Objective To investigate the role and mechanism of exosomes derived from mesenchymal stem cells in hyperbaric oxygen caused pulmonary oxygen toxicity.Methods Mice were divided into the control group that was exposed to normal air,and hyperbaric oxygen exposure groups treated with phosphate buffer saline(PBS)or exosomes,respectively.PBS and exosome treatment were given one day prior to exposure.Mice were subjected to 0.23 MPa pure oxygen for 8 hours.The lung wet-dry ratio,inflammation,exudation and pathological injury were analyzed,while cell death and antioxidant related molecules were detected.Results Pretreatment with exosome significantly attenuated lung injury caused by hyperbaric oxygen exposure by decreasing the lung wet-dry ratio,inflammation,and cell apoptosis.Conclusion Prophylactic administration of exosomes derived from mesenchymal stem cells can alleviate hyperbaric oxygen induced pulmonary oxygen poisoning by attenuating cell death and inflammation.

Objective: To evaluate the cost-utility of different immunization strategies for rabies in China, and to provide a reference for determining the optimal immunization strategy. Methods: The system dynamics model was used to simulate the epidemic of canine rabies and a decision tree model was conducted to analysis different immune strategies. Relevant probabilities were obtained through literature search and on-site investigation. Sensitivity analysis was used to explore the important influenced factors. Results: At baseline, from a social perspective, 70% vaccination of dogs was the optimal strategy compared to current vaccination strategy (43% vaccination in dogs, human category-Ⅱ exposure vaccination/category-Ⅲ exposure vaccination combined with RIG). The total cost was 14 084 354 CNY, and the total utility value was 22 078 616.23 QALYs, and the incremental cost-utility ratio was-62 148 147 CNY/QALY; if human vaccination was considered, 55% vaccination of dogs combined with strategy one was the optimal strategy, its incremental cost-utility ratio was-444 620 557 CNY/QALY. The probability that an injured dog carries rabies virus was the most sensitive parameter. When it was greater than 0.005 03, strategy four was the optimal strategy. When it was less than 82/100 000, strategy one was the optimal strategy; when it was between 82/100 000 and 120/100 000, strategy two was the optimal strategy; when it was between 120/100 000 and 503/100 000, strategy two was the optimal strategy. Conclusion It was conducive to increase the vaccination coverage of canine for the prevention and control of rabies.

To evaluate the cost?utility of different immunization strategies for rabies in China, and to provide a reference for determining the optimal immunization strategy. Methods The system dynamics model was used to simulate the epidemic of canine rabies and a decision tree model was conducted to analysis different immune strategies. Relevant probabilities were obtained through literature search and on?site investigation. Sensitivity analysis was used to explore the important influenced factors. Results At baseline, from a social perspective, 70% vaccination of dogs was the optimal strategy compared to current vaccination strategy (43% vaccination in dogs, human category?Ⅱ exposure vaccination /category?Ⅲ exposure vaccination combined with RIG). The total cost was 14 084 354 CNY, and the total utility value was 22 078 616.23 QALYs, and the incremental cost?utility ratio was-62 148 147 CNY/QALY;if human vaccination was considered, 55% vaccination of dogs combined with strategy one was the optimal strategy, its incremental cost?utility ratio was-444 620 557 CNY/QALY. The probability that an injured dog carries rabies virus was the most sensitive parameter. When it was greater than 0.005 03, strategy four was the optimal strategy. When it was less than 82/100 000, strategy one was the optimal strategy; when it was between 82/100 000 and 120/100 000, strategy two was the optimal strategy; when it was between 120/100 000 and 503/100 000, strategy two was the optimal strategy. Conclusion It was conducive to increase the vaccination coverage of canine for the prevention and control of rabies.

