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PubMed1993

Pain complaints and cognitive status among elderly institution residents.

OBJECTIVE: To examine the association between self-reported pain and cognitive impairment among frail elderly institution residents. DESIGN: A cross-sectional correlational study. SETTING: A large urban nursing home and congregate apartment complex housing predominantly Jewish elderly. PARTICIPANTS: Seven hundred fifty-eight elderly institution residents (30% in the nursing home, 70% in congregate apartments). The sample was 70% female and averaged 83.3 years of age. MEASUREMENTS: Respondent self-reports tapped pain intensity, number of localized pain complaints, cognitive status, and disability in performance of activities of daily living. Attending physicians or physician assistants rated respondents' health status. MAIN RESULTS: Pain intensity and number of localized pain complaints bore small but significant negative relationships to cognitive impairment. Pain was positively associated with physician-rated ill health and functional disability. The association between pain and cognitive status remained significant even when controlled statistically for effects of physical health and functional disability. Item-by-item examination of localized pain complaints indicated that markedly cognitively impaired individuals were less likely to report pain in the back and joints. However, examination of possible physical causes of reported pain revealed no differences between pain reports of cognitively impaired versus intact individuals in either the presence or the absence of a likely physical cause. CONCLUSIONS: These data provide no evidence for the "masking" of pain complaints by cognitive impairment. They suggest instead that, although cognitively impaired elderly may slightly underreport experienced pain, their self-reports are generally no less valid that those of cognitively intact individuals. Limitations of the research are acknowledged and implications for treatment of cognitively impaired institution residents are discussed.

Activities of Daily Living↗
PubMed1996

Impact of a 12-month exercise program on the physical and psychological health of osteopenic women.

OBJECTIVE: To describe the effect of a supervised physical activity program on the physical and psychological health of osteopenic women. DESIGN: A randomized controlled trial. SETTING: Sherbrooke, Quebec, Canada. PARTICIPANTS: A total of 124 community-living postmenopausal women, between 50 and 70 years of age, with low bone mass took part in the study. INTERVENTION: Subjects allocated to the experimental group performed weight-bearing exercises (walking, stepping up and down from benches), aerobic dancing, and flexibility exercises for 60 minutes, three times a week, over a period of 12 months. All subjects were invited to attend bi-monthly educational seminars covering topics related to osteoporosis. OUTCOME MEASURES: Spinal and femoral bone mineral density (BMD), functional fitness (flexibility, coordination, agility, strength/endurance, cardiorespiratory endurance), psychological well-being, back pain intensity, and self-perceived health. RESULTS: Spinal BMD stabilized in the exercisers while decreasing significantly in the controls (P = .031). No change in femoral BMD was observed in either group (P = .597). Four of the five parameters chosen to evaluate functional fitness, namely flexibility, agility, strength, and endurance, were affected positively by the exercise program (all P < .01). Adjusting for prescores by means of an analysis of covariance revealed a significant difference between the groups in psychological well-being, which favored the exercisers (P = .012). After 12 months, back pain reported by exercisers was lower than that reported by controls (P = .008). Finally, self-perceived health increased in the exercise group, whereas no difference was observed in the control group (P = .790). CONCLUSION: These results suggest that after 12 months, exercising can produce a significant increase above initial levels in the functional fitness, well-being, and self-perceived health of osteopenic women. Intensity of back pain can also be lowered by exercise. The exercise program succeeded in stabilizing spinal BMD but had no effect on femoral BMD.

Aged↗
PubMed1995

Effect of feeding state on the response of horses to repeated bouts of intense exercise.

Four mature Standardbred horses were used in a 2-period cross-over design experiment to evaluate the effect of feeding state (fed or fasted) on metabolic response to 2 repeated bouts of exercise. Horses were either fasted 15 to 16 h before exercise or fasted for 12 h and then fed 2 kg of whole corn 2.5 to 3 h before exercise. In the first period, 2 horses in each feeding state were exercised. In the second period, the treatments were switched. The exercise test consisted of 2 exercise bouts separated by a 90 min recovery period. Each exercise bout included a warm-up phase and a high intensity phase (1600 m at 11 m/s on a 2% graded treadmill). Blood samples collected during the exercise test were analysed for glucose, non-esterified fatty acids (NEFA), insulin and lactate concentrations. Fasted horses had lower insulin concentrations and higher NEFA concentrations at the onset of exercise (P < 0.05). NEFA concentrations were consistently higher (P < 0.05) in the fasted horses until the high intensity phase of the second exercise bout. Feeding state did not affect heart rate or plasma lactate responses to exercise. Plasma glucose concentrations tended to decline in the fed horses during the first exercise bout. Neither a positive nor a negative effect of feeding state on horses performing repeated bouts of intense exercise were found.

