Objective To investigate the effect of simulated high altitude and cold conditions on the model of severe abdominal infection in rabbits. Methods 60 New Zealand rabbits were randomly divided into plain group (altitude 100 m, temperature 5℃, n=20), sub-plateau group (altitude 1000 m, temperature –5℃, n=20) and plateau group (altitude 5000 m, temperature –25℃, n=20). Each group was kept in the corresponding animal feeding cabin for 14 days, then induced severe abdominal model by cecal ligation and puncture (CLP). The basic data were measured before operation, and the peripheral vein blood was extracted 24 and 72 hours after operation. The levels of C-reactive protein (CRP), procalcitonin (PCT), tumor necrosis factor-α (TNF-α), albumin (ALB), prealbumin (PAB) were measured by ELISA, and the white blood cell count (WBC) was performed. The rabbits were killed 72 hours after operation, the ascites were collected from the abdominal fluid, and collected liver, kidney and small intestine, and the pathological changes were observed by HE staining. Pearson correlation was used to analyze the correlation between the infection indexes and the high cold factors at high altitude. Results Seventy-two hours after operation, the survival rate of CLP model rabbits in plain group, sub-plateau group and plateau group was 65.0%(13/20), 35.0%(7/20), 10.0%(2/20), respectively. With the increase of altitude and the decrease of temperature, the survival rate of CLP model rabbits decreased gradually (P<0.01). All CLP rabbits began to show signs of less movement, curling, mental burnout, shortness of breath, coarse breath tone, diarrhea and eye corner exudates. In the plain group, the anal temperature increased continuously and then decreased slowly, with the highest value of 39.2℃ and the lowest value of 36.5℃; in the sub-plateau group, the anal temperature increased sharply and then decreased gradually, with the highest value of 40.6℃ and the lowest value of 34.9℃; in the plateau group, the anal temperature decreased rapidly, with the highest value of 41.2℃ and the lowest value of 34.0℃. At 24 and 72 hours after operation, the levels of PCT and TNF-α in venous blood of CLP model rabbits in plateau group and sub-plateau group were higher than those in plain group, and those in plateau group were higher than those in sub-plateau group (P<0.05); at 72 hours after operation, the levels of ALB and PAB in venous blood of CLP model rabbits in plateau group and sub-plateau group were lower than those in plain group, and those in plateau group were lower than those in sub-plateau group (P<0.05). Pearson correlation analysis showed that PCT, TNF-α were positively correlated with high altitude cold factors (r=0.288, r=0.368, P<0.05), WBC and CRP had no significant correlation with them (r=0.462, r=0.397, P>0.05). The results of ascite culture showed that 51, 69 and 107 pathogens were isolated from plain group, sub-plateau group and plateau group respectively, among which gram-negative bacteria accounted for 52.94%(27/51), 49.27%(34/69), 42.06%(45/107), and gram-positive bacteria accounted for 29.41%(15/51), 34.78%(24/69), 43.93%(47/107). Conclusion The high cold condition at high altitude is an important factor in the infection degree and death of CLP model rabbits. It can aggravate the infection of abdominal cavity and damage the important organ function, affect the nutrition absorption and metabolism of the body. The difference between the pathogenic bacteria and the plain area under this condition may affect the process and treatment of abdominal infection diseases, which is worth further study.

