Search PubMed⌕ Search

Biomedical subjects

M Frank

Publications and source records attributed to M Frank.

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

Effects of ryanodine on a myocardial membrane vesicular fraction.

The effects of ryanodine on calcium transport were examined on a microsomal fraction isolated from guinea pig atrial muscle by sucrose density ultracentrifugation. The Ca+2 binding capacity of the fraction was sufficient to account for relaxation and was unaltered by the addition of 5x10(-5)M ryanodine. Exposure of the sarcoplasmic reticulum (SR) to concentrations of ryanodine which produce negative inotropy significantly reduced ATP-dependent calcium transport which was associated with a significant increase in the Ca+2 activated ATPase activity. The effect of ryanodine was to reduce the Ca/P ratio by 50%. These results suggest that the negative inotropic effect of ryanodine in guinea pig atrium is associated with the uncoupling of Ca+2 transport from ATP hydrolysis.

Adenosine Triphosphatases↗
PubMed1974

A human leukemia cell with both B and T cell surface receptors.

Bone-marrow-derived (B) and thymus-derived (T) lymphocytes can be distinguished by the presence of a number of receptors and differentiation antigens. The presence of these markers has facilitated the identification and characterization of the mononuclear cells in a number of animal and human lymphoid malignancies. We describe here the immunological properties of human leukemia cells that are highly unusual, since they simultaneously bear the receptor for sheep erythrocytes characteristic of human T lymphocytes and the receptor for antigen-antibody-complement complexes characteristic of human B lymphocytes. A small number (about 2%) of normal human lymphocytes bearing both of these receptors was also identified.

Animals↗
PubMed1973

An analysis of hamster afferent taste nerve response functions.

Sensitivities to moderately intense stimuli representing four taste qualities to man were determined for 79 hamster chorda tympani fibers. Some fibers were very sensitive to sucrose, sodium chloride, or hydrochloric acid, but none were very sensitive to quinine. These sensitivities were not randomly distributed among fibers: the sucrose sensitivity was separated from and negatively correlated with the other sensitivities which were associated and positively correlated with each other. Moreover, there were a limited number of sensitivity patterns: (a) fibers responding best to sucrose responded second-best to salt, less to acid, not to quinine; (b) fibers responding best to salt either responded second-best to sucrose and not to acid or quinine; or second-best to acid, less to quinine, and not to sucrose; and (c) fibers responding best to acid responded second-best to salt, more to quinine, and less to sucrose than other fibers. Therefore, if four stimuli of different taste qualities are ordered from acceptable to unacceptable, neural response functions of most hamster chorda tympani taste fibers peak at one point. Sensitivities to nine other moderately intense stimuli which vary in quality to man were also determined for 46-49 of the fibers. Sensitivities to sweet stimuli were always associated with each other and separated from sensitivities to nonsweet stimuli. Sensitivities to nonsweet stimuli were all associated with each other; however, the strongest correlations were between sensitivities to stimuli of like quality, e.g., the three acids or the two sodium salts.

Animals↗