Immunogenicity and efficacy of serogroup A and D bacterins against Pasteurella multocida in mice.

Introduction: Pasteurella multocida is a widespread respiratory pathogen in pigs, causing swine pneumonia and atrophic rhinitis, and the capsular serogroups A and D are the main epidemic serogroups in infected animals. This study investigated the protective effects of serogroup A and D bacterins against current circulating P. multocida strains, to better understand the immunity generated by bacterins. Method: 13 serogroup A (seven A: L3 and six A: L6 strains) and 13 serogroup D (all D: L6 strains) P. multocida strains were isolated, and used as inactivated whole cell antigen to prepare P. multocida bacterins. Mice were immunized with these bacterins at 21-day interval and intraperitoneally challenged with the homologous and heterologous P. multocida strains, respectively. The antibody titer levels and immunization protective efficacy of vaccines were evaluated. Results: All of the bacterins tested induced high titer levels of immunoglobulin G antibodies against the parental bacterial antigen in mice. Vaccination with the six A: L6 bacterins provided no protection against the parent strain, but some strains did provide heterologous protection against A: L3 strains. Vaccination with the seven A: L3 bacterins provided 50%-100% protection against the parent strain, but none gave heterologous protection against the A:L6 strains. Immunization with the thirteen D: L6 bacterins offered 60%-100% protection against the parent strain, and almost all D: L6 strains gave cross-protection. Discussion: This study found that the cross-protectivity of serogroup A strains was poor, while serogroup D strains was effective, which provided some insights for P. multocida vaccine development.

Screening immune adjuvants for an inactivated vaccine against Erysipelothrix rhusiopathiae.

In this study, we screened adjuvants for an inactivated vaccine against Erysipelothrix rhusiopathiae (E. rhusiopathiae). Inactivated cells of E. rhusiopathiae strain HG-1 were prepared as the antigen in five adjuvanted inactivated vaccines, including a mineral-oil-adjuvanted vaccine (Oli vaccine), aluminum-hydroxide-gel-adjuvanted vaccine (Alh vaccine), ISA201-biphasic-oil-emulsion-adjuvanted vaccine (ISA201 vaccine), GEL02-water-soluble-polymer-adjuvanted vaccine (GEL vaccine), and IMS1313-water-soluble-nanoparticle-adjuvanted vaccine (IMS1313 vaccine). The safety test results of subcutaneous inoculation in mice showed that Oli vaccine had the most severe side effects, with a combined score of 35, followed by the ISA201 vaccine (25 points), Alh vaccine (20 points), GEL vaccine (10 points), and IMS1313 vaccine (10 points). A dose of 1.5LD50 of strain HG-1 was used to challenge the mice intraperitoneally, 14 days after their second immunization. The protective efficacy of Oli vaccine and Alh vaccine was 100% (8/8), whereas that of the other three adjuvanted vaccines was 88% (7/8). Challenge with 2.5LD50 of strain HG-1 resulted in a 100% survival rate, demonstrating the 100% protective efficacy of the Oli vaccine, followed by the GEL vaccine (71%, 5/7), IMS1313 vaccine (57%, 4/7), ISA201 vaccine (43%, 3/7), and Alh vaccine (29%, 2/7). Challenge with 4LD50 of strain HG-1 showed 100% (7/7) protective efficacy of the Oli vaccine and 71% (5/7) protective efficacy of the GEL vaccine, whereas the protective efficacy of other three adjuvanted vaccine was 14% (1/7). The Alh and GEL vaccines were selected for comparative tests in piglets, and both caused minor side effects. A second immunization with these two adjuvanted vaccines conferred 60 and 100% protective efficacy, respectively, after the piglets were challenged via an ear vein with 8LD100 of strain HG-1. After challenge with 16LD100 of strain HG-1, the Alh and GEL vaccines showed 40% and 100% protective efficacy, respectively. Our results suggested that GEL is the optimal adjuvant for an inactivated vaccine against E. rhusiopathiae.

Immune Protective Efficacy of China's Traditional Inactivated and Attenuated Vaccines against the Prevalent Strains of Pasteurella multocida in Mice.

