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Biomedical subjects

U Müller

Publications and source records attributed to U Müller.

At least 505 records · Page 28Linked to original sources
PubMed1983

Electron microscopic localization of choline acetyl transferase activity in the electric organ of Torpedo marmorata.

The light microscopic method for demonstration of choline acetyltransferase (CAT) activity based on the formation of a lead mercaptide of free SH-acetyl Coenzyme A was adapted for electron microscopy. In samples of electric organ of Torpedo marmorata CAT activity was found to be restricted to synaptic vesicles and cysternae. The precipitate formed was mostly fine grained and distributed more or less evenly throughout the vesicles. Generally, the reaction product seemed not to adhere to the inner side of the vesicle membrane. CAT activity was found only in the presynaptic region of the synapse, neither the synaptic cleft nor the postsynaptic region reacted positively. CAT activity was found also within synaptic vesicles in nerve endings prepared from electric organ. Samples of Torpedo brain reacted positively too. Complete suppression of CAT activity with inhibitors, judged on the basis of lead mercaptide deposited, was rather difficult to achieve. From a group of 10 presumed enzyme inhibitors, only 2 compounds reacted satisfactorily, namely trans-1,2-dihydro-2-imino-4-(1-naphthylvinyl)-1-pyridine-ethanol hydrobromide and 5,5-dithio-bis-(2-nitrobenzoic acid) (3,3'-6). On the whole, the results obtained show the viability of the method used and furthermore it offers also some new insight into the turnover of acetylcholine, since it may be deduced from the results that under certain circumstances acetylcholine may be synthesized in synaptic vesicles.

Animals↗
PubMed1983

[Thin-layer chromatographic determination of pyrantel in cow's milk and blood serum after oral administration of Banminth].

After oral administration of the anthelmintic Banminth to cows the effective agent pyrantel appeared unchanged in blood serum and milk. After a therapeutic dose of 12,1 mg pyrantel tartrate/kg body weight, a maximum level of 8-9 micrograms/l could be found in milk 0-24 h after the application; the highest concentration of 22 micrograms/l in blood serum appeared after 10 h and the half-life time of elimination was ca. 15 h. Pyrantel determination in milk and blood serum was performed by quantitative thin layer chromatography. Positive results could be verified by HPLC.

Administration, Oral↗
PubMed1983

Incorporation of small unilamellar liposomes loaded with horseradish peroxidase into isolated nerve endings from electric organ of Torpedo marmorata.

A population of small unilamellar liposomes loaded with horseradish peroxidase, an electron dense marker, was prepared by passing the lipid-protein-detergent micelles through Sephadex G-50. By electron microscopy it was shown that these artificial lipid vesicles were incorporated into the cytoplasm of isolated pure cholinergic nerve endings from the electric organ of Torpedo marmorata. This liposome carrier system may be useful in manipulating the internal parameters involved in presynaptic processes in the electric organ.

Acetylcholinesterase↗
PubMed1983

Crosslinking of HCG to its specific receptor of porcine ovarian membranes.

HCG receptors of porcine ovarian plasma membranes were loaded with 125I-hCG and covalently crosslinked with glutaraldehyde. The plasma membranes were labeled with tritium. The hCG receptor complex was solubilized in 1% SDS and subsequently chromatographed on Biogel P 300. 40-50% of 125I-radioactivity eluted near the void volume. 3H radioactivity in these fractions indicated the presence of crosslinked hormone receptor complexes. A second minor peak of 125I-radioactivity appeared at 55000 d. A third peak represented subunits of 125I-hCG. Analysis of the Biogel P 300 purified 125I-hCG receptor complex by polyacrylamide gel electrophoresis in sodium dodecyl sulfate resulted in two radioactivity peaks. The main peak corresponded to 90 000-100 000 d, the second peak was calculated to approximately 140 000 d. As a result the majority of the hormone receptor complex has a molecular weight of 90 000-100 000 d. Existence of subunits is discussed.

Animals↗
PubMed1983

Venom immunotherapy in hymenoptera sting allergy. Comparison of rush and conventional hyposensitization and observations during long-term treatment.

42 patients with confirmed hypersensitivity to honey bee (HBV) and/or yellow jacket (YJV) were treated with the respective venoms (7 with HBV, 5 with VJV and 30 with both venoms). Treatment tolerance, skin tests (ST), specific IgE- and specific IgG-antibodies were monitored before, after 3, 6, 12, 24 and 36 months. 21 patients had a rush and 21 a conventional treatment schedule. Maintenance dose was 100 micrograms. Adverse effects occurred as large local (8 patients), slight systemic (12 patients) and moderate to severe systemic reactions (4 patients). Of 24 re-exposed patients 17 had no reaction at all, six a markedly decreased and one an unchanged reaction. After 3 years of treatment ST became negative in nine of 31 patients on HBV and in seven of 26 patients on YJV. RAST became negative in three of 30 patients on HBV and 17 of 29 patients on YJV treatment. Both ST and RAST became negative in five HBV- and 10 YJV-treated patients. Loss of venom hypersensitivity according to diagnostic tests may correspond to actual desensitization and enable discontinuation of immunotherapy.

