肝X受体对获得性免疫反应及NOR-1的调节作用

肝X受体（liver X receptor,LXRs）是核受体超家族成员,能被氧化的胆固醇衍生物结合并激活,在胆固醇逆向转运中起着非常重要的作用。LXRs在人体的代谢和炎症中都有重要作用。现从获得性免疫反应中LXRs通过调控胞膜的重要组成物质-胆固醇胞内水平,从而抑制T细胞增殖的方向,在硫转移酶2B-肝X受体-膜转运体G1（SULT281-LXR—ABCG1）轴线上探讨LXRs对获得性免疫的调节作用,以及LXRs对神经元衍生孤核受体（NOR-1）的调控作用,以进一步认识LXRs的调控功能。     

Respiratory virus multiplex RT-PCR assay sensitivities and influence factors in hospitalized children with lower respiratory tract infections

Multiplex RT-PCR assays have been widely used tools for detection and differentiation of a panel of respiratory viral pathogens. In this study, we evaluated the Qiagen ResPlex II V2.0 kit and explored factors influencing its sensitivity. Nasopharyngeal swab (NPS) specimens were prospectively collected from pediatric inpatients with lower respiratory tract infections at the time of admission in the Shenzhen Children’s Hospital from May 2009 to April 2010. Total nucleic acids were extracted using the EZ1 system (Qiagen, Germany) and 17 respiratory viruses and genotypes including influenza A virus (FluA), FluB, parainfluenza virus 1 (PIV1), PIV2, PIV3, PIV4, respiratory syncytial virus (RSV), human metapneumovirus (hMPV), rhinoviruses (RhV), enteroviruses (EnV), human bocaviruses (hBoV), adenoviruses (AdV), four coronaviruses (229E, OC43, NL63 and HKU1), and FluA 2009 pandemic H1N1(H1N1-p) were detected and identified by the ResPlex II kit. In parallel, 16 real-time TaqMan quantitative RT-PCR assays were used to quantitatively detect each virus except for RhV. Influenza and parainfluenza viral cultures were also performed. Among the total 438 NPS specimens collected during the study period, one or more viral pathogens were detected in 274 (62.6%) and 201(45.9%) specimens by monoplex TaqMan RT-PCR and multiplex ResPlex, respectively. When results from monoplex PCR or cell culture were used as the reference standard, the multiplex PCR possessed specificities of 92.9–100.0%. The sensitivity of multiplex PCR for PIV3, hMPV, PIV1 and BoV were 73.1%, 70%, 66.7% and 55.6%, respectively, while low sensitivities (11.1%–40.0%) were observed for FluA, EnV, OC43, RSV and H1N1. Among the seven viruses/genotypes detected with higher frequencies, multiplex PCR sensitivities were correlated significantly with viral loads determined by the TaqMan RT-PCR in FluA, H1N1-p and RSV (p=0.011?0.000). The Qiagen ResPlex II multiplex RT-PCR kit possesses excellent specificity for simultaneous detection of 17 viral pathogens in NPS specimens in pediatric inpatients at the time of admission. The sensitivity of multiplex RT-PCR was influenced by viral loads, specimen process methods, primer and probe design and amplification condition.     

Association between non-suicidal self-injuries and suicide attempts in Chinese adolescents and college students: a cross-section study

Purpose

This study examined the association between non-suicidal self-injury (NSSI) and suicide attempts among Chinese adolescents and college students.

Methods

A total sample of 2013 Chinese students were randomly selected from five schools in Wuhan, China, including 1101 boys and 912 girls with the age ranging between 10 and 24 years. NSSI, suicidal ideation, suicide attempts and depressive symptoms were measured by self-rated questionnaires. Self-reported suicide attempts were regressed on suicidal ideation and NSSI, controlling for participants'' depressive symptoms, and demographic characteristics.

Results

The self-reported prevalence rates of NSSI, suicidal ideation, suicide attempts were 15.5%, 8.8%, and 3.5%, respectively. Logistic regression analyses indicated that NSSI was significantly associated with self-reported suicide attempts. Analyses examining the conditional association of NSSI and suicidal ideation with self-reported suicide attempts revealed that NSSI was significantly associated with greater risk of suicide attempts in those not reporting suicidal ideation than those reporting suicidal ideation in the past year.

Conclusions

These findings highlight the importance of NSSI as a potentially independent risk factor for suicide attempts among Chinese/Han adolescents and college students.     

