Procollagen-I, collagen telopeptide I, CEA, CA 15-3 as compared to bone scintigraphy in patients with breast cancer

The most common metastases of breast cancer (BC) are bone metastases. Serum pro-Iota collagen peptide (PICP) and I collagen telopeptide (ICTP) levels indicate the rate of bone collagen synthesis and bone resorption respectively and therefore indicate metastatic activity in the bone. We have studied the clinical importance of serum PICP and ICTP as well as CA 15-3 and CEA and compared them to bone scintigraphy findings indicating metastases from BC. Ninety seven women of mean age 58+/-8 years with BC were examined. The diagnosis of BC was histologically confirmed. Bone metastases were diagnosed in 68 of them by bone scans performed after the intravenous injection of 925 MBq of technetium-99m methylendiphosphonate, while 29 patients were free from bone metastases. We also examined 52 women of similar age, as controls. Serum PICP, ICTP, CA 15-3 and CEA were measured in both patients and controls. Serum levels of ICTP and CA 15-3 were significantly higher in patients with BC and bone metastases compared to patients without metastases (P<0.05), while PICP and CEA were only marginally higher. A statistically significant correlation was observed between the existence of bone metastases and ICTP serum levels (P<0.05). The sensitivity of PICP, ICTP, CEA and CA 15-3 was 28.1%, 48.6%, 78%, 42% respectively and their specificity was 83.9%, 94%, 65% and 86% respectively. In conclusion: ICTP and CA 15-3 are the most reliable markers of those studied for the diagnosis of bone metastases in BC. PICP alone or combined with ICTP were not sensitive enough. CA 15-3 showed sensitivity 78% and specificity 86%. When combining CA 15-3, ICTP and CEA the sensitivity and specificity increased to 82% and 96% accordingly.     

Change in levels of the carboxyterminal propeptide of type I procollagen, the carboxyterminal cross-linked telopeptide of type I collagen and osteocalcin in response to exercise in well-trained men and women

Physical exercise preserves bone mass. Measurements of bone biomarkers may reflect the events in bone during exercise. Fifteen healthy, well-trained individuals (7 men and 8 women) performed a running test for 21 min until exhaustion. Venous blood samples were drawn before and 30 min after the exercise to measure the levels of osteocalcin, the carboxyterminal propeptide of type I procollagen (PICP) and the carboxyterminal cross-linked telopeptide of type I collagen (ICTP). After exercise, the women had a marked increase in serum osteocalcin concentrations (from 7.5±5.0 μg/1 to 11.5±3.0 μg/1), whereas the level was unaffected in the men (from 14.5±3.0 μg/1 to 13.5±4.6 μg/l). In the men there was a marked increase in PICP (from 240±47 μg/1 to 268±56 μg/1) that was not seen in the women (from 244±70 μg/1 to 253±60 μg/1). In neither group did ICTP levels change. In conclusion, significant responses were seen in PICP and osteocalcin during exercise, indicating that such measurements may be valuable for the further delineation of the effects of physical activity on bone. Furthermore, the different responses in men and women point to interesting areas for future studies.     

Metabolic and blood catecholamine responses to exercise during alkalosis

The effects of metabolic alkalosis on muscle lactate accumulation and plasma catecholamine concentrations were studied in six highly trained subjects during short-term ergocycle exercises to exhaustion (375 W). The studies were performed after oral administration of NaHCO3 (alkalosis) and CaCO3 (placebo). There was a significant increase in resting blood pH after NaHCO3 ingestion (7.35 +/- 0.02) compared to placebo (7.27 +/- 0.02). A longer endurance time was achieved during alkalosis (75.3 +/- 8 s) than during control (61.5 +/- 2 s), but similar blood pH and HCO3- levels were found at exhaustion in both treatments. Metabolic alkalosis resulted in higher elevation in muscle lactate concentration (31.7 +/- 4.6 mmol.kg-1 wet weight) compared to control (17 +/- 4 mmol.kg-1 wet weight). Despite longer exercise duration in alkalosis, plasma norepinephrine and epinephrine concentrations at exhaustion were reduced by 30 and 34%, respectively. These results indicate that alkalosis increased muscle lactate accumulation during exhaustive exercise. These changes were associated with a reduced blood catecholamine response to exercise.     

