). Previous investigators, using a variety of assays, have reported high levels of CIC in as many as 86% of these patients. Our study followed the progress of 25 patients with CF over a period of 10 months to determine which, if any, clinical parameters correlated with the occurrence and/or concentration of CIC. Immune complex determinations were performed using a coprecipitation method with equine rheumatoid-complement complex. One hundred percent of the CF patients had CIC elevated above normal levels, however, levels of CIC did not correlate with the severity of an individual's acute exacerbation. Clinical parameters including pulmonary function tests, vital signs, total serum IgG levels, and other laboratory studies, were obtained on each individual and analyzed with respect to their relationship to CIC. Only four of 38 parameters examined had p<0.05. Factors that showed significant correlation to elevated CIC's in the highly elevated portion of our CIC population were 1) poor NIH score, 2) increased patient age, 3) low peak expiratory flow rate, and 4) elevated total serum IgG. These clinical values are associated more with the measurement of chronic disease. These data suggest that CICs cannot be used as an indication of short-term prognosis or as a monitor to follow the course of acute severe lung infections in the CF patient. Of interest was the observation that all patients who died during the course of the investigation had CIC levels greater than 80 /ng/ml.

ISSN:0031-3998    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

The existence of β-nerve growth factor (βNGF) in mouse cerebral cortical synaptosomal extracts was assessed using a newly developed radioimmunoasay and by bioassay. Displacement curves of labeled βNGF in the radioimmunoassay by synaptosomal extracts were parallel to the βNGF standard curves. In contrast, both mitochondrial and nonsynaptosomal extracts produced displacement curves in the βNGF radioimmunoassay which were nonparallel to standard βNGF. Intraventricular injections of purified βNGF in amounts 5 and 100 ng/mouse (six to 120 times that of whole brain βNGF concentrations) did not alter the endogenous synaptosomal βNGF concentrations. Synaptosomal extracts contained βNGF in relatively higher concentrations than the extracts of whole brain or cerebral cortex. Synaptosomal βNGF levels undergo a developmental change. The βNGF concentrations were highest in synaptosomal extracts of 12-day-old mouse cerebral cortex (the youngest age studied), and levels decreased with increasing age. Synaptosomal extracts of 12-day-old mouse cerebral cortex produced neurite outgrowth in the pheochromocytoma cell line 12 bioassay system and this response was completely inhibited by βNGF antibodies. In the pheochromocytoma cell line 12 cell bioassay, synaptosomal extracts also caused cell-cell aggregation which was unaffected by βNGF antibodies. These results provide evidence for the existence of βNGF in relatively high concentration in nerve terminals of mouse cerebral cortex.

ISSN:0031-3998    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Blood mononuclear cells from newborns and from adults, immune or nonimmune to herpes simplex virus, were cultured with IL 2 and herpes simplex virus and the amount of γ-interferon in the supernatant measured after 3 days. The newborn and nonimmune adult cells made equivalent trace amounts of γ-interferon in cultures containing either herpes simplex virus or IL 2 alone and there was a 5- to 10-fold increase in cultures containing both. Experiments in which the Leu 11+cells were either depleted or enriched suggest that this subset of natural killer cells is both necessary and sufficient for γ-interferon production in the absence of immune T cells.

ISSN:0031-3998    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

The biosynthesis of 5(S), 12(R)-dihydroxy- 6,14-cis-8,10-trans-eicosatetraenoic acid, leukotriene B4, by human polymorphonuclear leukocytes was examined in relation to age. The leukotriene B4production by polymorphonuclear leukocytes from unbilical cords, infants, and adults was assayed using high pressure liquid chromatography. The specificity of the leukotriene B4assay was examined by gas chromatography mass spectrometry. Polymorphonuclear leukocytes from 10 umbilical cords, 24 infants and children, and 10 adults were examined for their ability to synthesize leukotriene B4, in vitro after stimulation by the ionophore A23187 or platelet-activating factor. Among the infants and children, there was a slight agedependent increase of leukotriene B4production by polymorphonuclear leukocytes in response to ionophore A23187, but it was not statistically significant. Leukotriene B4production by polymorphonuclear leukocytes in the umbilical cords and infants was not significantly lower than that of polymorphonuclear leukocytes in adults in response to both ionophore A23187 and platelet-activating factor under our experimental conditions.

ISSN:0031-3998    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Reliable monitoring of arterial blood gas values in the fetal scalp microcirculation requires an unimpaired local skin blood flow. Previous studies have shown that in the fetus blood flow to “nonvital” organs and tissues is reduced during hypoxemia. However, data on fetal scalp blood flow during hypoxemia have not been reported. Therefore, the influence of hypoxemia on scalp blood flow was studied in four chronically catheterized fetal lambs of 125-135 days of gestation. Red blood cell flow in the fetal scalp was continuously measured by the laser Doppler method during nine experiments. Reducing the oxygen saturation of fetal carotid arterial blood from an average control value of 52 to 21% for 20 min resulted in an average decrease of the laser Doppler flow index of 7%.In vitrostudies revealed that more than half of the observed decrease in laser Doppler flow index could be attributed to enhanced absorption of light from the HeNelaser caused by the deoxygenation of oxyhemoglobin itself. In the first 20 min after hypoxia, fetal scalp blood flow remained below the prehypoxic value. It is concluded that moderate hypoxemia causes only a small decrease in fetal scalp blood flow, certainly when compared to the dramatic fall in scalp blood flow that has been observed when local or circular pressure is exerted onto the fetal scalp.

