摘要:

SummaryAn immunoassay for rat intestinal calcium-binding protein (CaBP) employing antibody raised in chickens using purified rat intestinal CaBP has been used to measure immunoreactive CaBP in the duodenum of suckling and weanling rats. A 5-fold increase in immunoreactivity, associated with a 2 1/2-fold increase in calcium-binding activity occurred at weaning, a period during which duodenal mucosal mass increased 2-fold and supernatant protein concentration increased 1 1/2-fold.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryLung tissue from human fetuses, with gestational ages ranging between 14–26 wk, was studied by histochemical and biochemical methods. The findings were similar in all tissues tested, without apparent correlation to gestational age. Staining that indicated carbonic anhydrase activity was found in the capillary endothelium and in the epithelium of some segments of the peripheral airways. The ciliated epithelium of the central airways was unstained. The distribution of the enzyme in the human fetal lung differed clearly from that in the adult human lung, where little or no enzyme has been found in the airway epithelium. The mean carbonic anhydrase activity in whole homogenates of fetal lung tissue was 24 enzyme units per g wet weight of tissue. Ninety % of this activity was recovered in the supernatant fraction. Assay of this fraction by a radioimmunosorbent technique showed the presence of the carbonic anhydrase isoenzyme HCA-C corresponding to 380 ng enzyme per mg tissue protein. Small amounts of HCA-B were also found but are thought to be attributable to contaminating erythrocytes; thus, the data suggest that both the capillary endothelium and the lung epithelium contain HCA-C, an isoenzyme of carbonic anhydrase known to be involved in electrolyte transport in many tissues.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryConsiderable attention has been focused recently on α2-macro-globulin (α2M), a major endopeptidase inhibitor in blood plasma, as a possible source of the primary defect in cystic fibrosis (CF). We report here studies designed to compare the structure of CF α2M with normal α2M to determine if there is a difference. The physicochemical properties of purified α2M as revealed by various electrophoretic techniques, covalent proteinase binding properties, and primary structural studies on a variety of partial hydrolyzates of CF α2M and normal α2M are compared. These studies were carried out on eight different individual isolates of CF α2M and three age-matched normal α2M preparations and α2M isolated from fetal cord blood. Three properties of CF α2M were studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE): (1) the existence of four identically-sized subunits in the native molecule (10), (2) the cleavage of this subunit into fragments of approximately 100,000 daltons upon interaction with proteinases (10), and (3) the cleavage of an alkaline/heat sensitive bond to produce 120,000 and 60,000 dalton fragments (11). Both CF and normal α2M were cleaved to the extent of 79–87%. CF α2M behaves identically with normal α2M with regard to all these properties. Salvesen and Barrett (24) have demonstrated that varying proportions of several [125I]-labeled proteinases form SDS-stable, non-reducible links to normal α2M. Two of the CF α2M preparations were studied to determine if similar covalent binding of proteinases occurred. The positions of the labeled and % of proteinase bound bands in SDS/reduced PAGE system were identical for normal α2M and CF α2M. These results indicate that CF α2M behaves normally with regard to covalent binding of proteinases. Qualitative comparison of the peptide fragments separated by SDS-PAGE or isoelectric focusing of CF and normal α2M produced by partial proteolysis with trypsin, chymotrypsin orStaphylococcus aureusV-8 proteinase did not reveal any differences unique to CF α2M. The cyanogen bromide fragmentation studies and the cysteine cleavage studies also indicated that no major change in the positions of methionyl residues or cysteinyl/cystinyl residues has occurred in CF α2M. The failure of all these different studies and those reported by others to demonstrate any differences between CF and normal α2M makes it highly unlikely that there is a primary defect in α2M in CF.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryThirty-four Western mixed breed lambs were delivered prematurely at 120 days gestational age (term = 150 days). Four lambs were sacrificed at birth, and four lambs were sacrificed with the onset of respiratory failure (PCO2> 80 torr) at about 30 min of age. The remaining lambs were treated by tracheal instillation with 50 mg of natural sheep surfactant lipid/kg body weight. These lambs were sacrificed 10 min, 40 min, 1.5 h and 3 h after surfactant treatment. Frequent blood gas and compliance measurements documented the clinical responses of the lambs.Lungs from treated lambs showed large increases relative to untreated lungs in air volumes as assessed by pressure-volume curves and by histology. However, the pressure-volume and histologic measurements did not distinguish between the posttreatment groups of lambs. Minimum surface tensions of alveolar washes fell from >30 dynes/cm to 6.3 dynes/cm 10 min after treatment and again rose to 21.6 dynes/cm within 3 h. Minimum surface tensions correlated well with the PO2values but not with the PCO2values measured before sacrifice. The combination of dilated distal airways and atelectasis resulted from increasing surface tensions with time and mechanical ventilation and may explain the clinical deterioration without much change in the volume of gas within the airways.