Capsular type A and D strains of Pasteurella multocida are the main epidemic serogroups in pigs in China. In this study, we preliminarily evaluated the immune protective efficacy of the two traditional vaccines, an inactivated C44-1 aluminum-hydroxide-gel-adjuvanted (Alh-C44-1) vaccine and a live EO630 vaccine, against currently circulating strains of P. multocida in a mouse model. Mice immunized twice with conventional vaccines generated higher antibody titers, and significantly higher levels of IgG were observed in the mice inoculated with the inactivated Alh-C44-1 vaccine on day 35 (p < 0.05) than those with the live EO630 vaccine. The mice immune protection test showed that the vaccination groups had a 57% or 71% protection effect against the serogroup B strain, but had no protective effect against epidemic strains. In conclusion, our study found that the widely used traditional P. multocida vaccines in China provide good protection against homologous strains, but could not provide cross-protection against heterologous strains in a mouse model.

Proton Pump Inhibitors Increase the Risk of Early Biliary Infection After Placement of Percutaneous Transhepatic Biliary Stents.

PURPOSE: To investigate the association between the use of proton pump inhibitors (PPIs) and the risk of early biliary infection (EBI) after the placement of percutaneous transhepatic biliary stents (PTBS) in patients with unresectable malignant biliary obstruction (MBO). MATERIALS AND METHODS: A total of 136 patients with unresectable MBO (82 males and 54 females) treated with PTBS were included in this multicenter retrospective study. PPIs were prescribed to MBO patients with dyspepsia. The risk factors for EBI were identified by univariate and multivariate analyses. The association between the use of PPIs and EBI was assessed by logistic analyses. RESULTS: A total of 72 (53%) patients were regular users of PPIs, and 33 (24%) patients developed EBI after PTBS. Univariate and multivariate analyses revealed that diabetes (hazard ratio [HR], 20.3; 95% confidence interval [CI], 5.6-72.9; P <.001), biliary stones (HR, 20.3; 95% CI, 5.6-72.9; P <.001) and PPIs (HR, 4.0; 95% CI, 1.2-12.8; P =.020) were risk factors for EBI. Further analyses of the correlation between the duration of PPIs use and EBI demonstrated that a prolonged use of PPIs significantly increased the risk of EBI (PPIs for <15 days vs 15-30 days: HR, 10.2; 95% CI, 3.1-33.3; P <.001; and PPIs <15 days vs ≥30 days; HR, 20.4; 95% CI, 2.2-192.3; P <.001). CONCLUSION: The use of PPIs increased the risk of EBI after PTBS in patients with unresectable MBO. Furthermore, the risk of EBI increased with a prolonged duration of PPIs use.

Recurrent Hemoptysis After Bronchial Artery Embolization: Prediction Using a Nomogram and Artificial Neural Network Model.

OBJECTIVE. The purpose of this study was to develop an effective nomogram and artificial neural network (ANN) model for predicting recurrent hemoptysis after bronchial artery embolization (BAE). MATERIALS AND METHODS. The institutional ethics review boards of the two participating hospitals approved this study. Patients with hemoptysis who were treated with BAE were allocated to either the training cohort (Hospital A) or the validation cohort (Hospital B). The predictors of recurrent hemoptysis were identified by univariable and multivariable analyses in the training cohort. A nomogram and ANN model were then developed, and the accuracy was validated by the Harrell C statistic and ROC curves in both the training and validation cohorts. RESULTS. A total of 242 patients (training cohort, 141; validation cohort, 101) were enrolled in this study. The univariable and multivariable analyses revealed that age of 60 years old or older (hazard ratio [HR], 3.921; 95% CI, 1.267-12.127; p = 0.018), lung cancer (HR, 18.057; 95% CI, 4.124-79.068; p < 0.001), bronchial-pulmonary shunts (HR, 11.981; 95% CI, 2.593-55.356; p = 0.001), and nonbronchial systemic artery involvement (HR, 4.194; 95% CI, 1.596-11.024; p = 0.004) were predictors of recurrent hemoptysis. The developed nomogram and ANN model had high accuracy, with a Harrell C statistic of 0.849 (95% CI, 0.778-0.919) internally (for the training cohort) and 0.799 (95% CI, 0.701-0.897) externally (for the validation cohort). The optimal cutoff value of the recurrent hemoptysis risk was 0.16. CONCLUSION. The nomogram and ANN model could effectively predict the risk for recurrent hemoptysis after BAE. Further interventions should be considered for patients with a high suspicion of risk (> 0.16) according to the nomogram.

