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PubMed1983

Fibrillar centres and condensed nucleolar chromatin in resting and stimulated human lymphocytes.

To provide more information on the ultrastructural morphology of fibrillar centres and condensed nucleolar chromatin, both these nucleolar components were studied in ultrathin sections of resting and phytohemagglutinin stimulated human lymphocytes. In comparison with resting cells, in stimulated lymphocytes fibrillar centres increased in number but their total size was smaller. In stimulated cells the size of individual fibrillar centers remained about the same. The size of the intranucleolar condensed chromatin was larger in stimulated than in resting cells. The proportion of the intranucleolar areas with condensed chromatin to the whole nucleolar area was relatively constant since no difference was noted between resting and stimulated cells. On the other hand, the proportion of the condensed intranucleolar chromatin to the condensed perinucleolar chromatin increased in stimulated lymphocytes in comparison with resting cells. The close morphological relationship between fibrillar centres and condensed intranucleolar chromatin was noted in ring shaped nucleoli of resting lymphocytes, this relationship was frequently remaining in nucleoli with less or more distinct nucleolonemata of stimulated cells.

Cell Nucleolus↗
PubMed1980

What information contains a rest contraction curve? a theoretical study with experimental results from the rabbit papillary muscle.

On the basis of a specialized two-Ca store model the degree of coupling q between the two stores was introduced. q is defined by the time constants of the model (leakage and coupling time constant) and varies between O (uncoupled stores) and 1 (maximal coupled stores). Provided that the contraction height in first approximation is proportional to the myoplasmic Ca concentration from the rest contraction curve the degree of coupling can be calculated using the coordinates of the maximum developed tension. From 13 rabbit papillary muscles the values of q were determined at different periods of rest thus demonstrating that q cannot be considered as constant in the first period of the pause. Accordingly, the time constants change rapidly at the beginning of the rest reaching relatively constant values after the half of the maximum time of the rest contraction curve. With respect to the hypothesis of intracellular recycling Ca controlling the contraction in cardiac muscle the great values of q (about 0.9 after a longer period of rest) suggest a very little loss of Ca from intracellular stores by leakages. From our calculations it is expected that in the maximum of the rest contraction curve the Ca concentration in both stores might differ insignificantly.

Animals↗
PubMed1980

Sequential haemodynamic effects of labetalol at rest and during exercise in essential hypertension.

The haemodynamic effects of labetalol were studied in patients with essential hypertension after acute and long-term administration. In the acute study 50 mg of labetalol was given i.v. to 10 patients. Eight of them were re-examined after three to four months of oral treatment with labetalol 300 mg t.i.d. Measurements were made at supine rest, after five minutes in the upright position, and after five minutes' supine bicycle exercise at 50 and 100 watt work loads. In the acute study cardiac output was unchanged except at the work load of 100 watt when it decreased 18%. The mean blood pressure decreased under all conditions, 11.6 mm Hg at supine rest, 22.3 mm Hg in the upright position and 15.9 mm Hg and 16.9 mm Hg at the two work loads. Heart rate was unchanged at supine rest, and reduced by 10% in the other situations. Total peripheral resistance was reduced significantly at rest in the supine and upright positions, but not during exercise. Pulmonary artery pressure was unchanged. In the long-term study cardiac output was unchanged except of the heavy work load when it decreased 11%. Mean blood pressure was reduced significantly by 14.6 mm Hg at supine rest, 16.8 mm Hg in the upright position and by 13.9 mm Hg and 13.4 mm Hg, respectively, at the two work loads. Heart rate was reduced significantly in all conditions by 10-14%. Total peripheral resistance decreased significantly at rest, but not during exercise, and pulmonary artery pressure was unchanged.

Blood Pressure↗
PubMed1995

Increased function of voltage-dependent Ca++ channels and Ca(++)-activated K+ channels in resting state of femoral arteries from spontaneously hypertensive rats at prehypertensive stage.

