Fluid-induced particle-size segregation in sheared granular assemblies.
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Journal Article↗
Biomedical subjects
H Herrmann
Publications and source records attributed to H Herrmann.
Crossover from directed percolation to compact directed percolation.
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Journal Article↗
Carbon catabolite repression of phenol degradation in Pseudomonas putida is mediated by the inhibition of the activator protein PhlR.
Enzymes involved in (methyl)phenol degradation of Pseudomonas putida H are encoded by the catabolic operon (phlA-L) on plasmid pPGH1. Transcription of this operon by the sigma54 (RpoN)-containing RNA polymerase is positively controlled by the gene product of the divergently transcribed phlR in response to the availability of the respective substrate. Additionally, phenol degradation is subject to carbon catabolite repression induced by organic acids (e.g., succinate, lactate, and acetate) or carbohydrates (e.g., glucose and gluconate). Analysis of lacZ fusion to the catabolic promoter and quantified primer extension experiments indicate that carbon catabolite repression also occurs at the transcriptional level of the catabolic operon. In this study, it is furthermore shown that carbon catabolite repression is a negative control. Titration of the postulated negative controlling factor was exclusively observed when extra copies of functional phlR gene were present in the cell. We therefore conclude that PhlR is the target and that carbon catabolite repression of phenol degradation occurs by interfering with the activating function of PhlR.
Bacterial Proteins↗
Vimentin in a cold-water fish, the rainbow trout: highly conserved primary structure but unique assembly properties.
We have isolated from a rainbow trout (Oncorhynchus mykiss) spleen cDNA library a clone coding for vimentin. The deduced amino acid sequence reveals a high degree of identity with vimentin from carp (81%), frog (71%), chick and human (73% each). Large stretches in the central alpha-helical rod are identical within all four classes of vertebrates, but in 17 residues spread over the entire rod, the two fish differ distinctly from the tetrapod species. In addition, in the more diverged non-helical head domain, a nonapeptide motif previously shown to be important for regular filament formation is conserved. Recombinant trout vimentin assembles into bona fide filaments in vitro, with a temperature optimum between 18 and 24 degrees C. Above 27 degrees C, however, filament assembly is abruptly abolished and short filaments with thickened ends as well as structures without typical intermediate filament appearance are formed. This distinguishes its assembly properties significantly from amphibian, avian and mammalian vimentin. Also in vivo, after cDNA transfection into vimentin-free mammalian epithelial cells, trout vimentin does not form typical intermediate filament arrays at 37 degrees C. At 28 degrees C, and even more pronounced at 22 degrees C, the vimentin-positive material in the transfected cells is reorganized in the perinuclear region with a partial fibrillar appearance, but typical intermediate filament arrays are not formed. Together with immunoblotting and immunolocalization data from trout tissues, where vimentin is predominantly found in glial and white blood cells, we conclude that vimentin is indeed important in its filamentous form in fish and other vertebrates, possibly fulfilling cellular functions not directly evident in gene targeting experiments carried out in mice.
Amino Acid Sequence↗
Characterization of Borrelia burgdorferi sensu lato strains isolated from Ixodes ricinus in Mecklenburg-Vorpommern, Germany.
Epidemiological studies in Mecklenburg-Vorpommern have shown a high prevalence of Borrelia burgdorferi-infected ticks. A total of 17 B. burgdorferi sensu lato strains were isolated from ticks and investigated by Western blots (immunoblot) with eight monoclonal anti-bodies against different epitopes of the outer surface protein A (OspA). Except for one, all strains could be classified using this system. The majority of strains belonged to the B. garinii-associated OspA serotypes 3, 5 and 6. Three isolates were classified as OspA serotype 2 (B. afzelii). B. burgdorferi sensu stricto strains (OspA serotype 1) as well as B. garinii-associated OspA serotype 4 were not present.
Animals↗
[Trauma in elderly patients].
The increasing proportion of old and very old people in the population has increased the task of treatment in the field of surgery and its main points. The decreasing function of and changes to the skeleton caused by osteoporosis have led to a number of fractures. The fracture near the hip joint is typical for this section of the population. 1180 patients from the Jena surgical clinic/casualty were analysed; the average age was over 75 years and the most common cause of accident was a fall. A quick operative treatment is recommended. In comparison with the risk factor of the ASA-classification 1.6% with factor I and 44.4% with factor IV died. Postoperative treatment is very important.
Accidental Falls↗
Localization and organization of phenol degradation genes of Pseudomonas putida strain H.
