Near infrared reactance for the estimation of body fatness in regularly exercising individuals.

Near infrared reactance (NIR) is used to measure body fat percentage (BF%), but there is little data on its use in non-obese, regularly exercising individuals. Therefore, this study aimed to examine the limits of agreement between NIR compared to dual x-ray absorptiometry (DXA) for the measurement of BF% in 2 cohorts of regularly exercising individuals. BF% was measured using DXA and NIR in a regular exercising (≥3 sessions/week), healthy active cohort (HA; n=57), and in a regularly exercising and resistance trained (≥2 sessions/week) cohort (RT; n=59). The RT cohort had lower BF% than the HA cohort (15.3±5.5% and 25.8±7.1%, P<0.001). In the HA and RT cohorts, NIR BF% was associated with DXA BF% (R2=0.72, SEE=3.7, p<0.001 and R2=0.50, SEE=4.1 p<0.001, respectively). In the HA cohort, NIR tended to under-predict BF% (mean difference: - 1.3%; 95% limits of agreement (LOA); - 8.8 to 6.2%) whereas in the RT cohort, NIR tended to over-predict BF% compared to DXA (mean difference: 1.1; 95% LOA; - 8.1 to 10.3%). In conclusion, NIR and DXA yield similar average BF% measurements in 2 cohorts of non-obese regularly exercising individuals. However, the rather broad LOA of NIR need to be considered when using NIR to screen for overweight and obesity, or measure and track changes in body composition.

Treatment of epithelioid hemangioendothelioma of bone using a novel combined approach.

Radiofrequency (RF) treatment has been used for a variety of malignant and benign conditions. However, treatment of a bone malignancy has yet to be reported. The authors present a 21-year old woman with multifocal epithelioid hemangioendothelioma (EH) treated by a combination of surgical excision, chemotherapy and four RF ablations. Follow-up radiographs of the RF-treated sites reveal no evidence of recurrent disease 71, 58, 49 and 33 months, respectively, after treatment.

Acute plasticity in the human somatosensory cortex following amputation.

We studied a patient after amputation of an arm and found that in less than 24 h stimuli applied on the ipsilateral face were referred in a precise, topographically organized, modality-specific manner to distinct points on the phantom. Functional magnetic resonance imaging (fMRI) performed one month later showed that brush-evoked activity in the brain demonstrates objective signal changes which correlate with perceptual changes in the phantom hand. This finding in humans corresponds to the observations of immediate plasticity in cortical pathways described in animals, including primates. The results suggest that reorganization of sensory pathways occurs very soon after amputation in humans, potentially due to the unmasking of ordinarily silent inputs rather than sprouting of new axon terminals.

Transforming growth factor-beta: possible roles in Dupuytren's contracture.

Transforming growth factor-beta (TGF-beta) is a multifunctional polypeptide that stimulates extracellular matrix deposition and fibroblast proliferation. Because both these features characterize Dupuytren's contracture, we investigated a possible role for TGF-beta in the etiology of this disorder. We studied receptor expression for TGF-beta, effects of TGF-beta 1 on DNA-synthesis, and in vitro production of TGF-beta 1 and TGF-beta 2 in both normal and Dupuytren-derived fibroblasts. We also studied the effects of epidermal growth factor (EGF) on growth of the different cell types. TGF-beta receptor profiles were different between the two cell types, as were TGF-beta 1 and EGF-induced stimulation of cell growth. Both cell types secreted both active and latent TGF-beta. Our results suggest that growth factors such as TGF-beta and EGF may play a role in Dupuytren's contracture.

Expression of transforming growth factor-beta (TGF-beta) receptors, TGF-beta 1 and TGF-beta 2 production and autocrine growth control in osteosarcoma cells.

Transforming growth factor-beta (TGF-beta) is a polypeptide with multiple physiological functions. Isoforms of this growth factor have important roles in control of the cell cycle, in regulation of cell-cell interactions and in growth and development. Malignant transformation has been shown to be associated with increased expression of TGF-beta. Since bone is the largest storage site and producer of TGF-beta, we speculated on the existence of an autocrine mechanism in osteosarcoma, a malignant bone tumor. Expression of TGF-beta cell surface receptors, effects on growth of TGF-beta and TGF-beta antibodies and production of 2 TGF-beta isoforms were studied in a panel of 7 osteosarcoma cell lines. In contrast to most previous reports on the effects of TGF-beta on osteosarcoma cell growth, we found a mitogenic effect of TGF-beta 1 in 4 of 7 osteosarcoma cell lines. Receptor profiles for TGF-beta were aberrant in 5 of the 7 cell lines tested, and production of TGF-beta 1 and TGF-beta 2 varied among cell lines. Addition of anti-TGF-beta antagonized the effects of endogenous TGF-beta. Our results suggest a potential role of TGF-beta in autocrine growth control of osteosarcoma cells.

Suramin inhibits growth and transforming growth factor-beta 1 (TGF-beta 1) binding in osteosarcoma cell lines.

Autocrine production of growth factors has been shown to be involved in the multistep process of tumorigenesis. The ability of suramin, a polyanionic anti-parasitic drug, to block growth factor-induced cell proliferation makes it a potential antineoplastic drug. We studied the effects of suramin on seven osteosarcoma cell lines. Using clinically achievable concentrations of suramin (50-400 micrograms/ml), we found a time- and dose-dependent inhibition of [3H]thymidine incorporation. We also showed that suramin is able, dose-dependently, to prevent binding of transforming growth factor (TGF)-beta 1 to its receptors. DNA synthesis inhibition by suramin was attenuated by TGF-beta 1 in some cell lines. Two cell lines that were inhibited by TGF-beta 1 were affected similarly by suramin as cell lines that were stimulated by TGF-beta 1. In conclusion, in five out of seven osteosarcoma cell lines, we showed a correlation between inhibition of growth factor-stimulated mitogenesis and binding of TGF-beta 1 to its receptor. Similar effects in TGF-beta 1-inhibited osteosarcoma cell lines suggest involvement of other mechanisms and/or growth factors. However, suramin proves to be a potent inhibitor of osteosarcoma cell proliferation in vitro.