Relationship among muscle strength, muscle endurance, and skeletal muscle oxygenation dynamics during ramp incremental cycle exercise.

Peak oxygen uptake (VO2), evaluated as exercise tolerance, is a strong predictor of life prognosis regardless of health condition. Several previous studies have reported that peak VO2 is higher in those with a greater decrease in muscle oxygen saturation (SmO2) in the active muscles during incremental exercise. However, the skeletal muscle characteristics of individuals exhibiting a greater decrease in SmO2 during active muscle engagement in incremental exercise remain unclear. This study aimed to clarify the relationship among muscle strength, muscle endurance, and skeletal muscle oxygenation dynamics in active leg muscles during incremental exercise. Twenty-four healthy young men were included and categorized into the non-moderate-to-high muscular strength and endurance group (those with low leg muscle strength, endurance, or both; n = 11) and the moderate-to-high muscular strength and endurance group (those with both moderate-to-high leg muscle strength and endurance; n = 13). All participants underwent cardiopulmonary exercise testing combined with near-infrared spectroscopy to assess whole-body peak VO2 and the change in SmO2 at the lateral vastus lateralis from rest to each exercise stage as skeletal muscle oxygenation dynamics. A linear mixed-effects model, with the change in SmO2 from rest to each stage as the dependent variable, individual participants as random effects, and group and exercise load as fixed effects, revealed significant main effects for both group (P = 0.001) and exercise load (P < 0.001) as well as a significant interaction between the two factors (P < 0.001). Furthermore, multiple-comparison test results showed that the change in SmO2 from rest to 40%-100% peak VO2 was significantly higher in the moderate-to-high muscular strength and endurance group than in the non-moderate-to-high muscular strength and endurance group. Maintaining both muscle strength and endurance at moderate or higher levels contributes to high skeletal muscle oxygenation dynamics (i.e., greater decrease in SmO2) during moderate- or high-intensity exercise.

Impact of COVID-19 vaccination status on hospitalization and disease severity: A descriptive study in Nagasaki Prefecture, Japan.

Coronavirus disease 2019 (COVID-19) was extraordinarily harmful, with high rates of infection and hospitalization. This study aimed to evaluate the impact of COVID-19 vaccination status and other factors on hospitalization and disease severity, using data from Nagasaki Prefecture, Japan. Confirmed cases of COVID-19 infection with vaccination status were included and the differences in characteristics between different vaccination statuses, hospitalization or not, and patients with varying levels of disease severity were analyzed. Furthermore, logistic regression was used to calculate odds ratio (ORs) and 95% confidence intervals (CI) to evaluate the association of various factors with hospitalization and disease severity. From March 14, 2020 to August 31, 2022, 23,139 patients were unvaccinated 13,668 vaccinated the primary program with one or two doses, and 4,575 completed the booster. Vaccination reduced the risk of hospitalization with an odd ratio of 0.759 (95% CI: 0.654-0.881) and the protective effect of completed booster vaccination was more pronounced (OR: 0.261, 95% CI: 0.207-0.328). Similarly, vaccination significantly reduced the risk of disease severity (vaccinated primary program: OR: 0.191, 95% CI: 0.160-0.228; completed booster vaccination: OR: 0.129, 95% CI: 0.099-0.169). Overall, unvaccinated, male, elderly, immunocompromised, obese, and patients with other severe illness factors were all risk factors for COVID-19-related hospitalization and disease severity. Vaccination was associated with a decreased risk of hospitalization and disease severity, and highlighted the benefits of completing booster.

A triple-imaging-modality system for simultaneous measurements of prompt gamma photons, prompt x-rays, and induced positrons during proton beam irradiation.

