Blood flow and its distribution must be appropriately regulated to ensure that perfusion is matched to local tissue demands. We investigated the role of ATP in triggering a conducted alteration in arteriolar diameter in the Saran-covered cheek pouch retractor muscle of anesthetized hamsters (n = 60). Vascular responses were observed using in vivo video microscopy upstream from the site of micropressure application of ATP (10(-8)-10(-4) M) either into the lumen or just outside the wall of first- and second-order arterioles. The role of nitric oxide (NO) in the vascular responses to ATP was determined by inhibiting NO synthase activity with N(omega)-nitro-L-arginine methyl ester (L-NAME) with and without coadministration of an excess of L-arginine. Intraluminal application of ATP led to a concentration-dependent vasodilation, which was conducted upstream along the arteriole. The dilatory response was blocked by systemic pretreatment with L-NAME and was maintained in the presence of an excess of L-arginine. In contrast, ATP introduced extraluminally resulted in a conducted vasoconstrictor response that was enhanced by pretreatment with L-NAME. The dilator response to intraluminal ATP, in the context of ATP release from erythrocytes under conditions associated with decreased supply relative to demand, supports a role for the erythrocyte in communicating local tissue needs to the vasculature, enabling the appropriate matching of oxygen supply to demand.
Abstract-Multiple sclerosis (MS) causes a wide variety of neurological deficits, with ambulatory impairment the most obvious cause of disability. Within 10 to 15 years of disease onset, 80% of persons with MS experience gait problems due to muscle weakness or spasticity, fatigue, and loss of balance. To facilitate mobility, persons with MS frequently use mobility assistive technology (MAT), such as canes, crutches, walkers, wheelchairs, and scooters. We systematically reviewed the published literature on MAT use among persons with MS. We used electronic reference lists such as Ovid MEDLINE and PubMed to search the literature. We located 50 articles that met the initial criteria of providing good evidence of the types of MAT devices and their benefits for individuals with MS. A limited number of articles with higher levels of evidence was found regarding benefits of MAT use specifically for persons with MS. Evidence-based literature provides the basis for the strongest method of measurable clinical performance; therefore, having a strong research study design is vital to the justification of MAT prescription and reimbursement decisions. However, a paucity of studies with higher levels of evidencebased practice exists.
Objective
To provide descriptive data on ambulatory ability and muscle strength in a large cohort of individuals with spina bifida enrolled in a National Spina Bifida Patient Registry (NSBPR) and to investigate factors associated with ambulatory status.
Design
Cross-sectional analysis of data from a multi-site patient registry
Results
Descriptive analysis of mobility variables for 2604 individuals with spina bifida age 5 and above are presented from 19 sites in the United States. Analysis of a subset of NSBPR data from 380 individuals from three sites accompanied by data from a specialized spina bifida electronic medical record revealed that those with no history of a shunt, lower motor level, and no history of hip or knee contracture release surgery were more likely to be ambulatory at the community level than at the household or wheelchair level.
Conclusion
This study is the first to examine factors associated with ambulatory status in a large sample of individuals with myelomeningocele and non-myelomeningocele subtypes of SB. Results of this study delineate the breadth of strength and functional abilities within the different age groups and subtypes of SB. The results may inform clinicians of the characteristics of those with varying ambulatory abilities.
Results indicate that the FMA was a reliable and stable tool for assessing the functional performance of individuals who use or need WMS interventions.
We determined the demographic, health, functional, and satisfaction factors related to lower-limb prosthesis or wheelchair use among veterans with lower-limb amputation. Forty-two veterans were recruited from the 20th National Disabled Veterans Winter Sports Clinic and the 26th National Veterans Wheelchair Games. Participants were at least 18 years of age, had a lower-limb amputation, and were either prosthesis or wheelchair users. Level of amputation was the most significant health-related characteristic determining the veterans' use of a prosthesis versus a wheelchair (p = 0.02). Veterans who had a higher level of amputation and used a prosthesis reported significantly greater difficulty navigating a ramp (p = 0.03), getting in and out of cars and buses (p = 0.03), carrying 10 lb of groceries (p = 0.02), and participating in sports and leisure activities (p = 0.03). The parameter "satisfaction related to prosthesis" did not determine selection of mobility device type. The interaction of demographics, health-related characteristics, and mobility device characteristics affects functional performance and influences the use of prostheses, wheelchairs, or both in persons with lowerlimb amputation. Long-term outcome assessments may help determine factors associated with either transition from one device to another or combined use of the devices over time.
According to the International Standards Organization 2631-1 standard on human vibration, individuals in a seated position are at risk of injury due to whole-body vibrations when exposed for long periods of time. Wheelchair users fit this description perfectly; however, little research has been conducted to evaluate the amount of vibration transmitted to a wheelchair user. The vibration exposure produced by traversing nine surfaces was evaluated by having 10 individuals without disabilities propel over them in both a manual wheelchair at 1 m/s and a powered wheelchair at 1 and 2 m/s. Root-mean squared (RMS) vertical vibration was examined to determine if differences existed between surfaces. At 1 m/s for both the manual and the powered wheelchair the 8-mm bevel interlocking concrete surface produced significantly higher RMS vertical vibration than the other surfaces. At 2 m/s in the powered wheelchair, the poured concrete surface (control) produced the significantly highest RMS vertical vibration. Based on the manual and power wheelchair results of this study, use of selected ICPI pavers would be acceptable for any route traveled by individuals using wheelchair. Furthermore, a 90 degrees herringbone pattern is preferred over the 45 degrees pattern, and it is recommended that for safety reasons regarding vibration exposure a bevel of less than 6 mm should be used.
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