BACKGROUND: Different derivatives of chitosan with different molecular weights or degrees of deacetylation show different anti-tumor effects.OBJECTIVE: To study the inhibition effect of water-soluble chitosan and its derivatives, such as sulfonated chitosan, carboxymethyl chitosan and chitooligosaccharides for the growth of hepatocellular carcinoma cell line SMMC7721.DESIGN, TIME AND SETTING: Controlled experiments based on observation were carried out in Jiangxi Institute of Digestive Disease (Nanchang, Jiangxi, China) from January 2004 to December 2006.MATERIALS: Hepatoma cell line SMMC7721 was provided by Jiangxi Institute of Digestive Disease (China). 85.5% deacetylated chitooligosaccharides and 85% deacetylated water-soluble chitosan were produced by Jinan Haidebei Ocean Biological Engineering Co., Ltd (China); Carboxymethyl chitosan and 88.5% deacetylated chitosan were the products of Shanghai Qisheng Biological Products Co., Ltd (China).METHODS: Sulfonated chitosan was prepared using 88.5% deacetylated chitosan and chlorosulfonic acid-formamide, and then was detected with infrared spectroscopy in the Detection Analysis and Test Center, East China University of Science and Technology. SMMC7721 cells in the log phase were inoculated into 96-well culture plates, which were then added with water-soluble chitosan, sulfonated chitosan, carboxymethyl chitosan and chitooligosaccharides with the final concentrations of 25, 50, 100, 200, 400 and 800mg/L. This test was repeated for 3 times, while the control group was also set each time. After 72 hours of routine culture, MTT solution was added into each well and inoculated for another 4 hours. After the culture was terminated, dimethyl sulfoxid was added. The absorbance value of each well was measured at 490nm wavelength on a microplate reader. Three tests were measured to obtain the mean value. Also the inhibition rate was calculated.MAIN OUTCOME MEASURES: Growth inhibition effect of chitosan and its derivatives on the hepatoma cell line SMMC7721.RESULTS: Among the chitosan and its derivates at four kinds of concentrations, water-soluble chitosan and sulfonated chitosan could significantly inhibit the growth of SMMC7721 cells (P<0.001), and the effect was the most significant in the case of sulfonated chitosan. Treatment with water-soluble chitosan and sulfonated chitosan at the concentration of 50mg/L could inhibit the growth of SMMC7721 cells in a dose-dependent manner, and reached a peak at the concentration of 400mg/L and 800mg/L, respectively. Carboxymethyl chitosan and chitooligosaccharides showed no growth inhibition effect (P>0.05).CONCLUSION: Water-soluble chitosan and sulfonated chitosan have significant antigrowth effects on hepatoma carcinoma cells, while carboxymethyl chitosan and chitooligosaccharides are ineffective.

ObjectiveTo explore the early diagnosis and effective treatment of redundant colon,and to reduce the misdiagnosis and shorten the medical treatment time before the diagnosis.MethodsClinical data of twentyseven patients with redundant colon from February 2005 to December 2011 were retrospectively analyzed in General Surgery Department of 117th and 322th People's Liberation Army Hospital.ResultsThe clinical symptoms of 27 patients nainly as early recurrent intractable constipation,bloating,abdominal pain,weight loss and other symptoms,were likely to be in a misdiagnosis.In addition to three patients with redundant sigmoid colon concurrent reverse came to hospital emergency with surgery,twenty-four cases' symptoms persisted and came to many hospitals with medical treatment up to 32 years,diagnosed by the out-patient barium enema.After surgical resection disease bowel,7-11 months follow-up,patients abdominal distension,abdominal pain,constipation,weight loss and other systemic unwell symptoms disappeared.ConclusionThis disease is rare,we must raise the medical staff's awareness of this disease.X-ray examination with barium enema is the best way to diagnose this disease.After diagnosis,surgery is the most effective treatment.

