Purpose::With the increasing level of automation in automobiles, the advent of autonomous vehicles has reduced the tendency of drivers and passengers to focus on the task of driving. The increasing automation in automobiles reduced the drivers' and passengers' focus on driving, which allowed occupants to choose a more relaxed and comfortable sitting position. Meanwhile, the occupant's sitting position went from a frontal, upright position to a more relaxed and reclined one, which resulted in the existing restraint systems cannot to keep occupants safe and secure. This study aimed to determine the effects of different reclining states on occupants' lumbar and neck injuries.Methods::This is an original research on the field of automotive safety engineering. Occupants in different initial sitting positions (25°, 35°, 45°, and 55°) were adapted to changes in seat back angle and restraint systems and placed in the same frontal impact environment. Neck injury indexes, lumbar axial compression force and acceleration, as well as occupant dynamic response during the impact, were compared in different sitting positions. The injury response and kinematic characteristics of occupants in different reclining positions were analyzed by the control variable method.Results::As the sitting angle increased, the occupant's head acceleration decreased, and the forward-lean angle decreased. Occupants in the standard sitting position had the greatest neck injury, with an N ij of 0.95, and were susceptible to abbreviated injury scale 2+ cervical medullary injuries. As the seatback angle increased, the geometric position of the lumbar spine tended to be horizontal, and the impact load transmitted greater forces to the lumbar spine. The occupant's lumbar injury was greatest in the lying position, with a peak axial compression force on the lumbar region of 5.5 KN, which was 2.3 KN greater than in the standard sitting position. Conclusion::The study of occupant lumbar and neck injuries based on different recline states can provide a theoretical basis for optimizing lumbar evaluation indexes, which is conducive to the understanding of the lumbar injury mechanism and the comprehensive consideration of occupant safety protection.

Objective The aim of the study was to investigate the expression of P-glycoprotein (P-gp)and nuclear factor κB (NF-κB) in the cerebral cortex of rat with chronic fluorosis,and to reveal the mechanisms of damaged nervous system resulted from the toxicity of fluoride.Methods Sixty SD rats were randomly divided into three groups.The rats in each group were given drinking water containing different levels of fluoride:control group less than 0.5 mg/L,small amount of fluoride exposure group 10.0 mg/L and large amount of fluoride exposure group 50.0 mg/L.The animals were examined at the sixth month after initiating the experiment.Protein levels of P-gp and NF-κB in brain tissues were detected by immunocytochemistry and Western blotting,and the P-gp protein and mRNA level by quantitative real time PCR method.Results As compared to the control group(28.21 ±6.13),the numbers of positive staining cells by P-gp antibody in the cortex of rat brains were significantly increased in both the small and the large amount of fluoride exposure groups[(48.46 ± 8.00),(53.72 ± 9.15),respectively,all P ＜ 0.05] ; the protein levels in the control group(100.00 ± 3.86)％ detected by Western blotting were significantly increased in the cortex of rat brains treated with fluoride in both the small and the large amount of fluoride exposure groups[(189.47 ± 3.14)％,(191.36 ± 11.09)％,respectively,all P ＜ 0.05].The significantly increased expression of NF-κB at the protein level was observed in the cortex of rat brains of the small and the large amount of fluoride exposure groups[(365.97 ± 6.04)％ and (417.15 ± 10.89)％,respectively] as compared with the control group[(100.00 ± 10.07)％,all P ＜ 0.05].The mRMA level of P-gp in the cortex of rat brains of the small and the large amount of fluoride exposure groups(2396 ± 427,3479 ± 371,respectively) were higher than that of the control group(260 ± 106,all P ＜ 0.05).Conclusion The increased expressions of P-gp and NF-κB in the cortex of rat brains are induced by chronic fluorosis,which might be connected with the mechanism of brain damages.

