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991.
Bernhard F. X. Reber Benno Schindelholz 《Pflügers Archiv : European journal of physiology》1996,432(5):893-903
Bradykinin and caffeine were used as two different agonists to study inositol 1,4,5-trisphosphate (IP3)-sensitive and caffeine/ryanodine-sensitive intracellular Ca2+ release in the outgrowing neurites of nerve-growth-factor (NGF)-treated rat phaeochromocytoma cells (PC12). Changes in neuritic
intracellular free Ca2+ ([Ca2+]i) in single cells were measured after loading with a 1:1 mixture of the acetoxymethyl (AM) ester of the Ca2+-sensitive dyes Fura-red and Fluo-3, in combination with confocal microscopy. Bradykinin-induced Ca2+ release was blocked by U73211, a specific phospholipase C inhibitor. Caffeine-induced Ca2+ release was very low in neurites at rest. It increased after the cells were preloaded with Ca2+. The Ca2+ signal evoked at high concentrations of bradykinin (>500 nM) arose from a trigger zone in the proximal part of the neurite,
as a bi-directional wave towards the growth cone and cell body. The speed of neuritic Ca2+ waves was reduced in cells loaded with the Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-tetraacetic acid/AM. Preloading of Ca2+ stores led to increased bradykinin-induced Ca2+ release, as seen for caffeine, and faster Ca2+ wave speeds. Caffeine evoked a simultaneous [Ca2+]i rise along the neurites of Ca2+ preloaded cells. Higher Ca2+ signal amplitudes and faster Ca2+ wave speeds, but no longer-lasting IP3-induced [Ca2+]i signals, correlated with increased caffeine-induced Ca2+ release in the neurites. At low concentrations of bradykinin (<1.0 nM), the Ca2+ signals ceased to propagate as complete Ca2+ waves. Instead, repetitive stochastic Ca2+ release events (neuritic Ca2+ puffs) were observed. Neuritic Ca2+ puffs spread across only a few microns, at a slower speed than neuritic Ca2+ waves. These Ca2+ puffs represent elementary Ca2+ release units, whereby the released Ca2+ ions form these elementary events into the shape of a Ca2+ wave.
Received: 16 April 1996 / Received after revision and accepted: 13 May 1996 相似文献
992.
J. -M. Chong Y. Shiozawa Y. Hayashi N. Funata T. Takizawa M. Koike M. Fukayama 《Virchows Archiv : an international journal of pathology》1996,428(4-5):261-266
We report a case of pancreatic acinar cell carcinoma which contained a large number of pleomorphic inclusions with fibrillary internal structures and mature zymogen granules. To clarify the significance of fibrillary inclusions in the differentiation of acinar cells of the pancreas, we further investigated fetal pancreases (gestational weeks 16, 17, 19, 20 and 28). We found two types of inclusions: type A, corresponding to fibrillary inclusion of neoplastic acinar cells, was observed only in a 19-week fetus; type B showed a homogeneous density similar to that of zymogen granules. Type B was observed in all the fetuses after the 17th gestational week. Although the type A inclusion might be generated throught a different mechanism than the type B inclusion, the appearance of a large number of fibrillary inclusions in neoplastic acinar cells may represent a transient form of zymogen granule. 相似文献
993.
Intrinsic glomerular cells, especially mesangial cells, are considered to be actively involved in the pathogenesis of glomerulonephritis (GN), but the precise mechanism(s) remains elusive. We have previously demonstrated that nephritogenic IgA immune complex can stimulate human mesangial cells (HMCs) to increase their production of interleukin-1 (IL-1) and interleukin-6 (IL-6). In order to evaluate the roles of cytokines such as IL-1 and/or IL-6 and mesangial cells as mediators of renal injury in GN, we have now examined the changes of HMCs and their secreted products in vitro, after stimulation with various concentrations of IL-1 and IL-6. Cytokine-activated HMCs showed the following changes: (1) increased cell size, with intracytoplasmic vaculoes, dilated endoplasmic reticulum, increased free ribosomes and polysomes, and mitochondrial swelling; (2) increased cell proliferation, reflected in thymidine incorporation and an increased proportion of S and G2/M phase cells by cell cycle analysis; (3) enhancement of IL-6 mRNA expression in HMCs with stimulation of IL-6 alone or IL-1 plus IL-6; and (4) release of large amounts of platelet activating factor (PAF), thromboxane B2 (TxB2), and superoxide anion. Taken together, these results strongly suggest that mesangial cell proliferation and increased production of immune/chemical mediators and superoxide anion can be directly induced by IL-1 plus IL-6. These changes may lead to ongoing renal injury. 相似文献
994.
Michael Heming Xiaolin Li Saskia Räuber Anne K. Mausberg Anna-Lena Börsch Maike Hartlehnert Arpita Singhal I-Na Lu Michael Fleischer Fabian Szepanowski Oliver Witzke Thorsten Brenner Ulf Dittmer Nir Yosef Christoph Kleinschnitz Heinz Wiendl Mark Stettner Gerd Meyer zu Hörste 《Immunity》2021,54(1):164-175.e6
995.
