Objective:To understand the molecular characteristics of the mutant strain of polymerase basic protein 2 (PB2) gene of influenza A (H1N1pdm) in Guangdong province, and to explore its specific molecular sites, so as to provide scientific basis for the prevention and control of influenza virus.Methods:Throat swab samples were collected from 2 cases infected with PB2 gene variant strains for virus isolation, and 23 influenza virus strains were selected from Guangdong province for sequencing analysis. The reference sequences and vaccine strain sequences provided by GISAID were used to perform evolutionary analysis on hemagglutinin (HA) and PB2 genes. Virus strain antigen analysis and neuraminidase (NA) inhibition test were carried out. PB2 protein model was constructed and polymerase activity was analyzed.Results:H399N amino acid mutation occurred in the HA gene of PB2-D701N and PB2-A271S variant strains, both of which belonged to the branch of 6B.1A.5a.2a. They belonged to the same big branch and different small branches as the vaccine strain A/Victoria/4897/2022, and they are all vaccine-like strains. In the three-dimensional structure, the mutations of PB2-D701N and PB2-A271S change charge and hydrophobicity.Conclusions:PB2-D701 and A271 were highly conserved, and PB2 mutant strains were not the dominant strains. The PB2 mutant had high antigenicity with the vaccine. The PB2 mutant strain is sensitive to NA inhibitors. The three-dimensional model predicted that PB2-D701N mutation could enhance virulence and affect transmissibility of influenza virus, while PB2-A271S mutation could affect polymerase activity and polymerase complex synthesis of influenza virus.

Abstract: Objective　To analyze the serotypes, drug resistance, and molecular epidemiological characteristics of non-typhoidal Salmonella in Chaozhou City, Guangdong Province in 2022, providing pathogenic support for the effective prevention and control of foodborne diseases. Methods In 2022, human-derived non-typhoidal Salmonella strains and food-derived strains were isolated through sentinel surveillance and food risk monitoring in Chaozhou City, Guangdong Province. The strains were subjected to serotyping, drug susceptibility testing, and whole-genome sequencing analysis. Results A total of 1 257 fecal specimens were collected for diarrhea surveillance in Chaozhou City in 2022, and 58 strains of non-typhoidal Salmonella were detected, with an isolation rate of 4.61%. Among 116 foodstuffs, 2 strains of non-typhoidal Salmonella were detected, with an isolation rate of 1.72%. Early childhood was the main age group for infection (14/144, 9.72%). The highest detection rate was in June (12/123, 9.76%). The 58 human-derived non-typhoidal Salmonella strains were classified into 12 serotypes, with Salmonella typhimurium being the most prevalent (44/58, 75.86%). In terms of drug resistance, 55 strains showed resistance, with a resistance rate of 91.67%, among which ampicillin, tetracycline, chloramphenicol, and streptomycin had the highest resistance rates, 76.67%, 70.00%, 67.67%, and 60.00%, respectively. Forty-nine strains were multi-resistant, accounting for 81.67%. From the molecular characteristics standpoint, multilocus sequence typing (MLST) divided the strains into 14 sequence typing (ST), with Salmonella typhimurium ST34 being the dominant type. Whole-genome single nucleotide polymorphism (wg-SNP) evolutionary analysis revealed high genetic heterogeneity among the studied strains, with Salmonella typhimurium clustering together and showing close evolutionary relationships to clinical samples of Salmonella enteritidis. Conclusions In 2022, the non-typhoidal Salmonella strains from Chaozhou showed a diversity of serotypes, with Salmonella typhimurium being predominant and exhibiting severe multidrug resistance. Molecular typing revealed diverse evolutionary characteristics.

