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Radiation-Induced Brachial Plexopathy: MR and Clinical Findings  

Microsoft Academic Search

Summary: A 54-year-old man had a slowly progressive bilateral brachial plexopathy 17 months after surgery and radiation ther- apy for a stage IV supraglottic carcinoma. MR imaging at pre- sentation showed a symmetric pattern of parascalene and inter- scalene hyperintense signal on T2-weighted images and after contrast enhancement. Although hyperintense signal has been more often associated with recurrent tumor than

Brian C. Bowen; Ashok Verma; Alfred H. Brandon; Jeffery A. Fiedler


Brachial plexopathy  

PubMed Central

Brachial plexus injury can occur as a result of trauma, inflammation or malignancies, and associated complications. The current topic is concerned with various forms of brachial plexopathy, its clinical features, pathophysiology, imaging findings, and management. Idiopathic brachial neuritis (IBN), often preceded with antecedent events such as infection, commonly present with abruptonset painful asymmetric upper limb weakness with associated wasting around the shoulder girdle and arm muscles. Idiopathic hypertrophic brachial neuritis, a rare condition, is usually painless to begin with, unlike IBN. Hereditary neuralgic amyotrophy is an autosomal-dominant disorder characterized by repeated episodes of paralysis and sensory disturbances in an affected limb, which is preceded by severe pain. While the frequency of the episodes tends to decrease with age, affected individuals suffer from residual deficits. Neurogenic thoracic outlet syndrome affects the lower trunk of the brachial plexus. It is diagnosed on the basis of electrophysiology and is amenable to surgical intervention. Cancer-related brachial plexopathy may occur secondary to metastatic infiltration or radiation therapy. Traumatic brachial plexus injury is commonly encountered in neurology, orthopedic, and plastic surgery set-ups. Trauma may be a direct blow or traction or stretch injury. The prognosis depends on the extent and site of injury as well as the surgical expertise. PMID:23661957

Khadilkar, Satish V.; Khade, Snehaldatta S.



Radiation-induced brachial plexopathy: Neurological follow-up in 161 recurrence-free breast cancer patients  

SciTech Connect

The purpose was to assess the incidence and clinical manifestations of radiation-induced brachial plexopathy in breast cancer patients, treated according to the Danish Breast Cancer Cooperative Group protocols. One hundred and sixty-one recurrence-free breast cancer patients were examined for radiation-induced brachial plexopathy after a median follow-up period of 50 months (13-99 months). After total mastectomy and axillary node sampling, high-risk patients were randomized to adjuvant therapy. One hundred twenty-eight patients were treated with postoperative radiotherapy with 50 Gy in 25 daily fractions over 5 weeks. In addition, 82 of these patients received cytotoxic therapy (cyclophosphamide, methotrexate, and 5-fluorouracil) and 46 received tamoxifen. Five percent and 9% of the patients receiving radiotherapy had disabling and mild radiation-induced brachial plexopathy, respectively. Radiation-induced brachial plexopathy was more frequent in patients receiving cytotoxic therapy (p = 0.04) and in younger patients (p = 0.04). The clinical manifestations were paraesthesia (100%), hypaesthesia (74%), weakness (58%), decreased muscle stretch reflexes (47%), and pain (47%). The brachial plexus is more vulnerable to large fraction size. Fractions of 2 Gy or less are advisable. Cytotoxic therapy adds to the damaging effect of radiotherapy. Peripheral nerves in younger patients seems more vulnerable. Radiation-induced brachial plexopathy occurs mainly as diffuse damage to the brachial plexus. 24 refs., 9 tabs.

Olsen, N.K.; Pfeiffer, P.; Johannsen, L.; Schroder, H.; Rose, C. (Odense Univ. Hospital (Denmark))



Brachial plexopathy  


Neuropathy - brachial plexus; Brachial plexus dysfunction; Parsonage Turner syndrome; Pancoast syndrome ... inflammatory or postviral brachial plexus disease called Parsonage Turner syndrome. Tests that may be done to diagnose this ...


Dose Constraints to Prevent Radiation-Induced Brachial Plexopathy in Patients Treated for Lung Cancer  

SciTech Connect

Purpose: As the recommended radiation dose for non-small-cell lung cancer (NSCLC) increases, meeting dose constraints for critical structures like the brachial plexus becomes increasingly challenging, particularly for tumors in the superior sulcus. In this retrospective analysis, we compared dose-volume histogram information with the incidence of plexopathy to establish the maximum dose tolerated by the brachial plexus. Methods and Materials: We identified 90 patients with NSCLC treated with definitive chemoradiation from March 2007 through September 2010, who had received >55 Gy to the brachial plexus. We used a multiatlas segmentation method combined with deformable image registration to delineate the brachial plexus on the original planning CT scans and scored plexopathy according to Common Terminology Criteria for Adverse Events version 4.03. Results: Median radiation dose to the brachial plexus was 70 Gy (range, 56-87.5 Gy; 1.5-2.5 Gy/fraction). At a median follow-up time of 14.0 months, 14 patients (16%) had brachial plexopathy (8 patients [9%] had Grade 1, and 6 patients [7%] had Grade {>=}2); median time to symptom onset was 6.5 months (range, 1.4-37.4 months). On multivariate analysis, receipt of a median brachial plexus dose of >69 Gy (odds ratio [OR] 10.091; 95% confidence interval [CI], 1.512-67.331; p = 0.005), a maximum dose of >75 Gy to 2 cm{sup 3} of the brachial plexus (OR, 4.909; 95% CI, 0.966-24.952; p = 0.038), and the presence of plexopathy before irradiation (OR, 4.722; 95% CI, 1.267-17.606; p = 0.021) were independent predictors of brachial plexopathy. Conclusions: For lung cancers near the apical region, brachial plexopathy is a major concern for high-dose radiation therapy. We developed a computer-assisted image segmentation method that allows us to rapidly and consistently contour the brachial plexus and establish the dose limits to minimize the risk of brachial plexopathy. Our results could be used as a guideline in future prospective trials with high-dose radiation therapy for unresectable lung cancer.

Amini, Arya [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); University of California Irvine School of Medicine, Irvine, California (United States); Yang Jinzhong; Williamson, Ryan [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); McBurney, Michelle L. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Erasmus, Jeremy [Department of Diagnostic Imaging, University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Allen, Pamela K.; Karhade, Mandar; Komaki, Ritsuko; Liao, Zhongxing; Gomez, Daniel; Cox, James [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Dong, Lei [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Welsh, James, E-mail: [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States)



Lightning strike-induced brachial plexopathy.  


