[Lymphoid cell infiltration into the pancreas of C57BL/6J mice]. / Infiltratsiia ot limfoidni kletki v pankreas na C57BL/6J mishki.

Peri-insular lymphoid infiltrations were observed in nondiabetic C57BL/6J mice. The type of infiltrating cells was determined by direct immunoperoxidase technique. A larger part of lymphoid cells did not show reaction with a goat antimouse IgG Rh conjugate. Intensive hyperplastic reaction and the presence of many immunoglobulin producing cells were observed in the lymph nodes adjoining the pancreas. Probably the observed infiltrations in the pancreas of nondiabetic C57BL + 6J mice were composed mainly of T lymphocytes, belonging to T helper subpopulation.

Morphological characteristics of the endocrine pancreas in alloxan diabetes after cyclosporin A administration.

Histological, immunocytochemical, morphometric and electron microscope studies were carried out on the pancreas of alloxan diabetic rats pretreated with cyclosporin A. High mortality, severe destruction of pancreatic B-cells and presence of sporadic mononuclear infiltrations in islets and around excretory ducts were observed. The results obtained show that cyclosporin A potentiates the toxic effect of alloxan on the pancreatic B-cells.

Positive effect of cyclophosphamide on the expression of MHC class II antigens.

Wistar rats, 6-8 weeks old, were treated intraperitoneally (i.p.) with a single dose of 20 or 200 mg/kg cyclophosphamide (CY), one day before their immunization with 50 mg/kg ovalbumin (OVA). On the third day after CY administration, cytological slides from peritoneal cells, obtained by lavaging the peritoneal cavity and cryosection from the mesenterial lymph nodes and spleen were prepared. The slides were stained by the method of peroxidase-antiperoxidase with monoclonal antibodies OX6 (Sera-Lab) against constant region determinant of rat class II antigens. The results obtained demonstrated a strong hyperexpression of MHC class II antigens in the peritoneal cells as well as in the lymph nodes and spleen from animals treated with CY and a stronger one, when after CY administration the animals were immunized with OVA. However, immunization with OVA alone did not stimulate notable augmentation of Class II antigen expression compared to healthy nontreated animals. The hyperexpression of class II antigens in animals treated with CY resulted from a pronounced lymphocytes depletion. This suggests that it is not lymphocytic gamma-interferon, as is commonly accepted, but some other factor(s), released from the accessory cells, that takes part in the mechanism of class II antigen hyperexpression.

[Ultrastructural studies of metastases of anaplastic tumors and non-Hodgkin's lymphoma as a contribution to differential diagnosis]. / Ultrastrukturelle Untersuchungen an Metastasen anaplastischer Tumoren und von Non-Hodgkin-Lymphomen als Beitrag zur Differentialdiagnose.

Difficulties in morphologic classification frequently arise in distinguishing between non-Hodgkin lymphoma and lymph node metastases from anaplastic tumors, mainly germ cell tumors and small cell carcinomas. The present study explores the role of ultrastructural features as a supplement to light microscopy in 14 cases of metastatic disease and 6 non-Hodgkin lymphomas. It appeared that the ultrastructure of the nucleoli, the arrangement of the nuclear bodies and the shape of nuclear invaginations are ultrastructural cell characteristics, which may contribute to the definitive diagnosis.