目的观察肝卵圆细胞在同种异体大鼠脾内移植的演变结果，为肝干细胞移植治疗临床肝功能衰竭提供实验依据。方法 采用改进的梯度离心法分离肝卵圆细胞，体外培养举定后移植人2/3肝切除的同种异体大鼠脾脏内。结果每只模型大鼠肝脏中可分离获得约1.69×10/ml肝卵圆细胞。体外培养的肝卵圆细胞呈现上皮细胞的生长特点，对OV6、细胞角蛋白19及甲胎蛋白染色呈阳性反应，对白细胞共同抗原染色呈阴性反应。肝卵圆细胞植入异体大鼠脾脏内可形成岛屿状肝组织结构，形成“肝化脾”。结论大鼠肝卵圆细胞具有肝干细胞的生物学特征，在一定条件下可分化为肝细胞及胆管上皮细胞。

本文对肝衰竭/重型肝炎的新进展进行综述。在定义上倾向于将急性肝衰竭与慢性肝衰竭及脑病型与非脑病型分开；对新近提出的终末期肝病模型（MELD）预后判断公式进行评价；应用拉米夫定（LAM）治疗伴乙型肝炎病毒（HBV）复制的肝衰竭有效，但肝炎肝硬化患者因不当停药所致肝功能不全患者有所增多；LAM加乙型肝炎病毒免疫球蛋白（HBIg）预防肝移植后HBV感染有效，但其逃逸株有增多趋势；当前国际上将肝性脑病（HE）分为三种类型，A型为急性肝衰竭相关（HEALFA-HE），B型为不伴有内在肝病的门体分流，C型指在慢性肝病/肝硬化基础上发生的HE。

Several studies have demonstrated that estrogen receptor (ESR1)participates in the pathogenesis of persistent hepatitis B virus (HBV) infection. To examine whether polymorphisms at the ESR1 gene locus are associated with persistent HBV infection, we resequenced ESR1 genomic region for single nucleotide polymorphisms (SNPs) in 27 unrelated Chinese. Two haplotypetagged SNPs (htSNP), T29C and A252966G, were selected for genotyping in 1,277 persistent HBV-infected cases, 748 spontaneously recovered controls, and 293 nuclear families using polymerase chain reaction (PCR)-restriction fragment length polymorphism (PCR-RFLP) analysis. We observed that the subjects bearing ESR1 29T/T genotype had an increased susceptibility to persistent HBV infection compared to those bearing at least one 29C allele (odds ratio 1.41; 95% CI, 1.17-1.71, P<0.001). Consistent with the results of population-based association study, a significantly greater than expected transmission of the 29T allele (56.4%) from heterozygous parents to offspring with persistent HBV infection was observed (χ2=4.60, P=0.33) using the transmission-disequilibrium test (TDT) in 293 nuclear families. Linkage disequilibrium (LD) mapping analysis indicated that the T29C polymorphism contained within a LD block located from promoter region to intron 3 of ESR1, suggesting that the strong association detected with T29C in ESR1 originated from ESR1 itself. In conclusion, our results suggest that the genetic variation at the ESR1 locus influences susceptibility to persistent HBV infection in a Chinese population.

The putative envelope 2(E2)gene of hepatitis C virus(HCV)contains a highly variable region referred to as hypervariable region 1(HVR1). We hypothesized that this genetic variability is driven by immune selection pressure, rather than representing the accumulation of random mutations in a region with relatively little functional constraint. To test this hypothesis, we examined the E2 sequence of a human inoculum that was passaged through eight chimpanzees, which appear to have a replicative rate(opportunity for chance mutation)similar to that of humans. Acute-phase plasma samples from a human(the inoculum)and six of eight serially infected chimpanzees were studied. For each, 33 cloned cDNAs were examined by a combined heteroduplex-single-stranded conformationa polymorphism assay to assess quasispecies complexity and optimize selection of clones with unique gel shift patterns(clonotypes)for sequencing. The sequence diversity of HCV was significantly lower in the chimpanzees than in the humans, and during eight serial passages there was no change in the sequence of the majority clonotype from each animal examined. Similarly, the rates of protein sequence altering(nonsynonymous)substitution were lower in the chimpanzees than in the humans. These findings demonstrate that nonsynonymous mutations indicate selection pressure rather than being an incidental result of HCV replication.

Novel genetically engineered retroviral vectors and targeting plasmids are described that enable the site-specific targeting of exogenous DNA into the genomes of cultured animal cells. The protocol involves the transduction of competent cells by a chimeric retroviral vector containing a transcription unit composed of two linked cassettes an upstream marker gene under the control of the viral 5 LTR; and a downstream reporter trap containing a strong promoter 5 to a 48 bp yeast FRT element. When cells containing such integrated units are co-transfected with a plasmid encoding yeast FLP recombinase and a promoterless targeting plasmid containing a reporter cDNA tract 3 to an homologous FRT element, the targeting plasmid recombines at the chromosomally preconfigured FRT site and a new hemizygous function is introduced into the downstream cassette. These reagents provide a new portable system for site-specific targeting of chemically modified genes into uniform and unique sites in genomically integrated transcription units.

当前，军队感染病学科面临两大挑战；①新发感染病（EID）及生物恐怖主义和生物战争的威胁，使学科的军事医学特征明显突出；②面对军队精简整编，专业人员产生多种想法。军队感染病学科的机遇是：①学科在军事医学中的地位明显增高；②当前EID的出现和生物恐怖主义的威胁，均与军事医学密切相关；③感染病仍一直是军人和百姓的常见病及多发病；④与地方相比，军队感染病学科仍处于国内领先地位；⑤一旦出现像2003年北京SARS流行那样的局面，最为快速和有效的方法仍是调动军队专业人员，组成医疗队开赴疫区。我军感染病学科建设与对策：①拓展学科范围；②加强学科及队伍的建设；③健全EID防治体系。21世纪军队感染病学科发展展望：①学科的军民两用特色更加突出；②学科精简与拓展并行不悖；③学科间交叉和协作将日益增多。