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Biomedical subjects

C Wagner

Publications and source records attributed to C Wagner.

At least 235 records · Page 13Linked to original sources
PubMed1991

Effects of ozone on the respiratory health, allergic sensitization, and cellular immune system in children.

To investigate the lasting effects of high ozone concentrations under environmental conditions, we examined the respiratory health, pulmonary function, bronchial hyperresponsiveness to methacholine, allergic sensitization, and lymphocyte subpopulations of 10- to 14-yr-old children. A total of 218 children recruited from an area with high ozone concentrations (Group A) were tested against 281 children coming from an area with low ozone concentrations (Group B). As to subjective complaints, categorized as "usually cough with or without phlegm," "breathlessness," and "susceptibility to chest colds," there was no difference between the two groups. The lung function parameters were similar, but in Group A subjects' bronchial hyperresponsiveness occurred more frequently and was found to be more severe than in Group B (29.4 versus 19.9%, p less than 0.02; PD20 2,100 +/- 87 versus 2,350 +/- 58 micrograms, p less than 0.05). In both groups the number of children who had been suffering from allergic diseases and sensitization to aeroallergens, found by means of the skin test, was the same. Comparison of the total IgE levels showed no difference at all between the two groups. As far as the white blood cells are concerned, the total and differential cell count was the same, whereas lymphocyte subpopulations showed readily recognizable changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollution↗
PubMed1990

Pipecolic acid biosynthesis in Rhizoctonia leguminicola. II. Saccharopine oxidase: a unique flavin enzyme involved in pipecolic acid biosynthesis.

The fungal parasite Rhizoctonia leguminicola produces two indolizidine alkaloids, slaframine and swainsonine, of physiological interest. These alkaloids are biosynthesized from pipecolic acid which in turn is derived from L-lysine in this fungus as shown in the accompanying paper (Wickwire, B.M., Harris, C.M., Harris, T.M., and Broquist, H.P. (1989) J. Biol. Chem. 265, 14742-14747): L-lysine----saccharopine----delta 1----piperideine-6- carboxylate----pipecolate. This paper concerns the discovery, purification, and properties of a flavoenzyme, termed saccharopine oxidase, which carries out the oxidative cleavage of saccharopine as follows: Saccharopine + O2----delta 1-piperidine-6-carboxylate + glutamate + H2O2 The enzyme was purified 2,000-fold to homogeneity (polyacrylamide gel electrophoresis) in 14% yield from R. leguminicola mycelia, and had a native molecular mass of about 45,000 daltons by gel filtration (fast protein liquid chromatography Superose). Evidence for the presence of a flavin in the enzyme was drawn from these considerations: (a) the enzyme, while oxidatively cleaving saccharopine, concomitantly reduces 2,6-dichlorophenolindophenol; (b) the purified enzyme has a fluorescence spectrum typical of flavins; and (c) the enzyme requires oxygen and produces hydrogen peroxide. Good correlation was shown with purified saccharopine oxidase between disappearance of saccharopine with the concomitant appearance of delta 1-piperideine-6-carboxylate plus glutamate. The enzyme has a pH optimum about 6 and a Km for saccharopine of 0.128 mM. The enzyme apparently exists in R. leguminicola to shunt saccharopine, a major lysine metabolite, into a secondary pathway of lysine metabolism leading to pipecolate and subsequently to slaframine and swainsonine.

Amino Acids↗
PubMed1990

Kinetics of secondary metabolite formation by wild type and mutant strains of Streptomyces griseus.

In a particle containing medium, the kinetics of formation of secondary metabolites of a Streptomyces wild type and a mutant strain were determined by spectrophotometric measurements of the anthracyclinone pigments and by the analysis of antibiotic activity of the substances produced. The results were related to the physiological state of the culture derived from the oxygen supply. The total cultivation time was about 400 hours. The production of secondary metabolites started at the end of the logarithmic growth phase (after about 30 hours). During the following cultivation remarkable differences between the two strains regarding the formation of pigments and antibiotics occurred. In the wild type strain producing daunomycinone glycosides and related compounds with antibiotic activity, these antibiotics are active as inhibitors (negative feedback). Therefore, at a certain concentration of antibiotics, the de-novo formation of anthracycline molecules was impaired. In the mutant strain, as the result of a genetic change, the secondary metabolite production was shifted to nonglycosylated compounds. The production of these substances is not influenced by feedback inhibition as in the case of the wild type strain. From that reason the amount of pigment increased slightly throughout the course of the experiment. Under our experimental conditions the measurement of oxygen supply was a suitable indicator of the physiological state of culture.

Antibiotics, Antineoplastic↗
PubMed1990

Sigmoid volvulus in childhood.

