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O Costa

Publications and source records attributed to O Costa.

At least 55 records · Page 3Linked to original sources
PubMed1989

M-mode echocardiography study of twenty-two top class racing cyclists.

In this study M-mode echocardiograms were performed on 22 top class racing cyclists in order to assess the incidence of structural heart alterations. A normal control group was composed of 20 sedentary men of similar age and surface body area. Statistical analysis was performed using the unpaired Student t-test. A normal LV mass was found in all athletes and normal left Ventricle diastolic diametre (LVDD) in 13 cyclists. Global and regional LV systolic functions were normal in all cyclists. Mitral valve analysis showed normal LV compliance in all athletes. Thus, the cyclists admitted to our study did not present LV hypertrophy and most of them had normal LVDD. Systolic and diastolic functions were normal in all of them.

Adaptation, Physiological↗
PubMed1987

Hearing loss in school children. A longitudinal study of sensorineural hearing impairment.

In a longitudinal study, 2325 children were hearing tested at age 7, 10 and 13 with screening audiometry. The screening level was 20 dB HL. Approximately 75% of the children passed the screening level at all ages. Hearing loss was more frequent in boys than in girls at age 13 (16%:9%). The left ear was more commonly affected than the right ear. High frequency dips increased for boys with age, but not for girls. The increasing incidence of hearing loss for boys with age is probably due to noisy leisure time activities.

Adolescent↗
PubMed1986

Antihistone antibodies detected by micro-ELISA and immunoblotting in mice with lupus-like syndrome (MRL/1, MRL/n, PN, and NZB strains).

Antihistone antibodies were searched for in autoimmune prone strains of mice: MRL/1, MRL/n, PN, and NZB by micro-enzyme-linked immunosorbent assay (micro-ELISA with total histones or H1 fraction as antigen) and immunoblotting using a solution of total histones containing H1, H2A, H2B, H3, and H4. In addition, we specified the localization of H1 fraction epitopes recognized by mouse anti-H1 autoantibodies using immunoblotting with H1 digested by alpha-1-chymotrypsin. All strains of autoimmune mice synthesize antihistone antibodies, principally MRL/1, then MRL/n and PN, and finally NZB. Among MRL/1 mice, the histone fractions best recognized by antihistone antibodies, are, in decreasing order: H1, H3, H4, H2B, and H2A. With MRL/n and, even more strikingly with PN mice, the antihistone antibodies recognize preferentially H1 and H2B as they do in human lupus. Finally, the binding of antihistone antibodies from NZB mice is slightly stronger for H2B than for the other histone fractions. The anti-H1 autoantibodies from MRL/1, MRL/n, and PN mice are mainly directed at epitopes located on the C terminal of the histone molecule.

Animals↗
PubMed1986

Anti-H1 histone antibodies in systemic lupus erythematosus: epitope localization after immunoblotting of chymotrypsin-digested H1.

Using micro enzyme-linked immunosorbent assay (micro-ELISA) anti-H1 antibodies are most frequently seen in systemic lupus erythematosus (SLE) (61.4% of patients). Positive anti-H1 ELISA reactions are rare in rheumatoid arthritis (RA) (5.8% of cases), melanomas (16.7%), leukaemias (13.6%) and other cancers (5.6%). In SLE, the immunoglobulins (Ig) which constitute anti-H1 antibodies are, by order of importance, IgM, IgG and IgA. By means of immunoblotting using H1 solutions digested by alpha-1-chymotrypsin fixed on collagen membranes, we have shown that all the SLE sera containing anti-H1 antibodies recognize the sequential epitopes that are found on the carboxy terminal tail and, for 28% of anti-H1 sera, also the epitopes present on the aminoterminal half. The technique used did not make it possible to determine with certainty whether anti-H1 autoantibodies are also directed against the conformational epitopes of the globular part of the molecule.

Antibodies, Neoplasm↗
PubMed1986

Antihistone antibodies detected by ELISA and immunoblotting in systemic lupus erythematosus and rheumatoid arthritis.

