23 resultados para Marginal gap
Resumo:
Three distinct categories of marginal zone lymphomas (MZLs) are currently recognized, principally based on their site of occurrence. They are thought to represent unique entities, but the relationship of one subtype with another is poorly understood. We investigated 17 non-splenic MZLs (seven nodal, 10 extranodal) by gene expression profiling to distinguish between subtypes and determine their cell of origin. Our findings suggest biological inter-relatedness of these entities despite occurrence at different locations and associations with possibly different aetiologies. Furthermore, the expression profiles of non-splenic MZL were similar to memory B cells.
Resumo:
HeLa cells expressing wild-type connexin43, connexin40 or connexin45 and connexins fused with a V5/6-His tag to the carboxyl terminus (CT) domain (Cx43-tag, Cx40-tag, Cx45-tag) were used to study connexin expression and the electrical properties of gap junction channels. Immunoblots and immunolabeling indicated that tagged connexins are synthesized and targeted to gap junctions in a similar manner to their wild-type counterparts. Voltage-clamp experiments on cell pairs revealed that tagged connexins form functional channels. Comparison of multichannel and single-channel conductances indicates that tagging reduces the number of operational channels, implying interference with hemichannel trafficking, docking and/or channel opening. Tagging provoked connexin-specific effects on multichannel and single-channel properties. The Cx43-tag was most affected and the Cx45-tag, least. The modifications included (1) V j-sensitive gating of I j (V j, gap junction voltage; I j, gap junction current), (2) contribution and (3) kinetics of I j deactivation and (4) single-channel conductance. The first three reflect alterations of fast V j gating. Hence, they may be caused by structural and/or electrical changes on the CT that interact with domains of the amino terminus and cytoplasmic loop. The fourth reflects alterations of the ion-conducting pathway. Conceivably, mutations at sites remote from the channel pore, e.g., 6-His-tagged CT, affect protein conformation and thus modify channel properties indirectly. Hence, V5/6-His tagging of connexins is a useful tool for expression studies in vivo. However, it should not be ignored that it introduces connexin-dependent changes in both expression level and electrophysiological properties.
Resumo:
Air samples were collected from Jan 16 to Mar 14, 2008 onboard the Oceanic II- The Scholar Ship which navigated an east–west transect from Shanghai to Cape Verde, and polybrominated diphenyl ethers (PBDEs) were analyzed in these samples. PBDE concentrations in the atmosphere over the open seas were influenced by proximity to source areas and land, and air mass origins. The concentrations of Σ21PBDEs over the East and South China Seas, the Bay of Bengal and the Andaman Sea, the Indian Ocean, and the Atlantic Ocean were 10.8 ± 6.13, 3.22 ± 1.57, 5.12 ± 3.56, and 2.87 ± 1.81 pg m−3, respectively. BDE-47 and -99 were the dominant congeners in all the samples, suggesting that the widely used commercial penta-BDE products were the original sources. Over some parts of Atlantic and Indian Ocean, daytime concentrations of BDE-47 and BDE-99 were higher than the concentrations at night. The strong atmospheric variability does not always coincide with a diurnal cycle, but the variability in air concentrations in such remote areas of the ocean remains strong. No significant trends were found for each of PBDE congener with latitude.
Resumo:
No abstract available.