A new method for determining transaminase activity based on the color change of the reaction solution was established, by using alanine-dependent transaminase VfTA from Vibrio fluvialis JS17 as the research object coupled with pyruvate oxidase and horseradish peroxidase. After the optimization of the conditions, the linear relationship between VfTA activity units and the absorbance at 400 nm was investigated. This method was also applied to determine the activity of commercial transaminase ATA117. The results showed that the detection limit of transaminase VfTA activity was up to 0. 45 U/mL and the detection limit of ATA117 activity was up to 0. 5 U/mL. The transaminase activity could be quickly judged according to the color depth of the reaction solution.

Diketoreductase can catalyze a double reduction of β,δ-diketo ester to corresponding dihydroxv product with enantiomeric excess(ee)and diastereomeric excess(de)both greater than 99.5%.In order to explore the catalytic mechanism of this unique enzyme,the present study investigated the diketone reduction process and reaction characteristics by diketoreductase.We found that two mono-hydroxy intermediates were produced during the diketone reduction and its reverse reaction.The two intermediates were further separated by C18 column chromatography and structurally confirmed by chiral HPLC with authentic standards.Two mono-hydroxy intermediates could be served as the substrates for the reduction by diketoreductase with different reaction velocities.The formation and disappearance of intermediates were largely affected by temperature and substrate concentration.In addition,steady state kinetics with the two intermediates showed different reaction rates in their disappearance.Collectively,the results indicate that the diketone reduction undergoes a two-step process with the formation of both intermediates,but the disappearance rates for the two intermediates are slightly different.

Objective To investigate whether rosuvastatin has the effects of anti-oxidative stress and attenuates vascular endothelial adhesiveness on the vessel wall in apolipoprotein E(apoE)knockedout mice. Methods Eighty 8-week-old apolipoprotein E-deficient mice and twenty 8-week-old C57BL/6 mice,were fed a normal chow diet for 12 weeks,and were divided into 2 weeks treatment group and 6 weeks treatment group.apoE knocked-out mice were subcutaneously injected with rosuvastatin at a dose of 1, 5, or 20 mg/kg daily for 2 or 6 weeks prior to sacrifice.Blood sample was taken by cardiopuncture and the aorta was obtained at the end of the 2th or 6th weeks. Results Total cholesterol level was significantly decreased after 2 or 6 weeks of 5,or 20 mg/kg rosuvastatin treatment[2 weeks:(480.7±35.3)mmol/L,(371.5±27.1)mmol/L;6 weeks:(400.1±37.6)mmol/L,(305.0±19.3)mmol/L],compared with 0 mg/kg group(20 weeks:(675.0±42.0)mmol/L;6weeks:(660.0±44.3)mmol/L](P＜0.05 or 0.01).But the changes of triglyceride and high-density lipoprotein were not like the above.The endothelial adhesiveness for monocytes was significantly attenuated after 2 weeks in 20 mg/kg group versus 0 mg/kg group[(2.24±0.72)%vs.(3.76 ±2.53)%](P＜0.05),and even more significantly after 6 weeks in 5,20 mg/kg groups[(1.94±0.40)%,(3.95±2.61)%](P＜0.01).In addition,rosuvastatin inhibited vascular expression of p22phox and superoxide production[0 mg/kg for 6 weeks group:(3.22±1.53)%,(4.75±2.62)μg/L;20 mg/kg for 6 weeks group:(1.41±0.72)%,(2.72±0.88)μg/L](all P＜0.05). Conclusions Rosuvastatin has a role of anti-oxidative stress and attenuates vascular endothelial adhesiveness on the vessel wall.

BACKGROUND:For the treatment of distal tibial fractures, open reduction and plate fixation, minimal y invasive percutaneous plate fixation and intramedul ary nail fixation are effective, but each has advantages and disadvantages. OBJECTIVE:To compare the effects of intramedul ary nail combined with blocking screws versus minimal y invasive percutaneous plate fixation in treating distal tibial fractures. METHODS:Fifty-one cases of distal tibial fractures were divided into two groups. The blocking screw group (23 cases) was treated with closed reduction and internal fixation with interlocking nail combined with blocking screws. The plate fixation group (28 cases) was treated with minimal y invasive percutaneous plate fixation. Fracture healing time, recovery of tibial function and complication occurrence were observed during fol ow-up. RESULTS AND CONCLUSION:Al patients were fol owed up for 8 to 32 months. (1) Except one patient in the plate fixation group, the other patients had bony union. The healing time was (4.6±1.7) months in the blocking screw group and (6.9±2.3) months in the plate fixation group. Significant differences in healing time were detected between the two groups (P<0.05). (2) The excel ent and good rate of tibial function recovery was significantly higher in the blocking screw group (100%) than in the plate fixation group (82%) (P<0.05). (3) No significant difference in the incidence of adverse events was determined between the blocking screw group (13%) and plate fixation group (18%) (P>0.05). (4) Results suggested that interlocking intramedul ary nail combined with blocking screw fixation in the treatment of distal tibial fractures can promote fracture healing and joint function recovery.

To explore the current status of children receiving primary health services at a community health service center in Shenzhen so as to provide references for the formulation of children health care policies.According to the patient electronic data in 2011,the clinical profiles were analyzed for children aged under 7 years seeking the advice of general practitioners (GPs) at Niuhu Community Health Service Center.Children aged under 7 years accounted for 12.4％ of all subjects.The causes of seeing the GPs were as follows:acute upper respiratory.infection(58.2％),acute bronchitis(14.9％),gastroenteritis(5.6％),trauma(3.3％)and dermatitis(3.2％).And no difference existed in the workload between pediatrists and surgeons,internists or herbalists.The common and frequent community diseases may be diagnosed and managed at a community health service center.