Objective. Prompt gamma photon, prompt x-ray, and induced positron imaging are possible methods for observing a proton beam's shape from outside the subject. However, since these three types of images have not been measured simultaneously nor compared using the same subject, their advantages and disadvantages remain unknown for imaging beam shapes in therapy. To clarify these points, we developed a triple-imaging-modality system to simultaneously measure prompt gamma photons, prompt x-rays, and induced positrons during proton beam irradiation to a phantom.Approach. The developed triple-imaging-modality system consists of a gamma camera, an x-ray camera, and a dual-head positron emission tomography (PET) system. During 80 MeV proton beam irradiation to a polymethyl methacrylate (PMMA) phantom, imaging of prompt gamma photons was conducted by the developed gamma camera from one side of the phantom. Imaging of prompt x-rays was conducted by the developed x-ray camera from the other side. Induced positrons were measured by the developed dual-head PET system set on the upper and lower sides of the phantom.Main results. With the proposed triple-imaging-modality system, we could simultaneously image the prompt gamma photons and prompt x-rays during proton beam irradiation. Induced positron distributions could be measured after the irradiation by the PET system and the gamma camera. Among these imaging modalities, image quality was the best for the induced positrons measured by PET. The estimated ranges were actually similar to those imaged with prompt gamma photons, prompt x-rays and induced positrons measured by PET.Significance. The developed triple-imaging-modality system made possible to simultaneously measure the three different beam images. The system will contribute to increasing the data available for imaging in therapy and will contribute to better estimating the shapes or ranges of proton beam.

Blueprints from plane to space: outlook of next-generation three-dimensional histopathology.

Here, we summarize the literature relevant to recent advances in three-dimensional (3D) histopathology in relation to clinical oncology, highlighting serial sectioning, tissue clearing, light-sheet microscopy, and digital image analysis with artificial intelligence. We look forward to a future where 3D histopathology expands our understanding of human pathophysiology and improves patient care through cross-disciplinary collaboration and innovation.

Development of an event-by-event based Li-ZnS(Ag) neutron imaging detector with selective neutron detection capability.

High sensitivity and high resolution is desired in such technologies as neutron radiography. However, the contamination of gamma photons in neutron images decreases the accuracy of neutron radiography. To solve this problem, we developed an event-by-event based neutron imaging system that can selectively detect neutrons. The developed neutron imaging system consists of an Li-ZnS(Ag) scintillator plate optically coupled to a flat panel photomultiplier tube (FP-PMT) with a light guide. Scintillation light emitted from the Li-ZnS(Ag) by the interaction with neutron-induced particles is used to calculate the position based on the center of mass calculations. The spatial resolution of the neutron imaging detector is ∼2.3 mm FWHM, and the sensitivity for 252Cf at 2 cm from the source with 2-cm-thick polystyrene is 20 cps/MBq. Background count fraction from 60Co gamma photons was 0.2 %. For various types of neutron absorption phantoms, high-contrast and high-resolution neutron images are obtained with the developed neutron imaging detector using a252Cf neutron source.

A comparative study of EM-CCD and CMOS cameras for particle ion trajectory imaging.

High-resolution and real-time imaging of particle ion trajectories is essential in nuclear medicine and nuclear engineering. One potential method to achieve high-resolution real-time trajectory imaging of particle ions involves utilizing an imaging system that integrates a scintillator plate with a magnifying unit and a cooled electron multiplying charge-coupled device (EM-CCD) camera. However, acquiring an EM-CCD camera might prove challenging due to the discontinuation of CCD sensor manufacturing by vendors. As an alternative imaging approach, a low-noise, high-sensitivity camera utilizing a cooled complementary metal-oxide-semiconductor (CMOS) sensor offers a promising solution for imaging particle ion trajectories. Yet, it remains uncertain whether CMOS-based cameras can perform as effectively as CCD-based cameras in capturing particle ion trajectories. To address these concerns, we conducted a comparative analysis of the imaging performance between a CMOS-based system and an EM-CCD-based system for capturing alpha particle trajectories. The results revealed that both systems could image the trajectories of alpha particle, but the spatial resolution with the CMOS-based camera exceeded that of the EM-CCD-based camera, primarily due to the smaller pixel size of the sensor. While the signal-to-noise ratio (SNR) of the trajectory image from the CMOS-based camera initially lagged behind that from the EM-CCD-based camera, this disparity was mitigated by implementing binning techniques on the CMOS-based camera images. In conclusion, our findings suggest that a cooled CMOS camera could serve as a viable alternative for imaging particle ion trajectories.

