As resident immune cells of central nervous system(CNS),microglia play a key role in immune surveillance and tissue repair.They can be activated by various types of pathological factors to form M1 or M2 phenotype,which mediates neuroinflam-mation or neuroprotective effects.At the same time,when the homeostasis of the microenvironment in which the neuron is located is broken,"signal"molecules are also released to induce microglial activation through ligand-receptor binding.Therefore,the regulation of microglia-neuron connection is of great significance for treatment of nervous system diseases.This article reviews the signaling mole-cules involved in the two-way interaction between microglial cells and neurons,and elucidates the immune mechanisms of microglia-neuron,thus providing a basis for targeted treatment of CNS diseases related to microglia activation.

OBJECTIVE To quantitatively evaluate the existing payment policies of diagnosis-related groups （DRGs）in China ， so as to provide reference for the formulation and improvement of policies. METHODS Totally 58 documents related to DRGs payment issued by the national and provincial medical security bureaus from 2017 to 2022 were processed by text mining method. PMC index evaluation model of DRGs payment policy was established. Nine typical DRGs payment policies were quantitatively evaluated and analyzed by 10 primary variables and 40 secondary variables. RESULTS Among the 9 policies，5 were excellent and 4 were acceptable. The average score of PMC index was 6.882. Generally ，there was still room for improvement because of the acceptable level. By comparing the two representative policies ，it was found that the main reasons was a lack of consideration in terms of supervision and management ，incentives and constraints when facing policy changes ，reason of the lower level of urban development. CONCLUSIONS Although DRGs payment policy in China is basically perfect ，there is still a lot of room for improvement in terms of extending the time limit of the policy ，summarizing and spreading the successful experience of pilot cities.

Objective To investigate the levels of trace elements in preschool children in Guangzhou and their relationships with nutritional status, and to provide a scientific basis for guiding children's nutritional diet and timely and reasonable supplementation of trace elements. Methods A cross-sectional study was used to perform physical examinations and collect blood samples from 5 002 children who were examined in the Department of Pediatric Health of a Maternal and Child Health Hospital in Guangzhou in 2018. The levels of trace elements including iron, zinc and copper were detected by atomic absorption spectrometer. Results The median (upper and lower quartile) levels of iron, zinc and copper for preschool children in a district of Guangzhou were 7.80 (7.39, 8.19) mmol / L, 69.0 (61.0, 76.5) μmol / L, 18.6 (15.9, 21.4) μmol / L. There was no significant difference in the levels of iron, zinc and copper between different genders (P>0.05). The levels of iron and zinc increased significantly with the age of children (P=0.000). There was no significant difference in the level of copper in different ages (P>0.05). The prevalence rates of iron, zinc and copper deficiency in preschool children were 14.93%, 21.93% and 0.24%, respectively, and there was no significant difference between different genders (P>0.05).There were no significant differences in the prevalence of iron and copper deficiency in different ages (P>0.05), while the zinc deficiency rate decreased with the age of children (P = 0.000). (P<0.05). The levels of iron and zinc in overweight children, and those suffering from malnutrition,and obesity were lower than those in normal children. There was no statistically significant difference in the levels of copper in children with different nutritional status (P>0.05). The prevalence rates of iron and zinc deficiency in children with malnutrition, overweight and obesity were higher than those in normal children. There was no significant difference in the prevalence of copper deficiency in children with different nutritional status (P>0.05). Conclusion The prevalence of iron, zinc deficiency is high in preschool children in Guangzhou. Preschool children with malnutrition, overweight and obesity are more prone to iron and zinc deficiency.