We describe a patient who presented with a history of lightning strike injury. Following the injury, he sustained acute right upper limb weakness with pain. Clinically, the lesion was located to the upper and middle trunk of the right brachial plexus, and the same confirmed with electrophysiological studies. Nerve damage due to lightning injuries is considered very rare, and a plexus damage has been described infrequently, if ever. Thus, the proposed hypothesis that lightning rarely causes neuropathy, as against high-voltage electric current, due to its shorter duration of exposure not causing severe burns which lead to nerve damage, needs to be reconsidered. PMID:25288846

Bhargava, Amita N; Kasundra, Gaurav M; Khichar, Subhakaran; Bhushan, Bharat S K



Lightning strike-induced brachial plexopathy  

PubMed Central

We describe a patient who presented with a history of lightning strike injury. Following the injury, he sustained acute right upper limb weakness with pain. Clinically, the lesion was located to the upper and middle trunk of the right brachial plexus, and the same confirmed with electrophysiological studies. Nerve damage due to lightning injuries is considered very rare, and a plexus damage has been described infrequently, if ever. Thus, the proposed hypothesis that lightning rarely causes neuropathy, as against high-voltage electric current, due to its shorter duration of exposure not causing severe burns which lead to nerve damage, needs to be reconsidered. PMID:25288846

Bhargava, Amita N.; Kasundra, Gaurav M.; Khichar, Subhakaran; Bhushan, Bharat S. K.



Une cause rare de plexopathie brachiale: une metastase d'un cancer du sein  

PubMed Central

Nous rapportons le cas d'une patiente de 50 ans ayant une histoire de cancer du sein et qui accuse une symptomatologie d'atteinte du plexus brachial. L'IRM montre une masse qui envahie le plexus brachial compatible avec une métastase. L'IRM est très utile pour le diagnostic et l'orientation thérapeutique des plexopathies brachiales chez les femmes présentant un cancer du sein

Maaroufi, Mustapha; Kamaoui, Imane; Boubbou, Meriem; Sqalli, Nadia; Tizniti, Siham



Emergency bedside sonographic diagnosis of subclavian artery pseudoaneurysm with brachial plexopathy after clavicle fracture.  


Clavicle fractures are common; however, complications are unusual. Two such complications, subclavian artery pseudoaneurysm and brachial plexopathy, are rare events that can cause significant morbidity and mortality. We report the case of a 53-year-old man who presented with shoulder swelling and right arm weakness for 1 week. Three weeks before, he had fallen and fractured his right clavicle. On presentation to our emergency department, his examination revealed a brachial plexopathy and a large supraclavicular mass. An emergency bedside triplex sonogram was performed to characterize the mass and revealed a swirling pattern within a fluid collection anterior to the subclavian artery, suggestive of a pseudoaneurysm. After computed tomography-angiography, the patient was taken to the operating room, where he underwent hematoma washout and subclavian artery stent-graft placement. This case illustrates how bedside point-of-care sonography can rapidly assist in the initial assessment of subclavian artery injury. PMID:22762908

Gullo, Jennifer; Singletary, E M; Larese, Shannon



Pictorial essay: Role of magnetic resonance imaging in evaluation of brachial plexus pathologies  

PubMed Central

Brachial plexopathies, traumatic and nontraumatic, often present with vague symptoms. Clinical examination and electrophysiological studies are useful but may not localize the lesion accurately. Magnetic resonance imaging (MRI) with its multiplanar imaging capability and soft tissue contrast resolution plays an important role in evaluation of the abnormal brachial plexus. PMID:23833427

Lawande, Malini; Patkar, Deepak P; Pungavkar, Sona



Infraclavicular brachial plexus injury following axillary regional block.  


Infraclavicular brachial plexopathy is a potential complication of axillary regional block. We retrospectively reviewed 13 such injuries and found the median nerve most often affected, followed by combined median and ulnar neuropathies, and then by various combinations involving the median, ulnar, radial, and musculocutaneous nerves. All were axon-loss in type and most were severe in degree electrophysiologically. The clinical and electrodiagnostic features of these injuries are strikingly similar to those sustained after axillary arteriography, which has been associated with the medial brachial fascial compartment (MBFC) syndrome. This syndrome is characterized by the evolution of neurologic deficits and pain following hematoma formation within a compartment of the upper arm. Thus, we believe that this mechanism underlies most nerve injuries that result from axillary angiography or axillary regional block. This has important treatment implications, as timely surgical intervention may lead to improved outcome. PMID:15221877

Tsao, Bryan E; Wilbourn, Asa J



Radiotherapy-induced lumbosacral plexopathy in a patient with cervical cancer: a case report and literature review  

PubMed Central

Radiotherapy-induced lumbosacral plexopathy in cervical cancer treatment is a very rare, but extremely serious complication. The clinical course is associated with severe bilateral lower leg pain, reduced sensation, different degrees of weakness, paresis or paralysis, and sometimes also urinary or fecal incontinence. Patient quality of life becomes significantly deteriorated. Escalating neurological disorders may make self-sufficient functioning impossible. Neurological symptoms, most often irreversible, may develop at different times after irradiation, even after more than 30 years. We present a case of neurological toxicity in a patient successfully treated for cervical cancer with pelvis and para-aortic lymph node irradiation and weekly cisplatin. Neurological symptoms developed a few weeks after completion of external irradiation, were gradually escalating and resulted in complete immobilization of the woman. We underline the significance of long-term, systematic physiotherapy and pharmacological therapy which has resulted in significant improvement of motion efficiency. The literature review concerns the questions of frequency, clinical course and mechanisms of radiation-induced plexopathy. PMID:23788877

Kosobucki, Radoslaw; Luczynska, Elzbieta; Bieda, Tomasz; Urbanski, Krzysztof



Unilateral brachial plexus injury as a complication of thoracoscopic sympathectomy for hyperhidrosis: a case report.  


Unilateral brachial plexus injury is a rare complication of thoracoscopic sympathectomy, which is generally considered to be a simple and safe procedure. We report on a 26-year-old man who developed weakness and numbness of the right arm after thoracoscopic sympathectomy for hyperhidrosis. Electromyographic study revealed evidence of denervation in the upper trunk of the right brachial plexus. A nerve conduction study on the right axillary nerve revealed a reduced compound muscle action potential amplitude at the right deltoid muscle. We suggest that this complication was caused by stretch and/or compression when the arm was hyperabducted during the operation. The outcome was excellent, with almost complete recovery 3 months later. The complication can be prevented by minimizing operation time and avoiding hyperabduction of the arm. The prognosis for postoperative brachial plexopathy is usually good with conservative management. PMID:13680580

Lee, Pei-Hsin; Hsieh, Lin-Fen; Hong, Chang-Zern



Use of intercostal nerves for different target neurotization in brachial plexus reconstruction  

