摘要:

SummaryThe study population comprised 106 infants ranging from 4 days to 19 wk old. Fluid (witch's milk) was obtained from the infants' breasts by manual expression. To measure volume, fluid was drawn into calibrated capillary pipettes. The frequency of obtaining witch's milk was 71% for all infants and 100% for infants less than 3 wk of age. It declined with increasing age. The median volume of fluid obtained was 20 μ per sampling for all infants and 55 μ for babies ≤ 3 wk of age. Frequency of witch's milk recovery was significantly related to the degree of manual pressure applied but was not related to sex of the baby.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryThe present study was designed to describe the relationships among thyroid status, myocardial growth and myocardial β-adrenergic receptors in the developing rat ventricle. In normal rat myocardium the β-adrenergic binding capacity (Bmax) for (-)-[3H] DHA decreased with increasing age and heart size. In order to determine the effect of thyroid status on ventricular growth characteristics and β-adrenergic receptors, animals were rendered: (1) hypothyroid with propylthiouracil (PTU), (2) euthyroid with PTU and daily thyroxine (T4) replacement, (3) hyperthyroid for several days with daily thyroxine injections or (4) normal controls with sham saline injections. Growth characteristics were similar in euthyroid and normal rat myocardium; ventricular weight, protein and DNA content were similar at postnatal days 5, 15 and 28. Growth in hypothyroid pups was normal until postnatal day 14 at which time the heart weight and protein content were significantly lower than in normal or euthyroid pups, whereas the number of β-adrenergic receptors was decreased in hypothyroid myocardium at all ages studied. On postnatal day 5 the (–)-[3H]DHA binding (Bmax) was 37 ± 9 in hypothyroid myocardium compared to 63 ± 8 fmole per mg protein mean ± S.D. in euthyroid myocardium. The function of the β-adrenergic receptors was also decreased in hypothyroid as compared to euthyroid or normal myocardium as demonstrated by a decrease in maximal catecholamine sensitive adenylate cyclase activity in myocardial membranes at 28 days of age. Treatment of hypothyroid or normal pups with T4resulted in an increase in heart size, protein content and β-adrenergic receptors. Ventricular DNA content, which describes hyperplastic growth, was not decreased in hypothyroid rats demonstrating that postnatal hypertrophic but not hyperplastic ventricular growth is dependent on thyroid hormone.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryPancreatic development was studied in rats 17–28 days of age. Control pups, weaned naturally at 21–24 days showed a gradual increase in body weight, pancreatic weight, total DNA and protein content with age. Pups weaned at 17 days showed a transient increase in pancreatic weight and protein content only at day 22; at no time did they show a difference in either DNA content or body weight. Pups nursed up to 25 days of age had a smaller body weight, but had DNA and protein content similar to control rats. Control pups showed gradual increases in lipase and trypsinogen with a sharp increase in amylase between days 22 and 25. Pups weaned at 17 days showed a precocious increase in trypsinogen and a sharp increase in amylase between days 19–22, but an immediate decrease in lipase which eventually returned to the control level at day 28. Pups nursed beyond the weaning stage showed an increase in lipase and trypsinogen but no sharp increase in amylase. A significant increase in all pancreatic enzymes, pancreatic mass, pancreatic DNA and protein content was seen in all groups of rats irrespective of their diet. The results suggest an inherent biological program as a basic control of pancreatic ontogeny with diet playing a modifying role.