ISSN:0031-3998    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Infantile Refsum's disease is characterized by high levels of phytanic acid and the absence of normal hepatic peroxisomes. We investigated thein vivoinfluence of phytol, a precursor of phytanic acid, on peroxisomes by both biochemical and morphological methods. Enhanced supply of phytol in the diet of adult mice causes proliferation of hepatic peroxisomes. The peroxisomal β-oxidizing capacity as well as exchanges of acyl moieties between peroxisomes and mitochondria are raised around 5- and 2- fold, respectively. In parallel a 1.5-fold increase of total catalase and mitochondrial butyryl-CoA dehydrogenase activities occurs, whereas peroxisomal urate oxidase and glycolate oxidase remain normally active. Serum triglyceride levels are decreased after 3 wk of phytol feeding; serum cholesterol levels remain unaffected. Phytol feeding also induces peroxisome proliferation in duodenal epithelium, in myocardium and in skin sebaceous glands, but not in kidney.

ISSN:0031-3998    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Milk gangliosides inhibitVibrio choleraeenterotoxin andEscherichia coliheat-labile enterotoxin. Human milk gangliosides showed considerably higher enterotoxin- inhibitory activity compared to bovine and formula milk gangliosides as measuredin vitroby enzymelinked immunosorbent assay andin vivoin rabbit small bowel loops. While gangliosides from less than 1 ml human milk inhibited 0.1 ng choleratoxinin vitroandin vivo, five to 10 times higher amounts of bovine milk gangliosides were necessary to achieve similar results. Analysis of the ganglioside composition in human, bovine, and bovine milkbased formula milk showed that the ganglioside patterns in human and bovine milk differed markedly. The ganglioside patterns of bovine milk and formula milk appeared identical. In human or bovine milk, the total amount of gangliosides was 11 mg/liter compared to 6 mg/liter in formula milk. The predominating ganglioside in human milk, monosialoganglioside 3 (74% of total gangliosides), was only a minor component (3%) of bovine milk gangliosides. Disialoganglioside 3 represented 80% of bovine milk gangliosides compared to 25% of the human milk gangliosides. Trace amounts of monosialoganglioside 1 were detected in human, as well as in bovine, milk by a sensitive high performance thin-layer chromatography immunoassay. The monosialoganglioside 1 content in human milk was 10 times higher than in bovine milk. We conclude that the higher nonimmunoglobulin enterotoxin-inhibitory activity in human milk compared to bovine milk is associated with the differences in the ganglioside fraction.

ISSN:0031-3998    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Estimates of average daily energy expenditure and minimal observed oxygen consumption are commonly used to characterize the energy metabolism of neonates. Yet, the errors inherent in these estimates have not been defined. Using measurements of oxygen consumption and carbon dioxide production made in healthy growing low birth weight infants during eight consecutive 3-h interfeeding epochs, we have determined the variability in the mean oxygen consumption, carbon dioxide production, respiratory quotient, total daily energy expenditure, and the minimal observed oxygen consumption among the feeding epochs. The coefficient of variation for oxygen consumption ranged from 3.1 to 9.1%, for minimal observed oxygen consumption from 3.7 to 16.7%, for carbon dioxide production from 3.3 to 7.4%, and for total daily energy expenditure from 2.9 to 7.6%. The SDs for respiratory quotient ranged from 0.008 to 0.066. From these 24-h data we have calculated the error in predicting daily estimates of the mean values for these variables if observations are made for less than 24 h. As expected, this error decreases with increasing duration of observation. These data should prove useful in the design and interpretation of investigations of neonatal energy expenditure.

ISSN:0031-3998    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Since there are limited studies concerning the hemodynamic effects of verapamil in pediatric patients, cardiovascular effects of clinical doses (100 or 300 μ/kg) of verapamil, given as a 2-min intravenous infusion, were examined in sodium pentobarbital anesthetized swine, aged 1 day (n=15) and 2 wk (n=18). Aortic and left ventricular pressures, index of left ventricular contractility, heart rate, and phasic superior mesenteric, renal, and femoral arterial flows were recorded; mean aortic pressure and vascular resistances were calculated. Maximum changes in cardiovascular function (mean %? ± SEM) occurred at the end of the infusion. Mean aortic pressure and index of left ventricular contractility decreased in all animals; responses were larger in magnitude with the higher dose. By 30 min after infusion of 300 μ/kg verapamil had ended, mean aortic pressure in both 1 day and 2 wk olds and index of left ventricular contractility and femoral flow in 1 day olds were still decreased. During infusion of verapamil, heart rate decreased (—11.6 ± 2.9) to the high dose in 1 day olds but increased (+6.4 ± 2.7) to 100 and 300 μ/kg verapamil in 2 wk olds. After infusion of 300 μ/kg verapamil ended, heart rate decreased and reached the nadir (—10.0 ± 2.9) by 10 min in 2 wk olds. Decreases in renal resistance (—7.6 ± 1.7) were not dose dependent while superior mesenteric resistance decreased (—12.9 ± 2.7) only to low dose verapamil in 2 wk olds. In 1 day olds decreases in renal and superior mesenteric resistance were not sustained throughout the infusion. The results indicate that verapamil has both age- and dose-dependent cardiovascular effects in newborn swine and suggest that verapamil be used with caution in infants.

ISSN:0031-3998    

出版商:OVID    

年代:1986

数据来源: OVID