摘要:

In 59 male and 59 female healthy children of average stature between 7 and 10 yr old, the normal range of plasma somatomedin C was investigated. The 95% tolerance limits narrowed progressively when the child's plasma somatomedin C status was described by the mean of one, two, three, or four determinations at 6-wk intervals. The 95% tolerance limits were therefore based on the mean of four determinations. In 97 children, age 7 to 10, below the 3.0 percentile in height, 44 had an average plasma somatomedin C below the 2.5 percentile. Among these hyposomatomedinemic short children, 19 were partially or totally deficient in growth hormone, 20 had normal immunoreactive growth hormone responses to dopa, glucagon, and sleep (nongrowth hormone deficient), and five had borderline provocative tests. Both growth hormone deficient and nongrowth hormone deficient children showed significant linear growth responses to 6-month courses of human growth hormone (0.16 to 0.70 unit/kg/wk). The responses of the latter group were 50 to 90% as great as those of the former.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The nocturnal serum of 13 nongrowth hormone deficient, hyposomatomedinemic short children and of 12 normal children of average height was analyzed by both polyclonal and biclonal radioimmunoassays. The biclonal/polyclonal ratio for immunochemical grade human growth hormone was 1.0, but for the nocturnal sera in both groups, this ratio was significantly less than 1.0 (range 0.5-1.2, average 0.7-0.8). The ratio did not differ significantly between the two groups of children.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

To examine the effect of prolactin (PRL) on transplacental water flow, we infused mannitol (500 ml; 20% solution) over 10 min into five chronically catheterized ewes (121-134 days' gestation), producing a peak maternal plasma osmolality by 10 min and fetal osmolality by 20 min. One day before or after, an identical amount of mannitol was infused into the same ewe during the 2nd h of a 2-h infusion of PRL (40 ± 2.2 µg/h) into a fetal leg vein. Mean (± SE) fetal plasma PRL levels were 6.9 ± 3.2 ng/ml at baseline. Steady state fetal PRL levels were 17.7 ± 7.4 ng/ml during PRL infusion. Maternal mannitol infused without administration of PRL to the fetus evoked a rise in fetal plasma osmolality similar to that following maternal mannitol during PRL administration to the fetus. Thus, as shown previously, PRL affects water permeability across the membranous chorioamnion, whereas results of the present study indicate that the hormone does not affect water transfer across the ovine chorionic villi (placenta).

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Mitochondria were prepared from the brown adipose tissue of control rats and animals made iron deficient by means of a low iron diet. The specific activities of the mitochondrial electron transport system (NADH, succinate and a-glycerophosphate oxidase activities) were markedly and significantly reduced in preparations of brown adipose tissue from the iron-deficient rats as compared with preparations from the control animals. In contrast, concentrations of the cytochrome pigments a + a3, and c + c1were normal and cytochromebwas slightly reduced (18%) in the mitochondrial preparations from the iron-deficient animals. Treatment of the iron-deficient animals with triiodothyronine significantly increased the amount of brown fat present per kilogram of body weight in both control and iron-deficient rats, but did not significantly affect the specific activities of the mitochondrial electron transport system.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Sustained convulsive seizures were induced with bicuculline in newborn rabbits and marmoset monkeys. In both species, seizures were predominantly tonic, with generalized polyspikes on the EEG. Brain glucose concentration fell dramatically during seizures in both species, and in many normoglycemic animals reached levels usually associated with severe hypoglycemia, suggesting that glucose transport from blood to brain could not keep pace with glucose utilization. Glucose loads given to rabbits induced hyperglycemia and during seizures maintained brain glucose well above concentrations needed to saturate hexokinase so that glycolytic rates were probably never limited by substrate availability. Blood and brain lactate concentrations rose during seizures but never reached levels considered cytotoxic. These data suggest that epileptic seizures can deplete brain glucose in normoglycemic neonates of several species, including subhuman primates.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The lymphocytes of human breast milk have been previously shown to be immunologically competent while the monocytes have been described as actively motile in some reports but not in another. Cells were separated from milk samples collected by lactating women 2 to 9 days postpartum. Milk cell migration and production of the lymphokine, monocyte chemotactic factor, by milk cells were assayed using membrane filters. Milk cells were poorly motile although prior culturing improved their migratory ability. Cell-free milk was chemotactic for blood monocytes. Chemotactic factor production was detected in only two of 16 phytohemagglutinin-stimulated milk cell cultures.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

