Reconstruction of organ doses for patients undergoing computed tomography examinations in Canada 1992-2019.

We derived the first comprehensive organ dose library for Canadian pediatric and adult patients who underwent computed tomography (CT) scans between 1992 and 2019 to support epidemiological analysis of radiation risk. We calculated organ absorbed doses for Canadian CT patients in two steps. First, we modeled Computed Tomography Dose Index (CTDI) values by patient age, scan body part, and scan year for the scan period between 1992 and 2019 using national survey data conducted in Canada and partially the United Kingdom survey data as surrogates.

Association of cardiovascular disease management drugs with Lewy body dementia: a case-control study.

Lewy body dementia is the second most common neurodegenerative dementia after Alzheimer's disease. Disease-modifying therapies for this disabling neuropsychiatric condition are critically needed. To identify drugs associated with the risk of developing Lewy body dementia, we performed a population-based case-control study of 148 170 US Medicare participants diagnosed with Lewy body dementia between 1 January 2008 and 31 December 2014 and of 1 253 043 frequency-matched controls.

Assessment of Cataract Risk after Diagnostic Head CT Scan Radiation Exposure in Ontario, Canada.

Ionizing radiation is one of the known risk factors for cataract development, however, there is still debate regarding the level of risk after low dose exposures. One of the largest sources of radiation exposure to the lens of the eye is diagnostic CT scans. The aim of this study was to examine whether ionizing radiation associated with head CT scans increases cataract risk in residents of Ontario, Canada.

Parathyroidectomy and the Risk of Major Cerebrovascular and Cardiovascular Events in the Elderly.

Objective: We aimed to determine the incidence of major cardiovascular and cerebrovascular events in elderly patients with primary hyperparathyroidism (pHPT) and the impact of parathyroidectomy.

Summary Background Data: pHPT is underdiagnosed and undertreated in the United States. It is associated with increased cardiovascular disease risk, but its association with cerebrovascular disease risk is not well-established.

Use of paracrine factors from stem cells to treat local radiation burns in rats.

Background: Mesenchymal stem cells based paracrine bioactive factors that deploy their task as an essential mechanism, but their efficiency for skin regeneration still requires clarification.

Methods: The mesenchymal stem cell-based paracrine factors were administered by subcutaneous injection of 0.5 mL peptides (general protein 8 mg/mL).

ORGAN DOSE ESTIMATION ACCOUNTING FOR UNCERTAINTY FOR PEDIATRIC AND YOUNG ADULT CT SCANS IN THE UNITED KINGDOM.

Since our previous publication of organ dose for the pediatric CT cohort in the UK, there have been questions about the magnitude of uncertainty in our dose estimates. We therefore quantified shared and unshared uncertainties in empirical CT parameters extracted from 1073 CT films (1978-2008) from 36 hospitals in the study and propagated these uncertainties into organ doses using Monte Carlo random sampling and NCICT organ dose calculator. The average of 500 median brain and marrow doses for the full cohort was 35 (95% confidence interval: 30-40) mGy and 6 (5-7) mGy, respectively.

Correction of confidence intervals in excess relative risk models using Monte Carlo dosimetry systems with shared errors.

In epidemiological studies, exposures of interest are often measured with uncertainties, which may be independent or correlated. Independent errors can often be characterized relatively easily while correlated measurement errors have shared and hierarchical components that complicate the description of their structure. For some important studies, Monte Carlo dosimetry systems that provide multiple realizations of exposure estimates have been used to represent such complex error structures.

Organ Doses From Diagnostic Medical Radiography-Trends Over Eight Decades (1930 to 2010).

This study provides a retrospective assessment of doses to 13 organs for the most common radiographic examinations conducted between the 1930s and 2010, taking into account typical technical parameters used for radiography during those years. This study is intended to be a resource on changes in medical diagnostic radiation exposure over time with a specific purpose of supporting retrospective epidemiological studies of radiation health risks. The authors derived organ doses to the brain, esophagus, thyroid, red bone marrow, lungs, breast, heart, stomach, liver, colon, urinary bladder, ovaries, and testes based on 14 common radiographic procedures and compared, when possible, with doses reported in the literature.

Selective Liquid-Phase Hydrogenation of a Nitro Group in Substituted Nitrobenzenes over Au/Al O Catalyst in a Packed-Bed Flow Reactor.

