摘要:

ExtractBetween 7 and 9 postnatal days, the kidney, spleen, heart, and liver from vitamin B6-deficient young either plateaued and failed to gain weight or lost weight, whereas brain continued to gain weight but at a more reduced rate than normal. The level of cofactor in kidney of experimental animals was below that of controls at all time points studied. α-L-Fucosidase activity was already moderately increased in deficient kidney at 3 postnatal days and remained elevated throughout the time course. β-D-galactosidase, acid phosphatase, and hexosaminidases A and B in vitamin B6-deficient young all showed moderate increases in activities after 9 days, at one or more time points. In brain, α-L-fucosidase activity was increased somewhat throughout the time course, but changes in β-D-glucuronidase, β-D-galactosidase, α-D-mannosidase, acid phosphatase, and hexosaminidases A and B did not occur until after 7 postnatal days.SpeculationWhen weights of kidney and brain were both normal, there was a marked elevation in α-L-fucosidase activity in these organs suggesting that this increase in enzyme activity may be a specific effect of vitamin B6deficiency. Elevated α-L-fucosidase activity in kidney may reflect alterations in fucose-containing glycosubstances of glomerular basement membranes.

ISSN:0031-3998    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

ExtractThere are several reports of secretory and other abnormalities present in cultured fibroblasts from patients with cystic fibrosis (CF). We have, therefore, investigated aspects of complex saccharide synthesis and secretion by such cells compared with fibroblasts derived from heterozygous (HZ) parents and from normal (N) children. The main glycosaminoglycans produced by skin fibroblasts duringin vitroculture were hyaluronic acid, heparan sulfates, and dermatan sulfate-like materials. Using double-label experiments with D-[3H]- or [14C]glucosamine and analyzing the products by ion exchange chromatography, it was shown for five CF, two HZ, and four N lines that these polysaccharides were secreted into the medium in approximately similar proportions to each other. Moreover, experiments in which three CF, nine HZ, and three N lines were grown in log phase for up to 5 days in the presence of [36S]sulfate and [3H]glucosamine indicate that, during such a period, CF fibroblasts do not secrete complex carbohydrates at rates significantly different from N or HZ cells. Neither do such cells show an abnormal intracellular accumulation of complex carbohydrates. The latter observation was further confirmed by preparing whole cell autoradiographs during growth of six CF, two HZ, and three N lines in the presence of D-[3H]glucosamine and, subsequently, after addition of unlabeled medium.SpeculationFibroblasts derived from children with cystic fibrosis are not abnormal with regard to their complex carbohydrate metabolism.

ISSN:0031-3998    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

ExtractThe widespread use of phototherapy for neonatal jaundice has caused some concern since little is known about the cellular consequences of such treatment. The present study was undertaken to determine the effects of photoactivated bilirubin on the structure of purified deoxyribonucleic acid. DNA illuminated in the presence of bilirubin exhibited altered physical chemical properties as evidenced by (1) a changed thermal helix coil transition profile, (2) a sensitivity of the treated DNA to alkaline degradation, and (3) a limited depolymerization of single-stranded DNA. The above changes were observed with a total light dosage representing only 5% of that received by a newborn infant during a 24-hr period of phototherapy in our nursery.SpeculationIn view of the known relationship between ability to modify cellular DNA and mutagenic and/or carcinogenic potential, the present results suggest that phototherapy is a complex process which may have potentially dangerous sequelae.

ISSN:0031-3998    

出版商:OVID    

年代:1975

数据来源: OVID

ISSN:0031-3998    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

ExtractKinetic data are presented for the decarboxylation of branched chain α-ketoacids (BCKA) by intact human fibroblasts. Cultured cells of normal individuals and nine patients with different clinical pictures of maple syrup urine disease (MSUD) are studied with both α-ketoisocaproic acid (2-oxo-4-methylpentanoic acid (KIC)) and α-ketoisovaleric acid (2-oxo-3-methylbutanoic acid (KIVA))

