CD4+ CD56+ natural killer T-like cells secreting interferon-γ are associated with incident coronary events.

BACKGROUND: CD3(+) CD56(+) natural killer T (NKT)-like cells are a subset of T cells characterized by expression of NK receptors and potent antitumour activity. It has also been suggested that they have a role in autoimmune disease, and levels of NKT-like cells are elevated in patients with coronary disease. OBJECTIVES: To investigate whether high levels of CD3(+) CD56(+) NKT-like cells are associated with an increased incidence of cardiovascular disease and a lower incidence of cancer. METHODS: This was a prospective study including 700 subjects participating in the baseline investigation of the Malmö Diet and Cancer study between 1991 and 1994. Leucocytes obtained at the baseline investigation and stored at -140 °C were thawed and CD3(+) CD56(+) cells analysed by flow cytometry. The incidence rates of cancer and coronary events during a mean follow-up of 15 years were determined through national registers. RESULTS: Subjects in the lowest tertile of interferon (IFN)-γ-expressing CD4(+) CD56(+) cells were found to have an increased risk of incidence of coronary events (log-rank test: P < 0.05). This association remained significant after controlling for age, sex, smoking, body mass index, hypertension, diabetes and the Th1/Th2 and Th1/Treg cell ratios in a Cox proportional hazards regression model (hazard ratio 1.98, 95% confidence interval 1.24-3.16), but not when the LDL/HDL ratio was included in the model. There were no associations between CD3(+) CD56(+) NKT-like cells and incident cancer. CONCLUSIONS: The present results could not confirm the hypothesis that low levels of CD3(+) CD56(+) NKT-like cells are associated with a higher incidence of cancer and a lower incidence of cardiovascular disease. However, we found that low levels of IFN-γ-expressing CD3(+) CD4(+) CD56(+) NKT-like cells were associated with an increased incidence of coronary events and that this association may be dependent on lipoproteins.

[Somatic disorders in outpatient psychiatry: the added value of a standard physical examination during the intake of outpatients]. / Somatiek in de ambulante psychiatrie: de toegevoegde waarde van een standaard lichamelijk onderzoek tijdens de ambulante intake.

BACKGROUND: It is well-known that psychiatric patients often suffer from severe somatic problems, such as diabetes mellitus and cardiovascular disease. Up till now, research has concentrated almost exclusively on the inpatient setting, but there is strong evidence that the correlation also exists in psychiatric patients who are outpatients. In the Netherlands there are, as yet, no clear recommendations regarding a standard form of somatic screening for the outpatient population. A pilot study performed by GGz Breburg has shown that somatic screening (without a physical examination) gave substantial additional value to treatment planning. AIM: To investigate the added value that a physical examination can provide when new psychiatric patients are screened for aspects of somatic concern (ASC). METHOD: Newly referred outpatients (n = 70) were screened somatically by means of a questionnaire and supplementary medical interview, and by laboratory tests and physical examination. If a somatic problem was found which had not been detected previously, the patient was referred back to to the general practitioner. RESULTS: At least one ASC was found in 81,4% of all patients. In 45,7% of all patients the asc had not been detected. 12% of all the newly discovered somatic problems were found exclusively via the physical examination. CONCLUSION: A physical examination provides substantial information and adds value to the somatic screening of psychiatric outpatients.

The relationship between shear rate and flow-mediated dilation is altered by acute exercise.

