Functional fitness and falls in older adults on haemodialysis

The number of older adults with end stage renal failure is rapidly increasing. Over the last 30 years, attitudes, technologies, resources and the premorbid health status of older adults have evolved and dialysis is now being offered routinely to this group. Dialysis is a life maintaining treatment but is demanding physically and psychologically and these burdens interplay with the normal consequences of aging. To ensure length of life is not preserved at the expense of quality requires focus on the interactions of end stage renal disease (ESRD), renal replacement therapy (RRT) and ageing-related problems, such as immobility and falls. However, despite these considerations being specifically referenced in national policy and recognised amongst dialysis groups internationally, there is limited literature regarding the specific and specialised needs of this patient group or guidance on focussed service development within the United Kingdom. This work describes the extent and impact of the problems at a local level, explores the depth and impact of these concerns for patients and staff. An extensive literature review was performed. The changing demographics of the renal patient population are described and current services set in the context of local and national planning and policy. The topics of kidney physiology, renal disease, physical fitness, falls, bone metabolism and rehabilitation in non-uraemic and dialysed older adults were studied. To respond to the patients’ reports and falls events, a study was proposed to assess measures of postural stability before and after a single haemodialysis session in older adults on maintenance haemodialysis. A small-scale exploratory study and feasibility pilot was problematic and prompted review of the research plans. Preliminary data must be interpreted with caution, but suggested that older haemodialysis patients might be weaker and less posturally stable than comparable non-dialysed older adults but that there was no significant effect of a haemodialysis session on the parameters measured. Reports of this initial study have been published in a peer-reviewed journal and presented locally and internationally. To evaluate fitness limitations from the patients’ perspective, a questionnaire study was administered to 66 older adult maintenance haemodialysis patients and 66 non-uraemic controls. The study revealed higher levels of inactivity, immobility, and dependency, less positive perception of life quality, lower mood, and fewer leisure and pleasure activities in the dialysis group. However, it did not reveal a significantly different falls incidence. This work is being prepared for publication. A third original project examined staff perceptions of patient fitness and exercise encouragement practices within our local unit. This demonstrated that staff members know of the benefits of encouraging exercise, accept it as part of their role and responsibility and want to promote exercise. Many are already doing so. However, some staff members lack knowledge and confidence. It is encouraging that staff members feel that patients are able and keen to improve their physical fitness and that they would take part in structured programs with regular encouragement and feedback. This work is submitted for national poster presentation and is being prepared for publication. The optimum design and implementation of exercise regimens for older haemodialysis patients is debated. The thesis concludes with a discussion of the findings and the implications both for service development and for future research. At the time of submission, a project scoping group is meeting to discuss the introduction of a lifestyle program involving exercise interventions, as recommended in this thesis, with the original data supporting a case of need. This group will seek finding for an exercise and lifestyle intervention project through the East Midlands Regional Innovation Fund

Liquid meal composition, postprandial satiety hormones, and perceived appetite and satiety in obese women during acute caloric restriction

OBJECTIVE: The purpose of this study was to compare postprandial satiety regulating hormone responses (pancreatic polypeptide (PP) and peptide tyrosine tyrosine (PYY)) and visual analog scale- (VAS) assessed perceived appetite and satiety between liquid high-protein (HP) and high-carbohydrate (HC) meals in obese women during acute (24-h) caloric restriction. DESIGN: Eleven obese premenopausal women completed two conditions in random order in which they consumed 1500 calories as six 250-calorie HP meals or six 250-calorie HC meals over a 12-h period. Blood samples were taken at baseline and every 20 min thereafter and analyzed for PP and PYY concentrations. At these same points, perceived hunger and fullness were assessed with a VAS. The incremental area under the curve (iAUC) was used to compare postprandial responses. RESULTS: THE 12-H PP AND PYY IAUC WERE GREATER (P0.05) DURING THE HP CONDITION (PP: 4727±1306 pg/ml×12 h, PYY: 1373±357 pg/ml×12 h) compared with the HC condition (PP: 2300±528 pg/ml×12 h, PYY: 754±246 pg/ml×12 h). Perceived hunger and fullness were not different between conditions (P>0.05). The greatest changes in PYY and perceived fullness occurred after the morning meals during both conditions. CONCLUSIONS: These data suggest that in obese women during acute caloric restriction before weight loss, i) liquid HP meals, compared with HC meals, result in greater postprandial PP and PYY concentrations, an effect not associated with differential appetite or satiety responses, and ii) meal-induced changes in PYY and satiety are greatest during the morning period, regardless of dietary macronutrient composition