Objective To analyze the features of hepatic neuroendocrine neoplasm ( HNEN ) with conventional ultrasound and contrast-enhanced ultrasound sonography (CEUS) ,and to evaluate the value in the diagnosis and differential diagnosis of HNEN by ultrasound . Methods Fifty patients of HNEN confirmed pathologically or clinically were enrolled . All patients underwent conventional ultrasound and CEUS . Among the patients ,5 cases were primary hepatic neuroendocrine neoplasm ( PHNEN) ,and 45 cases were metastatic hepatic neuroendocrine neoplasm ( MHNEN) . Conventional ultrasound and CEUS features of HNEN were analyzed and the distinctions between PHNEN and MHNEN were compared . Results Baseline ultrasound showed that 37 (74％ ) HNEN were multiple lesions located in liver ,23 ( 46％ ) lesions with hyperechoic appearance ,35 ( 70％ ) lesions with homogeneous echoic ,28 ( 56％ ) lesions were clearly marginated ,8 (16％ ) lesions were surrounded by acoustic halo ,and 12 ( 24％ ) lesions with posterior echo attenuation . CEUS showed that the majority of HNEN exhibited the enhanced pattern of rapid wash-in and wash-out" . Forty-six ( 92％ ) lesions showed hyper-enhancement in the arterial phase ,44 ( 88％ ) lesions showed iso-enhancement in the portal phase ,and 47 ( 94％ ) lesions showed hypo-enhancement in the late phase .Feeding vessels were observed in 31 ( 62％ ) lesions ,intralesional non-enhancement zone was observed in 17(34％ ) lesions ,and capsule enhancement in the delay phase was found in 10( 20％ ) lesions . MHNEN had smaller diameter [ ( 3 .92 ± 2 .77) cm vs (12 .82 ± 8 .85) cm , P = 0 .004] and less likely to present cystic structure intralesional than PHNEN ( 1/45 vs 2/5 , P < 0 .001 ) . The differences of other baseline ultrasonographic characteristics ,enhanced characteristics and enhanced time on CEUS between PHNEN and MHNEN were not statistically significant ( all P > 0 .05) . Conclusions HNEN has a certain characteristic that can be identified on ultrasonography . Ultrasound can provide some valuable information to diagnose HNEN . While it′s difficult to differentiate PHNEN and MHNEN owing to their similar ultrasonographic characteristics .

Objective To observe the effect of acupuncture on cystathionine gamma-lyase(CSE)and myeloperoxidase (MPO) in the colonic tissues of rats and to explore its mechanism for recovering the function of interstitial cells of Cajal(ICCs)in rats after colonic anastomosis . Methods Thirty SD rats were randomized into normal control group, model group(receiving colonic anastomosis) and acupuncture group. The acupuncture group received foot three-needle therapy on bilateral Zusanli(ST36), Sanyinjiao(SP6) and Taichong(LR3), once a day for 3 days after colonic anastomosis. And then the propulsive rate of the small intestine was measured. The count of ICCs with positively expressive c-kit in rat colonic tissues was measured by immunohistochemistry, the activity of CSE was observed by enzyme-linked immunosorbent assay (ELISA) and the activity of MPO was tested by biochemical method. Results Compared with the normal control group, the small intestinal propulsive rate in the model group was decreased, the number of ICCs with positively expressive c-kit was reduced, while the activities of CSE and MPO were increased(P<0.05). The acupuncture group had higher intestinal propulsive rate, more ICCs with positively expressive c-kit, and lower CSE and MPO activities than the model group(P<0.05).Conclusion Acupuncture can promote the recovering of postoperative gastrointestinal function, and its mechanism may be related to the regulation of CSE and MPO activities in the colonic tissues and to the restoration of ICCs function in the focus with positive c-kit.

The holding of the national college students' clinical skills competition reflects the importance of medical education for clinical practice training . Although through intensive itemized skills drills, the competitors can complete each individual operation with satisfaction, due to the lack of clinical experience, in the integrated circuit training, they will easily stray into question stemtrap. The concrete analysis of the national college students' clinical skills contest competition reflects the medical students' insufficient recognition of clinical skills, lack of the overall concept of the intensive medical treatment, not flexible and insufficient mastery of the connotation of the clinical skills, which seriously restricts the improvement of clinical education. Therefore this article raises special sugges-tions, referring to training focusing on “Airway and Circulation”, developing the critical care thinking based on the relationship of multi-organ and improving the first-aid capability of the team work, so as to provide reference for the improvement of training effect.

Objective To investigate the effect of acupuncture combined with antidepressant on behavioral changes and 5-hydroxytryptamine 1A and 2A receptor ( 5-HT1AR and 5-HT2AR) mRNA expression in nucleus raphes dorsalis (NRD) of sleep deprivation depression (SDD) rats. Methods Eight normal Sprague Dawley (SD) rats were caged together without any stimulus or treatment, serving as the normal group. Thirty-two SD rats were given solitary raise for 21 days, together with chronic unpredictable mild stress ( CUMS) and rapid eye movement ( REM) sleep deprivation to establish the model. Twenty-eight rats completed the modeling successfully, and were divided into model group, acupuncture group, medicine group, and combination group, 7 rats in each group. Rats in the model group were given modeling treatment but without any intervention. Rats in the acupuncture group were given acupuncture on acupoint Yintang, Shenting and bilateral Taichong, acupuncture stimulation lasting 15 s every 10 min and acupuncture retention for 20 min in each day. Rats in the medicine group were given gastric gavage of Zoloft solution (0.83 mg·kg-1·d-1) and Alprazolam solution (0.067 mg· kg-1·d-1) , and rats in the combination group were given both acupuncture and medicine intervention. The intervention for the three intervention groups lasted for 7 days. Results Compared with the normal group, body weight, Open-field scores and sucrose preference of the model rats were significantly decreased on modeling day 7, 14, 21 (P<0.05). On modeling day 28, body weight and Open-field scores of each intervention group were significantly increased compared with those of the model group (P<0.05), and Open-field scores of combination group differed from those of acupuncture group and medicine group ( P<0.05). Only sucrose preference of combination group was improved significantly compared with the model group (P<0.05). Compared with the model group, NRD 5-HT1AR mRNA expression level was increased in the combination group (P<0.05), and NRD 5-HT2AR mRNA expression level was down-regulated in all of the three intervention groups ( P<0.05). Conclusion Acupuncture and antidepressant treatment covering 7 days can evoke rapid effect on SDD rats, which can improve the slow effect of antidepressant.

