BACKGROUND:Tumor microenvironment can participate in the occurrence and development of gastric cancer and promote chemotherapy resistance in various ways.Among them,the tumor microenvironment crosstalk mediated by exosomal miRNAs can induce matrix reprogramming,participate in tumor heterogeneity,and form a microenvironment conducive to tumor proliferation,migration,invasion,immune escape,and chemotherapy resistance.OBJECTIVE:To review the mechanism of action of exosomal miRNAs in the microenvironment of gastric cancer and its application in the diagnosis and prognosis assessment of gastric cancer in recent years.METHODS:"Exosomal miRNAs,gastric cancer,angiogenesis,apoptosis,proliferation,migration,autophagy,invasion,immune response,chemotherapy resistance,biomarker"for English search terms and"exosomal miRNAs,gastric cancer"for Chinese search terms were searched in PubMed and CNKI databases.The search period was from 2017 to 2024.After preliminary screening by reading the title and abstract,the articles with poor correlation and repeated content were excluded,and 77 articles were finally included for induction and discussion.RESULTS AND CONCLUSION:(1)Exosomes,as important carriers of intercellular information exchange,can carry a variety of information substances such as miRNA,and realize intercellular signal transmission through three ways:activation of cell surface receptors on target cells,fusion with the plasma membrane of recipient cells,and endocytosis.(2)Exosomal miRNAs play an important role in the progression of gastric cancer by regulating the proliferation,apoptosis,autophagy,angiogenesis,invasion and metastasis,immune response,and the formation of drug resistance of gastric cancer cells.(3)The interaction between miRNAs and target mRNA and its regulatory network are widely found in tumorigenesis and human cancer development.Different types of exosomal miRNAs have different effects on the regulation of apoptosis of gastric cancer cells,and the effects of different exosomal miRNAs on apoptosis related proteins and pathways of gastric cancer cells are screened.Rational use of its inducers or inhibitors can regulate the apoptosis level of gastric cancer cells.(4)Exosomal miRNAs of different cell origin play an important role in the establishment of tumor microenvironment,angiogenesis,immune response,and chemotherapy resistance by inducing M1-polarized macrophages to M2 type.(5)Exosomal miRNAs exist extensively and stably in blood and other body fluids,and their differential expression in patients with gastric cancer can be used as a basis for diagnosis,prognosis,and treatment of patients with gastric cancer.Currently,exosomal miRNAs widely studied as biomarkers include miR-379-5p,miR-590-5p,miR-29s,miR-21,etc.Among them,the sensitivity and specificity of miR-590-5p are 63.7％and 86％,respectively.The expression level of miR-590-5p is closely related to the overall survival rate and the depth of invasion of gastric cancer patients.(6)The design of exosomal miRNAs mimics or inhibitors and their targeted delivery to the tumor site using nano-delivery vectors(such as exosomes and liposomes)to restore the normal level of miRNAs may be a new strategy for the treatment of gastric cancer.(7)Although exosomal miRNAs have great application prospects in the diagnosis and treatment of gastric cancer patients,there are still some problems to be solved.For example,the potential targets and mechanisms of exosomal miRNAs have not been fully explored,and their effectiveness and safety need to be further confirmed.The extraction and purification of exosomes lack standardized large-scale preparation processes.

BACKGROUND:At present,chemotherapeutic drugs are mainly used for the treatment of tumors,but there are problems such as drug resistance and adverse reactions.The exosome drug delivery system not only avoids the toxicity of synthetic nanoparticles,but also increases the bioavailability and biocompatibility of the drugs.It can be modified by biological,physical,and chemical methods to form a new type of nano-drug delivery platform.OBJECTIVE:To review the construction strategy of exosome drug delivery system,the application status of exosome drug delivery system in tumor diseases and the current challenges.METHODS:PubMed and CNKI were searched with"exosomal,tumor,microvesicle,extracellular vesicles,engineered,therapeutics,characterization,isolation,drug delivery,targeting,modification strategies,physics,chemistry,biology"as English search terms and"exosomes,drug delivery,tumor"as Chinese search terms.A total of 132 articles were included for in-depth induction and discussion.RESULTS AND CONCLUSION:(1)The technical methods of exosome extraction,including ultracentrifugation,filtration,and kit extraction,can efficiently isolate exosomes,but the process is complicated and time-consuming,and large-scale extraction of exosomes cannot be achieved.(2)Engineered exosomes can be divided into four categories:gene editing engineering,which improves function through genetic modification;endogenous engineering,using inflammatory factors and other pretreatment to enhance drug delivery;exogenously engineered to encapsulate drugs directly in exosomes;hybrid engineering,combining exosomes with lipid nanoparticles to form new particles.Some have entered clinical trials for cancer treatment,but most are at an early stage.In contrast,genetically engineered exosomes are considered as an important direction for future drug delivery due to their high targeting and customization potential.(3)There are still many limitations to realize the clinical transformation of engineered exosomes.At the technical level,large-scale production,purification,and drug loading efficiency are urgent to be solved.In production,high cost and batch stability affect its popularity.In terms of safety,immunogenicity and potential toxicity need to be comprehensively evaluated.Furthermore,the imperfect regulatory policies and the complexity of the approval process also constitute obstacles to its clinical translation.(4)In the future,it is necessary to promote the clinical translation process through technical innovation,cost control,safety improvement,and policy improvement.

