Allelopathic effects of the toxic cyanobacterium Microcystis aeruginosa on duckweed, Lemna gibba L.

Cyanotoxins are a group of compounds produced by cyanobacteria that can have severe physiological effects on other organisms, including humans. The potential allelopathic effects of Microcystis aeruginosa, a toxic cyanobacterium, on the duckweed plant, Lemna gibba L., were examined using three experimental methods: (1) a series of toxicity bioassays, (2) evaluation of toxin production by M.

The complexity of HLA class II (DRB1, DQB1, DM) associations with disseminated Mycobacterium avium complex infection among HIV-1-seropositive whites.

Earlier associations of polymorphism in classic HLA class II (DRB1 and DQB1) genes have been extended to include the accessory genes DMA and DMB as determinants of disseminated Mycobacterium avium complex (DMAC) infection among HIV-1-seropositive whites. From the Multicenter AIDS Cohort study, 176 DMAC cases were matched with 176 controls in a nested case-control study. PCR-based HLA genotyping techniques were used to resolve variants of DRB1 and DQB1 to their four-digit or five-digit alleles, and single-strand conformation polymorphism was used to resolve sequences in exon 3 at each DM locus.