58 research outputs found

    Wedge holography in flat space and celestial holography

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    In this paper, we study codimension two holography in flat spacetimes, based on the idea of the wedge holography. We propose that a region in a d+1 dimensional flat spacetime surrounded by two end of the world branes, which are given by d dimensional hyperbolic spaces, is dual to a conformal field theory (CFT) on a d-1 dimensional sphere. Similarly, we also propose that a d+1 dimensional region in the flat spacetime bounded by two d dimensional de Sitter spaces is holographically dual to a CFT on a d-1 dimensional sphere. Our calculations of the partition function, holographic entanglement entropy and two point functions, support these duality relations and imply that such CFTs are nonunitary. Finally, we glue these two dualities along null surfaces to realize a codimension two holography for a full Minkowski spacetime and discuss a possible connection to the celestial holography

    Proton beam therapy followed by pembrolizumab for giant ocular surface conjunctival malignant melanoma: A case report

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    The present study describes proton beam therapy as a clinical option to achieve local control of giant conjunctival melanoma in an aged person, instead of orbital exenteration. An 80‑year‑old woman with one‑year history of left‑eye injection and hemorrhage experienced rapid growth of the ocular surface black mass. At the initial visit, a black, elastic hard, hemorrhage‑prone, thickened mass in the size of 30x40 mm with a presumed wide stalk covered the total area of the lid fissure on the left side. Biopsy of the mass demonstrated anomalous melanin‑containing cells in fibrin and hemorrhage, which were positive for cocktail‑mix antibodies against tyrosinase, melanoma antigen recognized by T cells‑1 and human melanoma black‑45, indicative of malignant melanoma. One month after the initial visit, the patient underwent proton beam therapy at the total dose of 70.4 Gy (relative biological effectiveness) in 32 fractions (~10 min each) in one and a half months. One month after the end of proton beam therapy, 3.5 months from the initial visit, the patient was found by computed tomographic scan to have multiple metastatic lesions in bilateral lung fields. With the evidence of absent BRAF mutation, the patient underwent intravenous administration of pembrolizumab 77.2 mg every three weeks five times in total. Then, three months after proton beam therapy, ocular surface melanoma almost subsided and the clear cornea allowed visualization of the intraocular lens inside the eye. In three weeks, spontaneous corneal perforation was plugged with iris incarceration. The patient died suddenly of unknown cause 7.5 months from the initial visit. The local control of giant conjunctival melanoma was achieved by proton beam therapy, leading to patient's satisfaction and better quality of life. Proton beam therapy, followed by immune checkpoint inhibitors, would become the future standard of care for unresectable giant conjunctival melanoma

    Comparison of Field-in-Field Radiotherapy with Conformal Radiotherapy for Unilateral Cervical Malignant Lymphoma

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    This study compared field-in-field (FIF) radiotherapy with conformal radiotherapy with physical wedges for the treatment of unilateral cervical malignant lymphoma. Two treatment plans, the FIF technique and conformal RT, were generated for each of 32 patients with unilateral cervical malignant lymphoma. To compare the 2 treatment plans, dose-volume histograms of the planning target volume (PTV), the thyroid, submandibular gland, carotid artery, mucosa, spinal cord, and surrounding normal tissue, and monitor unit (MU) were analyzed. The FIF technique showed significant reduction in the mean dose of thyroid, submandibular gland, carotid artery and mucosa, the maximum dose of the spinal cord and PTV, and the volume receiving>107% of the prescribed dose of surrounding normal tissue (p<0.001). In addition, there were gains in the homogeneity index of the PTV for FIF. Furthermore, the total MU was also lower for the FIF technique than for the wedge technique (p<0.001). Compared with the wedge technique, the FIF technique improved the dose homogeneity of the PTV, reduced the dose to normal structures, and was associated with fewer MUs in the treatment of patients with cervical malignant lymphoma

    Peculiar mechanisms of graft recovery through anti-inflammatory responses after rat lung transplantation from donation after cardiac death

