Although, increased oxidative stress and hypomethylation of long interspersed nuclear element-1 (LINE-1) associate with bladder cancer (BCa) development, the relationship between these alterations is unknown. We evaluated the oxidative stress and hypomethylation of the LINE-1 in 61 BCa patients and 45 normal individuals. To measure the methylation levels and to differentiate the LINE-1 loci into hypermethylated, partially methylated and hypomethylated, peripheral blood cells, urinary exfoliated cells and cancerous tissues were evaluated by combined bisulfite restriction analysis PCR. The urinary total antioxidant status (TAS) and plasma protein carbonyl content were determined. The LINE-1 methylation levels and patterns, especially hypomethylated loci, in the blood and urine cells of the BCa patients were different from the levels and patterns in the healthy controls. The urinary TAS was decreased, whereas the plasma protein carbonyl content was increased in the BCa patients relative to the controls. A positive correlation between the methylation of LINE-1 in the blood-derived DNA and urinary TAS was found in both the BCa and control groups. The urinary hypomethylated LINE-1 loci and the plasma protein carbonyl content provided the best diagnostic potential for BCa prediction. Based on post-diagnostic samples, the combination test improved the diagnostic power to a sensitivity of 96% and a specificity of 96%. In conclusion, decreased LINE-1 methylation is associated with increased oxidative stress both in healthy and BCa subjects across the various tissue types, implying a dose-response association. Increases in the LINE-1 hypomethylation levels and the number of hypomethylated loci in both the blood- and urine-derived cells and increase in the oxidative stress were found in the BCa patients. The combination test of the urinary hypomethylated LINE-1 loci and the plasma protein carbonyl content may be useful for BCa screening and monitoring of treatment.

Background Difficult surgical procedures may result in a higher mental workload, leading to increased fatigue and subsequent errors. This study was aimed to investigate the effect of repeated simulation training in ureterorenoscopy in a high-fidelity setting on the performance and mental workload of novice operators. Methods Medical students voluntarily participated in the present simulation study. After a didactic and video-based lecture, they underwent simulation training involving a renal stone case, including a rigid cystoscope component (task 1, performing a WHO checklist, assembling a scope, and insertion of a guide-wire and an access sheath after examining the bladder) and a flexible ureterorenoscope component (task 2, retrieving a stone located in the upper calyx using a basket after inspecting the upper, middle, and lower calyx). Training was performed in a mock operating theater. Technical skills were assessed by one author (an experienced urologist) onsite using an Objective Structured Assessment of Technical Skills (OSATS) score at each training session. The mental workload was subjectively evaluated by the National Aeronautics and Space Administration Task Load Index (NASA-TLX) questionnaire after each training session. Results Seventeen students completed a minimum of 6 training sessions (male: female = 10: 7, median age of 22) over a median of 21 days (range, 10–32). In both tasks 1 and 2, the OSATS score improved over the 6 sessions with evidence of plateauing (MANOVA model, task 1: p < 0.0001, task 2: p < 0.0001). In contrast, the NASA-TLX score persistently decreased without plateauing (task 1: p = 0.0005, task 2: p = 0.0028). Conclusions Under repeated simulation training in ureterorenoscopy in a high-fidelity setting, participants showed a continual decrease of the mental workload, while the improvement of technical skills reached a plateau over the 6 sessions. Our study showed the important benefit of simulation training to reduce the mental workload by repeated scenario training before actual clinical practice. Electronic supplementary material The online version of this article (10.1186/s12909-019-1752-2) contains supplementary material, which is available to authorized users.

BackgroundTo evaluate the correlation between the International Prostate Symptom Score (IPSS), Visual Prostate Symptom Score (VPSS), and uroflowmetry parameters in Thai males and to examine the possibility in establishing a severity cut-off point for VPSS.MethodsBetween 1st February and 31st May 2016 a total of 200 men were enrolled onto the study and divided into high and low educated groups. All of them were requested to complete paperwork including their personal data, and then to complete a VPSS and IPSS questionnaire. Uroflowmetry, residual urine and prostate size were measured. The relationship between the answers to the VPSS and IPSS together with the other objective parameters was assessed using Spearman's rank test.ResultsThe mean age of the patients was 61.2 years. 69.9% of subjects were highly educated. There was a statistically significant correlation between VPSS and IPSS in total, and any individual scores except frequency score. There was weak correlation between the VPSS and the uroflowmetry parameters and prostate size. The low educated group had a statistically significant lower completion rate of both the VPSS (41.6% vs. 79.8%) and IPSS (61.2% vs. 81.2%) without assistance than the higher educated group and most of the lower educated group felt that the IPSS was easier to understand than the VPSS (51.2% vs. 48.8%, P < 0.001). A VPSS severity score ≤6 or ≥14 had a very high specificity that predicted the patients would have mild or severe symptoms (94.7% and 98.6%) while a VPSS between 7 and 13 had a high sensitivity (90.8%) but a low specificity (16.9%) when it came to the prediction of moderate symptoms.ConclusionVPSS showed a significant correlation to the IPSS and uroflowmetry parameters. A VPSS score ≤6, 7 to 13 and ≥14 may indicate mild, moderate, and severe symptoms respectively.