摘要:

ExtractIt has not been determined whether Rhoo(D-negative infants born of Rho(D)-positive mothers are sensitized during gestation or during parturition. Sensitization before use precludes the efficacious use of human Rhoimmune globulin as a prophylactic. The purpose of the present study is to identify the time of sensitization. Cord blood was collected from the placentas of 68 Rho(D)-negative infants whose mothers were Rho(D)-positive. Sixty-three of the 68 infants had one blood sample obtained between 1 and 9 months later. The paired samples were analyzed for anti-D by standard Coombs test and by automated antibody detection techniques. With the technique of automated antibody detection, we have been unable to demonstrate antibody in cord blood of the Rho(D)-negative infants of whom at least 7 of 63 (11 %) had detectable anti- D between 1 and 9 months of age. These data show that Rho(D)-negative infants do not have detectable antibody at birth but may develop detectable anti-D in the first months of life. This observation suggests that the sensitizing dose of Rho(D) antigen occurs at parturition rather than during gestationSpeculationThe detection of anti-D in Rho(D)-negative infants born of Rho(D)-positive mothers confirms the neonate's ability to respond to antigen exposure. If Rho(D)exposure produces sensitization only at parturition as this study implies, then there may be an immunoprophylactic role for human Rhoimmune globulin in the neonate.

ISSN:0031-3998    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

ExtractTwo previously described sisters with folic acid nondependent formiminoglutamic aciduria also excrete abnormally high amounts of hydantoin-5-propionic acid (HPA). HPA was identified by gas chromatography-mass spectrometry as theN,N′-bis-trimethylsilyl methyl ester- andN,O-permethyl derivatives. About 600 and 1,100 mmol HPA/mol creatinine, respectively, were found in 24-hr urine samples before and after ingestion of free histidine (three equal doses of 66 mg/kg each, with 4-hr intervals). The corresponding values in normal adults were 4.5 ±2.2 (n= 24) and 46.0 ± 16.4 mmol HPA/mol creatinine (n= 17) when measured by a new, highly specific mass fragmentographic method using deuterated HPA as the internal standard.SpeculationFormation of hydantoin-5-propionic acid from imidazolone propionic acid (ImOPA) by aldehyde oxidase represents a bypass at elevated concentrations of ImOPA caused,e.g., by formimino-L-glutamate:tetrahydrofolate-5-formiminotransferase (EC. 2.1.2.5) deficiency (as postulated for our cases), general or functional folate deficiency, or imidazolone propionic acid hydrolase deficiency (not yet detected). HPA excretion in urine measured by mass fragmentography may be a sensitive tool to detect such deficiencies and may complement or even replace the enzymatic measurement of formiminoglutamic acid excretion.

ISSN:0031-3998    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

ExtractThis paper describes an experiment of nature involving a chimeric calf with mannosidosis which had obtained a natural transplant of lymphocytes from its normal twin during fetal development as a result of fusion of the placentas. Karyotyping of 200 peripheral blood lymphocytes showed that 77% were 60,xx and 23% 60,xy. The α-mannosidase pH dependence activity profiles obtained for the chimera were similar to those for a mannosidosis calf in brain, liver, kidney, and plasma but for peripheral lymphocytes and lymph node extracts enzyme activities approaching those of the normal control calf were measured at pH 4.0–4.3. In the chimera, vacuolation of macrophages and fixed reticuloendothelial cells in lymph nodes and of pancreatic exocrine cells was considerably less than was observed in any of the 35 other calves with mannosidosis. There were considerably fewer oligosaccharides in the brain, lymph node, and liver of the chimera calf than in any of the five mannosidosis control calves. There is little doubt that the α-mannosidase produced by the population of normal cells influenced the pathology of the disease, but failure to significantly prevent the eventual clinical course even under these favorable transplant conditions is indicative that tissue or organ transplants are unlikely to be a successful cure for diseases with severe neurologic manifestations. If this disease had been purely visceral then it is postulated that the transplant would have been reasonably effective.SpeculationAlthough acidic α-mannosidase supplied by a natural transplant of lymphocytes, and perhaps other cells, was unable to cure or prevent all clinical manifestations of mannosidosis, the therapeutic effect noted in visceral organs indicates that transplants may be an effective means of treating some inborn errors of lysosomal catabolism that occur without severe neurologic involvement. The reduction of storage material within the brain of the chimera suggests that larger amounts of exogenous enzyme supplied over a prolonged period might be more effective in storage diseases with neurologic manifestations. If it can be established that a concentration gradient for storage material exists between certain tissues and tissue fluids then it may not be essential to actively deliver enzyme to the central nervous system.

