Genetic association of HLA-DRB1 multiple polymorphisms with dermatomyositis in Chinese population.

Genetic variation in HLA plays an important role in the pathogenesis of dermatomyositis (DM). The aim of this study was to investigate the association of HLA class II with DM in China. Two hundred and twenty-four DM patients and 300 healthy controls were randomly enrolled at China-Japan Friendship Hospital. High-resolution typing of HLA-DRB1 alleles was performed by sequencing based typing. The HLA-DQA1 and HLA-DQB1 alleles were determined by polymerase chain reaction sequence-specific primers. The frequencies of HLA-DRB1*09:01 (28.6% vs 11.3%, P < .0001, odds ratio, OR = 3.14, 95% confidence interval, CI = 2.47-3.99) and HLA-DRB1*12:01 (29.0% vs 11.0%, P < .0001, OR = 3.30, 95% CI = 2.59-4.20) in DM patients were significantly higher than that in healthy controls. No significant difference was found in HLA-DQA1 or DQB1 alleles between DM patients and healthy controls. Furthermore, DM patients with anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5) had a significantly higher frequency of HLA-DRB1*12:01 compared to that for patients without anti-MDA5 (P < .0001, OR = 4.77, 95% CI: 2.29-9.93). Multivariate binary logistic regression analysis was performed to identify the risk factors for interstitial lung disease. The HLA-DRB1*09:01 allele was a poor prognostic factor (P = .01, OR = 9.21, 95% CI: 1.47-57.50) for DM patients with anti-MDA5 autoantibody. In summary, our findings indicate that HLA-DRB1*09:01 and HLA-DRB1*12:01 alleles may contribute to susceptibility of adult DM in Han Chinese population. In addition, the DRB1*12:01 genotype is significantly associated with the presence of anti-MDA5 antibody in DM patients.

Targeted damage effects of high intensity focused ultrasound (HIFU) on liver tissues of Guizhou Province miniswine.

HIFU can pass through tissues and accurately damage target tissues inside organisms. This article reports on the oriented damage effects of HIFU upon miniswine internal and external liver tissues, and suggests a new conception of the 'biological focal field'. The results revealed that: (1) HIFU can be used to damage accurately liver tissues under the guide of a B-modal ultrasound device; (2) the scope of the injury is connected with sound intensity and irradiation time; and (3) the different layers of tissue through which the ultrasound has passed remain undamaged.

Quantitative proteomic study identified cathepsin B associated with doxorubicin-induced damage in H9c2 cardiomyocytes.

The study was performed to analyze the proteomic profiling of doxorubicin-treated H9c2 cardiomyocytes in order to identify novel protein biomarkers associated with doxorubicin-induced cardiomyopathy. The protein profiling of H9c2 cells in response to doxorubicin at an apoptosis-induced concentration of 0.5 µM were compared using iTRAQ analysis. Western-blot analysis was used to confirm differentially expressed proteins identified in the proteomic study. A total of 22 differently expressed proteins were identified in doxorubicin-treated H9c2 cells including 15 up-regulated and 7 down-regulated proteins. Gene Ontology (GO) analysis revealed that 10 altered proteins were enriched in the process of apoptosis. We further validated the expression of cathepsin B and its possible regulator nuclear factor kappa B (NF-κB) in H9c2 cells were increased during doxorubicin treatment using Western-blots. Differentially expressed proteins might provide clues to clarify novel mechanisms underlying doxorubicin-induced cardiomyopathy. Our results also suggest that increased cathepsin B expression might be associated with NF-κB up-regulation, and the exact mechanisms need to be clarified.

[Study on basophil releasability induced by anti-IgE in allergic rhinitis].

We have investigated the basophil releasability induced by anti-IgE in allergic rhinitis patients and normal subjects by reverse human basophil degranulation tests. The results showed that anti-IgE-mediated basophil releasability and total serum IgE were significantly higher in allergic rhinitis patients than that in normal subjects. However, anti-IgE-mediated basophil releasability, total serum IgE and blood eosinophil count were not closely correlated with each other.

Autonomous parvovirus DNA replication requires topoisomerase I and its activity is increased during infection.

