Detection of Leishmania causing visceral leishmaniasis in the Old and New Worlds by a polymerase chain reaction assay based on telomeric sequences.

We present a new polymerase chain reaction assay based on telomeric sequences of Leishmania donovani. When this assay was used in dilutions of purified L. donovani DNA, a strong amplification signal was observed with 1 fg of DNA.

Formation of mouse red cell rosettes by "hairy" cells.

Rosette formation with mouse red cells was observed in the "hairy" cells of four cases of leukaemic reticuloendotheliosis. A similar observation was made on B-lymphocytes from chronic lymphoid leukaemia but the monocytes in monocytoid leukaemia did not form rosettes. This finding provides new evidence for the B-cell nature of the "hairy" cell.

Cytochemical profile of B and T leukaemic lymphocytes with special reference to acute lymphoblastic leukaemia.

The PAS and acid phosphatase reactions showed a different pattern of positivity in the cells of lymphoproliferative disorders according to their B or T cell nature. In B-cell leukaemias (chronic lymphocytic and prolymphocytic) a low proportion of lymphocytes gave a positive result with the acid phosphatase reaction, while the majority were PAS positive in granular form. In contrast, in the T-prolymphocytic and T-lymphoblastic leukaemias the acid phosphatase reaction was positive in the majority of cells, while the PAS reaction was only positive in a minority.