Animals↗
PubMed2004

The CSF and arterial to internal jugular venous hormonal differences during exercise in humans.

Strenuous exercise increases the cerebral uptake of carbohydrate out of proportion to that of oxygen, but it is unknown whether such enhanced carbohydrate uptake is influenced by the marked endocrine response to exercise. During exhaustive exercise this study evaluated the a-v differences across the brain (a-v diff) of hormones that could influence its carbohydrate uptake (n= 9). In addition, neuroendocrine activity and a potential uptake of hormones via the cerebrospinal fluid (CSF) were assessed by lumbar puncture postexercise and at rest (n= 6). Exercise increased the arterial concentration of noradrenaline and adrenaline, but there was no cerebral uptake. However, following exercise CSF noradrenaline was 1.4 (0.73-5.5) nmol l(-1), and higher than at rest, 0.3 (0.19-1.84) nmol l(-1) (P < 0.05), whereas adrenaline could not be detected. Exercise increased both the arterial concentration of NH(4)(+) and its a-v diff, which increased from 1 (-12 to 5) to 17 (5-41) micromol l(-1) (P < 0.05), while the CSF NH(4)(+) was reduced to 7 (0-10) versus 11 (7-16) micromol l(-1) (P < 0.05). There was no release from, or accumulation in the brain of interleukin (IL)-6, tumour necrosis factor (TNF-alpha), heatshock protein (HSP72), insulin, or insulin-like growth factor (IGF)-I. The findings indicate that for maximal exercise, the concentration of noradrenaline is increased within the brain, whereas blood borne hormones and cytokines are seemingly unimportant. The results support the notion that the exercise-induced changes in brain metabolism are controlled by factors intrinsic to the brain.

Adult↗
PubMed2003

Enhancement of microvessel tortuosity in the vastus lateralis muscle of old men in response to endurance training.

Muscle microvascularization is usually quantified in transverse sections, in absolute terms (capillaries around fibres, CAF, or capillary-to-fibre ratio, C/F) or as CAF related to fibre area (CAF/area, CAFA). The capillary-to-fibre perimeter exchange ratio (CFPE) has been introduced in order to assess the role of the capillary-to-fibre interface in resistance to O(2) diffusion. The ratio between the length of capillaries in contact with fibres and fibre perimeter (LC/PF) has also been used as an index for capillary tortuosity. The possibility of change in capillary tortuosity with endurance training was not considered in previous studies. Consequently, this study investigated the effect of 14 weeks of endurance training on muscle microvascularization, including microvessel tortuosity, in 11 elderly men (8th decade). Microvessels were analysed using the CD31 antibody. Together with the significant increase in peak oxygen exchange and citrate synthase activity, there was a significant increase in C/F. While CFPE and CAFA remained unchanged, an important finding was the clear increase in LC/PF (56%; P < 0.001) for a same sarcomere length. We also found a strong correlation between oxidative enzyme activity and LC/PF both before and after training. These results indicate that endurance training induces significant remodelling in the microvessel network in elderly men and that an increase in the degree of microvessel tortuosity would be an important mechanism of adaptation to endurance training.

Aged↗
PubMed2004

Intense interval training enhances human skeletal muscle oxygen uptake in the initial phase of dynamic exercise at high but not at low intensities.

