A bacterial cell surface display technique based on an ice nucleation protein has been employed for the development of live vaccine against viral infection.Due to its ubiquitous ability to invade host cells,Salmonella typhimurium might be a good candidate for displaying viral antigens.We demonstrated the surface display of domain III of Japanese encephalitis virus E protein and the enhanced green fluorescent protein on S.typhimurium BRD509 using the ice nucleation protein.The effects of the motif in the ice nucleation protein on the effective display of integral protein were also investigated.The results showed that display motifs in the protein can target integral foreign protein on the surface of S.typhimurium BRD509.Moreover,recombinant strains with surface displayed viral proteins retained their invasiveness,suggesting that the recombinant S.typhimurium can be used as live vaccine vector for eliciting complete immunogenicity.The data may yield better understanding of the mechanism by which ice nucleation protein displays foreign proteins in the Salmonella strain.

Objective To investigate the clinical value of damage control resuscitation ( DCR) in the treatment of severe multiple injuries combined with traumatic hemorrhagic shock. Methods A retrospective analysis was done on 27 patients with severe multiple injuries combined with traumatic hemorrhagic shock treated by DCR. Another 32 patients treated with traditional aggressive/normotensive fluid resuscitation were used as control. Lactic acid clearance time, coagulation, diffuse intravascular coagulation (DIC) morbidity, and mortality were observed and compared between two groups. Results Compared with traditional aggressive/normotensive fluid resuscitation, DCR had better curative effect, shorter clearance time of lactic acid, more rapid recovery of blood coagulation function and lower incidence of DIC morbidity and lower mortality for patients with severe multiple injuries combined with traumatic hemorrhagic shock. Conclusions In the treatment of severe multiple injuries combined with traumatic hemorrhagic shock, the use of DCR can remarkably improve the survival rate of patients and also provide a new way for resuscitation and rescue of other types of shock patients.

Objecthe To equate the effects of recombinant human growth hormone (rhGH) on serum albumin lewis and intestinal mucosal morphology in rats with intracerebral hemorrhage. Methods A rat model of intracerebral hemorrhage was induced by autologous blood injection. Fifty-six SD rats were divided into sham-operation group (n =8), rhGH group (n =24; intraperitoneal injection of rhGH, 1 U/kg, once a day), and saline control group (n =24; intraperitoneal injection of equivalent normal saline, once a day). The rhGH and saline control groups were redivided into 1-, 7- and 14-day groups (n =8 in each group) after the procedure. The serum albumin concentration was detected at different time points in all groups. The changes of intestinal mucosal morphology were observed with Hematoxylin and Eosin (HE)staining and image analysis. Results Hie serum albumin lewis at all time points of intracerebral hemorrhage in the saline control group were all significantly lower than those in the sham-operation group (all P < 0. 01); The serum albumin level was increased gradually with the treatment process in the rhGH group, however, it was only significantly higher than the saline control group at day 14 (39.93 ±1.98 g/L νs. 37. 93 ±1.57 g/L) (P<0. 01). There were no significant differences between the rhGH group and the saline group in intestinal villus height and mucosal thickness at day 1 and 7 after intracerebral hemorrhage, however they were increased significantly at day 14 (P <0.01). The area of intestinal villi was reduced progressively at day 1, 7 and 14 after intracerebral hemorrhage, and with the treatment process the rhGH group was increased more progressively than the saline control group (P <0. 01). The depth of intestinal glands in the rhGH group was increased significantly than that in the saline control group (P <0. 01), but there was no significant difference at day 14; the density of glands in the rhGH group was significantly increased than that in the saline group at day 1 after intracerebral hemorrhage (P < 0. 01), and it was not increased significantly at day 7, however, it was not increased but decreased slightly at day 14. Conclusions The serum albumin level in rats with intracerebral hemorrhage was decreased significantly than that in the sham-operation group, and intracerebral hemorrhage could cause intestinal mucosal injury. rhGH increased the serum albumin level in rats with intracerebral hemorrhage. It might reduce intestinal mucosal injury to different degrees whether it was in the early or late intracerebral hemorrhage, and the late improvement was more significant. The improvement degree of rhGH on intestinal mucosal injury was positively correlated with the increased degrees of the serum albumin level.