BACKGROUND:Tumor microenvironment can participate in the occurrence and development of gastric cancer and promote chemotherapy resistance in various ways.Among them,the tumor microenvironment crosstalk mediated by exosomal miRNAs can induce matrix reprogramming,participate in tumor heterogeneity,and form a microenvironment conducive to tumor proliferation,migration,invasion,immune escape,and chemotherapy resistance.OBJECTIVE:To review the mechanism of action of exosomal miRNAs in the microenvironment of gastric cancer and its application in the diagnosis and prognosis assessment of gastric cancer in recent years.METHODS:"Exosomal miRNAs,gastric cancer,angiogenesis,apoptosis,proliferation,migration,autophagy,invasion,immune response,chemotherapy resistance,biomarker"for English search terms and"exosomal miRNAs,gastric cancer"for Chinese search terms were searched in PubMed and CNKI databases.The search period was from 2017 to 2024.After preliminary screening by reading the title and abstract,the articles with poor correlation and repeated content were excluded,and 77 articles were finally included for induction and discussion.RESULTS AND CONCLUSION:(1)Exosomes,as important carriers of intercellular information exchange,can carry a variety of information substances such as miRNA,and realize intercellular signal transmission through three ways:activation of cell surface receptors on target cells,fusion with the plasma membrane of recipient cells,and endocytosis.(2)Exosomal miRNAs play an important role in the progression of gastric cancer by regulating the proliferation,apoptosis,autophagy,angiogenesis,invasion and metastasis,immune response,and the formation of drug resistance of gastric cancer cells.(3)The interaction between miRNAs and target mRNA and its regulatory network are widely found in tumorigenesis and human cancer development.Different types of exosomal miRNAs have different effects on the regulation of apoptosis of gastric cancer cells,and the effects of different exosomal miRNAs on apoptosis related proteins and pathways of gastric cancer cells are screened.Rational use of its inducers or inhibitors can regulate the apoptosis level of gastric cancer cells.(4)Exosomal miRNAs of different cell origin play an important role in the establishment of tumor microenvironment,angiogenesis,immune response,and chemotherapy resistance by inducing M1-polarized macrophages to M2 type.(5)Exosomal miRNAs exist extensively and stably in blood and other body fluids,and their differential expression in patients with gastric cancer can be used as a basis for diagnosis,prognosis,and treatment of patients with gastric cancer.Currently,exosomal miRNAs widely studied as biomarkers include miR-379-5p,miR-590-5p,miR-29s,miR-21,etc.Among them,the sensitivity and specificity of miR-590-5p are 63.7％and 86％,respectively.The expression level of miR-590-5p is closely related to the overall survival rate and the depth of invasion of gastric cancer patients.(6)The design of exosomal miRNAs mimics or inhibitors and their targeted delivery to the tumor site using nano-delivery vectors(such as exosomes and liposomes)to restore the normal level of miRNAs may be a new strategy for the treatment of gastric cancer.(7)Although exosomal miRNAs have great application prospects in the diagnosis and treatment of gastric cancer patients,there are still some problems to be solved.For example,the potential targets and mechanisms of exosomal miRNAs have not been fully explored,and their effectiveness and safety need to be further confirmed.The extraction and purification of exosomes lack standardized large-scale preparation processes.

