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Biomedical subjects

A Winkler

Publications and source records attributed to A Winkler.

At least 73 records · Page 4Linked to original sources
PubMed1994

Cloning, nucleotide sequence, and expression of the Bacillus subtilis lon gene.

The lon gene of Escherichia coli encodes the ATP-dependent serine protease La and belongs to the family of sigma 32-dependent heat shock genes. In this paper, we report the cloning and characterization of the lon gene from the gram-positive bacterium Bacillus subtilis. The nucleotide sequence of the lon locus, which is localized upstream of the hemAXCDBL operon, was determined. The lon gene codes for an 87-kDa protein consisting of 774 amino acid residues. A comparison of the deduced amino acid sequence with previously described lon gene products from E. coli, Bacillus brevis, and Myxococcus xanthus revealed strong homologies among all known bacterial Lon proteins. Like the E. coli lon gene, the B. subtilis lon gene is induced by heat shock. Furthermore, the amount of lon-specific mRNA is increased after salt, ethanol, and oxidative stress as well as after treatment with puromycin. The potential promoter region does not show similarities to promoters recognized by sigma 32 of E. coli but contains sequences which resemble promoters recognized by the vegetative RNA polymerase E sigma A of B. subtilis. A second gene designated orfX is suggested to be transcribed together with lon and encodes a protein with 195 amino acid residues and a calculated molecular weight of 22,000.

ATP-Dependent Proteases↗
PubMed1994

[Not Available].

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Austria↗
PubMed1993

Cloning and characterization of heat-inducible promoters of Bacillus subtilis.

Heat-inducible DNA fragments of Bacillus subtilis were cloned with two different promoter probe vectors. The increased synthesis of the reporter enzymes seemed to be due to a transient increase in the transcription of the encoding genes. The structure of the heat-sensitive promoters resembles the consensus sequence of promoters recognized by the vegetative form of RNA polymerase of B. subtilis. Our results support data in literature that the heat shock response of B. subtilis is regulated by a different mechanism than in Escherichia coli, where alternative sigma factors direct the transcription of heat shock genes.

Bacillus subtilis↗
PubMed1992

Fotemustine plus dacarbazine in advanced stage III malignant melanoma.

19 patients with advanced malignant melanoma were treated with fotemustine and dacarbazine. Data recorded and available for evaluation in all patients included clinical and histopathological parameters of the primary melanoma, blood chemistry, blood cell count, chest X-ray, ultrasound and bone scan for initial staging of the site of metastases and follow-up during treatment. Dosage was fotemustine 100 mg/m2 and dacarbazine 200 mg/m2 intravenously twice monthly on days 1 and 8, repeated for a maximum of six courses. There were two complete and three partial responses in 5/19 patients (26%), and 8 patients (42%) had stable disease. 6 (32%) patients had no response. Median length of complete and partial responses was 3.9 months, and that of stable disease 4.2 months. The main side-effects were thrombocytopenia in 10 patients (53%) and nausea in 6 (32%); the nausea was easily suppressed by ondasetron. Thus, fotemustine-dacarbazine may be new treatment in advanced melanoma.

Adult↗
PubMed1991

Toxicokinetic aspects of chronic cyanide exposure in the rat.

Rats received 40, 80 and 160 mg KCN/kg body wt./24 h in the drinking water for 13 weeks. Fairly constant dose-related cyanide and thiocyanate levels were measured in blood, plasma and urine during the exposure. Blood cyanide concentrations were in the range of 16.0-25.5 nmol CN-/ml blood, thiocyanate concentrations in the range of 341-877 nmol SCN-/ml plasma following continuous administration of the maximum tolerated dose-level of 160 mg/kg body wt/24 h. The results suggest that continuous 13-week maximum tolerated cyanide exposure does not lead to saturation of cyanide detoxification pathways.

Administration, Oral↗
PubMed1991

Antigenic domains on the U1 small nuclear ribonucleoprotein-associated 70K polypeptide: a comparison of regions selectively recognized by human and mouse autoantibodies and by monoclonal antibodies.

Antigenic regions on the U1 small nuclear ribonucleoprotein (snRNP)-associated 70K polypeptide recognized by human and mouse autoantibodies or by monoclonal antibodies were identified and compared. Using a set of 70K fusion proteins as antigen in enzyme-linked immunosorbent assay and immunoblotting revealed that serum autoantibodies of human and of MRL/Mp mouse origin recognized a common region of the 70K polypeptide. Monoclonal anti-70K antibodies derived from a patient with mixed connective tissue disease, from an autoimmune MRL/Mp mouse, and from a BALB/c mouse immunized with purified U1 snRNP were all shown to bind to a part of the 70K polypeptide rich in charged residues and different from the region recognized by most human and MRL/Mp mouse serum autoantibodies.

Animals↗
PubMed1990

Ammonia absorption from the isolated reticulo-rumen of sheep.

