Rate of vertebral bone marrow perfusion revealed a significant decrease in subjects older than 50 years. Women demonstrated a higher marrow perfusion rate than men younger than 50 years and a more marked decrease than men older than 50 years.

No abstract

No abstract

cRelatively little is known about the hepatotoxicity of pyrazinamide (PZA). PZA requires activation by amidase to form pyrazinoic acid (PA). Xanthine oxidase then hydroxylates PA to form 5-hydroxypyrazinoic acid (5-OH-PA). PZA can also be directly oxidized to form 5-OH-PZA. Before this study, it was unclear which metabolic pathway or PZA metabolites led to hepatotoxicity. This study determines whether PZA metabolites are responsible for PZA-induced hepatotoxicity. PZA metabolites were identified and cytotoxicity in HepG2 cells was assessed. Potential PZA and PA hepatotoxicity was then tested in rats. Urine specimens were collected from 153 tuberculosis (TB) patients, and the results were evaluated to confirm whether a correlation existed between PZA metabolite concentrations and hepatotoxicity. This led to the hypothesis that coadministration of amidase inhibitor (bis-p-nitrophenyl phosphate [BNPP]) decreases or prevents PZA-and PZA metabolite-induced hepatotoxicity in rats. PA and 5-OH-PA are more toxic than PZA. Electron microscopy showed that PZA and PA treatment of rats significantly increases aspartate transaminase (AST) and alanine aminotransferase (ALT) activity and galactose single-point (GSP) levels (P < 0.005). PA and 5-OH-PA levels are also significantly correlated with hepatotoxicity in the urine of TB patients (P < 0.005). Amidase inhibitor, BNPP, decreases PZA-induced, but not PA-induced, hepatotoxicity. This is the first report of a cell line, animal, and clinical trial confirming that the metabolite 5-OH-PA is responsible for PZA-induced hepatotoxicity.

Aims: To assess the relations between exposure to traffic exhausts and indicators of oxidative DNA damage among highway toll station workers. Methods: Cross-sectional study of 47 female highway toll station workers exposed to traffic exhausts and 27 female office workers as a reference group. Exposure assessment was based on average and cumulative traffic density and a biomarker of exposure, urinary 1-hydroxypyrene-glucuronide (1-OHPG). Urinary 8-hydroxydeoxyguanosine (8-OHdG) was used as a biomarker of oxidative DNA damage. Plasma nitric oxide (NO) was measured as an indicator of oxidative stress related to traffic exhaust exposure.Results: The mean concentration of urinary 8-OHdG was substantially higher among the exposed nonsmokers (13.6 mg/g creatinine) compared with the reference non-smokers (7.3 mg/g creatinine; difference 6.3, 95% CI 3.0 to 9.6). The mean concentration of NO among the exposed (48.0 mmol/l) was also higher compared with the reference non-smokers (37.6 mmol/l; difference 10.4, 95% CI 20.4 to 21.2). In linear regression adjusting for confounding, a change in log(8-OHdG) was statistically significantly related to a unit change in log(1-OHPG) (b = 0.372, 95% CI 0.081 to 0.663). Conclusions: Results indicate that exposure to traffic exhausts increases oxidative DNA damage. Urinary 8-OHdG is a promising biomarker of traffic exhaust induced oxidative stress.

The dose-related association between driving duration and knee pain raises concerns about work-related knee joint disorders among professional drivers.

Differentiation of benign from malignant causes of vertebral compression fracture can be difficult at a single location. We studied 37 patients with solitary vertebral collapse (SVC) in the spine using magnetic resonance imaging (MRI). Sixteen of them were found to have a benign cause of SVC, while the remaining 21 were found to have malignancy. The following four MRI characteristics were investigated: ill‐ or well‐defined margin of the intravertebral lesion (P < 0.005); pedicle involvement (P < 0.05); MR enhancement pattern (P < 0.005); and paravertebral soft tissue lesion (PSL) (P < 0.025). It was found that cases of malignant SVC tended to have an ill‐defined margin, abnormal signal involvement of the pedicle, a marked and heterogenous MR enhancement pattern, and irregular nodular‐type PSL. Pedicle change with expansile lesion totally excluded a benign cause. By using these criteria, we were able to differentiate benign or malignant causes of SVC accurately.J. Magn. Reson. Imaging 1999;9:635–642. © 1999 Wiley‐Liss, Inc.

SUVmax and ADCmin of endometrial cancer derived from integrated PET/MR are inversely correlated and are associated with pathological prognostic factors.