34 research outputs found

    Anatomy-based prediction method for determining ipsilateral lung doses in postoperative breast radiation therapy assisted by diagnostic computed tomography images

    Get PDF
    Background: This study aimed to investigate whether ipsilateral lung doses (ILDs) could be predicted by anatomical indexes measured using diagnostic computed tomography (CT) prior to the planning stage of breast radiation therapy (RT). Materials and methods: The thoracic diameters and the length of lines drawn manually were measured on diagnostic CT images. The parameters of interest were the skin maximum lung distance (sMLD), central lung distance (CLD), Haller index (HI), and body mass index (BMI). Lung dose-volume histograms were created with conformal planning, and the lung volumes receiving 5–40 Gy (V5–V40) were calculated. Linear regression models were used to investigate the correlations between the anatomical indexes and dose differences and to estimate the slope and 95% confidence intervals (CIs). Results: A total of 160 patients who had undergone three-dimensional conformal RT after breast-conserving surgery were included. Univariable analysis revealed that the sMLD (p < 0.001), CLD (p < 0.001), HI (p = 0.002), and BMI (p < 0.001) were significantly correlated with the V20. However, multivariable analysis revealed that only the sMLD (slope: 0.147, p = 0.001, 95% CI: 0.162–0.306) and CLD (0.157, p = 0.005, 0.048–0.266) were strongly correlated with the V20. The p-value for the sMLD was the lowest among the p-values for all indexes, thereby indicating that the sMLD had the best predictive power for ILD. Conclusions: sMLD and CLD are anatomical markers that can be used to predict ILD in whole breast RT. An sMLD > 20.5 mm or a CLD > 24.3 mm positively correlated with a high ILD.

    Microarray analysis of expression of cell death-associated genes in rat spinal cord cells exposed to cyclic tensile stresses in vitro

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The application of mechanical insults to the spinal cord results in profound cellular and molecular changes, including the induction of neuronal cell death and altered gene expression profiles. Previous studies have described alterations in gene expression following spinal cord injury, but the specificity of this response to mechanical stimuli is difficult to investigate in vivo. Therefore, we have investigated the effect of cyclic tensile stresses on cultured spinal cord cells from E15 Sprague-Dawley rats, using the FX3000<sup>® </sup>Flexercell Strain Unit. We examined cell morphology and viability over a 72 hour time course. Microarray analysis of gene expression was performed using the Affymetrix GeneChip System<sup>®</sup>, where categorization of identified genes was performed using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) systems. Changes in expression of 12 genes were validated with quantitative real-time reverse transcription polymerase chain reaction (RT-PCR).</p> <p>Results</p> <p>The application of cyclic tensile stress reduced the viability of cultured spinal cord cells significantly in a dose- and time-dependent manner. Increasing either the strain or the strain rate independently was associated with significant decreases in spinal cord cell survival. There was no clear evidence of additive effects of strain level with strain rate. GO analysis identified 44 candidate genes which were significantly related to "apoptosis" and 17 genes related to "response to stimulus". KEGG analysis identified changes in the expression levels of 12 genes of the mitogen-activated protein kinase (MAPK) signaling pathway, which were confirmed to be upregulated by RT-PCR analysis.</p> <p>Conclusions</p> <p>We have demonstrated that spinal cord cells undergo cell death in response to cyclic tensile stresses, which were dose- and time-dependent. In addition, we have identified the up regulation of various genes, in particular of the MAPK pathway, which may be involved in this cellular response. These data may prove useful, as the accurate knowledge of neuronal gene expression in response to cyclic tensile stress will help in the development of molecular-based therapies for spinal cord injury.</p

    Selective CO<sub>2</sub> Fixation to Styrene Oxide by Ta-Substitution of Lindqvist-Type [(Ta,Nb)<sub>6</sub>O<sub>19</sub>]<sup>8−</sup> Clusters

