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   172篇
  免费   12篇
基础医学   54篇
临床医学   6篇
内科学   69篇
皮肤病学   2篇
外科学   17篇
药学   1篇
肿瘤学   35篇
  2017年   1篇
  2015年   1篇
  2014年   1篇
  2013年   1篇
  2012年   9篇
  2011年   8篇
  2010年   5篇
  2009年   5篇
  2008年   3篇
  2007年   10篇
  2006年   14篇
  2005年   11篇
  2004年   15篇
  2003年   10篇
  2002年   7篇
  2001年   4篇
  2000年   11篇
  1999年   3篇
  1998年   7篇
  1997年   1篇
  1996年   3篇
  1995年   1篇
  1994年   1篇
  1993年   2篇
  1992年   7篇
  1991年   10篇
  1990年   5篇
  1989年   2篇
  1988年   3篇
  1987年   1篇
  1986年   2篇
  1985年   2篇
  1984年   2篇
  1983年   2篇
  1982年   1篇
  1980年   1篇
  1979年   3篇
  1965年   1篇
  1956年   1篇
  1942年   2篇
  1940年   1篇
  1934年   1篇
  1933年   1篇
  1932年   1篇
  1931年   1篇
排序方式: 共有184条查询结果,搜索用时 15 毫秒
11.
Single nucleotide polymorphisms (SNPs) of the NOD2/CARD15 gene resulting in a diminished nuclear factor-kappaB (NF-kappaB) response to bacterial cell wall products have been associated with an increased incidence of Crohn disease. To assess a possible contribution of NOD2/CARD15 mutations to graft-versus-host disease (GvHD) and complications following allogeneic stem cell transplantation, we retrospectively typed DNA from donor/recipient pairs in 169 consecutive patients receiving transplants from related or unrelated donors. Mutated alleles were observed in 21% of patients and in 14% of donors. Cumulative incidence of 1-year, transplant-related mortality rose from 20% in donor/recipient pairs without mutated SNPs to 49% in pairs with recipient mutations (P =.03) and 59% in pairs with donor mutations (P <.005), and was highest in 12 pairs with mutated alleles in both donor and recipients (83%; P <.001). Similar associations were observed for severe overall and severe gastrointestinal GvHD. The impact of NOD2/CARD15 mutations was more prominent for HLA-identical sibling transplantations but was also observed in unrelated donor transplantation. Mutations proved to be independent risk factors for transplant-related mortality. Our findings indicate a major role of monocyte/macrophage dysfunction in the pathophysiology of GvHD and strongly suggest a future risk assessment or even donor selection through NOD2/CARD15 typing.  相似文献   
12.
High-dose chemotherapy with autologous peripheral blood stem cell transplantation (PBSCT) includes the risk of infectious complications due to neutropenia and therapy-induced immune deviation. In order to understand early immune recovery in this situation, we analyzed the distribution of cell subsets by flow cytometry and we measured cytokine production in a whole blood assay stimulated with lipopolysaccharide (LPS) in order to induce monocyte (MO) activation in 43 patients with solid tumors or lymphoma treated with two cycles of high-dose chemotherapy and PBSCT. Blood was collected at the following time points: before start of mobilization chemotherapy, before and after high-dose chemotherapy, and 10 and 30 days after PBSCT. In the lymphocyte compartment, we found a depletion of B cells and naive T cells and a transitory reduction of natural killer (NK) cells, whereas MO and neutrophils recovered rapidly. However, during early recovery, HLA-DR expression on MO and the percentage of CD16+ MO was considerably reduced. Production of proinflammatory cytokines interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-alpha upon LPS stimulation was severely impaired directly after chemotherapy and unexpectedly remained low during early recovery of myeloid cells, whereas production of IL-1RA was enhanced, indicating a shift of immune competent cells to an anti-inflammatory or anergic state early after PBSCT.This work was supported by Deutsche Krebshilfe (German Cancer Aid)  相似文献   
13.
14.
