Longer withdrawal time is not associated with increased patient discomfort in colonoscopy: a retrospective observational study

Purpose Withdrawal time of sufficient length is a quality indicator for colonoscopies. Nonetheless, whether extending the withdrawal time contributes to patient discomfort remains unknown. This study aimed to clarify the relationship between colonoscopy withdrawal time and patient discomfort. Methods A cohort of consecutive patients who underwent colonoscopy at a single institution from October 2018 to January 2020 was retrospectively analyzed. Initially, the relationship between the mean withdrawal time for each colonoscopist in no-finding examinations and polyp detection rate was investigated in 2,043 patients. Subsequently, the primary outcome of association between withdrawal time and patient discomfort, as determined by patient questionnaire, was assessed for each examination in 481 patients from the initial cohort. Results The mean withdrawal time was strongly correlated with polyp detection rate (correlation coefficient, 0.72; P<0.001). In contrast, longer withdrawal time was not associated with increased discomfort; however, there was a weak inverse correlation between patient discomfort and longer withdrawal time (correlation coefficient, –0.25; P<0.001). Similarly, multiple regression analysis adjusted for confounding variables revealed that longer withdrawal time was not associated with increased patient discomfort (regression coefficient, –0.04 for each 1-minute increase in the length of withdrawal time; P=0.45). Conclusion This study showed for the first time that longer withdrawal times did not result in increased discomfort, indicating that withdrawal time can be extended to sufficient length for optimal patient examination and polyp detection

Multiple White and Flat Elevated Lesions Observed in the Stomach: A Prospective Study of Clinical Characteristics and Risk Factors.

<p>This data was used for the following research.<br></p><p><br></p><p>Intern Med. 2018 Apr 27. doi: 10.2169/internalmedicine.9889-17. [Epub ahead of print]</p><p><br></p><p>Multiple White and Flat Elevated Lesions Observed in the Stomach: A Prospective Study of Clinical Characteristics and Risk Factors.</p><p><br></p><p>Majima K, Muraki Y, Shimamoto T.</p><p><br></p><p>Abstract</p><p></p><p>Objective Multiple white and flat elevated lesions (MWFLs) observed in the stomach have only been presented in abstracts at academic conferences over the last decade; therefore, relatively little is known about these lesions. Our aim was to prospectively clarify the clinical characteristics of MWFLs, to identify their risk factors and to retrospectively evaluate the clinical progression of these lesions. Methods A prospective analysis of clinical characteristics and risk factors was conducted in participants who underwent esophagogastroduodenoscopic screening at our hospital. A retrospective analysis of the medical chart of patients identified as having MWFLs was conducted to describe the clinical progression of these lesions. Results The prevalence rate of MWFLs was 10.4% (80/767), with the following risk factors identified on a logistic regression analysis: use of proton pump inhibitors (odds ratio [OR], 3.51; 95% confidence interval [CI], 1.92-6.43), female sex (OR, 1.92; 95% CI, 1.19-3.12) and a 1-year increase in age (OR, 1.05; 95% CI, 1.02-1.08). Among the 70 cases with MWFLs observed over a mean duration of 2.3 years, no progression of MWFLs was detected in 67 cases (96%). Among the 3 remaining cases, progression was mild, with none of the lesions progressing to malignancy. Conclusion The use of PPIs, female sex, and age are risk factors for MWFLs. We believe that endoscopists should recognize these lesions.</p

Increasing Melanin Radical in Mouse Skin by Low Dose X-Ray Irradiation

Dose estimation of low dose irradiation is difficult, because almost no marked symptom can be observed by low dose irradiation. To find possible index for low dose irradiation, effect of low dose X-ray irradiation to melanin radical in mouse tail skin was investigated.Female 7-week-old C3H mice were habituated for a week, and then hair was sampled by electric hair clipper from the back. An aliquot (~10 mg) of the hair sample was weighed accurately, stuffed in a plastic tube, and then measured by X-band (9.4 GHz) electron paramagnetic resonance (EPR) spectrometer. The mice were irradiated by X-ray with dose of 100 mGy/day on 5 days/week (Mon to Fri) for 12 weeks. Again, hair was sampled from the back after 12-week irradiation. The 2 cm tip of the tail was sampled and lyophilized. The hair and tail samples were measured by X-band EPR spectrometer. Next, 4-week irradiation experiment was carried out, with 10, 100, 500 mGy/day on 5 days/week.After the X-ray irradiation at 100 mGy/day for 12 weeks, no difference was obtained for melanin radical in hair before and after irradiation. In the next experiment, X-ray irradiation at 500 mGy/day for 4 weeks makes melanin radical in hair higher compared to non irradiated group, while the amount of melanin radical was reduced compared to before irradiation. Hair melanin radical may be responsible for X-ray irradiation but the baseline amount can be variable; however, the melanin radical amount in the tail skin was increased dose dependently. Melanin radical in skin can be a temporal marker for low dose irradiation.2011 Kagoshima Congress (Joint Meeting of 5th SFRR-Asia, 8th ASMRM, and 11th J-mit

