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Ann Arbor, MI, United States

Chu S.,University of California at Los Angeles | Boxer R.,University of California at Los Angeles | Madison P.,Veterans Affairs Greater Los Angeles | Kleinman L.,Veterans Affairs Greater Los Angeles | And 5 more authors.
Urology | Year: 2015

Objective To report the use of telemedicine to deliver general urologic care to remote locations within the Veterans Affairs Greater Los Angeles Healthcare System. We describe the diagnoses managed, patient satisfaction, safety, and benefit to patients in terms of saved travel time and expense. Methods We conducted a retrospective chart review examining care delivered through urology telemedicine clinics over a 6-month period. We examined the urologic conditions, patient satisfaction, and emergency department visits within 30 days of the visit. We estimated patient benefit by calculating travel distance and time and the saved travel-associated costs using Google Maps and US Census income data. Results Ninety-seven unique telemedicine visits were conducted and a total of 171 urologic diseases were assessed. The most common conditions were lower urinary tract symptoms (35%), elevated prostate-specific antigen level (15%), and prostate cancer (14%). One patient was seen in the emergency department within 30 days with an unpreventable urologic complaint. Patient satisfaction was "very good" to "excellent" in 95% of cases, and 97% would refer another veteran to the urology telemedicine clinic. Patients saved an average of 277 travel miles, 290 minutes of travel time, $67 in travel expenses, and $126 in lost opportunity cost. Conclusion Telemedicine was successfully and safely used to evaluate and treat a wide range of urologic conditions within the Veterans Affairs Greater Los Angeles Healthcare System, and saves patients nearly 5 hours and up to $193 per visit. Further investigation of the potential of telemedicine for the delivery of urologic care in a cost-effective manner is warranted. © 2015 Elsevier Inc.

St. Charles F.K.,St. Charles Consultancy | McAughey J.,and nter | Shepperd C.J.,and nter
Inhalation Toxicology | Year: 2013

Methodologies have been developed, described and demonstrated that convert mouth exposure estimates of cigarette smoke constituents to dose by accounting for smoke spilled from the mouth prior to inhalation (mouth-spill (MS)) and the respiratory retention (RR) during the inhalation cycle. The methodologies are applicable to just about any chemical compound in cigarette smoke that can be measured analytically and can be used with ambulatory population studies. Conversion of exposure to dose improves the relevancy for risk assessment paradigms. Except for urinary nicotine plus metabolites, biomarkers generally do not provide quantitative exposure or dose estimates. In addition, many smoke constituents have no reliable biomarkers. We describe methods to estimate the RR of chemical compounds in smoke based on their vapor pressure (VP) and to estimate the MS for a given subject. Data from two clinical studies were used to demonstrate dose estimation for 13 compounds, of which only 3 have urinary biomarkers. Compounds with VP > 10-5 Pa generally have RRs of 88% or greater, which do not vary appreciably with inhalation volume (IV). Compounds with VP < 10-7 Pa generally have RRs dependent on IV and lung exposure time. For MS, mean subject values from both studies were slightly greater than 30%. For constituents with urinary biomarkers, correlations with the calculated dose were significantly improved over correlations with mouth exposure. Of toxicological importance is that the dose correlations provide an estimate of the metabolic conversion of a constituent to its respective biomarker. © 2013 Informa Healthcare USA, Inc.

Liu C.,and nter | McAdam K.G.,and nter | Perfetti T.A.,Perfetti and Perfetti LLC
Mini-Reviews in Organic Chemistry | Year: 2011

This short review summarises some fundamental aspects of cigarette combustion and smoke formation, including how cigarettes burn, how cigarette smoke is formed and the complex and reactive nature of its composition. Particular emphasis has been placed on important factors which have to be controlled when generating, trapping and analyzing cigarette smoke. Examples are provided which demonstrate the sensitivity of cigarette smoke composition to the way it is produced and measured, a subject of particular importance for redox sensitive species such as free radicals and multiple valency-state metals. Recent regulatory interest in smoke constituent yields is summarized, as well as risk assessment approaches which have sought to identify the smoke constituents which make the greatest contribution to smoking related diseases. Limitations of these approaches are discussed, and a number of other aspects of cigarette smoke that have been suggested to contribute to the incidence of smoking related diseases are highlighted. © 2011 Bentham Science Publishers.

Zelik K.E.,University of Michigan | Collins S.H.,Carnegie Mellon University | Adamczyk P.G.,Intelligent Prosthetic Systems, Llc | Segal A.D.,and nter | And 10 more authors.
IEEE Transactions on Neural Systems and Rehabilitation Engineering | Year: 2011

Lower-limb amputees expend more energy to walk than non-amputees and have an elevated risk of secondary disabilities. Insufficient push-off by the prosthetic foot may be a contributing factor. We aimed to systematically study the effect of prosthetic foot mechanics on gait, to gain insight into fundamental prosthetic design principles. We varied a single parameter in isolation, the energy-storing spring in a prototype prosthetic foot, the controlled energy storage and return (CESR) foot, and observed the effect on gait. Subjects walked on the CESR foot with three different springs. We performed parallel studies on amputees and on non-amputees wearing prosthetic simulators. In both groups, spring characteristics similarly affected ankle and body center-of-mass (COM) mechanics and metabolic cost. Softer springs led to greater energy storage, energy return, and prosthetic limb COM push-off work. But metabolic energy expenditure was lowest with a spring of intermediate stiffness, suggesting biomechanical disadvantages to the softest spring despite its greater push-off. Disadvantages of the softest spring may include excessive heel displacements and COM collision losses. We also observed some differences in joint kinetics between amputees and non-amputees walking on the prototype foot. During prosthetic push-off, amputees exhibited reduced energy transfer from the prosthesis to the COM along with increased hip work, perhaps due to greater energy dissipation at the knee. Nevertheless, the results indicate that spring compliance can contribute to push-off, but with biomechanical trade-offs that limit the degree to which greater push-off might improve walking economy. © 2011 IEEE.

Morgenroth D.C.,and nter | Morgenroth D.C.,University of Washington | Segal A.D.,and nter | Zelik K.E.,University of Michigan | And 12 more authors.
Gait and Posture | Year: 2011

Lower extremity amputation not only limits mobility, but also increases the risk of knee osteoarthritis of the intact limb. Dynamic walking models of non-amputees suggest that pushing-off from the trailing limb can reduce collision forces on the leading limb. These collision forces may determine the peak knee external adduction moment (EAM), which has been linked to the development of knee OA in the general population. We therefore hypothesized that greater prosthetic push-off would lead to reduced loading and knee EAM of the intact limb in unilateral transtibial amputees.Seven unilateral transtibial amputees were studied during gait under three prosthetic foot conditions that were intended to vary push-off. Prosthetic foot-ankle push-off work, intact limb knee EAM and ground reaction impulses for both limbs during step-to-step transition were measured.Overall, trailing limb prosthetic push-off work was negatively correlated with leading intact limb 1st peak knee EAM (slope = -72 ± .22; p=.011). Prosthetic push-off work and 1st peak intact knee EAM varied significantly with foot type. The prosthetic foot condition with the least push-off demonstrated the largest knee EAM, which was reduced by 26% with the prosthetic foot producing the most push-off. Trailing prosthetic limb push-off impulse was negatively correlated with leading intact limb loading impulse (slope = -34 ± .14; p=.001), which may help explain how prosthetic limb push-off can affect intact limb loading.Prosthetic feet that perform more prosthetic push-off appear to be associated with a reduction in 1st peak intact knee EAM, and their use could potentially reduce the risk and burden of knee osteoarthritis in this population. © 2011 Elsevier B.V.

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