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Biomedical subjects

M Fuchs

Publications and source records attributed to M Fuchs.

At least 289 records · Page 16Linked to original sources
PubMed1975

Potential energy barriers to ion transport within lipid bilayers. Studies with tetraphenylborate.

Tetraphenylborate-induced current transients were studied in lipid bilayers formed from bacterial phosphatidylethanolamine in decane. This ion movement was essentially confined to the membrane in terior during the current transients. Charge movement through the interior of the membrane during the current transients was studied as a function of the applied potential. The transferred charge approached an upper limit with increasing potential, which is interpreted to be the amount of charge due to tetraphenylborate ions absorbed into the boundary regions of the bilayer. A further analysis of the charge transfer as a function of potential indicates that the movement of tetraphenylborate ions is only influenced by a certain farction of the applied potential. For bacterial phosphatidylethanolamine bilayers the effective potential is 77 +/- 4% of the applied potential. The initial conductance and the time constant of the current transients were studied as a function of the applied potential using a Nernst-Planck electrodiffusion regime. It was found that an image-force potential energy barrier gave a good prediction of the observed behavior, provided that the effective potential was used in the calculations. We could not get a satisfactory prediction of the observed behavior with an Eyring rate theory model or a trapezoidal potential energy barrier.

Biological Transport↗
PubMed1975

Use of traditional Indian medicine among urban native Americans.

The purpose of this paper is to provide a systematic explanation of the use of traditional medicine among the native American population living in the San Francisco Bay area. Several hypotheses concerning the factors associated with this behavior are tested. These include tribal grouping, socioeconomic and sociocultural factors, as well as the relationship between traditional medicine and modern Anglo medicine. The analysis is based on a probability sample of 277 native American families, systematically drawn from a specially prepared list of 5,000 in three Bay area counties with the largest native American population (Alameda, San Francisco, and Santa Clara). Traditional medicine was used by almost one of three families in the sample and it is shown that use of traditional medicine, although related to sociocultural factors, did not detract from the use of modern Anglo medicine.

Acculturation↗
PubMed1975

[Studies on the complete enzymatic hydrolysis of steroid conjugates in urine (author's transl)].

The incubation of urine with beta-glucuronidase/arylsuphatase from Helix pomatia results in the incomplete hydrolysis of urinary steroid conjugates, because inhibitors of these enzymes are present in urine; The inhibitors can be separated from the steroid conjugates by chromatography of the urine on a column of Amberlite XAD-2. By this method a complete enzymatic hydrolysis of urinary steroid conjugates is possible in 24 hours at 37 degrees C or in 2 hours at 55 degrees C.

Androsterone↗