A common side effect of therapeutic use of ionizing irradiation is endothelial cell damage resulting in a variety of clinical complications. Thus, preservation of endothelial function after irradiation could potentially limit toxicity. Using the murine endothelioma cell line bEnd2 we show here that induction of heme oxygenase-1 (HO-1) by cobalt protoporphyrine IX (CoPP) inhibits irradiation-induced apoptosis. In contrast, HO-1 induction by tin protoporphyrine IX (SnPP), a HO-1 inhibitor, does not affect survival after irradiation. The protective effects of CoPP could be partially reversed by blockade of HO-1 function with SnPP after induction by CoPP. Vice versa, blockade of HO-1 function by SnPP was reversible using CoPP. Treatment with CoPP inhibited cytochrome c release induced by irradiation. These results demonstrate that HO-1 induction and activation prior to irradiation inhibits endothelial apoptosis and might be used for possible cell protection in vivo.  相似文献   
15.
BACKGROUND: To determine whether patients with high-risk metastatic breast cancer draw benefit from combination chemotherapy as first-line treatment. PATIENTS AND METHODS: A total of 260 women with measurable metastatic breast cancer fulfilling high-risk criteria, previously untreated with chemotherapy for their metastatic disease, were randomized to receive either mitoxantrone 12 mg/m(2) or the combination of fluorouracil 500 mg/m(2), epirubicin 50 mg/m(2) and cyclophosphamide 500 mg/m(2) (FEC) every 3 weeks. Treatment was continued until complete remission plus two cycles, or until disease progression. In the case of partial remission or stable disease, treatment was stopped after 12 cycles. Second-line treatment was vindesine, mitomycin and prednisolone. Gain from treatment was estimated using a modified Brunner's score composed of time to progression, patients' rating of the treatment benefit, alopecia, vomiting and performance status. RESULTS: After recruitment from 1992 to 1997 and observation from 1997 to 1999, the final evaluation showed that single-agent treatment with mitoxantrone does not differ significantly from combination treatment with FEC in terms of response, objective remission rate, remission duration, time to response, time to best response, time to progression or overall survival. There was, however, a significant difference in gain from treatment using a modified Brunner's score favoring the single-agent treatment arm. There was no evidence that any subgroup would fare better with combination treatment. CONCLUSIONS: No significant difference was detected between the treatment with mitoxantrone as a single agent and the combination of low-dose FEC in terms of response or survival; therefore, the imperative of the necessity of first-line combination chemotherapy for patients with high-risk metastatic breast cancer may be questioned. Since toxicity and quality of life score favored the single-agent mitoxantrone treatment arm, this treatment may be offered to patients preferring quality of life to a potential small prolongation of survival.  相似文献   
16.
Functional competence as well as phenotype heterogeneity of macrophages depend on the completion of their maturation pathway. Differentiation of committed myeloid progenitor cells is induced by colony-stimulating factors (CSF), but no consistent data exist on which factor(s) induce the terminal maturation from the circulating blood monocyte to the mature macrophage. In vitro, monocyte to macrophage transformation occurs in the presence of serum and can be followed by the expression of the maturation-associated antigens gp65-MAX.1, gp68-MAX.3, and CD51. We describe that the differentiation-inducing activity in serum cannot be replaced by any of the known and available purified recombinant cytokines. In the absence of serum monocytes die in suspension cultures while surviving as non-differentiating cells when cultured adherent to plastic. In serum-free suspension cultures survival can be significantly improved by the addition of recombinant human macrophage (rhM)-CSF whereas other cytokines do not. At any stage of serum-free adherent culture, monocyte to macrophage differentiation can be induced rapidly by the addition of serum, whereas cytokines (rhM-CSF, recombinant human granulocyte macrophage [rhGM]-CSF, recombinant human granulocyte [rhG]-CSF, recombinant human interleukin [rhIL]-1, rhIL-3, rhIL-4, rhIL-6, tumor necrosis factor [TNF]-alpha, interferon [IFN]-alpha, IFN-gamma) alone or in combination are not effective. Serum-induced maturation, however, was suppressed in the presence of neutralizing anti-M-CSF antibodies. In addition to phenotype analysis, the secretory repertoire of rhM-CSF cultured monocytes was analyzed in comparison to serum cultured monocytes which further characterized them to be immature cells, i.e., low release of maturation-associated products such as alpha-2-macroglobulin, neopterin, fibronectin, and TNF-alpha, but high IL-6 secretion, an attribute of blood monocytes. We conclude that for monocyte survival in vitro the presence of endogenous M-CSF and possibly other autocrine factors elicited by cell adherence are required for the induction of macrophage maturation; however, yet undefined additional factor(s) are necessary. They are present in serum and may act in conjunction with M-CSF but are distinct from all known cytokines. Our in vitro system may be useful in the screening and discovery of these serum factor(s).  相似文献   
17.