AIM: Endothelial function is a predictor of cardiovascular health and is improved with exercise training. However, it is not clear how exercise acutely affects endothelial function. Previous studies present conflicting results, resulting from varied exercise protocols and ambiguity in data analysis after exercise. The aims of this study were to compare brachial artery endothelial function at rest and post-exercise in and to compare the data expressed as a percent change and normalized to shear rate (SR). METHODS: Fifteen young, healthy subjects completed flow-mediated dilation (FMD) tests at rest and immediately after a continuous 30-min treadmill exercise session. Flow-mediated dilation was calculated as percent change in diameter and also normalized for SR. RESULTS: Flow-mediated dilation was reduced after exercise (8.9 ± 4.3 to 5.8 ± 3.9%, P<0.05), but normalizing for SR nullified this difference (3.6 × 10(-4) ± 1.8 × 10(-4) to 2.7 × 10(-4) ± 2.4 × 10(-4) %, P=0.25). Baseline SR was significantly greater after exercise than at rest (224 ± 72 to 354 ± 158 s(-1) , P<0.05). Baseline diameter, time to peak diameter, and SR area under the curve were not different between the two conditions. The relationship between SR and FMD was strong at rest (r=0.82, P<0.001), but weak post-exercise (r=0.16, P=0.6). CONCLUSION: The weak relationship in FMD and SR after exercise suggests that these data should not be normalized following aerobic exercise. Thus, endothelial function was attenuated after a continuous 30-min aerobic exercise session.

The posterior parahippocampal gyrus is preferentially affected in age-related memory decline.

Atrophy in the medial temporal lobe is generally considered to be highly associated with age-related memory decline. Volume loss in the hippocampus and entorhinal cortex has extensively been investigated, but the posterior parts of the parahippocampal gyrus have received little attention. The present MRI study investigated whether volume differences in medial temporal lobe areas are differentially related to age-related memory decline. Thirty-nine subjects from a longitudinal study on cognitive aging (the Maastricht Aging Study) have been examined: 20 participants (mean age=67 years, range 52-80) with memory decline over a period of 12 years were matched to 19 participants without memory decline. Manual tracing was performed on 3T MR images to measure the volumes of the anterior, middle and posterior parts of the hippocampus and parahippocampal gyrus. A robust group difference and a significant association with memory decline were observed only in the posterior part of the parahippocampal gyrus. Our results may suggest that the posterior parahippocampal gyrus plays a key role in age-related memory decline.

Validity of bioelectrical impedance analysis to measure body fat in Air Force members.

This study determined if the bioelectrical impedance analysis (BIA) method was a more valid assessment of body fat in Air Force members than the current Air Force circumference (AF) method. Both methods were compared with hydrostatic weighing, which is the presumed standard for identifying body fat. Subjects included 50 male and 50 female active duty Air Force members between the ages of 19 and 47 years. The AF method had higher correlation coefficients and lower standard error of estimates for both male and female subjects (r = 0.91 [3.00%] and r = 0.79 [3.28%], respectively) than the BIA method (r = 0.84 [3.25%] and r = 0.75 [4.30%], respectively). The false-positive rates for individuals having excess body fat were greater for the AF method (14.7 and 29.3% for males and females, respectively) than the BIA method (7.3 and 8.8% for males and females, respectively). The data suggest that caution should be used when the current AF method or the BIA method is used to make individual Air Force career decisions.

Affective responses of physically active and sedentary individuals during and after moderate aerobic exercise.

BACKGROUND: This study examined the effects of aerobic fitness and exercise history on self-reported affect during and after acute aerobic exercise and quite reading. METHODS: Active and sedentary participants (N = 41) reported their psychological affect during two separate conditions in a counterbalanced design: (1) exercise on a cycle ergometer at 50% predicted VO2 max, and (2) quiet reading in a reclining chair. Affect was assessed prior to, every 3 minutes during, and at 5 and 20 minutes after each 24-minute exercise and reading period. RESULTS: Analysis revealed that active participants were significantly more positive than the sedentary group during exercise and at 5 minutes postexercise. The groups were similar in affect at 20 minutes postexercise. No between-group differences were found during the reading condition. Exercise enhanced affect compared to reading only for the active group. In addition, the affective responses of both groups were influenced by pre-exercise affect, with the greatest increases observed for those reporting the lowest affect before activity. CONCLUSIONS: These results suggest that affective responses during and after aerobic exercise were influenced by exercise history and aerobic fitness, but moderated by pre-activity scores.

The accuracy of the ACSM and a new cycle ergometry equation for young women.

