A longitudinal study of exercise metabolism during recovery from viral illness.

An élite athlete engaged in a longitudinal programme of physiological assessment suffered a loss of performance that was later ascribed to an asymptomatic viral illness. In this 15-month, single subject, repeated measures study it was possible to demonstrate a severe decrease of exercise performance following viral illness. The oxygen uptake equivalent to the onset of blood lactate accumulation of 4 mmol l-1 (OBLA) decreased by 17% following viral illness, then recovered slowly, but had not returned to pre-viral levels 50 weeks later. Steady state exercise metabolism was also affected. During prolonged exercise at 70% of VO2max the proportion of energy derived from carbohydrate metabolism increased and an inability to maintain euglycaemia was observed. In both the graded and prolonged exercise tests, a pronounced tachycardia was evident after viral illness, possibly as a result of a febrile response to the infection, or, a direct effect of the virus upon myocardial performance. These data provide some preliminary and unique findings of the effects of viral illness upon the physiological and metabolic responses to exercise in an élite athlete. The data also demonstrate the sensitivity of currently used laboratory measures of exercise performance to monitor the changes in physiological function during recovery from viral illness.     

Alteration of cerebral blood flow in patients with bacterial and viral meningoencephalitis.

PURPOSEOur purpose was to investigate cerebral blood flow disturbances in patients with bacterial and viral meningoencephalitis.METHODSForty-two patients with acute bacterial and viral meningoencephalitis and 14 control subjects were studied using 99mTc-hexamethylpropyleneamine oxime (HMPAO) single-photon emission computed tomography (SPECT). SPECT images were evaluated semiquantitatively. The results were compared with clinical severity of the meningoencephalitis assessed at the time of the SPECT study with the Hunt and Hess scale, with separately recorded focal clinical signs, and with the Glasgow outcome scale (GOS) after 3 weeks.RESULTSCount density values were significantly reduced in patients with bacterial meningoencephalitis as compared with the control subjects. Inhomogeneous tracer accumulation assessed by asymmetry indexes was significantly greater in patients than in the control group. With increasing Hunt and Hess scores, the count density values decreased and the asymmetry indexes increased. Patients with a poor outcome (GOS 1 to 3) had significantly higher asymmetry indexes and lower CDV values than did patients with a good outcome.CONCLUSIONGlobal and focal alterations of cerebral perfusion are frequent in bacterial and viral meningoencephalitis and correlate with acute clinical state.     

Infections and infestations of the gastrointestinal tract. Part 1: bacterial, viral and fungal infections

The purpose of this article is to review the imaging findings of various infections affecting the gastrointestinal tract. Barium examinations, computed tomography (CT), magnetic resonance imaging (MRI), and ultrasonography all play an important role in the diagnostic workup of gastrointestinal tract infections. Knowledge of differential diagnosis, sites of involvement, and typical imaging features of different infections can help in accurate diagnosis and guide treatment.     

The effects of hockey protective equipment on high-intensity intermittent exercise

PURPOSE: To examine the impact of hockey protective equipment on thermal and fluid homeostasis and power output, during a high-intensity, intermittent, exercise protocol. We hypothesized that protective equipment would increase core temperature and reduce sprint power after a simulated hockey game. METHODS: Eight men (26.8 +/- 1.7 yr) performed a repeated sprint test before and at the completion of a prolonged intermittent exercise protocol (game simulation) on a cycle ergometer under typical hockey ambient conditions. Reduction in exercise performance was calculated by comparing the pre- and postgame repeated sprint power outputs. The protocol was performed twice; once while wearing cotton undergarments only (NOPADS), and once while wearing cotton undergarments and the typical protective equipment worn during a hockey game (PADS). RESULTS: During the simulated game, skin temperatures (34.12 +/- 0.24 degrees C vs 28.85 +/- 0.31 degrees C) and core temperature accumulated area under the curve (70.85 +/- 8.52 vs 48.21 +/- 3.05 degrees C.min) were elevated in PADS versus NOPADS, respectively (P < 0.05). Sweat loss as a percent of body mass was greater in PADS versus NOPAD, as were working and recovery heart rates. Plasma lactate concentration was also higher after the simulated game in PADS versus NOPADS (9.64 vs 5.96 mM, P < 0.05). When comparing post- with pregame sprint power output, both peak and mean power outputs were reduced in PADS (P < 0.05), whereas NOPADS values were unchanged. CONCLUSIONS: Reduced power output at the completion of the simulated game in PADS was attributed to an elevated body temperature, dehydration, and a greater accumulation of blood lactate.     