Acute effects of moderate intensity resistance exercise on bone cell activity

Resistance exercise has positive effects on bone mass, but little is known about the mechanisms by which this occurs. The purpose of this study was to determine if a single bout of moderate intensity resistance exercise alters biochemical markers of bone cell activity. Indices of bone turnover were measured in nine healthy, untrained men (21.9 +/- 1.2 yrs old), before and following a single 45 minute session of resistance exercise, and during a control trial. A cross-over design was used so that all participants performed both trials in random order. Blood samples were collected immediately before, immediately after, and at 1, 8, 24, and 48 hours post exercise and analyzed for bone-specific alkaline phosphatase (BAP), type I collagen propeptide (PICP), and type I collagen N-telopeptide (sNTX). Urine from the second morning void was collected over four days (day before, day of, and two days following exercise) and analyzed for type I collagen N-telopeptide (uNTX). Exercise resulted in a significant increase (p < 0.05) in the ratio of biochemical markers of bone formation to bone resorption eight hours post exercise, largely due to a decrease in sNTX. Markers return to baseline within 24 hrs. These data suggest that moderate intensity resistance training acutely reduces bone resorption, leading to a favorable change in overall bone turnover, for at least 8 hours post exercise in untrained young men. Further work is needed to determine if long-term benefits to bone strength follow with persistent training.     

Substrate source use in older, trained males after decades of endurance training

PURPOSE: The purpose of this study was to compare substrate source use in older, long-term exercising, endurance-trained males with sedentary controls. METHODS: [U-C]palmitate and [6,6-H2]glucose tracers were applied to assess plasma free fatty acid (FFA) and glucose oxidation rates, and to estimate muscle- and/or lipoprotein-derived triacylglycerol (TG) and muscle glycogen use. Subjects were 10 long-term exercising, endurance-trained males and 10 sedentary controls (age 57 +/- 1 and 60 +/- 2 yr, respectively). Muscle biopsy samples were collected before and after exercise to assess muscle fiber type-specific intramyocellular lipid and glycogen content. RESULTS: During exercise, plasma palmitate Ra, Rd, and Rox were significantly greater in the trained subjects compared with the controls (Ra: 0.36 +/- 0.02 and 0.25 +/- 0.02; Rd: 0.36 +/- 0.03 and 0.24 +/- 0.02; Rox: 0.31 +/- 0.02 and 0.20 +/- 0.02 mmol.min, respectively, P < 0.01). This resulted in greater plasma FFA and total fat oxidation rates in the trained versus sedentary subjects (P < 0.001). Muscle- and/or lipoprotein-derived TG use contributed 10 +/- 2 and 11 +/- 3% in the trained and control groups, respectively (NS). No significant net changes in muscle fiber lipid content were observed. CONCLUSIONS: Older, endurance-trained males oxidize more fat during moderate-intensity exercise than do sedentary controls. This greater total fat oxidation rate is attributed to a higher plasma FFA release, uptake, and oxidation rate. In contrast, intramyocellular triacylglycerol does not seem to represent a major substrate source during 1 h of moderate-intensity exercise in older trained or sedentary men.     

Effect of acute plasma volume expansion on thermoregulation and exercise performance in the heat

PURPOSE: We investigated the effects of acute plasma volume expansion on exercise performance in the heat. METHODS: Six moderately trained men cycled for 40 min at 64 +/- 2% peak pulmonary oxygen uptake (VO2peak) followed by an individual performance time trial, where subjects completed a set amount of work (267 +/- 15 kJ) in as little time as possible. Exercise trials were performed at 35 degrees C with a relative humidity of 40%. Subjects performed two exercise trials: one after 13.1 +/- 1% acute plasma volume expansion (PVE), which was achieved by the intravenous infusion of 8 mL x kg(-1) body weight of Hemaccel (35 g x L(-1) polygeline, 145 mmol x L(-1) Na+, and 145 mmol x L(-1) Cl-) and the other without prior treatment (CON). RESULTS: Core temperature, skin blood flow, and heart rate progressively increased (P < 0.05) during exercise, but no differences were observed between trials. Plasma glucose and lactate were similar at rest and during exercise, as was VO2 during exercise. Exercise performance was not influenced by plasma volume expansion (CON 17.5 +/- 0.4 min and PVE 17.1 +/- 0.2 min). CONCLUSION: These data suggest that, in moderately trained men, plasma volume expansion alone does not enhance thermoregulatory function and exercise performance during moderate intensity exercise in the heat.     

