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排序方式: 共有409条查询结果,搜索用时 15 毫秒
1.
Comparison of three different purification methods for the routine preparation of [11C] Metomidate. 总被引:1,自引:0,他引:1
Markus Mitterhauser Wolfgang Wadsak Oliver Langer Joern Schmaljohann Georg Zettinig Robert Dudczak Helmut Viernstein Kurt Kletter 《Applied radiation and isotopes》2003,59(2-3):125-128
PET with (R)-[O-methyl-11C] metomidate ([11C] MTO) is an attractive method for the characterisation of adrenal masses discriminating lesions of adrenal cortical origin from noncortical lesions. [11C] MTO was prepared by the reaction of [11C] methyliodide with the corresponding free acid. Three purification methods have been compared. The method of choice uses preparative HPLC with a ready-to-use weak acidic solvent. 相似文献
2.
Immobilisation induces bone loss. Evidence from studies in animals and healthy humans that were immobilised for a limited time indicates that, in general, bone mass may be restored even in adults. Following conservative management of partial tears of the anterior cruciate ligament (ACL), bone loss is often negligible (2-3%). After surgical reconstruction, however, there is greater bone loss (15-20%), with little or no recovery. Bones adapt to the stresses they experience. Also, the largest forces in the musculoskeletal system arise from muscle pull. Tendons transmit these forces. Many surgical techniques for ACL reconstruction use autologous tendon grafts. We hypothesise that tissue harvesting causes weakening of the formerly intact tendon, which, in turn, leads to reduced muscle pull and subsequent bone loss in those parts of the bone that are loaded by the tendon. If our hypothesis holds true, it may change patients' and surgeons' choice of management. Clinical follow-up should assess the functional result with greater scrutiny, possibly including the assessment of bone mineral content. This may be particularly important since there is accumulating evidence that a decrease in bone mineral density (BMD) preceedes, and hence may be a cause of, osteoarthritis. 相似文献
3.
Oxygen uptake during whole-body vibration exercise: comparison with squatting as a slow voluntary movement 总被引:2,自引:0,他引:2
In this study we investigated metabolic power during whole-body vibration exercise (VbX) compared to mild resistance exercise.
Specific oxygen consumption (
) and subjectively perceived exertion (rating of perceived exertion, RPE; Borg scale) were assessed in 12 young healthy subjects
(8 female and 4 male). The outcome parameters were assessed during the last minute of a 3-min exercise bout, which consisted
of either (1) simple standing, (2) squatting in cycles of 6 s to 90° knee flexion, and (3) squatting as before with an additional
load of 40% of the subject's body weight (35% in females). Exercise types 1–3 were performed with (VbX+) and without (VbX–)
platform vibration at a frequency of 26 Hz and an amplitude of 6 mm. Compared to the VbX– condition, the specific
was increased with vibration by 4.5 ml·min–1·kg–1. Likewise, squatting and the additional load were factors that further increased
. Corresponding changes were observed in RPE. There was a correlation between VbX– and VbX+ values for exercise types 1–3
(r=0.90). The correlation coefficient between squat/no-squat values (r=0.70 without and r=0.71 with the additional load) was significantly lower than that for VbX–/VbX+. Variation in specific
was significantly higher in the squatting paradigm than with vibration. It is concluded that the increased metabolic power
observed in association with VbX is due to muscular activity. It is likely that this muscular activity is easier to control
between individuals than is simple squatting.
Electronic Publication 相似文献
4.
Metzler M Strissel PL Strick R Niemeyer C Roettgers S Borkhardt A Harbott J Ludwig WD Stanulla M Schrappe M Reinhardt D Creutzig U Beck JD Rascher W Repp R Langer T 《Genes, chromosomes & cancer》2004,41(3):291-296
Therapy-related acute myeloid leukemia (t-AML) characterized by the t(9;11)(p22;q23) translocation is one of the most frequent secondary malignancies. The timing of the initiation of translocation and of development of the malignant t(9;11) clone during chemotherapy is presently unknown. In the present study, we backtracked bone marrow samples from three children during treatment for acute lymphoblastic leukemia (ALL). Two patients developed a t(9;11)-positive t-AML 19 and 30 months after therapy start, whereas the third patient, diagnosed with a rare t(9;11)-positive ALL, suffered from an ALL relapse 23 months after initial diagnosis. The genomic MLL-MLLT3 (MLL-AF9) fusion site was amplified by a multiplex, nested long-range PCR and used as a clonal marker for quantification of the MLL-MLLT3-positive cells during chemotherapy. The t(9;11)-positive clone was detectable 13 and 18 months after therapy start in both t-AML cases, which was 6-12 months before clinical diagnosis of the secondary malignancy. In the t(9;11)-positive ALL patient, the identical leukemic clone reoccurred during maintenance therapy after a short molecular remission, 8 months before clinically overt ALL relapse. The time course and characteristics of the genomic breakpoints in the present t-AML cases support the hypothesis of translocation formation as a result of defective breakage repair after topoisomerase II cleavage. 相似文献
5.
