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G Viehberger

Publications and source records attributed to G Viehberger.

7 recordsLinked to original sources
PubMed1991

Effects of the duration of therapy with the LHRH agonist D-ser (BUT)6 Azgly10-LHRH (ICI 118-630) on the steroid hormone content and the morphology of human testicular tissue in the treatment of patients with advanced prostate cancer.

In 20 patients with locally advanced or metastatic prostate cancer, testicular tissue obtained by bilateral subcapsular orchidectomy was examined for steroid hormone content and morphological changes. Eight patients (group I) had not received previous treatment. Twelve patients had been treated with monthly subcutaneous doses of the depot luteinizing hormone-releasing hormone (LHRH) agonist D-ser (BUT)6 Azgly10-LHRH (ICI 118-630). Six patients (group II) had been treated for less than 6 months and 6 patients (group III) for more than 6 months. The longest duration of treatment with depot LHRH was 36 months. After 2 months of treatment (group II), maximum hormone suppression was achieved and remained unchanged even if treatment was continued for 3 years. The mean serum testosterone levels were decreased in group II (means = 0.586 mg/ml) and in group III (means = 0.575 mg/ml) and were found to be in the range of castration; a statistically significant reduction in luteinizing hormone (P less than 0.000001) and follicle-stimulating hormone (P less than 0.05) was observed in the treated patient groups. The content of the steroid hormones dihydroepiandrosterone sulfate (DHEA)-S, testosterone, androstenedione, oestradiol, progesterone and 17-alpha-hydroxyprogesterone/g testicular tissue was significantly lower in patients on LHRH agonists. The differences in concentration were particularly pronounced for DHEA-S, T and A. As in the case of serum concentrations, the testicular tissues showed no differences between groups II and III. In the treated groups a significant reduction in weight was seen, depending on the duration of therapy. Similarly, the structural changes visible by the aid of light and electron microscopes increased with the duration of therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1988

Effects of long term GnRH analogue treatment on hormone levels and spermatogenesis in patients with carcinoma of the prostate.

The effects of long term GnRH treatment with the biodegradable depot formulation of ICI 118.630 on hormone levels and spermatogenesis were investigated in 18 males with advanced prostate cancer. Plasma levels of FSH, LH, testosterone, DHEA-S and SHBG were monitored at regular intervals. The drug suppressed FSH, LH and testosterone significantly and did not affect DHEA-S and SHBG plasma levels. Tissue specimens for histologic assessment and quantitative analysis of germinal cell types were obtained at secondary orchidectomy in 16 patients immediately following GnRH analogue treatment. Germinal cell maturation was arrested at the spermatogonial stage. In two patients discontinuing treatment histologic assessment of secondary orchidectomy specimens 9 and 10 months after the last GnRH analogue depot injection resulted in germinal cell maturation to late spermatids in part of the tubule cross sections. These results indicate that long term administration of the GnRH analogue fails to produce complete testicular sclerosis and spermatogenic arrest might be reversible.

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PubMed1983

Ultrastructural and histochemical study of the gallbladder epithelia of rainbow trout and tench.

The simple, high columnar gallbladder epithelia of the rainbow trout (Salmo gairdneri, Rich.) and the tench (Tinca tinca, L.) are composed of light and dark cells. Within the dark cells two types must be distinguished: less hydrated, but normal epithelial cells and degenerating cells. The latter seem to be eliminated from the epithelium through phagocytosis by monocytes and macrophages, which possibly correspond with the 'basal regenerative cells' of earlier investigations. Since they are mainly found near the basement membrane, an hypothesis is put forth that they do not enter the gallbladder lumen, but migrate back into the subepithelial connective tissue after phagocytosis. Light and less hydrated dark cells are specialized for absorption of water and dissolved bile salts and for secretion of mucus, which mainly consists of acid glycoproteins. Interspecific differences are seen with regard to both functions. So, in the tench only single microvilli are developed apically, whereas a true brush border is seen in the rainbow trout. Thus, a higher absorptive rate can be assumed in the rainbow trout. Or, with respect to mucus secretion, in the rainbow trout the granular endoplasmic reticulum predominates, whereas in the tench the smooth endoplasmic reticulum, often associated with glycogen and even forming 'glycogen bodies', is better developed. In the rainbow trout fibrillar granules of highly condensed acid glycoproteins are seen to be secreted. In the tench only vesicles of flocculent content occur. Perhaps, these morphological and subsequent metabolic differences may be related to the various feeding habits of the predatory rainbow trout and the omnivorous tench. Seasonal variations as expected especially in the tench after winter rest could not be established.

Animals↗
PubMed1983

New aspects on the 'rodlet cell' in teleosts.

The enigmatic rodlet cells, hitherto interpreted mainly as unidentified parasitic stages ('Rhabdospora thélohani') or as a sort of secretory cell, have been studied with electron microscopical and histochemical methods in three teleost species (Cyprinus carpio L., Tinca tinca L., Salmo gairdneri Rich.). The typical inclusions, the rodlets, consist of a dense core and a less dense cortex, with a coarse flocculent outer zone. The latter shows a positive reaction for neutral polysaccharides respectively glycoproteins (with the silver proteinate method and the equivalent silver methenamine-staining), concurring with some of the light microscopic data. While this suggests the secretion of this material by the Golgi apparatus, the core gives contradictory results, pointing to genetic material instead of a secretory product. Although the Feulgen method (as standard test for DNA with only a few exceptions known) is negative, DNA is indicated by several other methods (light microscopical fluorescence staining with HOECHST 33258, EDTA-method after Bernhard (1969), enzyme digestions positive with DNAse and negative with RNAse). Taken together with some observations on the tissue reaction (phagocytosis of the often discharged rodlets by macrophages and also the more specifically acting heterophilic granulocytes; isolation of the rodlet cells from the adjoining tissue as seen e.g. with the ruthenium red method), an exogenous parasitic nature of these cells seems more plausible, even if the evidence is not sufficient for an exact classification of either the cell or its characteristical inclusions.

Animals↗
PubMed1982

Apical surface of the epithelial cells in the gallbladder of the rainbow trout and the tench.

The free surface of the epithelial cells in the gallbladder of the rainbow trout (a predatory fish) and the tench (an omnivorous fish) is characterized by well-developed microvilli. They are irregularly arranged in the tench, but form a true brush border consisting of regularly aligned microvilli in the rainbow trout. In both species membrane-bounded cytoplasmic protrusions, up to 5 micrometers in diameter, extend from the apical surface. These protrusions are free of granules, secretory vesicles or other organelles; only in the tench some of them contain glycogen. Thus, the previously used terms "apocrine and droplet secretion" are not justified; the epithelial protrusions are now to be regarded as droplets of degenerated cytoplasm. Since they resemble the protrusions reported in fetal and postnatal epithelial cells in the gallbladder of higher vertebrates, interspecific differences are discussed. There is no significant correlation between the seasonal activity of the fish and the abundance or structure of the cytoplasmic protrusions.

Animals↗
PubMed1979

Ultrastructure of skeletal muscle after CO2-laser incision.

The immediate effect of CO2-laser incision to the dorsal skin and underlying muscular tissue of rats was studied by light and electron microscopical methods. In the subcutaneous layer of skeletal muscle cells an increased susceptibility was found, resulting in distinct zones of cellular changes which are attributed mainly to thermal effects of the laser beam. The importance of these findings for the surgical application of lasers is discussed.

Animals↗