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Biomedical subjects

F Götz

Publications and source records attributed to F Götz.

At least 163 records · Page 9Linked to original sources
PubMed1989

Influence of a dopamine agonist (lisuride) on sex-specific behavioural patterns in rats. II. Long-term effects.

Intact female and neonatally castrated male rats were treated with the dopamine agonist/serotonin antagonist lisuride during the early postnatal differentiation period of the brain (Day 2-12) or during the peripuberal maturation period (Day 26-40). It was found that early postnatal as well as peripuberal activation of the dopaminergic system in females resulted in masculinized social play-fighting behaviour, and lisuride application as late as peripuberally resulted in permanent masculinization of sexual behaviour. Comparable trends were found after peripuberal androgen administration. On the other hand, the demasculinized social play fighting as well as the sexual behaviour of neonatally castrated males, which is usually bisexual or even predominantly heterotypical, could be normalized--at least in part-by early postnatal or peripuberal lisuride administration. These findings confirm once more our previous reports that neurotransmitters can act directly as organizers of the brain. This holds true not only for the differentiation period but also for the maturation period.

Animals↗
PubMed1989

Molecular characterization and sequence of phosphatidylinositol-specific phospholipase C of Bacillus thuringiensis.

The gene encoding monophosphatidylinositol inositol phosphohydrolase (PI-specific phospholipase C, PI-PLC) of Bacillus thuringiensis was cloned in Staphylococcus carnosus TM300. The complete coding region comprises 987 base pairs corresponding to a precursor protein of 329 amino acids (molecular weight, 38,095). The NH2-terminal sequence of the purified enzyme from Escherichia coli indicated that the mature PI-PLC consists of 299 amino acid residues with a molecular weight of 34,586. Polyacrylamide gel electrophoresis revealed the same molecular weight for the purified enzyme isolated from the DNA-donor strain of B. thuringiensis and from the E. coli clone. By computer analysis, the secondary structure was predicted. The enzyme from the E. coli recombinant shows no activity on other phospholipids and sphingomyelin. The cleaving specificity of PI-PLC was examined by thin layer chromatography.

Amino Acid Sequence↗
PubMed1989

[Surgical treatment of venous-induced erectile impotence in the male].

In 14 out of 94 patients with erectile dysfunction a venous insufficiency was suspected. Localization and securing of the venous leak were done by dynamic cavernosography. An insufficient penile blood supply could excluded by Doppler ultrasonography and measurement of the penile-brachial artery-pressure index. In 7 out of 13 patients treated by ligation of penile veins the erectile function was normalized after operation, in 4 cases an additional intracavernous injection therapy was necessary and in 2 patients the operation was unsuccessful. If impotence occurs once more due to venous collaterals the implantation of a penile prosthesis should considered.

Adult↗
PubMed1989

The influence of sex hormones on the development of sex-specific cholesterol serum levels in rats.

1. The development of sex-specific cholesterol serum levels (under a fat-enriched diet) depends on the sex hormone status during the postpuberal activation phase. 2. The efficiency of postpuberal sex hormones seems to be influenced by the presence of definite sex hormone levels during the prepuberal/puberal maturation phase. 3. An influence of the perinatal sex-specific brain differentiation on the development of sex-typical cholesterol biosynthesis as reported by Carlson et al. was not demonstrable, possibly because of our special diet regimes (fat-enriched diet).

Animals↗
PubMed1988

Gallidermin: a new lanthionine-containing polypeptide antibiotic.

Gallidermin is a new member of the class of lanthionine-containing peptide antibiotics, which are summarized under the common name lantibiotics. The lantibiotic gallidermin is produced by Staphylococcus gallinarum (F16/P57) Tü3928, and it exhibits activities against the Propionibacteria, involved in acne disease. Gallidermin differs from the recently discovered tetracyclic 21-residue peptide antibiotic epidermin only in a Leu/Ile exchange in position 6. The isolation procedures for gallidermin included adsorption directly from the culture broth, ion-exchange chromatography of the amphiphilic and basic polypeptide followed by desalting, and final purification by reversed-phase HPLC. The structural elucidation of the polypeptide containing four thioether bridges involved mainly a combination of automated gas-phase sequencing, thermospray liquid chromatography/mass spectrometry and fast-atom-bombardment mass spectrometry.

