Search PubMed⌕ Search

Biomedical subjects

M Krause

Publications and source records attributed to M Krause.

At least 181 records · Page 10Linked to original sources
PubMed1994

[Occupational exposure of workers in chemical factors and selected parameters of the respiratory system].

Workers employed in chemical factories are chronically exposed to harmful substances present in the air of the occupational environment. The aim of this paper was to find out whether this situation produces adverse effects on the respiratory system despite the observance of admissible concentrations of toxic substances in the air. Spirometric values such as FVC1 and FEV1%FVC were measured in 647 workers. It was found that workers in some departments (power station and polystyrene) showed restrictive and obturative disturbances of ventilation. In other departments workers exhibited less expressed respiratory disorders. Adverse effect of smoking and long period of employment on the respiratory system of workers was also revealed. These results indicate that apart from substances present in the occupational environment there are other factors which affect as well the respiratory system of persons employed in the chemical industry.

Adult↗
PubMed1993

Exendin-4 is a high potency agonist and truncated exendin-(9-39)-amide an antagonist at the glucagon-like peptide 1-(7-36)-amide receptor of insulin-secreting beta-cells.

Exendin-4 purified from Heloderma suspectum venom shows structural relationship to the important incretin hormone glucagon-like peptide 1-(7-36)-amide (GLP-1). We demonstrate that exendin-4 and truncated exendin-(9-39)-amide specifically interact with the GLP-1 receptor on insulinoma-derived cells and on lung membranes. Exendin-4 displaced 125I-GLP-1, and unlabeled GLP-1 displaced 125I-exendin-4 from the binding site at rat insulinoma-derived RINm5F cells. Exendin-4 had, like GLP-1, a pronounced effect on intracellular cAMP generation, which was reduced by exendin-(9-39)-amide. When combined, GLP-1 and exendin-4 showed additive action on cAMP. They each competed with the radio-labeled version of the other peptide in cross-linking experiments. The apparent molecular mass of the respective ligand-binding protein complex was 63,000 Da. Exendin-(9-39)-amide abolished the cross-linking of both peptides. Exendin-4, like GLP-1, stimulated dose dependently the glucose-induced insulin secretion in isolated rat islets, and, in mouse insulinoma beta TC-1 cells, both peptides stimulated the proinsulin gene expression at the level of transcription. Exendin-(9-39)-amide reduced these effects. In conclusion, exendin-4 is an agonist and exendin-(9-39)-amide is a specific GLP-1 receptor antagonist.

Animals↗
PubMed1993

[Community-acquired Acinetobacter pneumonia].

We report the history of a 38-year-old male native of Sri Lanka admitted to the emergency ward because of chest pain and shortness of breath. On physical and radiographic examination a bilateral predominantly right-sided pneumonia was found. The patient was admitted to the medical ICU and an antibiotic regimen with amoxicillin/clavulanic acid and erythromycin was initiated. Shortly afterwards septic shock developed. The patient was intubated and received high doses of catecholamines. He died 30 hours after admission to the hospital. Cultures from sputum, tracheal aspirate and blood grew Acinetobacter baumanni. Acinetobacter is an ubiquitous gram-negative rod with coccobacillary appearance in clinical specimens, that may appear gram-positive due to poor discoloration on Gram-stain. It is a well known causative agent of nosocomial infections, particularly in intensive care units. Community-acquired pneumonias, however, are quite rare. Sporadic cases have been reported from the US, Papua-New Guinea and Australia. Interestingly, these pneumonias are fulminant and have a high mortality. Chronic obstructive lung disease, diabetes, and tobacco and alcohol consumption appear to be predisposing factors. Due to the rapid course and poor prognosis, prompt diagnosis and adequate antibiotic treatment are indicated. Antibiotics use for community-acquired pneumonias, such as amoxicillin/clavulanic acid or macrolides, are not sufficient. Appropriate antibiotics for the initial treatment of suspected Acinetobacter infections include imipenem and carboxy- and ureidopenicillins combined with an aminoglycoside.

Acinetobacter↗
PubMed1993

["Facing"--a preliminary parameter in diagnosis of fetal skeletal abnormalities].

