Objective To observe the different characteristics of spontaneous activitiy after simulated weightlessness 21 days in rats , aimed to provide a evaluation method for space weightlessness induced function change in human beings and to provide a reference for researches on the astronauts protective measures .Methods 30 Wistar male rats were randomly divided into three groups , the control group , the sham tail-suspended hindlimb unloading group ( the sham group ) , the tail-suspended hindlimb unloading group ( the suspending group ) , ten animals in each group .All animals were placed in the simulated space flight environmental equipment which has a real -time monitor system for 21 days.During the 21 days, the intake of water , food and the body weight were measured every week .Meanwhile, five independent activity data were collect every day , for example, morning(8:00am~12:00am), afternoon(2:00pm~6:00pm), daytime(8:00am~8:00pm),night(8:00pm~8:00am),and whole day (8:00am ~8:00am).Results The spontaneous activity of normal rats in the control group between morning and afternoon had no significant difference , but it is significantly between night and daytime .The movement time and distance in night are 2 -3 times than that of the daytime.After 10 days of tail suspending , the circadian rhythm was disordered , and the spontaneous activity in day and night become more similar in rats of the suspending group .Because of the individual difference , the spontaneous activity is not stable at the first 10 days in rats of the sham group , but after 10 days, it become close to the control group .Conclusion Rat is nocturnal animal and sleeps in the daytime , the spontaneous activity in night is 2 -3 times as compared with the daytime.The sham tail-suspended hindlimb unloading 21 days can not influence the circadian rhythm in rats .Tail suspending 21 days will caused to the disappearance in the circadian rhythm in rats .

Objective To observe the changes of the totle nitric oxide synthase (NOS) activity in brain tissue,the metabolism of arsenic speciations in urine and the totle contents in blood,brain after rats drinking water containing different doses of arsenic.Methods Forty SD rats were divided into 4 groups according to random number table,10 rats in each group:control group,5 mg/L NaAsO2 group,10 mg/L NaAsO2 group and 50 mg/L NaAsO2 group.The animals were allowed free access to water and food.Body mass was weighted once a week.Expose to arsenic was continued for three months,then the animals were put to death and their blood,urine and brain tissues were collected.Determination of four kinds of speciations of arsenic (3 valence inorganic arsenic,iAs3+;5 valence inorganic arsenic,iAs5+;monomethylated arsenic,MMA;dimethylated arsenic,DMA) in urine was carried out by high performance liquid chromatography-hydride atomic fluorescence spectrometry.Total arsenic concentration in blood and brain tissue was detected by Atomic Fluorescence Spectrometry.The activity of total NOS in blood and brain tissue was detected using the spectrophotometer method.Results ①Weight:at the 5th-12th week after arsenic exposure,compared with the weight of control group [(420.93 ± 21.13),(441.52 ± 28.85),(462.45 ± 30.57),(470.16 ± 31.17),(484.92 ± 32.93),(483.79 ± 29.63),(482.02 ± 29.14),(483.89 ± 29.31) g],weight of rats in 50 mg/L NaAsO2 group [(391.66 ± 32.88),(410.17 ± 33.47),(426.96 ± 33.49),(427.15 ± 32.20),(441.78 ± 33.69),(438.27 ± 33.05),(440.98 ± 33.33),(441.46 ± 32.45) g] was significantly lighter (all P ＜ 0.05).