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1.
The understanding of how estrogen and progesterone (P(4)) drive uterine remodeling in rodents has largely been based on studies involving administration of exogenous hormones, using steroid receptor-deficient mice, or relying on vaginal smears. In all these cases, the actual serum levels of 17beta-estradiol (E(2)) and P(4) are not directly measured, and the relationship between physiological levels of female sex hormones and uterine remodeling in cycling mice has not been fully explored. Here, we measured the circulating levels of E(2) and P(4) in cycling mice and performed correlation analysis between hormone levels and epithelial and stromal uterine parameters, irrespective of the estrous stage. In parallel, these parameters were analyzed in relation to the more conventional method of vaginal smear classification of estrous stage. We found that circulating P(4) inversely correlated with uterine width, luminal epithelial proliferation, stromal apoptosis, and degradation of luminal epithelial basement membrane collagen type-IV. Circulating E(2) positively correlated with uterine width, stromal cell proliferation, and collagen type-I content, while it negatively correlated with glandular epithelial proliferation, loss of collagen type-IV surrounding glandular epithelium, and apoptosis in luminal, glandular, and stromal compartments. Our findings indicate that measuring P(4) or E(2) levels can predict many concurrent cellular and stromal events in the mouse uterus, suggesting that in naturally cycling mice cellular responses to hormone changes are not delayed, but occur very rapidly.  相似文献   
2.
The constitutive modeling of cyclic plasticity of soils has made great progress, especially in the area of sands liquefaction modeling. Nowadays, the problem of rutting of flexible pavements linked to permanent deformations occurring in the unbound layers is taken into account only by empirical formulas. This paper presents an elastoplastic model with both isotropic and kinematic hardening. The yield surface, plastic potential, and isotropic hardening are based on a model for sands, which takes into account the influence of the initial void ratio and of the mean stress on the mechanical behavior. A kinematic hardening has been added in order to take into account the mechanical behavior of the material for large cycle numbers. A complete model is then developed, simulations are presented, and comparisons with repeated load triaxial tests carried out on a subgrade soil (clayey sand), have been made. These comparisons underline the capabilities of the model to take into account the monotonic, cyclic, and ratchetting behavior of unbound materials for roads.  相似文献   
3.
The effect of MHC class I gene transfection on the metastatic properties of B16BL6 melanoma cells was investigated. BL6-8 melanoma cells transfected with H-2Kb or H-2Kd, but not H-2Dd or H-2Ld, genes showed a dramatic reduction in their ability to generate experimental metastases in immunosuppressed CB6F1 mice. This observation suggested that some changes in the metastatic phenotype may have been induced in the H-2K- transfected melanoma cells. Analyses of adhesive and invasive properties of BL6-8 melanoma cells transfected with H-2 class I genes have been performed. We found that the loss of metastatic properties in the H-2Kb or H-2Kd gene-transfected melanoma cells was associated with reduced adherence to endothelial cells, laminin and collagen IV, decreased ability to form homotypic cell aggregates and with a complete loss of VLA-4 integrin expression. In addition, BL6-8 melanoma cells transfected with H-2K genes demonstrated reduced ability to invade Matrigel that paralleled up-regulation of TIMP-1 expression. Incubation of untransfected BL6-8 clone or B16F1 cells with 5-azacytidine similarly resulted in up-regulation of TIMP-1, suggesting that the changes in methylation of TIMP-1 gene could be responsible for TIMP-1 expression in the H-2K-transfected BL6-8 melanoma cells. Transfection of BL6-8 cells with the H-2Dd/Ld genes did not affect their adhesive and invasive properties. Previously we reported that reduction in the metastatic properties of the H-2Kb transfected cells was associated with alterations in cell surface carbohydrates with appearance of alpha-galactosyl epitopes and reduction in cell surface sialylation. The present data indicate that, in addition to changes in cell surface carbohydrates, reduction in adhesive properties and up-regulation of TIMP-1 may be responsible for the observed loss of metastatic potential of BL6-8 cells transfected with the H-2K genes.  相似文献   
4.
