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Biomedical subjects

O Meyer

Publications and source records attributed to O Meyer.

At least 235 records · Page 13Linked to original sources
PubMed1990

Chronic ethanol intake and reduction of lung tumours from urethane in strain A mice.

Combinations of ethanol and urethane were added to the drinking-water of female strain A/Ph mice for 12 wk, at the end of which the animals were killed. Urethane concentrations were 0, 200, 500 and 1000 ppm and ethanol concentrations, 0, 5, 10 and 20% (v/v). All possible combinations of these urethane and ethanol concentrations were tested. Urethane induced primary lung adenomas in all treated mice in a dose-dependent manner. An average of 71 +/- 15 tumours/mouse were found, when the animals were killed, after treatment with 1000 ppm urethane for 12 wk. Ethanol alone did not alter the background incidence of tumours and produced only marginal hepatotoxicity. The tumour yields induced by urethane treatment were greatly reduced by simultaneous treatment with ethanol. The effect of ethanol was independent of urethane dose. When the concentrations of ethanol in the drinking-water were 20 and 10% the incidences of lung adenomas induced by urethane were reduced by about two-thirds and one-half, respectively. The effect of 5% ethanol, if any, was not statistically significant.

Adenoma↗
PubMed1990

Degradation of vinyl acetate by soil, sewage, sludge, and the newly isolated aerobic bacterium V2.

Vinyl acetate is subject to microbial degradation in the environment and by pure cultures. It was hydrolyzed by samples of soil, sludge, and sewage at rates of up to 6.38 and 1 mmol/h per g (dry weight) under aerobic and anaerobic conditions, respectively. Four yeasts and thirteen bacteria that feed aerobically on vinyl acetate were isolated. The pathway of vinyl acetate degradation was studied in bacterium V2. Vinyl acetate was degraded to acetate as follows: vinyl acetate + NAD(P)+----2 acetate + NAD(P)H + H+. The acetate was then converted to acetyl coenzyme A and oxidized through the tricarboxylic acid cycle and the glyoxylate bypass. The key enzyme of the pathway is vinyl acetate esterase, which hydrolyzed the ester to acetate and vinyl alcohol. The latter isomerized spontaneously to acetaldehyde and was then converted to acetate. The acetaldehyde was disproportionated into ethanol and acetate. The enzymes involved in the metabolism of vinyl acetate were studied in extracts. Vinyl acetate esterase (Km = 6.13 mM) was also active with indoxyl acetate (Km = 0.98 mM), providing the basis for a convenient spectrophotometric test. Substrates of aldehyde dehydrogenase were formaldehyde, acetaldehyde, propionaldehyde, and butyraldehyde. The enzyme was equally active with NAD+ or NADP+. Alcohol dehydrogenase was active with ethanol (Km = 0.24 mM), 1-propanol (Km = 0.34 mM), and 1-butanol (Km = 0.16 mM) and was linked to NAD+. The molecular sizes of aldehyde dehydrogenase and alcohol dehydrogenase were 145 and 215 kilodaltons, respectively.

Acetates↗
PubMed1990

Streptomyces thermoautotrophicus sp. nov., a Thermophilic CO- and H(2)-Oxidizing Obligate Chemolithoautotroph.

The novel thermophilic CO- and H(2)-oxidizing bacterium UBT1 has been isolated from the covering soil of a burning charcoal pile. The isolate is gram positive and obligately chemolithoautotrophic and has been named Streptomyces thermoautotrophicus on the basis of G+C content (70.6 +/- 0.19 mol%), a phospholipid pattern of type II, MK-9(H(4)) as the major quinone, and other chemotaxonomic and morphological properties. S. thermoautotrophicus could grow with CO (t(d) = 8 h), H(2) plus CO(2) (t(d) = 6 h), car exhaust, or gas produced by the incomplete combustion of wood. Complex media or heterotrophic substrates such as sugars, organic acids, amino acids, and alcohols did not support growth. Molybdenum was required for CO-autotrophic growth. For growth with H(2), nickel was not necessary. The optimum growth temperature was 65 degrees C; no growth was observed below 40 degrees C. However, CO-grown cells were able to oxidize CO at temperatures of 10 to 70 degrees C. Temperature profiles of burning charcoal piles revealed that, up to a depth of about 10 to 25 cm, the entire covering soil provides a suitable habitat for S. thermoautotrophicus. The K(m) was 88 mul of CO liter and V(max) was 20.2 mul of CO h mg of protein. The threshold value of S. thermoautotrophicus of 0.2 mul of CO liter was similar to those of various soils. The specific CO-oxidizing activity in extracts with phenazinemethosulfate plus 2,6-dichlorophenolindophenol as electron acceptors was 246 mumol min mg of protein. In exception to other carboxydotrophic bacteria, S. thermoautotrophicus CO dehydrogenase was able to reduce low potential electron acceptors such as methyl and benzyl viologens.

