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991.
992.
993.
Zhijie Li Chantal A Rivera Alan R Burns C Wayne Smith 《Journal of applied physiology》2004,97(2):641-647
C57BL/6 mice were subjected to hindlimb unloading (HU) for a period of 3 wk to determine the possible effects on epithelial wound healing. A standardized corneal epithelial wound was performed, and parameters of the inflammatory response and reepithelialization were analyzed over an observation period of 96 h. Wound closure was significantly retarded in mice during HU with reepithelialization being delayed by approximately 12 h. Both epithelial migration and cell division were significantly depressed and delayed. The inflammatory response to epithelial wounding was also significantly altered during HU. Neutrophils, as detected by the Gr-1 marker, were initially elevated above normal levels before wounding and during the first few hours afterward, but there was a significant reduction in neutrophil response to wounding at times where neutrophil influx and migration in controls were vigorous. A similar pattern was seen with CD11b+CD11c+ cells (monocyte lineage). Langerhans cells are normally resident within the peripheral corneal epithelium. They respond to injury by initially leaving the epithelial site within 6 h and returning to normal levels by 96 h, 2 days after reepithelialization is complete. During HU, this pattern is distinctly different, with Langerhans cell numbers slowly diminishing, reaching a nadir at 96 h, which is significantly below normal. Evidence for systemic effects of HU is provided by findings that collagen deposition within subcutaneous sponges was significantly reduced during HU. In conclusion, HU, a ground-based model simulating some physiological aspects of spaceflight, impairs wound repair of corneas. Multiple factors, both local and systemic, likely contribute to this delayed wound healing. 相似文献
994.
995.
The main purpose of this study was to evaluate the relationship between different methods proposed by the American College of Sports Medicine (ACSM) to prescribe exercise intensity using heart rate (HR) and oxygen uptake (VO2) in obese individuals. Sixty-eight overweight to severely obese adults were divided into three groups (tertile) based on their BMI. The groups were T1 group (BMI = 30.5 +/- 1.5, n = 23), T2 group (BMI = 34.3 +/- 1.0, n = 23), and T3 group (BMI = 40.2 +/- 3.7, n = 22). All subjects performed a graded exercise test using a ramp protocol on a treadmill. Individual linear regressions between %HR reserve (%HRR) and %VO2 reserve (%VO2R), %HRR and %VO2 peak (%VO2peak), %maximal HR (%HRmax) and %VO2R, and %HRmax and %VO2peak were calculated. When all the subjects were grouped together, the %HRR-%VO2R mean regression was partially related to the line of identity, while the %HRR-%VO2peak, %HRmax-%VO2R, and %HRmax-%VO2peak mean regressions were all significantly different than the line of identity (P < 0.001). The degree of obesity accounted for approximately 15% of the variation for both %HRR-%VO2R and %HRR-%VO2peak mean regressions. The %HRmax-%VO2R and %HRmax-%VO2peak mean regressions were not affected by the degree of obesity but resting HR accounted for 28-37% of the variation. The relationship between the exercise intensity determined by the %HRR-%VO2R and the %HRR-%VO2peak mean regression seems to be influenced by the degree of obesity. The degree of obesity does not affect the relationship between exercise intensity generated by the %HRmax-%VO2R or %HRmax-%VO2peak equations but the resting HR does. 相似文献
996.
997.
