Predictive value of serum uric acid/albumin ratio for acute kidney injury after cardiac valve surgery / 中华肾脏病杂志

Objective:To investigate the predictive value of serum uric acid/albumin ratio (sUAR) for acute kidney injury (AKI) after cardiac valve surgery.Methods:The clinical data of adult patients undergoing cardiac valve surgery under cardiopulmonary bypass from January 2021 to December 2021 from the Heart Center of Henan Provincial People's Hospital were collected retrospectively, and the sUAR was calculated. All patients were divided into AKI group and non-AKI group according to whether AKI occurred within 7 days after cardiac valve surgery, and the differences of clinical data between the two groups were compared. Multivariate logistic regression model was used to analyze the independent correlation factors of AKI after cardiac valve surgery. The receiver operating characteristic (ROC) curve was used to evaluate the performance of relevant indicators.Results:A total of 422 patients were enrolled, including 194 females (46.0%), 141 hypertension patients (33.4%) and 172 atrial fibrillation patients (40.8%). They were 57 (50, 65) years old. Their sUAR was 8.13 (6.57, 9.54) μmol/g, and hemoglobin was 135 (125, 145) g/L. There were 142 cases in AKI group and 280 cases in non-AKI group, and the incidence of AKI after cardiac valve surgery was 33.6%. Age, atrial fibrillation rate, baseline serum creatinine, N terminal pro B type natriuretic peptide, serum urea,serum uric acid, blood glucose and sUAR were higher in the AKI group than those in the non-AKI group (all P<0.05), and estimated glomerular filtration rate, lymphocyte count,hemoglobin and serum albumin were lower in the AKI group than those in the non-AKI group (all P<0.05). The median cardiopulmonary bypass time of patients in the AKI group was slightly longer than that in the non-AKI group, but the difference was not statistically significant [159 (125, 192) min vs. 151 (122, 193) min, Z=-0.797, P=0.426], and there were no statistically significant differences in other indicators between the two groups. The results of multivariate logistic regression analysis showed that sUAR ( OR=1.467, 95% CI 1.308-1.645, P<0.001), age ( OR=1.045, 95% CI 1.020-1.072, P<0.001), atrial fibrillation ( OR=2.520, 95% CI 1.580-4.020, P<0.001), hemoglobin ( OR=0.984, 95% CI 0.971-0.997, P=0.015) were the independent correlation factors. ROC curve analysis showed that the area under the curve ( AUC) of sUAR predicting AKI after cardiac valve surgery was 0.710 (95% CI 0.659-0.760, P<0.001) with a sensitivity of 85.2% and specificity of 45.0% for the sUAR cut-off point of 7.28 μmol/g. The AUC for the diagnosis of AKI after cardiac valve surgery was 0.780 (95% CI 0.734-0.825, P<0.001) with a sensitivity of 72.5% and specificity of 71.8% for the combination of sUAR with age, hemoglobin and atrial fibrillation. Conclusions:For patients undergoing cardiac valve surgery under cardiopulmonary bypass, preoperative high sUAR is an independent risk factor for postoperative AKI, and sUAR has a certain predictive value for postoperative AKI.

Interaction between Brucella melitensis 16M and small ubiquitin-related modifier 1 and E2 conjugating enzyme 9 in mouse RAW264.7 macrophages

Brucella is an intracellular pathogen that invades a host and settles in its immune cells; however, the mechanism of its intracellular survival is unclear. Modification of small ubiquitin-related modifier (SUMO) occurs in many cellular activities. E2 conjugating enzyme 9 (Ubc9) is the only reported ubiquitin-conjugating enzyme that links the SUMO molecule with a target protein. Brucella's intracellular survival mechanism has not been studied with respect to SUMO-related proteins and Ubc9. Therefore, to investigate the relationship between Brucella melitensis 16M and SUMO, we constructed plasmids and cells lines suitable for overexpression and knockdown of SUMO1 and Ubc9 genes. Brucella 16M activated SUMO1/Ubc9 expression in a time-dependent manner, and Brucella 16M intracellular survival was inhibited by SUMO1/Ubc9 overexpression and promoted by SUMO1/Ubc9 depletion. In macrophages, Brucella 16M-dependent apoptosis and immune factors were induced by SUMO1/Ubc9 overexpression and restricted by SUMO1/Ubc9 depletion. We noted no effect on the expressions of SUMO1 and Ubc9 in B. melitensis 16M lipopolysaccharide-prestimulated mouse RAW264.7 macrophages. Additionally, intracellular survival of the 16M△VirB2 mutant was lower than that of Brucella 16M (p < 0.05). VirB2 can affect expression levels of Ubc9, thereby increasing intracellular survival of Brucella in macrophages at the late stage of infection. Collectively, our results demonstrate that B. melitensis 16M may use the VirB IV secretion system of Brucella to interact with SUMO-related proteins during infection of host cells, which interferes with SUMO function and promotes pathogen survival in host cells.

