Secretion of laccase and manganese peroxidase by Pleurotus strains cultivate in solid-state using Pinus spp. sawdust

Pleurotus species secrete phenol oxidase enzymes: laccase (Lcc) and manganese peroxidase (MnP). New genotypes of these species show potential to be used in processes aiming at the degradation of phenolic compounds, polycyclic aromatic hydrocarbons and dyes. Hence, a screening of some strains of Pleurotus towards Lcc and MnP production was performed in this work. Ten strains were grown through solid-state fermentation on a medium based on Pinus spp. sawdust, wheat bran and calcium carbonate. High Lcc and MnP activities were found with these strains. Highest Lcc activity, 741 ± 245 U gdm-1 of solid state-cultivation medium, was detected on strain IB11 after 32 days, while the highest MnP activity occurred with strains IB05, IB09, and IB11 (5,333 ± 357; 4,701 ± 652; 5,999 ± 1,078 U gdm-1, respectively). The results obtained here highlight the importance of further experiments with lignocellulolytic enzymes present in different strains of Pleurotus species. Such results also indicate the possibility of selecting more valuable strains for future biotechnological applications, in soil bioremediation and biological biomass pre-treatment in biofuels production, for instance, as well as obtaining value-added products from mushrooms, like phenol oxidase enzymes.

Leucemia mieloide aguda MO: características clínicas y de laboratorio / Acute myeloid leukemia MO: clinical and laboratory features

Patients and methods: Eight patients, our of 368, with acute myeloid leukemia that were studied in the Hematology Laboratory of a public hospital in Santiago, were classified as LMA-MO. Results: Blast cell morphology was undifferentiated or of subtype FAB-L2 lymphoblastic leukemia with medium sized blasts, agranular basophilic cytoplasm, reticular nuclear chromatin and a prominent nucleolus. Cytochemical staining was negative for peroxidase and esterases, immunophenotyping showed the expression of one or more myeloid antigens (CD13, CD33) and was negative for lymphoid antigens. Immunocytochemical expression of myeloperoxidase was positive in the three cases where it was performed. Only one patient achieved complete remission and is free of disease after 36 months of follow up. All other patients died without obtaining remission, six shortly after the onser and one 12 months after. Conclusions: The diagnosis of LMA-MO is essential considering its dismal prognosis