Aberrant CYP1A1 Induction: Discrepancy of CYP1A1 mRNA and Aryl Hydrocarbon Hydroxylase Activity in Mutant Cells of Mouse Hepatoma Line, Hepa-1

We have isolated new benzo[α]pyrene-resistant clones, cl-21 and cl-32, of the mouse hepatoma line, Hepa-1. CYP1A1-dependent aryl hydrocarbon hydroxylase activity is not inducible by 2,3,7,8-tetrachlorodibenzo- p -dioxin or 3-methylcholanthrene in these two cell lines. However, mRNA of CYP1A1 is inducible in cl-21 and cl-32 cells, as in the wild-type cells, in spite of an undetectable level of cytosolic Ah receptor. The cl-21 cDNA of Cypla-1 was found to have a single mutation leading to an amino acid substitution from Leu (118) to Arg (118). However, the CYP1A1 protein band was not detected on Western immunoblots. The cDNA of cl-32 was found to have a single mutation leading to an amino acid change from Arg (359) to Trp (359). The presence of the mature protein in cl-32 was confirmed by Western blot analysis. Somatic cell hybridization experiments demonstrated that the phenotype of cl-21 and cl-32 is recessive and that these clones belong to the same complementation group. These data suggest that there may be a non-Ah receptor-mediated mechanism of CYP1A1 induction.     

Type 1 diabetes patients born to immigrants to Sweden increase their native diabetes risk and differ from Swedish patients in HLA types and islet autoantibodies

Delli AJ, Lindblad B, Carlsson A, Forsander G, Ivarsson S‐A, Ludvigsson J, Marcus C, Lernmark Å; for the Better Diabetes Diagnosis (BDD) Study Group. Type 1 diabetes patients born to immigrants to Sweden increase their native diabetes risk and differ from Swedish patients in HLA types and islet autoantibodies. Aim: To determine whether type 1 diabetes mellitus (T1DM) patients, having parents who immigrated to Sweden, have increased T1DM risk before 18 yr compared with countries of origin. We also determined whether they have different human leukocyte antigen (HLA) genetic markers and islet autoantibodies at diagnosis compared with Swedish patients. Methods: A total of 1988 (53% males) newly diagnosed and confirmed T1DM patients <18 yr registered within the Better Diabetes Diagnosis (BDD) study (May 2005 to September 2008) were included. Participants were classified into three groups: Swedish, non‐Swedish, and Mixed‐origin patients according to country of origin of two generations (parents and grandparents). These groups were compared with respect to T1DM HLA markers and islet autoantibodies [glutamic acid decarboxylase autoantibodies (GAD65Ab), insulin autoantibodies (IAA), and islet antigen‐2 autoantibodies (IA‐2Ab)]. Results: Only 30 (1.5%) patients were born outside Sweden. Swedish patients constituted 66%, non‐Swedish patients 8%, Mixed origins 17%, and 9% were of uncertain origin. Confirmed T1DM in patients within the study was 22 (95% CI: 21–23) patients/10⁵/yr rate for Swedish patients compared with 14 (95% CI: 13–15) among non‐Swedish patients. The HLA‐DQ8 haplotype (p < 0.0001) and DQ2/8 genotype (p < 0.02) predominated among Swedish compared with non‐Swedish patients. In contrast, DQ2 was the most frequent haplotype among non‐Swedish patients [OR = 1.5 (95% CI: 1.0–2.0), p < 0.04]. Multiple (≥2) autoantibodies (p < 0.04) and specifically IA‐2Ab (p < 0.001) were most prevalent among the Swedish patients. Multiple autoantibodies were associated with DQ8 among the Swedish patients only (p < 0.001). Conclusion: Patients born to parents who had immigrated to the high T1DM incidence environment of Sweden have, compared with Swedish patients, more frequent HLA‐DQ2 genetic markers and are diagnosed more often with GAD65Ab.     

Intra-articular fate of degradable poly(ethyleneglycol)-hydrogel microspheres as carriers for sustained drug delivery

A novel degradable microsphere (MS) for intra-articular drug delivery, composed of a polyethylene glycol (PEG) core containing degradable regions made of short poly-(lactic-co-glycolic acid) (PLGA) sequences – named PEG-hydrogel MS – was injected into the cavity of sheep shoulder joint, and compared to non-degradable MS devoid of hydrolysable crosslinker in terms of location, degradation and inflammation. One week after intra-articular injection both groups of MS were localized beneath the synovial lining of the synovial fringes located at bottom of the shoulder joint, while a fraction of particles remained in synovial fluid. Histological analyses made one and 4 weeks after intra-articular injection showed cell proliferation around the non-degradable MS entrapped within the synovium. By contrast, degradable PEG-hydrogel MS were surrounded by few cells. The degradation of degradable PEG-hydrogel MS within the synovium was slow and was not fully complete after four weeks. Our findings indicate that the tissue entrapment of MS below the synovial lining was independent of the material degradability, while degradable PEG-hydrogel MS are less inflammatory than the non-degradable one. Degradable PEG-hydrogel MS offer several advantages over the non-degradable MS as carriers for a sustained drug delivery in synovial tissue according to the low intensity of inflammatory reaction triggered in synovium.     