Exercise evaluation with metabolic and ventilatory responses and blood lactate concentration in mice.

This study aimed to clarify the differential exercise capacity between 2-month-old and 10-month-old mice using an incremental running test. Metabolic and ventilatory responses and blood lactate concentration were measured to evaluate exercise capacity. We examined whether incremental running test results reflected metabolic and ventilatory responses and blood lactate concentration observed during the steady-state running test. Metabolic response significantly declined with age, whereas ventilatory response was similar between the groups. A low-intensity/moderate exercise load of 10/min in an incremental running test was performed on both mice for 30 min. They showed a characteristic pattern in ventilatory response in 10-month mice. The results of incremental running tests didn't necessarily reflect the steady-state metabolic and ventilatory responses because some parameters showed an approximation and others did not in incremental and steady-state tests, which changed with age. Our study suggests metabolic and ventilatory responses depending on age and provides basic knowledge regarding the objective and quantitative assessment of treadmill running in an animal model.

Extremely Large Response of Phonon Coherence in Twisted Penta-NiN2 Bilayer.

Twisting has recently been demonstrated as an effective strategy for tuning the interactions between particles or quasi-particles in layered materials. Motivated by the recent experimental synthesis of pentagonal NiN2 sheet [ACS Nano 2021, 15, 13539], for the first time, the response of phonon coherence to twisting in bilayer penta-NiN2 , going beyond the particle-like phonon transport is studied. By using the unified theory of phonon transport and high order lattice anharmonicity, together with the self-consistent phonon theory, it is found that the lattice thermal conductivity is reduced by 80.6% from 33.35 to 6.47 W m-1 K-1 at 300 K when the layers are twisted. In particular, the contribution of phonon coherence is increased sharply by an order of magnitude, from 0.21 to 2.40 W m-1 K-1 , due to the reduced differences between the phonon frequencies and enhanced anharmonicity after the introduction of twist. The work provides a fundamental understanding of the phonon interaction in twisted pentagonal sheets.

Simultaneous imaging of luminescence and prompt x-rays during irradiation with spot-scanning proton beams at clinical dose level.

Prompt x-ray imaging is a promising method for observing the beam shape from outside a subject. However, its distribution is different from dose distribution, and thus a comparison with the dose is required. Meanwhile, luminescence imaging of water is a possible method for imaging the dose distribution. Consequently, we performed simultaneous imaging of luminescence and prompt x-rays during irradiation by proton beams to compare the distributions between these two different imaging methods. Optical imaging of water was conducted with spot-scanning proton beams at clinical dose level during irradiation to a fluorescein (FS) water phantom set in a black box. Prompt x-ray imaging was also conducted simultaneously from outside the black box using a developed x-ray camera during proton beam irradiation to the phantom. We measured images of the luminescence of FS water and prompt x-rays for various types of proton beams, including pencil beams, spread-out Bragg peak (SOBP) beams, and clinically used therapy beams. After the imaging, ranges were estimated from FS water and prompt x-rays and compared with those calculated with a treatment planning system (TPS). We could measure the prompt x-ray and FS water images simultaneously for all types of proton beams. The ranges estimated from the FS water and those calculated with the TPS closely matched, within a difference of several mm. Similar range difference was found between the results estimated from prompt x-ray images and those calculated with the TPS. We confirmed that the simultaneous imaging of luminescence and prompt x-rays were possible during irradiation with spot-scanning proton beams at a clinical dose level. This method can be applied to range estimation as well as comparison with the dose for prompt x-ray imaging or other imaging methods used in therapy with various types of proton beams at a clinical dose level.

Hybrid imaging of prompt x-rays and induced positrons using a pinhole gamma camera during and after irradiation of protons.