Spectral analysis of skin blood flowmotion before and after exercise in healthy trained and in sedentary subjects

Cutaneous blood flowmotion (CBF) can contribute to a reduction in the resistance in skin microvascular networks. The increase of CBF during exercise can improve the capacity of skin microvascular networks to transport and eliminate heat. In order to verify if the physical training could increase the skin blood flowmotion during exercise, we performed spectral analysis of cutaneous forearm laser Doppler signal, before and after acute maximal exercise in 15 healthy trained subjects (TS) and in 15 control sedentary subjects (SS). Within the total spectrum of 0.009 - 2.3 Hz, five frequency intervals of CBF were analysed: 0.009 - 0.02 Hz (endothelial activity), 0.02 - 0.06 Hz (sympathetic activity), 0.06 - 0.2 Hz (vascular myogenic activity), 0.2 - 0.6 Hz (respiratory activity), and 0.6 - 2.3 Hz (heart activity). In basal conditions, no difference between TS and SS was observed in the cutaneous blood perfusion (CBP), expressed in conventional perfusion units (PU), and in the mean value of CBF total spectrum power density (PD), measured in PU/Hz, while the absolute PD of the endothelial and myogenic CBF components was significantly higher (p < 0.05) in TS (0.69 +/- 0.62 PU/Hz and 0.47 +/- 0.43 PU/Hz, respectively) than in SS (0.29 +/- 0.16 PU/Hz and 0.23 +/- 0.16 PU/Hz, respectively). In both TS and SS, acute exercise induced a significant increase of CBP mean value (30.91 +/- 20.28 PU, p < 0.0005 and 16.45 +/- 7.02 PU, p < 0.0005; respectively) and of CBF total spectrum PD (6.65 +/- 4.13 Hz/PU, p < 0.001 and 4.17 +/- 1.86 Hz/PU, p < 0.05; respectively), with a significant difference of these two parameters between the two groups (p < 0.05). After exercise, CBF components regarding endothelial and myogenic activities maintained a higher PD mean value in TS in respect to SS (1.69 +/- 1.34 PU/Hz and 1.59 +/- 0.93 versus 0.91 +/- 0.44 and 0.98 +/- 0.48 PU/Hz respectively, p < 0.05). These findings suggest that physical training is associated with the increase of CBF and particularly on its endothelial and myogenic components in response to exercise. This can favour a greater reduction of resistance in skin microvascular networks during exercise and consequently an increase of its capacity to transport and eliminate heat.     

Biochemical markers of bone metabolism during distance running in healthy, regularly exercising men and women

The purpose of the present study was to evaluate the effects of long distance running on bone metabolism, using the biochemical markers ICTP (the carboxyterminal cross-linked telopeptide of type I collagen), PICP (the carboxyterminal propeptide of type I procollagen), osteocalcin and bALP (bone specific alkaline phosphatase) as well as parathyroid hormone (PTH) and serum calcium. Twenty healthy, regularly exercising individuals, 10 women and 10 men, participated in a running competition. The mean age was 38 (range 22–55) and 39 (range 22–53) years respectively, the performed distance 15 (range 5–30) and 28 (range 15–30) km respectively, with a speed of 5:30, 5:02 per kilometer respectively. Fasting blood samples were drawn in the morning the day before the race, and also the day after and two days after. A decrease of PICP concentrations among women was evident the day after the competition (from 170±17 μ/l to 158±17 μg/l) which returned to pre-exercise levels two days after the race (167±19 μg/l). Furthermore, a decrease of osteocalcin could be seen in the men one day after the exercise (from 12.1± 1.1 μg/l to 10.3±1.1 μg/l). In the men, there was also an increase of ICTP concentrations two days after (3.98±0.35 μg/l) this long-term and demanding exercise, when compared with pre-exercise levels (3.67±0.28). One single bout of longterm, exhaustive running exercise in well-trained men and women seems to induce a temporary inhibition of bone formation as well as a stimulation of bone resorption.     

