Biomedical subjects
Publications and source records attributed to W Fischer.
Case report on a leiomyosarcoma situated within the septum urethrovesicovaginale. The patients has been operated before on three times because of a leiomyofibroma at the same place. The histologic diagnose is based on morphologic and immunhistochemisch findings. The patient was treated with an exstirpation of the tumour only. Principal considerations about the radicality of the tumour therapy are deduced from.
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The interaction of three different Met-tRNAsMet from E. coli with bacterial elongation factor (EF) Tu X GTP was investigated by affinity chromatography. Met-tRNAfMet which lacks the base pair at the end of the acceptor stem binds only weakly to EF-Tu X GTP, while Met-tRNAmMet has a high affinity for the elongation factor. A modified Met-tRNAfMet which has a C1-G72 base pair binds much more strongly to immobilized EF-Tu X GTP than the native aminoacyl(aa)-tRNA with non-base-paired C1A72 at this position, demonstrating that the base pair including the first nucleotide in the tRNA is one of the essential structural requirements for the aa-tRNA X EF-Tu X GTP ternary complex formation.
The conformation of the anticodon loop of Escherichia coli tRNAArg was investigated. It is shown that the structure of the anticodon loop is influenced by the base composition of the anticodon stem, and the natural modification of the nucleoside residue 32 in the anticodon loop. The structural effects detected by analysis of the accessibility of the anticodon loop to nuclease S1 could be correlated with the ability of different Arg-tRNAArg species to suppress frame-shifting during translation of MS2 RNA.
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Ion transport through a gramicidin A like channel in the presence of solvent molecules with van der Waals parameters of water has been studied by means of the molecular dynamics simulation technique. It was found that the presence of solvent molecules in the channel has a tendency to equalize the effective masses of the ions through "association" thus giving the experimentally found ion selectivity to the gramicidin A channel.
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The presence and synthesis of c-myc protein and mRNA in the cell cycle has been studied. We find that c-myc mRNA is present, at equivalent levels, at all times in the cell cycle with the possible exception of mitosis. Furthermore, we demonstrate that this mRNA is transcribed in both G1 and G2 phases. An analysis of the c-myc protein in vivo shows that de novo synthesis occurs in G1 and G2 and the protein turns over with a half-life of approximately 20-30 min in both phases. Furthermore, the level of c-myc protein rapidly increases in cell populations when they re-initiate the cell cycle, thereafter decreasing as the culture reaches quiescence. The results therefore suggest that expression of c-myc can be rapidly modulated and that it is activated during the G0 to G1 transition, but is expressed thereafter in the cell cycle.
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Toluene-treated Staphylococcus aureus cells did not synthesize teichoic acid and lipoteichoic acid under the conditions used. The organism displayed, however, a high capacity of incorporating D-[14C]alanine into previously formed polymers. The reaction was dependent on ATP and enhanced by magnesium ions. The incorporation rate into lipoteichoic acid correlated with the rate of loss of alanine ester which occurred through transfer to teichoic acid and base-catalyzed hydrolysis. At pH 6.5 the loss (20% within 4 h) was completely compensated for by reesterification. At pH 7.5 the loss was 60%, but by accelerated incorporation it was reduced to 10%. Incorporation was also enhanced when the original substitution of lipoteichoic acid was lowered by previous growth of S. aureus at high salt concentration. The newly added alanine was randomly distributed along the poly(glycerophosphate) chain. The decreased alanine substitution of lipoteichoic acid after growth at high salt concentration was shown to result from a direct inhibition of alanine incorporation.
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Serine isoaccepting tRNAs were isolated from bulk tRNA of Escherichia coli by affinity chromatography on immobilized bacterial elongation factor Tu and their relative abundance was determined. The three major species, which are sufficient to read all six serine codons, were identified by sequencing. The sequence of a novel tRNASer with the anticodon GGA was elucidated.
