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Biomedical subjects

W Fischer

Publications and source records attributed to W Fischer.

At least 253 records · Page 14Linked to original sources
PubMed1986

Retrograde cell changes in medial septum and diagonal band following fimbria-fornix transection: quantitative temporal analysis.

Complete unilateral fimbria-fornix transections, including the overlying cingulate cortex, were administered to female rats. At time points from 1 day to 6 weeks, the septal-diagonal band region was examined using acetylcholinesterase histochemistry, Cresyl Violet cell staining, and choline acetyltransferase biochemistry. As early as 1 day following the transection a decrease in acetylcholinesterase positive cell body staining was observed in the medial septum; however, no loss of Nissl-stained neurons was measured in Cresyl Violet stained sections until 1 week after the lesion. Maximal loss of acetylcholinesterase-positive cells, as visualized after irreversible acetylcholinesterase inhibition, was measured at 1 week, and no further change was observed at time points up to 6 weeks after operation. The loss of acetyltransferase-positive cells was greatest in the medial septal area (-65%) and the vertical limb of the diagonal band (-55%). Little cell loss was measured in the horizontal limb of the diagonal band. This is consistent with the known projections of these cell bodies. Remaining acetylcholinesterase-positive cell bodies in the medial septum had shrunk by about 20% (measured as the diameter along the major axis). A marked neuronal cell loss (about 50%) was demonstrable in the medial septum and vertical limb of the diagonal band in the Cresyl Violet-stained sections, too. A pile-up of acetylcholinesterase-stained material was observed in the dorsal-lateral quadrant of the septal area just proximal to the lesion at 1 day following transection. This pile-up occurred in the medial septum and diagonal band area up to 1 week following the transection, and had nearly disappeared by 2 weeks post-transection. Choline acetyltransferase biochemical activity, measured in samples of whole septum, decreased significantly at 1 day but subsequently returned to control levels. By 2 weeks following transection, an increase in acetylcholinesterase-positive stained fibers was observed in the dorsal-lateral quadrant of the septum, ipsilateral to the lesion relative to the contralateral septum. This response, which was interpreted as sprouting from the lesioned axons proximal to the transection, probably accounted for the rise in choline acetyltransferase biochemical activity in the whole septum following the reduction on the first day.

Acetylcholinesterase↗
PubMed1986

Continuous infusion of nerve growth factor prevents basal forebrain neuronal death after fimbria fornix transection.

Neurons in the rat medial septum (MS) and vertical limb of the diagonal band of Broca (VDB) undergo a rapid and severe cell death after transection of their dorsal projection to the hippocampus by aspiration of the ipsilateral fimbria fornix and supracallosal striae. By 2 weeks posttransection, the extent of neuronal loss was 50% of the total neurons and 70% of the cholinergic neurons in the MS and 30% of the total neurons and 40% of the cholinergic neurons in the VDB. We hypothesized that (i) the death was due to the loss of a hippocampus-derived neuronotrophic factor, and (ii) exogenous nerve growth factor (NGF) might provide trophic support to the MS/VDB cholinergic neurons, in light of recent reports that the septal diagonal band cholinergic neurons are responsive to NGF and that NGF is present and produced in the hippocampus. In the present study, we attempted to prevent the transection-induced neuronal death by continuous infusion of exogenous 7S NGF (1 microgram/wk) through an intraventricular cannula device. We report here that NGF treatment significantly reduces both the total neuronal and cholinergic neuronal death found 2 weeks after fimbria fornix transection; there was a sparing of 50% of the neurons in the MS and essentially 100% of those in the VDB that otherwise would have died. We conclude that NGF also has a protective effect on noncholinergic neurons since calculations indicate that 80% of the NGF-affected neurons are noncholinergic.

Animals↗
PubMed1986

Interaction of purified lipoteichoic acid with the classical complement pathway.

Glycerophosphate-containing lipoteichoic acids (LTAs) interact with the first component of the classical complement pathway (C1). This resulted in the activation of the classical complement pathway in serum, shown by the consumption of C1, C2, and C4. The dose-dependent interaction of LTAs with purified C1 and C1q was dependent on the negative charges of the phosphate groups of LTA. It was reduced by charge compensation through D-alanine ester substituents and by sterical hindrance through di- and trihexosyl residues linked to position 2 of the glycerol moieties. The charge density of LTA may also play a role: poly(digalactosylglycerophosphate) LTAs, in which the phosphate groups are in a greater distance from each other, were less effective, and the loss of micellar organization by deacylation of LTA drastically reduced the complement activation capacity.

