摘要:

SummaryLuteinizing hormone (LH), follicle-stimulating hormone (FSH) estrone, and estradiol were measured radioimmunologically in more than 60 plasma specimens of 34 girls suffering from idiopathic precocious puberty. Although the median values of both gonadotropins in the plasma of the patients (LH = 1.0 ng/ml; FSH = 1.6 ng/ml) were higher than those from healthy prepubertal girls (LH = 0.6 ng/ml; FSH = 0.5 ng/ml), only 23 out of 64 LH levels and 30 out of 64 FSH levels exceeded the upper normal limit for age. While the median value of plasma estrone (13 pg/ml) was found to lie within the normal range for prepubertal girls (7–29 pg/ml) and only 13 out of 75 estrone values were pathologically elevated, the median value of plasma estradiol (22 pg/ml) was nearly 3 times higher than the normal median for prepuberty (8 pg/ml). Of 75 estradiol levels, 35 were above normal for age. Grouping the values according to the stage of sexual development revealed considerably lower gonadotropin and estrogen levels in the patients than in normally maturing girls of the same developmental stage. However, patients who were examined repeatedly at short intervals over a 1-month period showed an almost cyclic sequence of their estradiol levels similar to the pattern observed in healthy pubertal girls.SpeculationThe findings that plasma estrogens are relatively low in idiopathic precocious puberty in spite of well advanced sexual development suggest that the symptoms of this disturbance do not depend on estrogen concentrations alone. Other factors, such as enhanced receptor sensitivity or changes in the concentration of sexual hormone-binding globulin, must also be taken into consideration.

ISSN:0031-3998    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

SummaryOn day 21.5 a pregnant rat received a single injection of [1-14C]glycerol. The purpose was to study the transfer of glycerol through the placenta from the maternal to fetal plasma. From 3–20 min after injection the specific activity of glycerol in maternal and fetal plasma was measured. The results indicate that the mother can provide this molecule to the fetus. Similar results were obtained with the rabbit on day 28 of pregnancy.The possibility of the conversion of plasma glycerol to glucose has been investigated in the rat and rabbit fetus. This molecule was chosen chiefly to see whether the gluconeogenic pathway was functioning in the fetus above the triose phosphate step.At two stages of fetal development the capacity of the fetus to incorporate [1-14C]glycerol into glucose plus glycogen has been shown in the two species.In the rat fetus the conversion of [1-14C]glycerol to [14C)glucose increases from 19.5 to 21.5 days of gestation. For the rabbit this parameter increases from 25 to 28 days of gestation.On day 25 in the rabbit and day 19.5 in the rat the liver glycogen was labeled, but it did not accumulate the [14C]glucose from [1-14C]glycerol during the time that we have studied. In contrast, on day 28 in the rabbit and day 21.5 in the rat the incorporation of radioactivity increased as function of the time.However, the relative importance of glycerol as precursor of the glucose plus glycogen in the fetus remains to be elucidated.SpeculationThe available evidence suggests that in the fetal rat liver the gluconeogenesis does not appear until after birth. Quantitatively, the most important source of glucose for the fetus must be the mother.The existence of glycerol in the plasma of the rat and rabbit fetus may contribute to produce glucose and increase liver glycogen reserves near term.

ISSN:0031-3998    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

SummaryThe thermostability of cystathionine synthase and the effect of pyridoxal phosphate (PLP) on this thermostability were investigated in extracts of normal human liver and in extracts of liver, both before and during pyridoxine (vitamin B6) therapy, from members of a family with three clinically and biochemically typical, B6-responsive, synthase-deficient sibs.Incubation of crude extracts of normal liver at 55° (preincubation) for 3–4 min before assay consistently resulted in a more than 2-fold increase in specific activity (activation) of cystathionine synthase (Fig. 1). With periods of preincubation longer than 4 min, thermal inactivation occurred. When PLP was added to the preincubation mixture, slightly more activation occurred in the first 3–4 min, and there was no observable loss of activity for an additional 25 min.The activation phenomenon was not observed in extracts of liver which had been obtained from three synthase-deficient sibs before therapy with vitamin B6(Index of activation, Table 1). When extracts of liver obtained during vitamin B6therapy were studied, however, significant activation was observed. Synthase activity in extracts of liver from the patients' parents, obligate heterozygotes for synthase deficiency, and from a potentially heterozygous sister demonstrated activation similar to that found in control liver extracts.With periods of preincubation longer than 5 min, the inactivation of synthase in liver extracts from patients receiving pyridoxine-HCI occurred at the same rate as in liver extracts from heterozygotes and from normal subjects (Index of inactivation, Table 1). PLP completely prevented heat inactivation of enzyme from normal liver.SpeculationActivation of cystathionine synthase is an expression of the ability of the normal enzyme to undergo heat-induced conformational changes. The failure to activate the abnormal enzyme suggests it has an altered molecular structure.

