A simple method for quantifying IgM of low molecular weight.

A new and simple method for quantitation of IgM of low molecular weight in sera by radial immunodiffusion in 7% agar gel is described. The test is easy to perform and permits exact determination of low molecular weight IgM concentration down to very small quantities (1 mg%). Results obtained with the method described agree with previously used assay procedures and offer the advantage of convenience and rapidity.

A simple method for detection of IgG rheumatoid factor.

A simple method for detection of IgG rheumatoid factor (RF) in sera and joint fluid is described. The technique is based on the action of 0.1 M 2-mercaptoethanol mixed directly with the material. After 2 h of incubation determinations of human anti-IgG were performed by latex agglutination test. Comparison with data obtained by using the conventional method, sequential 24 h treatment with 0.1 M 2-mercaptoethanol and 0.01 M iodoacetamide, shows similar results for both methods. A correlation was observed between the presence of IgGRF in synovial fluid and a severe clinical course with invalidating forms in patients suffering rheumatoid arthritis.

DNA antibodies detected by microhemagglutination test in the diagnosis of systemic lupus erythematosus.

A method of tanned erythrocyte agglutination of wide applicability is described for the study of DNA antibodies. The practical aspects of the method have been explored in estimation of antibodies to DNA in human cases of systemic lupus erythematosus, discoid lupus erythematosus, rheumatoid arthritis, other collagenoses and not related diseases. This method was found to be of high sensitivity and specificity, detecting DNA antibodies only in sera of systemic lupus erythematosus. Results were compared with those obtained by immunofluorescence test using rat liver hepatocytes as source of nuclei.

Immunocompetence and its modification after BCG immunotherapy in patients with colon carcinoma.

The ability to develop cutaneous response to Mantoux, phytohemagglutinin (PHA) and dinitrochlorobenzene (DNCB) was studied in patients with carcinomas in the digestive tract, with particular emphasis on cancer of the colon, in patients with benign pathology and in a control group. The patients with a malignant disease in the digestive tract, considered as a group, showed a remarkable decrease of responses to Mantoux (31%), to PHA (21%) and to DNCB (58%) compared to the control group where incidence amounted to 61%, 73% and 100% respectively. The depression in the immune cellular response is more remarkable yet in colon carcinoma (Mantoux 11%, PHA 0%, DNCB 11%) all of which suggest that the impairment of the immune response depends on the tumor localization. An increase of unresponsiveness was also observed within the group with a benign pathology although the deterioration is lower than that observed in the malignant group. The patients with adenocarcinoma of the colon received BCG immunotherapy and the changes in cellular and humoral response were studied in them. Although the improving mechanism does not seem to affect simultaneously the various expressions of cell mediated immunity, a stimulating effect in the response was observed in what refers to recall antigen, inflammatory reaction and sensitization to DNCB. These changes ranked Mantoux greater than DNCB greater than PHA. There was a direct correlation between skin test reactivity to at least one antigen and the patient survival, but is not the case with the changes observed in the immunoglobulins level. The significance of these changes in relation to the possible anti-tumor effect is discussed.

Testosterone metabolism in vitro by male sexual accessory glands from normal and autoimmunized rabbits.

In vitro metabolism of (3H)-testosterone from male accessory gland homogenates from autoimmunized and normal rabbits was studied at different times of incubation. Results indicated that 5 alpha - androstane-3 alpha, 17 beta-diol was the main metabolite formed in both cases, though the presence of the 3 beta-isomer cannot be excluded. On autoimmunized rabbits with small histological alteration, transformation of the precursor (3H)-testosterone was significantly greater (40 min: P less than 0.01; 60 min: P less than 0.05). This led to a higher yield of 5 alpha-androstane-3 alpha, 17 beta-diol at both incubation times, being significant only at 40 min (P less than 0.02). The 4-androstene-3,17-dione also increased as compared with the normal group. In autoimmunized rabbits with a greater histological alteration, the bioconversion of (3H)-testosterone decreased for both incubation times, being significant only for the 40 min (P less than 0.05). A decreased interconversion to 4-androstene-3,17-dione was also observed, being significant only for 40 min (P less than 0.05). These results suggest that in an early stage of autoimmunization there might be a transient stimulation of enzyme activities in the sexual accessory glands. In another moment of the phenomena a more severe histological lesion with infiltration of male accessory glands was present. At the same time, decrease in the enzymatic activities could be noticed.