Objective To investigate the changes of reactive oxygen species(ROS) level and mitochondria fission-fusion-balance in cortical neurons of rats with chronic fluorosis and reveal the correlation between these two factors. Methods One hundred and twenty rats were randomly divided into 3 groups(control group, low-dose fluorosis group, high-dose fluorosis group) and 40 rats were in each group according to body weight and the experiments were carried out for 3 months or 6 months. The rats were fed with different concentrations of fluoride (NaF) to establish fluorosis models. Controls were fed with tap water( < 0.5 mg/L), experimental animals in low- or high-dose group were fed with water containing NaF 10.0,50.0 mg/L, respectively. The level of ROS and the morphology in mitochondria fission-fusion balance in neurons of the cortex of rat brains prepared with cortical frozen sections were detected with ROS fluorescent probe and MitoTracker RED probe, respectively. Results Significant differences of the level of ROS and the numbers of abnormal mitochondria in morphology in the cortical neurons were found between 3 groups at the experiment period of 3 month and 6 month(F= 3.07,3.06,3.05,3.07, all P < 0.05). As compared with control group(10.43 ± 5.98,4.12 ± 3.86) at the experiment period of 3 month, the level of ROS and the numbers of abnormal mitochondria in morphology in the cortical neurons were obviously increased in high-dose fluorosis group(25.48 ± 6.09,20.47 ± 6.09, all P < 0.05), whereas no significant changes were found in low-dose fluorosis group(11.67 ± 3.49,6.68 ± 3.48, all P> 0.05). Furthermore, the increases in both ROS level and abnormal numbers of mitochondria were significant observed in the cortical neurons of low-dose fluorosis group (63.02 ± 8.15, 49.33 ± 8.61) and high-dose fluorosis group(65.60 ± 7.40,53.10 ± 6.95) as compared with the control group (25.26 ± 6.41,20.26 ± 6.41) at the experimental period of 6 month (all P < 0.05). The abnormal numbers of mitochondria correlated with ROS level(r = 0.93,0.81, all P < 0.05). Conclusions Taking excessive amount of fluoride results in high level of oxidative stress and impaired the balance of mitochondrial fission-fusion,which is dependent on the feeding times and doses of fluoride. The mechanism of the mitochondrial abnormalities might be associated with the high level of oxidative stress induced by chronic fluorosis.

Objective To observe the expression of mitochondrial fission protein locus Fis1 and ultrastructural changes in the renal cells of rats with chronic fluorosis,and to reveal the mechanism in mitochondrial damage of the renal cells.Methods Sixty SD rats were randomly divided into 3 groups according to sex and body mass(20 in each group):control group,lower fluoride group and higher fluoride group.All the rats were fed with different doses of sodium fluoride in drinking water(0,10 and 50 mg/L,respectively).Six-month later,the expression of Fisl in renal cells was determined by real-time fluorenscence quantitative PCR and immunohistochemistry technology,the mitochondrial morphology of renal cells was observed under transmission electron microscopy (TEM).Results As compared with the control group(28.70 ± 12.41),Fis1 mRNA levels(91.48 + 34.83 and 582.09 ± 184.69) in renal cells of the lower fluoride and the higher fluoride groups were increased(all P ＜ 0.05).As compared with the control group(10.49 ± 7.66),Fisl protein levels(16.33 ± 10.26 and 21.50 ± 5.24) in renal cells of the lower fluoride and the higher fluoride groups showed a trend of increasing,the higher fluoride group was higher than that of the control group(P ＜ 0.05).By TEM,mitochondrial crest in renal cells of the lower fluoride and the higher fluoride groups was vague or disappeared,mitochondrial division section appeared.Conclusions Fluoride is a kind of toxicant that can cause damage to mitochondrion of renal cells,induce the expression of Fis1 in transcriptional and protein level,and lead to the obstacles of mitochondrial fusion-fission and ultrastructural abnormality of mitochondrion,which may play an important role in mechanism of mitochondrial damage in the renal cells of rats with chronic fluorosis.

