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Biomedical subjects

W Rossmanith

Publications and source records attributed to W Rossmanith.

At least 19 recordsLinked to original sources
PubMed1997

Processing of human mitochondrial tRNA(Ser(AGY))GCU: a novel pathway in tRNA biosynthesis.

The 5' end of mature tRNAs is formed by the endonucleolytic removal of a leader sequence. RNase P, the enzyme generally responsible for this event, makes use of structural information contained within the tRNA domain of the precursor to recognize substrates and direct cleavage to the tRNA's 5' end. Human mitochondrial tRNA(Ser(AGY)GCU, a tRNA that , a tRNA that shows several structural deviations from "classical" as well as mitochondrial tRNAs, the most prominent of which is the lack of a D domain, is processed at its 5' end via a novel, "non-RNase P" pathway. 5' end maturation of tRNA(Ser(AGY)GCU is the consequence of 3' end processing of the abutting tRNA(His), precisely flanking the tRNA(Ser(AGY)GCU gene at its 5' end. Deletion of this adjoining tRNA structure abolishes efficient 5' end maturation of tRNA(Ser(AGY)GCU in vitro, suggesting that the human mitochondrial tRNA(SeR(AGY)GCU employs a 5'abutting tRNA as a processing signal for 5' end maturation in a kind of molecular commensalism.

Base Sequence↗
PubMed1995

Human mitochondrial tRNA processing.

tRNA processing is a central event in mammalian mitochondrial gene expression. We have identified key enzymatic activities (ribonuclease P, precursor tRNA 3'-endonuclease, and ATP(CTP)-tRNA-specific nucleotidyltransferase) that are involved in HeLa cell mitochondrial tRNA maturation. Different mitochondrial tRNA precursors are cleaved precisely at the tRNA 5'- and 3'-ends in a homologous mitochondrial in vitro processing system. The cleavage at the 5'-end precedes that at the 3'-end, and the tRNAs are substrates for the specific CCA addition in the same in vitro system. Using a comparative enzymatic approach as well as biochemical and immunological techniques, we furthermore demonstrate that human cells contain two distinct enzymes that remove 5'-extensions from tRNA precursors, the previously characterized nuclear and the newly identified mitochondrial ribonuclease P. These two cellular isoenzymes have different substrate specificities that seem to be well adapted to their structurally disparate mitochondrial and nuclear tRNA substrates. This kind of approach may also help to understand the structural diversities and commonalities of tRNAs.

Cell Compartmentation↗
PubMed1995

RNase mitochondrial RNA processing cleaves RNA from the rat mitochondrial displacement loop at the origin of heavy-strand DNA replication.

Ribonuclease mitochondrial RNA processing cleaves RNAs from the mammalian mitochondrial main non-coding regulatory region, called the displacement loop. Our data demonstrate that rat cells contain a site-specific ribonuclease mitochondrial RNA processing activity. We found that this enzyme processes the rat mitochondrial displacement-loop RNA substrate at the level of the conserved sequence block 1, a result which is different from that for mouse. This finding correlates with the in-vivo transcriptional analysis of the rat displacement-loop region. Processing by homologous and heterologous ribonuclease mitochondrial RNA enzymes occurs in the same manner, suggesting a conserved mode of substrate recognition.

Animals↗
PubMed1993

RNase MRP and RNase P share a common substrate.

RNase MRP is a site-specific ribonucleoprotein endoribonuclease that processes RNA from the mammalian mitochondrial displacement loop containing region. RNase P is a site-specific ribonucleoprotein endoribonuclease that processes pre-tRNAs to generate their mature 5'-ends. A similar structure for the RNase P and RNase MRP RNAs and a common cleavage mechanism for RNase MRP and RNase P enzymes have been proposed. Experiments with protein synthesis antibiotics have shown that both RNase MRP and RNase P are inhibited by puromycin. We also show that E. coli RNase P cleaves the RNase MRP substrate, mouse mitochondrial primer RNA, exactly at a site that is cleaved by RNase MRP.