Evaluation of Antioxidative Ability of Antioxidative Food Factors by EPR Spin-Trapping, Stopped-Flow Kinetic Analysis, and Mitochondrial ROS Assay

Antioxidative food factors have attracted considerable interest with regard to the prevention against oxidative stress and associated diseases. However, evaluation and comparison of the antioxidative ability and function have scarcely been performed. In this study, we examined the antioxidative ability of eleven food factors, which are astaxanthin, canthaxanthin, zeaxanthin, lycopene, coenzyme Q10, sesamin, sesamol, catechin gallate, catechin hydrate, beta-carotene, and alpha-tocopherol, by the EPR spin-trapping of superoxide anion with DMPO, stopped-flow kinetic analysis with 2.2-diphenyl-1-picrylhydrazyl (DPPH) radical, and a newly-developed mitochondrial ROS scavenging assay.Among eleven food factors, catechin gallate and catechin hydrate efficiently scavenged superoxide anion, while coenzyme Q10 and sesamin showed no scavenging activity against superoxide anion. Furthermore, catechin gallate and catechin hydrate also scavenged DPPH radical much faster than sesamol and alpha-tocopherol in deaerated ethanol, while DPPH radical was not scavenged by the rest of the food factors. On the other hand, no different effectiveness was observed for all food factors using mitochondrial ROS scavenging assay, suggesting that the evaluation of antioxidative ability by only one method is not enough to evaluate the in vivo effects.Biomedical Redox Navigation (EPR2008: A Joint Conference of the 13th In Vivo ESR/EPR Spectroscopy & Imaging, the 10th International EPR Spin Trapping/Spin Labeling, and the 7th JSPS Core-to-Core Seminar

Evaluation of Antioxidative Properties of Food Factors in Relation to Inhibitory Activity of Radiation-Induced Apoptosis

We have recently reported that the radiation-induced apoptosis was efficiently inhibited by eleven food factors, which are vitamin E (alpha-tocopherol), astaxanthin, canthaxanthin, zeaxanthin, lycopene, coenzyme Q10, sesamin, sesamol, (-)-catechin gallate, (+)-catechin, and beta-carotene. However, very little is known about the mechanism for the radioprotective effect of the food factors. In this study, we compared the antioxidative properties of the eleven food factors, such as scavenging activities of reactive oxygen species and free radicals, the one-electron oxidation potentials, and ionization potentials (IP) calculated by the density functional theory. The results suggest that the lower the IP value is, the stronger the anti-apoptotic activity becomes, while no relationship was observed with other antioxidative parameters.2011 Kagoshima Congress (Joint Meeting of 5th SFRR-Asia, 8th ASMRM, and 11th J-mit

Comparison of in Vivo and in Vitro Antioxidative Parameters for Eleven Food Factors

In vivo antioxidative activity assays against reactive oxygen species generated in mitochondria, together with in vitro two radical-scavenging assays, electrochemical measurements, and theoretical calculations of ionization potentials (IP), were carried out for eleven food factors. Lycopene, with the smallest IP value, showed the highest anti-apoptotic activity

Roles of Mitochondria-Generated Reactive Oxygen Species on X-ray-Induced Apoptosis in a Human Hepatocellular Carcinoma Cell Line, HLE

HLE, a human hepatocellular carcinoma cell line was transiently transfected with normal human MnSOD and MnSOD without a mitochondrial target signal (MTS). Mitochondrial reactive oxygen species (ROS), lipid peroxidation and apoptosis were examined as a function of time following 18.8 Gy X-ray irradiation. Our results showed that the level of mitochondrial ROS increased and reached a maximum level 2 hours after X-ray irradiation. Authentic MnSOD, but not MnSOD lacking MTS, protected against mitochondrial ROS, lipid peroxidation and apoptosis. In addition, the levels of mitochondrial ROS were consistently found to always correlate with the levels of authentic MnSOD in mitochondria. These results suggest that only when MnSOD is located in mitochondria is it efficient in protecting against cellular injuries by X-ray irradiation and that mitochondria are the critical sites of X-ray-induced cellular oxidative injuries