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排序方式: 共有189条查询结果,搜索用时 15 毫秒
1.
Preventing the establishment of ectoparasitic poultry red mite (Dermanyssus gallinae) populations is key in ensuring welfare and egg production of laying hens and absence of allergic reactions of workers in poultry facilities. Using the Hazard Analysis and Critical Control Point method, a panel of experts identified hazards and associated risks concerning the introduction and spread of this mite in poultry facilities. Together we provide an overview of possible corrective actions that can be taken to prevent population establishment. Additionally, a checklist of the most critical control points has been devised as management tool for poultry farmers. This list was evaluated by Dutch and British poultry farmers. They found the checklist feasible and useful.  相似文献   
2.
    
Nitric oxide (NO) plays a significant role in the development of diabetic nephropathy. We investigated the effects of an antioxidant, carnosine, on streptozotocin (STZ)-induced renal injury in diabetic rats. We used four groups of eight rats: group 1, control; group 2, carnosine treated; group 3, untreated diabetic; group 4, carnosine treated diabetic. Kidneys were removed and processed, and sections were stained with periodic acid-Schiff (PAS) and subjected to eNOS immunohistochemistry. Examination by light microscopy revealed degenerated glomeruli, thickened basement membrane and glycogen accumulation in the tubules of diabetic kidneys. Carnosine treatment prevented the renal morphological damage caused by diabetes. Moreover, administration of carnosine decreased somewhat the oxidative damage of diabetic nephropathy. Appropriate doses of carnosine might be a useful therapeutic option to reduce oxidative stress and associated renal injury in diabetes mellitus.  相似文献   
3.
A definitive role for chromogranin A (CGA)-derived fragments in the control of the gastrointestinal smooth muscle contractility has not been yet established. The purpose of the present study was to evaluate, in vitro, the effects of the recombinant vasostatin 1-78 (VS-1), CGA 7-57 and CGA 47-66 on the mouse gastric mechanical activity, recording the changes of intraluminal pressure. VS-1, CGA 7-57 and CGA 47-66 produced concentration-dependent relaxations. Mouse anti-vasostatin-1 monoclonal antibody 5A8, recognising the region 53-57, abolished the relaxation induced by VS-1, indicating the specificity of the effect. The relaxation was significantly reduced by tetrodotoxin (TTX), blocker of neuronal voltage-dependent Na(+) channels, l-NAME, inhibitor of nitric oxide (NO) synthase, or apamin, blocker of small conductance Ca(2+)-dependent K(+) channels. The joint application of TTX and l-NAME did not show any additive effects, whereas TTX plus apamin abolished the VS-1 response. The results suggest that the N-terminal CGA-derived peptides are able to relax mouse gastric muscle and, therefore, they point out an inhibitory role of vasostatin I in the gastrointestinal tract. The relaxation is mediated in part by neural mechanisms through NO production and in part by non-neural mechanisms involving the opening of small conductance Ca(2+)-dependent K(+) channels.  相似文献   
4.
ABSTRACT

We have recently shown that rest-activity circadian rhythm significantly differed in women with Binge Eating Disorder (BED) compared to the Ctrl group. In details, patients with BED exhibited significantly reduced levels of MESOR and Amplitude with respect to the Ctrl group. In addition, in this previous study, the results of the actigraphic sleep monitoring provided no evidence of differences in sleep parameters between the two groups. We expanded the original sample obtaining a total of 28 volunteered women, 14 BED women, and 14 Ctrl. We recorded in all 28 participants a 5-day actigraphic monitoring to detect the rhythmometric parameters, interdaily stability, intradaily variability, L5, M10, and sleep parameters. During the study, BED’s women group kept an individual multidisciplinary therapy lasting five weekly days, from Monday to Friday, consisting in cognitive-behavioral therapy and nutritional program, administered in outpatient care from 8:00 a.m. at 5:00 p.m. The combination of both our previous and current study supports the conclusion that the sleep quality of the BED group is significantly better compared to Ctrl. The non-parametric indexes showed how interdaily stability, significantly correlated to sleep efficiency, was higher in BED group compared to the Ctrl group, indicating a better synchronization of rest-activity circadian rhythm. In conclusion, the maintenance of a regular lifestyle, such as imposed by the multidisciplinary therapy, is important to avoid alterations in the sleep-wake cycle, particularly in patients with eating disorders.  相似文献   
5.
