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Quantitation of complement C3b and C3d surface receptors on neoplastic IgM positive B lymphocytes.

C3b and C3d complement receptors on the surface of mononuclear cells from blood, lymph nodes, and spleens were investigated in twenty-nine CLL patients and in eight patients with non-Hodgkin malignant lymphoma. Compared with a normal material, especially the lymphoid tissues but also the blood of the patients contained a high number of C3d receptor positive lymphocytes with a strong expression of C3d receptors per cell. The majority of the cells with high C3d receptor expression also had SmIgM. The number of C3b receptor positive cells was decreased in the patients but the C3b receptor expression per cell was normal.

B-Lymphocytes↗

Immunochemical quantitation of complement components of Clq and C3 in sera and synovial fluids of patients with bone and joint diseases.

The amount of the initiating complement component (Clq) in the classical pathway and the first essential component (C3) in the alternative complement pathway were measured with a single radial immunodiffusion (SRID). A high ionic strength was used corresponding to that of 0 . 25 M NaCl and 0 . 01 M EDTA to avoid nonspecific binding of Clq with immune aggregates. Measurements were made on sera and/or synovial fluids from 165 patients with various bone and joint diseases. Values of Clq and C3 in synovial fluids were also expressed as ratios to that of albumin in the same specimens to avoid the influence of differences in volume of synovial fluid in various diseases, and this appeared to provide a reliable index reflecting pathological conditions. Both serum Clq and C3 levels were raised highly in rheumatoid arthritis, gout, and osteomyelitis, but the extent of the elevation of C3 was less conspicuous. Values of Clq and C3 in synovial fluids also markedly increased in rheumatoid arthritis.

Adolescent↗

Quantitation of complement proteins in rheumatic disease.

Complement proteins serve a critical function in the non-antigen-specific elimination of foreign substances and organisms and of immune complexes. Studies of genetic and acquired alterations of complement proteins have provided insights into the pathophysiology of a number of rheumatic diseases, especially those in which immune complexes are believed to have a role in pathogenesis. Complement levels may be helpful in the management of some patients with SLE or vasculitis, and in evaluation of synovial, pleural and pericardial fluids.

Arthritis, Rheumatoid↗

Quantitation of human complement fragment C4ai in physiological fluids by competitive inhibition radioimmune assay.

A method is described to quantitate complement fragment C4ai in human plasma, synovial fluid, and urine. Samples are first precipitated with 50% saturated (NH4)2SO4 to remove cross-reactive macromolecules C4 and pro-C4. Whereas greater than 97% of C4 is removed by this precipitation step, 88% of C4ai remains in solution. Second, the concentration of C4ai in supernatant fractions is determined by double antibody competitive inhibition radioimmunoassay. C4a was recently completely sequenced (Moon et al., 1981) and is readily available as a pure standard. Examination of the specificity of this method confirmed it was indeed specific for C4a antigenicity. Immunochemically depleted C4-deficient plasma and inulin-activated reconstituted C4-deficient plasma exhibited less than 0.1% of the immunoreactivity of untreated plasma. In addition, good agreement was observed in analyses of aggregated IgG activated serum between the experimentally determined concentration of C4ai and that expected from the initial concentration of C4. As a result, recovery and measurement of C4ai in physiological fluids with this method appear both quantitative and specific. Based on results from 17 adult volunteers, the average concentration of C4ai in normal plasma is 488 ng/ml. Interestingly, significant correlation could not be demonstrated between the levels of C4 and C4ai in normal plasma. The mean concentration of C4ai in human urine is 0.5 ng/ml.

Animals↗

Temperature-sensitive mutants of simian virus 40. I. Isolation aand preliminary characterization of B/C gene mutants.

Sixteen temperature-sensitive mutants of simian virus 40 were isolated after treatment of wild-type virus with UV light, nitrous acid, or nitrosoguanidine. All of the mutants were assigned to the B complementation group on the basis of quantitative complementation analyses. Characterization of several representative mutants revealed that under restrictive conditions such mutants produced immunologically identifiable tumor and viral capsid antigens, induced the synthesis of cellular DNA, and replicated infectious viral DNA. In addition, mutant particles produced at 33 degrees were more heat-labile than wild-type virus. This collection of mutants will be useful in an analysis of SV40 particle morphogenesis.

