Nipah virus (NiV) and related viruses form a distinct henipavirus genus within the Paramyxoviridae family. NiV continues to spillover into the humans causing deadly outbreaks with increasing human-bat interaction. NiV encodes the large protein (L) and phosphoprotein (P) to form the viral RNA polymerase machinery. Their sequences show limited homologies to those of non-henipavirus paramyxoviruses. We report two cryo-electron microscopy (cryo-EM) structures of the Nipah virus (NiV) polymerase L-P complex, expressed and purified in either its full-length or truncated form. The structures resolve the RNA-dependent RNA polymerase (RdRp) and polyribonucleotidyl transferase (PRNTase) domains of the L protein, as well as a tetrameric P protein bundle bound to the L-RdRp domain. L-protein C-terminal regions are unresolved, indicating flexibility. Two PRNTase domain zinc-binding sites, conserved in most Mononegavirales, are confirmed essential for NiV polymerase activity. The structures further reveal anchoring of the P protein bundle and P protein X domain (XD) linkers on L, via an interaction pattern distinct among Paramyxoviridae. These interactions facilitate binding of a P protein XD linker in the nucleotide entry channel and distinct positioning of other XD linkers. We show that the disruption of the L-P interactions reduces NiV polymerase activity. The reported structures should facilitate rational antiviral-drug discovery and provide a guide for the functional study of NiV polymerase.
Nipah Virus/chemistry* ; Cryoelectron Microscopy ; Viral Proteins/genetics* ; RNA-Dependent RNA Polymerase/genetics* ; Phosphoproteins/genetics* ; Humans ; Models, Molecular ; Protein Binding

Objective:To investigate the current situation of the use of transjugular intrahepatic portosystemic shunt (TIPS) for portal hypertension, which should aid the development of TIPS in China.Methods:The China Portal Hypertension Alliance (CHESS) initiated this study that comprehensively investigated the basic situation of TIPS for portal hypertension in China through network research. The survey included the following: the number of surgical cases, main indications, the development of Early-TIPS, TIPS for portal vein cavernous transformation, collateral circulation embolization, intraoperative portal pressure gradient measurement, commonly used stent types, conventional anticoagulation and time, postoperative follow-up, obstacles, and the application of domestic instruments.Results:According to the survey, a total of 13 527 TIPS operations were carried out in 545 hospitals participating in the survey in 2021, and 94.1% of the hospital had the habit of routine follow-up after TIPS. Most hospitals believed that the main indications of TIPS were the control of acute bleeding (42.6%) and the prevention of rebleeding (40.7%). 48.1% of the teams carried out early or priority TIPS, 53.0% of the teams carried out TIPS for the cavernous transformation of the portal vein, and 81.0% chose routine embolization of collateral circulation during operation. Most of them used coils and biological glue as embolic materials, and 78.5% of the team routinely performed intraoperative portal pressure gradient measurements. In selecting TIPS stents, 57.1% of the hospitals woulel choose Viator-specific stents, 57.2% woulel choose conventional anticoagulation after TIPS, and the duration of anticoagulation was between 3-6 months (55.4%). The limitation of TIPS surgery was mainly due to cost (72.3%) and insufficient understanding of doctors in related departments (77.4%). Most teams accepted the domestic instruments used in TIPS (92.7%).Conclusions:This survey shows that TIPS treatment is an essential part of treating portal hypertension in China. The total number of TIPS cases is far from that of patients with portal hypertension. In the future, it is still necessary to popularize TIPS technology and further standardize surgical indications, routine operations, and instrument application.