Objective To investigate the etiological characteristics of food poisoning isolates of Vibrio parahaemolyticus (VP) from 2019 to 2021 in Zhongshan City. Methods A total of 37 strains of Vibrio parahaemolyticus isolated from 8 food poisoning incidents in Zhongshan City from 2019 to 2021 were collected, including 1 residual food isolate and 36 human isolates. The genetic correlation of Vibrio parahaemolyticus food poisoning isolates in this region was analyzed by serological typing, virulence gene detection (TLH, TDH, and TRH), drug sensitivity test, pulsed field gel electrophoresis (PFGE) and multipoint sequence typing (MLST). Results The 37 strains of Vibrio parahaemolyticus were divided into 4 serotypes: O3:K6, O10:K4, O4:K8, and O4:KUT. The tdh+ and trh- were the main virulence genotypes, accounting for 97.30% (36/37). The drug resistance rate of cefazolin was 40.54% (15 strains R, 22 strains I), and no multidrug-resistant strains were found. The 37 VP strains were divided into 23 PFGE types and 6 cluster groups, with correlation coefficients ranging from 60.4%-100%. The multipoint sequencing typing showed that the 37 VP strains were divided into 9 ST types and 3 complex groups, of which ST3 type was the main type (23 strains, 62.1%). Conclusion This study has found that the dominant virulence types of Vibrio parahaemolyticus food poisoning isolates in Zhongshan City from 2019 to 2021 are tdh⁺ and trh^-, and 37 representative strains can be divided into 6 PFGE clusters and 9 ST types with MLST type being mainly ST3. This study has identified the rare serotype O10:K4 which has caused an increase in the proportion of food poisoning events, suggesting that we should strengthen detection and be alert to the risk of continued local epidemics of new rare serotype strains.

OBJECTIVE: To investigate the effects of overexpression of long noncoding RNA (lncRNA) MEG3 on the proliferation and invasion of glioblastoma U251 cells by suppressing the expression of hypoxia inducible factor 1 METHODS: The expression of lncRNA MEG3 and HIF1 RESULTS: The expression of MEG3 was significantly lower and HIF1 CONCLUSIONS MEG3 overexpression inhibits the proliferation and invasion of U251 cells through suppressing the expression of HIF1
Apoptosis ; Cell Line, Tumor ; Cell Movement/genetics* ; Cell Proliferation/genetics* ; Gene Expression Regulation, Neoplastic ; Glioblastoma/genetics* ; Humans ; MicroRNAs ; RNA, Long Noncoding/genetics*

Objective:To explore the clinical effect of open reduction in the treatment of Tile C pelvic fracture combined with acetabular fracture in a specific sequence.Methods:Retrospectively analyzed the clinical data of 53 patients with Tile C type pelvic fracture combined with acetabular fracture from January 2014 to January 2019, and were divided into specific sequence group and non-specific sequence group according to the sequence of intraoperative reduction. A total of 29 cases were observed in the specific sequence group, including 20 males and 9 females; aged 43.8±14.8 years old (18-71 years), and the fractures were reduced in the sequence of "inside and out, then up and down" during the operation. There were 24 cases in the non-specific sequence group, including 14 males and 10 females; aged 44.4±14.7 years old (18-69 years), and fracture reduction was not performed in this sequence during the operation. According