首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   165篇
  免费   19篇
耳鼻咽喉   3篇
儿科学   6篇
妇产科学   4篇
基础医学   21篇
口腔科学   1篇
临床医学   8篇
内科学   18篇
皮肤病学   5篇
神经病学   27篇
特种医学   6篇
外科学   37篇
预防医学   3篇
眼科学   1篇
药学   6篇
肿瘤学   38篇
  2022年   1篇
  2020年   1篇
  2019年   2篇
  2018年   1篇
  2017年   1篇
  2016年   1篇
  2015年   3篇
  2014年   5篇
  2013年   6篇
  2012年   10篇
  2011年   7篇
  2010年   1篇
  2009年   6篇
  2008年   3篇
  2007年   2篇
  2006年   6篇
  2005年   10篇
  2004年   6篇
  2003年   13篇
  2002年   4篇
  2001年   10篇
  2000年   6篇
  1999年   3篇
  1998年   4篇
  1997年   4篇
  1996年   7篇
  1995年   5篇
  1994年   4篇
  1993年   1篇
  1992年   5篇
  1991年   4篇
  1990年   4篇
  1989年   2篇
  1988年   5篇
  1987年   3篇
  1986年   2篇
  1985年   5篇
  1983年   1篇
  1981年   1篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1974年   3篇
  1973年   1篇
  1971年   3篇
  1970年   2篇
  1968年   2篇
  1967年   2篇
  1966年   1篇
排序方式: 共有184条查询结果,搜索用时 15 毫秒
1.
Fine needle aspiration biopsy was performed in two case of infiltrating skull lesions. The role played by this relatively simple procedure in avoiding a major operation is discussed.  相似文献   
2.
Newcastle disease virus (NDV) has received much attention recentlybecause of its non-specific immune stimulating potential andits various anti-tumor activities. Here we describe that NDVinduces synthesis of NO and causes an activation of nuclearfactor-kB (NF-kB) In murine macrophages. These reactions werepart of an activation process which included also stimulationof adenosine deaminase and inhibition of 5'-nucleotidase. NDV-mediatedNO synthesis and NF-kB activation were blocked by an antioxidant(butylated hydroxyanisole), by an inhibitor of protein tyrosinekinase (genistein) and of protein kinase A (H-89), but not byan inhibitor of protein kinase C (staurosporin). These datasuggest that signalling requirements of NF-kB activation andNO production in NDV-treated macrophages are similar.  相似文献   
3.
The metastatic process is characterized by a complex series of sequential steps involving constant interactions (mutual cross-talks) of metastasized tumor cells with their microenvironment (lymphocyte, macrophages, endothelial cells, etc.) in target organs. These interactions determine the outcome of metastasis (either the eradication of metastatic cells or their increased proliferation and invasion). Recently developed methods of tumor and host cell analysis at the molecular level allow better elucidation of molecular mechanisms of metastasis and of immune mechanisms involved in antitumor responses. Direct modulation of these processes will probably increase the success of clinical cancer treatment. Here we review data (a) on the expression of some costimulatory (MHC class II, CD80, sialoadhesin) and adhesion (LFA1, ICAM-1, VLA-4) molecules on both metastasized tumor cells and host cells and (b) on the production of a cytotoxic molecule, nitric oxide, by in situ activated Kupffer and endothelial cells in the process of liver metastasis. This study was performed with well-characterized murine ESbL T lymphoma cells transduced with the bacterial lacZ gene, which allows detection and quantification of metastases at the single cell level throughout lymphoma growth and metastasis. Experimental results are discussed in the context of recent literature.Abbreviations APC Antigen-presenting cells - hCRP Human C-reactive protein - ICAM Intercellular adhesion molecule - IFN Interferon - IL Interleukin - iNOS Inducible NO synthase - LFA Leukocyte function associated antigen - SER Sheep erythrocyte receptor - TA Tumor-associated rejection antigens - TNF Tumor necrosis factor - VCAM Vascular cell adhesion molecule - VLA Very late activated antigen  相似文献   
4.
