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Biomedical subjects

K Jahn

Publications and source records attributed to K Jahn.

At least 55 records · Page 3Linked to original sources
PubMed1994

Patch-clamp study of membrane properties and GABA-activated currents of rat magnocellular supraoptic neurons in thin slice preparation.

The magnocellular neurons of the rat supraoptic nucleus were investigated by using (a) the patch-clamp technique on thin brain slice preparations to demonstrate voltage- and GABA-activated ionic currents, and (b) immunohistochemistry to demonstrate the expression of the beta 2 and beta 3 subunits of the GABAA-receptor on their membrane surface and the contents of the neuropeptides vasopressin and oxytocin. During electrophysiological recording in the whole-cell mode neurons were stained with Lucifer Yellow and camera lucida drawings were made. Two types of neurons could be distinguished by their different K(+)-currents, an inactivating and a noninactivating type. All neurons had a fast Na+ inward current. GABAA-activated currents were characterized by investigation of their ionic conductance and by blocking experiments with the GABAA-antagonist bicuculline.

Animals↗
PubMed1990

[The value of functional tests in diagnosis of prolactinoma].

The present study in 37 hyperprolactinaemic patients was performed, to investigate the relationship between radiographic changes of the pituitary region and serum prolactin levels, clinical signs and the results of dynamic tests. Prolactin responsiveness after metoclopramide- and TRH-injection and the nocturnal profile of serum prolactin were examined in 25 women. The results of the dynamic tests did not correlate with the radiological diagnosis. However, serum prolactin concentrations correlated strongly with the radiographic evidence of a pituitary tumour. The results show, that prolactin stimulation tests and the evaluation of the nocturnal secretory pattern of prolactin are not useful for differentiating between adenoma and nonadenoma caused hyperprolactinaemia. However, determinations of prolactin serum levels are of great clinical importance in the diagnosis of prolactinomas.

Circadian Rhythm↗
PubMed1990

In vivo and in vitro effects of extracts from Cassia aubrevillei in onchocerciasis.

A traditional herbal drug, called "Ganna Ganna", is used in rural areas of Liberia to treat onchocerciasis. It is prepared from the bark of the "Ganna Ganna" tree, which was identified as Cassia aubrevillei. An aqueous extract was prepared from the bark according to informations from local people and its effects on microfilaria (mf) density and pruritus were studied in eleven patients with onchocerciasis. In four patients a 1.8-4.8 fold increase in mf density was observed after three weeks and in two patients mf counts dropped to almost zero. Histology and embryogram of adult worms, isolated after treatment, revealed no significant changes. All patients reported a rapid decline of pruritus and this effect lasted for up to three months. The in vitro effect of different extracts on mf viability was tested. The alcoholic extract gave the best results, killing mf within 24 h at concentrations of 50 micrograms/ml. Chrysophanic acid, an anthraquinone identified in the drug, also showed good in vitro microfilaricidal activity. It is concluded, that "Ganna Ganna" could be a useful adjuvant in the therapy of onchocerciasis and that further evaluation of the drug seems promising.

Adult↗
PubMed1989

[AIDS and females--a multicenter study].

Case studies and epidemic surveys clearly show that HIV can be transmitted from males to females, from females to children in utero, and from females to males, as well as from males to males. Studies of heterosexual transmission prove that the extent of transmission varies: female partners of HIV-infected men have the highest incidence; transmission from infected women to their children is approximately 25%-50%. The unsolved questions in gynecology and obstetrics are presented and examined on the basis of a multicenter study of the experience with AIDS and in consultation with HIV-infected patients, so that a better understanding of AIDS might lead to improved treatment and counselling.

Acquired Immunodeficiency Syndrome↗
PubMed1987

[Is there a correlation between the degree of proliferation of vaginal and urethral epithelium and the incidence of stress incontinence? A contribution to estrogen therapy in stress incontinence].

The extent of proliferation of the vaginal and urethral epithelium, as well as urodynamic parameters, were studied in 232 patients in order to determine whether there is a relation between the development of stress incontinence and hormone-related epithelial proliferation. A higher build-up of vaginal than of urethral epithelium was found in 74% of the patients. Even in post-menopause patients, epithelial atrophy in the vagina was only found in 29.3%, while in the urethra it was found in 61.3%. Therefore, the vaginal epithelium cannot with confidence be taken as a basis for conclusions concerning the condition of the urethral epithelium. In the group of 145 patients with urinary stress incontinence no link could be established between the extent of proliferation of the urethral epithelium, the urethral occlusion pressure and the functional length of the urethra: The occurrence of an age-related excessively low urethral occlusion pressure (hypotonic urethra) is independent of the extent of proliferation of the vaginal or urethral epithelium. Sedimentation phenomena are also seen equally frequently in cases with atrophic and eutrophic epithelium. Owing to the high percentage of overweight women among those with stress incontinence, the extent of proliferation of the vaginal and urethral epithelium often corresponds to premenopausal cell pictures even in perimenopausal and postmenopausal women; this is a consequence of increased estrogen production in the peripheral fatty tissue. Therefore, estrogen therapy is unsuccessful in women with pure urinary stress incontinence. However, the efficacy of an equivalent therapy, e.g., with estriol, has been confirmed in cases of active and combined incontinence.

Atrophy↗
PubMed1986

[Epidemiology of Chlamydia infections].

Cultural and serological tests for Chlamydia trachomatis infection were performed in 213 patients at Düsseldorf University Gynecological Clinic Düsseldorf. 16 of these patients were tissue culture positive. Titers of antibodies greater than 1:100 were found in 37 patients with the ELISA. In tumorpatients the incidence of acute infection is not different from others, however antibodies were found in 35% of all tumorsera tested.

Adult↗
PubMed1982

[Therapy of acromioclavicular luxation].

62 patients underwent surgery for dislocation of the acromioclavicular joint and were followed up. In acute cases the best results could be achieved by an open reposition in combination with temporarily splinting by a Kirschner-wire and suture of capsula and ligament. A plasty using autologous ligament is necessary in rare cases only. Open reposition, screwing according to Bosworth and a plasty with a strip of autogenous cutis (Bunnell) should be performed in delayed cases.

Acromioclavicular Joint↗