In the present study, the expression, purification, toxicity detection and the adjuvant effect of the heat-labile enterotoxin in non-toxic mutant mLT63 of Escherichia coli were investigated, in which the inductive expression was performed under optimal condition for inductive expression and the toxicity of the products obtained from inductive expression were tested for toxicity after being purified and concentrated with affinity chromatography. BALB/c mice were immunized orally with the mutant mLT63 associated with Helicobacter pylori (Hp) subunit vaccine UreB, Omp11. After immunization, the specific antibody levels in serum, extract from gastric tissues and fecal extract were determind by means of ELISA assay and the results were subjected to statistical analysis. It was demonstrated that the mutant mLT63 of heat-labile entrotoxin of E.coli constructed in our laboratory devoided of any toxic effect as revealed by the rabbit ileal loop assay, but its adjuvant effect could be demonstrated in the associated immunization of mice with Hp subunit vaccine UreB and Omp11.

Objective To study the variability of Traditional Chinese version of the Psycho-educational Profile-3rd edition (PEP-3) and Simplified Chinese version of the Psycho-educational Profile (C-PEP) as evaluating the special children. Methods 194 special children were evaluated with C-PEP and PEP-3 from April, 2011 to December, 2014. The scores of cognitive verbal/preverbal, expressive language, recep-tive language, gross motor, fine motor, visual-motor imitation, and communication and physical ability were compared. Results There were significant diferences in all the dimensions between PEP-3 and C-PEP scales (Z>3.446, P<0.01) except cognitive verbal/preverbal (Z=0.912, P=0.362). Conclusion There was difference between PEP-3 and C-PEP for the evaluation of special children.

BACKGROUND:The self-ligating bracket is superior to the conventional bracket in orthodontic treatment, but there are a lot of controversies. At present, researchers have different views on the function of self-ligating brackets. OBJECTIVE:To summarize the comparative study of self-ligating brackets and conventional brackest with the direction and development in recent years. METHODS:A computer-based search of PubMed (2000-2014) and CNKI (2000-2014) databases was done for relevant articles, using the key words of “self-ligating brackets; conventional orthodontic brackets” in English and Chinese, respectively. RESULTS AND CONCLUSION:Self-locking brackets saves chair side time, which has been confirmed and accepted. There are different views for the issue that self-ligating brackets can reduce friction in orthodontic treatment. It is widely accepted that, the self-ligating brackets using thin round wire had less friction than the conventional brackets; whether the friction of self-ligating brackets in the closed gap and fineness adjustment stages is less than the conventional brackets stil remains unclear, which need further clinical comparative studies. The self-ligating brackets showed no significant difference with the conventional brackets in arch expansion, reducing anchorage loss and root adsorption. The majority of relevant studies is performedin vitro, and cannot exactly simulate the dental conditions. A large-size experiment with the uniform criteria for therapeutic efficacy is needed to objectively evaluate self-ligating brackets.

BACKGROUND:Buccal Multiloop Removable Appliance can interceptively correct mutiple adolescent malocclusions. But the clinical problem of Buccal Multiloop fatigue fracture is not solved yet. How to prolong the fatigue fracture cycle is stil in the research stage. OBJECTIVE: To study the effect of different temperature of heat treatment on the Buccal Multiloop fatigue fracture cycle, thereby to select a relatively optimal method to enhance the fatigue fracture cycle. METHODS: Thirty-five left HL-2 Buccal Mltiloops were divided into seven groups according to different ways of heat treatment. Each group consisted of five samples. They were an untreated group, three pre-bending groups (320, 420, 520℃ heat treatment before bending) and three post-bending groups (320, 420, 520℃ heat treatment after bending). The dental stainless steel wires and Buccal Multiloop were respectively treated by low-temperature annealing. The data were recorded and evaluated after the samples tested by the 3D Simulating Movement of TMJ Testing Machine. The features of fatigue fracture were observed by scanning electron microscope. RESULTS AND CONCLUSION: The mean values of the Buccal Multiloop fatigue fracture cycle from largest to smalest were as folows: 520℃ pre-bending group > 420℃ pre-bending group > 320℃ pre-bending group > untreated group > 520℃ post-bending group > 320℃ post-bending group > 420℃ post-bending group. The fatigue fracture cycle of Buccal Multiloop made of the dental stainless steel wires after 520℃ annealing treatment was longer than others. By the observation of scanning electron microscope, the fracture crack extension area had the tendency to expand, transient interruption was delayed and the tissue structure became more uniform.

Objective:To verify the application value of team-based learning (TBL) joint case-based discussion (CBD) method applied in the course teaching of Introduction to General Practice.Methods:Students from two clinical oriented classes in the same grade were divided into the experimental group ( n=35) and the control group ( n=35). The control group implemented the traditional teaching method, and the experimental group implemented the TBL joint CBD method. The teaching effect were compared between the two groups. SPSS 20.0 was used for frequency description and statistical test analysis. Non-normal distribution data were tested with Mann-Whitney U test. Results:After the teaching, the average rank of multiple-choice questions (35.28) and analytic questions (42.24) in the experimental group were significantly higher than those of the control group (32.68 and 25.52, respectively, P<0.05). Conclusion:The TBL joint CBD method applied in the course of general practice helps to improve students' test achievement, enhance their overall quality, and lay a foundation for training comprehensive competencies of general practitioners.