Crystal structure of dibenzothiophene sulfone monooxygenase BdsA from Bacillus subtilis WU-S2B.

The dibenzothiophene (DBT) sulfone monooxygenase BdsA from Bacillus subtilis WU-S2B catalyzes the conversion of DBT sulfone to 2'-hydroxybiphenyl 2-sulfinate. We report the crystal structures of BdsA at a resolution of 2.80 Å. BdsA exists as a homotetramer with a dimer-of-dimers configuration in the crystal, and the interaction between E288 and R296 in BdsA is important for tetramer formation. A structural comparison with homologous proteins shows that the orientation and location of the α9-α12 helices in BdsA are closer to those of the closed form than those of the open form in the EDTA monooxygenase EmoA. Proteins 2017; 85:1171-1177. © 2017 Wiley Periodicals, Inc.

A new target region for changing the substrate specificity of amine transaminases.

(R)-stereospecific amine transaminases (R-ATAs) are important biocatalysts for the production of (R)-amine compounds in a strict stereospecific manner. An improved R-ATA, ATA-117-Rd11, was successfully engineered for the manufacture of sitagliptin, a widely used therapeutic agent for type-2 diabetes. The effects of the individual mutations, however, have not yet been demonstrated due to the lack of experimentally determined structural information. Here we describe three crystal structures of the first isolated R-ATA, its G136F mutant and engineered ATA-117-Rd11, which indicated that the mutation introduced into the 136(th) residue altered the conformation of a loop next to the active site, resulting in a substrate-binding site with drastically modified volume, shape, and surface properties, to accommodate the large pro-sitagliptin ketone. Our findings provide a detailed explanation of the previously reported molecular engineering of ATA-117-Rd11 and propose that the loop near the active site is a new target for the rational design to change the substrate specificity of ATAs.

Crystal structures of apo-DszC and FMN-bound DszC from Rhodococcus erythropolis D-1.

UNLABELLED: The release of SO2 from petroleum products derived from crude oil, which contains sulfur compounds such as dibenzothiophene (DBT), leads to air pollution. The '4S' metabolic pathway catalyzes the sequential conversion of DBT to 2-hydroxybiphenyl via three enzymes encoded by the dsz operon in several bacterial species. DszC (DBT monooxygenase), from Rhodococcus erythropolis D-1 is involved in the first two steps of the '4S' pathway. Here, we determined the first crystal structure of FMN-bound DszC, and found that two distinct conformations occur in the loop region (residues 131-142) adjacent to the active site. On the basis of the DszC-FMN structure and the previously reported apo structures of DszC homologs, the binding site for DBT and DBT sulfoxide is proposed. DATABASE: The atomic coordinates and structure factors for apo-DszC (PDB code: 3X0X) and DszC-FMN (PDB code: 3X0Y) have been deposited in the Protein Data Bank (http://www.rcsb.org).

[The proteasome inhibitor MG132 attenuates skeletal muscle atrophy in a rat model of chronic obstructive pulmonary disease].

