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Biomedical subjects

H Meyer

Publications and source records attributed to H Meyer.

At least 433 records · Page 24Linked to original sources
PubMed1981

Effects of unsymmetrical ester substituted 1,4-dihydropyridine derivatives and their optical isomers on contraction of smooth muscle.

The optical isomers of two nifedipine-like 1,4-dihydropyridine derivates have been synthesised and tested in vitro. The (-)-isomer (S-configuration of both compounds) was more potent than the racemate, which in turn was more potent than the (+)-isomer (R-configuration). The S-configuration isomers are approximately ten times more potent that nifedipine, and may represent the optimal structure and configuration for binding to and inhibiting calcium channels.

Animals↗
PubMed1981

[Synthesis and comparative pharmacological studies of 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)pyridine-3,5-dicarboxylates with non-identical ester functions (author's transl)].

Michael-addition of 3-aminocrotonic acid ester 7 to aralkylidene acetoacetic acid esters 6 is followed by ring closure to give novel 4-aryl-1,4-dihydro-2,6-dimethyl-pyridine-3,5-dicarboxylates 8 with non-identical ester functions. In the series of 3-nitrophenyl derivatives (8, Ar=3-nitrophenyl) the pharmacological activities (coronary vasodilation, antihypertensive activity) of the asymmetrically substituted derivatives are shown to be superior to those of the corresponding symmetrically substituted derivatives in many cases. One representative of this class 3-ethyl-5-methyl-1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylate (nitrendipine, Bay e 5009, No. 3) was selected for further development as an antihypertensive drug.

Animals↗
PubMed1981

[2-aminodihydropyridines / Structure and antihypertensive activity (author's transl)].

Replacement of the 2-alkyl group by amino in the structure of cardiovascular 4-aryl-2,6-dialkyl-1,4-dihydropyridine-3,5-dicarboxylates 1 is tolerated without loss of antihypertensive activity. The rules found for the substitution of the aromatic ring and the ester functions in 1 still hold for the novel 2-amino-1,4-dihydropyridines 6, 7 and 9 obtained by Michael addition of acetamidines to alpha, beta-unsaturated enones. 2-Dialkylamino-3,4-dihydropyridines 11 surprisingly also show good antihypertensive activity. In this case a displacement of the double bond in the heterocycle must also be taken into account. A 2-trifluoromethyl substitution in the phenyl residue and ester groups with low lipophilicity are optimal in this series.

Aminopyridines↗
PubMed1981

[Structure of the cell wall polysaccharide in the food protein yeast Candida spec H. III. Characterization of different phosphate bonds in the mannan-protein-phosphate complex].

The 31P-NMR spectra of the proteophosphomannan (PPM) and also that of mildly hydrolyzed PPM demonstrated phosphomonoester (in both preparations), acid labile and acid stable phosphodiester linkage, and polyphosphate. Decreasing in size by pronase digestion, separation, purification and characterization of the high and low molecular phosphates by 31P-NMR spectroscopy and chemical analysis revealed the mannan protein is phosphorylated in the N-glycosidically linked carbohydrate parts and in the O-glycosidically linked oligosaccharides. Another phosphate serves as a bridge between the serine of the protein and mannose, mannobioses and mannotrioses and between the threonine and a lipophilic acylglycerid unit. The origin of the polyphosphates has been discussed.

Candida↗
PubMed1980

The meeting goer's lament.

Executives spend about 69% of their time in meeting with at least two other people, according to a recent study out of McGill University. In spite of this, participants do not consider this to be time used wisely and, according to the respondents, the problem seems to be growing worse. Despite the claims of some executives that government regulations or increased corporate complexity underlies the problem, society at large is viewed as the source of the change. Meyer asserts that all institutions have become less authoritarian and the trend away from command has left persuasion and consensus as the basis for corporate level decision-making. Although executives seem to agree that most time is wasted because participants fail to be succinct, the author argues that leaders could improve meetings by choosing the right participants, guiding them briskly through the agenda, and closing the meeting before it degenerates into a shouting match. The article suggests that chief executives are concluding that meeting skills can be learned. Most of the FORTUNE 500 companies have hired outside experts to teach these skills and some companies are building inhouse units for the same purpose. Since meetings have become an integral part of the business day, Meyer concluded that the goal of the executive should be to use the meeting time well.

Attitude↗
PubMed1980

[Computed tomography and angiography in the evaluation of intracranial angiomas (author's transl)].

Angiographic results in 31 intracranial angiomas and CT-findings in 22 of this group were evaluated. Precise angiographic analysis remains the basis for planning and execution of neurosurgical therapy, even in the era of CT. Nevertheless, vascular malformations of all types seldom escape detection with CT. CT has also made possible extremely accurate diagnosis of larger malformations. It has provided an unprecedented wealth of information regarding hematoma, subarachnoidal hemorrhage, edema, infarction and atrophy. Scans both with and without injection of contrast material are essential for comparative purposes.

Angiography↗
PubMed1980

The underweight adolescent. Etiologic factors and a review.

A brief review of the causes of underweight in adolescence is presented to help the practitioner determine the cause of underweight in his patient. Poor nutrition is determined by several key observations: (1) history: (2) physical examination; (3) anthropometric measurements--height, weight, triceps skinfold thickness (TSF), mid-arm circumference (MAC), and mid-arm muscle circumference (MAMC). Causes of the underweight state may be divided into three categories: disease states; environmental conditions; and factors peculiar to the adolescent.

Adolescent↗
PubMed1980

Cyclic AMP phosphodiesterases of the rat ovary. Oestrous cycle dependent activity change of high affinity form.

In the rat ovary, from prenatal to adult stages, two electrophoretically distinct forms of cyclic AMP phosphodiesterase (E.C.: 3.1.4.17) occur. These forms were analysed for their affinity towards cAMP in both crude and partially purified preparations. Whereas the slow electrophoretic form, which has a low affinity towards cAMP, shows a linear Lineweaver-Burk plot, the fast electromorph exhibits anomalous kinetic behaviour in that cAMP affinity appears to increase with decreasing cAMP-concentration. This form shows dramatic alteration of maximum velocity during the oestrous cycle, attaining maximum activity at metoestrus. This rise of activity is sensitive to inhibition of protein synthesis.

3',5'-Cyclic-AMP Phosphodiesterases↗