PubMed Central

Intercostal nerve transfer is a valuable procedure in devastating plexopathies. Intercostal nerves are a very good choice for elbow flexion or extension and shoulder abduction when the intraplexus donor nerves are not available. The best results are obtained in obstetric brachial plexus palsy patients, when direct nerve transfer is performed within six months from the injury. Unlike the adult posttraumatic patients after median and ulnar nerve neurotization with intercostal nerves, almost all obstetric brachial plexus palsy patients achieve protective sensation in the hand and some of them achieve active wrist and finger flexion. Use in combination with proper muscles, intercostal nerve transfer can yield adequate power to the paretic upper limb. Reinnervation of native muscles (i.e., latissimus dorsi) should always be sought as they can successfully be transferred later on for further functional restoration. PMID:23878776

Lykissas, Marios G; Kostas-Agnantis, Ioannis P; Korompilias, Ananstasios V; Vekris, Marios D; Beris, Alexandros E



Radiation-induced pneumothorax  

SciTech Connect

Pneumothorax is an uncommon complication of radiation therapy to the chest. The proposed pathogenesis is radiation-induced fibrosis promoting subpleural bleb formation that ruptures resulting in pneumothorax. We report on two young patients with primary sarcomas without pulmonary metastases who developed spontaneous pneumothorax after irradiation. Neither patient had antecedent radiographic evidence of pulmonary fibrosis.

Epstein, D.M.; Littman, P.; Gefter, W.B.; Miller, W.T.; Raney, R.B. Jr.



Radiation Induced Genomic Instability  

PubMed Central

Radiation induced genomic instability can be observed in the progeny of irradiated cells multiple generations after irradiation of parental cells. The phenotype is well established both in vivo (Morgan 2003) and in vitro (Morgan 2003), and may be critical in radiation carcinogenesis (Little 2000, Huang et al. 2003). Instability can be induced by both the deposition of energy in irradiated cells as well as by signals transmitted by irradiated (targeted) cells to non-irradiated (non-targeted) cells (Kadhim et al. 1992, Lorimore et al. 1998). Thus both targeted and non-targeted cells can pass on the legacy of radiation to their progeny. However the radiation induced events and cellular processes that respond to both targeted and non-targeted radiation effects that lead to the unstable phenotype remain elusive. PMID:21556289

Morgan, William F.



Radiation-induced sarcoma  

Microsoft Academic Search

Opinion statement  Radiation-induced sarcomas can originate in either the irradiated bone or soft tissues. Most of these tumors are high-grade.\\u000a The most common histologic subtypes are malignant fibrous histiocytoma (MFH) and osteosarcoma, although other histologies\\u000a (eg, angiosarcoma, rhabdomyosarcoma) can occur. Tumor size and grade are the two most important prognostic factors for soft tissue\\u000a sarcomas, including those associated with radiation therapy.

Shreyaskumar R. Patel



Radiation-induced Fibrosarcoma  

PubMed Central

Six cases of fibrosarcoma arising in previously irradiated tissues are reported, out of a total of 220 cases of fibrosarcoma treated at Mount Vernon Hospital during the last 23 years. This rare occurrence may follow at any interval from 3 to 38 years after irradiation, usually after high dosage. Four of our six cases are known to have died of the disease. The literature regarding radiation-induced fibrosarcoma is reviewed and it is suggested that adequate excision or amputation may be curative, if undertaken early enough. ImagesFig. 5Figs. 6-8Figs. 9-11Figs. 1-4 PMID:5503597

Gane, N. F. C.; Lindup, Rhona; Strickland, P.; Bennett, M. H.



Radiation-Induced Bioradicals  

NASA Astrophysics Data System (ADS)

This chapter represents the second part of a review in which the production and application of radiation-induced radicals in biological matter are discussed. In part one the general aspects of the four stages (physical, physicochemical, chemical and biological) of interaction of radiation with matter in general and biological matter in particular, were discussed. Here an overview is presented of modem technologies and theoretical methods available for studying these radiation effects. The relevance is highlighted of electron paramagnetic resonance spectroscopy and quantum chemical calculations with respect to obtaining structural information on bioradicals, and a survey is given of the research studies in this field. We also discuss some basic aspects of modem accelerator technologies which can be used for creating radicals and we conclude with an overview of applications of radiation processing in biology and related fields such as biomedical and environmental engineering, food technology, medicine and pharmacy.

Lahorte, Philippe; Mondelaers, Wim


Radiation Induced Genomic Instability  

SciTech Connect

Radiation induced genomic instability can be observed in the progeny of irradiated cells multiple generations after irradiation of parental cells. The phenotype is well established both in vivo (Morgan 2003) and in vitro (Morgan 2003), and may be critical in radiation carcinogenesis (Little 2000, Huang et al. 2003). Instability can be induced by both the deposition of energy in irradiated cells as well as by signals transmitted by irradiated (targeted) cells to non-irradiated (non-targeted) cells (Kadhim et al. 1992, Lorimore et al. 1998). Thus both targeted and non-targeted cells can pass on the legacy of radiation to their progeny. However the radiation induced events and cellular processes that respond to both targeted and non-targeted radiation effects that lead to the unstable phenotype remain elusive. The cell system we have used to study radiation induced genomic instability utilizes human hamster GM10115 cells. These cells have a single copy of human chromosome 4 in a background of hamster chromosomes. Instability is evaluated in the clonal progeny of irradiated cells and a clone is considered unstable if it contains three or more metaphase sub-populations involving unique rearrangements of the human chromosome (Marder and Morgan 1993). Many of these unstable clones have been maintained in culture for many years and have been extensively characterized. As initially described by Clutton et al., (Clutton et al. 1996) many of our unstable clones exhibit persistently elevated levels of reactive oxygen species (Limoli et al. 2003), which appear to be due dysfunctional mitochondria (Kim et al. 2006, Kim et al. 2006). Interestingly, but perhaps not surprisingly, our unstable clones do not demonstrate a “mutator phenotype” (Limoli et al. 1997), but they do continue to rearrange their genomes for many years. The limiting factor with this system is the target – the human chromosome. While some clones demonstrate amplification of this chromosome and thus lend themselves to prolonged study, many tend to eliminate or rearrange the target chromosome until it is too small for further rearrangement. The observed frequency of induced instability by low and high linear-energy-transfer radiations greatly exceeds that observed for nuclear gene mutations at similar doses; hence, mutation of a gene or gene family is unlikely to be the initiating mechanism. Once initiated however, there is evidence in the GM10115 model system that it can be perpetuated over time by dicentric chromosome formation followed by bridge breakage fusion cycles (Marder and Morgan 1993), as well as recombinational events involving interstitial telomere like repeat sequences (Day et al. 1998). There is also increasing evidence that inflammatory type reactions (Lorimore et al. 2001, Lorimore and Wright 2003), presumably involving reactive oxygen and nitrogen species as well as cytokines and chemokines might be involved in driving the ustable phenotype (Liaikis et al. 2007, Hei et al. 2008). To this end there is very convincing evidence for such reactions being involved in another non-targeted effect associated with ionizing radiation, the bystander effect (Hei et al. 2008). Clearly the link between induced instability and bystander effects suggests common processes and inflammatory type reactions will likely be the subject of future investigation.

