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Biomedical subjects

J Aldenhoff

Publications and source records attributed to J Aldenhoff.

25 records · Page 2Linked to original sources
PubMed1985

Electrophysiological actions of corticotropin-releasing factor in the central nervous system.

A review of recent studies of the effects of corticotropin-releasing factor (CRF) on the electrical activity of central neurons indicates that CRF has predominantly excitatory actions in locus ceruleus, hippocampus, cortex, and some regions of hypothalamus. These brain areas are reported to contain immunoreactive CRF. Intracellular recordings in the hippocampal slice preparation demonstrate that the excitation in this preparation may arise from reduction of the afterhyperpolarizations (AHPs) following bursts of spikes. The postburst AHPs probably are produced by a Ca2+-dependent K+ conductance. Inasmuch as "Ca2+ spikes" recorded in the presence of tetrodotoxin are not diminished by CRF, this peptide appears to be acting either at the level of the Ca2+-dependent K+ conductance itself, or at the linkage between this conductance and Ca2+ influx or Ca2+ recognition sites. These excitatory effects are consistent with electroencephalographic recordings in awake animals, where intracerebroventricular CRF activates cortical and limbic areas and, at higher doses, evokes epileptiform activity in amygdala and hippocampus. However, predominantly inhibitory actions of CRF have been seen with extracellular single-unit recordings in a few central nervous system (CNS) areas such as lateral septum, thalamus, and the hypothalamic paraventricular nucleus. These findings, combined with those from immunohistochemical, biochemical, and behavioral studies, suggest 1) a possible neuromessenger role for CRF in extrahypothalamic regions and 2) a possible concerted function by CRF-containing elements in the CNS in an integrated behavioral response to stress.

Action Potentials↗
PubMed1980

Symptomatology and psychological aspects of male sexual inadequacy: results of an experimental study.

Forty-two male patients and their sexual partners were studied. Sixteen of the patients had psychogenic erectile failure (eight each with the primary and secondary forms), 16 were premature ejaculators, and 10 had diabetes-related impotence. Because of the higher mean age of the diabetics, two control groups were used, an age-matched older group (eight healthy males and their partners) and an age-matched younger group (16 healthy males and their partners). The results for the various groups on a semi-standardized interview about sexual behavior and on five psychological assessment scales were compared. Of the 88 questions on the semi-standardized interview, 11 permitted assignment of the patients to the correct group. The diabetics suffered from "prevailing erectile impotence." They viewed themselves as being less disturbed sexually than the other patients did, although on the basis of their symptoms their impotence was actually more severe. The patients with psychogenic erectile impotence had a "situational" sexual disorder in which sexual anxiety played an important role. They viewed themselves as more insecure than the diabetics and the controls and they overidealized their partners and mothers. There appear to be two subgroups of premature ejaculators: The E1 group of patients seemed to be less "neurotic" than the E2 group. On the psychological measures the latter was quite similar to the group of patients with psychogenic erectile impotence. All patient groups except E1 were significantly more depressed than the control groups.

Adult↗
PubMed1980

Psychophysiological aspects of male sexual inadequacy: results of an experimental study.

Forty-two male patients and their sexual partners were studied: 16 patients with "psychogenic" erectile failure (eight each with the primary and secondary forms), 16 premature ejaculators, and 10 patients with diabetes-related impotence. Due to the higher mean age of the diabetics, an age-matched older control group (eight healthy males and their sexual partners) and an age-matched younger control group (16 healthy males and their sexual partners) were also studied. In an experimental situation various psychophysiological parameters were evaluated. The viewing of films depicting sexual behavior produced psychophysiological reactions in all subjects. The patient groups and the controls differed on the following five parameters: amount of increase in systolic blood pressure, amount of increase in number of spontaneous fluctuations in skin resistance, erection amplitude, latency of erection, and duration of erection. In the diabetic group the three erection parameters were very depressed. In the group with primary psychogenic erectile impotence all five parameters were lower than in the controls, with the greatest difference in spontaneous fluctuations in skin resistance. The psychophysiological profile of the group of patients with secondary psychogenic erectile impotence was surprisingly similar to the profile of the diabetics, with a sharp increase in systolic blood pressure and in spontaneous fluctuations in skin resistance, but very depressed erection parameters. There were no marked differences between the controls and the premature ejaculators. There were only a few correlations between self-rated sexual arousal and psychophysiological measures of sexual stimulation and these were not very high. They were found mainly in the patient groups.

Adult↗
PubMed1979

Pituitary gonadal system function in patients with erectile impotence and premature ejaculation.

The pituitary testicular system was studied in men with psychogenic impotence. Eight patients with primary erectile impotence age 22--36 years, eight men with secondary erectile impotence age 29--55 years, and 16 men with premature ejaculation age 23--43 years were studied. The last group was further divided into two subgroups: E1 (n = 7) patients without and E2 (n = 9) patients with anxiety and avoidance behavior toward coital activity. Sixteen normal adult men age 21--44 served as a control group. Diagnosis was made after psychiatric and physical examinations. Patients complaining primarily of loss of libido were not considered in the study. Ten consecutive blood samples were obtained over a period of 3 hr from each patient. Luteinizing hormone (LH), total testosterone, and free (not protein-bound) testosterone were measured. Statistical analysis revealed no significant differences between patients and normal controls.

Adult↗
PubMed1975

[Experimental xenografting in widely divergent species: Interaction of humoral factors in hyperacute xenograft rejection in the rat-dog system (author's transl)].

The purpose of this paper is to test serum factors which are by interaction with cells responsible for the HXAR. Special stress was laid upon the examination of different serum fractions with or without the presence of preformed natural antibodies. Xenohemoperfusion: Rat kidneys were isolated and perfused in vitro with both whole blood resp. serum fractions and various perpheral cells of dogs. Rejection criterion was the diminishing renal blood flow at a constant pressure of the perfusion. Perfusate: Dog serum fractions were isolated by means of carton electrophoresis into the following fractions: Albumin, alpha-1, alpha-2, beta and gamma-globulin. Dog peripheral blood cells were separated into WBC, RBC and platelets by means of centrifugation and washing of EDTA whole blood. The serum fractions were tested for antibodies using hemagglutination and complement fixation techniques. 1. Hemoperfusion with serum fractions leads to a longer perfusion rate and to higher renal blood flow than perfusion with whole dog blood. 2. No preformed natural antibodies were found in the alpha-2 globulin fractions; however, perfusion with alpha-2 globulin fractions produced a rejection phenomenon both in combination with cells and erythrocytes. 3. Perfusion with serum fractions containing preformed natural antibodies produced a rejection only when WBC and thrombocytes were present. These results suggest that HXAR is induced by two different mechanisms: 1. The effect of humoral natural antibodies (found in the beta and gamma globulin fraction) together with peripheral cells. 2. The effect of a non-immunological humoral factor, found in the alpha-2 globulin fraction, leading to destruction of the xenogeneic organ, obviously to a minor degree dependent on interaction with peripheral cells.

Alpha-Globulins↗