ISSN:0031-3998    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

SummaryAn analysis of palmar crease variants was carried out in a group of “at risk” newborns, without any evident congenital anomalies. This group consisted of 108 prematures, 74 infants who were small for gestational age, 62 newborns with history of gestational complications, and 46 newborns with a history of intrauterine methadone exposure.A system of classification was developed based on observations of 500 normal newborns as control subjects, 466 normal mothers, and 200 normal children. The palmar crease variants can be divided into four main groups, schematically presented as normal variants, simian crease and its variants, Sydney line and its variants, and another group of unusual variants which do not fit into the other groups. A study of these groups revealed that familial components, race, sex, and age are factors that can influence the expression of palmar crease patterns. There is an increased frequency of abnormal creases in each of the groups of “at risk” newborns. Moreover, there is an apparent association of interrupted transverse creases and intrauterine methadone exposure.SpeculationOur findings suggest that examination of palmar creases and the demonstration of variant patterns may provide a useful, objective indicator of possible abnormal fetal development. Since it is important to utilize a standard scheme in routine newborn examination, both to identify palmar crease variants and to establish a baseline for comparative studies, a system for classification of palmar creases is presented.

ISSN:0031-3998    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

SummaryThis paper reports portal and peripheral blood glucose, insulin, and glucagon levels in small for gestational age (SGA) and appropriate for gestational age (AGA) newborns during the first 48 hr of life. These parameters were studied after an oral glucose and protein load (1 g/kg of each) after a 4-hr fast.In AGA and SGA infants, mean fasting blood glucose level was significantly higher in the portal vein than in the aorta (P< 0.05). After the load, mean blood glucose level rose significantly in both vessels.The mean fasting plasma insulin level was low and was similar in both vessels. After the load in the AGA group mean plasma insulin level rose significantly at 45 min in both vessels (P< 0.05) (52.1 ± 37.2 μU/ml in aorta and 91.8 ± 75.3 μU/ml in portal vein). In the SGA group, the insulin response was minimal in the aorta and in the portal vein; the increase was significant only in the portal vein (P< 0.05) at 180 min (47.1 ± 25.3 μU/ml).The mean fasting plasma glucagon level was higher in the portal vein than in the aorta in both groups (P< 0.05). After the load in AGA infants plasma glucagon rose significantly from

ISSN:0031-3998    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

SummarySimultaneous measurements of serum immunoreactive thyrocalcitonin (iTCT), immunoreactive parathyroid hormone (iPTH), calcium, inorganic phosphate, magnesium, and alkaline phosphatase were made in 37 normal children whose ages ranged from 6–12 years. Between the ages of 6 and 12 there is a statistically significant rise in serum iTCT levels (r= 0.4638;P< 0.01), and a fall in serum iPTH levels (r= 0.4976;P< 0.01). There is a highly significant inverse correlation between serum iTCT and iPTH levels (r= 0.5248;P< 0.005). Serum iTCT levels were inversely correlated with phosphate levels (r= 0.4989;P< 0.01), the latter being age dependent and falling significantly between the ages of 6 and 12 (r= 0.4802;P< 0.001). There was no significant relationship between serum calcium levels and iTCT, iPTH, or age. Serum magnesium levels were not correlated with calcium, iTCT, or iPTH levels.SpeculationSerum iTCT is important in the growth process, particularly in the steady growth towards the end of childhood. and the inverse relationship between iTCT and iPTH levels suggests that a dual control mechanism exists which is capable of striking the fine balance between bone anabolkm and catabolism necessary for normal skeletal growth.

ISSN:0031-3998    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

SummaryTo detect placental transfer of L-triiodothyronine (T3) in pregnant rats, we injected 1 μCi [125I]T3on the 16th, 18th, and 20th day of gestation. Three hours after the injection, which corresponds to the equilibrium time determined by a method of constant infusion, the pregnant rats and their fetuses were killed. The [125I]T3was extracted from the serum or the homogenate by butanol extractions and alkaline washes. The transfer rate was calculated from the quantity of [125I]T3in the serum of the fetuses after 3 hr and from the maternal metabolic clearance rate (8.19 ± 0.45 ml/hr/100 g body weight; mean ± SEM). At the 16th day of gestation, the placental transfer of T3was 0.82 ± 0.11% of the total maternal clearance rate/litter weight; it was 1.05 ± 0.25% at the 18th day of gestation and 0.58 ± 0.10% at the 20th day of gestation. There were no significant differences between these results. The maternal T3concentration was 68.27 ± 20.6 ng/100 ml and its production rate was 5.57 ± 0.31 ng/hr/100 g; with these data we calculated a maternal-fetal T3transfer of 46 ± 6 pg/hr. Furthermore, there was no T3transfer observed when the mother received 1.9 μg unlabeled T3, which led to a significant rise in maternal T3concentration (68.27 ± 20.6 ng to 102.23 ± 7.41 ng/100 ml;P< 0.01); there was no detectable T3, in the fetal serum. From these results we conclude that there is minimal or no placental transfer of T3in the rat and that the hypothalamic-pituitary-thyroid axis of the fetus develops autonomously.SpeculationThe present data plus the fact that the rats are hypothyroid at birth support the concept of an autonomous development of the hypothalamic-pituitary-thyroid axis. It suggests that the rat can serve as a useful model for development of this axis in the human.

