摘要:

Seven plasma protease inhibitors were analyzed in 8-yr-old children—75 PiZ (severely deficient), one PiZ—(with a null gene), 32 PiSZ (moderately deficient), and 35 normals. In PiZ and PiSZ α1-antitrypsin-deficient children, significantly higher concentrations of α2-macroglobulin (p<0.001) and antithrombin III (p<0.001) were found and significantly lower concentrations of α2-antiplasmin (p<0.001), C1-inactivator (p<0.01) and plasminogen (PiZp< 0.02, PiSZp<0.01). The inter-α-trypsin inhibitor concentrations differed in PiSZ children only (p<0.01). At this age the high α2-macroglobulin levels may be of importance to protect the lung tissue against free proteolytic activity, while importance of the other differences are unknown or reflect changes of purely theoretical interest.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

In previous research, we showed that when peripheral blood mononuclear cells (PBMC) from patients with idiopathic minimal lesion nephrotic syndrome (IMLNS) in relapse were cocultured with rat glomeruli, there was an increased glomerular basement membrane (GBM) uptake of35sulfate. This study was done to determine whether the increased uptake was due to substances secreted into the nephrotic PBMC culture supernatants.35sulfate uptake in rat GBM was significantly higher when glomeruli were cocultured with PBMC from 12 IMLNS patients in relapse (geometric mean [GM|=513 cpm/mg) than when simultaneous assays were done using either PBMC from eight control subjects (GM=158) (p<0.05) or glomeruli incubated without PBMC (GM=275 cpm/ mg) (p<0.01).35su!fate uptake did not increase when glomeruli were cocultured with PBMCs from 11 MLNS patients in remission. Rat GBM35sulfate uptake was significantly higher when glomeruli were incubated in the supernatants of the PBMC cultures from 16 IMLNS patients in relapse (GM=234 cpm/mg) than it was when glomeruli were cultured in the supernatants from normal control PBMC (GM=126 cpm/mg;p<0.002) or from glomeruli cultured alone (GM=141 cpm/mg) (p<0.04). Supernatants from PBMC cultures of 11 IMLNS patients in remission did not increase rat GBM35sulfate uptake. These data suggest that PBMC from IMLNS patients in relapse secrete a factor(s) released into supernatants that increases the35sulfate rat GBM uptake. Since sulfated compounds in the GBM play a role in glomerular permeability, this finding may have pathogenic significance.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The uptake of substrates by the pregnant uterus defines the “diet” of the uterus and conceptus. In order to determine the uterine substrate uptake, catheters were placed in the femoral artery and uterine veins of guinea pigs at 40-49 days gestation. After at least 2 days recovery from perioperative stress, systemic arterial and uterine venous concentrations of oxygen, glucose, lactate, acetoacetate,β-hydroxybutyrate, acetate, and free fatty acids were measured and metabolic quotients were calculated. The glucose/02quotient was 1.22 ± 0.07 (mean ± SEM), the Iactate/O2quotient was -0.40 ± 0.09, the acetoacetate/02quotient was 0.03 ± 0.02, theβ-hydroxybutyrate/ O2quotient was 0.01 ± 0.006, the acetate/O2quotient was 0.03 ± 0.01, and the free fatty acid/O2quotient was 0.24 ± 0.21. Among the substrates measured, glucose appears to be the major metabolic fuel of the pregnant guinea pig uterus, but does not account for all of the oxygen consumed by the uterus if adjusted for lactate production, since lactate is produced within the gravid uterus in large quantities. Acetoacetate andβ-hydroxybutyrate are utilized in negligible amounts.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Concentrations of IgG1, IgG2, and total IgG were measured by a solid phase radioimmunoassay in sera from 36 healthy adults and 114 healthy children. As expected, IgG2and total IgG had a positive correlation with age in children. In addition to age, several other factors were associated with significant differences in serum subclass concentrations. Female children had higher concentrations of IgG1than males, and black subjects had significantly higher concentrations of IgG1, IgG2, and total IgG than whites. Although Km(1) and Gm(23) immunoglobulin allotypes had no relation to subclass concentrations when tested as single factors, the Km(1) allotype interacted significantly with race so that Km(1)-positive black children had higher IgG2concentrations than other subjects. Our findings may explain, in part, recent observations of an association of the Km(1) allotype with altered immune responses of blacks to certain vaccines containing bacterial polysaccharides. In addition, our data indicate the need to control factors such as sex, race, and allotype in studies of subclass concentrations or immune responses.