    No full text
    Metal oxide clusters composed of group 5 metal ions, such as Nb and Ta, exhibit catalytic activities for CO2 fixation to styrene oxide (SO) due to the highly negative natural bonding charge of the terminal O atoms that could work as CO2 activation sites. In this study, tetrabutylammonium (TBA) salts of [TaxNb6−xO19]8− (TBA-TaxNb6−x, x = 0–6) were prepared and Ta-substitution effect on the catalytic properties of TBA-TaxNb6−x for CO2 fixation to SO was investigated. We found that TBA-Ta1Nb5 shows the highest styrene carbonate (SC) selectivity (95%) among TBA-TaxNb6−x, although the SO conversion monotonously increases with the incremental Ta substitution amount. The CO2 fixation to SO under various conditions and in situ X-ray absorption fine structure measurements reveal that CO2 is activated on both terminal O sites coordinated to the Ta (terminal OTa) and Nb (terminal ONb) sites, whereas the activation of SO proceeds on the terminal OTa and/or bridge O sites that are connected to Ta. Density functional theory (DFT) calculations reveal that the terminal OTa of TBA-Ta1Nb5 preferentially adsorbs CO2 compared with other ONb base sites. We conclude that the selective CO2 activation at terminal OTa of TBA-Ta1Nb5 without SO activation is a crucial factor for high SC selectivity in the CO2 fixation to SO

    Development of Novel PET Probes for Central 2-Amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) Receptors

    No full text
    We document the development of PET probes for central AMPA receptors and their application to in vivo imaging of animals. Initial screening of perampanel derivatives was performed to identify probe candidates. Despite the high autoradiographic contrast yielded by several radioligands, rat PET scans did not support their in vivo suitability. Further focused derivatization and second screening by ex vivo LC-MS measurements led to the selection of 2-[1-(3-methylaminophenyl)-2-oxo-5-(pyrimidin-2-yl)-1,2-dihydropyridin-3-yl]benzonitrile, 21a, and its analogs as candidates. [11C]21a was shown by autoradiography to specifically bind to the neocortex and hippocampus, consistent with AMPA receptor localization. PET imaging with [11C]21a demonstrated moderate uptake of radioactivity in rat and monkey brains, with the retention of radiosignals being consistent with autoradiograms, and the uptake was blocked by pretreatment with unlabeled 21a in a dose-dependent manner. The current approach has facilitated the discovery of a PET probe potentially suitable for translational research and development focused on AMPA receptors

    Longly-attached cap can contribute to en bloc underwater endoscopic mucosal resection of 20–30 mm colorectal intramucosal lesions

    No full text
    Background and study aims Underwater endoscopic mucosal resection (UEMR) is effective for colorectal intramucosal lesions. The aim of this study was to evaluate whether a longly-attached cap in UEMR improves the en bloc resection rate for 20–30 mm lesions. Patients and methods We performed a retrospective study at a tertiary institute. Candidates for the study were systematically retrieved from an endoscopic and pathological database from October 2016 to December 2020. We assessed the procedural outcomes with UEMR for lesions ≥ 20 mm in size and the clinical factors contributing to en bloc resection. Results A total of 52 colorectal lesions that underwent UEMR were included. The median procedure time was 271 (66–1264) seconds. The en bloc resection rate and R0 resection rate were 75 % and 73 %, respectively. Intraprocedural perforation occurred in one (1.9 %) case, but no bleeding occurred. Delayed bleeding occurred in one (1.9%) case, but no delayed perforation occurred. Regarding tumor size, macroscopic type, tumor location, and the presence or absence of a history of abdominal operation, there was no significant difference between the en bloc resection and piecemeal resection groups. The visibility of the whole lesion, a longly-attached cap, and sessile serrated lesions were more frequently observed in the en bloc resection group than in the piecemeal resection group (P < 0.001, P = 0.01, and P = 0.04, respectively). Multivariate analysis showed that a longly-attached cap was the only independent factor associated with en bloc resection (P = 0.02). Conclusions A longly-attached cap might contribute to en bloc resection

    Impact of preexisting interstitial lung disease on mortality in COVID-19 patients from the early pandemic to the delta variant epidemic: a nationwide population-based study

