Objective:To evaluate the effect of intra-articular injection of different concentrations of ozonated water on articular cartilage of rabbits with osteoarthritis (OA).Methods:Twenty-four clean-grade New Zealand white rabbits of both sexes, weighing 2.0-3.0 kg, aged 6 months, were divided into 4 groups ( n=6 each) using a random number table method: control group (group C), OA group, low concentration ozonated water group (L group) and high concentration ozonated water group (H group). The OA model was established by intra-articular injection of papain.At 2 weeks after the model was successfully established, 10.0 and 20.0 μg/ml ozonated water 1.0 ml was injected into the knee joint of rabbits in L and H groups, respectively, and 0.9% sodium chloride solution 1.0 ml was injected once a week, 3 times in total in OA group.At 1 week after the last injection, the cartilage tissue of the knee joint was removed and stained with toluidine blue for evaluation of Mankin score (under light microscope). The activity of caspase-3 in chondrocyte was detected by enzyme-linked immunosorbent assay. Results:Compared with group C, the Mankin score and caspase-3 activity were significantly increased in the other 3 groups ( P<0.05). Compared with group OA, the Mankin score and caspase-3 activity were significantly decreased in group L and group H ( P<0.05). Compared with group L, the Mankin score was significantly increased, and the activity of caspase-3 was decreased in group H ( P<0.05). Conclusion:Injecting ozonated water 10.0 μg/ml and 20.0 μg/ml into the knee joint cavity both can inhibit the apoptosis in chondrocytes and reduce the damage to articular cartilage, however, high concentration of ozonated water can cause the denaturation of the articular cartilage matrix in rabbits with OA.

Objective:To evaluate the effect of orexin-A on programmed necrosis during cerebral ischemia-reperfusion (I/R) in rats.Methods:Thirty clean-grade healthy adult male Spraugue-Dawley rats, weighing 280-320 g, were divided into 3 groups ( n=10 each) using a random number table method: sham operation group (Sham group), cerebral I/R group (I/R group) and orexin-A group (OA group). In I/R and OA groups, a rat model of global cerebral I/R injury was established by transesophageal cardiac pacing-induced cardiac arrest and cardiopulmonary resuscitation in anesthetized animals.Orexin-A 30 μg/kg (diluted to 0.5 ml in phosphate buffer solution) was intravenously injected at 10 min before establishing the model in OA group.Phosphate buffer solution 0.5 ml was intravenously injected at 10 min before establishing the model in Sham and I/R groups.The neurological deficit score (NDS) was assessed at 24 h of reperfusion, then the rats were sacrificed, and bilateral hippocampal tissues were obtained.The morphological structure of pyramidal cells in the hippocampal CA1 region was examined after HE staining, and normal pyramidal cells were counted.Western blot was used to detect the expression of receptor-interacting protein 1 (RIP1), RIP3 and mixed-lineage kinase domain-like protein (MLKL). Immuno-histochemistry was used to count RIP1, RIP3 and MLKL positive cells in the hippocampal CA1 region.The activity of superoxide dismutase (SOD) in hippocampi was determined by xanthine oxidase method, and the content of malondialdehyde (MDA) in hippocampi was determined by thiobarbituric acid method. Results:Compared with Sham group, the normal pyramidal cell count in the hippocampal CA1 region was significantly decreased, NDS was increased, the expression of RIP1, RIP3 and MLKL protein was up-regulated, the positive cell count was increased, the content of MDA in hippocampi was increased, and the activity of SOD in hippocampi was decreased in I/R and OA groups ( P<0.05). Compared with I/R group, the count of normal pyramidal cells in the hippocampal CA1 region was significantly increased, NDS was decreased, the expression of RIP1, RIP3 and MLKL protein was down-regulated, the count of positive cells was decreased, the content of hippocampal MDA was decreased, and the activity of hippocampal SOD was increased in OA group ( P<0.05). Conclusion:The mechanism by which orexin-A reduces cerebral I/R injury may be related to inhibiting programmed necrosis in rats.

