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C Adam

Publications and source records attributed to C Adam.

8 recordsLinked to original sources

Circulating immune complexes and C3d in human parasitosis.

Using the Raji cell radioimmune assay, we found low levels of circulating immune complexes (IC) in a small percentage of patients with schistosomiasis and filariasis. C3d levels, measured by immunoprecipitation, were elevated in a large number of these patients, whereas complement levels were within normal limits. Proteinuria was not found in any of the 55 patients studied. Circulating IC or elevated C3d levels were not found in any of the 19 patients with hydatidosis. The increased C3d levels, apparently not related to circulating IC, may be due to direct complement activation by parasite antigens or to sequestered IC. The latter hypothesis appears more attractive because the highest levels of C3d were found in schistosomiasis whereas schistosome antigens were unable to activate complement in vitro.

Antigen-Antibody Complex

A study of the material inhibiting EAC-rosette formation in the sera of patients with nephropathies.

Significant levels of EAC-rosette inhibition compared to control subjects were found in the sera of patients with focal and segmental hyalinosis (FSH), membranoproliferative glomerulonephritis (MPGN) and extra-membranous glomerulonephritis (EGN). In patients with IgA disease, although some sera produced high levels of inhibition, the group as a whole did not differ significantly from the controls. Evidence was obtained suggesting that the rosette inhibitory activity was due to immune complexes (IC) bearing C3 rather than C3 fragments. Firstly, the inhibitory activity was precipitable by 4% PEG, a concentration which does not precipitate the C3 fragments. Secondly, the inhibitory activity was selectively removed from the PEG precipitates by an anti-human immunoglobulin G immunoabsorbent. Finally, since it had been suggested that in some instances an unknown serum factor could inhibit EAC-rosette formation and activation of the alternative pathway of complement, the latter was studied and found to be normal in all the sera studied. Taken together, these results suggest that the inhibition of EAC-rosette formation obtained with the sera of the patients studied was due to the presence in these sera of some material behaving as IC. No clear-cut association was, however, seen between rosette inhibition and the presence or absence of Ig or C3 deposits in the kidney.

Adult

Mechanisms of activation of the properdin system. Studies on properdin electrophoretic mobility in agarose activation of the alternative pathway.

The electrophoretic mobility of properdin in agarose with and without EDTA examined in sera from normal subjects and from patients with mesangiocapillary glomerulonephritis, systemic lupus erythematosus, rapidly progressive glomerulonephritis, mesangial IgG-IgA disease, minimal change glomerulonephritis and partial lipodystrophy. In 'EDTA agarose", the properdin arc of normal serum was always cathodal (gamma), whereas in non-EDTA agarose it was always (beta), indicating that agarose activated properdin with its consequent conversion from a cathodal to an anodal form. Using this change in the mobility of properdin to investigate activation of the properdin system, it was found that the lower the C3 concentration of diseased sera, the less able were they to support properdin conversion by non-EDTA agarose. This relationship we interpret as a manifestation of the requirement of an intact C3b feedback pathway for properdin activation. This view was supported experimentally by (i) decreasing ability of non-EDTA agarose to shift properdin mobility in normal serum as it was progressively depleted of components of the alternative pathway by cobra venom factor, C3 nehritic factor or Mg2+, and (ii) the inability of non-EDTA agarose to shift properdin in sera depleted of C3 or factor B, and in serum deficient in C3. The report of other workers that activated properdin causes generation of C3b, coupled with our finding that properdin activation depends on the C3b feedback, indicates that a system exists in which activation of the C3b feedback cycle allows activation of properdin, allowing in turn further amplification of the C3b feedback. That the anodal form of properdin may be a property of activated properdin was shown by our observations that properdin eluted from zymosan was anodal and activated, and that the properdin in the supernatant normal serum incubated with inulin was anodal.

Complement C3

[Technical note on the isolation of arboviruses by inoculation in young mice: preparation of the mosquito brei].

Studying the effects of centrifugation and deep freezing on the quantity of yellow fever virus in a grinded pool of mosquitoes, the authors followed the mortality rate of inoculated baby mice with twenty five artificially infected mosquitoes treated in four different ways. The statistical analysis of the results show that centrifugation and deep freezing have both an effect on the titer of virus and that the addition of the two treatments have an effect superior to the addition of the separate effects of each of them. The authors propose a new technic for the preparation of pools of mosquitoes, without centrifugation or deep freezing.

Animals

[A serological survey of arboviruses in the human population of Senegal].

2,457 serum samples collected during an epidemiological survey on treponematosis in Senegal by the W. H. O. IR051 team in five areas of Senegal between 1972 and 1975 were studied for arbovirus antibodies using hemagglutination inhibition test. In addition 998 were studied using CF test and 1012 in neutralization test with yellow fever virus. The prevalence of arbovirus antibodies is important in all the country and does not vary basically between the different areas. In group A, chikungunya antibody is the most frequent and Sindbis antibody was found only in areas where migrant birds are resting. There is evidence of recent yellow fever infection in Upper Casamance and in Eastern Senegal. Most of the children are not immune and have to be immunized. Zika and Wesselsbron viruses show activity in all the areas and West-Nile, as Sindbis, is related to areas where birds are numerous. Bunyamwera virus activity is low.

Adult

[Long-term infection of a cell culture from newborn mouse brain with the FNV strain of yellow fever virus (author's transl)].

A cell culture from brains of one day old mice was infected with a high multiplicity of the French neurotropic strain of yellow fever virus (FNV); the infected cell culture produced and released infectious FNV for more than 180 days post-inoculation with titres between 10(0.6) and 10(6.4) PFU/ml. The cell sheet exhibited some rare plaques of round cells with a slow centrifugal extension; the destruction of the cell sheet was not complete before 200 days post-inoculation.

Animals