Group A Streptococci(GAS)can cause multiple diseases such as pharyngotonsillitis, scarlet fever, streptococcal toxic shock syndrome(STSS), necrotizing fasciitis, and so on, making it extremely difficult to monitor all GAS infections.Developed countries such as the United States and the United Kingdom have classified invasive GAS diseases/infections(iGAS) or certain specific types, such as STSS, as notifiable diseases.China only includes scarlet fever caused by GAS infections in the legal infectious diseases.Although case reports or clinical studies of STSS and necrotizing fasciitis in China can be found, there is a lack of investigation and summary on iGAS, and there are few materials to introduce its definition and diagnostic criteria.Based on a recently diagnosed typical case, this paper intends to introduce the definition and diagnostic criteria of iGAS adopted in the United States, the United Kingdom and other developed countries, as well as the valuable early manifestations and risk factors, and the incidence of iGAS.Given the epidemiological changes in GAS infections in recent years, this paper also emphasizes the importance of paying attention to GAS infections, especially iGAS, aiming to arouse the attention of China′s clinical doctors and urge them to carry out research on this group of diseases.

ObjectiveTo observe the effects of the water extract of modified Xiao Xianxiongtang on microenvironment of gastric cancer MGC-803 cells， and to explore its possible mechanism in inhibiting the invasion and metastasis and epithelial-mesenchymal transformation （EMT） of MGC-803 cells and regulating Wnt5a/Ca²⁺/nuclear factor of activated T-cells （NFAT） signaling pathway by regulating microenvironment. MethodThe model of MGC-803 cells was established by transforming growth factor-β₁ （TGF-β₁）. The MGC-803 cells were divided into blank group， model group， and modified Xiao Xianxiongtang （10， 20， 40 mg·L^-1） groups. After transfection of Wnt5a overexpression plasmid， they were divided into pEX-normal control （NC） group， pEX-Wnt5a group， pEX-NC+modified Xiao Xianxiongtang （40 mg·L^-1） group and pEX-Wnt5a+modified Xiao Xianxiongtang （40 mg·L^-1） group. The invasion ability， migration ability， key factors of microenvironment， epithelial mesenchymal transformation （EMT） gene， Wnt5a， calcineurin （CaN）， NFAT1， phosphorylated （p）-NFAT1 and NFAT1 nuclear protein expression and cell Ca²⁺ concentration of MGC-803 cells were observed. ResultCompared with the blank group， the microenvironment in the model group was significantly up-regulated（P<0.01）， and compared with the model group， modified Xiao Xianxiongtang （10，20， 40 mg·L^-1） could significantly inhibit the microenvironment（P<0.05， P<0.01）. Further experiments showed that compared with the blank group， the number of invasive cells increased， the scratch rate increased， the microenvironmental factors and EMT gene were activated and the Wnt5a/Ca²⁺/NFAT pathway was activated in the model group after overexpression of Wnt5a. Compared with the model group， modified Xiao Xianxiongtang could inhibit cell distant invasion and reduce healing， inhibit microenvironment， EMT development， and Wnt5a/Ca²⁺/NFAT signal transduction， reduce NFAT1 nuclear expression and NFAT1-mediated transcriptional activity， thus reduce cell Ca²⁺ concentration， and reverse the effect of Wnt5a （P<0.05， P<0.01）. ConclusionModified Xiao Xianxiongtang could regulate Wnt5a/Ca²⁺/NFAT pathway and inhibit the invasion and metastasis of gastric cancer and EMT progression by improving tumor microenvironment.

Background: Expression of microRNA⁃320 (miR⁃320) is down regulated in acute pancreatitis, and the mechanism of its effect on acute pancreatitis is still unclear. Aims: To investigate the effect of miR⁃320 on intestinal injury in rats with acute pancreatitis and its mechanism. Methods: Rats were randomly divided into sham operation group, model group, miR⁃ 320 agonist group (agomir miR ⁃ 320 group), miR ⁃ 320 agonist control group (agomir NC group), JAK2 inhibitor group (AG490 group), and NF⁃κB pathway inhibitor group (PDTC group). The rat model of acute pancreatitis was established by retrograde injection of 5% sodium taurocholate to the bile duct. The automatic biochemical analyzer was used to detect serum levels of amylase and lipase; ELISA assay was used to detect serum levels of TNF⁃α and IL⁃1β; HE staining was used to observe the pathological changes of rat pancreas and ileum; TUNEL staining was used to observe cell apoptosis in rat ileum; real⁃time fluorescent quantitative PCR (RT⁃qPCR) was used to detect the expression of miR⁃320 in ileum tissue; Western blotting method was used to detect the expressions of JAK2/STAT3 and NF⁃κB signaling pathway related proteins in ileum. Results: Compared with sham operation group, the pancreas and ileum were severely injured in model group, and the pathological score and ileum cell apoptosis were significantly increased (P<0.05), serum levels of amylase, lipase, TNF⁃ α, and IL⁃1β were significantly increased (P<0.05), the expression of miR⁃320 in ileum tissue was significantly decreased (P<0.05), the ratios of p⁃JAK2/JAK2, p⁃STAT3/STAT3, p⁃p65/p65, and p⁃IκBα/IκBα in ileum tissue were significantly increased (P<0.05). Compared with model group, the pathological damages of pancreas and ileum in agomir miR ⁃ 320 group, AG490 group and PDTC group were reduced, and the pathological score and ileum cell apoptosis were significantly decreased (P<0.05), serum levels of amylase, lipase, TNF ⁃ α, and IL ⁃ 1β were significantly decreased (P<0.05), the expression of miR⁃320 in ileum tissue was significantly increased (P<0.05), the ratios of p⁃JAK2/JAK2, p⁃STAT3/STAT3, p⁃ p65/p65, and p⁃IκBα/IκBα in ileum tissue were significantly decreased (P<0.05). Conclusions: MiR⁃320 can improve the intestinal injury in rats with acute pancreatitis by inhibiting the activation of JAK2/STAT3 and NF⁃κB signaling pathways.