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryAn 11-month-old boy with muscle hypotonia and neurologic deteriorations had lactic acidosis, pyruvic acidemia and alaninemia due to deficiency of the pyruvate dehydrogenase complex in his platelets and of pyruvate decarboxylase in his muscle. When placed on a low carbohydrate-high fat diet for 6 months, his blood levels of lactate and pyruvate became nearly normal, but his cerebrospinal fluid levels of lactate and pyruvate remained high. Despite this dietary therapy, neurologic deterioration progressed slowly. He died of pneumonia after artificial respiration for 3 wk. At autopsy, extensive symmetric necrotic lesions were found in the brain including proliferation of capillaries and gliosis in the brain stem and diffuse demyelination in the white matter. These lesions were consistent with those observed in Leigh's disease. The activities of the pyruvate dehydrogenase complex and pyruvate decarboxylase in various tissues obtained at autopsy were less than 10% of control values; however, the activities of pyruvate carboxylase and α-ketoglutarate decarboxylase were within the normal limits. This patient with Leigh's disease had an isolated deficiency of pyruvate decarboxylase in various tissues.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryChanges in glomerular number and perfusion during maturation of the guinea pig were compared with the response to uninephrectomy at birth or 84 days of age. From birth to adulthood, there was a 21% increase in number of glomeruli identified by the presence of India ink previously injectedin vivo. For animals uninephrectomized at birth, a similar increase occurred several wk earlier than in sham-operated littermates; however, uninephrectomy in adulthood resulted in no further increment. Although the number of glomeruli in the left kidney varied by 25% within each group, the difference in number between right and left kidneys of individual animals averaged only 4%.Additional glomeruli not identified by India ink were subsequently revealed by application of Wright's stain. These comprised 13–17% of the glomeruli containing India ink in 1 and 22-day-old sham groups, but only 2% in 22-day-old uninephrectomized or adult animals. Approximately 3/4 of all glomeruli indentified by India ink were present in the outer cortex of 22-day-old uninephrectomized and sham-operated guinea pigs; the cortical distribution of Wright-stained glomeruli in the latter group was similar.Paraffin sections of kidneys revealed scattered glomeruli not containing India ink in 1-day-old and 22-day-old sham guinea pigs, but almost none in 22-day-old uninephrectomized animals. There were no glomeruli in an early stage of formation in any of the sections examined.It is concluded that during development, an increase in number of glomeruli identified by India ink represents nephrons which are underperfused in the neonate but are completely perfused at maturity. This process is accelerated by uninephrectomy in early development, but is unaffected by uninephrectomy in adulthood, at which time glomerular perfusion is virtually homogeneous.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryConcanavalin A surface receptors were detected on brush border enterocytes from child intestinal biopsies by the concanavalin A-peroxidase method. On electron microscopy, these receptors appeared as electron-dense deposits, located on a band running along the innermost part of the brush border membrane glycocalyx. In the five control subjects tested, brush border length was 1.06 ± 0.18 μ, and band thickness, 19 ± 4 nm. Deposits were regular in shape and evenly spaced out along the entire membrane, reflecting homogeneous glycosylation of the normal brush border. In seven patients with villous atrophy induced by gluten, the brush border was damaged and its length was 1.04 ± 0.39 μ. The thickness of the electron-dense deposit band was 19 ± 6 nm; deposit shape was irregular and the band ran discontinuously along the membrane. The degree of this abnormality seemed to correspond to the degree of brush border damage. In six treated coeliac patients with normalized mucosa, the brush border was structurally normal but it was significantly longer (1.25 ± 0.32 μ) than in the controls (p< 0.01). The electron-dense band was significantly thinner (16 ± 7 nm) than in the controls (p< 0.01). The distribution of the electron-dense deposits was sporadic in some parts of the band and regular in others. These results suggest abnormal glycosylation of the brush border membrane in coeliac disease, and might be due to the presence of abnormal glycoconjugates. It remains to be established if these changes are induced by gluten toxicity or are the consequences of nonspecific intestinal disorders.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryThe number and distribution of bombesin immunoreactive pulmonary neuroendocrine cells (PNEC) in fetuses and infants up to 6 months of age was determined on postmortem lung specimens. Individual cells and clusters of cells (neuroepithelial bodies) were found in airways of all sizes, although greater than 95% of the positive cells were located in bronchioles, terminal bronchioles, and respiratory bronchioles. These infants were separated into two groups. In control infants, who died primarily from noncardiopulmonary causes, bombsin immunoreactive neuroendocrine cells were identified throughout the latter half of gestation. As gestation advanced, progressively more positive bronchioles/cm2of lung tissue and cells/bronchiole were identified. In these control infants, the number of positive bronchioles/cm2and cells/bronchiole were at the highest level at or near the time of delivery and then gradually declined throughout the first 6 months of life. In contrast, infants who died of acute hyaline membrane disease (1–7 days of life) or bronchiopulmonary dysplasia (2 wk to 6 months of life) demonstrated marked differences in the number of identifiable bombesin immunoreactive neuroendocrine cells when compared to control infants. In early hyaline membrane disease, the number of positive bronchioles/cm2and cells/bronchiole was markedly decreased. During the transition to chronic bronchopulmonary dysplasia, there appeared to be a marked increase in the number of bombesin immunoreactive cells. The peak number of cells occurred at 2–3 months of life, when substantially more bombesin-immunoreactive cells could be identified in children with bronchopulmonary dysplasia than control infants of similar age.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

