To screen and identify a chitosanase with high stability, we cloned the chitosanase gene from Bacillus atrophaeus with a high protease yield from the barren saline-alkali soil and expressed this gene in Escherichia coli. The expressed chitosanase of B. atrophaeus (BA-CSN) was purified by nickel-affinity column chromatography. The properties including optimal temperature, optimal pH, substrate specificity, and kinetic parameters of BA-CSN were characterized. The results showed that BA-CSN had the molecular weight of 31.13 kDa, the optimal temperature of 55 ℃, the optimal pH 5.5, and good stability at temperatures below 45 ℃ and pH 4.0-9.0. BA-CSN also had good stability within 4 h of pH 3.0 and 10.0, be activated by K⁺, Na⁺, Mn²⁺, Ca²⁺, Mg²⁺, and Co²⁺, (especially by Mn²⁺), and be inhibited by Fe³⁺, Cu²⁺, and Ag⁺. BA-CSN showcased the highest relative activity in the hydrolysis of colloidal chitosan, and it had good hydrolysis ability for colloidal chitin. Under the optimal catalytic conditions, BA-CSN demonstrated the Michaelis constant K_m and maximum reaction rate V_max of 9.94 mg/mL and 26.624 μmoL/(mL·min), respectively, for colloidal chitosan. In short, BA-CSN has strong tolerance to acids and alkali, possessing broad industrial application prospects.
Bacillus/genetics* ; Hydrogen-Ion Concentration ; Escherichia coli/metabolism* ; Glycoside Hydrolases/biosynthesis* ; Substrate Specificity ; Enzyme Stability ; Chitosan/metabolism* ; Temperature ; Kinetics ; Cloning, Molecular ; Bacterial Proteins/biosynthesis* ; Recombinant Proteins/genetics*

Objective:To analyze the clinic effects of arthroscopic partial trapeziectomy and suture button suspensionplasty in the treatment of first carpometacarpal joint (CMCJ) Eaton stage II/III arthrosis.Methods:A retrospective study was conducted on a total of 15 cases (16 hands) of patients including 5 males (1 bilateral) and 10 females with CMCJ stage II/III arthrosis who underwent surgical treatment at the first affiliated hospital of Shenzhen university from January 2020 to June 2022, with mean age of 56.7±6.4 years (range, 46-75 years). The duration from pain to treatment was 7.8±3.2 months (range, 4-14 months). X-ray showed narrowing of CMCJ with osteophytes and distal radial subluxation. All the patients were treated with arthroscopic partial trapeziectomy and suture button suspensionplasty. The preoperative and last postoperative follow-up radiographs, visual analogue scale (VAS), thumb's Kapandji scores, disabilies of the arm, shoulder, and hand (DASH) scores, grip and pinch strength and time to return to work were compared.Results:All cases were followed up for 19.6±6.3 months (range, 11-36 months). The postoperative X-ray showed all the CMCJs were reduced with a normal height of first metacarpal. The mean time for patients to return to their daily activities was 18.69±3.70 d and the mean time to return to work was 24.63±4.91 d. The average VAS score decreased from 6.56±1.15 preoperatively to 1.00 (0.75, 1.25). The preoperative Kapandji's score was 8.00±0.82 and the postoperative Kapandji's score was 8.00 (7.25, 9.00). The average DASH values improved from 24.06±3.19 to 4.00 (3.00, 5.00). The were significant differences except for Kapandji score ( Z=-4.905, P<0.001; Z=-0.121, P=0.905; Z=-4.846, P<0.001). The mean grip and pinch strength showed improvement from an average of 16.4 (14.13, 18.68) kg and 1.70±0.35 kg to 26.14±3.27 kg and 3.58±0.91 kg with significant difference ( Z=-4.617, P<0.001; t=-7.669, P<0.001). Conclusion:Arthroscopic partial trapeziectomy and suture button suspensionplasty is a minimally invasive surgery for the treatment of first CMCJ Eaton stage II/III arthrosis. By this technique, the patients' existing instability and pain problems can be solved.

Background/Aims: The clinical practice pattern of polypectomy is not well-investigated in Asian countries. We aimed to survey Asian endoscopists about their preferred polypectomy techniques for given conditions and images of polyps. Methods: A survey was performed using questionnaires composed of two parts: a scenariobased questionnaire using scenarios of polyps, which were adopted from the European Society of Gastrointestinal Endoscopy guidelines, and an image-based questionnaire using provided endoscopic images of polyps. Results: A total of 154 endoscopists participated in this survey. The most preferred resection techniques for diminutive (≤5 mm), small (6–9 mm), and benign-looking intermediate (10–19 mm) nonpedunculated polyps were cold forceps polypectomy, hot snare polypectomy, and endoscop-ic mucosal resection (EMR), respectively, in both the scenario- and image-based questionnaires. For benign-looking large (≥20 mm) nonpedunculated polyps, EMR and endoscopic submucosal dissection (ESD) were preferred in the scenario- and image-based surveys, respectively. In case of malignant nonpedunculated polyps, EMR and ESD were preferred for intermediate-sized and large lesions, respectively, according to the scenario-based survey. However, ESD was preferred in both intermediate-sized and large malignant nonpedunculated polyps according to the imagebased survey. Trainee endoscopists, endoscopists working in referral centers, and endoscopistsin the colorectal cancer–prevalent countries were independently associated with preference of cold snare polypectomy for removing small polyps. Conclusions The polypectomy practice patterns of Asian endoscopists vary, and cold snare polypectomy was not the most preferred resection method for polyps <10 mm in size, in contrast to recent guidelines.

