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Biomedical subjects

O Meyer

Publications and source records attributed to O Meyer.

At least 307 records · Page 17Linked to original sources
PubMed1984

[Determination of anti dsDNA antibodies by immunofluorescence using Crithidia luciliae. I--Diagnostic and prognostic value in systemic lupus erythematosus. Comparison with the Farr radioimmunoassay].

Antibodies to double stranded (ds) DNA were sought by the indirect immunofluorescence method using Crithidia luciliae in 196 sera from patients suffering from hepatic, thyroid or inflammatory rheumatic disorders. Anti ds DNA antibodies were demonstrated in 29 out of 45 systemic lupus erythematosus (SLE) sera. Lower titers were found in 3 out of 7 sera from drug-induced SLE, 2 out of 6 from mixed connective tissue diseases, 1 out of 60 from scleroderma, 2 from unclassified arthritis, 8 out of 40 from rheumatoid arthritis with antinuclear factors, and in 4 out of 15 sera from chronic hepatitis. For SLE diagnosis the sensitivity of the method was 73 percent, its specificity was 87 percent. 84 percent of these results were in agreement with those obtained with the Farr method, but titers did not correlate well. The sensitivity of the Farr method was 64.5 percent, its specificity was 85 percent. In this study, high titers of anti ds DNA antibodies demonstrated on Crithidia Luciliae did not correlate with disease severity. Low titers of anti14C labelled DNA antibodies demonstrated by the Farr assay correlated with inactive SLE without nephritis. The immunofluorescence assay using Crithidia luciliae is a valid method to detect anti ds DNA antibodies but does not allow prognostic conclusions in SLE.

Animals↗
PubMed1984

[Levels of anti-nDNA using immunofluorescence on Crithidia luciliae. II. Prognostic value of complement-fixing anti-nDNA. Longitudinal study of 16 lupus disorders].

Measurements of the hemolytic complement level and titrations of anti dS DNA antibodies by immunofluorescence using Crithidia luciliae and by the Farr binding assay were performed in 13 females and 3 males suffering from systemic lupus erythematosus (SLE). In each patient, 2 to 5 serum samples were analyzed during a mean follow up time of 16.6 months. The complement fixing ability of the anti dS DNA antibodies was also investigated. In this longitudinal study the titers of the dS DNA antibodies detected by immunofluorescence correlated with the Farr binding assay results. Mean anti dS DNA antibody titers were significantly higher and CH 50 levels were lower when SLE was active. Among sera with anti dS DNA antibodies, only sera with high titers (greater than or equal to 1/80), fixed complement. Study of individual cases disclosed that an increase in complement fixing anti dS DNA antibodies could occur in the absence of disease activity. Sera from patients with severe organ involvement, in particular with nephritis had low titers of anti dS DNA antibodies with no complement fixation activity. There was no relationship between falls in serum complement level and the complement fixation ability of anti dS DNA antibodies. Thus, complement fixation capacity of anti dS DNA antibodies correlates better with antibody titer than with SLE severity or activity.

Adult↗
PubMed1984

[IgG-type antihistone antibodies. Diagnostic value in rheumatoid polyarthritis, scleroderma, spontaneous and drug-induced lupus].

IgG anti-histone antibodies were detected by indirect immunofluorescence in 6 out of 70 sera from rheumatoid arthritis with antinuclear factors, in 1 out of 13 from scleroderma, in 14 out of 25 from spontaneous systemic lupus erythematosus (SLE) and in 11 out of 14 from drug induced lupus. Rheumatoid arthritis patients with IgG anti-histone antibodies were characterized by the severity of joint involvement and by the high frequency of extraarticular features of the disease. SLE patients with anti-histone antibodies only differed from patients without such antibodies by a higher frequency of Raynaud phenomenon (p less than 0.05). Longitudinal studies of spontaneous SLE showed that IgG anti-histone antibodies correlated with disease activity (p less than 0.001). A significant correlation was demonstrated between anti-histone IgGs and anti-ds-DNA antibodies assessed by the Farr binding assay (p less than 0.0001). IgG anti-histone antibodies were rarely found in sera from patients with drug induced antinuclear antibodies without symptoms of SLE (1 out of 6 sera). In drug induced lupus, IgG anti-histone antibodies were found in the absence of high titers of anti-ds-DNA antibodies, and this discrepancy appeared to suggest the diagnosis of drug induced lupus. Finally, anti-histone antibodies were present in 5 out of 7 sera from acebutolol induced lupus.

Aged↗
PubMed1984

[The evaluation of anti-native dna antibodies. Comparison of two methods of dosage, study of reproducibility, and diagnostic value of each method].

