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Alen Hajnal Sergio Fonseca Jeffrey M. Kinsella-Shaw Paula Silva Claudia Carello M.T. Turvey 《Neuroscience letters》2007
Nonvisual perceptions of a wielded object's spatial properties are based on the quantities expressing the object's mass distribution, quantities that are invariant during the wielding. The mechanoreceptors underlying the kind of haptic perception involved in wielding – referred to as effortful, kinesthetic, or dynamic touch – are those embedded in the muscles, tendons, and ligaments. The present experiment's focus was the selectivity of this muscle-based form of haptic perception. For an occluded rod grasped by the hand at some intermediate position along its length, participants can attend to and report selectively the rod's full length, its partial lengths (fore or aft of the hand), and the position of the grip. The present experiment evaluated whether participants could similarly attend selectively when wielding by foot. For a given rod attached to and wielded by foot or attached to (i.e. grasped) and wielded by hand, participants reported (by magnitude production) the rod's whole length or fractional length leftward of the point of attachment. On measures of mean perceived length, accuracy, and reliability, the degree of differentiation of partial from full extent achieved by means of the foot matched that achieved by means of the hand. Despite their neural, anatomical, and experiential differences, the lower and upper limbs seem to abide by the same principles of selective muscle-based perception and seem to express this perceptual function with equal facility. 相似文献
3.
Neuromuscular adaptation during prolonged strength training, detraining and re-strength-training in middle-aged and elderly people 总被引:6,自引:0,他引:6
Häkkinen K Alen M Kallinen M Newton RU Kraemer WJ 《European journal of applied physiology》2000,83(1):51-62
Effects of a 24-week strength training performed twice weekly (24 ST) (combined with explosive exercises) followed by either
a 3-week detraining (3 DT) and a 21-week re-strength-training (21 RST) (experiment A) or by a 24-week detraining (24 DT) (experiment
B) on neural activation of the agonist and antagonist leg extensors, muscle cross-sectional area (CSA) of the quadriceps femoris,
maximal isometric and one repetition maximum (1-RM) strength and jumping (J) and walking (W) performances were examined. A
group of middle-aged (M, 37–44 years, n=12) and elderly (E, 62–77, n=10) and another group of M (35–45, n=7) and E (63–78, n=7) served as subjects. In experiment A, the 1-RM increased substantially during 24 ST in M (27%, P < 0.001) and E (29%, P < 0.001) and in experiment B in M (29%, P < 0.001) and E (23%, P < 0.01). During 21 RST the 1-RM was increased by 5% at week 48 (P < 0.01) in M and 3% at week 41 in E (n.s., but P < 0.05 at week 34). In experiment A the integrated electromyogram (IEMG) of the vastus muscles in the 1-RM increased during
24 ST in both M (P < 0.05) and E (P < 0.001) and during 21 RST in M for the right (P < 0.05) and in E for both legs (P < 0.05). The biceps femoris co-activation during the 1-RM leg extension decreased during the first 8-week training in M (from
29 ± 5% to 25 ± 3%, n.s.) and especially in E (from 41 ± 11% to 32 ± 9%, P < 0.05). The CSA increased by 7% in M (P < 0.05) and by 7% in E (P < 0.001), and by 7% (n.s.) in M and by 3% in E (n.s.) during 24 ST periods. Increases of 18% (P < 0.001) and 12% (P < 0.05) in M and 22% (P < 0.001) and 26% (P < 0.05) in E occurred in J. W speed increased (P < 0.05) in both age groups. The only decrease during 3 DT was in maximal isometric force in M by 6% (P < 0.05) and by 4% (n.s.) in E. During 24 DT the CSA decreased in both age groups (P < 0.01), the 1-RM decreased by 6% (P < 0.05) in M and by 4% (P < 0.05) in E and isometric force by 12% (P < 0.001) in M and by 9% (P < 0.05) in E, respectively, while J and W remained unaltered. The strength gains were accompanied by increased maximal voluntary
neural activation of the agonists in both age groups with reduced antagonist co-activation in the elderly during the initial
training phases. Neural adaptation seemed to play a greater role than muscle hypertrophy. Short-term detraining led to only
minor changes, while prolonged detraining resulted in muscle atrophy and decreased voluntary strength, but explosive jumping
and walking actions in both age groups appeared to remain elevated for quite a long time by compensatory types of physical
activities when performed on a regular basis.
Accepted: 2 May 2000 相似文献
4.
5.
