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Biomedical subjects

A Alonso

Publications and source records attributed to A Alonso.

At least 613 records · Page 34Linked to original sources
PubMedDate not supplied

Immunological findings in human beings with autoimmune uveitis.

Thirty-four adult patients suffering from uveitis of unknown origin were submitted to an immunological protocol where specific and non-specific parameters were checked. Serum IgA, IgG and IgM appeared within normal values meanwhile IgE-PRIST was undoubtedly increased in 27 out of 34 patients. The presence of autoantibodies such as antimitochondrial and antismooth muscle were detected in a few patients with Harada's syndrome; high serum levels of immune complexes were also detected in this little group of patients with posterior uveitis. Serum complement fractions showed no significant changes. Antirretinal IgG antibodies were present in almost 40% of the patients especially in those who also have autoantibodies and immunocomplexes. The histoimmunofluorescent technique revealed positive images at the retinal membrane agreeing with the histopathological lesions obtained in the experimental model. The positive cross reactivity between bovine tissue sections and the sera from patients with uveitis reinforced the idea of the presence of common epitopes in the S-antigen of both origins. LT-CD4 and LT-CD8 serum lymphocytes showed contradictory results though both subpopulations appeared diminished. The ratio between them kept within the normal range or slightly increased (2.3-2.8). Sensitized lymphocytes to the S-antigen were detected by the MIF technique in one-third of the patients. The presence of IgG antiretinal antibodies led us to speculate about the possibility that an ADCC mechanism could also participate in the etiopathogenesis of the autoimmune uveitis. On the other hand the presence of a specific antiretinal IgE antibody must play a paramount role in increasing the vascular permeability and thus enhancing the humoral and cellular events in the inflammatory focus.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Immunochemical properties of the antigens of Blattaria sudamericana.

An extract of the cockroach Blattaria sudamericana (BS), a very common insect in Argentina, was passed through Sephadex G-200 and DEAE cellulose ion exchange columns. This method yielded 2 proteins and 6 hexoses whose quantities were determined by absorbance in a LKB Uvicord spectrophotometer at 280 nm and 470 nm respectively. Protein contents were also recorded by the Lowry method and the micro-Kjehldal technique. Adult albino rabbits were immunized with a mixture of BS and complete Freund's adjuvant over a period of thirteen weeks. The antisera obtained were studied by the Ouchterlony method, the immunoelectrophoresis and the passive hemagglutination technique against BS and the eluated fractions with the highest protein content. Molecular weights were studied with the usual marker proteins subjected to gel filtration by a Sephadex G-200 column. Each protein concentration was 13.5 mg/ml in a volume of 1.5 ml meanwhile BS was 42 mg/ml. This antigen showed a molecular weight of 180,000 daltons. Fifty untreated atopic patients of both sexes with ages between 19 and 74 years suffering perennial rhinitis and bronchial asthma were chosen according to the American Thoracic Society criteria. Their IgE levels ranged between 110 and 3000 KU/L with an average of 620 KU/L. IgE anti-BS-RAST showed positive results in half of the patients while type I positive skin tests with BS 1:100 appeared in 62% of the atopic group.

Adult↗
PubMedDate not supplied

Focal segmental glomerular sclerosis in three generations of a single family.

We studied members of three generations of a family presenting a nephropathy characterized by proteinuria, occasional microscopic hematuria, progressive deterioration of renal function and an autosomic dominant hereditary pattern. In seven percutaneous needle biopsies, examination by light microscopy showed findings compatible with Focal Segmental Glomerulosclerosis (FSGS) in six patients and Focal Global Glomerulosclerosis (FGG) in one case. Deposits of immunoglobulins IgM, IgA and C3 following mesangial and peripheral distribution were observed. According to electron microscopy, the basal membrane was unchanged though electron dense deposits were found at subendothelial, subepithelial and mesangial locations.

Adolescent↗
PubMedDate not supplied

[Autoimmune uveitis. I. Immunochemical properties of the soluble fractions of bovine retina].

Adult albino rabbits were immunized with bovine retina and complete Freund's adjuvant by the intradermal route. Blood was obtained by complete bleeding of the rabbits and stored at -20 degrees C. Their eyes were enucleated and submitted to histopathological techniques. Humoral antiretinal antibodies were detected by Ouchterlony, immunoelectrophoresis and crossed-immunoelectrophoresis, yielding precipitins presumably of the IgG type. Sensitized lymphocytes were also detected by their incubation with the retinal extract and the soluble fractions belonging to the peaks no 1 and no 2 ("S antigen") in the MIF and TTL techniques. The whole extract was passed through a Sephadex G 100 and DEAE cellulose columns and several soluble fractions were obtained. Two major protein peaks were detected (no 1 and no 2) that were subdivided into five other protein peaks (1A, 1B, 2A, 2B and 2C). Sugars were not present and molecular weights were 50,000 daltons for peak no 2 and higher than 66.000 for peak no 1. The whole protein content of the extract and of the different soluble fractions were established by the Lowry method. Histopathological studies revealed extensive lesions of the uveal tract consisting of a cellular infiltrate rich in lymphocytes and monocytes. Increased vascularization of retina was also appreciated. This experimental model represents a guide in the approach to the human uveitis of unknown origin whose immunological findings will be presented in a forthcoming issue.

Animals↗