Hans Degens Thomas Mark Maden-Wilkinson Alex Ireland Marko T. Korhonen Harri Suominen Ari Heinonen Zsolt Radak Jamie S. McPhee Jörn Rittweger 《Age (Dordrecht, Netherlands)》2013,35(3):1007-1015
Ageing is accompanied with a decline in respiratory function. It is hypothesised that this may be attenuated by high physical activity levels. We performed spirometry in master athletes (71 women; 84 men; 35–86 years) and sedentary people (39 women; 45 men; 24–82 years), and calculated the predicted lung age (PLA). The negative associations of age with forced expiratory volume in 1 s (FEV1; 34 mL·year?1) and other ventilatory parameters were similar in controls and master athletes. FEV1pred was 9 % higher (P?<?0.005) and PLA 15 % lower (P?=?0.013) in athletes than controls. There were no significant differences between endurance and power athletes and sedentary people in maximal inspiratory and expiratory pressure. Neither age-graded performance nor weekly training hours were significantly related to lung age. Life-long exercise does not appear to attenuate the age-related decrease in ventilatory function. The better respiratory function in master athletes than age-matched sedentary people might be due to self-selection and attrition bias. 相似文献
6.
Michael W. Panas Jaimie D. Sixsmith KeriAnn White Birgit Korioth-Schmitz Shana T. Shields Brian T. Moy Sunhee Lee Joern E. Schmitz William R. Jacobs Jr. Steven A. Porcelli Barton F. Haynes Norman L. Letvin Geoffrey O. Gillard 《Infection and immunity》2014,82(12):5317-5326
Mycobacteria, the etiological agents of tuberculosis and leprosy, have coevolved with mammals for millions of years and have numerous ways of suppressing their host''s immune response. It has been suggested that mycobacteria may contain genes that reduce the host''s ability to elicit CD8+ T cell responses. We screened 3,290 mutant Mycobacterium bovis bacillus Calmette Guerin (BCG) strains to identify genes that decrease major histocompatibility complex (MHC) class I presentation of mycobacterium-encoded epitope peptides. Through our analysis, we identified 16 mutant BCG strains that generated increased transgene product-specific CD8+ T cell responses. The genes disrupted in these mutant strains had disparate predicted functions. Reconstruction of strains via targeted deletion of genes identified in the screen recapitulated the enhanced immunogenicity phenotype of the original mutant strains. When we introduced the simian immunodeficiency virus (SIV) gag gene into several of these novel BCG strains, we observed enhanced SIV Gag-specific CD8+ T cell responses in vivo. This study demonstrates that mycobacteria carry numerous genes that act to dampen CD8+ T cell responses and suggests that genetic modification of these genes may generate a novel group of recombinant BCG strains capable of serving as more effective and immunogenic vaccine vectors. 相似文献
7.
T. M. Maden-Wilkinson J. S. McPhee J. Rittweger D. A. Jones H. Degens 《Age (Dordrecht, Netherlands)》2014,36(1):383-393
Secular changes and intra-individual differences in body shape and size can confound cross-sectional studies of muscle ageing. Normalising muscle mass to height squared is often suggested as a solution for this. We hypothesised that normalisation of muscle volume to femur volume may be a better way of determining the extent of muscle lost with ageing (sarcopenia). Thigh and femur muscle volumes were measured from serial magnetic resonance imaging sections in 20 recreationally active young men (mean age 22.4 years), 25 older men (72.3 years), 18 young women (22.1 years) and 28 older women (72.0 years). There were no age-related differences in femur volume. The relationship between thigh muscle volume and femur volume (R2 = 0.76; exponent of 1.12; P < 0.01) was stronger than that with height (R2 = 0.49; exponent of 3.86; P < 0.01) in young participants. For young subjects, the mean muscle/bone ratios were 16.0 and 14.6 for men and women, respectively. For older men and women, the mean ratios were 11.6 and 11.5, respectively. The Z score for the thigh muscle/bone volume ratio relative to young subjects was −2.2 ± 0.7 for older men and −1.4 ± 0.8 for older women. The extent of sarcopenia judged by the muscle/bone ratio was approximately twice that determined when normalising to height squared. These data suggest that the muscle/bone ratio captures the intra-individual loss of muscle mass during ageing, and that the age-related loss of muscle mass may be underestimated when normalised to height squared. The quadriceps seems relatively more affected by ageing than other thigh muscles. 相似文献
8.