The purpose of this study was to determine the accuracy of the American College of Sports Medicine's (ACSM) equation for estimating the oxygen cost of exercise performed by women on a cycle ergometer. Sixty healthy, young females performed a five-stage submaximal cycle ergometry test. Results indicated the SEE for the predicted oxygen values ranged from 79-156 ml.min-1, with total errors (E) ranging from 107-275 ml.min-1. Correlations between the actual and predicted values ranged from r = -0.22 to r = 0.38. The r, SEE, and E were 0.96, 118, and 172, respectively for all of the power loads combined. A revised equation was developed based upon the actual VO2-power relationship. This equation appears as: VO2 (ml.min-1) = kgm.min-1 x 1.6 ml.min-1 + ((3.5 ml.kg-1.min-1 x kg body weight) + 205 ml.min-1). Cross validation was performed on an independent sample of 40 subjects. All of the SEE and E were lower and all of the correlations were higher at each power load in the validation sample. Since the revised equation is based on an actual VO2-power relationship, it would appear that it provides a more accurate depiction of the cycle ergometry VO2-power relationship for women. These facts support its use.

The effects of anabolic steroids on myocardial structure and cardiovascular fitness.

To determine the effects of anabolic steroids on myocardial structure, VO2max, and body composition, experienced age-matched male weight trainers (M age 26.5 yr) who either used (U) (N = 11) or did not use (NU) (N = 13) anabolic steroids were evaluated. Steroid users were tested while off cycle (U-OFF) for at least 8 wk, again at the peak (U-ON) of their subsequent cycle, and to the nonuser group of weight trainers. Echocardiographic measurements revealed significant differences in left ventricular (LV) mass (182.8 +/- 26.9 g vs 210.6 +/- 42 g; P < 0.05) and interventricular septum thickness (IVS) (10.3 +/- 1.2 mm vs 11.1 +/- 1.2 mm; P < 0.05) between U-OFF and U-ON, respectively. NU measurements were also significantly different than U-ON for LV mass and IVS (186.5 +/- 36.2 g; P < 0.05 and 9.3 +/- 1.2 mm; P < 0.05, respectively). LV diameter in diastole was significantly greater in U-ON (59.1 mm) than in NU (55.7 mm; P < 0.05). In addition, LV posterior wall thickness in diastole was greater in U-ON compared with NU (11.2 mm vs 9.5 mm; P < 0.05). VO2max values for both user groups were significantly lower than those for NU (U-OFF = 41.0 +/- 4.5 ml.kg-1.min-1, U-ON = 41.0 +/- 5.7 ml.kg-1.min-1, and NU = 50.2 +/- 6.4 ml.kg-1.min-1; P < 0.05). Despite these morphological changes within the myocardium, there were no concomitant increases in shortening fraction.

Validation of a cycle ergometry equation for predicting steady-rate VO2.

The purpose of this study was to validate an equation used for predicting the oxygen cost of leg cycle ergometry. This equation was previously shown to be more accurate than the one of the American College of Sports Medicine (ACSM) and appears as: VO2 (ml.min-1) = kgm.min-1 x 1.9 ml.min-1 + ((3.5 ml.kg-1.min-1 x kg body weight) + 260 ml.min-1). Fifty healthy males, ages 18-38 yr old, performed a six-stage (0, 180, 360, 540, 720, and 900 kgm.min-1) submaximal cycle ergometry test while their oxygen uptake was measured. Results indicated the standard error of estimate for the predicted oxygen consumption values ranged from 80-156 ml.min-1, with correlations between the actual and predicted values ranging from r = 0.35 to r = 0.67. Total errors ranged from 92-160 ml.min-1. All of the standard errors and total errors were lower and all of the correlations, except one, were higher at each power load in the validation sample than the original sample. These statistics support the generalizability and accuracy of the new equation. It would appear that the new equation may make accurate predictions in independent samples and is more precise than the ACSM equation.

The accuracy of the ACSM cycle ergometry equation.

