Lithium suppresses excitotoxicity-induced striatal lesions in a rat model of Huntington's disease

Huntington's disease is a progressive, inherited neurodegenerative disorder characterized by the loss of subsets of neurons primarily in the striatum. In this study, we assessed the neuroprotective effect of lithium against striatal lesion formation in a rat model of Huntington's disease in which quinolinic acid was unilaterally infused into the striatum. For this purpose, we used a dopamine receptor autoradiography and glutamic acid decarboxylase mRNA in situ hybridization analysis, methods previously shown to be adequate for quantitative analysis of the excitotoxin-induced striatal lesion size.Here we demonstrated that subcutaneous injections of LiCl for 16 days prior to quinolinic acid infusion considerably reduced the size of quinolinic acid-induced striatal lesion. Furthermore, these lithium pre-treatments also decreased the number of striatal neurons labeled with the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. Immunohistochemistry and western blotting demonstrated that lithium-elicited neuroprotection was associated with an increase in Bcl-2 protein levels.Our results raise the possibility that lithium may be considered as a neuroprotective agent in treatment of neurodegenerative diseases such as Huntington's disease.     

A family-based association study of PLP1 and schizophrenia

Recently, proteolipid protein 1 (PLP1) has been identified as downregulated in schizophrenia by quantitative PCR and other technologies. In this work we attempted to investigate the role of PLP1 in the etiology of schizophrenia using a family based association study in 487 Chinese Han family trios. The TDT for allelic association demonstrated that, in male, a weak association was detected in SNP rs475827 with p=0.0294, suggesting that the genetic polymorphisms within PLP1 in male are likely to confer an increased susceptibility to schizophrenia in the Chinese population.     

Transforming growth factor-beta facilitates breast carcinoma metastasis by promoting tumor cell survival

We have shown recently that the hyaluronan receptor, CD44, and matrix metalloproteinase 9 (MMP-9) form a complex on the surface of TA/St mouse mammary carcinoma cells that activates latent transforming growth factor-beta (TGF-β) and is required for tumor invasion. Disruption of the CD44/MMP-9 complex by expression of soluble CD44 results in the loss of tumor invasiveness and abrogates tumor cell survival in host lung parenchyma following intravenous injection into syngeneic mice. To explore the molecular nature of the survival signals derived from the CD44/MMP-9 complex during the development of tumor metastasis, we investigated the possibility that activation of latent TGF-β by the CD44/MMP-9 complex is responsible for tumor cell survival in host lung parenchyma. TA3 cells overexpressing dominant negative soluble CD44 (TA3sCD44), which compromises native CD44 function and the ability of TA3 cells to develop metastases, were transfected with constitutively active or latent TGF-β2 and tested for their ability to form tumors in syngeneic mice. Our results demonstrate that expression of the constitutively active, but not the latent, form of TGF-β2 rescues TA3sCD44 cells from apoptosis during lung colonization. These observations provide evidence that activation of latent TGF-β constitutes an event downstream of CD44-dependent signals that is required for tumor cell survival and metastatic colony formation. The functional axis composed of CD44, MMP-9 and TGF-β may therefore play an important role in the metastatic proclivity of selected tumor types. Abbreviations: ECM – extracellular matrix; HA – hyaluronan; HSPG – heparan sulfate proteoglycan; MMP – matrix metalloproteinase; TGF-β– transforming growth factor β This revised version was published online in July 2006 with corrections to the Cover Date.     

Klinefelter 综合征的临床与细胞遗传学分析

分析和探讨Klinefelter综合征的，临床以及细胞遗传学特征，通过遗传咨询和染色体核型综合分析进行疾病的诊断。确诊Klinefelter综合征88例，年龄13天-48岁，其中〈1岁3例，占3．4％；1～12岁11例，占12．5％；13～18岁6例，占6．8％；〉18岁68例，占77．3％。睾丸小是Klinefelter综合征最典型的表现。青春发动期以前难以发现。核型为47，XXY（包括变异）77例，占87．5％；嵌合型8例，占9．1％；48，XXYY2例，占2．3％；49，XXXXY1例，占1．1％，细胞遗传学染色体核型分析为确诊的主要手段。     

单克隆抗体间接荧光法分型检测单纯疱疹病毒的实验研究

本文选择３株抗单纯疱疹病毒型共同性和型特异性单克隆抗体，建立了分型检测单纯疱疹病毒的单克隆抗体间接荧光法（ＭｃＡｂ－１ＦＡ）．特异性试验和重复性试验证实，ＭｃＡｂ－ＩＦＡ特异性强、重复性好．用此法检测了不同部位来源的５１份临床分离株，分型检测结果与ＥＬＩＳＡ法检测结果一致．提示ＭｃＡｂ－ＩＦＡ有可能成为实验室分型检测单纯疱疹病毒可靠的方法．     

Immune regulation in self tolerance: functional elimination of a self-reactive, counterregulatory CD8+ T lymphocyte circuit by neonatal transfer of encephalitogenic CD4+ T cells lines.