Objective. Prompt x-ray imaging using a low-energy x-ray camera is a promising method for observing a proton beam's shape from outside the subject. Furthermore, imaging of positrons produced by nuclear reactions with protons is a possible method for observing the beam shape. However, it has not been possible to measure these two types of images with a single imaging system due to the limited imaging capability of existing systems. Imaging of both prompt x-rays and the distribution of positrons may compensate for the shortcomings of each method.Approach. We conducted imaging of the prompt x-ray using a pinhole x-ray camera during irradiation with protons in list mode. Then, after irradiation with protons, imaging of annihilation radiations from the produced positrons was conducted using the same pinhole x-ray camera in list mode. After this imaging, list-mode data were sorted to obtain prompt x-ray images and positron images.Main results. With the proposed procedure, we could measure both prompt x-ray images and induced positron images with a single irradiation by a proton beam. From the prompt x-ray images, ranges and widths of the proton beams could be estimated. The distributions of positrons were slightly wider than those of the prompt x-rays. From the time sequential positron images, we could derive the time activity curves of the produced positrons.Significance. Hybrid imaging of prompt x-rays and induced positrons using a pinhole x-ray camera was achieved. The proposed procedure would be useful for measuring prompt x-ray images during irradiation to estimate the beam structures as well as for measuring the induced positron images after irradiation to estimate the distributions and time activity curves of the induced positrons.

Development of an ultrahigh resolution real time alpha particle imaging system for observing the trajectories of alpha particles in a scintillator.

High-resolution imaging of alpha particles is required in the detection of alpha radionuclides in cells or small organs for the development of radio-compounds for targeted alpha-particle therapy or other purposes. We developed an ultrahigh resolution, real time alpha-particle imaging system for observing the trajectories of alpha particles in a scintillator. The developed system is based on a magnifying unit and a cooled electron multiplying charge-coupled device (EM-CCD) camera, combined with a 100-µm-thick Ce-doped Gd3Al2Ga3O12 (GAGG) scintillator plate. Alpha particles from an Am-241 source were irradiated to the GAGG scintillator and imaged with the system. Using our system, we measured the trajectories of the alpha particles having different shapes in real time. In some of these measured trajectories, the line shapes of the alpha particles that flew in the GAGG scintillator were clearly observed. The lateral profiles of the alpha-particle trajectories were imaged with widths of ~ 2 µm. We conclude that the developed imaging system is promising for research on targeted alpha-particle therapy or other alpha particle detections that require high spatial resolution.

Integrating cytology into routine digital pathology workflow: a 5-year journey.

Despite recent advances in digital imaging, the adoption of digital cytology is challenging due to technical limitations. This study describes our 5-year institutional experience with the implementation of digital cytology. The routine cytology workflow included conventional two-step screening by cytotechnologists, followed by sign out by pathologists. We introduced sign out of cytologic cases using a microscopic digital imaging platform operated by cytotechnologists, which allowed for remote review of slides by cytopathologists via video streaming. We also provided cytologic correlation to support the virtual slide-based sign out of histopathological specimens and for a weekly pathology-radiology conference. In addition, positive cytology cases were archived for integration into the laboratory information system and for prospective computational pathology studies. We also summarized lessons learned over the years and outlined our vision for future developments. This unique experience may serve as a role model for other institutions.

Prompt X-ray imaging during irradiation with spread-out Bragg peak (SOBP) beams of carbon ions.

