Pulmonary arteriovenous malformations.
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Arteriovenous Malformations↗
Biomedical subjects
R J Robertson
Publications and source records attributed to R J Robertson.
Prescribing exercise in multiple short bouts versus one continuous bout: effects on adherence, cardiorespiratory fitness, and weight loss in overweight women.
OBJECTIVE: To investigate whether prescribing exercise in several short-bouts versus one long-bout per day would enhance exercise adherence, cardiorespiratory fitness, and weight loss in overweight adult females in a behavioral weight control program. DESIGN: Randomized controlled trial with subjects randomized to either a short-bout exercise group (SB, n = 28, age = 40.4 +/- 5.9 yrs) or a long-bout exercise group (LB, n = 28, age = 40.9 +/- 7.3 yrs), with subjects followed for a period of 20 weeks. Both groups were instructed to exercise 5 days per week with exercise duration progressing from 20 to 40 min per day. The LB group performed one exercise bout per day, whereas the SB group performed multiple 10 min bouts of exercise per day. The recommended caloric intake for all subjects was 5022-6277 kJ/day (1200-1500 kcal/day), with fat reduced to 20% of caloric intake. SUBJECTS: Fifty-six obese, sedentary females (BMI = 33.9 +/- 4.1 kg/m2). MEASUREMENTS: Exercise participation was assessed from self-reported diaries and Tri-Trac Accelerometers. Cardiorespiratory fitness was assessed using a submaximal cycle ergometer test. RESULTS: Exercising in multiple short-bouts per day improved adherence to exercise: the SB group reported exercising on a greater number of days (mean +/- s.d. = 87.3 +/- 29.5 days vs 69.1 +/- 28.9 days; P < 0.05) and for a greater total duration (223.8 +/- 69.5 min/week vs 188.2 +/- 58.4 min/week; P = 0.08) than the LB group. Predicted VO2Peak increased by 5.6% and 5.0% for the LB and SB groups, respectively (P < 0.05). There was a trend for the weight loss to be greater in the SB group (-8.9 +/- 5.3 kg) compared to the LB group (-6.4 +/- 4.5 kg; P < 0.07). CONCLUSION: These results suggest that short-bouts of exercise may enhance exercise adherence. Short-bouts of exercise may also enhance weight loss and produce similar changes in cardiorespiratory fitness when compared to long-bouts of exercise. Thus, short-bouts of exercise may be preferred when prescribing exercise to obese adults.
Adult↗
Case report: the use of turbo-FLASH MRI for delineating vascular anatomy in bronchopulmonary sequestration.
We present a case of intralobar bronchopulmonary sequestration diagnosed by MRI using a turbo-FLASH sequence. This sequence offers certain advantages over the conventional MRI techniques used previously.
Adult↗
The acute effects of exercise intensity on HDL-C metabolism.
To determine whether exercise intensity influences acute HDL-C responses, 12 male recreational runners (24.8 +/- 4 yr) who ran 15-30 miles.wk-1 exercised on a motor driven treadmill at 60% (L) and 75% (H) VO2max. A counterbalanced experimental design was utilized and energy expenditure was 800 Kcal. Fasting blood samples were obtained 24 h before exercise (24 PRE), immediately post-(IPE), 1 h post- (1 h PE), 6 h post- (6 h PE), and 24 h post- (24 h PE) exercise and analyzed for HDL-C and HDL2&3-C. In addition, postheparin plasma samples, obtained 24 h PRE, 6 h PE, and 24 h PE were analyzed for lipolytic activity--LPLA and HTGLA. An exercise trial by time interaction was observed for HDL-C (P < 0.01). Post-hoc analysis revealed no change in HDL-C following the L trial. However, an increase in HDL-C was observed 24 h PE (P < 0.01) following the H trial. The increase in HDL-C was attributed to an elevated HDL3-C (P < 0.01), with no change in HDL2-C. Analysis of plasma lipolytic activity revealed an increase in LPLA 24 h PE (P < 0.05) which may be responsible for the postexercise alterations in HDL-C. However, HTGLA decreased 6 h PE (P < 0.01) and 24 h PE (P < 0.05). We conclude that increases in HDL-C levels following endurance activity are influenced, in part, by the exercise intensity.
Adult↗
A thermal perception scale for use during resting exposure to cold air.