Epicardial Conductors Can Lower the Defibrillation Threshold in Rabbit Hearts

During a defibrillation shock, epicardial conductors can introduce anti-stimulatory effects due to lowering of the voltage gradient in myocardial tissue under the conductor and stimulatory effects due to membrane polarization near edges. We hypothesized that increasing the area of conductors increases the defibrillation threshold (DFT), while increasing the amount of stimulatory edge of conductors decreases the DFT. To test this, we measured the DFT in excised rabbit hearts with and without sets of rectangular conductors having 250 or 500 mm2 area and 100, 200 or 400 mm length of edges perpendicular to the line intersecting the shock electrodes. Unlike previous reports in which conductors increased or did not change DFT, present results indicate a conductor geometry having area of 250 mm2 and edge of 200 mm decreases the DFT. This result is consistent with the hypothesis that stimulatory effects of the edge of a conductor can enhance defibrillation shock efficacy

Functional fitness and falls in older adults on haemodialysis

The number of older adults with end stage renal failure is rapidly increasing. Over the last 30 years, attitudes, technologies, resources and the premorbid health status of older adults have evolved and dialysis is now being offered routinely to this group. Dialysis is a life maintaining treatment but is demanding physically and psychologically and these burdens interplay with the normal consequences of aging. To ensure length of life is not preserved at the expense of quality requires focus on the interactions of end stage renal disease (ESRD), renal replacement therapy (RRT) and ageing-related problems, such as immobility and falls. However, despite these considerations being specifically referenced in national policy and recognised amongst dialysis groups internationally, there is limited literature regarding the specific and specialised needs of this patient group or guidance on focussed service development within the United Kingdom. This work describes the extent and impact of the problems at a local level, explores the depth and impact of these concerns for patients and staff. An extensive literature review was performed. The changing demographics of the renal patient population are described and current services set in the context of local and national planning and policy. The topics of kidney physiology, renal disease, physical fitness, falls, bone metabolism and rehabilitation in non-uraemic and dialysed older adults were studied. To respond to the patients’ reports and falls events, a study was proposed to assess measures of postural stability before and after a single haemodialysis session in older adults on maintenance haemodialysis. A small-scale exploratory study and feasibility pilot was problematic and prompted review of the research plans. Preliminary data must be interpreted with caution, but suggested that older haemodialysis patients might be weaker and less posturally stable than comparable non-dialysed older adults but that there was no significant effect of a haemodialysis session on the parameters measured. Reports of this initial study have been published in a peer-reviewed journal and presented locally and internationally. To evaluate fitness limitations from the patients’ perspective, a questionnaire study was administered to 66 older adult maintenance haemodialysis patients and 66 non-uraemic controls. The study revealed higher levels of inactivity, immobility, and dependency, less positive perception of life quality, lower mood, and fewer leisure and pleasure activities in the dialysis group. However, it did not reveal a significantly different falls incidence. This work is being prepared for publication. A third original project examined staff perceptions of patient fitness and exercise encouragement practices within our local unit. This demonstrated that staff members know of the benefits of encouraging exercise, accept it as part of their role and responsibility and want to promote exercise. Many are already doing so. However, some staff members lack knowledge and confidence. It is encouraging that staff members feel that patients are able and keen to improve their physical fitness and that they would take part in structured programs with regular encouragement and feedback. This work is submitted for national poster presentation and is being prepared for publication. The optimum design and implementation of exercise regimens for older haemodialysis patients is debated. The thesis concludes with a discussion of the findings and the implications both for service development and for future research. At the time of submission, a project scoping group is meeting to discuss the introduction of a lifestyle program involving exercise interventions, as recommended in this thesis, with the original data supporting a case of need. This group will seek finding for an exercise and lifestyle intervention project through the East Midlands Regional Innovation Fund

Stimulatory Current at the Edge of an Inactive Conductor in an Electric Field: Role of Nonlinear Interfacial Current–Voltage Relationship