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    Background: Although lung transplantation from donation after cardiac death (DCD), especially uncontrolled DCD, is limited by warm ischemic periods, the molecular mechanism of warm ischemia-reperfusion-injury (IRI) has not been well elucidated. The purpose of this study was to clarify the particular longitudinal mechanisms of molecular factors involved in warm IRI. Methods: Cold ischemic-time (CIT)-group lungs were retrieved and subjected to 3-h of cold preservation, whereas warm ischemic-time (WIT)-group lungs were retrieved after 3-h of warm ischemia. Orthotopic rat lung transplantation was performed and the grafts were reperfused for 1 or 4-h. The graft functions, gene expression, and activation of inflammatory molecules in the grafts were analyzed. Exhaled-carbon-monoxide-concentration (ExCO-C) was measured during reperfusion. Results: Only the WIT-group showed obvious primary graft dysfunction at 1-h reperfusion, but the graft function was recovered during 4-h reperfusion. Most of pro-inflammatory cytokines and stress-induced molecules showed different expression and activation patterns between CIT and WIT groups. In the WIT-group, the expressions of anti-inflammatory molecules, IL-10 and HO-1, were significantly increased at 1-h reperfusion compared to the CIT-group, and these high levels were maintained through 4-h reperfusion. Furthermore, ExCO-C levels in the WIT-group increased immediately after reperfusion compared to the CIT-group. Conclusions: This study indicates that warm IRI may involve a different mechanism than cold IRI and anti-inflammatory pathways may play important roles in the graft recovery after lung transplantation from uncontrolled DCD

    Analysis of Factors Associated With Radiation-Induced Bronchiolitis Obliterans Organizing Pneumonia Syndrome After Breast-Conserving Therapy

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    Purpose: To evaluate factors associated with radiation-induced bronchiolitis obliterans organizing pneumonia (BOOP) syndrome after breast-conserving therapy. Methods and materials: A total of 702 women with breast cancer who received radiotherapy after breast-conserving surgery at seven institutions between July 1995 and December 2006 were analyzed. In all patients, the whole breast was irradiated with two tangential photon beams. The criteria used for the diagnosis of radiation-induced BOOP syndrome were as follows: (1) radiotherapy to the breast within 12 months, (2) general and/or respiratory symptoms lasting for >or=2 weeks, (3) radiographs showing lung infiltration outside the radiation port, and (4) no evidence of a specific cause. Results: Radiation-induced BOOP syndrome was seen in 16 patients (2.3%). Eleven patients (68.8%) were administered steroids. The duration of steroid administration ranged from 1 week to 3.7 years (median, 1.1 years). Multivariate analysis revealed that age (>or=50 years; odds ratio [OR] 8.88; 95% confidence interval [CI] 1.16-67.76; p = 0.04) and concurrent endocrine therapy (OR 3.05; 95% CI 1.09-8.54; p = 0.03) were significantly associated with BOOP syndrome. Of the 161 patients whose age was >or=50 years and who received concurrent endocrine therapy, 10 (6.2%) developed BOOP syndrome. Conclusions: Age (>or=50 years) and concurrent endocrine therapy can promote the development of radiation-induced BOOP syndrome after breast-conserving therapy. Physicians should carefully follow patients who received breast-conserving therapy, especially those who are older than 50 years and received concurrent endocrine therapy during radiotherapy

    Interfractional Seminal Vesicle Motion Relative to the Prostate Gland for Image-guided Radiotherapy for Prostate Cancer with/without Androgen Deprivation Therapy: A Retrospective Cohort Study

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    We investigated differences in seminal vesicle (SV) length and interfractional SV motion relative to the prostate gland in prostate cancer patients. We compared 32 patients who received androgen deprivation therapy (ADT) before radiotherapy with 12 patients receiving radiotherapy alone at Okayama University Hospital in August 2008-July 2011. We examined the right and left SVs’ length and motion by computed tomography (CT) to determine the ADT’s effects and analyzed 347 CT scans in a multiple linear regression model. The ADT patients’ SV length was significantly shorter than the non-ADT patients’. The differences in right and left SV lengths between the ADT and non-ADT patients were 6.8 mm (95% CI 2.0-11.7 mm) and 7.2 mm (95% CI 3.1-11.3 mm) respectively in an adjusted regression model. SV motion did not differ between the ADT and non-ADT patients in terms of interfractional motion of the SV tips and the SVs’ center relative to the prostate gland. The ADT patients had significantly shorter SVs compared to the non-ADT patients, but no difference in SV motion was observed. SV interfractional motion should thus be compensated using the same planning margins, regardless of whether ADT is used

    Dose distribution of intensity-modulated proton therapy with and without a multi-leaf collimator for the treatment of maxillary sinus cancer: a comparative effectiveness study.