② Urine arsenic:the medians of iAs3+ content (0.00,57.30,236.33,857.80 μg/L) were compared between control group,5,10 and 50 mg/L NaAsO2 groups,the differences were statistically significant (x2 =31.982,P ＜ 0.01);the medians of iAs5+ content (0.00,0.00,80.75,162.90 μg/L) were compared between control group,5,10 and 50 mg/L NaAsO2 groups,the differences were statistically significant (x2 =24.206,P ＜ 0.01);the medians of DMA content (12.83,1 711.13,l0 386.20,37 038.90 μg/L) were compared between control group,5,10 and 50 mg/L NaAsO2 groups,the differences were statistically significant (x2 =34.338,P ＜ 0.01).③Blood arsenic:total arsenic content in serum of rats [(5.04 ± 1.57),(25.40 ± 7.33),(32.28 ± 7.75),(56.11 ± 19.87) mg/L] was compared between control group,5,10 and 50 mg/L NaAsO2 groups,the differences were statistically significant (F =27.78,P ＜ 0.05).④Brain arsenic:total arsenic content in brain tissue of 5,10 and 50 mg/L NaAsO2 groups [(0.57 ± 0.20),(1.56 ± 0.52),(3.63 ± 0.48) μg/g] was respectively compared with that of control group [(0.11 ± 0.06) μg/g],the differences were statistically significant (all P ＜ 0.05).⑤NOS activity:compared with control group [(27.69 ± 5.56) kU/L],total NOS activity [(33.63 ± 2.26),(34.19 ± 2.55) kU/L] in serum of rats in 10 mg/L NaAsO2 group and 50 mg/L NaAsO2 group increased significantly (all P ＜ 0.05);compared with control group [(1.79 ± 0.79) U/(mg·prot)],total NOS activity [(2.63 ± 0.60)U/(mg ·prot)] in brain tissue of 50 mg/L NaAsO2 group increased significantly (P ＜ 0.05).Conclusions A high dose of arsenic exposure can increase totle contents of arsenic in blood,brain and the activity of total NOS in rat brain tissue.

Anaphylaxis is increasingly in children, which is currently undernotified, underdiagnosed, and undertreated in China.In order to further improved the understanding and management of anaphylaxis, this issue reviews the pathogenesis, triggers and risk factors, clinical diagnosis and management of anaphylaxis, thus offers the recommedations of anaphylaxis in Chinese children based on previous published evidence-based guidelines and practice parameters.Recommendation aims to develop guiding principles for the diagnosis and management of anaphylaxis in children, and provide a framework for the development of new guidelines.

Objective To observe the effects of different levels of sodium arsenite ( NaAsO2) on mRNA expression of pigment epithelium-derived factor (PEDF) and apoptosis-related factors in PC12 cells ( rat neuron properties pheochromocytoma). Methods PC12 cells were treated with different levels of NaAsO2 [0 (control group), 2, 5, 10 μmol/L] for 24 hours. The mRNA expression of PEDF and apoptosis-related factors (Bax, Bcl-2) were detected by real-time quantitative PCR. Results There were significant differences in the mRNA expressions of PEDF between the 4 groups (F=102.28, P<0.05), the mRNA expressions of PEDF in the group of 2, 5, 10μmol/L (0.70 ± 0.07, 0.33 ± 0.04, 0.23 ± 0.10) was lower than that of control group (1.15 ± 0.11, P< 0.05); there were no significant differences in the mRNA expressions of Bax between the 4 groups (0, 2, 5, 10 μmol/L groups: 0.95 ± 0.12, 0.80 ± 0.11, 0.88 ± 0.11, 1.01 ± 0.11, F= 2.01, P> 0.05); there were significant differences in the mRNA expressions of Bcl-2 between the 4 groups (F=19.87, P<0.05), the mRNA expressions of Bcl-2 in the group of 2, 5, 10 μmol/L (0.65 ± 0.03, 0.49 ± 0.04, 0.57 ± 0.09) were lower than that of control group (0.95 ± 0.11, all P<0.05);there were significant differences in the mRNA expressions of Bax/Bcl-2 between the 4 groups (F=8.352, P<0.05), the mRNA expressions of in the group of 5, 10μmol/L (1.80 ± 0.72, 1.82 ± 0.36) were higher than that of control group (1.02 ± 0.24, all P<0.05). Conclusion NaAsO2 may increase the expression of apoptosis-related factorsBax/Bcl-2 mRNA by decreasing the expression of PEDF mRNA in PC12 cells, leading to apoptosis in PC12 cells.