The present study tested the hypothesis that intense interval training enhances human skeletal muscle blood flow and oxygen uptake (VO2) at the onset of dynamic exercise. We also investigated whether possible training effects were dependent on exercise intensity. Six habitually active males carried out 7 weeks of intermittent-exercise one-legged knee-extensor training at an intensity corresponding to approximately 150% of peak thigh VO2 on three to five occasions per week. After the training period, cardiovascular and metabolic measurements were performed during knee-extensor exercise with the trained leg (TL) and the control leg (CL) for 10 min at intensities of 10 and 30 W, and also for 4 min at 50 W. Femoral venous blood flow was higher (P < 0.05) in TL than CL from 75 to 180 s at 30 W ( approximately 75 s: 3.43 +/- 0.20 versus 2.99 +/- 0.18 l min(-1)) and from 40 to 210 s at 50 W ( approximately 75 s: 5.03 +/- 0.41 versus 4.13 +/- 0.33 l min(-1)). Mean arterial pressure was not different between legs. Thus, thigh vascular conductance was higher (P < 0.05) in TL than CL from 35 to 270 s at 30 W and from 150 to 240 s at 50 W. Femoral arterial-venous (a-v) O2 difference was higher (P < 0.05) in TL than CL from 20 to 70 s at 30 W, but not different between TL and CL at 50 W. Thigh VO2 was higher (P < 0.05) in TL than CL from 20 to 110 s at 30 W ( approximately 45 s: 0.38 +/- 0.04 versus 0.30 +/- 0.03 l min(-1)), and from 45 to 240 s at 50 W ( approximately 45 s: 0.64 +/- 0.06 versus 0.44 +/- 0.08 l min(-1)). No differences were observed between TL and CL during exercise at 10 W. The present data demonstrate that intense interval training elevates muscle oxygen uptake, blood flow and vascular conductance in the initial phase of exercise at high, but not at low, intensities.

Adult↗
PubMed2000

Near-infrared study of fluctuations in cerebral hemodynamics during rest and motor stimulation: temporal analysis and spatial mapping.

We have noninvasively studied the motor cortex hemodynamics in human subjects under rest and motor stimulation conditions using a multichannel near-infrared tissue spectrometer. Our instrument measures optical maps of the cerebral cortex at two wavelengths (758 and 830 nm), with an acquisition time of 160 ms per map. We obtained optical maps of oxy- and deoxy-hemoglobin concentration changes in terms of amplitudes of folding average, power spectrum and coherence at the stimulation repetition frequency, and the phase synchronization index. Under periodic motor stimulation conditions, we observed coherence and frequency or phase synchronization of the local hemodynamic changes with stimulation. Our main findings are the following: (1) The amplitude of the hemodynamic response to the motor stimulation is comparable to the amplitude of the fluctuations at rest. (2) The spatial patterns of the oxy- and deoxy-hemoglobin responses to the stimulation are different. (3) The hemodynamic response to stimulation shows a spatial localization and a level of phase synchronization with the motor stimulation that depends on the stimulation period.

Adult↗
PubMed2006

Impact of perforation impedance on the transmission loss of reactive and dissipative silencers.

The effect of perforation impedance on the acoustic behavior of reactive and dissipative silencers is investigated using experimental and computational approaches. The boundary element method (BEM) is applied for the prediction of transmission loss of silencers with different perforation geometries. The variations are considered in the porosity (8.4 and 25.7%) and hole diameter (0.249 and 0.498 cm) of perforations for both reactive and dissipative silencers, as well as the fiber filling density (100 and 200 kg/m3) for the latter. The acoustic impedance for a number of perforations in contact with air alone and fibrous material has been incorporated into the predictions, which are then compared with the measured transmission loss using an impedance tube setup. The results demonstrate the significance of the accuracy of the perforation impedance in the predictions for both reactive and dissipative silencers.

Acoustics↗
PubMed2005

Seven year changes in health status and priorities for improvement of health in patients with rheumatoid arthritis.

OBJECTIVES: To examine possible changes in priorities for improvement in health and health status from 1994 to 2001 within the setting of the Oslo Rheumatoid Arthritis (RA) Register, which provides representative data for the entire RA population in the county. METHODS: All living patients in the Oslo RA Register area received a postal questionnaire in 1994 and 2001, including the Arthritis Impact Measurement Scales 2 (AIMS2), Short Form-36, the modified Health Assessment Questionnaire, and pain and fatigue visual analogue scales (VAS). Priorities for improvement in health were examined through question 60 in AIMS2, where patients are asked to indicate three of 12 areas of health where they would most like to see improvement. RESULTS: The number of respondents aged 20-79 years in 1994/2001 was 932/830, with similar demographic characteristics (78.8/78.3% were female, mean age 60.6/60.8, and disease duration 12.6/13.9 years). Health status was improved in all dimensions, with statistical improvement for the physical dimension, global health and pain, from 1994 to 2001. The profile of priorities remained mostly unchanged. Improvement in pain had the highest priority in both cohorts. Both symptom modifying and disease modifying drugs were more extensively used in 2001. CONCLUSIONS: Health status had improved from 1994 to 2001, probably because of access to better and more aggressive treatments. Pain remained the area of highest priority for improvement among patients with RA-despite an improved level of pain in 2001.

