BACKGROUND:Heterotopic ossification is a dynamic growth process.Diverse heterotopic ossification subtypes have diverse etiologies or induction factors,but they exhibit a similar clinical process in the intermediate and later phases of the disease.Acquired heterotopic ossification produced by trauma and other circumstances has a high incidence. OBJECTIVE:To summarize the molecular biological mechanisms linked to the occurrence and progression of acquired heterotopic ossification in recent years. METHODS:The keywords"molecular biology,heterotopic ossification,mechanisms"were searched in CNKI,Wanfang,PubMed,Embase,Web of Science,and Google Scholar databases for articles published from January 2016 to August 2022.Supplementary searches were conducted based on the obtained articles.After the collected literature was screened,131 articles were finally included and summarized. RESULTS AND CONCLUSION:(1)The occurrence and development of acquired heterotopic ossification is a dynamic process with certain concealment,making diagnosis and treatment of the disease difficult.(2)By reviewing relevant literature,it was found that acquired heterotopic ossification involves signaling pathways such as bone morphogenetic protein,transforming growth factor-β,Hedgehog,Wnt,and mTOR,as well as core factors such as Runx-2,vascular endothelial growth factor,hypoxia-inducing factor,fibroblast growth factor,and Sox9.The core mechanism may be the interaction between different signaling pathways,affecting the body's osteoblast precursor cells,osteoblast microenvironment,and related cytokines,thereby affecting the body's bone metabolism and leading to the occurrence of acquired heterotopic ossification.(3)In the future,it is possible to take the heterotopic ossification-related single-cell osteogenic homeostasis as the research direction,take the osteoblast precursor cells-osteogenic microenvironment-signaling pathways and cytokines as the research elements,explore the characteristics of each element under different temporal and spatial conditions,compare the similarities and differences of the osteogenic homeostasis of different types and individuals,observe the regulatory mechanism of the molecular signaling network of heterotopic ossification from a holistic perspective.It is beneficial to the exploration of new methods for the future clinical prevention and treatment of heterotopic ossification.(4)Meanwhile,the treatment methods represented by traditional Chinese medicine and targeted therapy have become research hotspots in recent years.How to link traditional Chinese medicine with the osteogenic homeostasis in the body and combine it with targeted therapy is also one of the future research directions.(5)At present,the research on acquired heterotopic ossification is still limited to basic experimental research and the clinical prevention and treatment methods still have defects such as uncertain efficacy and obvious side effects.The safety and effectiveness of relevant targeted prevention and treatment drugs in clinical application still need to be verified.Future research should focus on clinical prevention and treatment based on basic experimental research combined with the mechanism of occurrence and development.

Objective:To explore the current status of surgery for portal hypertension to grasp current status and future development of surgery in China.Methods:This study is jointly sponsored by China Hepatobiliary & Pancreatic Specialist Alliance & Portal Hypertension Alliance in China (CHESS).Comprehensive surveying is conducted for basic domestic situations of surgery for portal hypertension, including case load, surgical approaches, management of postoperative complications, primary effects, existing confusion and obstacles, liver transplantation(LT), laparoscopic procedures and transjugular intrahepatic portosystemic shunt(TIPS), etc.Results:A total of 8 512 cases of portal hypertension surgery are performed at 378 hospitals nationwide in 2021.Splenectomy plus devascularization predominated(53.0%)and laparoscopy accounted for 76.1%.Primary goal is preventing rebleeding(67.0%) and 72.8% of hospitals used preventive anticoagulants after conventional surgery.And 80.7% of teams believe that the formation of postoperative portal vein thrombosis is a surgical dilemma and 65.3% of hospitals practiced both laparoscopy and TIPS.The major reasons for patients with portal hypertension not receiving LT are due to a lack of qualifications for LT(69.3%)and economic factors(69.0%).Conclusions:Surgery is an integral part of management of portal hypertension in China.However, it is imperative to further standardize the grasp of surgical indications, the handling of surgical operation and the management of postoperative complications.Moreover, prospective, multi-center randomized controlled clinical studies should be performed.