Objective To investigate the effects of total flavones from Oxytropis falcata Bunge on hepatic fibrosis(HF)induced by carbon tetrachloride and liver transforming growth factor(TGF-β)/Smad signaling pathway.Methods Forty-eight male rats were randomly divided into normal group(intraperitoneal injection of peanut oil,intragastric administration of 0.9％NaCl),model group(intraperitoneal injection of 40％CC14 peanut oil solution induced HF model,intragastric administration of 0.9％NaCl),positive control group(modeling,intragastric administration of 0.2 mg·kg-1 of colchicine),experimental-L,-M,-H groups(modeling,intragastric administration of 100,200 and 400 mg·kg-1 of total flavonoid extract of Oxytropis falcata Bunge),8 individuals in each group,for 4 consecutive weeks.The histopathological changes were observed by hematoxylin-eosin and Masson staining.Serum liver function and liver fibrosis were measured;erum inflammatory factors were detected;fluorescence quantitative polymerase chain reaction(RT-qPCR)was used to determine gene expression in liver.Results The pathological injury of liver tissue in the model group was serious,and a large number of inflammatory factors and collagen fibers were accumulated,while the rest of the treatment groups had different degrees of remission.In normal group,model group,positive control group,experimental-L,-M,-H groups,glutamic-pyruvic transaminase levels were(49.28±12.44),(5 885.42±948.37),(4 454.60±489.27),(4 650.47±843.53),(3 761.75±887.30)and(3 544.90±1 066.75)μg·L-1;glutamic-oxaloacetic transaminase levels were(186.90±46.89),(5 936.23±793.81),(3 971.37±780.28),(4 360.30±863.35),(3 943.10±439.47)and(3 971.38±631.08)μg·L-1;hyaluronic acid levels were(45.08±17.16),(104.32±36.06),(66.83±20.09),(70.30±21.07),(60.00±9.68)and(59.02±10.73)μg·L-1;laminin levels were(23.13±3.89),(60.85±13.66),(35.67±9.92),(39.98±9.39),(36.55±12.21)and(34.68±24.83)μg·L-1;type Ⅲ procollagen level were(24.98±5.34),(82.58±30.14),(40.70±16.14),(51.08±23.21),(43.60±12.48)and(44.20±11.66)p±g·L-1;interleukin(IL)-1β levels were(37.63±1.24),(46.10±3.23),(39.22±2.36),(41.33±0.93),(40.25±2.04)and(39.18±2.23)pg·mL-1;tumor necrosis factor-α levels were(314.58±20.56),(383.71±16.97),(349.00±7.93),(348.88±25.11),(325.75±27.84)and(335.07±21.33)pg·mL-1;TGF-β1 mRNA expression of relative quantity respectively were 1.00±0.00,60.99±15.70,9.61±1.59,7.37±1.09,6.41±0.64,6.87±1.09;Smad7 mRNA relative expression were 1.00±0.00,0.34±0.05,0.21±0.03,0.35±0.02,0.38±0.02,0.42±0.03.The above indexes in the model group were compared with the normal group,and the above indexes in the experimental-M,-H groups were compared with the model group,and the differences were statistically significant(P＜0.05,P＜0.01,P＜0.001).Conclusion Total flavonoids of Oxytropis falcata Bunge have protective effects on CC14-induced liver fibrosis in rats,and the mechanism may be related to the regulation of TGF-β/Smad pathway.

Background::Very low birth weight (VLBW) infants are the key populations in neonatology, wherein morbidity and mortality remain major challenges. The study aimed to analyze the clinical characteristics of VLBW infants.Methods::A retrospective cohort study was conducted in West China Second Hospital between January 2016 and December 2021. Neonates with a birth weight of <1500 g were included. Mortality, care practices, and major morbidities were analyzed, and compared with those of previous 7 years (2009-2015).Results::Of the total 1750 VLBW, 1386 were infants born with birth weight between 1000-1499 g and 364 infants were born with weight below 1000 g; 42.9% (751/1750) required delivery room resuscitation; 53.9% (943/1750) received non-invasive ventilation only; 38.2% (669/1750) received invasive ventilation; 1517 VLBW infants received complete treatment. Among them, 60.1% (912/1517) of neonates had neonatal respiratory distress syndrome (NRDS), 28.7% (436/1517) had bronchopulmonary dysplasia (BPD), 22.0% (334/1517) had apnea, 11.1% (169/1517) had culture-confirmed sepsis, 8.4% (128/1517) had pulmonary hemorrhage, 7.6% (116/1517) had severe intraventricular hemorrhage (IVH)/periventricular leukomalacia (PVL), 5.7% (87/1517) had necrotizing enterocolitis (NEC), and 2.0% (31/1517) had severe retinopathy of prematurity. The total and in-hospital mortality rates were 9.7% (169/1750) and 3.0% (45/1517), respectively. The top three diagnoses of death among those who had received complete treatment were sepsis, NRDS, and NEC. In 2009-2015, 1146 VLBW were enrolled and 895 infants received complete treatment. The proportions of apnea, IVH, and IVH stage ≥3/PVL, were higher in 2009-2015 compared with those in 2016-2021, while the proportions of NRDS and BPD were characterized by significant increases in 2016-2021. The total and in-hospital mortality rates were 16.7% (191/1146) and 5.6% (50/895) respectively in 2009-2015.Conclusion::Among VLBW infants born in 2016-2021, the total and in-hospital mortality rates were lower than those of neonates born in 2009-2015. Incidences of NRDS and BPD increased in 2016-2021, which affected the survival rates and long-term prognosis of VLBW.