Complement Activating Enzymes↗
PubMed1986

[The influence of central monoaminergic systems on the anticonvulsive action of propranolol].

The influence of substances modulating the activity of central monaminergic systems on the anticonvulsant effect of propranolol was investigated with the maximal electroshock test in mice. The results demonstrated that especial the noradrenergic system plays an important role in modulating the efficacy of propranolol. Pharmacological stimulation of the noradrenergic system (e. g. with desipramine, pargyline, yohimbine) resulted in an enhanced anticonvulsant effect of propranolol. Compounds that suppress the noradrenergic transmission reduced this action. On the other hand manipulations of serotonergic (with 5,7-DHT, 5-HTP, PCPA) or dopaminergic (with 6-OHDA + desipramine, apomorphine) mechanisms seems to be without marked influence on the protective effect of propranolol in maximal electroshock.

5-Hydroxytryptophan↗
PubMed1986

[Epileptic psychosis and nonconvulsive status epilepticus with ictal bradycardia and asystole].

Case report of a 35 years old patient, who, without previous history of epilepsy, within two years experienced two long-lasting psychotic episodes due to non-convulsive status epilepticus with complex partial seizures. During the second psychotic episode she developed ictal vegetative phenomena such as profuse sweating, flush, apnoea, and, above all and most alarming, periods of severe bradycardia and asystolia with clinical signs of syncope. Ictal asystolia, though being an uncommon sing of epileptic seizures, may be one cause of sudden unexpected death in epileptics.

Adult↗
PubMed1986

[Retard effect of acemetacin from a commercial preparation--kinetics in humans following single and multiple administration].

Acemetacin was given to 14 volunteers in a randomized cross-over arrangement as one single administration of 90 mg (1-(p-chlorobenzoyl)-5-methoxy-2-methylindole-3-acetoxyacetic acid) (as Rantudil, Rantudil forte and Rantudil retard) and the courses of blood levels curves compared. Half-life of absorption was considerably higher with the retard formulation (2.01 instead of 0.58 h). The blood level maximum (tmax) was significantly (p less than 0.05) delayed by the retardation, blood levels were lower after 2 h (p less than 0.01), not significantly different 3-4 h after administration and higher (p less than 0.05) than the immediate release form after 6-10 h. AUC's are 5.82 +/- 4.04 (normal) and 6.75 +/- 3.24 (mumol X l-1 X h retarded). The mean residence time was prolonged from 4.1 to 6.3 h, yielding a sustained release quotient of 1.54. After multiple administration (2 retard capsules/d for 8 d) cmax corresponded to the results obtained after single application, maximum levels at 1.24 mumol X l-1 (mean) being somewhat higher than after single application (1.11 mumol X l-1), which is the usual steady-state behavior. Minimum levels in the steady-state (cmin) were 0.24-0.53 mumol X l-1. Bioavailability (AUC's between applications) was not significantly different. No accumulation was found. Levels measured during 8 days of administration of the Rantudil retard formulation corresponded to blood levels from computer simulations. Biological half-life was 4.03 h, which was similar to data obtained with Rantudil (3 X 60 mg/d) in rheumatic patients.

Delayed-Action Preparations↗
PubMed1986

[Hysteria and psychosis].

The relationship between endogenous-psychotic and hysterical behavior is presented in this paper on the basis of typical patients' accounts. Various patterns of behavior are revealed: chronic hysterical psychotic syndromes, acute hysterical psychotic syndromes, hysterical exalted psychotic episodes, simulated hysterical psychotic syndromes, hysterical behavior in the attempt to cope with psychosis, and pseudohysterical behavior in endogenous psychoses. The specific aspects of the doctor-patient relationship in the case of these patients are described.

Adaptation, Psychological↗
PubMed1986

[Is Teflon treatment of female urinary incontinence still justified?].

