Objective To investigae microbial community structure of lower respiratory tract in severe hospital-acquired pneumonia(SHAP)patients in intensive care unit(ICU)using metagenomic next-generation sequencing(mNGS).Methods mNGS was performed on bronchoalveolar lavage fluid(BALF)of 84 patients with SHAP.Patients were grouped based on age,smoking status,underlying diseases and duration of artificial airway.The differences in α diversity,β diversity,microbial composition and community structure of airway microbiota were compared between different groups.The differential airway microbiota associated with artificial airway were screened,and microbial co-occurrence networks was constructed to observe the interaction in microorganisms.Results Results of α diversity analysis revealed that diversity and evenness of the microbial community were higher in young adults compared to those of middle-aged patients,while microbial diversity and evenness were significantly reduced in patients with comorbid stroke.In the group of artificial airway treatment,the diversity and uniformity of microorganisms decreased as the duration of artificial airway treatment increased.The diversity was the lowest when the artificial airway treatment lasted for more than 3 days.β diversity analysis confirmed that there were significant differences in the distinct microbial community structures between the>3 days support group and the non-intubated and≤3 days support cohorts.Acinetobacter baumannii was dominant in all groups.The bacterial diversity was significantly higher in the middle-aged group,the non-smoking group,the group without artificial airway therapy,the group without diabetes mellitus,the group with artificial airway therapy≥3 days and the group with chronic lung disease than those of other groups.In particular,pseudomonas aeruginosa,corynebacterium striatum and veillonella parvula were enriched in these groups.Difference analysis showed that there were significant differences in pseudomonas aeruginosa and corynebacterium striatum between the group with artificial airway treatment>3 days,the group without artificial airway therapy and the group with artificial airway treatment≤3 days.Network co-occurrence showed that there may be synergistic or antagonistic relationships between some microorganisms.Conclusion The microbial diversity of the lower respiratory tract in patients with SHAP significantly decreases in the elderly,those with concurrent stroke and those receiving artificial airway treatment.For these groups,rational use of antibiotics should be adopted to guide precise anti-infection treatment.

Objective To investigae microbial community structure of lower respiratory tract in severe hospital-acquired pneumonia(SHAP)patients in intensive care unit(ICU)using metagenomic next-generation sequencing(mNGS).Methods mNGS was performed on bronchoalveolar lavage fluid(BALF)of 84 patients with SHAP.Patients were grouped based on age,smoking status,underlying diseases and duration of artificial airway.The differences in α diversity,β diversity,microbial composition and community structure of airway microbiota were compared between different groups.The differential airway microbiota associated with artificial airway were screened,and microbial co-occurrence networks was constructed to observe the interaction in microorganisms.Results Results of α diversity analysis revealed that diversity and evenness of the microbial community were higher in young adults compared to those of middle-aged patients,while microbial diversity and evenness were significantly reduced in patients with comorbid stroke.In the group of artificial airway treatment,the diversity and uniformity of microorganisms decreased as the duration of artificial airway treatment increased.The diversity was the lowest when the artificial airway treatment lasted for more than 3 days.β diversity analysis confirmed that there were significant differences in the distinct microbial community structures between the>3 days support group and the non-intubated and≤3 days support cohorts.Acinetobacter baumannii was dominant in all groups.The bacterial diversity was significantly higher in the middle-aged group,the non-smoking group,the group without artificial airway therapy,the group without diabetes mellitus,the group with artificial airway therapy≥3 days and the group with chronic lung disease than those of other groups.In particular,pseudomonas aeruginosa,corynebacterium striatum and veillonella parvula were enriched in these groups.Difference analysis showed that there were significant differences in pseudomonas aeruginosa and corynebacterium striatum between the group with artificial airway treatment>3 days,the group without artificial airway therapy and the group with artificial airway treatment≤3 days.Network co-occurrence showed that there may be synergistic or antagonistic relationships between some microorganisms.Conclusion The microbial diversity of the lower respiratory tract in patients with SHAP significantly decreases in the elderly,those with concurrent stroke and those receiving artificial airway treatment.For these groups,rational use of antibiotics should be adopted to guide precise anti-infection treatment.

