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   94篇
  免费   5篇
  99篇
  2021年   3篇
  2018年   1篇
  2016年   1篇
  2015年   2篇
  2014年   6篇
  2013年   6篇
  2012年   7篇
  2011年   11篇
  2010年   11篇
  2009年   4篇
  2008年   4篇
  2007年   5篇
  2006年   5篇
  2005年   1篇
  2004年   3篇
  2003年   5篇
  2002年   3篇
  2001年   3篇
  2000年   1篇
  1998年   4篇
  1996年   2篇
  1995年   2篇
  1994年   1篇
  1993年   2篇
  1991年   2篇
  1990年   1篇
  1987年   1篇
  1978年   1篇
  1976年   1篇
排序方式: 共有99条查询结果,搜索用时 15 毫秒
1.
A case of primary nonsecretory plasmacytoma of the spleen is reported. On laparotomy and splenectomy a 920 g spleen was removed, measuring 16×14×6 cm. The cut surface of the entire spleen showed that the tumour occupied most of the splenic tissue. A bone marrow aspirate and trephine, skeletal survey showed no signs of myeloma. Biopsy of the liver and regional lymph nodes was normal. Immunocytochemistry of the splenic tumour showed positivity for pan-B and plasma cell markers. After splenectomy the patient was treated with chemotherapy according to protocol VBCMP (M2).  相似文献   
2.

Introduction  

There is growing evidence that interleukin 17 (IL-17) producing T cells are involved in the pathogenesis of systemic lupus erythematosus (SLE). Previous studies showed that increased percentages of T-cell subsets expressing the costimulatory molecules CD80 and CD134 are associated with disease activity and renal involvement in SLE. The aim of this study was to investigate the distribution and phenotypical characteristics of IL-17 producing T-cells in SLE, in particular in patients with lupus nephritis, with emphasis on the expression of CD80 and CD134.  相似文献   
3.

Introduction  

Advanced glycation end products (AGEs) are produced and can accumulate during chronic inflammation, as might be present in patients with rheumatoid arthritis (RA). AGEs are involved in the development of cardiovascular disease. The aim of this study is to evaluate whether AGEs are increased in patients with long-standing RA and whether AGE accumulation is related to disease activity, disease severity and measures of (premature) atherosclerosis, such as endothelial activation, endothelial dysfunction and intima media thickness (IMT).  相似文献   
4.
    