ISSN:0031-3998    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

ExtractIn human fetal liver ornithine decarboxylase (EC. 4.1.1.17 (ODC)) was found to have a K, of 3.3 x 10−4M. During human fetal development, hepatic ODC activity declined from a peak of 379 pmol/60 min/mg protein in the youngest tissue examined (5.2 cm crown-rump length, 10 weeks of gestation) to values of 1.3 ± 0.2 in fetuses greater than 12 cm (14–15 weeks of gestation). Explants of human fetal liver maintained in organ culture for 32 hr demon-strated no ODC activity in the presence or absence of insulin (1 U/ml). Explants of rat fetal liver achieved a steady state of ODC activity (12% of the fresh tissue activity) after 16 hr in organ culture and maintained this for an additional 14 hr.SpeculationRegulation of hepatic ODC activity in the developing human fetus may result from hormonal influences, particularly human growth hormone (HCH) and very possibly human chorionic somatomamotropin (HCS).

ISSN:0031-3998    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

ExtractNine distressed premature lambs were studied before, during, and after ventilation with fluorocarbon liquid (FC-80). It was found that premature lambs, delivered by cesarean section, could be adequately ventilated with oxygenated liquid for periods up to 3 hr. Using fluarocarbon liquid in conjunction with the described liquid breathing system, it was possible to maintain remarkably good pulmonary gas exchange and acid-base balance during normothermic conditions. In addition, peak intratracheal pressures measured during recovery from liquid ventilation were significantly reduced (P < 0.001) as compared with preliquid ventilation values. This improvement in lung function is in direct contrast to the deterioration in that of the adult animal following liquid ventilation as reported previouslySpeculationAlthough an enormous amount of studies remain to be performed, at this time it is appealing to speculate about the possibilities of this therapeutic modality in the preterm human neonate with respiratory distress. We cannot help but think that this method of therapy serves a twofold purpose: (1) maintenance of infants with lungs too stiff to ventilate with gas, and (2) a treatment for reducing surface-active forces in infants with marginal lung stability

ISSN:0031-3998    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

ExtractWhole blood lactate, pyruvate, and oxygen concentrations were measured simultaneously in the umbilical vein, fetal femoral artery, maternal artery, and uterine vein in 14 chronically catheterized pregnant ewes and their fetuses. Lactate was found to be taken up in significant amounts across the placental circulation by the fetuses, whereas pyruvate was not.The lactate concentration of fetal blood was higher than that of maternal blood; however, fetal lactate levels correlated with maternal arterial levels (P≤ 0.01). The mean lactate concentrations in all samples were: common umbilical vein, 2.105 mM; fetal femoral artery, 1.986 mM; and maternal artery, 0.823 mM. Where uterine venous lactate concentrations were measured, the lactate content of the uterine vein exceeded that of the maternal artery by a mean of 0.088 mmol/liter (P< 0.005). The mean fetal gain in lactate across the placental circulation was 0.118 mmol/liter (P< 0.005). This is equivalent to a gain of 1.2 g carbon/kg/24 hr by the growing lamb fetus. The mean fraction of fetal oxygen consumption that could be accounted for by oxidation of lactate was 0.32.The pyruvate concentration of fetal blood was higher than that of maternal blood; however, fetal pyruvate levels correlated with maternal arterial levels (P< 0.05). The mean pyruvate concentrations in all samples were: common umbilical vein, 0.084 mM, fetal femoral artery, 0.094 mM; and maternal artery, 0.053 mM. Where uterine venous pyruvate concentrations were measured, they exceeded the maternal arterial concentrations by a mean of 0.005 mmol/liter (P= 0.001). Pyruvate appeared to be lost by the fetus across the placental circulation by a mean of 0.010 mmol/liter. This loss of pyruvate correlated with the placental fetal to maternal pyruvate concentration gradient (P< 0.05).Correlations between maternal arterial and fetal lactate concentrations imply that fetal lactate levels are influenced by maternal levels. The increase in lactate concentration of both fetal and maternal blood during circulation through the placenta indicates placental production of lactate. The pyruvate concentrations observed, however, are consistent with either fetal to maternal flow of pyruvate or placental productionSpeculationLactate, after glucose and amino acids, is the third most important fetal substrate identified in the fetal lamb. Its role as a fetal fuel now needs to be evaluated in other animal species.