Prompt secondary electron bremsstrahlung X-ray (prompt X-ray) imaging using a low-energy X-ray camera is a promising method for observing a beam shape from outside the subject. However, such imaging has so far been conducted only for pencil beams without a multi-leaf collimator (MLC). The use of spread-out Bragg peak (SOBP) with an MLC may increase the scattered prompt gamma photons and decrease the contrast of the images of prompt X-rays. Consequently, we performed prompt X-ray imaging of SOBP beams formed with an MLC. This imaging was carried out in list mode during irradiation of SOBP beams to a water phantom. An X-ray camera with a 1.5-mm diameter as well as 4-mm-diameter pinhole collimators was used for the imaging. List mode data were sorted to obtain the SOBP beam images as well as energy spectra and time count rate curves. Due to the high background counts from the scattered prompt gamma photons penetrating the tungsten shield of the X-ray camera, the SOBP beam shapes were difficult to observe with a 1.5-mm-diameter pinhole collimator. With the 4-mm-diameter pinhole collimators, images of SOBP beam shapes at clinical dose levels could be obtained with the X-ray camera. The use of a 4-mm-diameter pinhole collimator attached to the X-ray camera is effective for prompt X-ray imaging with high sensitivity and low background counts. This approach makes it possible to image SOBP beams with an MLC when the counts are low and the background levels are high.

Role of the amygdala-medial orbitofrontal relationship in odor recognition in the elderly.

INTRODUCTION: In patients with mild cognitive impairment, pathological changes begin in the amygdala (AMG) and hippocampus (HI), especially in the parahippocampal gyrus and entorhinal cortex (ENT). These areas play an important role in olfactory detection and recognition. It is important to understand how subtle signs of olfactory disability relate to the functions of the above-mentioned regions, as well as the orbitofrontal cortex (OFC). In this study, we evaluated brain activation using functional magnetic resonance imaging (fMRI), performed during the presentation of olfactory stimuli (classified as "normal odors" not inducing memory retrieval), and investigated the relationships of the blood oxygen level-dependent (BOLD) signal with olfactory detection and recognition abilities in healthy elderly subjects. METHODS: Twenty-four healthy elderly subjects underwent fMRI during olfaction, and raw mean BOLD signals were extracted from regions of interest, including bilateral regions (AMG, HI, parahippocampus, and ENT) and orbitofrontal subregions (frontal inferior OFC, frontal medial OFC, frontal middle OFC, and frontal superior OFC). Multiple regression and path analyses were conducted to understand the roles of these areas in olfactory detection and recognition. RESULTS: Activation of the left AMG had the greatest impact on olfactory detection and recognition, while the ENT, parahippocampus, and HI acted as a support system for AMG activation. Less activation of the right frontal medial OFC was associated with good olfactory recognition. These findings improve our understanding of the roles of limbic and prefrontal regions in olfactory awareness and identification in elderly individuals. CONCLUSION: Functional decline of the ENT and parahippocampus crucially impacts olfactory recognition. However, AMG function may compensate for deficits through connections with frontal regions.

Acceptance and Preference for COVID-19 Vaccine among Japanese Residents at Early Stage of the Epidemic in Japan.

Background: This study aimed to survey the attitudes toward COVID-19 vaccines and their acceptability among the Japanese public as soon as the United States Food and Drug Administration (FDA) authorized vaccines and their rollouts started around the world. Methods: An anonymous cross-sectional survey was conducted in Japan between 4 January and 5 March 2021. A questionnaire was administered to evaluate attitudes toward COVID-19 vaccines according to demographic characteristics, vaccine characteristics, and vaccine production. Results: A total of 1037 completed responses were received. More than half (63.5%) of the participants responded positively (extremely likely/likely) toward COVID-19 vaccines. The highest acceptance to be vaccinated was discovered among the youngest age group. As expected, participants who had never delayed acceptance or refused the vaccine in their history of vaccination had a significantly higher willingness to be vaccinated against COVID-19 (p < 0.001). Females (OR = 2.66, 95% CI: 1.99−3.58) and participants who had ever delayed acceptance or refuse the vaccine (OR = 3.49, 95% CI: 2.42−5.05) had higher odds of COVID-19 vaccine hesitancy. Participants with a postgraduate degree (OR = 0.64, 95% CI: 0.40−1.00) presented the highest willingness to be vaccinated against COVID-19. More than two-thirds (72.9%, 95% CI: 70.4%−75.8%) of the participants did not mind a booster dose required following primary vaccination. A total of 63.2% (95% CI: 60.0%−66.0%) of the participants only accepted a nearly 90% effective or above vaccine at preventing COVID-19. At the same, 86.4% (95% CI: 84.4%−88.4%) of the participants reported only accepting a vaccine with minor side effects. Conclusions: The moderate levels of COVID-19 vaccine acceptance found in the early phase of the pandemic demonstrate that it is important to improve the implementation of effective management for vaccine promotion and the acceptability of the vaccine to slow or delay transmission.