Objective To explore the correlation between the serum albumin level and the jejunal mucosal morphology in rats with cerebral hemorrhage and to find out the mechanism of the resulting hypoproteinemia.Methods A rat model of cerebral hemorrhage was used to detect the serum albumin level and the morphologic parameters of jejunal mucosa on day 1,7 and 14 after the hemorrhage.The results were compared to the normal control group and the sham-operated group. The correlation between the serum albumin level and the parameters of the jejunal mucosal morphology was explored.Results The serum albumin level was positively correlated with the small intestinal villous height(r =0.869,P＜0.01),villous area(r=0.659,P＜0.01),mucosal thickness (r=0.915,P＜0.01),depth of intestinal glands(r=0.545,P＜0.05)and density of intestinal glands(r=0.475,P＜0.05).Conclusion The serum albumin level is closely related to the morphologic changes of the jejunal mucosa.

Objective: o explore the antibacterial effect of combined use of photon-induced photoacoustic streaming (PIPS) and silver nanoparticles (AgNPs) on Enterococcus faecalis biofilm in root canals. Methods: A total of 36 isolated teeth with single root canal were collected to establish an experimental root canal model of Enterococcus faecalis infection. Samples were randomly divided into six groups and 0.9% NaCl, 2% NaClO, 0.1% AgNPs solutions were used with conventional needle irrigation (CNI) or PIPS for root canals. Colony count method was used to measure the number of Enterococcus faecalis biofilm in root canals before and after treatment, and the percentage of colony count reduction was calculated. Results: The inhibitory effect of Enterococcus faecalis biofilm in all experimental groups was stronger than that in the control group (P<0.05). The decrease amplitude of 0.9% NaCl, 2% NaClO, 0.1% AgNPs assisted with PIPS was greater than that of 0.9% NaCl, 2% NaClO, 0.1% AgNPs assisted with CNI (P<0.05). The decrease in the 0.1% AgNPs assisted with PIPS group was significantly greater than that in the 2% NaClO assisted with PIPS group (P<0.05). Conclusion PIPS-assisted AgNPs solution washing can significantly improve the effect of clearing Enterococcus faecalis biofilm in root canals.

Objective: To investigate the effect of ribosomal DNA (rDNA) copy number variation caused by hexavalent chromium exposure on DNA damage response in different cell lines, so as to provide insights into the involvement of hexavalent chromium-induced rDNA copy number variation in DNA damage responses. : Methods Human lung epithelial BEAS-2B cells and human embryonic lung MRC-5 cells were treated with 2 μmol/L potassium dichromate for 24 hours, and then cells were transferred to fresh media for further incubation, while cells treated with the same volume of phosphate buffer solution served as controls. Cells treated with potassium dichromate for 24 hours, and 3 and 7 days post-detoxification, were harvested, and rDNA copy number was quantified in cells using a quantitative fluorescent real-time PCR assay. Cell cycle, apoptosis and DNA damage were detected using a Muse cell analyzer, and the DNA damage was evaluated with the proportion of ataxia telangiectasia-mutated (ATM) gene activation, proportion of double-strand DNA breaks and the percentage of the H2A.X variant histone phosphorylatio. : Results The 45S and 5S rDNA copy numbers of were significantly higher in MRC-5 cells than in BEAS-2B cells [(1.54±0.26) vs. (1.02±0.18), P<0.05; (6.97±1.07) vs. (3.00±0.15), P<0.05]. The 45S rDNA copy number was lower in MRC-5 cells 3 days post-detoxification (0.80±0.04) than in controls (P<0.05), and was higher in BEAS-2B cells 3 days post-detoxification (1.43±0.07) than in controls (P<0.05) . G0/G1 phase arrest was found in MRC-5 cells 24 hours post-treatment, and the apoptotic rates were significantly higher in MRC-5 cells 3 and 7 days post-detoxification than in controls [(11.53±1.53)%, (18.33±0.70)% vs. (3.53±0.93)%, P<0.05]. The overall apoptotic rates 24 hours post-treatment and 3 days post-detoxification [(2.80±0.17)%, (3.33±0.57)% vs. (1.53±0.61)%, P<0.05], proportion of ATM gene activation 3 days post-detoxification [(3.37±0.67%) vs. (1.18±0.22)%, P<0.05], proportion of double-strand DNA breaks 3 days post-detoxification [(4.45±0.85)% vs. (0.97±0.21)%, P<0.05] and percentage of the H2A.X variant histone phosphorylation 3 days post-detoxification [(1.68±0.56)% vs. (0.29±0.06)%, P<0.05] in BEAS-2B cells were higher than in controls. Conclusions Hexavalent chromium-induced rDNA copy number variation affects DNA damage response in different cell lines. A stronger DNA damage response is found in BEAS-2B cells with a low rDNA copy number, and a relative stable response is observed in MRC-5 cells with a high rDNA copy number.