Different neutralizing agents were used as pH controller to investigate their effects on the growth and succinic acid production of Actinobacillus succinogenes NJ113. The fermentation results showed that Ca(OH)2, CaCO3 and NH4OH were not suitable for succinic acid production by A. succinogenes NJ113 because of their negative effects on cell growth. When Na-base was used, cells would flocculate and lump, and due to the sodium ion concentration reaching to a high level, OD660 dropped sharply after 12 h of fermentation. Mg-base was better because there was no significant inhibition by magnesium ion. Two combined neutralizing agents were used to maintain pH level, one with NaOH and Mg(OH)2 while the other with Na2CO3 and Mg(OH)2. The optimum ratios of the combined neutralizing agents were both 1:1 (g:g) when using 100 g/L glucose. When NaOH and Mg(OH)2 were chosen with the ratio of 1:1(g:g), 69.8 g/L of the succinic acid and 74.5% of the yield was obtained.
Actinobacillus ; genetics ; metabolism ; Fermentation ; Hydrogen-Ion Concentration ; Industrial Microbiology ; Magnesium Hydroxide ; pharmacology ; Sodium Hydroxide ; pharmacology ; Succinic Acid ; metabolism

Spent cells recovered from anaerobic fermentation by Actinobacillus succinogenes were used as nitrogen source for succinic acid production. Three methods were investigated for cell wall-breaking. The results showed that enzymatic hydrolysis was more effective for higher succinic acid yield. When the enzymatic hydrolysate of spent cells was added to reach a total nitrogen concentration 1.11 g/L (equivalent to 10 g/L yeast extract), the succinic acid concentration was 42.0 g/L, but it increased slightly when enhancing the level of enzymatic hydrolysate. However, when 5 g/L yeast extract was supplemented with the enzymatic hydrolysate of spent cells, the succinic acid concentration reached 75.5 g/L after 36 hours and, the succinic acid productivity was 2.10 g/(L x h), which increased by 66.7% compared with the fermentation using 10 g/L yeast extract. Therefore, enzymatic hydrolysate of spent cells could replace 50% yeast extract in the original medium for succinic acid production.
Actinobacillus ; metabolism ; Anaerobiosis ; Culture Media ; pharmacology ; Fermentation ; Industrial Waste ; Succinic Acid ; metabolism

Objective:To establish the minimum inhibitory concentration (MIC) detection method of Yersinia pestis by determining MIC of 11 kinds of antibiotics against Yersinia pestis, to master the inhibition range of common antibiotics on Yersinia pestis, and provide baseline data for clinical treatment of plague. Methods:According to Clinical Labor Standard Institution (CLSI), the agar plate dilution method was used to determine the MIC of 11 kinds of antibiotics against 118 strains of Yersinia pestis, including ofloxacin, ciprofloxacin, trimethoprim-sulfamethoxazole, kanamycin, streptomycin, ceftriaxone, ampicillin, chloramphenicol, spectinomycin, cefuroxime and tetracycline. MIC 50 and MIC 90 (the minimum concentration of drug which could inhibit 50% and 90% of bacterial growth) were calculated. The consistency was observed by comparing the results with those of the disk diffusion method. One hundred and eighteen strains of Yersinia pestis were isolated from natural plague foci of Qinghai Province and preserved by Qinghai Institute for Endemic Disease Prevention and Control. Results:Among 118 strains of Yersinia pestis tested, no single or multiple strains of Yersinia pestis resistant to 11 kinds of antibiotics were found, which was consistent with the results of the disk diffusion method. The MIC 50 and MIC 90 of 11 kinds of antibiotics against 118 strains of Yersinia pestis were obtained. Conclusions:The MIC detection method of Yersinia pestis is successfully established. This method can be used to measure the MIC of antibiotics against Yersinia pestis in high throughput and evaluate the sensitivity of Yersinia pestis to antibiotics. It is an efficient, economical and practical experimental method.

Antibodies, Monoclonal, Murine-Derived ; adverse effects ; Antineoplastic Agents ; adverse effects ; Humans ; Lung Diseases, Interstitial ; chemically induced ; Rituximab ; Waldenstrom Macroglobulinemia ; drug therapy

Objective:To investigate the bacterial composition and antimicrobial resistance profile of clinical isolates from bloodstream infections in China.Methods:The clinical bacterial strains isolated from blood culture were collected during January 2020 to December 2020 in member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS). Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute(CLSI, USA). WHONET 5.6 was used to analyze data.Results:During the study period, 10 043 bacterial strains were collected from 54 hospitals, of which 2 664 (26.5%) were Gram-positive bacteria and 7 379 (73.5%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (38.6%), Klebsiella pneumoniae (18.4%), Staphylococcus aureus (9.9%), coagulase-negative Staphylococci (7.5%), Pseudomonas aeruginosa (3.9%), Enterococcus faecium (3.3%), Enterobacter cloacae (2.8%), Enterococcus faecalis (2.6%), Acinetobacter baumannii (2.4%) and Klebsiella spp (1.8%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 27.6% and 74.4%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci were detected. More than 95% of Staphylococcus aureus were sensitive to rifampicin and SMZco. No vancomycin-resistant Enterococci strains were detected. Extended spectrum β-lactamase (ESBL) producing Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 48.4%, 23.6% and 36.1%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.3% and 16.1%, respectively; 9.6% of carbapenem-resistant Klebsiella pneumoniae strains were resistant to ceftazidime/avibactam combination. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii. The prevalence rate of carbapenem-resistance of Pseudomonas aeruginosa was 23.2%. Conclusions:The surveillance results in 2020 showed that the main pathogens of bloodstream infection in China were gram-negative bacteria, while Escherichia coli was the most common pathogen, and ESBL-producing strains declined while carbapenem-resistant Klebsiella pneumoniae kept on high level. The proportion and the prevalence of carbapenem-resistant Pseudomonas aeruginosa were on the rise slowly. On the other side, the MRSA incidence got lower in China, while the overall prevalence of vancomycin-resistant Enterococci was low.