Vigorous exercise training is not associated with prevalence of ventricular arrhythmias in elderly athletes

AIM: Physical activity, when vigorous, is not devoided of arrhythmic risk. Since the risk of developing arrhythmias increase as an otherwise healthy person ages, the question arises as to whether high intensity physical activity could be dangerous in the elderly person. The present study addressed the incidence of arrhythmias in elderly athletes in comparison to age-matched control subjects. METHODS: We studied 49 male athletes engaged in various sport disciplines, mean age 62.3+/-2.3 and 24 sedentary or moderately physically active healthy males, mean age 62.9+/-1.7 years (Controls). All subjects underwent 2-D, M-mode and Doppler echocardiographic examination, resting ECG and exercise stress test followed by 24-hour electrocardiographic monitoring. RESULTS: No pathological findings were detected in both experimental groups at echocardiographic examination. Exercise performance was greater in athletes than controls (206.9+/-5.2 vs 156.3+/-12 watt, p<0.01). During exercise test, no significant between-groups difference was detected in the incidence of ventricular arrhythmias, that is multiple premature ventricular contractions (MPVC), polymorphous premature ventricular contractions (PPVC) and repetitive premature ventricular contractions (RPVC). No subject featured horizontal or downsloping ST segment depression in both groups. At 24-hour electrocardiographic monitoring the incidence of the overall number of premature ventricular contractions was significantly greater in controls than athletes (87.0% vs 63.3%, p<0.05), whereas no significant difference were detected in the incidence of discrete ventricular arrhythmias between athletes (4.1% MPVC, 14.3% PPVC, 8.2% couplets) and controls (0.5% MPVC, 16.7% PPVC, 12.5% couplets). CONCLUSION: These finding indicate that in elderly, otherwise healthy, athletes vigorous training even to competition does not result in a greater incidence of ventricular arrhythmias, although caution should be made for a careful preparticipation evaluation.     

Effect of energy restriction and exercise on vitamin B-6 status of women during lactation

PURPOSE: Lactation increases vitamin B-6 requirements because its concentration in breast milk is related to maternal intake and it is essential for infants. Exercise may also increase the requirement because it increases utilization and excretion of vitamin B-6. Therefore, the purpose of this study was to determine whether energy restriction and exercise affected vitamin B-6 status of lactating women. METHODS: Breastfeeding women with a body mass index > or = 25 and < or = 30 kg x m(-2) were randomly assigned at 4 wk postpartum to either restrict energy intake by 500 kcal x d(-1) and exercise for 45 min x d(-1), 4 d x wk(-1) (weight loss group, WG) or maintain usual diet and not exercise (control group, CG) for 10 wk. Women were given a supplement containing 2.0 mg of vitamin B-6. Measurements included vitamin B-6 concentrations in breast milk and plasma, plasma pyridoxal 5'-phosphate, and erythrocyte alanine aminotransferase activity. RESULTS: The WG lost more weight (-4.4 +/- 0.4 vs -0.9 +/- 0.5 kg, P < 0.01) than the CG. Cardiovascular fitness increased by 12% in the WG, compared to 3% in the CG (P = 0.09). Milk vitamin B-6 concentrations increased in both groups (161 +/- 107 and 191 +/- 85 nmol x L(-1), WG and CG, respectively, P = 0.05). There were no significant differences in other vitamin B-6 parameters. Weight and length gain (2.06 +/- 0.21 and 1.83 +/- 0.17 kg; 8.6 +/- 0.6 and 7.2 +/- 0.5 cm; WG and CG, respectively) of infants was not significantly different between groups. CONCLUSIONS: Energy restriction and exercise from 4 to 14 wk postpartum in overweight, breastfeeding women consuming adequate dietary intakes and 2.0 mg of supplemental vitamin B-6 does not adversely affect vitamin B-6 status or infant growth.     