Journal Article↗
PubMed1990

Longitudinal immunoblotting variations of auto-antibody reactivity of patients with systemic lupus erythematosus.

The purpose of this study was to examine longitudinally the different patterns of nuclear and cytoplasmic antigen recognition by sera from patients with SLE during clinical flare and remission using immunoblotting (IB) techniques. Serum samples (n = 150) were obtained from 35 SLE patients during a follow-up period averaging 4.7 years. Three patients (10 sera) were in complete remission: the IB pattern of these 3 patients remained unchanged; 32 SLE patients experienced one or more clinical flares: in 5 cases (20 sera) the IB analysis showed no detectable antibody. The following dominant IB patterns were seen in the remaining 27 active SLE patients: anti-Sm (n = 7), anti-Sm/RNP (n = 7), anti-SS-B and/or anti-Ro (n = 6), anti-histones (n = 5), anti-70 Kd (unidentified) (n = 2). No IB pattern was able to differentiate mild forms of SLE from severe cases. In 9 of 21 clinical flares, the serum IB pattern was not different from that of the patient's serum drawn during remission (3 severe and 6 mild flares). Diversity of the antibodies increased in 7 cases (5 severe, 2 mild flares); and a shift from one pattern to another was observed 5 times (2 severe, 3 mild flares). Twenty three subsequent remissions were studied: in 14 cases the IB profile was unmodified (5 severe, 9 mild SLE), and the diversity of the antibody narrowed in 4 cases (2 severe, 2 mild SLE). The IB pattern shifted from one pattern to another (2 severe, 4 mild SLE) in 5 instances.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[Profile of antinuclear antibodies in 14 cases of extinct systemic lupus erythematosus for more than 3 years].

In order to study the profile of antinuclear antibodies (ANA) and anticytoplasm in the clinical recovery period, we searched for ANA by 4 methods (indirect immunofluorescence on HEp-2 and Crithidia luciliae cells, double diffusion in agar against veal thymus and human spleen, immunoprint with a total extract of HeLa cells) in 14 patients with SLE extinct since more than 3 years. The population under study consisted of 12 women and 2 men, aged 43 years on average at the time of study (extremes: 28-64 years). The average lapse of time between the diagnosis of SLE and date of sampling is of 12.6 years (extremes: 3-22 years). The average remission/clinical recovery time during the study is of 8.9 years (extremes: 3-22 years). Seven patients were administered mild corticotherapy (average dose of prednisone: 4.7 mg/day). All the sera preserved ANA or anticytoplasm, distributed in the following way: presence of antinucleus: 10/14 (71.5%); average titre 40; speckled aspect: 10/10; presence of anti-DNA: 0/14; presence of anti-ECT: 2/14 (14.3%): anti-SSB 1 case, anti-RNP 1 case; positive immunoprint: 12/14 (85.7%): anti-Sm 5 cases (isolated or associated), isolated anti-SSB 2 cases; isolated anti-Ro 2 cases; various unidentified 3 cases. These results suggest that the production of ANA and anticytoplasm other than anti-DNA continues during the period of clinical extinction of SLE, underlining the rarity of a complete biological recovery and the necessity of long term clinical surveillance.

Adult↗
PubMed1990

[Clinico-biological classification of systemic lupus].

