Identification of a new oncofoetal antigen associated with several types of human carcinomas.

In experimental animals, oncofoetal antigens1 have been found to be associated with both chemical-2 and virus-induced tumours3. In man the two best known oncofoetal antigens are the α-foetoprotein (AFP) described by both Abelev4 and Tatarinov5 and the carcinoembryonic antigen (CEA) of the human digestive system identified by Gold and Freedman6. We describe here a different human oncofoetal antigen, common to several types of carcinomas and various foetal organs. This antigen has been identified by rabbit antisera raised against semipurified fractions of colon carcinoma soluble extracts. Because of its β-immunoelectrophoretic mobility, this antigen will be referred to as β-oncofoetal antigen (BOFA)

Pregnancy and multiple sclerosis: the initial results from a Brazilian database Gravidez e esclerose múltipla: resultados preliminares de base de dados Brasileira

PURPOSE: Pregnancy management poses an extra challenge to physicians and their multiple sclerosis (MS) patients. There are few papers reporting databases on the subject. METHOD: Brazilian database from nine MS clinical and research units, with complete data on 47 pregnant women (49 pregnancies). RESULTS: Despite relatively high exposure to MS medications, no birth defects were reported. Low birth weight and prematurity were similar to those for developing countries. Three complications may have been associated with these medications, while three others were considered to be of purely obstetric nature. CONCLUSION: Our results confirm previous findings on lower relapse rate during pregnancy and add to the present literature informing on data related to drug exposure.<br>PROPÓSITO: O manejo da gravidez cria um desafio extra aos médicos e aos pacientes com esclerose múltipla (EM). Existem poucos trabalhos relatando bases de dados neste tema. MÉTODO: Base de dados brasileira de nove centros clínicos e de pesquisa na EM, com dados completos de 47 mulheres grávidas (49 gestações). RESULTADOS: Apesar da exposição a drogas para EM ter sido relativamente alta, não foram registradas malformações. Baixo peso e prematuridade foram semelhantes àqueles de países em desenvolvimento. Três complicações podem ter sido associadas a drogas, enquanto outras três foram consideradas como sendo de natureza puramente obstétrica. CONCLUSÃO: Nossos resultados confirmam os achados de menor taxa de surtos na gestação e adicionam dados relacionados a exposição a drogas, na literatura atual

IgG-mediated immune suppression in mice is epitope specific except during high epitope density conditions

Abstract Specific IgG antibodies, passively administered together with erythrocytes, suppress antibody responses against the erythrocytes. Although used to prevent alloimmunization in Rhesus (Rh)D-negative women carrying RhD-positive fetuses, the mechanism behind is not understood. In mice, IgG suppresses efficiently in the absence of Fcγ-receptors and complement, suggesting an Fc-independent mechanism. In line with this, suppression is frequently restricted to the epitopes to which IgG binds. However, suppression of responses against epitopes not recognized by IgG has also been observed thus arguing against Fc-independence. Here, we explored the possibility that non-epitope specific suppression can be explained by steric hindrance when the suppressive IgG binds to an epitope present at high density. Mice were transfused with IgG anti-4-hydroxy-3-nitrophenylacetyl (NP) together with NP-conjugated sheep red blood cells (SRBC) with high, intermediate, or low NP-density. Antibody titers and the number of single antibody-forming cells were determined. As a rule, IgG suppressed NP- but not SRBC-specific responses (epitope specific suppression). However, there was one exception: suppression of both IgM anti-SRBC and IgM anti-NP responses occurred when high density SRBC-NP was administered (non-epitope specific suppression). These findings answer a longstanding question in antibody feedback regulation and are compatible with the hypothesis that epitope masking explains IgG-mediated immune suppression