A series of substituted nitrobenzenes with the general formula XC H NO (X=Cl, CH=CH , or C(O)CH ) dissolved in toluene were reduced with hydrogen over the 1.9 % Au/Al O catalyst at 60-110 °C and 10-20 bar in a three-phase packed-bed reactor operating in up-flow mode. Under these conditions, hydrogenation of isomeric ClC H NO gives exclusively chloroanilines.

NCICT: a computational solution to estimate organ doses for pediatric and adult patients undergoing CT scans.

We developed computational methods and tools to assess organ doses for pediatric and adult patients undergoing computed tomography (CT) examinations. We used the International Commission on Radiological Protection (ICRP) reference pediatric and adult phantoms combined with the Monte Carlo simulation of a reference CT scanner to establish comprehensive organ dose coefficients (DC), organ absorbed dose per unit volumetric CT Dose Index (CTDIvol) (mGy/mGy). We also developed methods to estimate organ doses with tube current modulation techniques and size specific dose estimates.

Organ Dose Estimates for Hyperthyroid Patients Treated with (131)I: An Update of the Thyrotoxicosis Follow-Up Study.

The Thyrotoxicosis Therapy Follow-up Study (TTFUS) is comprised of 35,593 hyperthyroid patients treated from the mid-1940s through the mid-1960s. One objective of the TTFUS was to evaluate the long-term effects of high-dose iodine-131 ((131)I) treatment (1-4). In the TTFUS cohort, 23,020 patients were treated with (131)I, including 21,536 patients with Graves disease (GD), 1,203 patients with toxic nodular goiter (TNG) and 281 patients with unknown disease.

Bayesian dose-response analysis for epidemiological studies with complex uncertainty in dose estimation.

Most conventional risk analysis methods rely on a single best estimate of exposure per person, which does not allow for adjustment for exposure-related uncertainty. Here, we propose a Bayesian model averaging method to properly quantify the relationship between radiation dose and disease outcomes by accounting for shared and unshared uncertainty in estimated dose. Our Bayesian risk analysis method utilizes multiple realizations of sets (vectors) of doses generated by a two-dimensional Monte Carlo simulation method that properly separates shared and unshared errors in dose estimation.

S values for 131I based on the ICRP adult voxel phantoms.

To improve the estimates of organ doses from nuclear medicine procedures using (131)I, the authors calculated a comprehensive set of (131)I S values, defined as absorbed doses in target tissues per unit of nuclear transition in source regions, for different source and target combinations. The authors used the latest reference adult male and female voxel phantoms published by the International Commission on Radiological Protection (ICRP Publication 110) and the (131)I photon and electron spectra from the ICRP Publication 107 to perform Monte Carlo radiation transport calculations using MCNPX2.7 to compute the S values.

[The effectiveness of molixan as a means of correction of chemoradiation therapy negative manifestations in patients with oropharyngeal cancer].

The effectiveness of the peptide immunomodulator molixan as a means of support and correction of chemoradiation therapy of oral mucositis have been studied in 36 patients with primary regional cancer of the oral mucosa and the oropharynx. Combined chemotherapy of patients with cisplatin and standard radiotherapy was associated with progression of oral mucositis and hematopoietic disorders which manifested themselves in the form of neutro-, lympho- and thrombocytopenia. Therapeutic intramuscular application of molixan at a dose of 60 mg once a day after a fraction of irradiation made it possible to reduce the severity of oral mucositis (from grade III-IV to grade I-II), as well as to maintain in patients a higher level of white blood cells and platelets in the blood, which made it possible to complete the planned course of chemoradiation therapy.

Accounting for shared and unshared dosimetric uncertainties in the dose response for ultrasound-detected thyroid nodules after exposure to radioactive fallout.

Dosimetic uncertainties, particularly those that are shared among subgroups of a study population, can bias, distort or reduce the slope or significance of a dose response. Exposure estimates in studies of health risks from environmental radiation exposures are generally highly uncertain and thus, susceptible to these methodological limitations. An analysis was published in 2008 concerning radiation-related thyroid nodule prevalence in a study population of 2,994 villagers under the age of 21 years old between August 1949 and September 1962 and who lived downwind from the Semipalatinsk Nuclear Test Site in Kazakhstan.

[Experimental model of severe local radiation injuries of the skin after X-rays].

The experimental model of severe local radiation injuries skin under the influence of a relatively soft X-rays on a modified device RAP 100-10 produced by "Diagnostica-M" (Russia) was proposed. The model can be used as pre-clinical studies in small experimental animals in order to improve the treatment of local radiation injuries, especially in the conditions of application of cellular therapy.

Incontinentia pigmenti in an XY boy: case report and review of the literature.