Objective:To analyze the molecular epidemiology and virulence characteristics of polymyxin-resistant Klebsiella pneumoniae ( K. pneumoniae). Methods:From 2011 to 2016, 1 376 strains of K. pneumoniae were isolated from various clinical specimens of hospitalized patients in First Affiliated Hospital of Wenzhou Medical University. Agar dilution method was used to screen out the polymyxin-resistant strains.Polymerase chain reaction (PCR) was used to detect the genes related to polymyxin resistance, and real-time fluorescence quantitative PCR was used to detect the relative mRNA expression level of drug resistant genes. Pulsed-field gel electrophoresis, multilocus sequence typing and Galleria mellonella larvae infection model were performed to analyze the molecular epidemiological and virulent characteristics. Results:A total of 14 strains (1.02%) of polymyxin-resistant K. pneumoniae were detected among 1 376 K. pneumoniae isolates. Subsequent sequencing identified mutations leading to amino-acid changes (K2E, F28C) in MgrB of 10 isolates and D150G in PhoQ of nine isolates, and genes such as mcr and crrB were not detected in all drug-resistant strains. Compared with standard strains, the relative expression levels of pmrH and pmrD mRNA of these drug resistant strains were increased. Analysis of the molecular epidemiology indicated that the 14 drug-resistant strains were divided into nine clones. Galleria mellonella larvae infection model revealed polymyxin-resistant K. pneumoniae isolates had higher virulence. Conclusions:Polymyxin-resistant K. pneumoniae has mutations in mgrB and phoQ genes, and mgrB mutation may play a key role in the change of virulence profiles. The homology among the polymyxin-resistant K. pneumoniae stains in this study is low.

Objective: To investigate the distribution and expression of T3SS virulence genes in clinically isolated Pseudomonas aeruginosa (P. aeruginosa) strains and its correlation with drug resistance. Methods: A total of 68 P. aeruginosa isolates were collected from the First Affiliated Hospital of Wenzhou Medical University in 2015. The antimicrobial susceptibility was detected by the agar dilution method. The distribution of virulence genes such as exoU, exoS, exoT and exoY from different isolates was detected by PCR. The expression levels of transcriptional regulator genes (ptrA and exsA) and effector-related genes (exoT and exoS) in some isolates were determined by real-time fluorescence quantitative PCR, and the Pearson correlation analysis was used to analyze the results. Results: The detection rates of exoT and exoY in 68 P. aeruginosa isolates were higher, accounting for 79.4% and 75.0%, respectively. The detection rate of exoT in wound-sourced isolates was significantly higher than that in sputum (97.0% vs 61.8%, P＜0.01). In addition, the genotype of exoU - /exoS + was the most common, accounting for 51.5% (35/68). The resistance rates of sputum-sourced isolates to imipenem and meropenem were significantly higher than that of wound-sourced isolates (47.1% vs 8.8%, 47.1% vs 14.7%, P＜0.01). The resistance rates of isolates carrying exoU gene to carbapenems, aminoglycosides and fluoroquinolones were higher than those of isolates carrying exoS, exoT or exoY genes. Pearson correlation analysis showed that the expression level of ptrA gene was negatively correlated with those of exoT, exoS and exsA genes (P＜0.05). Conclusion The P. aeruginosa isolates from our hospital carrying T3SS virulence genes exoT and exoY are common, and the virulence genes are related to the drug resistance of P. aeruginosa. In addition, ptrA may be a potential negative regulatory gene for the expression of T3SS virulence genes.

