Biomedical subjects

M Kassai

Publications and source records attributed to M Kassai.

6 recordsLinked to original sources

PubMed1991

[Early cancer of the esophagus].

The authors report four cases with the postoperative diagnosis of the early cancer of the esophagus. The histological type of the tumor was squamous cell carcinoma in three cases and adenocarcinoma in the remaining one. The tumors were localized in the lower part of the esophagus. Left sided thoraco-laparotomy was carried out in two cases. They used a right sided thoracotomy with abdominal and neck incisions. Trans-mediastinal esophagectomy was performed in the remaining one case. The continuity of the gastrointestinal tract was restored by substernal colon interposition in a case, by substernal stomach in another one and by oesophago-jejunostomy in the remaining two cases. New diagnostic possibilities and the international results of the treatment of the early esophageal cancer are discussed.

Adenocarcinoma↗

PubMed1990

Functional and immunogenetic characterization of FcR-blocking antibody.

The characteristics and functional importance of FcR-blocking antibodies and their production were investigated after immunization with whole blood, "buffy coat" and purified platelets. We studied the presence of FcR-blocking antibody in haemodialyzed, transfused patients waiting for kidney transplantation, and we found strong correlation between the blocking effect and better graft survival. We suggest that this blocking antibody does not attack FcR as primary target. Investigation of blocking activity of ten different immune sera on 50 healthy panel cells showed that target antigen has some polymorphic varieties. On basis of family studies it seems that the target antigen is not linked to HLA haplotype. The blocking effect of sera could be removed by absorption of CD8+ cells, B lymphocytes, platelets and granulocytes, but not with erythrocytes, monocytes, CD8- cells and NK cells.

Absorption↗

PubMed1990

Differences in non-MHC restricted cytotoxic activities of human peripheral blood lymphocytes after transfusion with allogeneic leukocytes or platelets possessing class I and/or class II MHC molecules.

MHC-unrestricted cytotoxic activity of peripheral blood lymphocytes (PBL) from 4-6 healthy donors was investigated before and after transfusion with allogeneic leukocytes or platelets. Natural killer and lectin-dependent cellular cytotoxicity (LDCC) of PBL was tested against K562 and Raji target cells in a 4-h and 16-h 51Cr-release assay, respectively. After allotransfusion with leukocytes, we found increased cytotoxic activity of each donor's PBL against all the three targets on day 3 or 7. The highest non-specific cytotoxic activity was detected against the relatively NK resistant Raji target cells. The increase of cytotoxic activity was lowest against the LDCC target (PHA-treated Raji) cells. On the contrary, no changes in cytotoxic activity against any targets were observed after allotransfusion with platelets (possessing class I HLA antigens but no HLA class II molecules). Our results suggest that HLA class II molecules, presumably by inducing immune responses, are essential for activation/generation of non-specific killing of tumor targets after leukocyte transfusion. Thrombocytes, known to be less immunogenic than leukocytes, are not effective in in vivo enhancing of non-specific cytotoxicity. Cellular activation of PBL following leukocyte allotransfusion was confirmed by detection of elevated serum neopterin and beta-2-microglobulin levels on day 3. This was not the case after platelet allotransfusion. In addition, the expression of ICAM-1 antigen (as a molecule involved directly in MHC-unrestricted cytotoxicity) was also found to be increased in two donors' PBL on day 3 after leukocyte transfusion in contrast to transfusion with platelets.

Biopterins↗

PubMed1990

Caretaking environments.

Recent statistics validate the impact of the Human Immunodeficiency Virus (HIV) on women and children in the United States. An increasing number of women of childbearing age are being infected by sharing needles and syringes with HIV-positive individuals and by having sex with partners who are either known or unknown sources of HIV infection. These women subsequently expose their children to the virus during pregnancy and at birth. Frequently, these children are both HIV-positive and addicted to drugs. In response to the increasing needs of these women and their children who are frequently homeless, orphaned, or without adequate care, private, municipal, county, and federal groups and agencies have either redefined their services or developed new programs. The dedication of these groups has resulted in caretaking environments and programs which furnish the infected women and children and their families with medical care, physical, emotional, and financial support.

Adult↗

PubMed1989

Dynamism of the development of "Fc receptor-blocking antibodies" after immunization with buffy coat.

Eight healthy male blood donors who had not received transfusion previously, were immunized 5 times at 6-week intervals. The immunization was carried out with "buffy coat" separated from 400 ml freshly obtained donor blood. Donor-recipient pairs showed a mismatching for 1 to 4 HLA antigens. The production of HLA antibodies could be demonstrated in 4 patients during the repeated immunizations. Fc receptor-blocking antibody activity was determined with the erythrocyte antibody inhibition (EAI) method in serum samples for the recipients. An increase in the Fc receptor-blocking antibody serum level could be detected already on the second day after the first immune stimulus. Fc receptor-blocking activity was maximum on the 10th day after immunization. After repeated immune stimuli, the increased non-specific Fc receptor-blocking antibody activity was demonstrated independently of the appearance of specific HLA cytotoxic antibodies.

Antibody Formation↗

PubMed1988

Comparative study of alloimmune reactions induced by leukocyte and platelet transfusions in humans: characteristic changes of activation markers, gamma interferon, and FcR blocking antibody production.

This study was undertaken to define immune responses induced by leukocyte and platelet transfusions. We offer evidence that activation by alloimmunization with intravenously administered "buffy coat" cells results in immune alterations similar to the early rejection episodes following kidney transplantation. Thus, IL-2 and HLA-DR expression increased on PBL 2 and 3 days after antigen exposure and paralleled elevations of IFN-gamma, neopterin, and beta 2 microglobulin levels. No significant changes were detected in the number of T-cell subpopulations. Alloimmunization by purified platelets alone that express only class I MHC antigens failed to induce the above alteration, even after repeated exposure. Repeated alloimmunization with "buffy coat" cells or isolated platelets stimulated a progressive increase up to 100% blocking activity on EA rosette formation. We conclude that the expression of activation markers on PBL and the production of IFN gamma and neopterin reflect the early phase of alloimmune response induced by leukocytes. This type of alloactivation is not a prerequisite for the development of FcR-blocking antibody, which is produced after pure platelet transfusion as well.

Binding, Competitive↗