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.

Objective:To evaluate the relationship between the mechanism of mild hypothermia-induced reduction of neuronal apoptosis during cerebral ischemia-reperfusion (I/R) and calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2)/adenosine monophosphate-activated protein kinase (AMPK) signaling pathway in rats.Methods:Forty SPF male Sprague-Dawley rats, aged 6-8 weeks, weighing 200-250 g, were divided into 5 groups ( n=8 each) using a random number table method: sham operation group (Sham group), cerebral I/R group (IR group), hypothermia + cerebral I/R group (HIR group), hypothermia + cerebral ischemia-reperfusion + solvent group (HIR-DMSO group) and hypothermia + ischemia-reperfusion + CaMKK2 inhibitor STO-609 group (HIR-STO609 group). A global cerebral I/R injury model was established using the four-vessel occlusion method. In HIR group, HIR-DMSO group, and HIR-STO609 group, an ice blanket was used to reduce the body temperature immediately after cerebral ischemia, bringing the core body temperature down to 32.5-33.5 ℃, and rewarming was carried out 4 h later. One hour before developing the model, STO-609 solution 4 μl was injected into the lateral ventricle in HIR-STO609 group, and the equal volume of dimethyl sulfoxide solution was given instead in HIR-DMSO group. At the end of reperfusion, the modified neurological severity score (mNSS) was performed. Then the rats were sacrificed under deep anesthesia, and the hippocampal tissues were taken to observe the pathological results of the hippocampal tissues (using HE staining and Nissl staining) and to determine the apoptosis rate of neurons (by TUNEL method) and expression of B-cell lymphoma 2(Bcl-2), Bcl-2-associated X (Bax), CaMKK2, phosphorylated AMPK (p-AMPK) and AMPK (by Western blot). Results:Compared with Sham group, the mNSS and apoptosis rate of neurons in the hippocampal tissues were significantly increased, the expression of Bax was up-regulated, the expression of Bcl-2, CaMKK2 and p-AMPK was down-regulated, and the ratio of p-AMPK/AMPK was decreased in IR group ( P<0.05). Compared with IR group, the mNSS and apoptosis rate of neurons in the hippocampal tissues were significantly decreased, the expression of Bax was down-regulated, the expression of Bcl-2, CaMKK2 and p-AMPK was up-regulated, and the ratio of p-AMPK/AMPK was increased in HIR group ( P<0.05). Compared with HIR group, the mNSS and apoptosis rate of neurons in the hippocampal tissues were significantly increased, the expression of Bax was up-regulated, the expression of Bcl-2, CaMKK2 and p-AMPK was down-regulated, the ratio of p-AMPK/AMPK was decreased ( P<0.05), and no significant change was found in the aforementioned parameters in HIR-DMSO group ( P>0.05). Conclusions:Mild hypothermia can inhibit neuronal apoptosis by up-regulating the CaMKK2/AMPK signaling pathway, thus reducing cerebral I/R injury in rats.

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.

Objective:To evaluate the relationship between the mechanism of mild hypothermia-induced reduction of neuronal apoptosis during cerebral ischemia-reperfusion (I/R) and calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2)/adenosine monophosphate-activated protein kinase (AMPK) signaling pathway in rats.Methods:Forty SPF male Sprague-Dawley rats, aged 6-8 weeks, weighing 200-250 g, were divided into 5 groups ( n=8 each) using a random number table method: sham operation group (Sham group), cerebral I/R group (IR group), hypothermia + cerebral I/R group (HIR group), hypothermia + cerebral ischemia-reperfusion + solvent group (HIR-DMSO group) and hypothermia + ischemia-reperfusion + CaMKK2 inhibitor STO-609 group (HIR-STO609 group). A global cerebral I/R injury model was established using the four-vessel occlusion method. In HIR group, HIR-DMSO group, and HIR-STO609 group, an ice blanket was used to reduce the body temperature immediately after cerebral ischemia, bringing the core body temperature down to 32.5-33.5 ℃, and rewarming was carried out 4 h later. One hour before developing the model, STO-609 solution 4 μl was injected into the lateral ventricle in HIR-STO609 group, and the equal volume of dimethyl sulfoxide solution was given instead in HIR-DMSO group. At the end of reperfusion, the modified neurological severity score (mNSS) was performed. Then the rats were sacrificed under deep anesthesia, and the hippocampal tissues were taken to observe the pathological results of the hippocampal tissues (using HE staining and Nissl staining) and to determine the apoptosis rate of neurons (by TUNEL method) and expression of B-cell lymphoma 2(Bcl-2), Bcl-2-associated X (Bax), CaMKK2, phosphorylated AMPK (p-AMPK) and AMPK (by Western blot). Results:Compared with Sham group, the mNSS and apoptosis rate of neurons in the hippocampal tissues were significantly increased, the expression of Bax was up-regulated, the expression of Bcl-2, CaMKK2 and p-AMPK was down-regulated, and the ratio of p-AMPK/AMPK was decreased in IR group ( P<0.05). Compared with IR group, the mNSS and apoptosis rate of neurons in the hippocampal tissues were significantly decreased, the expression of Bax was down-regulated, the expression of Bcl-2, CaMKK2 and p-AMPK was up-regulated, and the ratio of p-AMPK/AMPK was increased in HIR group ( P<0.05). Compared with HIR group, the mNSS and apoptosis rate of neurons in the hippocampal tissues were significantly increased, the expression of Bax was up-regulated, the expression of Bcl-2, CaMKK2 and p-AMPK was down-regulated, the ratio of p-AMPK/AMPK was decreased ( P<0.05), and no significant change was found in the aforementioned parameters in HIR-DMSO group ( P>0.05). Conclusions:Mild hypothermia can inhibit neuronal apoptosis by up-regulating the CaMKK2/AMPK signaling pathway, thus reducing cerebral I/R injury in rats.