Objective To investigate the effects of advanced pregnancy on DNA methylation level of hippocampus in the offspring rats. Methods 12- and 3-month-old female SD rats were mated with 3-month-old male SD rats. The offspring(s)from older mother were marked as AMA group, and those from younger mother were marked as control group. The brain and hippocampus samples of the offsprings were taken at the 7th, 14th and 28th day after birth. The mRNA levels of DNA methyltransferase (Dnmt)1, Dnmt3A and Dnmt3B were detected by real-time fluorescent quantitative PCR (RT-PCR). The protein expression levels of Dnmt1, Dnmt3A and Dnmt3B were measured by Western blotting. Immunofluorescence and ELISA were used to detect the localization and expression level of 5-methylcytosine (5-mC) in hippocampus. Results RT-PCR showed the Dnmt1 mRNA level was markedly lower in hippocampus of AMA group than that in control group on day 28 after birth (P<0.05); Western blotting analysis showed the expression level of Dnmt3A protein was obviously higher in hippocampus of the AMA group than that in control group on day 7 after birth (P<0.05), while the expression levels of Dnmt1 and Dnmt3A were lower in AMA group than those in control group on day 28 after birth (P<0.05). Immunofluorescence test showed that the 5-mC level in hippocampus was significantly higher in AMA group than that in control group on day 7 and 14 after birth (P<0.05). ELISA showed that the 5-mC level in hippocampus increased slightly but without statistical significance in AMA group than that in control group on day 7, 14 and 28 after birth (P>0.05). Conclusion Advanced pregnancy may lead to the expression disorder of Dnmts and the increased DNA methylation level in offspring's hippocampus, which may be one of the potential mechanisms of offspring's brain dysfunction.

Objective To explore the predictive value of red volume distribution width (RDW) for the clinical outcome of sepsis in the elderly. Methods Two hundred and ten elderly patients with sepsis admitted to the General Hospital of Eastern Theater Command of PLA from January 2018 to December 2019 were included. The highest Acute Physiology and Chronic Health Evaluation (APACHE Ⅱ)score and sequential organ failure (SOFA) score were calculated during sepsis. According to clinical outcome, 210 patients were divided into septic shock (n=93) /non-shock (n=117) groups; severe (n=79)/mild organ dysfunction (n=131) groups and death (n=60)/survival groups (n=150). The differences in age, sex, smoking and drinking history, medical history, APACHE Ⅱ score, SOFA score, RDW were compared between the different groups. Spearman's correlation analysis was used to analyze the correlation between RDW and APACHE Ⅱscore, SOFA score, total hospital days and ICU hospital days. Unconditional logistic regression was used to analyze the risk factors for septic shock, severe organ dysfunction and death in elderly patients with sepsis. Receiver operating characteristic (ROC) curves were adopted to analyze the predictive value of RDW, SOFA score, and APACHE Ⅱ score for septic shock and severe organ dysfunction in elderly patients with sepsis. Results The RDW, APACHE Ⅱ score, SOFA score, the incidence of severe organ dysfunction and death in the septic shock group were higher than those of the non-sepsis group; RDW, APACHE Ⅱscore, SOFA score, the incidences of septic shock and mortality in the severe organ dysfunction group were higher than those in the mild organ dysfunction group; RDW, APACHE Ⅱ score, SOFA score, the incidence of septic shock and severe organ dysfunction in the death group were higher than those in the survival group, there was a significant difference between each group (P<0.05); RDW was positively correlated with APACHE Ⅱ score, SOFA score, total hospital days and ICU hospital days (P<0.001); Elevated RDW was an independent risk factor for septic shock and severe organ dysfunction (P<0.05); the risk of septic shock and severe organ dysfunction was significantly increased when RDW>20% (P<0.05); The ROC AUC of SOFA score was 0.958, sensitivity was 0.817, specificity was 0.940, ROC AUC of RDW combined with SOFA score was 0.959, sensitivity was 0.968, specificity was 0.676 in predicting septic shock; The ROC AUC of APACHE Ⅱ score was 0.973, sensitivity was 0.911, specificity was 0.931, the ROC AUC of the RDW combined with APACHE Ⅱ score was 0.978, sensitivity was 0.972, and specificity was 0.668 in predicting severe organ dysfunction. Conclusions RDW is an independent risk factor to predict septic shock and severe organ dysfunction in elderly patients with sepsis; RDW combined with SOFA score and RDW combined with APACHE Ⅱ score have better sensitivity to predict septic shock and severe organ dysfunction than any single factor.