ObjectiveTo investigate a cluster epidemic of coronavirus disease 2019 （COVID-19） infections in a school in Longchuan County， Yunnan Province， and further guide the prevention and control of COVID-19 in the border area. MethodsAccording to the Protocol on Prevention and Control of Novel Coronavirus Pneumonia （8th Edition）， an epidemiological investigation was performed on all COVID-19 cases to collect the information on demographics， onset， diagnosis and treatment， prognosis， and epidemiological history. Close contacts were also tracked to determine the transmission chains. ResultsIn this cluster epidemic， a total of 37 COVID-19 cases were identified， including 32 females and 5 males aged from 13 to 25 years， who were 35 students and 2 teachers. The student cases were found in four classes of two grades. Furthermore， gene sequencing showed that all cases had been infected with delta variants， belonging to the same transmission chain that was not related to the previous epidemics in Dehong Prefecture. In additionally， a total of 2 127 close contacts were found. After 21 days of centralized quarantine for medical observation， all close contacts tested negative for SARS-CoV-2. In the COVID-19 cases， only one case remained positive for SARS-CoV-2， while the other 36 cases were successfully treated and became negative. ConclusionThis school cluster is caused by the border villagers who contacted the water polluted with SARS-CoV-2. It warrants more strict management of students from border villages and their belongings to prevent similar epidemics in school settings.

Objective: To determine whether intrauterine infection with hepatitis B virus (HBV) occurs in early pregnancy and to characterize associated virulence factors. Methods: Villi tissues and blood samples of 45 HBV surface antigen (HBsAg)-positive pregnant women were collected during the first trimester and HBV DNA loads were quantified by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The expression of GCM1, HBsAg and hepatitis B core antigen (HBcAg) in villi tissues were detected by immunohistochemical method. Results: Data from qRT-PCR showed that HBV DNA was detected in 14 of 45 villi tissues (positive rate of 31.11%), and 24 of 45 blood samples (positive rate of 53.33%), further statistical analysis showed that the positive rates of HBV DNA between blood samples and villi tissues were not significantly different (χ²=4.555, P=0.054). Among them, 12 samples were consistently positive between the villi and blood specimens, and HBsAg, HBeAg, HBeAb, HBV DNA from peripheral blood in these pregnant women were significantly higher than those of the other women (P value was 0.007, 0.004, 0.000, and 0.000 respectively). The multivariate logistic regression analysis showed that blood HBV DNA greater than 106 IU/ml was independently associated with HBV DNA positive in villi, and the HBsAg, HBeAg, villi tissues HBV DNA positive rates of these pregnant women were significantly higher than those of the other pregnant women (all P value were 0.000). Immunohistochemistry results showed that all 45 cases were positive for GCM1 expression in the cell nucleus. Nine cases also had HBsAg expression in the cytoplasm. Only one case was found to express HBV core antigen (HBcAg) in the nucleus. Conclusions HBV DNA and HBsAg can be detected from villi tissues harvested during the first trimester in HBsAg-positive pregnant women, and the results suggest an early occurrence of intrauterine infection of fetuses with high HBV levels.

As the highest academic institution, the academic committee is the core of the academic management system and organizational structure in medical colleges and universities. The regulations on the Academic Committees are the criteria for the academic operation of colleges and universities. Since the promulgation of the "Regulations on Academic Committees of Higher Education" by the Ministy of Educa-tion in 2014, medical colleges and universities have gradually improved the construction of the regulations. However, few studies have been conducted on the construction of academic committees in medical colleges and universities. The present paper analyzed the regulations on the academic committees of 20 medical colleges and universities, pointed out the inadequacies of the regulations on the academic committees of the medical colleges and universities in China from the aspects of the functions and construction, aiming to provide reference for the construction of the academic management system for modern medical colleges and universities.

