RESUMO
Adding biological passivation agent during composting is one of the most effective ways to reduce the toxicity of heavy metals in contaminated livestock manure. To further improve biological passivation, we obtained a strain with high-heavy metal compounds tolerance to passivate heavy-metal contaminated manure and to characterize heavy-metal biosorption. High-tolerance microorganisms for lead and cadmium were isolated and screened from swine manure composting samples. The strain was identified by its morphology and molecular biology. After the influence of different pH, temperature and salt concentrations on growth of the strain were investigated, the optimal growth conditions were obtained for further analysis of its biosorption characteristics of lead and cadmium. The bacterium with tolerance to lead and cadmium termed SC19 was obtained, whose lead resistance was 600 mg/L and cadmium resistance was 120 mg/L. The isolate was further identified as Cedecea sp., and then its optimum pH was 7.0, temperature was 37 °C, and salt concentration was 0.5%. Lead removal was highest after 30 min of adsorption by the SC19 strain cultured for the stationary phase 36 h, and the maximum removal rate and biosorption capacity of lead were 60.7% and 329.13 mg/g, respectively. Meanwhile, cadmium removal was highest after 30 min of adsorption by the strain cultured for the logarithmic phase 8 h, and the maximum removal rate and biosorption capacity of cadmium were 51.0% and 126.19 mg/g, respectively. Fourier Transform InfraRed (FT-IR) results revealed that the biosorption process mainly happened on the surface of SC19 cell and many active groups on the cell surface could chelate the Pb²⁺ and Cd²⁺. By comprehensive comparison, it was showed that strain SC19 shared a certain capacity of Pb²⁺ and Cd²⁺ biosorption, and the bacterium provided precious microbial germplasm resources for biological passivation of heavy metal contaminated manure.
RESUMO
<p><b>OBJECTIVE</b>To explore the prognostic significance of monosomal karyotype (MK) in patients with acute myeloid leukemia (AML).</p><p><b>METHODS</b>The clinical data of 498 AML patients were analyzed retrospectively.</p><p><b>RESULTS</b>Of the 498 patients, 233 (46.8%) cases had an abnormal karyotype. 42 patients fulfilled the criteria for MK, which were 8.4% of all cases and 18.0% of patients with abnormal karyotype, respectively. The most frequent autosomal monosomies were -7 and -17. 70 patients had complex karyotype (CK), in all patients and patients with abnormal karyotype accounted for 14.1% and 30.0%, respectively. Patients with MK were associated with significantly older (median age 62.5 vs 52 years, P=0.003), and lower HGB concentrations (62.5 vs 77 g/L, P=0.009) and lower WBC counts (7.0×10⁹/L vs 11.7×10⁹/L, P=0.008). Among MK cases, the most frequent chromosome abnormalities were complex karyotype, -7, -5, 7q-, and 5q-. In univariate analysis, MK patients had worse survival than those without MK (7.3 months vs 26.3 months, P<0.001). CK patients also had poorer outcomes than patients without CK (14.8 months vs 26.3 months, P<0.001). In CK patients, survival was worse in MK patients than patients without MK (7.4 months vs 19.2 months, P=0.007). By COX analysis, MK was an independent prognostic factor, beyond NCCN criteria and CK [HR=2.610 (1.632-4.175), P<0.001].</p><p><b>CONCLUSION</b>MK was an independent adverse prognostic factor in AML patients.</p>