Morphogenesis and Regulation of Bergmann Glial Processes During Purkinje Cell Dendritic Spine Ensheathment and Synaptogenesis

星形胶质细胞在突触形成中发挥重要作用,但星形胶质细胞突起如何在发育过程中与突触结构相联系还不是很清楚。本文分析在小脑突触发生过程中Bergmann胶质细胞(BG)突起生长的类型。本文发现在这个过程中,BG突起向外生长与树突棘增多的包被作用相关。此外,双光子时间分辩显像显示BG突起是高度动态的,在棘包被过程中突起趋于稳定。虽然突触活力依赖于肌动蛋白的聚合作用,但细胞骨架调节器Rac1和RhoG的活动在胶质细胞突起的动力或密度上并未发挥作用,而是对于保持突起长度起关键性作用。本文扩展这个发现,探查突起形态和包被之间的关系,发现缩短的突起导致棘覆盖的减少。本文进一步发现在BG表达dn-Rac1和低水平突触包被的区域,显示突触数量的增加。这些分析提示BG突起如何生长并包围突触结构,阐明BG突起结构对突触包被适当发育的重要性,并提示包被在突触形成中的作用。     

Isolated Coccygeal Tuberculosis

Isolated tuberculosis of the coccyx is extremely rare. A 35-year-old man presented with a 3-month history of coccygeal and gluteal pain. Computed tomography and magnetic resonance imaging revealed osseous destruction and a large enhancing mass involving the coccyx with anterior and posterior extension. Pathologic examination of the surgical specimen revealed necrosis, chronic granulomatous inflammation, and multinucleated giant cells consistent with tuberculosis. This case highlights the importance of considering tuberculosis as a diagnosis even though unusual sites are involved.     

PHARMACOLOGICAL''RESCUE''OF THE CORPUS LUTEUM RESULTS IN INCREASED INHIBIN PRODUCTION

Inhibin production by the corpus luteum was investigated by undertaking pharmacological rescue of the corpus luteum with hCG in four healthy women. Blood samples were collected daily for two menstrual cycles. Starting 7 days after the LH surge in the second cycle, incremental doses of hCG (125-8000 IU) were administered daily for 7 days resulting in hCG levels comparable to those seen in normal pregnancy. Following hCG, the luteal phase was prolonged and there were significant increases in the plasma concentrations of inhibin (P less than 0.05), and oestradiol (P less than 0.05). The progesterone concentration was maintained at the mid-luteal phase peak and as a result was significantly higher than those on the equivalent days of the control cycle (P less than 0.05). It was concluded that rescue of the corpus luteum with physiological levels of hCG resulted in a significant output of inhibin, thus suggesting that the corpus luteum is a significant source of inhibin in early pregnancy.     

Two pathways of exocytosis of cytoplasmic granule contents and target cell killing by cytokine-induced CD3+ CD56+ killer cells

Cytokine-induced killer (CIK) cells are non-major histocompatibility complex-restricted cytotoxic cells generated by incubation of peripheral blood lymphocytes with anti-CD3 monoclonal antibody (MoAb), interleukin-2 (IL-2), IL-1, and interferon-gamma. Cells with the greatest effector function in CIK cultures coexpress CD3 and CD56 surface molecules. CIK cell cytotoxicity can be blocked by MoAbs directed against the cell surface protein leukocyte function associated antigen-1 but not by anti-CD3 MoAbs. CIK cells undergo release of cytoplasmic cytotoxic granule contents to the extracellular space upon stimulation with anti-CD3 MoAbs or susceptible target cells. Maximal granule release was observed from the CD3+ CD56+ subset of effector cells. The cytoplasmic granule contents are lytic to target cells. Treatment of the effector cells with a cell-permeable analog of cyclic adenosine monophosphate (cAMP) inhibited anti-CD3 MoAb and target cell- induced degranulation and cytotoxicity of CIK cells. The immunosuppressive drugs cyclosporin (CsA) and FK506 inhibited anti-CD3- mediated degranulation, but did not affect cytotoxicity of CIK cells against tumor target cells. In addition, degranulation induced by target cells was unaffected by CsA and FK506. Our results indicate that two mechanisms of cytoplasmic granule release are operative in the CD3+ CD56+ killer cells; however, cytotoxicity proceeds through a cAMP- sensitive, CsA- and FK506-insensitive pathway triggered by yet-to-be- identified target cell surface molecules.     

Erythropoietin production in a primary culture of human renal carcinoma cells maintained in nude mice

The present studies report erythropoietin (Ep) production in primary cultures of a human renal carcinoma from a patient with erythrocytosis that has been serially transplanted to BALB/c nude mice. The levels of erythropoietin in the culture media were estimated using the exhypoxic polycythemic mouse assay (EHPCMA), fetal mouse liver erythroid colony- forming technique (FMLC), and a radioimmunoassay (RIA). The spent culture media of the exponentially growing cells contained less than 10 mU/ml of Ep measured by RIA. However, after the cells became confluent, Ep levels (RIA) in the spent media showed a marked increase to approximately 300 mU/ml. Ep levels estimated using the FMLC and EHPCMA were approximately 2/3 and 1/10, respectively, of those measured by RIA. Rabbit antiserum to highly purified human urinary Ep (70,400 U/mg protein) was utilized for immunocytochemical (peroxidase-antiperoxidase method) localization of Ep in the cultured cells. Very few of the cells in exponential growth exhibited Ep-like immunoreactivity, whereas intense Ep-like immunoreactivity was observed in the cytoplasm of the cells maintained in culture for a prolonged period after reaching confluency. The most intense staining was observed in some of the cells forming domes. The domes developed after the cells reached confluency, and their numbers increased with increasing time in confluent culture, in parallel with the increase in Ep levels in the spent media. This primary cell culture system of a renal cell carcinoma maintained in nude mice, which produces immunologically and biologically active Ep, may provide a useful model for studies of the mechanism of Ep production.