Objective: To investigate the effect of chrysotile exposure on ribosomal DNA (rDNA) copy number and DNA damage response, so as to provide insights into the mechanism of asbestos-induced carcinogenesis. Methods: Human pleural mesothelial MeT-5A cells were treated with chrysotile suspensions at doses of 1.25, 2.5 and 5 μg/cm2 (low-, medium-, high-dose group), while PBS served as controls. MeT-5A cells were harvested 6, 24, 48 and 72 h post-treatment, and the rDNA copy numbers and the BIRC5, HRAS, GINS4 and RRM2 mRNA expression were determined using a quantitative real-time PCR (qPCR) assay. The apoptosis of MeT-5A cells and DNA damage were detected using Muse cell analyzer. The rDNA copy numbers, DNA damage responses and BIRC5, HRAS, GINS4 and RRM2 mRNA expression were compared in MeT-5A cells treated with different doses of chrysotile suspensions. Results: There were significant differences in 45S rDNA copy numbers among low-, medium-, high-dose groups and the control groups 6, 48 and 72 h post-treatment with chrysotile suspensions, and significantly lower 45S rDNA copy numbers were measured in low-, medium- and high-dose groups than in the control group 6 h post-treatment, while significantly higher 45S rDNA copy numbers were found in the high-dose group than in low- and medium-dose groups 48 and 72 h post-treatment (all P<0.05). There were significant differences in 5S rDNA copy numbers among low-, medium-, high-dose groups and the control groups 24, 48 and 72 h post-treatment with chrysotile suspensions, and significantly lower 5S rDNA copy numbers were measured in medium- and high-dose groups than in the control group 24 and 48 h post-treatment, while significantly lower 5S rDNA copy numbers were found in medium- and high-dose groups than in the low-dose group 24, 72 h post-treatment (all P<0.05). There were significant differences in the overall apoptotic rate of MeT-5A cells among groups at different time points, and the overall apoptotic rate of MeT-5A cells were significantly higher in medium- and high-dose groups than in the control group (all P<0.05), with late-stage apoptosis predominantly detected. There were significant differences in the rates of ATM activation and DNA double-strand break in MeT-5A cells among groups 72 h post-treatment, and higher rates of ATM activation and DNA double-strand break were measured in medium- and high-dose groups than in the control group (all P<0.05). In addition, there were significant differences in the relative mRNA expression of BIRC5, HRAS, GINS4 and RRM2 genes among groups 24 and 48 h post-treatment, and significantly lower BIRC5, HRAS, GINS4 and RRM2 mRNA expression was quantified in medium- and high-dose groups than in the control group (all P<0.05). Conclusion Exposure to chrysotile may induce rDNA copy number variations and altered expression of nucleolar proteins in human pleural mesothelial cells, which may be involved in the regulation of DNA damage responses.

