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排序方式: 共有268条查询结果,搜索用时 140 毫秒
1.
Endogenous CD8+ T cell expansion during regression of monoclonal EBV-associated posttransplant lymphoproliferative disorder. 总被引:5,自引:0,他引:5
V P Khatri R A Baiocchi R Peng A R Oberkircher J M Dolce P M Ward G P Herzig M A Caligiuri 《Journal of immunology (Baltimore, Md. : 1950)》1999,163(1):500-506
There are experimental data which suggest that the primary immune effector cell responsible for maintaining immune surveillance against the outgrowth of EBV-transformed B cells in humans is the CTL, but in vivo proof of this is lacking. In this study we perform a series of cellular and molecular assays to characterize an autologous, endogenous immune response against a transplantation-associated, monoclonal, EBV+ posttransplant lymphoproliferative disorder (PTLD). Following allogeneic bone marrow transplantation, a patient developed a monoclonal PTLD of donor B cell origin. With a decrease in immune suppression, we document the emergence of endogenous, donor-derived CD3+CD8+ CTLs, followed by regression of the PTLD. The TCR Vbeta repertoire went from a polyclonal pattern prior to the development of PTLD to a restricted TCR Vbeta pattern during the outgrowth and regression of PTLD. Donor-derived CD3+CD8+ T lymphocytes displayed MHC class I-restricted cytolytic activity against the autologous EBV+ B cells ex vivo without additional in vitro sensitization. The striking temporal relationship between the endogenous expansion of a TCR Vbeta-restricted, CD3+CD8+ population of MHC class I-restricted CTL, and the regression of an autologous monoclonal PTLD, provides direct evidence in humans that endogenous CD3+CD8+ CTLs can be responsible for effective immune surveillance against malignant transformation of EBV+ B cells. 相似文献
2.
The analysis of planktonic rotifer populations: A plea for long-term investigations 总被引:20,自引:10,他引:10
Alois Herzig 《Hydrobiologia》1987,147(1):163-180
Short-term species succession, and long-term community development, of planktonic rotifer populations of the temperate zone and factors influencing species' abundance (ie., physical and chemical limitations, food and exploitative competition, mechanical interference competition, predation, parasitism) are described and discussed. The long-term development of plankton communities in three European lakes is described and the major events are discussed in relation to ecological interactions. Frequently, the shortcomings of our knowledge about population ecology and ecophysiology of rotifers prevent explanations of short-term and, especially, of long-term developments of these plankton organisms. The need for qualitative and quantitative observations in the field and in the laboratory over long periods becomes obvious. 相似文献
3.
Mechanisms of beta-adrenergic stimulation of cardiac Ca2+ channels revealed by discrete-time Markov analysis of slow gating. 总被引:2,自引:0,他引:2
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Individual cardiac Ca2+ channels cycle slowly between a mode of gating in which the channel is available to open, and one in which the channel remains silent. The regulation of this multisecond cycling process by isoproterenol was investigated by single-channel recording and the development of a discrete-time Markov model that describes the slow switching among modes in terms of (de) phosphorylation reactions. The results provide evidence that isoproterenol increases Ca2+ channel activity by a reciprocal regulatory mechanism: not only is the phosphorylation rate of the channel increased, but also the dephosphorylation rate decreased. The discrete-time Markov formalism should prove useful as a general tool for understanding the mode switching demonstrated by a number of ionic channels. 相似文献
4.
Mancini C Rivanera D Lilli D Di Cuonzo G Angeletti S Lorino G De Sanctis GM Barbacini IG Leonetti G Bianchi P Chircu LV Galli C 《Clinical and diagnostic virology》1995,4(4):293-299
Patients with hepatitis C virus (HCV) infection may have different patterns of antibody response to various structural and non-structural viral antigens. We have correlated the serological patterns to the clinical features of chronic infection and to viral replication in 68 HCV-Ab-positive patients with chronic liver disease at different stages (19 with cirrhosis-hepatocellular carcinoma, 38 with chronic active hepatitis and 11 with chronic persistent hepatitis). Serum samples from each patient were assayed for HCV-IgM by enzyme immunoassay and for HCV-RNA by the polymerase chain reaction using primer sets derived from the 5'-non-coding region. The prevalence of HCV-IgM was high (54 patients (79.4%)) and the study showed a good correlation between high values of anti-HCV-IgM and the presence of HCV-RNA in serum, since HCV-RNA was detected in 35 of the 54 IgM-positive patients (64.8%) and notably in 19 of the 20 subjects with high levels of specific IgM. Conversely, all the 35 sera containing HCV-RNA were also reactive for HCV-IgM, while none of the HCV-IgM-negative sera was HCV-RNA reactive. Positivity rates for both HCV-RNA and IgM anti-HCV were higher in the more advanced stages of disease; thus, the clinical pattern of HCV chronic hepatitis seems to be strictly related to the serological pattern and the presence of HCV-RNA. 相似文献
5.
