[Cryptococcal meningitis in an immunocompetent patient - a case report].

Cryptococcal meningitis is a severe neurological infection caused by the yeast Cryptococcus neoformans. It often occurs as an opportunistic infection; rarely, it may be seen in healthy people as well. The most common source of the infection is inhalation of infected bird droppings. The cryptococci may persist in the lungs and nearby lymph nodes for a long time. There are no or mild clinical manifestations of the pulmonary infection. The disease often manifests only after the cryptococci penetrate into the CNS. The case report documents the development of cryptococcal meningitis in an immunocompetent patient. It was diagnosed by microscopic detection of the yeast in the cerebrospinal fluid. The finding was confirmed by detecting cryptococcal DNA in the cerebrospinal fluid and culture. Despite immediate initiation of antifungal therapy and intensive care, the patient died.

The presence of P-glycoprotein in L1210 cells directly induces down-regulation of cell surface saccharide targets of concanavalin A.

Overexpression of P-glycoprotein (P-gp), a plasma membrane drug transporter (ABCB1, a member of the ABC transporter family), is the most prevalent cause of multidrug resistance in cancer tissues. Lectin concanavalin A (ConA) induces massive cell death of L1210 leukemia cells (S). Cell sublines of L1210 in which P-gp overexpression was induced by selection with vincristine (R) or by stable transfection with a plasmid encoding full-length human P-gp (T) were less sensitive to ConA. Both P-gp-positive cell lines exhibited typical P-gp-mediated multidrug resistance. Resistance of R and T cells to ConA was associated with lower binding of ConA as compared to S cells when analysed by the following methods: (i) SDS PAGE and electroblotting of proteins in the crude membrane fraction followed by detection with biotinylated ConA and avidin-peroxidase, and (ii) fluorescent cytometry or confocal microscopy of the intact cells with surfaces labeled by FITC-ConA. These data indicated that the presence of P-glycoprotein in L1210 cells independently of the mode of its expression induced down-regulation of cell surface saccharide targets of ConA. Therefore, this feature may be considered as a secondary cellular response to P-glycoprotein expression.