ISSN:0031-3998    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

SummaryPlasminogen, total protein, and surface-active material were measured in antniotic fluid in 112 pregnancies at 11–42 weeks' gestation. In 65 of these pregnancies, cord blood was also analyzed for serum plasminogen and total protein. Plasminogen was detected in 25 of 114 amniotic fluid samples, and 23 came from pregnancies of less than 37 weeks' gestation. Plasminogen was found in 15 of 32 amniotic fluid samples from pregnancies with complications, but only in 10 of 80 “uncomplicated” pregnancies. The mean cord serum plasminogen was relatively constant in births or abortuses of 17 to 30 weeks' gestation, but was present in increasing amounts in births of gestational ages from 30 to 40 weeks. The concentration of plasminogen in cord serum was directly related to the cord total protein (r= 0.7513,P< 0.001). The cord plasminogen concentration was significantly higher in infants with a positive foam stability test (5.6 ± 0.3 mg/100 ml) than in the combined group of infants with negative and intermediate tests (4.3 ± 0.16,P< 0.005). However, infants with a positive foam stability also had a significantly greater gestational age than infants with a negative or intermediate foam stability test. With one exception, infants with a low cord plasminogen (below 4 mg/100 ml) developed respiratory distress syndrome (RDS) only if amniotic fluid surfactant was low. The data suggest that low levels of serum plasminogen are correlated with severe lung disease only in the presence of surfactant deficiency.SpeculationIn infants that develop the respiratory distress syndrome, many serum proteins are found in diminished concentration in the umbilical cord blood. Interest has naturally focused on the antiproteinases because a functional deficiency in these could contribute to fibrin deposition, a characteristic finding in hyaline membranes. However, it has been difficult to determine whether antiproteinases are low because of increased consumption or as a result of nonspecific leakage of many proteins from the blood. Even the evidence of a selectively greater depletion of α1-antitrypsin than the larger molecule, plasminogen, or other cord

ISSN:0031-3998    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

SummaryTwo male patients with late stage (uremic) infantile nephropathic cystinosis (INC) (Table 1) were treated by mouth with the reducing agent dithiothreitol (DTT), at doses not exceeding 25 mg-kg-1body weight three times per day. Three sequential periods of observation were obtained in both patients: on thiol (8.5 months); off thiol (8–9 months); on thiol again (7 months or longer). Other than nausea and vomiting at the maximum dose range, no apparent toxicity was observed. One subject died in uremia in the 24th month of the study.The half-cystine concentration in peripheral blood leukocytes decreased during both treatment periods in each patient from initial pretreatment levels in excess of 8 nmol·mg-1protein (normal <0.1 nmol mg-1) to 10–20% of initial values (Table 2 and Fig. 1,AandB). Reduction in total number of blood leukocytes or in the neutrophil fraction, where cystine storage occurs selectively in cystinosis, did not occur (Table 3) as a possible explanation for these findings; nor did storage of samples, a possible artifact, influence the cystine content of cystinotic cells (Fig. 2).Multiple site rectal mucosa biopsy clearly revealed cystine storage but serial biopsies did not reflect a positive DTT response when compared with the leukocyte assay (Table 4). High intersample variation in cystine content, even between samples taken at one time, prevented measurement of a treatment response.DTT had no apparent detrimental effect on the concentration of representative proteins, including hemoglobin (Table 3), serum insulin, and serum immunoglobulin during the treatment trials. Renal function (glomerular and tubular) was severely depressed and did not improve during the period of observation in either patient (Table 2; Fig. 3,AandB).Postmortem tissues from one patient revealed 10–40-fold excess cystine accumulation in kidney cortex and liver (Table 5). However, these levels of accumulation are at the lower range of or even below published values for cystine in cystinotic kidney and liver.Whereas chemical methods are not reliable for detecting and measuring DTT in biologic fluids, preliminary evidence indicates that a silylated derivative of oxidized DTT can be detected in the urine of patients receiving DTT by mouth (Fig. 4). This finding suggests that the thiol is absorbed and excreted.SpeculationThe defect in cystine metabolism (or transport) in cystinosis remains unknown. However, if administered early in the course of INC, DTT might prevent the occurrence of irreversible phenotypic components by preventing cystine accumulation.

ISSN:0031-3998    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

SummaryAn ionophore A23187-induced increase in membrane permeability to calcium ions in culture medium produced a rabbit tracheal mucociliary response indistinguishable from that caused by cystic fibrosis (CF) sera on three different occasions. Specific chelation of calcium ions with EGTA in the basal medium Eagle (BME) media with no additive or in native CF sera abolished the mucociliary disturbances in all cases. Increased membrane permeability to calcium may be important in the production of the mucociliary response by CF serum factor(s) in the tracheal assay system.SpeculationCF serum factor(s) may be acting on the cultured rabbit tracheal explant cellular membranes to produce altered permeability to ions. This alteration in membrane permeability may be promoting a loss of intracellular communication and cellular injury. Such changes on the cellular level may be related to the pathophysiology of this genetic disorder.

ISSN:0031-3998    

出版商:OVID    

年代:1977

数据来源: OVID