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排序方式: 共有604条查询结果,搜索用时 31 毫秒
1.
Sutada Lotinun Glenda L Evans James T Bronk Mark E Bolander Thomas J Wronski Erik L Ritman Russell T Turner 《Journal of bone and mineral research》2004,19(7):1165-1171
We examined the time course effects of continuous PTH on cortical bone and mechanical properties. PTH increased cortical bone turnover and induced intracortical porosity with no deleterious effect on bone strength. Withdrawal of PTH increased maximum torque to failure and stiffness with no change in energy absorbed. INTRODUCTION: The skeletal response of cortical bone to parathyroid hormone (PTH) is complex and species dependent. Intermittent administration of PTH to rats increases periosteal and endocortical bone formation but has no known effects on intracortical bone turnover. The effects of continuous PTH on cortical bone are not clearly established. MATERIALS AND METHODS: Eighty-four 6-month-old female Sprague-Dawley rats were divided into three control, six PTH, and two PTH withdrawal (WD) groups. They were subcutaneously implanted with osmotic pumps loaded with vehicle or 40 microg/kg BW/day human PTH(1-34) for 1, 3, 5, 7, 14, and 28 days. After 7 days, PTH was withdrawn from two groups of animals for 7 (7d-PTH/7d-WD) and 21 days (7d-PTH/21d-WD). Histomorphometry was performed on periosteal and endocortical surfaces of the tibial diaphysis in all groups. microCT of tibias and mechanical testing by torsion of femora were performed on 28d-PTH and 7d-PTH/21d-WD animals. RESULTS AND CONCLUSIONS: Continuous PTH increased periosteal and endocortical bone formation, endocortical osteoclast perimeter, and cortical porosity in a time-dependent manner, but did not change the mechanical properties of the femur, possibly because of addition of new bone onto periosteal and endocortical surfaces. Additionally, withdrawal of PTH restored normal cortical porosity and increased maximum torque to failure and stiffness. We conclude that continuous administration of PTH increased cortical porosity in rats without having a detrimental effect on bone mechanical properties. 相似文献
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BACKGROUND: There are obvious advantages to increasing donor retention. However, for reasons of blood safety, certain donors may, in fact, be more desirable to retain than others. “Safe” donors are defined as those who provided a blood donation that was negative on all laboratory screening tests and who subsequently reported no behavioral risks in response to an anonymous survey. This study identifies the most important factors affecting the intention of “safe” donors to provide another donation. STUDY DESIGN AND METHODS: An anonymous survey asking about donation history, sexual history, injecting drug use, and recent donation experience was mailed to 50,162 randomly selected allogeneic donors (including directed donors) who gave blood from April through July or from October through December 1993 at one of the five United States blood centers participating in the Retrovirus Epidemiology Donor Study. Before mailing, questionnaires were coded to designate donors with nonreactive laboratory screening tests at their most recent donation. RESULTS: A total of 34,726 donors (69%) responded, with substantially higher response among repeat donors. According to reported intentions only, the vast majority of “safe” donors indicated a high likelihood of donating again within the next 12 months. Only 3.4 percent reported a low likelihood of donating again. A comparison of those likely to return and those unlikely to return reveals significant differences in demographics and in ratings of the donation experience. A higher proportion of those unlikely to return were first-time donors, minority-group donors, and donors with less education. The highest projected loss among “safe” donors was seen for those who gave a fair to poor assessment of their treatment by blood center staff or of their physical well-being during or after donating. CONCLUSION: These data suggest that efforts to improve donors' perceptions of their donation experience, as well as attention to the physical effects of blood donation, may aid in the retention of both repeat and first-time donors. 相似文献
3.
Rosenberg ZS; Jahss MH; Noto AM; Shereff MJ; Cheung Y; Frey CC; Norman A 《Radiology》1988,167(2):489-493
Computed tomography (CT) was performed in 42 patients with 49 clinically suspected tears of the posterior tibial tendon. Twenty-eight of the 49 suspected tears were subsequently surgically explored and repaired. Three patterns of tendon abnormalities were recognized on CT scans: type I-intact, hypertrophied, heterogeneous tendon; type II-attenuated tendon; and type III-absence of a portion of a tendon. Types I and II correlated with partial rupture seen during surgery, and type III correlated with complete rupture of the tendon. CT findings were accurate in 96% of the patients who underwent surgery. In four cases (14%), tendon rupture was seen on CT scans, but the extent of the injury was underestimated and the rupture was misclassified. Reactive periostitis of the distal tibia was seen in 71% of diseased tendons and may represent an important factor in the diagnosis of tendon rupture. 相似文献
4.
Intestinal schistosomiasis japonica: CT-pathologic correlation 总被引:1,自引:0,他引:1
Lee RC; Chiang JH; Chou YH; Rubesin SE; Wu HP; Jeng WC; Hsu CC; Tiu CM; Chang T 《Radiology》1994,193(2):539
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Czarniak E Samet A Bronk M Rybak B Kochowska-Bronk M Zajac-Lenczewska I Ksiazek J Skokowski J 《Pneumonologia i alergologia polska》2003,71(1-2):31-35
The clinical specimens received from patients hospitalized in Department of Thoracic Surgery between 1997 and 2001 were microbiologically examined. The main specimen for microbiological examination was pleural fluid (median 34%). The frequency of specimens from bronchial tree increased significantly (from 4% to 26%) with concurrent decrease of sputum (from 29% to 6%). Among isolated pathogens, Gram negative rods were the most frequent (median 48%) and Pseudomonas sp. was the main pathogen among them. Occurrence of staphylococci was median 22% and Staphylococcus aureus, with a little decrease in analyzed period, was still the main Gram positive pathogen. Simultaneously the occurrence of MRSA in the last three years dropped three times. The number of isolations of yeasts have risen from 5.8% to 10.3%. 相似文献
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Evidence for carrier-mediated uptake and efflux of sugars at the serosal side of the rat intestinal mucosa in vitro.
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A modification of the everted sac technique is described which allows several sacs to be prepared rapidly and simultaneously from the same segment of rat intestine. 2. A method has been developed for comparing the transport of two sugars by measuring changes in the ratios of their concentrations as they pass across the intestinal wall. 3. With this method significant differences were observed between the D-[3H]galactose and L-[14C]glucose ratios in the mucosal epithelium, the serosal tissue and the serosal compartment. These results indicate that both the efflux of galactose from the serosal side of the mucosal epithelium and the uptake of the sugar into the mucosa are carrier-mediated processes. 4. The mediated efflux of galactose at the serosal side of the epithelial layer is inhibited by the presence of phlorizin on the mucosal side and to some extent by any reduction in the mucosal Na+ concentration. Both of these treatments inhibited galactose uptake at the brush border. Serosal efflux of the sugar appeared to be saturated at high concentrations of D-galactose. 5. Pre-treatment of the sacs with mercuric chloride considerably reduced D-galactose uptake from the luminal side, but did not affect its efflux relative to L-glucose at the serosal side of the mucosal epithelium. 6. Carrier-mediated sugar uptake into the mucosal epithelium from the serosal side was also examined. The role of the bidirectional, carrier-mediated sugar transport processes at the serosal pole of the mucosal epithelial cell in transintestinal transport is discussed. 相似文献