Objective To investigate the alterations and phenotypes of dendritic cells, inflamma-tory monocytes and macrophages in immunocompetent mice during Pneumocystis murina ( P.murina) infec-tion for further analysis of the function of these cells during P.murina infection.Methods Wild type male C57BL/6 mice at age 6-8 weeks were randomly divided into two groups including the group with P.murina infection and the group receiving sham surgery.The mice without any intervention were used to set up the blank control group.The loads of P.murina strains in lung tissues of each mouse were quantified by TaqMan real-time fluorescence polymerase chain reaction after the infection.Histopathological examination was per-formed to evaluate the degree of inflammation in lung tissues.The numbers of dendritic cells, inflammatory monocytes and macrophages in lung tissues, peripheral blood and bone marrow samples, and the changes of inflammatory monocytes in spleen tissues were measured by flow cytometry analysis.The expression of major histocompatability complexⅡ(MHCⅡ), CX3C chemokine receptor 1 (CX3CR1) and CC chemokine re-ceptor 2 ( CCR2 ) by dendritic cells, inflammatory monocytes and macrophages in lung tissues during P.murina infection were analyzed by flow cytometry analysis.All of the data were collected one, two, three and four weeks after the corresponding treatments.Results The loads of P.murina strains in P.murina in-fected mice were elevated after two and three weeks infection, but decline at week 4 (P>0.05).Significant pathological changes including the alveolar destruction, inflammatory cell infiltration and thickened alveolar septum in mice with P.murina infection were observed under a microscope at week 3 and week 4.Compared to the sham surgery treatment group, the number of CD11c+CD11b+dendritic cells were increased in lung tissues, but decreased in blood samples during P.murina infection ( P<0.05) .The levels of inflammatory monocytes in blood samples fell at week 3 and then rose at week 4 during P.murina infection (P<0.05). No significant difference with the change of macrophages in mice was observed during P.murina infection ( P>0.05).The CD11c+CD11b+dendritic cells in lung tissues of mice with P.murina infection expressed high levels of MHCⅡand CX3CR1, and low levels of CCR2.The inflammatory monocytes in lung tissues of mice expressed high levels of CCR2, moderate levels of MHCⅡand low levels of CX3CR1 during P.murina in-fection.High levels of CX3CR1 and low levels of MHCⅡ and CCR2 were observed in macrophages from lung tissues of mice with P.murina infection.Conclusion Highly expressed CD11c+CD11b+dendritic cells and MHCⅡwere detected in lung tissues of mice during P.murina infection, indicating that CD11c+CD11b+dendritic cells were involved in the host defense against P.murina infection.

Objective To investigate the deletion pattern of 4.8 kb mitochondrial DNA(mito-DNA) in liver,kidney,and brain of rats with chronic fluorosis and to explore the significance of mitochondria in the pathogenesis of chronic fluorosis.Methods Sixty SD rats were randomly divided into 3 groups according to body mass (20 in each group):control,low-fluoride and high-fluoride groups,and they were fed with different concentrations of fluoride in drinking water (0,10,50 mg/L,respectively) for 6 months.Mito-DNA in liver,kidney and brain was detected by real-time PCR.Results The amounts of 4.8 kb mito-DNA in liver(2.1 × 10-3,1.6 × 10-3),kidney (1.7 × 10-3,1.4 × 10-4) and brain cortex (1.5 × 10-5,1.3 × 10-5) in low-and high-fluoride groups were significantly reduced,as compared with that of control group (2.9 × 10-3,2.0 × 10-3,1.1 × 10-4,all P ＜ 0.05).The amount of 4.8 kb mito-DNA in kidney in high-fluoride group was lower than that in low-fluoride group (P ＜ 0.05).Conclusions Excessive fluoride intake can result in missing of 4.8 kb mito-DNA in liver,kidney and brain cortex.The abnormal of mito-DNA might be related to the dysfunction of mitochondrial respiratory chain.

