Objective To study the effect of Streptococcus pneumoniae pneumonia (S.pp) on the lung structure and function of mice. Methods Fifty neonatal BALB/c mice (1-week-old) were randomly divided into S.pp group and control group (25 each).Mice in S.pp group were infected intranasally with 2×10⁷ cfu of S. pneumoniae (D39) in 5 μl to establish the S.pp model, same dosage of PBS were used synchronously to treat the mice in control group. Three and five weeks after treatment, lung tissues and bronchoalveolar lavage fluid (BALF) of the two groups were collected, HE staining was performed to detect the pathological changes of lung tissue and alveolar structure; the collagen fiber deposition around alveoli was identified by Masson staining; the levels of IL-25, IL-33 and thymic stromal lymphopoietin (TSLP) in BALF were examined by ELISA. Five weeks after the infection, lung resistance was evaluated by EMKA pulmonary system. Results HE staining showed that, compared with control group, the radial alveolar count (RAC) decreased significantly in infancy and adult S.pp group (8.00±1.10 vs. 3.53±0.35, P=0.018; 13.73±2.49 vs.4.02±0.21, P=0.018), the mean linear intercept (MLI) increased obviously (88.99±5.55 vs. 127.10±9.54, P=0.006; 74.45±4.84 vs. 131.30±17.86, P=0.020), and the alveolar septum thickness increased markedly [(2.38±0.18) μm vs. (3.28±0.13) μm,P=0.002; (3.41±0.60) μm vs. (5.78±0.75) μm, P=0.023]. Compared with control group, the mean alveolar diameter (MAD)increased significantly in infancy S.pp group [(167.00±8.85) μm vs. (193.40±5.14) μm, P=0.042], but no significant difference existed between control group and adult S.pp group. The infiltration of inflammatory cells around alveoli increased obviously in infancy and adult S.pp group compared with that in control group (1.68±0.24 vs. 0.72±0.12, P=0.002; 1.88±0.30 vs.0.67±0.23, P=0.006). Compared with control group, the concentrations of IL-25, IL-33 and TSLP in BALF of adult S.pp group increased significantly [(36.16±2.80) pg/ml vs. (45.16±1.74) pg/ml, P=0.024; (52.06±1.70) pg/ml vs. (61.42±1.50) pg/ml,P=0.004; (13.32±0.74) pg/ml vs. (16.71±0.54) pg/ml, P=0.007]; Collagen fiber deposition around alveoli increased markedly[(0.01±0.01) mm² vs. (0.44±0.01) mm², P<0.001], and the airway resistance increased significantly when the concentration of inhaled aerosolized methacholine reached to 12.5–50.0 mg/ml in adult S.pp group mice (P<0.001). Conclusion Streptococcus pneumoniae pneumonia may induce the decrease of mean alveolar count, the increase of MLI, the alveolar septum thickness and airway resistance in BALB/c mice, thus lead to abnormal lung tissue structure and function.

Objective To explore the effect and mechanism of carbazochrome sodium sulfonate on acute lung injury in septic rats. Methods Healthy male Wistar rats were randomized into 5 groups: sham group (n=25), sepsis group (n=25), low dose group (carbazochrome sodium sulfonate: 8 mg/kg)(n=25), middle dose group (carbazochrome sodium sulfonate: 40 mg/kg)(n=25), and high dose group (carbazochrome sodium sulfonate: 80 mg/kg)(n=25). Two additional groups, the autophagy inhibition group(3-MA)(n=10) and the sepsis middle dose group (carbazochrome sodium sulfonate: 40 mg/kg)(n=10), are also included in this study. After the preparation of septic rats by cecal ligation and puncture, the different doses of carbazochrome sodium sulfonate or 3-MA were given by intraperitoneal injection. The survival curve is drawn. After CLP 24 hours, the lung Micro-CT of those survival rats were examined. The arterial blood gas, pulmonary index and vascular permeability of lung tissue were measured. Pathological changes of lung tissues were observed by HE staining. The level of autophagic marker (LC3-Ⅱ/LC3-Ⅰ) of lung tissue was measured by Western blotting. Results Compared with sepsis group, the survival rate of the rats of carbazochrome sodium sulfonate groups increased, the arterial blood oxygen partial pressure and oxygenation index increased, the pulmonary index and vascular permeability decreased, and the differences were statistically significant (P<0.05). Both lung Micro-CT and HE staining showed that the lung lesions were more serious in sepsis group, while carbazochrome sodium sulfonate alleviated these lesions. Western blotting results showed that, the ratio of LC3-Ⅱ/LC3-Ⅰ in lung tissue of septic rats was higher than sham group (5.1±2.7 vs. 2.7±0.7, P<0.05), while the ratio of LC3-Ⅱ/LC3-Ⅰ in lung tissue in the low dose and middle dose carbazochrome sodium sulfonate groups was further increased than sepsis group (6.8±2.6, 8.9±1.4 vs. 5.1±2.7, both P<0.05). The value of LC3-Ⅱ/LC3-Ⅰ in the lung tissue of rats in 3-MA group was significantly lower than that in the middle dose carbazochrome sodium group (3.1±1.7 vs. 8.7±1.6), and the difference was statistically significant (P<0.05). Conclusion The mechanism by which carbazochrome sodium sulfonate-alleviating lung injury is related to the up-regulation of autophagy level in septic rats.

