Effects of electromagnetic pulse on reproduction of adult male mice / 中华放射医学与防护杂志

Objective To investigate the effects of electromagnetic pulse (EMP) on reproductive function of male adult mice.Methods A total of 48 healthy adult male BALB/c mice (8 weeks old) were randomly divided into sham group and EMP group with 24 animals in each group.The mice were wholebody exposed or sham exposed to EMP at 720 kV/m for 100 pulses with 1 Hz repetition rate and 40 ns pulse width.At 1,7,14 and 35 d after EMP exposure,the mice were anesthetized and the sperms were collected from the bilateral epididymal tail.After that,the sperm quality including the number of sperms,the ratio of abnormalities and the survival rate was evaluated.In addition,the morphology of testis was observed by HE staining and the diameter of seminiferous tubules was measured by Image J 1.43 u software.The protein level of stem cell factor (SCF) and glial-derived neurotrophic factor (GDNF) in testis tissue were detected by ELISA and Western blot.Results The sperm quality and the morphology of testis did not change obviously at different times after exposing mice to EMP at 720 kV/m for 100 pulses,compared with sham group (P＞0.05).The diameters of seminiferous tubules at 1,7,14 and 35 d after exposure were (196.85+ 16.65),(196.79+ 14.33),(196.35±22.71) and (198.60±25.88) μm in exposed mice,respectively,while (204.31±27.13),(197.07± 18.11),(194.37±21.45) and (200.59± 19.36) Iμm in sham exposed mice,respectively.There was no significant difference between two groups (P＞0.05).Additionally,the levels of SCF and GDNF in testis tissue between EMP group and sham group had no statistically significant difference (P＞0.05).Conclusion Under this exposure condition,EMP couldn't affect the reproductive function of male adult mice.

Enhanced recovery after surgery combined with clinical pathway management in laparoscopic biliary exploration / 中华肝胆外科杂志

Objective To study the safety,efficacy and advantages of enhanced recovery after surgery (ERAS) combined with clinical pathway management in laparoscopic common bile duct exploration and lithotomy (Laparoscopic common bile duct exploration,LCBDE).Methods 78 patients who underwent LCBDE in the Department of Hepatobiliary and Pancreatic Surgery in the First Hospital of Fuyang District in Hangzhou were selected as the non-ERAS group (the control group).76 patients who underwent LCBDE treated with fast track surgery and ERAS clinical pathway management were selected as the ERAS group.The data between the two groups which included the postoperative insulin resistance index,changes in C-reactive protein,duration of postoperative analgesic use and analgesia,timing of first passage of postoperative flatus,postoperative abdominal tube removal,postoperative bile leakage,recurrence of biliary stones,intestinal ileus and other complications.Results All the two groups were discharged home successfully.On preoperative 7 day,the differences on the postoperative insulin resistance index and the levels of C reactive protein were significantly different (P＜0.05).The time to first get out of bed after operation,the postoperative analgesic use,the time to first passage of flatus,the time to postoperative abdominal drainage tube removal,and the time to clamping of the T tube after operation were significantly different (all P＜0.05).The postoperative complications of pulmonary infection,abdominal infection and the incidence of prolonged intestinal ileus were significantly different (all P＜0.05).Conclusions ERAS combined with clinical pathway management reduced postoperative stress reaction and complication rate.The treatment accelerated recovery and shortened hospital stay for patients who underwent LCBDE,which led to good social and economic benefits.

Research progress in astronaut onboard plyometric training: a review / 军事医学

As an effective physical training method to improve the explosive power of athletes, plyometric training(exercise) has made great contributions to the physical training of Chinese Olympic Teams.However,the way this method is used for astronaut onboard training and the maintenance of human body strength is not yet clear enough.There is no training program or system of astronaut onboard training currently available that uses this training method in China.Based on the analysis of related researches at home and abroad, this paper comprehensively and systematically expounds the principles of plyometric training and research related to athletic performance.The view that this method is used for astronaut onboard training is also proposed innovatively in this paper.The aim of this study is to expand the field of physical training for astronauts and provide reference for the training of weightlessness protection in the field of aerospace in China.