    No full text
    Abstract Background COVID-19 patients with preexisting interstitial lung disease (ILD) were reported to have a high mortality rate; however, this was based on data from the early stages of the pandemic. It is uncertain how their mortality rates have changed with the emergence of new variants of concern as well as the development of COVID-19 vaccines and treatments. It is also unclear whether having ILD still poses a risk factor for mortality. As COVID-19 continues to be a major concern, further research on COVID-19 patients with preexisting ILD is necessary. Methods We extracted data on COVID-19 patients between January 2020–August 2021 from a Japanese nationwide insurance claims database and divided them into those with and without preexisting ILD. We investigated all-cause mortality of COVID-19 patients with preexisting ILD in wild-type-, alpha-, and delta-predominant waves, to determine whether preexisting ILD was associated with increased mortality. Results Of the 937,758 adult COVID-19 patients, 7,333 (0.8%) had preexisting ILD. The proportion of all COVID-19 patients who had preexisting ILD in the wild-type-, alpha-, and delta-predominant waves was 1.2%, 0.8%, and 0.3%, respectively, and their 60-day mortality was 16.0%, 14.6%, and 7.5%, respectively. The 60-day mortality significantly decreased from the alpha-predominant to delta-predominant waves (difference − 7.1%, 95% confidence intervals (CI) − 9.3% to − 4.9%). In multivariable analysis, preexisting ILD was independently associated with increased mortality in all waves with the wild-type-predominant, odds ratio (OR) 2.10, 95% CI 1.91–2.30, the alpha-predominant wave, OR 2.14, 95% CI 1.84–2.50, and the delta-predominant wave, OR 2.10, 95%CI 1.66–2.66. Conclusions All-cause mortality rates for COVID-19 patients with preexisting ILD decreased from the wild-type- to the more recent delta-predominant waves. However, these patients were consistently at higher mortality risk than those without preexisting ILD. We emphasize that careful attention should be given to patients with preexisting ILD despite the change in the COVID-19 environment

    Impact of Systemic Autoimmune Diseases on Treatment Outcomes and Radiation Toxicities in Patients with Stage I Non-Small Cell Lung Cancer Receiving Stereotactic Body Radiation Therapy: A Matched Case-Control Analysis

    No full text
    We aimed to evaluate the impact of systemic autoimmune diseases (SADs) on treatment outcomes and radiation toxicities following stereotactic body radiation therapy (SBRT) for stage I non-small cell lung cancer (NSCLC). We queried an institution-based database on patients with SADs treated with SBRT for lung cancer between 2001 and 2016 (SAD group). Each patient was matched to three controls without SADs. The primary outcomes of interest were the overall survival (OS) and local control rate (LCR). The secondary outcomes were radiation toxicities of grades ≥2 (≥G2). Twelve patients with SADs were matched to 36 controls. The median follow-up duration was 3.6 years. There was a significant intergroup difference in the OS (hazard ratio [HR]: 4.11, 95% confidence incidence [CI]: 1.82–9.27, p p p = 0.550) and late (OR: 2.20, 95% CI: 0.32–15.10, p = 0.422) ≥G2 radiation pneumonitis. No other ≥G2 toxicities were identified. In conclusion, although radiation toxicities are not enhanced by SADs, SADs are risk factors of poor prognosis following SBRT for stage I NSCLC

    Changes in the Characteristics and Outcomes of COVID-19 Patients from the Early Pandemic to the Delta Variant Epidemic: A Nationwide Population-based Study

    No full text
    The coronavirus disease 2019 (COVID-19) pandemic has dramatically changed because of virus mutations, vaccine dissemination, treatment development and policies, among other factors. These factors have a dynamic and complex effect on the characteristics and outcomes of patients. Therefore, there is an urgent need to understand those changes and update the evidence. We used a large-scale real-world data set of 937,758 patients with COVID-19 from a nationwide claims database that included outpatients and inpatients in Japan to investigate the changes in their characteristics, outcomes and risk factors for severity/mortality from the early pandemic to the delta variant-predominant waves. The severity of COVID-19 was defined according to the modified World Health Organization clinical-progression ordinal scale. With changing waves, mean patient age decreased, and proportion of patients with comorbidities decreased. The incidences of “severe COVID-19 or death (i.e. ≥severe COVID-19)” and “death” markedly declined (5.0% and 2.9%, wild-type-predominant; 4.6% and 2.2%, alpha variant-predominant and 1.4% and 0.4%, delta variant-predominant waves, respectively). Across the wave shift, risk factors for ≥severe COVID-19 and death, including older age, male, malignancy, congestive heart failure and chronic obstructive pulmonary disease, were largely consistent. The significance of some factors, such as liver disease, varied as per the wave. This study, one of the largest population-based studies on COVID-19, showed that patient characteristics and outcomes changed during the waves. Risk factors for severity/mortality were similar across all waves, but some factors were inconsistent. These data suggest that the clinical status of COVID-19 will change further with the coming epidemic wave.</p
    corecore