British pilot study of exercise therapy. I. Middle-aged men.

The physiological and biochemical effects of a carefully graduated course of vigorous gymnasium training with two or three weekly exercise sessions lasting only 15 minutes have been studied in middle-aged London business men. Activity diaries and psychological questionnaires indicated that these men had a positive attitude to exercise which was probably greater than average. The gymnasium exercises caused a large oxygen debt and considerable rises in plasma catecholamines and lactate levels. A close correlation was found between the pulse rate during exercise and the Borg scale of perceived exertion, so that both could be used to ensure that short periods of exercise were sufficiently vigorous to produce a training effect, and protect against over-exertion. The acceptability of this particular exercise regime was shown by the low fall-out and injury rate. It is suggested that this exercise training programme possesses many features which are advantageous if increased physical activity is to be more widely used as a method of reducing some of the risk factors in coronary heart disease.     

Prospective study of respiratory infections at the U.S. Naval Academy

Midshipmen at the U.S. Naval Academy have recently suffered epidemics of upper respiratory tract infections. Seeking to determine cause, in June 1998 we enrolled 1,243 (99.5%) of 1,249 new midshipmen (plebes) and followed them during their first 11 months of training. Eighty-five plebes sought medical attention for acute respiratory disease. Using culture, serologic studies, and polymerase chain reaction, considerable evidence for respiratory pathogen infection was found among the ill subjects: Chlamydia pneumoniae in 41 (52.6%), Mycoplasma pneumoniae in 19 (25.3%), influenza in 11 (14.2%), Streptococcus pneumoniae in 6 (7.3%), and adenovirus in 1 (1.2%). Additionally, 873 (81%) the 1,077 plebes who completed an end-of-year questionnaire complained of having one or more respiratory symptoms (> 12 hours) during their first year of school. Of these, 132 (15%) reported that the symptoms significantly affected their performance. Study results suggest that respiratory infections were frequent, had a significant adverse impact on training, and were often attributable to bacterial pathogens.     

Cardiorespiratory and neuromuscular responses during water aerobics exercise performed with and without equipment

The aim of the study was to compare the cardiorespiratory and neuromuscular responses to water aerobics exercise performed with and without equipment. 15 women performed stationary jogging combined with elbow flexion/extension without equipment, with water-drag forces equipment and with water-floating equipment, at 2 submaximal cadences and at maximal cadence. Heart rate, oxygen uptake and electromyographic signal from biceps brachii, triceps brachii, biceps femoris and rectus femoris were collected during the exercise. The heart rate and oxygen uptake showed significantly higher values during the execution of the water aerobics exercise with either equipment compared to the execution without equipment. In addition, significant difference was found between submaximal cadences. For neuromuscular responses, no significant differences were found between the submaximal cadences for all muscles analyzed; however, significant differences were found between these submaximal cadences and the maximal cadence. Similarly, the results showed no significant differences between the execution of the exercise with or without equipment, except in the muscle activation of triceps brachii and biceps femoris, which was higher when using water-floating and water-drag forces equipment, respectively. In conclusion, the water aerobics exercise presented higher cardiorespiratory responses with equipment and also increased the cadence of execution. Nevertheless, neuromuscular responses were higher only at maximal cadence.     

NMR spectroscopy study of heart phospholipids. An exercise and anabolic steroids effect.