Animals↗

Genetic dissection of a behavioral quantitative trait locus shows that Rgs2 modulates anxiety in mice.

Here we present a strategy to determine the genetic basis of variance in complex phenotypes that arise from natural, as opposed to induced, genetic variation in mice. We show that a commercially available strain of outbred mice, MF1, can be treated as an ultrafine mosaic of standard inbred strains and accordingly used to dissect a known quantitative trait locus influencing anxiety. We also show that this locus can be subdivided into three regions, one of which contains Rgs2, which encodes a regulator of G protein signaling. We then use quantitative complementation to show that Rgs2 is a quantitative trait gene. This combined genetic and functional approach should be applicable to the analysis of any quantitative trait.

Animals↗

Quantitative developmental genetic analysis reveals that the ancestral dipteran wing vein prepattern is conserved in Drosophila melanogaster.

Quantitative complementation tests provide a quick test of the hypothesis that a particular gene contributes to segregating phenotypic variation. A set of wild-type alleles is assayed for variation in their ability to complement the degree of dominance of the quantitative effect of a loss of function allele. Analysis of 15 loci known to be involved in wing patterning in Drosophila melanogaster suggests that the genes decapentaplegic, thickveins, EGFR, argos and hedgehog, each of which are involved in secreted growth factor signaling, may contribute to wing shape variation. The phenotype of one deficiency, Df(2R)Px2, which removes blistered/Plexate, is also highly sensitive to the wild-type genetic background and at intermediate expressivity reveals six ectopic veins. These form in the same locations as a projection of the ancestral pattern of dipteran wing veins on- to the D. melanogaster wing. This atavistic phenotype indicates that the wing vein prepatterning mechanism can be conserved in highly derived species, and implies that homoplasic venation patterns may be produced by derepression of vein primordia.

Animals↗

Passive immunization against Pseudomonas with a ribosomal vaccine-induced immune serum and immunoglobulin fractions.

Passive protection of mice against Pseudomonas aeruginosa using specific antisera and immunoglobulin fractions induced by immunizing rabbits with a ribosomal vaccine is reported. The results demonstrated that protection by the ribosomal vaccine against challenge with live organisms can be serum mediated. Previous work has shown that the vaccine can be separated into two components on the basis of molecular weight and that both higher (peak A)- and lower (peak B)-molecular-weight fractions were capable of inducing active immunity in mice. The present report indicates that both fractions are also capable of eliciting the production of mouse-protective antibody in rabbits. Agar gel diffusion with antisera to peaks A and B or unfractionated vaccine indicated a common antigenic component among them in addition to an extra antigen in unfractionated vaccine not present in peak B. Passive hemagglutination with antisera to peaks A and B demonstrated high-titer agglutinating antibody only with antiserum to peak A when a method of erythrocyte sensitization for lipopolysaccharide antigens was used. Also, passive hemagglutination was greatly inhibited by small amounts of lipopolysaccharide prepared from the same organism from which the vaccine was made. Both antisera to peaks A and B fixed complement with either A or B antigens. Antisera to peaks A and B, when reacted with peak B antigen, had about the same complement fixation titer (as determined by a quantitative complement fixation test). However, when peak A antigen was used, antiserum to peak A had about twice the complement fixation titer that antiserum to peak B had. These results are consistent with previous observations which suggest that the ribosomal vaccine contains lipopolysaccharide in addition to an unidentified immunogenic principle associated with ribosomes. Furthermore, this immunogen was present in both peaks A and B, but detectable amounts of lipopolysaccharide were present only in peak A. The relative importance of the immunoglobulin G (IgG) and IgM classes of antibodies was also compared. The results indicated that both IgG and IgM isolated from immune rabbit serum are protective in mice. Only IgG precipitated with the vaccine in agar gel diffusion, but both IgG and IgM were active in passive hemagglutination and in complement fixation. The passive hemagglutination titer of the IgM was higher than that of the IgG, but the complement fixation titer of the IgG was higher than that of the IgM. The mouse-protective capability of the IgG and IgM was about the same.

Animals↗