ISSN:0031-3998    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

ExtractPyritinol-HC1 was tested for its impact on the cognitive functions of children with learning disabilities. This study is a contribution to scientific discussion on the complicated methodologic problems in evaluating the clinical efficacy of psychopharmacologic agents.Sixty-seven pupils of slow learner classes between the ages of 11 and 16 years were treated for 6 months with 300 mg pyritinol-HCl/24 hr or placebo under strict double-blind conditions. Drug intake was stimulated and controlled by means of intense psycho-social interaction with the mothers of the subjects.The dependence variables used to test medication effects were 22 parameters of cognitive performance measured in psychologic tests for perceptual and intellectual functions which were administered immediately before and after the medication phase.First the gainscores before and after treatment with pyritinol or placebo within the 22 cognitive parameters were statistically compared. In addition, an analysis of covariance on the corrected results of the second test (treating the results of first testing as covariates) and a two group discriminant analysis for overall differences were performed.None of the 22 parameters showed statistically significant treatment effects with respect to average performance (t(pyritinol - placebo) = 1.96 to 1.31), neither could the two groups be separated by discriminant analysis (Hotelling'sT2= 35.4,df—22 and 43,P= 0.465).With respect to variability of gainscores, however, in four parameters there was a significantly higher variance in the pyritinol group (F= 1.85–2.33,P< 0.05, < 0.02, respectively). This fact may signify that pyritinol-HCl had different effects on different subjects. By means of prognostic stratification we therefore attempted to define objective criteria for a selection of subjects with probable positive treatment effects. None of the 15 tested criteria, such as body weight, age, perceptual handicaps, or reduced short term memory, IQ range, proved, however, to be critical for a prognosis of pyritinol effects within the present test population.SpeculationAlthough there is no evidence for a general improvement of cognitive functions within the whole test population through treatment with pyritinol-HCl, the results presented suggest slight medication effects in a positive as well as a negative direction for not as yet specifiable subpopulations. The definition of objective indications for the drug seems to be a major problem in testing psychopharmacologic agents.

ISSN:0031-3998    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

ExtractPolyamine concentrations have been measured in blood samples from a series of cystic fibrosis (CF) patients and control subjects. Analyses were made by a fluorometric method, in which the amines were reacted with dansyl chloride and separated by thin layer chromatography on Kieselguhr. There was no significant difference between the polyamine concentrations of blood samples from CF patients and control subjects. Also, the spermidine-spermine ratio was similar in both groups. Polyamines were also analyzed in exocrine fluids, and although none could be detected in either CF or control sweat or saliva, significant amounts of spermine and spermidine were present in all samples of bile and duodenal fluids. It thus seems likely that the biliary route is a significant pathway in the human for excretion of polyamines.SpeculationThe observation that polyamines are excreted in considerable concentrations via the bile in children may be of interest in view of the reports of elevated urinary polyamine concentrations in neoplastic states. Since measurable amounts of spermine and spermidine

ISSN:0031-3998    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

ExtractThe ability of εamino caproic acid (EACA)-treated normal serum and of cystic fibrosis (CF)-affected and carrier sera to promote the release of lysosomal enzymes from sensitized human polymorphonuclear leukocytes (PMN) was assessed through the measurement of β;-glucuronidase and myeloperoxidase acitivity after exposure of these cells to the various test sera. This study was initiated to extend the analogies between preciliary dyskinesia factor (pre-CDF), separated from the cell-free media of cultures derived from CF homozygous and heterozygous individuals, and C3a anaphylatoxin. The extent of lysosomal degranulation of human PMN exposed to fresh untreated sera of each of five controls, seven CF homozygotes, and eight heterozygotes, as expressed by the amount of β-glucuronidase released, was 7.84% (± 0.934) for control sera, 14.01% (±1.79) for CF-affected sera, and 10.61% (±1.43) for heterozygous sera. The difference between CF homozygotes and control subjects is significant (P<0.001), as is the difference between CF-affected and carrier individuals (0.001 <P< 0.005) and between control subjects and carriers (0.001 < P < 0.005), when β;-glucuronidase release is measured. Analogously, values of myeloperoxidase released by the three groups studied reflect differences similar to those of β;-glucuronidase. However, the differences between control subjects and CF heterozygous individuals are not significant. Treatment of these sera with 1 M EACA gave values for β-glucuronidase and myeloperoxidase release which are slightly reduced when compared with those obtained with fresh, untreated samples. EACA apparently reduces the activity of β;-glucuronidase released from PMN. Amicon filtration studies of these serum samples demonstrated that degranulating ability and the presence of ciliary dyskinesia, as assessed by rabbit tracheal bioassay, are not always associated. Therefore, the relationship between pre-CDF and the degranulator activity in native CF-affected and carrier sera is unclear, in part because of the limitations inherent in the test systems employed.SpeculationThe pathophysiology of CF can be explained by excessive degranulation of exocrine glandular cells, resulting in inspissation of their ducts. The finding of degranulator molecules in CF sera allows for a test of this hypothesis. The possibility exists that this degranulating activity, as well as the molecules responsible for ciliary dyskinesia, whether they are the same or different molecular species, may represent an excess of normal products. These molecules, related to C3a anaphylatoxin and/or kinins, are present in excess in CF because of the deficiency of an enzyme which normally controls their level by inactivation.

