Spinal cord injury (SCI) can lead to severe sensory and motor dysfunction pathologically characterized by direct axonal rupture, nerve cell necrosis and apoptosis. Traditional interventions, such as drug therapy and cell therapy, have limited efficacy associated with a poor prognosis in patients of SCI. In recent years, exosomes have become a new hotspot for spinal cord injury repair for their unique phospholipid properties and nucleic acid and protein inclusions. Exosomes can be produced by various cells with the assistance of molecules related to intracellular vesicle transport, such as endosomal sorting complex proteins, rat sarcoma-associated proteins and lipids. Those exosomes with structural and functional diversity due to the molecular composition of their respective cell sources, can be targeted on different receptor cells and play a key role in inhibiting glial scar formation, reducing inflammation and promoting nerve regeneration and repair. By identifying the target of exosomes derived from mesenchymal stem cells, neural stem cells, and Schwann cells for spinal cord injury repair, individualized therapy becomes possible based on the specific cell and molecular background of the patient's injury type, thus enhancing the effectiveness and safety of therapy. However, clinical use of exosomes still has limitations because of its rapid clearance, unstable therapeutic concentration in injured site and lack of separation and purification methods that both satisfies the separation efficiency and specificity. On the basis of the separation and purification methods summarized by International Society of Extracellular Vesicles, efforts are made by using 3D culture and stimulation of physical and chemical factors to improve exosome production and activity, using synthetic extracellular vesicle mimics with higher yield to replace exosomes and loading exosomes with scaffolds such as hydrogels and 3D printing materials to provide a stable environment for promoting nerve repair.

To evaluate the safety of the domestic 13-valent pneumococcal polysaccharide conjugate vaccine-tetanus toxoid protein (PCV13-TT) after its licensure. The adverse event following immunization (AEFI) and the vaccination data of PCV13-TT in Zhejiang province from July 2020 to October 2021 were collected from national adverse event following immunization surveillance system and Zhejiang provincial immunization information system. Descriptive epidemiological method was used for this analysis. From July 2020 to October 2021, 302 317 doses of PCV13-TT were administered in children under 6 years old in Zhejiang Province and 636 AEFI case reports were received, with a reporting rate of 21.04 per 10 000 doses. Of these AEFI cases, 97.17% were mild vaccine product-related reaction (20.54 per 10 000 doses) and 95.44% occurred in the 0-1 d after vaccination (20.08 per 10 000 doses). The most common clinical diagnoses of AEFI included fever (224 cases), redness (204 cases), and induration (190 cases), while allergic rash (11 cases) was the most common diagnosis among the abnormal reactions. In conclusion,the present results bolstered that the domestic PCV13-TT was generally well tolerated in children under 6 years old in Zhejiang Province.
Child ; Humans ; Child, Preschool ; Vaccines, Conjugate/adverse effects* ; Pneumococcal Vaccines/adverse effects* ; Vaccination ; Immunization ; Polysaccharides

The competency-based medical education has formed a global trend, and puts forward a greater challenge for educational design of resident training. The traditional curriculum cannot meet the goal of competency-based education as the curriculum design is lack of theoretical support. Curriculum design is the core of training content, and serves as a significant contributing factor of training outcome. Based on the six-step approach curriculum design, the theory and practice are integrated to form a curriculum design based on theoretical guidance. Through feedback evaluation, the current curriculum design is continuously improved in order to achieve a higher competency-based training quality. With the 5-year experiences and practice, preliminary reform demonstrates effectiveness. The current study hopes to share the teaching reform experiences of residency training base and provide references for colleagues of medical education.

