Effect of Prophylactic Use of Silymarin on Anti-tuberculosis Drugs Induced Hepatotoxicity / 결핵및호흡기질환

BACKGROUND: The first line of anti-tuberculosis (TB) drugs are the most effective standard of drugs for TB. However, the use of these drugs is associated with hepatotoxicity. Silymarin has protective effects against hepatotoxicity of anti-TB drugs in animal models. This study aims to investigate the protective effect of silymarin on hepatotoxicity caused by anti-TB drugs. METHODS: This is a prospective, randomized, double-blind and placebo-controlled study. Patients were eligible if they were 20 years of age or order and started the first-line anti-tuberculosis drugs. Eligible patients were randomized for receiving silymarin or a placebo for the first 4 weeks. The primary outcome was the proportion of patients who showed elevated serum liver enzymes more than 3 times the upper normal limit (UNL) or total bilirubin (TBil) > 2× UNL within the first 8 weeks of anti-TB treatment. RESULTS: We enrolled a total of 121 patients who silymarin or a placebo to start their anti-TB treatment, for the first 8 weeks. The proportions of elevated serum liver enzymes more than 3 times of UNL at week 2, week 4, and week 8 did not show any significant difference between the silymarin and placebo groups, at 0% versus 3.6% (p>0.999); 4.4% versus 3.6% (p>0.999); and 8.7% versus 10.8% (p=0.630), respectively. However, patients with TBil >2× ULN at week 8 were significantly low in the silymarin group (0% versus 8.7%, p=0.043). CONCLUSION: Our findings did not show silymarin had any significant preventive effect on the hepatotoxicity of anti-TB drugs.

Correlation between Bone Mineral Density Measured by Dual-Energy X-Ray Absorptiometry and Hounsfield Units Measured by Diagnostic CT in Lumbar Spine

OBJECTIVE: Use of quantitative computed tomography (CT) to evaluate bone mineral density was suggested in the 1970s. Despite its reliability and accuracy, technical shortcomings restricted its usage, and dual-energy X-ray absorptiometry (DXA) became the gold standard evaluation method. Advances in CT technology have reduced its previous limitations, and CT evaluation of bone quality may now be applicable in clinical practice. The aim of this study was to determine if the Hounsfield unit (HU) values obtained from CT correlate with patient age and bone mineral density. METHODS: A total of 128 female patients who underwent lumbar CT for back pain were enrolled in the study. Their mean age was 66.4 years. Among them, 70 patients also underwent DXA. The patients were stratified by decade of life, forming five age groups. Lumbar vertebrae L1-4 were analyzed. The HU value of each vertebra was determined by averaging three measurements of the vertebra's trabecular portion, as shown in consecutive axial CT images. The HU values were compared between age groups, and correlations of HU value with bone mineral density and T-scores were determined. RESULTS: The HU values consistently decreased with increasing age with significant differences between age groups (p<0.001). There were significant positive correlations (p<0.001) of HU value with bone mineral density and T-score. CONCLUSION: The trabecular area HU value consistently decreases with age. Based on the strong positive correlation between HU value and bone mineral density, CT-based HU values might be useful in detecting bone mineral diseases, such as osteoporosis.

Regression Models for Haplotype-Based Association Studies

In this paper, we provide an overview of statistical models for haplotype-based association studies, and summarize their features based on the design matrix. We classify the design matrix into the two types: direct and indirect. For these two kinds of matrices, we present and compare characteristics using a simple hypothetical example, and a real data set. The motivation behind this study was to provide practitioners with an improved understanding, to facilitate the informed selection of the appropriate haplotype-based model and to improve the interpretability of the models.