Summary Elementary Na+ currents were recorded at 19°C in cell attached and inside-out patches from cultured neonatal rat cardiocytes in order to study the effect of cAMP and other 6-aminopurines.The treatment of the cardiocytes with db-cAMP (1×10–3 mol/liter) led to a decline of reconstructed macroscopic peakI
Na to 62±7.6% of the initial control value. This reduction in NP0 was mostly accompanied by a decrease in burst activity. Openstate kinetics were preserved even in DPI-modified, noninactivating Na+ channels. Since the stimulator of the adenylate cyclase, forskolin (1×10–6 mol/liter), evoked a similar pattern of response, the NP0 decrease can be considered as the functional correlate of Na+ channel phosphorylation brought about by cAMP-dependent protein kinase. As found in inside-out patches, cAMP (1×10–3 mol/liter) remained effective under cell-free conditions and reduced reconstructed macroscopic peakI
NA to about 50% of the initial control value when the absence of Mg-ATP at the cytoplasmic membrane surface prevents phosphorylation reactions. A very similar response developed in the cytoplasmic presence of other 6-aminopurines including ATP (1×103 mol/liter), adenosine (1×10–4 mol/liter), adenine (1×10–5 mol/liter) and hypoxanthine (1×10–5 mol/liter). This susceptibility to adenine suggests that cardiac Na+ channelsin situ could sense intracellular fluctuations of adenine nucleotides, most likely of ATP. 相似文献
6.
Matthias Hardtke-Wolenski Lilli Kraus Christel Schmetz Britta Trautewig Fatih Noyan Florian W. R. Vondran Hueseyin Bektas Juergen Klempnauer Elmar Jaeckel Thorsten Lieke 《PloS one》2013,8(10)
Background
T cells are known to participate in the response to tumor cells and react with cytotoxicity and cytokine release. At the same time tumors established versatile mechanisms for silencing the immune responses. The interplay is far from being completely understood. In this study we show contacts between tumor cells and lymphocytes revealing novel characteristics in the interaction of T cells and cancer cells in a way not previously described.Methods/ Findings
Experiments are based on the usage of a hydrophilic fluorescent dye that occurs free in the cytosol and thus transfer of fluorescent cytosol from one cell to the other can be observed using flow cytometry. Tumor cells from cell lines of different origin or primary hepatocellular carcinoma (HCC) cells were incubated with lymphocytes from human and mice. This exposure provoked a contact dependent uptake of tumor derived cytosol by lymphocytes – even in CD4+ T cells and murine B cells – which could not be detected after incubation of lymphocytes with healthy cells. The interaction was a direct one, not requiring the presence of accessory cells, but independent of cytotoxicity and TCR engagement.Electron microscopy disclosed 100-200nm large gaps in the cell membranes of connected cells which separated viable and revealed astonishing outcome. While the lymphocytes were induced to proliferate in a long term fashion, the tumor cells underwent a temporary break in cell division. The in vitro results were confirmed in vivo using a murine acute lymphoblastic leukemia (ALL) model. The arrest of tumor proliferation resulted in a significant prolonged survival of challenged mice.Conclusions
The reported cell-cell contacts reveal new characteristics i.e. the enabling of cytosol flow between the cells including biological active proteins that influence the cell cycle and biological behaviour of the recipient cells. This adds a completely new aspect in tumor induced immunology. 相似文献7.
Maria Rohm Anke Sommerfeld Daniela Strzoda Allan Jones Tjeerd P. Sijmonsma Gottfried Rudofsky Christian Wolfrum Carsten Sticht Norbert Gretz Maximilian Zeyda Lukas Leitner Peter P. Nawroth Thomas M. Stulnig Mauricio Berriel Diaz Alexandros Vegiopoulos Stephan Herzig 《Cell metabolism》2013,17(4):575-585
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8.
Organic Solar Cells: Following the Morphology Formation In Situ in Printed Active Layers for Organic Solar Cells (Adv. Energy Mater. 1/2016)
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9.
V. Álvarez-López A. Prieto-Fernández J. Janssen R. Herzig J. Vangronsveld P.S. Kidd 《International journal of phytoremediation》2016,18(4):406-415
In this study different bacterial inoculation methods were tested for tobacco plants growing in a mine-soil contaminated with Pb, Zn, and Cd. The inoculation methods evaluated were: seed inoculation, soil inoculation, dual soil inoculation event, and seed+soil inoculation. Each inoculum was added at two bacterial densities (106 CFUs mL?1 and 108 CFUs mL?1). The objectives were to evaluate whether or not the mode of inoculation or the number of applied microorganisms influences plant response. The most pronounced bacterial-induced effect was found for biomass production, and the soil inoculation treatment (using 106 CFUs mL?1) led to the highest increase in shoot dry weight yield (up to 45%). Bacterial-induced effects on shoot metal concentrations were less pronounced; although a positive effect was found on shoot Pb concentration when using 108 CFUs mL?1 in the soil inoculation (29% increase) and in the seed+soil inoculation (34% increase). Also shoot Zn concentration increased by 24% after seed inoculation with 106 CFUs mL?1. The best effects on the total metal yield were not correlated with an increasing number of inoculated bacteria. In fact the best results were found after a single soil inoculation using the lower cellular density of 106 CFUs mL?1. 相似文献