This study aims to establish a high-performance size-exclusion chromatography (HPSEC) method for determining the content of the classical swine fever virus (CSFV) E2 protein and screen the optimal stabilizer to enhance the stability of this protein. The optimal detection conditions were determined by optimizing the composition of the mobile phase, and characteristic chromatographic peaks were identified by SDS-PAGE and Western blotting. The specificity, repeatability, precision, linearity, limit of detection (LOD), and limit of quantitation (LOQ) of the method were assessed. The method established was used to determine the content of CSFV E2 protein antigen and vaccine. Differential scanning fluorimetry (DSF) was employed to screen the buffer system, pH, and salt ion concentrations, and sugar, amino acid, and alcohol stabilizers were further screened. The results showed that using a 200 mmol/L phosphate buffer provided the best column efficiency. An antigen-specific chromatographic peak appeared at the retention time of 18 min, which was identified as the CSFV E2 protein by SDS-PAGE and Western blotting. The method exhibited high specificity for detecting the CSFV E2 protein, with no absorbance peak observed in the blank control. The relative standard deviation (RSD) of the peak area for six repeated injections of the CSFV E2 protein was 0.74%, indicating good repeatability of the method. The RSD for repeated detection of two different concentrations of CSFV E2 protein samples by different operators at different time points was less than 2%, suggesting good intermediate precision of the method. The peak area of the CSFV E2 protein was linearly related to its concentration, with the regression equation showing R² of 1.000. The LOD and LOQ of the method were 14.88 μg/mL and 29.75 μg/mL, respectively. Application of the developed method in the detection of three batches of CSFV E2 protein antigen and three batches of vaccine demonstrated results consistent with those from the bicinchoninic acid (BCA) assay, which meant that the method could accurately determine the content of CSFV E2 protein antigen and vaccine. The DSF method identified 50 mmol/L Tris-HCl at pH 8.0 as the optimal buffer, and the addition of sugar and alcohol stabilizers further improved the stability of the CSFV E2 protein. The HPSEC method established in this study is simple, fast, and exhibits good accuracy and repeatability, enabling precise measurement of the CSFV E2 protein content. It is expected to play a crucial role in the quality control of the CSFV E2 vaccine. Furthermore, the strategy for improving the CSFV E2 protein stability, identified through DSF screening, has significant implications for enhancing the stability of the CSFV E2 vaccine.
Classical Swine Fever Virus/chemistry* ; Chromatography, Gel/methods* ; Animals ; Swine ; Viral Envelope Proteins/immunology*

Objective:To investigate the role of oxidative stress and silent information regulator 2 homolog 1 (SIRT1) in cartilage injury in Kashin-Beck disease (KBD) by evaluating the level of oxidative stress and the effect of oxidative injury on SIRT1 expression in patients with KBD.Methods:In May 2017, Twenty patients with KBD were selected from Guide County of Qinghai Province as the KBD group, and 40 healthy subjects were selected as the control group, 5 ml elbow venous blood was collected, centrifuged, and the upper plasma was retained. The glutathione peroxidase (GPX) activity and reactive oxygen species (ROS) level were determined by enzyme linked immunosorbent assay (ELISA), and SIRT1 mRNA level was determined by real-time fluorescence quantitative PCR (RT-qPCR). Meanwhile, 150 μmol/L tert-butyl hydroperoxide (tBHP) was selected to damage chondrocytes; and different concentrations of sodium selenite (Na 2SeO 3) were used to intervene in chondrocytes to detect cell viability, and appropriate concentration of Na 2SeO 3 was selected for