The present study examined the possible role of voltage-dependent Ca++ channels (VDCs) and Ca(++)-activated K+ (KCa) channels in the regulation of resting tone of arteries from spontaneously hypertensive rats (SHR) at a prehypertensive stage. Differences in the effects of agents that interact with these channels were assessed in endothelium-denuded strips of femoral arteries isolated from 4-week-old SHR and age-matched normotensive Wistar-Kyoto rats (WKY). Systolic blood pressures at this age were not significantly different between SHR and WKY. The arterial strips from SHR maintained a myogenic tone in the resting state; that is the resting tone in the SHR artery was abolished when either the bathing solution was replaced with a Ca(++)-free solution or 10(-7) M nifedipine was added. Studies using 1- or 5-min pulse labeling of the arteries with 45Ca showed that the resting Ca++ influx was significantly increased in SHR when compared with WKY, and this increase in SHR was abolished by 10(-7) M nifedipine. In strips preloaded with fura-PE3, the addition of 3 x 10(-6) M verapamil to resting muscles decreased the resting cytosolic Ca++ level and caused a relaxation. These effects of verapamil were more evident in SHR than in WKY. The addition to the strips of charybdotoxin and iberiotoxin, blockers of large conductance KCa channels, caused a concentration-dependent contraction, which was significantly greater in SHR than in WKY.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1995

Resting asynchronous left ventricular contraction abnormality analyzed by a phase method in spastic angina pectoris.

UNLABELLED: Quantitative phase analysis of equilibrium ventriculography was performed to study the character of left ventricular (LV) wall motion abnormalities in patients with spastic angina pectoris, who may have clinically and electrocardiographically silent ischemia combined with myocardial stunning, during rest and hyperventilation stress testing. METHODS: Phase analysis of the left ventricle at rest was performed by equilibrium radionuclide ventriculography in 13 control subjects and 36 patients with spastic angina pectoris. First-pass methodology along with hyperventilation stress testing was performed to assess spasm occurrences. Phase analysis of equilibrium multigated blood-pool scintigrams was performed to evaluate LV asynchrony at rest. RESULTS: The mean s.d. of LV phase distribution in the patients with variant and vasospastic angina was greater than that in the healthy control subjects (11.28 +/- 1.79 and 10.02 +/- 1.57 degrees versus 6.16 +/- 1.07 degrees). In addition, the mean s.d. of LV phase distribution in the variant angina group was greater than that in the vasospastic angina group. Furthermore, a linear correlation was found between the s.d. of LV phase distribution at rest and the percent decrease in ejection fraction during hyperventilation stress. CONCLUSION: Asynchronous LV contraction without significant hypokinesis was detected at rest in spastic angina pectoris. The severity of this asynchronous contraction corresponded well with decreases in ejection fraction during hyperventilation stress testing. Thus, analysis of the s.d. of LV phase distribution at rest is expected to provide useful information regarding LV asynchrony in spastic angina pectoris.

Adult↗
PubMedDate not supplied

Blood pressure reactivity in the evaluation of resting blood pressure and mood responses to pindolol and propranolol in hypertensive patients.

OBJECTIVE: The purpose of this exploratory study was to evaluate the relationship of blood pressure reactivity during exercise to treatment responsiveness to two commonly used beta-adrenergic blocking agents, propranolol and pindolol. DESIGN: Prospective, placebo-controlled, balanced, cross-over clinical trial. SETTING: University-affiliated medical center. PATIENTS: A convenience sample of 19 white male subjects with mild to moderate essential hypertension were studied. The mean age was 63.4 years (SD = 5.2). The mean resting systolic blood pressure (SBP) was 158.6 mm Hg (SD = 12.3) and mean resting diastolic blood pressure (DBP) was 96.4 mm Hg (SD = 8.6). They had no clinical evidence of secondary hypertension, diabetes, heart, liver, pulmonary, or renal disease. OUTCOME MEASURES: Resting blood pressure; blood pressure reactivity to exercise; self-report measures of depressive symptoms, and mood disturbances. INTERVENTION: Antihypertensive medication was tapered off and subjects were free of all prescription drugs for 2 weeks. Subjects were randomly assigned to propranolol-pindolol or pindolol-propranolol group. Each 4- to 6-week treatment phase was preceded by a 2-week placebo phase. At the end of the initial placebo phase and each active drug treatment phase, subjects were assessed for depression and mood disturbances by use of standardized measures and were given a graded exercise test on a cycle ergometer. Resting blood pressure was assessed weekly and before each exercise test. RESULTS: Significant relationships between DBP reactivity to exercise during the placebo phase and the degree of blood pressure and mood responsiveness to pindolol and propranolol treatment were observed. Subjects demonstrating high DBP reactivity required high doses of beta-blocker for resting DBP reduction, and these subjects showed the least change in mood at high doses. Similar patterns were found for the relationship of SBP reactivity and blood pressure and mood responsiveness to drug treatment, but these relationships were not statistically significant. CONCLUSIONS: DBP reactivity to exercise during the placebo phase provides unique information about the essential hypertensive patient. DBP reactivity and drug dose were important determinants of resting blood pressure and mood responsiveness to both pindolol and propranolol. DBP reactivity and perhaps SBP reactivity may be useful measures in the study of central adrenergic and peripheral cardiovascular pathophysiology.