Objective To analyze factors that affect axial mechanical performance of the posterior pedicle fixation system. Methods The mechanical model for axial mechanical properties of the posterior pedicle fixation system was established to perform mechanical analysis. By referring to the Standard YY/T 0961-2014, tests on axial ejection force and axial clamping torque of JHL-I multi-axis components, JHL-I single-axis components, JHL-V multi-axis components and JHL-V single-axis components were performed by using Instron E3000 and Instron E10000 mechanical testing machines. Results The ejection rigidity of the single-axis component of vertebral nail system was significantly higher than that of the multi-axis component of vertebral nail system; the torsion rigidity of JHL-V was higher than that of JHL-I. The type and size of the locking bolt as well as its locking torque were the main factors affecting axial ejection force of the posterior spinal pedicle fixation system; the size of the locking bolt and the diameter of the connection rod were the main factors affecting axial clamping torque of the system; axial mechanical properties of the system could be improved by increasing the diameter of the connecting rod, the coefficient of friction between each connecting element, and the pitch diameter of the locking bolt. Conclusions The research findings provide references for optimizing and improving axial mechanical properties of the posterior pedicle fixation system.

Objective To test the validity for mechanical equation of the TC4 self-tapping bone screw and analyze the influence of bone screw parameters on its mechanical properties. Methods In order to derive the equation of self-tapping and pull-out for bone screw, the physical model of bone screw-polyurethane foam block was built. By reference of ASTMF543-07 standard specification and test method for metallic medical bone screw, the mechanical verification tests of selected conical head shallow thread locking bone screw (HAZ) and conical head deep thread locking bone screw (HBZ) with different diameters were performed on Instron E3000 mechanical testing machine, and the data of self-tapping force, self-tapping torque and pull-out force from 5 groups of bone screws were tested respectively. Results The calculated and measured values were basically the same, except for a few points with large individual errors. The average error of the two values was 11.02%, so the theoretical calculation formula was highly credible. The bone screw with a larger diameter or a higher tooth height would require greater self-tapping force and pull-out force. Conclusions The research results provide the calculation basis for mechanical properties of bone screw and the research direction for optimization and improvement of bone screw in future.

Objective To evaluate the clinical safety of the collagen nerve scaffold with longitudinally oriented microchannels in bridging peripheral nerve defect.Methods Five patients with 8 peripheral nerve defects of 18 to 30 (mean,23.8) mm in length were involved in the pilot study and treated from July,2017 to March,2018,including 6 digital nerves and 2 medial antebrachial cutaneous nerves.The defects were repaired with the collagen nerve scaffold with longitudinally oriented microchannels independently developed.Routine therapy of prophylactic systemic antibiotics but no immunosuppressive drugs was given to all patients post-operatively.All patients were followed-up by regular review in the outpatient department combined with WeChat and telephone.The clinical safety of the nerve scaffold was preliminarily evaluated through observing the condition of the healing of the local wound and the whole body.The blood routine examineation and biochemical test were detected.The statistical analysis of the measurement data was performed by the analysis of variance of repeated measurement data,and the difference was statistically significant when P＜0.05.Results All patients were followed-up for 7 to 15 months (average,10 months).No adverse events such as infection,allergy,damage of liver and kidney function occurred.The operative incisions healed primarily,with no redness,exudation and rupture in the local area.There was no systemic symptoms such as fever,nausea,vomiting,skin itching,etc.The results of blood routine tests and biochemical tests were normal.The data of tests was compared,and the difference was not statistically significant (P＞0.05).Conclusion The preliminary study shows that it is clinically safe to bridge peripheral nerve defects with the collagen nerve scaffold with longitudinally oriented microchannels.

