PubMed Health⌕ Search

Biomedical subjects

H Wick

Publications and source records attributed to H Wick.

13 recordsLinked to original sources
PubMed1979

[The importance of amino acids].

Complete AS mixtures which permit prolonged parenteral feeding are known. It is possible to achieve normal growth even in nursing infants with such solutions (reference should be made to the contributions of Professor Riccour and Professor Schärli). On the other hand the composition of an AS solution of maximum biological value, e.g. for the growing body, is not yet known. Improvements in this respect can be envisaged although they are relevant only to certain patients. Changes in the method administration of AS may affect the biological value. Continuous administration throughout the 24 hours by-passing the portal vein, as is usual today, must considerably impair the capacity of the liver to regulate the pattern of plasma amino acids. Possibly, an approximation to physiological proportions is possible and useful through intermittent administration. Further progress in this aspect of parenteral feeding can undoubtedly be expected.

Amino Acids↗
PubMed1979

Congenital defect in intracellular cobalamin metabolism resulting in homocystinuria and methylmalonic aciduria. II. Biochemical investigations.

Biochemical investigations are reported in an infant with methylmalonic aciduria and homocystinuria who died at 4 months of age. Postmortem analysis of liver obtained 2 weeks after the child was treated with vitamin B12 revealed deficient activity of both cobalamin dependent enzymes: N5-methyltetrahydrofolate: homocysteine methyltransferase (requiring Me-Cbl), and methylmalonyl CoA mutase (requiring Ado-Cbl). MMA-CoA mutase activity could be restored to normal in vitro by added Ado-Cbl, but MeTHF-HCy transferase activity was not significantly enhanced by addition of Me-Cbl. Though the serum total cobalamin was normal, total cobalamin in liver and kidney was abnormally low. In the kidney Me-Cbl and Ado-Cbl were disproportionally decreased whereas in the liver only Ado-Cbl was significantly reduced. This suggests that at least some of the CN-Cbl administered was converted to the coenzymes in liver which would explain the reduction of MMA- and HCy-excretion during therapy. The results show 1. that this infant suffered from a congenital defect in one of the steps of intracellular cobalamin metabolism or transport common to the synthesis of both coenzymes, 2. that life-long treatment with vitamin B12 (OH-Cbl) may be of value in similar cases, particularly if given early in the course of the disease.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed1979

Congenital defect in intracellular cobalamin metabolism resulting in homocysteinuria and methylmalonic aciduria. I. Case report and histopathology.

The case is described of an infant who suffered from progressive, severe dystrophy, hemolytic and megaloblastic anemia, hematuria, proteinuria and slight uremia. He died at 4 months of age following two acute episodes of heart failure. Abnormally increased excretion of methylmalonate and homocystine was detected by our screening program for metabolic disorders. Amino acid analyses showed that the plasma and urine levels of methionine were very low whereas those of cystathionine were raised. Vitamin B12 deficiency, malabsorption or abnormal cobalamin transport were excluded by a normal serum total cobalamin and normal transcobalamins. These findings suggested a congenital error of cobalamin metabolism. Treatment with vitamin B12 resulted in a biochemical though not a clinical response. Postmortem examination revealed severe vascular lesions with changes in the kidney characteristic of thrombotic microangiopathy supporting a diagnosis of hemolytic-uremic syndrome. It is assumed that the elevated plasma homocysteine induced the vascular lesions by causing detachment of endothelium.

Blood Vessels↗
PubMed1978

An improved method for preparation of samples for the simultaneous assay of some antiepileptic drugs by gas-liquid chromatography.

A new simple extraction method, e.g., for subsequent quantitative determination of some antiepileptic drugs by GLC is described. HCl and an internal standard are added to 100 microliter of plasma or any biological fluid. This mixture is applied directly to an Extrelut column. Lipophilic substances (i.e. the antiepileptic drugs diphenylhydantoin, primidone and phenobarbital) are then extracted into 20 ml of ether and the solvent is evaporated to dryness. Direct GLC analysis of the on-column methylated drugs is performed using a P-N-detector.

Barbiturates↗
PubMed1977

Thiamine dependency in a patient with congenital lacticacidaemia due to pyruvate dehydrogenase deficiency.

A patient with congenital lactic acidosis, muscular hypotonia and severe ataxia is reported. The aetiology of his disease was found to be a deficiency of pyruvate dehydrogenase (E.C. 4.1.1.1.). Thiamine treatment (1.8 g/day) was successful in correcting biochemical and clinical symptoms. The mechanism of its action is probably based on activation of pyruvate dehydrogenase through interference in the physiologic regulation.

Alanine↗
PubMed1977

Diastereoisomeric N-tetrahydrofurfurylnoroxymorphones with opioid agonist--antagonist properties.