Mild-intensity running exercise recovered motor function by improvement of ankle mobility after unilateral brain injury of mice using three-dimensional kinematic analysis techniques.

Motor dysfunction, such as gait impairment, is a major disability induced by traumatic brain injury or stroke. Treadmill running is often used as a physical exercise (Ex) clinically and experimentally for the recovery of patients. In animal experiments, although dynamic behavioral deficits can be evaluated using scoring systems, local and minor behaviors are difficult to determine. This study aims to evaluate motor dysfunction and recovery after brain damage (BD) with/without mild-intensity running Ex in mice using three-dimensional (3D) kinematic analysis. To determine exercise intensity, C57/BL6-strain male young adult mice were examined in an incremental running test while the pulmonary gas exchange of O2 and CO2 were measured. The animals were then subjected to left hemidecortication as BD, and some mice performed Ex (10 m/min for 30 min 5 times/wk) for 4 weeks. The BD with Ex and BD or sham-operated mice (sham) without (w/o) Ex had their gait recorded by four synchronized cameras, and gait was evaluated via 3D-kinematic analysis. The BD w/o Ex mice significantly differed in stride, step, and stride width for both limbs compared to the sham w/o Ex mice. The BD with Ex mice showed improvement. The BD w/o Ex mice had restricted ankle movements and impairment in dorsal/planter flexing using trajectory analysis. Consistent with these impairments, the nonaffected side also exhibited a different trajectory, suggesting compensatory movements. These results suggest that the appropriate Ex after BD recovered motor function. Furthermore, the present study suggested that 3D-kinematic analysis is a powerful tool for detecting minor behavioral alterations owing to the impairment of the affected side and the compensation of the unaffected side.

Optimization of the energy window setting in Ir-192 source imaging for high-dose-rate brachytherapy using a YAP(Ce) gamma camera.

PURPOSE: Although real-time imaging of the high-activity iridium-192 (Ir-192) source position during high-dose-rate (HDR) brachytherapy using a high-energy gamma camera system is a promising approach, the energy window was not optimized for spatial resolution or scatter fraction. METHODS: By using a list-mode data-acquisition system that can acquire energy information of a cerium-doped yttrium aluminum perovskite (YA1O3: YAP(Ce)) gamma camera, we tried to optimize the energy window's setting to improve the spatial resolution and reduce scatter fraction. RESULTS: The spatial resolution was highest for the central energy of the window at ∼300 keV. The scatter fraction was also smallest for the central energy of the window at ∼300 keV, and the scatter fraction was more than 48 % smaller than that for the full energy window. CONCLUSIONS: We clarified that the spatial resolution can be improved and the scatter fraction can be reduced through optimizing the energy window of the YAP(Ce) gamma camera by setting the central energy of the window to ∼300 keV for HDR brachytherapy.

Protocol for educational programs on infection prevention/control for medical and healthcare student: A systematic review and meta-analysis.

