PubMed Health⌕ Search

Biomedical subjects

G Braun

Publications and source records attributed to G Braun.

At least 73 records · Page 4Linked to original sources
PubMed1980

Changes in blood-brain permeability resulting from D-amphetamine, 6-hydroxydopamine and pimozide measured by a new technique.

A new technique is described for measurement of diffusion across the blood-brain barrier using intraventricularly administered 68Ga-EDTA, and determining loss from the brain with a scintillation camera. Repeated injections via permanent cannulas showed that the diffusion half-time was reduced to 50% of control values after intraventricular d-amphetamine and 6-hydroxydopamine; pimozide had no effect.

Animals↗
PubMed1980

Centrally active N-substituted analogs of 3,4-methylenedioxyphenylisopropylamine (3,4-methylenedioxyamphetamine).

The known central nervous system activity of 3,4-methylenedioxyphenylisopropylamine and its N-methyl homolog prompted the synthesis of a series of analogs with substituents on the nitrogen atom. Most of these analogs (R = alkyl, alkenyl, hydroxy, alkoxy, and alkoxyalkyl) were prepared by the reductive alkylation of 3,4-methylenedioxyphenylacetone with the appropriate amine and sodium cyanoborohydride. Hindered isomers were synthesized indirectly. Measurements of their pharmacological activity in several animal assays and in human subjects indicated that the central activity decreased with the increasing bulk of the N-substituent.

3,4-Methylenedioxyamphetamine↗
PubMed1980

[The value of computer tomography and sonography in the investigation of the pancreas (author's transl)].

Three hundred and five patients were examined by computer tomography and sonography. In 117 patients no abnormalities were found in the pancreas. The accuracy of computer tomography was 87%, of sonography 85%. In 41 patients the presence of a carcinoma of the pancreas was confirmed histologically. In this group the sensitivity of computer tomography was 83%, of sonography 85%. Thirty-four patients suffered from acute pancreatitis. In this group sensitivity of the two methods was equal at 79%. 113 patients had changes of chronic pancreatitis. Sensitivity of computer tomography was 84%, of sonography 70%. Computer tomography is better at demonstrating calcification in the pancreas. Atrophy of the pancreas cannot be diagnosed by sonography.

Acute Disease↗
PubMed1980

[Research on the central activity and analgesia of N-substituted analogs of the amphetamine derivative 3,4-methylenedioxyphenylisopropylamine].

N-substituted analogs of 3,4-methylenedioxyphenylisopropylamine (MDA) were tested ror analgesic potency and influence on motor activity in mice following potency and influence on motor activity in mice following oral administration. These compounds also were tested for thei psychotomimetic potency in man. Unsubstituted MDA and its monoalkyl-homologs with a low number of C-atoms (N-methyl-, N-methyl-, N-ethyl-MDA) showed both enhancement of motor-activity in mice and psychotomimetic effects in man. MDA and N-methyl-MDA also showed an analgesic effec wthich was enhanced by the inclusion of a weakly labis group (N-mallyl, N-hydroxyethyl). These latter two compounds, however, did not influence motor-activity, which makes them more recommendable as possible analgesic compounds. Structural parallels between these compounds, morphine, endorphins and enkephalins, may explain their similar spectrum of pharmacological effects.

3,4-Methylenedioxyamphetamine↗
PubMed1978

An iodinated catecholamine congener for brain imaging and metabolic studies.

The iodinated O-methylated catecholamine congener, 4-iodo-2,5-dimethoxyphenylisopropylamine (4-I-DPIA), has potential as a new agent for imaging and metabolic studies of the brain and lung. The organ distribution and brain uptake of radioiodine-labeled 4-I-DPIA were studied in the dog and monkey by whole-body scanning, gamma-camera scintigraphy, and organ assay. The brain takes up 2% of the injected dose, with a half-time of 8 sec in the monkey, and the lung takes up 11.8%. An unusual finding was a concentration in the retina, five times that in any other CNS tissue. 4-I-DPIA may have potential in the imaging of normal brain tissues and thereby delineating nonfunctional areas damaged by infarction, trauma, or malignancy, and may also be useful in metabolic studies of catecholamine function. Adequate radioactivity can theoretically be administered with a quantity of 4-I-DPIA 1/10,000 of the pharmacologically active levels. The agent may also find application in lung imaging because of the high pulmonary uptake.

Amphetamines↗
PubMed1977

Synthesis and body distribution of several iodine-131 labeled centrally acting drugs.

1-(4-iodo-2,5-dimethoxyphenyl)-2-aminopropane (3B), 4-iodo-2,5-dimethoxyphenylethylamine (3A), and 1-(4-iodo-2,5, dimethoxyhenyl)-2-aminobutane (3C) have been synthesized with 131I. Labeled iodine monochloride reacts with the appropriately substituted phthalimide at the aromatic 4 position, and the phthalic acid group is removed with hydrazine. Body distribution was measured in rats; the most prominent difference between the three compounds was a much greater concentration in the lung with 3b than with 3a or 3c. gamma-Ray scintigraphs of 3a-c in rats and of 3b in a dog indicate an uptake by the brain similar to that of the bromine analogue of 3b (DOB) in humans. [82Br]-DOB has been suggested as a potential brain scanning agent for nuclear medicine; 3b would have the advantage over DOB of providing the superior gamma-ray imaging properties of 131I or 123I.

Animals↗