An analysis is made in this paper of therapeutic results obtained at Charité Berlin from 14 cases of pure stress incontinence and 6 cases of combined stress-urge incontinence, with reference being made to general benefits and setbacks of transurethral Teflon injection to cope with female urinary incontinence. Five women underwent teflon therapy as the first operation performed on them. Seven women had had one operation before and the rest more than one. Continence was restored in 6 patients (30 per cent), and 3 patients (15 per cent) were improved. The presurgical situation was of minor influence. The definite result was outlined as early as three months from surgery. Urodynamically, Teflon had a favourable impact primarily on functional urethral length and on the stress quotient. However, elevation of the bladder base was radiographically detectable in less numerous cases. Only partial agreement was found to exist between objectivated improvement and subjectively perceived and reported therapeutic results, with falsely positive and falsely negative findings occurring with equal frequency. Micturition was insubstantially impaired by Teflon. However, it should be adopted as a matter of principle that in future teflon should no longer be applied to women for urinary incontinence unless conservative therapy or other surgical incontinence techniques must be skipped for whatever reasons and unless no more effective sphincter substitute is available.

Adult↗
PubMed1986

[Quantitative EEG analysis of a single dose of psychotropic drugs in healthy probands].

In a series of 74 experiments in a double blind study, 25 healthy test persons were medicated with a single dose of Clomipramin, Desipramin, Imipramin, Diazepam, Carbamazepin, Haloperidol, and a placebo. At the end of one hour, and again at the end of three hours, an EEG was made whose frequency analysis revealed significant changes in about half the test persons. The antidepressives induced an increase in the theta waves, the slow alpha waves, and the slow beta waves, and a decrease in the fast alpha waves. The factors influencing the EEG are discussed.

Adult↗
PubMed1986

[Measuring reaction times in healthy probands before and following a single dose of psychotropic drugs].

A single dose of Clomipramin, 50 mg; Amitriptylin, 50 mg; Desipramin, 50 mg; Imipramin, 50 mg; Diazepam, 10 mg; Carbamazepin, 200 mg; Haloperidol, 3 mg; were each administered orally, and Clomipramin, 25 mg was administered intravenously, and reaction times were measured and compared with those obtained after administering a placebo. The statistical examination was conducted using Wilcoxon's test. In the case of Amitriptylin, Diazepam, and Haloperidol, there was a statistically significant reduction in the reaction times.

Humans↗
PubMed1986

[Sexuality and urinary incontinence].

In an attempt to investigate correlations between sexuality and urinary incontinence (UI), fifty-one women with stress incontinence (18), urge incontinence (12), or combined stress/urge incontinence (21) were interviewed on their sexual behaviours, prior to and after development of UI. The results were compared with data on the average female population in the GDR. Women with subsequent UI were found to have perceived cohabitarche as extremely beautiful or disgusting or anorgastic with significantly higher frequency, as compared to the general female population. The average number of sexual partners and frequency of cohabitations had been higher with women in whom UI was to develop later on. Their sexual behaviours did not come closer to those of the general female population until UI was growing manifest. While marital problems were quoted as causes of UI by 39 per cent of the interviewers, only 14 per cent gave a negative assessment of their present partnerships. Reduced sexual relationships were often (47 per cent) offset by vicarious sexual activities. These women were more often than others suspected of trying to find a pretext for evading sexual intercourse on grounds of marital problems. Yet, one third of women with UI said that during orgasm they would strongly press downward, which might result in additional strain on the pelvic floor. In other words, sexual disorders and UI appeared to favour each other. Hence, psychosomatic and sexological investigations on interhuman relations should be adopted as part of comprehensive therapeutic planning to cope with urinary incontinence.

Adult↗
PubMed1986

[Results of electrical sensitivity tests of the urethra and vagina in functional urinary incontinence].

Urethral and vaginal sensibility has been tested in 90 patients with urinary incontinence by means of urethral catheter and vaginal electrodes. Monophasic rectangular impulses with a frequency of 2 Hz, a duration of 2 msec and a variable intensity were used. The urethral sensibility threshold was 10.5 mA in patients with urge incontinence and 14.8 mA with stress incontinence. The vaginal sensibility threshold was by 20 mA higher and correlated well with the urethral one in its differentation of stress and urge incontinence. Because the big scattering of the values there was no statistical significance. Therefore this method is only valid to clarify patients complaints and to define impulse parameters for therapeutic intravaginal electric stimulation.

Adult↗