Bone mineral density assessment for research purpose using dual energy X-ray absorptiometry.

Dual energy X-ray absorptiometry (DXA) has become the most common method for measuring bone mineral density (BMD) of small animals in metabolic bone disease research, and errors should be minimized in all procedures involved in research studies in order to increase the accuracy of the study results. DXA is simpler and rapid compared to micro-computed tomography for quantitative analysis of change in trabecular bone of test subject. In human research, measuring BMD is widely used; postoperative evaluation on orthopedic surgery, evaluation of osteoporosis medication in menopause and many other areas of study. For the study, the inspector should be trained by the equipment manufacturer regarding the utilization and analysis of the equipment and regular phantom testing should be conducted to ensure the stability of the equipment, and precision tests should be conducted to analyze the positioning and data analysis. They should also be familiar with the clinical trials and conduct studies based on the approval of the Institutional Review Board. In the absolute BMD measurement of the human body, it is necessary to apply and compare the position and condition, rotation degree, region of interest, and area of the scan in the follow-up test. In the case of small animals, animal selection, measurement and equipment should be modeled to match the research. Therefore, we would like to provide information for researchers to minimize the errors, effective data management and accurate data presentation. This article reviews the process of DXA measurement for research purpose including plan for DXA examination, BMD measurement in a human body study and small animal studies.

Assessment of exposure to heavy metals and health risks among residents near abandoned metal mines in Goseong, Korea.

Metal contamination from mining activity is of great concern because of potential health risks to the local inhabitants. In the present study, we investigated the levels of Cd, Cu, As, Pb, and Zn in environmental samples and foodstuffs grown in the vicinity of the mines in Goseong, Korea, and evaluated potential health risks among local residents. Soils near the mines exceeded the soil quality standard values of Cu, As, and Zn contamination. The concentrations of Cd, Cu, Pb, and Zn in crop samples collected from the study area were significantly higher than those of the reference area. Some rice samples collected from the study area exceeded the maximum permissible level of 0.2 mg Cd/kg. The intake of rice was identified as a major contributor (≥75%) to the estimated daily intake among the residents. The average estimated daily intakes of metals were, however, below the provisional tolerable daily intake.

Quantitative assessment of bone marrow cellularity by magnetic resonance imaging in workers with long-term exposure to solvents.

This study was conducted to develop a noninvasive method of bone marrow cellularity evaluation in solvent-exposed painters. Six painters with hypocellular marrow and 132 referents were examined using magnetic resonance imaging (MRI). Full examination of the peripheral blood and bone marrow biopsy was done on each patient. Signal indices were calculated from the signal intensities measured at the vertebral bodies from T12 to S1 and on the paraspinal muscles on both the T1- and the T2-weighted image (T1WI and T2WI). Bone marrow cellularities of the painters were between 20.3% and 33.6%. Signal indices at T1WI were greater in the hypocellular marrow cases compared to those of the referents (p<0.05, p<0.01) and were significantly higher in older women compared with men (p<0.05). After adjusting for age and gender, the signal index of cases at S1 of T1WI was higher than that of the referents by 0.364. Five of the six cases had signal index at S1 of T1WI higher than the mean +1 standard deviation for the same age group and gender. MRI signal indices can be used as a useful indicator of bone marrow cellularity in a high-risk population after adequate adjustment.