Novel Detection Method for Evaluating the Activity of an Alkaline Serine Protease from Bacillus clausii.

Until now, the detection methods for serine proteases have been quite time-consuming or cannot indicate the "real" protease activity. Here, a rapid and simple method for determining the "real" activity of serine proteases toward AAPX (a kind of mixed polypeptide substrates, with X representing 20 standard amino acids) was developed. This AAPX method has high reliability, sensitivity, and repeatability and can be used for detecting the serine protease activity spectrophotometrically. Additionally, the site-directed saturation mutagenesis library of alkaline serine protease PRO (BcPRO) from Bacillus clausii was screened with this AAPX method. Three beneficial mutants S99R, S99H, and S99W were identified, and S99W displayed the highest activity. In comparison to wild-type BcPRO, S99W exhibited enhanced catalytic performance toward eight AAPX monomers, and the molecular dynamics simulation revealed the mechanism responsible for its improved activity toward AAPM. Consequently, this work provides an efficient method for detecting, characterizing, mining, and high-throughput screening of serine proteases.

Associations between Variants in BDNF/BDNFOS Gene and Lumbar Disc Herniation Risk among Han Chinese People.

Lumbar disc herniation (LDH) is a low back pain disorder and associated with several single nucleotide polymorphisms (SNPs). However, the role of brain-derived neurotrophic factor (BDNF) and BDNFOS gene in LDH susceptibility remains unknown. To examine whether the variants contribute to LDH, 7 SNPs were genotyped in 380 patients and 692 healthy controls among Han Chinese population. Multiple genetic models, stratification by age/gender and haploview analysis was used by calculating odds ratio (OR) and 95% confidence intervals (CIs). Rs11030064 in BDNFOS gene was associated with modified susceptibility for LDH at age ≤50 years but three loci (rs6265, rs11030104 and rs10767664) of BDNF gene increased LDH risk at age >50 years. Further, rs11030096 polymorphism in BDNFOS gene was associated with LDH the increased susceptibility of LDH in females. Haplotype analysis shown that haplotype "GCC" in the block (rs988712, rs7481311, and rs11030064) increased LDH risk (OR = 1.49, 95% CI = 1.06-2.10, p = 0.022) at age ≤50 years. However, there was no significant association between BDNF/BDNFOS gene and LDH risk in the overall before stratified analysis. For the first time, our results provide evidence on polymorphism of BDNF / BDNFOS gene associated with LDH risk in Chinese Han population.

[Posterolateral minimal incision, poking reduction, and simple internal fixation in treatment of collapsed fractures of posterolateral tibial plateau].

Objective: To explore the effectiveness of limited incision, poking reduction, and simple internal fixation in the treatment of collapsed fractures of the posterolateral tibial plateau. Methods: Between October 2010 and January 2016, 16 patients with collapsed fractures of the posterolateral tibial plateau underwent posterolateral incision, poking reduction, and simple internal fixation. There were 10 males and 6 females with the age of 22-63 years (mean, 43.5 years). The injury was caused by falling in 5 cases, traffic accident in 7 cases, and falling from height in 4 cases. All cases had closed fractures. The left knee was involved in 9 cases and the right knee in 7 cases. The injury-to-admission time was 2 hours to 3 days (mean, 10 hours). X-ray films showed that the articular surface collapsing was more than 2 mm. According to Schatzker criteria, 6 cases were rated as type II and 10 cases as type III. Twelve cases had fracture of fibular head. The incision length, operation time, intraoperative blood loss, and incision healing were recorded; fracture healing was observed, and tibial plateau angle and posterior slope angle were measured on X-ray films; loss of articular surface reduction was observed by CT scan; and American Hospital for Special Surgery (HSS) score was used to evaluate the knee joint function. Results: The incision length was 7-10 cm (mean, 8.6 cm); operation time was 35-55 minutes (mean, 46 minutes); intraoperative blood loss was 10-35 mL (mean, 28 mL). Primary healing of incision was obtained. Skin pain occurred in 1 case at 2 months because Kirschner wire retracted. Fifteen cases were followed up 8-21 months (mean, 13.5 months). The fracture healing time was from 3 to 6 months (mean, 4.8 months). There was no significant difference in tibial plateau angle and posterior slope angle between at immediate after operation and at last follow-up ( t=-1.500, P=0.156; t=-1.781, P=0.097). The anatomic reduction rate of articular surface was 93.8% (15/16) at immediate after operation. At last follow-up, the recollapse height of articular surface was 0.1-1.2 mm (mean, 0.36 mm). According to the HSS score system, the results were excellent in 12 cases, good in 2 cases, and fair in 1 case, and the excellent and good rate was 93.3%. Conclusion: The limited incision by posterolateral approach, poking reduction, and simple internal fixation have the advantages of small injury, full exposure, and easy operation in the treatment of simple posterolateral tibial plateau fractures; bone graft support and simple internal fixation can prevent recollapse of the articular surface and achieve satisfactory knee function.

[Treatment of displaced humeral supracondylar fractures in children with external fixation using plaster or splint].

OBJECTIVE: To investigate the therapeutic effects of closed reduction and external fixation (plaster or splint) for the treatment of displaced humeral supracondylar fractures in children. METHODS: From March 2007 to September 2009,33 children (15 female and 18 male) with humeral supracondylar fractures treated in our hospital, ranging from 3 to 12 years old with an average of 6.4 years old. All the fractures were extension-type injuries, the flexion injures were excluded in our study. The humeral supracondylar fractures were classified according to Gartland classification. There were 21 Type H and 12 type III. In the initial treatment, all the patients were treated with closed reduction and external immobilization. The blood supply of the damaged upper extremity was evaluated before and after treatment. Clinical assessment was obtained at final follow-up using Flynn criteria, and radiologic assessment was obtained using Baumann and lateral humerocapitellar angles. RESULTS: All the children were treated successfully with closed reduction in the initial time; 24 children maintained limb alignment by external immobilization. Nine patients lost position due to the swelling around the elbow which affected unstable external fixation during the follow-up, 5 of which were treated with a repeated closed reduction and internal fixation with Kirschner wires, 4 of which were treated with traction. Thirty-one patients had a satisfactory outcome and 2 patients had an unsatisfactory outcome according to the Flynn criteria at the latest follows-up. CONCLUSION: Closed reduction and external stabilization is an important method for the treatment of displaced humeral supracondylar fractures in children. Making regular follow-up visits after closed reduction and casting is important for patients to maintain acceptable alignment, avoid complications and diagnose any loss of reduction.