470 research outputs found
Effects of the Behaviors of Benthic Fish Pseudogobio Esocinus on Substratum Environment on Sand River
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
A comparison of the signal pathways between the TNF alpha- and oridonin-induced murine L929 fibrosarcoma cell death.
Oridonin, an active component isolated from Rabdosia rubescences, has been reported to have antitumor effects. In this study, we compared the signal transduction pathways between TNFalpha-and oridonin-induced L929 cell death. Oridonin and TNFalpha initiated apoptotic morphologic changes, but DNA fragmentation was found in TNFalpha-treated L929 cells but not in oridonin-treated ones. The pan-caspase inhibitor (z-VAD-fmk), caspase-8 inhibitor (z-IETD-fmk) and caspase-3 inhibitor (z-DEVD-fmk) augmented oridonin-and TNFalpha-induced cell death. However, the caspase-9 inhibitor (z-LEHD-fmk) only increased oridonin-induced L929 cell death. Moreover, poly (ADPribose) polymerase (PARP) was cleaved in oridonin-treated L929 cells but not in the TNFalpha-treated groups, and the caspase-3 inhibitor (z-DEVD-fmk) failed to inhibit PARP cleavage. These results showed that only oridonin-induced L929 cell death required PARP degradation in a caspase-3 independent manner. In addition, oridonin increased the ratio of Bax/Bcl-2 protein expression, but TNFalpha did not. TNFalpha induced p38 and ERK activation, whereas oridonin triggered only ERK activation. We also investigated the effect of oridonin on intracellular TNFalpha expression, and found that oridonin augmented endogenous pro-TNFalpha expression and its upstream protein IkB phosphorylation. These results indicated that although oridonin promoted endogenous pro-TNFalpha expression, a great difference existed between the signal pathways through which TNFalpha-and oridonin-induced cell death.</p
Primary strumal carcinoid tumor of the ovary: A pregnant patient exhibiting severe constipation and CEA elevation
► We present a rare case of a PYY-positive primary strumal carcinoid tumor of the ovary during pregnancy. ► MRI was useful for the preoperative diagnosis, and the prenatal course was uneventful after the operation. ► Colitis due to severe constipation caused by PYY, which is an inhibitor of intestinal mobility, might induce serum CEA elevation
The augmentation of TNFalpha-induced cell death in murine L929 fibrosarcoma by the pan-caspase inhibitor Z-VAD-fmk through pre-mitochondrial and MAPK-dependent pathways.
We investigated the mechanism of the pan-caspase inhibitor z-VAD-fmk's augmentation of TNFalpha-induced L929 cell death and found this mechanism differs from that of TNFalpha-induced L929 cell death. In the presence of 20 ng/ml TNFalpha, z-VAD-fmk initiated apoptosis and necrosis in the majority of L929 cells as measured by an agarose gel electrophoresis and lactate dehydrogenase(LDH)activity based assay. Mitochondrial permeability transition (MPT) inhibitor (cyclosporine A) effectively inhibited z-VAD-fmk-augmented cell death. In addition, z-VAD-fmk plus TNFalpha increased Bax expression without affecting Bcl-2 and cytochrome expression. Western-blot analysis showed that z-VAD-fmk plus TNFalpha caused persistent JNK activation and ERK inactivation. Poly(ADP-ribose) polymerase (PARP) inhibitor (DPQ) effectively reversed the cell death which was augmented by z-VAD-fmk, and z-VAD-fmk plus TNFalpha also caused PARP cleavage to an 85 KDa fragment. These results indicate that in the presence of TNFalpha, z-VAD-fmk further augments cell death which requires the mitochondrial permeability transition and the JNK activation. However, we did not detect the changes in cytochrome c expression and the participation of caspase-9 in this process, suggesting that there might exist an unknown signal pathway(s) from the mitochondria to the downstream protein PARP, which is cleaved in a caspase-independent manner.</p
Single-Conductor Transmission-Line Model for Bent Wire Structures
A bend in a single-conductor line is a primary cause of radiation associated with the antenna mode; conversely, the radiation is fed back, resulting in attenuation and distortion of the current waveform. Despite being a fundamental phenomenon, its dynamics have not been sufficiently characterized. Therefore, this study presents a single-conductor transmission-line model for bent wire structures comprising multiple straight elements by using the local variables of charge per-unit-length and current along a thin conductor. The proposed model is validated over a wide frequency range using the method of moments. The total charge and current distributions that an external field induces on a bent structure are classified into three components: the scattering source distribution, traveling wave corresponding to the Sommerfeld mode, and radiation reaction. These components suggest an overall field-line coupling process: initially, an external electromagnetic field induces a scattering current in the structure, which in turn drives traveling and radiation-reaction currents at the ends, resulting in propagation along the line accompanied by radiation losses. The presented model is advantageous for designing electromagnetic phenomena corresponding to antennas and metamaterials and for addressing electromagnetic interference problems using passive circuit elements. A case study that makes use of the precise and descriptive model is included to predict the field emissions associated with the antenna mode around a bend
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