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Biomedical subjects

O Meyer

Publications and source records attributed to O Meyer.

At least 271 records · Page 15Linked to original sources
PubMed1987

Anti-mitochondrial type 5 antibodies and anti-cardiolipin antibodies in systemic lupus erythematosus and auto-immune diseases.

Twenty sera from patients with systemic lupus erythematosus (SLE) and high titre of IgG anti-cardiolipin antibodies (ACA) were studied in order to evaluate the prevalence of anti-mitochondrial type 5 antibodies (AMA 5). None of these sera were found to be AMA 5 positive but five of 18 were positive for VDRL. Twenty sera from patients with AMA 5 were studied in order to evaluate the prevalence of ACA: only six of 20 were positive for ACA. In contrast to this finding, 15 of the 20 sera positive for AMA 5 were also positive for VDRL (P less than 0.001). The six sera positive for ACA and AMA 5 were absorbed with cardiolipin micelles. This absorption eliminated the ACA activity but not the AMA 5 activity. Despite the clinical similarities between the two groups of patients with AMA 5 or ACA, these data suggest that patients with AMA 5 and patients with ACA belong to two different subsets of SLE or SLE-like syndromes and that AMA 5 antigen is different from cardiolipin.

Autoantibodies↗
PubMed1987

[Antiphospholipid antibodies in a series of 25 cases of lupus without antinuclear antibodies. Comparison with a series of 91 lupus patients with antinuclear antibodies].

Twenty-five patients with at least 3 of 1982 ARA criteria of SLE but without the ANA, were compared with 91 patients with 4 or more of the ARA criteria of lupus with positive ANA. The ANA-negative group was characterised by the low incidence of skin involvement, serous effusions and alopecia, and a relatively high incidence of thrombocytopaenia and venous and arterial thrombosis. Three types of antiphospholipid antibodies were looked for: the VDRL, antiprothrombinase and anticardiolipin antibodies by an immuno-enzymatic method. The VDRL was the only antibody which was significantly commoner in the ANA-negative group. Statistical studies showed that the three methods of demonstrating antiphospholipid antibodies detected crossed but not identical specificities. In the ANA-positive group only the antiprothrombinase was associated with a high incidence of venous thrombosis and stroke. In the ANA-negative group, only the anticardiolipin antibodies were associated with a high incidence of arterial or venous thrombosis. Two subgroups may be identified in the group of ANA-negative lupus patients: firstly, those with high anticardiolipin antibody titres with a high incidence of thrombotic and haematological complications, and, secondly, patients with low anticardiolipin antibody levels with a high incidence of cutaneous involvement, serous effusions and Raynaud's phenomenon.

Adolescent↗
PubMed1986

The pterin (bactopterin) of carbon monoxide dehydrogenase from Pseudomonas carboxydoflava.

Radioactively labeled carbon monoxide (CO) dehydrogenase has been obtained in good yield and purity from Pseudomonas carboxydoflava grown in the presence of [32P]phosphate. One enzyme molecule contained an average of 8.32 molecules of phosphate. The entire phosphate content was confined to 2 molecules of FAD and 2 molecules of a pterin. These were noncovalently bound. Molybdoenzyme cofactors could be extracted into N-methyl formamide; pterins were isolated by thin-layer chromatography. CO dehydrogenase contained a novel pterin, different from molybdopterin, which was also resolved in other bacterial molybdoenzymes. Therefore, it was tentatively named bactopterin. The characteristic features of bactopterin were as follows. A relative molecular mass, Mr, of 730 which was much greater than that of molybdopterin (330) (Mr values refer to molybdenum-free forms of the cofactors; presumably, the latter were also devoid of the sulfhydryl groups contained in the native compounds). A content of 2 molecules of phosphate/molecule compared to only 1 phosphate in molybdopterin. Bactopterin was three times less susceptible to air oxidation than molybdopterin. Native bactopterin was cleaved by perchloric acid into two phosphorous-containing fragments with Mr of 330 and 420. The smaller one is believed to be very similar to molybdopterin, the larger one was not a pterin but probably contained an aromatic structure.

Aldehyde Oxidoreductases↗
PubMed1986

Carcinogenicity study on butylated hydroxytoluene (BHT) in Wistar rats exposed in utero.

Groups of 60, 40, 40 and 60 F0 Wistar rats of each sex were fed a semi-synthetic diet containing butylated hydroxytoluene (BHT) in concentrations to provide intakes of 0, 25, 100 or 500 mg/kg body weight/day, respectively. The F0 rats were mated and groups of 100, 80, 80 or 100 F1 rats of each sex were formed from 40, 29, 30 and 44 litters, respectively. After weaning, the highest dose (500 mg BHT/kg/day) was lowered to 250 mg/kg/day for the F1 rats. The numbers of litters of ten or more pups at birth decreased with increasing BHT dose. At weaning, treated F1 rats had lower body weights than the controls, the extent of the reduction being dose related; the effect, which persisted throughout the study, was most pronounced in the males. The survival of BHT-treated F1 rats of both sexes was significantly better than that of the controls. No significant changes attributable to BHT treatment were found in the haematological parameters. F1 females on the highest dose showed an increase in serum cholesterol and phospholipids, and serum triglycerides were reduced in this group in both sexes. Dose-related increases in the numbers of hepatocellular adenomas and carcinomas were statistically significant (at P less than 0.05 or lower) in male F1 rats when all groups together were tested for heterogeneity or analysis for trend. The increase in hepatocellular adenomas and carcinomas in treated female F1 rats was only statistically significant for adenomas (at P less than 0.05) in the analysis for trend. All hepatocellular tumours were detected when the F1 rats were more than 2 yr old. Tumours were found in many other organs of some of the treated rats, but their incidence was not significantly different from that in controls. The role of BHT in the development of hepatocellular tumours requires further elucidation.