Objective To investigate the preoperative risk factors of occurrence of intra-operative ventricular fibrillation (VF) in patients with acute inferior myocardial infarction undergoing emergency percutaneous coronary intervention(PCI). Methods A retrospective approach was conducted, 572 patients with acute inferior myocardial infarction admitted to Cangzhou City People's Hospital from May 2016 to May 2018 were enrolled, and they were divided into VF group (50 cases) and non-VF group (520 cases) according to whether the intra-operative complication of VF occurred. The clinical data of the two groups of patients were collected, and the related risk factors were analyzed by univariate and multivariate analyses to explore the preoperative risk factors related to VF intra-operative occurrence in patients with acute inferior myocardial infarction undergoing emergency PCI; the receiver operating characteristic (ROC) curve was drawn to evaluate the test efficiencies of all kinds of risk factors. Results The univariate analysis showed that the ratio of Killip > Ⅰ grade, infarct area size/blood potassium concentration (IS/[K]) and symptom onset to balloon dilatation time (SOTBT) in the VF group were significantly higher than those in the non-VF group [Killip > Ⅰ grade:36.5% (19/52) vs. 24.0% (125/520), IS/[K]: 3.2±0.3 vs. 2.5±0.8, SOTBT (hours): 6.3 (2.1, 8.0) vs. 4.6 (1.8, 6.5)], the differences were statistically significant (all P < 0.05); the T wave peak to T end interval/QT interval (Tp-e/QT) and blood potassium level of the VF group were significantly lower than those of the non-VF group [Tp-e/QT: 0.3±0.1 vs. 0.4±0.1; blood potassium (mmol/L): 2.8±0.5 vs. 4.1±1.2, both P < 0.05]. Multivariate logistic regression analysis showed that the SOTBT > 6 hours [odds ratio (OR) = 8.337], Killip >Ⅰ grade (OR = 1.721), hypokalemia (OR = 1.031) and high IS/[K] (OR = 9.167) were independent risk factors for intra-operative occurrence of VF in patients with acute inferior myocardial infarction during emergency PCI (all P < 0.05). ROC curve analysis showed that the area under the ROC curve (AUC) of serum potassium, IS/[K], SOTBT > 6 hours and Killip > Ⅰ grade for predicting the intra-operative occurrence of VF during emergency PCI for patients with acute inferior myocardial infarction had certain values, their AUC were 0.633, 0.837, 0.821, 0.682, respectively, suggesting that IS/[K] and SOTBT > 6 hours had moderate predictive values, and serum potassium, Killip > Ⅰ grade had relatively low predicative values; when the optimal cut-off value of IS/[K] was 2.8, the sensitivity was 85.5% and the specificity was 80.0%. Conclusion SOTBT > 6 hours, Killip > Ⅰ grade, hypokalemia, and high IS/[K] are independent risk factors of intra-operative occurrence of VF in patients with acute inferior myocardial infarction undergoing emergency PCI.