Antihistone antibodies were sought in sera from patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), melanomas, leukemias and other cancers (particularly breast cancer) by micro-ELISA, using a solution of total histones as antigen. This solution contained H1 and core histones (H2A, H2B, H3 and H4). ELISA was positive in 59.8% of SLE cases, 5.2% of RA cases, 11.1% of melanomas, 13.6% of leukemias and 5.6% of other cancers. Immunoblotting using total histones enabled us to clarify the histone fraction recognized by antihistone antibodies. In SLE, these were mainly anti-H1 and anti-H2B antibodies. In RA, antibodies recognized all histone fractions. However, some sera from patients with RA stained the H4 band more intensely.

Arthritis, Rheumatoid↗
PubMed1985

Antibodies to ribonucleic acids detected by ELISA in systemic lupus erythematosus, systemic sclerosis and rheumatoid arthritis.

The natural and synthetic antiribonucleic acid antibodies (anti-RNA) are more frequently found in systemic lupus erythematosus (SLE) (80%) than in systemic sclerosis (66%) or in rheumatoid arthritis (RA) (54.5%). SLE sera contain antibodies directed against a broader variety of RNA than systemic sclerosis sera and most RA sera. Fifty-two percent of SLE and 29.2% of systemic sclerosis sera recognized at least 5 of the 7 RNA types studied, whereas RA sera recognized only one or 2. Synthetic antipolynucleotide antibody activities are mainly antipolyriboguanylic-ribocytidylic acid (prG-rC), antipolyriboadenylic-ribouridylic acid (prA-rU) and polyriboadenylic acid (prA) antibody in SLE, antipolyriboguanylic acid (prG) and antipolyribocytidylic acid (prC) antibody in systemic sclerosis and anti-prG-rC, anti-prC antibody in RA.

Arthritis, Rheumatoid↗
PubMed1984

Non-specific binding of heat-aggregated IgG to histone detected by ELISA.

Anti-histone antibodies are currently detected by micro ELISA in systemic lupus erythematosus sera from humans, mice and dogs. Here we show that the control-heated sera may bind non-specifically to the whole histones and histone fractions. The heated immunoglobulins binding to histones are mainly IgG and to a lesser extent IgA, but never IgM. These false positive ELISA reactions occurred only with aggregated IgG which binds to histones via Fc; IgM rheumatoid factor prevented their fixation. Immune complexes do not seem to interfere significantly in the detection of anti-histone antibodies with the ELISA test.

Antibodies↗
PubMed1984

Specificities of antinuclear antibodies detected in dogs with systemic lupus erythematosus.

Five hundred and eighty dogs with at least one clinical sign compatible with a systemic lupus erythematosus (SLE) were entered in a prospective study aimed at evaluating the prevalence of antinuclear antibodies (ANAb). SLE was diagnosed in 38 of these dogs (group A) which fulfilled at least four American Rheumatism Association (ARA) criteria; of these, sixteen had ANAb titers greater than or equal to 4096. The 23 dogs which met three or two ARA criteria (group B) had an ANAb geometric mean titer (GMT) of 259. Dogs (group C) with only 1 criterium had an ANAb GMT of 75. Anti-ds-DNA Ab were present in 6 dogs from group A (16%), and 2 dogs from group B (9%). Anti-histone Ab were present among dogs from group A, B and C with frequencies of 81%, 67% and 26%, respectively. Among dogs from group A, the ANAb titers and the levels of anti-histone Ab correlated positively when individual sera were considered. Antibodies against the soluble nuclear antigen (SNA) were detected in 74%, 39% and 13% of the dogs from groups A, B and C, respectively. Antibodies initially described in human SLE also exist in SLE dogs. Anti-Sm Ab were found in 24% of dogs in group A. With anti-RNP Ab the frequency was still lower (10%). However, two other types of anti-SNA Ab against RNAse and trypsin-resistant antigens, not found in human "reference sera", were often detected. The first type (anti-type 1 Ab) was found in 26% and 9% of group A and group B, The first type (anti-type 1 Ab) was found in 26% and 9% of group A and group B, respectively; the second type (anti-type 2 Ab) is less frequent, and was found in 13% and 17% of group A and B, respectively. It appears that testing for anti-Sm, anti-type 1 and anti-histone Ab should be performed in order to improve the diagnosis of SLE in dogs.

