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81.

Matrix metallopeptidase 2 (MMP-2) and matrix metallopeptidase 9 (MMP-9) are involved in the breakdown of extracellular matrix in normal physiological processes as well as in disease processes, such as cancer metastasis. We conducted this work to study the role of MMP-2 and MMP-9 in breast cancer by measuring their plasma concentrations before and after surgery. Also, to examine if their levels can reflect the stage of disease and prognosis. Forty-eight breast cancer patients and 13 patients with benign breast diseases were included in the study. MMP-2 and MMP-9 levels were measured by ELISA and semi-quantitative real-time PCR. MMP-2 and MMP-9 levels in plasma were determined by ELISA immediately before surgery and during 6 to 12 months after curative surgery. We observed a significant increase in the level of MMP-9 mRNA expression in breast cancer patients in comparison to their normal breast tissues and to tissues of benign breast disease. In all TNM tumor stages, the plasma levels of MMP-2 and MMP-9 were increased significantly before curative surgery in the studied patients with breast carcinoma and decreased significantly after surgery. Both MMP-2 and MMP-9 may be used as a possible marker for follow-up or as a marker that reflects the response of the disease to treatment.

  相似文献   
82.
Transmitted culture can be viewed as an inheritance system somewhat independent of genes that is subject to processes of descent with modification in its own right. Although many authors have conceptualized cultural change as a Darwinian process, there is no generally agreed formal framework for defining key concepts such as natural selection, fitness, relatedness and altruism for the cultural case. Here, we present and explore such a framework using the Price equation. Assuming an isolated, independently measurable culturally transmitted trait, we show that cultural natural selection maximizes cultural fitness, a distinct quantity from genetic fitness, and also that cultural relatedness and cultural altruism are not reducible to or necessarily related to their genetic counterparts. We show that antagonistic coevolution will occur between genes and culture whenever cultural fitness is not perfectly aligned with genetic fitness, as genetic selection will shape psychological mechanisms to avoid susceptibility to cultural traits that bear a genetic fitness cost. We discuss the difficulties with conceptualizing cultural change using the framework of evolutionary theory, the degree to which cultural evolution is autonomous from genetic evolution, and the extent to which cultural change should be seen as a Darwinian process. We argue that the nonselection components of evolutionary change are much more important for culture than for genes, and that this and other important differences from the genetic case mean that different approaches and emphases are needed for cultural than genetic processes.  相似文献   
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The human pancreatic cell line BxPC-3 displays two classes of binding sites with high and low affinity for VIP. The order of potency of VIP-related peptides in inhibiting either [125I]VIP or [125I]N-AcPACAP27 binding and in stimulating cAMP production was typical of the human VIP receptor. By combining affinity labeling with glycosidase treatments, we have characterized the VIP receptor as a Mr = 68,200 glycoprotein, consisting of a Mr = 39,300 polypeptide core with at least three N-linked oligosaccharide chains. In addition, our results revealed the presence of a low amount of sialic acid residues in the carbohydrate moiety of receptor.  相似文献   
85.
Portulaca oleracea leaves were found to contain 0.42% of a mucilage mixture. The mucilage was fractionated into an acidic and a neutral fraction. The acidic fraction consists of galacturonic acid residues joined by α-(1→4)-linkages; 60% of these residues are present as the calcium salt, and esterified galacturonic acid residues are absent. The neutral fraction is composed of 41% of arabinose and 43% of galactose residues, besides traces of rhamnose residues.  相似文献   
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Previous studies demonstrated a direct correlation with loss of kangai-1 (KAI1), a metastasis suppressor, and poor prognosis in human prostate and other cancers. In this study, we have characterized the age-dependent downregulation of KAI1 in the TRAMP model which was reversed when mice were fed a genistein-enriched diet. We demonstrated here that doses of genistein (5 and 10 microM)--achievable by supplement intake--significantly induced the expression of KAI1, both at the mRNA and protein levels (up to 2.5-fold), and decreased the invasiveness of TRAMP-C2 cells >2.0-fold. We have pinpointed KAI1 as the invasion suppressor, since its knockdown by siRNA restored the invasive potential of genistein-treated TRAMP-C2 cells to control levels. This work provides the first evidence that genistein treatment may counteract KAI1 downregulation, which is observed in many cancer types and therefore, could be used in anti-metastatic therapies.  相似文献   
88.
Vascular tissue differentiation is essential to enable plant growth and follows well-structured and complex developmental patterns. Based on recent data obtained from Arabidopsis and Populus, advances in the understanding of the molecular basis of vascular system development are reviewed. As identified by forward and/or reverse genetics, several gene families have been shown to be involved in the proliferation and identity of vascular tissues and in vascular bundle patterning. Although the functioning of primary meristems, for example the shoot apical meristem (SAM), is well documented in the literature, the genetic network that regulates (pro)cambium is still largely not deciphered. However, recent genome-wide expression analyses have identified candidate genes for secondary vascular tissue development. Of particular interest, several genes known to regulate the SAM have also been found to be expressed in the vascular cambium, highlighting possible overlapping regulatory mechanisms between these two meristems.  相似文献   
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The response to ATP of peritoneal macrophages from wild-type (WT) and P2X7-invalidated (KO) mice was tested. Low concentrations (1–100 μM) of ATP transiently increased the intracellular concentration of calcium ([Ca2+]i) in cells from both mice. The inhibition of the polyphosphoinositide-specific phospholipase C with U73122 inhibited this response especially in WT mice suggesting that the responses coupled to P2Y receptors were potentiated by the expression of P2X7 receptors. One millimolar ATP provoked a sustained increase in the [Ca2+]i only in WT mice. The response to 10 μM ATP was potentiated and prolonged by ivermectin in both mice. One millimolar ATP increased the influx of extracellular calcium, decreased the intracellular concentration of potassium ([K+]i) and stimulated the secretion of interleukin-1β (IL-1β) only in cells from WT mice. Ten micromolar ATP in combination with 3 μM ivermectin reproduced these responses both in WT and KO mice. The secretion of IL-1β was also increased by nigericin in WT mice and the secretory effect of a combination of ivermectin with ATP in KO mice was suppressed in a medium containing a high concentration of potassium. In WT mice, 150 μM BzATP stimulated the uptake of YOPRO-1. Incubation of macrophages from WT and KO mice with 10 μM ATP resulted in a small increase of YOPRO-1 uptake, which was potentiated by addition of 3 μM ivermectin. The uptake of this dye was unaffected by pannexin-1 blockers. In conclusion, prolonged stimulation of P2X4 receptors by a combination of low concentrations of ATP plus ivermectin produced a sustained activation of the non-selective cation channel coupled to this receptor. The ensuing variations of the [K+]i triggered the secretion of IL-1β. Pore formation was also triggered by activation of P2X4 receptors. Higher concentrations of ATP elicited similar responses after binding to P2X7 receptors. The expression of the P2X7 receptors was also coupled to a better response to P2Y receptors.  相似文献   
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