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1.
Christian P?tschke Wolfram Kessler Stefan Maier Claus-Dieter Heidecke Barbara M. Br?ker 《PloS one》2013,8(11)
Patients with sepsis are often immune suppressed, and experimental mouse models of sepsis also display this feature. However, acute sepsis in mice is also characterized by a generalized B cell activation and plasma cell differentiation, resulting in a marked increase in serum antibody concentration. Its effects on humoral memory are not clearly defined. We measured the effects of experimental sepsis on long-term immunological memory for a defined antigen: we induced colon ascendens stent peritonitis (CASP) 8 weeks after 2 rounds of immunization with ovalbumin. Four weeks later, the antigen-specific bone marrow plasma cell count had doubled in immunized non-septic animals, but remained unchanged in immunized septic animals. Sepsis also caused a decrease in antigen-specific serum antibody concentration. We conclude that sepsis weakens humoral memory by impeding the antigen-specific plasma cell pool’s development, which is not complete 8 weeks after secondary immunization. 相似文献
2.
Schroeder CP Goeldner EM Schulze-Forster K Eickhoff CA Holtermann P Heidecke H 《Biological trace element research》2004,99(1-3):17-25
Selenite is frequently used in combination with cancer chemotherapeutic agents to reduce side effects. However, the cytoprotective
activity of selenite may also reduce the efficacy of chemotherapeutic drugs on tumor cells. This study was designed to examine
the effects of selenite combined with cytotoxic agents used in clinical protocols [e.g., doxorubicine, docetaxel, 5-fluorouracil
(5-FU), methotrexate (MTX), mafosphamide, mitomycin C, gemcitabine, etoposide, cisplatin, irinotecan, and oxaliplatin] on
the proliferation of various carcinoma cell types. The data demonstrated that selenite had no marked effects on the antiproliferative
activity of docetaxel, doxorubicine, 5-FU, MTX, and mafosphamide in MDA-MB-231 breast cancer cells. Likewise, no consistent
changes were observed in A549 lung cancer cell proliferation when selenite was combined with cisplatin, etoposide, gemcitabine,
or mitomycin C. On the other hand, selenite potentiated the cytotoxicity of 5-FU, oxaliplatin, and irinotecan in HCT116 colon
cancer cells by approx 1.1-fold, 2.7-fold, and 2.6-fold, respectively. In SW620 colon cancer cells, selenite induced a 1.5-fold
and 4.3-fold increase of the antiproliferative activity of 5-FU and oxaliplatin, respectively. Whereas irinotecan showed no
effects on SW620 cell growth, a combination with selenite resulted in 23% inhibition. Our results indicate that selenite did
not reduce the antiproliferative activity of chemotherapeutic agents in vitro. In addition, selenite was able to increase
the inhibitory activity of docetaxel in A549 lung cancer cells, and of 5-FU, oxaliplatin, and irinotecan in HCT116 and SW620
colon cancer cells implying selenite is potentially useful as an adjuvant chemotherapeutic agent. 相似文献
3.
Siems W Capuozzo E Crifò C Sommerburg O Langhans CD Schlipalius L Wiswedel I Kraemer K Salerno C 《Biochimica et biophysica acta》2003,1639(1):27-33
Carotenoid supplementation in the treatment of diseases associated with oxidative stress has been recently questioned because of the cell damage and the increased risk of lung cancer in male smokers. Because of the complex role of neutrophils in lung diseases, we investigated whether carotenoid derivatives could affect respiratory burst and apoptosis of human neutrophils purified from peripheral blood. Stimulation of superoxide production was induced by nanomolar and micromolar concentrations of carotenoid cleavage products with aliphatic chains of different length, but not by carotenoids lacking the carbonyl moiety. The stimulatory effect of carotenoid cleavage products was observed in cells activated by phorbol myristate acetate (PMA), while a slight inhibition of superoxide production was noticed with cells activated by the chemotactic tripeptide N-formyl-Met-Leu-Phe (f-MLP). At higher concentrations, carotenoid cleavage products inhibited superoxide production in the presence of both PMA and f-MLP. In the presence of 20 microM carotenoid cleavage products, inhibition of superoxide production was accompanied by DNA fragmentation and increased level of intracellular caspase-3 activity. 相似文献
4.
Inhibition of natural killer cells results in acceptance of cardiac allografts in CD28-/- mice 总被引:9,自引:0,他引:9
Maier S Tertilt C Chambron N Gerauer K Hüser N Heidecke CD Pfeffer K 《Nature medicine》2001,7(5):557-562
Successful transplantation of allogeneic organs is an important objective in modern medicine. However, sophisticated immune defense mechanisms, primarily evolved to combat infections, often work against medical transplantation. To investigate the roles of natural and adaptive immune responses in transplant rejection, we functionally inactivated key effector systems of the innate (NK cells) and the adaptive immune system (CD28-mediated costimulation of T cells) in mice. Neither of these interventions alone led to acceptance of allogeneic vascularized cardiac grafts. In contrast, inhibition of NK-receptor-bearing cells combined with CD28-costimulation blockade established long-term graft acceptance. These results indicate a concerted interplay between innate and adaptive immune surveillance for graft rejection. Thus we suggest that inactivation of NK-receptor-bearing cells could be a new strategy for successful survival of solid-organ transplants. 相似文献
5.