Due to traditional professional divisions, the practice of endoscopy by gastro-intestinal surgeons in China remains controversial. However, with the evolution of treatment philo-sophies, medical technology, and equipment advancements, a trend of integration between tradi-tional surgery and endoscopy is emerging. Gastrointestinal surgeons performing endoscopy can maxi-mize patient benefits, and they naturally possess advantages in conducting endoscopic procedures. It is recommended to further establish entry thresholds for surgeons to perform endoscopy, provide standardized endoscopic training for surgeons, and coordinate efforts at the administrative depart-ment. With the support of artificial intelligence, more patients can receive minimally invasive, indivi-dualized, and precise treatments.

Objective To propose a measurement method based on improved YOLOv8 for the anterior segment parameters of ultrasonic biological microscopy(UBM)images to solve the problems of the ophthalmic ultrasound images in low quantity,high annotation cost and weak model generalization ability.Methods Firstly,data enhancement using StyleGAN3 was carried out to improve YOLOv8 model in decreased sensitivity to UBM images and increased generalization ability;secondly,the pseudo-labels of virtual UBM images were generated based on the YOLOv8 model with the original UBM images as the dataset and the method of pseudo-label self-training in semi-supervised learning;finally,the YOLOv8 model was trained with the expan-ded dataset and improved with the global context network(GCNet)module,and the prediction results of the YOLOv8 model were sorted using the key-point ranking algorithm,and the measurements of the anterior segment physiological parameters were computed after screening qualified images based on prior knowledge.Results Compared with the hand-labeled results by the ophthalmologists,the localization error of the StyleGAN3 data-enhanced and self-trained YOLOv8 model was(61.94±40.66)μm,and the mean relative errors for the measurements of anterior chamber angle distance,pupil diameter,ciliary sulcus distance,central corneal thickness,anterior chamber depth and lens thickness were 0.62％,1.35％,0.68％,4.87％,0.93％and 0.75％,respectively.Conclusion The method proposed enhances the accuracy of the measurement method for anterior segment parameters of UBM images,and can meet real-time requirements.[Chinese Medical Equipment Journal,2024,45(2):8-16]