Affect↗
PubMed1993

[Computer display work and rest position of the vergence system].

Subjects with different characteristics of the vergence system resting state (close or distant resting vergence, large and small increase upon depression of the eyes) worked with a VDU in a relatively high and a relatively low position for 1 1/2 hours. The directions of gaze were about -5 degrees and -35 degrees below the horizontal. A shorter observation distance was chosen with the lower VDU position than with the higher one, and it increased during the course of the work. In the high VDU position the increase was particularly strong for subjects with a distant resting vergence. The discrepancy between the angle of convergence during visual work and the resting vergence was larger in subjects with a distant resting vergence than in subjects with close one, and it was larger with the higher than with the lower VDU position (except in subjects with a minimal effect of eye depression on resting vergence). However, corresponding differences in visual fatigue as assessed by means of a questionnaire could not be found. Nevertheless the majority of subjects preferred the low VDU position. A number of additional consequences of a low VDU position support the conclusion that it would be advantageous for many users to tilt the display backward and to sink it below the level of the table surface.

Adult↗
PubMed1993

The pattern of agonist-evoked cytosolic Ca2+ oscillations depends on the resting intracellular Ca2+ concentration.

The agonists acetylcholine (ACh) and cholecystokinin (CCK) have been shown to evoke markedly different patterns of cytosolic Ca2+ oscillations in the same isolated pancreatic acinar cells. ACh induces high frequency sinusoidal oscillations (spiking) associated with activation of Ca2+ influx. CCK evokes longer lasting discrete transients separated by long intervals, and these low frequency transients persist for many minutes in the absence of extracellular Ca2+. Using digital imaging of fura-2 fluorescence, we have now monitored the free cytoplasmic Ca2+ concentration ([Ca2+]i) simultaneously in many individual cells from the same population. In the resting condition [Ca2+]i ranged from about 50 to 300 nM. When the resting [Ca2+]i was below 150 nM, ACh (50-100 nM) invariably evoked typical high frequency spiking. In the majority of cells which had a resting [Ca2+]i higher than 150 nM, ACh also evoked low frequency transients. Although initiated by ACh, these transients displayed the temporal and functional characteristics of the CCK-evoked transients. Removal of extracellular Ca2+ for a few minutes had no effect on this type of oscillation, whereas such a procedure reversibly abolished the ACh-evoked high frequency response. For the response evoked by 10-30 pM Ca2+ signal amplitude and the resting [Ca2+]i. Because the Ca2+ signal amplitude and the resting [Ca2+]i. Because CCK could never induce high frequency spiking there is some receptor specificity in dictating the time course of Ca2+ oscillations, but the resting [Ca2+]i is a major determinant of the Ca2+ signal pattern.

Acetylcholine↗
PubMed1995

[Radionuclide ejection fraction at rest and in exercise in chronic aortic insufficiency. Pre- and postoperative study in asymptomatic or paucisymptomatic patients].

Twenty patients (17 men and 3 women: average age 50 +/- 14 years) with asymptomatic or paucisymptomatic aortic regurgitation were studied to compare the values of radionuclide left ventricular ejection fraction (EF) at rest and on exercise before (1) and 6 +/- 1 months (2) and 5.7 +/- 1.1 years (3) after surgery. The resting EF was similar at all three examinations: 53 +/- 8 (1); 57 +/- 8 (2); 55 +/- 16 (3). However, it increased significantly on exercise from 40 +/- 10 (1) to 54 +/- 12 (2) (p < 0.001) and to 52 +/- 20 (3) (p = 0.036 versus 1). In the 7 patients with resting EF greater than 55 before surgery, there was no postoperative improvement: 61 +/- 6 (1); 61 +/- 5 (2); 65 +/- 9 (3). However, the exercise EF increased from 44 +/- 13 (1) to 55 +/- 17 (2) and 69 +/- 11 (3) (p = 0.004 vs 1). In 13 patients with resting EF < 55%, the value increased in the early postoperative phase but not later: resting: 49 +/- 5 (1); 55 +/- 8 (2) (p = 0.04); 49 +/- 17 (3) (NS vs 1); effort: 38 +/- 7 (1); 54 +/- 10 (2) (p < 0.001); 40 +/- 16 (3) (NS vs 1). Left ventricular systolic function only returns to normal and exercise after surgery in patients with resting preoperative EF > or = 55%, but nothing indicates that this normalisation is an absolute condition for a successful surgical result in aortic insufficiency in terms of survival and quality of life.

