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Biomedical subjects

M Wieser

Publications and source records attributed to M Wieser.

At least 19 recordsLinked to original sources
PubMed2006

The effects of systematic resistance training in the elderly.

The aim of the study was to examine the effects of a maximal resistance training following the principles of the most effective resistance training known from sport adapted to elderly people. Twenty-four subjects were randomly assigned into a training group (10 females and 4 males, age; 76.2 +/- 3.2 years) that underwent a training program and a control group (6 females and 4 males, age; 76.6 +/- 2.7 years) that did not participate in the training program. Before and after the training period, both groups were identically examined (blood and urine sample, spiroergometric testing, morphological measurements). The training group underwent a 12-week training program. Eight different exercises for the largest muscle groups of the largest joints were defined as one training circle. Training took place twice a week and commenced with two training circles per week (one circle per training session). After every four weeks, one training circle per week was added until four training circles per week were reached. Before, after every four weeks (changes in training amount) and after the training period, the maximum strength was measured. Data was analysed by the independent T-test and the analysis of variance, in case of significance, the dependent T-test and the Scheffé-test were used. In the resistance training group, the fat-free body mass was increased by approximately 2.9 +/- 0.5 kg, with no significant difference between females and males. Ergometrical fitness was increased by approximately 15 %, while the maximum oxygen uptake was increased by approximately 12 %. Maximum strength was increased between 26 % (bench pull) and 38 % (leg press). Resistance training that consisted of two training sessions per week was found to be at least as efficient as resistance training that included three training sessions per week, provided that the number of sets performed were equal. Seventy-five-year-old females were found to have a significantly higher body fat content than males of the same age (37 % versus 26 %, respectively). However, the decrease in body fat mass due to resistance training was found to be equal in both females and males (- 4 +/- 0.8 kg). Furthermore, there was almost no difference in muscle strength between the sexes for this age group (for example; leg press: females 86 kg versus males 82 kg).

Adipose Tissue↗
PubMed2005

Establishment of human fibroma cell lines from a MEN1 patient by introduction of either hTERT or SV40 early region.

Establishment of tumor cell lines as model systems for studying tumor biology or as a part of immunotherapeutic anti-cancer strategies is of high importance, whereby the highest possible preservation of the original tumor cell phenotype is a prerequisite for these aims. Since overexpression of the catalytic subunit of human telomerase (hTERT) is known to minimally alter the cellular phenotype, we focused on the establishment of cell lines derived from human fibroma from a MEN1 patient by ectopic expression of hTERT. Additionally, a cell line was generated by introduction of the early region of SV40 (SV40 ER). Both approaches resulted in continuous cell lines, and neither T1-LOHG (hTERT) nor SV1-LOHG (SV40 ER) showed a transformed phenotype. While SV40 ER-transfected cells underwent dramatic changes in morphology and growth characteristics, hTERT-expressing cells indeed retained a phenotype highly similar to the parental cells. Nevertheless, hTERT overexpression resulted in increased growth rates after about 70 population doublings (PD) and alterations of mRNA levels of genes associated with tumor pathogenesis. Thus, our data suggest that ectopic hTERT expression leads to immortalization of LOHG-F, sustaining many characteristics of the non-transfected counterparts, but continuous growth in vitro is associated with changes of the cellular phenotype.

Antigens, Polyomavirus Transforming↗
PubMed2004

Nephrogenic fibrosing dermopathy in two patients with systemic lupus erythematosus.

Nephrogenic fibrosing dermopathy (NFD) is a novel fibrosing disorder of the skin with characteristic histopathology. It affects patients with impaired renal function and appears to be independent from the type of kidney disease. Its aetiopathology is unknown and presently no standard therapy exists. We report a patient with systemic lupus erythematosus (SLE) and glomerulonephritis who developed diffuse indurated erythematous plaques covering nearly the entire legs and trunk. She had never received dialysis. The second patient suffered from SLE and antiphospholipid syndrome related thrombotic glomerulopathy. After 10 weeks of haemodialysis she developed the same skin condition. To the best of our knowledge, these are the first reports of NFD occurring in patients with SLE.

Antiphospholipid Syndrome↗
PubMed2001

Targeted inhibition of telomerase in human cancer: will it be a double-edged sword?

