To capture a state of the enzyme in complex with an intact substrate, we developed and adopted a novel freezing method in crystal preparation procedure. Neither the elimination of the catalytically indispensable ligands, nor mutation or modification of the active site is required. At -20 degrees C, we soaked the crystal of 6-phosphate-beta-glucosidase (Bg1A) in the liquor containing p-nitrophenyl-beta-D-glucopyranoside-6-phosphate (pNPbetaG6P). The diffraction data at 2 A resolution was collected and an intact and unambiguous electron density map of pNPbetaG6P was obtained. These results provide an effective method for the research of cryoenzymology and the intermediate state of enzyme-substrate complex in the future.
Cold Temperature ; Crystallization ; Glucosidases ; chemistry ; metabolism ; Substrate Specificity ; X-Ray Diffraction

OBJECTIVETo investigate the effect of noise on the antioxidant capacity in different regions of brain tissue in guinea pigs.

METHODSThirty male white red-eye guinea pigs were equally and randomly divided into five groups: 1-, 3-, 7-, and 14-day groups after noise exposure and control group. The guinea pigs of the experimental groups were exposed to steady white noise with a sound pressure level at 100 dB for 8 h per day and for 2 consecutive days. The auditory brainstem response (ABR) of guinea pigs, as well as the glutathione (GSH) level, methane dicarboxylic aldehyde (MDA) level, and superoxide dismutase (SOD) activity in the cerebrum, cerebellum, and hippocampus, was determined prior to and 1, 3, 7, and 14 days after noise exposure.

RESULTSAfter noise exposure, the shifts in ABR threshold of the experimental groups were significantly higher than that of the control group (P<0.05). Compared with those in the control group, the SOD activity and GSH level both significantly decreased in the cerebrum tissue of each experimental group after noise exposure (P<0.05) and MDA content significantly increased in the 1-day group (P<0.05). As for cerebellum tissue, the SOD activity and GSH level in the 7-day group were significantly lower than those in the control group (P<0.05), but there was no difference in MDA level between each experimental group and the control group (P>0.05). In comparison with those in the control group, the GSH and MDA levels in the 1-day group after noise exposure were significantly higher, and the GSH and MDA levels in the 3-day group and the MDA level in the 7-day group after noise exposure were significantly lower (all P<0.05).

CONCLUSIONNoise exposure can lead to hearing loss and affect the antioxidant capacity of brain tissue, which indicates that the improvement in antioxidant levels may alleviate noise-induced damage.

Animals ; Antioxidants ; chemistry ; Brain ; metabolism ; Brain Chemistry ; Evoked Potentials, Auditory, Brain Stem ; Glutathione ; chemistry ; Guinea Pigs ; Male ; Malondialdehyde ; chemistry ; Noise ; adverse effects ; Superoxide Dismutase ; chemistry

Objective To determine the risk factors for emergence agitation (EA) during the recovery period after general anesthesia.Methods One thousand and thirty-four patients of both sexes aged 18-89 yr undergoing general anesthesia were divided into EA group and non-EA group.EA occurring during recovery from general anesthesia was assessed by using Riker sedation-agitation scale.Age,sex,complication,education,medical history,ASA physical status,type and duration of anesthesia and operation,volume of blood loss,fluid replacement,urine volume,duration of stay in PACU,number of drainage tubes and so forth were recorded.Multivariate logistic regression was used to analyze the risk factors for the occurrence of EA.Results Thirty-six patients developed EA during recovery from anesthesia.The incidence of EA was 3.5 ％.Logistic regression indicated that high risk operation,premedication with diazepam,induction of anesthesia without midazolom and fluid replacement during operation were the risk factors for EA (P ＜ 0.05).Conclusion High-risk operation,premedication with diazepam,induction of anesthesia without midazolom and fluid replacement during operation are the risk factors for EA during recovery from general anesthesia.

Objective To investigate the effects of ketamine on neuronal nitric oxide synthase (nNOS) activity and carboxy-terminal PDZ ligand of nNOS (CAPON) expression in the prefrontal lobe of mentally depressed rats.Methods Adult male Sprague-Dawley rats,aged 2.5-3.0 months,weighing 210-260 g,were used in the study.Menial depression was induced by exposing the rats to chronic unpredictable mild stress.Twenty-four animals in which mental depression was successfully induced were randomly divided into 2 groups (n =12 each):mental depression group (group D) and ketamine group (group K).Another 12 rats were chosen and served as control group (group C).Group K received intraperitoneal ketamine 10 mg/kg once a day for 7 consecutive days,while groups C and D received intraperitoneal normal saline 10 ml/kg instead of ketamine.Sucrose preference test and open field test were performed before administration and at 1 day after the end of administration.The total distance,number of rearing and sucrose preference percentage (SPP) were recorded.The rats were sacrificed 1 day after the last test for determination of the expression of nNOS and CAPON protein (using immuno-histochemistry)and mRNA (by RT-PCR) in the prefrontal lobe.Results Compared with group C,the total distance was shortened,the number of rearing and SPP were significantly decreased,the expression of nNOS protein and mRNA was up-regulated and the expression of CAPON protein and mRNA was down-regulated in groups D and K (P ＜ 0.05).Compared with group D,the total distance was prolonged,the number of rearing and SPP were significantly increased,the expression of nNOS and mRNA was down-regulated and the expression of CAPON protein and mRNA was up-regulated in group K (P ＜ 0.05).Conclusion Ketamine can improve the depressive state through promoting the expression of CAPON and inhibiting nNOS activity in the prefrontal lobe of mentally depressed rats.