Objective To evaluate the effect of ulinastatin on programmed necrosis in hippocampal neurons in a rat model of global cerebral ischemia-reperfusion (I/R).Methods Forty-eight clean-grade healthy adult male Sprague-Dawley rats,aged 8 weeks,weighing 280-320 g,were divided into 3 groups (n=16 each) using a random number table method:sham operation group (Sham group),global cerebral I/R group (I/R group) and ulinastatin group (UT group).Global cerebral I/R was produced by 4-vessel occlusion method in chloral hydrate-anesthetized rats in I/R and UT groups.Ulinastatin 100 000 U/kg was injected via the tail vein at the onset of ischemia in group UT,and the equal volume of normal saline was given instead in Sham and I/R groups.Neurological deficit score (NDS) was estimated at 6,12 and 24 h of reperfusion.Animals were sacrificed at 24 h of reperfusion,brains were removed and the hippocampi were obtained for examination of pathological changes (with a light microscope) and for determination of the malondialdehyde (MDA) content and superoxide dismutase (SOD) activity (by spectrophotometry),and expression of receptor-interacting protein kinase 1 (RIPK1),RIPK3,and mixed lineage kinase domain-like protein (MLKL) in hippocampal tissues (by Western blot).Results Compared with Sham group,the NDS was significantly increased at each time point,the MDA content was increased,the SOD activity was decreased,and the expression of RIPK1,RIPK3 and MLKL was up-regulated in I/R and UT groups (P＜ 0.05).Compared with I/R group,the NDS was significantly decreased at each time point,the MDA content was decreased,the SOD activity was increased,and the expression of RIPK1,RIPK3 and MLKL was down-regulated in UT group (P＜0.05).The pathological changes of hippocampi were significantly attenuated in UT group when compared with I/R group.Conclusion The mechanism by which ulinastatin ameliorates global cerebral I/R injury is related to inhibiting programmed necrosis in hippocampal neurons of rats.

Objective To evaluate the development of cerebral anoxia during controlled hypoten-sion with nicardipine or urapidil after carotid endarterectomy in patients. Methods Forty-four patients of either sex, aged 48-64 yr, scheduled for elective carotid endarterectomy under general anesthesia, requi-ring controlled hypotension after operation, were divided into nicardipine group ( group N ) and urapidil group ( group U) using a random number table method, with 22 patients in each group. Nicardipine at 2. 5μg·kg-1 ·min-1 was intravenously infused in group N, and urapidil 2μg·kg-1 ·min-1 was intravenously infused in group U. After systolic blood pressure was decreased to 130-140 mmHg, the consumption of nicardipine was adjusted to 0. 2 - 0. 5 μg·kg-1 ·min-1 and the consumption of urapidil to 1-2μg·kg-1 ·min-1 in group N and group U, respectively, to maintain systolic pressure at 130-140 mmHg. Heart rate ( HR) , cardiac index ( CI) , bispectral index ( BIS) value, regional cerebral oxygen saturation (rSO2) and end-tidal pressure of carbon dioxide (PETCO2) were recorded after entering the operating room ( baseline) , at the beginning of controlled hypotension ( T1 ) , and at 5, 10, 20, 30, 60 and 120 min af-ter systolic blood pressure was decreased to the target hypotension ( T2-7 ) . Development of cerebral anoxia( the relative decrease in rSO2>12％ of the baseline value) was recorded in controlled hypotension period. Results Compared with the value at T1 , the HR at T2,3 and CI at T3-7 were significantly increased ( P<0. 05), and no significant change was found in rSO2, PETCO2 or BIS value at the other time points in group N (P>0. 05), and rSO2 was significantly decreased at T3-7 (P<0. 05), and no significant change was found in HR, CI, PETCO2 or BIS value at the other time points in group U (P>0. 05). Compared with group N, the HR at T2,3, CI at T3-7 and rSO2 at T3-7 were significantly decreased in group U (P<0. 05). The incidence of cerebral anoxia was significantly higher in group U than in group N ( P<0. 05) . Conclu-sion Controlled hypotension with nicardipine is recommended after carotid endarterectomy in order to avoid the development of cerebral anoxia in the patients.

Objective To evaluate the role of nuclear factor erythroid 2-related factor 2 ( Nrf2 ) signaling pathway in endoplasmic reticulum stress response during lipopolysaccharide ( LPS)-induced acute lung injury ( ALI) in mice. Methods Forty clean-grade healthy male C57BL∕6 mice, aged 6-8 weeks, weighing 22-26 g, were divided into 4 groups ( n=10 each) using a random number table method: control group ( group C) , group ALI, salubrinal group ( group S) and salubrinal plus brusatol group ( group S+B) . Animals were intratracheally instilled with 5 mg∕kg of LPS diluted in normal saline to establish the model of ALI. Animals were intratracheally instilled with 100 μl of normal saline in group C. Mice in group S were intraperitoneally injected with endoplasmic reticulum stress response inhibitor 1 mg∕kg salubrinal at 1 and 24 h after LPS instillation. Mice of group S+B were intraperitoneally injected with brusatol 2 mg∕kg once every other day for 10 days prior to LPS instillation, and the other treatments were similar to those previously de-scribed in group S. Mice were sacrificed at 48 h after LPS administration, and lungs were removed for mi-croscopic examination of the pathological changes of lung tissues which were scored and for determination of contents of IL-17A, tumor necrosis factor-alpha ( TNF-α) and interleukin-6 ( IL-6) in lung tissues ( by en-zyme-linked immunosorbent assay) and expression of Nrf2, CCAAT∕enhancer-binding protein homologous protein (CHOP) and caspase-12 in lung tissues (by Western blot). Lung water content was calculated. Results Compared with group C, the lung water content and contents of IL-17A, TNF-α and IL-6 were significantly increased, the expression of CHOP and caspase-12 in cytoplasma was up-regulated, and the ex-pression of Nrf2 in nuclei was down-regulated in ALI and S+B groups, and the lung water content and con-tents of IL-17A, TNF-α and IL-6 were significantly increased, the expression of Nrf2 in nuclei and CHOP in cytoplasma was up-regulated, and the expression of caspase-12 was down-regulated in group S ( P<0. 05) . Compared with group ALI, the lung water content and contents of IL-17A, TNF-α and IL-6 were significantly decreased, the expression of CHOP and caspase-12 in cytoplasma was down-regulated, the ex-pression of Nrf2 in nuclei was up-regulated ( P<0. 05) , and the pathological changes were significantly at-tenuated in group S. Compared with group S, the lung water content and contents of IL-17A, TNF-α and IL-6 were significantly increased, the expression of CHOP and caspase-12 in cytoplasma was up-regulated, the expression of Nrf2 in nuclei was down-regulated ( P<0. 05) , and the pathological changes of lung tis-sues were accentuated in group S+B. Conclusion Nrf2 signaling pathway is involved in the process of en-doplasmic reticulum stress response during LPS-induced ALI in mice.

Objective To evaluate the effect of pulsed radiofrequency (PRF) on spinal adenosine triphosphate (ATP)-P2X4-NLRP3 signaling pathway in rats with neuropathic pain.Methods Forty healthy clean-grade adult male Sprague-Dawley rats,aged 2-3 months,weighing 220-260 g,were divided into 4 groups (n =10 each) using a random number table method:sham operation group (group S),neuropathic pain group (group NP),sham PRF group (group SPRF) and PRF group.Neuropathic pain was induced by chronic constriction injury to the left sciatic nerve of anesthetized rats.Rats received PRF treatment on 7th day after establishing the model in group PRF.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured before establishing the model (T0) and at 3,7,10,14,21 and 28 days after establishing the model (T1-6).The rats were then sacrificed and the spinal cord was removed for determination of P2X4 and NLRP3 expression (by Western blot) and interleukin-1beta (IL-1β),IL-2,IL-6 and tumor necrosis factor-alpha (TNF-α) contents (by enzymelinked immunosorbent assay).Results Compared with group S,the MWT and TWL were significantly decreased at T1-6,the expression of P2X4 and NLRP3 was up-regulated,and the contents of IL-1β,IL-2,IL-6 and TNF-α were increased in NP,SPRF and PRF groups (P＜0.05).Compared with group NP and group SPRF,the MWT and MWT were significantly increased at T3-6,the expression of P2X4 and NLRP3 was down-regulated,and the contents of IL-1 β,IL-2,IL-6 and TNF-α were decreased in group PRF (P＜0.05).Conclusion The mechanism by which PRF alleviates neuropathic pain is related to inhibiting ATP-P2X4-NLRP3 signaling pathway in rats.

Objective To investigate the chlorhexidine acetate-resistance in Klebsiella pneumoniae ( K. pneumoniae) clinical isolates and to analyze the possible mechanisms and molecular epidemiology of re-sistant isolates. Methods A total of 332 K. pneumoniae clinical isolates were collected in the First Affilia-ted Hospital of Wenzhou Medical University in 2015. Standard agar dilution was used to screen chlorhexidine acetate-resistant isolates. The minimum inhibition concentrations ( MIC) of chlorhexidine acetate to resistant isolates with and without the presence of carbonyl cyanide m-chlorophenyl hydrazone ( CCCP) , which was an efflux pump inhibitor, were analyzed. Efflux pump genes of cepA, qacE and qacΔE1 that carried by and ex-pressed in those isolates were detected by polymerase chain reaction ( PCR) and quantitative real-time PCR ( RT-qPCR) , respectively. The biofilm formation ability was measured by crystal violet staining. The homol-ogy among the chlorhexidine acetate-resistant isolates was investigated with multilocus sequence typing ( MLST) and pulsed-field gel electrophoresis ( PFGE) . Results Twenty-five K. pneumoniae strains were re-sistant to chlorhexidine acetate. The MIC values of chlorhexidine acetate for them were reduced by at least four-fold in the presence of CCCP. Strains carrying the genes of cepA, qacE and qacΔE1 accounted for 100％, 40％ and 40％, respectively. The expression of the efflux pump genes in the chlorhexidine acetate-resistant isolates was higher than that in the susceptible isolates. The biofilm formation ability of the chlo-rhexidine acetate-resistant isolates was better than that of the susceptible isolates. Furthermore, negative, weak-positive and positive biofilm formation ability was observed in four ( 16％) , 20 ( 80％) and one (4％) strains, respectively. The results of MLST and PFGE showed that the 25 chlorhexidine acetate-resist-ant isolates belonged to 19 different sequence types ( ST) with diverse PFGE patterns. Conclusions This study suggested that active efflux was the main mechanism of chlorhexidine acetate resistance in K. pneumoni-ae. The 25 chlorhexidine acetate-resistant K. pneumoniae strains possessed different biofilm formation ability and shared low homology.

Objective To investigate the effects of perioperative parecoxib sodium on serum surfactant protein A and inflammatory response in elderly patients undergoing video-assisted thoracoscopic pneumonectomy,Methods Sixty-two ASA Ⅰ or Ⅱ elderly patients,aged 65-78 years,weighing 51-79 kg,scheduled for elective video-assisted thoracoscopic pneumonectomy under general anesthesia,were randomly divided into 3 groups:0.3 mg/kg parecoxib sodium group (group P1,n=21),0.6 mg/kg parecoxib sodium group (group P2,n =21) and control group (group C,n =20).The patients were given intravenous parecoxib sodium of 0.3 mg/kg immediately before induction of anesthesia and at 12 h after operation in group P1,and also parecoxib sodium of 0.6mg/kg immediately before induction of anesthesia and at 12 h after operation in group P2,while the equal volume of normal saline was given in group C.Blood samples were taken from the central vein before the induction of anesthesia(T0),after operation(T1),12 h after operation(T2) and 24 h after operation(T3).The concentration of serum surfactant protein A (SP-A),TNF-α,IL-6 and IL-8 were determined by ELASA.The incidence of pulmonary complications at 72 h after operation were also recorded.Results Compared with T0,the concentration of serum SP-A,TNF-α,IL-6 and IL-8 increased significantly in all groups at T1-T3 (P＜0.05).Compared with C group,the concentration of serum SP-A,TNF-α,IL-6 and IL-8 in groups P1 and P2 decreased significantly at T1-T3 (P＜0.05),there were no significant differences between groups P1 and P2.The incidence of postoperative pulmonary complications had no statistically significant differences between the three groups.Conclusion Parecoxib sodium can significantly reduce the concentration of serum SP-A and alleviate the inflammatory response in elderly patients undergoing video-assisted thoracoscopic pneumonectomy.