Adolescent↗
PubMed1983

Molecular architecture of fungal cell walls. An approach by use of fluorescent markers.

Fluorescent probes have been applied to analyze the molecular architecture of fungal cell surfaces. Binding patterns of aniline blue and FITC-labeled wheat germ agglutinin (FITC-WGA) elucidated class-specific properties. Aniline-blue-induced fluorescence was distributed over the entire cell walls from Ascomycetes, but was confined to sporangial walls of Zygomocetes, hyphal tips and a few other sites in Basidiomycetes, while no fluorescence was found with sporangia and rhizoids of Chytridiales. FITC-WGA in Zygomycetes and in Ascomycetes was restricted to few sites (e.g. apex of hyphae), in Basidiomycetes and Chytridiales label was evenly associated with the entire surface of hyphal walls, or sporangia and rhizoids. For Oomycetes, Zygomycetes, Ascomycetes, and Basidiomycetes differences in the molecular architecture between apex and hyphal side walls were discerned, although the chemical nature of these differences is distinct for each class. Species specific differences, due to differences in binding patterns of several lectins are not apparent at fungal cell surfaces. The degree of intraspecies variation was found to be larger than interspecies diversification, suggesting changeableness of the molecular architecture of fungal cell walls. This is in contrast to assertions which we made by working on algae. There species-specific lectin binding patterns have been described.

Ascomycota↗
PubMed1983

[Neurologic component and resulting therapeutic concept of patellar chondropathy and chondromalacia].

Observations of nerve root lesions in spontaneous peripatellar pain led to new aspects concerning the etiology of periarticular pain and chondromalacia patellae. We regard the spontaneous peripatellar pain as an enthesiopathia resulting from an innervation disorder. We believe that also chondromalacia can be caused by nerve root lesions. As a consequence, a change in conservative and operative management is necessary. The aim is a balanced gliding and rotational stability of the patella. This means a muscular compensation of the weakened muscle part and stabilisation of the lumbar and hip region. Surgical techniques should only be applied to normalize the gliding of the patella. There is no indication for ventralisation of tuberositas tibiae.

Cartilage Diseases↗
PubMed1983

Changes in contractility and oxygen metabolism of isolated canine heart following application of urapidil.

Changes of contractility and oxygen metabolism following the administration of urapidil (Ebrantil) are described. Investigations were carried out on isolated, metabolically supported canine hearts. Results show that this drug has a myocardial effect in addition to its known antihypertensive effect. Moreover, a dose-dependent negative inotropism is coupled with a reduction in myocardial oxygen consumption. Urapidil reduces the cardiac metabolic rate, decreases cardiac load due to a reduction in peripheral resistance, and has a negative inotropic action. These properties are usually found only in beta-blockers.

Animals↗
PubMed1983

[Serum uric acid as a prognostic parameter in prenatal monitoring of gestoses].

A correlation between gestosis and increase of serum uric acid level has been known for a longtime. From the 6th month of pregnancy we found significantly increased values in all hypertensive pregnant women. In the 7th and 8th month of pregnancy there was a high significant deviation in gestoses second degree (classification of the organisation gestosis). In the two last months of pregnancy all gestoses deviated high significantly from the uric acid level in serum of the normal collective. There is a correlation between pathologically increased mean uric acid values in the 9th and 10th lunar month and increased systolic and diastolic blood pressure values. The uric acid level in pregnant women with gestosis, whose illness or its consequences led to cesarean section, is significantly higher than in patients with normal delivery. In accordance with literature we could not find a limit above the fetus dies. In our opinion determination of plasma uric acid in late pregnant hypertensive women is one additional parameter calculating both maternal prognosis and fetal risk.

Female↗
PubMed1982

The role of Yp in sex determination: new evidence from X/Y translocations.

A 33-year-old man had azoospermia and tubular atrophy as in the Klinefelter syndrome but short stature. He had a 46,X,t(X/Y) (Xqter lead to p22.3::Yp11 lead to Yqter) translocation and was H-Y antigen-positive. This excludes one of the genes controlling H-Y antigen from the terminal portion of the short arm of the Y chromosome. This case and the two similar ones in the literature indicate that the proximal Yp portion is required for the differentiation of a male gonad. The pattern of X inactivation was random in the patient's fibroblasts, whereas in the lymphocytes the translocated chromosome was preferentially inactivated; comparison with other cases shows that the quantity of Y chromosome material involved in these translocations does not influence the X inactivation patterns. In the three cases with this dicentric translocation the X chromosome centromere is consistently the active one. Our case indicates that the choice of which centromere is inactivated is independent of the replication pattern of the X chromosome. Our patient and a few other relevant cases from the literature confirm that factors controlling height are located on the distal portion of Xp and of Yp.

Adult↗