The present investigation introduces a thermal perception scale (TS) for use during protracted resting cold exposure. The scale contains categories ranging consecutively from 0, i.e., Nothing at all, to 10, i.e., Very, very cold. Eight Caucasian men were randomly exposed to ambient air in a climatically controlled environmental chamber of 8 degrees, 12 degrees, and 27 degrees C for 120 min. on 3 separate occasions and monitored for rectal temperature (Tre), mean skin temperature (Tsk), ventilation (VE), and oxygen consumption (VO2). The terminal perceptual categories were anchored for 8 subjects and a standard set of instructions was presented prior to each trial. The anchor temperature was the room air in the anteroom which was 27 degrees C, representing 0, i.e., "Nothing at all," to extend the scale so that subsequent judgments on the scale were expressed in relation to this category. In addition, the subjects were also asked to imagine the coldest that they have ever experienced and this was designed to anchor "Very, very cold." The relations between scale scores and the thermoregulatory variables were examined with a simple linear regression and coefficients of correlation and determination for each subject. High coefficients of determination between Tsk, VO2, and VE indicated that, for individual subjects, the scores on the scale were related to VE, Tsk, and VO2. High reliability coefficients for TS were also reported. In addition, the ratings and VO2 relation tended to be similar between subjects. Therefore, this scale appears to be a valid and reliable tool for measuring the perception of cold when at rest in air.
Acclimatization↗
Effects of body morphology and mass on thermal responses to cold water: revisited.
Seven male volunteers were divided into two groups based on body morphology and mass. The large body mass (LM) group (n = 4) was 21.2 kg heavier and 0.32 m2.kg-1 smaller in surface area-to-mass ratio (P < 0.05) than the small body mass (SM) group (n = 3). Both groups were similar in total body fat and regional skinfold thicknesses. All subjects were immersed to the first thoracic vertebrae for 120 min in stirred water at 18 degrees C. Overall, tissue insulation was similar (P > 0.05) between the SM and LM groups across time. Perceptual ratings of thermal sensation increased (P < 0.05) across time. Therefore, as cold water immersion progressed, tissue insulation was similar and thermal sensation increased (P < 0.05) in males matched for subcutaneous fat and total fat but differing in body mass and morphology.
Analysis of Variance↗
Effect of repeated exercise bouts on high density lipoprotein-cholesterol and its subfractions HDL2-C and HDL3-C.
Nine sedentary men (mean age, 22.8 yrs) were studied during and after treadmill exercise at 65% VO2max to determine the number of repeated exercise bouts required to bring about a sustained elevation in HDL-cholesterol and its subfraction HDL2-C and HDL3-C. A Latin square counterbalanced design was used. Thirty minute exercise sessions were undertaken in the following patterns: (1) single bout, (2) two bouts on alternate days, and (3) three bouts on alternate days. The exercise bouts in patterns 2 and 3 were separated by 48 h. Patterns 1, 2 and 3 were conducted 7 days apart. Blood samples were obtained prior to each pattern and at 5 min, 24 and 48 h after the last session within each pattern. There were no significant differences in triglycerides and total cholesterol between the selected blood sampling points for all patterns. Total HDL-C remained higher (p < 0.05) than the pre-exercise level 5 min [pattern 1: 39.0 vs 41.2 mg.dl-1, pattern 2: 37.1 vs 39.2 mg.dl-1, pattern 3: 38.8 vs 42.7 mg.dl-1] and 24 h [pattern 1: 39.0 vs 39.4 mg.dl-1, pattern 2: 37.1 vs 39.1 mg.dl-1, pattern 3: 38.8 vs 42.6 mg.dl-1] post-exercise. Total HDL-C declined to pre-exercise values 48 h post-exercise in all patterns. HDL2-C was lower (p < 0.05) than pre-exercise 48 h for all exercise patterns. For all patterns, HDL3-C levels were higher (p < 0.05) at the 5 min and 48 h post-exercise time points than at the pre-exercise.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Amino acid arterial concentration and muscle exchange during submaximal arm and leg exercise: the effect of dihydroxyacetone and pyruvate.
The mixture of dihydroxyacetone and pyruvate (DHAP) is an ergogenic aid that enhances muscle glucose extraction during prolonged aerobic exercise. In order to evaluate the effect of DHAP on muscle amino acid extraction during exercise, we measured arterial concentration and muscle exchange of amino acids in 18 untrained healthy male subjects (aged 20-30 years) performing dynamic arm (60% VO2 max, n = 9) or leg (70% VO2 max, n = 9) exercise to exhaustion with and without dietary supplementation of DHAP. The subjects consumed diets (146 kJ kg body weight-1 day-1) containing either 100 g polyglucose, Polycose (placebo, P) or DHAP (3:1, treatment) substituted for a portion of carbohydrate. The two diets were administered in a double-blind, random, crossover order for a 7-day period. At least 7 days separated the dietary protocols. Blood samples were drawn through radial artery and axillary or femoral vein catheters at rest, during exercise and at exhaustion. Arterial alanine concentration increased by 30% during arm exercise and by 50-60% during leg exercise. No other arterial amino acid concentration changed during exercise. At exhaustion, arterial alanine concentration decreased to pre-exercise levels with arm exercise but remained elevated after leg exercise. Despite changes in arterial concentrations of alanine with exercise, muscle exchange of alanine was not altered with exercise. Exercise did not alter muscle exchange of any amino acid. Arterial amino acid concentrations and muscle exchange of amino acids with exercise were similar with or without DHAP feeding.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Physiological responses to maximal treadmill and handweighted exercise.
