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Biomedical subjects

K Thiele

Publications and source records attributed to K Thiele.

At least 37 records · Page 2Linked to original sources

Effects of different interferons on the replication of herpes simplex virus in human T lymphocytes.

Human T cells were activated with PHA and after 48 h they were treated with preparations of different human interferons (IFNs). After a further incubation period of 24 h, the cells were washed and infected with herpes simplex virus type 1 (HSV-1). Reduced virus titers were observed in T cells pretreated with IFN-alpha or IFN-beta, whereas IFN-gamma showed no antiviral effects. These findings indicate that IFN-gamma does not exert protection against viral infection in this system. We investigated the synthesis of HSV-coded early and late proteins in T cells pretreated with IFN-alpha and IFN-beta. Immunofluorescence studies revealed inhibition of expression of the immediate early alpha-protein ICP 4. Induction of DNA-polymerase, a viral beta-protein, was inhibited both by IFN-alpha and IFN-beta in a dose-dependent manner. As suggested by SDS-polyacrylamide gel electrophoresis, other viral beta- and gamma-proteins of HSV were inhibited by IFN-alpha and IFN-beta as well.

Cell Division↗

The role of prostacyclin in the hypercapnic and hypoxic cerebrovascular dilations.

The cerebral blood flow (CBF H/A) and the production of a stable prostacyclin metabolite, 6-Keto PGF 1 alpha ( 6KPGF ) was studied in 5 baboons in control, hypercapnic and hypoxic conditions. In steady-state conditions CBF H/A was measured by the clearance of an intra-arterial bolus injection of 133xenon and arterial and cerebral venous blood was sampled for assay of 6KPGF by radioimmunoassay. Both hypercapnia and hypoxia significantly increased CBF H/A and both increments were abolished by indomethacin. However, only hypoxia showed an increased 6KPGF production. Thus, hypoxia, but not hypercapnia, appears to produce cerebral vasodilation by increasing prostacyclin production.

6-Ketoprostaglandin F1 alpha↗

[New biologically active theophylline derivatives. Synthesis and pharmacologic properties of flufylline and fluprofylline].

Within the course of the research project for finding new cardiovascular drugs we have synthetized since 1976 piperazine- and piperidine derivatives of theophylline. The screening shows for the substances Sgd 19578 (flufylline) and Sgd 14480 (fluprofylline) a long-lasting blood pressure lowering activity as well as a remarkable serotonin- and histamine antagonism and broncholytic activity. On the basis of these results these compounds were selected for further investigation.

5-Hydroxytryptophan↗

Sgd 101/75: a sympathomimetic that can be used to identify a new subtype of alpha-adrenoceptor, the alpha 1s-adrenoceptor.

When Sgd 101/75 was compared with clonidine in a number of tests for CNS activity, Sgd 101/75 exhibited little activity in any test. Sgd 101/75 raised BP without affecting HR in several species of anaesthetised animals. The rise in BP was subject to tachyphylaxis, could be antagonised by alpha 1-adrenoceptor antagonists, and was obtainable in reserpinised animals. The vasopressor effect of NA was antagonised by Sgd 101/75. Thus Sgd 101/75 is a directly acting partial agonist for vascular alpha 1-adrenoceptors. On the coaxially stimulated guinea-pig ileum and field stimulated rat vas deferens, the twitch response to single pulse stimulation was reduced by NA or clonidine stimulating prejunctional alpha 2-adrenoceptors. Sgd 101/75 antagonised these inhibitory effects competitively (pA2 for antagonism of clonidine on the vas = 6.12). Sgd 101/75 acted as a specific partial agonist on the alpha 1-adrenoceptors of the guinea-pig taenia caecum that subserve relaxation of this tissue. Sgd 101/75 was a full agonist on the alpha 1-adrenoceptors of the rat anococcygeus in vitro. Phenoxybenzamine (300 pM for 30 min, followed by 20 washes over the next 30 min) reduced contractions of the anococcygeus to Sgd 101/75, but produced little inhibition of NA-induced contractions. In phenoxybenzamine-pretreated preparations, Sgd 101/75 (400 microM) did not antagonise NA (maximal effect and EC50 values not changed significantly), so it was concluded that Sgd 101/75 and NA interact with different alpha 1-adrenoceptor subtypes in this tissue. The subtype specifically activated by Sgd 101/75 was designated the alpha 1s-adrenoceptor. The mouse anococcygeus contained alpha 1s-adrenoceptors, whereas this receptor was absent from the rabbit anococcygeus.

Adrenergic alpha-Agonists↗

[New cerebrally active basic dithienyl compounds (author's tranls)].

A review on new cerebrally active basic dithienyl compounds related to (+)-(R)-alpha-((S)-1-[(3,3-di-3-thienylallyl)amino]-ethyl)-benzylalcohol (tinofedrine) is presented. Tinofedrine was selected out of a large number of related compounds on account of its high increase of cerebral blood flow, its improvement of heart performance, of the metabolism of the brain, and because it is well toleraded. Different routes of synthesis are discussed.

Animals↗

[Spectroscopic characterisation of tinofedrine (author's transl)].

With the aid of spectroscopical methods the structure of (+)-(R)-alpha-[(S)-1-[(3,3-di-3-thienylallyl)amino]-ethyl]-benzyl-alcohol (tinofedrine, 1), a new cerebrally active compound, was confirmed. The relative and absolute configuration is discussed in view of spectroscopic data.

Chemical Phenomena↗

[Beclobrate and eniclobrate hydrochloride, new diphenylmethane derivatives as agents for lowering cholesterol and triglyceride levels. Part I: Synthesis and consideration of structure-activity relationships (author's transl)].

Within the course of a research project for finding new lipid-lowering substances with better therapeutic indices than the standard agent in use, various diphenylmethane derivatives were synthesized and tested with respect to their activity and toxicity. On the basis of these results Sgd 24774 (beclobrate) and Sgd 33374 (eniclobrate-hydrochloride) were selected for further investigation and clinical studies.

Animals↗

[A contribution to the stereospecific synthesis of antifungal imidazolyloxime-ethers/Oxiconazole nitrate (Sgd 301-76), a new broadspectrum antifungal agent (author's transl)].

A stereospecific synthesis of antifungal imidazolyloxime-ether derivatives is reported. The compound Sgd 301-76 (oxiconazole nitrate) = (Z)-1-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)-O-(2,4-dichlorobenzyl)-ethanoneoxime-nitrate was selected for clinical trials. The (E)- and (Z)-assignments, respectively, were made on the basis of 1-H-NMR-spectral data.

Antifungal Agents↗