Adult↗
PubMed1995

Metabolite and hormonal response in smokers during rest and sustained exercise.

To evaluate the effects of acute and chronic smoking on blood glucose homeostasis, concentrations of metabolites, and hormonal responses at rest and during submaximal exercise, seven male smokers and seven similar nonsmokers were studied after an overnight fast. Nonsmokers (NS) and chronic smokers, abstaining from smoking (CS), were tested during rest and 60 min of cycle ergometry exercise at 49.7 +/- 0.8% of VO2peak. Smokers were restudied after acutely smoking (AS) two cigarettes prior to rest and one prior to exercise. Blood glucose levels were similar among NS, CS, and AS at all times. Lactate levels were elevated in AS compared with NS during exercise (2.32 +/- 0.22 mM vs 1.81 +/- 0.11; P < 0.05), with no differences in alanine. Free fatty acid levels were initially lower at rest in CS (0.45 +/- 0.04 mM) than in either AS (0.77 +/- 0.11) or NS (0.64 +/- 0.06; p < 0.05), but no other differences were found. During exercise, CS had lower glycerol levels (0.31 +/- 0.02 mM) than either AS (0.38 +/- 0.02) or NS (0.41 +/- 0.02; P < 0.05). Nevertheless, respiratory exchange ratio values were not significantly different during steady-state rest or exercise; and insulin, glucagon, and norepinephrine levels were also similar. Smokers effectively maintained normal blood glucose levels with only minor changes in some metabolite and hormone concentrations during rest and sustained exercise.

Blood Glucose↗
PubMed1997

Attractant resting boxes for rapid collection and surveillance of Aedes aegypti (L.) inside houses.

Three different resting station designs made of cardboard covered with black cloth were evaluated for their attractiveness to Aedes aegypti populations resting inside houses in Thailand. Box designs attracted more females (but not males) than an open-panel design. Thirty to 60% of all adult Ae. aegypti resting inside houses were collected by aspirating from 2-4 resting boxes placed inside houses. Tall boxes (90 cm) did not attract more females or males than short boxes (45 cm). Forty-two percent more females (but fewer males) were attracted to boxes when oviposition bowls were placed inside the boxes. Four boxes per house attracted 32% more mosquitoes than two boxes. Aspirating from artificial resting stations is an efficient and rapid method for sampling male and teneral, bloodfed, and gravid female Ae. aegypti resting inside houses.

Aedes↗
PubMed1997

Brief exposures of resting fibroblasts to okadaic acid stimulate DNA synthesis.

To study further the factors providing for cellular quiescence, we used okadaic acid (OA) at concentrations (0.1, 1, 10 or 100 nM) inhibiting type 1 and/or type 2A protein phosphatases in mammalian cell cultures. Brief (2 h) exposure of resting (0.2% serum for 72 h) NIH 3T3 mouse fibroblasts to OA with subsequent incubation of cells in a medium with 0.2% serum, stimulated DNA synthesis at all concentrations studied. Maximal stimulation was observed following pre-incubation of resting cells with 10 nM OA. Treatment of cycling cells (10% serum) with OA (2 h pulses at 12 h intervals for 72 h) prevented their exit to the resting state on transfer to a medium with 0.2% serum. Brief exposures of resting cells to OA did not affect the rate of protein synthesis. OA pulses in the late pre-replicative period had no effect on the entry of serum-stimulated cells into the S phase. Cell fusion experiments with resting (serum-deprived) and proliferating (serum-stimulated) NIH 3T3 cells, using radioautography with a double-labelling technique, revealed that pre-incubation of resting cells with OA for 2 h before and after fusion abrogates their ability to suppress the onset of DNA synthesis in the nuclei of proliferating cells in heterodikaryons. The results indicate that protein phosphatases of type 1 and/or 2A may be involved in the growth-arrest machinery that provides for cellular quiescence.

3T3 Cells↗
PubMed1997

Ultra-early risk stratification after myocardial infarction via pharmacological stress echocardiography: the relative value of resting function, viability and myocardial ischemia.

