[The presence of antibodies to IBR/IPV virus in cattle in the environs of Leyden (author's transl)]. / Het voorkomen van antistoffen tegen I.B.R./I.P.V. bij runderen in de omgeving van Leiden

The appearance of IBR among cattle in the environs of Leyden is reported. Possible explanations of local differences in the incidence of IBR and possible effects on IBR immunisation of cattle in these areas are referred to in the discussion.

Tubuloreticular structures and antinuclear antibodies in autoimmune and non-autoimmune diseases.

Tissues obtained at random from patients suffering from autoimmune and non-autoimmune diseases were studied for the presence of tubuloreticular structures (TRS). It could be demonstrated that the occurrence of TRS in renal tissue is not a specific characteristic of systemic lupus erythematosus whereas the presence of such structures in skin tissue might be suggestive for this disease. The serum of some of the patients could be studied for the presence of antinuclear antibodies (ANA). A statistically significant correlation was found between TRS and ANA in the group of patients with autoimmune diseases. The possibility is discussed that this correlation might favour the theory that viruses may be involved in the aetiology of autoimmune diseases, particularly of systemic lupus erythematosus.

The localisation of hepatitis B antigen and immunoglobulin G in liver tissue: an immunofluorescence, light and electron microscopic study.

Liver tissue specimens for 43 HBAg seropositive patients and 22 HBAg seronegative individuals were investigated for the presence of HBAg with the immunofluorescence technique. Histological diagnoses were established with light microscopy on routinely stained frozen liver sections. The liver specimens of 42 out of the 43 HBAg-positive patients showed positive fluorescence. Three distinct fluorescence patterns could be observed: diffuse, focal and solitary. The diffuse pattern appeared to occur particularly in chronic aggressive or persistent hepatitis, the focal pattern was seen only in the group of patients without obvious alterations and the solitary pattern especially in acute hepatic necrosis.

Tubuloreticular structures in human lymphoid cell lines. A cell biological study.

Human lymphoid cell lines were studied as an experimental model for the spontaneous or induced occurrence of tuburloreticular structures (TRS). It was possible to induce TRS after culturing the EB-3 cell line with 20 mug/ml bromodeoxyuridine (BrUdR) during 96 h. Starvation, culturing at lower temperature (32 degrees) or inhibition of DNA synthesis did not give rise to the production of TRS. The response to BrUdR could be blocked with 60 mug/ml thymidine but not with 60 mug/ml deoxycytidine. The addition of 5 mug/ml cytarabine or the removal of BrUdR at different times resulted in inhibition of TRS induction, indicating that BrUdR had to be incorporated into DNA during at least 48 h. After incorporation, neither the presence of BrUdR nor DNA synthesis was necessary for the production of TRS. These experiments and the finding that in the cell line IHTC-33, which does not produce Epstein-Barr virus associated antigens, TRS were spontaneously present, exclude a correlation between TRS and these antigens. However, the induction of TRS by BrUdR may be related to the activation of another (latent) virus.