Background/Aims: The clinical practice pattern of polypectomy is not well-investigated in Asian countries. We aimed to survey Asian endoscopists about their preferred polypectomy techniques for given conditions and images of polyps. Methods: A survey was performed using questionnaires composed of two parts: a scenariobased questionnaire using scenarios of polyps, which were adopted from the European Society of Gastrointestinal Endoscopy guidelines, and an image-based questionnaire using provided endoscopic images of polyps. Results: A total of 154 endoscopists participated in this survey. The most preferred resection techniques for diminutive (≤5 mm), small (6–9 mm), and benign-looking intermediate (10–19 mm) nonpedunculated polyps were cold forceps polypectomy, hot snare polypectomy, and endoscop-ic mucosal resection (EMR), respectively, in both the scenario- and image-based questionnaires. For benign-looking large (≥20 mm) nonpedunculated polyps, EMR and endoscopic submucosal dissection (ESD) were preferred in the scenario- and image-based surveys, respectively. In case of malignant nonpedunculated polyps, EMR and ESD were preferred for intermediate-sized and large lesions, respectively, according to the scenario-based survey. However, ESD was preferred in both intermediate-sized and large malignant nonpedunculated polyps according to the imagebased survey. Trainee endoscopists, endoscopists working in referral centers, and endoscopistsin the colorectal cancer–prevalent countries were independently associated with preference of cold snare polypectomy for removing small polyps. Conclusions The polypectomy practice patterns of Asian endoscopists vary, and cold snare polypectomy was not the most preferred resection method for polyps <10 mm in size, in contrast to recent guidelines.

Objective To investigate the clinical value of prenatal MRI in the diagnosis and differential diagnosis of congenital bronchopulmonary sequestration (BPS). Methods From January 2009 to December 2014, 16 fetuses with BPS were diagnosed by fetal MRI in Huzhou Maternity and Child Care Hospital and Shanghai Children′s Medical Center Affiliated to Shanghai Jiaotong University School of Medicine. The clinical data of these cases were analyzed retrospectively. All were singleton pregnancy, and MRI was carried out within 24-48 hours after routine prenatal ultrasound. All the neonates underwent postnatal enhanced CT scan or surgical biopsy after birth, and the results were compared to prenatal MRI diagnosis. Results (1)With prenatal MRI, 16 cases were diagnosed BPS. The lesions located in left lung in 10 cases, and right lung in 6 cases. As the scope of the lesion, 3 cases located in the whole left lung, 6 cases limited to the left lower lobe, and 1 case was subdiaphragmatic on the left side. 2 cases located in the whole right lung and 4 cases limited to the right lower lobe. One case complicated oligoamnios, and one had pleural effusion. Supplying vessels could be found in 14 cases.(2)When the postnatal results were compared with prenatal MRI, 15 cases were comfirmed as BPS (15/16), including 10 intralobar cases 5 extralobar cases. One that was diagnosed as BPS by prenatal MRI was confirmed to be congenital cystic adenomatoid malformation (CCAM) by pathology. The accuracy of prenatal MRI diagnosis of BPS was 15/16. Prenatal ultrasound missed one case and misdiagnosed two cases, as one was mistakened as CCAM and the other as cystic teratoma. Conclusion Prenatal MRI has good clinical value in the diagnosis and differential diagnosis of fetal BPS.

Objective To evaluate the protective effects of oxymatrine injection on rats with endotoxic shock. Methods Wistar rat model of endotoxic shock was produced in this study. Twenty-four Wistar rats were randomly divided into normal control group (n=8), endotoxic shock group (n=8) and oxymatrine injection treatment group (n=8). Fifteen min?utes after the infusion of LPS (15 mg/kg) from femoral vein, oxymatrine was injected from femoral vein in treatment group, then we observed the mean arterial pressure (MAP) for six hours. At the end of experiment blood samples were harvested for measurement of urea and creatinine (Cr), which reflect renal function. Also contents of IL-6, IL-10, TNF-αin the renal ho?mogenate were detected. Results Oxymatrine can prevent progressive decrease of MAP in endotoxin shock treatment group. The contents of plasma urea and Cr were significantly higher in endotoxin shock group than those of control group. The contents of IL-6, IL-10 and TNF-αin renal homogenate increased obviously, but after the injection of oxymatrine, the contents of urea and Cr significantly decreased in treatment group, also IL-6 and TNF-α were significantly declined. Conclusion Oxymatrine provides protection at renal function after endotoxin shock, and its mechanism may be related to inhibit the releasing of inflammatory cytokines in kidney.

