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Biomedical subjects

F Götz

Publications and source records attributed to F Götz.

At least 145 records · Page 8Linked to original sources
PubMed1990

Transcription of HIV1 is inhibited by DNA methylation.

A possible role of DNA methylation as a factor in HIV latency was studied by methylating a HIV1-LTR-CAT plasmid in vitro and measuring its expression after transfection on Vero cells. Methylation with a eukaryotic DNA methylase resulted in a 70% inhibition of chloramphenicol acetyltransferase expression, in the absence as well as in the presence of the HIV1 trans-activator protein TAT in the cell. A similar degree of transcription inhibition was obtained by methylation of the only Hpa II site at position-143 in the HIV1-LTR with the bacterial Hpa II methylase. In contrast to the effect by eukaryotic methylation, the inhibition by Hpa II methylation could be partially reversed by cotransfection of the TAT gene. The reason may lie in an about 40% demethylation at the Hpa II site which was concomitantly observed.

Animals↗
PubMed1990

Transformation of Staphylococcus epidermidis and other staphylococcal species with plasmid DNA by electroporation.

In this paper, the influence of various parameters on plasmid transformation by electroporation of Staphylococcus epidermidis Tü3298 was investigated. Cell growth conditions, various concentrations and forms of plasmid DNA, field strength, pulse duration and media for electroporation and regeneration were tested. In order to obtain optimal transformation efficiency, the cells were incubated for 30 min with DNA before pulsing. With the optimized procedure, other staphylococcal species such as S. aureus, S. staphylolyticus and S. carnosus were transformed with an efficiency up to 3 X 10(5) transformants per micrograms pC194 plasmid DNA.

DNA, Bacterial↗
PubMed1990

Modified laparoscopic appendectomy in surgery. A report on 388 operations.

Laparoscopic appendectomy, introduced in gynecology by Semm in 1982, has been modified and practiced in our surgical ward since May 1987 in more than 450 patients suffering from all stages of acute and chronic vermix diseases. We report our data on the first series of 388 operations, in which we had the encouraging experience that laparoscopic appendectomy is a practicable and reasonable alternative to routine surgery.

Acute Disease↗
PubMed1990

Dynamic cavernosography as a means to test coital impotence.

In our days the radiologic examination method of dynamic cavernosography is still in the state of infancy but has already passed the test as an indispensable means to locate the site of a venous leak and to diagnose other pathologic penile conditions. Its field of application covers penile fracture, the extension of induratio penis plastica, the degree of fibrosis in the postpriapic state, the testing of tumour penetration. The method being invasive it is important to apply it in the proper diagnostic order, as soon as clear proof has been furnished that the potency disorder is not due to impaired reflex activity, has not developed on a psychic background and the Doppler test has revealed normal arterial flow conditions.

Erectile Dysfunction↗
PubMed1990

Increased cell-mediated cytotoxicity against beta-cells in streptozotocin-treated offspring of mother animals with gestational hyperglycaemia.

The offspring of mother animals with mild gestational hyperglycaemia exhibited basal hyperinsulinism, decreased glucose tolerance and increased susceptibility to streptozotocin diabetes. Following low-dose successive streptozotocin treatment a significantly increased spleen cell cytotoxicity against beta-cells was found in these animals as compared to the offspring of gestational normoglycaemic control mothers. Such increased cell-mediated cytotoxicity, considered as enhanced autoimmune reactivity, was positively correlated to blood glucose levels and negatively correlated to pancreatic insulin contents. Thus, hyperinsulinism, occurring during pre- and neonatal brain organization and produced by gestational hyperglycaemia, is a predisposing teratogenetic risk factor not only for the development of type II, but also of type I diabetes. Thus, it is comprehensible that the prevalence of type I diabetes in children could be decisively reduced by preventing gestational hyperglycaemia in their mothers (Dörner et al., 1985).

Animals↗
PubMed1990

Early postnatal overfeeding and diabetes susceptibility.

Milk intake of suckling rats was controlled by adjusting little size at birth to maximum (small litter, overnutrition), ten (normal litter, normal nutrition) or about 19 (large litter, undernutrition) pups. After weaning all animals received the same diet ad libitum. Overnutrition before weaning resulted in an early postnatal hyperinsulinaemia, decreased glucose tolerance and increased susceptibility to streptozotocin-induced diabetes in adulthood. However, the preweaning undernutrition seemed to have no preventive effect on diabetes susceptibility in adulthood. The study suggested that early postnatal overnutrition, which is associated with an early postnatal hyperinsulinemia, can increase diabetes susceptibility in adult life.

Animals↗
PubMed1990

[Laparoscopic appendectomy--alternative therapy in all stages of appendicitis?].

1989 we reported on our first series of 277 laparoscopic appendectomies. This technique was introduced by Semm in 1982. We acquired this procedure in 1987 and modified this operation-technique for surgical routine. We could demonstrate that laparoscopic appendectomy can be performed in chronic, acute and even in peracute cases. We introduce the facts of 500 laparoscopic appendectomies.