BACKGROUND:At present,chemotherapeutic drugs are mainly used for the treatment of tumors,but there are problems such as drug resistance and adverse reactions.The exosome drug delivery system not only avoids the toxicity of synthetic nanoparticles,but also increases the bioavailability and biocompatibility of the drugs.It can be modified by biological,physical,and chemical methods to form a new type of nano-drug delivery platform.OBJECTIVE:To review the construction strategy of exosome drug delivery system,the application status of exosome drug delivery system in tumor diseases and the current challenges.METHODS:PubMed and CNKI were searched with"exosomal,tumor,microvesicle,extracellular vesicles,engineered,therapeutics,characterization,isolation,drug delivery,targeting,modification strategies,physics,chemistry,biology"as English search terms and"exosomes,drug delivery,tumor"as Chinese search terms.A total of 132 articles were included for in-depth induction and discussion.RESULTS AND CONCLUSION:(1)The technical methods of exosome extraction,including ultracentrifugation,filtration,and kit extraction,can efficiently isolate exosomes,but the process is complicated and time-consuming,and large-scale extraction of exosomes cannot be achieved.(2)Engineered exosomes can be divided into four categories:gene editing engineering,which improves function through genetic modification;endogenous engineering,using inflammatory factors and other pretreatment to enhance drug delivery;exogenously engineered to encapsulate drugs directly in exosomes;hybrid engineering,combining exosomes with lipid nanoparticles to form new particles.Some have entered clinical trials for cancer treatment,but most are at an early stage.In contrast,genetically engineered exosomes are considered as an important direction for future drug delivery due to their high targeting and customization potential.(3)There are still many limitations to realize the clinical transformation of engineered exosomes.At the technical level,large-scale production,purification,and drug loading efficiency are urgent to be solved.In production,high cost and batch stability affect its popularity.In terms of safety,immunogenicity and potential toxicity need to be comprehensively evaluated.Furthermore,the imperfect regulatory policies and the complexity of the approval process also constitute obstacles to its clinical translation.(4)In the future,it is necessary to promote the clinical translation process through technical innovation,cost control,safety improvement,and policy improvement.

To achieve better results of the goal of training students' abilities in medical education,formative assessment has been implemented in medical immunology teaching for grade 2014 clinical medicine students.The evaluation indexes of medical immunology teaching have been constructed.Formative assessment has been implemented in classroom teaching,self-learning and group discussion,experimental teaching and network exams by following the principles of feedback,guidance and encouragement.Compared with summative assessment,formative assessment can dynamically reflect the learning progress of immunology and improve the learning effect.The deficiencies andpuzzlesin implementing the formative assessment have also been rethought and discussed deeply.

Objective To understand the current prevalence of clonorchiasis in Jiangxi Province. Methods A survey was performed according to the scheme of the 3rd Principal Human Parasites of Jiangxi Province. Based on the ecological regions,a stratified cluster sampling method was applied by the economic and geographic situation. In rural areas,the investigation of C. si?nensis was carried out together with the soil?transmitted helminths investigation,and in the urban areas,the random cluster sam?pling method was applied for the C. sinensis investigation. There were 92 survey sites from 32 counties. The eggs of C. sinensis in stool were examined by Kato?Katz technique,and health knowledge was also investigated by questionnaires in some people at the same time. Results A total of 23 606 sample residents were investigated,and 138 were found infected with C. sinensis, with the infection rate of 0.58%. Light infection was found in most of them. Totally 124 C. sinensis infected persons focused in Xinfeng County,and only a few of infected people scattered in the other counties. In Xinfeng County,851 residents were investi?gated. Among them,the infected people were found in all the age groups except the 0?year age group. The highest infection rate appeared in the 70? years group(24.00%). The male infection rate was 20.29%,which was higher than that of the female (6.25%),showing a statistically significant difference(P<0.01). The infection rate was highest in the population who received high school or technical secondary school education(31.48%). For the occupation distribution,the infection rate was highest in public officers(39.39%). The questionnaire survey showed that the infection rate in the populations in Xinfeng County who had the history of eating raw fish or raw shrimp was 33.15%. Conclusions The distribution of C. sinensis infection presents a region?al aggregation in Xinfeng County,but in other areas,the distribution is sporadic. It is necessary to continue to carry out the para?sitic disease screening,and in Xinfeng County,it is necessary to strengthen the comprehensive prevention and control interven?tion.