A cellular cancer therapy is described with unique efficiency even in late-stage disease. in situ activated tumor-immune T cells, induced in allogeneic, tumor-resistant, MHC identical but superantigen different donor mice (B10.D2) could transfer strong graft-versus-leukemia (GvL) effects accompanied by only mild graft-versus-host (GvH) reactivity. Systemic immune cell transfer into 5 Gy irradiated DBA/2 mice bearing up to 4 week established syngeneic tumors and macrometastases led to massive infiltration of tumor tissues by CD4 and CD8 donor T lymphocytes. Upon interaction of immune CD4 donor T cells with host antigen presenting cells in synergy with immune CD8 donor T cells attacking the tumor cells directly, primary tumors (1.5 cm diameter) were encapsulated and rejected from the skin and liver metastases eradicated. For the first time, such adoptive cellular immunotherapy (ADI) was followed in individual live animals by P-31-NMR spectroscopy of primary tumors. An approximately 25,000 fold excess of metastatic tumor cells could be rejected as revealed quantitatively by FACScan analysis of lacZ gene transfected tumor cells.  相似文献   
5.
We studied nitric oxide (NO) production, adenosine deaminase (ADA) and 5'-nucleotidase (5-N) activity as a function of macrophage activation in the model of spontaneous metastasis of ESbL T lymphoma cells transduced with the lacZ gene. Liver and spleen macrophages were isolated and examined directly ex vivo without further experimental manipulation. Transient arrest of liver metastasis was accompanied by an increase of NO production and ADA activity and by a decrease of 5-N activity. An aggressive expansion of metastasis was correlated with a drop of NO production and ADA activity and with an increase of 5-N activity. To test the involvement of in situ activated Kupffer cells in an antimetastatic response, two immunotherapy protocols were used: i) active immunization with lymphoma cells and ii) adoptive transfer of antitumor immune spleen cells. Both treatments caused an upregulation of ADA activity and NO production in Kupffer cells, which correlated with host resistance against metastases.  相似文献   
6.
The purpose of the study was to investigate influence of glucosaminyl muramyl dipeptide (GMDP) and its derivatives on adenosine deaminase (ADA, CE 3.5.4.4.) and 5'-nucleotidase (5-N, CE 3.1.3.5) activity in murine macrophages in vitro. The intensity of superoxide radicals (O2-) formation by these cells has been also studied. GMDP incubated with macrophages was found to inhibit substantially the activity of 5-N, without affecting the activity of ADA in these cells. The maximal effect on 5-N activity was noted following 24 h of co-culture and was accompanied by a higher intensity of O2- formation. GMDP added in doses ranging from 0.01 to 1 microgram/ml induced a gradual decrease in 5-N activity, with an increase in activity of the O2- -generating system. The GMDP analog with double dipeptide link GM(DP)2 has demonstrated the same activating effect as GMDP. The presence of dipeptide alanyl-D-isoglutamine in the GMDP structure is necessary for realization of the drug activating effect, as N-acetylglucosaminyl-N-acetylmuramyl failed to influence macrophage activity. Neither D-D nor L-L isomers of the drug affect the 5-N activity and O2- formation in macrophages. The mechanism of macrophages activation induced by GMDP may include the inhibition of 5-N activity and the stimulation in production of superoxide radicals.  相似文献   
7.
Complete thrombosis followed by recanalization of giant aneurysms is an infrequent process that has been exceptionally mentioned in relation to nongiant saccular aneurysms. A 25-year-old male presented with a right temporal hematoma and associated subarachnoid hemorrhage. Cerebral angiography revealed a small blister-like dilatation at the right middle cerebral artery bifurcation. The cerebral hematoma was surgically removed and a large thrombosed aneurysm was discovered and was wrapped. Follow-up angiography revealed complete recanalization of the aneurysm with preservation of all the arterial branches and the aneurysm was then completely occluded with detachable coils. This case provides insight into the well-known but poorly understood dynamic process of thrombosis and recanalization of cerebral aneurysms. The possible role of a cerebral hematoma in the pathogenesis of this process is discussed.  相似文献   
8.