Objective To imitate the pathological process of bronchiolitis obliterans(BO) post lung transplantation and in-vestigate the phenomenon of epithelial-mesenchymal transition ( EMT ) in small airway epithelial cells and its relation to BO . Methods We established the rat model of allogeneic orthotropic left lung transplantation with grafts from F 344 rats transplanted to Lewis rats by the Tri-cuff anastomosis.Then rats were daily injected intraperitoneally with cyclosporine (5 mg· kg-1 · d-1 ) for 10 days, intratracheally applied with lipopolysaccharide(0.5 mg/kg) at the 28th day and killed at the 90th day post-surger-y.We observed the histological structure of the lung grafts by HE and Masson staining , detected E-cadherin and Vimentin ex-pression in lung grafts and normal ones of F344 rats by immunohistochemistry, then analyzed the relation between small airway remodeling and the alterations in EMT markers expression .Enumeration data was analyzed with Fisher exact test and Spearman rank correlation was applied in correlation analysis .Results We found inflammatory cell infiltration , fibroplasia of bronchiole walls and significant lumen stenosis in lung graft mesenchyma.In lung grafts, the positive expression of E-cadherin was 5(total 13), which was significantly lower than that in normal lungs(7/8, P<0.05), and conversely the positive expression of Vim-entin was higher than normal ones(10/13 vs 2/8, P <0.05).The Spearman rank correlation analysis demonstrated that E-cadherin expression bear a negative correlation with Vimentin expression(r=-0.750, P<0.01).Conclusion Our study established a disease model imitating the pathological process of BO .And EMT was observed in small airway epithelial cells of the BO-exhibited lung grafts, indicating that EMT was involved in the process of BO airway remodeling .Thus it may reveal no-vel therapeutic targets for BO post lung transplantation by further investigation into the mechanism and pathological significance of EMT in small airway epithelial cells.

Background: Serum immunoglobulin A antibodies against Epstein–Barr virus (EBV), viral capsid antigen (VCA?IgA) and early antigen (EA?IgA), are used to screen for nasopharyngeal carcinoma (NPC) in endemic areas. However, their routine use has been questioned because of a lack of specificity. This study aimed to determine the distributions of different subtypes of antibody and to illustrate how the natural variation patterns affect the specificity of screening in non?NPC participants. Methods: The distribution of baseline VCA?IgA was analyzed between sexes and across 10?year age groups in 18,286 non?NPC participants using Chi square tests. Fluctuations in the VCA?IgA level were assessed in 1056 non?NPC participants with at least two retests in the first 5?year period (1987–1992) after the initial screening using the Kaplan–Meier method. Results: The titers of VCA?IgA increased with age (P < 0.001). Using a previous serological definition of high NPC risk, nasopharyngeal endoscopy and/or nasopharyngeal biopsy would be recommended in 55.5% of the non?NPC partici?pants with an initial VCA?IgA?positive status and in 20.6% with an initial negative status during the 5?year follow?up. However, seroconversions were common; 85.2% of the participants with a VCA?IgA?positive status at baseline con?verted to negative, and all VCA?IgA?negative participants changed to positive at least once during the 5?year follow?up. The EA?IgA status had a high seroconversion probability (100%) from positive to negative; however, it had a low probability (19.6%) from negative to positive. Conclusions: Age? and sex?specific cutoff titer values for serum anti?EBV antibodies as well as their specific titer fluc?tuation patterns should be considered when defining high NPC risk criteria for follow?up diagnostics and monitoring.

Lung cancer is the most common cancer and the leading cause of cancer death in the world, among which non-small cell lung cancer (NSCLC) accounts for about 85% of the total lung cancer. With the widespread of computed tomography (CT) and other imaging screening methods, the pathological types of lung cancer have changed from central squamous cell carcinoma to the early-stage lung adenocarcinoma, which is manifested as isolated pulmonary nodules and ground glass nodules on CT. Early diagnosis and treatment of lung cancer is of crucial clinical significance, and the continuous development and improvement of minimally invasive interventional techniques provide more options for lung cancer treatment, such as stereotactic radiation, percutaneous ablation, and bronchial intervention. This paper will make a review on the principle, advantages, disadvantages and prospects of minimally invasive interventional therapy commonly used in clinical practice.

Malocclusion,identified by the World Health Organization(WHO)as one of three major oral diseases,profoundly impacts the dental-maxillofacial functions,facial esthetics,and long-term development of～260 million children in China.Beyond its physical manifestations,malocclusion also significantly influences the psycho-social well-being of these children.Timely intervention in malocclusion can foster an environment conducive to dental-maxillofacial development and substantially decrease the incidence of malocclusion or reduce the severity and complexity of malocclusion in the permanent dentition,by mitigating the negative impact of abnormal environmental influences on the growth.Early orthodontic treatment encompasses accurate identification and treatment of dental and maxillofacial morphological and functional abnormalities during various stages of dental-maxillofacial development,ranging from fetal stages to the early permanent dentition phase.From an economic and societal standpoint,the urgency for effective early orthodontic treatments for malocclusions in childhood cannot be overstated,underlining its profound practical and social importance.This consensus paper discusses the characteristics and the detrimental effects of malocclusion in children,emphasizing critical need for early treatment.It elaborates on corresponding core principles and fundamental approaches in early orthodontics,proposing comprehensive guidance for preventive and interceptive orthodontic treatment,serving as a reference for clinicians engaged in early orthodontic treatment.