The transmembrane form of tumor necrosis factor (mTNF), expressed on activated monocytes (MO) and macrophages (MPhi), is able to induce apoptosis in human endothelial cells (EC). Apoptosis is mediated by two distinct mechanisms: direct cell contact and a yet-unidentified soluble protein, death factor X. In addition, mTNF acts as a receptor that transduces a "reverse signal" into MO/MPhi when bound to the TNF receptor on EC. Reverse signaling by mTNF confers resistance to bacterial lipopolysaccharide (LPS). Stimulation of reverse signaling by mTNF blocks the ability of MO/MPhi to produce death factor X and proinflammatory cytokines. We have investigated which signaling pathways are used by mTNF acting as receptor. Reverse signaling triggers two independent pathways that can be distinguished by protein kinase C (PKC) inhibitors. The suppression of LPS-induced death factor X is dependent on PKC, whereas the suppression of LPS-mediated cytokine release is not. LPS and reverse signaling stimulate the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway. It is interesting that the activation of reverse signaling by mTNF renders MO/MPhi refractory to a subsequent activation of the MAPK/ERK pathway by LPS. Thus, reverse signaling achieves LPS resistance in monocytic cells through interference with key signal-transduction pathways.  相似文献   
18.
Clinical trials to evaluate the potential of adoptive immunotherapy in cancer patients have been restricted to the use of lymphoid effector cells. Of the other probably even more important host defense system against tumor growth, the mono-nuclear phagocyte system, only monocytes (mo) have been reinfused which, however, represent immature precursor cells and acquire full functional competence only upon further maturation. This is a report on 7 patients who received autologous macrophages (MO) grown in vitro from blood mo and activated by interferon-gamma (IFN gamma). Mononuclear cells were isolated from whole blood by cytapheresis and cultured for 7 days with 2% autologous serum on hydrophobic Teflon foils. Eighteen house before cell harvest, recombinant human IFN gamma was added at 200 IU/ml. Mo-derived MO were purified by counter-current elutriation. Starting with 10(8) MO cells, therapy was escalated up to the maximal number of MO obtainable from one single preparation cycle. Currently, 26 therapies have been performed with the maximal dose being 1.7 x 10(9) MO per infusion. Except for low grade fever (less than 38 degrees C), MO autografts were well tolerated, with no side effects observed. Biological response was followed by analyzing the serum levels of beta 2-microglobulin, neopterin, interleukin-6, tumor necrosis factor, and lysozyme. While in 3 out of 7 patients serum neopterin increased in response to MO therapy, other biological response parameters remained at pretreatment levels. Radiolabeled MO were shown to first accumulate in the lungs, then to pool into liver and spleen.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
19.
In recent years, reduced-intensity conditioning (RIC) regimens before allogeneic stem cell transplantation (SCT) are increasingly used in patients not eligible for conventional conditioning. We did a retrospective, multicenter analysis to assess the feasibility of conditioning with fludarabine and treosulfan before allogeneic SCT in multiple myeloma patients. Thirty-four patients with a median age of 51.5 years were included in the analysis. All patients underwent myeloablation after conditioning followed by stable engraftment, and 29 of 31 evaluable patients (94%) showed early complete hematopoietic chimerism. Non-hematological toxicities were limited and encompassed mainly fever in neutropenia and infections. Grade II-IV acute and chronic graft-versus-host disease was observed in 33 and 39%, respectively. With a median follow-up of 708 days (range 60-1729 days), the median progression-free survival was 180 days. The treatment-related mortality was 10% on day 100 and 25% after 1 year. The median overall survival has not yet been reached. Our data indicate that conditioning with fludarabine and treosulfan before allogeneic SCT is feasible in intensively pretreated multiple myeloma patients and leads to stable engraftment and complete hematopoietic chimerism. Randomized trials are warranted to determine if this approach might be incorporated in an algorithm of multiple myeloma treatment.  相似文献   
20.
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