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Biomedical subjects

M L Stein

Publications and source records attributed to M L Stein.

At least 37 records · Page 2Linked to original sources
PubMed1988

Inhibition of thromboxane biosynthesis by 3-pyridinol carboxypentyl ethers substituted with a hydroxylated octyl chain.

Racemic 6-[4-(3'-hydroxy-1'-octenyl)-3-pyridyloxy]hexanoic and 6-[4-(3'-hydroxyoctyl)-3-pyridyloxy] exanoic acids have been synthesized and their activity as inhibitors of the biosynthesis of thromboxane A2 in human serum has been studied, in comparison with isomers having the eight-carbon chain in the 2 position. Very high, selective activity was found for the new 4-substituted 3-pyridinol ethers, whereas the 2-substituted compounds showed no action.

Depression, Chemical↗
PubMed1987

In vitro inhibition of Trichomonas vaginalis growth by some ortho-phenacyloxy-benzyl alcohols and their derivatives.

Some phenacyl ethers of different ortho-hydroxy-benzyl alcohols and analogues have been synthesized and tested for the in vitro activity towards Trichomonas vaginalis. The most active compounds had a minimum inhibitory concentration of 6.25 micrograms/ml and appeared to be of a certain interest as representative of a new type of anti-Trichomonas substances not containing a nitro group.

Acetophenones↗
PubMed1986

Synthesis of guanylhydrazones derived from 3-pyridinol and evaluation of their effect on serum thromboxane B2 and prostaglandin E2 production.

3-Pyridyloxyacetaldehyde guanylhydrazone and the guanylhydrazones of pyridine-2- and -4-aldehydes substituted at the 3-position with the omega-carboxypentyloxy chain were synthesized in order to evaluate their activity as thromboxane synthase inhibitors in vitro. The tested compounds inhibit thromboxane B2 biosynthesis in human serum. The first appears to be a selective inhibitor of thromboxane synthase, since there was a concomitant rise in Prostaglandin E2 (PGE2) level. The derivative of 4-pyridinealdehyde was the more active one of the other two compounds but it also markedly lowered PGE2 biosynthesis proving to be an inhibitor of cyclooxygenase.

Chemical Phenomena↗
PubMed1985

2-Substituted-3-pyridinolethers as hypolipidemic and platelet aggregation inhibiting agents.

Some 2-substituted 3-pyridinolethers were synthesized, with one side chain bearing a carboxylic function; among these there are products having structure analogies with the prostaglandins. The results of hypolipidemic and hypocholesterolemic tests on experimental hyperdyslipidemic animals, as well as those on the inhibition of platelets aggregation and on fibrinolytic activity are reported.

Animals↗
PubMed1980

[Synthesis of p-aminobenzenesulfonyldiazine].

New sulfones were synthesized; these are analogues of bis-(4-aminophenyl)sulfone (DDS) but contain, instead of one benzene nucleus, a heterocycle that is a pyrimidine, pyrazine or pyridazine nucleus. This was substituted with amine, methoxy, methyl groups or halogens in order to obtain long-acting drugs, similarly to those obtained in the field of sulfonamides. The synthesis was accomplished by reaction of sodium p-amino- or p-acetamidobenzensulfinate with the corresponding halodiazine; only the p-aminophenyl 3-aminopyridazin-6-yl sulfone was obtained by acid hydrolysis. The compounds showed good antitubercular activity in vitro.

Antitubercular Agents↗
PubMed1978

Bilateral herniation of renal pelves: a complication of cutaneous pyelostomy.

The first reported case of bilateral herniations of the renal pelves as a complication of cutaneous pyelostomy is presented. We describe a modification of the original surgical technique that may prevent herniation, based on fixation of the pelvis to the lumbodorsal fascia as well as the cut edge of the pelvis to the skin. In our patient the bilateral herniations were corrected by repairing the fascial defects and suturing of the pelvis to the fascia.

Chromosomes, Human, 6-12 and X↗
PubMed1978

The three dose components of negative pion beam and their role in pion radiotherapy.

A new method has been developed for analyzing therapeutic negative pion beams into three LET (linear energy transfer) dose components inherent in such a beam. The technique utilizes thin silicon detectors to obtain pulse height spectra produced by the various particles in the beam traversing the detectors. It is shown that a low LET group is correlated with the incoming pions, muons and electrons; a medium LET group corresponds to protons, deuterons, tritons, and high energy alpha particles; and a high LET group is due to low energy alpha particles, 3He and recoil particles. Several beams used clinically have been studied.

Energy Transfer↗
PubMed1975

Structure-activity relationships in reactivators of organophosphorus-inhibited acetylcholinesterase. 10. Hydroxyiminomethylarylethenylpyridine methiodides.

The synthesis of styrylpyridine methiodides where a hydrogen of the pyridyl moiety was replaced by the hydroxyiminomethyl group produced highly effective inhibitors of acetylcholinesterase. As starting materials 4-methylpyridine-2-aldoxime and 2-methylpyridine-4-aldoxime methiodides were prepared which, together with 4-imidazolylethenyl-pyridine-2-aldoxime methiodide, were the only substances for which some activity as reactivators of phosphorylated electric eel cholinesterase in vitro could also be found.

Cholinesterase Inhibitors↗
PubMed1975

[Isoxazoles substituted with 4-pyridyl and o-chlorophenyl radicals].

By reaction of suitable hydroxamic acids chlorides with beta-ketoesters, we have prepared the ethyl esters of isoxazol-4-carboxylic acids, substituted in the 3- and 5-positions with 4-pyridyl and o-chlorophenyl groups, and some of their esters and amides of pharmaceutical interest. 3-(4-Pyridyl)-5-(o-chlorophenyl)isoxazole was obtained either by decarboxylation of the acid or by oxidation of the syn and anti oximes of 3-(o-chlorophenyl)-1-(4-pyridyl)-2-propen-1-one; from the syn oxime the corresponding isoxazoline was also obtained. Pharmacological screening shows that some of the new compounds have a myolytic activity.

Animals↗
PubMed1975

[New isoxazol /5,4-b/ pyridine-3-acetic acids].

We prepared two isoxazol [5,4-b] piridin-3-acetic acids by two different synthetic methods. 4,6-Dimethylisoxazole [5,4-b] pyridin-3-acetic acid was obtained by reaction with hydroxylamine of 4-hydroxy-5,7-dimethyl-2H-pyrano [2,3-b]pyridin-2-one, which was in turn prepared starting from 2-hydroxy-3-acetyl-4,6-dimethylpyridine. Isoxazolo [5,4-b] pyridine-3-acetic acid was obtained starting from 3-methyl-5-aminoisoxazole and has shown interesting auxin activity.

Acetates↗