Bone density, body composition and menstrual history of sedentary female former gymnasts, aged 20-32 years.

Few studies have examined the effects of retirement from sports involving regular, high impact and weight bearing activity on bone mass. This cross-sectional study compared total body and regional areal bone mineral density (aBMD, g/cm(2)) within female former gymnasts and women who had never participated in structured sport or exercise, and explored relations between aBMD of these former gymnasts and their duration of retirement. Eighteen sedentary female former gymnasts (GYM) and 18 sedentary controls (CON) were recruited. GYM displayed a broad range of duration of retirement (3-12 years) and a wide age range (20-32 years). GYM and CON were paired individually to match for age, body mass and stature. GYM had commenced training at least 3 years pre-menarche and had trained post-menarche for 2 or more years. They had trained continuously for 5-12 years and had retired between age 14 and 22 years. Measurements of aBMD and body composition were made using dual energy X-ray absorptiometry (DXA). Group mean values of physical and skeletal characteristics were compared using paired t-tests. Linear regression was used to explore possible relations of aBMD within GYM to duration of retirement. GYM displayed a higher aBMD than CON at all measurement sites, which ranged in magnitude from 6% for the total body ( P=0.004), to 11% for the total femur ( P=0.006). Elevations of aBMD within GYM equated to T-scores ranging from +0.8 (arms) to +1.7 (legs). There were no differences in body composition or age of menarche between groups, although 11 of 18 GYM reported a history of irregular menses. There was no significant decline of aBMD with increasing duration of retirement in GYM. The results suggested that an elevated bone mass in female former gymnasts was retained during early adulthood, in spite of a cessation of training for up to 12 years.

Differences in bone density, body composition, physical activity, and diet between child gymnasts and untrained children 7-8 years of age.

Strategies that enhance the acquisition of bone mass may be protective against osteoporosis. BMD was compared in 20 artistic gymnasts (10 boys; 10 girls) and 20 untrained children ages 7-8 years. Higher regional values of BMD were observed in female gymnasts than untrained girls. If retained to adulthood, this higher BMD may protect skeletal integrity in later life. Strategies that enhance the acquisition of bone mass in children may assist with the prevention of osteoporosis. This study explored the effects of regular high-impact and weight-bearing activity before the age of 7 years on total and regional bone mineral density (BMD). Twenty artistic gymnasts (10 boys and 10 girls) and 20 untrained children, 7-8 years of age, were recruited. The untrained children were matched to gymnasts by sex, height, weight, and age. Female gymnasts trained 8-10 h per week and had trained regularly for 3-4 years. Male gymnasts trained 4-6 h per week and had trained for 1-2 years. Measurements of bone mineral density were made using DXA for total body BMD (TBBMD); lumbar spine, both areal (aSBMD) and volumetric (vSBMD); total spine; pelvis; arms; and legs. Significant mean differences (8-10%) in aSBMD, vSBMD, arm BMD, and TBBMD were observed between female gymnasts and untrained girls (p < 0.05: aSBMD, vSBMD, and TBBMD body mass (BM); p < 0.01: arm BMD). A nonsignificant trend toward a higher TBBMD/BM and arm BMD was observed in male gymnasts compared with untrained boys. Trends toward a higher BMD within the pelvis, legs, and total spine were also observed in gymnasts. There were no differences in total and regional BMD between untrained boys and untrained girls. The results suggest that gymnastics training before the age of 7 years enhances the acquisition of bone mass at selected skeletal sites. The magnitude of this enhancement seems to be linked to the cumulative volume of such training. If retained during adolescence and young adulthood, a surfeit of bone acquired through high-impact and weight-bearing activity in early childhood may protect skeletal integrity in later life.

[Resistance to therapy in primary nephrotic syndrome: effect of MDR1 gene activity]. / Odpornosc na leczenie w przebiegu pierwotnego zespolu nerczycowego: wplyw aktywnosci genu MDR1.

