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Biomedical subjects

H Auer

Publications and source records attributed to H Auer.

89 records · Page 5Linked to original sources
PubMed1984

Paradoxical effects of methylmercury on the kinetics of cytochrome c oxidase.

A stoichiometric amount of methylmercuric chloride substantially inhibits cytochrome c oxidase function under steady-state turnover conditions, where the enzyme is using its substrates, cytochrome c and oxygen, rapidly and continuously. Under these conditions, a reduction in activity of approximately 40% is observed. This is in accord with the results of Mann and Auer [Mann, A.J., & Auer, H.E. (1980) J. Biol. Chem. 255, 454-458], who used mercuric chloride and ethylmercuric chloride. Paradoxically, we found that addition of methylmercuric chloride can increase the activity of cytochrome c oxidase during its initial substrate utilization. This rate enhancement, measured under conditions where the enzyme cycles only a few times, is maximal for the resting state of the enzyme. "Pulsed" cytochrome c oxidase (i.e., enzyme that has been recently reduced and reoxidized) is considerably activated with respect to the resting enzyme, showing faster turnover rates (Antonini, 1977; Brunori et al., 1979). No significant rate enhancement upon treatment with methylmercuric chloride is seen in initial substrate utilization if the enzyme is pulsed immediately before the assay. The apparently contradictory effects of methylmercuric chloride on the resting and pulsed states of the oxidase under low turnover conditions may be reconciled by a model in which mercurial binding greatly stabilizes the enzyme in a state resembling that of the pulsed enzyme. A decrease in conformational flexibility may be the basis of the mercurial-induced diminution in activity of the enzyme during steady-state turnover conditions.

Animals↗
PubMed1983

A solid-phase indirect haemadsorption assay (SPIHA) for detection of immunoglobulin m antibodies to Toxoplasma gondii: application to diagnosis of acute acquired toxoplasmosis.

A solid-phase indirect haemadsorption assay (SPIHA) for the detection of immunoglobulin M (IgM) antibodies to Toxoplasma gondii is described. Polystyrol microtiter plates are coated with anti-human IgM (mu-chain-specific) antibodies and then sequentially allowed to react with patient's serum and sheep erythrocytes sensitized with soluble antigen of Toxoplasma gondii. A total of 111 sera were tested in fluorescent antibody test (FAT and IgM-FAT), complement fixation test (CFT), indirect haemagglutination assay (IHA), and in SPIHA. 47 sera were from individuals with a suspected or verified acute Toxoplasma infection. In most of these cases the SPIHA allowed a clear interpretation with respect to the status of the infection, even when the IgM-FAT was not conclusive. In contrast to IgM-FAT, rheumatoid factor or exceedingly high specific IgG antibodies did not interfere with results in SPIHA. A laboratory-acquired infection enabled us to demonstrate the course of immune response measured by SPIHA as well as by IgM-FAT, FAT, CFT, and IHA. The method proposed here is well appropriated to IgM detection, simple to perform, inexpensive, and thus representing an alternative to IgM-FAT, convenient for the routine laboratory.

Complement Fixation Tests↗
PubMed1982

[Immunoenzyme test with whole trophozoites of Toxoplasma gondii].

In a comparative study 151 human sera were tested for IgG and IgM antibodies against Toxoplasma gondii in the Fluorescent-Antibody-Test (FAT) as well as in the Enzyme-Linked Immunosorbent Assay (ELISA) using the same antigen (whole trophozoites of Toxoplasma gondii). A positive correlation was found between the results obtained in FAT and ELISA. The detection of specific IgG antibodies revealed a correlation of 100% and 97.5% in positive and negative sera, respectively. Only 8 out of 111 positive sera showed deviations of more than +/- 1 step within the titre ranges. While detecting specific IgM antibodies a highly significant correlation (99.3%) between FAT and ELISA was obtained for negative sera. 5 positive IgM sera showed titre end-points of 1:64 and 1 serum an end-point titre of 1:256 in FAT as well as in ELISA; however, a comparison was not done because of the small amount of positive IgM sera having been available.