ISSN:0031-3998    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

ExtractThe carcinoembryonic antigen (CEA) activity was measured in urine, saliva, and plasma in children with and without cystic fibrosis (CF). Serial determinations of plasma CEA were also made in four of these patients to determine whether plasma CEA level varies with changes in clinical condition. Characterization of CEA-active molecules in the saline extracts of urine, saliva, plasma, and sputum were made with the technique of Sepharose 6B column chromatography. The plasma CEA levels (4.4 ± 2.4 ng/ml) in CF children were found to be significantly higher than the reported upper range for normal subjects (2.5 ng/ml), or those for our control patients of comparable age 1.6 ± 0.7 ng/ml). Good correlation (correlation coefficient 0.87) was found between the levels of plasma CEA and Schwachman scores in 22 patients. Parallel changes of plasma CEA levels with changes in the clinical condition were also observed in the follow-up studies. In these four patients the plasma-CEA level was best correlated with the profuseness of rales and rhonchi and the amount of sputum production. Although CEA activity was present in the urine and saliva of CF patients, the CEA concentration did not differ significantly from that of normal control subjects.Column chromatography was performed on urine, saliva, plasma, and sputum from patients with cystic fibrosis. One heterogenous peak with a molecular weight of approximately 200,000 was noted in all fluids examined and was similar to the CEA peak obtained from colon tumors. Another peak appeared in the void column which corresponded to a molecular weight equal to or greater than 1 million. The latter peak was found in all fluids except plasma. The activity profiles of CEA activity of the physiologic fluids in normal patients and patients with cystic fibrosis were similarSpeculationThe correlation of plasma CEA levels with the amount of sputum production in patients with CF may explain the similar elevation of Plasma-CEA in chronic bronchitis, pulmonary tuberculosis, pneumonia, and in smokers. In all of these subjects there is an increase in sputum production. It is also possible that CEA-active glycoproteins in the sputum and in the plasma of patients with cystic fibrosis are disease-associated abnormal glycoproteins. Further investigation may provide new leads to the pathogenesis of cystic fibrosis

ISSN:0031-3998    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

ExtractThe influenza A/Hong Kong/1968-ts-1[E] (H3N2) candidate live virus vaccine strain, which had previously been shown to be safe and protective in seronegative adult volunteers, was administered intranasally to 21 children at a dose of 105TCID50. One group contained 15 children (5–11 years of age) who lacked serum anti-body to the hemagglutinin (≤ 1:8), but possessed serum antibody to the neuraminidase antigen. The second group included six children (2/4/12–3/10/12 years of age) who lacked serum antibody to both hemagglutinin and neuraminidase surface antigens of the influenza A virus. Twelve of the 15 children in the first group were infected, but only one child developed mild rhinitis; 6 of the 12 infected vaccinees shed virus for a short interval, while 11 of the group developed …