The genetic organization of the DNA region encoding the phenol degradation pathway of Pseudomonas putida H has been investigated. This strain can utilize phenol or some of its methylated derivatives as its sole source of carbon and energy. The first step in this process is the conversion of phenol into catechol. Catechol is then further metabolized via the meta-cleavage pathway into TCA cycle intermediates. Genes encoding these enzymes are clustered on the plasmid pPGH1. A region of contiguous DNA spanning about 16 kb contains all of the genetic information necessary for inducible phenol degradation. The analysis of mutants generated by insertion of transposons and cassettes indicates that all of the catabolic genes are contained in a single operon. This codes for a multicomponent phenol hydroxylase and meta-cleavage pathway enzymes. Catabolic genes are subject to positive control by the gene product(s) of a second locus.
Amino Acid Sequence↗
Truncation mutagenesis of the non-alpha-helical carboxyterminal tail domain of vimentin reveals contributions to cellular localization but not to filament assembly.
We have investigated the effect of stepwise truncating the carboxyterminal domain ("tail") of the intermediate filament (IF) protein vimentin of the clawed toad, Xenopus laevis, on filament assembly in vitro and, using cell transfection, in vivo and also on the cellular topology of the structures formed. All truncations examined, except the minimal one missing the last 11 amino acids which made the protein more sensitive to changes of ionic strength, did not significantly alter IF assembly in vitro, as judged by electron microscopy, viscometry and determination of viscoelastic properties with a laser-operated torsion pendulum. Stable transfections of vimentin-free mammalian cells with cDNAs encoding these mutations resulted at 28 degrees C, i.e. the permissive temperature for assembly of Xenopus vimentin, in the formation of extended IF bundle arrays. At 37 degrees C, however, the mutants lacking more than the last 35 amino acids could leave the cytoplasm and accumulated in the nucleus, indicating a certain topogenic element is located in the tail and directs cytoplasmic restriction in the wild-type protein although this does not form IFs under these conditions. Transfer to the nucleus is, however, abolished if the IF-consensus motif at the end of the rod domain is removed, suggesting that this part of the molecule also contributes to nuclear location. Similar results were obtained with human vimentin: While the rod entered the nucleus, headless vimentin, unable to form IFs, remained restricted to the cytoplasm owing to its tail domain. In contrast, tailless human vimentin and tailless mouse desmin, which are fully assembly-competent in vitro, both formed extensive IF arrays in the cytoplasm but did not accumulate in the nucleus. We conclude that in class III IF proteins stepwise deletions in the tail, while not considerably altering IF assembly in vitro, can change the topogenesis of IF proteins and structures in the living cell.
Amino Acid Sequence↗
[Incidence of Borrelia burgdorferi in the Greifswald area of the Vorpommern region of the Mecklenburg-Vorpommern district].
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Adolescent↗
Plasma profiles of somatotropin and IGF-I in diary cows following application of two preparations of recombinant bovine somatotropin in a sustained release vehicle.
Milk production, plasma bovine somatotropin (bST) and insulin-like growth factor I (IGF-I) were measured in dairy cows following a single subcutaneous injection of a slowly released preparation of either recombinant enterokinase linker bST (somidobove: 640 mg) or recombinant methionyl bST (sometribove: 500 mg). There was a 3-7-fold increase in plasma bST concentrations during the first three postinjection hours in cows treated with both sometribove (from 3.4 +/- 0.8 to 11.2 +/- 3.0 ng ml-1) or somidobove (from 2.3 +/- 0.3 to 17.5 +/- 2.6 ng ml-1). In the next 8 days the bST concentration in the bST-treated cows varied, but was still significantly increased above the controls. In the following days, the concentrations of bST did not differ from the controls. Plasma concentrations of IGF-I increased nearly 2-fold as early as 24 h following recombinant bST administration and then continued to rise so that by 48 h postinjection they were nearly four times higher (control 16.2, bST-treated 61.7 ng ml-1). From 48 h after sometribove injection, IGF-I concentrations remained at a plateau (varying between 60.4 and 85.7 ng ml-1) till day 11. Then it decreased slowly, but still remained higher on day 14 than those in placebo-treated cows (44.4 +/- 17.8 ng ml-1 in bST-treated animals; 12.2 +/- 7.5 ng ml-1 in the controls). Although IGF-I level was increasing in all bST-treated animals, the absolute IGF-I increase was not related to the increase in milk production.
Animals↗
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↗
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↗
[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↗
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↗
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↗
[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↗
[BNS epilepsy after the second triple (DPT) vaccination?].
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Diagnosis, Differential↗
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↗