Animals↗
PubMed1982

Reduction of carrageenan- bradykinin- and histamine-induced acute inflammation by experimental eosinophilia in rats.

An examination was made of the effects of eosinophilia on acute inflammation. Sprague Dawley rats were infected with Trichinella spiralis larvae which resulted in a blood eosinophilia. Groups of rats with the induced eosinophilia, and untreated rats without the eosinophilia, were treated with carrageenan, bradykinin or histamine in the hind paw to induce local inflammation. Paw oedema induced by carrageenan as a measure of the inflammation was much reduced in those rats with an eosinophilia, and slightly but significantly reduced in the site treated with histamine or bradykinin. Though other anti-inflammatory factors may have participated, it is believed that the reduction in inflammation was due to the eosinophils. Pretreatment of the rat paws with an eosinophil chemotactic factor tetrapeptide (ECF-A) caused no chemotaxis and therefore no effect on histamine-induced oedema.

Animals↗
PubMed1981

[Human fascioliasis in Austria (author's transl)].

Two cases of human fascioliasis in Austria (a 3-year-old boy and a 4-year-ond girl) are reported. A description is given of the clinical picture and the diagnostic procedures employed in the two cases. The importance of the serodiagnosis of fascioliasis is demonstrated, especially in the case of liver flukes; 4 different serological tests, partly of high sensitivity, were performed. After unsuccessful therapy with Resochin both children were treated with dehydroemetine; after a 4-week interval during which no eggs of Fasciola were found in several stool samples from either child, ova were yet again detected in the faces of the boy. The problems concerning the chemotherapy of fascioliasis are discussed.

Antibodies↗
PubMedDate not supplied

[Toxocariasis in a 5-year-old boy--manifesting as bronchial asthma and behavioral disorder].

We report on a five year old boy who was admitted to hospital because of obstructive airway disease; initially, findings were interpreted to indicate bronchial asthma. In addition, the patient presented with a behavioural abnormality of aggressiveness and hyperactivity. Laboratory examinations showed an elevated IgE level and eosinophilia, chest x-ray revealed infiltrations in both lungs. After excluding a spectrum of chronic lung disorders by relevant investigations, serological testing for parasitosis revealed massively elevated toxocara IgG antibodies. The diagnosis of a "covert form" of toxocarosis was established and an antihelminthic therapy with albendazole was initiated. Chronic respiratory symptoms in childhood can also indicate the presence of a parasitic infestation.

Albendazole↗
PubMedDate not supplied

Nucleolus organizer regions in the chromosomes of the llama.

Silver nitrate (Ag-AS) staining was applied to chromosome preparations from the llama (Lama glama). The NORs were detected on the secondary constrictions of the short arms or the stalks of five small acrocentric chromosome pairs.

Animals↗
PubMedDate not supplied

A new type of Robertsonian translocation in the domestic dog.

A cytogenetic analysis of 112 domestic dogs led to the detection of a new Robertsonian translocation (Robertsonian translocation 1/31). This translocation was restricted to the poodle breed; it occurred in high frequency and was encountered in the homozygous and heterozygous state.

Animals↗
PubMedDate not supplied

NORs, heterochromatin, and R-bands in three species of Cervidae.

Chromomycin A3 banding of the chromosomes of three species of Cervidae (red deer, fallow deer, roe deer) allows the demonstration of both centromeric constitutive heterochromatin and R-banding patterns useful for identifying all the chromosomes of a given karyotype. In all three species significant amounts of chromomycin-bright heterochromatin are present at the centromeres of all autosomes. The X chromosomes of all investigated species contained appreciable amounts of centromeric heterochromatin. AgNO3 staining was applied sequentially to detect the location of active nucleolus organizer regions (NORs). The distribution of NORs was reasonably conservative in the investigated species.

Animals↗