The purpose of this study was to determine the accuracy of the American College of Sports Medicine's equation for estimating the oxygen cost of exercise performed on a cycle ergometer. Sixty healthy males, ages 19-39 yr old, performed a five stage (30, 60, 90, 120, and 150 W) submaximal cycle ergometer test while their oxygen uptake was measured. Results indicated the standard error of estimate for the predicted oxygen values ranged from 0.11 to 0.22 l.min-1, with correlations between the actual and predicted values ranging from r = 0.22 to r = 0.50. Total errors ranged from 0.23 to 0.31 l.min-1. The actual oxygen cost was underestimated from 0.16 to 0.29 l.min-1 (P less than 0.05) by the equation at each workload. A revised equation was developed based upon the actual VO2-power relationship. The resulting slope was lower and the intercept higher when compared with the current ACSM equation. The slope and intercept of the revised equation are more consistent with values published in the literature. This equation appears as: VO2 (ml.min-1) = kgm.min-1 x 1.9 ml.min-1) + ((3.5 ml.kg-1.min-1 x kg body weight) + 260 ml.min-1). Predicted values from the revised equation were more accurate as reflected by slightly higher correlations, lower total errors, and lower mean differences from actual VO2 measurements than those from the current equation.

Response of invertebrates to lotic disturbance: a test of the hyporheic refuge hypothesis.

Recovery following hydrological disturbances is usually rapid for lotic invertebrates. Stream ecologists have assumed that recovery is facilitated by behavioral migrations during floods down into the hyporheic zone (the interstitial spaces of a streambed) to seek temporary refuge from possible erosion (the "hyporheic refuge hypothesis"). We provide the first explicit test of this hypothesis by evaluating three predictions of the hypothesis. We coupled field observations of the response of meiofaunal invertebrates to floods with field and flume experiments. The study site was a sandy-bottom stream in northern Virginia. Prediction 1, that loss of fauna from a streambed during floods should be minimal as long as the depth of scour in the streambed is less than the depth of the hyporheic zone, was not supported for any taxon. For two floods which varied considerably in magnitude, 50-90% of the fauna was lost from the bed despite the fact that the depth of scour (10-30 cm) was significantly less than the total depth of the hyporheic zone (50 cm). Prediction 2, that fauna should move deeper into the bed at higher flows, was supported by field observations during only one of two floods and then only for rotifers. In flume experiments that tested for finer scale behavioral movements, significant vertical migrations were found for copepods and chironomids which moved 1.5-3.5 cm downward as mean velocity (3 cm off bottom) was increased from 5-23 cm/s. Movements down by rotifers were not found in the flume experiments. Prediction 3, that the hyporheic zone is the most important source of colonists to defaunated areas, was supported in part by field experiments. The hyporheic route was not the primary route for any taxon but it was as important for the rotifers and copepods as water column or streambed surface routes. We conclude that, even though smallscale (cm's) migrations into the streambed in response to increased flow may be observed for some taxa and the hyporheic zone may serve as a partial source of colonists following disturbances, movements down are not adequate in preventing significant losses of meiofauna during floods.

Cardiac structure and function in weight trainers, runners, and runner/weight trainers.

The purpose of this study was to describe and compare cardiac structure and function in adult male weight trainers, runners, and those who do both activities. Subjects had actively participated in the various training programs for the previous five years. Age ranged from 28.4 to 31.3 years in the three groups. Echocardiography was used to assess selected heart diameters, volumes, indices of contractility, and thicknesses, while VO2 max and percent body fat were measured using standard methods. Heart structure and function were expressed in absolute terms and relative to total body weight. An alpha level of .05 was used in all comparisons. Results indicated the runners demonstrated significantly greater relative LVIDd, LVIDs, and LVPW than the weight trainers. The runner/weight trainers possessed significantly greater relative LVIDd, LVIDs, LVPW, IVS, and LVEDV than the weight trainers. No significant differences, absolute or relative, existed between the runner and runner/weight trainer groups in any of the myocardial structure and function variables. It was concluded that men who run or run and weight train have similar structural and functional characteristics of the heart and possess greater relative internal diameter and left ventricular wall thickness than men who only weight train.