Anti-nuclear and anti-cytoplasmic antibodies are found in nearly 99% of systemic lupus erythematosus (SLE) patients. Among the different antibodies described, 2 are highly specific for SLE although their frequencies differ considerably. Anti-dsDNA (anti-native DNA) antibodies are detected at some point during disease evolution in 65-95% of the patients, whereas anti-Sm antibodies occur in only 7-30% of the cases, with wide variations according to race and geographical origin. The present study attempts to correlate specific clinical manifestations as a function of certain antibodies: SLE with anti-U1 RNP, with or without anti-dsDNA; SLE with anti-histones; SLE with anti-Ro (SS-A); SLE with anti-phospholipid antibodies or anti-type 5 mitochondrial antibodies; and SLE with anti-ribosomal antibodies. The diversity of these clinical-biological subgroups tends to imply that SLE is a syndrome rather than a distinct disease state.

Antibodies, Antinuclear↗
PubMed1989

[Methods for determining antinuclear antibodies and their clinical significance].

Antinuclear antibodies are directed against different nuclear antigens such as deoxyribonucleic acid, ribonucleic acid, nucleoproteins, histones and non-histones-antigens. The importance of ANAs in the characterization of different systemic rheumatic diseases, e.g. autoimmune diseases, has been recognized. The most commonly used assay for ANAs is indirect immunofluorescence. Several methods, such as radioimmunoassays, double immunodiffusion in agarose gel, counterimmunoelectrophoresis or immunoblotting, have been developed and serve to identify antibodies of different specificities. This overview describes the clinical importance of ANAs with reference to the methods of detection. The immunologic diagnosis aspect of different autoimmune and collagen diseases is presented.

Antibodies, Antinuclear↗
PubMed1989

Homology and distribution of CO dehydrogenase structural genes in carboxydotrophic bacteria.

The 17 (S), 30 (M) and 87 kDa (L) subunits of CO dehydrogenases from the CO-oxidizing bacteria Pseudomonas carboxydoflava, Pseudomonas carboxydohydrogena and Pseudomonas carboxydovorans OM5 were isolated and purified. The N-terminal sequences of same subunits from different bacteria showed distinct homologies. Dot blot hybridization employing oligonucleotide probes derived from the sequences of the S-subunit of P. carboxydovorans OM5 and the M-subunit of P. carboxydohydrogena and DNA of the plasmid-containing CO-oxidizing bacteria Alcaligenes carboxydus, Azomonas B1, P. carboxydoflava, P. carboxydovorans OM2, OM4 and OM5 indicated that all genes encoding these subunits reside on plasmids. That in P. carboxydovorans OM5 CO dehydrogenase structural genes are located entirely on plasmid pHCG3 was evident from the absence of hybridization employing DNA from the cured mutant strain OM5-12. CO dehydrogenase structural genes could be identified on the chromosome of the plasmid-free bacteria Arthrobacter 11/x, Bacillus schlegelii, P. carboxydohydrogena and P. carboxydovorans OM3. There was no example of a plasmid-harboring carboxydotrophic bacterium that did not carry CO dehydrogenase structural genes on the plasmid. The N-terminal sequences of CO dehydrogenase structural genes were found to be conserved among carboxydotrophic bacteria of distinct taxonomic position, independent of the presence of plasmids. It is discussed whether this might be the consequence of horizontal gene transfer.

Alcaligenes↗
PubMed1989

Recurrent thrombosis and renal vascular disease in patients with a lupus anticoagulant.

In five patients suffering from recurrent thrombosis and/or fetal death, a lupus anticoagulant was associated with a renal vasculopathy. Ischaemic episodes also involved the skin, heart, eyes and/or central nervous system. All patients were hypertensive. Two had renal insufficiency, two had non-nephrotic proteinuria, and in the last patient renal cortical ischaemia was detected by a tomographic scan in the absence of proteinuria. Renal biopsy showed thrombosis and/or intimal fibrosis of intrarenal vessels, and normal or ischaemic glomeruli without proliferative lesions. High-titres of anticardiolipin antibodies were found in 3 of 3 cases, and persisted after steroid therapy even if the circulating anticoagulant factor disappeared. All patients received corticosteroid therapy, alone or in combination with immunosuppressive drugs; two patients had prolonged oral anticoagulation, but thrombotic episodes recurred after stopping the drug. One patient died; the remaining four survived 18 months to 11 years after diagnosis, with stable chronic renal insufficiency in one of them. These results show that a lupus anticoagulant may be associated with prominent renal vascular disease, in the absence of proliferative glomerular lesions, and suggest that continuous anticoagulation may be beneficial in these patients.

