Bone mineral density in 11–13-year-old boys: relative importance of the weight status and body composition factors

This study was aimed to investigate the influence of being overweight on bone mineral status in 11–13-year-old boys, who were divided into overweight (OW; n = 110) and normal weight (NW; n = 154) groups. Bone mineral density (BMD) at the whole body (WB), lumbar spine (LS) and femoral neck (FN), bone mineral content (BMC) at the WB, and body composition were assessed. Calculation of the bone mineral apparent density (BMAD) was completed for the WB, LS and FN. The BMC/height ratio was also computed. OW boys displayed similar values (P > 0.05) for LS and FN BMAD and lower (P < 0.05) WB BMAD, despite significantly higher values (P < 0.05) for more widely used WB and LS BMD, WB BMC and WB BMC/height in comparison with NW boys. Fat-free mass index (FFMI; kg/m²) had the highest correlation coefficients from the calculated body composition indices with all bone mineral values in NW boys. In OW boys, the FFMI had the highest correlation only with FN BMD, while other measured bone mineral values had highest correlations with either BMI or FMI indices. In conclusion, OW boys have higher crude WB BMD, BMC and BMC/height ratio in comparison with NW boys. However, the bone growth appears to be insufficient to compensate for the higher mechanical load applied on the bone by higher FM and also FFM values in OW boys. Excessive adiposity does not have a protective effect on the development of BMAD in growing boys reaching puberty.     

Bone metabolism in elite male rowers: adaptation to volume-extended training

We examined the effect of 6-month volume-extended training on bone metabolism in elite male rowers. Twelve elite male rowers (20.8±3.0 years; 192.9±4.7 cm; 91.9±5.3 kg; body fat 10.1±2.3%; 6.2±0.5 l min⁻¹) participated in this study. Bone biochemical markers, hormones, bone mineral content (BMC), and bone mineral density (BMD) were assessed before and after training. Average weekly training volume was significantly higher (P<0.05) during the 6 months of heavy training compared to relative rest (11.6±0.4 h week⁻¹ vs. 16.8±0.6 h week⁻¹), while intensity remained the same. At the end of training, only arm BMD was significantly increased by 5.7%. Osteocalcin (16.6%), insulin-like growth factor-1 (IGF-1) (20.2%) and the bioavailability IGF-1 index (17.9%) were significantly increased. Before heavy training, relationships were observed between the whole body BMD and growth hormone (r=0.64; P≤0.02), lumbar spine BMD and 1.25(OH)₂ vitamin D (r=0.69; P≤0.04), arm BMD and testosterone (r=0.59; P≤0.05), and arm BMD and adiponectin (r=0.59; P≤0.05). No relationship was found between BMC or BMD and blood biochemical measures 6 months later (r=0.56; P≥0.05). In addition, osteocalcin was related to IGF-1 (r>0.58; P<0.048) and bioavailability IGF-1 index (r>0.59; P≤0.055) before and after training. In summary, heavy training had a moderately favorable effect on BMD. Bone tissue at specific skeleton sites is sensitive to changes in training volume even in athletes with already high BMD values. Changes in BMD and bone formation may be caused by changes in specific hormones such as IGF-1 and adiponectin in male athletes.     

von Willebrand factor and transforming growth factor-beta modulate immune response against coagulation factor VIII in FVIII-deficient mice

In up to 25% haemophilia A patients, the administration of coagulation factor VIII (FVIII) preparations for treatment of haemorrhages results in production of factor VIII specific antibodies. Plasma-derived FVIII preparations contain other plasma proteins, which may modulate the immune response to FVIII. We used FVIII-deficient mice to assess the role of von Willebrand factor (VWF) and cytokine transforming growth factor beta-1 (TGF-β1) in the immune response against FVIII. Using the FVIII and FVIII in complex with VWF purified from the plasma-derived FVIII preparation, we demonstrated that a lower concentration of FVIII antibody was induced in FVIII–VWF-treated mice compared to FVIII-treated mice (p < 0.05). The addition of recombinant latent TGF-β1 to FVIII decreased the antibody response against FVIII compared to FVIII treatment alone (p < 0.01). The obtained results suggest that VWF and latent TGF-β1 present in plasma-derived FVIII preparations reduce the immune response against FVIII. However, we cannot exlude possible modulatory effects of other plasma proteins.     

Regular physical activity influences plasma ghrelin concentration in adolescent girls

PURPOSE: We examined the effect of regular physical activity on plasma ghrelin concentration after onset of puberty in girls. In addition, we also examined the association of fasting plasma ghrelin concentration with various plasma biochemical, body composition, and aerobic capacity variables in healthy adolescent girls. METHOD: Fifty healthy schoolgirls ages 11 to 16 yr were divided either into a physically active (N = 25) or a physically inactive (N = 25) group. The physically active group consisted of swimmers who had trained on an average of 6.2 +/- 2.0 h.wk(-1) for the last 2 yr, whereas the inclusion criterion for the physically inactive group was the participation in physical education classes only. The subjects were matched for age (+/- 1 yr) and body mass index (BMI; +/- 2 kg.m(-2)). Maturation I group (14 matched pairs) included pubertal stages 2 and 3, and maturation II group (11 matched pairs) included pubertal stages 4 and 5. RESULTS: Physically active girls had significantly higher (P < 0.05) mean plasma ghrelin levels than the physically inactive girls (maturation I: 1152.1 +/- 312.9 vs 877.7 +/- 114.8 pg.mL(-1); maturation II: 1084.0 +/- 252.5 vs 793.4 +/- 164.9 pg.mL(-1)). Plasma ghrelin concentration was negatively related to percent body fat, fat mass, peak oxygen consumption per kilogram of body mass, leptin, estradiol, insulin, and insulin-like growth factor-I (IGF-I) (r > -0.298; P < 0.05). Multivariate linear regression analysis to determine the predictors of ghrelin concentration using the variables that were significantly associated with ghrelin concentration demonstrated that plasma IGF-I was the most important predictor of plasma ghrelin concentration (beta = -0.396; P = 0.008). CONCLUSION: Regular physical activity influences plasma ghrelin concentrations in girls with different pubertal maturation levels. Plasma IGF-I concentration seems to be the main determinant of circulating ghrelin in healthy, normal-weight adolescent girls.     

A randomized,parallel, vehicle-controlled comparison of two erythromycin/benzoyl peroxide preparations for acne vulgaris

BACKGROUND: Topical erythromycin/benzoyl peroxide (EBP), marketed for acne treatment, must be compounded by a pharmacist and requires subsequent refrigeration, warranting the development of alternate formulations. OBJECTIVE: This trial compared the efficacy and tolerability of a single-use EBP combination package (EBP Pak) with those of its matching vehicle control (VC Pak) and the original, reconstituted formulation packaged in a jar (EBP Jar). The matching VC for the original formulation (VC Jar) was used to achieve study blinding. METHODS: In this double-blind, parallel-group, multicenter study, patients were randomly assigned to the 4 treatment arms. The primary efficacy evaluations were lesion reductions from baseline and treatment success (as defined by a Physician's Global Acne Severity score of 0 [clear] or 0.5 [sparse comedones with few or no inflammatory lesions]). Secondary evaluations were Physician's Global Acne Severity scores, facial-oiliness scores, and end-point patient evaluations of global improvement and treatment acceptability. Tolerability was based on the incidence and severity of adverse events. RESULTS: Three hundred twenty-seven patients (age range, 12-46 years) were randomly assigned to the 4 treatment groups (EBP Pak, 124; VC Pak, 42; EBP Jar. 121; VC Jar, 40). Mean percent reductions in total acne lesions, inflammatory acne lesions, and come-dones from baseline were significantly greater with EBP Pak than with VC Pak (P < or = 0.001 for the intent-to-treat patient population after 8 weeks). Statistical significance for all lesion parameters was demonstrated at week 2 (P < 0.05) and maintained throughout the study. At 8 weeks, a significantly greater proportion of patients demonstrated treatment success with the EBP Pak compared with VC Pak (28% vs 2%, respectively; P < 0.001). The EBP Pak was comparable to the EBP Jar in terms of reduction in acne lesions, Physician's Global Acne Severity scores, and end-of-treatment patient evaluations of global improvement. No serious drug-related adverse events were reported. CONCLUSIONS: Results of this 8-week trial demonstrate that the single-use combination package of EBP is well tolerated, effective, and comparable to the original formulation for the treatment of acne vulgaris in this selected patient population.     

CHRONIC REJECTION: PROSPECTS FOR THERAPEUTIC INTERVENTION IN FIBROPROLIFERATIVE VASCULAR DISEASE

The graft survival rates of sensitized kidney recipients have been shown to be lower than those of nonsensitized patients. Therefore, panel reactive antibody (PRA) and cross-match determination is accepted as mandatory screening for renal transplantation candidates. Our recent previous study showed that simvastatin has a significant immunosuppressive effect in PRA-positive and/or crossmatch-positive patients. We present the long-term pre and post-transplantation outcomes of simvastatin treatment in highly sensitized dialysis patients. Thirty patients were followed for a mean period of 22 months. The PRA and flow cytometric measurements were performed at monthly intervals. Ten patients underwent successful kidney transplantation (eight living-related and two cadaveric). None of the patients developed hyperacute or acute rejection, and there was no graft loss during the 16.1±8.2 months of post-transplantation follow up. Of the 18 patients who stayed on dialysis throughout the study with PRA-positivity, six were lost to follow up and three spontaneously stopped taking the simvastatin. In the latter three cases, the PRA levels rose significantly after the drug was discontinued. Eight of the remaining nine PRA-positive patients showed significant drops in mean PRA level over the study period, and entered the range considered acceptable for transplantation. Only one patient showed persistently high PRA levels throughout the study. In one patient, the drug had to be discontinued because of acute toxic hepatitis. In conclusion, the results indicate that long-term continuous simvastatin therapy is effective in immunized and highly sensitized dialysis patients. Meanwhile, it has a beneficial effect on 1-year graft survival rates in sensitized renal transplantation patients.