Morgan, William F.



Pelvic radiculopathies, lumbosacral plexopathies, and neuropathies in oncologic disease: a multidisciplinary approach to a diagnostic challenge  

PubMed Central

Abstract The purpose of this article is to familiarize the reader with the anatomy of the major pelvic nerves and the clinical features of associated lumbosacral plexopathies. To demonstrate this we illustrate several cases of malignant lumbosacral plexopathy on computed tomography, magnetic resonance imaging, and positron emission tomography/computed tomography. A new lumbosacral plexopathy in a patient with a prior history of abdominal or pelvic malignancy is usually of malignant etiology. Biopsies may be required to definitively differentiate tumour from posttreatment fibrosis, and in cases of inconclusive sampling or where biopsies are not possible, follow-up imaging may be necessary. In view of the complexity of clinical findings often confounded by a history of prior surgery and/or radiotherapy, a multidisciplinary approach between oncologists, neurologists, and radiologists is often required for what can be a diagnostic challenge. PMID:24433993

Berry, Jonathan; Nisbet, Angus; Bloomfield, David; Burkill, Guy



Radiation-induced intestinal inflammation  

PubMed Central

Radiation induces an important inflammatory response in the irradiated organs, characterized by leukocyte infiltration and vascular changes that are the main limiting factor in the application of this therapeutic modality for the treatment of cancer. Recently, a considerable investigative effort has been directed at determining the molecular mechanisms by which radiation induces leukocyte recruitment, in order to create strategies to prevent intestinal inflammatory damage. In these review, we consider current available evidence on the factors governing the process of leukocyte recruitment in irradiated organs, mainly derived from experimental studies, with special attention to adhesion molecules, and their value as therapeutic targets. PMID:17589918

Molla, Meritxell; Panes, Julian



Brachial artery injuries in children.  


Treatment of brachial artery injuries in children, particularly those resulting from supracondylar humeral fractures, is controversial when distal pulses are absent yet the hand remains warm and pink. This article presents a retrospective study of eight children, ages 3 to 13, who underwent brachial arterial exploration because of absent distal pulses following arm trauma. Absent pulses indicate diminished blood flow, and in all eight cases brachial artery obstruction or severance was confirmed at surgery. In four of the children, who presented with cold, devascularized hands as a result of posterior elbow dislocations, supracondylar humeral fracture, or dog bites, there is no debate regarding revascularization. The other four children, with type III supracondylar humerus fractures, had pulseless, pink hands as a result of brachial artery thrombosis or arterial tethering. Brachial artery flow was reestablished in all cases with return of distal pulses, and no vascular complications. The authors believe that artery exploration is indicated when distal pulses are not present. PMID:23628561

Snyder, Aaron; Crick, John C



Radiation-induced esophageal carcinoma  

Microsoft Academic Search

Radiation-induced carcinoma of the esophagus is rare and only 8 cases have been reported since 1957. This article presents 2 additional patients in whom esophageal carcinoma developed in segments previously exposed to large therapeutic doses of irradiation. The first patient had received 5,000 rads to her mediastinum and the second patient 3,200 rads to her neck region. The latent intervals

Elizabeth W. O'Connell; William B. Seaman; Gary G. Ghahremani



Radiation-induced genomic instability  

NASA Technical Reports Server (NTRS)

Quantitative assessment of the heritable somatic effects of ionizing radiation exposures has relied upon the assumption that radiation-induced lesions were 'fixed' in the DNA prior to the first postirradiation mitosis. Lesion conversion was thought to occur during the initial round of DNA replication or as a consequence of error-prone enzymatic processing of lesions. The standard experimental protocols for the assessment of a variety of radiation-induced endpoints (cell death, specific locus mutations, neoplastic transformation and chromosome aberrations) evaluate these various endpoints at a single snapshot in time. In contrast with the aforementioned approaches, some studies have specifically assessed radiation effects as a function of time following exposure. Evidence has accumulated in support of the hypothesis that radiation exposure induces a persistent destabilization of the genome. This instability has been observed as a delayed expression of lethal mutations, as an enhanced rate of accumulation of non-lethal heritable alterations, and as a progressive intraclonal chromosomal heterogeneity. The genetic controls and biochemical mechanisms underlying radiation-induced genomic instability have not yet been delineated. The aim is to integrate the accumulated evidence that suggests that radiation exposure has a persistent effect on the stability of the mammalian genome.

Kronenberg, A.



Radiation-induced cardiovascular effects  

NASA Astrophysics Data System (ADS)

Recent epidemiological studies indicate that exposure to ionising radiation enhances the risk of cardiovascular mortality and morbidity in a moderate but significant manner. Our goal is to identify molecular mechanisms involved in the pathogenesis of radiation-induced cardiovascular disease using cellular and mouse models. Two radiation targets are studied in detail: the vascular endothelium that plays a pivotal role in the regulation of cardiac function, and the myocardium, in particular damage to the cardiac mitochondria. Ionising radiation causes immediate and persistent alterations in several biological pathways in the endothelium in a dose- and dose-rate dependent manner. High acute and cumulative doses result in rapid, non-transient remodelling of the endothelial cytoskeleton, as well as increased lipid peroxidation and protein oxidation of the heart tissue, independent of whether exposure is local or total body. Proteomic and functional changes are observed in lipid metabolism, glycolysis, mitochondrial function (respiration, ROS production etc.), oxidative stress, cellular adhesion, and cellular structure. The transcriptional regulators Akt and PPAR alpha seem to play a central role in the radiation-response of the endothelium and myocardium, respectively. We have recently started co-operation with GSI in Darmstadt to study the effect of heavy ions on the endothelium. Our research will facilitate the identification of biomarkers associated with adverse cardiac effects of ionising radiation and may lead to the development of countermeasures against radiation-induced cardiac damage.

Tapio, Soile


Radiation-induced leiomyosarcoma of the oropharynx  

PubMed Central

Leiomyosarcoma is a malignant mesenchymal tumor originating from smooth muscle cells, which most frequently develops in the myometrium and in the gastro-intestinal tract. Reviewing the international literature, radiation-induced sarcoma arise in 0.035 to 0.2 % of all irradiated patients. Especially in the head and neck region, radiation-induced leiomyosarcoma is an extremely rare lesion. The authors report a case of a radiation-induced leiomyosarcoma of the tonsillar region of the oropharynx in a 51-year-old male patient, who had undergone radiation therapy of this region 38 years before. The lesion was treated by radical surgery. Diagnostic steps, histological presentation and therapy are described in detail and the literature concerning radiation induced malignancies in general as well as radiation induced leiomyosarcoma in particular is reviewed. The highlights of this case are an extremely uncommon location and a rare pathological entity of radiation induced malignancies. PMID:16925805

Pfeiffer, Jens; Boedeker, Carsten Christof; Ridder, Gerd Jurgen; Maier, Wolfgang; Kayser, Gian



Perineural tumor spread of bladder cancer causing lumbosacral plexopathy: an anatomic explanation.  