Although it is common in the adult population, sigmoid volvulus is unusual in childhood. We report the cases of four children treated for sigmoid volvulus, and we review an additional 44 cases. The mean age of occurrence was 8 years. Predisposing factors were present in 33%. Abdominal pain (66%), vomiting (31%), and obstipation (10%) were the most common symptoms. Abdominal findings included distention (69%), tenderness (41%), and a mass (10%). The classic roentgenographic omega sign of volvulus was present on plain films in only 29% of the cases. Barium enema examination was diagnostic in 61% of the cases in which it was used. Nonoperative treatment by barium enema or proctoscopy was successful in all 17 cases in which it was attempted. The recurrence rate after nonoperative treatment was 31%. Thirty children had operation. The mortality in the group of patients having "derotation" alone was 29%. Immediate resection was associated with a 25% mortality; none of the patients who had elective resection died. Sigmoid resection is the definitive treatment for children as well as adults, but nonoperative decompression to allow for elective resection should be attempted in patients who have no evidence of peritonitis.

Adult↗
PubMed1990

[Incidence of caries and degree of dental hygiene in nursery school children of the City of Heidelberg and the Rhine-Neckar district].

A study conducted by the Heidelberg Public Health authorities shows that mass examinations by dental surgeons in kindergartens enhance the degree of "cleanup" achieved in "first teeth" sets. The continual contact between Public Health authorities and the kindergartens also results in motivating the educationists to promote increased inclusion of the subject "Teeth and Health of the Human Denture" in the kindergarten itineraries. Special prophylaxis programmes will have to be worked out in future for a small group of children in whom dental caries is particularly active, since such children are not covered by group prophylactic measures.

Child Day Care Centers↗
PubMed1990

[Determination of hemoglobin concentration using the hemoglobin azide method in traumatic emergencies].

UNLABELLED: The present study examined the clinical practicability of a new hemoglobin measurement device based on a modified azide-methemoglobin reaction (HiN3 method) in trauma patients. The accuracy of the HiN3 method was compared to the internationally well accepted hemiglobincyanide method (HiCN method) in arterial, capillary, and venous blood samples. PATIENTS AND METHODS: 1. Comparison of the methods. In 62 trauma patients, hemoglobin measurements using the HiN3 method were compared to results obtained by the HiCN method. Blood samples were taken simultaneously from the same patient to evaluate each measurement procedure in arterial (group 1), capillary (group 2), and venous blood samples (group 3). 2. Accuracy. To evaluate the accuracy of both methods we compared two venous blood samples taken simultaneously from the same patient. 3. Reproducibility. For measurement of the reproducibility of the HiN3 method, the first two results of each three-time-measurement were compared. Statistical analysis of the results was performed using regression analysis. RESULTS: 1. Comparison of the methods. Comparing the results of hemoglobin measurements resulting from the HiN3 and HiCN methods, a strong correlation was found in arterial (Fig. 2), capillary (Fig. 3), and venous blood (Fig. 4). 2. Accuracy. The HiN3 method had an accuracy of +/- 1.47% and the HiCN method +/- 2.55%. 3. The reproducibility of the HiN3 method was +/- 1.25% (Fig. 5); however, one pair of samples did show a significantly different initial value (Hb 8.4 g/dl in I, but 10.4 g/dl in I and III). DISCUSSION: From our examinations in trauma patients, we can recommend this easy to handle device, particularly for acute diagnostic purposes in emergency patients and for trend evaluations both in the hospital and in the prehospital period for rapid and precise hemoglobin determinations.

Adult↗
PubMed1989

Phosphorylation modulates the activity of glycine N-methyltransferase, a folate binding protein. In vitro phosphorylation is inhibited by the natural folate ligand.

Glycine N-methyltransferase (EC 2.1.1.20) was recently identified as a major folate binding protein of rat liver cytosol (Wagner, C., and Cook, R. J. (1984) Proc. Natl. Acad. Sci. U.S.A. 81, 3631-3634). Activity of the enzyme is inhibited when the natural folate ligand, 5-methyltetrahydropteroylpentaglutamate (5-CH3-H4PteGlu5), is bound. It has been suggested that glycine N-methyltransferase plays a role in regulating the availability of methyl groups in the liver. Purified transferase was phosphorylated in vitro by the catalytic subunit of cAMP-dependent protein kinase. If 5-CH3-H4PteGlu5 was first bound to the transferase, phosphorylation was inhibited. Phosphorylation of glycine N-methyltransferase in vitro increased its activity approximately 2-fold. 5-CH3-H4PteGlu5 inhibited the activity of newly phosphorylated enzyme as well as native enzyme. Freshly isolated rat hepatocytes incorporated 32P-labeled inorganic phosphate into this folate binding protein. Chemical analysis of purified enzyme showed about 0.55 mol of phosphate present per mol of glycine N-methyltransferase subunit. These results indicate that phosphorylation of glycine N-methyltransferase may provide a mechanism for modulating the activity of this enzyme and support its role in regulating the availability of methyl groups.