The two diastereoisomeric N-tetrahydrofurfurylnoroxymorphones and their hydrochlorides 1a and 1b have been prepared and studied pharmacologically; The N-(R)-tetrahydrofurfuryl derivative 1a proved to be an opioid agonist--antagonist and the N-(S)-tetrahydrofurfuryl derivative 1b a pure antagonist. As an analgesic, 1a is 25 times more potent than morphine, but it does not show morphine-like side effects in mice. In withdrawn morphine-dependent rhesus monkeys, 1a only partially suppresses abstinence. Its therapeutic ratio is exceptionally favorable compared with those of morphine and pentazocine. As antagonists, 1a and 1b have comparable potencies of 0.25 and 0.20 of that of nalorphine, respectively, in vivo. In vitro, however, 1a is 28 times (guinea pig ileum) or 6.5 times (mouse vas deferens) more potent than 1b. The antagonist properties of 1a and 1b were not anticipated according to known structure--activity relationships.

Analgesia↗
PubMed1976

Congenital methylmalonic acidemia: a variant of the B12 'non-responsive' form with evidence for reduced affinity of methylmalonyl-CoA mutase for its B12-coenzyme.

Methylmalonate metabolism was investigated in fibroblasts and leukocytes of two unrelated patient with a B12-nonresponsive type of congenital methylmalonic acidemia. Intact fibroblasts from both patients showed a defective metabolism of methyl-14 c-malonate to 14CO2, whereas no such defect was found in their intact peripheral leukocytes. In disrupted fibroblasts, the conversion of methylmalonyl coenzyme A to succinyl coenzyme A was markedly reduced but was completely normalized by the addition of 5'-deoxyadenosylcobalamin (AdoCb1; 10(-5) mol/l), the specific coenzyme of methylmalonyl coenzyme A mutase. Assays with decreasing concentrations of AdoCbl (10(-5)-10(-11) mol/l) suggested a reduced affinity of the mutase apoenzyme for its coenzyme, implicating yet another variant of this heterogeneous disease.

Amino Acid Metabolism, Inborn Errors↗
PubMed1976

[General pharmacology and secretion inhibitory action of (8r)-3alpha-hydroxy-8-isopropyl-1alphaH,5alphaH-tropanium bromide-(+/-)-tropate (ipratropiumbromide) (author's transl)].

(8r)-3alpha-Hydroxy-8-isopropyl-1alphaH,5alphaH-tropaniumbromide-(+/-)-tropate (ipratropiumbromide, Sch 1000) is a quaternary tropic acid tropane ester with pronounced anticholinergic activities (inhibition of secretion and spasmolysis). The effect of the substance of all parasympathetically innervated organs ist 1.4 to 2 times stronger than that of atropine. As an inhibitor of the secretion of free hydrochloric acid in the stomach it proved to be 5 times more effective than atropine. Central activities were not observed. The duration of action of Sch 1000 exceeds that of atropine by far.

Animals↗
PubMed1976

[The effect of (8r)-3alpha-hydroxy-8-isopropyl-1alphaH,5alphaH-tropaniumbromide-(+/-)-tropate ((ipratropiumbromide) on tracheobronchial spasm, bronchial and salivary secretions, ECG and heart rate (author's transl)].

At very low doses (8r)-3alpha-hydroxy-8-isopropyl-1alphaH,5alphaH-tropaniumbromide-(+/-)-tropate (ipratropiumbromide, Sch 1000, Atrovent) and atropine inhibit acetylcholine-induced bronchospasms in guinea-pigs and dogs. The dose ratio main effect vs. most sensitive side effect (inhibition of saliva secretion) is 1:10 for i.v. injection and 1:100 for aerosol application. When both compounds are administered in a nebulized form bronchodilatation occurs immediately. The maximum effect of Sch 1000 occurs somewhat later than that of atropine but the duration of action is much longer. Bronchial secretion in guinea-pigs is increased by small doses of Sch 1000 and atropine. These doses correspond to bronchodilating doses.

Acetylcholine↗
PubMed1975

Acute neonatal nonketotic hyperglycinemia: normal propionate and methylmalonate metabolism.

Propionyl-CoA carboxylase and combined methylmalonyl-CoA (MMA-CoA) racemase and -mutase activities were studied in liver and fibroblasts of two patients with the acute neonatal form of nonketotic hyperglycemia. In all experiments, these enzyme activities studied in tissues of the patients were within the range of healthy control subjects, whereas no propionyl-CoA carboxylase activity was measurable in the fibroblasts of a patient with propionic acidemia. Subcellular fractionation of liver and fibroblasts indicated that the normal amounts of MMA-CoA found after incubation of whole tissue homogenate were formed by propionyl-CoA carboxylase, a mitochondrial enzyme, and not be acetyl-CoA carboxylase, which theoretically could also be involved in the carboxylation of propionyl-CoA. From the above data as well as from clinical and biochemical observations in three patients, it was concluded that there exists a true nonketotic hyperglycinemia which is not related etiologically to the different disorders of the ketotic hyperglycinemia syndrome. True nonketotic hyperglycinemia is not associated with ketoacidosis even after loading with propionate- and MMA precursors. It must be distinguished by exclusion from mild forms of the ketotic hyperglycinemia syndrome which may present clinically as hyperglycinemia without ketosis.

Acute Disease↗