Exercise induced arterial hypoxemia in swimmers

AIM: Exercise induced arterial hypoxemia (EIAH) is a reduction in arterial oxygenation, which may result from a drop in arterial oxygen pressure and therefore in oxygen saturation. We examined EIAH in swimmers, while till now it was known to occur in cyclists and runners. METHODS: We studied 8 male highly trained swimmers (age: 23+/-1.7; (.-)VO(2peak), 5.3+/-0.1 l/min and 8 male ex-swimmers (age: 21.5+/-0.6; (.-)VO(2peak), 3.4+/-0.3 l/min). All subjects performed 200-meter freestyle at maximum effort. Hemoglobin saturation (SaO(2)%) was measured using a finger pulse oximeter before exercise in the water in an upright position and immediately after exercise, within 5 seconds. RESULTS: Highly trained swimmers developed a statistically significant decrease in SaO(2)% (from 98.3+/-0.3 to 94+/-0.9, p= or <0.01) after exercise, while ex-swimmers did not (from 98.4+/-0.3 to 96.8+/-0.3 ns). The 4% decrease in SaO(2)% observed in highly trained swimmers can be characterized as mild EIAH. CONCLUSIONS: Our study suggests that highly trained swimmers but not ex-swimmers may develop mild EIAH after 200 meters freestyle swimming at maximum effort.     

Effect of pre-exercise fructose ingestion on endurance performance in fed men

Twelve trained males, in a fed state, were studied to examine the effect of pre-exercise fructose ingestion on endurance capacity during prolonged cycling exercise. Sixty minutes prior to exercise, subjects ingested either 60 or 85 g fructose or a sweet placebo. Mean exercise intensity initially required 62% of the maximal aerobic power and thereafter increased to elicit 72 and 81% of maximal aerobic power at 90 and 120 min of exercise, respectively. Exercise time (mean +/- SE) to exhaustion was significantly increased after fructose ingestion, as compared to placebo ingestion (145 +/- 4 vs 132 +/- 3 min, P less than 0.01). During the exercise, no differences were observed between both trials for oxygen uptake, heart rate, or perceived exertion. Serum glucose and insulin levels between both trials were not significantly different throughout the experiment. There were also no significant differences in serum-free fatty acids and glycerol levels as well as respiratory exchange ratio between fructose and placebo trials during the exercise. The results suggest that fructose ingestion is of benefit before prolonged exercise, because it provides a carbohydrate source to contracting muscles without transient hypoglycemia and a depression of fat utilization, and thereby delays the fatigue.     

The effect of free glutamine and peptide ingestion on the rate of muscle glycogen resynthesis in man

The present study investigated previous claims that ingestion of glutamine and of protein-carbohydrate mixtures may increase the rate of glycogen resynthesis following intense exercise. Eight trained subjects were studied during 3 h of recovery while consuming one of four drinks in random order. Drinks were ingested in three 500 ml boluses, immediately after exercise and then after 1 and 2 h of recovery. Each bolus of the control drink contained 0.8 g x kg(-1) body weight of glucose. The other drinks contained the same amount of glucose and 0.3 g x kg(-1) body weight of 1) glutamine, 2) a wheat hydrolysate (26% glutamine) and 3) a whey hydrolysate (6.6% glutamine). Plasma glutamine, decreased by approximately 20% during recovery with ingestion of the control drink, no changes with ingestion of the protein hydrolysates drinks, and a 2-fold increase with ingestion of the free glutamine drinks. The rate of glycogen resynthesis was not significantly different in the four tests: 28 +/- 5, 26 +/- 6, 33 +/- 4, and 34 +/- 3 mmol glucosyl units x kg(-1) dry weight muscle x h(-1) for the control, glutamine, wheat- and whey hydrolysate ingestion, respectively. It is concluded that ingestion of a glutamine/carbohydrate mixture does not increase the rate of glycogen resynthesis in muscle. Glycogen resynthesis rates were higher, although not statistically significant, after ingestion of the drink containing the wheat (21 +/- 8%) and whey protein hydrolysate (20 +/- 6%) compared to ingestion of the control and free glutamine drinks, implying that further research is needed on the potential protein effect.     

Effect of chronic aerobic exercise on cutaneous microcirculatory flow response to insulin iontophoresis and to ischemia in elderly males

The aim of this study was to assess whether chronic aerobic exercise can favourably influence the vascular activity of insulin in elderly subjects. We measured in arbitrary units (A. U.) the cutaneous blood flow basally and in response to iontophoresis of insulin, by the means of a Laser Doppler flowmeter, on the right arm of 10 elderly athletes (10 males, aged 65 +/- 6 years) and of 10 sex- and age-matched sedentary subjects. The cutaneous blood flow response to ischemia was also explored in the right leg of the same subjects by means of the same instrument. No significant differences in cutaneous arm and leg blood flow were observed basally between athletes and sedentary subjects (7.25 +/- 2.65 A. U. versus 6.35 +/- 4.04 A. U. and 9.74 +/- 5.11 A. U. versus 9.41 +/- 6.40 A. U., respectively). Cathodal iontophoresis (six poulses of 0.1 mA each for 20 s, with 40-s interval between stimulations) of regular insulin (0.1 ml Humulin R 100 IU/ml diluted 1/10 with 0.9 % saline) induced a significant increase of cutaneous blood flow in both groups (p < 0.01 in athletes, p < 0.01 in sedentary subjects). However the maximal cutaneous blood flow response to insulin was higher in athletes than in sedentary subjects (24.69 +/- 13.34 A. U. versus 14.33 +/- 7.73 A. U., respectively, p < 0.05) as well as the curve of the net blood flux response to insulin iontophoresis (% change from baseline in response to insulin minus % change from baseline in response to saline iontophoresis) (p < 0.001 ANOVA for repeated measures). After ischemia there was a significant increase of leg cutaneous blood flow in both groups (p < 0.001 in athletes and in sedentary subjects) with higher blood flow response in athletes than in sedentary subjects (38.18 +/- 17.08 A. U. versus 26.01 +/- 6.39 A. U., respectively, p < 0.05). The time reached from the release of ischemia to peak-flow was significantly longer in sedentary subjects than in athletes (43.5 +/- 28.5 s versus 20.0 +/- 9.3 s, p < 0.05, respectively). These results suggest that chronic aerobic exercise increases insulin vasodilatory activity and improves endothelial function in elderly subjects.     

Correlation of procollagen (I) with prostate specific antigen and bone scan for the diagnosis of bone metastases in patients with prostate carcinoma

Procollagen (I) carboxyterminal propeptide (PICP) is a metabolite of procollagen, a precursor molecule of collagen type I, which accounts for more than 90% of the organic matrix of the bones. Serum PICP levels indicate the rate of bone collagen synthesis and therefore the osteoblastic activity. In this study we evaluate the clinical usefulness of serum PICP as an indicator of bone metastases in patients with prostate cancer in relation to bone scan and to prostate specific antigen (PSA) measurements. We found no similar study in the literature relating these three tests. Seventy-eight patients (median age 63+/-4,3 years) with prostate adenocarcinoma were examined. The diagnosis was confirmed histologically. Bone metastases were diagnosed in 42 (54%) of them assessed by bone scans (Group A), while the remaining 36 patients (46%) had no bone metastases (negative bone scans and X-rays) (Group B). We also examined 21 patients with benign prostate hyperplasia as a control group (Group C). All patients had serum PICP measurements, bone scans with (99m)Tc-MDP and PSA measurements. None of them had a history of disease or of using drugs known to affect bone metabolism. Serum levels of PICP were assayed by a radioimmunoassay (RIA) kit (Orion Cooperation, Farmos Diagnostics, Finland). Serum PSA was also tested by a RIA kit (Tandem-R, Hybritech Inc, USA). PICP levels in Group A were 265+/-89 microg/l, in Group B 128+/-39 microg/l and in Group C patients 110+/-48 microg/l. High levels of PICP above 170 microg/l, were diagnostic of bone metastases with sensitivity 54%, specificity 93% and accuracy 84%. In comparison, PSA levels above 4 ng/ml were also diagnostic with a sensitivity of 68%, specificity of 91% and accuracy 88%. Patients with low levels of PICP, lower than 90 microg/l, n=31, had no bone metastases. The positive prognostic value of bone scan was 74% with a sensitivity of 76%, specificity of 58% and accuracy 71%. Positive bone scans combined with very high levels of PICP and PSA, had positive prognostic value 97%, with sensitivity of 78%, specificity of 96% and accuracy 97%, while bone scans with levels of PICP lower than 170 microg/l, had positive prognostic value of 32%. Levels of PICP and PSA were significantly higher in patients with prostate cancer and bone metastases in comparison to patients with benign prostate hyperplasia (P<0.0001) respectively. Also, levels of PICP and PSA were higher in patients with prostate cancer without metastases as compared to prostate hyperplasia (P<0.0005 and P<0.0001 respectively) (Wilcoxon-Mann-Whitney test). When metastases were more extensive, PICP levels were higher than PSA. It is concluded that PICP as a marker of osteoblastic activity is useful for diagnosing bone metastases of prostate adenocarcinoma but when co-evaluated with PSA and the bone scan, the diagnostic accuracy of these three diagnostic procedures is much higher.     

Alactic anaerobic performance in subjects with sickle cell trait and hemoglobin AA

The aim of the present study was to assess the performance of subjects with sickle cell trait (SCT) during brief and explosive exercise involving mainly anaerobic metabolism. One hundred and ninety-six black subjects underwent SCT screening, which revealed the presence of 16 subjects with SCT and 180 subjects with normal hemoglobin (HbAA). All subjects performed four tests: 1) a 100-m sprint, 2) a long-jump, 3) a Leger-Boucher shuttle test and 4) a jump-and-reach test. A control group (n = 18) selected from the 180 subjects with HbAA was matched according to the sex, age, weight and height of the SCT subjects (SCTs). The performances of the SCTs (n = 16) were compared with those of the control group. The performances were similar between the SCTs and control group for the sprint test, long-jump and the Leger-Boucher shuttle test. There was, however, a significant difference for the jump-and-reach test between the two groups: the SCTs (i. e., males plus females, and males and females considered separately) reached a significantly greater height (p < 0.05) than the matched subjects of the control group (63.7 +/- 3.6 vs. 58.6 +/- 3.1 cm, 72.3 +/- 3.9 vs. 67.1 +/- 2.4 cm and 52.7 +/- 3.2 vs. 45.3 +/- 2.0 cm for SCTs versus non-SCTs, for the group, the males and the females, respectively). The results of the present study suggest that the performance of brief and explosive exercise may be enhanced by HbS.     

非营养性吸吮对早产儿胃泌素及生长发育的影响

目的探讨非营养性吸吮对早产儿胃泌素及生长发育的影响。方法以2010年2月～2011年1月我科收治的早产儿68例为研究对象,随机分为非营养性吸吮（NNS）组和对照组,测定出生后第1天开奶前及出生后第7天、第14天血清胃泌素水平,同时记录生长发育指标（头围、身长、体重）。结果①NNS组胃泌素水平在出生后第7、14天高于对照组（P〈0.05）;②与对照组相比,NNS组第7、14天体重增长差异有统计学意义（P〈0.05）;③NNS组胃肠外营养时间较对照组缩短,有统计学意义（P〈0.05）。结论 NNS可以促进早产儿血清胃泌素分泌及体重的增长,还可以缩短胃肠外营养时间。     

Adiposity, lipid levels, and brief endurance training in nonobese adolescent males

Physical activity during childhood and adolescence may influence the development of childhood obesity and cardiovascular disease later in life. Research focused prospectively on the effects of training on lipid levels in nonobese subjects, and studies using noninvasive measurements of subcutaneous and intraabdominal fat are lacking. It was hypothesized in nonobese sedentary adolescent males that a brief endurance-type exercise training intervention would reduce body fat and improve lipid profiles. Thirty-eight healthy, nonobese sedentary adolescent males (mean age 16 +/- 0.7 years old; 18 controls, 20 trained) completed a 5-week prospective, randomized, controlled study. Adiposity was measured using magnetic resonance images of the thigh and abdomen (subcutaneous abdominal adipose tissue [SAAT] and intraabdominal adipose tissue [IAAT]). Lipid measurements included serum triglycerides (TG), total cholesterol (TC), HDL and LDL cholesterol. There was no change in body weight in either control or training groups. Training led to small but significant reductions in thigh fat (-4.6 +/- 1.5%, p < 0.03) and SAAT% (1.7 +/- 0.8%, p < 0.02). There was no change in IAAT%. Unexpectedly in the control group there were significant increases in thigh fat (5.2 +/- 1.7%, p<0.01), SAAT% (1.8 +/- 0.6, p < 0.007) and IAAT% (4.5 +/- 1.1, p < 0.0007). Training-induced changes in adiposity were not accompanied by changes in circulating lipids. In nonobese adolescent males a brief period of endurance training led to reductions in body fat depots without weight change while body fat increased rapidly in the control group. Exercise training did not change lipid levels, the latter may require more sustained alterations in patterns of physical activity.     

Exercise capacity of cardiac asymptomatic hereditary hemochromatosis subjects

PURPOSE: The exercise capacity of cardiac asymptomatic subjects with hereditary hemochromatosis (HH) has not been well described. In this study, we tested whether the iron overload associated with HH affected exercise capacity with a case control study design. METHODS: Forty-three HH and 21 normal control subjects who were New York Heart Association functional class I underwent metabolic stress testing using the Bruce protocol at the clinical center of the National Institutes of Health. Exercise capacity was assessed with minute ventilation (.VE), oxygen uptake (.VO2), and carbon dioxide production (.VCO2) using a breath-by-breath respiratory gas analyzer. RESULTS: The exercise capacity of HH subjects was not statistically different from that of control subjects (exercise time 564 +/- 135 vs 673 +/- 175 s, P = 0.191; peak .VO2 29.6 +/- 6.4 vs 32.5 +/- 6.7 mL.kg(-1).min(-1), P = 0.109; ventilatory threshold 19.0 +/- 3.4 vs 21.0 +/- 5.0 mL.min(-1).kg(-1), P = 0.099; data are for HH vs control subjects). Ventilatory efficiency was comparable between groups (.VE/.VCO2 slope 23.7 +/- 3.2 vs 23.4 +/- 4.2, P = 0.791). No significant correlation between the markers of iron levels and the markers of exercise capacity was noted. Iron depletion by 6-month phlebotomy therapy in 18 subjects who were newly diagnosed did not affect exercise testing variables (exercise time 562 +/- 119 vs 579 +/- 118 s, P = 0.691; peak .VO2 29.5 +/- 3.7 vs 29.1 +/- 4.7 mL.kg(-1).min(-1), P = 0.600; ventilatory threshold 18.5 +/- 2.8 vs 17.9 +/- 3.8 mL.kg(-1).min(-1), P = 0.651; data are from before and after phlebotomy therapy). Abnormal ischemic electrocardiographic responses and complex arrhythmias were more frequently seen in HH subjects. CONCLUSIONS: The aerobic exercise capacity of asymptomatic HH subjects seems not to be statistically different from that of normal subjects. The iron levels do not seem to affect exercise capacity in asymptomatic HH subjects.     

Exercise MR imaging in the assessment of pulmonary regurgitation and biventricular function in patients after tetralogy of fallot repair

PURPOSE: To assess the responses of pulmonary regurgitation (PR) and biventricular function to submaximal exercise by using a magnetic resonance (MR) imaging exercise protocol with young adult patients who underwent tetralogy of Fallot repair at a young age. MATERIALS AND METHODS: Fifteen patients with corrected tetralogy of Fallot (mean age, 17.5 years +/- 2.5 [SD]) underwent MR imaging at rest and during exercise for the evaluation of PR and biventricular function. Results were compared with findings from 16 control subjects (mean age, 17.5 years +/- 2.3). Mean age at tetralogy of Fallot repair was 2.1 years +/- 1.6, and mean follow-up time after repair was 15.4 years +/- 2.6. Exercise level at MR imaging was calculated individually and corresponded to 60% of peak oxygen uptake. The parameters of cardiac function obtained at rest and during exercise were compared by using a paired t test. An unpaired t test was used to compare parameters of cardiac function between patients and control subjects. RESULTS: PR decreased during exercise (from 27 mL/m(2) +/- 17 to 23 mL/m(2) +/- 15; P =.012). At rest, right ventricular (RV) ejection fraction was normal (>47%) in 80% of patients. RV response to exercise in the patient group was abnormal compared with response in the control group, as demonstrated by an increase in RV end-diastolic volume index (132 mL/m(2) +/- 36 to 137 mL/m(2) +/- 38; P =.041) and no significant change in end-systolic volume index or ejection fraction. In only one patient, RV ejection fraction increased by more than 5%. Left ventricular response was not different between patients and control subjects. CONCLUSION: MR imaging is well suited to assess cardiac response to exercise, and findings revealed a decrease in PR and an abnormal RV response to exercise in patients with corrected tetralogy of Fallot.