Heatstroke is a disease with high morbidity and mortality that causes a patient's core body temperature to be higher than 40.5℃ and combined with organ dysfunction when human body exposed to high temperature, high humidity and slow air circulation environment or after strenuous exercise. Early diagnosis and early cooling can significantly improve patient prognosis, increase patient survival rate and reduce complications. The cooling measures include extravascular cooling which mainly refers to physical cooling of body surface and intravascular cooling is mainly for patients who are not suitable for physical cooling or whose diagnosis and treatment are delayed due to lack of resources, especially for patients with heatstroke, which has a better cooling effect and can improve the prognosis of patients. Currently, the commonly used intravascular cooling measures in clinical practice mainly include intravascular infusion cooling, intravascular temperature management devices cooling and continuous blood purification.This article reviews the classification, mechanism, clinical application, advantages and disadvantages of intravascular cooling.

Stress fracture is a kind of weight-bearing lower extremity bone injury that usually occurs in athletes, recruits and other specific groups. It is one of the most important reasons that stop them from normal training and may affect athletes'career and military warfare capability. Many intrinsic and extrinsic factors may increase the risk of stress fracture, and preventive measures against these risk factors are the main direction of stress fracture prevention research. At the same time, the importance of more accurate diagnosis and treatment of stress fractures is heightened by the fact that the missed diagnosis or malpractice of stress fractures can have an adverse impact on the career of athletes or military recruits, placing an additional burden on the medical system. In this paper, the treatment and prevention of stress fractures are summarized, and the future prospects are prospected.

Objective To compare the consistency and accuracy between rapid direct detection method (rapid method)and traditional detection method (traditional method) for bacterial identification and drug sensitivity test of positive blood culture specimens. Methods The bloodstream infection specimens of the outpatients, emergency patients and inpatients of the Chinese PLA General Hospital from 2019 to 2020 were collected and placed in a blood culture apparatus. After the blood culture alarm, positive blood culture specimens were collected. At the same time, the rapid method and the traditional method were used for culture. After culture, bacteria identification and drug susceptibility test were conducted respectively, and the consistency of bacteria identification and drug susceptibility test between the two methods was recorded and compared. Results Among the 149 positive blood specimens from patients with bloodstream infection, 79 strains of Gram-positive cocci and 70 strains of Gram-negative bacilli were identified by traditional method; 75 strains of Gram-positive cocci and 67 strains of Gram-negative bacilli were identified by the rapid method. Compared with the traditional method, the overall coincidence rate of the rapid method in identify bacteria was 95.3%(142/149), among which the coincidence rate of Gram-positive cocci was 94.9%(75/79), and that of Gram-negative bacilli was 95.7%(67/70). In the traditional method, 76 strains (96.2%) of Gram-positive cocci and 66 strains (94.3%) of Gram-negative bacteria can effectively identify their species; 3 strains (3.8%) of Gram-positive cocci and 4 strains (5.7%) of Gram-negative bacilli could effectively identify their genera. In the rapid method, 52 strains (69.3%) of Gram-positive cocci and 63 strains (94.0%) of Gram-negative bacilli could effectively identify their species, 20 strains (26.7%) of Gram-positive cocci and 3 strains (4.5%) of Gram-negative bacilli could effectively identify their genera. According to the criteria of drug sensitivity test results, the coincidence rates between the rapid method and the traditional method for drug sensitivity test of Gram-positive cocci and Gram-negative bacilli were more than or equal to 90.0%, the general error rates were less than 10.0%, the serious error rates were less than 3.0%except compound sulfamethoxazole, and the extremely serious error rates were less than 1.5%. Conclusion The rapid method can effectively shorten the time of identification and drug sensitivity test, and the identification results are accurate. It is helpful for clinicians to make a clear diagnosis and adjust the treatment plan in time, quickly shift from empirical use of broad-spectrum antibiotics to targeted treatment, and provide more effective treatment plan for patients.