BACKGROUND: Echocardiographically recognized resting function, myocardial viability (by low-dose dobutamine) and stress-induced ischemia (by high-dose dipyridamole) are potent predictors of subsequent events, but their relative value in patients evaluated very early after acute myocardial infarction remains to be established. AIM OF THE STUDY: To assess the feasibility and usefulness of an integrated approach with resting and pharmacological stress echo for risk stratification in patients evaluated very early after myocardial infarction. METHODS: Sixty acute myocardial infarction patients without contraindications to stress testing, and who were being given thrombolytic therapy, underwent resting echo (16-segment model of left ventricle, each segment scored from 1 = normo-hyperkinetic to 4 = dyskinetic), high-dose dipyridamole (up to 0.84 mg/kg over 10') and low-dose dobutamine (up to 10 mcg/kg/min) echo on the third-fourth day after drug withdrawal. The response was "ischemic" with a dipyridamole-induced increase in the regional score > 1 in segments with a resting score < 3, and "viable" with a dobutamine-induced decrease in the regional score > 1 in segments with resting score > 1. All patients underwent coronary angiography on the tenth-twelfth day after the acute event, and all of them were followed up for 15 +/- 10.04 months. RESULTS: Ischemia elicited by dipyridamole appeared in 29 patients (48%) and dobutamine-induced viability was observed in 28 (47%). Ischemic events occurred in 26 patients (43.4%), five of which during the early in-hospital period. There were three deaths (5%), one re-AMI (1.7%), 7 Canadian Class III-IV angina (12%) and 15 (25%) early revascularization procedures undertaken independently of stress echo results. Events occurred in 21 patients (72%) with dipyridamole-induced ischemia and in 5 (16%) without it (p < 0.001). Likewise, events occurred in 13 patients (46.4%) with dobutamine-induced inotropic recovery and in 13 (40.6%) without it (p = ns). Event-free survival occurred in 64% of dipyridamole-positive patients, as opposed to 90% of dipyridamole-negative patients (p = 0.025). Dipyridamole echocardiographic test sensitivity and specificity for events were 81 and 74%, respectively. Sensitivity and specificity for events of dobutamine viability were 46 and 55%, respectively. In a multivariate logistic analysis, dipyridamole-induced myocardial ischemia was the strongest predictor of subsequent events (p = 0.01). According to Cox analysis, dipyridamole positivity had a relative risk estimate of 4. CONCLUSIONS: Pharmacological stress echo is feasible even very early after acute myocardial infarction via a useful approach based on low-dose dobutamine to assess myocardial viability, and high-dose dipyridamole to assess ischemia. For risk stratification purposes, stress-induced myocardial ischemia outperforms resting function and myocardial viability, and it is independent of angiographic data. Revascularization procedures do not seem to be effective when only viability is present.

Adrenergic beta-Agonists↗
PubMed1997

Resting B cells from autoimmune lupus-prone New Zealand Black and (New Zealand Black x New Zealand White)F1 mice are hyper-responsive to T cell-derived stimuli.

To determine whether B cells from New Zealand Black (NZB) and (New Zealand Black x New Zealand White)F1 (NZB/W) mice possess intrinsic defects that lead to altered immune responsiveness, we purified resting B cells from these mice and compared their surface phenotype and function with those of resting B cells isolated from BALB/c and DBA/2 nonautoimmune mouse strains. Flow cytometric analysis of freshly isolated resting B cells revealed that NZB and NZB/W resting B cells are conventional B2-type cells similar to their nonautoimmune counterparts. Despite this, resting B cells from young NZB and NZB/W mice express lower levels of CD23 on their surface and aberrant levels of intracellular IgM. Upon stimulation, resting B cells from young NZB and NZB/W mice demonstrate increased proliferation, IgM secretion, or enhanced expression of costimulatory molecules in response to a variety of different T cell-derived stimuli, including cytokines and signals generated through CD40. Therefore, B cell hyper-responsiveness to T cell stimuli is immunodominant or codominant in NZB/W mice. Taken together, our results suggest that intrinsic B cell hyper-responsiveness may play a role in the pathogenesis of autoimmune disease in NZB and NZB/W mice. The increased clonal expansion of these B cells together with increased Ig production and enhanced costimulatory capacity serve to amplify the immune response. In the context of normal but incomplete T cell tolerance, B cell hyperresponsiveness to the limited signals provided by partially tolerant T cells may be sufficient to yield an autoantibody response.

Animals↗
PubMed1998

Effect of a novel environment on resting heart rate in panic disorder.