Appendectomy↗
PubMed1989

Purification and substrate specificity of Staphylococcus hyicus lipase.

The Staphylococcus hyicus lipase gene has been cloned and expressed in Staphylococcus carnosus. From the latter organism the enzyme was secreted into the medium as a protein with an apparent molecular mass of 86 kDa. This protein was purified, and the amino-terminal sequence showed that the primary gene product was indeed cleaved at the proposed signal peptide cleavage site. The protein was purified from large-scale preparations after tryptic digestion. This limited proteolysis reduced the molecular mass to 46 kDa and increased the specific activity about 3-fold. Although the enzyme had a low specific activity in the absence of divalent cations, the activity increased about 40-fold in the presence of Sr2+ or Ca2+ ions. The purified lipase has a broad substrate specificity. The acyl chains were removed from the primary and secondary positions of natural neutral glycerides and from a variety of synthetic glyceride analogues. Thus triglycerides were fully hydrolyzed to free fatty acid and glycerol. The enzyme hydrolyzed naturally occurring phosphatidylcholines, their synthetic short-chain analogues, and lysophospholipids to free fatty acids and water-soluble products. The enzyme had a 2-fold higher activity on micelles of short-chain D-lecithins than on micelles composed of the L-isomers. Thus the enzyme from S. hyicus has lipase activity and also high phospholipase A and lysophospholipase activity.

Amino Acid Sequence↗
PubMed1989

Improved purification and biochemical properties of phosphatidylinositol-specific phospholipase C from Bacillus thuringiensis.

Monophosphatidylinositol inositol phosphohydrolase (phosphatidylinositol-specific phospholipase C. PtdIns-PLC. EC 3.1.4.10) has been purified from a Bacillus thuringiensis culture supernatant and from the cellular fraction of a recombinant Escherichia coli clone containing the PtdIns-PLC gene from B. thuringiensis. The two-step purification procedure involved ion-exchange chromatography on DEAE-Sepharose followed by separation on a Mono-Q/FPLC-column with yields of 32% and 50%, respectively. The molecular mass was determined to be 34 kDa by SDS/PAGE. The isoelectric point of the enzyme was 5.15. The amino-terminal sequences were shown to be identical for the enzymes purified from both organisms. PtdIns-PLC was inhibited by divalent cations using mixed micelles of Triton X-100 and pure phosphatidylinositol. PtdIns-PLC activity was detectable on polyacrylamide gels by activity staining on phosphatidylinostiol-containing agarose.

Amino Acid Sequence↗
PubMed1989

Subunit association defects in Escherichia coli ribosome mutants lacking proteins S20 and L11.

The subunit association capacity of 30S and 50S ribosomal subunits from Escherichia coli mutants lacking protein S20 or L11 as well as of 50S subunits depleted of L7/L12 was tested by sucrose gradient centrifugation and by a nitrocellulose filtration method based on the protection from hydrolysis with peptidyl-tRNA hydrolase of ribosome-bound AcPhe-tRNA. It was found that the subunits lacking either S20 or L11 display an altered association capacity, while the 50S subunits lacking L7/L12 have normal association behavior. The association of S20-lacking 30S subunits is quantitatively reduced, especially at low Mg2+ concentrations (5-12 mM), and produces loosely interacting particles which dissociate during sucrose gradient centrifugation. The association of L11-lacking 50S subunits is quantitatively near-normal at all Mg2+ concentrations and produces loosely associating particles only at low Mg2+ concentrations (5-8 mM); the mechanism of their association with 30S subunits, however, or the structure of the resulting 30S-50S couples is altered in such a way as to cause the ejection of an AcPhe-tRNA molecule pre-bound to the 30S subunits in response to poly(U).

Bacterial Proteins↗
PubMed1989

[Surgical treatment of impotence caused by venous dysfunction].

The authors examined 94 patients suffering from sexual impotence. On the basis of the history, erection induced with papaverine and the results of Doppler's operation as well as dynamic cavernosography of the penis venous excape was found in the background of impotence of 14 patients. Operation was performed with 13 patients in the course of which the draining vein depicted by cavernosography was ligated. 7 patients have erection spontaneously and 4 on papaverine given intracavernously. The operation was unsuccessful with 2 patients which was due in one case to the existing spongiocavernous fistula and in the other to the development of early collateral circulation.

Erectile Dysfunction↗
PubMed1989

Surgical treatment of impotence due to venous outflow.

Coital impotence was studied in 94 patients. In 14 of them the history, as well as the papaverine-induced erection, penile Doppler test and dynamic cavernosography suggested venous outflow as a basic process. In 13 who underwent surgery, the draining vein visualized by dynamic cavernosography was tied down. Seven patients now have spontaneous erection, four present it upon intravenous papaverine injection. Two operations failed: one for an existent spongiocavernous fistula, the other for the development of collateral circulation in the early phase.

Adult↗
PubMed1989

Prognosis of testicular tumour since the introduction of complex therapy.