Sarah T. Menacho Ramesh Grandhi Alen Delic Mohammad Anadani Wendy C. Ziai Issam A. Awad Daniel F. Hanley Adam de Havenon 《Journal of stroke and cerebrovascular diseases》2021,30(3):105540
Objectives: Intracranial pressure (ICP) monitors have been used in some patients with spontaneous intracranial hemorrhage (ICH) to provide information to guide treatment without clear evidence for its use in this population. We assessed the impact of ICP monitor placement, including external ventricular drains and intraparenchymal monitors, on neurologic outcome in this population.Materials and MethodsIn this secondary analysis of the Minimally Invasive Surgery Plus Alteplase for Intracerebral Hemorrhage Evacuation III trial, the primary outcome was poor outcome (modified Rankin Scale score 4-6) and the secondary outcome was death, at 1 year from onset. We compared outcomes in patients with or without an ICP monitor using unadjusted and adjusted logistic regression models. The analyses were repeated in a balanced cohort created with propensity score matching.ResultsSeventy patients underwent ICP monitor placement and 424 did not. Poor outcome was seen in 77.1% of patients in the ICP-monitor subgroup compared with 53.8% in the no-monitor subgroup (p<0.001). Of patients in the ICP-monitor subgroup, 31.4% died, compared with 21.0% in the no-monitor subgroup (p=0.053). In multivariate models, ICP monitor placement was associated with a >2-fold greater risk of poor outcome (odds ratio 2.76, 95% CI 1.30–5.85, p=0.008), but not with death (p=0.652). Our findings remained consistent in the propensity score-matched cohort.ConclusionThese results question whether ICP monitor–guided therapy in patients with spontaneous nontraumatic ICH improves outcome. Further work is required to define the causal pathway and improve identification of patients that might benefit from invasive ICP monitoring. 相似文献
6.
Qin Wang Decai Chen Shu Mei Cheng Patrick Nicholson Markku Alen Sulin Cheng 《Journal of bone and mineral research》2015,30(3):528-534
Osteoporotic hip fracture is a serious clinical event associated with high morbidity and mortality. Understanding femoral growth patterns is important for promoting bone health in the young and preventing fractures in later life. In this study, growth patterns of areal bone mineral density (aBMD) and geometric properties of the proximal femur were measured by dual‐energy X‐ray absorptiometry. They were studied in 251 girls from premenarche (11.2 ± 0.7 years) to late adolescence (18.3 ± 1.1 years) and compared with their premenopausal mothers (n = 128, aged 44.9 ± 4.1 years) and postmenopausal grandmothers (n = 128, aged 70.0 ± 6.3 years). Hip axis length (HAL) was the first to reach peak growth velocity (?10.5 months before menarche), followed by neck diameter (ND) and neck cross‐sectional area (CSA), (?7.1 and ?4.1 months before menarche, respectively). Both neck‐shaft angle (NSA) and aBMD of neck and total hip peaked at menarche. At 18 years (7‐year follow‐up), girls already had higher femoral neck aBMD but similar HAL and NSA compared with their mothers. Grandmothers had the longest HAL, narrowest NSA, widest ND but lowest aBMD and CSA. Hip strength index (HSI), an index of femoral neck strength during a fall, dropped rapidly after menarche in girls but thereafter remained relatively constant. Grandmothers had lower HSI than either mothers or girls. In conclusion, differences in proximal femoral bone mass and structure in adulthood are largely established before menarche, indicating that heritable factors are responsible for most of the individual variance. The development of geometric properties precedes aBMD in puberty, resulting in relatively constant hip strength after menarche. This asynchronous growth leads to adaptation of bone strength to the imposed loads, avoiding fractures in a biologically efficient manner. Both deterioration of aBMD and inadequate compensatory change in bone geometry after menopause contribute to the increased fracture risk later in life. © 2014 American Society for Bone and Mineral Research. 相似文献
7.
Massari D Prpic-Massari L Kehler T Kastelan M Curkovic B Persic V Ruzic A Laskarin G 《Rheumatology international》2012,32(9):2777-2784
The objective of the present study was to investigate possible changes in granulysin (GNLY)-mediated cytotoxicity of peripheral blood lymphocytes in psoriatic arthritis (PsA) patients with respect to different phases of the disease. We prospectively enrolled 25 PsA patients in the active phase, 26 PsA patients in remission and 24 healthy controls. The simultaneous detection of intracellular GNLY and cell surface antigens (CD3 and CD56) was performed with flow cytometry. GNLY apoptotic protein was visualised by immunocytochemistry. Natural killer (NK) cell cytotoxicity was analysed with a cytotoxicity assay against human erythroleukaemia K-562 cells. The percentage of GNLY(+) cells did not differ significantly between PsA patients in the acute phase and those in remission; however, it was always higher than in healthy examinees due to the increased percentage of GNLY(+) cells within T cells, NKT cells, and both, and in the CD56(+dim) and CD56(+bright) NK subsets. The mean fluorescence intensity for GNLY was higher in all lymphocyte subpopulations in the acute phase than in remission and in healthy controls. Accordingly, GNLY-mediated NK cell cytotoxicity against K-562 cells of active phase PsA patients was significantly higher than that in patients in remission or in healthy controls. These findings demonstrated the involvement of GNLY in the worsening of PsA and suggested that GNLY mediated the development of joint lesions. 相似文献
8.