Despite high remission rates after chemotherapy, only 30–40% of acute myeloid leukemia (AML) patients survive 5 years after diagnosis. This extremely poor prognosis of AML is mainly caused by treatment failure due to chemotherapy resistance. Chemotherapy resistance can be caused by various features including activation of alternative signaling pathways, evasion of cell death or activation of receptor tyrosine kinases such as the insulin growth factor-1 receptor (IGF-1R). Here we have studied the role of the insulin-like growth factor-binding protein-7 (IGFBP7), a tumor suppressor and part of the IGF-1R axis, in AML. We report that IGFBP7 sensitizes AML cells to chemotherapy-induced cell death. Moreover, overexpression of IGFBP7 as well as addition of recombinant human IGFBP7 is able to reduce the survival of AML cells by the induction of a G2 cell cycle arrest and apoptosis. This effect is mainly independent from IGF-1R activation, activated Akt and activated Erk. Importantly, AML patients with high IGFBP7 expression have a better outcome than patients with low IGFBP7 expression, indicating a positive role for IGFBP7 in treatment and outcome of AML. Together, this suggests that the combination of IGFBP7 and chemotherapy might potentially overcome conventional AML drug resistance and thus might improve AML patient survival.Only 30–40% of acute myeloid leukemia (AML) patients survive 5 years after diagnosis.1 This extremely poor prognosis is mainly caused by treatment failure due to chemotherapy resistance. This resistance is often a multifactorial phenomenon that can include enhanced expression or activation of receptor tyrosine kinases such as the insulin growth factor-1 receptor (IGF-1R).2, 3 The IGF-1R stimulates proliferation, protects cells from apoptosis and has been implicated in the development and maintenance of various cancers.4, 5 Several oncogenes require an intact IGF-1R pathway for their transforming activity6 and moreover, disruption or inhibition of IGF-1R activity has been shown to inhibit the growth and motility of a wide range of cancer cells in vitro and in mouse models.4, 5 IGF-1Rs are membrane receptors and binding of their ligand, the insulin-like growth factor-1 (IGF-1), results in receptor phosphorylation and activation of MAPK and PI3K/Akt signaling.4 Importantly, IGF-1, normally produced by the liver and bone marrow stromal cells, can stimulate the proliferation of cancer cells in vitro and genetic manipulations that reduce IGF-1 signaling can lead to decreased tumor growth.7, 8In hematological malignancies, a role for IGF-1 signaling has been demonstrated in multiple myeloma (MM) where it stimulates growth and potently mediates survival.9 Several anti-IGF-1R strategies have been shown to inhibit MM growth.10, 11 In AML, expression of the IGF-1R and IGF-1 was detected in AML cell lines and primary AML blasts and stimulation with IGF-1 can promote the growth of AML cells.12, 13, 14 In addition, neutralizing IGF-1R antibodies and the tyrosine kinase inhibitors (TKIs) NVP-AEW541 and NVP-ADW742, have been shown to inhibit proliferation and to induce apoptosis.15, 16In addition to its mitogenic and anti-apoptotic roles, directly influencing tumor development, IGF-1R appears to be a critical determinant of response to numerous anti-cancer therapies, including TKIs and chemotherapy.2, 3, 17, 18, 19, 20, 21, 22 In AML, activated IGF-1R signaling has been linked to cytarabine resistance, a drug included in every AML treatment schedule.17 Notably, in several cancer cell lines, a small subpopulation of drug-tolerant cancer cells exists that maintains their viability, after treatment with a lethal drug dose, via engagement of the IGF-1R.18The activity of the IGF-1R is tightly controlled at multiple levels, including their processing, endocytosis, trafficking and availability of its ligands.4 Ligand bioavailability is partly controlled by the family of secreted insulin-like growth factor-binding protein (IGFBP1 to IGFBP6), which can bind to IGFs therewith regulating the interaction of these ligands to their receptors. However, as IGFBPs are able to induce IGF-dependent and IGF-independent effects, the results of several studies on their role in cancer cell survival appeared to be controversial and complex.23, 24 In addition to IGFBPs, various IGFBP-related proteins have been identified.23, 25 One of these is the IGFB-related protein 1, also known as insulin-like growth factor-binding protein-7 (IGFBP7). IGFBP7 has 30% homology to IGFBP1 to IGFBP6 in its N-terminal domain and functions predominantly as a tumor suppressor.23, 24, 25, 26 In contrast to IGFBP1 to IGFBP6, which bind to the IGFs,23 IGFBP7 is a secreted protein that can directly bind to the IGF-1R and thereby inhibits its activity.27 The abundance of IGFBP7 is inversely correlated with tumor progression in hepatocellular carcinoma.28 Importantly, decreased expression of IGFBP7 has been associated with therapy resistance29, 30 and increasing IGFBP7 levels can inhibit melanoma and breast cancer growth.31, 32 IGFBP7 was originally identified as being involved in Raf-mediated apoptosis and senescence33 and also has been shown to induce senescence in mesenchymal stromal cells.34We established that IGFBP7 induces a cell cycle block and apoptosis in AML cells and cooperates with chemotherapy in the induction of leukemia cell death. AML patients with low IGFBP7 expression have a worse outcome than patients with high IGFBP7 expression, indicating that AML patients might benefit from a combination therapy consisting of chemotherapy and IGFBP7. Our results define IGFBP7 as a focus to enhance chemotherapy efficacy and improve AML patient survival.  相似文献   
5.
  总被引:4,自引:0,他引:4  
Cachexia is commonly seen in cancer and ischaracterized by severe muscle wasting, but little is known about theeffect of cancer cachexia on expression of contractile protein isoforms such as myosin. Other causes of muscle atrophy shift expression ofmyosin isoforms toward increased fast (type II) isoform expression. Weinjected mice with murine C-26 adenocarcinoma cells, a tumor cell linethat has been shown to cause muscle wasting. Mice were killed 21 daysafter tumor injection, and hindlimb muscles were removed. Myosin heavychain (MHC) and myosin light chain (MLC) content was determined inmuscle homogenates by SDS-PAGE. Body weight was significantly lower intumor-bearing (T) mice. There was a significant decrease in muscle massin all three muscles tested compared with control, with the largestdecrease occurring in the soleus. Although no type IIb MHC was detectedin the soleus samples from control mice, type IIb comprised 19% of thetotal MHC in T soleus. Type I MHC was significantly decreased in T vs. control soleus muscle. MHC isoform content was not significantly different from control in plantaris and gastrocnemius muscles. Thesedata are the first to show a change in myosin isoform expression accompanying muscle atrophy during cancer cachexia.

