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Biomedical subjects

M Schlumpf

Publications and source records attributed to M Schlumpf.

At least 91 records · Page 5Linked to original sources
PubMed1976

Finger blood flow in healthy subjects of different age and sex and in patients with primary Raynaud's disease.

Finger blood flow measured at rest and after 3 minutes of circulatory arrest by strain gauge venous occlusion plethysmography was significantly higher (p less than 0.001) in a group of 13 healthy young men than in a group of 12 healthy young women. The flow values in 13 women in the meopause reached almost the level found in men. Hormonal factors might explain these differences. Between the group of the healthy young women and the 12 patients with Raynaud's disease there were only gradual differences in finger blood flow. Peak flow after 3 minutes of circulatory arrest was significantly lower in the patients (p less than 0.05). Whereas flow at rest showed only a tendency to lower values (mean room temperature 24 degrees C). The spontaneous and cold induced vasopastic attacks characterized by a decrease in finger volume and by very low or not measurable finger flow.

Adult↗
PubMed1975

Catecholamines in mutant mouse cerebellum: fluorescence microscopic and chemical studies.

Catecholamine-containing fibers have been examined in the cerebella of normal and hypocerebellar mutant mice using Falck-Hillarp and glyoxylic acid histofluorescence techniques. The amounts of norepinephrine and dopamine were also determined chemically in the same mutants. Green fluorescent fibers in cerebella of normal mice are similar in size and distribution to those described in the rat. Weanling and adult weaver, reeler and staggerer mice all manifest greatly increased specific catecholamine fluorescence per unit area in cerebellar cortex, but the patterns of fluorescent fibers are distinctive. In weaver, the fibers are of normal diameter, surround Purkinje cell bodies and appear to climb along major dendrites. In reeler, similar fibers form a plexus around cortical and non-cortical Purkinje cells; relatively normal fluorescent fiber patterns are present in well-organized cortical regions, while stouter disoriented fibers course through the shallow molecular layer in disorganized regions. Staggerer cerebellar cortex exhibits the greatest fluorescence with most terminals appearing as matted tangles adjacent cell bodies. Clearly defined fibers, however, can be distinguished in the molecular layer running perpendicular to the pia or for long distances in the coronal plane parallel to the pia. The major catecholamine determined chemically is norepinephrine. Reeler cerebella contain normal absolute levels and a doubled concentration of norepinephrine. In contrast, and despite the fluorescence findings, the total norepinephrine content of weaver and staggerer cerebella is significantly reduced and concentrations are not significantly different from normal.

Animals↗
PubMedDate not supplied

Impaired host resistance to Trichinella spiralis as a consequence of prenatal treatment of rats with diazepam.

In utero exposure of Long Evans rats to low dosages of diazepam has previously been found to result in depression of cellular and humoral immune responses until adulthood, with marked changes in cytokine release by splenocytes and splenic macrophages. In order to assess the significance of these alterations in immune cells with regard to host resistance, we investigated the resistance of adult offspring towards Trichinella spiralis. Time-pregnant rats were treated with diazepam (1.25 mg/kg/day) or vehicle from gestational day 14 to 20. Male offspring were infected with T. spiralis at 2 months of age. This infection model tests the participation of T- and B-cell populations and of macrophages. Prenatally diazepam-exposed animals exhibited an impaired defence towards T. spiralis. The number of muscle larvae was increased as determined in digested carcasses and by morphometric analysis of the tongue. Moreover, antibody titers were altered, i.e., IgG was decreased and IgA was elevated in the prenatally diazepam-exposed group. These results demonstrate an impaired defense towards T. spiralis in adult rats after prenatal exposure to diazepam.

Animals↗
PubMedDate not supplied

Prenatal exposure to diazepam causes sex-dependent changes of the sympathetic control of rat spleen.

Prenatal exposure to low doses of benzodiazepines has been found to affect immune functions (25,26). Because the immune system is controlled by the autonomic nervous system, we investigated the sympathetic activity in the spleen for a possible contribution to impaired immune function. Twenty-eight-day-old offspring of prenatally diazepam- or vehicle-treated Long-Evans rats (diazepam 1.25 mg/kg/day SC, gestational day 14-20) were injected IP with sheep red blood cells (SRBC) to evoke an immune reaction. Baseline splenic noradrenaline (NA) turnover was higher in females than in males. Prenatal diazepam treatment resulted in reduced NA turnover in the spleen of SRBC-stimulated female, but not male, offspring. beta-Adrenergic binding sites in spleen membrane fractions, studied with 3H-dihydroalprenolol, showed no differences, indicating that changes in NA turnover were not compensated by changes in receptor expression. Sex-specific developmental effects of diazepam have been described earlier, e.g., in selective effects on perinatal corticosterone levels in female offspring (26).

Animals↗
PubMedDate not supplied

Laminar distribution of GABAA receptor alpha 1, beta 2, and gamma 2 subunit mRNAs in the granular and agranular frontal cortex of the rat during pre- and postnatal development.

The expression of mRNAs encoding the three GABAA receptor subunits that are associated with the most abundant benzodiazepine-sensitive GABAA receptor in adult cortex, that is, the alpha 1, beta 2, and gamma 2 subunits, was studied in rat cortex during pre- and postnatal development by means of in situ hybridization, gamma 2 and beta 2 mRNAs become detectable in neocortex at gestational day 16 (GD16), alpha 1 at GD18. gamma 2 mRNA exhibits the highest level of expression at early ages, while alpha 1 mRNA levels are low. beta 2 mRNA rises steeply during the last days of gestation. Around birth, it shows the highest expression of the three subunits studied in cortex, and increases further until postnatal day 15 (PD15). The expression of alpha 1 subunit mRNA also increases markedly shortly before birth and accelerates between PD8 and PD15, when it reaches higher levels than the other two subunits. Following the initial high expression, gamma 2 mRNA increases gradually and slowly until PD25. During prenatal development, highest expression of all three subunit mRNAs is found in the upper layers of cortex, that is, cortical plate and marginal zone. The subplate layer does not start to express GABAA receptor subunit mRNAs until GD18. At birth, all developing layers of the cortex express mRNAs for the three subunits, except the marginal zone. Highest levels are found in the upper part of the cortical plate. At the end of the first postnatal week (PD8), the laminar distribution of mRNA expression in neocortex becomes more differentiated. For all three subunit mRNAs, highest expression is then observed in neuron-like cells in layer IV in the granular areas, and over layers III and upper V in agranular areas. Subsequently, between PD8 and PD25, increasing levels of expression are observed over the pyramidal cell layer V. This regionally differentiated, developmental pattern suggests a close relationship between development of GABAA receptor subunits, ingrowth of thalamocortical projections, and maturation of neocortical circuitry.

Animals↗