BACKGROUND:Through a ful investigation of biodegradable scaffolds, we propose a new self-expanding degradable poly-L-lactide coated endotracheal stent based on the design, production, experimental and clinical applications of nickel titanium memory alloy stent. OBJECTIVE:To design a kind of biodegradable endotracheal stent with poly-L-lactide and hydroxyapatite, and to test its mechanical properties, biocompatibility and biodegradation capacity. METHODS:With the technology of computer aided design, the stents were prepared with poly-L-lactide (Mr RESULTS AND CONCLUSION:The average radial supporting force of the tracheal stent was 7.8 kPa, the percentage of stent surface coverage was less than 20%, the stent expansion rate was≥4%, and the stent longitudinal shortening rate was≤9%, which reached the mechanical requirements for degradable endotracheal stents. After 4-16 weeks, there was no significant inflammatory response. The decline in molecular weight changes and weight loss ratio was higher for in vivo degradation than in vitro degradation at different time (P<0.05). These findings indicate that poly-L-lactide/hydroxyapatite composite stents have good mechanical properties, biocompatibility and biodegradability. 150 000) and hydroxyapatite materials, 20 mm to 26 mm in diameter. The mechanical properties were tested using a universal testing machine. These poly-L-lactide/hydroxyapatite stents were implanted into dog models of tracheal stenosis at an appropriate size. The histopathological changes of the tracheas were observed, and biodegradation property was studied via molecular weight changes and weight loss ratio after 4, 8, 12, 16 weeks.

Objective To investigate and analyze the double-disk inhibiting synergy test for detecting AmpC β-lactamase pro-duced by Klebsiella pneumoniae and to evaluate its application value in clinical laboratory.Methods The cefoxitin disk agar diffu-sion method,cefoxitin three-dimensional method,double-disk inhibiting synergy test and drug resistance gene multiplex PCR assay were adopted to detect the clinically isolated bacterial strains.Results Among 137 clinically isolated strains of Klebsiella pneumoni-ae,22 strains were insensitive to cefoxitin and 11 strains were positive by the three-dimensional method;in the double-disk inhibiting synergy test,18 strains were positive for the FOX/FOX+PBA group and 11 strains were positive for the CTT/CTT+PBA group respectively;in the multiplex PCR assay,19 strains were positive.The coincidence rate of the cefoxitin three-dimensional method and multiplex PCR methods was 47.4%(9/19),in the double-disk inhibiting synergy test,the coincidence rate of the positive re-sults in the CTT/CTT+PBA group and the multiplex PCR methods was 57.9%(11/19);the coincidence rate of the FOX/FOX+PBA group and multiplex PCR methods was 94.7%(18/19).Conclusion The double-disk inhibiting synergy test is simple with highly accurate results,in which the FOX/FOX+PBA double-disk synergy test could be applied to detect AmpC β-lactamase pro-duced by clinical isolates of Klebsiella pneumoniae.

OBJECTIVE To investigate the in vitro antimicrobial susceptibility of Streptococcus pneumoniae and guide the rational use of drug clinically. METHODS We performed statistical analysis of the susceptibility of 62 strains of S.pneumoniae isolated in our hospital from May 2007 to Aug 2008. RESULTS S.pneumonia e could be isolated from various specimens,most of them were isolated from sputum(84.0%).S.pneumoniae could be detected from many hospital wards,but more strains isolated from pediatric(67.8%) and respiratory(11.4%) departments.A total of 67.7% of S.pneumoniae isolates were penicillin non-susceptible,the resistance prevalence to tetracycline was 87.1%,to erythromycin 79.0% and to trimethoprim/sulfamethoxazole 49%,while they were highly susceptible to ofloxacin(90.3%),vancomycin(91.9%),levofloxacin(95.2%),moxifloxacin(96.8%) and rifampicin(98.4%),and more strains showed multi-resistance from penicillin non-susceptible isolates. CONCLUSIONS The resistance to penicillin of S.pneumoniae is serious in our hospital.The tetracycline and erythromycin are not the best ckoice in treating S.pneumoniae infection,and the new fluroquinolones show strong activity against S.pneumoniae.