Objective To construct an accurate clinical model of lower limb varicose veins in rats through surgery that provides theoretical support for evaluating drug therapy.Methods 30 SD rats,15 males and 15 females,were randomly divided into a control group and surgical group.In the surgical group,the rats lower limb veins(including the small saphenous vein and femoral vein)were ligated via improved lower limb vein ligation,i.e.,the small saphenous vein was completely ligated with the femoral vein,and the thrombosis result ed in a lasting increase in the internal pressure of the deep veins of the lower limb,causing varicose symptoms.On the 6th week after surgery,the varicose veins of the rats in the surgical group were scored to select those that were successfully modeled.Then,the successfully modeled rats were randomly divided into a model group and Maizhiling group.Maizhiling 62.5 mg/kg was orally administered to the treatment group once a day,while the control and model group received an equal volume of physiological saline orally every day for 20 consecutive days.On the day before administration and 7 d,14 d and 20 d after administration,macro photography and scoring were performed on the lower limbs of the rats.After completion,an approximately 1 cm long saphenous vein above the ankle joint of the lower limb on the surgical side was removed from the model group and Maizhiling group rats,while from the control group,the corresponding saphenous vein of the lower limb on the same side was removed.Pathological tissue observation was performed using HE staining,Masson staining,and immunohistochemical examination for interleukin-2(IL-2)and tissue inhibitor of metalloproteinases(TIMP-1).Results Of the 22 rats in the surgical group,20 were successfully modeled,with a success rate of 91％.According to the manifestations of venous dilation,varicose veins,and redness in the lower limbs of rats,the varicose vein score of the model group increased significantly compared with that of the control group(P＜0.01).After the therapeutic dose of Maizhiling was administered,the varicose vein score in the Maizhiling group decreased significantly compared with that of the model group(P＜0.01).Pathological examination showed significant varicose-vein-like changes and mild inflammation in the model group.The Maizhiling group showed reduced varicose veins and inflammation.Conclusions A rat model of lower limb varicose veins was successfully established,providing a new research method for the study of drugs and treatment method related to lower limb varicose diseases.