pre protection. Total RNA and DNA of chondrocytes were extracted. The mRNA levels of SIRT1, DNA methyltransferase 1 (DNMT1), and the DNA methylation level in the SIRT1 promoter region were determined by RT-qPCR. At the same time, Hoechst 33342 staining was used to detect chondrocyte apoptosis. Results:The plasma GPX activity [(35.48 ± 8.82) U/g·Hb] in KBD group was lower than that in control group [(40.43 ± 6.68) U/g·Hb, t = - 2.43, P = 0.018], and the ROS level [(577.10 ± 96.92) U/ml] was higher than that in control group [(526.44 ± 62.63) U/ml, t = 2.13, P = 0.043]. GPX activity was positively correlated with SIRT1 mRNA level ( r s = 0.44, P = 0.005), while ROS level was negatively correlated with SIRT1 mRNA level ( r s = - 0.39, P = 0.006). After 48 hours of treatment with 150 μmol/L tBHP (tBHP injury group), the survival rate of chondrocytes decreased to (55.27 ± 2.96)%; and the survival rate of chondrocytes pre-protected with 0.10 μg/ml Na 2SeO 3 (selenium protection group) was significantly higher than that of tBHP injury group ( P < 0.05). Compared with control group, the SIRT1 mRNA level of chondrocytes in tBHP injury group was significantly decreased; while the DNA methylation level in the SIRT1 promoter region, DNMT1 mRNA level and cell apoptosis rate were significantly increased ( P < 0.05). Compared with tBHP injury group, the selenium protection group had higher levels of SIRT1 mRNA in chondrocytes, lower levels of DNA methylation in the SIRT1 promoter region, DNMT1 mRNA, and cell apoptosis rate ( P < 0.05). The apoptosis rate was negatively correlated with SIRT1 mRNA level ( r s = - 0.78, P = 0.004), and positively correlated with the DNA methylation level in the SIRT1 promoter region ( r s = 0.76, P = 0.006). Conclusions:KBD patients have increased levels of oxidative stress, which may be associated with low expression of SIRT1. Oxidative injury may down-regulate SIRT1 expression and promote chondrocytes apoptosis by catalyzing DNA methylation in the SIRT1 promoter region.

Objective:To study the clinical characteristics of neonatal gastric perforation (NGP) and risk factors of mortality.Methods:From January 2015 to May 2022, infants with NGP admitted to NICU of our hospital were retrospectively studied. They were assigned into the survival group and the death group. Clinical manifestations, laboratory and imaging results, surgical treatments and prognosis were compared and risk factors of mortality were determined.Results:A total of 27 infants with NGP were enrolled, including 17 males and 10 females. 24 were premature infants and 3 were term infants. 26 infants had low birth weight. 3 infants had neonatal resuscitation due to asphyxia, 10 received positive pressure ventilation before the onset of perforation symptoms, 2 showed gastrointestinal malformations and 3 with septic shock before surgery. The median age of onset was 2.0 d. The main presenting symptom was abdominal distension, with most perforations occurring at the greater curvature of the stomach. 20 cases had congenital gastric muscular layer defects. 21 cases survived and 6 cases died. Age of onset was later in the death group than the survival group [2.5 (2.0, 7.8) days vs. 1.9 (1.4, 3.0) days]. The survival group had higher preoperative platelet count than the death group [(218±80) ×10 9/L vs. (126±73)×10 9/L]. The incidences of thrombocytopenia, septic shock and multi-organ dysfunction syndrome before surgery in the survival group were significantly lower than the death group ( P<0.05). Logistic regression analysis showed that preoperative thrombocytopenia was a risk factor for NGP mortality ( OR=19.000, 95% CI 2.029-177.932, P=0.010). Conclusions:NGP is more common in male infants, premature infants and low birth weight infants. The most common etiology is congenital gastric muscular layer defects. The mortality rate is high and preoperative thrombocytopenia is a risk factor for mortality.