During the COVID-19 pandemic, infection protection/control education has become increasingly important for not only healthcare professionals but also students undertaking medical, nursing, physical therapy, occupational therapy, and other related courses. A review of the literature on infection control education reveals that the target participants often comprise healthcare workers, and very few studies of infection control education focus on students. We have developed a protocol for the systematic review of the literature on simulation-based infection prevention/control education for students undertaking medical, nursing, rehabilitation, and other related courses. The protocol for the systematic review and meta-analysis has been drafted in alignment with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Systematic literature search will be performed for the period between 1990 (January) and 2022 (September) using the CENTRAL, MEDLINE, and Scopus databases. We will qualitatively and quantitatively examine the effects of simulation-based infection education for students in this systematic review and meta-analysis. Two investigators will independently search the databases according to the defined search strategy. The full-text of the selected articles will be screened independently keeping in mind the inclusion criteria by a pair of reviewers. Descriptive data will be extracted from each study regarding: study design, methods, participants, and outcomes. A meta-analysis will be performed if the quantitative data is suitable. Heterogeneity will be assessed using the standard χ2. Odds ratio for categorical data and weighted mean differences for continuous data and their 95% confidence intervals will be calculated and used for analysis. Where statistical pooling is not possible, the findings of the quantitative papers will be presented in narrative form. The qualitative aspect will employ narrative (descriptive) synthesis. Our review will make a valuable contribution to the domain of simulation-based infection prevention/control for students enrolled in medical and/or related courses.

Technical note: Short-time sequential high-energy gamma photon imaging using list-mode data acquisition system for high-dose-rate brachytherapy.

PURPOSE: Measurement of the dwell time and moving speed of a high-activity iridium-192 (Ir-192) source used for high-dose-rate (HDR) brachytherapy is important for estimating the precise dose delivery to a tumor. For this purpose, we used a cerium-doped yttrium aluminum perovskite (YA1O3 :YAP(Ce)) gamma camera system, combined with a list-mode data acquisition system that can acquire short-time sequential images, and measured the dwell times and moving speeds of the Ir-192 source. METHODS: Gamma photon imaging was conducted using the gamma camera in list mode for the Ir-192 source of HDR brachytherapy with fixed dwell times and positions. The acquired list-mode images were sorted to millisecond-order interval time sequential images to evaluate the dwell time at each position. Time count rate curves were derived to calculate the dwell time at each source position and moving speed of the source. RESULTS: We could measure the millisecond-order time sequential images for the Ir-192 source. The measured times for the preset dwell times of 2 s and 10 s were 1.98 to 2.00 s full width at half maximum (FWHM) and 10.0 s FWHM, respectively. The dwell times at the first dwell position were larger than those at other positions. We also measured the moving speeds of the source after the dwells while moving back to the afterloader and found the speed increased with the distance from the edge of the field of view to the last dwell position. CONCLUSION: We conclude that millisecond-order time sequential imaging of the Ir-192 source is possible by using a gamma camera and is useful for evaluating the dwell times and moving speeds of the Ir-192 source.

Cumulative risk of developing a new symptom in patients with primary biliary cholangitis and its impact on prognosis.

Background and Aim: Symptoms of primary biliary cholangitis (PBC) frequently impair one's quality of life (QOL). Nonetheless, with improved treatment, the prognosis of PBC also improves. QOL plays an important role in patients with PBC. In this study, we aimed to reevaluate the transition of new symptom development in PBC and its predictive factors. Methods: This retrospective multicenter study enrolled 382 patients with PBC for symptom analysis. The impact of a newly developed symptom on PBC prognosis was investigated by Kaplan-Meier analysis with propensity score matching and logistic progression analysis. Results: The cumulative risk of developing a new symptom after 10 and 20 years of follow-up was 7.6 and 28.2%, and specifically that of pruritus, which was the most common symptom, was 6.7 and 23.3%, respectively. In Cox hazard risk analysis, serum Alb level (hazard ratio [HR], 1.097; 95% confidence interval [CI], 1.033-1.165; P = 0.002), the serum D-Bil level (HR, 6.262; 95% CI, 2.522-15.553, P < 0.001), and Paris II criteria (HR, 0.435; 95% CI, 0.183-1.036; P = 0.037) were significant independent predictors of a new symptom. Kaplan-Meier analysis showed that the overall survival and liver-related death were not significant between patients with and without a new symptom. Conclusion: The cumulative risk of new symptom development is roughly 30% 20 years after diagnosis and could be predicted by factors including serum albumin levels, serum D-Bil level, and Paris II criteria.