Biochemistry/history* ; China ; Exercise/physiology* ; History, 20th Century ; History, 21st Century ; Humans ; Sports Medicine/history*

Black carbon (BC) is the most strongly light-absorbing component of particulate matter and is largely emitted from the incomplete combustion of fossil and biomass fuels. It has a graphite structure with less carbonized, irregular, microcrystalline, and heterogeneous components, which is determined by pyrolysis conditions. BC can be absorbed by human body via inhalation or ingestion route and then be transported to various organs through the blood circulation system in human body. When crossing different biological barriers (such as blood-brain barrier, placenta barrier, and blood-testis barrier), BC may further act on these targets and induce various toxicities. This review first distinguished between BC and carbon black, and then introduced analytical methods of BC in various environmental samples: microscopic observation, chemothermal oxidation methods, other chemical oxidation methods, and molecular marker analysis. We summarized the principles, technical characteristics, and application to environmental samples of these methods, and discussed the ideas and perspectives of determination of BC in biological samples for human biomonitoring.

Objective: To describe the distribution and drug resistance of pathogens at hematology department of Jiangsu Province from 2014 to 2015 to provide reference for empirical anti-infection treatment. Methods: Pathogens were from hematology department of 26 tertiary hospitals in Jiangsu Province from 2014 to 2015. Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or agar dilution method. Collection of drug susceptibility results and corresponding patient data were analyzed. Results: The separated pathogens amounted to 4 306. Gram-negative bacteria accounted for 64.26%, while the proportions of gram-positive bacteria and funguses were 26.99% and 8.75% respectively. Common gram-negative bacteria were Escherichia coli (20.48%) , Klebsiella pneumonia (15.40%) , Pseudomonas aeruginosa (8.50%) , Acinetobacter baumannii (5.04%) and Stenotropho-monas maltophilia (3.41%) respectively. CRE amounted to 123 (6.68%) . Common gram-positive bacteria were Staphylococcus aureus (4.92%) , Staphylococcus hominis (4.88%) and Staphylococcus epidermidis (4.71%) respectively. Candida albicans were the main fungus which accounted for 5.43%. The rates of Escherichia coli and Klebsiella pneumonia resistant to carbapenems were 3.5%-6.1% and 5.0%-6.3% respectively. The rates of Pseudomonas aeruginosa resistant to tobramycin and amikacin were 3.2% and 3.3% respectively. The resistant rates of Acinetobacter baumannii towards tobramycin and cefoperazone/sulbactam were both 19.2%. The rates of Stenotrophomonas maltophilia resistant to minocycline and sulfamethoxazole were 3.5% and 9.3% respectively. The rates of Staphylococcus aureus, Enterococcus faecium and Enterococcus faecalis resistant wards vancomycin were 0, 6.4% and 1.4% respectively; also, the rates of them resistant to linezolid were 1.2%, 0 and 1.6% respectively; in addition, the rates of them resistant to teicoplanin were 2.8%, 14.3% and 8.0% respectively. Furthermore, MRSA accounted for 39.15% (83/212) . Conclusions Pathogens were mainly gram-negative bacteria. CRE accounted for 6.68%. The rates of Escherichia coli and Klebsiella pneumonia resistant to carbapenems were lower compared with other antibacterial agents. The rates of gram-positive bacteria resistant to vancomycin, linezolid and teicoplanin were still low. MRSA accounted for 39.15%.

OBJECTIVES: Metformin is the basic drug for treating diabetes, and the plateau hypoxic environment is an important factor affecting the pharmacokinetics of metformin, but there have been no reports of metformin pharmacokinetic parameters in patients with diabetes mellitus type 2 (T2DM) in the high-altitude hypoxic environment. This study aims to investigate the effect of the hypoxic environment on the pharmacokinetics and assess the efficacy and safety of metformin administration in patients with Type 2 diabetes mellitus (T2DM). METHODS: A total of 85 patients with T2DM taking metformin tablets in the plateau group (n=32, altitude: 1 500 m) and control group (n=53, altitude: 3 800 m) were enrolled according to the inclusion and exclusion criteria, and 172 blood samples were collected in the plateau group and the control Group. A ultra-performance liquid chromatography/tandem mass spectrometry (UFLC-MS/MS) method was established to determine the blood concentration of metformin, and Phoenix NLME software was used to establish a model of pharmacokinetics of metformin in the Chinese T2DM population. The efficacy and serious adverse effects of metformin were compared between the 2 groups. RESULTS: The population pharmacokinetic modeling results showed that plateau hypoxia and age were the main covariates for model building, and the pharmacokinetic parameters were significantly different between the plateau and control groups (all P<0.05), including distribution volume (V), clearance (CL), elimination rate constant (Ke), half-life(T_1/2), area under the curve (AUC), time to reach maximum concentration (T_max). Compared with the control group, AUC was increased by 23.5%, T_max and T_1/2 were prolonged by 35.8% and 11.7%, respectively, and CL was decreased by 31.9% in the plateau group. The pharmacodynamic results showed that the hypoglycaemic effect of T2DM patients in the plateau group was similar to that in the control group, the concentration of lactic acid was higher in the plateau group than that in the control group, and the risk of lactic acidosis was increased after taking metformin in the plateau population. CONCLUSIONS Metformin metabolism is slowed down in T2DM patients in the hypoxic environment of the plateau; the glucose-lowering effect of the plateau is similar, and the attainment rate is low, the possibility of having serious adverse effects of lactic acidosis is higher in T2DM patients on the plateau than on the control one. It is probably suggested that patients with T2DM on the plateau can achieve glucose lowering effect by extending the interval between medication doses and enhancing medication education to improve patient compliance.
Humans ; Diabetes Mellitus, Type 2/drug therapy* ; Metformin/therapeutic use* ; Acidosis, Lactic ; Tandem Mass Spectrometry ; Hypoxia ; Glucose

Metformin is the most common first-line oral hypoglycemic drug ，but there are large individual differences in pharmacokinetic parameters and pharmacodynamics during clinical use. The dosage of some patients should be adjusted to achieve satisfactory therapeutic effect. Pharmacokinetic parameters of metformin are affected by many factors ，including respects of transporter gene polymorphism ，drug interaction ，intestinal flora ，plateau hypoxia and physiological function and so on. In order to guide the clinical individualized use of metformin ，this study reviews the research progress on the influencing factors of metformin pharmacokinetics.