At a gestational age of 27.9 days, pregnant rabbits were infused with enprofylline, a new xanthine with potent antiasthmatic effects. Following a priming dose of 5 mg/kg, 20 mg/kg were infused over a 2-h period. Controls received Ringer's solution. On completion of the infusion, the fetuses were delivered and the effect on their surfactant system was evaluated. Surface tension in airway fluid, measured with the pulsating bubble surfactometer, at minimal bubble size in the third cycle, was 21.8 ± 2.2 (mean ± SE)versus28.7 ± 1.7 mN m-1(p<0.01). Pressure-volume loops of the lungs of the fetuses showed that at a deflation pressure 10 cm H2O the volume was 64 ± 3versus49 ± 3% (p<0.0005). The lung lavage fluid had a phospholipid phosphorus content of 41.9 ± 3.8versus18.5 ±1.3 µg/g dry lung (p<0.0005). The values indicate that enprofylline caused a release of surfactant into the fetal airways.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

We have created a model of chronic hypoxemia in the newborn lamb by decreasing pulmonary blood flow in the presence of an atrial septal defect. Via a left lateral thoracotomy, we place an inflatable balloon around the pulmonary artery and perform an atrial septostomy under direct vision. We also insert several vascular catheters and place an electromagnetic flow transducer around the ascending aorta. Three days after surgery, we inflated the balloon in 11 lambs such that arterial oxygen saturation decreased to 60 to 75%. Studies were performed on these lambs twice weekly and weekly on 12 normoxemic lambs. Growth decreased sharply (47 ± 123versus221 ± 82 g/ day) at the onset of hypoxemia and remained low, although oxygen consumption followed the normal gradual decline. Heart rate remained elevated throughout the study. Arterial Pco2levels decreased from 40 ± 5 to 35 ± 7 torr and remained low. Systemic blood flow decreased at balloon inflation but quickly returned to normal. Mixed venous saturation was low, but could decrease further with shivering. Systemic oxygen delivery decreased initially but returned to normal as Hb concentration rose (from 9.4 ± 1.5 to 12.5 ± 2.2 g/dl). P50 increased normally over the study period. Four of the 11 hypoxemic lambs died during the study. These data show that, in the chronically hypoxemic newborn, systemic oxygen delivery is maintained primarily by a rising Hb. Total body oxygen consumption is maintained at rest but is redistributed away from anabolic requirements and toward cardiorespiratory work. This signal to decrease growth occurs despite less than maximal oxygen extraction at rest.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

We measured the biochemical response for four patients with maple syrup disease to pharmacologic doses of thiamine, and correlated their response to their branched chain a-ketoacid dehydrogenase activity. We observed a linear correlation between the concentrations of each plasma branched-chain amino acid and its corresponding ketoacid analogue. In addition, the renal tubular reabsorption of branched-chain amino and ketoacids was nearly complete within these physiologic concentrations. Three children responded to thiamine therapy with a reduction in concentration of plasma and urinary branched-chain amino and ketoacids. Each responder had at least 5% activity for branched chain a-ketoacid dehydrogenase in their mononuclear blood cells and in whole cell fibroblasts from cultured skin when compared to the activity in normal control cells. We propose that each child with maple syrup urine disease be assessed for their response to thiamine by quantifying the concentration of branched-chain amino acids in plasma before and after vitamin supplementation.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID