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H Herrmann

Publications and source records attributed to H Herrmann.

At least 37 records · Page 2Linked to original sources
PubMed1993

Temperature-sensitive intermediate filament assembly. Alternative structures of Xenopus laevis vimentin in vitro and in vivo.

In assembly assays of intermediate filaments (IFs) from vimentin of the amphibian species Xenopus laevis we have observed the formation of so far unknown structures at temperatures above 28 degrees C. Upon assembly in vitro at temperatures above 34 degrees C massive aggregates, partly with a protofilamentous substructure, were found and their formation correlated with drastically reduced end-viscosity. Large spheroidal, dense aggregates with a complex suborganization were also seen to form at 37 degrees C in the cytoplasm of living mammalian cells devoid of endogenous vimentin upon transfection with cDNA encoding the amphibian vimentin, and this was also true for vimentin forced to accumulate in the nucleoplasm by the introduction of a "nuclear localization signal". Upon shift from the non-permissive (37 degrees C) to the permissive (28 degrees C) temperature, such aggregates of non-IF vimentin structures gradually disappeared and a normal-looking IF meshwork formed. The results, which are discussed in relation to other structures assembled by IF proteins, indicate a marked thermosensitivity in the amino acid sequence of the vimentin which seems to have been reduced during evolution of warm-blooded animals. They further show that members of the multigene gene family of IF proteins can occur in structures totally different from IFs.

Animals↗
PubMed1993

Effect of trospium chloride on gastrointestinal motility in humans.

The aim of this double-blind, placebo-controlled, cross-over study was to investigate the effect of trospium chloride on gall bladder contraction, gastric emptying of a liquid meal, gastrooesophageal reflux, and orocaecal transit time in healthy subjects. Gall bladder contraction was examined by ultrasonography before and after stimulation with two raw eggs. Gastric emptying was evaluated by an intubation technique and by sonography. To determine gastrooesophageal reflux and orocaecal transit time, 24-hour pH metry and a hydrogen breath test were used. The gall bladder ejection fractions were significantly lower after oral treatment with both 4 x 10 mg and 4 x 20 mg trospium compared to placebo, but no difference was seen between the two doses of drug. Gastric emptying of a liquid meal was significantly delayed after intake of 4 x 15 mg trospium, whilst the time course of the intragastric volume determined by ultrasound did not differ from that after placebo, suggesting an antisecretory effect of trospium on gastric secretion. The fractional time of oesophageal pH < 4 as a percentage of the entire 24-hour investigation period was significantly increased by treatment with trospium 3 x 15 mg per day. The orocaecal transit time of 10 g lactulose was significantly prolonged. Provided that the observed effects on gall bladder contraction, gastric emptying, and orocaecal transit time are reproduced in disease states, trospium should be regarded as a potentially useful antispasmodic agent.

Adult↗
PubMed1993

[The value of parasternal lymphoscintigraphy with microcolloids in the staging and follow-up of breast carcinoma].

Over a period of twelve years we have performed 793 parasternal lymphoscintigrams with microcolloids in 272 patients with unilateral carcinoma of the breast. In 173 patients we were able to follow their course with an average of four examinations and an average period of observation of 48 months. The parasternal lymph nodes could be identified in 59.6% (on the side of the tumour in 55.1%, on the contralateral side in 64.2%). Expressed as an index with maximal value of 1, the (non-)demonstration constant was 0.79 (side of the tumour 0.78, opposite side 0.80). Comparison of the total scans with the initial findings showed general loss of scintigraphic uptake which, however, is not reflected during individual ICR localisation. Patients with the highest prevalence of parasternal metastases showed atypical uptake. There was no change in uptake in those patients who subsequently developed distant metastases.

Adult↗
PubMed1993

New aerobic benzoate oxidation pathway via benzoyl-coenzyme A and 3-hydroxybenzoyl-coenzyme A in a denitrifying Pseudomonas sp.

