Staphylococcus aureus is a Gram-positive bacterium with strong pathogenicity. With the widespread use of antibiotics， its multi-drug resistance has gradually increased. Among them， methicillin-resistant S. aureus （MRSA） is one of the main pathogens of hospital and community infections. Antimicrobial peptides are short-chain peptides with good antibacterial effects and low drug resistance， which have been widely studied in recent years. This study summarizes the mechanism of action of antimicrobial peptides and related study on antimicrobial peptides against MRSA from different sources. It is found that the mechanisms of action of antimicrobial peptides include targeting bacterial cell membranes， bacterial cells， and bacterial cell walls， etc. Besides isolating antimicrobial peptides with anti-MRSA activity from animals， plants， and microorganisms， antimicrobial peptides can also be obtained through synthetic methods. Among them， GHa-derived peptides from animal sources， Ib-AMP4 from plant sources， Ph-SA from microbial sources， the synthetic peptide LLKLLLKLL-NH2， and so on， due to their effective antibacterial activity， rapid bactericidal speed， and low toxicity， are promising candidates for anti-MRSA drugs.

Objective:To analyze the predictive value of echocardiography combined with diaphragmatic ultrasound on the outcome of removing machine for patients who underwent cardiac valve replacement for mechanical ventilation.Methods:Retrospectively,a total of 57 patients who adopt mechanical ventilation after underwent cardiac valve replacement in the First People's Hospital of Yibin from January 2022 to March 2023 were selected as the study subjects.According to the results of removing machine,the patients were divided into failed group(11 cases)and successful group(46 cases).All patients underwent echocardiography combined with diaphragmatic ultrasound examination.The indicators of echocardiography,included left ventricular ejection fractions(LVEF),right ventricular fractional area change(RVFAC)and systolic myocardial velocity(Sa),between different groups were compared.The early diastolic mitral annular tissue velocity(e')was recorded to calculate the ratio of early diastolic transmitral flow velocity(E)to e'(E/e'),and the indicators of echocardiography and diaphragmatic ultrasound.Logistic regression analysis was performed to analyze the factors affecting the failure of removing machine.Receiver operating characteristic(ROC)curve was drawn to evaluate the predictive values of echocardiography and diaphragmatic ultrasound indicators for the failure of removing machine in mechanical ventilation.Results:The differences of the differences of LVEF,RVFAC and Sa between failed group and successful group were no significant(P>0.05).The E/e'value of the successful group was 10.06±1.30,which was significantly lower than 12.69±2.96 of the failed group,and the difference was statistically significant(t=2.084,P＜0.05).The diaphragm thickening fraction(DTF)and diaphragm excursion(DE)values of the successful group were respectively 41.34±10.74 and 13.04±1.18,which were significantly higher than 19.67±5.37 and 11.27±0.94 of the failed group,respectively,and the differences between the two groups were statistically significant(t=2.148,2.776,P＜0.05).The results of logistic regression analysis showed that low expression of DTF and DE,as well as high expression of E/e',were all influence factors for the failure of removing machine for patients adopted mechanical ventilation after underwent cardiac valve replacement.The ROC results showed that the best cut-off value of the prediction model was 0.0893,and the area under curve(AUC)values were 0.713(95%CI:0.646～0.758),0.710(95%CI:0.651～0.779),0.752(95%CI:0.657～0.805)and 0.886(95%CI:0.782～0.991).Conclusion:The combination of echocardiography and diaphragm ultrasound has better prediction for the outcome of removing machine,which high higher clinical application value.