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Urinary acidification was studied in six unrelated infants with fetal alcohol syndrome and eight healthy age-matched infants. Creatinine clearance, fractional sodium excretion, plasma renin activity, and plasma aldosterone were normal in all patients but fractional potassium excretion was lower in the patients than in the controls (p=0.0001). After ammonium chloride loading, minimum urine pH was significantly higher in FAS patients than in control subjects (5.5 ± 0.1 and 4.7 ± 0.1, respectively,p=0.00005). Net acid excretion was also lower in the patients (24.5 ±1.7 Eq/min) than in the controls (27.8 ± 2.1 Eq/min,p=0.008). Following sodium bicarbonate loading, fractional bicarbonate excretion was significantly higher (p=0.00005) and fractional potassium excretion significantly lower (p=0.002) in the patients than in the controls with comparable blood pH and bicarbonate levels. Treatment with chlorothiazide lowered plasma potassium and raised plasma bicarbonate to normal levels (p=0.05). Concomitantly, fractional sodium excretion, fractional potassium excretion, and urinary net acid excretion increased significantly (p=0.01). We conclude that patients with fetal alcohol syndrome have a defect in distal acidification and potassium excretion which cannot be attributed to abnormal aldosterone secretion.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Using a specific and sensitive radioimmunoassay, we found epidermal growth factor (EGF) in moose milk during early lactation in normal and sialoadenectomized mice. Levels of EGF peaked around the 6th day postpartum and decreased thereafter up to day 12. Sephadex G-50 column chromatography of milk from normal and sialoadenectomized mice showed a single immunoreative component comigrating with purified 6045 dalton EGF from the mouse submandibular gland. The concentrations of EGF were similar in milk collected from the breast and the stomach of the offspring immediately after feeding. The molecular profiles, concentrations, and ontogeny of EGF in milk of control and sialoadenectomized mice were also similar, suggesting that the submandibular gland is not the major source of EGF in mouse breast milk.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

To evaluate the role of the quantitative adaptation in dietary protein at weaning in the growth and maturation of the rat gastrointestinal tract, we studied parameters of tissue mass, DNA synthesis, and enzyme activities in suckling pups weaned by day 17 to a semipurified synthetic, isocaloric diet that contained either 8 or 27% casein (controls). Rats of both groups were studied on days 21, 28, and 35 postpartum. On day 21, protein restriction had little effect on mean body weight, wet stomach and liver weight, gut length and colonic, jejunal or ileal mucosal weights per centimeter, whereas on day 35, all these tissue mass parameters were significantly (p<0.01 versus controls) depressed in the 8% protein group. DNA and protein content expressed per intestinal segment or per total organ and the protein/DNA ratio paralleled the changes in tissue mass, except that total DNA of the small intestine was decreased by 33% (p<0.01 versus controls) in 21-day-old rats with protein restriction. In the same age group, DNA synthesis rate, measured by the incorporation rate of [3H]-thymidine per milligram tissue DNA, was markedly depressed in the small intestine (4- fold decrease;p<0.001versuscontrols) and in the liver (2-fold decrease;p<0.05versuscontrols) while in the colon the effect of protein restriction occurred later (day 35). Plasma corticosterone concentrations were equivalent in 8% and 27% protein groups on days 21 and 28 but on day 35, the mean value in the 8% protein group fell to a level of about one-third of the controls (p<0.01). Calculated for the total intestine, sucrase, maltase, and diamine oxidase activities remained unchanged in both groups throughout the experimental period indicating that the increases in specific enzyme activities in 8% protein rats were due to decreased tissue protein content. In 8% protein rats, both the specific and total activity of lactase, measured on days 28 and 35, was increased by at least 3-fold (p<0.01) over the control values, whereas aminopeptidase activity was significantly decreased (p<0.05 versus controls). Our data demonstrate that the adaptation in dietary protein at weaning modulates the ontogenic changes in tissue DNA synthesis and plays a role in completing the growth of the rat gastrointestinal tract. However, this dietary adaptation is not critical for the maturation of functions linked to intestinal absorption.