We present two cases of biopsy-proven neoplastic lumbosacral plexopathy from perineural spread of bladder cancer: one patient presented with predominantly sciatic nerve involvement and the second predominantly with obturator nerve involvement. These two patterns of perineural spread from bladder cancer were supported by imaging in our cases and solidified by review of the literature. Based on the innervation of the bladder, we provide an anatomic explanation for this observation. To our best knowledge, such an anatomic, mechanistic basis for perineural tumor spread in bladder cancer has not yet been described. PMID:25338118

Aghion, Daniel M; Capek, Stepan; Howe, Benjamin M; Hepel, Jaroslaw T; Sambandam, Sundaresan; Oyelese, Adeotounbo A; Spinner, Robert J



Radiation-induced moyamoya syndrome  

SciTech Connect

Purpose: The moyamoya syndrome is an uncommon late complication after radiotherapy (RT). Methods and Materials: A PubMed search of English-language articles, with radiation, radiotherapy, and moyamoya syndrome used as search key words, yielded 33 articles from 1967 to 2002. Results: The series included 54 patients with a median age at initial RT of 3.8 years (range, 0.4 to 47). Age at RT was less than 5 years in 56.3%, 5 to 10 years in 22.9%, 11 to 20 years in 8.3%, 21 to 30 years in 6.3%, 31 to 40 years in 2.1%, and 41 to 50 years in 4.2%. Fourteen of 54 patients (25.9%) were diagnosed with neurofibromatosis type 1 (NF-1). The most common tumor treated with RT was low-grade glioma in 37 tumors (68.5%) of which 29 were optic-pathway glioma. The average RT dose was 46.5 Gy (range, 22-120 Gy). For NF-1-positive patients, the average RT dose was 46.5 Gy, and for NF-1-negative patients, it was 58.1 Gy. The median latent period for development of moyamoya syndrome was 40 months after RT (range, 4-240). Radiation-induced moyamoya syndrome occurred in 27.7% of patients by 2 years, 53.2% of patients by 4 years, 74.5% of patients by 6 years, and 95.7% of patients by 12 years after RT. Conclusions: Patients who received RT to the parasellar region at a young age (<5 years) are the most susceptible to moyamoya syndrome. The incidence for moyamoya syndrome continues to increase with time, with half of cases occurring within 4 years of RT and 95% of cases occurring within 12 years. Patients with NF-1 have a lower radiation-dose threshold for development of moyamoya syndrome.

Desai, Snehal S. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, Houston, TX (United States); Paulino, Arnold C. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, Houston, TX (United States)]. E-mail:; Mai, Wei Y. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, Houston, TX (United States); Teh, Bin S. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, Houston, TX (United States)



Radiation-Induced Grafting on Polyamides.  

National Technical Information Service (NTIS)

The objective of the project was to investigate radiation-induced grafting on polyamides, with emphasis on fluorine-containg vinyl monomers. The principal experimental technique was the gamma ray irradiation of polyamide film samples immersed in suitable ...

J. E. Wilson



Radiation-induced accelerated coronary arteriosclerosis  

SciTech Connect

There is a paucity of information on radiation-induced coronary heart disease. A young patient with myocardial infarction following mediastinal irradiation is described. The role of radiotherapy and chemotherapy on the subsequent development of coronary heart disease is discussed.

Mittal, B.; Deutsch, M.; Thompson, M.; Dameshek, H.L.



Ultrasound-Guided Supraclavicular Brachial Plexus Block  

Microsoft Academic Search

In this study, we evaluated state-of-the-art ultrasound technology for supraclavicular brachial plexus blocks in 40 outpatients. Ultrasound imaging was used to identify the brachial plexus before the block, guide the block needle to reach target nerves, and visualize the pattern of local anesthetic spread. Needle position was further confirmed by nerve stimulation before injec- tion. The block technique we describe

Vincent W. S. Chan; Anahi Perlas; Regan Rawson; Olusegun Odukoya



MR imaging of the brachial plexus.  


Continuous improvements in magnetic resonance scanner, coil, and pulse sequence technology have resulted in the ability to perform routine, high-quality imaging of the brachial plexus. With knowledge of the anatomy of the plexus, and a familiarity with common pathologic conditions affecting this area, radiologists can provide valuable imaging evaluation of patients with brachial plexus pathologies. PMID:24210315

Lutz, Amelie M; Gold, Garry; Beaulieu, Christopher



Diagnosis of brachial root and plexus lesions  

Microsoft Academic Search

The diagnosis and management of lesions of the brachial roots and of the brachial plexus is improved by appropriate investigation, both in acute and chronic disorders. The choice of investigation should be determined by the clinical problem. Since they are relatively non-invasive, electrophysiological investigations are particularly useful. In this review the role of these investigations is considered in relation to

M. Swash



Radiation-induced changes in bone.  


Radiation therapy has important applications in curative, adjuvant, and palliative therapy for a wide range of malignant conditions. Evidence of radiation therapy may be seen on radiologic images obtained subsequent to therapy. Bone growth disturbances may be observed in the immature axial or appendicular skeleton. Complications in the mature skeleton include osteoradionecrosis, pathologic fracture, and radiation-induced neoplasms. Radiologic features of mandibular osteoradionecrosis include ill-defined cortical destruction without sequestration. In osteoradionecrosis of the ribs, clavicle, scapula, and humerus, radiography may demonstrate osteopenia, disorganization and coarsening of trabecular architecture, and cortical irregularity; computed tomography more clearly depicts subtle fractures, alterations in bone architecture, and dystrophic soft-tissue calcification. In osteoradionecrosis of the spine, hematopoietic cellular elements of the spinal marrow are replaced with fat, which has high signal intensity on T1-weighted magnetic resonance images and intermediate signal intensity on T2-weighted images. Radiation-induced changes in the pelvis include osteopenia, increased bone density, and widening and irregularity of the sacroiliac joints. Radiation-induced osteochondromas are radiographically identical to those that arise spontaneously. Radiographic findings in radiation-induced sarcoma demonstrate an aggressive pattern of bone destruction. Awareness of the varied radiographic manifestations of radiation-induced changes in bone and correlation with clinical features and the radiation field will usually allow distinction of these changes from those associated with other pathologic conditions. PMID:9747611