Objective To analyze the level of cardiac troponin I (cTnI) in children with left-to-right shunt congenital heart disease (CHD). Methods In this study, 146 children with secundum atrial septal (ASD) defect, 132 children with ventricular septal defect (VSD) and 300 healthy children were recruited. The levels of cTnI and N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured and their correlation with clinical data was analyzed. Results The serum cTnI and NT-proBNP levels in both ASD and VSD patients were signiifcantly higher than those in normal children (H=3.89 and 5.27, P<0.01). The serum cTnI and NT-proBNP levels in VSD patients were signiifcantly higher than those in ASD patients (P<0.05). The ratio of pulmonary to systemic arterial pressure (Pp/Ps), pulmonary vascular resistance index (PVRI) and standardized left ventricular end diastolic volume in VSD patients were signiifcantly higher than those in ASD patients (P<0.05). Multiple regression analysis showed that Pp/Ps was signiifcantly correlated with cTnI in VSD patients. (β=0.81, SE=0.03, P=0.000). Conclusions Signiifcant volume and pressure overload due to a left-to-right shunt induce myocardial injury and could lead to irreversible myocardial remodeling in children with CHD. The serum cTnI level is a sensitive biomarker for myocardial damage in VSD patients.

Objective:To assess the efficacy and the safety of the radiofrequency catheter ablation (RFCA) for the septal accessory pathway (AP) in children.Methods:From September 2013 to March 2019, 626 patients plan to underwent RFCA for paroxysmal supraventricular tachycardia (PSVT) in Shanghai Children′s Medical Center Affiliated to Shanghai Jiaotong University School of Medicine.Among them, 74 consecutive patients with right or left septal APs were included in the study and their clinical and RFCA data were analyzed.Results:The age of these 74 children (45 males, 29 female) was (7.8±3.5) years, ranging from 10 months to 13 years.The body weight (BW) was (27.7±14.4) kg, with 3 patients BW<15 kg.A discordant ventricular wall motion (DVWM) was found in 5 patients, and the combined congenital heart diseases were discovered in 2 patients.A three dimensional mapping system was applied in 69 ablations, and 3 ablations were performed only with the fluoroscopy monitor of 5 cases.According to the AP location, the number of cases located in the anteroseptal, the midseptal, the mouth of coronary sinus, the left posteroseptal and the right posteroseptal, were 28, 18, 10, 10 and 8, respectively.The ablation operations were applied in 72 patients.The initial acute success reached in 67 (93.1%) patients.The ablation energy was (18.0±1.8) W, the fluoroscopy time during the ablations was (4.7±2.7) minutes, and the procedure duration was (151.5±58.6) minutes.One inadvertent complete atrioventricular block (AVB) was noted as the ablation-related complication.All 5 children with the pre-DVWM were recovered after ablations.During a follow-up of (23.8±10.8) months, 4 patients experienced the recurrence of preexcitation syndrome atrioventricular reentrant tachycardia.Conclusions:With the 3D-mapping system, the RFCA of septal APs can be performed safely and effectively in pediatric patients of paroxysmal supraventri-cular tachycardia.However, as the ablation-related complication, AVB should not be ignored.

Objective To evaluate the effect of continuous passive motion (CPM) as an adjunct to active physiotherapy on pain and range of motion (ROM) after knee arthroplasty. Methods 20 female osteoarthritis patients (40 knees) undergoing bilateral knee arthroplasty were assigned into two groups. The experimental group received CPM and active physiotherapy twice a day while the control group received active physiotherapy only. They were assessed with visual analogue scale (VAS) and goniometer on pain and ROM of knee before and after operation. Results There were no statistical difference between these two groups for any outcome measures either 2 weeks or 3 months after operation (P>0.05), and they all improved in pain and ROM 3 months after operation compared with before (P<0.01). Conclusion CPM as an adjunctive therapy is not found to have an additional effect on pain or ROM 3 months after operation while active physiotherapy was used.

Objective To study the molecular biology of rifampin-depending M. Tuberculosis. Methods The seguence (a 319-bp DNA fragment) of rpoB gene were analyzed by automated DNA sequencing machine. (2) The fingerprints of genomic DNA were obtained by random amplified polymorphic DNA (RAPD) fingerprinting. (3)The protein electrophoresis of bacterium by SDS-polyacrylamide gel (SDS-PAG).(4) The cases of pulmonary tuberculosis by rifampin-depending strains were retrospectively analyzed. Results (1) rpoB gene sequenced: The point mutationrate of rifampin-depending strainswas 96.7%(29/30) and that of rifampin-residtant strains 81.1%(30/37), P

Animals ; Connective Tissue Growth Factor ; metabolism ; Fibrosis ; Herbicides ; poisoning ; Lentivirus ; Lung ; pathology ; Paraquat ; poisoning ; Poisoning ; pathology ; Pulmonary Fibrosis ; pathology ; RNA Interference ; RNA, Small Interfering ; Rats

GATA6 transcription factor belongs to the GATA family and contains 2 conserved zinc ifnger DNA binding domains. GATA6 not only presents in embryonic tissues but also found in heart, lung and pancreas and is essential for the maintenance of their function.The present review focuses on the critical roles of GATA6 in heart development and atrial septal defect to provide theoretical basis for diagnosis and treatment of atrial septal defect.