Pathogenic Characterization of European Genotype Porcine Reproductive and Respiratory Syndrome Virus Recently Isolated in Mainland China.

BACKGROUND: Porcine reproductive and respiratory syndrome virus (PRRSV) is an important pathogen in pig that causes tremendous economic loss in the global swine industry. PRRSV is divided into the European and North American genotypes, with virulence ranging from apathogenic-moderately virulent to highly pathogenic. The emergence of new highly virulent type 1 strains and coexistence of the two genotypes complicate the differential diagnosis, disease prevention, and control of PRRSV. Although the emergence of a novel type 1 PRRSV strain in mainland China was first confirmed in 2011, there is no information available concerning the pathogenesis of this strain. OBJECTIVES: We sought to determine the pathogenesis of a newly emerged Chinese type 1 PRRSV strain HLJB1. METHODS: Pigs were infected with HLJB1 and characterized using serological and histopathological tests. RESULTS: HLJB1 infection induced transient chemosis, reddened conjunctiva, skin cyanosis, mild transient pyrexia, dyspnea, and tachypnea between 7 and 13 days post-infection. Gross pneumonic lesions were characterized by multifocal, tan-mottled areas. Lymph nodes and spleen were enlarged. Characteristic microscopic lesions consisted of pulmonary consolidation and alveolar septal thickening with red blood cell infiltration, depletion of splenic lymphocytes, and hyperplasia and activation of macrophage. No pigs infected with HLJB1 died during the experiment. CONCLUSION: Our findings indicate that Chinese type I PRRSV strain HLJB1 caused classic PRRSV-specific lesions. As it caused lower viremia in pigs compared with other classic type 1 isolates, HLJB1 is less virulent than other type I strains.

Purification of porcine reproductive and respiratory syndrome virus using ultrafiltration and liquid chromatography.

Porcine reproductive and respiratory syndrome (PRRS) virus causes severe and persistent disease in pigs worldwide. Its heterogeneity poses a major challenge for the effective prevention and control of PRRS. Purified viruses are essential for serological studies. Traditional methods for purifying PRRS virus are time- and labor-intensive and difficult to scale-up and requires long processing time. Here, we describe a rapid, simple, scalable process for PRRS virus purification. Highly pure viral particles were obtained after ultrafiltration and liquid chromatography, as confirmed by SDS-PAGE and electron microscopy. The overall process achieved a recovery of 50% of raw virus, with a purity close to that obtained by CsCl coupled with sucrose density gradients. The purification process described here should be useful in large-scale production of highly pure PRRS virus.

Proteomic analysis of chicken peripheral blood mononuclear cells after infection by Newcastle disease virus

Characteristic clinical manifestations of Newcastle disease include leukopenia and immunosuppression. Peripheral blood mononuclear cells (PBMCs) are the main targets of Newcastle disease virus (NDV) infection. To survey changes in proteomic expression in chicken PBMCs following NDV infection, PBMC proteins from 30 chickens were separated using two-dimensional electrophoresis (2-DE) and subjected to mass spectrometry analysis. Quantitative intensity analysis showed that the expression of 78 proteins increased more than two-fold. Thirty-five proteins exhibited consistent changes in expression and 13 were identified as unique proteins by matrix assisted laser desorption ionization-time of flight mass spectrometer/mass spectrometer including three that were down-regulated and 10 that were up-regulated. These proteins were sorted into five groups based on function: macromolecular biosynthesis, cytoskeleton organization, metabolism, stress responses, and signal transduction. Furthermore, Western blot analysis confirmed the down-regulation of integrin-linked kinase expression and up-regulation of lamin A production. These data provide insight into the in vivo response of target cells to NDV infection at the molecular level. Additionally, results from this study have helped elucidate the molecular pathogenesis of NDV and may facilitate the development of new antiviral therapies as well as innovative diagnostic methods.