BIOVOLUME CALCULATION FOR PELAGIC AND BENTHIC MICROALGAE 总被引:17,自引:0,他引:17
Helmut Hillebrand Claus-Dieter Dürselen David Kirschtel Utsa Pollingher Tamar Zohary 《Journal of phycology》1999,35(2):403-424
Microalgal biovolume is commonly calculated to assess the relative abundance (as biomass or carbon) of co-occurring algae varying in shape and/or size. However, a standardized set of equations for biovolume calculations from microscopically measured linear dimensions that includes the entire range of microalgal shapes is not available yet. In comparison with automated methods, the use of microscopical measurements allows high taxonomic resolution, up to the species level, and has fewer sources of error. We present a set of geometric shapes and mathematical equations for calculating biovolumes of >850 pelagic and benthic marine and freshwater microalgal genera. The equations are designed to minimize the effort of microscopic measurement. The similarities and differences between our proposal for standardization and previously published proposals are discussed and recommendations for quality standards given. 相似文献
6.
M. Blösch K. Flügel M. Dornbusch Paul Isenmann H. Kumerloeve G. Jaeschke U. Schulz J. Gaisler D. Povolný Z. ebek F. Tenora J. Nicolai Peter Kunkel Dietrich Heidecke und George E. Watson 《Journal of Ornithology》1968,109(1):127-134
Ohne Zusammenfassung 相似文献
7.
This study examines the efficacy of published δ18O data from the calcite of Late Miocene surface dwelling planktonic foraminifer shells, for sea surface temperature estimates for the pre-Quaternary. The data are from 33 Late Miocene (Messinian) marine sites from a modern latitudinal gradient of 64°N to 48°S. They give estimates of SSTs in the tropics/subtropics (to 30°N and S) that are mostly cooler than present. Possible causes of this temperature discrepancy are ecological factors (e.g. calcification of shells at levels below the ocean mixed layer), taphonomic effects (e.g. diagenesis or dissolution), inaccurate estimation of Late Miocene seawater oxygen isotope composition, or a real Late Miocene cool climate. The scale of apparent cooling in the tropics suggests that the SST signal of the foraminifer calcite has been reset, at least in part, by early diagenetic calcite with higher δ18O, formed in the foraminifer shells in cool sea bottom pore waters, probably coupled with the effects of calcite formed below the mixed layer during the life of the foraminifera. This hypothesis is supported by the markedly cooler SST estimates from low latitudes—in some cases more than 9 °C cooler than present—where the gradients of temperature and the δ18O composition of seawater between sea surface and sea bottom are most marked, and where ocean surface stratification is high. At higher latitudes, particularly N and S of 30°, the temperature signal is still cooler, though maximum temperature estimates overlap with modern SSTs N and S of 40°. Comparison of SST estimates for the Late Miocene from alkenone unsaturation analysis from the eastern tropical Atlantic at Ocean Drilling Program (ODP) Site 958—which suggest a warmer sea surface by 2-4 °C, with estimates from oxygen isotopes at Deep Sea Drilling Project (DSDP) Site 366 and ODP Site 959, indicating cooler than present SSTs, also suggest a significant impact on the δ18O signal. Nevertheless, much of the original SST variation is clearly preserved in the primary calcite formed in the mixed layer, and records secular and temporal oceanographic changes at the sea surface, such as movement of the Antarctic Polar Front in the Southern Ocean. Cooler SSTs in the tropics and sub-tropics are also consistent with the Late Miocene latitude reduction in the coral reef belt and with interrupted reef growth on the Queensland Plateau of eastern Australia, though it is not possible to quantify absolute SSTs with the existing oxygen isotope data. Reconstruction of an accurate global SST dataset for Neogene time-slices from the existing published DSDP/ODP isotope data, for use in general circulation models, may require a detailed re-assessment of taphonomy at many sites. 相似文献
8.
The synthetic efficiency of endohexosaminidase-catalysed glycosylation reactions using N-glycan oxazolines as donors was investigated as two reaction parameters were varied. Both the addition of quantities of an organic co-solvent and modulation of reaction pH between 6.5 and 8.0 were found to have different effects on reactions catalysed by either Endo A (and two available mutants) or Endo M, indicating subtle differences between these two family GH85 enzymes. Fine tuning of reaction pH, or the addition of quantities of an organic co-solvent, resulted in beneficial increases in achievable synthetic efficiency by effecting a reduction in the rate of competitive hydrolytic processes. 相似文献
9.
Dorothea Haas Hongying Gan-Schreier Claus-Dieter Langhans Alexandros Anninos Gisela Haege Peter Burgard Andreas Schulze Georg F. Hoffmann Jürgen G. Okun 《Gene》2014
Biochemical detection of inborn errors of creatine metabolism or transport relies on the analysis of three main metabolites in biological fluids: guanidinoacetate (GAA), creatine (CT) and creatinine (CTN). Unspecific clinical presentation of the diseases might be the cause that only few patients have been diagnosed so far. We describe a LC–MS/MS method allowing fast and reliable diagnosis by simultaneous quantification of GAA, CT and CTN in urine, plasma and cerebrospinal fluid (CSF) and established reference values for each material. 相似文献
10.
Jeannine Günther Angela Kill Mike Oliver Becker Harald Heidecke Judith Rademacher Elise Siegert Mislav Radi? Gerd-Rüdiger Burmester Duska Dragun Gabriela Riemekasten 《Arthritis research & therapy》2014,16(2):R65