OBJECTIVETo perform a retrospective cohort study in order to determine the differences in short-term curative effect of ribavirin in combination with interferon alfa (IFNa)-2a vs. pegylated (Peg)-IFNa-2a in patients with chronic hepatitis C (CHC).

METHODSOne-hundred-and-eighty-eight treatment of the CHC patients who were administered combination therapy of ribavirin with IFNa from 2010 to 2012. One-hundred-and-thirty-three of the patients received the therapy with IFNa-2a and the remaining 55 received Peg-IFNa-2a. Hepatitis C virus (HCV) load and levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured at treatment weeks 4, 12, 24, and 48. Adverse reactions were recorded. Differences between the groups were assessed by statistical analysis.

RESULTSThe patients in the Peg-IFNa-2a group and the IFNa-2a group showed no significant difference in sex distribution, age, smoking habits, or drinking habits at baseline (all P more than 0.05). Both antiviral therapies significantly reduced the HCV load and levels of ALT and AST (baseline levels vs. all treatment weeks examined, P less than 0.05); however, the reduction in the HCV load at week 4 was significantly more robust with the Peg-IFNa-2a therapy (2.96 ± 0.66) log10 IU/ ml vs. (3.47 ± 1.42)1og10 IU/ml; F =4.14, P=0.04). The Peg-IFNa-2a group also showed a significant higher rate of rapid virological response (RVR) than the IFNa-2a group (72.72% vs .57.14%; x²=4.37, P=0.04), but there were no statistically significant differences found between the two groups for early virological response rate (EVR), endpoint antiviral treatment virologic response rate (ETR), biochemical response rate, or rate of adverse reactions (all P more than 0.05).

CONCLUSIONRibavirin in combination with Peg-IFNa-2a produces a better RVR than in combination with IFNa-2a .Yet, the EVR, ETR, biochemical response rate, and rate of adverse reactions is similar for the two forms of IFNa-2a. Further studies are required to determine the potential superiority of Peg-IFNa-2a for a long-term curative effect.

Adolescent ; Adult ; Aged ; Antiviral Agents ; therapeutic use ; Child ; Child, Preschool ; Drug Therapy, Combination ; Female ; Hepatitis C, Chronic ; drug therapy ; Humans ; Infant ; Infant, Newborn ; Interferon-alpha ; therapeutic use ; Male ; Middle Aged ; Polyethylene Glycols ; therapeutic use ; Recombinant Proteins ; therapeutic use ; Retrospective Studies ; Ribavirin ; therapeutic use ; Treatment Outcome ; Young Adult

To analyze and evaluate the knowledge of Chinese Guidelines of Diabetes Prevention and Treatment in Shanghai medical staff. 175 medical staff working in endocrinology or community health were enrolled and evaluated by a questionnaire of guidelines about the state of professional, training, and related knowledge. Only 16. 6% medical staffwere trained about the guidelines( 46. 67% from the general hospitals, 14. 75% from secod-level hospital and 7. 14% persons from the community hospitals, P＜0. 01 ). The total correct answer rate of the guidelines was 37. 36%. The correct rate of community hospitals was lower than others( P＜0. 05 ). The rate of doctors' was higher than nurses'( P＜0. 05 ). There were difference between doctors and nurses with the key point of diabetes care knowledge in different level hospitals. The effective method of clinical training in diabetes care should be explored. We still have to work hard to promote the effect of diabetes control and prevention. Effective training about the guidelines should be enhanced. The cooperation between general hospitals and community health institutions in diabetes prevention and treatment should be enhanced.

Objective To review the diagnosis and treatment of hepatic veno-occlusive disease(HVOD)induced by sedum aizoon in HBsAg positive patients. Methods Clinical data of 35 HBsAg positive cases who took sedum aizoon decoction and developed HVOD were collected, the clinical manifestation, imaging examination, histological examination of liver puncture biopsy, and the outcomes of patients were reviewed. Results Hepatomegaly, liver dysfunction, abdominal effusion and map-like density changes in liver CT scan were observed in 35 patients. Liver biopsy wag performed in 17 patients. In histopathological examination, the swelling and point-like necrosis of liver cells, expansion and congestion of sinus, endothelial swelling, wall thickening, incomplete lumen occlusion of small liver vascular were observed. Map-like density changes in liver CT scan were found in all 17 patients who were diagnosed by histological examination. Fifteen patients presented small amount of ascites within 4 weeks of onset, 13 of whom recovered or improved after treated with low-molecular weight heparin and albumin; while among the remaining 20 patients. only half of them were benefited from the same treatments. Conclusion HVOD can be diagnosed by liver CT scan instead of histological examination; treatment of patients in early stage may improve the outcome.