Animals↗
PubMed1993

Definition of the Th/To ribonucleoprotein by RNase P and RNase MRP.

We show that the Th/To ribonucleoprotein is defined by (i) the co-immunoprecipitation of two RNAs, (ii) the co-immunoprecipitation of four major polypeptides and (iii) the quantitative immune recognition of both RNase P and RNase MRP. No serum was found that recognizes either one of these two enzymes exclusively. The specific co-immunoprecipitation of RNase MRP and RNase P by all Th/To ribonucleoprotein autoantibodies indicates that the anti-Th/To autoimmune response is directed against both enzymes in a quantitatively indistinguishable manner. Thus the Th/To ribonucleoprotein is defined by RNase P and RNase MRP.

Antibody Specificity↗
PubMed1992

Equine lentivirus, comparative studies on four serological tests for the diagnosis of equine infectious anaemia.

Serological diagnosis of equine infectious anemia is of necessity group-reactive, i.e. based on viral core protein p26, because viral envelope components as well as the host's immune response to them undergo rapid antigenic change. Since 1970 the agar gel-immunodiffusion test ("Coggins-test") has been the diagnostic method of choice. Recently, ELISA tests have been introduced for faster and theoretically more sensitive serodiagnosis, while Western blots have been used to clarify doubtful results obtained in Coggins-tests. A commercial competitive ELISA was found to give practically equivalent results to the Coggins-test. The sensitivity of this market product is intentionally kept marginal in order to avoid false-positive "reactor horses". Another commercial ELISA, non-competitive, gave inconsistent results, creating great turmoil among horse owners when falsely positive. Caution is also indicated when interpreting Western blots. Sera of strongly positive horses gave as many as eleven bands, of medium positives fewer bands, and of the weakest reactors solely the p26 band. Single p26 banding was, however, also encountered in 5% healthy horses, in two of them consistently over time, which are accordingly considered non-specific. In order to be interpreted as positive, a Western blot for this equine lentivirus must band with its core protein plus at least one glycoprotein, similar to the recommended criterion for a positive reading of serum samples from AIDS patients.

Animals↗
PubMed1990

The effect of laparoscopic treatment of polycystic ovarian disease by CO2-laser or Nd:YAG laser.

The feasibility and efficacy of laparoscopic CO2 laser and Nd:YAG non-contact laser application for the treatment of polycystic ovarian disease (PCOD) were evaluated in 30 patients (19 patients treated with the CO2 laser, and 11 with the Nd:YAG laser). The criteria for inclusion of PCOD in our study were: amenorrhea or oligomenorrhea with chronic anovulation, failure to ovulate in response to clomide or human menopausal gonadotropin, elevated serum levels of luteinizing hormone (LH) or an elevated LH/follicle-stimulating hormone ratio, exaggerated LH response to gonadotrophin-releasing hormone (GnRH), elevated serum androgen levels, and ultrasonographic features of polycystic ovaries. Eight pregnancies after CO2 laser and three after Nd:YAG laser were achieved. Decline of serum androgen concentrations was noted in both groups, but was significantly higher in the Nd:YAG laser group (from 3.4 +/- 0.4 ng/ml to 2.2 +/- 0.2 ng/ml). Nine patients checked before and after laser treatment showed a decrease in the characteristically exaggerated pituitary response to exogenous GnRH injection. There were no consistent findings of the pattern in LH pulsatility studied in 5 patients after Nd:YAG laser treatment. Ovarian status was investigated in 11 patients by second-look laparoscopy or cesarian section. There were absolutely no adhesions after Nd:YAG laser coagulation. Filmy adhesions were seen in 3 patients in the CO2 laser group.

Amenorrhea↗
PubMed1990

Changes in circulating hormone levels after ovarian wedge resection in patients with polycystic ovary syndrome.

