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Biomedical subjects

J Grimm

Publications and source records attributed to J Grimm.

At least 145 records · Page 8Linked to original sources
PubMed1977

[Study of systolic ventricular volume changes by means of current measurement of contrast media].

Systolic changes of left ventricular volume were estimated after left ventricular contrast injections in dogs by roentgen-videodensitometry with adjustable windows. Good correlations were found between densitometric volume changes and the integral of electromagnetic aortic flow, as measured every 20 msec (r greater than or equal to 0.95 in 118 of 124 systoles analyzed). Videodensitometry avoids the time consuming frame-to-frame analysis with the errors inherent in geometric assumptions in ventricular volume measurements.

Animals↗
PubMed1976

Influence of serum and insulin on the accumulation of aminoisobutyrate by rat hepatoma cells.

1. Cultured rat hepatoma cells accumulate 2-aminoisobutyrate to high concentrations by a transport mechanism probably of the A type mediation. 2. Transport is enhanced by the presence of serum. When cells are deprived of serum the rate of transport declines over a period of hours; conversely addition of serum leads over a period of hours to increase in transport activity. In the presence of serum the apparent Km for aminoisobutyrate uptake is about 8 mM. In cells deprived of serum the Km is much higher. 3. Addition of insulin produces both an immediate increase in the rate of aminoisobutyrate uptake and a time-dependent rise. 4. The presence of alanine diminished aminoisobutyrate uptake in a concentration-dependent fashion. Competition is seen both in the presence and absence of serum but not when cells are incubated at 4 degrees C. 5. Preincubation with alanine for 1 h also diminishes aminoisobutyrate uptake when the alanine is removed. Cells take a period of several hours to recover from the depression of transport induced by alanine. 6. Transport of aminoisobutyrate rapidly declines in the presence of cycloheximide. Actinomycin had no effect for at least 8 h.

Alanine↗
PubMed1976

The influence of insulin on various enzyme activities in human and rat hepatoma cells.

1. Incubation of human and rat hepatoma cells with insulin (1 mU/10(6) cells) decreases their content of adenosine 3':5'-monophosphate by more than half after 1 h and by about a quarter after 4 h. 2. The activities of the ATP-metabolising enzymes, adenylate kinase and Mg2+-adenosine triphosphatase are significantly increased by insulin within 1 h and after 4 h. Activity of succinate dehydrogenase and lactic dehydrogenase showed no change at either time interval. 3. Insulin markedly stimulated glucose 6-phosphate dehydrogenase activity within 1 h but by 4 h the increase was less apparent. Glutamate dehydrogenase activity by contrast was not increased by 1 h but was elevated at 4 h.

Adenosine Monophosphate↗
PubMed1975

[Proceedings: Quantification of mitral valve insufficiency by means of videodensitometric measurement of the amount of contrast media in angiocardiography].

A new indicator quantity principle is presented which permits estimation of the regurgitant fraction in mitral incompetence from left heart angiocardiography by videodensitometric measurement of contrast medium content in the left heart chambers. In 90 experiments on dogs, a linear correlation of r = 0.89 was established between simultaneous determinations of mitral regurgitation by videodensitometry and electromagnetic flow measurement. Since only 1 catheter is needed for the injection of contrast medium and concomitant aortic incompetence can be computed from the same videodensitograms, this method is considered to be of special interest in clinical heart catheterization.

Angiocardiography↗