Objective To construct an accurate clinical model of lower limb varicose veins in rats through surgery that provides theoretical support for evaluating drug therapy.Methods 30 SD rats,15 males and 15 females,were randomly divided into a control group and surgical group.In the surgical group,the rats lower limb veins(including the small saphenous vein and femoral vein)were ligated via improved lower limb vein ligation,i.e.,the small saphenous vein was completely ligated with the femoral vein,and the thrombosis result ed in a lasting increase in the internal pressure of the deep veins of the lower limb,causing varicose symptoms.On the 6th week after surgery,the varicose veins of the rats in the surgical group were scored to select those that were successfully modeled.Then,the successfully modeled rats were randomly divided into a model group and Maizhiling group.Maizhiling 62.5 mg/kg was orally administered to the treatment group once a day,while the control and model group received an equal volume of physiological saline orally every day for 20 consecutive days.On the day before administration and 7 d,14 d and 20 d after administration,macro photography and scoring were performed on the lower limbs of the rats.After completion,an approximately 1 cm long saphenous vein above the ankle joint of the lower limb on the surgical side was removed from the model group and Maizhiling group rats,while from the control group,the corresponding saphenous vein of the lower limb on the same side was removed.Pathological tissue observation was performed using HE staining,Masson staining,and immunohistochemical examination for interleukin-2(IL-2)and tissue inhibitor of metalloproteinases(TIMP-1).Results Of the 22 rats in the surgical group,20 were successfully modeled,with a success rate of 91％.According to the manifestations of venous dilation,varicose veins,and redness in the lower limbs of rats,the varicose vein score of the model group increased significantly compared with that of the control group(P＜0.01).After the therapeutic dose of Maizhiling was administered,the varicose vein score in the Maizhiling group decreased significantly compared with that of the model group(P＜0.01).Pathological examination showed significant varicose-vein-like changes and mild inflammation in the model group.The Maizhiling group showed reduced varicose veins and inflammation.Conclusions A rat model of lower limb varicose veins was successfully established,providing a new research method for the study of drugs and treatment method related to lower limb varicose diseases.

Objective: To understand the awareness and service utilization of HIV preexposure prophylaxis (PrEP) and postexposure prophylaxis (PEP) among the young students aged 15-24 in Hefei, so as to provide reference for the prevention and treatment of AIDS among young students in the future. Methods: From May to June 2022, a stratified random cluster sampling method was used to select two different types of universities(undergraduate and vocational colleges) in Hefei, and a crosssectional survey was conducted among the 916 young students at the selected schools. The Chisquare test was used for statistical analysis. Results: Among the surveyed young students, 88.4% had heterosexual orientation, and 12.4% had sexual behavior including 8.8% of homosexual sexual behavior and 91.2% of heterosexual sexual behavior. The rate of condom use was 70.0% in the last homosexual intercourse, and the rate of condom use was 83.7% in the last heterosexual intercourse. About 41.9% of young students heard of PrEP, and the proportions of young students who knew about PrEP, consulted PrEP and used PrEP were 43.0%, 15.9% and 9.4% respectively. About 38.3% of young students had heard of PEP, and the proportions of young students who knew about PEP, consulted PEP and used PEP were 18.2%, 15.4% and 6.0%. Conclusions The awareness rate and utilization rate of PrEP and PEP among young students in Hefei are relatively low. PrEP and PEP publicity should be combined with education of HIV knowledge, and enhance the awareness rate of the young students, in order to reduce the risk of AIDS infection among young students with highrisk behaviors.

Background Schizophrenia patients often face high level of stigma and low level of self-esteem,significantly hindering their recovery.Mindfulness-based intervention has proven be effective in reducing stigma and improving self-esteem.However,traditional mindfulness intervention typically involve high costs and require long-term professional involvement.Objective To explore the effects of blended mindfulness interventions on stigma and self-esteem in patients with stable schizophrenia,so as to provide references for reducing stigma,enhancing self-esteem and promoting recovery.Methods Patients receiving outpatient treatment at the Third Hospital of Daqing from June 2022 to January 2023,who met the diagnostic criteria for schizophrenia in the International Classification of Diseases,tenth edition(ICD-10)and were in a stable phase,were recruited for the study(n=84).According to the random number table method,participants were randomly assigned to study group and control group,with 42 cases in each group.Both groups received treatment with the second-generation antipsychotic medications,while the study group additionally received blended mindfulness intervention for 8 weeks,with sessions lasting 45～60 minutes,three times a week.Both groups were evaluated with Five Facet Mindfulness Questionnaire(FFMQ),Internalized Stigma of Mental Illness Inventory(ISMI)and Rosenberg Self-Esteem Scale(RSES)at baseline and after 8-week intervention.Covariance analysis was used to compare the FFMQ,ISMI and SES scores between two groups after 8-week intervention.Results After 8-week intervention,there were statistically significant differences between two groups in total FFMQ scores,as well as in the observation,acting with awareness,non-judgment and non-reactivity subscale scores(F=50.680,12.952,13.567,22.799,14.043,P<0.01).Statistically significant differences were observed in total ISMI scores,and in the alienation,stereotype endorsement,discrimination experience,stigma resistance and social withdrawal subscale scores(F=513.125,148.990,125.055,75.996,154.850,54.125,P<0.01).The difference in RSES scores between two groups was also statistically significant(F=19.478,P<0.01).Conclusion Blended mindfulness intervention may help improve the mindfulness and self-esteem in stable schizophrenia patients while reducing stigma.