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    BACKGROUND: Severe complications, such as eye damage and dysfunciton of salivary glands, have been reported after radiotherapy among patients with head and neck cancer. Complications such as visual impairment have also been reported after proton therapy with pencil beam scanning (PBS). In the case of PBS, collimation can sharpen the penumbra towards surrounding normal tissue in the low energy region of the proton beam. In the current study, we examined how much the dose to the normal tissue was reduced by when intensity-modulated proton therapy (IMPT) was performed using a multi-leaf collimator (MLC) for patients with maxillary sinus cancer. METHODS: Computed tomography findings of 26 consecutive patients who received photon therapy at Okayama University Hospital were used in this study. We compared D2% of the region of interest (ROI; ROI-D2%) and the mean dose of ROI (ROI-mean) with and without the use of an MLC. The organs at risk (OARs) were the posterior retina, lacrimal gland, eyeball, and parotid gland. IMPT was performed for all patients. The spot size was approximately 5-6 mm at the isocenter. The collimator margin was calculated by enlarging the maximum outline of the target from the beam's eye view and setting the margin to 6 mm. All plans were optimized with the same parameters. RESULTS: The mean of ROI-D2% for the ipsilateral optic nerve was significantly reduced by 0.48 Gy, and the mean of ROI-mean for the ipsilateral optic nerve was significantly reduced by 1.04 Gy. The mean of ROI-mean to the optic chiasm was significantly reduced by 0.70 Gy. The dose to most OARs and the planning at risk volumes were also reduced. CONCLUSIONS: Compared with the plan involving IMPT without an MLC, in the dose plan involving IMPT using an MLC for maxillary sinus cancer, the dose to the optic nerve and optic chiasm were significantly reduced, as measured by the ROI-D2% and the ROI-mean. These findings demonstrate that the use of an MLC during IMPT for maxillary sinus cancer may be useful for preserving vision and preventing complications

    Investigation by Imaging Mass Spectrometry of Biomarker Candidates for Aging in the Hair Cortex

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    BACKGROUND: Human hair is one of the essential components that define appearance and is a useful source of samples for non-invasive biomonitoring. We describe a novel application of imaging mass spectrometry (IMS) of hair biomolecules for advanced molecular characterization and a better understanding of hair aging. As a cosmetic and biomedical application, molecules whose levels in hair altered with aging were comprehensively investigated. METHODS: Human hair was collected from 15 young (20±5 years old) and 15 older (50±5 years old) volunteers. Matrix-free laser desorption/ionization IMS was used to visualize molecular distribution in the hair sections. Hair-specific ions displaying a significant difference in the intensities between the 2 age groups were extracted as candidate markers for aging. Tissue localization of the molecules and alterations in their levels in the cortex and medulla in the young and old groups were determined. RESULTS: Among the 31 molecules detected specifically in hair sections, 2--one at m/z 153.00, tentatively assigned to be dihydrouracil, and the other at m/z 207.04, identified to be 3,4-dihydroxymandelic acid (DHMA)--exhibited a higher signal intensity in the young group than in the old, and 1 molecule at m/z 164.00, presumed to be O-phosphoethanolamine, displayed a higher intensity in the old group. Among the 3, putative O-phosphoethanolamine showed a cortex-specific distribution. The 3 molecules in cortex presented the same pattern of alteration in signal intensity with aging, whereas those in medulla did not exhibit significant alteration. CONCLUSION: Three molecules whose levels in hair altered with age were extracted. While they are all possible markers for aging, putative dihydrouracil and DHMA, are also suspected to play a role in maintaining hair properties and could be targets for cosmetic supplementation. Mapping of ion localization in hair by IMS is a powerful method to extract biomolecules in specified regions and determine their tissue distribution
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