More than 80% of human malignancies express telomerase activity, while normal somatic tissues in general lack it. During each normal cell division, there is a constant loss of DNA sequences at chromosomal ends, which is due to the 'end-replication problem' of conventional DNA polymerase. Critical shortening of telomeres induces cell cycle arrest and eventually cell death. Telomerase, a ribonucleoprotein complex with a RNA (TR) and a catalytic subunit (TERT) as core components, is able to add reitineratedly telomeric repeat sequences to the very ends of chromosomes. It was suggested that activation of telomerase in tumor cells has a major impact on their continuous growth. Indeed, transfection of TERT constructs into various normal human cell types led to telomere elongation or stabilization and, most importantly, cellular immortalization. Conversely, inhibition of telomerase in tumor cell lines induced growth arrest, at least in first experimental settings. Such initial success implies that drug-mediated abrogation of telomerase action might be an ideal adjuvant treatment for cancer patients. There are, however, legitimate concerns about the generalization of such an approach.

Cell Division↗
PubMed2000

Nitrilase of Rhodococcus rhodochrous J1. Conversion into the active form by subunit association.

Nitrilase-containing resting cells of Rhodococcus rhodochrous J1 converted acrylonitrile and benzonitrile to the corresponding acids, but the purified nitrilase hydrolyzed only benzonitrile, and not acrylonitrile. The activity of the purified enzyme towards acrylonitrile was recovered by preincubation with 10 mM benzonitrile, but not by preincubation with aliphatic nitriles such as acrylonitrile. It was shown by light-scattering experiments, that preincubation with benzonitrile led to the assembly of the inactive, purified and homodimeric 80-kDa enzyme to its active 410-kDa aggregate, which was proposed to be a decamer. Furthermore, the association concomitant with the activation was reached after dialysis of the enzyme against various salts and organic solvents, with the highest recovery reached at 10% saturated ammonium sulfate and 50% (v/v) glycerol, and by preincubation at increased temperatures or enzyme concentrations.

Acrylonitrile↗
PubMed2000

Rapid identification of Staphylococcus epidermidis.

During the collection of airborne bacteria in a museum in England some bacterial strains were isolated which due to their fatty acid profiles were clearly identified as members of the genus Staphylococcus. As fatty acid compositions of coagulase-negative staphylococci are very similar, differing only in quantities but not in qualities, further identification at the species level without a fatty acid database was not achieved. Investigation of the isolates using the Staph ID 32 API system resulted in an identification of the isolates as Staphylococcus epidermidis (probabilities of 79.7-95.5%). For further genotypic characterization of these isolates, some Staphylococcus epidermidis strains from different sources and the type strains of Staphylococcus aureus, Staphylococcus capitis, Staphylococcus epidermidis, Staphylococcus gallinarum, Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus warneri and Staphylococcus xylosus were subjected to repetitive-sequence PCR, including enterobacterial repetitive intergenic consensus (ERIC) PCR, BOX-PCR and repetitive extragenic palindromic unit sequence (REP) PCR. ERIC- and BOX-PCR yielded a species-specific banding pattern for all Staphylococcus epidermidis strains. Furthermore, all staphylococcal reference strains investigated exhibited distinct banding patterns, clearly distinguishable from that of Staphylococcus epidermidis. No species-specific banding patterns could be observed after REP-PCR. As species identification of coagulase-negative staphylococci by fatty acid analyses and biochemical tests is known to be difficult ERIC- and BOX-PCR seem to be excellent tools for the identification of Staphylococcus epidermidis isolates.

Air Microbiology↗
PubMed1999

Indoor air quality at the Correr Museum, Venice, Italy.

Two multidisciplinary field surveys, one in winter and the other in summer have monitored the indoor microclimate, air pollution, deposition and origin of the suspended particulate matter and microorganisms of the Correr Museum, Venice. In addition, this study was focused to identify the problems caused by the heating and air conditioning system (HAC) and the effects due to the presence of carpets. Heating and air conditioning systems (HACs), when chiefly designed for human welfare, are not suitable for conservation and can cause dangerous temperature and humidity fluctuations. Improvements at the Correr Museum have been achieved with the assistance of environmental monitoring. The carpet has a negative influence as it retains particles and bacteria which are resuspended each time people walk on it. The indoor/outdoor pollutants ratio is greater in the summertime, when doors and windows are more frequently open to allow for better ventilation, illustrating that this ratio is mainly governed by the free exchange of the air masses. The chemical composition, size and origin of the suspended particulate matter have been identified, as well as the bacteria potentially dangerous to the paintings. Some general suggestions for improving indoor air quality are reported in the conclusions.

Aerosols↗
PubMed1999

Purification and characterization of vanillyl-alcohol oxidase from Byssochlamys fulva V107.