Objective:To investigate the incidence and influencing factors of allergic reactions to cephalosporins.Methods:A cross-sectional study of 29 medical institutions in Zhejiang Province was conducted from April 2021 to June 2021.The incidence of allergic reactions to cephalosporins was investigated,and the influencing factors of cephalosporin-induced allergic reactions were analyzed by Poisson regression.Results:A total of 56 155 patients were included in this study.The total incidence of allergic reactions to cephalosporin was 1.67‰,the highest incidence of anaphylaxis occurred for ceftizoxime(4.27‰),followed by ceftriaxone(3.49‰)and cefotaxime(2.40‰).There was no significant difference in the incidence of allergic reactions between patients with negative skin tests and those without skin tests(1.75％o vs.1.63‰,RR=1.07,95％CI:0.70-1.63,P＞0.05).Poisson regression showed that body mass index(BMI)＜18.5 kg/m2(RR=2.43,95％CI:1.23-4.82,P＜0.05)and history of β-lactam antibiotics allergy(RR=33.88,95％CI:1.47-781.12,P＜0.05)increased cephalosporin-induced anaphylaxis.Compared with cefuroxime,the risk of allergic reactions was increased for ceftriaxone(RR=3.08,95％CI:1.70-5.59,P＜0.01),ceftazidime(RR=1.89,95％CI:1.03-3.47,P＜0.05),and ceftizoxime(RR=3.74,95％CI:1.64-8.50,P＜0.01).Conclusions:Lower BMI and history of β-lactam antibiotics allergy increase the risk of cephalosporin allergic reactions.The routine skin test may not reduce the occurrence of allergic reactions to cephalosporins. This study has been registered at Chinese Clinical Trial Registry(ChiCTR2200064314).

Objective:To discuss the effect of oridonin on the proliferation,migration,epithelial-mesenchymal transition(EMT),and apoptosis of the human nasopharyngeal carcinoma HONE-1 cells,and to clarify its related antitumor mechanism.Methods:The HONE-1 cells were treated with different concentrations(0,5,10,20,40,80,and 160 mg·L-1)of oridonin for 48 h.CCK-8 method was used to detect the inhibitory rates of proliferation of the cells in various groups and the drug concentration for subsequent experiment was confirmed.The HONE-1 cells were divided into control group,3 mg·L-1 oridonin group,and 6 mg·L-1 oridonin group.After 24 and 48 h of culture,CCK-8 method was used to detect the proliferation activities of the cells in various groups;5-ethynyl-2'-deoxyuridine(EdU)method was used to detect the rates of EdU-positive cells in various groups;colony formation assay was used to detect the numbers of clone formation in the cells in various groups;Transwell chamber experiment and cell wound assay were used to detect the numbers of migration cells and the scratch healing rates of the cells in various groups;real-time fluorescence quantitative PCR(RT-qPCR)method was used to detect the expression levels of cyclin-dependent kinase 1(CDK1)and cyclin-dependent kinase 4(CDK4)mRNA in the cells in various groups;Western blotting method was used to detect the expression levels of E-cadherin,Vimentin,Caspase-3,and poly ADP-ribose polymerase 1(PARP1)proteins in the cells in various groups.Results:The CCK-8 method results showed that the half-maximal inhibitory concentration(IC50)of oridonin at 48 h was 12.18 mg·L-1,and 1/4 IC50 and 1/2 IC50 values were used as the concentrations for subsequent experiments.Compared with control group,after treated for 24 and 48 h,the proliferation activities of the cells in 3 and 6 mg·L-1 oridonin groups were decreased(P＜0.05 or P＜0.01),the rate of EdU-positive cells were decreased(P＜0.05 or P＜0.01),the numbers of clone formation and migraton cells were decreased(P＜0.05 or P＜0.01),the scratch healing rates were decreased(P＜0.05 or P＜0.01),the expression levels of CDK1 and CDK4 mRNA in the cells were decreased(P＜0.05 or P＜0.01),the expression levels of E-cadherin,Caspase-3,and PARP1 proteins were increased(P＜0.05 or P＜0.01),and the expression levels of Vimentin protein were decreased(P＜0.05).Conclusion:Oridonin can inhibit the proliferation,clone formation,and migration of the human nasopharyngeal carcinoma HONE-1 cells by downregulating the expression of cell cycle-related proteins and EMT,and promote the apoptosis to exert an antitumor effect.