Adult↗
PubMed1976

The reproducibility of submaximal work heart rates-an interim report.

Work heart rates were taken from four subjects performing standardized bouts of work on the Monark Ergometer. Whilst a linear relationship was observed between heart rate and work intensity on any one day, it is evident that day to day variations in the position (intercept) of these lines exists. The slopes are virtually identical for all subjects and for different days, however the position of the lines differs widely both between and within subjects. The best linear regression equation developed for the prediction of heart rate after 180 seconds of work from pre-exercise heart rate and work intensity was found to have 95% confidence limits of +/- 12.7 beats. Heart rates are reproducible 95% of the time to within +/- 12.2 beats when pre-exercise heart rate is ignored.

Heart Rate↗
PubMed1998

Effect of exercise induced hypoxaemia on myocardial repolarisation in severe chronic obstructive pulmonary disease.

BACKGROUND: Exercise training is being promoted increasingly for patients with chronic obstructive pulmonary disease (COPD). Many of these patients experience exercise related arterial desaturation but the clinical importance of these hypoxaemic episodes is not known. QTc dispersion is a marker of myocardial repolarisation abnormalities and there has been much interest in its role as a non-invasive predictor of cardiac arrhythmias and sudden death. However, little is known about the dynamic effects that exercise and hypoxaemia have on QTc dispersion in patients with COPD. METHODS: 20 patients with severe COPD (FEV1 < 40% predicted) undertook two 15 minute treadmill tests at a speed calculated to produce a constant workload of 50% maximum oxygen consumption (VO2max) during which they were blindly given either air or 35% oxygen in random order. Physiological measurements taken throughout exercise included 12 lead electrocardiograms from which QTc dispersion values were calculated according to standard criteria. Nine of the patients who desaturated with exercise were studied further. A similar degree of hypoxaemia was induced at rest by giving them a titrated mixture of air and oxygen and the changes in QTc dispersion were recorded. RESULTS: 11 of the 20 patients developed significant hypoxaemia (desaturation by > or = 5% to < 90%) with exercise breathing air. There were no significant changes in QTc dispersion with either exercise or hypoxaemia. There were no significant changes in QTc dispersion when comparing those who did and did not desaturate, and those with and without a high baseline QTc dispersion values (60 ms). Induced hypoxaemia without exercise also failed to worsen QTc dispersion. CONCLUSIONS: No evidence was found to suggest that exercise, even when associated with hypoxaemia, causes myocardial repolarisation abnormalities in patients with COPD.

Aged↗
PubMed2004

Oscillatory patterns in a rotating aqueous suspension.

Suspensions of granular material in glycerin-water mixtures agitated in horizontally aligned rotating tubes show a whole variety of patterns. The stationary pattern of a homogeneous distribution and a chain of rings have been investigated before. Here we report on two types of oscillatory states in the same system. For a certain range of the rotation frequency and sufficiently high viscosity traveling waves propagate with constant velocity back and forth along the tube in an almost homogeneous distribution of sedimenting particles. The transition from a stationary to the traveling-wave state is found to be an imperfect supercritical bifurcation. The dependence of the wave length and speed on the tube's rotation frequency and the dynamic viscosity of the fluid are determined. Experiments with low viscosities show no traveling waves but low-frequency oscillations, when the previously known chain of rings undergoes a secondary instability.

Glycerol↗
PubMed2004

The foam/emulsion analogy in structure and drainage.

The often quoted analogy between foams and emulsions is experimentally tested by studying properties after settling and under forced drainage of oil-in-water emulsions of drop size similar as for bubbles generally used in foam experiments. Observations with regard to structure, water fraction and drainage wave properties confirm the expected similarity in the low flow rate range. However, while for foams a convective circulation on the scale of the container sets in for values of water fraction exceeding about 0.2, no such convection is found in emulsions. Here instabilities are only encountered at water fractions of about 0.4, close to the void fraction of random packings of spheres. These take on the form of descending pulses of increased water fraction and lead to the transition from a frozen to a locally agitated structure.

Biophysics↗