Mitchell, M J; Logan, P M



Radiation Dose to the Brachial Plexus in Head-and-Neck Intensity-Modulated Radiation Therapy and Its Relationship to Tumor and Nodal Stage  

SciTech Connect

Purpose: The purpose of this retrospective study was to determine tumor factors contributing to brachial plexus (BP) dose in head-and-neck cancer (HNC) patients treated with intensity-modulated radiotherapy (IMRT) when the BP is routinely contoured as an organ at risk (OAR) for IMRT optimization. Methods and Materials: From 2004 to 2011, a total of 114 HNC patients underwent IMRT to a total dose of 69.96 Gy in 33 fractions, with the right and left BP prospectively contoured as separate OARs in 111 patients and the ipsilateral BP contoured in 3 patients (total, 225 BP). Staging category T4 and N2/3 disease were present in 34 (29.8%) and 74 (64.9%) patients, respectively. During IMRT optimization, the intent was to keep the maximum BP dose to {<=}60 Gy, but prioritizing tumor coverage over achieving the BP constraints. BP dose parameters were compared with tumor and nodal stage. Results: With a median follow-up of 16.2 months, 43 (37.7%) patients had {>=}24 months of follow-up with no brachial plexopathy reported. Mean BP volume was 8.2 {+-} 4.5 cm{sup 3}. Mean BP maximum dose was 58.1 {+-} 12.2 Gy, and BP mean dose was 42.2 {+-} 11.3 Gy. The BP maximum dose was {<=}60, {<=}66, and {<=}70 Gy in 122 (54.2%), 185 (82.2%), and 203 (90.2%) BP, respectively. For oropharynx, hypopharynx, and larynx sites, the mean BP maximum dose was 58.4 Gy and 63.4 Gy in T0-3 and T4 disease, respectively (p = 0.002). Mean BP maximum dose with N0/1 and N2/3 disease was 52.8 Gy and 60.9 Gy, respectively (p < 0.0001). Conclusions: In head-and-neck IMRT, dose constraints for the BP are difficult to achieve to {<=}60 to 66 Gy with T4 disease of the larynx, hypopharynx, and oropharynx or N2/3 disease. The risk of brachial plexopathy is likely very small in HNC patients undergoing IMRT, although longer follow-up is required.

Truong, Minh Tam, E-mail: [Department of Radiation Oncology, Boston Medical Center and Boston University School of Medicine, Boston, MA (United States); Romesser, Paul B.; Qureshi, Muhammad M.; Kovalchuk, Nataliya; Orlina, Lawrence; Willins, John [Department of Radiation Oncology, Boston Medical Center and Boston University School of Medicine, Boston, MA (United States)] [Department of Radiation Oncology, Boston Medical Center and Boston University School of Medicine, Boston, MA (United States)



Brachial plexus anatomy: normal and variant.  


Effective brachial plexus blockade requires a thorough understanding of the anatomy of the plexus, as well as an appreciation of anatomic variations that may occur. This review summarizes relevant anatomy of the plexus, along with variations and anomalies that may affect nerve blocks conducted at these levels. The Medline, Cochrane Library, and PubMed electronic databases were searched in order to compile reports related to the anatomy of the brachial plexus using the following free terms: "brachial plexus", "median nerve", "ulnar nerve", "radial nerve", "axillary nerve", and "musculocutanous nerve". Each of these was then paired with the MESH terms "anatomy", "nerve block", "anomaly", "variation", and "ultrasound". Resulting articles were hand searched for additional relevant literature. A total of 68 searches were conducted, with a total of 377 possible articles for inclusion. Of these, 57 were found to provide substantive information for this review. The normal anatomy of the brachial plexus is briefly reviewed, with an emphasis on those features revealed by use of imaging technologies. Anomalies of the anatomy that might affect the conduct of the various brachial plexus blocks are noted. Brachial plexus blockade has been effectively utilized as a component of anesthesia for upper extremity surgery for a century. Over that period, our understanding of anatomy and its variations has improved significantly. The ability to explore anatomy at the bedside, with real-time ultrasonography, has improved our appreciation of brachial plexus anatomy as well. PMID:19412559

Orebaugh, Steven L; Williams, Brian A



Renaissance of supraclavicular brachial plexus block.  


Due to frequent complications, especially pneumothorax, supraclavicular brachial plexus block became less popular. Ultrasonography is a very powerful tool in modern medicine and a real milestone in regional anaesthesia. Ultrasound- guided supraclavicular brachial plexus block reduces the probability of major complications occurrence (like pneumothorax, Horner's syndrome, phrenic nerve palsy). In this review we present the usefulness of ultrasonographic imaging and how to perform efficient ultrasound-guided blockade safely. PMID:24643926

Sadowski, Marek; Tu?aza, Bernadeta; Lysenko, Lidia



Management of brachial artery aneurisms in infants  

Microsoft Academic Search

Brachial artery aneurisms in children under 1 year of age are very rare. The main risk is distal ischaemic complication. We\\u000a report four infants suffering from brachial artery aneurism of unknown origin. In all cases we used Doppler ultrasonography\\u000a to validate the clinical diagnosis. Pre-operative vascular check-up was negative for other aneurismal location. Surgical excision\\u000a with direct end-to-end anastomosis was

Olivier N. Pagès; Francesca Alicchio; Boris Keren; Saidou Diallo; Francis Lefebvre; Jean S. Valla; Marie L. Poli-Merol



Brachial Plexus Injuries Peripheral Nerve Injuries  

Microsoft Academic Search

\\u000a Evolving microsurgical techniques have significantly changed our attitude to surgical reconstruction of peripheral nerve lesions,\\u000a including those of the brachial plexus. However, because of the considerable distance the nerves have to regenerate after\\u000a restoring anatomical continuity in the brachial plexus, the results in adults have been modest, despite the more sophisticated\\u000a methods available. In contrast, similar methods in children give

Alain L. Gilbert; Rolfe Birch


MR imaging of the brachial plexus  

Microsoft Academic Search

In this retrospective study we describe the MR imaging findings in 230 consecutive patients with suspected pathology in or near the brachial plexus. These patients were\\u000astudied from 1991 through to 1996.\\u000aChapter 2 describes the anatomy and the MR imaging techniques. As the anatomy\\u000aof the brachial plexus and the related structures is quite complicated, we eventually\\u000ause as

Hendrik Wouter van Es



[Transgenerational transmission of radiation induced genomic instability].  