探讨过继转输胚胎抗原耐受T细胞对小鼠自然流产模型妊娠预后及宿主孕鼠免疫细胞对父系抗原免疫耐受状态的影响。以CBA/J×BALB/c为正常妊娠模型 ,CBA/J×DBA/ 2为自然流产模型 ,将自然流产模型CBA/J孕鼠于孕 4d (着床期 )分别腹腔注射大鼠抗小鼠CD80和CD86mAb或大鼠同型IgG。于孕 9d ,应用免疫磁珠阴性分选三组孕鼠的脾脏T细胞 ,并将三组T细胞分别转输至孕 4d的CBA/J×DBA/ 2孕鼠。于宿主孕鼠孕第 9天 ,采用单向混合淋巴细胞反应分析宿主孕鼠脾脏免疫细胞对父系抗原的增殖能力 ,并用流式细胞术分析经父系抗原刺激的宿主孕鼠脾脏T细胞内IL 2表达水平。于孕 1 4d分别观察宿主孕鼠的胚胎吸收率。结果显示 ,过继转输胚胎抗原耐受T细胞和转输正常妊娠模型孕鼠的T细胞均可诱导宿主孕鼠脾脏免疫细胞对父系抗原的增殖能力及IL 2的表达显著下降 (P <0 0 5 ) ,孕 1 4d胚胎吸收率也显著下降 (P <0 0 5 )。这些结果表明 ,于孕早期过继转输胚胎抗原耐受T细胞和转输正常妊娠模型孕鼠的T细胞能诱导宿主孕鼠母 胎免疫耐受 ,防止母体对胚胎的免疫排斥 ,从而使自然流产模型的妊娠预后达到正常妊娠水平。 相似文献
996.
Mansy SS 《Ultrastructural pathology》2004,28(1):15-21
Easy manipulation and preservation of cells in suspension through the different steps of sample processing for electron microscopy examination is essential for proper diagnosis. The author used agarose gel as an embedding media for processing cells in suspension for electron microscopic examination. The AgarCyto cell block procedure of Kerstens et al. (J Histochem Cytochem. 2000; 48: 709—718) was used to begin electron microscopic processing of exfoliated urothelial cells in voided urine or cells in suspension. Processing of agarose cell block simultaneously for light and electron microscopic examination represents a great advantage offered by this innovated technique. 相似文献
997.
CD25 has become widely used as a marker for a subset of regulatory CD4(+) T cells present in the thymus and periphery of mice, rats and humans. However, CD25 is also expressed on conventionally activated T cells that are not regulatory and not all peripheral regulatory T cells express CD25. The identification of a stable and unique marker for regulatory T cells would therefore be valuable. This study provides a detailed account of the phenotype of CD4(+)CD25(+) regulatory T cells in rats. In the thymus, CD4(+)CD8(-)CD25(+) cells were found to have a more mature phenotype than the corresponding CD4(+)CD8(-)CD25(-) cells with respect to expression of Thy1 (CD90), CD53 and CD44, suggesting that CD25 expression, and perhaps commitment to regulatory function, might be a late event in thymocyte development. CD4(+)CD25(+) cells in both the thymus and periphery were found to have enriched and heterogeneous expression of activation markers such as OX40 (CD134) and OX48 (an antibody determined in this study to be specific for CD86). CD4(+)CD25(+) T cells were also found to have enriched expression of CD80, at both the mRNA and protein level. However, functional studies in vitro and in vivo showed that neither OX40 or CD86 were useful markers for the further subdivision of regulatory T cells. Our studies indicate that, at present, CD25 remains the most useful marker to enrich for regulatory CD4(+) T cells in rats and no further subdivision of the regulatory component of CD4(+)CD25(-)CD45RC(low) T cells has yet been achieved. 相似文献
998.
Interleukin-21 is a T-helper cytokine that regulates humoral immunity and cell-mediated anti-tumour responses 总被引:3,自引:0,他引:3 下载免费PDF全文
Cytokines and their receptors represent key targets for therapeutic intervention. Ligands are being used to supplement cell numbers that become depleted as a result of disease (organ failure, infection) or subsequent disease treatments (i.e. chemotherapy). Conversely, the inhibition of target cell binding by cytokines is an established strategy for abrogating pathologic cellular activities common to many immunological diseases. Considerable effort in biomedical research is being focused on the cytokine families that play a dominant role in regulating immunity and then prioritizing each member for its therapeutic potential. Currently, the interleukin-2 (IL-2) family of cytokines is widely recognized for its central involvement in controlling lymphocyte function and is the most explored for medical utility. Collectively, these proteins (or their antagonists) are either marketed drugs or have received advanced testing for an impressive array of indications including cancer, infectious disease, transplantation, inflammation and allergic asthma. Here we review the current understanding of IL-21, the most recent member of this cytokine family to be discovered. As will be discussed, IL-21 shares many of the same attributes as its relatives in that it has broad immunoregulatory activity and can modulate both humoral and cell-mediated responses. Its ability to stimulate durable anti-tumour responses in mice defines one therapeutic indication that merits clinical development. 相似文献
999.
In this present series, we studied in detail the cytologic features of five histopathologically verified cases of central giant-cell granuloma (CGCG). All the patients in this series were female, with an age range of 11-60 years. There were three cases with involvement of the lower jaw and two cases had upper jaw involvement. Cytology smears showed dispersed single cells in the background. Nuclei of the individual cells were round to ovoid with fine chromatin and inconspicuous nucleoli. The cytoplasm of these cells was moderate in amount with indistinct cell borders. Many randomly scattered multinucleated giant cells with 10-20 nuclei were present in the background. Combination of clinical features, radiologic pictures, and cytologic features may be helpful for diagnosis of CGCG on fine-needle aspiration cytology. 相似文献
1000.