ISSN:0031-3998    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

ExtractRat fetal livers were homogenized and incubated for up to 3 hr in Eagle's medium. Both phosphoenolpyruvate carboxykinase (PEPK) and tyrosine transaminase (TTA) activities in the high speed supernatant increased 5-fold and 10-fold, respectively, during incubation. Neither cycloheximide nor actinomycin D inhibited this rise in activity. Inasmuch as no change in activity during incubation was found in the whole homogenate, it is concluded that a redistribution of the enzyme occurs between cell fractionsSpeculationIt is suggested that the initial increase in TTA and PEPK activities in the liver very soon after birth may be due to release of preformed enzyme from polysomes and that this triggers a sequence of events leading to new enzyme synthesis

ISSN:0031-3998    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

ExtractThis paper reports the investigation of a case of Hartnup disorder, in which tolerance tests were carried out with a mixture of free amino acids simulating casein and a partial enzymic hydrolysate of casein containing small peptides. The investigation also included measurement of renal clearances of amino acids. The patient, a girl aged 26 months, was given by mouth 5 g amino acid mixture in water, blood samples being taken before the dose and at 15, 30, and 45 min after the dose. The procedure was repeated with an equivalent dose (4.7 g) of the enzymic hydrolysate, containing the same amount of nitrogen. The results were compared with those from six normal adults Who were given 10 g amino acid mixture and on another occasion an equivalent dose of an enzymic hydrolysate of casein containing small peptides. In the adults, the increments in the plasma level of a given amino acid were similar whether the amino acid mixture or the enzymic hydrolysate was given. In the patient, a different pattern was seen. In some cases (Lys, Arg, and Pro) there was a large increase in plasma levels after both the amino acid mixture and the enzymic hydrolysate, as in the adult controls. In others (Gly, His, Tyr, Ser, Glu) there was no increase or a decrease in plasma levels after the amino acid mixture, but an increase after the enzymic hydrolysate. In a third category (Ala, Val, Leu, He, Met, Phe), increments after the enzymic hydrolysate were greater than after the amino acid mixture. The results with Thr were unexpected: after the amino acid mixture there was an initial rise in plasma levels and after the enzymic hydrolysate an initial fall. Renal clearances of Pro, Glu, Asp, and Lys were normal and those of Arg and Gin were slightly increased. The clearance of Gly was slightly increased and the clearances of His, Tyr, Ser plus Asn, Ala, Val, Leu, He, Met, Phe, and Thr were greatly increased. The results suggest the following. Absorption of free Lys, Arg, and Pro was normal. Absorption of free Gly, His, Tyr, and Ser was probably severely impaired and that of Val, Leu, He, Met, and Phe probably subnormal. Absorption of Glu and Ala was probably also subnormal. We cannot account for the results obtained with Thr. The results indicate that many neutral amino acids are malabsorbed in Hartnup disorder, and that free Glu may also be malabsorbed. Amino acids which are poorly absorbed in the free form are better absorbed from peptides. Most of the amino acids with a substantial increase in renal clearance also provided evidence of malabsorption. The finding of an increased renal clearance of Gly agrees with several previous observations in Hartnup disorderSpeculationIt is now known that di- and tripeptides are taken up intact by the absorptive cells of the small intestine, in addition to free amino acids. After uptake, the peptides undergo hydrolysis. Previous investigations in Hartnup disorder and cystinuria, combined with physiologic investigations, have shown that mucosal uptake of small peptides is independent of that of amino acids. The present investigation of a case of Hartnup disorder suggests that although many neutral amino acids are poorly absorbed in this condition when given in the free form, absorption of all these “affected” amino acids is better when given in peptide form. It appears that the peptide uptake system or systems of the intestinal mucosa are unaffected by the transport defect of Hartnup disorder, and that this is the explanation of the ability of the patients to maintain a reasonable state of nutrition when on an adequate diet, and of the frequent absence of obvious evidence of intestinal disturbance …

ISSN:0031-3998    

出版商:OVID    

年代:1976

数据来源: OVID