Change of approach in dealing with testicular carcinoma has made it necessary to set up a central organization covering a larger geographic area in Hungary where 242 patients had been treated since 1980. Progress in the development of therapy-oriented methods cleared the way for reliable and accurate stage determination. Data analysis seems to indicate that correct therapeutic principles combined with plenty of surgical, radiological and chemotherapeutic experience may contribute a lot to improving the pathologic prospects. The mortality rates for the pure seminoma group and for the non-seminomatous plus mixed-cell group of patients were 7.5% and 26.5%, respectively. The results promise additional chances--even with increasing morbidity--to reduce the mortality rate and the incidence of complications.

Adult↗
PubMed1989

Papaverine-induced erection.

Sixty-one patients suffering from impotentia coeundi were treated with local dosages of papaverine hydrochloride, injected into the corpus cavernosum. In patients with neurogenic, psychogenic or a mild form of vascular disorders the injection induced erections which lasted on from 20 minutes to between 4 and 5 hours. Sixteen volunteers who were taught to self-administer the solution, injected the preadjusted dosage into the corpus cavernosum each time before the intended sexual act.

Adult↗
PubMed1989

Structural gene isolation and prepeptide sequence of gallidermin, a new lanthionine containing antibiotic.

Peptide antibiotics containing lanthionine and 3-methyllanthionine bridges, named lantibiotics are of increasing interest. A new lantibiotic, gallidermin, has been isolated from Staphyloccus gallinarum. Here we report the isolation of its structural gene which we name gdmA. In all lantibiotics so far studied genetically, three peptides can be formally distinguished: (i) the primary translation product, which we call the prepeptide; (ii) the propeptide lacking the leader sequence and (iii) the mature lantibiotic. Unlike the plasmid-coded epidermin, gdmA is located on the chromosome. The gdmA locus codes for a 52 amino acid residue prepeptide, consisting of an alpha-helical leader sequence of hydrophilic character, which is separated from the C-terminus (propeptide) by a characteristic proteolytic processing site (Pro-2 Arg-1 Ile1). Although pro-gallidermin differs from pro-epidermin (a recently isolated lantibiotic) only by a single amino acid residue exchange. Leu instead of Ile, the N-terminus of the prepeptide differs by an additional two exchanges.

Amino Acid Sequence↗
PubMed1989

Sex-specific effects on the fetal neuroendocrine system during acute stress in late pregnancy of rat and the influence of a simultaneous treatment by tyrosine.

It is well-known that prenatal chronic intermittent stress affects the reproductive system of both sexes. Investigating the effects of an acute maternal stress on the fetal neuroendocrine system, parameters such as hypothalamic catecholamines. CRF, GRF, LH-RH, beta-endorphin, hypophysial beta-endorphin and beta-LPH as well as plasma LH, corticosterone and androstenedione were measured. Pregnant rats of Wistar strain were exposed to restraint stress at day 22 of gestation or to forced immobilization at day 20 of gestation, respectively, and were sacrificed before stress and 10, 30, 60, and 120 min after starting stress. A decrease of fetal hypothalamic catecholamines and an increase of LH-RH content of the hypothalamus as well as of plasma catecholamines were observed under stress on day 22 of gestation. On day 20 of gestation hypothalamic beta-endorphin was depleted in male and unchanged in female fetuses under stress. A depletion of hypothalamic CRF was observed in male fetuses, whereas female fetuses showed an increase of hypothalamic CRF. An increase of GRF was found in fetuses of both sexes. Pituitary opioid content increased in fetuses of both sexes initially, but was depleted secondarily in male fetuses. The LH plasma level was markedly reduced in male, the corticosterone level was elevated in fetuses of both sexes as well as the androstenedione level in female fetuses. A simultaneous treatment of mother animals with tyrosine--a catecholamine precursor--prevented the depletion of hypothalamic and pituitary beta-endorphin as well as in part the reduction of plasma LH levels in male fetuses. Hypothalamic GRF content does not increase under tyrosine treatment in male fetuses, whereas in female fetuses the stress-induced increase of GRF content was rather pronounced under tyrosine than attenuated. These results indicate that fetal hypothalamic neurotransmitters and neurohormones (such as LH-RH, CRF, GRF and opioids) are involved in changing circulating hypophysial and adrenal hormones in fetuses exposed to maternal stress in late pregnancy, whereby sex-specific different pathways might be effective in fetal stress processing. The prenatal administration of tyrosine prevented at least in part--those neurohormonal changes which are affecting the sex-specific brain differentiation.

Androstenedione↗
PubMed1989

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

Lisuride induces in juvenile male and especially in female rats a significant increase of the initiating activity in tests on social play-fighting behaviour. In neonatally castrated as well as in prenatally stress exposed males, castrated in adulthood, which exhibit under androgen alone bisexual or even predominantly heterotypical sexual behaviour, additional treatment with lisuride resulted in a temporary normalization of sexual orientation in the homotypical male direction. In castrated androgen treated females, lisuride induces a partial conversion of sexual orientation to heterotypical male direction.

Animals↗