Animals↗
PubMed1989

Advances in bioconversion of anthracycline antibiotics.

During the last decade new anthracycline-type structures with potential usefulness in cancer treatment have been supplied both by new microbial strains and by bioconversions of precursor molecules employing cells or enzymes. We highlight recent advances in bioconversion of anthracycline structures with the main focus on late transformations such as are carried out by oxidoreductases.

Journal Article↗
PubMed1989

Extracorporeal shock wave lithotripsy in a renal transplant patient.

We report a case of nephrolithiasis in a transplanted kidney that was treated successfully with extracorporeal shock wave lithotripsy. The patient experienced transient partial obstruction after lithotripsy and, thus, intense monitoring of the transplant patient is necessary.

Adolescent↗
PubMed1989

Effect of dietary methyl group deficiency on one-carbon metabolism in rats.

Amino acid-defined diets deficient in methyl groups have been shown to result in a very high incidence of hepatocellular carcinoma. It has been suggested that this is a result of decreased levels of S-adenosylmethionine and the undermethylation of DNA. Accordingly, the enzyme glycine N-methyltransferase (GNMT, EC 2.1.1.20) may play a major role in maintaining the levels of S-adenosylmethionine in liver in response to changes in dietary methionine. The effect of methyl-deficient, amino acid-defined diets on GNMT activity and S-adenosylmethionine levels in rat liver was therefore investigated. When rats were fed a defined amino acid diet containing no choline in which homocysteine was substituted for the methionine of the control diet at an equimolar level, there was a rapid and marked decrease in growth rate in spite of the fact that the rats consumed 85% of the food eaten by control rats fed a nutritionally adequate, defined amino acid diet. The GNMT activity in livers of methyl-deficient rats decreased rapidly, but there was no difference in amount of GNMT protein as measured immunologically. In methyl-deficient rats, the levels of S-adenosylmethionine were maintained but the levels of S-adenosylhomocysteine were rapidly elevated compared to control values. These changes are consistent with the postulated role of GNMT in regulating methyl group metabolism.

Amino Acids↗
PubMed1989

Effect of dietary methyl group deficiency on folate metabolism in rats.

The carcinogenic effects of methyl-deficient, amino acid-defined diets have been attributed to alterations in cellular methylation reactions. These diets contain no choline, and methionine is replaced by homocysteine. Hence, all methyl groups needed for methionine biosynthesis with subsequent formation of S-adenosylmethionine and polyamines must be formed de novo utilizing folate-dependent reduction of one-carbon units. In rats fed the methyl-deficient diet, there was a marked decrease in total liver folate levels. This decrease was apparent in the levels of the individual forms of folate: 10-HCO-H4folate, 5-HCO-H4folate, 5-CH3-H4folate and H4folate. The percent of the total folate pool made up by 5-CH3-H4folate did not change, however, until after the rats had been fed the methyl-deficient diet for 4 wk, and then an increase was seen. After the methyl-deficient rats were switched to a nutritionally adequate control diet containing methionine and choline, all values rapidly reversed. Increased use of folate for methyl group biosynthesis may be responsible for the loss of folates from the liver.

Amino Acids↗
PubMed1989

Relationship between heparin binding characteristics and ability of human spermatozoa to penetrate hamster ova.

Heparin binding site affinity and density on human spermatozoa were compared between fertile and infertile men with normal or abnormal results in the zona-free hamster ova-sperm penetration assay (SPA). A portion of fresh semen from fertile donors and potentially infertile men was processed through the SPA while the remainder of the ejaculate was used to quantitate heparin binding on spermatozoa. Saturation binding assays with [3H]heparin (15-375 nM) were analysed for 3 groups of men: (1) infertile patients with abnormal SPA results, (2) infertile patients with normal SPA results and (3) fertile donors. The heparin binding site density was significantly higher in men who possessed normal SPA results (infertile men and fertile donors) than in infertile men with abnormal scores in the SPA. There was no difference in heparin binding affinity between the three groups. These findings suggest that the heparin binding-site density may be related to the ability of human spermatozoa to undergo successfully the acrosome reaction.

Animals↗
PubMed1988

Biosynthesis of anthracyclinones.

Recent biosynthetic studies confirmed that anthraquinones are involved as intermediates in the pathway to anthracyclines. The present knowledge in this field has been reviewed. Furthermore, a new generalized order of biosynthetic intermediates from the hypothetical polyketide to aklavinone and related anthracyclinones has been proposed involving tricyclic precursors and 7-hydroxy-naphthacenequinones, which also have been found in mutants of anthracycline-producing strains.

Anthraquinones↗