Objective To investigate the possible mechanism of proline/serine rich coil protein 1 and annexin A2 (PSRC1-ANXA2) interaction to attenuate the progression of atherosclerosis. Methods To detect the PSRC1 binding proteins, RAW264.7 macrophages were divided into two groups: control group (Ad-GFP) and PSRC1 overexpression group (Ad-PSRC1), treated with ox-LDL (100 μg/ml) for 24 h after adenovirus transfection, and the PSRC1-binding proteins were detected by non-labeled quantitative macrophages. The above protein spectra were verified by co-immunoprecipitation (Co-IP) and immunofluorescence assay. To detect the effect of PSRC1 overexpression on ANXA2 secretion after ox-LDL stimulation, RAW264.7 macrophages were divided into four groups: control group, ox-LDL group, Ad-GFP+ox-LDL group and Ad-PSRC1+ox-LDL group. The levels of ANXA2 in the cultured supernatant were determined by enzyme-linked immunosorbent assay (ELISA). To detect the knockdown effect of adenovirus Ad-shANXA2 on AXNA2, RAW264.7 macrophages were divided into two groups: Ad-GFP group and Ad-shANXA2 group. The mRNA levels of ANXA2 in RAW264.7 macrophages were detected by real-time fluorescence quantitative PCR (RT-qPCR). To detect the effect of ANXA2 knockdown on the progression of aortic plaque and the secretion of inflammatory factors, 24 ApoE^-/- mice were randomly divided into four groups (6 each): chow diet+Ad-GFP group, chow diet+Ad-shANXA2 group, high fat diet+Ad-GFP group and high fat diet+Ad-shANXA2 group. The atherosclerosis areas (AS) of aorta and aortic root were detected by oil red O staining. The serum levels were determined by ELISA assay of interleukin-1β (IL-1β) and IL-6 in high fat diet+Ad-GFP group and high fat diet+Ad-shANXA2 group. Results The results of proteomics analysis showed that, after stimulation with ox-LDL, the binding of PSRC1 and ANXA2 increased significantly, and the combination was of specificity. Immunofluorescence also showed that the co-localization of PSRC1 and ANXA2 existed in the cells. RT-PCR revealed that, compared with Ad-GFP group, the ANXA2 level decreased significantly in Ad-shANXA2 group (0.198±0.065 vs. 1.002±0.069, P<0.05). ELISA results showed that, compared with the control group, the ANXA2 level increased significantly in the ox-LDL group [(2027.23±93.55) pg/ml vs. (697.01±30.08) pg/ml, P<0.01], and compared with Ad-GFP+ox-LDL group, the ANXA2 level reduced significantly in Ad-PSRC1+ox-LDL group [(1061.65±68.52) pg/ml vs. (2098.67±318.41) pg/ml, P<0.01]. In animal experiments, oil red O staining revealed that no statistical difference existed in the area of aortic gross and aortic root plaques between the two groups of chow diet.Compared with high-fat diet+Ad-GFP group, the percentage of aortic plaque area decreased significantly, and of aortic root section also decreased significantly in high-fat diet+Ad-shANXA2 group (5.29%±1.14% vs. 12.28%±2.48%, P<0.05; 1.31%±0.04%vs. 2.83%±0.22%, P<0.05). ELISA test found that, compared with high-fat diet+Ad-GFP group, the IL-1β level decreased significantly [(122.90±9.80) pg/ml vs. (172.90±21.83) pg/ml, P<0.05], and the IL-6 level decreased also [(3.65±0.12) pg/ml vs.(5.97±0.42) pg/ml, P<0.05] in high-fat diet+Ad-shANXA2 group. Conclusion Over-expression of PSRC1 in macrophages can attenuate the progression of atherosclerosis, where the increased binding of PSRC1 to ANXA2, and the inhibition of ANXA2 release, thereby inhibiting the release of inflammatory factor may be the possible related mechanism.