The purpose of this investigation was to compare the peak physiological responses among four protocols that employed different amounts of handweighted exercise in 16 males (aged 26.3 +/- 4.1 years). The four protocols were (a) uphill treadmill running (UR; 3.36 m.s-1, 2.5% grade increase-3 min-1); (b) uphill treadmill walking while pumping 1.36-kg handweights (HW) (UWHW; 1.79 m.s-1, 5.0% grade increase x 3 min-1; (c) treadmill walking while pumping .91-kg HW (WHW; 1.79 m.s-1, 0% grade, .91-kg HW increase x 3 min-1); and (d) standing in place and pumping HW (SHW; arm work as described in WHW). It was hypothesized that the peak responses would be inversely proportional to the estimated muscle mass activated (i.e., UR = UWHW > WHW > SHW). Dependent variables included peak oxygen uptake (VO2 peak), peak heart rate (HRpeak), peak ventilation (Ve peak), and peak respiratory exchange ratio (RERpeak). No differences were noted between UR and UWHW with respect to any of the dependent variables. All variables (except RERpeak) were greater (p < .01) in UR and UWHW than either WHW or SHW. RERpeak was greater (p < .01) in UR and UWHW than in WHW. VO2 peak and HRpeak were greater (p < .01) in WHW when compared to SHW. Mean VO2 peak was 97.5, 69.7, and 60% of UR for UWHW, WHW, and SHW, respectively. Therefore, walking and pumping handweights provides a maximal stimulus to the oxygen transport system.
Adult↗
A controlled study of sacroiliitis in Behçet's disease.
Radiographs of the sacroiliac joints of 34 patients with Behçet's disease were read blind by a senior radiologist. They were compared with those from 25 controls, 14 of whom were healthy. The remainder (11) had other rheumatological disorders including six who had AS. One patient with Behçet's disease had radiologically proven sacroiliitis only but her history was atypical and she was B27 positive. All patients with AS had definite sacroiliitis. Five out of 34 patients with Behçet's disease and four of 25 controls (three healthy, one with SLE) had equivocal sacroiliitis. Whilst appreciating that the numbers in this study are not large, we find no evidence of an increased prevalence of sacroiliitis in Behçet's disease.
Adult↗
Effect of a single exercise bout on serum triglycerides in untrained men.
Seven sedentary men (mean age, 22.5 yrs) were studied during and after treadmill exercise at 65% VO2max to determine the effect of a typical acute exercise bout on serum triglycerides. A venous blood sample was drawn immediately prior to a 30 minute treadmill exercise session, 5 min, 24 and 48 h after exercise. There were no significant differences in triglycerides and total cholesterol between the selected blood sampling points. Total HDL-C was higher (p < 0.05) at 5 min (44.0 SE +/- 3.0 mg.dl-1) than pre-exercise (41.5, SE +/- 3.0 mg.dl-1). Total HDL-C did not differ between pre-exercise and both 24 and 48 h. Unlike prolonged heavy exercise, a typical exercise session does not bring about alterations in serum triglycerides.
Adult↗
Are beta-endorphins and thermoregulation during cold-water immersion related?
The purpose of this investigation was to determine the relationship between core temperature (Tre), tissue insulation (I), and beta-endorphins (beta-END) during immersion in cold water. To test this, 21 males were immersed to the first thoracic vertebra for 120 min in stirred water at either 18 degrees, 22 degrees, or 26 degrees C. Subjects were divided with respect to body fat [high fat (HF) = 18-22%, n = 11; low fat (LF) = 8-12%, n = 10] and randomly assigned to one of the three temperatures. Blood was drawn at 25 and 5 min (T-25 and T-5, respectively) before immersion, after 1 h of immersion, and 5 min before the completion of the second hour (T + 60 and T + 120, respectively). No significant relationship was found between delta beta-END and delta I or delta Tre. The relationship between the changes in thermoregulatory variables and delta beta-END did not differ between the HF and LF groups. Also, beta-END (adjusted for plasma volume) was lower (P < 0.05) in the HF vs. the LF group. beta-END (pg.ml-1) increased (P < 0.05) as time increased from T-25 to T + 60 and were not progressive with duration of immersion. Thus, beta-END did not increase in proportion to level of heat loss.