Adult↗
PubMed1989

[The effect of ivermectin on reactivated somatic larva of Ancylostoma caninum Ercolani 1859 (Ancylostomidae) in the pregnant dog].

It was evaluated by means of a controlled test to what extent reactivated larvae of Ancylostoma caninum were influenced by single or double treatment with ivermectin. The investigations were done with a total of ten experimentally infected bitches. The single treatment of dams two to ten days ante partum with 0.5 mg or 1 mg ivermectin per kg bodyweight reduced the wormburden of their puppies on an average by 96.6% and 98.5%, respectively. The double treatment with 0.5 mg/kg bodyweight ante and post partum each with an interval of ten days completely prevented lactogenic infections with Ancylostoma caninum. Following a single application of 0.5 mg ivermectin per kg bodyweight the excretion of larvae was markedly delayed and remained on a low level. In addition the infections of the puppies of single treated dams became patent on an average 9.5 and 14.5 days later than the controls. In the bitches no side-effects, neither local nor general, were seen after the treatment with ivermectin. All forty puppies of the treated bitches were born without visible damages.

Ancylostoma↗
PubMed1989

Removal of CO dehydrogenase from Pseudomonas carboxydovorans cytoplasmic membranes, rebinding of CO dehydrogenase to depleted membranes, and restoration of respiratory activities.

In Pseudomonas carboxydovorans, CO dehydrogenase and hydrogenase were found in association with the cytoplasmic membrane in a weakly bound and a tightly bound pool. The pools could be experimentally distinguished on the basis of resistance to removal by washes in low-ionic-strength buffer. The tightly bound pool of the enzymes could be differentially solubilized under conditions leaving the electron transport system intact and with the nondenaturing zwitterionic detergent 3-(3-cholamidopropyl) dimethylammonio 1-propane-sulfonic acid (CHAPS) and the nonionic detergent dodecyl beta-D-maltoside. In vitro reconstitution of depleted membranes with the corresponding supernatants containing CO dehydrogenase led to binding of the enzyme and to reactivation of respiratory activities with CO. The reconstitution reaction required cations with effectiveness which increased with increasing ionic charge: monovalent (Li+), divalent (Mg2+, Mn2+), or trivalent (Cr3+, La3+). Reconstitution of depleted membranes with CO dehydrogenase was specific for CO-grown bacteria. Cytoplasmic membranes from H2- or heterotrophically grown Pseudomonas carboxydovorans had no affinity for CO dehydrogenase at all, indicating the absence of the physiological electron acceptor of the enzyme, which presumably is cytochrome b561, or another membrane anchor.

Aldehyde Oxidoreductases↗
PubMed1989

Anti-Scl-70 antibodies detected by immunoblotting in progressive systemic sclerosis: specificity and clinical correlations.

One hundred and forty five serum samples from patients with a connective tissue disease and 30 serum samples from healthy blood donors were analysed by immunoblotting. The presence of anti-Scl-70, which seems to discriminate between progressive systemic sclerosis (PSS) and the CREST (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia) syndrome, was found in 31/64 (48%) patients with PSS, in 6/55 (11%) patients with systemic lupus erythematosus, in 2/26 (8%) patients with mixed connective tissue disease, and in none of 30 healthy blood donors. These data resulted in a specificity of 93% for this antibody in systemic sclerosis. For patients with PSS the duration of disease was significantly shorter in those with anti-Scl-70 antibodies than in those without, whereas the presence of anti-Scl-70 did not correlate with severity of disease. An 82% prevalence of anticentromere antibodies in patients with the CREST variant compared with a 4% prevalence in patients with PSS or with overlap syndrome confirms the high diagnostic value of this autoantibody for the CREST variant of PSS.

Aged↗