Transcriptomic Insights into Metabolism-Dependent Biosynthesis of Bacterial Nanocellulose.

Bacterial nanocellulose (BNC) is an attractive green-synthesized biomaterial for biomedical applications and various other applications. However, effective engineering of BNC production has been limited by our poor knowledge of the related metabolic processes. In contrast to the traditional perception that genome critically determines biosynthesis behaviors, here we discover that the glucose metabolism could also drastically affect the BNC synthesis in Gluconacetobacter hansenii. The transcriptomic profiles of two model BNC-producing strains, G. hansenii ATCC 53582 and ATCC 23769, which have highly similar genomes but drastically different BNC yields, were compared. The results show that their BNC synthesis capacities were highly related to metabolic activities such as ATP synthesis, ion transport protein assembly, and carbohydrate metabolic processes, confirming an important role of metabolism-related transcriptomes in governing the BNC yield. Our findings provide insights into the microbial biosynthesis behaviors from a transcriptome perspective, potentially guiding cellular engineering for biomaterial synthesis.

Long-term variation of the levels, compositions and sources of size-resolved particulate matter in a megacity in China.

To investigate the long-term trends and variations of the levels, compositions, size distribution and sources of particulate matter (PM), long-term monitoring campaigns of PM10 and PM2.5 were performed in a megacity in China (Chengdu) during the period from 2009 to 2011. The average concentration of PM10 was 172.01±89.80 µg/m(3) and that of PM2.5 was 103.15±59.83 µg/m(3), with an average PM2.5/PM10 of 0.60. Enrichments of the important species indicated that the fractions of crustal elements were higher in PM10 than those in PM2.5, while the abundance of organic carbon (OC) and secondary ions was enriched in the fine PM. Quantitative source apportionments of both PM10 and PM2.5 were performed by PMF. PM10 and PM2.5 in Chengdu were influenced by similar source categories, and their percentage contributions were in the same order: crustal dust was the highest contributor, followed by vehicular exhaust, secondary sulfate, secondary nitrate and cement dust. Crustal dust and cement dust contributed a higher percentage to PM10 than to PM2.5, while vehicular exhaust and secondary particles provided higher percentage contributions to PM2.5. In addition, PMF-HCA was performed to investigate the characteristics of the sources of the clustered samples, identifying three periods: crustal dust dominant-period, secondary sulfate dominant-period and comprehensive source influenced-period. Planting, reduction of precursors, and banning high-emission vehicles should be implemented to control crustal dust, secondary particles and vehicular exhaust in Chengdu. Furthermore, the size-resolved and the period-resolved control would be more effective.

Phase I safety and pharmacokinetic study of bevacizumab in Chinese patients with advanced cancer.

BACKGROUND: bevacizumab is a humanized recombinant vascular endothelial growth factor (VEGF) monoclonal antibody, which specifically binds to VEGF and inhibits tumor cell growth, proliferation and metastasis. We aimed to investigate the safety and pharmacokinetics of bevacizumab in Chinese patients with advanced cancer. METHODS: Thirty-nine Chinese patients with metastatic or relapsed cancers who failed prior therapy were enrolled in this phase I study of bevacizumab. Bevacizumab was infused by a calculated pump at doses from 5 mg/kg to 15 mg/kg in 90 minutes. Patients underwent serial pharmacokinetic evaluations. Patients that received at least one infusion of bevacizumab were included in the safety study. RESULTS: Thirty-five patients finished all 5 infusions following protocol. One patient withdrew after 3 infusions due to grade 3 proteinuria. Common adverse events possibly related to the study drug were proteinuria (17/39, 43.6%), hypertension (13/39, 33.3%), gingival bleeding (7/39, 17.9%), epistaxis (6/39, 15.4%), pharyngeal inflammation (6/39, 15.4%), fatigue (6/39, 15.4%) and stomatitis (4/39, 10.3%). Bevacizumab pharmacokinetics was linear within the range of 5 mg/kg q2w--10 mg/kg q2w and 15 mg/kg q3w. CL (clearance), Vd (volume of distribution at elimination) and Vss (volume of distribution at steady state) were similar after single and multiple doses at 5, 10 and 15 mg/kg. CONCLUSIONS: Bevacizumab is well tolerated in Chinese patients. No unexpected adverse events were observed. There is no racial difference in the pharmacokinetics.