[Variations of brain magnetic resonance imaging among manganese-exposed workers].

OBJECTIVE: Variations of the signal intensities in the magnetic resonance (MR) T(1)-weighted image (T(1)WI) of globus pallidus among manganese(Mn)-exposed workers were explored to provide a scientific basis for exposed biomarker of manganese-injured central nervous system (CNS). METHODS: The brain MR T(1) and T(2) WI in eighteen male asymptomatic Mn-exposed, eight manganism and nine healthy control workers were examined routinely by adopting a 1.5 Tesla signal superconducting system. The SIGP and the signal intensity in frontal white matter (SIFWM) in the same side were determined, then pallidal index (PI) was calculated. Concentration of MnO(2) in workplaces and content of manganese in red blood cell (MnRBC) among workers were respectively determined by flame atomic absorption spectrometer (AAS) and inductively coupled plasma-atomic emission spectrophotometry (ICP-AES). The follow-up investigation in the eight high Mn-exposed workers was made one year later. RESULTS: The results showed that the median of air MnO(2) in smelting workplace was 0.64 mg/m(3)(0.07 - 5.40 mg/m(3)), which were respective 0.56 mg/m(3)(0.09 - 1.71 mg/m(3)) in power distribution room (low Mn-exposure) and 0.89 mg/m(3) (0.07 - 5.40 mg/m(3)) in furnace (high Mn-exposure). PI in the Mn-exposed and high Mn-exposed workers were both higher than those of the manganism and control workers(116.4 +/- 8.2, 119.0 +/- 7.9, 105.3 +/- 8.4 and 102.2 +/- 1.5, respectively. Mn vs control, t' = 7.146, P = 0.000; Mn vs manganism, t = 3.181, P = 0.004. High Mn-exposure vs control, t' = 7.446, P = 0.000; high Mn-exposure vs manganism, t = 3.763, P = 0.001). The increased signal in T(1)WI of globus pallidus was observed in Mn-exposed workers, especially in high Mn-exposed workers. The content of manganese in red blood cell of Mn-exposed and control workers was significantly higher than those of the manganism workers [(151.6 +/- 40.5) ng/ml, (149.2 +/- 21.3) ng/ml, (154.5 +/- 46.6) ng/ml, (144.4 +/- 14.2) ng/ml, (20.8 +/- 7.4) ng/ml respectively. The difference was significant in statistics. Manganism vs control, t = 20.206, P = 0.000; manganism vs Mn, t' = 13.144, P = 0.000; manganism vs low and high Mn, t' = 12.964, 9.957, respectively, P = 0.000]. Only a decreased median of air MnO(2) in furnace was found one year later (0.89, 0.31 mg/m(3), Z = -2.142, P = 0.032). The difference was significant in statistics. CONCLUSION: Our data suggests that SIGP of MR T(1)WI among workers was obviously increased by manganese-exposure. PI may be taken as the signal of CNS injury which was induced by manganese-exposure.

Ursodeoxycholic acid for primary biliary cirrhosis.

BACKGROUND: Primary biliary cirrhosis is an uncommon autoimmune liver disease with unknown aetiology. Ursodeoxycholic acid (UDCA) has been used for primary biliary cirrhosis, but the effects remain controversial. OBJECTIVES: To evaluate the benefits and harms of UDCA on patients with primary biliary cirrhosis against placebo or no intervention. SEARCH STRATEGY: We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials on The Cochrane Library, MEDLINE, EMBASE, SCI-EXPANDED, The Chinese Biomedical CD Database, LILACS, and the references of identified studies. The last search was performed in January 2007. SELECTION CRITERIA: Randomised clinical trials evaluating UDCA versus placebo or no intervention in patients with primary biliary cirrhosis. DATA COLLECTION AND ANALYSIS: The primary outcomes were mortality and mortality or liver transplantation. Binary outcomes were reported as odds ratio (OR) or relative risk (RR) and continuous outcomes as weighted mean difference, all with 95% confidence intervals (CI). Meta-regression was used to investigate the associations between UDCA effects and quality of the trial, UDCA dose, trial duration, and patient's severity of primary biliary cirrhosis. We also used Bayesian meta-analytic approach to estimate the UDCA effect as sensitivity analysis. MAIN RESULTS: Sixteen randomised clinical trials evaluating UDCA against placebo or no intervention were identified. Data from three trials have been updated. Nearly half of the trials had high risk of bias. The combined results demonstrated no significant effects favouring UDCA on mortality (OR 0.97, 95% CI 0.67 to 1.42) and mortality or liver transplantation (RR 0.92, 95% CI 0.71 to 1.21). The findings were supported by the Bayesian meta-analyses. UDCA did not improve pruritus, fatigue, autoimmune conditions, liver histology, or portal pressure. UDCA seemed to improve biochemical variables, like serum bilirubin, ascites, and jaundice, but the findings were based on few trials with sparse data. The use of UDCA is significantly associated with adverse events, mainly weight gain. AUTHORS' CONCLUSIONS: This systematic review did not demonstrate any benefit of UDCA on mortality and mortality or liver transplantation of patients with primary biliary cirrhosis. The few beneficial effects could not be due to random errors or outcome reporting bias.