Objective:To explore the correlation between early inflammation indicators and the severity of coronavirus disease 2019 (COVID-19).Methods:A retrospective study was conducted. Patients with COVID-19 admitted to Wenzhou Central Hospital from January 17 to February 14, 2020 were enrolled. The general information, chest CT before admission, the first laboratory parameters and chest CT within 24 hours after admission were collected. Patients were followed up for 30 days after the first onset of dyspnea or pulmonary imaging showed that the lesions progressed more than 50% within 24 to 48 hours (according to the criteria for severe cases) as the study endpoint. According to the endpoint, the patients were divided into two groups: mild type/common type group and severe/critical group, and the differences in general information and inflammation index of the two groups were compared. Logistic regression was used to analyze the inflammation index and the severity of COVID-19. Receiver operating characteristic (ROC) curve was draw to evaluate the predictive value of early inflammation indicators for severe/critical in patients with COVID-19.Results:A total of 140 patients with COVID-19 were included, 74 males and 66 females; the average age was (45±14) years old; 6 cases (4.3%) of mild type, 107 cases (76.4%) of common type, and 22 cases (15.7%) of severe type, 5 cases (3.6%) were critical. There were significantly differences in ages (years old: 43±13 vs. 57±13), the proportion of patients with one chronic disease (17.7% vs. 55.6%), C-reactive protein [CRP (mg/L): 7.3 (2.3, 21.0) vs. 40.1 (18.8, 62.6)], lymphocyte count [LYM (×10 9/L): 1.3 (1.0, 1.8) vs. 0.8 (0.7, 1.1)], the neutrophil/lymphocyte ratio [NLR: 2.1 (1.6, 3.0) vs. 3.1 (2.2, 8.8)] and multilobularinltration, hypo-lymphocytosis, bacterial coinfection, smoking history, hyper-tension and age [MuLBSTA score: 5.0 (3.0, 5.0) vs. 5.0 (5.0, 7.0)] between mild/common group and severe/critical group (all P < 0.05). Univariate Logistic regression analysis showed that CRP, NLR, MuLBSTA score, age, and whether chronic diseases were associated with the severity of COVID-19 [odds ratio ( OR) and 95% confidence interval (95% CI) were 1.037 (1.020-1.055), 1.374 (1.123-1.680), 1.574 (1.296-1.911), 1.082 (1.042-1.125), 6.393 (2.551-16.023), respectively, all P < 0.01]. Further multivariate Logistic regression analysis showed that CRP and MuLBSTA score were risk factors for the development of COVID-19 to severe/critical cases [OR and 95% CI were 1.024 (1.002-1.048) and 1.321 (1.027-1.699) respectively, both P < 0.05]. ROC curve analysis showed that the area under the curve for CRP and MuLBSTA score to predict severe/critical cases were both 0.818, and the best cut-off points were 27.4 mg/L and 6.0 points, respectively. Conclusion:CRP and MuLBSTA score are related to the severity of COVID-19, and may have good independent predictive ability for the development of severe/critical illness.

In recent years, tumor immunotherapy with immune checkpoint as the target has attracted much attention because of its remarkable efficacy. However, with the application of immune-checkpoint inhibitors (ICIs), more and more immune-related adverse events (irAEs) have been reported. IrAEs impose an additional risk of death on tumor patients treated with ICIs, limiting the widespread use of ICIs. To help patients actively prevent irAEs, biomarkers with the predictive value of irAEs are of great significance. This paper reviews the biomarkers with predictive value for irAEs from the aspects of serology, genetics and microbiology.

Objective To analyze the prediction efficiency of scoring models at home and abroad on delayed graft function (DGF) after renal transplantation in China. Methods The clinical data of 112 donors and 220 recipients undergoing renal transplantation were prospectively analyzed. The DGF predicted by KDRI model, Jeldres model, and model of our center was compared with actual DGF incidence of renal transplant recipients. The prediction efficiency of each model was analyzed. The predictive accuracy was compared by the area under curve (AUC) of receiver operating characteristic (ROC) curve. Results The DGF incidence of 220 renal transplant recipients was 14.1% (31/220). DGF prediction using KDRI model showed that 41 cases were high risk donors, the AUC was 0.57, the sensitivity was 0.37, the specificity was 0.66, and the positive predictive value was 22%. DGF prediction using Jedres model showed that 22 cases were high risk recipients, the AUC was 0.56, the sensitivity was 0.13, the specificity was 0.92 and the positive predictive value was 20%. DGF prediction using the model of our center showed that 25 cases were high risk donors, the AUC was 0.80, the sensitivity was 0.53, the specificity was 0.84, the positive predictive value was 40%. Conclusions Compared with the KDRI and Jedres models, the prediction model of our center has higher AUC and sensitivity with a better prediction efficiency on DGF. Therefore, it is a suitable evaluation system of donors from donation after citizen's death in Chinese.