Alanine↗
PubMed1988

Prepeptide sequence of epidermin, a ribosomally synthesized antibiotic with four sulphide-rings.

The genetic basis for the biosynthesis of large polypeptide antibiotics such as nisin has not been explained so far. We show here that the structural gene epiA encoding the antibiotic epidermin from Staphylococcus epidermidis is located on a 54-kilobase plasmid and codes for a 52-amino-acid prepeptide, which is processed to the tetracyclic 21-peptide amide antibiotic. The mature sequence of epidermin corresponds to the C-terminal 22-peptide segment of pre-epidermin and contains the precursor amino acids Ser, Thr and Cys, from which the unusual amino-acid constituents are derived. The more lipophilic epidermin is cleaved at a hydrophilic turn between Arg-1 and Ile+1 from the N-terminal segment-30 to -1, which probably assumes a partially amphiphilic alpha-helix conformation. We propose that the N-terminus (-30 to -1) plays a cooperative role during modification reactions and prevents toxicity of the mature epidermin to the producing strain before the antibiotic is cleaved off and secreted.

Amino Acid Sequence↗
PubMed1988

The effect of an acute maternal stress on beta-endorphin and growth hormone releasing factor in the rat fetus.

Pregnant rats were injected with saline or L-tyrosine methylester HCl (200 mg/kg) and subjected to an acute forced immobilization stress on day 20 of gestation. At 10, 30, 60, and 120 minutes after the onset of stress, their fetuses were dissected out, and the contents of hypothalamic and pituitary immunoreactive beta-endorphin (IR-beta-EP) and hypothalamic immunoreactive growth hormone-releasing factor (IR-GRF) were determined by specific radioimmunoassays. The maternal stress arose a significant decrease of hypothalamic IR-beta-EP at 30 minutes, while pituitary IR-beta-EP slightly elevated at 30 minutes, then declined at 60 minutes. Hypothalamic IR-GRF showed a gradual increase during the maternal stress. Tyrosine supplementation tended to attenuate stress-induced changes in hypothalamic and pituitary IR-beta-EP, but the response of hypothalamic IR-GRF was less modified by tyrosine. These results showed the functional changes in fetal central beta-EP and GRF under maternal stress in the late gestational life, and suggested that catecholaminergic regulations participate, at least in part, in the fetal neuroendocrine response to maternal stress.

Animals↗
PubMed1988

Teratogenetic maternofoetal transmission and prevention of diabetes susceptibility.

Gestational diabetes and impaired glucose tolerance in pregnancy were found to be important teratogenetic risk factors for the development of diabetes in the offspring. Mechanisms of action and prevention of maternofetal transmission of teratogenetic susceptibility to diabetes are presented. Gestational diabetes induced in the F0 generation produced the following effects in the F1 and/or F2 generation: Early postnatal hyperinsulinaemia, decreased noradrenaline and serotonin and increased endorphin concentrations in specific brain regions, permanent hypoplasia of the hypothalamic ventromedial nuclei, decreased insulin responsiveness to glucose, impaired glucose tolerance and increased diabetes susceptibility.

Animals↗
PubMed1987

The molecular organization of the lysostaphin gene and its sequences repeated in tandem.

The gene encoding lysostaphin of Staphylococcus staphylolyticus was cloned in Escherichia coli and its DNA sequence was determined. The complete coding region comprises 1440 base pairs corresponding to a precursor of 480 amino acids (molecular weight 51 669). It was shown by NH2-terminal amino acid sequence analysis of the purified extracellular lysostaphin from S. staphylolyticus that the mature lysostaphin consists of 246 amino acid residues (molecular weight 26926). Polyacrylamide gel electrophoresis revealed a similar molecular weight for the most active form. By computer analysis the secondary protein structure was predicted. It revealed three distinct regions in the precursor protein: a typical signal peptide (ca. 38 aa), a hydrophilic and highly ordered protein domain with 14 repetitive sequences (296 aa) and the hydrophobic mature lysostaphin. The lysostaphin precursor protein appears to be organized as a preprolysostaphin.

Amino Acid Sequence↗
PubMed1987

Surgery of calculous hydrocalyx (calyceoplastic surgery).