Topoisomerases I and II (topo I and topo II) are nuclear enzymes functioning to resolve DNA topological problems during replication, transcription, and other DNA processes. We tested the effects of camptothecin and VP16, specific inhibitors of topo I and II, respectively, on the DNA replication of parvoviruses LuIII and H-1 and found that viral DNA synthesis was suppressed by camptothecin but not by VP16. Transcription of H-1 virus was measured by a nuclear runoff assay and showed no inhibition by camptothecin. Interestingly, topo I in the LuIII virus-infected cell nuclear extract appears to have more activity for covalently binding to viral DNA than that in mock-infected cell nuclear extracts. Our data suggested that this activity was not due to an increased transcription of the topo I gene or to greater amounts of topo I.

Trans-activation of H-1 parvovirus P38 promoter is correlated with increased binding of cellular protein(s) to the trans-activation responsive element (tar).

The parvovirus H-1 P38 promoter contains a trans-activation responsive element (tar). It was previously shown that the parvovirus H-1 nonstructural protein NS1 positively regulates the expression of the P38 promoter for the viral capsid protein gene via the tar (Rhode and Richard, 1987, J. Virol. 61, 2807-2515). To characterize the mechanism of trans-activation by the tar, we used gel shift assays to demonstrate that there exist proteins in virus-infected cellular extracts which have higher binding activity than that found in mock-infected extracts. These observations in vitro are consistent with the expression by P38 constructs with the wild-type promoter linked to a reporter gene, chloramphenicol acetyl transferase (cat), in vivo. We also provide evidence that the protein(s)-tar complex has a molecular mass of approximately 75 kDa in an SDS-polyacrylamide gel, which is less than NS1, and this complex cannot be precipitated by NS1 antibody, which suggests that NS1 mediates the trans-activation by inducing an alteration in the binding activity of some cellular protein(s) in an indirect manner. These data support our previous hypothesis for the activation of the P38 promoter, in which the trans-activator(s) interacts with the tar effectively in the presence of NS1, leading to the formation of the transcription initiation complex by protein-protein associations (Gu, Chen, and Rhode, 1992, Virology 187, 10-17).

Parvovirus H-1 P38 promoter requires the trans-activation region (tar), an SP1 site, and a TATA box for full activity.

In the parvovirus H-1 P38 promoter, there are sequences identified as a TATA box, an SP1 site, and a trans-activation responsive element (tar). It was previously shown that the parvovirus H-1 nonstructural protein NS1 positively regulates the expression of the P38 promoter for the viral capsid protein gene via the tar. To characterize the tar element further, a series of single-point mutations of the tar was constructed and the mutants were compared to wild-type for the trans-activation of the P38 promoter using a cat reporter gene. Most of the tar mutations had a negative effect on the P38 promoter and some of them reduced activity as much as 70%. However, when several mutants with multiple-point mutations in the tar were tested, no significant additive effect was observed. We examined the function of the SP1 site in the trans-activation of the P38 promoter by replacing the wild-type SP1 sequence with synthetic DNA fragments, OSP1 or 2SP1, containing no SP1 or two SP1 sites respectively, in a P38 construct with a cat reporter gene. The results indicate that P38 expression varies in proportion to the number of SP1 sites, suggesting a role for the SP1 site during trans-activation by NS1. The role of the TATA box on the P38 promoter was also examined by mutagenizing TATA to CACG. The activity of this promoter was reduced to 43%. When a construct mutated at both the SP1 and TATA box sites was tested for its activity, about 22% of the wild-type activity remained, implying that this remaining activity was contributed largely by the tar element. A model is proposed for how the tar element activates the wild-type and SP1-TATA minus promoters in the presence of NS1.

Protection against anthrax toxin by vaccination with a DNA plasmid encoding anthrax protective antigen.

A DNA vaccine encoding the immunogenic and biologically active portion of anthrax protective antigen (PA) was constructed. Spleen cells from BALB/c mice immunized intramuscularly with this vaccine were stimulated to secrete IFN gamma and IL-4 when exposed to PA in vitro. Immunized mice also mounted a humoral immune response dominated by IgG1 anti-PA antibody production, the subclass previously shown to confer protection against anthrax toxin. A 1:100 dilution of serum from these animals protected cells in vitro against cytotoxic concentrations of PA. Moreover, 7/8 mice immunized three times with the PA DNA vaccine were protected against lethal challenge with a combination of anthrax protective antigen plus lethal factor.

Antiretroviral agents inhibit infection of human cells by porcine endogenous retroviruses.

The efficacy of antiretroviral drugs against porcine endogenous retroviruses (PERV) that may be harbored in pig organs intended for transplantation was examined in human cells in vitro. The nucleoside analogs zidovudine and dideoxyinosine were found to effectively inhibit PERV replication.