Pascale Peyron Julien Vaubourgeix Yannick Poquet Florence Levillain Catherine Botanch Fabienne Bardou Mamadou Daffé Jean-Fran?ois Emile Bruno Marchou Pere-Joan Cardona Chantal de Chastellier Frédéric Altare 《PLoS pathogens》2008,4(11)
Tuberculosis (TB) is characterized by a tight interplay between Mycobacterium tuberculosis and host cells within granulomas. These cellular aggregates restrict bacterial spreading, but do not kill all the bacilli, which can persist for years. In-depth investigation of M. tuberculosis interactions with granuloma-specific cell populations are needed to gain insight into mycobacterial persistence, and to better understand the physiopathology of the disease. We have analyzed the formation of foamy macrophages (FMs), a granuloma-specific cell population characterized by its high lipid content, and studied their interaction with the tubercle bacillus. Within our in vitro human granuloma model, M. tuberculosis long chain fatty acids, namely oxygenated mycolic acids (MA), triggered the differentiation of human monocyte-derived macrophages into FMs. In these cells, mycobacteria no longer replicated and switched to a dormant non-replicative state. Electron microscopy observation of M. tuberculosis–infected FMs showed that the mycobacteria-containing phagosomes migrate towards host cell lipid bodies (LB), a process which culminates with the engulfment of the bacillus into the lipid droplets and with the accumulation of lipids within the microbe. Altogether, our results suggest that oxygenated mycolic acids from M. tuberculosis play a crucial role in the differentiation of macrophages into FMs. These cells might constitute a reservoir used by the tubercle bacillus for long-term persistence within its human host, and could provide a relevant model for the screening of new antimicrobials against non-replicating persistent mycobacteria. 相似文献
998.
999.
Acetone extracts of the threelichen species Evernia prunastri, Hypogymnia physodes and Cladoniaportentosa were investigated for activityagainst eight plant pathogenic fungi: Pythium ultimum, Phytophthorainfestans, Rhizoctonia solani, Botrytis cinerea, Colletotrichumlindemuthianum, Fusarium solani, Stagonospora nodorum and Ustilagomaydis. Particularly, E. prunastriand H. physodes exhibit total or stronginhibition on P. ultimum, U.maydis and P. infestans growth. Incontrast, Cladonia extracts were lessactive to reduce growth of these fungi.Lichenic acids were also examined forantifungal activity. P. infestans growthwas severely inhibited by evernic acid. P.ultimum and P. infestans growth wereslightly but significantly inhibited by evernicacid and (–) usnic acid, respectively. Growthinhibition of U. maydis was also observedfor the latter lichenic acid. These resultsconfirm the previously observed activities oflichen extracts. This suggests that secondarylichen metabolites might be of potential use asantifungal agents. 相似文献
1000.
Chantal Barthomeuf Suzanne Lim Mehrdad Iranshahi Philippe Chollet 《Phytomedicine》2008,15(1-2):103-111
Metastatic malignant melanoma have a bad prognosis (median survival: 6-8 months) mainly due to the development of lung, hepatic and brain metastases. In this study we have used the resazurin reduction test and FACS analysis to assess the cytostatic and cytotoxic effect of umbelliprenin from Ferula szowitsiana (Apiaceae) on human solid cancer cells and human primary fibroblasts. We have observed that the cell susceptibility to umbelliprenin decreases in the order M4Beu (metastatic pigmented malignant melanoma)>A549 (nonsmall cell lung carcinoma) approximately PC3 (androgen-resistant prostate carcinoma)>PA1 (ovary teratocarcinoma)>human primary fibroblasts approximately MCF7 (breast adenocarcinoma)>DLD1 (colon adenocarcinoma). M4Beu cell-proliferation is inhibited through cell-cycle arrest in G1 and induction of caspase-dependent apoptosis. The finding that the cytotoxic effect of umbelliprenin is markedly more pronounced in M4Beu cells than in primary fibroblasts, suggests a therapeutic margin. As M4Beu cell proliferation is more potently inhibited by umbelliprenin (IC50 12.3 microM) than by the citrus coumarin auraptene (7-geranyloxycoumarin, IC50 17.1 microM) previously reported capable of inhibiting the prevalence of lung metastasis in mice bearing B16BL6 murine melanoma, our data suggest that umbelliprenin orally administered and foods and folk medicines containing this coumarin, may afford protection against the development and early recurrence of malignant melanoma. In vivo investigations are needed to test these hypotheses. 相似文献