Vanillyl-alcohol oxidase from Byssochlamys fulva V107 was purified to apparent homogeneity as shown by SDS-PAGE and gel-permeation HPLC. The enzyme is a homodimeric flavoenzyme consisting of two 58 kDa subunits. It catalyzes the dehydrogenation of different 4-hydroxybenzylic structures, including the conversion of 4-hydroxybenzyl alcohols such as vanillyl alcohol to the corresponding aldehydes, eugenol to coniferyl alcohol, and 4-alkylphenols to 1-(4-hydroxyphenyl)alcohols. The latter reaction was S-stereospecific and was used for the synthesis of S-1-(4-hydroxyphenyl)ethanol and -propanol with enantiomeric excesses of 81.9 and 86.0%, respectively. The catalytic and structural similarities to a Penicillium vanillyl-alcohol oxidase and Pseudomonas 4-alkylphenol methylhydroxylases are discussed.

Journal Article↗
PubMed1999

Purification, characterization and gene cloning of 6-hydroxynicotinate 3-monooxygenase from Pseudomonas fluorescens TN5.

6-Hydroxynicotinate 3-monooxygenase, a membrane-bound, 42-kDa monomeric enzyme from Pseudomonas fluorescens TN5 was purified and characterized. The enzyme catalyzes the oxidative decarboxylation of 6-hydroxynicotinate and depends on O2, NADH and FAD with the holoenzyme containing 1 M of FAD per 1 M of enzyme. The isolated enzyme was used for the synthesis of 2,5-dihydroxypyridine, a precursor for the chemical synthesis of 5-aminolevulinic acid, which is applied as a plant growth hormone, a herbicide and in cancer therapy. A 1.8-kbp DNA fragment, which contains the ORF encoding 6-hydroxynicotinic acid 3-monooxygenase, was cloned, sequenced and expressed in Escherichia coli. The deduced 385 amino acid sequence of the cloned ORF is in agreement with the enzyme molecular mass, amino acid sequence of an internal peptide, contains a putative FAD-binding site and is homologous to similar flavoproteins such as salicylate 1-monoxygenase.

Amino Acid Sequence↗
PubMed1999

Agrococcus citreus sp. nov., isolated from a medieval wall painting of the chapel of Castle Herberstein (Austria).

A bacterial strain, D-1/1aT, isolated from a medieval wall painting of the chapel of Herberstein (Styria, Austria) was characterized by a polyphasic approach. Strain D-1/1aT shared 98.1% 16S rRNA sequence similarity to Agrococcus jenensis. The chemotaxonomic characteristics including polar lipid pattern, whole cell sugars, quinone system, polyamine pattern, cell wall composition and fatty acid profile were in good agreement with those of Agrococcus jenensis. The G+C content of the DNA was determined to be 74 mol%. The value of 47% DNA reassociation obtained after DNA-DNA hybridization between DNA of Agrococcus jenensis and strain D-1/1aT as well as differences in the amino acid composition of the peptidoglycan and in physiological characteristics demonstrate that the isolate represents a new species of the genus Agrococcus. The name Agrococcus citreus sp. nov. is proposed for the new species harbouring isolate D-1/1aT. The type strain is DSM 12453T.

Actinomycetales↗
PubMed1999

The indoor environment of a modern museum building, the Sainsbury Centre for Visual Arts, Norwich, UK.

A multi-disciplinary approach was used to investigate the indoor environment of a modern museum building, and its suitability for the conservation of the collection therein. Climate, gaseous and particulate pollution and the concentrations of bacteria were measured in summer and winter campaigns. While the environment overall was found to be an acceptable one, a number of drawbacks were highlighted, the most serious of these being the large temperature and humidity fluctuations that occurred in the summer.

Air Microbiology↗
PubMed1998

Carbon dioxide fixation by reversible pyrrole-2-carboxylate decarboxylase from Bacillus megaterium PYR2910.

Pyrrole-2-carboxylate decarboxylase from Bacillus megaterium PYR2910 attains a balanced reaction equilibrium with an equilibrium constant of 0.3-0.4 M. Therefore, the enzyme catalyzes the reverse carboxylation of pyrrole after addition of bicarbonate. For the synthesis of pyrrole-2-carboxylate, the reverse reaction was optimized and the equilibrium was shifted towards the carboxylate. The product yield was 230 mM (25.5 g/l) pyrrole-2-carboxylate from 300 mM pyrrole in a batch reaction and 325 mM (36.1 g/l) from 400 mM pyrrole in a fed-batch reaction, using both whole cells and the purified enzyme in a pH 8.0 reaction mixture with bicarbonate saturation of 1.9 M. Kinetic studies indicated, that bicarbonate is the reactive species used by this carbon dioxide-fixation enzyme.

