Value of thromboelastography in monitoring effect of hypothermia on coagulation function in major trauma patients / 中华创伤杂志

Objective To investigate effect of hypothermia on coagulation function in major trauma patients and assess value of thromboelastography (TEG) monitoring.Methods Twenty-two patients with major trauma admitted to the emergency intensive care unit between January 2010 and June 2011 were enrolled in the study.The venous blood of the patients was sampled for TEG determination at different temperatures (37,35 and 33 ℃) to analyze variation of the indices including coagulation reaction time (R),clot formation time (K),rate of clot formation (Angle),maximum amplitude (MA)and coagulation index (CI).The patients were divided into normal coagulation group and abnormal coagulation group based on the CI value at 37 ℃ to analyze effects of temperature on TEG indices in both groups and their differences between groups.Results (1) Among 22 patients,TEG indices including R and K trended upward (P ＜ 0.01),but Angle,MA and CI trended downward (P ＜ 0.01) with decline of the temperatures.(2) K and Angle values,indicators of fibrinogen function,were obviously inhibited (P ＜ 0.05) with the temperature decreasing from 37 ℃ to 35 ℃,but other TEG indices had no significant changes.Whereas,all TEG indices were significantly inhibited when the temperature was decreased from 35 ℃ to 33 ℃.(3) There were significant differences in variation of each TEG index inhibited by hypothermia (P ＜ 0.01).All TEG indices showed significant differerces in the pairwise comparison,except for the differences between R and K as well as between Angle and MA (P ＜0.01).(4) R and K were increased,but Angle,MA and CI were decreased in both groups,with decline of the temperatures.Moreover,all TEG indices in the abnormal group were worse than those in the normal group.Conclusions Hypothermia has significant effect on coagulation function of patients with major trauma.TEG,which may be measured at any temperature,is more accurate in reflection of patients' actual coagulation function and is helpful for choice of an appropriate temperature in the mild hypothermia therapy.

Effects of gene design on recombinant protein expression: a review / 生物工程学报

It has become a hotspot and keystone in gene engineering and bioengineering to produce recombinant proteins through heterologous expression systems. Unfortunately, not all the genes could be successfully and effectively expressed in heterologous hosts. The role of gene itself in regulating translation process through its intrinsic sequence characteristics such as codon bias, codon pair bias, GC content, mRNA secondary structure and mRNA stability, has been gradually elucidated. Here we review these factors that influence the translation processes and their corresponding optimization methods in the process of gene design. We emphatically discussed codon bias and codon pair bias and their optimization methods. In particular, the latest theories of codon harmonization and codon pair harmonization were discussed and compared with the traditional codon and codon pair optimization strategies in gene design.

Application of fluorescent-activated cell sorting (FACS) technique in the research of rabbit limbal stem cells / 眼科研究

Objective The fluorescence-activated cell sorting (FACS) technique is a method for the identification and isolation of different cell populations.At present,the special surface marker for limbal stem cells has been not found yet.This study aimed to investigate the application of FACS technique in the research of rabbit limbal stem cells.MethodsCorneal limbal tissue was obtained from New Zealand white rabbits and cultured using the explant culture method in SHEM.Side population cells (SP cells) and non-SP cells were sorted from cultured rabbit limbal epithelium cells by FACS at a excitation wavelength 350 nm,and acquistion length 450 nm (blue light) and 675 nm (red light).The SP cells and non-SP cells were identified by detecting the expression of ABCG2 and K3/K12.The colony-forming efficiency of SP cells and non-SP cells were evaluated by the observation of cellular vitality with trypan blue staining.The percentage of colony formation was calculated as the colony number in various group/200×100%.ResultsIn 48-72 hours after primary culture,limbal epithelial cells migrated from the cultured tissue mass to form the mambrane-like structure and achieved 70%-80% confluence.The cells showed round,polygon and flattened shape.The proportion of SP cells in cultured limbal epithelial cells was 0.22%±0.09% with a colony-forming efficiency of 5.52±0.45% in SP cells and 0.78%±0.73% in non-SP cells,with a statistically significant difference between the two populations (t＝2.17,P＜0.01).After verapamil,an inhibitor of the expression of the ABCG2 protein,was added into the medium,the proportion of SP cells in the cultured limbal epithelial cells declined to 0.04%±0.006%.The SP cells presented a positive immunoresponse for ABCG2 and absence of immunoresponse for K3/K12,but a contradictory staining result was found in non-SP cells.ConclusionFACS can be applied in the research of limbal stem cells.