OBJECTIVE To explore the incidence rate,pathogen distribution and characteristics of drug resistance of ventilator-associated pneumonia(VAP) patients due to acute lung injury and acute respiratory distress syndrome(ALI/ARDS) after severe injury,and analyze impact factors on VAP.METHODS All 183 cases with ALI/ARDS after severe injury from Jan 2004 to Mar 2008,were admiitted and given mechanic ventilation over 48 hours in our ICU and EICU.RESULTS VAP was found in 98 cases,accounted for 53.56%.Among them,42 were early-onset VAP and the other 56 were late-onset VAP.Altogether 276 pathogens were isolated,and most of them were Pseudomonas aeruginosa,Staphylococci aureus,Klebsiella pneumoniae,Acinetobacter baumannii and Escherichia coli.In 41 cases only one pathogen was isolated,the other 57 cases were with two or above pathogens.The revealed important risk factors were coma,prolonged mechanical ventilation,tracheotomy,antiacid treatment,use of antimicrobial agents and low albumin.CONCLUSIONS The incidence rate of VAP due to ALI/ARDS is high,and most of the isolated pathogens are drug resistant.Mixed infections are found commonly in these cases.

Objective To compare the therapeutic effect of low-frequency electrical stimulation at the acupoints with that of conventional Western medication among patients with post-stroke insomnia,and explore the underlying mechanism.Methods Totally 120 stroke survivors with insomnia were randomly divided into an intervention group,a medication group and a placebo group,each of 40.The intervention group received low-frequency electrical stimulation at the Dazhui and Shenshu acupoints once a day for 30 consecutive days.The medication group received 1 mg estazolam capsules and the placebo group took 1 mg starch capsules.The average levels of plasma dopamine (DA) of the 3 groups were compared before and after the intervention and therapeutic efficacy was estimated.Results After the intervention,the total effective rate of the intervention group was 95％ (38/40).For the medication group it was 92.5％ (37/40) and for the placebo group it was 17.9％ (7/39).The former two treatments were significantly more effective than no treatment (the placebo).There was no significant change in the average level of plasma DA before and after the treatment in the placebo group,but significant improvement was observed in the other two groups.There was no significant difference in plasma DA between the two treatment groups after the treatment.Conclusion Low-frequency electrical stimulation at acupoints is safe and equally as effective as estazolam for treating post-stroke insomnia.Both may alleviate post-stroke insomnia by increasing plasma DA levels.

Objective To study the effect of group rehabilitation therapy on upper limb and hand function in hemiplegic patients after stroke.Methods Sixty-four stroke survivors with hemiplegia were randomly divided into a group rehabilitation group (GG) (32 cases) and a control group (CG) (32 cases).All patients in both groups were given basic medication and conventional rehabilitation treatment.In addition,the patients in CG were given routine upper limb function training,while the patients in GG were provided with the group rehabilitation therapy.Before and after eight weeks of training,the upper limb function and hand function of both groups were measured using the up-per-extremity portion of the Fugl-Meyer Motor Assessment (FMA-UE) and upper extremities functional test (UEFT).Abilities of daily living were measured using the modified Barthel index (MBI).Anxiety and depression were evaluated using the self-rating anxiety scale (SAS) and self-rating depression scale (SDS).Results Before intervention there was no significant difference between the two groups in any of the assessments (P ＞ 0.05).At the end of training,all measurements in both groups were significantly better than those before training (P ＜ 0.05),and the UEFT,MBI,SAS and SDS scores were significantly better in GG than in the CG (P ＜ 0.05).Conclusion The group rehabilitation therapy,in addition to routine training,can improve the upper extremity function,hand function and abilities of daily living,and alleviate anxiety and depression in patients with post-stroke hemiplegia.

Objective To investigate the effects of motor imagery therapy combined with scalp acupuncture on balance and walking abilities in hemiplegic stroke survivors.Methods A total of 120 patients with post-stroke hemiparesis were randomly divided into 3 groups,each of 40 cases.All patients were given basic medication and conventional rehabilitation treatment.In addition,the motor imagery group accepted motor imagery therapy,the scalp acupuncture group received scalp acupuncture,and the treatment group was provided with the above both for 6 weeks.The 10 m maximum walking speed (10 m MWS),Berg balance scale (BBS),functional ambulation classification (FAC) and timed up and go test (TUGT) were conducted to evaluate balance and gait abilities before and after the intervention.Results There were no significant differences among the 3 groups in any of the assessments (P ＞ 0.05) before intervention (P ＞ 0.05).After six weeks' intervention,all measurements of the 3 groups were significantly better than those before that (P ＜ 0.05),and the effects of the treatment group were significantly better than those of the other 2 groups (P ＜ 0.05).Conclusion Motor imagery therapy combined with scalp acupuncture can distinctly improve the balance and walking abilities in hemiplegic stroke survivors,superior to the effect of solely motor imagery therapy or scalp acupuncture.

Objective To investigate the effect of motor imagery therapy supplemented with scalp acupuncture for improving the lower limb motor function of stroke patients with hemiplegia.Methods A total of 120 hemiplegic stroke patients were randomly divided into an experimental group and a control group with 60 patients in each.All were given routine medical care and scalp acupuncture (stimulating the posterior and anterior oblique line of the parietal-temporal lobe contralateral to the hemiplegic limb).The treatment was given daily for 3 weeks as one session,and 2 sessions were administered to both groups.The experimental group was given motor imagery therapy in addition.Each treatment took about 25 min every day for 3 weeks as one session,and again 2 consecutive sessions were administered.The temporal and spatial gait parameters (10m maximum walking speed,stride length and cadence) of all of the patients were assessed,the Fugl-Meyer lower extremity assessment (FMA-L) was conducted and functional ambulation classifications (FACs) were assigned before therapy and at the end of the 6 weeks.Results After 6 weeks of treatment,all of the measures had improved significantly for both groups.The experimental group,however,had improved significantly more than the control group.Conclusion Motor imagery therapy can supplement scalp acupuncture to improve lower limb motor function in hemiplegic stroke patients.

Objective To investigate the genotype and epidemiology of plasmid‐mediated AmpC β‐lactamases produced by the clinical strains of Escherichia coli and Klebsiella pneumoniae .Methods A total of 176 clinical nonrepetitive cefoxitin non‐sensitivity isolates of Escherichia coli and Klebsiella pneumoniae was collected from July 2011 to August 2012 .Polymerase chain reaction (PCR) for AmpC enzyme gene amplification and DNA sequencing were carried out for genotype of AmpC beta‐lactamases .Results The results of PCR showed that the positive rate of ampC of the 176 strains of Escherichia coli and Klebsiella pneumoniae AmpC was 18 .2% ,mainly DHA type ,counting for 59 .4% ,CIT counting for 37 .5% ,EBC counting for 3 .1% .The positive rate of ampC of Escherichia coli was 11 .4% ,mainly CIT type ,counting for 77 .8% ,the positive rates of DHA type and EBC type both were 11 .1% .The positive rate of ampC of Klebsiella pneumoniae were 23 .7% ,mainly DHA type ,counting for 78 .3% ,CIT type count‐ing for 21 .7% .The results of DNA sequencing showed that there were 18 strains DHA‐1 type and 1 strain ampC gene type of Morganella morganii in DHA type strains ,the concordance rate was 97 .0% ,10 CIT type strains was CMY‐2 type ,1 strain was CMY‐42 ,one strain was CMY‐4 type ,EBC type was ampC gene type of Enterobacter cloacae ,the concordance rate was 99 .0% .A total of 32 strains of gene sequencing were registered as KJ127248 - KJ127279 in GenBank .Conclusion The main genotypes of plasmid‐mediated ampC enzyme produced by Escherichia coli and Klebsiella pneumoniae were CMY‐2 and DHA‐1 respectively .

Objective To construct a mutant strain of Streptococcus mutans ( S.mutans ) with clpC-deletion and to investigate the role of clpC gene in genetic competence.Methods The fragment of clpC gene and the kanamycin resistant cassette flanked by two loxP sites were amplified by PCR.The purified fragment of clpC gene was cloned into pMD-19T simple vector to construct pCKX1.The pCKX1 vector was digested with ClaⅠ/EcoRⅠ, then blunted and introduced into lox71-KMR-lox66 to obtain pCKX2 vector via homologous recombination.The pCKX2 vector was linearized with SalⅠ and transformed into S.mutans UA159 strain.The positive strains constructed via homologous recombination were screened with kanamycin and transformed with the thermosensitive plasmid pCrePA.The KMR cassette was excised after incubating at 30℃ for 48 hours.Then the pCrePA plasmid was removed after overnight incubating at 37℃for the prepara-tion of clpC-deletion mutant.Total RNA were extracted from the S.mutans UA159 strain and the clpC-dele-tion mutant strain respectively, and then reverse transcribed into first strand cDNA.The target gene frag-ments were amplified by RT-PCR and analyzed by the agarose gel electrophoresis and sequencing.After be-ing verified by PCR and sequencing, the S.mutans UA159 strain and the clpC-deletion mutant strain were re-spectively transformed with E.coli-S.mutans shuttle vector pDL276 to observe the competence development induced by the competence-stimulating peptide (CSP).Results The PCR and sequencing results showed that the pCKX2 vector and the mutant strain with clpC-deletion were constructed successfully via homologous recombination.No clpC gene was detected in the clpC-deletion mutant as indicated by RT-PCR analysis.The formation of competent clpC-deletion mutant was delayed and the competence state was prolonged as com-pared with its parent strains.Conclusion The clpC gene negatively regulated the formation of competent S.mutans.