Nuclear factor I (NFI) or its isolated DNA-binding domain (NFI-BD) enhances initiation of adenovirus DNA replication up to 50-fold at low concentrations of the precursor terminal protein-DNA polymerase (pTP-pol) complex. Both in solution and when bound to DNA, NFI-BD can form a complex with pTP-pol. To investigate the mechanism of enhancement by NFI, we determined the stability of a functional preinitiation complex formed in vitro between pTP-pol and the origin. Challenge experiments with a distinguishable template containing an identical origin revealed that in the absence of NFI, this preinitiation complex was very sensitive to competition for pTP-pol. Addition of NFI-BD increased the half-life of the complex at least 10-fold and led to the formation of a template-committed preinitiation complex. In agreement with this, binding of pTP-pol to origin DNA in band-shift assays was enhanced by NFI. By DNase I footprinting we show that the specificity of binding as well as induction of structural changes in origin DNA by pTP-pol are increased by NFI. These results indicate that NFI, by binding and positioning pTP-pol, stabilizes the complex between pTP-pol and the core origin, and thus enhances initiation of DNA replication.  相似文献   
6.
Due to the pivotal role that dendritic cells (DC) play in eliciting and maintaining functional anti-tumor T cell responses, these APC have been exploited against tumors. DC express several receptors for the Fc portion of IgG (Fcγ receptors) that mediate the internalization of antigen-IgG complexes and promote efficient MHC class I and II restricted antigen presentation. In this study, the efficacy of vaccination with DC pulsed with apoptotic B16 melanoma cells opsonized with an anti-CD44 IgG (B16-CD44) was explored. Immature bone marrow derived DC grown in vitro with IL-4 and GM-CSF were pulsed with B16-CD44. After 48 h of pulsing, maturation of DC was demonstrated by production of IL-12 and upregulation of CD80 and CD40 expression. To test the efficacy of vaccination with DC+B16-CD44, mice were vaccinated subcutaneously Lymphocytes from mice vaccinated with DC+B16-CD44 produced IFN-γ in response to B16 melanoma lysates as well as an MHC class I restricted B16 melanoma-associated peptide, indicating B16 specific CD8 T cell activation. Upon challenge with viable B16 cells, all mice vaccinated with DC alone developed tumor compared to 40% of mice vaccinated with DC+B16-CD44; 60% of the latter mice remained tumor free for at least 8 months. In addition, established lung tumors and distant metastases were significantly reduced in mice treated with DC+B16-CD44. Lastly, delayed growth of established subcutaneous tumors was induced by combination therapy with anti-CD44 antibodies followed by DC injection. This study demonstrates the efficacy of targeting tumor antigens to DC via Fcγ receptors.  相似文献   
7.
8.
BACKGROUND: Macrofollicular encapsulated papillary carcinoma (MEPC) is a variant of papillary carcinoma with a favorable clinical course. Its characteristic histologic pattern could be mistaken for that of an adenoma or hyperplastic nodule. Fine needle aspiration of this neoplasm may not show the particular nuclear features of papillary carcinoma, so the cytologic diagnosis may be benign. CASE REPORTS: Three paradigmatic cases of MEPC with different histologic patterns, diagnosed as a follicular neoplasm using fine needle aspiration biopsy (FNAB) are described. Preoperative cytology showed scattered clusters of thyrocytes with prominent nuclear pleomorphism and irregularities and focal oxyphilic changes mixed with colloid and aggregates of typical thyrocytes. The histologic picture exhibits small, neoplastic foci showing a microfollicular structure within an encapsulated neoplasm with a macrofollicular pattern. In microfollicular areas obvious nuclear pseudoinclusions were seldom observed. CONCLUSION: MEPC represents a challenging tumor subtype that infrequently shows the pathognomonic cytologic characteristics of papillary carcinoma, and therefore it is much more difficult to diagnose with a FNAB. Nuclear pleomorphism and irregularity of the nuclear membrane of thyrocytes are clues to this variant, although in some cases a clear-cut preoperative diagnosis cannot be made.  相似文献   
9.