Objective:To investigate the risk factor analysis and model prediction of bleeding after endoscopic retrograde cholangiopancreatography in patients with malignant obstructive jaundice (MOJ).Methods:A retrospective analysis was performed on 302 patients with MOJ treated with ERCP who were treated in the No. 363 Hospital Affiliated to Southwest Medical University from January 2015 to June 2021. The general clinical data of the patients were collected, and the biochemical indicators of the pancreatic and bile ducts were detected. The patients were followed up after discharge, and the patients were divided into a bleeding group ( n=47) and a control group ( n=255) according to whether the follow-up patients were bleeding after ERCP. Compared the general and clinical data of the two groups of patients, including age, gender, platelet count, presence of bile duct stones, acute cholangitis, acute pancreatitis, number of stones, intraoperative bleeding, pancreatic cancer, cholangiocarcinoma, large stone diameter, stone incarceration, duodenal papillary diverticulum, and pre-surgical incision. The measurement data that obey the normal distribution were represented by the mean±standard deviation ( ± s), and the two independent sample t test was used for the comparison between groups; the data that do not conform to the normal distribution were represented by M ( Q1, Q3), and the comparison between groups was used Mann-Whitney U test. The comparison of enumeration data between groups adopted chi-square test. Logistic multivariate regression was used to analyze the independent risk factors of postoperative bleeding after ERCP, and a nomogram prediction model was established and verified according to the independent risk factors of postoperative bleeding. Results:The two groups of patients were compared in age, gender, platelet count, bile duct stones, acute cholangitis, acute pancreatitis, the number of stones, intraoperative bleeding and other aspects, the difference was not statistically significant ( P>0.05). The percentages of pancreatic cancer, cholangiocarcinoma, large stone diameter, stone incarceration, duodenal papillary diverticulum, and surgical pre-incision in the bleeding group were 12.77%, 17.02%, 19.15%, 51.06%, 59.57%, and 14.89%, respectively. , the percentages of the control group were 3.92%, 5.10%, 9.02%, 19.22%, 17.65%, and 5.88%, and the difference was statistically significant between the two groups ( P<0.05). Taking postoperative bleeding as the dependent variable, and using the indicators with statistical differences in univariate analysis as independent variables, multivariate Logistic regression analysis showed that the patient had pancreatic cancer ( OR=1.838, 95% CI: 1.524-4.613, P=0.041), cholangiocarcinoma ( OR=2.548, 95% CI: 1.870-5.116, P=0.015), stone incarceration ( OR=3.078, 95% CI: 2.374-6.012, P<0.001), duodenum Intestinal papillary diverticula ( OR=1.140, 95% CI: 1.045-1.628, P<0.001), surgical pre-incision ( OR=1.640, 95% CI: 1.321-1.928, P<0.001) were associated with postoperative bleeding in MOJ patients after ERCP independent risk factors. The predictive ability of duodenal papillary diverticulum was the highest; the predictive ability of stone incarceration and cholangiocarcinoma was the second, and there was no significant difference between them; the predictive ability of pancreatic cancer, stone diameter, and pre-incision on bleeding after ERCP in MOJ patients smaller. Pancreatic cancer, cholangiocarcinoma, large stone diameter, stone incarceration, duodenal papillary diverticulum, and pre-incision scores were 42, 63, 28, 65, 76, and 34 points respectively, and the total score was 308 points corresponding to the nomogram model. The predictive power of the nomogram was 61.6%, and overall, the nomogram had good predictive performance. Harrell concordance index analysis and ROC curve were used to evaluate the model discrimination, the C-index calculation result was 0.826 (95% CI: 0.771-0.847), the ROC curve AUC was 0.843 (95% CI: 0.801-0.884), and the ROC prediction The value and the calculation result of C-index are relatively close. The model discrimination is applied in this study and has a certain prediction effect. The nomogram model in the Calibration curve predicted the probability of postoperative bleeding after ERCP in MOJ patients with high consistency with the actual probability. Conclusion:ERCP is safe and feasible for most patients with MOJ, but for patients with pancreatic cancer, bile duct cancer, large stone diameter, stone incarceration, and duodenal papillary diverticulum, it should be performed with caution, and preoperative incision should be avoided, to reduce the risk of postoperative bleeding. In addition, the nomogram model has a strong predictive ability in predicting bleeding after ERCP in patients with MOJ, which is worthy of reference in clinical research.

Objective: To describe the CT features and clinical characteristics of pediatric patients with coronavirus disease 2019 (COVID-19).Method: A total of 9 COVID-19 infected pediatric patients were included in this study.Clinical history,laboratory examination,and detailed CT imaging features were analyzed.All patients underwent the first CT scanning on the same day of being diagnosed by realtime reverse-transcription polymerase chain reaction (rRT-PCR).A low-dose CT scan was performed during follow-up.Results: All the child patients had positive results.Four patients had cough and one patient had fever.One patient presented both cough and fever.Two children presented other symptoms like sore throat and stuffy nose.One child showed no clinical symptom.Five patients had positive initial CT findings with subtle lesions like ground-glass opacity (GGO) or spot-like mixed consolidation.Three patients were reported with negative results in the initial and follow-up CT examination.One patient was reported with initial negative CT findings but turning positive during the first follow-up.All patients had absorbed lesions on follow-up CT images after treatment.Conclusion: Pediatric COVID-19 patients have certain imaging and clinical features as well as disease prognosis.Children with COVID-19 tend to have normal or subtle CT findings and relatively better outcome.