to the type of pelvic and acetabular fracture injury, we choose the appropriate position and surgical approach. After open reduction, the fracture was fixed with internal plants. The intraoperative blood loss, operation time, visual analogue scale (VAS) score were compared between the two groups. The quality of fracture reduction was evaluated by Matta score, pelvic fracture function recovery was evaluated by Majeed score, and acetabular fracture was evaluated by hip joint modified Merle d'Aubigné-Postel score.Results:There was no statistically significant difference in general data between the two groups before operation ( P>0.05), which was comparable. The intraoperative blood loss of the specific sequence group and the non-specific sequence group were 1 031.1±513.7 and 1 406.3±738.1 ml, and the operation time was 3.5±1.0 and 4.8±1.4 h; The differences between the two groups were statistically significant ( P<0.05). 53 patients were followed up for 14.8±1.6 months (12-18 months) after operation. The average postoperative VAS scores of specific sequence group and non-specific sequence group were 1.3±1.1 and 1.5±1.3 respectively, and there was no statistically significant difference. The effectiveness of the pelvic fracture Matta score standard was evaluated in the specific sequence group: excellent in 22 cases, good in 5 cases, fair in 2 cases, excellent and good rate was 93.1%; non-specific sequence group excellent in 10 cases, good in 6 cases, fair in 5 cases, poor in 3 cases, excellent and good rate was 66.7%, the difference was statistically significant ( P<0.05). Matta score of acetabular fracture: 21 cases were excellent in specific sequence group, 5 cases were good, 3 cases were poor, excellent and good rate was 89.7%; 9 cases were excellent in non-specific sequence group, 8 cases were good, 7 cases were poor, excellent and good rate was 70.8 %, the difference is statistically significant ( P<0.05). The results of the last follow-up pelvic fractures were evaluated by Majeed score: 20 cases were excellent in the specific sequence group, 7 were good, 2 were fair, excellent and good rate was 93.1%; 10 were excellent in the non-specific sequence group, 5 were good, 5 were fair, and 4 were poor, excellent and good rate was 62.5%, the difference was statistically significant ( P<0.05). At the last follow-up, the modified Merle d'Aubigné-Postel score was used to evaluate the efficacy: 20 cases were excellent in the specific sequence group, 5 were good, 4 were fair, the excellent and good rate was 86.2%; In the non-specific sequence group, 9 cases were excellent, 7 cases were good, 4 cases were fair, and 4 cases were poor, excellent and good rate was 66.7%, the difference was statistically significant ( P<0.05). During the follow-up period, none of the patients in the two groups developed fracture nonunion, heterotopic ossification, iatrogenic neurovascular injury, and femoral head necrosis. Trauma arthritis occurred in 4 patients in the non-specific sequence group. Conclusion:"Inside and out, then up and down" sequential reduction of Tile C pelvis combined with acetabular fracture can significantly shorten the operation time and reduce the amount of intraoperative blood loss. The surgical procedure is reasonable, which helps to improve the quality of fracture reduction and promote the functional recovery of patients.