The endogenous viral superantigen 7 in DBA/2 mice serves as a target antigen on syngeneic ESb-MP lymphoma cells for allogeneic graft-vs-leukaemia reactive cells. Allogeneic viral superantigen 7 reactive Vbeta6+ T cells are able to transfer graft-vs-leukaemia reactivity and to kill specifically viral superantigen 7+ ESb-MP tumour cells in vitro. Here we elucidate the mechanism of this superantigen specific cell lysis. Already 10 min after co-incubation with in vitro stimulated Vbeta6+ T cells, viral superantigen 7+ ESb-MP tumour cells show an apoptotic phenotype (Annexin V-positivity, DNA-fragmentation). This extremely rapid type of cell death is not mediated by the death inducing ligands CD95L, TRAIL and TNF but by perforin and granzyme B. Surprisingly, neither mitochondria nor any of the known caspases appear to be involved in this type of tumour cell killing. In contrast, nitric oxide, released by activated macrophages and endothelial cells, induces in the same tumour cells another type of apoptosis which is much slower and involves mitochondria and caspase activation. A synergistic effect between the two different effector mechanisms of superantigen reactive donor cytotoxic T lymphocytes and nitric oxide releasing host macrophages and endothelial cells might explain the effective immune rejection of even advanced metastasised cancer in this graft-vs-leukaemia animal model.  相似文献   
9.
T cell memory,anergy and immunotherapy in breast cancer   总被引:7,自引:0,他引:7  
T cell immunity in breast cancer is suggested to play a role in tumor dormancy, a period of stability which can correspond to the time interval between primary treatment and tumor recurrence. Bone marrow in breast cancer patients seems to be particularly important because it is highly enriched with cancer specific memory T cells. Similar cells can be found in peripheral blood, but these appear to be functionally anergic. The immune system of primary operated breast cancer patients does not seem to be completely anergized. Bone marrow derived memory T cells can be reactivated ex vivo and show functional reactivity, including tumor rejection in NOD/SCID mice. Promising results were obtained from a postoperative phase-II active specific immunotherapy study. In this study, 32 patients treated with an optimal formulation of a virus-modified autologous tumor vaccine (ATV-NDV) appeared to have a significant 5-year survival benefit. Our results suggest that cancer reactive memory T cells which are enriched in the bone marrow of breast cancer patients, can be activated ex vivo via autologous dendritic cells pulsed with breast cancer tumor antigens, or they can be activated in situ via a tumor vaccine, which combines tumor antigens with virus infection. The findings should encourage further studies in breast cancer on active specific immunotherapy with tumor vaccines or adoptive immunotherapy with activated memory T cells.  相似文献   
10.
We have previously shown that nitric oxide (NO) induces apoptosis in different human neoplastic lymphoid cells through caspase activation. Here we studied the NO-mediated apoptosis in human breast cancer cell lines derived from primary tumor (BT-20) or from metastasis (MCF-7). NO donor glycerol trinitrate (GTN) induced apoptosis in both cell lines which was completely abrogated after pretreatment with the broad spectrum caspase inhibitor zVAD-fmk. NO triggered also a time-dependent activation of caspase-1, caspase-3, and caspase-6 in these cells. Moreover, NO caused a release of mitochondrial protein cytochrome c into the cytosol, an increase in the number of cells with low mitochondrial transmembrane potential and with high level of reactive oxygen species production. However, NO did not induce mRNA expression of CD95 (APO-1/Fas) ligand. FAS-associated phosphatase-1 (FAP-1) molecule was constitutively expressed at the mRNA level and did not show any changes upon NO treatment in both breast cancer cell lines. The expression of the pro-apoptotic protein Bax and of the anti-apoptotic protein Bcl-2 remained unchanged in MCF-7 and BT-20 cells upon GTN treatment. We suggest that the mechanism of NO-mediated activation of the caspase cascade and subsequent apoptosis in human breast cancer cells required mitochondrial damage (in particular, cytochrome c release, disruption of mitochondrial transmembrane potential and generation of reactive oxygen species) but not the activation of the CD95/CD95L pathway.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号