Serum gonadotropin, prolactin, estradiol, sex hormone binding globulin (SHBG) and androgen levels were measured before, 5 days and 6 weeks following ovarian wedge resection in 9 patients with polycystic ovary syndrome. Elevated levels of LH, androstenedione, testosterone and dehydroepiandrosterone-sulphate (DHEA-S) were found before surgery. There was a marked decrease in androstenedione and DHEA-S levels 5 days following wedge resection, but a rebound effect could be observed 6 weeks later. Serum gonadotropin, prolactin, testosterone and SHBG concentrations were practically unaffected by surgery. At 6-12 months follow up patients showed regular, mainly ovulatory cycles, but pregnancy occurred only in two cases.

Adolescent↗
PubMed1990

Pulsatile luteinizing hormone secretion in women with polycystic ovary syndrome under clomiphene citrate. Differences between responders and nonresponders.

Although administration of Clomiphene Citrate (CC) is an effective therapy for ovulation induction in PCO patients, 15 to 20% of PCO patients do not ovulate following CC treatment. The aim of this study was to compare the endocrine dynamics (LH pulsatile pattern, FSH and steroid hormone changes) in 6 patients who ovulated (PCOS) and 6 PCO patients who did not ovulate in response to CC (PCOR). Blood was collected at 15 min intervals for 4 hr on day 9 of the first menstrual cycle (control cycle) and on day 9 of the following (treatment) cycle. In this cycle all women received 100 mg CC/day from day 5 to day 9. LH was determined in all samples whereas FSH and estradiol were measured every 60 min. No significant differences were observed regarding the age, body mass index, degree of hirsutism, ovarian volumes and basal levels of reproductive hormones between both groups of PCO women. During the control cycle, the LH pulse amplitude and transverse LH mean concentrations in PCOR patients were higher than in PCOR patients whereas the LH pulse frequency was similar in both groups. No difference was found in FSH and estradiol values between both groups. Compared to the control cycle, PCOR patients showed no change in the pulse amplitudes and no difference in LH, FSH and estradiol values following CC treatment. In contrast, during the CC therapy in PCOS patients an increase in the LH amplitude (p less than 0.05), the transverse mean LH concentration (p less than 0.05), FSH and estradiol was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Viraemia and abortions are not prevented by two commercial equine herpesvirus-1 vaccines after experimental challenge of horses.

Eighteen horses, vaccinated on a number of occasions over a period of 12 to 20 months with either a live equine herpesvirus-1 (EHV-1) or an inactivated EHV-1 vaccine, were challenged by the intranasal instillation of the subtype 1 virus isolated from the 1983 outbreak of abortion and paralytic disease at the Lipizzan Stud, Piber, Austria. The prechallenge serum titres of all vaccinated horses were remarkably low, although most horses had received their last vaccine dose only 3 weeks before test-infection. Higher titres were obtained with the inactivated product than with the live virus vaccine. However, no obvious differences were found between the two vaccines in their ability to prevent disease, in that all vaccinated and two 'sentinel' horses became infected and developed viraemia and some degree of clinical disease after challenge; five of the 10 in-foal mares aborted.

Abortion, Veterinary↗
PubMed1989

[A western blot test for the serological diagnosis of equine infectious anemia].

After electrophoretic separation in SDS-PAGE structural proteins of the virus of Equine Infectious Anemia (EIA) were easily blotted by the semi-dry-blotting method onto nitrocellulose filters. Strips of these filters were used for antibody demonstration, and positive reactions thereof were intensified by a biotin-avidin-peroxidase system. Sensitivity of this system was so high as to allow readable interpretation of bands up to the dilution of 1:6,400 of a strongly positive serum. Frequently this procedure allowed to make a firm diagnostic Western-Blot diagnosis on far weaker equine sera. Interpretation of results proved, however, difficult with sera, which formed one single band only. This observation, although of weak grade, had to be made in some 5% of sera stemming from horses with a certainly negative history of EIA. Consequently, we conclude, that a policy followed in the serodiagnostic Western-Blot of human AIDS should also be adopted for the interpretation of the EIA Western-Blot, namely to declare as positive merely horse sera which evidence more than one single band, whereof at least one band should represent a viral glycoprotein.