Background: Incontinentia pigmenti (IP) is a rare genetic skin disorder with X-linked dominant inheritance and a characteristic sequence of cutaneous manifestations, which is regarded as lethal in XY males.

Objective: To report a case of a surviving XY male with the common IKBKG (NEMO) gene deletion confirming IP.

Methods And Results: A newborn XY male with suspected IP underwent a skin biopsy on affected tissue for histopathology.

Evaluation of the use of surrogate tissues for calculating radiation dose to lymphatic nodes from external photon beams.

Lymphatic node chains of the human body are particularly difficult to realistically model in computational human phantoms. In the absence of a lymphatic node model, researchers have used the following surrogate tissues to calculate the radiation dose to the lymphatic nodes: blood vessels, muscle and the combination of the muscle and adipose tissues. In the present work, the authors investigated whether and in which extent the use of different surrogate tissues is appropriate to assess the lymph node dose, using a realistic model of lymphatic nodes that the authors recently reported.

A recurrent PDGFRB mutation causes familial infantile myofibromatosis.

Infantile myofibromatosis (IM) is the most common benign fibrous tumor of soft tissues affecting young children. By using whole-exome sequencing, RNA sequencing, and targeted sequencing, we investigated germline and tumor DNA in individuals from four distinct families with the familial form of IM and in five simplex IM cases with no previous family history of this disease. We identified a germline mutation c.

Computational lymphatic node models in pediatric and adult hybrid phantoms for radiation dosimetry.

We developed models of lymphatic nodes for six pediatric and two adult hybrid computational phantoms to calculate the lymphatic node dose estimates from external and internal radiation exposures. We derived the number of lymphatic nodes from the recommendations in International Commission on Radiological Protection (ICRP) Publications 23 and 89 at 16 cluster locations for the lymphatic nodes: extrathoracic, cervical, thoracic (upper and lower), breast (left and right), mesentery (left and right), axillary (left and right), cubital (left and right), inguinal (left and right) and popliteal (left and right), for different ages (newborn, 1-, 5-, 10-, 15-year-old and adult). We modeled each lymphatic node within the voxel format of the hybrid phantoms by assuming that all nodes have identical size derived from published data except narrow cluster sites.

[Experience of contemporary treatment of radiation burns in individuals subjected to ionizing radiation].

The article presents new approach to treatment of radiation disorders presenting as indolent ulcers. The approach is based on autologous multipotent mesenchimal stromal cells applied locally and injected around the injuried zone. The ulcers heal due to the fact that the transplanted cells stimulate local regeneration processes, angiogenesis, ceased inflammation and apoptosis.

Successful treatment of localised radiation lesions in rats and humans by mesenchymal stem cell transplantation.

Transplantation of mesenchymal stem cells (MSCs), at early and later stages after local exposure of rats to 140 Gy 90Sr/90Y beta radiation, was found to stimulate recovery of damaged skin. The area of local radiation injuries (LRIs) and accelerated healing of radiation ulcers was obtained. Clinical evolution showed the high efficiency of the transplantations of autologous MSCs for the treatment of deep beam ulcers, usually refractive to standard conservative treatment.

Cutaneous mastocytosis with atypical mast cells and giant cytoplasmic granules.

A 12-year-old male presented with an 8-year history of five firm cream colored papules on the right vertex of the scalp. A biopsy showed a dense infiltrate of monomorphous mast cells involving the dermis and extending into the subcutis. A relatively well-circumscribed cluster of larger cells showed pleomorphic nuclei with bilobed and multilobed morphology.

[Mesenchymal stem cells transplantation in the treatment of radiation skin lesions].

Transplantation of mesenchymal stem cells, both at early and later stage after local exposure of rats source beta radiation dose, 90Sr/90Y 140 GR, stimulates recovery of damaged skin. Diminution area local radiation injuries and accelerate healing radiation ulcers. Clinically shows the high efficiency of the transplantations autologous mesenchymal stem cells in treatment of deep beam ulcers, intractable standard conservative treatment.

Predictions of dispersion and deposition of fallout from nuclear testing using the NOAA-HYSPLIT meteorological model.

The NOAA Hybrid Single-Particle Lagrangian Integrated Trajectory Model (HYSPLIT) was evaluated as a research tool to simulate the dispersion and deposition of radioactive fallout from nuclear tests. Model-based estimates of fallout can be valuable for use in the reconstruction of past exposures from nuclear testing, particularly where little historical fallout monitoring data are available. The ability to make reliable predictions about fallout deposition could also have significant importance for nuclear events in the future.