Objective:To explore the predictive factors of pathological complete response (pCR) after neoadjuvant chemoradiotherapy for middle-low rectal cancer.Methods:A case-control study was conducted. The inclusion criteria were as follows: (1) colonoscopy, digital examination or magnetic resonance imaging (MRI) showed a distance from the lower edge of the tumor to the dentate line of no more than 10 cm; (2) complete clinicopathological data were available; (3) preoperative biopsy revealed adenocarcinoma; (4) preoperative pelvic MRI or endorectal ultrasonography was performed; (5) no distant metastasis was found. Exclusion criteria: (1) preoperative radiotherapy and chemotherapy were not administrated according to the standard; (2) simultaneous multiple primary cancer and familial adenomatous polyposis were observed. According to the above criteria, clinicopathological data of 245 patients with middle-low rectal cancer undergoing preoperative neoadjuvant chemoradiotherapy in Changhai Hospital of Navy Medical University from January 2012 to December 2019 were retrospectively collected. Univariate analysis and multivariate logistic analysis were used to identify the clinical factors predicting pCR. pCR is defined as complete disappearance of cancer cells under the microscope in cancer specimens (including lymph nodes) after neoadjuvant chemoradiotherapy.Results:A total of 72 patients with pCR were enrolled in this study. Univariate analysis showed that preoperative T stage, tumor circumference, tumor morphology, carbohydrate antigen (CA) 19-9, interval between the end of neoadjuvant therapy and operation were associated with pCR (all P<0.05). The above 5 variables were included in multivariate logistic analysis and the results revealed that the T stage (OR=5.743, 95% CI: 2.416-13.648, P<0.001), tumor circumference (OR=7.754, 95% CI: 3.822-15.733, P<0.001), tumor morphology (OR=0.264, 95% CI: 0.089-0.786, P=0.017) and the interval between the end of neoadjuvant therapy and operation (OR=0.303, 95% CI: 0.147-0.625, P=0.001) were independent predictive factors of pCR, while CA 19-9 level was not an independent factor (OR=1.873, 95% CI:0.372-9.436, P=0.447). Conclusion:By knowing the clinical features of preoperative T stage, tumor circumference, tumor morphology and the interval between neoadjuvant chemoradiotherapy and operation, patients with higher likelyhood of pCR after neoadjuvant chemoradiotherapy may be identified.

Objective:To explore the predictive factors of pathological complete response (pCR) after neoadjuvant chemoradiotherapy for middle-low rectal cancer.Methods:A case-control study was conducted. The inclusion criteria were as follows: (1) colonoscopy, digital examination or magnetic resonance imaging (MRI) showed a distance from the lower edge of the tumor to the dentate line of no more than 10 cm; (2) complete clinicopathological data were available; (3) preoperative biopsy revealed adenocarcinoma; (4) preoperative pelvic MRI or endorectal ultrasonography was performed; (5) no distant metastasis was found. Exclusion criteria: (1) preoperative radiotherapy and chemotherapy were not administrated according to the standard; (2) simultaneous multiple primary cancer and familial adenomatous polyposis were observed. According to the above criteria, clinicopathological data of 245 patients with middle-low rectal cancer undergoing preoperative neoadjuvant chemoradiotherapy in Changhai Hospital of Navy Medical University from January 2012 to December 2019 were retrospectively collected. Univariate analysis and multivariate logistic analysis were used to identify the clinical factors predicting pCR. pCR is defined as complete disappearance of cancer cells under the microscope in cancer specimens (including lymph nodes) after neoadjuvant chemoradiotherapy.Results:A total of 72 patients with pCR were enrolled in this study. Univariate analysis showed that preoperative T stage, tumor circumference, tumor morphology, carbohydrate antigen (CA) 19-9, interval between the end of neoadjuvant therapy and operation were associated with pCR (all P<0.05). The above 5 variables were included in multivariate logistic analysis and the results revealed that the T stage (OR=5.743, 95% CI: 2.416-13.648, P<0.001), tumor circumference (OR=7.754, 95% CI: 3.822-15.733, P<0.001), tumor morphology (OR=0.264, 95% CI: 0.089-0.786, P=0.017) and the interval between the end of neoadjuvant therapy and operation (OR=0.303, 95% CI: 0.147-0.625, P=0.001) were independent predictive factors of pCR, while CA 19-9 level was not an independent factor (OR=1.873, 95% CI:0.372-9.436, P=0.447). Conclusion:By knowing the clinical features of preoperative T stage, tumor circumference, tumor morphology and the interval between neoadjuvant chemoradiotherapy and operation, patients with higher likelyhood of pCR after neoadjuvant chemoradiotherapy may be identified.