Objective:To evaluate the right atrial volume and function abnormalities in patients with pulmonary hypertension (PH) by four-dimensional automatic quantitation technique, and to explore the application value of this technique in evaluating the risk stratification and World Health Organization functional class(WHO-FC) of PH patients.Methods:Eighty-four adult patients with PH diagnosed by right heart catheterization from April to October 2022 in Fuwai Central China Cardiovascular Hospital were consecutively enrolled as the PH group. All cases were divided into 3 groups according to the mean pulmonary arterial pressure (mPAP): mild PH group ( n=28), moderate PH group ( n=28), severe PH group ( n=28). Twenty-eight healthy volunteers matched by gender and age were included in the same period as the control group. The volume and strain parameters of the right atrium were obtained by analyzing the four-dimensional image of the right atrium using four-dimensional automatic quantitation technique, including right atrial minimum volume index (RAVImin), right atrial maximum volume index (RAVImax), right atrial presystolic volume index (RAVIpreA), right atrial ejection fraction (RAEF), right atrial passive ejection fraction (RAPEF), right atrial active ejection fraction, RAAEF, longitudinal strains of right atrial reserve, conduit and systolic period (RASr, RAScd, RASct), circumferential strains of right atrial reserve, conduit and systolic period (RASr-c, RAScd-c, RASct-c). The differences in right atrial parameters among four groups were compared.ROC curve was used to analyze the diagnostic efficiency of right atrial four-dimensional strain parameters for PH patients with WHO-FC≥Ⅲ. Pearson linear correlation analysis was used to investigate the relationships between RASr and right atrial area (RAA), NT-proBNP and tricuspid annular plane systolic excursion to pulmonary arterial systolic pressure ratio (TAPSE/sPAP). Results:①Compared with the control group, RAEF, RAPEF, RASr, RAScd, RASr-c, RAScd-c were significantly decreased in mild, moderate and severe PH groups; while RAAEF, RASct, RASct-c were significantly increased in mild PH group and significantly decreased in moderate and severe PH groups, and the differences were statistically significant (all P<0.05). RAVImin, RAVImax, RAVIpreA gradually increased among the control, mild PH, moderate PH and severe PH groups, and the differences were statistically significant (all P<0.05). RAEF, RAPEF, RAAEF, RASr, RAScd, RASct, RASr-c, RAScd-c, RASct-c were decreased successively among mild, moderate and severe PH groups, and the differences were statistically significant (all P<0.05). ②ROC curve showed that RASr had the highest diagnostic efficiency in PH patients with WHO-FC ≥Ⅲ, and the cut-off value was 20.5% (AUC=0.914, P<0.001). ③Correlation analysis showed that RASr was correlated with RAA, NT-proBNP and TAPSE/sPAP ( r=-0.803, -0.621, 0.739; all P<0.001). Conclusions:The degree of right atrial function impairment increased in patients with mild, moderate and severe PH in turn. RASr is the best predictor of WHO-FC ≥Ⅲ in patients with pulmonary hypertension and is a potential parameter for risk stratification in patients with PH.

Objective:To explore the application value of three-dimensional visualization technology in the analysis of anatomic variation of peripancreatic vessels in patients with pancreatic space occupation.Methods:A total of 98 cases in Yijishan Hospital of Wannan Medical College, the First Affiliated Hospital of University of Science and Technology of China, the First Affiliated Hospital of Anhui Medical University, the Second Affiliated Hospital of Anhui Medical University, the First Affiliated Hospital of Bengbu Medical College, Fuyang People's Hospital from June 2018 to December 2019 were retrospectively analyzed. Of 94 patients were enrolled, including 56 males and 38 females, aged (61.2±7.2) years. Abdominal organs and blood vessels were reconstructed by 3D visualization technology, and anatomic variation of peripancreatic vessels was analyzed, including abdominal trunk, hepatic artery system, portal vein system and dorsal pancreatic artery.Results:The three-dimensional reconstruction rate of celiac trunk vessels was 100.0% (94/94). The 60 cases of abnormal celiac trunk were as follows: liver and spleen trunk in 5 cases (5.3%), stomach and spleen trunk in 1 case (1.1%), liver, stomach and spleen mesentery trunk in 3 cases (3.2%), liver, stomach and spleen mesentery trunk in 17 cases (18.1%), celiac trunk with one or more inferior phrenic arteries in 34 cases (36.2%). There were 69 cases (73.4%) of Michels type Ⅰ, 2 cases (2.1%) of Michels type Ⅲ, 1 case (1.1%) of Michels Ⅴ, 2 cases (2.1%) of Ⅷ, and 1 case (1.1%) of type Ⅸ of hepatic artery system. There were 17 cases (18.1%) of accessory left hepatic artery from celiac trunk which did not belong to Michels classification. Left accessory hepatic artery originated from left gastric artery and left hepatic artery originated from superior mesenteric artery in 1 case (1.1%), right accessory hepatic artery originated from celiac trunk combined with proper hepatic artery and right anterior hepatic artery combined with gastroduodenal artery originated from right posterior hepatic artery in 1 case (1.1%). Abnormal walking of dorsal pancreatic artery in 3 cases. The inferior mesenteric vein flowed into the superior mesenteric vein in 38 cases (40.4%), and the inferior mesenteric vein flowed into the splenic vein and superior mesenteric vein in 4 cases (4.3%).Conclusion:Three-dimensional visualization technique is helpful to determine the variation of peripancreatic vessels, and has certain significance for accurate preoperative evaluation and surgical guidance of patients with pancreatic space occupation.