In fistulated sheep (50-60 kg live weight) the absorption of ammonia from the reticulo-rumen in vivo was studied applying the technique of the temporarily isolated and washed reticulo-rumen. It was found that, at ammonia concentrations between 3 and 18 mM, ammonia efflux and ammonia net absorption were linearly related to the ammonia concentration in the artificial rumen fluid, whereas influx of ammonia nitrogen from endogenous sources remained almost constant. When the concentration of unionized NH3 was changed at the ratio 1:10:76 by varying the pH from 5.8 to 6.8 and 7.7, ammonia net absorption did not reflect the concentration ratio of unionized NH3, indicating either flux of NH4+ ions or titration of NH4+ to NH3 at the absorptive surface. In the experiments with buffer solutions without ammonium salts and extended over 2 h, ammonia concentrations in the artificial rumen fluid increased due to endogenous nitrogen influx and reached levels far beyond the expected plateau concentration of about 2 mM. Labelling of the N pool in the isolated organ by 15N showed that ammonia efflux had almost ceased in these experiments. It is argued that as yet unidentified changes have taken place in the artificial rumen fluid during the experiment, but there is some reason to believe that volatile fatty acid (VFA) absorption was affecting ammonia absorption.

Absorption↗
PubMed1989

The impact of a resident dog on an institution for the elderly: effects on perceptions and social interactions.

A longitudinal case study was made of a sub-unit of a nursing home to examine the perceptions and social interactions of patients and staff after introduction of a resident dog. A behavioral mapping procedure was used to determine staff and patient interactions 6 weeks before and 6 weeks and 22 weeks after the dog's arrival. Interviews were also conducted with patients and staff. Six weeks after the dog's arrival, a significant increase in frequency of interactive behaviors was seen for both staff and patients. By 22 weeks, behaviors for patients had reverted to base-line levels, while remaining high for staff.

Aged↗
PubMed1989

Eosinophilic fasciitis with porphyria cutanea tarda and progressive destructive arthritis.

The course of arthritis with eosinophilic fasciitis is poorly documented. We report a patient in whom polyarthritis preceded the clinical appearance of eosinophilic fasciitis and progressed over a 14-year period to a destructive process with inflammatory and degenerative characteristics. Porphyria cutanea tarda and transient extramedullary pancytopenia complicated this patient's disease.

Arthritis↗
PubMed1988

Monoclonal autoantibody recognizing a unique set of small nuclear ribonucleoprotein complexes.

A murine IgG2a, kappa-monoclonal autoantibody (mAb) F78 is described that recognizes a novel epitope associated with small nuclear ribonucleoprotein complexes (snRNP). F78 selectively immunoprecipitated a unique pattern of small nuclear RNA (U1, U2, and U4 to U6) characterized by a marked depletion of U1 and an elevated proportion of U2 compared with known patterns immunoprecipitated by previously described anti-RNP (2.73) and anti-Sm (7.13, Y12) mAb. Analysis of immunoprecipitated RNA from extracts previously cleared with mAb F78 and probed with anti-RNP mAb 2.73 further indicated the presence of two distinct subsets of U1. Immunoblots of whole cell extracts separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) without heating showed that F78 selectively bound to a trypsin-sensitive component of apparent m.w. greater than 120,000 which was decreased in size following RNase A treatment. The anti-Sm mAb, but not the anti-RNP mAb, also recognized this component in unheated samples. Heating before SDS-PAGE resulted in abrogation of binding to the F78 epitope. Immunoprecipitation of unlabeled or [35S]methionine-labeled cell extracts with F78 revealed the presence of most snRNP peptides, but the absence of peptide C and the 68,000 m.w. component, known to be selectively associated with U1-specific snRNP. Two-dimensional SDS-PAGE analysis of F78 immunoprecipitates confirmed that the epitope recognized by this mAb resides on a heat-dissociable complex containing snRNP-related peptides B, B', D, E, F, and G, but lacking U1-associated peptides. F78 mAb therefore defines a subset of snRNP which lack anti-RNP associated U1 RNA as well as peptides known to be selectively associated with this RNA species. It apparently recognizes an epitope associated with an assembled form of these particles and may be useful in examining structures involved in RNA processing.

Antibodies, Monoclonal↗
PubMed1988

Value and limitations of calcium channel blockade in the treatment of pulmonary hypertension associated with CREST--case reports.

Reversible vasospasm has been hypothesized to underlie the development of pulmonary hypertension in patients with CREST. Drugs that prevent arterial spasm have been used to treat pulmonary hypertension with variable results. The disparate pulmonary hemodynamic responses to calcium channel blockade reported herein suggest that CREST patients with mild pulmonary hypertension may have a component of reversible vasospasm responsive to vasodilator therapy, whereas patients with moderate to severe pulmonary hypertension may have fixed vessel lesions precluding a satisfactory response to calcium channel blockade.

Adult↗
PubMed1987

Cytomegalovirus retinitis in rheumatic disease: a case report.

We describe a 67-year-old white man with Wegener's granulomatosis who was treated with cyclophosphamide, then with azathioprine, and who subsequently developed cytomegalovirus retinitis. The patient initially improved on a course of adenine arabinosine, but his retinitis has progressed, despite discontinuation of immunosuppressive therapy. We show that cytomegalovirus retinitis does occur in patients with rheumatic diseases who receive immunosuppressive therapy.

Adult↗
PubMed1987

Ocular complications of Tangier disease.

Tangier disease, or familial high-density lipoprotein deficiency, is an inherited disorder resulting in tissue deposition of excessive cholesterol esters. Although associated corneal clouding has been reported to produce little visual impairment, this patient with Tangier disease had corneal clouding, decreased corneal sensation, and cicatricial ectropion and experienced slowly progressive marked visual impairment. All ocular cases of Tangier disease are reviewed. Ectropion and incomplete eyelid closure may precede corneal clouding and should be recognized as signs associated with Tangier disease. The combination of exposure keratopathy and corneal infiltration can cause significant visual impairment.

Aged↗