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Bacillus cereus belongs to Gram-positive bacteria, which is widely distributed in nature and shows certain pathogenicity. Different B. cereus strains carry different subsets of virulence factors, which directly determine the difference in their pathogenicity. It is therefore important to study the distribution of virulence factors and the biological activity of specific toxins for precise prevention and control of B. cereus infection. In this study, the hemolysin BL triayl was expressed, purified, and characterized. The results showed that the bovine pathogenic B. cereus hemolysin BL could be expressed and purified in the prokaryotic expression system, and the bovine pathogenic B. cereus hemolysin BL showed hemolysis, cytotoxicity, good immunogenicity and certain immune protection in mice. In this study, the recombinant expression of hemolysin BL triayl was achieved, and the biological activity of hemolysin BL of bovine pathogenic ceroid spore was investigated. This study may facilitate further investigating the pathogenic mechanism of B. cereus hemolysin BL and developing a detection method for bovine pathogenic B. cereus disease.
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Cattle , Animals , Mice , Bacterial Proteins/metabolism , Bacillus cereus/metabolism , Hemolysin Proteins/metabolism , Virulence Factors/metabolism , Enterotoxins/metabolismABSTRACT
Objective:To evaluate the role of miR-205-3p in oncosis in astrocytes subjected to oxygen-glucose deprivation and restoration (OGD/R) and the relationship with aquaporin4 (AQP4).Methods:Primary astrocytes were cultured in vitro to the logarithmic growth phase and divided into 5 groups ( n=16 each) using a random number table method: control group (C group), OGD/R group (O group), OGD/R+ miR-205-3p mimic group (M group), OGD/R+ miR-205-3p inhibitor group (I group), and OGD/R+ negative control group (NC group). Cells were cultured routinely in C group.Cells were subjected to 4 h of oxygen-glucose deprivation in a 37℃ anaerobic incubator (containing 94% N 2, 1% O 2 and 5% CO 2) followed by restoration of O 2-glucose supply for 24 h in O group.Cells in M, I and NC groups were transfected with miR-205-3p mimic, miR-205-3p inhibitor and miR-205-3p negative control for 48 h, respectively, and then cells were subjected to 4 h of oxygen-glucose deprivation followed by restoration of O 2-glucose supply for 24 h. The cell viability was evaluated by CCK-8 assay, the cell injury and oncosis were analyzed by flow cytometry, the expression of AQP4 mRNA was detected by quantitative reverse transcription-polymerase chain reaction, and the expression of AQP4 and porimin was detected by Western blot. Results:Compared with C group, the expression of miR-205-3p was significantly down-regulated, the cell viability was decreased, the rates of cell injury and oncosis were increased, and the expression of AQP4 protein and mRNA and porimin was up-regulated in O group ( P<0.05). Compared with O group, the expression of miR-205-3p was significantly up-regulated, the cell viability was increased, the rates of cell injury and oncosis were decreased, and the expression of AQP4 protein and mRNA and porimin was down-regulated in M group, the expression of miR-205-3p was significantly down-regulated, the cell viability was decreased, the rates of cell injury and oncosis were increased, and the expression of AQP4 protein and mRNA and porimin was up-regulated in I group ( P<0.05), and no significant changes were found in NC group( P>0.05). Conclusions:miR-205-3p is involved in oncosis in astrocytes subjected to OGD/R, which is associated with regulation of AQP4 expression.
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Objective:To evaluate the role of exosomes in neuronal injury induced by M1 microglia.Methods:Liposolysaccharide 100 ng/ml and interferon-γ (IFN-γ)20 ng/ml were added to well-growing BV2 microglia to induce the polarization of microglia into M1 phenotype.Cell supernatant of M1 microglia was collected and M1 microglia exosomes (M1-exo) were extracted with exosome kit.The well-growing N2a cells were divided into 4 groups ( n=24 each) using a random number table method: control group (group C), M1 microglia group (group M), exosome group (group E), and exosome inhibitor+ M1 microglia group (group G+ M). The cells in group C were conventionally cultured, the cells in group M were cultured with the supernatant of M1 microglia for 24 h, and the cells in group E were cultured with M1 microglia-derived exosomes for 24 h. In G+ M group, exosome inhibitor GW4869 was added, M1 microglia were incubated for 24 h, then the supernatant was collected and added to N2a cells, and the cells were incubated for 24 h. Cell viability of N2a cells was measured by the cell counting kit 8 assay, cell apoptosis rate was determined by flow cytometry.The expression of apoptosis-related genes Bcl-2 and Bax mRNA was detected by quantitative real-time-polymerase chain reaction, and the expression of apoptosis-related genes Bcl-2 and Bax protein was detected by Western blot. Results:Compared with group C, the cell viability was significantly decreased, the apoptosis rate was increased, the expression of Bcl-2 protein and mRNA was down-regulated, and the expression of Bax protein and mRNA was up-regulated in the other three groups ( P<0.05). Compared with group M, the cell viability was significantly increased, the apoptosis rate was decreased, the expression of Bcl-2 protein and mRNA was up-regulated, and the expression of Bax protein and mRNA was down-regulated in group G+ M ( P<0.05). There was no significant difference in the above indexes between group E and group M ( P>0.05). Conclusions:M1 microglia can mediate neuronal injury via exosomes.