Objective To investigate the isolation and culture of porcine bone marrow mesenchymal stem cell (BMSC) with α-1, 3-galactosyltransferase (GGTA1) gene knockout (GTKO), GTKO/ human CD46 (hCD46) insertion and cytidine monopho-N-acetylneuraminic acid hydroxylase (CMAH)/GGTA1 gene knockout (Neu5GC/Gal), and the protective effect of co-culture with porcine islets on islet cells. Methods Bone marrow was extracted from different transgenic pigs modified with GTKO, GTKO/hCD46 and Neu5GC/Gal. Porcine BMSC were isolated by the whole bone marrow adherent method and then cultured. The morphology of BMSC was observed and the surface markers of BMSC were identified by flow cytometry. Meantime, the multi-directional differentiation induced by BMSC was observed, and the labeling and tracing of BMSC were realized by green fluorescent protein (GFP) transfection. The porcine BMSC transfected with GFP were co-cultured with porcine islet cells. Morphological changes of porcine islet cells were observed, and compared with those in the porcine islet cell alone culture group. Results BMSC derived from pigs were spindle-shaped in vitro, expressing biomarkers of CD29, CD44, CD73, CD90, CD105 and CD166 rather than CD34 and CD45. These cells were able to differentiate into adipocytes, osteoblasts and chondrocytes. Porcine BMSC with GFP transfection could be labeled and traced, which could be stably expressed in the daughter cells after cell division. Porcine BMSC exerted certain protective effect on islet cells. Conclusions GFP-labeled porcine BMSC modified with GTKO, GTKO/hCD46 and Neu5GC/Gal are successfully established, which exert certain protective effect upon islet cells.

Objective:To investigate the impacts of hirudin(HRD)on neuronal apoptosis and inflammatory response in rats with cerebral infarction by regulating Ras homolog gene family member A(RhoA)/Rho-associated coiled-coil-forming protein kinase(ROCK)signaling pathway.Methods:SD rats were grouped into Ct group,Model group,low-dose HRD group(HRD-L group,13.33 mg/kg),high-dose HRD group(HRD-H group,26.66 mg/kg),positive control Nimodipine group(NMDP group,40 mg/kg),U-46619(RhoA agonist,0.03 mg/kg)group and HRD-H+U-46619 group(26.66 mg/kg+0.03 mg/kg),with 24 rats per group.Except for the Ct group,rats in other groups constructed the rat model of cerebral infarction by the modified suture method.The rats in the Ct group only exposed the blood vessels without incision and suture insertion.After 1 hour of successful modeling,drug treatment was car-ried out,once a day for 4 weeks.Zea-Longa method was applied to evaluate the neurological function of rats;dry and wet weight meth-od was applied to detect the water content of rat brain tissue;2,3,5-triphenyltetrazolium chloride(TTC)staining was applied to deter-mine the volume of cerebral infarction in rats;TUNEL staining was applied to detect the apoptosis of neurons in the CA1 region of the hippocampus of rats.The levels of TNF-α,IL-1β and IL-6 in rat hippocampus were detected by ELISA;the protein expressions of cleaved-Caspase-3 Cleaved-Caspase-3,Bcl-2-associated X protein(Bax),RhoA,ROCK1 and ROCK2 in rat hippocampus were de-tected by Western blot.Results:Compared with Ct group,the neurological function scores,brain tissue water content,cerebral in-farction volume percentage,neuron apoptosis rate,levels of TNF-α,IL-1β,IL-6,the protein expressions of Cleaved-Caspase-3,Bax,RhoA,ROCK1 and ROCK2 increased in the Model group(P<0.05).Compared with Model group,the neurological function scores,brain tissue water content,cerebral infarction volume percentage,neuron apoptosis rate,levels of TNF-α,IL-1β,IL-6,the protein expressions of Cleaved-Caspase-3,Bax,RhoA,ROCK1 and ROCK2 decreased in HRD-L group,HRD-H group,NMDP group,however,the corresponding index changes in the U-46619 group showed an opposite trend(P<0.05).Compared with HRD-H group,the neurological function scores,brain tissue water content,cerebral infarction volume percentage,neuron apoptosis rate,levels of TNF-α,IL-1β,IL-6,the protein expressions of Cleaved-Caspase-3,Bax,RhoA,ROCK1 and ROCK2 were increased in the HRD-H+U-46619 group(P<0.05).Conclusion:HRD may inhibit neuronal apoptosis and inflammatory response in rats with cerebral infarction by inhibiting RhoA/ROCK signaling pathway.