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryWe studied thein vitroproliferative characteristics of marrow erythroid progenitors, colony forming unit-erythroid (CFU-E) and burst forming unit-erythroid (BFU-E), in two infants with Diamond-Blackfan syndrome before and during prednisone treatment. Patient 1, had a brisk erythropoietic response to prednisone and the anemia improved; Patient 2 was steroid-unresponsive. Marrow from Patient 1 yielded linear increases in numbers of colonies in erythropoietin dose-response studies, and the magnitude of response was much greater while on prednisone compared to pre-treatment. Cultures of stem cell rich fractions of marrow from Patient 1 separated by unit gravity sedimentation (STA-PUT) revealed moderately reduced CFU-E and BFU-E numbers before prednisone, but normal colony numbers during treatment. Patient 2 differed because CFU-E and BFU-E were almost absent at all erythropoietin doses before and during therapy. Even stem cell rich marrow fractions initially yielded very low colony numbers which did not increase significantly while on prednisone.These findings suggest that in Patient 1 there were adequate numbers of progenitors that were able to differentiate normally only in the presence of prednisone. In Patient 2 the erythropoietic failurein vivoandin vitrowas unaffected by prednisone.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryTo study the action of corticosteroids on erythroid precursors, (burst forming unit-erythroid and colony forming unit-erythroid) in Diamond-Blackfan Syndrome (DBS), marrow from a newly diagnosed untreated infant was studiedin vitrowith prednisone and dexamethasone. This patient subsequently proved to be steroid responsive. Colony numbers increased linearly in an erythropoietin (EPO) dose response study. There was marked enhancement of colony numbers at all EPO doses after adding either prednisone (10-6M) or dexamethasone (10-9M) to the cultures. The data indicate that corticosteroids augment erythropoiesis at both early (BFU-E) and late (CFU-E) stages of development in DBS. In contrast, marrow from a second infant with DBS, clinically steroid resistant, failed to respond to steroidsin vitro.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryProtease inhibitors and protease (caseinolytic, elastinolytic and esterolytic) activity were analysed in 190 milk samples from 94 mothers from day 1 to day 160 after delivery The main protease inhibitors in human milk are α1-antichymotrypsin and α1-antitrypsin. As measured by electroimmunoassay, the level of α1-antichymotrypsin in day 1 colostrum was higher than that in normal serum. Trace amounts of inter-α-trypsin inhibitor, α2-antiplasmin, α2-macroglobulin, antithrombin III, or antileukoprotease could be demonstrated. According to their protease inhibiting activity, the 53 milk samples from day 1–3 could be divided into two groups. (1) Presence of protease inhibiting activity (n= 35). Both α1-antitrypsin and α1-antichymotrypsin appeared intact and were able to form complexes with added trypsin or chymotrypsin although the major part of α1-antichymotrypsin showed a retarded electrophoretic mobility. The proteolytic activity was undetectable or low in these samples. (2) No protease inhibiting activity, in spite of the presence of immunoreactive inhibitors (n= 18). α1-Antichymotrypsin had a precipitate pattern similar to group 1, whereas α1-antitrypsin had a major fraction with slightly retarded mobility and two minor peaks in the α-1and β-regions. These precipitate patterns were unchanged on addition of human trypsin or chymotrypsin compatible with the presence of nonreactive inhibitor only. These samples had a caseinolytic and esterolytic activity with an electrophoretic mobility in the β-region.All samples from day 4 and later had a demonstrable protease inhibiting activity.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryClinical, biochemical and ultrastructural assessment of five Black children from four unrelated kindreds, who had morphologic and laboratory features of hereditary pyropoikilocytosis (HP) is described. In two of the unrelated propositi, both with relatives having elliptocytosis, the apparent HP gradually evolved into elliptocytosis. The mode of inheritance appeared to be autosomal dominant in one family and autosomal recessive in the other. None of the three children from two separate families with true HP had a parent with HP or elliptocytosis. A sixth Black child, whose mother also had elliptocytosis, demonstrated typical elliptocytosis from birth and never demonstrated the HP phenotype. Sequential quantitation of heat induced red cell fragmentation using histogram analyses revealed unchanged findings in three patients with true HP but progressive amelioration in the two patients with HP phenotype who eventually developed elliptocytic morphology. Previously unreported lesions in both true and apparent HP patients included endovesicle formation and submembrane particles, which were detected by electron microscopy, an increase in Heinz body formation, and elevation of oxidized glutathione levels. Our study demonstrates shared abnormalities present both in some neonates with elliptocytosis and in neonates with HP, which preclude the diagnosis of HP in infancy and provide further evidence of the heterogeneity of the elliptocytosis syndrome.