异穿心莲内酯固体脂质纳米粒的制备及体外释放研究

目的 采用星点设计-效应面法优化异穿心莲内酯固体脂质纳米粒(IA-SLN)处方工艺,并考察其体外释放特性.方法 采用薄膜-超声分散法制备IA-SLN,以包封率、粒径、Zeta电位为评价指标,考察载体比例、投药量、聚山梨酯80质量分数3因素对制备工艺的影响,并对结果进行方程拟合,用效应面法预测最佳工艺条件;采片用透析法研究IA-SLN体外释放机制.结果 包封率、平均粒径、Zeta电位都以二项式拟合最优,复相关系数R2分别为0.985 6、0.913 6、0.933 4,根据优化方案制备的IA-SLN包封率96.62％、平均粒径162.4 nm、Zeta电位-31.6 mV.IA-SLN体外释放符合non-Fick's扩散机制,药物扩散和脂质骨架溶蚀具有协同作用.结论 星点设计-效应面法可用于IA-SLN的工艺优化,所建立的数学模型预测性良好.     

Protection of White Leghorn chickens by recombinant fowlpox vector vaccine with an updated H5 insert against Mexican H5N2 avian influenza viruses

Despite decades of vaccination, surveillance, and biosecurity measures, H5N2 low pathogenicity avian influenza (LPAI) virus infections continue in Mexico and neighboring countries. One explanation for tenacity of H5N2 LPAI in Mexico is the antigenic divergence of circulating field viruses compared to licensed vaccines due to antigenic drift. Our phylogenetic analysis indicates that the H5N2 LPAI viruses circulating in Mexico and neighboring countries since 1994 have undergone antigenic drift away from vaccine seed strains. Here we evaluated the efficacy of a new recombinant fowlpox virus vector containing an updated H5 insert (rFPV-H5/2016), more relevant to the current strains circulating in Mexico. We tested the vaccine efficacy against a closely related subcluster 4 Mexican H5N2 LPAI (2010 H5/LP) virus and the historic H5N2 HPAI (1995 H5/HP) virus in White Leghorn chickens. The rFPV-H5/2016 vaccine provided hemagglutinin inhibition (HI) titers pre-challenge against viral antigens from both challenge viruses in almost 100% of the immunized birds, with no differences in number of birds seroconverting or HI titers among all tested doses (1.5, 2.0, and 3.1 log₁₀ mean tissue culture infectious doses/bird). The vaccine conferred 100% clinical protection and a significant decrease in oral and cloacal virus shedding from 1995 H5/HP virus challenged birds when compared to the sham controls at all tested doses. Virus shedding titers from vaccinated 2010 H5/LP virus challenged birds significantly decreased compared to sham birds especially at earlier time points. Our results confirm the efficacy of the new rFPV-H5/2016 against antigenic drift of LPAI virus in Mexico and suggest that this vaccine would be a good candidate, likely as a primer in a prime-boost vaccination program.     

黄曲霉毒素B1转化体外原代培养的大鼠肝上皮细胞

利用基因转染技术，研究黄曲霉毒素B1在人c-myc基因和p450IA2基因转染的基础上，转化体外原代大鼠脉上皮细胞的可能性及其部分分子机理。首先构建Xm-6／c-myc真核表达载体，并将其转染Alexander细胞，免疫组化实验证明重组的c-mvc基因可在肝细胞中表达。随后分别将c-myc和人p450IA2表达载体转染无血清原代培养的新生Wistar大鼠肝细胞，结果发现p450IA2基因可代谢活化5ng／ml的AFB1，并且在外源c-myc基因辅助下，诱导大鼠肝上皮细胞获得生长优势。其中随机挑选的1例在渡过长达4个月的“危机”期后，获得永生化生长能力。从CK-18和大鼠白蛋白的表达情况和细胞超微结构特征，明确了转化细胞来源于肝上皮细胞。核型分析、免疫组化和Northern杂交分析提示，大鼠肝上皮细胞转化与其基因组稳定性改变和TGFα高表达相关。