Objective To investigate the influence of dynamic mechanical stimulation on the annulus fibrosus (AF) cells seeded on silk scaffolds.Methods AF cells were isolated from rabbits and were seeded on the scaffold,then cultured for 3,7,14 days with different range of dynamic compression.Stereomicroscope and scanning electron microscope (SEM) was used to observe the surface morphology of tissue engineering annulus fibrosus cells (TE-AFs).After fixation,samples were harvested for histological staining.AF cells related extracellular matrix (ECM) was evaluated by the quantitative analysis of total DNA,proteoglycan and collagen I.The mechanical properties were compared within different groups.Results Stereomicroscope and SEM results showed that the colors of TE-AFs in all groups were deepening with time going.SEM showed cell adhesion on the scaffold and the secretion of extracellular matrix.Histological,immunohistochemical staining,biochemical quantitative analysis and total DNA content showed that the AF cells inside scaffolds could support AF cell attachment,proliferation and secretion.As a result,the compressive properties were enhanced with increasing culture time.Stereomicroscope showed that the colors of TE-AFs in all groups were deepening with time going after dynamic compression.HE staining,Safranin O staining and Type Ⅰ collagen staining showed that cell proliferation and secretion,GAG secretion and collagen secretion were increased with time going within different groups.Quantitation of GAG achieved maximum in 15％ strain group,and quantitation of collagen achieved maximum in 10％ strain group.The total DNA content achieved maximum in 5％ strain group,and compression elastic modulus achieved maximum in 15％strain goup.The height of TE-AFs did not change after mechanical stimulation for 14 days.Conclusion Suitable mechanical stimulation is a positive factor for new AF tissue engineering that will tend to the nature tissue.Excessive compression can accelerate the progress of cell apoptosis.

Objective To explore the clinical significance of tumor pathological length in evaluation of prognosis of esophageal squamous cell carcinoma.Methods 421 patients with esophageal squamous cell carcinoma were selected as study subjects.Each patient's data of gender,age,pathological examination(tumor pathological length),survival time,cancer stage,operation mode were collected.The patients were divided into two groups:≤4 cm group(189 cases) and >4 cm group(232 cases), and the constituent ratios of gender,age,or operation mode and the survival rate between the two groups were analyzed.Results There were no significant differences in gender composition,age structure and operation mode between the two groups(x2=2.03,2.41,0.06,all P>0.05);There was positive correlation between tumor pathological length and TNM stage(CMH=68.07,P<0.01).The 25%,50% and 75% quantiles of survival period in the group whose tumor length was less than or equal to 4 cm were 28,40 and 58 months,respectively,which in the group whose tumor length was more than 4 cm were 19,31 and 61 months,and there was significantly difference between the two groups(x2=44.88,P<0.01), the group whose tumor length was less than or equal to 4 cm had higher survival rate than the group whose tumor length was more than 4 cm.In the further stratification analysis by TNM stage,the group whose tumor length was less than or equal to 4 cm had higher survival rate than the group whose tumor length was more than 4 cm in theⅠstage patients(x2=5.61,P<0.05);the group whose tumor length was less than or equal to 4 cm had higher survival rate than the group whose tumor length was more than 4 cm in theⅡstage patients(x2=4.62,P<0.05);the group whose tumor length was less than or equal to 4 cm had higher survival rate than the group whose tumor length was more than 4 cm in the Ⅲ stage patients(x2=4.88,P<0.05).Conclusion Tumor pathological length is an effective prognostic factor for esophageal squamous cell carcinoma,and the critical value can be determined as 4 cm.

Objective To establish an animal model of annulus fibrosus (AF) partial defect for the repairing of interver?tebral disc (IVD) defect. Methods Image J 1.46r software was used to measure the T12/L1-L6/S1 intervertebral height in ovine lumbar spine X-ray films. AF thickness was measured by axial split disc. A 11 blade was used to make a trapezoid de?fect of upper bottom 3 mm, lower bottom 5 mm, height 5 mm and thickness 3 mm, whose lower bottom toward the nucleus pulposus (NP) in the left front of ovine lumbar IVD in vitro. The minimally invasive lateral approach was used to make the same type of trapezoid defect in the left front of the ovine lumbar IVD in vivo. The trapezoidal defect length of the axial divid?ing disc was measured, AF and a small amount of NP from trapezoidal defect in IVD were weighed, and the production of trapezoidal defect in IVD was evaluated. Results The lumbar intervertebral space height of ovine was (4.45 ± 0.28) mm. There were significant differences in the thickness of AF (4.08±0.50) mm , thickness (3 mm) and height (5 mm) of trapezoidal defect (P<0.05), respectively. There were no significant differences in trapezoidal defects in ovine lumbar IVD in vitro on the upper bottom (3.03 ± 0.09)mm, the lower bottom (5.03 ± 0.09) mm, the height (4.97 ± 0.10) mm, the thickness(3.02 ± 0.06) mm and the trapezoidal defect predetermined value on the upper bottom 3 mm, the lower bottom 5 mm, the height 5 mm and the thickness 3 mm (P>0. 05). The weights of the AF and NP taken out from ovine lumbar IVD in vitro and in vivo were (0.162 ± 0.011) g and (0.166 ± 0.014) g, and there was no significant difference between them (P > 0.05). Conclusion Through the operation of minimally invasive lateral approach, the method of making a trapezoidal defect in the experiments can establish animal model of AF partial defect, which meets the requirements for the repairing of IVD defect, and is simple, safe and reliable.