SummaryThe virologic and histologic characteristics of congenital cytomegalovirus infection (CMV) were defined in 65 neonatal guinea pigs born from 27 mothers infected during pregnancy. Infectious virus or tissue lesions were present in 54% of the neonates tested. Guinea pig CMV was detected most often in the salivary glands (72%) and spleen (33%) of infected guinea pigs. Less frequently, virus was also detected in the brain, lung, pancreas and liver. Tissue lesions were most frequently observed in the brain and kidney, but also occurred in the salivary glands, liver, pancreas, thymus and spleen. The histopathology was identical to that observed in infants with congenital CMV infection. Infectious virus and histopathology were present in newborn guinea pigs born from mothers infected at any time during gestation. Newborns from mothers infected during early stages of gestation had virus present most frequently in the salivary glands, whereas offspring of mothers infected in late pregnancy had virus present in several tissues. Acute maternal guinea pig CMV infection produced generalized CMV infection of the offspring which was followed by persistent infection in neonatal salivary glands. Lesions remained present in several neonatal tissues including the brain. The long term consequences of such lesions in affected guinea pigs remain to be determined. The results of the study emphasize the similarities between human congenital CMV infection and congenital guinea pig CMV infection, thereby underlining the utility of this animal model as a means of understanding human congenital CMV infection.

ISSN:0031-3998    

出版商:OVID    

年代:1982

数据来源: OVID