A denitrifying Pseudomonas sp. is able to oxidize aromatic compounds compounds completely to CO2, both aerobically and anaerobically. It is shown that benzoate is aerobically oxidized by a new degradation pathway via benzoyl-coenzyme A (CoA) and 3-hydroxybenzoyl-CoA. The organism grew aerobically with benzoate, 3-hydroxybenzoate, and gentisate; catechol, 2-hydroxybenzoate, and protocatechuate were not used, and 4-hydroxybenzoate was a poor substrate. Mutants were obtained which were not able to utilize benzoate as the sole carbon source aerobically but still used 3-hydroxybenzoate or gentisate. Simultaneous adaptation experiments with whole cells seemingly suggested a sequential induction of enzymes of a benzoate oxidation pathway via 3-hydroxybenzoate and gentisate. Cells grown aerobically with benzoate contained a benzoate-CoA ligase (AMP forming) (0.1 mumol min-1 mg-1) which converted benzoate but not 3-hydroxybenzoate into its CoA thioester. The enzyme of 130 kDa composed of two identical subunits of 56 kDa was purified and characterized. Cells grown aerobically with 3-hydroxybenzoate contained a similarly active CoA ligase for 3-hydroxybenzoate, 3-hydroxybenzoate-CoA ligase (AMP forming). Extracts from cells grown aerobically with benzoate catalyzed a benzoyl-CoA- and flavin adenine dinucleotide-dependent oxidation of NADPH with a specific activity of at least 25 nmol NADPH oxidized min-1 mg of protein-1; NADH and benzoate were not used. This new enzyme, benzoyl-CoA 3-monooxygenase, was specifically induced during aerobic growth with benzoate and converted [U-14C]benzoyl-CoA stoichiometrically to [14C]3-hydroxybenzoyl-CoA.

Acyl Coenzyme A↗
PubMed1993

Hormone ontogeny in the ovine fetus. XXVII. Pulsatile and copulsatile secretion of luteinizing hormone, follicle-stimulating hormone, growth hormone, and prolactin in late gestation: a new method for the analysis of copulsatility.

To analyze the secretion patterns of LH, FSH, GH, and PRL in the late gestational sheep fetus in vivo, we measured simultaneous plasma levels of these hormones during a period of frequent sampling under basal conditions (samples every 15 min for 5 h) in 17 chronically catheterized sheep fetuses. To calculate mean plasma levels and areas under the curve, we analyzed hormone pulses and coincident pulse patterns to assess interactions between the release of these pituitary hormones. Mean plasma levels for all fetuses were: LH, 0.8 +/- 0.2 ng/ml (mean +/- SEM); FSH, 4.6 +/- 0.7 ng/ml; GH, 136.6 +/- 16.5 ng/ml; and PRL, 40.5 +/- 10.3 ng/ml. Pulse analysis detected 20 LH pulses during 5100 min of total sampling time, which gave a mean interpulse interval of 255.0 min. For GH, 37 pulses were detected; the mean interpulse interval was 129.7 min. Twenty PRL pulses yielded a mean interpulse interval of 225.0 min. FSH pulses could not be analyzed due to the long half-life of this hormone, but hormone level fluctuations were screened for maxima. A new method was developed to detect an interaction between hormone pulses. The probability of the simultaneous occurrence of hormone pulses was calculated and compared with the rate of coincidences found in the experiments. Analysis of copulsatile release of LH, GH, and PRL revealed 11 GH pulses coinciding with the LH pulses (P = 0.0020). An interaction between the pulsatile release of LH and GH can, therefore, be assumed. There was also a significant interaction between GH and PRL. Seven PRL pulses preceded the GH pulses by 15 min (P = 0.0014). In contrast, no significant copulsatile release could be observed between LH and PRL; 95.5% of LH pulses were accompanied by a maximum FSH level, suggesting an interaction between LH and FSH secretion. In summary, we show that LH, GH, and PRL (and possibly FSH) are secreted in a pulsatile fashion in the ovine fetus. Furthermore, the pulsatile releases of LH, FSH, and GH as well as GH and PRL are temporarily coupled, as demonstrated by a significant number of coincident pulses between LH/GH and GH/PRL and a high number of FSH hormone maxima concomitant with LH pulses.

Activity Cycles↗
PubMed1993

[Suspected vaccination complications or atypical vaccination course. Diagnostic assessment of 58 vaccine recipients].

The "list of recommended vaccinations" of the regional Ministries of Health is the legal basis for routine vaccination programmes in each region of Germany; the recommendations of the Federal Commission on Vaccinations, "STIKO", are not legally binding. These programmes of the different regions provide legal grounds for determining claims for damage against a vaccinating doctor. In cases of damage, the Ministry of Health is liable for the damage to a patient caused by a recommended vaccination. Irrespective of these clear and comprehensive legal provisions, in case of an atypical course the patient is entitled to careful diagnosis of the complaint and appropriate medical treatment. However, later claims by the patient for damage can only be decided correctly if the necessary diagnostic data have been carefully collected at the acute stage of the disease. In our 58 patients suffering from atypical vaccination courses or suspected complications, we were able to show in each case that the symptoms are the result of interference by infectious diseases or that there was some other clear diagnosis; in no case did we find that the vaccination had caused disease or permanent damage.

Adolescent↗
PubMed1992

Identification of a nonapeptide motif in the vimentin head domain involved in intermediate filament assembly.

The assembly of soluble vimentin subunits into intermediate filaments (IFs) is dependent on information located in the amino-terminal domain. Using site-directed mutagenesis of a Xenopus laevis vimentin cDNA and an Escherichia coli production system to obtain pure mutated protein, we have identified, in the head domain, a nine amino acid motif (SSYRRIFGG), evolutionarily conserved from amphibia to man, which plays an important role in the orderly formation of IFs. Exchanges in the central di-arginine and in the two aromatic residues interfere with IF assembly of vimentin in vitro: on assembly under standard assembly conditions (160 mM-NaCl) most of the protein is included in dense aggregates, with a variable and minor proportion of IFs, whereas at lower ionic concentrations short and incomplete IF-like structures are formed. The deletion of the whole motif results in a protein that under standard assembly conditions (e.g. 160 mM-NaCl) predominantly and rapidly precipitates into large aggregates of non-IF material, whereas at lower ionic strength (e.g. 50 mM-NaCl) both IFs and dense aggregates are formed simultaneously. Our results show that the mutated protein can assume different forms at the same time and under the same conditions. This motif alone is insufficient for the formation of normal IFs as demonstrated by a mutant in which the motif has been brought closer to the alpha-helical rod domain by deletion of 55 internal amino acid residues. Corresponding observations have been made, by immunofluorescence microscopy, upon transfection of cultured epithelial cells lacking vimentin IFs. The importance of the head domain motif for the assembly and higher-order arrangement of IFs is discussed.

3T3 Cells↗
PubMed1992

An expression vector system providing plasmid stability and conditional suicide of plasmid-containing cells.

A cloning vector system was constructed on the basis of the pBR322 derivative pEG1 by introducing the whole parB locus of plasmid R1 cloned behind the promoter of the alkaline phosphatase gene (phoA) of Escherichia coli. The parB locus in combination with the phoA promoter ensures both (i) plasmid stabilization due to the post-segregational killing of plasmid-free cells during growth and (ii) killing of the cells induced by the potential environmental signal phosphate limitation. This vector, therefore, appears to be a model system for increasing the stability of recombinant plasmids and for decreasing the potential risks in the application of recombinant bacteria in industrial fermentations.

Alkaline Phosphatase↗
PubMed1992

Interference in vimentin assembly in vitro by synthetic peptides derived from the vimentin head domain.

The importance of the amino-terminal domain ("head") of type III intermediate filament (IF) proteins in IF assembly has been examined by testing the influence of synthetic peptides representing a highly conserved decameric motif, KSSSYRRIMFGG, located near the amino terminus of vimentin. When added to soluble vimentin subunits this peptide induces, at fourfold molar excess or slightly above, the appearance of short, regular rod-like structures as determined by electron microscopy of negatively stained and rotary-shadowed preparations as well as by viscometry. At higher peptide concentrations large, irregularly shaped aggregates of mostly non-IF structures formed, but this aggregation was reversible by prolonged dialysis against low ionic strength buffer. The aggregating effect of this peptide was highly sequence-specific and was not seen with point-mutated sequences such as RR----TR or with unrelated peptides containing a central diarginine, indicating that it is not simply ionic. When different hexapeptides representing different "head" positions were compared, only the central sequence, SYRRXF, was as effective as the decamer. The addition of peptide during IF assembly did not prevent filament formation, although 50-fold molar excess of peptide resulted in a drastic increase (up to 40 nm) in the width of the filaments, which also appeared less regular, thus reflecting some interference with assembly. In contrast to the effects on soluble vimentin, the decameric peptide did not disturb IFs, indicating that the binding domain is "masked" or stabilized in the filaments. To identify the domain to which the peptide binds, three different binding assays using vimentin fragments and genetically engineered vimentin deletion mutants were employed. The results indicate that the binding domain of the near-amino-terminal peptide is located at the start of the alpha-helical "rod" domain of the protein. Possible mechanisms of interaction of these two portions of vimentin during IF assembly are discussed.

Amino Acid Sequence↗
PubMed1992

Assembly of a tail-less mutant of the intermediate filament protein, vimentin, in vitro and in vivo.

Recent reports on the possible contribution of the non-alpha-helical carboxy-terminal domain ("tail") of type III intermediate filament (IF) proteins to IF assembly have been controversial. To examine the importance and role of this domain, we have therefore engineered a Xenopus laevis vimentin cDNA to code for a tail-less polypeptide and have used it in combination with prokaryotic and eukaryotic expression systems. Here we show that tail-less vimentin, isolated from transfected bacteria (Escherichia coli), when used for assembly in vitro, forms normal-looking, loosely packed IFs. By viscometry we demonstrate that this tail-less vimentin assembles at an even higher rate and into longer IFs than wild-type vimentin. In vivo, i.e., by forced expression in transfected type III IF-free cultured epithelial cells, tail-less vimentin was also recovered in short fibrillar structures, in rodlets and in small as well as large spheroidal aggregates ("granules") that did not reveal any IF substructure. Surprisingly, however, spheroidal aggregate structures formed from the tail-deleted vimentin, were seen not only in the cytoplasm but also in the nucleus, indicating a role of the tail in higher order organization and compartmentalization of the vimentin IF system.

Animals↗
PubMed1991

Assembly and structure of calcium-induced thick vimentin filaments.

Using a viscometric assay and various electron microscopic procedures (negative staining, rotary shadowing, ultrathin sectioning) we have determined the influences of different kinds of ions and of ionic strength on the structures formed by assembly of soluble subunits of vimentin from bovine lens tissue or from Escherichia coli transformed with Xenopus vimentin cDNA. In contrast to the assembly of typical, i.e., 8 to 14-nm, intermediate-sized filaments (IFs) at elevated (e.g., 160 mM) concentrations of monovalent cations and at millimolar Mg2+ concentrations, filaments formed in the presence of Ca2+ ions (e.g., 5 mM) appeared at a lower rate, attained lower viscosity and were considerably thicker and shorter. The largest diameter measured was that for the recombinant amphibian protein: 24.2 +/- 8.5 nm in negative staining, 28.7 +/- 5.6 nm in sections. These thick Ca(2+)-induced filaments, however, revealed the same approximately 2 nm protofilament composition and approximately 20 nm cross-striation pattern as typical IFs, indicative of a similar molecular arrangement. The significance of this unusual structural IF protein assembly is discussed.

Animals↗
PubMed1990

[Long-term therapy of tumor pain using morphine-retard tablets].

We analysed the effect of sustained-release morphine tablets in 174 patients with severe cancer pain. A good relief of pain could be obtained in 65% of the patients within the first week and in 80% of the patients at the end of therapy. The mean daily dose was at 178 mg morphine, six patients needed more than 1000 mg per day. The sustained-release morphine was given at fixed intervals, in 80% of the cases every eight hours. No severe side-effects were associated with long-term morphine therapy. We often saw nausea and vomiting, constipation and drowsiness, but these side-effects decreased after the first weeks of treatment. Only in ten patients we had to stop therapy because of side-effects. Morphine can be used successfully in the treatment of cancer pain for long periods without concern about tolerance.

Administration, Oral↗
PubMed1990

Lidocaine metabolite formation as a measure of liver function in patients with cirrhosis.

A method for rapid assessment of hepatic function in cirrhotics based on the formation of the lidocaine metabolite, monoethylglycinexylidide (MEGX), was evaluated. The formation kinetics and urinary excretion patterns of MEGX clearly distinguished cirrhotics (n = 12) from healthy volunteers (n = 16). In a prospective study, we compared the prognostic value of the MEGX test with that of traditional parameters in transplant candidates. Patients who underwent transplantation during follow-up were excluded. The study included 58 adult patients with biopsy-proven posthepatitic or biliary cirrhosis. During the follow-up period of 120 days, 10 of 58 patients died of their liver disease. At the time of inclusion, we recorded MEGX formation, indocyanine green (ICG) half-life, caffeine clearance, and the Child-Pugh score. These variables were subjected as covariates to a survival analysis (Cox proportional hazards regression model). The results of the MEGX and the ICG test were significantly related to the 120-day survival. In the stepwise analysis, none of the parameters evaluated contributed to a further significant improvement of our predictive ability when added to the values of ICG (improvement: p less than 0.0005) and MEGX (improvement: p less than 0.0005). These findings suggest that the ICG and MEGX tests were the best short-term prognostic indicators. The easy handling favors the MEGX test over the ICG test as a tool for assessment of hepatic function and short-term prognosis in transplant candidates with cirrhosis.

Adult↗
PubMed1990

[Comparative study of parenteral and oral immunization to influenza in a large clinical trial. 1. Results of clinico-epidemiologic studies].

360 volunteers were recruited for the investigation from a homologous collective. 174 were immunized parenterally with "Influmun" from SSW Dresden, GDR. 176 volunteers were immunized twice orally with an interval of 60 days with an influenza vaccine inactivated by x-ray using enteric-coated capsules. In an interval of six months ARI-symptoms were investigated. Between 13th and 17th week 1988 an increased ARI-morbidity in the Greifswald-region was observed in which influenza A viruses were involved. In comparison with 312 non-immunized persons of the same age, sex and living area the immunized volunteers of the two groups showed 83.4% less sickness days. 30 persons of the non-immunized group got ill for totally 217 days, whereas only nine persons of the two immunized groups were put on the sicklist for totally 36 days. No significant differences concerning the occurrence and duration of acute respiratory infections (ARI) between the two differently immunized groups could be observed.

Administration, Oral↗
PubMed1989

Lignocaine metabolite formation as a measure of pre-transplant liver function.

A method for rapid assessment of hepatic function in liver donors based on the formation of the lignocaine metabolite monoethylglycinexylidide (MEGX), was used in a prospective study of 69 donor-recipient pairs. The probability of graft survival over 120 days was significantly higher for livers from donors with MEGX test values above 90 micrograms/l than for those from donors with MEGX values of 90 micrograms/l or below. Other liver function tests (bilirubin, prothrombin time, activity of aminotransferases, glutamate dehydrogenase, and cholinesterase, indocyanine green clearance, and galactose elimination capacity) were inefficient at predicting early outcome of transplantation. For a 20-day graft survival, the MEGX test showed prognostic sensitivity of 73% and specificity of 78%. These findings suggest that the MEGX formation test could be valuable for selection of donor organs.

Adolescent↗
PubMed1989

[Therapy of sterility from the viewpoint of females].

361 gynecological out-patients were questioned by means of a standardised questionnaire concerning their attitude towards the following possibilities of therapy procedures in case of sterility: 1. Artificial Insemination by Husband (AIH) 2. Artificial Insemination by Donor (AID) 3. In Vitro Fertilization (IVF) 4. Surrogate motherhood 5. Microsurgery Clearly positive was their attitude towards microsurgery, AIH and IVF. The patients would, in case of a corresponding sterility problem, accept such therapy for themselves. Negative, however, was their attitude towards AID and surrogate motherhood. Acceptance turned out to be significantly higher in regard to the medically and psychologically more precarious procedures like IVF, AID and surrogate motherhood, when asked whether they would tolerate such therapy for other involuntarily childless couples. Acceptance and valuation of procedures repeatedly followed the same order: microsurgery was judged "most moral" and "most natural", then AIH, IVF, AID and last surrogate motherhood. So traditional ideas of standards and values are decisive factors of acceptance. Emotionally the experience of sexuality, the progenitive act and pregnancy seem to belong together. The more a medical-technical procedure will interfere with their privacy the less it will be accepted. No difference in attitude was to be detected in regard to demographic criterions like age or religion. Sterile women, however, were far more prepared to undergo a physically as well as emotionally strenuous therapy in order to have their childwish come true. Personal involvement plays a decisive role in the acceptance of medically and psychologically more precarious procedures like IVF and AID. In comparison the extent of medical-technical efforts, and health risks, seem to be of minor importance.

Adolescent↗
PubMed1989

Expression of intermediate filament proteins during development of Xenopus laevis. I. cDNA clones encoding different forms of vimentin.

To provide a basis for studies of the expression of genes encoding the diverse kinds of intermediate-filament (IF) proteins during embryogenesis of Xenopus laevis we have isolated and characterized IF protein cDNA clones. Here we report the identification of two types of Xenopus vimentin, Vim1 and Vim4, with their complete amino acid sequences as deduced from the cloned cDNAs, both of which are expressed during early embryogenesis. In addition, we have obtained two further vimentin cDNAs (Vim2 and 3) which are sequence variants of closely related Vim1. The high evolutionary conservation of the amino acid sequences (Vim1: 458 residues; Mr approximately 52,800; Vim4: 463 residues; Mr approximately 53,500) to avian and mammalian vimentin and, to a lesser degree, to desmin from the same and higher vertebrate species, is emphasized, including conserved oligopeptide motifs in their head domains. Using these cDNAs in RNA blot and ribonuclease protection assays of various embryonic stages, we observed a dramatic increase of vimentin RNA at stage 14, in agreement with immunocytochemical results obtained with antibody VIM-3B4. The significance of very weak mRNA signals detected in earlier stages is discussed in relation to negative immunocytochemical results obtained in these stages. The first appearance of vimentin has been localized to a distinct mesenchymal cell layer underlying the neural plate or tube, respectively. The results are discussed in relation to programs of de novo synthesis of other cytoskeletal proteins in amphibian and mammalian development.

Amino Acid Sequence↗