People are exposed to a variety of different harmful factors through their daily life, diet, and occupational environment, and exposure to these dangerous factors results in varying degrees of damage to the organism. The damage to mitochondria from exposure to chemical harmful factors in environment is of increasing concern. The integrity of the mitochondrial genome is critical for mitochondrial function and cellular homeostasis, and mitochondria are susceptible to damage and mitochondrial dysfunction when stimulated by various harmful chemical environmental factors. It has been shown that exposure to a variety of chemical pollutants can produce varying degrees of damage to mitochondria, and these pollutants may cause mitochondrial structural and functional disorders by inducing oxidative stress, including impaired electron respiratory chain transmission, alterations in mitochondrial membrane potential, mitochondrial DNA mutations/deletions, and mitochondrial DNA copy number variation. Mitochondrial damage can further lead to abnormal cell function, apoptosis, and death, which induce related diseases. Therefore, this paper provides a review of the role of chemical factor exposure in the environment, such as heavy metals, on mitochondrial damage.

Objective: To explore the changes in ribosomal DNA copy number in peripheral blood among patients with pneumoconiosis and its influencing factors, so as to provide insights into prevention and treatment of pneumoconiosis. Methods: Eighty-eight patients with pneumoconiosis who visited a designated hospital and 71 community residents with no history of pneumoconiosis or dust exposure were selected as the pneumoconiosis group and control group, and age, smoking history, drinking history and cumulative years of exposure to dust were collected through questionnaire surveys. The copy number of 45S rDNA and 5S rDNA was detected using real-time fluorescence quantitative PCR, and the differences between the two groups were compared. Factors affecting the copy number of 45S rDNA and 5S rDNA were identified by a multiple linear regression model. Results: The pneumoconiosis group had a median age of 56.00 (interquartile range, 15.25) and a mean cumulative dust exposure duration of (12.40±8.08) years, with 56.82% smoking and 62.50% drinking. The control group had a median age of 64.00 (interquartile range, 37.00) years, with 32.39% smoking and 26.76% drinking. The median copy number of 45S rDNA in the pneumoconiosis group was 1.29 (interquartile range, 0.59), which was lower than 2.10 (interquartile range, 1.88) in the control group; the median copy number of 5S rDNA in the pneumoconiosis group was 5.33 (interquartile range, 0.85), which was higher than 4.66 (1.34) in the control group (both P<0.05). Multiple linear regression analysis identified age (β=-0.034) and pneumoconiosis (β=-1.595) as factors affecting 45S rDNA copy number, age (β=-0.013) as a factor affecting 5S rDNA copy number, and age (β=0.018) as a factor affecting 5S rDNA copy number in the pneumoconiosis group (all P<0.05). Conclusions Compared with community residents with no history of pneumoconiosis or dust exposure, the copy number of 45S rDNA in peripheral blood among patients with pneumoconiosis is reduced and the copy number of 5S rDNA is increased.

People are exposed to a variety of different harmful factors through their daily life, diet, and occupational environment, and exposure to these dangerous factors results in varying degrees of damage to the organism. The damage to mitochondria from exposure to chemical harmful factors in environment is of increasing concern. The integrity of the mitochondrial genome is critical for mitochondrial function and cellular homeostasis, and mitochondria are susceptible to damage and mitochondrial dysfunction when stimulated by various harmful chemical environmental factors. It has been shown that exposure to a variety of chemical pollutants can produce varying degrees of damage to mitochondria, and these pollutants may cause mitochondrial structural and functional disorders by inducing oxidative stress, including impaired electron respiratory chain transmission, alterations in mitochondrial membrane potential, mitochondrial DNA mutations/deletions, and mitochondrial DNA copy number variation. Mitochondrial damage can further lead to abnormal cell function, apoptosis, and death, which induce related diseases. Therefore, this paper provides a review of the role of chemical factor exposure in the environment, such as heavy metals, on mitochondrial damage.