Stability of genome is one of the evolutionary important trait of cells. Various mutations (gene, chromosomal, genomic) as well as artificial manipulations with genomes (inbreeding, DNA transfection, introduction of Br-DU in DNA) cause the genetic instability. Ionizing radiation is known as the factor which induced instability of genome in late mitotic descendants of cells after in vitro and in vivo exposure. Radiation induced genetic instability can be transmitted through germline cells. On the cell level both types of radiation induced genomic instability are manifested in elevated frequency of mutations, chromosome aberrations, micronuclei, increased radiosensitivity, disappearance of adaptive response, changes in gene expression. In studies of 1970-1980 years clear evidences on the different morphological and functional injuries in tissues of irradiated organisms as well as in tissues of the progeny of exposed parents were obtained. On the organism level the instability of mitotic and of meiotic progeny of irradiated cells is resulted in increased risk of cancer and of other somatic diseases. It seems to be useful to review the earlier radiobiology literature where delayed and transgenerational effects of ionizing radiation on tissues and on organisms level were clearly shown in animals. For the estimation of pathogenic role of radiation induced genomic instability in humans, particularly in children of exposed parents the parallel study of the same human cohorts using clinical parameters and various characteristic of genomic instability seems to be very important. PMID:17020095

Vorobtsova, I E



Quercetin inhibits radiation-induced skin fibrosis.  


Radiation induced fibrosis of the skin is a late toxicity that may result in loss of function due to reduced range of motion and pain. The current study sought to determine if oral delivery of quercetin mitigates radiation-induced cutaneous injury. Female C3H/HeN mice were fed control chow or quercetin-formulated chow (1% by weight). The right hind leg was exposed to 35 Gy of X rays and the mice were followed serially to assess acute toxicity and hind leg extension. Tissue samples were collected for assessment of soluble collagen and tissue cytokines. Human and murine fibroblasts were subjected to clonogenic assays to determine the effects of quercetin on radiation response. Contractility of fibroblasts was assessed with a collagen contraction assay in the presence or absence of quercetin and transforming growth factor-? (TGF-?). Western blotting of proteins involved in fibroblast contractility and TGF-? signaling were performed. Quercetin treatment significantly reduced hind limb contracture, collagen accumulation and expression of TGF-? in irradiated skin. Quercetin had no effect on the radioresponse of fibroblasts or murine tumors, but was capable of reducing the contractility of fibroblasts in response to TGF-?, an effect that correlated with partial stabilization of phosphorylated cofilin. Quercetin is capable of mitigating radiation induced skin fibrosis and should be further explored as a therapy for radiation fibrosis. PMID:23819596

Horton, Jason A; Li, Fei; Chung, Eun Joo; Hudak, Kathryn; White, Ayla; Krausz, Kristopher; Gonzalez, Frank; Citrin, Deborah



Delayed brachial plexus paralysis due to subclavian after clavicular fracture  

Microsoft Academic Search

Injuries to the brachial plexus and subclavian artery are serious complications of shoulder girdle trauma. Due to the close anatomical relationship between the brachial plexus and the subclavian artery in the thoracic outlet, both structures are often simultaneously involved in shoulder girdle injuries. Isolated lesions of the subclavian artery or the brachial plexus can also occur, especially with clavicular fractures.

B. Hansky; E. Murray; K. Minami; R. Kiirfer


Magnetic Resonance Neurography Diagnosed Brachial Plexitis: A Case Report  

Microsoft Academic Search

Sarikaya S, Sumer M, Özdolap S, Erdem CZ. Magnetic resonance neurography diagnosed brachial plexitis: a case report.Idiopathic brachial plexitis is a rare disorder presenting with pain and weakness in the shoulder girdle and upper extremity. Idiopathic brachial plexitis can mimic other conditions that cause acute pain and weakness around the shoulder, and its diagnosis can be challenging. There is no

Selda Sarikaya; Murat Sumer; ?enay Özdolap; C. Zuhal Erdem



Radiation-induced intracranial malignant gliomas  

SciTech Connect

The authors present seven cases of malignant gliomas that occurred after radiation therapy administered for diseases different from the subsequent glial tumor. Included among these seven are three patients who were treated with interstitial brachytherapy. Previously reported cases of radiation-induced glioma are reviewed and analyzed for common characteristics. Children receiving central nervous system irradiation appear particularly susceptible to induction of malignant gliomas by radiation. Interstitial brachytherapy may be used successfully instead of external beam radiotherapy in previously irradiated, tumor-free brain, and thus may reduce the risk of radiation necrosis. 31 references.

Shapiro, S.; Mealey, J. Jr.; Sartorius, C.



Radiation-induced injury of the esophagus  

SciTech Connect

Forty patients with functional or morphologic esophageal abnormalities following radiotherapy were identified. Abnormalities included abnormal motility with and without mucosal edema, stricture, ulceration and pseudodiverticulum, and fistula. Abnormal motility occurred 4 to 12 weeks following radiotherapy alone and as early as 1 week after therapy when concomitant chemotherapy had been given. Strictures developed 4 to 8 months following completion of radiotherapy. Ulceration, pseudodiverticulum, and fistula formation did not develop in a uniform time frame. Radiation-induced esophageal injury is more frequent when radiotherapy and chemotherapy are combined than it is with radiotherapy alone.

Lepke, R.A.; Libshitz, H.I.



Radiation-Induced Esophagitis Exacerbated by Everolimus  

PubMed Central

Background Everolimus, a potent mammalian target of rapamycin (mTOR) inhibitor, has shown anticancer activity against various types of cancer, including renal cell carcinoma (RCC); however, little information is available on the efficacy and safety of the combination of everolimus and radiotherapy. We report a case of radiation-induced esophagitis that might have been exacerbated by the sequential administration of everolimus. Case Presentation A 63-year-old Japanese man with RCC complained of back pain, and magnetic resonance imaging revealed vertebral metastases. He received radiotherapy (30 Gy/10 fractions) to the T6–10 vertebrae. Everolimus was administered immediately after the completion of radiotherapy. One week later, he complained of dysphagia, nausea and vomiting. An endoscopic examination of the esophagus showed erosive esophagitis in the middle to lower portions of his thoracic esophagus, corresponding to the irradiation field. Conclusion Clinicians should be aware that everolimus might lead to the unexpected exacerbation of radiation toxicities. PMID:23898276

Miura, Yuji; Suyama, Koichi; Shimomura, Akihiko; Miyakawa, Jimpei; Kobayashi, Hiroki; Uki, Akiyoshi; Okaneya, Toshikazu; Takano, Toshimi



Radiation-induced electron migration along DNA  

SciTech Connect

Radiation-induced electron migration along DNA is a mechanism by which randomly produced stochastic energy deposition events can lead to nonrandom types of damage along DNA manifested distal to the sites of the initial energy deposition. Electron migration along DNA is significantly influenced by the DNA base sequence and DNA conformation. Migration along 7 base pairs in oligonucleotides containing guanine bases was observed for oligonucleotides irradiated in solution which compares to average migration distances of 6 to 10 bases for Escherichia coli DNA irradiated in solution and 5.5 base pairs for Escherichia coli DNA irradiated in cells. Evidence also suggests that electron migration can occur preferentially in the 5{prime} to 3{prime} direction along DNA. Our continued efforts will provide information regarding the contribution of electron transfer along DNA to formation of locally multiply damaged sites created in DNA by exposure to ionizing radiation.