Objective:To understand the etiology of a confirmed case of Coronavirus Disease 2019 (COVID-19).Methods:The pharyngeal swabs, serum and nasal swabs of a case of COVID-19 were inoculated into Vero-E6 cell tubes for virus isolation. The cytopathic effect (CPE) were observed daily. Collecting cell’s isolation when CPE was over 75%, after repeated freezing and thawing for 3 times, the supernatant was centrifugally taken, and the images of the virus were obtained by transmission electron microscopic observation, and the nucleic acid of the virus was extracted, second generation sequencing and sequence evolution analysis were used to identify and type the virus strains.Results:One strain of 2019 novel coronavirus (2019-nCoV) was successfully isolated from the nasal swab of this case of COVID-19, and one strain of herpes simplex virus type 1 (HSV-1) was also successfully isolated from the throat swab of the same case.Conclusions:COVID-19 cases have the possibility of co-infection with 2019-nCoV and HSV-1.

Objective: To evaluate the feasibility and short-term efficacy of a novel and simplified closure method developed by our team for the defect closure after endoscopic full-thickness resection (EFTR) for gastric submucosal tumors (SMT) in the gastric wall. Methods: A prospective single-arm clinical study was used. Inclusion criteria: (1) the lesion was located in the fundus or the greater curvature of the stomach, and was confirmed to originate from the muscularis propria layer; (2) the diameter of the tumor was ≤3.5 cm, and the tumor had no extensive adhesion to the peritoneal tissues and organs in extraperitoneal cavity; (3) the tumor had no malignant features under ultrasound endoscopy; (4) the patient agreed to participate in the study; (5) patients with severe complications were excluded. Based on the above criteria, 20 patients with gastric SMT at the Endoscopy Center of Zhongshan Hospital of Fudan University from January 2015 to March 2018 were enrolled in this study, including 5 males and 15 females with mean age of 61.1 (38 to 70) years. Grasping forceps-assisted endo-loop snare ligation device which is called "Shao-Mai" method was used to close the defect site. All the patients underwent EFTR and "Shao-Mai" method to perform defect closure. After successful tumor resection by EFTR, an endo-loop was anchored onto the edge of the gastric defect with grasping forceps assistance and closed tightly. The observation indicators included tumor size, en bloc resection, operation time, postoperative complications and hospital stay. The follow-up indicators included tumor residual, local recurrence, and metachronous lesions. Results: All the 20 lesions were located in the muscularis propria with a size of 0.5-3.5 (mean 1.4) cm. Three of them were located in the greater curvature of the mid-upper gastric body, 17 were located in the fundus. The endoscopic "Shao-Mai" closure was successfully performed after EFTR in all the 20 cases. Endoscope was used uniquely through the entire process, without laparoscopic assistance. The operative time was 20-100 (mean 43.8) minutes, while the "Shao-Mai" closure procedure took a range of 3-30 (mean 10.1) minutes. The en bloc resection rate was 100%. The pathological diagnosis included 17 gastrointestinal stromal tumors and 3 leiomyomas. No major complications occurred during or after surgery. All the patients were discharged 1-11 (mean 3.1) days after operation. The wounds of all the cases were healed completely six months after operation and only scar was observed without ulcer. No residual lesion, tumor recurrence or metastasis, leakage or fistula of digestive tract were found during the follow-up period of 15-54 (median 41) months. Conclusion The endoscopic "Shao-Mai" closure method is a simplified novel way, which is feasible, effective, and safe for closing the gastric defect after EFTR.

Objective To investigate the clinical efficacy of tibiocalcaneal arthrodesis using bone transport technique in the treatment of traumatic talus infection or loss. Methods A retrospective case series study was conducted to analyze the clinical data of 15 patients with talus infection or loss admitted to the provincial hospital affiliated to Shandong University from June 2011 to October 2017. There were 13 males and two females, aged from 19 to 47 years, with an average age of 27 years. Thirteen patients had talus infection and two patients had talus loss. All patients underwent tibiocalcaneal fusion with external fixator using bone transport technique, including four patients treated with annular external fixator and 11 with unilateral external fixator. Six patients with severe infection underwent debridement at stage I and osteotomy at stage II, and the other nine underwent debridement and osteotomy at the same time. The length of new bone, the fixation time of external fixator and complications were recorded. The American Orthopedic Foot and Ankle Society ( AOFAS ) score was used to evaluate the efficacy. Results All patients were followed up for 18-35 months, with an average of 26 months. The length of new bone in proximal tibial osteotomy area was 5-16 cm, with an average of 9 cm. The external fixators were removed after bone healing at docking site and maturation of new bone. The fixation time of external fixator ranged from 13 to 27 months, with an average of 18 months. No complications such as needle breakage, recurrence of infection and calcaneal varus occurred, and the length of both lower limbs was equal. AOFAS score was increased from preoperative (42. 0 ± 3. 6)points (31-55 points) to (76. 0 ± 4. 2)points (69-86 points ) at the last follow-up. Conclusion Tibiocalcaneal arthrodesis using bone transport technique is proved to be effective in treating traumatic talus infection or loss, which can repair the bone defect after debridement, improve the ankle-hindfoot function and improve the quality of life.

