No description available.

No description available.

Recent reports suggest that human immunodeficiency virus (HIV), the virus causing AIDS, may cause autonomic nervous system (ANS) dysfunction. ANS abnormalities on cardiovascular reflex tests have been demonstrated in HIV+ persons, persons infected with HIV, who have signs of illness or have used intravenous drugs. In this study the cardiovascular reflex function of 11 HIV+ homosexual or bisexual males meeting the Centers for Disease Control criteria for absence of illness was compared to that of 11 uninfected homosexual or bisexual males of similar ages. Somatic, depression and fatigue differences between groups were assessed using an ANS symptom checklist, the Beck Depression Inventory (BDI) and the Profile of Mood States (POMS). Six of the 11 HIV+ subjects were impaired on the cardiovascular reflex tests. Differences on the BDI and POMS were not attributable to a depressive mood or despair, but rather to presence of mild symptoms of HIV infection and fatigue.

Several new techniques were developed to assess quantitatively the degree to which patients with Huntington's disease (HD) are aware of their deficits, to evaluate the relation between cognitive impairment and unawareness of deficits, and to determine whether patients exhibit differential awareness of their motor disturbance and cognitive deficits. Results of a questionnaire measure indicated that HD patients rated their own difficulties with motor and cognitive activities of daily life significantly lower than relatives rated patients' problems, and this discrepancy was related to patients' level of cognitive impairment. In contrast, patients were reasonably accurate when predicting their performance on specific motor and cognitive tasks when compared to both their actual performance and relatives' predictions. Several interpretations of these findings are discussed, and the role of frontal lobe dysfunction in the awareness problems characterizing dementia is considered.

No description available.

No description available.

No description available.

Eight healthy males performed two rides to exhaustion at a work load corresponding to 125% Q02 max, one hr after ingesting either NaHCO3 (E) or NaCl (C). Mean + SE pre-exercise blood pH, HCO3 and base excess (BE) values were respectively 7.42 + 0.01, 28.2 + 1.5 mmol/l and 2.02 + 0.1 mmol/l for the E condition, and 7.39 + 0.01, 24.4 + 0.7 mmol/l and -0.4 + 0.7 mmol/l for the C condition (P < 0.05 for all variables). Cycling time to exhaustion (E = 100.66.1; C = 98.6 + 5.7 sec) and total "02 during recovery (E 17.7 + 0.9; C = 17.3 + 0.8 1/30 min) did not differ between treatments. Blood pH, HCO3 and BE were significantly higher while the hydrogen ion to lactate ratio (LH+I/ELAI) was significantly lower in E than in C during recovery. Blood LA levels were also greater in E than in C during the latter part of recovery although peak individual values were not significantly different between trials CE = 14.4 + 0.4; C = 13.3 + 0.0 mmol /1) . In view of the insignificant differences in cycling time, peakLA production was greater in E than in C. Rather it individual LA and total recovery 002, it is not likely that Given this protocol, alkalosis does not help to sustain an appears that LA efflux was enhanced by the NaHCO3 feeding. Additionally, the return of the acid-base status in blood to resting conditions was more rapid during alkalosis does not help to sustain an intense exercise bout. These data suggest, however, that NaHCO3 may be of benefit following repeated work bouts.

The purpose of this study was to investigate the influence of oral NaHCOa administration on the alteration of acid-base balance and performance of high-intensity interval swimming. Ten male college swimmers were studied on five test days within a two-week period. Each test day consisted of five 100-yd freestyle swims with a two-minute rest interval between each bout. Subjects received two NaHCO3, two placebo and one no-drink treatments for the five test days. One hour before the onset of swimming the subjects were given 300 ml of citric acid flavored solution containing either NaCl (placebo) or NaHC03 (experimental), or received no drink. The dose of NaHCO3 solution was 0.25 9/kg-1 body weight. Before the sprint trial test a 300-yd warmup swimming was performed followed by a nine-minute rest. Performance times for each 100-yd swim were recorded. Blood samples were obtained before and one hour after treatment, two minutes after warmup and the last bout of swim. Blood, pH, lactate, standard bicarbonate (SBC) and base excess (BE) were measured. After the statistical analysis had shown there were no differences between the corresponding values of two trials for the same treatment, the data for identical treatments were combined and reanalyzed statistically as one group. All the corresponding variables between placebo and no-drink revealed no differences. Performance times of the fourth and fifth swimming bouts were faster (P < 0.05) and blood lactate after exercise was higher (P < 0.05) in NaHCO3 condition. Blood pH, SBC, BE were higher (P < 0.05) at post-treatment, post-warmup and post-last bout of swim in NaHCO3 condition. The difference between NaHCO3 and the other two conditions on the increment of lactate (2.0 mM) was proportional to that on the decrement of SBC (2.2 meq/1) after exercise. The data from the placebo and NaHCO3 treatments shown a positive correlation between hydrogen ion and lactate concentrations (r = 0.923) and a negative correlation between SBC and lactate concentrations (r = -0.941) after warmup and exercise. These data are in agreement with previous findings that during repeated bouts of exercise pre-exercise administration of NaHCO3 improves performance, possibly by facilitating the efflux of lactate and hydrogen ions from working muscles and thereby delaying the onset of fatigue.

A "velocity-video" system was developed with the intent of measuring forward body velocity changes and technical skill during swimming. The system consists of a "swim-meter", video camera, A-D converter, Apple IIE computer, Microkey system, VCR and monitor. A correlation of 1.0 was found between the velocity computed by the "velocity-video" system and a known speed. Furthermore, comparison of the velocity pattern of breaststroke from video with digitized film revealed a correlation of 0.95. These results suggest that the "velocity-video" system is a valid method of describing swimming velocity and corresponding changes in body position. The second part of this investigation examined the relationship between physiological economy (ml 02-U_1-LBW-7L), technical skill, swim power, and performance between "superior" and "good" male and female breaststrokers. Swimmers were categorized based on best 100 yd performance time. To study physiological economy oxygen uptake was determined after a 400 yd submaximal breaststroke swim. No significant difference in economy (ml 02•m-1 -LBW-1) was noted between the superior and good swimmers for both males and females. The superior male swimmers, however, were found to have lower blood lactate values compared to the good male breaststrokers', 1.85 + 0.39 vs. 4.49 ± 0.86 mM•1-1. The superior males and females were found cover a greater distance per stroke compared to the good males and females, respectively. The ability to generate power and/or peak power was found to be an important factor in sprint performance (r = 0.91 and 0.92, respectively). During a submaximal effort the superior swimmers spent a greater amount of time during the glide and leg recovery phases of the breaststroke cycle than the good swimmers. The results of the present study suggest that the superior breaststrokers were characterized by there ability to minimize drag during the glide and leg recovery phases of the stroke cycle. This suggests greater technical skill as evidenced by the superior swimmers' ability to cover a greater distance per stroke cycle at a given speed.