Mechanism of action differences in the antitumor effects of transmembrane and secretory tumor necrosis factor-alpha in vitro and in vivo

The proinflammatory cytokine tumor necrosis factor-alpha (TNFα) exists naturally in two forms, a 26 kDa transmembrane form (TM-TNFα), and a 17 kDa secretory form (S-TNFα). The biological roles for each of these forms of TNFα in tumor killing have not been completely elucidated. Therefore, in this study, three different recombinant retroviral vectors, wild-type TNFα, solely secretable TNFα mutant, and uncleavable transmembrane TNFα mutant, were constructed by molecular techniques and stably transfected into a murine hepatic carcinoma cell line (H22). TNFα, either secreted in cell culture supernatants by secretable TNFα mutant- or wild-type TNFα-producing tumor cells, or as a treansmembrane form expressed on the cell surface of uncleavable TNFα mutant- or wild-type TNFα-synthesizing tumor cells, was demonstrated to be cytotoxic against the TNF sensitive L929 cell line. The H22 cells transfected with the three different forms of TNFα were shown to kill parental H22 cells in an in vitro cytotoxicity assay [effect/target (E/T) ratio-dependent manner], and their maximal killing rates were ~38–43% at E/T ratio of 5:1. The injection of total 2.5×10⁵ mixed cells containing transfected and parental H22 tumor cells at different ratios into syngeneic mice resulted in the inhibition of tumor growth with a maximal inhibition rates of ~57~72% at E/T ratio of 5:1. A transient weight loss was found in mice bearing solely secretable TNFα mutant producing tumors, whereas no obvious side effects were seen in mice bearing uncleavable TNFα mutant or wild-type TNFα expressing tumors. Finally, we demonstrate that tumors secreting S-TNFα promoted the subsequent infiltration of CD4⁺ T cells, and to a lesser extent CD8⁺ T cells, to the tumor site. The TM-TNFα expressing tumors up-regulated Fas (CD95) expression and inhibited the expression of tumor metastasis associated molecule CD44v3. These results suggest that S-TNFα and TM-TNFα kill cancer cells in vivo through different mechanisms of action. We conclude that the non-secreted form of TNFα may be an ideal candidate for cancer gene therapy due to its therapeutic potential and lowered side effect profile.     

Microgram-grade concentration of chlorine dioxide induces one-step plant regeneration in chrysanthemum

In Vitro Cellular & Developmental Biology - Plant - Efficient in vitro regeneration of chrysanthemum requires virus-free plants for production. Previous studies have employed various exogenous...     

Enhancing enzymatic activity of penicillin G acylase by coexpressing pcm gene

Penicillin G acylase (PGA; E.C. 3.5.1.11) is an important enzyme which has broad applications in industries of β-lactim antibiotics production. In this study, a promising PGA gene from Alcaligenes faecalis (afpga) and another pcm gene encoding protein isoaspartate methyltransferase (PIMT) were constructed into pET43.1a⁽⁺⁾ and pET28a⁽⁺⁾, respectively. The recombinant plasmids pETAFPGA and pETPCM were transformed into the same host cell Escherichia coli BL21 (DE3). Results suggested that the two plasmids could peacefully exist in the host cell and the two genes could be efficiently expressed after induction. The product of pcm gene could function as a helper molecule for enzyme AFPGA. PIMT increased the enzymatic activities in supernatant of ferment broth (1.6 folds) and cell lysate (1.8 folds), while it did not significantly affect the expression level of penicillin G acylase.     

RcMYBPA2 of Rosa chinensis functions in proanthocyanidin biosynthesis and enhances abiotic stress tolerance in transgenic tobacco

Plant Cell, Tissue and Organ Culture (PCTOC) - Proanthocyanidins (PAs) are major antioxidant flavonoids that play a key role in protecting plants against adverse environmental stress, but the...     

Three New Species of Cyphellophora (Chaetothyriales) Associated with Sooty Blotch and Flyspeck

The genus Cyphellophora includes human- and plant-related species from mammal skin and nails, plant materials, and food. On the basis of analysis of ITS, LSU, TUB2 and RPB1 data and morphological characters, three new species, Cyphellophora phyllostachysdis, C. artocarpi and C. musae, associated with sooty blotch and flyspeck disease, were added to this genus. The 2D structure of ITS1 and ITS2 confirmed this taxonomic status. Pathogenicity tests on apple fruit indicated that C. artocarpi could be a sooty blotch and flyspeck pathogen of apple.