  相似文献   
6.
  总被引:4,自引:0,他引:4  
  相似文献   
7.
  总被引:3,自引:0,他引:3  
Although endurance training has been shown to profoundly affect the oxidative capacity of skeletal muscle, little information is available concerning the impact of endurance training on skeletal muscle isomyosin expression across a variety of muscle fiber types. Therefore, a 10-wk running program (1 h/day, 5 days/wk, 20% grade, 1 mile/h) was conducted to ascertain the effects of endurance training on isomyosin expression in the soleus, vastus intermedius (VI), plantaris (PLAN), red and white medial gastrocnemius (RMG and WMG), and red and white vastus lateralis muscles (RVL and WVL). Evidences of training were noted by the presence of a resting and a submaximal exercise bradycardia, as well as an enhancement in peak O2 consumption in the trained rodents relative to the nontrained controls. No evidence for skeletal muscle hypertrophy was observed subsequent to training when muscle weight was normalized to body weight. Shifts in the isomyosin profile of the trained VI, RMG, RVL, and PLAN were seen relative to the nontrained controls. Specifically, training affected the slow myosin (SM) composition of the VI by decreasing the relative content of the SM2 isoform by 14% while increasing that of the SM1 isoform (P less than 0.05). In addition, training elicited various degrees of a fast to slower myosin transformation in the RMG, RVL, and PLAN. All three muscles showed a significant reduction in the fast myosin 2 isoform (P less than 0.05), with significant increases in intermediate myosin in the RVL and PLAN along with elevations in SM2 in the RMG and PLAN (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
8.
    
The lipid-linked precursor ofN-type glycoprotein oligosaccharides was isolated from porcine thyroid microsomes after in cubation with UDP[3H] Glucose. The carbohydrate was released from dolichol pyrophosphate by mild acid hydrolysis, purified by gel filtration and characterized by 500-MHz1H-NMR spectroscopy in combination with enzymatic degradation. The parent oligosaccharide was found to be Glc3Man9Glc-NAc2. The three glucose residues are present in the linear sequence Glcα1-2Glα1-3 Glc, the latter being α(1-3)-linked to one of the mannose residues. In order to establish the branch location of the triglucosyl unit, the parent compound was digested with jack-bean α-mannosidase. The oligosaccharide product was purified by gel filtration, and identified by1H-NMR as Glc3Man5GlcNAc2 lacking the mannose residues A, D2, B and D3. Therefore, the structure of the precursor oligosaccharide is as follows: $$begin{gathered} c b a D_1 C 4 hfill Glcalpha 1 - 2Glcalpha 1 - 3Glcalpha 1 - 3Manalpha 1 - 2Manalpha 1 - 2Manalpha 1 hfill 3 swarrow 3 2 1 hfill Manalpha 1 - 2Manalpha 1 Manbeta 1 - 4GlcNAcbeta 1 - 4GlcNAc hfill D_{2 } A 3 6 hfill Manalpha 1 hfill 6 hfill Manalpha 1 - 2Manalpha 1 nwarrow 4 hfill D_3 B hfill end{gathered} $$   相似文献   
9.
10.
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