Comparison of energy expenditure in men and women at rest and during exercise recovery.

The purpose of this study was to compare the energy expenditure (EE) of men and women at rest and during a 1 h recovery from 30 min of exercise at 40% of VO2max. Subjects were five physically active lean men (mean age, % fat, and VO2max = 34.8 +/- 8.1 years, 8.1 +/- 3.2% and 63.8 +/- 8 ml.kg-1.min-1, respectively) and five physically active lean women (mean age, % fat, and VO2max = 26.2 +/- 5.1 years, 17.6 +/- 4.5%, and 50.2 +/- 13.6 ml.kg-1.min-1, respectively). Energy expenditure (EE) was measured continuously by standard open circuit spirometry for 20 min at rest and for 1 h immediately after 30 min of exercise at 40% of VO2max. Independent t tests and ANCOVA were used to compare EE of men and women at rest and during exercise recovery. EE at rest in the men was significantly greater using a t test (p less than .05) than in the women but it was not when the data were adjusted with ANCOVA using body weight, VO2max in ml.kg-1.min-1, and percent body fat as covariates. The EE during 1 h of recovery was also significantly higher in the men using a t test (p less than .05) and after the data were adjusted for differences in VO2max (p less than .02). With body weight and percent fat as covariates. The EE during 1 h of recovery was also significantly higher in the men using a t test (p less than .05) and after the data were adjusted for differences in VO2max (p less than .02).(ABSTRACT TRUNCATED AT 250 WORDS)

Physiological responses to aerobic exercise during pregnancy and post-partum.

Maternal physiological responses to exercise during pregnancy and post-partum were studied. The results indicated that: (a) the maternal submaximal oxygen consumption (1/min) at a constant heart rate remained essentially unchanged during the last two trimesters of pregnancy and eight months post-partum, (b) the fetal heart rate returned to near-baseline levels within a two-minute exercise recovery, and (c) the infant birth data were all within the normal range. It would appear that moderate aerobic exercise during pregnancy may be done without apparent harm to either mother or baby, and could possibly benefit the mother by maintaining her aerobic fitness during pregnancy.

The relationship between aerobic activity and cognitive performance under stress.

This study examined the relationship between regular aerobic activity and cognitive performance under stress when personality and inherent aptitude were statistically controlled. Aerobically conditioned subjects have been shown to mediate the physiological response to stress under physical challenge. Would aerobically conditioned subjects also respond more efficiently to psychological stress under cognitive challenge? Forty volunteers completed a battery of personality and aptitude measures and then completed two cognitive tasks (written tests of logic), one under a condition of no stress, the other while being verbally pressured by a test monitor. Heart rate and blood pressure were measured during and after each cognitive task. Contrary to the experimental hypothesis, aerobic activity was related to inferior cognitive performance and to elevated blood pressure under stress. Inherent cognitive aptitude and personality traits emerged as far more important correlates of cognitive performance under stress than did the level of exercise.

Physiological training effects of playing youth soccer.

The purpose of this investigation was to determine if a 9-wk youth soccer program had any effect on cardiorespiratory fitness (VO2max and VO2submax), peak knee torque, and flexibility. Subjects were 20 sixth grade boys, 11 of whom were members of a YMCA soccer team: 9 were normally active boys who were not participating in any organized sport during the study who served as a control group. Mean ages (+/- SD) were 11.8 +/- 0.34 and 11.5 +/- 0.60 yr for the soccer and control group, respectively. Initial VO2max values of 49.83 and 47.42 ml . kg-1 . min-1 for the soccer and the control group, respectively, are similar to those reported in the literature for untrained normal boys of this age. Results indicated that playing soccer three times weekly increased VEmax and reduced VO2 (ml . kg-1 . min-1 and 1 . min-1) at a submaximal running speed (all P's less than 0.05), while no change in VO2max was noted. No significant training effect was observed in peak knee torque or flexibility subsequent to soccer training. It is concluded that the effects of playing soccer in these subjects resulted in no change in cardiorespiratory fitness, peak knee torque, or flexibility.