摘要:

There is accumulating evidence that in adult men excessive amounts of gonadotropins induce testicular desensitization to further gonadotropin stimulus. We evaluted the effects of endogenous gonadotropins and of repeated doses of exogenous human chorionic gonadotropin (hCG) on steroidogensis by studying prepubertal and prepubertal boys. The boys received either two intramuscular injections of hCG 4 days apart (protocol I) or four injections at 3- to 4-day-intervals (protocol II). In protocol I, serum testosterone, 17α-hydroxyprogesterone, and estradiol were measured basally and for 6 days after the second injections, and in protocol II, before each injection and 4 days after the last injection. In the prepubertal boys, serum testoterone increased from very low basal levels to 10.3 (protocol I) and 8.3 nmol/liter (protocol II). In protocol I the increase after the first injection was 64-fold and in protocol II there was an increase after each injection to a final level 144-fold of the basal. No significant changes were seen in the estradiol levels. In the pubertal boys at genital stage G2, the serum testosterone levels increased after the first two injections, but at genital stage G3, the levels increased only after the first injection. Maximal testoterone increases were 27- and 8-fold, respectively. In pubertal boys estradiol levels inncreased progressively throughout the stimulation. The major testosterone response was after the first does of hCG and repeated doses, at least in the pubertal boys, increased estradiol but not testosterone levels, thus causing an estrogen-mediated 17,20-lyase block. We there fore suggest that a single-dose hCG test deserves further evalution for diagnostic use.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The present study was designed to investigate the role of noradrenaline (NA), dopamine (DA), and serotonin (5-HT) in the adaptation of premature infants to alterations of sodium balance. Urinary excretion of NA, DA, and 5-HT was measured spectrofluorimetrically in a group of low birth weight premature infants with (group S) and without (group NS) NaCl supplementation. Group S consisted of 10 infants with a birth weight of 1200-1750 g (mean, 1493 g) and gestational age of 28–31 wk (mean, 30.1 wk). Group S included 10 infants with mean birth weight of 1414 g (range, 1150–1600 g) and mean gestational age of 30.5 wk (range, 27–32 wk). Measurements were made on the 7th day and weekly thereafter until the 5th wk of life. NaCl supplementation was given in a dose of 3–5 and 1.5–2.5 mEq/kg/day for 8–21 and 22–35 days, respectively.In group NS, mean urinary excretion of NA and DA increased from 8.6 ± 1 . 5 and 15.8 ± 2.4 µg/day to maximum values of 21.4 ± 5.5 (p<0.05) and 33.4 ± 6.0 µg/day (p<0.01) in weeks 2–3, respectively. 5-HT excretion averaged about 60 µg/day and showed no consistent change during the course of the study.NaCl supplementation prevented the rise of NA and DA excretion above the initial baseline values. The postnatal course of 5-HT excretion, however, remained unaffected by NaCl supplementation. Urinary excretion of NA in weeks 2–3 (p<0.05) and DA in weeks 2–4 (p<0.05) were significantly lower in group NS.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Type I procollagen concentrations were measured by radioimmunoassay in sera from 14 growth hormone-deficient children before and during 12 months of treatment with human growth hormone. Basal procollagen levels were lower than those of control children and comparable to those of normal adults. With treatment, the mean procollagen level increased into the range of the control children and was significantly greater than the baseline level at 1, 2, 3*, and 12 months (p<0.01; *p<0.05). Although there was no significant statistical correlation between the growth velocity during treatment and the serum procollagen level, there was a suggestion that a high basal procollagen may be predictive of a less than optimal response to human growth hormone.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Lung weight, DNA, RNA, protein, and total body weight were analyzed in fetuses from 14 pregnant Sprague-Dawley rats fed a nutritionally complete liquid diet containing v/v 6% ethanol (ethanol group). Each ethanol rat was matched with an isocalorically pair-fed animal (control group) who received the same liquid diet with carbohydrate substituted for ethanol. The rats were killed on day 20 of gestation. The mean maternal blood ethanol concentration at 0700 h on day 20 was 170 ± 22 (SE) mg/dl. Compared to controls, ethanol fetuses had reduced body weight (21%), lung dry weight (39%), lung wet weight/body weight ratio (10%), DNA (21%), RNA (25%), protein (28%), and protein/DNA ratio (8%) (p<0.05). The results indicate that prenatal ethanol exposure inhibits cellular growth in the fetal lung, resulting in hypoplastic lungs which have fewer and smaller cells. The effect on the lung appears to be greater than on the body as a whole. These hypoplastic lungs may be predisposed to the development of pulmonary disease and may explain observations of more frequent and severe lower respiratory infections in children with prenatal ethanol exposure.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Vasodilators are used in newborns under conditions where hypoxia may be prominent. To study the effects of vasodilator therapy on organ oxygen delivery we measured blood flow (using radioactive microspheres) and arterial oxygen content in six chronically catheterized newborn lambs. Cardiac output and its distribution were measured during normoxia, hypoxia (10% O2and 5% CO2), and hypoxia with a nitroprusside infusion. Hypoxia decreased oxygen content but did not change heart rate, mean blood pressure, or cardiac output. When nitroprusside was infused during hypoxemia, oxygen content and heart rate were not affected, but mean arterial blood pressure fell (39% decrease). During hypoxemia, blood flow increased to the heart, brain, and carcass but decreased to the gastrointestinal tract. When nitroprusside was infused during hypoxemia, blood flow decreased to the heart, brain, kidneys, and carcass. Oxygen delivery (arterial O2content X blood flow) decreased to the brain as well as to kidneys, stomach, and carcass when nitroprusside was given to the hypoxemic lamb.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Five enzymes were measured in 50 liver specimens (18 normal liver, 20 Reye liver, 12 diverse liver disorders other than Reye syndrome). The enzymes were: glutamic dehydrogenase (E.C. 1.4.1.3), monoamine oxidase (E.C. 1.4.3.4), lactate dehydrogenase (E.C. 1.1.1.27), DgIucose- 6-phosphate dehydrogenase (E.C. 1.1.1.49), catalase (E.C. 1.11.1.6). The Reye syndrome group showed significant decreases in glutamic dehydrogenase (56%) and monoamine oxidase (70%) compared to normal control tissue and these changes were not characteristic of the non-Reye liver disorder group as a whole. Neither catalase nor lactate dehydrogenase appeared to be altered significantly in the Reye or in the abnormal control group compared with normal controls. Thus, only the prominent decreases in the mitochondrial enzyme activities appeared to be highly characteristic of Reye syndrome. Paradoxically, the means of the five hepatic enzymes and the admission levels of two serum enzymes indicative of liver damage (alanine and aspartate aminotransferase) were remarkably similar for both survivors and nonsurvivors of Reye syndrome.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The nature of the lipases released into the circulation during low level continuous infusion of heparin (1 unit/ml total parenteral nutrition) and after bolus heparin injection (10 units/kg) was investigated in a group of 11 low birth weight infants (gestational age 27–34 wk, and postnatal age of 7–26 days) receiving total parenteral nutrition with Intralipid (0.5 g/kg). Hepatic lipase and extrahepatic lipoprotein lipase were differentiated with the aid of an antibody specific for human hepatic lipase. The data show that continuous low level heparin infusion leads to a constant baseline postheparin lipolytic activity of 0.77 ± 0.18 µmol free fatty acids released per milliliter serum per hour. Bolus heparin injection leads to peak lipolytic activity levels of 3.77 ± 0.46 µmol free fatty acids per milliliter serum per hour, 10 min after injection. About two-thirds of the total postheparin lipolytic activity was of the hepatic type during low level continuous infusion or after bolus injection of heparin.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Serum diamine oxidase (DAO) activities were measured in 20 control patients and in 24 patients with gastroenteritis. Results (mean ± SE) were as follows: 1) control patients (n=20), 36.2 ± 5.7 pmol h-1ml-1; 2) gastroenteritis (acute phase) (n=11), 31 ± 4.9 pmol h-1ml-1; 3) gastroenteritis (healing phase) (n=21), 18 ± 1.9 pmol h-1ml-1. Patients with gastroenteritis in the healing phase had significantly lower DAO values when compared to control patients (p<0.001) and to gastroenteritis patients in the acute phase (p<0.05). In eight patients where both acute and healing phase values could be measured, a significant decrease between acute and healing phase was found (p<0.001). Patients with severe gastroenteritis tended to have lower DAO activity values than patients with moderate gastroenteritis (p=0.10). Our results support the hypothesis that serum DAO activity is a marker of the total mass of functional enterocytes, the decrease of which during gastroenteritis is reflected in a decrease of serum DAO activity values.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