Adult↗
Primary malignant localized fibrous tumours of the pleura: clinical, radiological and pathological features.
Localized fibrous tumours of the pleura are rare primary pleural tumours that may exhibit malignant behaviour in approximately 20% of cases. The clinical, radiological and pathological features of five patients with malignant localized fibrous tumours of the pleura are presented. Clinical symptoms included chest pain, breathlessness and cough. Hypertrophic pulmonary osteoarthropathy (HPOA) occurred in one patient. Chest radiographs and thoracic computed tomography (CT) demonstrated large necrotic masses, with focal calcification and compressive atelectasis of the underlying lung. Histological features were variable and resulted in designation of these tumours as localized fibrous tumours of the pleura of low or high grade malignancy. The grading of malignancy did not correlate with final outcome, adequacy of surgical excision being the most important factor. These tumours have been referred to as benign pleural fibromas or localized mesotheliomas, but these names are inaccurate and the term localized fibrous tumour of the pleura is to be preferred. This term should also include tumours such as malignant fibrous histiocytoma of the pleura.
Aged↗
Changes in peak oxygen uptake following computerized functional electrical stimulation in the spinal cord injured.
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Adult↗
The validity of regulating exercise intensity by ratings of perceived exertion.
The purpose of this investigation was to examine the regulation of exercise intensity by using Ratings of Perceived Exertion (RPE). The RPE equivalent to 50% and 70% VO2max was estimated by using standard clinical protocols on a treadmill and cycle ergometer. Subjects then produced the target RPEs on these modalities. Physiological validity of perceptually regulated exercise intensity was determined by comparing VO2 and heart rate between estimation and production trials at the same relative intensity. With one exception, RPE was found to be a valid means of regulating exercise intensity both intra- and intermodally at 50% and 70% VO2max. Perceptual regulation of intramodal treadmill exercise was not valid at 70% VO2max in that both VO2 and heart rate were significantly lower during production than estimation. The present results also indicate that target RPE estimated during a cycle ergometer graded exercise test is more accurate for regulating exercise intensity than when the target RPE is estimated during a treadmill test. The lower accuracy found for treadmill production at the higher exercise intensity may have been caused by the use of a test protocol during the estimation trial that included relatively slow speeds and large inclines. In general, RPE provide a physiologically valid method of regulating exercise intensity.
Adolescent↗
Abatement of exertional perceptions following dynamic exercise: physiological mediators.
Perceptual and physiological congruity was examined during recovery from high-intensity dynamic exercise. Nine males (24.8 +/- 0.6 yr; VO2max; 52.3 +/- 1.5 ml.kg-1.min-1) undertook in random order four maximal treadmill protocols. Treadmill speed was held constant (5.3 km.h-1) while grade was incremented by 2, 4, 6, or 8% every 3 min for protocols A, B, C, and D, respectively. Ratings of perceived exertion (RPErec; Borg 15-point scale), ventilation (VE), respiratory rate (RR), oxygen uptake (VO2), and heart rate (HR) were measured preexercise and during each min of a 12-min supine postexercise period that immediately followed treadmill testing. Ratings were obtained for the peripheral perceptual signal arising from the legs (RPErec-L), the respiratory-metabolic signal from the chest (RPErec-C), and the overall body signal (RPErec-O). Blood pH was measured preexercise and during min 1, 6, and 12 of recovery. RPErec-L and RPErec-O were lower (P less than 0.05) and blood pH higher (p less than 0.05) following protocol A than D at all recovery time points. RPErec-C, VE, and RR were lower (P less than 0.05) for protocol A than D at all recovery time points. Differences among protocols were not noted for VO2 or HR at any recovery time point. The decay in signal strength for both RPErec-L and RPErec-O following high-intensity exercise reflected the abatement of metabolic acidosis. RPErec-O was influenced by the abatement of pulmonary ventilation during the postexercise period.
Acidosis↗
Secretor status and heterosexual transmission of HIV.
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Enzyme-Linked Immunosorbent Assay↗
The radiology of Askin tumours.
The Askin tumour is a highly malignant primitive neuroectodermal tumour (PNET) of the chest wall occurring in children and young adults. We describe three cases to illustrate the clinical and radiological aspects of this tumour, which are not well documented. Patients present with a chest wall mass, pain and constitutional symptoms. Radiology demonstrates a large soft tissue chest wall mass, local rib erosion and pleural effusion. Recurrence tends to be local chest wall, pulmonary or skeletal. The prognosis is poor. Askin tumours must be considered in the differential diagnosis of chest wall masses in children and young adults.
Bone and Bones↗