A comparative study on the development of rabbit male accessory gland organ-specific autoantigens.

Experimental cryosurgery of rabbit male accessory glands (RMAG) induced highly specific autoantibodies. They revealed in rabbit male accessory glands the presence of autoantigens when tested by passive cutaneous anaphylaxis reaction and passive haemagglutination test. Using the same techniques, the antisera were confronted with extracts of male accessory glands from rabbits of different ages. It was demonstrated that the autoantigens involved in both tests appear at about the age of three months. The significance of these findings in correlation with the initiation of the organ growth is discussed.

Detection of autoimmune response to rabbit epididymal and seminal spermatozoa.

Conventional and anaphylactic autoantibodies to rabbit epididymal and seminal spermatozoa were detected in sera of rabbits autoimmunized by several procedures. Antibodies against epididymal spermatozoa were found in 85% of rabbits showing lesions of varying degrees in testes. When the comparison was made with antibodies to antigens of spermatozoa from semen, the correlation was markedly lower. The data prove the importance of a proper selection of the antigenic material when looking for antibodies to spermatozoa in studies of autoimmunity and fertility.

Histological lesion and testosterone biosynthesis impairment in testes from autoimmune rabbits.

The aim of the present report is to study comparatively the biosynthesis of testosterone in normal and autoimmune rabbit testes, with different degrees of histological lesion, by in vitro double tracer incubation experiments. For this purpose (3H)-pregnenolone and (14C)-progesterone were used as precursors in the presence of testicular homogenates from both groups of animals. In the autoimmune animals, an impairment in the biotransformation of the precursors leading to a lesser synthesis of testosterone was demonstrated. An accumulation of dehydroepiandrosterone, 17 alpha-hydroxyprogesterone and androstenedione was frequently found. It was also shown that the metabolic impairment seemed to be produced at an earlier stage than the histological modifications. On the other hand, a correlation between the degree of testicular damage and the intensity of metabolic impairment could not be demonstrated conclusively.

Tissue-specific antigens and autoantigens in the early developing rabbit male repoductive accessory glands.

A comparative study was undertaken dealing with the postnatal development of rabbit male accessory glands specific macromolecules with and without autoantigenic properties. The two types of macromolecules were investigated in male accessory glands from rabbits of different ages, fron newborn up to six months old. The results obtained by passive hemagglutination, inhibition of hemagglutination and immunodiffusion tests, show that both types of macromolecules rise to a sufficient amount to be detected at approximately 3 months of age. The possible mechanisms explaining the autoantigenicity or the lack of this property in the macromolecules under study are discussed.

Induction of organ-specific antigens of the rabbit male accessory glands by injection of testosterone or gonadotrophin.

Highly specific antiserums for two antigens of rabbit male accessory glands, called FII and FV, were used to study the effect of hormonal treatment on their appearance during postnatal development. Single or double serial injection of testosterone, or human chorionic gonadotrophin, produces an increase in accessory gland and testis weight, and at the same time induces the synthesis of a detectable amount of specific antigens. This was proved by using groups of animals 4 and 6 1/2 weeks old. The antigens were consistently absent in accessory glands from normal and control animals of the same age. The histologic characteristics of maturation were also observed. Ultrastructural studies revealed an increase in number of microvilli supranuclear vaculoes with secretory content and well developed rough endoplasmic reticulum. These changes were more easily detected in young animals treated with chorionic gonadotrophin. The significance of these findings is discussed in relation to the presence of specific carriers (cytosols).

[Immunochemical characterization of rabies virus: determination of precipitable antigens]. / Caracterización inmunoquímica de virus rábico: determinación de antigenos precipitables.

Immunodiffusion and immuno-electrophoresis techniques were used to detect rabies precipitable antigens. The passive haemagglutination test with group "O" human red cells treated with tannic acid, was used as control test. The study was done with brain suspensions of rabies virus infected mice (CVS strain). Mouse and horse rabies antisera were used. The analysis of the results of both immunochemical assays showed the presence of two specific antigenic fractions of rabies virus. The same two fractions were detected when the antigens were heated. Experiments with brain extracts centrifuged at high speed, suggested that the antigenic fractions are of the "soluble" type.