胆管疤痕相关因子在梗阻型胆管损伤后不同时间段的表达

目的:探讨手术时机的选择对胆道修复后吻合口狭窄的影响.方法:运用家犬制作梗阻型胆管损伤的动物模型,通过HE染色及Masson特染分析损伤后胆管壁的结构改变及胶原增生情况,免疫组织化学法测定胆管梗阻损伤后不同时间段巨噬细胞MΦ、α-平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)、转化生长因子-β1(transforming growth factor-β1,TGF-β1)表达情况.结果:胆管损伤后早期(BDL5)出现黏膜水肿,部分弹力纤维断裂,随着梗阻时间延长,黏膜层变薄,成纤维母细胞及胶原组织不断增生,纤维呈无规则排列,随着损伤时间的延长,胶原纤维增生不断增强[28.47±4.06(BDL5)vs59.92±9.13(BDL30)],但是疤痕相关因子MΦ、α-SMA及TGF-β1在损伤后5d即出现高表达[MΦ:0.262±0.031(BDL0)vs0.409±0.034(BDL5),α-SMA:0.239±0.035(BDL0)vs0.387±0.018(BDL5),TGF-β1:0.245±0.033(BDL0)vs0.386±0.029(BDL5),P>0.05],而后随着损伤时...     

EGCG对鼻咽癌CNE-2裸鼠移植瘤放疗的增敏作用及机制

目的探讨表没食子儿茶素没食子酸酯（EGCG）对鼻咽癌裸鼠移植瘤放疗的增敏作用及可能机制。方法将低分化鼻咽癌CNE-2细胞株接种于20只4～6周龄雄性BALA/C裸鼠皮下,肿瘤长至4～6mm时随机分为对照组、EGCG组、放疗组、EGCG＋放疗组。分别采用生理盐水、EGCG、放疗、EGCG＋放疗等干预。21天取出肿瘤,计算肿瘤抑制率;HE染色观察肿瘤细胞形态变化;RT-PCR检测瘤组织Caspase-3mRNA表达。结果与对照组相比,其他三组肿瘤抑制率均明显升高,EGCG＋放疗组显著高于EGCG组及放疗组（P〈0.05）;对照组肿瘤细胞生长旺盛,EGCG组、放疗组、EGCG＋放疗组可见大量凋亡及坏死细胞,其中以EGCG联合放疗组最明显。Caspase-3mRNA表达均明显升高,而以EGCG＋放疗组最为明显（P〈0.05）。结论 EGCG能增强鼻咽癌CNE-2裸鼠移植瘤对放疗的敏感性,其机制可能与上调Caspase-3mRNA的表达有关。     

Zinc induces protein phosphatase 2A inactivation and tau hyperphosphorylation through Src dependent PP2A (tyrosine 307) phosphorylation

The activity of protein phosphatase (PP) 2A is downregulated and promotes the hyperphosphorylation of tau in the brains of Alzheimer's disease (AD), but the mechanism for PP2A inactivation has not been elucidated. We have reported that PP2A phosphorylation at tyrosine 307 (Y307) is involved in PP2A inactivation. Here, we further studied the upstream mechanisms for PP2A phosphorylation and inactivation. We found that zinc, a heavy metal ion that is widely distributed in the normal brain and accumulated in the susceptible regions of AD brain, could induce PP2A inhibition, phosphorylation of PP2A at Y307 and tau hyperphosphorylation both in rat brains and cultured N2a cells, while zinc chelating prevented these changes completely. Upregulation of PP2A chemically or genetically attenuated zinc-induced tau hyperphosphorylation, whereas mutation of Y307 to phenylalanine abolished the zinc-induced tyrosine phosphorylation and inactivation of PP2A. Zinc could activate Src, while PP2, a specific Src family kinases inhibitor, attenuated zinc-induced PP2A phosphorylation and inactivation, indicating that zinc induces PP2A Y307 phosphorylation and inactivation through Src activation. In human tau transgenic mice, zinc chelator rescued PP2A activity, prevented Src activation, and reduced hyperphosphorylated and insoluble tau levels. We concluded that zinc induces PP2A inactivation and tau hyperphosphorylation through Src-dependent pathway, regulation of zinc homeostasis may be a promising therapeutic for AD and the related tauopathies.     