Objective To investigate the clinical value of changing the diagnostic criteria for non-alcoholic fatty liver disease (NAFLD) to metabolism-associated fatty liver disease (MAFLD) in the risk-stratification and management of cardiovascular disease. Methods A total of 234 patients with fatty liver diagnosed by ultrasound examination were selected from February 2019 to September 2020 in the Gastroenterological Department of the Sixth Medical Center of Chinese PLA General Hospital. All the enrolled patients were collected of the anthropological parameters, history of chronic diseases [hypertension, type 2 diabetes mellitus (T2DM)], liver function, blood lipid, hemoglobin, platelet, blood uric acid, blood urea, bile acid, fasting blood glucose and nonalcoholic fatty liver disease fibrosis score (NFS). According to the different diagnostic criteria of fatty liver, 157 patients who met the diagnostic criteria of NAFLD were classified as NAFLD group and 213 patients who met the diagnostic criteria of MAFLD were classified as MAFLD group. The MAFLD group was regrouped and compared according to the presence or absence of T2DM and alcohol consumption. Results The proportion of male patients, hypertension, T2DM and the levels of alanine aminotransferase(ALT), aspartate aminotransferase (AST), glutamyl transpeptidase (GGT), total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) and the hemoglobin in the NAFLD group were lower than those in the MAFLD group; and the level of high density lipoprotein cholesterol (HDL-C) in the NAFLD group was higher than that in the MAFLD group, the difference was statistically significant (P<0.05). In the MAFLD group, 75 patients were combined with T2DM and 138 had no T2DM. The proportion of patients with hypertension and the levels of ALT, AST, GGT and alkaline phosphatase (ALP) in patients with T2DM were higher than those without T2DM, and the proportion of patients without liver fibrosis (NFS <–1.455) was lower than those without T2DM, the difference was statistically significant (P<0.05). There were no significant differences in age, gender and BMI between the two groups (P>0.05). In the MAFLD group, 70 patients were drinkers and 143 non-drinkers. The age of the drinking group was lower than that of the non-drinking group, and the proportion of male, hypertension, T2DM and the levels of BMI, ALT, AST, GGT, pre-albumin, TG, TC, LDL-C, hemoglobin, uric acid and fasting blood glucose in the drinking group were higher than those in the non-drinking group, with statistical significance (P<0.05). Conclusion The diagnostic criteria of MAFLD are easier to identify high-risk population of cardiovascular diseases than those of NAFLD, which is helpful for targeted management.

Objective To investigate the risk factors related to carotid atherosclerosis in aircrew. Methods With a retrospective case-control study, aircrew admitted in the Air Force Medical Center from January 2016 to December 2019 and underwent carotid artery ultrasound examination were recruited as the subjects. Those ultrasound diagnosed as carotid atherosclerosis(n=110) were set as case group, and age- and sex-matched aircrew with normal ultrasonography (n=110) were as control group. The differences in risk factors of atherosclerosis and flight factors between the two groups were compared. Logistic regression analysis was performed to explore the risk factors of carotid atherosclerosis in aircrew. Results The total flight time and average annual flight time of the aircrew in case group were significantly longer than those in the control group [4700(3015, 6200) h vs. 4050(3000, 5275) h,P=0.048; 168.82(129.79, 200.81) h vs. 147.73(120.26, 185.11) h, P=0.045]. The prevalence of hypertension and hyperlipidemia were higher in case group than those in control group [28.2%(31/110) vs. 14.5%(16/110), P=0.015; 56.4%(62/110) vs. 32.7%(36/110),P=0.000]. The percentage of aircrew without any risk factors of atherosclerosis was lower in case group than that in control group[12.7%(14/110) vs. 21.8%(24/110)], while the percentage of aircrew with ≥4 risk factors was significantly higher in case group than that in control group [12.7%(14/110) vs. 0%(0/110)]. Significant difference existed in the number of atherosclerotic risk factors between the two groups (P=0.003). Logistic regression analysis showed that hyperlipidemia and average annual flight time were the independent risk factors for carotid atherosclerosis in aircrew (P<0.05). Conclusion Hyperlipidemia and the long average annual flying time have a significant influence on the incidence of carotid atherosclerosis in aircrew.

Vascular endothelial glycocalyx (VEG), a protein-polysaccharide complex located on the cell membrane of vascular endothelial cell lumen, has physiological effects such as anti-inflammation, anti-thrombosis and protection of endothelium.The structural and functional abnormalities of VEG in pulmonary capillaries play an important role in the occurrence and progression of sepsis-mediated acute lung injury (ALI). On one hand sepsis induces ALI by activating heparanase and destroying glycocalyx; on the other hand, it inhibits the repair of lung tissue by preventing the timely reconstruction of glycocalyx. This article summarizes the recent studies to explore the relationship between the structural and functional impairment of VEG and sepsis-related ALI, as well as the value and prospect of glycocalyx in the diagnosis and treatment of sepsis-related ALI.