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Objective To evaluate the role of hippocampal adenosine monophosphate-activated protein kinase (AMPK) signaling pathway in reduction of postoperative cognitive dysfunction by electroacupuncture (EA) preconditioning in aged rats.Methods A total of 150 healthy male Sprague-Dawley rats,aged 18-20 months,weighing 400-500 g,were randomly divided into 5 groups (n=30 each) using a random number table:control group (group C);splenectomy group (group O);preconditioning with EA at non-acupoint group (group NEA);preconditioning with EA at Baihui acupoint group (group EA);preconditioning with EA at Baihui acupoint + AMPK inhibitor group (group EAC).EA and EAC groups received EA at Baihui acupoints with a sparse-dense wave at an intensity of 1 mA and a frequency of 2 Hz/15 Hz for 30 nin,once a day,for 5 consecutive days,and splenectomy was performed at 24 h after the end of the last stimulation.Group NEA received EA at the points 2 mm lateral to the acupoints of Baihui,and the other treatments were similar to those previously described in group EA.Compound C 20 mg/kg was injected intraperitoneally at 5 min before operation in group EAC.Morris water maze test was performed at 1,3 and 5 days after operation,and the escape latency and swimming distance were recorded.The rats were then sacrificed,and brains were removed for examination of the pathological changes in the hippocampal CA3 region and for determination of the expression of AMPK,phosphorylated AMPK (p-AMPK),nuclear factor kappa B (NF-κB),interleukin-1beta (IL-1β),and tumor necrosis factor-alpha (TNF-α) by Western blot.Results Compared with group C,the escape latency and swimming distance were significantly prolonged,and the expression of AMPK,p-AMPK,NF-κB,IL-13,and TNF-α was significantly up-regulated in O,NEA,EA and EAC groups (P＜0.05).Compared with group O,the escape latency and swimming distance were significantly shortened,and the expression of AMPK,p-AMPK,NF-κB,IL-1β and TNF-α was significantly down-regulated in EA and EAC groups (P＜0.05),and no significant change was found in the parameters mentioned above in group NEA (P＞0.05).Compared with group EA,the escape latency and swimming distance were significantly prolonged,the expression of AMPK and p-AMPK was significantly down-regulated,and the expression of NF-κB,IL-1β and TNF-α was significantly up-regulated in group EAC (P＜0.05).Conclusion Activation of hippocampal AMPK signaling pathway is involved in EA preconditioning-induced improvement in postoperative cognitive dysfunction in aged rats.
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BACKGROUND:After years of development, various in vitro loading devices for vascular tension stress have been created both at home and abroad, mainly including rectangular base stretching method, circular base deformation method and four-point bending beam load method. Although the circular base deformation method can wel reflect the real situations in vivo such as the expansion of the alveoli and vascular pulsation, the strain on the membrane is actinomorphic. The four-point bending beam load method can just bring limited strain range and load time, along with a difficult strain regulation. OBJECTIVE: To develop anin vitro loading device for vascular tension stress using the rectangular base stretching method. METHODS:Thisin vitro loading device for vascular tension stress developed according to mechatronics design consisted of power supply module, control module, drive module and data acquisition module. The device could achieve the tensile control on silicon diaphragm by high-precision control of the motor rotation angle and rotational speed. RESULTS AND CONCLUSION: Through tests and experiments, the device could meet the required range of parameters and simulatein vitro human tensile stress environment, which is preliminarily considered to develop successfuly, achieving that: (1) two work patterns: stress mode and strain mode so as to solve the standardization of silicone substrate as loading device; (2) tensile stress can be adjusted in a range of 0-5×105 Pa; (3) tensile strain can be adjusted in 0-40% range; (4) stretching frequency can be in the regulation of 0-80 times/min and the stretching time can be controled.
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Objective To compare the clinical effect of sternocleidomastoid muscle medial border entry and neck line approach in thyroid reoperation .Methods 124 patients with thyroid reoperation were randomly divided into two groups ,62 cases in each group .The observation group used sternocleidomastoid muscle medial border entry , the control group received neck line approach .The surgical approach and the impact of postoperative complications of the two groups were analyzed .Results Side subtotal bilateral subtotal ,full cut side ,bilateral full cut ,side subtotal+side full cut five kinds of surgical methods were implemented in the two groups ,the surgery way of both groups had no sig-nificant difference(χ2 =0.784,P>0.05).In the observation group,the total time of surgery and revealed thyroid , blood loss,hospital stay were better than those of the control group (t=13.357,4.489,18.364,7.294,all P<0.01). Conclusion In patients with thyroid reoperation using sternocleidomastoid can get a clearer anatomical level ,which helps to reduce surgical trauma ,improve the patients'treatment effect .
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Objective To investigate the epidemiology of 10 000 patients with mammary gland disease.Methods 10 000 mammary gland disease cages during 1987～2006 in Yangquan Tumor Institute were collected,all patients had integrity case files and were diagnosed by molybdenum target radiography,near infrared ray,sonography,aspiration-needle biopsy or polyrrhea smear examination.Results In 8919 outpatient treated cases,7493 suffered cyclomastopathy(84%).1081 cases were inpatient cared(11%),the top five mammary gland disease are:breast cancer 342 cases,cyclomastopathy 252 cases,adenofibroma 104 cases,intraductal papilloma 86 cases and ductal ectasia 76 cages.For breast cancer patients,there were 125 cases during 1987～1996,3 were 21～30 years old and 23 were 31～40 years old.The number during 1997～2006 was 217,24 were 21～30 years old and 69 were 31～40 years old.Conclusion In 10000 cases,there are 7745 cyclomastopathy patients(77.45%)which takes the first place.Especially for 342(3.42%)breast cancer cases,the incidence grew up and patients age was much younger.