Ruowei Li Marco V. Narici Robert M. Erskine Olivier R. Seynnes Jörn Rittweger Rado Pišot Boštjan Šimunič Martin Flück 《Journal of anatomy》2013,223(5):525-536
Costameres are mechano-sensory sites of focal adhesion in the sarcolemma that provide a structural anchor for myofibrils. Their turnover is regulated by integrin-associated focal adhesion kinase (FAK). We hypothesized that changes in content of costamere components (beta 1 integrin, FAK, meta-vinculin, gamma-vinculin) with increased and reduced loading of human anti-gravity muscle would: (i) relate to changes in muscle size and molecular parameters of muscle size regulation [p70S6K, myosin heavy chain (MHC)1 and MHCIIA]; (ii) correspond to adjustments in activity and expression of FAK, and its negative regulator, FRNK; and (iii) reflect the temporal response to reduced and increased loading. Unloading induced a progressive decline in thickness of human vastus lateralis muscle after 8 and 34 days of bedrest (−4% and −14%, respectively; n = 9), contrasting the increase in muscle thickness after 10 and 27 days of resistance training (+5% and +13%; n = 6). Changes in muscle thickness were correlated with changes in cross-sectional area of type I muscle fibers (r = 0.66) and beta 1 integrin content (r = 0.76) at the mid-point of altered loading. Changes in meta-vinculin and FAK-pY397 content were correlated (r = 0.85) and differed, together with the changes of beta 1 integrin, MHCI, MHCII and p70S6K, between the mid- and end-point of resistance training. By contrast, costamere protein level changes did not differ between time points of bedrest. The findings emphasize the role of FAK-regulated costamere turnover in the load-dependent addition and removal of myofibrils, and argue for two phases of muscle remodeling with resistance training, which do not manifest at the macroscopic level. 相似文献
9.
10.
The variation of morphological and functional cardiac manifestation in Fabry disease: potential implications for the time course of the disease. 总被引:6,自引:0,他引:6
Frank Weidemann Frank Breunig Meinrad Beer Joern Sandstede Stefan St?rk Wolfram Voelker Georg Ertl Anita Knoll Christoph Wanner Joerg M Strotmann 《European heart journal》2005,26(12):1221-1227
AIMS: The aim of this clinical cross-sectional study was to investigate the cardiac interrelation of morphological and functional abnormalities in patients with Fabry disease. METHODS AND RESULTS: Fifty-one patients (5-78 years) were compared with 25 controls (8-77 years). In all subjects, end-diastolic thickness of the left ventricle was measured by echocardiography and ultrasonic peak systolic strain rate (SR) was extracted to assess regional myocardial function. Magnetic resonance imaging was performed to assess late-enhancement for the detection of myocardial fibrosis in Fabry patients (n=39). In patients, women <20 years of age had no hypertrophy, no late-enhancement, and normal radial and longitudinal function (SR longitudinal=-1.7+/-0.5 s(-1); P=n.s. compared with controls). Ten women, >20 years of age, had no hypertrophy, no late-enhancement, normal radial and longitudinal function in the septal wall, but reduced longitudinal function in the lateral wall (SR=-1.4+/-0.5 s(-1)). All male patients without hypertrophy and no late-enhancement had normal radial function but reduced longitudinal function in both the septal and lateral walls (SR=-1.3+/-0.3 s(-1)). Patients with hypertrophy but without late-enhancement (n=13) had reduced radial and longitudinal function. Twelve patients displaying hypertrophy and late-enhancement had severely reduced radial and longitudinal function (SR=-1.1+/-0.5 s(-1)). Two of them with the worst impairment of regional function (SR=-0.8+/-0.6 s(-1)) died in the follow-up period. CONCLUSION: These results illustrate the variation of morphological changes and its functional consequences in Fabry cardiomyopathy. 相似文献