Bacillus megaterium↗
PubMed1998

Pyrrole-2-carboxylate decarboxylase from Bacillus megaterium PYR2910, an organic-acid-requiring enzyme.

Inducible pyrrole-2-carboxylate decarboxylase, which catalyzes the decarboxylation of pyrrole-2-carboxylate to pyrrole and CO2 in stoichiometric amounts, was purified from Bacillus megaterium PYR2910. The purity of the enzyme was shown by SDS/PAGE and gel-permeation HLPC. The enzyme has a molecular mass of approximately 98 kDa and consists of two identical subunits. It is highly specific for pyrrole-2-carboxylate, and also catalyzes the reverse reaction, the carboxylation of pyrrole. A unique feature of this enzyme is its requirement of an organic acid, such as acetate, propionate, butyrate or pimelate. A possible catalytic mechanism including a cofactor function of organic acid is discussed.

Acetates↗
PubMed1998

Purification and characterization of gallic acid decarboxylase from pantoea agglomerans T71

Oxygen-sensitive gallic acid decarboxylase from Pantoea (formerly Enterobacter) agglomerans T71 was purified from a cell extract after stabilization by reducing agents. This enzyme has a molecular mass of approximately 320 kDa and consists of six identical subunits. It is highly specific for gallic acid. Gallic acid decarboxylase is unique among similar decarboxylases in that it requires iron as a cofactor, as shown by plasma emission spectroscopy (which revealed an iron content of 0.8 mol per mol of enzyme subunit), spectrophotometric analysis (absorption shoulders at 398 and 472 nm), and inhibition of the enzyme activity by 2,2'-bipyridyl, o-phenanthroline, and EDTA. Another interesting feature of this strain is the fact that it contains a tannase, which is used together with the gallic acid decarboxylase in a two-enzyme resting cell bioconversion to synthesize valuable pyrogallol from readily available tannic acid.

Journal Article↗
PubMed1997

Purification and characterization of 2,4,6-trichlorophenol-4-monooxygenase, a dehalogenating enzyme from Azotobacter sp. strain GP1.

The enzyme which catalyzes the dehalogenation of 2,4,6-trichlorophenol (TCP) was purified to apparent homogeneity from an extract of TCP-induced cells of Azotobacter sp. strain GP1. The initial step of TCP degradation in this bacterium is inducible by TCP; no activity was found in succinate-grown cells or in phenol-induced cells. NADH, flavin adenine dinucleotide, and O2 are required as cofactors. As reaction products, 2,6-dichlorohydroquinone and Cl- ions were identified. Studies of the stoichiometry revealed the consumption of 2 mol of NADH plus 1 mol of O2 per mol of TCP and the formation of 1 mol of Cl- ions. No evidence for membrane association or for a multicomponent system was obtained. Molecular masses of 240 kDa for the native enzyme and 60 kDa for the subunit were determined, indicating a homotetrameric structure. Cross-linking studies with dimethylsuberimidate were consistent with this finding. TCP was the best substrate for 2,4,6-trichlorophenol-4-monooxygenase (TCP-4-monooxygenase). The majority of other chlorophenols converted by the enzyme bear a chloro substituent in the 4-position. 2,6-Dichlorophenol, also accepted as a substrate, was hydroxylated in the 4-position to 2,6-dichlorohydroquinone in a nondehalogenating reaction. NADH and O2 were consumed by the pure enzyme also in the absence of TCP with simultaneous production of H2O2. The NH2-terminal amino acid sequence of TCP-4-monooxygenase from Azotobacter sp. strain GP1 revealed complete identity with the nucleotide-derived sequence from the analogous enzyme from Pseudomonas pickettii and a high degree of homology with two nondehalogenating monooxygenases. The similarity in enzyme properties and the possible evolutionary relatedness of dehalogenating and nondehalogenating monooxygenases are discussed.

Amino Acid Sequence↗
PubMed1994

Metabolism of 4-chlorophenol by Azotobacter sp. GP1: structure of the meta cleavage product of 4-chlorocatechol.

A mutant strain of Azotobacter sp. GP1 converted 4-chlorophenol to 4-chlorocatechol under cometabolic conditions. Under the same conditions the wild-type strain accumulated a yellow compound, which by chemical and spectroscopic methods was identified as 5-chloro-2-hydroxy-6-oxohexadienoic acid (5-chloro-2-hydroxy-muconic semialdehyde). The structure of this compound indicates a meta-proximal cleavage of 4-chlorocatechol.

Azotobacter↗