Aim To determine the possibilities and mechanisms of EGFR, a receptor protein tyrosine kinase associated with many important cellular processes re-sponsible for cardiovascular remodeling in renovascular hypertensive rats. Methods 2K1C hypertensive rats were used in the present study. Blood pressure was measured with the tail-cuff method. LVMI and his-topathological changes in the cardiovascular system were analysed. EGFR expressions of aorta and myocar-dium as well as phosphorylation levels of ERK in hy-pertensive rats were detected by immunohistochemistry and Western blot analysis, respectively. Results Sys-tolic blood pressure was markedly increased 2 weeks after 2K1C surgery. Cardiovascular remodeling induced by hypertension was confirmed by elevated LVMI, pro-liferation of collagen fibers in myocardial interstitium, histopathological changes in cardiovascular system and increased IMT of thoracic aorta 6 weeks after 2 K1 C surgery. Compared with sham rats, EGFR expression in the ventricular myocardium of 2 K1 C rats was signifi-cantly increased at 6 weeks ( P<0. 05 ) , and the EG-FR/GAPDH ratio was higher in 2 K1 C rats with higher systolic blood pressure ( P < 0. 05 ) . Phosphorylation level of ERK 1/2 was upregulated correspondingly in 2 K1 C rats ( P <0. 01 ) . Increased EGFR expression was also found in aortas of 2K1C rats, particularly in tunica intima and media. Conclusion EGFR and its down-stream kinases ERK 1/2 are involved in cardio-vascular remodeling in association with the severity of hypertension in renovascular hypertensive rats.

Based on microfabrication technology and electrochemical modification method, a micro electrochemical sensor for nitrate ( NO-3 ) determination was developed. A micro sensor chip with working electrode and counter electrode was used as the signal convertor of the sensor. The area of the micro working_electrode was only 1 mm2 . As an electrocatalysis sensitive material, copper was electrodeposited onto the working electrode by square_wave pulse current electrodeposition method. The morphologies and components of freshly deposited materials were examined by scanning electron microscopy ( SEM ) and X_ray diffraction ( XRD) to explore key factors that affected the electrocatalytic ability of the deposited copper layer for reducing nitrate ions. The experimental results revealed that under the optimal conditions, the deposited copper layer was macroporous and had a larger effective surface area that could serve as a more effective electrocatalyst in facilitating nitrate reduction. Electrochemical response of the macroporous copper layer was characterized by linear sweep voltammetry in acidic supporting electrolytes ( pH=2 ) . The electroanalytical results showed that the modified microsensor had marked sensitivity for standard nitrate samples within the concentration range from 12. 5 to 3000 μmol/L (in the range of 12. 5-200 μmol/L yielded straight line:y1=-0. 1422x-10. 326, R12=0. 9976, while in the range of 200-3000 μmol/L yielded straight line: y2=-0. 0984x-22. 144, R22=0. 9927) with a detection limit of 2 μmol/L (S/N=3). The developed electrochemical microsensor was also employed for nitrate determination in water samples collected from lakes and rivers near the city of Beijing. The results were in good agreement with the data given by qualified water quality detection institute, with the deviations from 3 . 9% to 15 . 4%.