A modified surgical technique for calculous hydrocalyx, based on partial calyceal resection with simultaneous correction of the morphological abnormality responsible for stone formation is described. Access to the calyx is gained by a modified marginopolar resection. The modification developed by the authors consists in carrying the resection line laterally to the vertical axis of the kidney. The parenchyma is closed by U-shaped "hair-pin" stitches. Preparation of the limbic, pelvic and ureteral areas is abstained from, thus avoiding scarring which might affect renal lymph and blood flow and interfere with urinary transport. The results obtained in 85 cases of calculous hydrocalyx over an 8-year period were satisfactory. The rate of calculous recurrences was not higher than 3.5 per cent.

Humans↗
PubMed1987

Sexual differentiation of gonadotrophin secretion, sexual orientation and gender role behavior.

The positive estrogen feedback was found to be a relatively sex-specific reaction of the hypothalamo-hypophyseal system in rats as well as in human beings. It is dependent--most of all--on the estrogen convertible androgen level during sexual brain differentiation, but also on an estrogen priming effect in adulthood. The lower the estrogen convertible androgen or primary estrogen level during brain differentiation, the higher is the evocability of a positive estrogen action on LH secretion in later life. In clinical studies, we were able to induce a positive estrogen feedback on LH secretion in most intact homosexual men in clear-cut contrast to intact hetero- or bisexual men. These findings were strongly confirmed by Gladue and associates. In addition, the evocability of a positive estrogen feedback was also demonstrable in most homosexual male-to-female transsexuals in significant contrast to hetero- or bisexual male-to-female transsexuals. These findings suggest that homosexual males possess, at least in part, a predominantly female-differentiated brain, which may be caused by a low estrogen convertible androgen level during brain organization. Recently, the following relations were found between sex hormone levels during brain differentiation and sex-specific responses in adulthood: (1) estrogens--which are mostly converted, however, from androgens--are responsible for the sex-specific organization of gonadotrophin secretion and hence the evocability of a positive estrogen feedback in later life; (2) estrogens and androgens, occurring during brain differentiation, predetermine synergistically sexual orientation and (3) androgens--without conversion to estrogens--are responsible for the sex-specific organization of gender role behaviour in later life. Furthermore, the organization periods for sex-specific gonadotrophin secretion, sexual orientation and gender role behaviour are not identical but overlapping. Thus, combinations as well as dissociations between deviations of the neuroendocrine organization of sex-specific gonadotrophin secretion, sexual orientation and gender role behaviour are conceivable. Most recently, female-type sexual orientation could be converted to male-type sexual orientation in adult rats by administration of the dopamine agonist and serotonin antagonist lisuride.

Androgens↗
PubMed1986

Studies on lipase directed export of Escherichia coli beta-lactamase in Staphylococcus carnosus.

The lipase (lip) gene of Staphylococcus hyicus was used to study the expression of the Escherichia coli beta-lactamase (bla) gene in S. carnosus. The bla gene, devoid of its promotor and most of the signal sequence, was fused to the lip structural gene at various positions. A set of 11 secretion vectors (pLL beta 1 to pLL beta 11) was isolated and analysed. All secretion vectors caused beta-lactamase production and activity in S. carnosus. However, the amount of hybrid proteins secreted was influenced by the length of the NH2-terminal lipase portion. An increased concentration, comparable to that of the native lipase, of secreted lipase/beta-lactamase hybrid proteins was only found when the lipase portion of the construct comprised more than 101 amino acids of the NH2-terminal region of the lipase preprotein; the proposed lipase signal peptide is 36 amino acids long. If the hybrid proteins constructed contained 101 or less amino acids of the NH2-terminal lipase preprotein, only low amounts of secreted hybrid proteins were detectable and a significant portion of the hybrid proteins and beta-lactamase activity was found in the cellular fraction. The results indicate that the lipase possesses adjacent to the signal peptide a peptide domain that is essential for the secretion of the lipase/beta-lactamase hybrid proteins.

Amino Acid Sequence↗
PubMed1986

Induced precipitation of calcium-oxalate crystals and its prevention in laboratory animals.

Induced precipitation of Ca-oxalate crystals and the possibility of its prevention were studied in dogs. In the first phase of the experiments precipitation of Ca-oxalate crystals in canine renal tubules was induced by intraperitoneal administration of Na-glyoxylate. Preventive medication (lipoic acid, vitamin B1, Milurit), applied in the second phase, resulted in a significant depression of induced precipitation. The successful experiments serve as a basis for clinical research aimed at a preventive medication of recurrent Ca-oxalate stone formation.

Animals↗