Transfer of encephalitogenic, CD4+ T lymphocyte lines into syngeneic adult Lewis rats not only leads to the development of experimental autoimmune encephalomyelitis (EAE), but, in addition, to the expansion of counterregulatory, CD8+ T lymphocyte clones which are able to lyse specifically the encephalitogenic T cells in vitro and to neutralize their encephalitogenic capacity in vivo. In striking contrast, in neonatal rats, which still lack myelin (autoantigens), injection of the same encephalitogenic lines neither mediates EAE, nor confers protection in later life against the myelin-specific T cells. In fact, this treatment results in the life-long functional elimination of counterregulatory, clonotypic CD8+ T lymphocytes, which cannot even be reinduced by repeated injections of the relevant CD4+ T line. These data seem to point to a self-protective T cell control mechanism which is developed within the immune system prior to, and thus independent of the appearance of the appropriate self antigen.     

CD4 monoclonal antibody pairs for immunosuppression and tolerance induction

A pair of rat anti-mouse CD4 monoclonal antibodies (mAb) have been selected which bind to different epitopes of the molecule. Both the mAb are rat IgG2b and show clear synergistic activity in complement lysis in vitro. When injected together in vivo, they exhibit an improved immunosuppressive effect, compared to each antibody alone, on allogeneic graft rejection, humoral responses and on tolerance induction. Limiting dilution analysis indicates that the in vivo depletion of interleukin 2-producing cells is improved using both mAb by 2-3-fold over that obtained with the individual antibodies. As little as 60 ng per mouse of the CD4 antibody pair was sufficient to allow the induction of tolerance to human gamma-globulin, even without elimination of the CD4+ cells. The results suggest that appropriate antibody pairs may be good candidates for effective immunosuppressive serotherapy in man.     

小鼠S180移植瘤血管生成作用及其调节机制的研究

目的：观察肉瘤180(S180)移植瘤发展过程中血管生成及血管生成调节因子的变化,并对其调节机制进行探讨。 方法： 利用Km小鼠的S180移植瘤模型，采用FⅧ因子免疫组化染色检测肿瘤血管生成，ELISA和EIA法检测荷瘤鼠肿瘤组织和血浆中血管内皮生长因子（VEGF）和内皮抑制素（endostatin）水平，采用多元回归分析肿瘤组织微血管计数、血管形态与瘤重变化的关系。 结果： 随着荷瘤时间延长，肿瘤组织内微血管计数，瘤内血管相对总量增加，血管的相对面积增大（P<0.05）；肿瘤组织匀浆中VEGF水平在荷瘤10 d、15 d均显著高于5 d组（P<0.05）；endostatin在肿瘤匀浆和血浆中均在荷瘤15 d达到最高（P<0.05）；V/E比值无显著变化；微血管计数、血管相对总面积与瘤重变化有相关性（P<0.01）。 结论： S180移植瘤病期发展中微血管数目增加，血管口径增大，且与瘤重变化呈正相关；肿瘤发展过程中肿瘤局部血管生成正调节因子逐渐增加，促进血管生成；肿瘤局部血管生成调节因子处于相对的平衡。     

Manumycin诱导细胞凋亡抑制乳腺癌细胞SK-BR-3活性

目的:研究manumycin对乳腺癌腹腔转移癌细胞株SK-BR-3的抑癌效应及其诱导凋亡。方法:用MTT法检测manumycin对SK-BR-3细胞的抑癌作用。免疫印迹方法检测p38 MAPK蛋白表达。用caspase-3活性检测试剂盒定量检测manumycin诱导细胞凋亡的水平及评估特异性的p38 MAPK抑制剂SB203580对凋亡的影响。结果:经6 μmol/L、18 μmol/L、54 μmol/L manumycin处理SK-BR-3细胞24 h时,其抑制率分别为(7.4±3.9)%、(21.0±4.4)%和(64.7±4.1)%,呈量效关系。其中后2者的细胞活性与对照组比有显著差异(P<0.01)。用药24 h的IC₅₀为42.5 μmol/L。同时此药物可明显增加caspase-3的活性,且这一效应可部分地被p38抑制剂SB203580阻断。免疫印迹结果显示manumycin促进p38的磷酸化。结论:manumycin可通过诱导SK-BR-3细胞凋亡而产生抑癌作用,p38 MAPK是manumycin诱导细胞凋亡的通路之一。     

Small intestinal organoid-derived SP cells contribute to repair of irradiation-induced skin injury

Side population (SP) cells, characterized by their ability to efflux the fluorescent dye Hoechst 33342, were isolated from the small intestine of mice. In the abdominal irradiation model, small intestinal organoid-derived SP (sioSP) cells from ROSA 26 mice were submucosally injected into the small intestinal of the irradiated C57BL/6 mice. In contrast to the control mice, mice receiving sioSP cell transplantation demonstrated far less skin injury. Most importantly, hairs in the irradiated body part of the transplanted mice almost remained black, whereas the counterpart in the control mice almost turned white. Histochemistry studies showed the donor cells gave rise to skin cells in the irradiated skin. Thus, our study demonstrated for the first time that stem cells from the small intestine can differentiate into skin cells under local cues and thus supports the theory of stem cell plasticity.