To evaluate the cost?utility of different immunization strategies for rabies in China, and to provide a reference for determining the optimal immunization strategy. Methods The system dynamics model was used to simulate the epidemic of canine rabies and a decision tree model was conducted to analysis different immune strategies. Relevant probabilities were obtained through literature search and on?site investigation. Sensitivity analysis was used to explore the important influenced factors. Results At baseline, from a social perspective, 70% vaccination of dogs was the optimal strategy compared to current vaccination strategy (43% vaccination in dogs, human category?Ⅱ exposure vaccination /category?Ⅲ exposure vaccination combined with RIG). The total cost was 14 084 354 CNY, and the total utility value was 22 078 616.23 QALYs, and the incremental cost?utility ratio was-62 148 147 CNY/QALY;if human vaccination was considered, 55% vaccination of dogs combined with strategy one was the optimal strategy, its incremental cost?utility ratio was-444 620 557 CNY/QALY. The probability that an injured dog carries rabies virus was the most sensitive parameter. When it was greater than 0.005 03, strategy four was the optimal strategy. When it was less than 82/100 000, strategy one was the optimal strategy; when it was between 82/100 000 and 120/100 000, strategy two was the optimal strategy; when it was between 120/100 000 and 503/100 000, strategy two was the optimal strategy. Conclusion It was conducive to increase the vaccination coverage of canine for the prevention and control of rabies.

Influenza virus , the causative agent of influenza , has characteristics of fast transmission and strong infectivity, posing a major threat to public health .Currently, with widely use of the first-line antiviral neuraminidase inhibitors , drug-resistant strains have appeared and brought difficulties to the precaution and treatment of influenza .This article reviews influenza virus structural characteristics , drug-resistance mechanisms , resistance situation and detection methods of drug-resistant virus strains , aiming to provide a reference for future research on influenza virus drug-resistance and clinical medication .

Objective To explore the relation between vitamin D deficiency and susceptibility to spinal tuberculosis. Methods A total of 163 hospitalized patients with untreated spinal tuberculosis in Tianjin Haihe hospital were enrolled in this study from June 2013 to May 2016. A total of 170 individuals participated in health examination program at the same period were enrolled as the control group. The serum level of 25-hydroxyvitamin D [25(OH)D] was measured by enzyme linked immunosorbent assay. The 25(OH)D grading included serious deficiency group (<25 nmol/L), deficiency group (≥25 nmol/L and <50 nmol/L), insufficiency group (≥50 nmol/L and <75 nmol/L) and sufficiency group (≥75 nmol/L). Histopathological classification was confirmed by intraoperative findings. Results The serum level of 25(OH)D was significantly lower in patient group [23.99(20.55,29.54)nmol/L] than that of control group [42.94(35.68,51.04) nmol/L] (P<0.01), and which was also significantly lower in four seasons than that of controls (P<0.05). The serum levels of 25(OH)D were significantly higher in summer group than those of winter group in both patient and control groups (P<0.008 3). The proportion of patients with serious deficiency of 25(OH)D was significantly higher in spring and winter groups in patient group, which was significantly lower in summer group (P<0.01). There was no significant difference in patients with serious deficiency of 25(OH)D between four seasons (P<0.01). For control group, there was a higher proportion of cases with deficiency of 25(OH)D in four seasons, and there was no significant difference in the distribution of seasons (P>0.05). In patient group, there were 107 cases of caseous necrosis type, 56 cases of hyperplasia type, and the proportion of caseous necrosis type was significantly higher in the severe deficiency group (79.17%, 76/96) than that of deficiency group (46.27%, 31/67, P<0.01). Conclusion Excluding the effect of season, vitamin D deficiency is associated with susceptibility to spinal tuberculosis and histopathologic classification.

Objective To investigate the effect of N-acetylcysteine ( NAC) on lung and heart injury of rats with a fast floating escape induced decompression sickness .Methods Eighty male Sprague-Dawley rats were randomly and evenly divided into four groups:control group and three NAC prevention groups .The NAC groups were treated with different doses of NAC(250, 500 or 1000 mg/kg)by intraperitoneal injection 1 h before entrance.In the control group, rats were given an equal volume of saline1h before entrance.The air was pressurized at the 2t/7 exponential rate to 1.5 MPa which was maintained for 4 min and then uniformly decompressed to atmospheric pressure .The extravehicular survival and pathological changes in the lung and heart tissue were detected 0.5 h after rat egress.Results The survival rate of rats treated with NAC 500 mg/kg(90%) was significantly higher than that of those treated with saline (65%)alone (P<0.05).There was large break and fusion in the structure of pulmonary alveolus of control group besides obvious erythrocyte exudation , cardiac muscle fibers edema ,and obvious denaturation and break .Conclusion NAC can play a protective role in rats with a fast floating escape induced decompression sickness by mitigating the injury to and inflammation of lung and heart tissue .