Objective To explore the possible causative factors of appearance of ventricular fibrillation (VF) during emergency percutaneous coronary intervention (PCI) in patients with acute inferior myocardial infarction. Methods Five hundred and seventy two patients with acute inferior myocardial infarction who underwent emergency PCI 24 hours after onset from May 2016 to May 2018 in Cangzhou People's Hospital were enrolled, they were divided into a VF group (52 cases) and a non-VF group (NVF, 520 cases) according to whether VF occurred or not during PCI. The differences in clinical data, characteristics of coronary artery disease and coronary artery score (Gensini score) between the two groups were compared; multivariate Logistic regression analysis was used to analyze the risk factors related to the occurrence of VF during emergency PCI; the receiver operating characteristic curve (ROC) was drawn to evaluate the efficacy of each risk factor. Results There were no statistical significant differences in sex, age, past histories of drinking alcohol, smoking, hypertension, diabetes, previous use of β blockers, aspirin, the peak values at admission of systolic blood pressure, heart rate, creatine kinase isoenzyme (CK-MB) and cardiac troponin I (cTnI), etc between the two groups (all P > 0.05). The proportions of patients with grade 0 blood flow in myocardial infarction thrombolysis (TIMI) before recanalization, with high thrombus load, criminal vessels being right coronary artery (RCA) and proximal segment of RCA, Gensini score in VF group were significantly higher than those in NVF group [TIMI 0: 80.8% (42/52) vs. 58.1% (302/520), high thrombus load: 71.2% (37/52) vs. 58.1% (302/520), criminals being RCA: 84.6% (44/52) vs. 73.7% (383/520), the occlusion site of infarction-related artery (IRA) being the proximal segment of RCA: 61.5% (32/52) vs. 41.2% (214/520), Gensini scores: 93.84±16.48 vs. 61.37±20.01, all P < 0.05]. The multiple logistic regression analysis showed that the risk factors for VF occurrence during emergency PCI for patients with acute inferior myocardial infarction included the criminals being RCA [odds ratio (OR) = 1.967, 95% confidence interval (95% CI) = 1.696-3.015, P =0.032], TIMI blood flow grade 0 before re-canalization (OR = 3.032, 95%CI = 1.248-3.675, P = 0.043), the occlusion site of infarction-related artery (IRA) being the proximal segment of RCA (OR = 2.288, 95%CI = 1.458-3.895, P =0.024), Gensini score (OR = 6.558, 95%CI = 2.168-13.359, P = 0.001] and high thrombus load (OR = 1.781, 95%CI =1.016-3.017, P = 0.033); they all were risk factors of occurrence of ventricular fibrillation during emergency PCI in patients with acute inferior myocardial infarction (all P < 0.05). ROC curve analysis showed that TIMI blood flow grade 0 before re-canalization, Gensini score and higher thrombus load had certain predictive value for VF occurrence during emergency PCI for acute inferior wall myocardial infarction; the area under ROC curve (AUC) was 0.613, 0.869 and 0.605, and 95% CI was 0.540-0.687, 0.787-0.969 and 0.521-0.675, the P value was 0.007, 0.000 and 0.012, respectively, suggesting that Gensini score had moderate predictive value for intra-operative VF, while the predictive values of TIMI blood flow grade 0 before re-canalization and higher thrombus load were relatively low. When the Gensini score had an optimal cutoff value of 96.50, the sensitivity was 85.50% and the specificity was 81.20%. Conclusion The risk factors of VF occurrence in emergency PCI for patients with acute inferior myocardial infarction are criminal vessel RCA, TIMI blood flow grade 0 before re-canalization, IRA occlusion site being proximal segment of RCA, Gensini score and high thrombus load; pre-recanalization TIMI blood flow grade 0, Gensini score and higher thrombus load all have certain predictive value for the occurrence of VF in emergency PCI for acute inferior myocardial infarction.

Objective To investigate the prognostic risk factors of patients with acute inferior myocardial infarction and intra-operative occurrence of ventricular fibrillation (VF) when undergoing emergency percutaneous coronary intervention (PCI). Methods The data of 52 patients with acute inferior myocardial infarction treated in Cangzhou City People's Hospital from May 2016 to May 2018 were retrospectively analyzed, and they were divided into poor prognosis group (19 cases) and good prognosis group (33 cases) according to whether cardiovascular events occurred during 1 year of follow-up. The patients' gender, age, smoking or not, histories of diabetes, hypertension, hyperlipidemia, and the results of well performed color echocardiography within recent 3 days, such as left ventricular ejection fraction (LVEF), cardiac infarction size (IS), and coronary Gensini score were recorded in the two groups; the indicators with statistical significance in univariate analysis were included in the multivariate logistic regression analysis to screen out the prognostic risk factors of patients with acute inferior wall myocardial infarction undergoing emergency PCI and occurrence of intra-operative VF; Receiver operating characteristic (ROC) curve was drawn to evaluate the values of coronary Gensini score and IS in predicting intraoperative occurrence of VF in patients with acute inferior wall myocardial infarction undergoing emergency PCI. Results During 1-year follow-up, 19 of 52 patients with acute inferior myocardial infarction occurred VF, the incidence being 36.5%. The univariate analysis showed that the IS and Gensini score in poor prognosis group were significantly higher than those in the good prognosis group [IS: (3.2±0.2)% vs. (2.5±0.4)%, Gensini score: 98.8±12.5 vs. 85.7±8.4, both P < 0.05], the LVEF level was significantly lower in the poor prognosis group than that in the good prognosis group (0.37±0.08 vs. 0.46±0.11, P < 0.05). The multivariate Logistic regression analysis showed that IS [odds ratio (OR) = 5.016] and coronary Gensini score (OR = 2.415) were the risk factors of occurrence of cardiovascular events after surgery in patients with acute inferior myocardial infarction and intra-operative VF when undergoing PCI (P < 0.05). The ROC curve analysis showed that IS and coronary Gensini scores had certain predictive values for the prognosis of patients with acute inferior myocardial infarction and occurrence of intra-operative VF when undergoing emergency PCI, the area under the ROC curve (AUC) was 0.863 and 0.597, respectively, indicating that IS had a medium predictive value, while the value of coronary Gensini score was lower, when the IS optimal cut off value was 3.0, the sensitivity was 89.4% and the specificity was 88.0%. Conclusion High IS and Gensini score are the risk factors of prognosis of patients with acute inferior myocardial infarction and intra-operative occurrence of VF when undergoing emergency PCI.