Construction of a cooling and heating substrate holder for the preparation of thin films for electron microscopy.

The PVD preparation of thin, oriented films for electron microscopy of materials with high adatom mobilities on the substrates requires cooling of the substrate holder. The construction of such a holder for cooling the substrate to -50 and heating it to 500 degrees C is described.

In situ identification of activated Ta1+ T lymphocytes in human leprosy skin lesions.

Using a monoclonal antibody, anti-Ta1, that identifies antigen-activated T lymphocytes in vitro, we sought to identify activated T lymphocytes in leprosy skin lesions. Greater numbers of Ta1 positive T lymphocytes were observed in tuberculoid leprosy, lepromin skin tests, and reversal reactions as compared with lepromatous leprosy or erythema nodosum leprosum (ENL) (p less than 0.001). With a double-staining technique, we found that the majority of these activated T lymphocytes were of the helper/inducer phenotype. No differences of Ta1 positive lymphocytes were observed in the peripheral blood. The defective cell-mediated immune response in lepromatous and ENL patients correlates with, and may be related to the failure of T-helper/inducer activation or proliferation in the presence of Mycobacterium leprae.