Objective:To investigate the current status of hospitalized neonatal death of different gestational ages in Shaanxi Province.Methods:All neonatal deaths in six hospitals in Shaanxi Province from 2016 to 2020 were retrospectively analyzed, and the differences in perinatal complications, the causes of death, and the age at death were compared using Chi-square (or Fisher's exact ) test. Results:(1) Totally, 220 488 neonates were delivered in the obstetric department of the six hospitals during the study period; 71 782 out of them were admitted to the neonatal department. While 424 neonatal death was reported, giving the total hospitalized neonates mortality rate of 5.5‰ (394/71 782), which included 152 deaths of transferred patients ( n=9 103, 16.7‰), 226 premature (53.3%), 196 term (46.2%), and two post-term infants (0.5%). (2) Among mothers of dead neonates, 73.6% were found to have at least one perinatal complication. The most common one was fetal distress (146 cases, 34.4%), followed by gestational diabetes mellitus (113 cases, 26.7%), amniotic fluid abnormalities ( n=73, 17.2%), maternal infectious diseases ( n=71, 16.8%), and hypertensive disorders in pregnancy (HDP) ( n=52, 12.3%). The lower the gestational age, the higher the proportion of multiple pregnancies and assisted reproduction technology applied (Fisher exact test, P<0.05). On the contrary, the higher the gestational age, the higher the cesarean section rate ( χ 2=26.69, P<0.001). HDP was more likely to occur in the gestational age of 28-31 +6 and 32-34 +6 weeks ( χ 2=37.16, P<0.001), and amniotic fluid abnormalities were more likely to occur in those over 37 weeks ( χ 2=27.47, P<0.001). (3) The five leading causes of neonatal death were neonatal respiratory distress syndrome (NRDS, n=100, 23.6%), neonatal asphyxia ( n=88, 20.8%), maternal infectious diseases ( n=80, 18.9%), and birth defects ( n=54, 12.7%), and pulmonary hemorrhage ( n=22, 5.2%). The first three causes of death in term and post-term infants were neonatal asphyxia ( n=65, 32.8%), birth defects ( n=42, 21.2%), and infectious diseases ( n=26, 13.1%). NRDS ( n=83, 36.7%), infectious diseases ( n=54, 23.9%), and neonatal asphyxia ( n=23, 10.2%) were the three leading causes of death of premature babies. (4) Out of the 326 (76.9%) neonatal deaths within seven days after birth, 162 (38.2%) died within 24 h after birth and 164 cases (38.7%) between one to seven days after birth. Conclusions:Most neonatal deaths occurred among preterm ones and within seven days after birth, whose mothers suffered perinatal complications. The causes of neonatal death vary among different gestational age groups.

Objective:To study risk factors and clinical outcomes of nosocomial infection (NI) in extremely premature infants (EPIs).Methods:From January 2017 to December 2021, EPIs admitted to NICU of our hospital were retrospectively studied. The infants were assigned into NI group and non-NI group. The NI group were further assigned into survival group and death group. Single factor analysis was conducted using chi-square test, t-test and non-parametric test. Multiple logistic regression was used to analyze risk factors of NI and death.Results:A total of 115 cases were enrolled, including 67 (58.3%) in NI group, 54 in survival group and 12 in death group. One case gave up treatment. 48 cases were in non-NI group. 81 episodes of nosocomial infections occurred in NI group and the case infection rate was 70.4% (81/115). 48 cases (41.7%) had late-onset sepsis, 14 (12.2%) neonatal necrotizing enterocolitis, 13 (11.3%) pneumonia, 1 (0.9%) urinary tract infection and 1 (0.9%) thrush. Hemodynamic significant patent ductus arteriosus (hsPDA) and long duration of parenteral nutrition were independent risk factors for NI in EPIs ( P<0.05). The incidence of bronchopulmonary dysplasia (BPD) (100.0% vs. 70.8%) and mortality (17.9% vs. 2.1%) in NI group was higher than non-NI group ( P<0.05). Septic shock was an independent risk factor for the death due to NI. Conclusions:The incidence of NI in EPIs is high. hsPDA and long duration of parenteral nutrition are independent risk factors for NI in EPIs. EPIs with NI have high incidence of BPD and mortality and septic shock is an independent risk factor for death.