Objective To analyze the peripheral 1-de-amino-8-D-arginine vasopressin (hereinafter referred as DDAVP)irritant test as the best cut-off point for the differential diagnosis of Cushing's disease and ectopic adreno-cortico-tropic-hormone(ACTH) syndrome (hereinafter referred as EAS), so as to explore the value of peripheral DDAVP irritant test in differential diagnosis of ACTH-dependent Cushing's syndrome. Methods The clinical data of 102 cases with ACTH-dependent Cushing's syndrome, diagnosed in the Endocrinology Department of the First Medical Center of Chinese PLA General Hospital from January 2016 to December 2019, were retrospectively analyzed, including 93 cases with Cushing's disease (Cushing's disease group) and 9 cases with EAS (EAS group). Based on the ROC curve, the blood ACTH level after stimulation was used as the detection variable, and the diagnosis result of Cushing's disease was used as the status variable to search the best cut-off point for the diagnosis of Cushing's disease. The sensitivity and specificity were analyzed of the peripheral DDAVP irritant test in the differential diagnosis of EAS and Cushing's disease at different cut-off points. Results Compared with Cushing's disease group, the course of disease was shorter and the basic blood cortisol and ACTH values were higher in EAS group with statistical significance (P<0.05). On the ROC curve, taking the increase by 33.6% of ACTH after stimulation as the cut-off point, the sensitivity and specificity for Cushing's disease and EAS were 98.9% and 55.6%, respectively, which were the best cut-off point. With the increase of blood ACTH value after stimulation, the sensitivity for diagnosing Cushing's disease decreased. If the increase by 20.0% of blood cortisol value after stimulation as the cut-off point simultaneously, then, the sensitivity for diagnosing Cushing's disease decreased and the specificity not increased. Thus, the blood ACTH was more specific than the blood cortisol. If taking the increase by 33.6% of the blood ACTH after peripheral DDAVP stimulation test, as well as the greater than or equal to 50.0% of the blood cortisol suppression ratio (or urinary free cortisol suppression ratio) in classical high-dose dexamethasone suppression test (HDDST) were taken as cut-off points, the sensitivity and specificity for identifying ACTH dependent Cushing's syndrome were 73.3% and 87.5%, respectively. Conclusion When taking the increase by 33.6% of blood ACTH after peripheral DDAVP stimulation as the cut-off point, the sensitivity was the highest in diagnosing Cushing's disease, so this method can be used as a screening test for and improve the detection rate of Cushing's disease.

Postpartum hemorrhage is the most common cause of maternal death worldwide with an upward trend of incidence recent years. There are many reasons leading to postpartum hemorrhage with very complicated pathogenesis. Recent years, various studies have found that a close relationship existed between the plasma fibrinogen concentration and postpartum hemorrhage and its severity. Prenatal fibrinogen detection is helpful to predict the occurrence of severe postpartum hemorrhage, Detection of postpartum fibrinogen level, and timely correction of transient coagulation dysfunction is an important way to remedy severe postpartum hemorrhage. At the present stage, many domestic hospitals have taken prenatal fibrinogen detection as a routine test item, but it has not yet been taken as an independent risk factor for postpartum hemorrhage. At the same time, the fibrinogen threshold might leading to severe postpartum hemorrhage and whether the lowest fibrinogen level is related to the amount of bleeding are still uncertain. The present review summarized the research progress of the clinical application of plasma fibrinogen measurement in the prediction of severe postpartum hemorrhage and accurate assessment of the amount of bleeding when postpartum hemorrhage occurs, and to explore the clinical value of fibrinogen detection in postpartum hemorrhage. Meanwhile, Suggestions for relative clinical work and future research are presented in order to improve the prognosis of postpartum hemorrhage.

Type 2 diabetes mellitus (T2DM) is often clinically associated with mi- and macrovascular diseases, but is often ignored in the early stage of the disease. Therefore, more auxiliary detection methods are needed clinically for early screening and auxiliary diagnosis of T2DM and high-risk patients. Arteriosclerosis detection--especially pulse wave velocity (PWV), as a non-invasive and effective method for measuring arterial stiffness, has been applied more and more widely in clinic recent years. Existing studies have shown that increased arterial stiffness is an important predictor of the occurrence and development of vascular diseases in T2DM. The value of PWV in the prediction of atherosclerosis is particularly important in order to better predict the occurrence of disease and start health management as soon as possible. Therefore, the relationship between PWV and mi- and macrovasular complications in T2DM is reviewed in present paper to provide early warning for patients with T2DM who have early vascular risk.

The outbreak of coronavirus disease 2019 has made nucleic acid detection widely known. Fluorescent quantitative polymerase chain reaction (PCR) technique is the most commonly used nucleic acid detection method in this epidemic control. However, its requirements on operators, instruments and sites limited its application in some scenarios with lower resources or outside laboratories. Isothermal amplification technology, especially recombinase polymerase amplification(RPA) technology, has the advantages of mild reaction conditions, high sensitivity, excellent specificity and short reaction time, which let it has a good application prospect in the rapid detection of a variety of pathogenic microorganisms. In this paper, the development and application of RPA technology are reviewed and summarized to provide a reference for the further research and promotion of this technology.

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 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 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 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.