ObjectiveTo investigate the transcriptional changes of nitochondria fission and fusion gene loci and reactive oxygen species (ROS) level in cortical neurons of rats with chronic fluorosis,and to reveal their roles in mitochondria damage due to chronic fluorosis.MethodsSD rats were fed with different doses of fluoride through drinking water[＜ 0.5(control),10,50 mg/L,respectively] for 3 and 6 months.The level of ROS and mRNA contents of mitochondria fission gene loci Drp1/Fis1 and fusion gene locus Mfn1 in the cortical neurons of rat brains were detected with ROS fluorescent probe and real-time PCR,respectively.ResultsAs compared with control group [10.43 ± 5.98,(3.4 ± 0.6) × 103,(8.8 ± 1.4) × 10,(1.2 ± 0.2) × 102] at the experiment period of 3 months,the level of ROS and mRNA contents of mitochondria fusion gene locus Mfn1 and fission gene loci Drp1/Fis1 in the cortical neurons were obviously increased in the rats fed with 50 mg/L fluoride through drinking water[25.48 ± 6.09,(1.0 ± 0.2) × 1011,(3.0 ± 1.6) × 103,(8.9 ± 3.6) × 102,all P ＜ 0.05],whereas no significant changes were found in the rats fed with 10 mg/L fluoride[11.67 ± 3.49,(3.1 ± 0.3) × 104,(6.7 ± 2.7) × 10,(5.0 ± 0.9) × 10,all P ＞0.05].Furthermore,at 6 months of the experiment the increases in ROS level(63.02 ± 8.15,65.60 ± 7.40) and mRNA contents of mitochondria fission gene loci Drp1/Fis1 [(2.0 ± 0.8) × 106,(4.0 ± 0.6) × 105,(3.8 ± 1.3) × 103,(1.3 ± 0.2) × 103] and the decrease in mitochondrial fusion gene locus Mfn1[(3.0 ± 0.4) × 106、(4.0 ± 0.9) × 104]were observed in the cortical neurons of the rats fed with 10 mg/L and 50 mg/L fluoride as compared with the control group[25.26 ± 6.41,(3.0 ± 0.8) × 109,(5.1 ± 0.8) × 103,(2.8 ± 0.7) × 102,all P ＜ 0.05].Conclusions Excessive intake of fluorine leads to elevated ROS levels,and decreased transcription of mitochondrial fusion gene loci Mfn1,which is positively correlated with the time and dose-exposed to fluoride.The changes of mitochondrial fission and fusion gene loci in the cortical neurons may be related to high level of oxidative stress induced by chronic fluorosis.

PCR method was used to introduce the code sequence of Factor Xa cleavage site to the 5′ end of cecropin CMIV mutant gene X, then the gene was cloned into the expression vector pGEX-KG, and was highly expressed in E. coli BL21 by IPTG induction. The fusion protein was purified by affinity-chromatography and was cleaved by Factor Xa. Cecropin X with antibacterial activity was obtained after purified by ion-exchange chromatography.

Adult ; Humans ; Lymphomatoid Papulosis ; diagnosis ; Young Adult

OBJECTIVETo compare the diagnostic value of barium enema (BE), computed tomography (CT) and magnetic resonance imaging(MRI) in primary colorectal carcinoma.

METHODSA total of 64 patients with suspected colorectal carcinoma received BE (n=39), spiral CT (n=31) and MRI (n=42). The detective results were compared with the surgical results.

RESULTSAmong 64 patients, 54 cases were pathologically proved as colorectal carcinoma. The diagnostic sensitivity of BE,CT and MRI was 96.9% ,96.2% and 97.1% ,and the overall accuracy was 92.3% 83.9 % and 90.5% respectively. The overall accuracy of CT and MRI for tumor T staging was 73.1% and 82.9% respectively.

CONCLUSIONBE can be considered as a primary approach for diagnosing colorectal carcinoma, CT and MRI be necessary diagnostic approaches. Combined BE with MRI is the best choice for diagnosing of colorectal carcinoma.

Adult ; Aged ; Aged, 80 and over ; Barium Sulfate ; Colorectal Neoplasms ; diagnostic imaging ; pathology ; Enema ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Neoplasm Staging ; Sensitivity and Specificity ; Tomography, Spiral Computed