Interleukin-7 Receptor Single Nucleotide Polymorphism rs6897932 (C/T) and the Susceptibility to Systemic Lupus Erythematosus

Emerging evidences were accumulated to support the view that aberrant interleukin-7 (IL-7) signaling might be associated with autoimmunity. Former studies demonstrated the single nucleotide polymorphism (SNP) rs6897932 C/T in the IL-7 receptor (IL-7R) gene was associated with susceptibility to autoimmune diseases, including multiple sclerosis and type I diabetes. Given these, this study was conducted to investigate whether an association existed between SNP rs6897932 and the susceptibility to systemic lupus erythematosus (SLE), a severe systemic autoimmune disease. In this context, 816 SLE patients and 816 controls from a Chinese population were recruited for this study, and the results showed that the major allele C of rs6897932 showed a higher frequency in SLE patients compared with controls (P?=?0.039, C versus T); significant difference was also detected under a recessive model with regard to the distribution of genotype frequencies between SLE patients and controls (P?=?0.041, CC versus CT + TT), which was not consistent with the results under a dominant model (P?=?0.349, CC + CT versus TT). Moreover, association studies were also performed contraposing the relationship between the SNP rs6897932 C/T and lupus nephritis as well as 10 clinical features of SLE; however, no significant association signal was found regarding the distribution of allele and genotype frequencies between SLE patients positive and negative for the presence of 11 sub-phenotypes. In conclusion, the major allele C of SNP rs6897932 may be associated with increased SLE risk in Chinese populations, and further studies are still encouraged to shed light on the true associations between SLE and its susceptibility genes with respect to IL-7R gene.     

Effect of strontium ions on the growth of ROS17/2.8 cells on porous calcium polyphosphate scaffolds

Preparation, characterization and cellular biocompatibility study of a series of calcium polyphosphate containing 0-100 mol% of Ca2+ replaced by Sr2+ were reported. The osteoblastic ROS17/2.8 cell line was used and seeded on the strontium-doped calcium polyphosphate (SCPP) scaffolds to estimate its optimal dose and to study its potential to support the growth of osteoblastic cells for bone tissue engineering. The effects of SCPP on cells' proliferation and differentiation were evaluated by MTT and ALP activity assay. The results showed that porous SCPP did not exert cytotoxic effect on the cells. In addition, the proliferation and differentiation of the growth of ROS17/2.8 cells on the SCPP containing a low dose of strontium showed a higher level compared to the control, and the SCPP containing 1% strontium was optimal according to the results of MTT and ALP activity assay. The cells on the porous SCPP formed a continuous layer on the outer and inner surface observed by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The bunchy collagens were excreted from the cells and the calcium granules wrapped by collagens were sedimentated on the surface of cells. The results suggested that the biodegradable SCPP could stimulate the proliferation and differentiation of ROS17/2.8 cells in vitro after addition of proper dose of strontium. The porous SCPP may be a promising material for the bone tissue engineering.     

Hepatitis C virus-specific cellular and humoral immune responses following immunization with a multi-epitope fusion protein

Hepatitis C virus (HCV) is an important causative agent of acute and chronic hepatitis worldwide. We prepared a fusion protein in the vector of pET-11d that included three conserved broadly neutralizing B-cell epitopes and a series of T-cell epitopes located in the HCV NS3 region. In vivo administration of this fusion construct resulted in specific CD8+ cytotoxic lymphocytes in both PBMCs and splenocytes that could recognize specific antigen sites that could be detected by FACS. An HCVcc system was established and applied to detect HCV-specific neutralizing antibodies. These results suggest that the multi-epitope fusion protein is immunogenic and can elicit both humoral and cellular immune responses. In particular, this fusion protein is able to elicit HCV-specific neutralizing antibodies, which are critical for viral clearance. This construct may be significant for vaccine development and could be a potential candidate to be included in the design of a prophylactic and therapeutic vaccine against HCV.     