Objective: To evaluate the in vitro activity of ceftazidime-avibactam (CAZ-AVI) alone or in combination with colistin (COL) against clinically isolated extensively drug-resistant Pseudomonas aeruginosa (XDR-PA). Methods: Minimum inhibitory concentration (MIC) of 16 clinical XDR-PA isolates was determined by broth dilution method and chessboard design when CAZ-AVI and COL were used alone or in combination, then the combined inhibitory concentration index (FICI) was calculated. Class A [Klebsiella pneumoniae carbapenemase β-lactamase (bla_KPC), Guiana extended-spectrum β-lactamase (bla_GES)], Class B [imipenemase β-lactamase (bla_IMP), Verona-Integronmetallo β-lactamase (bla_VIM), New Delhi metallo β-lactamase (bla_NDM), German imipenemase β-lactamase (bla_GIM), Sao Paulo metallo -β- lactamase (bla_SPM)], Class C [AmpC β-lactamase (bla_AmpC)], Class D [oxacillinase β-lactamase (bla_OXA)] β- lactamase-related resistance genes were detected by polymerase chain reaction. Drug-resistant mutation frequencies of each strain were determined on a drug-containing plate. The time kill curves of three XDR-PA were plotted by colony counting method. A biofilm model was established in vitro, and the synergistic effect of CAZ-AVI and COL on biofilm inhibition was detected by methythiazolyl tetrazolium assay (MTT). Results: The MICs of 16 XDR-PA for CAZ-AVI ranged from 1 mg/L to 128 mg/L, and three of the isolates showed resistance (MIC > 8 mg/L). The FICI range of CAZ-AVI combined with COL was 0.312-1.000. Four isolates were synergistic, while the other 12 isolates were additive. Three isolates resistant to CAZ-AVI contained Class B resistance genes such as bla_IMP and bla_VIM, while 13 susceptible isolates carried resistance genes belonging to Class A, C or D. The logarithm values of mutation frequencies of drug resistance in CAZ-AVI group, COL group and combination group were -4.81±0.88, -7.06±0.69 and -9.70 (-9.78, -9.53), respectively. There were significant differences among the three groups (H = 33.601, P < 0.001), and between every two groups (adjusted P < 0.05). In time kill curves, the phytoplankton load of three XDR-PA decreased more than 6 log CFU/L when these two drugs were used together, and number of PA1819 planktonic bacteria decreased more than 5.1 log CFU/L compared with monotherapy group. Viable quantity in biofilm (A₄₉₀) of normal saline group, CAZ-AVI group, COL group and CAZ-AVI-COL group were 0.665±0.068, 0.540±0.072, 0.494±0.642 and 0.317±0.080, respectively. There was significant difference between the other two groups (all P < 0.001), except for that between CAZ-AVI group and COL group (P = 0.109). Conclusions CAZ-AVI combined with COL can effectively improve the bactericidal effect of each drug alone on XDR-PA. The regimen can also reduce the production of drug-resistant bacteria and inhibit the formation of biofilm. Therefore, it is a potential treatment for XDR-PA infection.

OBJECTIVE: To evaluate the in vitro activity of ceftazidime-avibactam (CAZ-AVI) alone or in combination with colistin (COL) against clinically isolated extensively drug-resistant Pseudomonas aeruginosa (XDR-PA). METHODS: Minimum inhibitory concentration (MIC) of 16 clinical XDR-PA isolates was determined by broth dilution method and chessboard design when CAZ-AVI and COL were used alone or in combination, then the combined inhibitory concentration index (FICI) was calculated. Class A [Klebsiella pneumoniae carbapenemase β-lactamase (bla_KPC), Guiana extended-spectrum β-lactamase (bla_GES)], Class B [imipenemase β-lactamase (bla_IMP), Verona-Integronmetallo β-lactamase (bla_VIM), New Delhi metallo β-lactamase (bla_NDM), German imipenemase β-lactamase (bla_GIM), Sao Paulo metallo-β-lactamase (bla_SPM)], Class C [AmpC β-lactamase (bla_AmpC)], Class D [oxacillinase β-lactamase (bla_OXA)] β-lactamase-related resistance genes were detected by polymerase chain reaction. Drug-resistant mutation frequencies of each strain were determined on a drug-containing plate. The time kill curves of three XDR-PA were plotted by colony counting method. A biofilm model was established in vitro, and the synergistic effect of CAZ-AVI and COL on biofilm inhibition was detected by methythiazolyl tetrazolium assay (MTT). RESULTS: The MICs of 16 XDR-PA for CAZ-AVI ranged from 1 mg/L to 128 mg/L, and three of the isolates showed resistance (MIC > 8 mg/L). The FICI range of CAZ-AVI combined with COL was 0.312-1.000. Four isolates were synergistic, while the other 12 isolates were additive. Three isolates resistant to CAZ-AVI contained Class B resistance genes such as bla_IMP and bla_VIM, while 13 susceptible isolates carried resistance genes belonging to Class A, C or D. The logarithm values of mutation frequencies of drug resistance in CAZ-AVI group, COL group and combination group were -4.81±0.88, -7.06±0.69 and -9.70 (-9.78, -9.53), respectively. There were significant differences among the three groups (H = 33.601, P < 0.001), and between every two groups (adjusted P < 0.05). In time kill curves, the phytoplankton load of three XDR-PA decreased more than 6 log CFU/L when these two drugs were used together, and number of PA1819 planktonic bacteria decreased more than 5.1 log CFU/L compared with monotherapy group. Viable quantity in biofilm (A₄₉₀) of normal saline group, CAZ-AVI group, COL group and CAZ-AVI-COL group were 0.665±0.068, 0.540±0.072, 0.494±0.642 and 0.317±0.080, respectively. There was significant difference between the other two groups (all P < 0.001), except for that between CAZ-AVI group and COL group (P = 0.109). CONCLUSIONS CAZ-AVI combined with COL can effectively improve the bactericidal effect of each drug alone on XDR-PA. The regimen can also reduce the production of drug-resistant bacteria and inhibit the formation of biofilm. Therefore, it is a potential treatment for XDR-PA infection.
Anti-Bacterial Agents/therapeutic use* ; Azabicyclo Compounds/therapeutic use* ; Ceftazidime/therapeutic use* ; Colistin/therapeutic use* ; Drug Combinations ; Drug Resistance, Bacterial/genetics* ; Microbial Sensitivity Tests ; Pseudomonas Infections/drug therapy* ; Pseudomonas aeruginosa ; beta-Lactamases