The duplicatibility of dosing anti-native (double-stranded) DNA antibodies using Farr's radioimmunological method (RIE) and indirect immunofluorescence on Crithidia luciliae (IF-CL) has been demonstrated in the literature and from a multicenter study undertaken in 10 immunological laboratories. The duplicatibility of tests run at the same time and also between tests done at different intervals by RIE in our laboratory was better than that by IF-CL. The coefficients of maximum change were respectively 3% (variation in results during one run of the test), and 6% (variation in results between different runs of the test) for the RIE method and 34% (variation during one run) and 38% (variation between different runs) using the IF-CL method. This multicenter study showed that the duplicatibility of Farr's radioimmunological test was good among the different laboratories, only antibody levels near the upper limit of normal giving some discordant results were found in 91%, the discordant results being due to falsely-positive or falsely-negative tests, and sometimes also to the differing affinity of the anti-native DNA antibodies in the two methods. The sensitivity of both methods in making a diagnosis of systemic lupus erythematosus from the literature varies from 60 to 98% for the RIE method and from 44 to 98% for the IF-CL method. The predictive value of a positive test between these two methods varies from 65 to 100% depending on the series, which means that there are other conditions than systemic lupus erythematosus (SLE) (rheumatoid arthritis, Sjögren's syndrome, hepatitis...) where anti-native DNA antibodies can be found.

Adult↗
PubMed1984

Animal feeding study with nitrite-treated meat.

In order to detect possible formation of carcinogenic N-nitroso compounds from nitrite and nitrosatable compounds in meat, studies were carried out with 70 male and 140 female F0 rats, divided into six groups, and 60, 100, 70, 60, 60 and 66 of their male and female offspring. One control group received casein and other groups chopped pork as the sole protein source (45%, mass/mass) on a fresh basis, either salted (sodium chloride) or not. For test groups, nitrite was also added to the meat before autoclaving and storing the diet and represented mass fractions of 200, 1 000 and 4 000 mg/kg, as sodium nitrite. The results do not demonstrate any effect on reproduction and no significant carcinogenic effect was revealed. However, an observed tendency toward an increased number of tumour-bearing rats in the highest dose group, plus the possible formation of carcinogenic N-nitroso compounds in nitrite-treated meat products, led to a recommendation to reduce the use of nitrite. Results from a concomitant study demonstrate that it is possible to produce many cured-meat products with the addition of only 50 mg/kg nitrite.

Animal Feed↗
PubMed1984

[Changes in vascular endothelial cells induced by serum from scleroderma and other connective tissue diseases].

The growth inhibition of in vitro vascular endothelial cell cultures by sera from patients with connective tissue disease was studied. Seven out of 30 sera from patients with progressive systemic sclerosis (PSS) exhibited a cytotoxic effect. The cytotoxic serum factor(s) was not specific to patients with symptoms (11 out of 27 sera from patients with a mixed connective tissue disease, MCTD; 5 out of 34 sera from patients with a systemic lupus erythematosus, SLE). The cytotoxic effect was not specific for vascular endothelial cells, it was also found on fibroblast cells cultures. Inhibitor(s) of cell growth in vitro was independent of antinuclear and anticytoplasmic antibodies and appeared as a common feature of all connective tissue disease with vascular symptoms.

Cells, Cultured↗
PubMed1983

Studies by e.p.r. spectroscopy of carbon monoxide oxidases from Pseudomonas carboxydovorans and Pseudomonas carboxydohydrogena.

E.p.r. spectra were obtained at 8-120 K for carbon monoxide oxidases isolated from the carboxydotrophic bacteria Pseudomonas carboxydovorans and Pseudomonas carboxydohydrogena. Spectra from the two enzymes are extremely similar to one another. Under appropriate conditions each enzyme shows signals from Mo(V) atoms in two different chemical environments, as well as showing signals from two distinct iron-sulphur centres, presumed to be [2Fe-2S] clusters, and weak FADH X free-radical signals. Parameters of most of the signals were measured, and they show considerable similarities to those of the corresponding signals from xanthine oxidase and related enzymes. Though the signals from carbon monoxide oxidases appear and disappear under reducing and oxidizing conditions, we have so far failed to demonstrate the kinetic competence of any of them. It seems likely that this was due to the presence in the enzyme preparation examined of high amounts of desulpho carbon monoxide oxidase together with another non-functional form of the enzyme giving a stable 'Resting' Mo(V) e.p.r. signal.

Aldehyde Oxidoreductases↗
PubMed1983

Carbon monoxide-insensitive respiratory chain of Pseudomonas carboxydovorans.