OBJECTIVE: To investigate the effect of the proteasome inhibitor MG-132 on skeletal muscle atrophy in a rat model of chronic obstructive pulmonary disease (COPD) and its potential mechanisms. METHODS: The COPD rat model was established by instillation of LPS and exposure to the cigarette smoke. Then the COPD rats were randomly divided into 3 groups (each group n = 12): COPD model control group, MG-132 high dose group (MG-132 0.1 mg·kg(-1)·d(-1)) and low dose group (MG-132 0.05 mg·kg(-1)·d(-1)), and normal control group. After 1 week and 4 week, 6 rats of each group were sacrificed, and then the following parameters were determined: the weight of the diaphragm muscle, the concentration of TNF-α in the serum and diaphragm via enzyme-linked immunosorbent assay (ELISA). Muscle atrophy F-box protein (MAFbx), NF-κBp65, and IκB-α mRNA levels were determined by RT-PCR. The protein levels of MAFbx, NF-κBp65 and IκB-α in diaphragm were measured by Western blot. The single factor analysis of variance was used for statistical analysis among the groups, while t test was used for comparison between 2 groups, and Pearson linear correlation analysis was also performed. RESULTS: The weight of diaphragm muscle from 1 week and 4 week normal control group [(0.99 ± 0.06) mg and (1.20 ± 0.04) mg] were reduced as compared to those of COPD model control group [(0.83 ± 0.09) mg and (1.01 ± 0.06) mg], high dose group [(0.85 ± 0.02) mg and (1.11 ± 0.06) mg], and low dose group [(0.83 ± 0.03) mg and (1.04 ± 0.02) mg]. The reduction of diaphragm muscle weight in the high dose group and the low dose group was significantly less than that in the COPD model control group, with a more marked difference as compared with the 4 week high dose group. The TNF-α levels in diaphragm from 4 week high dose group [(106 ± 8) ng/L] and low dose group [(122 ± 7) ng/L] were decreased as compared to that of the COPD model control group [(143 ± 24) ng/L]. The levels of NF-κBp65 and MAFbx mRNA from the 4 week high dose group (2.17 ± 0.42) and low dose group (1.74 ± 0.14) and the protein expression (1.13 ± 0.04 and 1.27 ± 0.05) were also decreased as compared to those of the COPD model control group (mRNA 2.81 ± 0.31 and 4.87 ± 0.34, protein expression 1.32 ± 0.04 and 1.44 ± 0.07). The levels of IκB-α mRNA and protein expression (0.96 ± 0.08 and 0.83 ± 0.06) were higher than those of the COPD model control group (0.25 ± 0.02 and 0.58 ± 0.06), (t = 1.57-24.9, P < 0.05). The levels of the TNF-α levels in serum and diaphragm were correlated positively with the levels of MAFbx and NF-κBp65 mRNA and protein expression (r = 0.672-0.875, P < 0.01), but negatively with the levels of IκB-α mRNA and protein expression (r = -0.656--0.927, P < 0.01). CONCLUSIONS: The proteasome inhibitor MG-132 significantly inhibited IκB-α degradation thus preventing NF-κB activation. This effect resulted in preventing skeletal muscle atrophy in the COPD rats.

[Expression of ubiquitin associated protein 1 gene and tumor-suppressor gene p16 in acute leukemia].

In order to investigate the expression and the relationship of ubiquitin associated protein 1 (ubap1) gene and tumor-suppressor gene p16 in acute leukemia, 68 cases of acute leukemia and 22 control cases were selected in this experiment, FQ-PCR technique was used to detect the mRNA expression level of ubap1 gene and p16 gene in their bone marrow cells. The results showed that as compared with the control group, the ubap1 gene in acute leukemia group highly expressed (p<0.01), while the p16 gene lowly expressed (p<0.01). But grouping of patients according to FAB revealed that as compared with the control group, the ubap1 gene expression displayed statistical difference only in M4 and M5 of adult AML (p<0.05), while the p16 gene expression in all groups of adult AML showed significant difference (p<0.05) except M1 and M2. In addition to this, the ubap1 gene and p16 gene mRNA expression in AL was not relate with chromosome abnormality (p>0.05). A negative correlation (r=-0.827, p<0.01) was found between the ubap1 gene and p16 gene mRNA expressions in the control group. It is concluded that the upregulation of ubap1 gene expression mainly and the downregulation of p16 gene expression mainly may simultaneously participate in the pathogenesis of acute leukemia. High expression of ubap1 gene influences the M4 and M5 subtypes in AML. This discovery provides important theoretical basis for the further investigation of pathogenesis and targeting therapy of AL.