ISSN:0031-3998    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

ExtractEighty-nine kidneys obtained from human fetuses, 6–31 weeks of gestational age, were studied for the presence of apical periluminal antigen. Sera of rats in which nephrotic renal disease had been produced and which were known to contain considerable amounts of periluminal antibodies were used. Of the less than 12-week-old fetal kidneys, 24% showed the presence of periluminal antigen and this value increased (up to 100%) in older fetuses.SpeculationIt is believed that this observation favors the concept that this antigen is synthesized in proximal tubular cells rather than reabsorbed into them. This supports the concept that the experimental model is an endogenous complex disease. In accordance with these results, the disease incidence, using human fetal kidneys and kidneys obtained from newborn rats, was 60% and 62%, respectively.

ISSN:0031-3998    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

ExtractThe effects of intravenous infusion of arginine (20 g/m2) after an overnight fast on plasma immunoreactive growth hormone (GH), insulin (IRI), and glucagon (IRG), and blood glucose were examined in five groups of children and adolescents: 10 normal individuals, 18 with idiopathic short stature, 6 with isolated growth hormone deficiency, 8 with panhypopituitarism, and 6 with anorexia nervosa. The mean fasting plasma GH concentration was significantly elevated in the group with anorexia nervosa (P< 0.05), and similar to the value for the normal group in all other groups. After arginine infusion, four- to sixfold increases of plasma GH were observed in the normal children, and similar increases were seen in those with idiopathic short stature as well as in those with anorexia nervosa; whereas, in the children with isolated growth hormone deficiency or panhypopituitarism, there was no significant increase in plasma GH. Fasting blood glucose concentrations were significantly lower than normal in subjects with isolated growth hormone deficiency (p< 0.05), panhypopituitarism (P< 0.001), and anorexia nervosa (P< 0.001), whereas fasting plasma IRI and IRG concentrations were similar to the values in the normal group. Plasma IRI increased eightfold at the end of the 30-min arginine infusion in the normal subjects; the increase was slightly but not significantly less in those with idiopathic short stature, and significantly less in those with isolated growth hormone deficiency (P< 0.05), panhypopituitarism (P< 0.001), and anorexia nervosa (P< 0.05). Arginine infusion resulted in two- to threefold increases of plasma IRG in the normal group, and similar increases were observed in all of the other groups tested. These results suggest that whereas pancreatic β cell responsiveness may be deficient in children and adolescents with isolated growth hormone deficiency, panhypopituitarism, or anorexia nervosa, pancreatic a cell responsiveness, to arginine at least, appears to be intact under these conditions.SpeculationAlthough plasma glucagon responses to arginine infusion were not less in subjects with hypopituitarism or anorexia nervosa than in normal subjects, relative hypoglucagonemia may have existed, since both basal and postarginine infusion plasma glucagon levels were not higher than normal in the presence of significantly lower blood glucose values. Thus, the present study does not exclude a deficient pancreatic α cell response to hypoglycemia. Alternatively, nonavailability of substrates for gluconeogenesis may have a more important influence than hormonal factors in the genesis of the hypoglycemia observed in these states.

ISSN:0031-3998    

出版商:OVID    

年代:1975

数据来源: OVID