Experiments employing electron transport inhibitors, room- and low-temperature spectroscopy, and photochemical action spectra have led to a model for the respiratory chain of Pseudomonas carboxydovorans. The chain is branched at the level of b-type cytochromes or ubiquinone. One branch (heterotrophic branch) contained cytochromes b558, c, and a1; the second branch (autotrophic branch) allowed growth in the presence of CO and contained cytochromes b561 and o (b563). Electrons from the oxidation of organic substrates were predominantly channelled into the heterotrophic branch, whereas electrons derived from the oxidation of CO or H2 could use both branches. Tetramethyl-p-phenylenediamine was oxidized via cytochromes c and a exclusively. The heterotrophic branch was sensitive to antimycin A, CO, and micromolar concentrations of cyanide. The autotrophic branch was sensitive to 2-n-heptyl-4-hydroxyquinoline-N-oxide, insensitive to CO, and inhibited only by millimolar concentrations of cyanide. The functioning of cytochrome a1 as a terminal oxidase was established by photochemical action spectra. Reoxidation experiments established the functioning of cytochrome o as an alternative CO-insensitive terminal oxidase of the autotrophic branch.

Carbon Monoxide↗
PubMed1983

[Significance of anti-centromere antibodies. Clinical value].

The authors report 38 cases of patients with antinuclear antibodies directed against the centromere of the chromosomes. These were 32 cases of scleroderma, 2 cases of Raynaud's syndrome, 2 cases of rheumatoid arthritis, 1 case of polymyositis and 1 case of disseminated lupus erythematosus. In the cases of scleroderma, anti-centromere antibodies were detected in 54 p. cent of cases of Crest syndrome, for which they are a good laboratory marker; they were found more rarely in case of sclerodactyly (26 p. cent of cases) and acrosclerosis (14 p. cent of cases) and not at all in cases of localized scleroderma, diffuse scleroderma or eosinophilic fasciitis. Anti-centromere antibodies may be the only antinuclear antibodies in these patients. They can be detected using rapidly dividing cell cultures.

Adult↗
PubMed1983

[Significance of reduced complement level in the articular fluid. 81 cases].

Based on their own experience, the authors report that a fall in the complement level of joint fluid, which is particularly common in rhumatoid arthritis, is also seen in cases of systemic lupus eryrthematosis and a variety of arthritis: infectious arthritis, gout, articular chondrocalcinosis and psoriatic rheumatism. This should be taken into account when evaluating the diagnostic value of this test in rheumatoid arthritis.

Arthritis, Infectious↗
PubMed1983

[Anti-collagen antibodies. Their detection in rheumatoid polyarthritis, chronic atrophic polychondritis and various chronic inflammatory rheumatism].

The authors administered by passive haemagglutination, natural or denatured type I and II anticollagen antibodies in the serum of 83 rheumatoid polyarthritis, 20 ankylosing spondylarthritis, 30 relapsing polychondritis, 13 diffuse sclerodermics, 12 Gougerot-Sjögren syndrome patients. Type II natural anti-collagen antibodies are common in relapsing polychondritis (37 percent). They are rarer in rheumatoid polyarthritis (15 percent) and the frequency is identical to that found in patients suffering from gonarthrosis and coxarthrosis. Natural type II anti-collagen antibodies may be occur in etiopathogenesis of relapsing polychondritis. Denatured II ant-collagen antibodies are common during ankylosing spondylarthritis (35 percent) and diffuse sclerodermia, and are found in rheumatoid polyarthritis (23 percent) and in Gougerot Sjögren syndrome (25 percent). They possibly play a pathological role in these diseases although this has not been proved. They are detected almost as often in the synovial fluid of inflammatory rheumatisms (53 percent) and in gonarthrosis (41 percent).

Adult↗
PubMed1982

[Anticentromere antibodies. Diagnostic and prognostic value].

The results of investigations for antinuclear antibodies in scleroderma and other connective diseases are reported. An indirect fluorescence method on Hep-2 cell smears was used. Antibodies directed against chromosomal centromeres were detected in 25 cases: 19 sera of patients with diffuse scleroderma, 2 cases of Raynaud's disease, 2 cases of rheumatoid arthritis and 1 case each of lupus and dermatomyositis. A significant correlation was found between the presence of anticentromere antibodies and benign forms of scleroderma, notably the CREST syndrome.

Antibodies, Antinuclear↗
PubMed1982

[Mechanisms and prognosis of neutropenia in Felty's syndrome. 27 cases (author's transl)].

Twenty patients with Felty's syndrome were investigated. Isotopic studies of polymorphonuclear neutrophils, bone marrow biopsies and autoradiographies, and cultures of granulous stem cells showed that neutropenia resulted from three mechanisms acting simultaneously: hypermargination of the neutrophils predominantly in the spleen, decreased production of granulocytes in the bone marrow, and peripheral hyperdestruction of the neutrophils. Anti-granulocyte antibodies were detected in 3/12 patients. Other factors present in the serum of 2/4 patients seem capable of inhibiting the growth of granulocytic stem cells. Secondary bacterial infection (77%) may explain the severity of the prognosis: 13 out of 27 patients died 4 years on average after neutropenia was diagnosed.

Agranulocytosis↗