Animals↗
PubMed1989

[Training of the immune system of foals against ERP virus infections by frequent vaccination with presently available commercial vaccines].

During 3 foaling seasons around 150 Lipizzaner foals were vaccinated against ERP with commercial vaccines and groups thereof were serotested in CF and SN for their humoral immune response. In addition, 6 horses of cheaper common breeds were vaccinated on the University premises, were continuously serologically screened and subjected to virulent nasal test infection. The live-virus vaccine Prevaccinol interfered so profoundly and up to the 20th week of life with maternal antibodies that its further use was discontinued. The inactivated vaccine Pneumabort-K proved to be of impressive immunogenicity, but without any doubt must be used 4 times instead of 3 times only during the first year of life as recommended by its manufacturer. Proofs that the vaccination intervals as recommended on the packing slips are too far-spaced and that 3 basic doses of vaccine induce unsatisfactory protection became apparent under two aspects. Firstly, yearling mares experienced an enzootic field infection by subtype 1 of EHV 1 while on summer pasture. Secondly, experimental nasal infection of horses of the University herd gave takes certified clinically, virologically, and serologically. Data as well as arguments are brought forward which shed doubt on the merits of CF-titers as indicators of immunity as recommended by other authors; SN-titers were shown to be more dependable parameters. With regard to the frequently needed revaccinations there is an absolute "must" for the producer of Pneumabort-K to purify this product before marketing it.

Animals↗
PubMed1988

Bovine adenoviruses. VI. An enzyme-linked immunosorbent assay for detection of antibodies to bovine adenovirus types belonging to subgroups I and II.

An enzyme-linked immunosorbent assay (ELISA) was developed for detection of antibodies against the officially recognized bovine adenoviruses (BAV). Soluble antigens of adenoviruses were extracted from bovine kidney (BAV-1 and BAV-3) or bovine testicle (BAV-4, -6, and -7) cell cultures, respectively. Presence of the major hexon antigen, known to be the most essential compound for serological cross-reactivity, was demonstrated on a discontinuous sodium-dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). The relatively crude polypeptide preparations were coated onto microelisa plates and tested for specific reactivity with available type-specific antisera of calves. Plates coated with BAV-1 showed reactivity with antibodies against types 1 and 3, but did not react with hyperimmune serum against BAV-4. Soluble antigens of BAV-4 react to a high extent with homologous antiserum but did not cross-react with a hyperimmune serum against BAV-1. Both these hyperimmune sera had been prepared in colostrum-free calves. Several calf sera produced by cooperating researches in colostrum-free calves were tested for homologous and cross-reactivity. In addition, ELISA plates coated with BAV-4 were tested on 33 sera of conventionally reared calves, earlier infected experimentally with homologous BAV-4. ELISA titres correlated well in 28 of them with seroneutralization titres; in 5 other sera correlation was poor, but in no case to a degree which would have resulted in a dissenting diagnosis. The use of BAV types 1 and 4 as representatives of bovine adenovirus subgroup I and II will allow easy and economical surveillance of these frequently occurring antibodies in diagnostic laboratories.

Adenoviridae↗
PubMed1986

beta-1-Glycoprotein determination in normal and disturbed pregnancy.

beta-1-Glycoprotein (SP1) concentration of 170 women with undisturbed pregnancy under 18th week were taken as reference. SP1 levels of 72 patients with threatening abortion but favorable outcome were compared with those of 70 patients with threatening abortion and subsequent miscarriage. Decreased SP1 levels were determined in most (88%) patients who aborted, whereas 88.8% of patients with favorable outcome had SP1 levels within normal range. The predictive value of SP1 determination in early pregnancies is emphasized.

Abortion, Threatened↗