Objective:To investigate the role of lncRNA H19 in evaluating prognosis and regulating radioresistance of colon cancer, aiming to provide a new potential target for the diagnosis and treatment of colon cancer.Methods:The value of lncRNA H19 in the clinicopathological parameters and prognosis of colon cancer was assessed based on bioinformatics technology. The expression of lncRNA H19 in HCT116 and SW620 cells was regulated through siRNA and overexpression plasmid transfection, respectively. The effect of regulating lncRNA H19 expression on the proliferation, DNA synthesis, radiosensitivity and cell cycle of colon cancer cells after X-ray irradiation were detected by CCK8, EdU, cell clonogenic survival assay and flow cytometry.Results:The expression of lncRNA H19 was significantly upregulated in colon cancer tissues and correlated with poor prognosis in colon cancer patients. LncRNA H19, as a high-risk gene for colon cancer, had a significant advantage for prognostic assessment of colon cancer (AUC=0.816). Furthermore, the expression of lncRNA H19 was upregulated after X-ray irradiation in colon cancer cells. Knockdown of lncRNA H19 (siRNA-H19) significantly increased the radiosensitivity in HCT116 cells, while overexpression of lncRNA H19 (H19-OE) enhanced the radioresistance in SW620 cells. Moreover, flow cytometry revealed that the G 2/M phase arrest induced by X-ray irradiation was obviously aggravated after siRNA-H19 treatment in colon cancer cells, which suggested that lncRNA H19 might regulate the radiosensitivity by inhibiting cell cycle progression. Conclusion:LncRNA H19 plays a key role in the prognostic assessment and regulating the radiosensitivity in colon cancer, which can be used as a potential target for improving radiosensitivity of colon cancer radiotherapy.

Selexipag i s a kind of oral highly selective prostacyclin （IP）receptor agonist ，which can inhibit the contraction and proliferation of pulmonary artery smooth muscle cells. Because of its good patient compliance and high receptor affinity ，it is currently used in the treatment of pulmonary hypertension （PH）. This article reviews the mechanism of action ，pharmacokinetics/ pharmacodynamics and application of selexipag in the treatment of PH. The results show that selexipag alone or in combination with endothelin receptor antagonists and （or）phosphodiesterase inhibitors can effectively reduce the risk of worsening/death events ， delay disease progression ，and improve patients ’life quality in patients with adult pulmonary arterial hypertension （PAH）of WHO cardiac function Ⅱ-Ⅲ grade. However ，its application in children with PAH and patients with chronic thromboembolic PH needs further exploration.

To analyze the clinical characteristics and genetic data of a child with type Ⅱ Bruce syndrome (type Ⅱ BS) admitted to the Department of Orthopedics, Shanxi Children′s Hospital at May 2020.A 3-day-old boy was admitted due to the pain and swelling of the right lower limb 3 days after birth.Due to the patient had multiple fractures, callus formation after clavicle and rib fracture, greendstick fracture of the humerus, right femur fracture, left tibia and fibula fracture, congenital clubfoot, and congenital contracture of wrist, elbow, hip and knee joint, and therefore, chromosome diseases were considered.Gene sequencing data showed gene mutation in PLOD2 with compound heterozygosity deletion of the child (proband), and mutation and heterozygosity deletion came from their parents, respectively.The patient was diagnosed as type Ⅱ BS.This case report alarms clinicians to identify a missense mutation of PLOD2 and loss of heterozygosity, so as to reduce the misdiagnosis rate and achieve early diagnosis and treatment.

