Comamonas sp. 3ah48 is a dibenz[a,h]anthracene-degrading bacterium that is tolerant to heavy metals
LETTERS IN APPLIED MICROBIOLOGY
Authors: Okai, M.; Ohki, Y.; Yamamoto, S.; Takashio, M.; Ishida, M.; Urano, N.
Abstract
Industrialization often causes polycyclic aromatic hydrocarbon (PAH) and heavy metal contamination of soil and water. In this study, we isolated a bacterium from bottom mud water around a park of Kawasaki Port, Japan, that degrades the 5-ring PAH dibenz[a,h]anthracene (DBA). The strain, Comamonas sp. 3ah48, degraded 29% of DBA (30 mu g ml(-1)) in 7 days, and the degradation level increased drastically, to 59%, by the addition of glutamate to the medium. The strain also degraded 40, 14, 15 and 19% of pyrene (Pyr), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF) and benzo[g,h,i]perylene (BghiP) respectively. Benzo[a]pyrene (BaP) was degraded only when glutamate was added to the medium. Strain 3ah48 retained its degradation levels in the presence of 2 mmol l(-1) Co2+, Zn2+ or Cr2+, at almost the same level as that without metal, and increased the DBA degradation level to 57% in the presence of 2 mmol l(-1) Cu2+, suggesting the possibility of the presence of laccase.
BOLD MRI to evaluate early development of renal injury in a rat model of diabetes
JOURNAL OF INTERNATIONAL MEDICAL RESEARCH
Authors: Wang, Qidong; Guo, Chuangen; Zhang, Lan; Zhang, Rui; Wang, Zhaoming; Xu, Ying; Xiao, Wenbo
Abstract
Objective To investigate changes in renal oxygenation levels by blood-oxygenation-level dependent (BOLD)-magnetic resonance imaging (MRI), and to evaluate BOLD-MRI for detecting early diabetic renal injury. Methods Seventy-five rats, with unilateral nephrectomy, were randomly divided into streptozotocin-induced diabetes mellitus (DM, n=65) and normal control (NC, n=10) groups. BOLD-MRI scans were performed at baseline (both groups) and at 3, 7, 14, 21, 28, 35, 42, 49, 56, 63 and 70 days (DM only). Renal cortical (C) and medullary (M) R2* signals were measured and R2* medulla/cortex ratio (MCR) was calculated. Results DM-group CR2* and MR2* values were significantly higher than NC values following diabetes induction. R2* values increased gradually and peaked at day 35 (CR2*, 33.950.34 s(-1); MR2*, 43.79 +/- 1.46 s(-1)), then dropped gradually (CR2*, 33.17 +/- 0.69 s(-1); MR2*, 41.61 +/- 0.95 s(-1) at day 70). DM-group MCR rose gradually from 1.12 to 1.32 at day 42, then decreased to 1.25 by day 70. Conclusions BOLD-MRI can be used to non-invasively evaluate renal hypoxia and early diabetic renal injury in diabetic rats. MCR may be adopted to reflect dynamic changes in renal hypoxia.