Four cases with abnormalities of foetal faces are demonstrated--thanatophoric dwarfism, cheilognathopalotoschisis, osteogenesis imperfecta, achondrogenesis (Type I). A relationship to skeletal dysplasia was shown. We think, that the representation of foetal faces and their profile plays an important part in second trimester ultrasound screening between 18 and 22 weeks of gestational age.

Abnormalities, Multiple↗
PubMed1992

The pie-1 and mex-1 genes and maternal control of blastomere identity in early C. elegans embryos.

During C. elegans embryogenesis an 8-cell stage blastomere, called MS, undergoes a reproducible cleavage pattern, producing pharyngeal cells, body wall muscles, and cell deaths. We show here that maternal-effect mutations in the pie-1 and mex-1 genes cause additional 8-cell stage blastomeres to adopt a fate very similar to that of the wild-type MS blastomere. In pie-1 mutants one additional posterior blastomere adopts an MS-like fate, and in mex-1 mutants four additional anterior blastomeres adopt an MS-like fate. We propose that maternally provided pie-1(+) and mex-1(+) gene products may function in the early embryo to localize or regulate factors that determine the fate of the MS blastomere.

Animals↗
PubMed1992

Body-wall muscle formation in Caenorhabditis elegans embryos that lack the MyoD homolog hlh-1.

The myoD family of DNA binding proteins has been implicated in the control of myogenesis in a variety of organisms. Searches for homologs in the nematode Caenorhabditis elegans yielded only one gene, designated hlh-1, expressed in body-wall muscle cells and their precursors. To assess the role of hlh-1 in C. elegans myogenesis, genetic deficiencies spanning the hlh-1 locus were isolated after gamma irradiation. Embryos homozygous for these deficiencies exhibited extensive body-wall muscle differentiation, including expression of several characteristic myofilament proteins and weak contracile behavior. Thus, zygotic hlh-1 expression was not required for body-wall muscle precursors to adopt muscle cell fates.

Amino Acid Sequence↗
PubMed1992

Time-dependent regenerative influence of predegenerated nerve grafts on hippocampus.

Our previous studies have revealed that the predegeneration facilitated the neurite outgrowth from hippocampus following the peripheral nerve grafts implantation. The aim of the present work is to find whether the stimulative power of peripheral nerve grafts depends on the time lapse after the transection. Autologous predegenerated distal stumps of the rat sciatic nerves were implanted into the hippocampus on the 7th, 14th, 28th, and 35th day following the transection. Six weeks later, horseradish peroxidase conjugated with fluorescein isothiocyanate was injected into the graft and frozen sections of brains were made. Fluorescence microscope examination has shown that FITC-HRP labeled cells were present among the hippocampal neurons in all the brains under examination, excluding these grafted with 14-day predegenerated peripheral nerves. The FITC-HRP labeled neurons were particularly numerous when the 7- and 35-day-old predegenerated stumps were used as grafts.

Animals↗
PubMed1992

Salmonella typhimurium bacteremia: association with the virulence plasmid.

Virulence plasmids, which are found in a small number of Salmonella serotypes, greatly enhance the extraintestinal growth of salmonellae and lower the LD50 by 2-5 logs in experimental murine infections. To determine if virulence plasmids are important in the pathogenesis of Salmonella bacteremia in humans, blood and fecal isolates of Salmonella typhimurium from California were examined for the presence of a virulence plasmid. Colony blots were done using a labeled probe made from the highly conserved EcoRI fragment of the Salmonella dublin virulence plasmid. A total of 42% of the fecal and 76% of the blood isolates hybridized with the probe. This is the first evidence that the virulence plasmid is important in the pathogenesis of Salmonella bacteremia in humans.

Bacteremia↗
PubMed1992

Epidermal growth factor receptors in porcine endometrium: binding characteristics and the regulation of prostaglandin E and F2 alpha production.