In two patients assay of α-l,6-amyloglucosidase activity by incorporation of [l4C]glucose into glycogen revealed normal activity in leukocytes, erythrocytes, and fibroblasts, whereas no activity was detected in liver and muscle. No activity in any tissue was found when enzyme activity was assayed by following the release of glucose from a phosphorylase limit dextrin. Labeling of glycogen by incubation with crude tissue homogenates according to the protocol used for the [14C]glucose method and subsequent degradation of the outer portion of the polysaccharide molecule with β-amylase showed that with tissues from normal controls more than 90% of the label of the glycogen was retained in the limit dextrin. When fibroblasts or leukocytes of the patients served as enzyme source up to 80% of the label was released after incubation with β-amylase or phosphorylase a. Addition of Tris to the assay inhibited enzyme activity in fibroblast homogenates of the patients and of controls to the same extent and had no effect on the distribution of the label between supernatant and limit dextrin after β-amylolysis of the labeled glycogen. A pH curve performed with fibroblast preparations from the patients and a normal control did not reveal differences in the effect of changes in pH on [14C]glucose incorporation. We propose that incorporation of [14C]glucose into glycogen by the enzyme present in the patients' cells was into α-1,4 linkages in glycogen.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

We characterized some of the consequences of intrauterine growth retardation in rat pups growth retarded [small for gestational age (SGA)] due to bilateral maternal uterine artery ligation. Pups of sham and nonoperated (normal) mothers served as controls. SGA pups had significantly reduced body and carcass mass throughout the study while body mass did not differ between sham and normal pups after 4 days. Brain mass was similar in the three groups at any age, while at 21 days and later, SGA liver weight as % body mass exceeded that of sham or normals. At 21 days, a 48-h fast reduced plasma glucose significantly in SGA compared to sham and normal pups; SGA plasma insulin was decreased and glucagon increased. Hepatic phosphoenolpyruvate carboxykinase activity and glycogen content were similar among groups. SGA pups did have significantly reduced plasma alanine and elevated betahydroxybutyrate levels. No differences in the responses to fasting occurred at 28 or 35 days. These data indicate that intrauterine growth retardation has profound effects on postnatal growth and metabolism.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID