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Objective@#To evaluate the performance of a chromogenic agar developed by our laboratory for the isolation and culture of Clostridium difficile (CDCA). @*Methods@#The chromogenic specificity of CDCA was evaluated by inoculation of C. difficile and other standard strains, and the sensitivities of CDSA (BD), CDIF (BioMérieux) and CDCA were determined by the C. difficile standard strains respectively. A total of 120 clinical stool specimens were cultured for C. difficile by three chromogenic media respectively. The colonies were further identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and tpi gene was also detected. The sample which could be identified as C. difficile in any of the three chromogenic medium was defined as true positive. @*Results@#Most of standard strains were inhibited by CDCA, however some Clostridium species including C. clostridiiforme, C. bifermentans, C. tertium and Bacteroides fragilis grew lightly with chromogenic reaction. The sensitivities of CDSA, CDIF and CDCA were 2.0×105 CFU/mL, 8.0×101 CFU/mL and 4.0×10 2 CFU/mL, respectively. Among the 120 samples, 31 (25.8%) were defined as true C. difficile positive samples, while the positive rate of CDSA, CDIF and CDCA were 25 (20.8%), 28 (23.3%) and 26 (21.7%), respectively. There was no significant difference for clinical diarrhea specimens among the three chromogenic media (χ 2 =0.418, P=0.811). In comparison to the standard, the sensitivity, specificity, positive predictive value and negative predictive value were 83.8%, 100%, 100% and 94.7% for CDCA; 90.3%, 98.9%, 96.6% and 96.7% for CDIF; and 80.6%, 100%, 100% and 93.7% for CDSA. @*Conclusion@#The CDCA developed by our laboratory could be used to preliminarily isolate C. difficile with good specificity and sensitivity.
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Objective In comparison with Xpert C.difficile/Epi through detection of Clostridium difficile toxin genes from clinical stool , the performance of a laboratory-developed ( LD) assay was evaluated in detail.Methods A total of 176 stool specimens collected from patients with diarrhea in the First People′s Hospital of Yuhang District and the People′s Hospital of Yingzhou , Ningbo from August 1 to December 30 were detected by the two assays in parallel , and meanwhile the C.difficile strains will be isolated and identified for C.difficile toxin genes by a conventional PCR assay .The Cross-tabs Analysis was used for the results by using SPSS20.0 software.Results In comparison with the results of Xpert C.difficile/Epi as the standard, the LD assay had a sensitivity of 91.7％(22/24), a specificity of 100％(152/152), a positive predictive value (PPV) of 100％(22/22), and negative predictive value (NPV) 98.7％(152/154).The results of two assays were statistically coherent (Kappa=0.950, P<0.001).In comparison with culture and detection of toxin genes results , the LD assay had a sensitivity of 90.0％ ( 18/20 ) , a specificity of 97.0％(152/156), a PPV of 81.8％ (18/22), and NPV of 98.7％ (152/154)(Kappa=0.838, P<0.001), and the Xpert C.difficile/Epi assay had a sensitivity of 90.0％ (18/20), a specificity of 96.0％(150/156), a PPV of 75.0％(18/24), and NPV of 98.7％ (150/152)(Kappa=0.792, P<0.001). Conclusions The performance of the LD assay was similar to that of the Xpert C .difficile/Epi kit in detection of toxigenic C.difficile.The LD assay could be directly applied to detection of toxigenic C.difficile from clinical stool samples .The clinical application of this LD assay will also provide a domestic and promising diagnostic assay for diagnosis of C.difficile infection in China.
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Objective To evaluate the clinical value of 16 slice spiral CT 3D imaging in bone and joint trauma. Methods 30 patients with bone and joint trauma were collected.The patients received the 16 slice CT three-dimensional imaging and X -ray examination .The detection rate of bone and joint trauma , bone fracture , the collapse of the diagnosis were compared between the two methods .Results The detection rate of tibial fracture of 16 slice CT was 26.20％,which was higher than 3.33％of X-ray (χ2 =5.19,P=0.02).The detection rate of spinal fractures of 16 slice CT was 28.50％,which was higher than 6.67％of X-ray (χ2 =5.45,P=0.02).The detection rate of rib fracture of 16 slice CT was 30.00％,which was higher than 10.00％of X-ray (χ2 =4.81,P=0.02).The detection rate of pelvic fracture of 16 slice CT was 14.50％,which was higher than the X -ray (χ2 =4.29,P=0.04).The detection rate of tibial broken bone of 16 slice CT was 20.00％,which was higher than 3.33％ of X-ray (χ2 =4.04,P=0.04).The detection rate of pelvis broken bone of of 16 slice CT was 13.33％,which was higher than X-ray (χ2 =4.29,P=0.04).Conclusion 16 slice spiral CT three -dimensional reconstruction can accurately display the three-dimensional shape of lesions ,but also display the anatomical structure of spatial relations ,it is an ideal method for the diagnosis of fracture fragments of traumatic fracture .
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Objective@#To study the protective effect of N-acetylcysteine on acute lung injury induced by PFIB inhalation and its mechanism.@*Methods@#Survival experiment: 48 male ICR (CD-1) mice were randomly divided into 4 groups, i. e., PFIB control group, NAC prevention group, NAC treatment group, and NAC prevention + treatment group, each group contains 12 animals. The mice of PFIB C group were exposed to PFIB without any treatment. The mice of NAC P group were exposed to PFIB 30min after NAC administration. The mice of NAC T group were exposed to PFIB 1h before NAC administration, The mice of NAC P+T group were administrated with NAC twice (30 min before and 1h after PFIB inhalation) . 150 mg/kg NAC was given by each time. The 7 days survival rate of mice after lethal dose PFIB exposure was observed. 18 male Wistar rats were randomly divided into 3 groups i.e., normal control group (N-C) , PFIB control group (PFIB-C) and NAC prevention group (NAC-P) , with each group contains 6 animals in the second experiment. The rats of N-C group received no treatment. The rats of NAC-P group and PFIB-C group were exposed to PFIB 30min after treatment of NAC (420 mg/Kg, i.p.) and saline, respectively. The respiratory functions of animals were tested before and 24 h after PFIB inhalation. The arterial blood gas was analyzed after rats were anesthetized 24 hours post sublethal dose PFIB exposure. Then samples of BALF, plasma and lung tissue were collected. Wet lung/body weight ratio, protein and phospholipid content in BALF, and T-SOD, GSH, GSH-Px in plasma and lung tissue were measured. The expression of Peroxiredoxin 2 was detected by Westernblot assay.@*Results@#NAC prevention can significantly improve the survival of mice exposed to a lethal dose PFIB while NAC treatment is ineffective. Severe lung edema was observed in rats 24 h after PFIB exposure. Compared to N-C group, the wet lung/body weight ratio, protein and phospholipid content in BALF, and respiratory rate of PFIB control group all increased significantly (P<0.01) . The arterial oxygen partial pressure (PaO2) reduced significantly (P<0.05) . The GSH-Px activity in lung tissue reduced significantly (P<0.01) while the expression of Peroxiredoxin 2 increased significantly (P<0.01) . NAC prophylaxis significantly reduced the wet lung/body weight ratio, protein and phospholipid content in BALF, respiratory rate of rats exposed to PFIB (P<0.01) . Compared with PFIB-C group, the PaO2 (P<0.05) and the activity of GSH-Px (P<0.01) and the expression of Peroxiredoxin 2 in lung tissue (P<0.01) were increased significantly.@*Conclusion@#Acute lung injury induced by PFIB inhalation is related to oxidative stress caused by the stimulation to lung. induced and pulmonary subjected to stimulate the generation of exposure, NAC prevention can regulation of the redox system in lung tissue and protect target organ of the treated animals effectively.
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OBJECTIVE To clarify the long-term toxicity to the respiratory system in a rat model of acute lung injury (ALI) induced by a single low-dose of perfluoroisobutylene(PFIB) inhalation expo?sure,and observe the possible beneficial effect of early intervention via Qingkailing(QKL) injection. METHODS Totally 224 male Wistar rats were randomly divided into 4 groups:normal control group in which air exposure was followed by a saline 10 mL · kg-1(ip),QKL control group in which QKL 10 mL · kg-1 was ip given after air exposure,PFIB exposure group in which rats were exposed to PFIB 280 mg·m-3 for 5 min only,and QKL treatment group in which QKL 10 mL·kg-1 was given ip at 1 h after PFIB exposure. Lung functions of rats were measured at 24 h,3,6,12,24,36 and 48 weeks after exposure. The arterial blood gas,lung coefficient,protein content in bronchoalveolar lavage fluid(BALF),hydroxy?proline(HYP) content in lung tissue and plasma,and other indicators were detected or analyzed. RESULTS Within 24 h after PFIB exposure,the lung coefficient and protein content in BALF were increased significantly(P<0.01),whereas the PaO2(P<0.01) and SaO2(P<0.05) indices in arterial blood decreased significantly in PFIB group compared with normal control. The inhalation time , exhalation time,tidal volume(TV),expired volume(EV)and relaxed time were reduced significantly (P<0.01). However,all the above indicators returned to normal in 3 weeks,but TV,EV and peak expiratory flow were significantly lower than in normal group at 48 weeks(P<0.05). HYP contents in lung tissues,compared with normal control(P<0.05),were reduced significantly within 24 h after PFIB exposure,increased significantly in 6 weeks(P<0.05),then returned to normal in 12 weeks. HYP contents in plasma increased significantly compared with normal control(P<0.05) within 24 h after PFIB exposure but returned to normal in 3 weeks. The protein contents in BALF of QKL treatment group were significantly lower than those in PFIB group(P<0.01) within 24 h after PFIB exposure. From 24 h to 24 weeks after PFIB exposure,changes of pulmonary functions were similar to those in PFIB group. At 48 weeks,TV and EV in QKL treatment group were more significantly increased than those in PFIB group(P<0.05). CONCLUSION Rats with ALI induced by a single low dose of PFIB exposure undergo compensatory repair except for pulmonary capacity and pulmonary ventilation functions. Early treatment with QKL reduces protein content of BALF and alleviates pulmonary edema,and has some beneficial effect on lung function recovery later.