Epidermal growth factor (EGF) and its receptor have been implicated in the control of uterine cell growth and differentiation. The objectives of this study were to determine EGF binding characteristics and effects of EGF on prostaglandin (PG) production in vitro by glandular and stromal cells from porcine endometrium. Endometrial tissues were taken from 10 sows on Day 13 of pregnancy (first day of estrus = Day 0). Glandular and stromal cells were separated by enzymatic dispersion and sieve filtration and cultured for 3 days. EGF-binding assay was carried out at 20 degrees C in the presence of 0.2 nM 125I-EGF with increasing concentrations of unlabeled EGF (0-12 nM). Scatchard analyses revealed one class of high-affinity binding sites in each cell type with apparent equilibrium dissociation constants (n = 6) of 2.96 +/- 0.60 nM and 2.48 +/- 0.50 nM for stromal and glandular cells, respectively. The apparent binding capacities were 199.3 +/- 34.8 fmol/10(6) cells for stromal cells and 40.7 +/- 6.5 fmol/10(6) cells for glandular cells. Effects of EGF on PG production were determined by including 1, 5, 10, or 20 ng/ml EGF in the medium for the final 24 h of the 72-h culture. EGF increased PGE (p less than 0.01) and PGF2 alpha (p less than 0.05) secretion by stromal cells. The highest concentration (20 ng/ml) of EGF increased secretion of PGE and PGF2 alpha by 133% and 64%, respectively, over controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Four homologous domains in the primary structure of GrsB are related to domains in a superfamily of adenylate-forming enzymes.

The entire nucleotide sequence of the Bacillus brevis grsB gene encoding the gramicidin S synthetase 2, which activates and condenses the four amino acids proline, valine, ornithine and leucine has been determined. The gene contains an open reading frame of 13,359 bp which encodes a protein of 4453 amino acids with a predicted Mr of 510,287. The gene is located within the gramicidin S biosynthetic operon, also containing the genes grsT and grsA, whose nucleotide sequences have been determined previously. Within the GrsB amino acid sequence four conserved and repeated domains of about 600 amino acids (45-50% identity) have been identified. The four domains are separated by non-homologous sequences of about 500 amino acids. The domains also share a high degree of similarity (20-70%) with eight peptide synthetases of bacterial and fungal origin as well as with conserved sequences of nine other adenylate-forming enzymes of diverse origin. On the basis of sequence homology and functional similarities, we infer that those enzymes share a common evolutionary origin and present a phylogenetic tree for this superfamily of domain-bearing enzymes.

Amino Acid Isomerases↗
PubMed1992

Evaluation of antihistamine-related daytime sleepiness. A double-blind, placebo-controlled study with terfenadine.

The daytime sleepiness potentially associated with antihistamines was evaluated by the multiple sleep latency test (MSLT) in a study comparing terfenadine with placebo. According to a double-blind, randomized, cross-over design, 12 healthy men were given either 120 mg terfenadine or placebo once daily in the morning, for 3 consecutive days with a 5-day interval. EEG-polygraphic recordings were made each study day at 9:30 and 11:30 a.m., and 1:30, 3:30, and 5:30 p.m., and the tendency to fall asleep was measured. All mean stage-1 sleep latencies throughout the study failed to show any significant difference between terfenadine and placebo. Accordingly, psychomotor performance assessed by visual and auditory reaction time did not change after treatment. The results of this study confirmed that terfenadine does not induce daytime sleepiness as objectively measured by MSLT.

Adult↗
PubMed1992

Regulation of plasmid virulence gene expression in Salmonella dublin involves an unusual operon structure.

The 80-kb plasmid pSDL2 of Salmonella dublin Lane is essential for lethal systemic infection in experimental mice. A cluster of five plasmid genes, designated spvR, spvA, spvB, spvC, and spvD, is sufficient to express the plasmid-related virulent phenotype. The spvR gene product has recently been identified as a positive regulator of spvB expression in the stationary phase of bacterial growth (F. C. Fang, M. Krause, C. Roudier, J. Fierer, and D. G. Guiney, J. Bacteriol. 173:6783-6789, 1991). In this study, we evaluated the role of SpvR in the transcription of the downstream virulence genes spvABCD. Analysis of mRNA synthesis revealed that SpvR promotes transcription of the downstream spvABCD genes in the stationary growth phase. Transcript mapping of the spv region demonstrated an unusual operon structure involving messages for spvA, spvAB, spvABC, and spvABCD. Quantitative measurement of transcription and of gene expression by use of translational spv-lacZ fusions suggested that SpvA, SpvB, SpvC, and SpvD are produced in decreasing abundance. Primer extension assays identified two transcriptional start sites 70 and 98 bp upstream of the start codon of spvA, but none upstream of spvB, spvC, or spvD. Deletion of a 320-bp EcoRI-ApaI segment that contains both start sites abolished expression of the downstream spvB and spvC genes. Our results establish a central function of SpvR as a positive regulator of the downstream spvABCD genes in the stationary phase of bacterial growth and indicate that the primary mechanism of regulation is by activation of promoters upstream of spvA.