BACKGROUND: Thoracoscopic safe and effective hemostasis is an important condition for rapid rehabilitation of thoracic surgery. Placing hemostatic materials during surgery is a commonly used method in lung cancer laparoscopic surgery. Among them, resorbable oxidized cellulose is a commonly used hemostatic material. This research aims to observe the hemostatic effect of resorbable oxidized cellulose in lung cancer surgery. METHODS: A retrospective analysis of 42 patients with thoracoscopic lung cancer undergoing radical surgery in the Department of Thoracic Surgery, First Affiliated Hospital of Zhejiang University School of Medicine from July 1, 2018 to December 1, 2018, and intraoperative use of regenerative oxidized cellulose to stop bleeding The clinical and pathological data were selected and the perioperative indicators were selected as the outcome events for statistical analysis. RESULTS: The mean operative time was (120.5±57.3) min. The mean intraoperative blood loss was (26.8±21.6) mL. The average postoperative drainage volume was (513.6±359.5) mL. The average postoperative chest tube indwelling time was (2.6±1.2) d. CONCLUSIONS The use of absorbable regenerated oxidized cellulose in the radical operation of thoracoscopic lung cancer has a good hemostasis effect, and is suitable for hemostasis of wounds after lymph node dissection.

Malocclusion is an oral disease with a high prevalence. The goal of orthodontic treatment is health, aesthetics, function and stability. The transmission straight wire appliance and technique is an innovative orthodontic system with independent intellectual property rights invented by Professor Jiuxiang Lin′s team based on decades of clinical experience, which provides a new solution for the non-surgical correction of skeletal malocclusions, especially class Ⅲ malocclusion, and it is also a good carrier for the implementation of the concept of healthy orthodontics. Due to the lack of guidelines, how to implement standardized application of transmission straight wire technique remains a problem to be solved. This technical specification was formed by combining the guidance from Professor Jiuxiang Lin and joint revision by a number of authoritative experts from the Orthodontic Special Committee, Chinese Stomatological Association, with reference to relevant literatures, and combined with abundant clinical experience of many experts. This specification aims to provide reference to standardize the clinical application of transmission straight wire technique, so as to reduce the risk and complications, and finally to improve the clinical application level of this technique.

Objective    To discuss the efficacy of type Ⅱ hybrid aortic arch repair for type A aortic dissection in patients of different age groups. Methods    We retrospectively analyzed the clinical data of 126 patients with type A aortic dissection admitted to the Fuwai Hospital between January 2016 and December 2018, including 78 (61.9%) males and 48 (38.1%) females, with an average age of 61.8±6.9 years. The patients were divided into an elderly group (≥60 years, n=82) and a non-elderly group (<60 years, n=44). The preoperative, intraoperative and postoperative data of patients in the two groups were compared. Results    The age between the elderly and non-elderly group was significantly different (65.9±4.1 years vs. 54.3±4.1 years, P<0.010), and no significant difference was found between the two groups in other preoperative baseline data. There were 6 (4.8%) patients of early death, 3 (2.4%) patients of stroke and 2 (1.6%) patients of paralysis. A total of 194 stents were implanted, and the average dimeter of the stents was 33.6±1.8 mm and the average length was 199.0±6.7 mm. The non-elderly group had shorter mechanical ventilation time (31.9±41.7 h vs. 61.0±89.2 h, P=0.043) and ICU stay time (77.8±51.4 h vs. 143.1±114.4 h, P<0.001) than the elderly group. There was no significant difference in in-hospital mortality rate, reoperation rate or survival rate between the two groups (P>0.05). Follow-up time was 1-43 (22.6±10.8) months, and 3 patients were lost. There were 104 (82.5%) patients of complete thrombus formation of false lumen in stent and endoleak was reported in 11 (9.2%) patients. Conclusion    Type Ⅱ hybrid aortic arch repair offers an alternative approach to acute type A aortic dissection with acceptable early and mid-term clinical effects. The non-elderly patients have a similar early treatment effect to the elderly patients, but have a better mid-term outcome.

External apical root resorption is among the most common risks of orthodontic treatment, and it cannot be completely avoided and predicted. Risk factors causing orthodontic root resorption can generally be divided into patient- and treatment-related factors. Root resorption that occurs during orthodontic treatment is usually detected by radiographical examination. Mild or moderate root absorption usually does no obvious harm, but close attention is required. When severe root resorption occurs, it is generally recommended to suspend the treatment for 3 months for the cementum to be restored. To unify the risk factors of orthodontic root resorption and its clinical suggestions, we summarized the theoretical knowledge and clinical experience of more than 20 authoritative experts in orthodontics and related fields in China. After discussion and summarization, this consensus was made to provide reference for orthodontic clinical practice.
Humans ; Tooth Movement Techniques/adverse effects* ; Root Resorption/etiology* ; Consensus ; Dental Cementum ; Risk Factors