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Biomedical subjects

C Weiss

Publications and source records attributed to C Weiss.

At least 253 records · Page 14Linked to original sources
PubMed1980

Regional distribution of glutathione reductase in the adult rat brain.

Glutathione reductase was measured in 10 selected areas of the adult rat brain. Activitives varied over a 2.5-fold range. The caudate-putamen and cortical areas contained the highest activities. Several gray matter structures contained intermediate activities. The substantia nigra and the corpus callosum, a white matter structure, contained the lowest activities. The caudate-putamen, a catecholamine rich area, may produce H2O2 via MAO and would require glutathione reductase to recycle glutathione oxidized by glutathione peroxidase. However, the distribution of glutathione reductase activity also suggests a role in reducing oxidants formed during tissue respiration.

Animals↗
PubMed1980

Periodic microflow pattern measured with a new microflow probe within the rat kidney cortex.

With a newly developed microflow probe of high spatial resolution periodic changes of flow occurring within a tissue sphere of a radius of less than or equal to 50 micrometer have been observed. The frequency distribution of the periodic changes of flow was similar to the frequencies observed earlier with different techniques in the same preparation and in other organs (Basar and Weiss, 1970; Weiss and Thiemann, 1973). Preferred frequencies were: 0.02 Hz, 0.06 Hz and 0.1 Hz. Manufacture, calibration, the complete setup, and the estimation of the power of spatial resolution of the microflow probe are described. Periodic heating of the flow-sensing thermocouple at the tip of the probe (luminal diameter less than or equal to 10 micrometer) obviates the use of a reference thermocouple, renders the system (relatively) insensitive against uncontrolled changes of ambient temperature, and thus allows measurements with a very high sensitivity.

Animals↗
PubMed1980

Regional distribution of glutathione peroxidase in the adult rat brain.

Glutathione peroxidase activity was measured in 10 areas of perfused adult rat brain with the use of a fluorometric assay coupled to NADPH oxidation. The caudate-putamen and the substantia nigra had the highest activities. Cortical areas and several nuclear areas had somewhat lower activity. Activity was lowest in a white matter structure (corpus callosum). High activity of glutathione peroxidase may be related to the need to reduce hydrogen peroxide arising in the course of monoamine metabolism.

Animals↗
PubMed1980

[Lymphographic pattern in lymphogranulomatosis -- a study on the prognostic value and relation to histology (author's transl)].

The possibilities offered by lymphography with regard to supplying clear information in respect of prognosis and histology in patients with lymphogranulomatosis, were analysed in 83 patients via retrospective evaluation of clinical data and x-ray findings, using a computer. Disclosure of pathological lymphangiographic changes signifies poor prognosis not requiring further differentiation. Analysis of the pathological storage patterns appears to indicate that these are images of an infiltrative process proceeding in three stages. Solitary filling defects appear first, followed by a lucunar image and, finally, a cystic storage pattern. No different prognostic conclusions can be drawn from the individual stages. No correlation was found between lymphographic storage patterns and histological findings.

Adolescent↗
PubMed1979

Depressed PHA transformation and acute leukemia in macroglobulinemia.

Two out of fifty-three patients with macroglobulinemia developed acute leukemia following chemotherapy. The Phytohemagglutinin (PHA) Transformation Index performed prior to the appearance of acute leukemia was found to be markedly depressed in these two patients in comparison with ten other patients with macroglobulinemia. In addition, a clone with monosomy 7 was detected in one of the currently reported patients when the leukemic process became apparent. The cytogenetic analysis was normal in the same patient 48 months earlier, when macroglobulinemia was diagnosed. The low PHA Transformation Index and the chromosomal hypodiploidy are of interest and their clinical significance merits further investigation.

Adolescent↗
PubMed1979

Periodic changes in blood flow in the in vivo rat kidney.

The frequency response of the blood flow through the rat kidney in vivo has been studied. A piston controlled by a random-signal generator compressed the abdominal aorta proximal to the renal artery eliciting stochastical arterial pressure changes of an amplitude of less than or equal to 5 mm Hg. This small amplitude allowed to study the system under physiological conditions. In accord with earlier results from isolated kidneys pressure induced maxima of flow resistance were found at 0.005 Hz and at 0.1 Hz, thus demonstrating that in vivo humoral and/or nervous factors do not significantly alter the renal vascular response to changes of arterial pressure.

Animals↗
PubMed1979

Effects of procaine and extracellular calcium concentration on response of rat stomach fundus muscle to acetylcholine and 5-hydroxytryptamine.

1. When rat stomach fundus muscle was incubated for 30 min in Tyrode solution from which calcium chloride had been omitted, there was an almost complete abolition of the contractile response to 5-hydroxytryptamine (5-HT) while that to acetylcholine (ACh) was still present. 2. The maximum tension obtainable with ACh remained the same in external calcium concentrations ranging from 0.45 to 3.6 mM, but the pD2 value increased. 3. A concentration of at least 0.9 mM calcium was needed to maintain a maximum contraction with 5-HT, and the pD2 for this agent also increased significantly with increase in calcium content of the medium. 4. The effects of procaine on the responses of the muscle to 5-HT and ACh were similar to the respective changes induced by lowering the calcium concentration, and were reduced by the addition of calcium. 5. Concentrations of 2.2 x 10(-7) to 3.6 x 10(-5) M procaine reduced the effects of both 5-HT and KCl and suppressed the maximum responses. 6. The maximum responses to KCl and 5-HT were restored at higher concentrations of procaine (greater than 3.6 x 10(-4) M), while the effect of ACh was reduced. 7. It is suggested that 5-HT, like KCl, is almost entirely dependent on extracellular calcium for inducing muscle contraction, while ACh may utilize calcium from bound stores.

Acetylcholine↗