Animals↗
PubMed1986

[Anti-keratin antibodies. A marker of progressive rheumatoid arthritis].

Anti-keratin antibodies have been detected by indirect immunofluorescence on rats esophageal sections in 122 rheumatoid polyarthritis, 100 seropositive and 22 seronegative. The frequency of anti-keratin antibodies is 58 p. cent in seropositive rheumatoid polyarthritis and 41 p. cent in seronegative rheumatoid polyarthritis. Anti-keratin antibodies have a very good specificity (96 p. cent) for rheumatoid polyarthritis since in a group of 105 controls, only 4 sera were found to have a low titre of anti-keratin antibodies (1 ankylosing spondyloarthritis, 2 sclerodermis, 1 healthy subject). The mean titre of antikeratin antibodies is higher in seropositive rheumatoid polyarthritis than in seronegative rheumatoid polyarthritis. Within seropositive rheumatoid polyarthritis, the titre of anti-keratin antibodies is correlated with the titre of rheumatoid factors determined by the latex test (r' = 0.464, p less than 0.01). The presence of anti-keratin antibodies is correlated with the degree of functional handicap evaluated by the functional index of Steinbrocker (p less than 0.02) and with the biological evolution evaluated by the sedimentation rate (p less than 0.001). No correlation was found with accidents of intolerance to fundamental treatments (gold salts, D-penicillamine), especially skin diseases. Anti-keratin antibodies represent therefore a diagnostic marker for seropositive rheumatoid polyarthritis as well as seronegative ones and an evolutive marker of seropositive rheumatoid polyarthritis.

Adult↗
PubMed1986

[D-penicillamine: mechanism of cellular action and induced autoimmune diseases].

The fall in the IgM rheumatoid factors under treatment is not sufficient to explain the effectiveness of D-penicillamine in rheumatoid arthritis. The mechanism of action of D-penicillamine is still poorly elucidated. In vitro, in the presence of copper ions, D-penicillamine inhibits the lymphoblastic transformation induced by polyclonal mitogens; it decreases the production of immunoglobulins by lymphocytes stimulated by the Pokeweed mitogen. This inhibitory action is exerced on the helper T lymphocytes via the production of hydrogen peroxide (H2O2). Monocytes are capable of blocking the inhibitory action of D-penicillamine. The mechanism of the auto-immune complications induced by D-penicillamine is controversial. Two theories have been proposed:--a modification of the auto-antigens due to the presence of the highly reactive thiol group;--an interference with the lymphoid cells involved in suppressor or effector lymphocyte cellular co-operation. These auto-immune complications can be classified into two groups: organ-specific diseases such as myasthenia, polymyositis, thyroiditis, and non organ-specific diseases such as Sjögren's syndrome and lupus. The suspension of D-penicillamine generally leads to the resolution of the symptoms, but corticosteroid and immunosuppressant treatment is sometimes required.

Animals↗
PubMed1986

[Comparative profile of antinuclear antibodies in Gougerot-Sjögren syndrome with and without diffuse interstitial pulmonary fibrosis].

Eleven patients with an isolated Gougerot-Sjögren syndrome and a diffuse interstitial fibrosis were compared with twenty patients with an isolated Gougerot-Sjögen without pulmonary involvement. Patients with pulmonary fibrosis are younger and the evolution of their dry syndrome is shorter (p less than 0.05) than in patients without fibrosis. The frequency of extra-articular clinical manifestations (except for the lung) is identical in both groups. Antinuclear antibodies are present in 100 p. cent of patients with pulmonary fibrosis. Specific antibodies of soluble nuclear antigens are detected in 64 p. cent of them. This frequency is 55 p. cent in the group without pulmonary fibrosis. The specificities of these antibodies are anti-U1-RNP (3 cases), anti-SS-B (La) (3 cases), anti-SS-A (Ro) (2 cases), non identified (1 case). There was no serum containing antibodies Jo1 or anti-Sm. This immunological profile is identical to the profile found in isolated Gougerot-Sjögren syndromes without pulmonary fibrosis. The search for specific antibodies of soluble nuclear antigens permits to differentiate pulmonary fibrosis secondary to an isolated Gougerot-Sjögren syndrome, from primary diffuse interstitial fibrosis and fibrosis associated to a polymyositis.

Adult↗