The expression and significance of p-IRE-1α in rat liver with insulin resistance / 中华内分泌代谢杂志

Fed with high-fat diet and assessed by hyperinsulinemia-euglycemia clamp technique, rat models with insulin resistance were successfully induced. Compared with normal chow group ( NC ), serum concentrations of free-fatty acids(FFAs) and baseline insulin in high-fat diet group(HF) was higher( P＜0.05 ), the average glucose infusion rate from 60 to 120 min( GIR60-120 ) was lower( P＜0.01 ), and the expression of p-IRE-lα in the liver was higher( P＜0.05 ). Furthermore, the expression of p-IRE-1α in the liver was positvely correlated with the serum concentration of FFAs. All these data indicate that high-fat diet may induce endoplasmic reticulum stress in the liver by elevating serum concentration of FFAs, and may participate in the genesis of insulin resistance via p-IRE-1α.

Effect of HbA1c meeting the standard or not on microalbuminuria,blood lipids and liver enzymes in patients with type 2 diabetes / 中国医师杂志

Objective To investigate the effect of HbA1c meeting the standard or not on microalbuminuria,blood lipids and liver enzymes in patients with type 2 diabetes.Methods A retrospective analysis was performed on 457 subjects who had type 2 diabetes.They were divided into substandard group and standard group according to HbA1c result.The general information and relevant laboratory indicators of patients were.collected and compared between two groups.Results The microalbuminuria,serum triglyceride and liver enzymes (glutamyl transpeptidase,alkaline phosphatase,aspertate aminotransferase) were significantly different between two groups [ (189.8 ± 235.3) mg/dl vs (38.9 ± 85.5) mg/dl,(2.64 ± 2.99) mmol/L vs (2.02 ± 1.50)mmol/L,(41.7 ±52.9)U/L vs (29.7 ±24.9)U/L,(83.6 ±28.6) U/L vs (74.3 ±25.8)U/L,(26.7 ±19.1)U/L vs (22.0 ±10.5) U/L,P ＜0.05].HbA1c level was positively correlated with microalbuminuria,glutamyl transpeptidase and alkaline phosphatase (r =0.209,0.115,0.11,P ＜0.01).The microalbuminuria was an independent risk factor of affecting HbA1c to reach the standard (OR = 1.009,P ＜0.05).Conclusions HbA1c meeting the standard or not can influence many factors except blood glucose.

Sequencing and expression of the xylanase gene 2 from Trichoderma reesei Rut C-30 and characterization of the recombinant enzyme and its activity on xylan.

The Xyn2 gene, which encodes endo-beta-1,4-xylanase2, in Trichoderma reesei Rut C-30 was amplified by PCR from first-strand cDNA synthesized on mRNA isolated from the fungus. The nucleotide sequence of the cDNA fragment was verified to encode 190-amino-acid residues of a protein with a calculated molecular mass of 21 kDa. The cDNA was cloned into pET30alpha expression vector and subsequently expressed in Escherichia coli under the control of strong bacteriophage T7 transcription and translation signals. The enzyme activity assay verified the recombinant protein as xylanase. The isoelectric point and highest activity were 7.5 and 1,600 U/mg, respectively. Like with the T. reesei Xyn2, the highest activity of the recombinant Xyn2 was at 50 degrees C. However, the recombinant enzyme had an improved thermostability and more than 65% of its activity retained after 30 min incubation at 60 degrees C. In addition, the recombinant Xyn2 was active over the range of pH 3.5-7.5 with maximum activity at pH 5.0. Using birchwood xylan, the determined apparent K(m) and k(cat) values were 0.15 mg/ml and 119.7 s(-1), respectively. The enzyme was highly specific towards xylans and exhibited very low activity towards cellulosic substrates. Analysis of the products from birchwood xylan degradation confirmed that the enzyme was an endo-xylanase with xylobiose and xylose as the main degradation products. These properties should make the enzyme a suitable applicant in various industrial applications.