Objective To compare five different detectors in output factor(OF)measurement for the CyberKnife(CK)system,and to select a suitable detector. Methods OFs for 12 different sizes of CK collimators were measured by EBT3films and 5 different commercially available detectors,consisting of diode detectors PTW 60017 and PTW 60018,ionizing chamber detectors PTW 31010 and PTW 30013,and diamond detector PTW 600019.OF was compared between different detectors and different measurement orientations. Results When the size of collimator was larger than 30 mm,the OF deviation among five detectors was less than 1%.When the size of collimator was smaller than 30 mm,however,the OF deviation among five detectors became large and obviously increased with the decrease in the size of collimator. With a OF deviation less than 2%,PTW 60019 achieved the best agreement with films. Compared with films,diode detectors gave slightly higher OFs,while ionizing chamber detectors gave much smaller OFs. The OF measurement was also affected by measurement orientation. PTW 60019 gave a smaller OF in the direction parallel to the central axis than in the direction perpendicular to the central axis of the radiation field,while PTW 31010 had an opposite result. Conclusions When the size of collimator is larger than 30 mm,PTW 31010,PTW 60017,PTW 60018,and PTW 60019 can be directly used for the OF measurement. When the size of collimator is smaller than 30 mm,correction is needed for the OF measurement using the above detectors. PTW 30013 is not suitable for the OF measurement in the small radiation field.

Objective To evaluate four detectors for the off-axis ratio profile measurements of a CyberKnife system, and provide reference and suggestions for selecting and using the correct detectors. Methods Profiles were acquired by using four detectors, PTW-60017, PTW-60018, PTW-60019 and IBA-SFD, at different depths for different collimator sizes, with the detector stem being oriented both perpendicular and parallel to the central beam axis. The differences of profiles and the influence of detector orientation on measurement result were analyzed. Results All full width at half maximum ( FWHM) of field measured by four detectors in parallel orientation was larger than that in actual field size. The deviation was increased with the size of collimator and measurement depth, with the maximum deviation of 1. 9 mm. The maximum deviation of FWHM among four detectors was 0. 2 mm. The penumbra was the smallest for IBA-SFD, and the largest for PTW-60019. The maximum deviation of penumbra was 0. 3 mm. The IBA-SFD tended to over-respond in the out-of-field region when the collimator size was larger than 30 mm. Both FWHM and penumbra in perpendicular orientation were smaller than those in parallel orientation for PTW-60017, PTW-60018 and PTW-60019, especially at 5 mm collimator. However, the trend was opposite for IBA-SFD. With the increase of collimator aperture, the difference between the right and left penumbra acquired by four detectors was increased, with more obvious stem effects. Conclusions Similar profiles were acquired by four detectors, but the detector characteristics and effects of detector orientations should be considered.