Gene therapy represents a promising treatment for the Alzheimer׳s disease (AD). However, gene delivery specific to brain lesions through systemic administration remains big challenge. In our previous work, we have developed an siRNA nanocomplex able to be specifically delivered to the amyloid plaques through surface modification with both CGN peptide for the blood-brain barrier (BBB) penetration and QSH peptide for -amyloid binding. But, whether the as-designed nanocomplex could indeed improve the gene accumulation in the impaired neuron cells and ameliorate AD-associated symptoms remains further study. Herein, we prepared the nanocomplexes with an siRNA against -site amyloid precursor protein-cleaving enzyme 1 (BACE1), the rate-limiting enzyme of A production, as the therapeutic siRNA of AD. The nanocomplexes exhibited high distribution in the A deposits-enriched hippocampus, especially in the neurons near the amyloid plaques after intravenous administration. In APP/PS1 transgenic mice, the nanocomplexes down-regulated BACE1 in both mRNA and protein levels, as well as A and amyloid plaques to the level of wild-type mice. Moreover, the nanocomplexes significantly increased the level of synaptophysin and rescued memory loss of the AD transgenic mice without hematological or histological toxicity. Taken together, this work presented direct evidences that the design of precise gene delivery to the AD lesions markedly improves the therapeutic outcome.

Liver fibrosis is a common pathological process in the progression of various chronic liver diseases to liver cirrhosis and liver cancer, and liver biopsy with the highest accuracy in diagnosis cannot be used as a routine examination due to several drawbacks. This article introduces several serological and imaging methods used in clinical practice and analyzes their advantages/disadvantages and the current status of research. It is believed that thanks to the efforts of experts and scholars, noninvasive diagnostic methods have become more and more important and may replace liver biopsy and become an effective method for the diagnosis of liver fibrosis in the near future.

Objective To compare the characteristics of clinical pathology between patients with early recurrence and those with late recurrence of colorectal cancer.Methods Clinicopathological data of 391 recurrence patients after surgery from Changhai Hospital were recruited between Jan 2005 and Dec 2015.The clinical and pathological characteristics of primary cancer in early recurrence group (less than 2 years after surgery) and late recurrence group (2 year or more after surgery) were compared.Results 246 patients had early recurrence (62.9％) and 145 had late recurrence (37.1％).Liver,systemic metastases and peritoneum were the main sites of distant recurrence in the early recurrence group,whereas liver,lung and systemic metastases were the most frequent sites of metastases in the late recurrence group.Patients with the increased tumor perimeter,lymph node metastasis,increased CEA and CA19-9,without postoperative adjuvant treatment and microsatellite stability are more likely to have early recurrence.5-year overall survival rate for patients with early recurrence was significantly lower than those with late recurrence.Conclusions This study showed that clinical and pathological factors are significantly associated with recurrence of colorectal cancer.Two years after surgery is an important period for the recurrence of colorectal cancer.

Objective To investigate the MRI manifestations of secondary toxoplasmosis encephalitis in HIV patients and summarize the characteristics of MRI changes.Methods MRI images of 3 5 HIV patients with secondary toxoplasmosis encephalitis were analyzed retrospectively.Results Of 35 patients,27 showed multiple lesions and 8 showed single lesion.Lesions mainly involved the brain gray matter j unction or basal ganglia.MRI showed lamellar,nodular or round lesions,which showed low signal on T1WI,and slightly higher and unevenly high signal on T2WI.Irregular liquid signal or nodular slightly lower signal was showed on T2WI in 14 cases,and short T1signal was showed in 15 cases.Circular lesions could be seen"cattle eye"in 18 cases.For 11 cases of enhanced scan of a single lesion,a ring enhancement was displayed,and coexistence of patchy,nodular and annular enhancement were showed in multiple lesions,in which parts of the multi-circular enhancemens were clustered.Conclusion MRI manifestations of HIV patients with secondary toxoplasmosis encephalitis show primarily multiple lesions on the gray matter j unction or basal ganglia.The lesions show high signal on T1WI and"cattle eye"on T2WI,and existence of flaky,nodular and ring enhanced lesion or clustered enhancement are showed on enhanced imaging,which is of a certain specificity.