Thermostable carbohydrate binding module increases the thermostability and substrate-binding capacity of Trichoderma reesei xylanase 2.

To improve the thermostability of Trichoderma reesei xylanase 2 (Xyn2), the thermostabilizing domain (A2) from Thermotoga maritima XynA were engineered into the N-terminal region of the Xyn2 protein. The xyn2 and hybrid genes were successfully expressed in Pichia pastoris using the strong methanol inducible alcohol oxidase 1 (AOX1) promoter and the secretion signal sequence from S. cerevisiae (alpha-factor). The transformants expressed the hybrid gene produced clearly increased both the thermostability and substrate-binding capacity compared to the corresponding strains expressed the native Xyn2 gene. The activity of the hybrid enzyme was highest at 65 degrees C that was 10 degrees C higher than the native Xyn2. The hybrid enzyme was stable at 60 degrees C and retained more than 85% of its activity after 30-min incubation at this temperature. The hybrid enzyme was highly specific toward xylan and analysis of the products from birchwood xylan degradation confirmed that the enzyme was an endo-xylanase with xylobiose and xylotriose as the main degradation products. These attributes should make it an attractive applicant for various applications. Our results also suggested that the N-terminal domain A2 is responsible for both the thermostability and substrate-binding capacity of T. maritima XynA.

Expression of a Trichoderma reesei beta-xylanase gene in Escherichia coli and activity of the enzyme on fiber-bound substrates.

A recombinant gene Xyn2 (570bp) encoding the main Trichoderma reesei Rut C-30 endo-beta-1,4-xylanase was successfully cloned and expressed in Escherichia coli BL21 under the control of strong bacteriophage T7 transcription and translation signals. The molecular weight of the recombinant protein was estimated by SDS-PAGE to be 24 kDa. The expressed protein was purified by Ni(2+)-NTA affinity chromatography and enzyme activity assay verified the protein as a xylanase. Like with the T. reesei Xyn2, the optimal activity of the recombinant Xyn2 was at 50 degrees C. However, the recombinant xylanase had an improved thermostability and more than 70% of its activity remained after 30 min incubation at 60 degrees C. In addition, the recombinant xylanase was active over the range of pH 3.5-7.5 with maximum activity at pH 5.0. The enzyme was highly specific towards xylans but exhibited very low activities towards cellulosic substrates. Using Birchwood xylan, the determined apparent K(m) and k(cat) values were 0.11 mg/ml and 106 s(-1), respectively. These properties should make the enzyme an attractive candidate for various industrial applications.

Strain improvement of Trichoderma reesei Rut C-30 for increased cellulase production.

The strain of Trichoderma reesei Rut C-30 was subjected to mutation after treatment with N-methyl-N'-nitro-N-nitrosoguanidine (NG) for 6 h followed by UV irradiation for 15 min. Successive mutants showed enhanced cellulase production, clear hydrolysis zone and rapid growth on Avicel-containing plate. Particularly, the mutant NU-6 showed approximately two-fold increases in activity of both FPA and CMCase in shake flask culture when grown on basal medium containing peptone (1%) and wheat bran (1%). The enzyme production was further optimized using eight different media. When a mixture of lactose and yeast cream was used as cellulase inducer, the mutant NU-6 yielded the highest enzyme and cell production with a FPase activity of 6.2 U ml(-1), a CMCase activity of 54.2 U ml(-1), a ß-glucosidase activity of 0.39 U ml(-1), and a fungal biomass of 12.6 mg ml(-1). It deserved noting that the mutant NU-6 also secreted large amounts of xylanases (291.3 U ml(-1)). These results suggested that NU-6 should be an attractive producer for both cellulose and xylanase production.