Comparative cytological studies were conducted in urethra and vagina of 40 women with stress incontinence, another 40 with urge incontinence and 53 clinically intact women for morphological assessment of urinary incontinence. Evaluation was based on maturation index, maturation value, and dynamic estrogenicity index. During sexual maturity no significant difference regarding proliferability of urethral and vaginal epithelium was found existing between clinically intact women and patients with stress or urge incontinence. Differences of maturation values above 30 between urethral and vaginal cells were recordable only from post-menopause patients with urge incontinence, providing for certain possible conclusions as to the form of urinary incontinence. However, in post-menopause patients, oral and vaginal estriol therapy was followed by significant rise in intermedial and superficial cells in both organs. Improvement of stress and urge incontinence was recordable subjectively also from estriol therapy during sexual maturity, independent from urethral or vaginal cell patterns. Hence, urethral cytology is only conditionally suitable for differential diagnosis and optimization of therapy of urinary incontinence. Primarily it is suitable to coping for disturbances of micturition with an uncharacteristic urinary urge symptomatology or chronic urethritis.
A seven-week group-centered dynamic therapy course was conducted with 12 patients within the framework of a long-term treatment for schizophrenic patients. The purpose and method of treatment and the course of the group sessions are described. Analysis of the Freiburg personality inventory yielded no changes; the degree of agreement between the group mean profile and that of neurotics was striking. Analysis of the Frankfurt complaint questionnaire (Suellwold) revealed a reduction in the number of affirmative answers during and after treatment. The treatment is considered to have had positive results, although it has to be embedded in a more comprehensive treatment plan with supportive individual psychotherapy, psychopharmaceutic treatment and sociotherapy.
Pulse-chase experiments with [2-3H]glycerol and [14C]acetate revealed that in Staphylococcus aureus lipoteichoic acid biosynthesis plays a dominant role in membrane lipid metabolism. In the chase, 90% of the glycerophosphate moiety of phosphatidylglycerol was incorporated into the polymer: 25 phosphatidylglycerol + diglucosyldiacylglycerol leads to (glycerophospho)25-diglucosyldiacylglycerol + 25 diacylglycerol. Glycerophosphodiglucosyldiacylglycerol was shown to be an intermediate, confirming that the hydrophilic chain is polymerized on the final lipid anchor. Total phosphatidylglycerol served as the precursor pool and was estimated to turn over more than twice for lipoteichoic acid synthesis in one bacterial doubling. Of the resulting diacylglycerol approximately 10% was used for the synthesis of glycolipids and the lipid anchor of lipoteichoic acid. The majority of diacylglycerol recycled via phosphatidic acid to phosphatidylglycerol. Synthesis of bisphosphatidylglycerol was negligible and only a minor fraction of phosphatidylglycerol passed through the metabolically labile lysyl derivative. In contrast to normal growth, energy deprivation caused an immediate switch-over from the synthesis of lipoteichoic acid to the synthesis of bisphosphatidylglycerol.
Prescribing patterns were studied in a psychiatric outpatient clinic. Psychiatrists tended to prescribe large quantities of antidepressants or other drugs. In contrast, the daily doses for antidepressants and neuroleptics were often too low. Significant variations were noted between three outpatient clinics in the choices among a various psychotropic drugs from a given therapeutic group.
Elongation factor Tu from Escherichia coli or Thermus thermophilus was immobilized on cyanogen bromide-activated Sepharose. Immobilized elongation factor Tu X GDP could be converted to Tu X GTP, which is able to bind aminoacyl-tRNA. When bulk tRNA from E. coli, baker's yeast, or bovine liver was aminoacylated by one amino acid only, the resulting aminoacyl-tRNA could be separated in one step from the rest of the tRNA using an affinity column of immobilized elongation factor Tu X GTP. Specific tRNA isoacceptors can be isolated in amounts sufficient for gel electrophorectic analysis, sequence determinations, and hybridization experiments.