Animals↗
PubMed1982

Antibodies to native type I and II collagens detected by an enzyme linked immunosorbent assay (ELISA) in rheumatoid arthritis and systemic lupus erythematosus.

Anti-native type I and/or type II collagen antibodies measured by an immunoenzymatic immunosorbent assay were found to be present in 22.2% of the rheumatoid arthritis cases studied, 27.5% of systematic lupus erythematosus patients and 28.6% of patients with Overlap Syndrome. These antibodies were not associated with any particular clinical or radiological form of rheumatoid arthritis. Nevertheless, antibodies to native type I and/or type II collagens were associated with seropositive rheumatoid arthritis and antibodies to native type II collagen with rheumatoid arthritis which have antinuclear antibodies. In addition antibodies to native type I collagen were especially present in rheumatoid arthritis with extra-articular symptoms. Antibodies to native collagens disappear or are diminished after corticosteroid treatment. Unlike gold, D-penicillamine or non-steroid anti-inflammatory drugs have no effect on levels of antibodies to native type I and II collagens.

Adrenal Cortex Hormones↗
PubMed1980

Clinical and laboratory features of canine lupus syndromes.

Determination of the specificities of antinuclear antibodies in the sera of 20 dogs presenting with symptoms of a lupus-like syndrome permitted their separation into 2 groups. The first group of 14 dogs all had antibody activity to DNA-histone antigen(s), and 4 of them also had antibodies to native DNA (nDNA). The Farr test with standard buffer was found to be unsatisfactory for the measurement of anti-nDNA antibodies in dog sera due to a high incidence of false positive reactions; these could be eliminated by the inclusion of sodium dodecyl sulfate in the buffer system. The second group of 6 dogs was characterized by the presence of antibodies to extractable nuclear antigen. In every serum tested diseased dogs had a diminished level of circulating thymic factor as compared to controls of the same age, suggesting that a diminution of suppressor T cells may be an etiologic factor.

Animals↗
PubMed1980

[Not Available].

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Biology↗
PubMed1980

Lupus-like syndrome in some strains of nude mice.

Nude mice (strains ORL, C57BL, BALB/C), as well as neonatally thymectomized mice, develop spontaneous antinuclear antibodies (ANab) and antidouble-stranded DNA antibodies (dsDNAab). Later, these animals develop a lupus-like syndrome in which immunoglobulin (Ig) deposits appear, first in the kidney glomeruli, then at the dermoepidermal junction and in the choroid plexus. In the beginning, these Ig are IgM and IgG2; later, IgG1 and IgA deposit in the kidneys. The classes of the Ig of the deposits correspond to those of the circulating ANab-Ig, except for IgA. Acid eluates from kidneys and skin, contain anti-DNA histone ab. An increased C1q binding activity is observed in 8- to 12-wk-old ORL nude mice with ANab, but is not observed in age-matched ORL nude mice without ANab. These data indicate the participation of ANab in the constitution of immune complexes and of tissular Ig deposits in nude mice. The antinuclear autoimmunization process, in nude as well as in thymectomized mice, might be interpreted as a defect of T suppressor cells, which normally control autoimmune clones. However, in contrast with the preceding strains of nude mice, nude mice from the IFFA centre, which have a different genetic background, develop neither ANab, nor dsDNAab, nor glomerular lesions. Three hypotheses can be proposed to explain these particularities of IFFA nude mice. They either have an immune response regulating system, independent of the thymus which is defective or absent in the other strains, or they are deprived of lymphocytes able to produce ANab and dsDNAab, or there are not enough free nuclear antigens to stimulate an immune response. Preliminary results obtained in our laboratory favour the first hypothesis.

Animals↗