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Young Healthy Adults (young + healthy_adult)

Distribution by Scientific Domains

Medical Sciences	50%
Life Sciences	50%

Selected Abstracts

The neural control of bimanual movements in the elderly: Brain regions exhibiting age-related increases in activity, frequency-induced neural modulation, and task-specific compensatory recruitment

HUMAN BRAIN MAPPING, Issue 8 2010
Daniel J. Goble
Abstract Coordinated hand use is an essential component of many activities of daily living. Although previous studies have demonstrated age-related behavioral deficits in bimanual tasks, studies that assessed the neural basis underlying such declines in function do not exist. In this fMRI study, 16 old and 16 young healthy adults performed bimanual movements varying in coordination complexity (i.e., in-phase, antiphase) and movement frequency (i.e., 45, 60, 75, 90% of critical antiphase speed) demands. Difficulty was normalized on an individual subject basis leading to group performances (measured by phase accuracy/stability) that were matched for young and old subjects. Despite lower overall movement frequency, the old group "overactivated" brain areas compared with the young adults. These regions included the supplementary motor area, higher order feedback processing areas, and regions typically ascribed to cognitive functions (e.g., inferior parietal cortex/dorsolateral prefrontal cortex). Further, age-related increases in activity in the supplementary motor area and left secondary somatosensory cortex showed positive correlations with coordinative ability in the more complex antiphase task, suggesting a compensation mechanism. Lastly, for both old and young subjects, similar modulation of neural activity was seen with increased movement frequency. Overall, these findings demonstrate for the first time that bimanual movements require greater neural resources for old adults in order to match the level of performance seen in younger subjects. Nevertheless, this increase in neural activity does not preclude frequency-induced neural modulations as a function of increased task demand in the elderly. Hum Brain Mapp, 2010. © 2010 Wiley-Liss, Inc. [source]

Mumps: Not an Innocent Bystander in Solid Organ Transplantation

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 9 2009
M. C. Baas
Recently two major outbreaks of mumps have occurred: in the UK more than 56,000 cases were notified between 2004 and 2005, and in the United States, 6,584 cases were reported in 2006. Most patients were young healthy adults, in whom mumps normally has a benign course. Little is known about mumps in the immunocompromised patient. Here, we report a case of a 56-year renal transplant recipient who developed acute irreversible transplant failure due to interstitial nephritis caused by mumps. RNA of the mumps virus was detected in the urine as well as in a renal biopsy. In view of the ongoing presence of the mumps virus in the population, one should be aware of the possible occurrence of this infection in immunocompromised patients. [source]

Feasibility of T and Z scores from magnetic resonance imaging data for quantification of cartilage loss in osteoarthritis

ARTHRITIS & RHEUMATISM, Issue 10 2003
R. Burgkart
Objective T scores (an indicator of the difference between patients and young healthy subjects) and Z scores (an indicator of the difference between patients and age-matched healthy subjects) are used in the diagnosis of osteoporosis and form the current basis for the definition of osteoporosis by the World Health Organization. We tested the feasibility of using T and Z scores derived from quantitative cartilage imaging with magnetic resonance imaging (MRI) for the diagnosis of osteoarthritis (OA). Methods High-resolution MR images of tibial cartilage were acquired from 126 young healthy adults (ages 20,35 years), 24 age-matched elderly healthy adults (ages 50,75 years), 7 OA patients prior to tibial osteotomy, and 7 OA patients prior to knee arthroplasty. Cartilage volume, thickness, surface area, and original joint surface area (before onset of disease) were determined in the medial and lateral tibia. Results The cartilage volume of the medial tibia of osteotomy patients with varus malalignment displayed moderate T scores (,1.0), and more negative T scores (,3.8) were observed in knee arthroplasty patients with varus malalignment. Normalization of the cartilage volume to the original joint surface area substantially enhanced the scores in patients undergoing osteotomy (,2.3) and in patients undergoing knee arthroplasty (,5.5), and this was superior to the normalization ratios of cartilage volume to body height and cartilage volume to body weight, in terms of distinguishing the loss of articular cartilage. Conclusion Quantitative analysis of OA by MRI is feasible using T and Z scores. However, cartilage volume should be normalized to the individual joint surface area in order to maximize the discriminatory power of this technique for the diagnosis of OA. [source]

Asymmetry of the active nonweightbearing foot and ankle range of motion for dorsiflexion-plantar flexion and its coupled movements in adults

CLINICAL ANATOMY, Issue 7 2007
Virgilio F. Ferrario
Abstract Asymmetries in ankle range of motion (ROM) have been reported, but often the uninvolved limb is used as a reference in clinical practice. The study wanted to quantify the intraindividual asymmetries in dorsi-plantar flexion foot and ankle ROM and its coupled foot movements. Active triplanar nonweightbearing ROM of the foot and ankle was recorded in young healthy adults (30 male volunteers, mean age 22.8 years; 35 female volunteers, mean age 23.8 years) using an optoelectronic set-up. The sagittal plane movement (mean ROM female subjects right side 71.3°, left side 71.4°, P > 0.05; mean ROM male subjects right side 69°, left side 68.9°, P > 0.05; sex difference, P < 0.001) was coupled with frontal (mean ROM female subjects right side 16.6°, left side 14.8°, P > 0.05; male subjects right side 17°, left side 15.3°; P > 0.05; no sex difference) and horizontal (mean ROM female subjects right side 19.6°, left side 18.8°, P < 0.001; male subjects right side 17.6°, left side 16.2°, P < 0.001; sex < 0.001) plane motions. Individual fluctuating asymmetries up to 15° (principal movement), and up to 29° (associated movements) were measured. Overall, 20% of female and 34% of male subjects had principal plane asymmetries >5°, and 50% of the subjects had asymmetries >5° in the associated movements. In young adults, individual asymmetries in ankle joint complex dorsi-plantar flexion should be taken into account when using the uninvolved, contralateral limb as a reference for clinical examination. Clin. Anat. 20:834,842, 2007. © 2007 Wiley-Liss, Inc. [source]