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Biomedical subjects

G Virella

Publications and source records attributed to G Virella.

At least 145 records · Page 8Linked to original sources
PubMed1979

Nephelometric detection of soluble immune complexes: methodology and clinical applications.

We have developed a method for the detection of immune complexes by laser nephelometry which is simple, reproducible, suitable for automation, and generally adaptable for diagnostic testing. Light dispersion by antigen-antibody complexes in the test samples is measured after addition of polymeric buffer, which enhances the aggregation of complexes but does not significantly affect unbound immunoglobulins. The method was used to measure immune complexes formed in vitro by incubation of tetanus toxoid with serum from a rabbit previously hyperimmunized with the same antigen, and to compare the levels of immune complexes in human sera obtained from normal adults and from 37 patients with collagen vascular diseases or endocarditis. When precautions were taken to avoid interference produced by the presence of lipoproteins or by freezing of the samples, the results obtained with human sera were consistent with those expected for normal controls and for patients with conditions thought to be associated with the presence of soluble immune complexes.

Animals↗
PubMed1979

Assay of immunoglobulins in supernatants of lymphoid cell lines by conventional laser nephelometry.

An adaptation of the nephelometric assay for serum immunoglobulins has been developed for detection and quantitation of extracellular immunoglobulins in cultures of lymphoblastoid cell lines. This assay employs the standard equipment for laser nephelometry and commercial reagents for immunoglobulin quantitation. By adjusting dilutions of controls and sample volumes of culture supernatants, amounts of IgG and IgM below 1 microgram/ml can be detected in culture supernatants. At concentrations between 1 and 4 microgram/ml, day-to-day and within-run variations for IgM assays were 16 and 11% respectively. The possibility of measuring immunoglobulins secreted by cell lines by conventional laser nephelometry opens several areas of application in the study of the functional activity of B cells and of cell-cell interactions.

B-Lymphocytes↗
PubMed1979

Induction of extraglomerular renal damage in experimental chronic serum sickness. I. Histologic and immunofluorescence findings.

Histologic and immunofluorescence studies were performed in nine rabbits after daily administration of human serum albumin at a fixed dosage for periods up to 26 weeks. All but one of the rabbits studied by immunofluorescence showed IgG, C3, and fibrinogen deposits in the renal glomeruli and in the tubules or peritubular tissues. In most cases, human serum albumin could also be identified in the deposits. In two rabbits killed at week 10, kidney pathology was minimal; in one of the rabbits killed in the early phases of the disease and in all rabbits killed after week 20, there were obvious pathologic changes affecting glomeruli, tubules, and/or interstitium. Tubulointerstitial changes were absent in only one of the rabbits killed at late stages of human serum albumin administration, in spite of evidence of tubular deposition of immune complexes. These observations suggest that tubulointerstitial damage is at least as frequent as glomerular damage during the induction of chronic serum sickness.

Animals↗
PubMed1978

Nephelometric method for determination of rheumatoid factor.

We have developed a nephelometric technique for determining titers of rheumatoid factor. Serum dilutions are added to a mixture of commercially available latex particles of small size (0.098 micrometer) and human gamma-globulin. Rheumatoid sera induce a substantial increase in the light scattering properties of the mixture, and the highest dilution significantly increasing the light scattering is considered as the titer for that serum. This technique is simple to use, provides objective results, and can be automated for analysis of large numbers of samples.

Humans↗
PubMed1978

New immunofluorescent antibody test for diagnosis of candidiasis using macrophages-engulfed antigens as substrate.

A new method for detection of antibodies to polysaccharidic antigens of Candida albicans is described. The method is based on the selective uptake of carbohydrate-rich antigens by mouse peritoneal macrophages, the antibodies being revealed by indirect immunofluorescence after incubation of fixed, antigen-containing macrophages with sera (MU/IFA test). This test shows greater sensitivity than counterimmunoelectrophoresis individuals. The combination of CIE using cytoplasmic antigens and MU/IFA using surface antigens and MU/IFA using surface antigens is useful in a considerable majority of cases for diagnosis of clinical infection.

Animals↗
PubMed1978

"Idiopathic" Bence-Jones proteinuria.

During a prospective screening for proteinuria in diabetic patients, isolated Bence-Jones proteinuria was detected in 2 cases. The first patient, a 52-year-old black female, was seen for evaluation of a slow but progressive weight loss which was attributed to poor adjustment of insulin therapy. The patient gained weight after an increase of the daily insulin administration. She had plasmocytosis in a bone marrow aspirate, but no other evidence of myelomatosis. The second patient, a 59-year-old black male who was seen for routine evaluation of his diabetes, had no clinical or laboratory evidence of myelomatosis. Although precise definition of these cases as "benign" or "idiopathic" Bence-Jones proteinuria is impossible without prolonged follow-up, at the time of presentation they appeared to fit this classification. This observation is one further example that isolated Bence-Jones proteinuria may be seen without any evidence of malignant B-cell dyscrasia.

Bence Jones Protein↗
PubMed1978

X-linked immunodeficiency with increased IgM: clinical, ethnic, and immunologic heterogeneity.

Two cases of immunodeficiency with increased IgM are reported. Patient 1 was a black male 3.5 years old who had recurrent pyogenic infections, failure to thrive, oral thrush, and systemic cryptococcal infection. Patient 2 was a 9-year-old white female who had recurrent cervical abscesses. Serum immunoglobulin determinations by radial immunodiffusion in both patients showed marked depression of IgG and IgA and marked elevation of IgM. A low molecular weight circulating monomeric IgM was demonstrated by immunoelectrophoresis and gel filtration in the second patient; this was not present in the first case. In vitro impairment of cellular immunity was observed in both patients. Administration of dialyzable leukocyte extracts (transfer factor) led to improvement of cell-mediated immunity in patient 1. The etiology of this syndrome apparently has several different genetic bases. These patients demonstrate heterogeneity in genetic, ethnic, immunologic, and other features of the syndrome.

Child↗