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The present study examined the developmental changes in the adrenergic control of glycogenolysis in the rat model. A relatively newβ-adrenergic radioligand,125I-iodocyanopindolol (ICP), was examined in binding assays with rat liver plasma membrane (LPM). ICP demonstrated both a higher specificity and a greater affinity forβ-adrenergic receptors than any previously availableβ- adrenergic radioligand used to study rat LPM. Utilizing this new ligand it was found thatβ-adrenergic receptor density decreased from 114 ± 4 fmol mg-1in newborn LPM to 19 ± 3 fmol mg-1in adult male LPM. In contrast α-adrenergie receptor density examined using3H-prazosin increased from 161 ± 14 fmol mg-1in the newborn to 554 ± 59 fmol mg-1in the adult male. The results of ICP displacement assays employing variousβ2-adrenergic agonsists and antagonists indicated that ICP binding sites wereβ2-adrenergic receptors. Both guanosine triphosphate and its nonhydrolyzabie synthetic analog guanylyl-imidodiphosphate lowered the affinity of epinephrine for ICP binding sites similarly in newborn and adult LPM. Thus the coupling of receptor to guanine nucleotide regulatory protein appeared to be the same in both age groups examined. In isolated hepatocytes glycogen phosphorylase activation was mediated byβ2-adrenergic stimuli in the newborn and predominantly a-adrenergic stimuli in the aduit male. These results suggest that the change in glycogen phosphorylase activation fromβ- to predominantly α-adrenergic mechanisms seen with maturation is related to changes in receptor density.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The purpose of this work was to assess the toxic lectin ricin (RCAII) as a probe for the study of intestinal permeability in the developing small bowel. Jejunal explants from suckling and adult rabbits were exposed to varying dosages of RCAIIfor 30 min at 25° C and then cultured in toxin-free medium. The RCAIIdose required to inhibit protein synthesis during 6 h of culture increased from 0.1μg/ml in 4-day-old rabbits to 25μg/ml in weanling rabbits. RCAIIcytotoxicity was almost completely blocked by 0.1 M lactulose in all age groups. The kinetics ofI25I-RCAIIbinding to purified microvillus membranes were determined by incubating a fixed concentration of membrane protein (30μg) with increasing concentrations of labeled lectin (2-18μg/ml). Binding attained saturation with adult but not with suckling animal membranes. The latter yielded a curvilinear relationship in Scatchard plots, suggesting either several classes of binding sites or negative cooperativity. RCAIIbinding was confined to the delipidated fraction of the membranes and decreased by 42% from 6 days old to adult age. The extreme sensitivity of colostral epithelium to RCAIIis probably related to the high level of endocytosis exhibited by the immature membrane of suckling rabbits. The development of increasing resistance to the toxin, and associated decrease in binding, might be related to disappearance of saccharide sites in productive surface receptors occurring in the developmental course of intestinal glycosylation.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The presence of high concentrations of sodium in the sweat of patients with cystic fibrosis is widely accepted by all investigators as one of the most important manifestations of the genetic defect. However, the simple means of sweat collection utilized for diagnostic purposes has been extended to the biochemical and physical analysis of the macromolecular components of human sweat. The most popular technique for the attainment of sweat has been collection of sweat droplets from the skin surface following heat stimulation. In this report, it is demonstrated that a far superior means of sweat collection exists based on a new collection device called the MACRODUCT. Utilizing this device, in conjunction with thin-layer isoelectric focusing, demonstrated that human sweat contains sexspecific proteins expressed in adult males and absent or greatly decreased from females and prepubertal males. Additionaly, results are presented which suggest that the presence of epidermal keratins are an excellent marker for sweat contaminated with nonsweat gland-derived macromolecules.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID