Direct Black 38, a kind of benzidine-based azo dye, is widely used as a dye for fabric, leather, cotton, cellulosic material, paper, wool, silk, and so on. Benzidine-based azo dyes are proven as a mutagen and linked to bladder cancer. In 1978, Natonal Institute for Occupational Safety and Health recommended that three widely used benzidine-based dyes (Direct Black 38, Direct Blue 6, and Direct Brown 95) should be treated as carcinogens. In this experiment, metabolism of the benzidine-based dye. Direct Black 38 was examined by using an isolated liver perfusion system. To measure the metbolites of Direct Black 38,/ 8.0 micrometer, 30.5 micrometer and 63,3 micrometer of Direct Black 38 was added into the recirculating perfusate of the isolated perfused rat liver. Samples were collected at 0, 10, 20, 30, 60, 90. 120 minute. They were treated with sep-pak and methanol, and the metabohtes were detected and quantified with high performance liquid chromatography (HPLC). Residual non-reactive dye in the perfusate and liver was reduced to benzidine and then analyzed by HPLC. Detected metabolites of ?Direct^-Black 38 were benzidine, N-acetylbenzidine, and N,N'-diacetylbenzidine. The average conentration of benzidine was 0.1 micrometer and this concentration was maintained throughout the experimental period. The average concentration of N-acetylbenzidine was 0.22 micrometer and took the same pattern of benzidine. When 30.5 micrometer of Direct BIact 38 was added to the perfusate, only. N,N'-diacetylbenzidin.e increased slightly with time. From the above results we suggest that only small amount of Dirst Black 38 might be metabolized to benzidine regardless of the s, amount of the Direct Black 38. There are some possible explanations. The liver was damaged during the perparation. And the function of the perfused liver decreased rapidly because adsorbing of dye. The benzidine, acetylbenzidine and diacetylbenzidine metabolized to other metabolites were not detected in this experiment.
Animals ; Carcinogens ; Chromatography, High Pressure Liquid ; Chromatography, Liquid ; Coloring Agents ; Liver* ; Metabolism* ; Methanol ; Occupational Health ; Perfusion ; Rats* ; Silk ; Urinary Bladder Neoplasms ; Wool

Management of migraine, one of common primary headache disorders, involves the diverse strategies non-pharmacological treatment, such as headache diary, lifestyle modification, regular exercise and relaxation, cognitive behavioral therapy and neurostimulation, and pharmacological treatment. Among the treatments, this review described a pharmacologic treatment of migraine, classified into acute and preventive treatment based on the severity and the frequency of headache. It introduced the way to optimize pharmacological treatment and updated the latest treatment for migraine.

The aim of this study was to investigate the change of microbial contamination levels in the different areas and at the different time points after application of a quaternary ammonium compound (QAC) that has mechanical antimicrobial effect. The microbial contamination levels were measured in three different areas; unit chair handle, spit sink area and hand piece holder at different time points using adenosine triphosphate (ATP) monitoring system and ATP surface test kit. Hand piece holder showed the highest level of microbial contamination. In most of the clinics, QAC significantly reduced the levels of microbial contamination, and maintained antimicrobial activity for 4 to 6 months. QAC may be used effectively in dental clinics due to the duration of antimicrobial effect and the minimal exposure of chemicals and further studies are needed with large sample size.

Objective: The optimal imaging approach for evaluating pathological nipple discharge remains unclear. We investigated the value of adding ductography to ultrasound (US) for evaluating pathologic nipple discharge in patients with negative mammography findings. Materials and Methods: From July 2003 to December 2018, 101 women (mean age, 46.3 ± 12.2 years; range, 23–75 years) with pathologic nipple discharge were evaluated using pre-ductography (initial) US, ductography, and post-ductography US. The imaging findings were reviewed retrospectively. The standard reference was surgery (70 patients) or > 2 years of followup with US (31 patients). The diagnostic performances of initial US, ductography, and post-ductography US for detecting malignancy were compared using the McNemar’s test or a generalized estimating equation. Results: In total, 47 papillomas, 30 other benign lesions, seven high-risk lesions, and 17 malignant lesions were identified as underlying causes of pathologic nipple discharge. Only eight of the 17 malignancies were detected on the initial US, while the remaining nine malignancies were detected by ductography. Among the nine malignancies detected by ductography, eight were detected on post-ductography US and could be localized for US-guided intervention. The sensitivities of ductography (94.1% [16/17]) and post-ductography US (94.1% [16/17]) were significantly higher than those of initial US (47.1% [8/17]; p = 0.027 and 0.013, respectively). The negative predictive value of post-ductography US (96.9% [31/32]) was significantly higher than that of the initial US (83.3% [45/54]; p = 0.006). Specificity was significantly higher for initial US than for ductography and post-ductography US (p = 0.001 for all). Conclusion The combined use of ductography and US has a high sensitivity for detecting malignancy in patients with pathologic nipple discharge and negative mammography. Ductography findings enable lesion localization on second-look post-ductography US, thus facilitating the selection of optimal treatment plans.