Objective:To investigate the clinicopathological characteristics, treatment methods and prognosis of renal primary neuroendocrine neoplasms.Methods:The clinical data of 42 patients with renal neuroendocrine neoplasms admitted to the First Affiliated Hospital of Zhengzhou University from October 2011 to June 2021 were retrospectively analyzed.There were 17 males and 25 females. The median age was 60.0 (50.0, 67.0) years old.The CT enhancement scan lesion was slightly intensified with less intensification than normal renal parenchyma.The clinic manifestation included lumbar abdominal pain in 7 cases, hematuria in 3 cases, abdominal distension in 1 cases, and asymptomatic in 8 cases. The average diameter of tumor was 8.0 (4.0, 10.0) cm. The tumor of 13 cases was in the left, and 6 cases was in the right. 6 cases were in T 1 stage, 11 cases were in T 2, 11 cases were in T 3, and 14 cases were in T 4.17 cases had lymph node metastasis, 11 cases had distant metastasis.The surgical method was radical nephrectomy in 27 cases, nephrectomy in 5 cases and interventional embolization in 4 case, and no operation in 6 cases, including 5 with chemotherapy alone and 1 with supportive care.Patients were classified by WHO Classification of renal tumors of the urinary system and the male reproductive organs (2016) into high-differentiated renal neuroendocrine tumors (NET, including carcinoid and atypical carcinoids) and high-grade renal neuroendocrine carcinoma (NEC, including small cell neuroendocrine carcinoma and large cell neuroendocrine carcinoma). The clinicopathological characteristics and prognosis of the 2 groups were compared, and the Cox proportional regression risk model was used to analyze the clinical factors affecting the prognosis. Results:In the NET group, 12 cases were carcinoids and 7 cases were atypical carcinoids. In the NEC group, 23 cases were small cell carcinomas.The mean Ki-67 index of 42 cases was 35% (4.5%, 62.5%). The proportion of positive expression of the neuroendocrine markers CD56, chromogranin A (CgA), and synapsin (Syn) were (37/42), (15/42), and (38/42), respectively. A total of 42 patients were followed up, and the median follow-up time was 60 (35, 99) months, and the median survival time was 25 (15, 60) months. The 3-year and 5-year overall survival rates were 40.0% and 21.2%. The 3-year and 5-year overall survival rates in the NET group were 72.6% and 42.3%.The 3-year and 5-year overall survival rates in the NEC groups were 6.3% and 0, respectively. The mean Ki-67 index was 3% (2%, 10%) in the NET group, 2 patients received postoperative chemotherapy and 3 patients had early progression after initial treatment.The mean Ki-67 index in the NEC group was 60% (40%, 80%), 15 patients received postoperative chemotherapy, and 13 patients had early progression of initial treatment.There were statistically differences in treatment method, postoperative chemotherapy, Ki-67 index, and early disease progression (all P <0.05) between the two groups.The results of univariate analysis showed that sex, age, early progression, treatment method, tumor differentiation, and Ki-67 index were all factors influencing patient prognosis (all P <0.05). Cox multivariate analysis showed that poorly differentiated NEC ( HR=13.964, P=0.003) and early progression ( HR=3.626, P=0.018) were independent risk factors for patient survival, and renal radical surgery ( HR=0.197, P=0.033) was independent protective factors for patient survival. Further subgroup analysis showed that the median survival time of the NEC patients with adjuvant chemotherapy after surgery was significantly longer compared with the patients without adjuvant chemotherapy (21 and 9 months, P=0.012). Conclusions:Primary renal neuroendocrine tumors are clinically rare, often manifested as lumbar and abdominal pain, and radical renal surgical treatment is preferred.The NET has a better prognosis and NEC prognosis is extremely poor, but NEC patients can have survival benefit from chemotherapy. NEC and early progression of the disease are independent prognostic risk factors, and radical renal surgical treatment is an independent protective factor for prognosis.

The clinical data of 5 patients with autoimmune encephalitis admitted to the psychiatric department of the 904th Hospital of the Joint Logistics Service Force from January 2016 to June 2020 were retrospectively analyzed. Among 5 patients, 4 had stress psychological events within one month before the onset, and 3 had precursor symptoms such as fever and vomiting. They were all characterized by rapid progress of atypical mental and behavioral abnormalities and cognitive impairment. In terms of neurological symptoms, 1 case had faciobrachial dystonic seizures (FBDS), 3 cases had seizures, 2 cases had involuntary movement, and 4 cases had autonomic dysfunction, including central hypopnea, arrhythmia, blood pressure instability and paroxysmal facial flushing. Most neurological symptoms occur within 1 month of the onset. MRI revealed abnormalities in cerebral cortex, thalamus, temporal lobe and insular lobe in 4 cases; EEG demonstrated bilateral short-range medium amplitude θ wave in 2 cases. Abnormal cerebrospinal fluid (CSF) pressure was detected in 4 cases and 2 cases had abnormal cell number CSF. Three patients had positive anti-N-methyl-D-aspartate receptor (NMDAR) antibody, one patient had positive anti-LGI1 antibody, and one patient had positive anti-γ-aminobutyric acid B receptor (GABA BR) antibody. One case was discharged automatically, the remaining 4 patients were treated with glucocorticoid or combined with gamma globulin and cyclophosphamide, antiepileptic drugs, antipsychotic drugs and other symptomatic treatment, and their symptoms were relieved. Patients were followed up for six months, there was slightly slow residual reaction in 2 cases and personality change in 1 case. Autoimmune encephalitis characterized by mental symptoms is likely to be misdiagnosed as mental disorders. Clinicians should identify symptoms different from mental disorders, taking into account of the possibility of autoimmune encephalitis, to make early diagnosis and treatment.