Because 31P NMR spectral analysis of phospholipid (PL) is an accurate and rapid technique for resolving the quantity of PL resonances and involving minimum chemical manipulations that may affect the integrity of the tissue (24-26), we studied the effect of anabolic steroid injection, exercise training, or a combination of both treatments on whole heart phospholipids using 31P NMR spectral analysis. Male Sprague-Dawley rats were randomly assigned to 4 groups of 11 each: sedentary control (C), steroid-treated (ST), exercise-trained (E), and exercise plus steroid-treated (ES). The ST and ES rats were administered nandrolone decanoate by i.m. injection every 7-9 d during the 10 wk study, while the C and E rats were injected with glycerol. The exercise rats ran on a treadmill, wearing a collar weight for 50 min/day, 5 days/wk. There was a significant difference in body wt among the four groups at the conclusion of the study; however, no significant differences in heart wt or in the ratio of heart wt:body wt were observed among the four groups. Myocardial phospholipid profiles of the exercise-trained rats were significantly (p less than 0.05) different from those of the untrained rats. The changes were enhanced somewhat by the steroid treatment. The profiles differed in the relative amounts of four of the nine myocardial phospholipids detected: phosphatidylcholine, phosphatidylethanolamine (PE), PE plasmalogen, and phosphatidylserine. We conclude that the observed changes in whole heart phospholipid compositions are due to experimental treatment specifically from exhaustive exercise and not from anabolic steroids or cardiac hypertrophy.(ABSTRACT TRUNCATED AT 250 WORDS)     

British pilot study of exercise therapy. II. Patients with cardiovascular disease.

Two groups of middle-aged men, one with and one without overt cardiovascular disease, were studied while they were taking part in a specially designed course of exercise therapy in a gymnasium. The "patients" group had at least two months pre-treatment to allow physical recovery and mental re-education before their initial very small test dose of exercise. Using short periods of progressive, mainly weight-loaded, isotonic exercises carefully regulated by control of pulse rate and avoidance of symptoms of over-exertion, both groups showed large increases in effort capacity and reductions in resting pulse rate, blood pressure and plasma lipid levels within two months. The safety of this particular form of exercise was shown in this high-risk population by the low drop-out rate and the absence of cardiovascular accidents in the gymnasium over a ten year period. It is suggested that, given suitable training of the staff and using the safeguards described, the presence of doctors and a cardiac resuscitation team is unnecessary in a gymnasium specializing in cardiac rehabilitation. This makes it possible for rehabilitation and physiotherapy departments throughout the country to carry out this effective and positive form of exercise therapy.     

Prospective study of kinesthesia after ACL reconstruction

Previous studies used a variety of methods to assess kinesthesia, thus no consensus exists regarding kinesthetic adaptation after anterior cruciate ligament (ACL) reconstruction. This study prospectively examined whether kinesthesia is adapted after ACL reconstruction, and then discussed the actual angular velocity required to properly assess kinesthesia in ACL-reconstructed patients. 31 patients were evaluated using the threshold to detect passive motion (TTDPM) test, which was applied preoperatively, and at 3, 6, and 12 months following surgery. TTDPMs were measured at 15° or 45° of knee flexion toward both extension and flexion with angular velocities of 0.1°/s or 0.2°/s. ACL-reconstructed knees showed significantly impaired TTDPMs compared to healthy knees before the operation at 15° of knee flexion toward extension and at 45° of knee flexion toward both extension and flexion at 0.2°/s (15° of knee flexion toward extension, P=0.036; 45° of knee flexion toward extension, P=0.015; 45° of knee flexion toward flexion, P=0.030). However, there were no significant differences after 3 months of follow-up. On the basis of these results, applying 0.2°/s seems appropriate to assess TTDPM for patients with an ACL reconstruction, and kinesthesia is adapted within 12 months after the operation. Sensory function and biomechanical stability are also adapted following ACL reconstruction.