Cardiac electric field stimulation is critical for the mechanism of defibrillation. The presence of certain inactive epicardial conductors in the field during defibrillation can decrease the defibrillation threshold. We hypothesized this decrease is due to stimulatory effects of current across the interface between the inactive conductor and the heart during field stimulation. To examine this current and its possible stimulatory effects, we imaged transmittance of indium-tin-oxide (ITO) conductors, tested for indium with x-ray diffraction, created a computer model containing realistic ITO interfacial properties, and optically mapped excitation of rabbit heart during electric field stimulation in the presence of an ITO conductor. Reduction of ITO to indium decreased transmittance at the edge facing the anodal shock electrode when trans-interfacial voltage exceeded standard reduction potential. The interfacial current-voltage relationship was nonlinear, producing larger conductances at higher currents. This nonlinearity concentrated the interfacial current near edges in images and in a computer model. The edge current was stimulatory, producing early postshock excitation of rabbit ventricles. Thus, darkening of ITO indicates interfacial current by indium reduction. Interfacial nonlinearity concentrates current near the edge where it can excite the heart. Stimulatory current at edges may account for the reported decrease in defibrillation threshold by inactive conductors

L-VRAP-a lunar volatile resources analysis package for lunar exploration

The Lunar Volatile Resources Analysis Package (L-VRAP) has been conceived to deliver some of the objectives of the proposed Lunar Lander mission currently being studied by the European Space Agency. The purpose of the mission is to demonstrate and develop capability; the impetus is very much driven by a desire to lay the foundations for future human exploration of the Moon. Thus, LVRAP has design goals that consider lunar volatiles from the perspective of both their innate scientific interest and also their potential for in situ utilisation as a resource. The device is a dual mass spectrometer system and is capable of meeting the requirements of the mission with respect to detection, quantification and characterisation of volatiles. Through the use of appropriate sampling techniques, volatiles from either the regolith or atmosphere (exosphere) can be analysed. Furthermore, since L-VRAP has the capacity to determine isotopic compositions, it should be possible for the instrument to determine the sources of the volatiles that are found on the Moon (be they lunar per se, extra-lunar, or contaminants imparted by the mission itself

Using job strain and organizational justice models to predict multiple forms of employee performance behaviours among Australian policing personnel

The overall purpose of this investigation was to examine the relationship between stress-related working conditions and three forms of employee performance behaviours: in-role behaviours, citizenship behaviours directed at other individuals and citizenship behaviours directed at the organization. The potentially stressful working conditions were based on the job strain model (incorporating job demands, job control and social support) as well as organizational justice theory. A sample of Australian-based police officers (n = 640) took part in this study and the data were collected via a mail-out survey. Multiple regression analyses were undertaken to assess both the strength and the nature of the relationships between the working conditions and employee performance and these analyses included tests for additive, interactional and curvilinear effects. The overall results indicated that a significant proportion of the explained variance in all three outcome measures was attributed to the additive effects of demand, control and support. The level of variance associated with the organizational justice dimensions was relatively small, although there were signs that specific dimensions of justice may provide unique insights into the relationship between job stressors and employee performance. The implications of these and other notable findings are discussed.<br /

Gastrointestinal Symptoms in 2- to 5-Year-Old Children in the Study to Explore Early Development

Gastrointestinal symptoms (GIS) are commonly reported in children with autism spectrum disorder (ASD). This multi-site study evaluated the prevalence of GIS in preschool-aged children with ASD/(n = 672), with other developmental delays (DD)/(n = 938), and children in the general population (POP)/(n = 851). After adjusting for covariates, children in the ASD group were over 3 times more likely to have parent-reported GIS than the POP group, and almost 2 times more likely than the DD group. Children with GIS from all groups had more behavioral and sleep problems. Within the ASD group, children with developmental regression had more GIS than those without; however, there were no differences in autism severity scores between children with and without GIS. These findings have implications for clinical management

Design of adjustable Tuned Mass Dampers using elastomeric O-rings

Tuned mass dampers (TMDs) are widely used in passive vibration control, and have been implemented on many engineering structures. In general, the design of TMDs is unique to each application; the choice of damping material and its in-situ performance are key issues that can affect design and prototyping costs. The present contribution demonstrates that TMDs can be built using ubiquitous and low-cost elastomeric O-rings. It is shown that the damping and stiffness characteristics of the O-ring can be predicted a priori, in order to achieve an initial design that is fit for purpose. Furthermore, it is shown that the nonlinear characteristics of the O-ring enable the device to be easily tuned in-situ, in order to optimise the final system. Finally, the simple configuration of the device makes it well suited to through-mounting or surface-mounting on thin-walled flexible structures such as beams and plates