De Vita S Quartuccio L Salvin S Corazza L Zabotti A Fabris M 《Rheumatology (Oxford, England)》2012,51(4):627-633
9.
Maurizio Alen Trippolini Svenja Janssen Roger Hilfiker Peter Oesch 《Journal of occupational rehabilitation》2018,28(2):322-331
Purpose To analyze the reliability and validity of a picture-based questionnaire, the Modified Spinal Function Sort (M-SFS). Methods Sixty-two injured workers with chronic musculoskeletal disorders (MSD) were recruited from two work rehabilitation centers. Internal consistency was assessed by Cronbach’s alpha. Construct validity was tested based on four a priori hypotheses. Structural validity was measured with principal component analysis (PCA). Test–retest reliability and agreement was evaluated using intraclass correlation coefficient (ICC) and measurement error with the limits of agreement (LoA). Results Total score of the M-SFS was 54.4 (SD 16.4) and 56.1 (16.4) for test and retest, respectively. Item distribution showed no ceiling effects. Cronbach’s alpha was 0.94 and 0.95 for test and retest, respectively. PCA showed the presence of four components explaining a total of 74% of the variance. Item communalities were >0.6 in 17 out of 20 items. ICC was 0.90, LoA was ±12.6/16.2 points. The correlations between the M-SFS were 0.89 with the original SFS, 0.49 with the Pain Disability Index, ?0.37 and ?0.33 with the Numeric Rating Scale for actual pain, ?0.52 for selfreported disability due to chronic low back pain, and 0.50, 0.56–0.59 with three distinct lifting tests. No a priori defined hypothesis for construct validity was rejected. Conclusions The M-SFS allows reliable and valid assessment of perceived self-efficacy for work-related tasks and can be recommended for use in patients with chronic MSD. Further research should investigate the proposed M-SFS score of <56 for its predictive validity for non-return to work. 相似文献
10.
Sencer Goklemez Annie P. Im Liang Cao Filip Pirsl Seth M. Steinberg Lauren M. Curtis Sandra A. Mitchell Edward W. Cowen Judy Baruffaldi Jeremy Rose Jacqueline Mays Alen Ostojic Noa G. Holtzman Frances T. Hakim Steven Z. Pavletic 《American journal of hematology》2020,95(4):387-394
Chronic graft-versus-host disease (cGVHD) is the leading late complication after allogeneic hematopoietic stem cell transplantation (HSCT). Many patients receive multiple lines of systemic therapy until cGVHD resolves, but about 15% remain on systemic treatment for more than 7 years after cGVHD diagnosis. This study describes the clinical and biological factors of patients who present with cGVHD persisting for ≥7 years (persistent cGVHD). Patients with persistent cGVHD (n = 38) and those with cGVHD for <1 year (early cGVHD) (n = 83) were enrolled in a prospective cross-sectional natural history study. Patients in the persistent cGVHD group were a median of 10.2 years from cGVHD diagnosis (range 7-27 years). Fifty-eight percent of persistent cGVHD patients (22/38) were receiving systemic immunosuppression, compared to 88% (73/83) in the early cGVHD group. In multivariable analysis, bone marrow (BM) stem cell source, presence of ENA autoantibodies, higher NIH lung score, higher platelet counts, and higher IgA levels were significantly associated with persistent cGVHD. A high sensitivity panel of serum biomarkers including seven cytokines diagnostic for cGVHD was analyzed and showed significantly lower levels of BAFF and CXCL10 in patients with persistent cGVHD. In conclusion, standardly accepted clinical measures of disease severity may not accurately reflect disease activity in patients with persistent cGVHD. However, many patients with persistent cGVHD are still receiving systemic immunosuppression despite lacking evidence of disease activity. Development of reliable clinical biomarkers of cGVHD activity may help guide future systemic treatments. 相似文献