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Biomedical subjects

J Schultz

Publications and source records attributed to J Schultz.

At least 163 records · Page 9Linked to original sources
PubMed1977

Platelet immuno-assay (PIA) as a simple and sensitive technique for the detection of antigens.

The platelet immuno-assay (PIA) is a simple and inexpensive technique to detect antigens with ng/ml sensitivity using micro-titer equipment and commercially available antisera. It can be easily adapted for virtually any antigen to which rabbit antiserum containing specific IgG-antibodies cna be obtained. The assay is inhibited by IgG and C1q in amounts greater than or equal to 125 microgram/ml and 12.5 microgram/ml respectively. Its application is thus limited to those fluids where IgG and C1q are present in less than these concentrations.

Animals↗
PubMed1977

[Dysontogenetic giant cyst].

Casuistics of congenital dysontogenetic giant cyst which has lead to the displacement and the restriction of the function of the two kidneys. Therapeutic experiment with repeated instillations of formaldehyde for the obliteration of cysts.

Adult↗
PubMed1976

Studies on the chlorinating activity of myeloperoxidase.

Two methods were utilized to demonstrate the peroxidation of chloride ion to a free species (HOCl or Cl2) by myeloperoxidase. The peroxidase caused the volatilization of radioactivity from soultions containing hydrogen peroxide and [36Cl]NaCl, and catalyzed the formation of HOCl when solutions contianing these components were passed through a Millipore filter to which the peroxidase was adsorbed. In this flow system, 90 mug of canine myeloperoxidase generated 80 muM HOCl in the presence of 200 muM H2O2 at a rate corresponding to a turnover of 100 min-1. Under these conditions, o-tolidine, whose oxidation can be coupled to Cl- peroxidation in free solution, did not accelerate turnover. In contrast to chloroperoxidase and horseradish peroxidase, myeloperoxidase does not utilize chlorite for chlorination reactions. This oxidant inactivates the enzyme. At low pH, chloride ion suppresses the oxidation of myeloperoxidase (to the stable compound II) by both hydrogen peroxide and hypochlorite. Acceptor chlorination is therefore not a rate-controlling reaction in the myeloperoxidase mechanism, and the potential of the functional peroxidase couple is higher than the HOCl/Cl- couple under chlorinating conditions. The product-forming step may be a reverse of compound I formation at the expense of HOCl, rather than the chlorination of Cl- by a chloroperoxidase-like chlorinating intermediate.

Animals↗
PubMed1976

Hormone-stimulated glycogenolysis in isolated goldfish hepatocytes.

Hepatocytes isolated from the liver of the common goldfish Carassius auratus L. with crude bacterial collagenase maintained ATP levels for at least 2 h. Glycogenolysis was maximally activated by 1 X 10(-6) M epinephrine and 5.8 X 10(-9) M glucagon. In liver cells incubated in calcium-free buffer containing 1 mM ethylene glycol-bis-(beta-aminoethylether)-N,N'-tetraacetic acid, basal glycogenolysis was enhanced by the addition of 1-4 mM calcium but the elevation of cyclic AMP and glycogenolysis due to epinephrine was unaffected by calcium. The divalent cation ionophore A23187 did not alter basal or hormone-stimulated glycogenolysis. Isoproterenol was approximately as potent as epinephrine but phenylephrine was glycogenolytic only at very high concentrations. l-Propranolol competitively inhibited the increased glycogenolysis due to catecholamines but phentolamine was ineffective as a blocking agent. Isoproterenol and epinephrine stimulated glycogenolysis at lower concentrations than those required to elevate cyclic AMP accumulation. Phenylephrine was without effect on cyclic AMP. Propranolol competitively inhibited both epinephrine- and isoproterenol-stimulated cyclic AMP accumulation, but phentolamine did not block either response. Catecholamine-stimulated glycogenolysis in goldfish liver is apparently a beta-adrenergic effect. However, low concentrations of epinephrine enhance glycogenolysis without affecting total cyclic AMP.

Adenosine Triphosphate↗
PubMed1976

Lack of glucose effect on the induction of 5-aminolevulinate synthetase and tyrosine aminotransferase in the isolated perfused rat liver.

In the isolated perfused rat liver, both 5-aminolevulinate synthetase and tyrosine aminotransferase were induced by the addition of 3.5 mmol/l allylisopropylacetamide and 58 mumol/l dexamethasone to the perfusion medium. Glucose (40 mmol/l) did not affect either the induction of these enzymes or the intrahepatic level of cyclic AMP. The results suggest that the glucose effect on the induction of 5-aminolevulinate synthetase and tyrosine aminotransferase in vivo is mediated by extrahepatic factors.

5-Aminolevulinate Synthetase↗