The systemic administration of high-dose recombinant IL 2 mediated significant reductions of established 3-day pulmonary micrometastases from both weakly immunogenic and nonimmunogenic sarcomas. However, when treatment with IL 2 was delayed for 10 days after the injection of tumor cells in an attempt to treat grossly visible pulmonary macrometastases, only those established from weakly immunogenic sarcomas remained susceptible. Established 10-day pulmonary nodules from the nonimmunogenic sarcomas became refractory to IL 2 therapy. We utilized selective depletion of lymphocyte subsets in vivo by the systemic administration of specific monoclonal antibodies to cells bearing either the L3T4 or Lyt-2 marker or a heteroantiserum to cells bearing the ASGM-1 glycosphingolipid to identify lymphocytes involved in IL 2-induced tumor regression. Cells with potent lymphokine-activated killer (LAK) activity against fresh tumor targets in vitro were identified in the lungs of IL 2-treated mice. By flow cytometry analysis, the majority of these effector cells were Thy-1+, L3T4-, Lyt-2-, ASGM-1+. Depletion in vivo of ASGM-1+ cells before the onset of IL 2 administration eliminated the successful therapy of 3-day pulmonary metastases from nonimmunogenic sarcomas, with concurrent elimination of LAK cell activity in the lungs. In mice with 3-day pulmonary metastases from weakly immunogenic sarcomas, both Lyt-2+ cells and ASGM-1+ cells were involved in IL 2-mediated tumor regression, but Lyt-2+ cells appeared to be the more potent mediator in the response. Lyt-2+ cells were also involved in the elimination of grossly visible 10-day macrometastases from these weakly immunogenic tumors. Depletion of L3T4+ cells had no effect on tumor regression. Thus, although LAK effectors derived from ASGM-1+ precursors can eliminate pulmonary micrometastases regardless of tumor immunogenicity, Lyt-2+ cells are predominant effectors in the elimination of both pulmonary micro- and macrometastases from weakly immunogenic sarcomas.  相似文献   
10.
  总被引:5,自引:0,他引:5  
Leukocyte adhesion is mediated totally and transendothelial migration partially by heterotypic interactions between the 1- and 2-integrins on the leukocytes and their ligands, Ig-like cell adhesion molecules (Ig-CAM), VCAM-1, and ICAM-1, on the endothelium. Both integrins and Ig-CAMs are known to have signaling capacities. In this study we analyzed the role of VCAM-1-mediated signaling in the control of endothelial cell-cell adhesion and leukocyte transendothelial migration. Antibody-mediated cross-linking of VCAM-1 on IL-1-activated primary human umbilical vein endothelial cells (pHUVEC) induced actin stress fiber formation, contractility, and intercellular gaps. The effects induced by VCAM-1 cross-linking were inhibited by C3 toxin, indicating that the small GTPase p21Rho is involved. In addition, the effects of VCAM-1 were accompanied by activation of Rac, which we recently showed induce intercellular gaps in pHUVEC in a Rho-dependent fashion. With the use of a cell-permeable peptide inhibitor, it was shown that Rac signaling is required for VCAM-1-mediated loss of cell-cell adhesion. Furthermore, VCAM-1-mediated signaling toward cell-cell junctions was accompanied by, and dependent on, Rac-mediated production of reactive oxygen species and activation of p38 MAPK. In addition, it was found that inhibition of Rac-mediated signaling blocks transendothelial migration of monocytic U937 cells. Together, these data indicate that VCAM-1-induced, Rac-dependent signaling plays a key role in the modulation of vascular-endothelial cadherin-mediated endothelial cell-cell adhesion and leukocyte extravasation. human umbilical vein endothelial cells; vascular-endothelial cadherin; F-actin; reactive oxygen species; p38 mitogen-activated protein kinase; vascular cell adhesion molecule  相似文献   
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