Objective To investigate the intervention of chemokine receptor 4(CXCR4) antagonist AMD3100 in lung tissues of rats during pulmonary oxygen intoxication.Methods Forty SD rats were randomly divided into 4 groups:normal pressure air PBS group, normal pressure air antagonist group , oxygen exposure PBS group and oxygen exposure antagonist group, each consisting of 10 animals.The last two groups were compressed to 0.23 MPa at an exponential rate of 0.1 MPa/min by pure oxygen.Pathological changes of lung tissues were observed by hematoxylin eosin stain.Changes in TNF-αand IL-1βexpression levels in the lung tissues of rats were detected by ELISA.Changes in CXCR4 expression levels were ob-served by Western blotting.Results Pathological examination indicated that edema and hemorrhage in the alveolar and pulmonary interstitial tissue of oxygen exposure antagonist group were lighter than in oxygen exposure PBS group.The levels of TNF-α, IL-1βand cleaved-caspase-3 in the lung tissues of the oxygen exposure antagonist group were lower than in oxy-gen exposure PBS group.Conclusion Blocking CXCR4 with AMD3100 can effectively alleviate lung injury during pulmo-nary oxygen intoxication.

Objective To study the effect of nicardipine on fast floating escape induced lung injury in animal models with decompression sickness .Methods Sixty male SD rats were randomly and evenly divided into three groups:blank control, control and nicardipine groups .The nicardipine group was given nicardipine 50 mg/kg orally 0.5 h before entrance.In the control group, rats were given an equal volume of saline 0.5 h before entrance.The blank control group only stayed in the vehicle without any pressurized procedure .The air was pressurized at the 2t/7 exponential rate to 1.5 Mpa which was maintained for 4 min, and then uniformly decompressed to atmospheric pressure .The extravehicular survival and lung pathology were observed in rats after 0.5 h, IL1-βand TNF-αexpression levels were detected by ELISA , and the Caspase 3 expression in lung tissue was detected by Western blot .Results The incidence and mortality rate were 80%and 50%respectively in control group ,and 100%and 80%in the experimental group .The surviving animals in the two groups suffered from alveolar and interstitial lung hemorrhage , with widened interstitial lung .IL1-βin the experimental group was significantly higher than in the normal control group , while TNF-αhad no significant change .After nicardipine treatment pro-caspase 3 did not change significantly , but cleaved-caspase 3 increased significantly .Conclusion Nicardipine can aggravate lung injury caused by fast floating escape-induced decompression sickness if used before decompression.

Objective To investigate the effect of PPAR-δ on the lung injury of rats induced by hyperbaric oxygen (HBO2) exposure.Methods Sixty male Sprague-Dawley rats were randomly divided into six groups:air+vehicle, air+GW0742, and air+GSK0660, HBO2 +vehicle, HBO2 +GW0742, HBO2 +GSK0660.Lung injury was induced in rats by HBO2exposure (2.3 ATA, 100%O2, 8 h).Rats were injected with vehicle[10%DMSO in 0.3 ml NaCl 0.9%(v/v)] or GW0742 (0.3 mg/kg, ip) or GSK0660 (1 mg/kg, ip) at 1, 6 and 12 hours before either air or oxygen exposure .Protein levels in the bronchoalveolar lavage fluid ( BALF) , wet/dry ratio of the lung and the pathological changes in the lung tissue were detected 30 min after rats′egress.Results and Conclusion For the HBO2 +GW0742 group, the protein levels in BALF, the wet/dry ratio of the lung and the pathological changes in lung tissues all significantly decreased compared with those of the air group .These changes in HBO 2 +GSK0660 group tended to increase the level of lung injury .PPAR-δhas a protective effect on pulmonary oxygen toxicity induced by HBO 2 .