Objective To analyze the changes of endoplasmic reticulum stress (ERS) in the spleen of water-improving fluorosis rat,to explore the mechanism of fluoride-induced immune system damage,and to provide a scientific basis for prevention and control of endemic fluorosis.Methods Forty-eight male Wistar rats of SPF grade were randomly divided into control group and low,medium and high fluoride dose groups according to body mass (120-140 g),12 rats in each group.The sodium fluoride (NaF) content was 0,50,100 and 150 mg/L,respectively.The animals were allowed free access to water and food.After 12 weeks of fluoride exposure,6 rats in each group were selected to isolate the spleen;the remaining rats in each group were changed to drink distilled water containing no NaF,and the spleen was separated after 12 weeks of feeding.The levels of mRNA of glucoseregulated protein (GRP78),spliced X-box binding protein 1 (XBP1-s),activating transcription factor 4 (ATF4),homologous protein (CHOP) and cysteine containing aspartate specific protease 12 (Caspase-12) in spleen were determined by quantitative real-time PCR (qRT-PCR).Results Before the water-improving,the expressions of GRP78 (1.00 ± 0.09,1.69 ± 0.35,1.39 ± 0.29,1.19 ± 0.19),XBP1-s (1.00 ± 0.12,1.40 ± 0.23,1.24 ± 0.26,1.38 ± 0.11),ATF4 (1.00 ± 0.17,1.86 ± 0.56,2.33 ± 0.55,1.95 ± 0.74),CHOP (1.00 ± 0.53,2.84 ± 0.68,3.06 ± 1.29,2.50 ± 0.35) and Caspase-12(1.00 ± 0.12,1.90 ± 0.29,1.56 ± 0.35,1.76 ± 0.23) mRNA in the control group and low,medium and high fluoride dose groups were statistically significant (F =8.45,5.38,6.38,8.21,11.31,P ＜ 0.05).Except for the GRP78 in high fluoride dose group,the above indicators in fluoride groups were higher than the control group (P ＜ 0.05).After the water-improving,the expressions of GRP78 (1.00 ± 0.36,0.75 ± 0.13,0.98 ± 0.41,0.47 ± 0.19),XBP1-s (1.00 ± 0.25,0.70 ± 0.06,0.74 ± 0.17,0.65 ± 0.21),ATF4 (1.00 ± 0.51,0.66 ± 0.09,0.91 ± 0.34,0.81 ± 0.29),CHOP (1.00 ± 0.36,0.92 ± 0.12,0.84 ± 0.16,0.67 ± 0.20) and Caspase-12 (1.00 ± 0.45,0.65 ± 0.11,0.65 ± 0.25,0.51 ± 0.27) mRNA in the control group and low,medium and high fluoride dose groups were not statistically significant (P ＞ 0.05).Before and after the water-improving,the expressions of XBP1-s,ATF4,CHOP and Caspase-12 mRNA were statistically significant in fluoride groups (P ＜ 0.05),and the GRP78 only had a statistically significant difference in the low fluoride dose group (P ＜ 0.05).Conclusions Fluoride exposure causes ERS response in rat spleen,up-regulation of ERS-related gene expression,which is decreased after water-improving,and the ERS response is weakened.The water-improving may contribute to the recovery of fluoride-induced immune function damage.