MDR1 gene encodes for a transmembranous glycoprotein, gp-170, which acts as a drug export pump and is also a cyclosporine(CsA)-binding protein. This study aimed at evaluating MDR1 expression in NS sensitive(S) and resistant(R) to therapy (steroids/S/, cyclophosphamide/C/, CsA) patients. Twenty six boys, 13 girls aged 3-8 years were included to the study. MDR1 was analysed using: 1) evaluation of gp-170 activity according to DiC2/3/ [3,3-Diethyloxa-carbocyanine Iodide] by means of flow cytometry and as 2) mRNA expression of MDR1 determined by RT-PCR. The analysis was performed in the lymphocyte subset CD4/CD45RA presenting suppressor-inducer activity. Negative control, Jurkat-T-cell line, not expressing the MDR1 phenotype, was transfected with viral expression vector containing a full-length cDNA for the human MDR1 gene. We found that: in SR-NS the high expression of MDR1 was associated mainly with the suppressor-inducer T-cells (CD45RA+CD4+) and was subsequently enhanced during an ineffective treatment with C and/or CsA. C-R-NS and CsA-R-NS were partially reversible by S- and R-Verapamil; this was in vitro confirmed by inhibition of export pump activity, gp-170. SS-NS, C-S-NS and CsA-S-NS presented the low expression and activity of MDR1 comparing to R-children (p < 0.001) and healthy controls (p < 0.00001). Resistance to therapy in NS patients seems to be resulted from the enhanced expression of MDR1 gene and subsequent high activity of export pump P-gp-170. Calcium channel blockers may reverse the MRD1-related resistance in the therapy of NS. Analysis of MDR1 may help to detect of suspected therapy resistance in NS.

Responses of bone turnover markers to repeated endurance running in humans under conditions of energy balance or energy restriction.

Distance running in humans has been associated with both positive and negative effects on the balance of bone remodelling. There is evidence to suggest that the negative effects may be linked to a failure to balance energy expenditure with an adequate energy intake. Energy restriction is known to reduce the synthesis and serum concentration of insulin-like growth factor 1 (IGF-1), which plays an important role in bone formation. The purpose of the present study was to compare the effects of repeated periods of prolonged treadmill running, under conditions of either energy balance or energy restriction, on markers of bone turnover and serum IGF-1 concentration in trained distance runners. Eight male distance runners [mean age 25.1 (SD 5.9) years, maximal oxygen uptake 61.8 (SD 4.9) ml x kg(-1) x min(-1)] undertook an exercise and diet regime on two separate occasions, 2 weeks apart. On each occasion they performed an intensive, 60 min treadmill run on 3 consecutive days. On one occasion their energy intake was restricted to approximately 50% of their estimated energy requirement (RES), whereas on the other occasion they remained in energy balance (BAL). The N-terminal pro-peptide of type 1 collagen (P1NP), osteocalcin and IGF-1 were measured in serum collected between 0800 and 0900 hours, when fasted and rested, on the day before and the day after each regime. The cross-linked N-telopeptides of type 1 collagen and deoxypyridinoline were measured from 24 h urine collections made on the day before and the final day of each regime and adjusted for creatinine excretion. The results showed that the serum concentration of both P1NP and IGF-1 declined by 15% (P = 0.008) and 17% (P = 0.007) respectively in response to RES, but did not change in response to BAL (P > 0.05). A strong relationship was observed between the magnitude of the reduction in the serum concentration of P1NP and IGF-1 after RES (r = 0.97; P < 0.001). There were no changes in the other bone markers in response to either regime. The results suggested that in trained distance runners, repeated periods of prolonged running do not affect the balance of bone turnover unless energy balance is simultaneously altered. These findings support the link between a negative energy balance, a reduced synthesis or serum level of IGF-1 and reduced collagen synthesis. They may also help to explain the bone remodelling imbalance that has been observed in some male and female distance runners.