Objective To explore the incidence and clinical significance of corona mortis vessels.Methods From December 2015 to December 2017,48 patients with pelvic acetabular fractures were treated with the Stoppa approach,including 36 males and 12 females,aged 30 to 67 years,with an average age of 47.2±8.2 years.There were 52 sides of hemipelvis in the all including 44 cases of unilateral pelvic acetabular fractures and 4 cases of bilateral pelvic acetabular fractures.In the 48 patients,there were 6 pelvic fractures,40 acetabular fractures and 2 pelvic combined with acetabular fractures.According to Judet-Letournel classification:there were 6 cases of anterior column fracture,4 cases of anterior column with anterior wall fracture,2 cases of anterior column with posterior transverse fracture,4 cases of transverse fracture,6 cases of "T" shape fracture and 20 cases of double column fracture.According to Tile classification,there were 2 cases of B1 type,2 cases of B3 type,2 cases of C1 type,and 2 cases of C2 type.The time from injury to surgery was 5 to 16 days,with an average of 8.3±2.8 days.All patients were treated with the Stoppa approach for reduction and fixation.The incidence,number and type of corona mortis vessels across the superior pubic branch,and the diameter and the distance between the vessels and the pubic symphysiswere detected and recorded.Results In the 52 hemi pelvis,there were 46 sides with an anastomotic blood vessel,and no anastomotic blood vessel was found in 6 sides,with the incidence of corona mortis vessels of 88.5％ (46/52).Among them,36 cases were venous type,with the incidence of 78.3％ (36/46);8 cases were arterial type,with the incidence of 17.4％ (8/46);2 cases were mixed type,with the incidence of 4.3％(2/46);corona mortis venous blood vessel diameter was 1.8-3.7 mm,with an average of 2.9±0.5 mm;arterial blood vessel diameter was 2.4-3.0 mm,with an average of 2.7±0.3 mm;the distance between the vessels and the pubic symphysis was 48-71 mm,with an average of 56.9±5.8 mm.Conclusion The corona mortis vessels are common,with the incidence through Stoppa approach about 88.5％.In the clinical treatment of pelvic acetabular fractures,we should pay attention to careful separation of pubic branches exposed by the Stoppa approach,especially when using ilioinguinal approach to avoid corona mortis vessels injury and haemorrhage.

Objective To observe the differences of biological property of glioma stem cells (GSCs) and glioma non-stem cells (nGSCs), and their related protein expressions. Methods The proliferations of GSCs1, GSCs2 and nGSCs1 and nGSCs2 were detected by CCK8 after two, 4, 6, 8, 10 and 12 d of culture in vitro. The sensitivities of the cells to temozolomide (TMZ) were detected by CCK8 after 2 d of culture. The adhesion abilities of cells were tested by adhesion assay. Transwell assay was used to detect the migration and invasion abilities of cells. The activity of matrix metalloproteinase-2 (MMP-2) was detected by gelatin zymography. Western blotting and immunofluorescence staining were used to detect the protein expressions of Notchl and epidermal growth factor receptor (EGFR). Results The survival rate of nGSCs1 was significantly higher than that of GSCs1 and the survival rate of nGSCs2 was significantly higher than that of GSCs2 after 4, 6, 8, 10 and 12 d of culture (P<0.05). The inhibitory concentration (IC)50 of TMZ for GSCs1, nGSCs1, GSCs2 and nGSCs2 was (1536.0±17.67) μmol/L, (514.5±13.44) μmol/L, (2543.0±39.87) μmol/L, (889.6±17.43) μmol/L, respectively (P<0.05). Number of GSCs1 adhering to extracellular matrix proteins Fibronectin and Collagen I was significantly larger than that of nGSCs1, and that of GSCs2 was significantly larger than that of nGSCs2 (P<0.05). The number of migrated GSCs112 and 24 h of cultivation was statistically larger than that of nGSCs1, and that of GSCs2 was statistically larger than that of nGSCs2 (P<0.05). The number of invaded GSCs124 and 36 h of cultivation was larger than that of nGSCs1, and that of invaded GSCs2 was larger than that of nGSCs2, with statistical differences (P<0.05). The activity of MMP2 secreted by GSCs1 was significantly higher than that by nGSCs1, and that of MMP2 secreted by GSCs2 was significantly higher than that by nGSCs2 (P<0.05). Western blotting showed that the relative protein expression level of EGFR/Notch1 in GSCs1 was significantly lower than that in nGSCs1, and that in GSCs2 was significantly lower than that in nGSCs2 (P<0.05). The results of immunofluorescence staining were consistent with those of Western blotting; EGFR protein strongly expressed in nGSCs and weakly expressed in GSCs; Notch1 protein strongly expressed in GSCs and weakly expressed in nGSCs. Conclusion As compared with the high-EGFR-expressing and proliferative primary glioma cells, the high-Notch1-expressing glioma stem cells have higher activity level of MMP-2,stronger abilities of adhesion, migration and invasion, which may be contributed to glioma treatment resistance and its occurrence.