NAD(P)(H)-dependent oxidoreductase catalyzes the reduction of ketones or aldehydes to prepare a wide variety of valuable chiral alcohols or amines. However, expensive cofactors are absolutely required for the biocatalytic processes with oxidoreductases, which severely hinder their industrial applications. Consequently, the issue on reducing cofactor costs has become one of the major focuses in the field of biocatalysis. With the substantial development in recent years, a number of strategies have been proposed and implemented to solve the cofactor issues in the oxidoreductase catalyzed biocatalysis, including the establishment of cofactor regeneration system, the improvement of endogenous cofactor availability via metabolic engineering and the development of biomimetic agents to replace cofactors. In this review, recent trends and advances on these strategies are presented, and respective advantages and shortcomings are also discussed with a number of examples.
Alcohols ; metabolism ; Biocatalysis ; Ketones ; metabolism ; Metabolic Engineering ; NADH, NADPH Oxidoreductases ; metabolism ; Oxidation-Reduction

Objective To compare intramedullary nailing assisted by minimally invasive cerclage with simple intramedullary nailing in the treatment of femoral long oblique subtrochanteric fractures.Methods From April 2010 to September 2015,our department treated 39 patients with femoral long oblique subtrochanteric fracture.Of them,16 were treated by cephalomedullary nailing combined with minimally invasive cerclage (observation group of 11 males and 5 females with an average age of 42.8 ± 13.2 years) and 23 by simple cephalomedullary nailing (control group of 17 males and 6 females with an average age of 46.2 ± 10.1 years).Their operation time,intraoperative blood loss,radiologic results (union time and alignment) and functional results [Visual Analog Scale (VAS) and Harris hip score] were compared between the 2 groups.Results The 39 patients were followed up from 12 to 30 months (average,15 months).For the observation group,the varus angle (2.2°± 1.4°) was significantly smaller than for the control group(4.1°±2.2°),the VAS scores at 1 and 3 months postoperatively (3.43 ± 1.54,1.13 ± 1.20) were significantly lower than for the control group (5.61 ± 1.41,3.34 ± 1.82),and the clinical union ratio at 3 months postoperatively(87.5％,14/16) significantly higher than for the control group (47.8％,11/23) (P ＜ 0.05).There were no significant differences between the 2 groups in terms of operation time,intraoperative blood loss,Harris hip score at one year postoperatively,VAS score at 6 months postoperatively,or clinical union ratio at 6 or 12 months postoperatively(P ＞ 0.05).Conclusions Cephalomedullary nailing is effective for the treatment of femoral long oblique subtrochanteric fractures no matter it is assisted by minimally invasive cerclage or not.However,since minimally invasive cerclage has the advantage of improving reduction and mechanical stability,combination of minimally invasive cerclage and cephalomedullary nailing may be more advantageous in early pain-relieving and functional recovery.

Objective To explore the incidence of tibial plateau fracture with ligament injuries and the early diagnosis and management of the condition. Methods Fifty seven cases of tibial plateau fractures which had been treated operatively from Jan. 2001 to Jun.2003 and had satisfactory reduction of the articular surface were reviewed. The stability of their knee joints was analyzed. Results The follow up lasted 6 to 30 months with an average of 15 months. The incidence of knee unstability was low. The four potential reasons for the postoperative knee stability were found to be: 1) the low prevalence of ligament injury with displaced fractures of tibial plateau; 2) incomplete ligament disruption or mild ligament injury; 3) anatomic reduction and rigid internal fixation; 4) fine and detailed plan for immobilization and functional exercise. Conclusion The prevalence of complete ligament disruption is low, and nonoperative management can result in satisfactory outcomes for tibial plateau fracture with incomplete ligament injury.

Nosiheptide is a typical thiopeptide antibiotic displaying potent activity toward various drug-resistant strains of Gram-positive pathogens.Although nosiheptide lacks in vivo activity, and good water-solubility with a series of uncontrollable analogues, which may limit its clinical application, glycosylated analogues may overcome problem of low activity and may improve its druggability.In search of novel glycosylated nosiheptide producers, we applied a genome mining strategy that identified Actinoalloteichus sp.AHMU CJ021 that contains all genes required.However, despite the presence of a predicted glycosyltransferase, glycosylated derivatives of nosiheptide were not detected, after following one strain many compounds (OSMAC) strategy and heterologous expression of a regulatory protein NocP.Nevertheless, nosiheptide produced by this strain was remarkably pure, and further experiments were conducted to improve its production by optimization of the culture medium.Under optimal conditions, 58.73 mg/L nosiheptide was produced, representing an almost 6-fold improvement compared to the original fermentation medium.Therefore, we consider Actinoalloteichus sp.AHMU CJ021 a suitable potential candidate for industrial production of nosiheptide, which provides the basis for solving the problem of nosiheptide structural analogues.

Natural products are one of the most important sources for druggable lead compounds given their diverse structures and activities.Nevertheless,very few of them can be directly developed to drugs.The undesirable druggability of natural products result from their weaker activity,lower aqueous solubility and poorer stability.Since improving druggability by chemical modifications is restricted by the limited access to the complex structures of natural products,enzymatic modification has gradually become one of important tools for the structural modification of natural products.Meanwhile,since enzymatic glycosylation by glycosyltransferases has shown certain advantages such as excellent regio-and stereo-selectivity,high catalytic efficiency and mild conditions.It has been a promising route for the improvement of druggability for natural products.In the present review,we summarize different glycosyltransferases and their application for structural modification of natural products as well as the challenges issues involved in the glycosylation,which provides a general perspective on the enzymatic modification of natural products for the improvement of their draggability.