Objective To study the expression characteristics of Let-7 genes in breast cancer.Methods Twenty-eight patients with breast cancer were randomly selected,and their cancer tissue and adjacent normal tissue were collected.TRIzol was used to extract the total RNA and real-time quantitative PCR was used to detect the relative gene expression levels.Results The expression of precursor Let-7 in cancer tissue was (9.65 ± 2.31),which was lower than that in normal tissue (10.05 ± 2.81),P =0.048.Precursor Let-7 had dependence relationship with the long menstruation (b =0.816,P =0.029).The menarche age showed a positive correlation with precursor Let-7 in normal tissue (r =0.502,P =0.048) and a negative correlation in cancer tissue (r =-0.484,P =0.049) Conclusions The expression of precursor Let-7 in cancer tissue is lower than that in normal tissue.The period of menstruation is a protective factor to breast cancer.

Objective To investigate the dynamic changes of symptom clusters among nasopharyngeal carcinoma patients receiving radiotherapy and provide evidence for intervention clinically.Methods The data were collected at three time points that were before radiotherapy,during the radiotherapy and after radiotherapy, by surveying 273 first visit of nasopharyngeal carcinoma patients from May 201 4 to January 201 5 with a self-designed general information questionnaire and the Chinese version of the M.D.Anderson symptom inventory and observing the changes of symptom clusters in our hospital.One-way analysis of variance and the exploratory factor analysis were applied to observe the incidence of symptoms and the changes of symptom clusters during radiotherapy.Results The statistics revealed that the incidence and intensity of all the symptoms at 3 time points were significantly increased(P <0.05),except the symptom of amnesia.There were 3 symptom clusters among 3 time points,named as gastrointestinal symptom cluster,sickness symptom cluster and somatic symptom cluster,but the composition and the variance were different at different time point.Gastrointestinal symptom cluster was made of nausea and vomiting,adding poor appetite only before radiotherapy.The gastrointestinal symptom cluster was most prominent before radiotherapy.Sickness symptom cluster consisted of drowsiness, numbness symptom before radiotherapy, while it consisted of shortness of breath, numbness, difficulty remembering symptoms in other time.Somatic symptom cluster mainly consisted of pain and fatigue,dry mouth symptom joining it during and after radiotherapy.Conclusions With the treatment of radiotherapy,the incidence and intensity of symptoms are significantly enhanced,and the constitution of symptom clusters is different at different stage.Therefore,it is important for clinical nurses to strengthen dynamic assessment of all symptoms,monitor the changes and composition of symptom clusters,thus establish corresponding management measures to improve patients′quality of life.

Objective To investigate the expression of phosphorylated mammalian target of rapamycin (p-mTOR) and phosphorylated eukaryotic translation initiation factor 4E binding protein 1 (p-4EBP1) in pathologic scar,and comprehend its role and significance in the pathologic scar formation.Methods SP immunohistochemical method was used to detect the expression of p-mTOR and p-4EBP1 in 20 cases of keloid,20 cases of hypertrophic scar,20 cases of non-pathologic scar and 20 cases of normal skin tissue.The positive rates of expression in different tissues were analyzed,and the relationship in pathological scar was explored.Results The positive rates of p-mTOR and p-4EBP1 in keloidand hypertrophic scar were 75.0％ (15/20),60.0％ (12/20) and 60.0％ (12/20),50.0％ (10/20),nom-pathologic scars were 20％ (4/20),10％ (2/20);normal skin tissue were 10％ (2/20),5％ (1/20),which were higher respectively compared with the two control groups (P＜ 0.05);there was a highly positive correlation between p-mTOR and p-4EBP1 expression in pathologic scar (r=0.323,P＜0.05).Conclusions p-mTOR and p-4EBP1 might be involved and cooperated in promoting the progress of pathologic scars.

A rapid resolution liquid chromatography quadrupole time-of-flight mass spectrometric ( RRLC-QTOF/MS) method was used to profile the metabolites of urine samples from atherosclerosis ( AS) patients and healthy controls and find the differential metabolites which could provide the scientific evidence to explain the pathogenesis and early disease diagnose. In the study, 15 AS patients ( age46. 84±2. 41 years) and 15 healthy controls ( age45 . 72±1 . 93 years ) was screened out by VaSera VS-1000 . The urine samples were analyzed by RRLC-QTOF/MS and the resulting data matrices were analyzed by multivariate statistical analysis ( Principal Component Analysis, PCA ) to find the potential biomarkers. The results showed that the urine samples of AS patients were successfully distinguished from those of healthy controls. Besides, a total of two significantly changed metabolites, uric acid and Guanidineacetic acid, had been found and identified as potential biomarkers, which suggested that the disorder of purine metabolism and amino acid metabolism played an important role in the mechanism of AS.