Objective:To investigate the clinical effect of minimally invasive treatment of supracondylar fracture of humerus with nerve injury and the need for surgical exploration of nerve.Methods:From August 2017 to September 2020, 34 cases of children with supracondylar fracture of humerus with nerve injury in the Department of orthopedics of Shanxi Children′s Hospital were selected for retrospective analysis.Closed reduction, Kirschner wire fixation and small incision surgery were used to explore the injured nerve.The follow-up period ranged from 6 months to 3 years, with a follow-up time of (2.15±0.49) years.The elbow function, radial nerve, median nerve and ulnar nerve function were evaluated according to the trial standard of upper limb peripheral nerve function evaluation of Hand Surgery Society of Chinese Medical Association.Results:The elbow function of children in this group: excellent 31 cases, good 2 cases, fair 1 cases, poor 0 cases, excellent 33 cases.Three patients failed to take early functional rehabilitation exercise.Two patients recovered after 2.5 months of treatment by professional orthopedic rehabilitation therapists and physical therapy.One of them did not cooperate with functional rehabilitation training.After 3.5 months of treatment by orthopedic rehabilitation therapists, elbow and finger functions were not affected.Two weeks after nerve injury: radial nerve function evaluation: excellent in 15 cases, good in 3 cases, fair in 4 cases, poor in 0 cases, excellent in 18 cases.Median nerve function evaluation: excellent in 5 cases, good in 2 cases, fair in 6 cases, poor in 0 cases, excellent in 7 cases.Ulnar nerve function evaluation: excellent 5 cases, good 0 cases, fair 1 cases, poor 0 cases, excellent 5 cases.At 3 months after injury, the excellent and good rate of radial nerve, median nerve and ulnar nerve was 100%.Conclusion:The supracondylar fracture of humerus with nerve injury is treated by minimally invasive surgery, and the nerve exploration is still a few.The recovery of nerve injury after surgery is smooth, and the clinical effect is good.

Objective To investigate the expression and significance of inducible nitric oxide synthase (iNOS), platelet-derived growth factor (PDGF)-B and lipopolysaccharide (LPS) in rat models with Budd-Chiari syndrome (BCS) . Methods BCS model was established by partial ligation of inferior vena cava in the posterior segment of the liver. The experimental rats were divided into control group (n=20), model group (n=20) and sham group (n=20) . Liver tissues were collected for immunohistochemistry, HE and Masson staining, and the expression levels of iNOS, PDGF-B and LPS were determined. Results The LPS value in model group was higher than that in both control group and sham group (P=0.001) . The mRNA and protein expressions of iNOS and PDGF-B in model group were higher than those in both control group and sham group (P=0.001) . Statistically significant differences in mRNA and protein expressions of iNOS and PDGF-B existed between each other among the subgroups (P=0.001) . In model group iNOS was positively correlated with PDGF-B and LPS; liver fibrosis was positively correlated with LPS and negatively correlated with PDGFB. Conclusion The damage and repair of BCS is a complicated process. The iNOS, PDGF-B and LPS may play different roles in different stages of BCS. How to regulate their balance in liver fibrosis may be a direction that deserves further study.

Objective To investigate the effect and prognosis of anterior posterior surgery combined with internal fixation on treatment of patients with severe idiopathic thoracolumbar scoliosis.Methods A total of 60 patients with severe idiopathic thoracolumbar scoliosis were randomly divided into two groups.The anterior and posterior group was treated with anterior and posterior internal fixation,and posterior group was treated with posterior combined with internal fixation.Effect,preoperative and postoperative indicators and condition during follow-up were observed.Results There were significant differences in operation time,blood loss,length of stay between two groups (P<0.05).There was no significant difference of fusion segments between two groups (P>0.05).There were significant differences in the main bending angle Cobb,kyphosis and trunk shift between two groups (P<0.05).There were no significant differences in the final follow-up Cobb angle loss,the degree of kyphosis loss,the correction rate of Cobb angle and the correction rate of kyphosis between two groups (P>0.05).Conclusion Anterior combined with posterior internal fixation is similar to posterior internal fixation in treatment of patients with severe idiopathic thoracolumbar scoliosis,but the operation time and hospital stay are shorter by posterior internal fixation,and the amount of bleeding is greater and the risk is higher.