Objective To discuss the accuracy and objectivity of student standardized patients (SSP) in objective structured clinical examination(OSCE). Methods On March 30 and 31, 2013, 168 seven-year program medical students of class 2006 and 2007 took part in OSCE. Differences in as-sessment results between SPP and those given by professional doctors at 3 SP sites(angina pectoris SSP station, acute cholecystitis SSP station, depression SSP station) were analyzed. Each site had 4 items for assessment, with a total score of 100. Scores were given in strict accordance with a set of unified scoring rules. Counting data were presented as x±s. Data were verified using t test. P<0.05 was considered statis-tically considerable. Results At angina pectoris station, respective scores of SSP and professional physi-cians were 85.2±7.1 and 85.5±6.6, P=0.688. At acute cholecystitis station, respective score of SSP and professional physicians were 89.1±5.2 and 88.2±6.2, P=0.150. At depression station, respec-tive score of SSP and professional physicians were 79.8±7.5 and 78.2±7.0, P=0.078. Conclusion There is no statistical difference between scores given by SSP and those given by the physicians in OSCE. This proves that SSP who received standardized training delivers fair and accurate results in OSCE , and therefore is recommended for future application.

Objective To investigate the usefulness of parametric imaging of contrast-enhanced ultrasound(CEUS) in imaging hepatocellular carcinoma (HCC) using dynamic vascular patterns (DVP). Methods Thirty clinically or pathologically proven HCCs that had undergone CEUS were randomly included. SonoLiver CAP sofeware was used to analyze the CEUS images and reconstruct DVP parametric images. Results The rise time, time to peak and mean transit time were (16. 72±11. 07) s, (29. 92±14. 13) s,(115. 03±90. 91)s in HCC versus (26. 59±9. 60) s, (41.67±12. 59) s, (159.26±123. 74) s in the surrounding liver parenchyma (all P <0. 05). The perfusion index was (90. 41±102. 49) % in HCC versus (54. 10±24. 99)% in surrounding liver parenchyma( P = 0.044). DVP curve and DVP parametric image could both be divided into three types:washout,non-washout and cystic type. The percentages of which were 76.7% (23/30), 20.0% (6/30) and 3.3% (1/30) in DVP curves, respectively, and 66.7% (20/30), 30.0% (9/30) and 3.3% (1/30) in DVP parametric images,respectively. Conclusions Parametric image of CEUS could demonstrates the difference of flow perfusion static between HCC and surrounding liver parenchyma dynamically and directly.

Objective To evaluate the diagnostic performance of real-time contrast-enhanced ultrasound (CEUS)in characterizing complex cystic focal liver lesions(FLLs).Methods Sixty seven complex cystic FLLs in 65 patients were examined with baseline ultrasound(BUS)and CEUS.BUS and CEUS images were reviewed by a resident radiologist and a staff radiologist independently.Diagnostic performance was evaluated using receiver operating characteristic(ROC)analysis and the interobserver agreement was analyzed by weighted k statistics.Results After ROC analysis,the areas under the ROC curve(Az)were 0.917 for the staff radiologist and 0.774(P=0.044)for the resident radiologist on BUS,and were 0.935 and 0.922(P=0.42)on CEUS.A significant difference in Az between BUS and CEUS was found for the resident radiologist(0.774 versus 0.922,P=0.047),whereas not found for the staff radiologist(0.917 versus 0.935,P=0.38).Better results of specific diagnosis were obtained on CEUS[28.4%(19/67)before versus 58.2%(39/67)after review of CEUS images for resident radiologist,and 26.9%(18/67)versus 76.1%(51/67)for staff radiologist,both P＜0.001].Interobserver agreement was improved after review of CEUS images[K=0.325(95%confidence interval:0.214-0.436)on BUS versus k=0.774(95%confidence interval:0.688-0.860)on CEUS].Conclusions Real-time CEUS improves the capability of discrimination between malignant and benign lesions and specific characterization for complex cystic FLLs,as well as the interobserver agreement.