Base Sequence↗
PubMed1992

Haemorheological parameters in patients with retinal artery occlusion and anterior ischaemic optic neuropathy.

The haemorheological parameters haematocrit (Hct), plasma viscosity (PV), red cell aggregation (RCA), red cell filterability (RCF), apparent whole blood viscosity (WBV), and fibrinogen were measured in 31 patients with retinal artery occlusion (RAO), 25 patients with anterior ischaemic optic neuropathy (AION), and 19 patients with giant cell arteritis (GCA). The patient groups were compared with controls of same age and similar prevalence of cardiovascular risk factors. Patients with RAO and AION have a significantly decreased RCF in comparison with controls. All other parameters showed no differences. Patients with GCA had significantly decreased Hct and RCF and increased PV and fibrinogen. After 2 weeks of systemic treatment with high dose steroids in patients with GCA the plasma viscosity had returned to normal and was even lower than in controls, and the Hct and fibrinogen had reached normal levels.

Adult↗
PubMed1992

Functional conservation of nematode and vertebrate myogenic regulatory factors.

The Caenorhabditis elegans protein, CeMyoD, is related to the vertebrate myogenic regulatory factors MyoD, myogenin, MRF-4 and Myf-5. Like its vertebrate counterparts, CeMyoD accumulates in the nucleus of striated muscle cells prior to the onset of terminal differentiation. CeMyoD also shares functional similarities with the vertebrate myogenic regulatory factors. Viral LTR driven expression of CeMyoD in mouse 10T1/2 cells can convert this cell line into myoblasts as well as efficiently trans-activate mouse muscle-specific promoters. Furthermore, mouse MyoD expression can activate a CeMyoD-beta-galactosidase reporter construct in a 10T1/2 co-transfection assay.

Amino Acid Sequence↗
PubMed1992

[application of electromyography (EMG) in recognition of lumbo-sacral back pain].

Power spectra of electromyograms (EMG) of back muscles in the lumbo-sacral area were compared in two groups of subjects. In the first one EMGs were registered in 49 young, healthy, males working in standing posture. The recordings were carried out at rest, after application of a 20 kg load and at the onset of pain. In the second group 31 subjects of both sexes and different age, suffering from intense back pain of various etiology, were investigated and compared with a group of 15 healthy persons. In the first group the power level increased after the loading, and in 42 subjects it showed further rise when the pain appeared. In the second group the power level at the range of 25 to 400 Hz, at rest, was significantly higher in the back pain patients than in healthy subjects. The results are discussed from the point of view of their applicability for the diagnosis of back pain.

Adult↗
PubMed1992

The influence of peripheral nerve graft's predegeneration stage on the regrowth of hippocampal injured neurites and concomitant changes in submicrosomal fraction proteins of grafts.

The present work has a twofold aim: 1. To ascertain whether the stimulative influence of peripheral nerve grafts on injured hippocampal neurons depends on the time lapse after transection and; 2. To examine whether the mentioned effect runs parallel to the time-dependent changes of proteins contents and composition in the submicrosomal fraction from transected rat sciatic nerves. Fluorescence microscope examination revealed that FITC-HRP labeled cells extending their neurites into the implanted peripheral nerve segments were particularly numerous among the hippocampal neurons when 7- and 35-day-old predegenegated distal stumps were used as grafts. Discontinuous SDS-slab polyacrylamide gel electrophoresis of submicrosomal fraction proteins obtained from distal stumps of rat sciatic nerves was performed at the 7, 14, 21 and 35 days after transection. Among the obtained protein fractions the most interesting seem to be the ones of 47 and 54 kDa, which reached maximal levels at the 7th day and the 50 kDa fraction with a maximum at the 35th experimental day. It is possible that the growth promoting power of the employed grafts depends on the presence of proper proteins.

Animals↗