Relation between bone turnover, oestradiol, and energy balance in women distance runners.

OBJECTIVE: To explore relations between biochemical markers of bone turnover, indices of nutritional status, and serum oestradiol concentration in women distance runners. METHODS: Thirty three women distance runners of mean age (SD) 27.2 (1.8) years participated. Eighteen were defined as eumenorrhoeic, nine as amenorrhoeic, and six as oligomenorrhoeic. Mean (SD) running distance was 47.6 (22.4) km/week. Using bivariate correlation and regression analysis, serum levels of osteocalcin and bone alkaline phosphatase (BAP) and also urine deoxypyridinoline/creatinine (Dpyr/Cr) were correlated with mean daily energy balance, body mass index (BMI; kg/m2), and serum levels of total 3,5,3'-triiodothyronine and oestradiol within each group by menstrual status. RESULTS: All the amenorrhoeic women were in negative energy balance; they had a lower BMI, lower serum levels of oestradiol, triiodothyronine, osteocalcin and BAP and a lower urine Dpyr/Cr than any of the oligomenorrhoeic or eumenorrhoeic women. These variables were also lower in oligomenorrhoeic than in eumenorrhoeic women. Positive correlations were observed between serum levels of osteocalcin or BAP and both BMI and serum oestradiol concentration in amenorrhoeic, but not in oligomenorrhoeic or eumenorrhoeic women. Urine Dpyr/Cr did not correlate with any other variable within any group. Serum oestradiol concentration correlated positively with BMI in amenorrhoeic and oligomenorrhoeic, but not eumenorrhoeic women. CONCLUSIONS: Positive correlations between serum levels of bone formation markers, BMI and serum oestradiol concentration in our amenorrhoeic runners suggested that their reduced bone formation was linked to a low BMI and an oestrogen deficiency. Reduced bone turnover in amenorrhoeic distance runners has not previously been shown. These findings emphasise the importance of body mass and its possible link with a chronic energy deficit and hypothalamic dysfunction on bone remodelling balance in amenorrhoeic runners.

The relationship between serum oestradiol concentration and energy balance in young women distance runners.

Reproductive dysfunction in women distance runners has been linked to an imbalance between energy intake (EI) and energy expenditure (EE) which leads to an energy deficit. To determine whether ovarian suppression is associated with an energy deficit, the relationships between serum oestradiol (E2) concentration and indices of energy balance (EB) were explored in a group of women runners with a variety of menstrual patterns and a range of activity levels. Subjects comprised 33 women distance runners of mean (SD) age 27.2 (1.8) years. Sixteen of these women were defined as eumenorrhoeic (11-13 menstrual bleeds per year during the past 2 years), 8 as oligomenorrhoeic (< or = 3 menstrual bleeds per year for 2 years) and 9 as amenorrhoeic (absence of menses for > 1 year). Their volume of running training ranged from 36 to 97 km x wk(-1) [mean (SD): 68.6 (21.4) km x wk(-1). The body mass index (BMI) and percent body fat (BF) of each subject was measured. Their mean daily energy balance (EB) was calculated by subtracting their dietary EI from their estimated EE recorded over 7 days. Serum concentrations of E2, total T3 and IGF-1 were measured from a fasting blood sample (taken in early follicular phase for Eu women). Relationships between serum E2, T3 and IGF-1, EB, BMI and BF were explored using bivariate correlation and regression analysis. The results showed that the most powerful predictors of serum E2 concentration were estimated EB (r = 0.88, P<0.001), serum T3 (r=0.94, P<0.001) and IGF-1 (r=0.84; P<0.001). Weaker correlations were observed between serum E2 and BMI (r=0.42; P=0.008) and serum E2 and BF (r=0.48; P=0.004). These relationships add support to the hypothesis that reproductive dysfunction in women distance runners is associated with an energy deficit.

Bone turnover in amenorrhoeic and eumenorrhoeic women distance runners.

Bone remodelling has not been assessed in women distance runners with chronic amenorrhoea. The purpose of this study was to compare indices of bone turnover and energy balance in runners with chronic amenorrhoea, runners with a history of regular menstrual cycles and sedentary controls. Subjects comprised 3 groups of 9 women, matched for age [mean+/-SEM: 27.2+/-1.8 yrs] and categorised as amenorrhoeic runners (AmR), eumenorrhoeic runners (EuR) and eumenorrhoeic sedentary controls (SC). Serum concentrations of bone formation markers [osteocalcin (OC), carboxy-terminal propeptide of type 1 collagen (P1CP), bone alkaline phosphatase (BAP)], E2, total T3 and IGF-1 were measured from a fasting morning blood sample. Urine levels of bone resorption markers [pyridinoline (Pyr) and deoxypyridinoline (Dpyr)] were measured and corrected for creatinine excretion. Mean daily energy balance (EB) was calculated by subtracting dietary energy intake (EI) from energy expenditure (EE) estimated from reported activity patterns over 7 days. The results showed that all bone turnover markers were lower in AmR than in EuR or SC (P<0.001: OC, BAP and P1CP; P<0.05: Pyr and Dpyr). Furthermore, when z-scores for each bone marker in runners were calculated against mean values for SC (by subtracting each measure of bone turnover from the mean value for SC and expressing the difference as a fraction of the SD of this mean value), bone resorption appeared to outweigh formation in AmR, but not in EuR. Serum concentrations of E2, T3 and IGF-1 were also lower in AmR than in EuR or SC (P<0.001: all hormones), as was EB (P<0.001). These findings suggested that in AmR there was some factor which was reducing bone turnover and in particular, bone formation. This factor might have been linked to an energy deficit and the effects of this deficit on body mass, body composition and metabolism.

[Poisoning with "poppers", a rare cause of methemoglobinemia observed in emergency cases]. / L'intoxication au "poppers", cause rare de méthémoglobinémie observée aux urgences.

BACKGROUND: Methemoglobulinemia should be entertained as a differential diagnosis in patients with cyanosis. Recently in France there has been an increase in the number of cases of acquired methemoglobulinemia due to inhalation of poppers. CASE REPORTS: Four patients were admitted to the emergency room of a Paris hospital in a state of unconsciousness with cyanosis. All four patients had inhaled poppers shortly before admission. The clinical course was rapidly favorable after intravenous infusion of methylene blue in 3 cases. DISCUSSION: Poppers are inorganic aliphatic nitrites used for their relaxing effect on smooth muscle and for their aphrodisiac effect. One poorly recognized effect is the development of methemoglobulinemia. Tissue hypoxia results because methemoglobulin cannot bind oxygen, leading to a brown or blue coloration of the blood. Methemoglobulin usually results from exposure to a wide variety of oxidizing compounds including certain drugs. Methylene blue is the specific treatment for symptomatic methemoglobulinemia. These four cases emphasize the toxic effect of products sold in sex shops and calls attention to the life-threatening risks involved.

Responses of plasma glutamine, free tryptophan and branched-chain amino acids to prolonged exercise after a regime designed to reduce muscle glycogen.

Prolonged exercise can elicit a reduction in the plasma glutamine concentration and an increase in the plasma concentration ratio of free tryptophan (FTrp) to branched-chain amino acids (BCAA). The purpose of this investigation was to study the effects of a 60-min bout of vigorous treadmill running with dietary manipulation on plasma concentrations of glutamine, FTrp and BCAA after an exercise and diet regime designed to reduce muscle glycogen. Seven male distance runners [mean (SD) age: 29.3 (2.1) years; VO2max: 62.7 (3.3) ml.kg-1.min-1] acted as subjects. Each undertook a regime designed to reduce muscle glycogen, then performed a 60-min treadmill run (75% VO2max) under two dietary conditions: after a 14-h fast (fasted) and after ingestion of a high carbohydrate meal (30 kJ.kg-1: 80% carbohydrate, 10% protein, 10% fat) 3 h before running (fed). Plasma concentrations of glutamine, FTrp, BCAA, free fatty acids (FFA), glycerol and glucose were measured 5 min before and 5 min after the run, under each dietary condition. Plasma glutamine did not change in response to exercise when fasted (P > 0.05), but increased when fed (P = 0.007). Plasma FTrp increased under both dietary conditions (P < 0.001), but the magnitude of this increase was greater when fasted than when fed (P < 0.001). Plasma BCAA did not change under either dietary condition (P < 0.05). Increases in the plasma FTrp/BCAA ratio reflected increases in plasma FFA and glycerol concentrations (P < 0.001; both dietary conditions) and these changes were all greater under fasted conditions when a fall in blood glucose concentration was observed (P = 0.007). These data emphasise the importance of dietary carbohydrate intake between repeated bouts of prolonged exercise on responses of plasma glutamine, FTrp and BCAA during subsequent exercise.

The reproducibility of cardiopulmonary responses to exercise using a swim bench.

The purpose of this study was to establish reproducible assessments of cardiopulmonary responses to exercise using a computer-interfaced isokinetic swim bench. Five male and four female highly trained swimmers with mean age of 19.2 +/- 1.2 (yrs), stature 1.75 +/- 0.02 (m) and body mass of 65.8 +/- 2.9 (kg) performed an incremental exercise test on two occasions within one week. Oxygen consumption (VO(2)), heart rate (HR) and exercise intensity were recorded throughout the exercise test. Measurements were made of the peak oxygen consumption (VO(2peak)), peak heart rate (HR(peak)) peak exercise intensity (EI(peak)) and the submaximal heart rate vs exercise intensity (HR/EI) and oxygen consumption vs exercise intensity (VO(2)/EI) relationships. The values for VO(2peak), HR(peak) and EI(peak) from all tests were 2.85 +/- 0.26 (I.min(-1)), 171 +/- 2.8 (b.min(-1)) and 86.2 +/- 6.8 (watts) respectively. The differences in these peak values from repeated tests were 0.06 I.min(-1), 1.8 b.min(-1) and 1.3 W, which were not significant (p > 0.05; paired t-test). These represented 2.1, 1.0 and 1.5% respectively. The HR/EI and VO(2)/EI relationships were shown to be linear (at least r = 0.99 and r = 0.98 respectively) and the differences in these relationships from repeated tests were not significant (p > 0.05, ANCOVA) showing adjusted mean differences of 0.02 I.min(-1) and 0.5 b.min(-1) for the group. These results suggest that this method, which uses a swim bench, provides reproducible measurement of the cardiopulmonary responses to exercise in swimmers.

Human cytotoxic T lymphocytes. II. Frequency analysis of cyclosporin A-sensitive alloreactive cytotoxic T-lymphocyte precursors.

A limiting dilution (LD) culture system was used to investigate the effect of cyclosporin A (CsA) on the activation and differentiation of human alloreactive cytotoxic T-lymphocyte precursors (CTL-p). CsA reduced in a dose-dependent fashion the frequency of alloantigen-inducible CTL-p. With most normal individuals tested there was a 20- to 50-fold reduction of alloreactive CTL-p frequencies in the presence of 500-1000 ng/ml CsA. Both unseparated T cells and CD8+ T cells were CsA-sensitive under LD culture conditions. Importantly, however, alloreactive CTL-p from two out of 21 normal individuals were found to be largely CsA-resistant. CsA did not affect the growth of MLR-primed CTL in secondary LD culture. Furthermore, CsA slightly inhibited the cytolytic activity of some alloantigen-specific CTL clones. These results are discussed with respect to the clinical use of CsA in transplantation medicine.