Objective To explore the risk factors of early femoral head necrosis in patients with femoral neck fracture after operation,and to establish a nomogram prediction model.Methods A total of 167 patients with femoral neck fracture from Jan-uary 2020 to April 2022 were selected and divided into necrosis group and non-necrosis group according to whether femoral head necrosis occurred in the early postoperative period.There were 21 males and 17 females in the necrosis group,aged from 33 to 72 years old,with an average of(53.49±10.96)years old,and the time from injury to operation ranged from 40 to 67 hours,with average time of(53.46±7.23)hours.There were 72 males and 57 females in the non-necrosis group,aged from 18 to 83 years,with an average of(52.78±12.55)years old,and the time from injury to operation was 18 to 65 hours,with an aver-age time of(39.88±7.79)hours.The potential influencing factors,including patient gender,diabetes mellitus,hypertension,chronic liver disease,posterior inclination angle of the femoral head,operation mode,fracture displacement,fracture line loca-tion,preoperative braking traction,screw arrangement mode,reduction quality,age,body mass index(BMI),and injury to operation time were subjected to single factor analysis.Logistic multivariate regression analysis was conducted for factors with a significance level of P＜0.05.Results The incidence of femoral head necrosis in 167 patients with femoral neck fracture was 22.76％.The following factors were identified as independent risk factors for early postoperative femoral head necrosis in pa-tients with femoral neck fractures:coexisting diabetes[OR=5.139,95％CI(1.405,18.793),P=0.013],displaced fracture[OR=3.723,95％CI(1.105,12.541),P=0.034],preoperative immobilization[OR=3.444,95％CI(1.038,11.427),P=0.043],quality of reduction[OR=3.524,95％CI(1.676,7.411),P=0.001],and time from injury to surgery[OR=1.270,95％CI(1.154,1.399),P=0.000].The Hosmer-Lemeshow goodness-of-fit test(x2=3.951,P=0.862),the area under the receiver operator characteristic(ROC)curve was 0.944[P＜0.001,95％CI(0.903,0.987)],with a sensitivity of 89.50％,the specificity was 88.40％,the maxi-mum Youden index was 0.779,and the overall trend of the model correction curve was close to the ideal curve.Model regres-sion equation was Z=1.637 × diabetes+1.314× fracture displacement+1.237 × preoperative braking traction+1.260 × reduc-tion quality+0.239 ×injury to operation time-18.310.Conclusion The occurrence of early femoral head necrosis in patients with femoral neck fracture postoperatively is affected by multiple factors.The risk early warning model established according to the factors has good predictive efficacy.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Tissue engineering envisions functional substitute creation for damaged tissues. Insulin-like growth factor-1 (IGF-1) plays roles in bone marrow mesenchymal stem cell (BMSC) osteogenic differentiation (OD), and we investigated its specific mechanism. BMSCs were cultured and OD was induced. Surface antigens (CD105, CD90, CD44, CD45, CD34) were identified by flow cytometry. Adipogenic, chondrogenic, and osteogenic differentiation abilities of BMSCs were observed. BMSCs were cultured in osteogenic medium containing 80 ng/mL IGF-1 for 3 weeks. Alkaline phosphatase activity, calcification level, osteogenic factor (runt related protein 2 [RUNX2], osteocalcin [OCN], osterix [OSX]), total (t-) ERK1/2 and phosphorylated-(p-) ERK1/2 levels, and SRY-related high-mobility-group box 4 (SOX4) levels were assessed by alkaline phosphatase staining and Alizarin Red staining, Western blot, and reverse transcription-quantitative polymerase chain reaction. The mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway inhibitor (PD98059) was used to inhibit the MAPK/ERK pathway in IGF-1-treated BMSCs. Small interfering-SOX4 was transfected into BMSCs to down-regulate SOX4.IGF-1 increased alkaline phosphatase activity, cell calcification, and osteogenic factor (RUNX2, OCN, OSX) levels in BMSCs, indicating that IGF-1 induced rat BMSC OD. SOX4, and p-ERK1/2 and t-ERK1/2 levels were elevated in IGF-1-induced BMSCs, which were annulled by PD98059. PD98059 partly averted IGF-1-induced rat BMSC OD. SOX4 levels, alkaline phosphatase activity, cell calcification, and osteogenic factor (RUNX2, OCN, OSX) levels were reduced after SOX4 down-regulation, showing that downregulation of SOX4 averted the effect of IGF-1 on inducing rat BMSC OD. IGF-1 induced rat BMSC OD by stimulating SOX4 via the MAPK/ERK pathway.

Tissue engineering envisions functional substitute creation for damaged tissues. Insulin-like growth factor-1 (IGF-1) plays roles in bone marrow mesenchymal stem cell (BMSC) osteogenic differentiation (OD), and we investigated its specific mechanism. BMSCs were cultured and OD was induced. Surface antigens (CD105, CD90, CD44, CD45, CD34) were identified by flow cytometry. Adipogenic, chondrogenic, and osteogenic differentiation abilities of BMSCs were observed. BMSCs were cultured in osteogenic medium containing 80 ng/mL IGF-1 for 3 weeks. Alkaline phosphatase activity, calcification level, osteogenic factor (runt related protein 2 [RUNX2], osteocalcin [OCN], osterix [OSX]), total (t-) ERK1/2 and phosphorylated-(p-) ERK1/2 levels, and SRY-related high-mobility-group box 4 (SOX4) levels were assessed by alkaline phosphatase staining and Alizarin Red staining, Western blot, and reverse transcription-quantitative polymerase chain reaction. The mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway inhibitor (PD98059) was used to inhibit the MAPK/ERK pathway in IGF-1-treated BMSCs. Small interfering-SOX4 was transfected into BMSCs to down-regulate SOX4.IGF-1 increased alkaline phosphatase activity, cell calcification, and osteogenic factor (RUNX2, OCN, OSX) levels in BMSCs, indicating that IGF-1 induced rat BMSC OD. SOX4, and p-ERK1/2 and t-ERK1/2 levels were elevated in IGF-1-induced BMSCs, which were annulled by PD98059. PD98059 partly averted IGF-1-induced rat BMSC OD. SOX4 levels, alkaline phosphatase activity, cell calcification, and osteogenic factor (RUNX2, OCN, OSX) levels were reduced after SOX4 down-regulation, showing that downregulation of SOX4 averted the effect of IGF-1 on inducing rat BMSC OD. IGF-1 induced rat BMSC OD by stimulating SOX4 via the MAPK/ERK pathway.