We describe the case of a 34-year-old man with AIDS who developed severe anemia due to chronic pure red cell aplasia (PRCA) caused by parvovirus B19. Following initial treatment with an infusion of intravenous immunoglobulin (IVIg), 1 g/kg, PRCA resolved, but there was a recurrence of severe anemia in 3 months. Retreatment with 2 g/kg IVIg over 2 days resulted in normalization of hemoglobin and a significantly longer remission duration. Two doses of 0.4 g/kg IVIg q 4 wk failed to prevent a relapse of PRCA in our patient. The dose and schedule of IVIg in the treatment of PRCA caused by parvovirus B19 in AIDS requires further definition.  相似文献   
5.
The object of this study is to characterize of Algerian Alfa (Esparto grass or Stipa tenacissima L), and also to examine the effect of chemical treatment on different properties of this fiber. The surface of the Alfa vegetable fibers was modified by alkali treatment in 5% (NaOH) aqueous solution for 2, 4, 6, 8, 16, 24, 48, and 72 h. The chemical, physical, and morphological properties of the Alfa fibers were investigated. The results show that the Alfa fibers are composed of 39% cellulose, 33% hemicelluloses, 20% lignin, and certain minerals (e.g., SiO2, K2O, and CaO). The alkali treatment of the fibers contributes to a decrease in the rate of moisture absorption and to an increase the crystallinity and stiffness. The processing time for adequate alkali treatment is observed at 6 h.  相似文献   
6.
7.
The aim of this study is to approach the possibilities of stimulated infrared thermography in dimensional characterization of defects situated in mural paintings. For this purpose, it is suggested to proceed in two stages. First, an in situ longitudinal thermal-diffusivity measurement is developed. Then the characterization of the depth of the studied defect by means of an extended photothermal analysis and a comparison between theory and experiment is carried out. In this article is shown that this approach allows a good estimate of the depth of a plastazote inclusion in a partial copy of the “Saint Christophe” of the Campana collection in the Louvre Museum.  相似文献   
8.
The concept of tumor suppression by tissue inhibitor of metalloproteinases (TIMPs) has evolved primarily from studies of genetically modulated tumor cells. The next step is to focus on the host and assess the protective potential of host TIMP-1 on primary tumor growth and metastasis. We generated two transgenic mouse lines with altered Timp-1 expression in skin and liver: one overexpressed Timp-1 (Timp-1(high)), and the other had antisense RNA-mediated Timp-1 reduction (Timp-1(low)). ESbL-lacZ T-lymphoma cells provided the tumor challenge, as they form primary tumors upon intradermal injection with spontaneous metastasis to liver. Metastases were examined in X-Gal-stained whole-organ mounts. Timp-1 overexpression inhibited intradermal tumor growth and spontaneous metastasis, leading to prolonged survival of the mice. The opposite effects occurred in Timp-1(low) mice, leading to shorter host survival. Experimental metastasis assays showed that Timp-1-compromised livers in Timp-1(low) mice showed at least a doubling of metastatic foci and numerous additional micrometastases, indicative of increased host susceptibility. However, Timp-1(high) mouse livers showed an unaltered metastatic load in the experimental metastasis assay. In conclusion, these data demonstrate that Timp-1 levels within a tissue predetermine the development and progression of T-cell lymphoma.  相似文献   
9.
10.
Convective drying (CO) is the most common technique for drying herbs, although it may diminish phenolic compounds content. Microwave drying (MW) has been suggested as an alternative, although its effects on phenolic compounds remain to be explored. The aim of this study is to compare the effects of different convective temperatures (40, 80 and 120 °C) and microwave powers (100, 500 and 1000 W) on drying time, polyphenols classes (HPLC-DAD) and antioxidant capacity in celery, coriander and parsley leaves. Microwave procedure reduced drying time (MW: 3 h–7 min; CO: 25–1.5 h) resulting more effective than CO. Increasing temperatures led to an initial decrease in total phenolic content (TPC) and antioxidant activity followed by an increase, potentially by the release of bound phenolic acids. Regarding MW, the highest polyphenol content was generally observed at 500 W, probably due to the hydroxycinnamic acid's rise. Antioxidant capacity was similar at 500 and 1000 W. There was a good agreement between TPC and antioxidant capacity. Consequently, MW seems a good alternative to reduce drying time. However, the maintenance or improvement of phenolic activity depends on the food matrix. Indeed, the best drying system and conditions to preserve phenolic compounds were variable depending on the herb type: celery (CO at 40 °C), coriander (both CO at 40 °C and MW at 500 W) and parsley (MW at 100 W).  相似文献   
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