BACKGROUND: Nowadays, biological tissue engineering is a growing field of research. Biocompatibility is a key indicator for measuring tissue engineering biomaterials, which is of great significance for the replacement and repair of damaged tissues. METHODS: In this study, using gelatin, carboxymethyl chitosan, and sodium alginate, a tissue engineering material scaffold that can carry cells was successfully prepared. The material was characterized by Fourier transforms infrared spectroscopy. In addition, the prepared scaffolds have physicochemical properties, such as swelling ratio, biodegradability.we observed the biocompatibility of the hydrogel to different adult stem cells (BMSCs and ADSCs) in vivo and in vitro. Adult stem cells were planted on gelatin-carboxymethyl chitosan-sodium alginate (Gel/SA/CMCS) hydrogels for 7 days in vitro, and the survival of stem cells in vitro was observed by live/died staining. Gel/SA/CMCS hydrogels loaded with stem cells were subcutaneously transplanted into nude mice for 14 days of in vivo culture observation. The survival of adult stem cells was observed by staining for stem cell surface markers (CD29, CD90) and Ki67. RESULTS: The scaffolds had a microporous structure with an appropriate pore size (about 80 lm). Live/died staining showed that adult stem cells could stably survive in Gel/SA/CMCS hydrogels for at least 7 days. After 14 days of culture in nude mice, Ki67 staining showed that the stem cells supported by Gel/SA/CMCS hydrogel still had high proliferation activity. CONCLUSION Gel/SA/CMCSs hydrogel has a stable interpenetrating porous structure, suitable swelling performance and degradation rate, can promote and support the survival of adult stem cells in vivo and in vitro, and has good biocompatibility. Therefore, Gel/SA/CMCS hydrogel is a strong candidate for biological tissue engineering materials.

Objective:To study the relationship between white matter injury (WMI) and brain maturity in preterm infants at full-term corrected gestational age (cGA).Methods:A retrospective study was performed in preterm infants [GA≤32 weeks or birth weight (BW) ≤1 500 g] admitted to the neonatal intensive care unit of the First Affiliated Hospital of Xi'an Jiaotong University from January 2017 to August 2018 and the Northwest Women and Children's Hospital from January 2017 to June 2017. The infants received conventional magnetic resonance imaging (MRI) at cGA 37~42 weeks. The infants were assigned into the WMI group and the control group according to the WMI scoring system, including the total maturation scores (TMS) and four sub-item scores.Results:A total of 118 premature infants were enrolled in this study (17 cases in the WMI group and 101 cases in the control group). The GA was (30.3±1.7) weeks, and BW was (1 356±268) g. The proportion of delayed TMS in the WMI group was significantly higher than the control group [58.8%(10/17) vs. 31.7%(32/101), P<0.05]. The TMS of the WMI group were significantly lower than the control group [(10.7±1.8) vs. (11.8±1.5), P<0.05]. The sub-item scores of TMS showed that the myelination [(2.8±0.6) vs. (3.1±0.4), P<0.05] and glial cell migration bands of the WMI group [(1.6±0.4) vs. (2.1±0.6), P=0.004] were significantly lower than the control group and no significant differences existed in cortical folding and involution of germinal matrix tissue scores between the two groups. Conclusions:The brain maturity of preterm infants with WMI is substantially delayed than those without WMI, including delayed myelination and delayed disappearance of glial cell migration bands.