Immune biology of macaque lymphocyte populations during mycobacterial infection

Immune responses of lymphocyte populations during early phases of mycobacterial infection and reinfection have not been well characterized in humans. A non-human primate model of Mycobacterium bovis bacille Calmette-Guerin (BCG) infection was employed to characterize optimally the immune responses of mycobacteria-specific T cells. Primary BCG infection induced biphasic immune responses, characterized by initial lymphocytopenia and subsequent expansion of CD4+, CD8+ and gammadelta T cell populations in the blood, lymph nodes and the pulmonary compartment. The potency of detectable T cell immune responses appears to be influenced by the timing and route of infection as well as challenge doses of BCG organisms. Systemic BCG infection introduced by intravenous challenge induced a dose-dependent expansion of circulating CD4+, CD8+ and gammadelta T cells whereas, in the pulmonary compartment, the systemic infection resulted in a predominant increase in numbers of gammadelta T cells. In contrast, pulmonary exposure to BCG through the bronchial route induced detectable expansions of CD4+, CD8+ and gammadelta T cell populations in only the lung but not in the blood. A rapid recall expansion of these T cell populations was seen in the macaques reinfected intravenously and bronchially with BCG. The expanded alphabeta and gammadelta T cell populations exhibited their antigen specificity for mycobacterial peptides and non-peptide phospholigands, respectively. Finally, the major expansion of T cells was associated with a resolution of active BCG infection and reinfection. The patterns and kinetics of CD4+, CD8+ and gammadelta T cell immune responses during BCG infection might contribute to characterizing immune protection against tuberculosis and testing new tuberculosis vaccines in primates.     

The Chinese Visible Human (CVH) datasets incorporate technical and imaging advances on earlier digital humans

We report the availability of a digitized Chinese male and a digitzed Chinese female typical of the population and with no obvious abnormalities. The embalming and milling procedures incorporate three technical improvements over earlier digitized cadavers. Vascular perfusion with coloured gelatin was performed to facilitate blood vessel identification. Embalmed cadavers were embedded in gelatin and cryosectioned whole so as to avoid section loss resulting from cutting the body into smaller pieces. Milling performed at ?25 °C prevented small structures (e.g. teeth, concha nasalis and articular cartilage) from falling off from the milling surface. The male image set (.tiff images each of 36 Mb) has a section resolution of 3072 × 2048 pixels (～170 µm, the accompanying magnetic resonance imaging and computer tomography data have a resolution of 512 × 512, i.e. ～440 µm). The Chinese Visible Human male and female datasets are available at http://www.chinesevisiblehuman.com . (The male is 90.65 Gb and female 131.04 Gb). MPEG videos of direct records of real‐time volume rendering are at: http://www.cse.cuhk.edu.hk/~crc     

肾炎患者血中C3d水平及CD16+单核巨噬细胞膜补体调节蛋白的表达

目的 :探讨肾炎患者补体激活时活化单核巨噬细胞 (CD16 Mo MΦ)膜辅因子蛋白 (MCP)、促衰变因子 (DAF)及同种限制因子 2 0 (HRF 2 0 )表达水平。方法 :采用流式细胞术测定 136例肾小球肾炎患者血中CD16 Mo MΦMCP、DAF和HRF 2 0表达水平 ,采用ELISA法测定血清C3d及荷C3d 免疫复合物的 (C3d IC)水平。结果 :MC病人血清C3d、C3d IC水平及血中CD16 Mo MΦMCP、DAF、HFR 2 0表达水平与正常组无显著差异 (P >0 0 5 ) ,GS、MN及PGN病人血清C3d水平、血中CD16 Mo MΦMCP、DAF、HRF 2 0表达水平及MN、PGN病人C3d IC水平均显著高于正常组 (P <0 0 1) ,且MCP、DAF、HRF 2 0表达水平与血清C3d水平呈显著正相关 (P <0 0 1)。结论 :肾小球肾炎补体激活时血中CD16 Mo MΦMCP、DAF、HRF 2 0表达水平显著上调 ,以保护CD16 Mo MΦ不被激活的补体损伤。从而 ,CD16 Mo MΦ浸润肾组织并产生促炎作用 ,参于肾小球肾炎的发病及发展。     

细胞内钙离子螯合剂抑制HSV-1诱导Hela细胞的凋亡作用

目的：探讨HSV-1在诱导Hela细胞凋亡中，细胞内游离钙浓度的变化及钙离子螯合剂对HSV-1诱导Hela细胞凋亡的抑制作用。方法：HSV-1感染Hela细胞后，用扫描电镜及透射电镜观察凋亡情况。用荧光探针标记细胞内游离Ca^2 ，在不同时间观察细胞内游离Ca^2 浓度的变化。结果：HSV-1感染Hela细胞后，出现了典型的凋亡形态学变化。细胞内游离Ca^2 浓度在HSV-1感染Hela细胞后12h达高峰；典型的凋亡形态学变化出现在HSV-1感染Hela细胞后24h。细胞内Ca^2 螯合剂能显著抑制HSV-1诱导的Hela细胞凋亡。结论：细胞内游离Ca^2 在HSV-1诱导的Hela细胞凋亡过程中，具有重要作用，此实验结果为临床治疗相关疾病提供了有用的线索。