Several studies have found higher resting heart rate among patients with panic disorder compared to healthy controls, whereas others have found no differences. It has been suggested that these differences may result from anticipatory anxiety. The purpose of this study was to compare the resting heart rates of 10 patients with panic disorder, 11 patients with social phobia, and 13 healthy controls during two consecutive visits to our laboratory. There were no significant differences between groups on resting heart rate on either day. However, patients with panic disorder did have significantly higher resting heart rates on day 1 versus day 2. This suggests that patients with panic disorder may experience greater anticipatory anxiety which is manifested in a higher resting heart rate than patients with social phobia or healthy controls. Implications for previous and future reports on resting heart rate measures in patients with panic disorder are discussed.

Adult↗
PubMed1996

Differences between observed and predicted energy costs at rest and during exercise in three subsistence-level populations.

Estimates of daily energy expenditure are important for many areas of research in human ecology and adaptability. The most common technique for estimating human energy expenditure under field conditions, the factorial method, generally relies on activity-specific energy costs derived from published sources, based largely on North American and European subjects. There is concern that such data may not be appropriate for non-Western populations because of differences in metabolic costs. The present study addresses this concern by comparing measured vs. predicted energy costs at rest and during sub-maximal exercise in 83 subjects (52 males, 31 females) from three subsistence-level populations (Siberian herders and highland and coastal Ecuadorian farmers). Energy costs at rest (i.e., lying, sitting and standing) and while performing a standard stepping exercise did not significantly differ among the three groups. However, resting energy costs were significantly elevated over predicted levels (+ 16% in men, + 11% in women), whereas exercising costs were comparable to predicted values (-6% in men, + 3% in women). Elevations in resting energy needs appear to reflect responses to thermal stress. These results indicate that temperature adjustments of resting energy costs are critical for accurately predicting daily energy needs among traditionally living populations.

Adaptation, Physiological↗
PubMed1997

Quantitative evaluation of blood flow distribution to exercising and resting skeletal muscles in patients with cardiac dysfunction using whole-body thallium-201 scintigraphy.

BACKGROUND AND HYPOTHESIS: Decreased blood flow to working muscles makes an important contribution to exercise intolerance in patients with chronic heart failure. This study was undertaken to examine whether maldistribution of skeletal muscle blood flow is closely related to exercise intolerance in patients with cardiac dysfunction. METHODS: Whole-body thallium scintigraphy was performed during one-leg exercise in 11 patients with left ventricular (LV) dysfunction (LV ejection fraction < 45%). Blood flow distribution to the exercising and resting legs was quantified by expressing regional thallium counts as a percentage of the whole-body counts at rest, at the level of anaerobic threshold, and at peak exercise. RESULTS: At anaerobic threshold, the thallium activity of exercising muscle increased from 4.2 +/- 0.7 to 14.0 +/- 2.5% (p < 0.05) in the thigh and from 1.7 +/- 0.3 to 4.1 +/- 0.9% (p < 0.05) in the calf, compared with the resting value. Consequently, the ratio of thallium activity between exercising and resting legs increased to 2.7 +/- 0.7 (p < 0.05) in the thigh and to 2.3 +/- 0.7 (p < 0.05) in the calf. When plotted as a function of anaerobic threshold, thallium activity of the exercising thigh (r = 0.78, p < 0.05) and the thallium ratio between exercising and resting thigh (r = 0.69, p < 0.05) declined with the reduction of exercise tolerance. These correlations were not observed in calves. CONCLUSION: Whole-body thallium scintigraphy demonstrated a maldistribution of leg blood flow in patients with reduced aerobic exercise capacity, suggesting that this abnormality could play an important role in exercising intolerance in these patients.

Adult↗
PubMed2002

Rising cortisol at childcare: relations with nap, rest, and temperament.

An unexpected rise in cortisol across the day in full-day, center-based childcare has been recently observed. Most of the children in these studies exhibited the rise across the day at childcare, but the expected drop at home. Possible explanations include more or less napping at childcare than at home. This study measured cortisol during childcare at 10:30 a.m., pre-rest, post-rest, and 3:30 p.m. for 35 children, and at 10:30 a.m. and 3:30 p.m. at home for 8 children. Duration and quality of rest were coded during nap periods. For 91% of children, cortisol rose at childcare and for 75% dropped at home. None of the napping variables were related to the rise at childcare nor were differences found between home and childcare rest. Factors other than daytime rest periods seem likely to account for the rise in cortisol across the childcare day, possibly factors involving the interactional demands of group settings during this developmental period.

Arousal↗