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryNormal hemostasis depends in part on the balance achieved between proaggregatory and prothrombotic platelet thromboxane A2, measured as its stable end-product thromboxane B2(TXB2), and vascular prostacyclin (PGI2), which inhibits platelet aggregation and is antithrombotic. Cystathionine-β-synthase deficiency is characterized by a high frequency of thromboembolic disease. We therefore studied,in vitro, the effects of homocysteine and related compounds on platelet TXB2and vascular PGI2formation.In paired samples of platelet rich plasma, which had been preincubated with L-homocystine (1 mM), mean production of the two platelet cyclooxygenase products, TXB2and 12-hydroxy-5,8,10-heptadecatrienoic acid increased significantly from control levels [13.6% ± 1.9 to 19.8% ± 2.1 (P< 0.02) TXB2and 29.8% ± 4.2 to 39.4% ± 4.1 (P< 0.01) HHT]. In the presence of D.L-homocysteine (1 mM), mean platelet TXB2and 12-hydroxy-5,8,10-heptadecatrienoic acid production was also significantly increased [12.7% ± 1.5 to 16.9% ± 1.5 (P< 0.01) TXB2and 27% ± 4 to 31% ± 4.1 (P< 0.02) HHT]. Cystine, cysteine, or methionine (1 mM) did not have similar effects in this test system. Homocysteine and homocystine were without effect on the synthesis of vascular PGI2by umbilical artery segments [control, 0.22 ± 0.03 to 0.21 ± 0.03 ng/mg with D.L-homocysteine and 0.20 ± 0.04 control to 0.19 ± 0.04 ng/mg with D.L-homocystine]. A homocyst(e)ine-induced increase in platelet thromboxane production in the absence of an increase in vascular prostacyclin, if presentin vivo, may contribute to the vascular thromboses characteristic of human homocystinemias (homocystinurias).

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryBile acid malabsorption in cystic fibrosis reduces intraluminal bile acid concentration and may impair fat absorption. The cause of this malabsorption is unknown but it is believed due to intraluminal inhibition of uptake by undigested dietary nutrients. The purpose of this study was to determine the bile acid absorptive capability of cystic fibrosis intestine in a physiologic environment. Direct ileal mucosal taurocholic acid uptake was examinedin vitroin seven patients with cystic fibrosis, and seven children and adolescents with ileostomies as controls. Jejunal uptake was studied in five normal individuals. A Crosby-Kugler biopsy capsule was used to obtain all tissues. Tissue was incubated in Krebs buffer, 10 mM glucose, and taurocholic acid at 0.1, 1.0 and 10.0 mM with shaking at 37°C. Significant reduction of taurocholic acid uptake was present in every cystic fibrosis patient with mean uptake rates being 24%, 38%, and 29% of control ileum, respectively, at the three concentrations. Values paralleled those for passive jejunal taurocholic acid uptake in controls. These data illustrate a marked reduction in taurocholic acid uptake capability of cystic fibrosis ileal mucosa and may indicate a cellular defect suggestive of a primary lesion in this disease.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryThe newborn beagle pup serves as a model for neonatal intraventricular hemorrhage (IVH). Fluctuations in germinal matrix blood flow are felt to play a major role in the pathogenesis of IVH. We studied regional cerebral blood flow in awake newborn beagle pups utilizing [14C]-iodoantipyrine as a blood flow indicator and quantitative autoradiography. The equilibrium [tissue]:[blood] partition coefficient for iodoantipyrine was 1.13 ± .06 for grey matter. Blood flow was calculated for cerebral cortex (frontal = 59 ± 9 ml/100 g/min), 14 subcortical nuclear structures (e.g., caudate = 45 ± 6 ml/100 g/min), 3 white matter structures (centrum semiovale = 7 ± 1 ml/100 g/min), and germinal matrix (7 ± 1 ml/100 g/min) (mean ± S.E.).We conclude that under normal physiologic conditions the germinal matrix receives relatively low blood flow. This information can be used for comparison with germinal matrix blood flow during adverse experimental conditions.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID