Our study offers nationwide epidemiological data on fractures in Hungary. The incidence of fractures increased by age, regardless of the type of fracture. Incidence of hip fractures in Hungary fits in the previously established geographic trends in Europe. Our results fulfil a need for fracture data from Central Europe.
Targeted disruption of the histidine decarboxylase gene (HDC ؊/؊ ), the only histamine-synthesizing enzyme, led to a histamine-deficient mice characterized by undetectable tissue histamine levels, impaired gastric acid secretion, impaired passive cutaneous anaphylaxis, and decreased mast cell degranulation. We used this model to study the role of histamine in bone physiology. Compared with WT mice, HDC ؊/؊ mice receiving a histamine-free diet had increased bone mineral density, increased cortical bone thickness, higher rate of bone formation, and a marked decrease in osteoclasts. After ovariectomy, cortical and trabecular bone loss was reduced by 50% in HDC ؊/؊ mice compared with WT. Histamine deficiency protected the skeleton from osteoporosis directly, by inhibiting osteoclastogenesis, and indirectly, by increasing calcitriol synthesis. Quantitative RT-PCR showed elevated 25-hydroxyvitamin D-1␣-hydroxylase and markedly decreased 25-hydroxyvitamin D-24-hydroxylase mRNA levels. Serum parameters confirming this indirect effect included elevated calcitriol, phosphorus, alkaline phosphatase, and receptor activator of NF-B ligand concentrations, and suppressed parathyroid hormone concentrations in HDC ؊/؊ mice compared with WT mice. After ovariectomy, histamine-deficient mice were protected from bone loss by the combination of increased bone formation and reduced bone resorption.
Comparative studies have been carried out on two axial flow fan rotors of controlled vortex design (CVD), at their design flowrate, in order to investigate the effects of circumferential forward skew on blade aerodynamics. The studies were based on computational fluid dynamics (CFD), validated on the basis of global performance and hot wire flow field measurements. The computations indicated that the forward-skewed blade tip modifies the rotor inlet condition along the entire span, due to its protrusion to the relative inlet flow field. This leads to the rearrangement of spanwise blade load distribution, increase of losses along the dominant part of span, and converts the prescribed spanwise blade circulation distribution towards a free vortex flow pattern. Due to the above, reduction in both total pressure rise and efficiency was established. By moderation of the radial outward flow on the suction side, being especially significant for nonfree vortex blading, forward sweep was found to be particularly useful for potential reduction of near-tip loss in CVD rotors. Application of reliable CFD-based design systems was recommended for systematic consideration and control of both load-and loss-modifying effects due to nonradial blade stacking.
The mechanism by which thyroid hormones promote bone growth has not yet been elucidated. In vitro, thyroid hormones stimulate insulin-like growth factor-I (IGF-I) production by osteoblasts, which is important for the anabolic effects of the hormone on bone. To determine whether the IGF-I/IGF binding protein (IGFBP) profile is affected when thyroid hormone production is altered in vivo, we studied 36 women who had recently been diagnosed with hyperthyroidism (age: 29-67 years; 19 with Graves' disease, 17 with toxic nodular goiter) and 36 age-matched healthy women as controls. Serum IGF-I, and its binding proteins (IGFBP-3, IGFBP-4, and IGFBP-5), as well as bone mineral density (BMD) at the lumbar spine, femoral neck, and radius midshaft were measured before and 1 year after antithyroid (methimazole) treatment. Serum IGF-I levels were significantly increased in the hyperthyroid patients before treatment (214 +/- 18.2 ng/mL vs. 145 +/- 21.3 ng/mL; p < 0.05). There was no difference in IGF-I levels of patients with Graves' disease and toxic nodular goiter. Serum IGF-I concentrations returned to normal after treatment with methimazole. Serum IGFBP-3 and IGFBP-4 values were significantly elevated in the hyperthyroid group before treatment (3960 +/- 220 ng/mL and 749.7 +/- 53.1 ng/mL vs. 2701 +/- 180 ng/mL and 489.9 +/- 32.4 ng/mL; p < 0.05 and p < 0.01, respectively) and were reduced to those of controls after treatment. Serum IGFBP-5 of hyperthyroid subjects was not different from that of controls either before or after therapy. Serum free thyroxine showed a positive correlation with serum levels of IGF-I (r = 0.73, p < 0.05), IGFBP-3 (r = 0.59, p < 0.05), and IGFBP-4 (r = 0.67, p < 0.05) but not IGFBP-5. BMD at the radius midshaft was significantly lower in hyperthyroid patients at the start of the study and showed a positive correlation with serum IGF-I (r = 0.58; p < 0.001) and a negative correlation with IGFBP-4 (r = -0.61; p < 0.05). Radius BMD showed a 7.2% increase in the hyperthyroid group after 1 year of methimazole treatment, and the correlation between BMD and serum IGF-I disappeared. Our data indicate that thyroid hormones may influence the IGF-I/IGFBP system in vivo in hyperthyroidism. The anabolic effects of increased levels of IGF-I may be limited in hyperthyroidism due to the increases of inhibitory IGFBPs that can counteract the anabolic effects and contribute to the observed net bone loss.
The impact of recombinant human growth hormone (rhGH) treatment on growth, bone mineral metabolism, and bone mineral density (BMD) was evaluated in six children (3 girls, 3 boys) with familial hypophosphatemic rickets (XLH). Five were prepubertal (aged 6-8.8 years), one 15.3-year-old boy had combined XLH and GH deficiency, but had not been treated with rhGH previously. rhGH was administered daily for 1 year, at a dose of 1 IU/kg per week, combined with 1,25-dihydroxyvitamin D3 and oral phosphate therapy. Z scores for growth velocity and height improved significantly (-2.9 vs. 2.5, P < 0.01, and -2.2 vs. -1.5, P < 0.01, respectively). However, the ratio of Z score for height to that of subischial leg length decreased significantly (0.65 vs. 0.43, P < 0.01), indicating disproportionate growth in favor of the trunk. The height-corrected BMD Z increased slightly (-0.99 vs. -0.94, P < 0.05). A slight increase in serum phosphate occurred (0.78 vs. 0.88 mmol/l, P < 0.02). Tubular reabsorption of phosphate/glomerular filtration rate increased from 0.45 mmol/l to 0.55 mmol at 6 months (P < 0.02), but returned to the initial level at 12 months. These results indicate that children with XLH can benefit from the positive effect of rhGH on growth, however treatment could aggravate the already existing tendency to disproportionate growth. GH production should be evaluated in poorly growing patients with XLH, because it can mask GH deficiency. rhGH can be safely combined with conventional treatment in XLH. Further studies are needed to determine the effect of treatment on final height and maximal BMD.
This paper presents a complex heuristic method for the evaluation of fetal heart sounds, applying simultaneously several algorithms, where the autocorrelation technique has been completed with the wavelet transform and the matching pursuit methods. In this way, a more reliable heart rate variability can be achieved and further parameters of the cardiac operation can be assessed in addition to the conventional cardiotocographic examination. This also comprises those parameters, which can be investigated only with long-term or continuous monitoring, and those, which rely on a very accurate estimation of the heart rate variability. The proposed method provides a way for assessing fetal heart murmurs, which is a completely new possibility for monitoring the well-being of the fetus.
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