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J F Quaranta

Publications and source records attributed to J F Quaranta.

66 records · Page 4Linked to original sources
PubMed1980

[Beta-2-microglobulin and rheumatoid factor levels in the synovial fluid (author's transl)].

The object of this study was to determine whether levels of beta-2-microglobulin and of rheumatoid factor measured by an enzyme-immunoassay allowed good discrimination between inflammatory and degenerative arthropathies. A multiparametric study of synovial fluid was performed on 85 specimens from patients with rheumatoid arthritis, chondrocalcinosis, mechanical arthritis and traumatic arthopathies. A beta-2-microglobulin level of less than 4 mg/l is a result very mich in favor of a non-inflammatory arthropathy (48/49 cases). The quantification of intra-articular rheumatoid factor allows for reclassification in the context of sero-negative rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed1980

Rheumatoid factor in the elderly. New methodology.

Many authors have shown a progressive incidence of auto-antibodies in the elderly as age increases. Among the auto-antibodies found, the highest incidence concerns the Rheumatoid Factor (RF). Using an original enzyme-immunoassay of RF (RF-EIA), we were surprised to find a low incidence of RF in a sample of 100 healthy persons aged from 65 to 98 years (8%). Moreover, the finding of other auto-antibodies confirms this frequency inferior to other workers results. On the other hand, the level of present auto-antibodies is generally low, far below those usually found in auto-immune diseases. These results confirm a disturbance of the immune system in the elderly, but the levels observed make this disturbance more an humoral stigma of aging than a proof of a subjacent dysimmune disease.

Aged↗
PubMed1980

[Clinical applications of enzyme-immunoassay of rheumatoid factor].

The authors describe a method of enzymo-immunological estimation of rheumatoid factor. This estimation, of non-competitive type, includes 3 stages : the rheumatoid factor is first extracted from the serum by fixation on the aggregated IgG linked to cellulose powder; then its presence is revealed by fixation of an oxidase IgG glucose conjugate on the solid phase; finally, the enzyme activity linked to the solid phase is measured. This activity is directly related to the concentration of rheumatoid factor present. The estimation, carried out on 2 050 patients including 114 with rheumatoid arthritis, is well correlated with technic of the Rose-Waaler reaction. Furthermore, the greater sensitivity, the better reproducibility and the quantitative character of this method might improve the supervision of patients with rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed1980

[Enzymo-immunologic determination of the class of antiglobulin factors].

The authors describe an enzymo-immunologic method of determination of the class of rheumatoid factors (RF). This technic includes 3 main stages : 1) extraction of RF by fixation on aggregated rabbit IgG previously adsorbed on the walls of a plastic tube; 2) recognition of RF linked to the solid phase by anti-IgG addition, and addition of human IgA and IgM linked to glucose oxidase; 3) revelation of the enzyme activity linked to the solid phase : this enzyme activity directly depends on the levels of RF to be estimated. The results are expressed as a percentage of the fixation of a reference serum obtained from a patient with rheumatoid arthritis (RA). This serum presents an antiglobulin activity in the 3 major classes of immunoglobulins. The coefficients of variation of intra- and intersystem reproductibility lay between 5,6 and 17.8%. The specificity of the estimation was controlled by the localisation of the antiglobulin activity of the sera after chromatography on Sephadex G200 and by estimation of RF after their absorption by an aggregated IgG immunoadsorbant. This technic was applied to the identification of RF in RA (90 cases); in diseases not related to RA and in control subjects : the sensitivity of this method appears greater than that of technics previously described (immuno-fluorescence, Rose-Waaler reaction) in fact, only 12,2% of sera of patients with RA remain negative with this new test. However, this greater sensitivity does not seem to have altered the clinical specificity of the test : in fact, only 8,4% of the sera of patients with diseases unrelated to RA are positive by this method, which, moreover, may be explained by the age of these subjects (average age 71.5 years).

Aged↗
PubMed1978

A sandwich method of enzyme-immunoassay. II. Quantification of rheumatoid factor.

A sandwich enzyme-immunoassay (EIA) has been applied to the determination of the rheumatoid factor (RF). This non-competeitive assay comprises 3 steps: 1) the RF to be assayed is extracted for the biological medium by an immunosorbent of aggregated IgG linked to cellulose; 2) the solid phase is then incubated with the enzyme-labeled aggregated IgG; 3) the enzymatic activity of the immunosorbent is then measured with a suitable chromogenic reagent. This activity is a direct function of the amount of RF to be assayed. This assay gave reproducible results in the range 0.5-50.0 IU/ml. A good agreement was obtained between the EIA and the Waaler-Rose test but no correlation was obtained with the latex slide-test. This assay permits a quantitation of RF with a good reproducibility (coefficient of variation in the range of 10% for moderately elevated values) and thus allows a closer follow-up of patients. The results do not depend on the interpretation of the technician performing the test, which can be easily automated. Finally, it may detect some RF devoid of agglutinating activity.

Animals↗
PubMedDate not supplied

Use of the leishmanin skin test and western blot analysis for epidemiological studies in visceral leishmaniasis areas: experience in a highly endemic focus in Alpes-Maritimes (France).

Fifty unselected subjects living in Alpes-Maritimes, France, a high risk area for visceral leishmaniasis due to Leishmania infantum, were examined simultaneously by the leishmanin skin test and the Western blot technique in 1993; 32% and 38%, respectively, gave a positive reaction. The concordance of the 2 methods was 82%. Thus, in this high risk area, a large proportion of inhabitants had been exposed to the parasite. The use of these 2 tests should permit the detection of potential cases of reactivated leishmaniasis in prospective follow-up investigations.

Adolescent↗
PubMedDate not supplied

Detection by Western blot of four antigens characterizing acute clinical leishmaniasis due to Leishmania infantum.

Western blot analysis of sera from 32 patients with acute clinical leishmaniasis due to Leishmania infantum showed the simultaneous presence of antibodies against 4 antigens with molecular masses of 18, 21, 23, 31 kDa. The simultaneous presence of these 4 antigens was specific to the clinical disease and it was not detected in 47 sera from asymptomatic individuals living in the leishmaniasis endemic area of Alpes-Maritimes (southern France) or in 37 sera from patients with other protozoan infections.

Acute Disease↗