Fuciarelli, A.F.; Sisk, E.C.; Miller, J.H. [Pacific Northwest Lab., Richland, WA (United States); Zimbrick, J.D. [National Research Council, Washington, DC (United States)



Radiation induced carcinoma of the larynx  

SciTech Connect

A squamous cell carcinoma presented in a 20 year old female nonsmoker three years after receiving a high dosage of radiation therapy to the base of the skull, face and entire neuroaxis and intense combination chemotherapy for a parameningeal rhabdomyosarcoma of the paranasal sinuses is reported. The larynx received a dose of about 3,500 rads over an eight week period. This dosage in conjunction with the associated intense chemotherapy regimen given to the patient may explain the appearance of a radiation induced tumor in an unusually short latent period. This certainly represents a risk in young patients in whom an aggressive combined approach is taken and the physician should be aware of.

Amendola, B.E.; Amendola, M.A.; McClatchey, K.D.



Radiation-induced mutation at minisatellite loci  

SciTech Connect

We are studying the radiation-induced increase of mutation rate in minisatellite loci in mice and humans. Minisatellite mutations were scored by multilocus DNA fingerprint analysis in the progeny of {gamma}-irradiated and non-irradiated mice. The frequency of mutation in offspring of irradiated males was 1.7 higher that in the control group. Germline mutation at human minisatellite loci was studied among children born in heavily polluted areas of the Mogilev district of Belarus after the Chernobyl accident and in a control population. The frequency of mutation assayed both by DNA fingerprinting and by eight single locus probes was found to be two times higher in the exposed families than in the control group. Furthermore, mutation rate was correlated with the parental radiation dose for chronic exposure {sup 137}Cs, consistent with radiation-induction of germline mutation. The potential use of minisatellites in monitoring germline mutation in humans will be discussed.

Dubrova, Y.E. [Univ. of Leicester (United Kingdom)]|[Vavilov Institute of General Genetics, Moscow (Russian Federation); Nesterov, V.N.; Krouchinsky, N.G. [Research Institute for Radiation Medicine, Mogilev (Belarus)] [and others



Radiation Induced Surface Activity Phenomenon: 2. Report - Radiation Induced Boiling Enhancement  

SciTech Connect

To delineate the effect of Radiation Induced Surface Activity (RISA) on boiling phenomenon, surface wettability in high-temperature environment or Leidenfrost condition and critical heat flux (CHF) of oxide metals irradiated by gamma rays were investigated. When the temperature of the heating surface reaches the wetting limit temperature, water-solid contact vanishes because of a stable vapor film between the droplet and the metal surface, i.e., a Leidenfrost condition. The wetting limit temperature increased with integrated irradiation dose. The CHF of oxidized titanium was improved up to 100% after 800 kGy {sup 60}Co gamma ray irradiated. Radiation Induced Boiling Enhancement (RIBE) phenomenon was firstly confirmed through the experiments. (authors)

Tatsuya Koga; Yasuyuki Imai; Tomoji Takamasa [Tokyo University of Mercantile Marine, 2-1-6 Etchu-jima, Koto-Ku, Tokyo 135-8533 (Japan); Koji Okamoto [University of Tokyo (Japan); Kaichiro Mishima [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan)



Clinical and dosimetric factors of radiation-induced esophageal injury: Radiation-induced esophageal toxicity  

Microsoft Academic Search

Abstract Abstract Abstract Abstract AIM: To analyze the clinical and dosimetric predictive factors for radiation-induced esophageal injury in patients with non-small-cell lung cancer (NSCLC) during three- dimensional conformal radiotherapy (3D-CRT). METHODS: We retrospectively analyzed 208 consecutive patients (146 men and 62 women) with NSCLC treated with 3D-CRT. The median age of the patients was 64 years (range 35-87 years). The

Wen-Bo Qiao; Yan-Hui Zhao; Yan-Bin Zhao; Rui-Zhi Wang


Theory Of Radiation-Induced Attenuation In Optical Fibers  

NASA Technical Reports Server (NTRS)

Improved theory of radiation-induced attenuation of light in optical fibers accounts for effects of dose rates. Based on kinetic aspects of fundamental physics of color centers induced in optical fibers by radiation. Induced attenuation is proportional to density of color centers, and part of this density decays by thermal-annealing/recombination process after irradiation.

Liu, Tsuen-Hsi; Johnston, Alan R.



Radiation-induced osteosarcoma of the sphenoid bone  

Microsoft Academic Search

The case of a patient who developed osteosarcoma in the sphenoid bone 15 years after radiation therapy for a craniopharyngioma is reported. Radiation-induced osteosarcoma of the sphenoid bone has not been reported previously. Reported cases of radiation-induced osteosarcomas are reviewed.

S. Tanaka; S. Nishio; T. Morioka; M. Fukui; K. Kitamura; K. Hikita



Countermeasures for Space Radiation Induced Malignancies and Acute Biological Effects  

Microsoft Academic Search

The hypothesis being evaluated in this research program is that control of radiation induced oxidative stress will reduce the risk of radiation induced adverse biological effects occurring as a result of exposure to the types of radiation encountered during space travel. As part of this grant work, we have evaluated the protective effects of several antioxidants and dietary supplements and

Ann Kennedy



Absence of upper trunk of the brachial plexus.  


The brachial plexus is a complicated plexus supplying the upper limb. The brachial plexus is of great practical importance to the surgeon. It is encountered during operations upon the root of the neck, and hence it is in danger. Variations in the formation of the brachial plexus are common; and knowledge of the variation of the brachial plexus may be useful for surgeons, for improved guidance during supraclavicular block procedures, and for surgical approaches for brachial plexus. Here we report a case in which the superior trunk of the brachial plexus was found to be absent on the right side during a study on the cadaver-neck specimens in the Department of Anatomy. PMID:23776793

Adam, Ali H; Mohammed, Ammar M A; Grebballa, Abbas; Rizig, Sahar



Radiation-induced cancer: a modern view  

PubMed Central

Diagnostic medical radiation has been the most rapidly increasing component of population background radiation exposure in Western countries over the past decade. This trend is set to increase as CT scanning is readily available with burgeoning use in everyday clinical practice. Consequently, the issue of cancer induction from the doses received during diagnostic medical exposures is highly relevant. In this review we explain current understanding of potential cancer induction at low doses of sparsely ionising radiation. For cancers that may be induced at low doses, a mechanistic description of radiation-induced cancer is discussed, which, in combination with extrapolation of data based on population cohort studies, provides the basis of the currently accepted linear no-threshold model. We explore the assumptions made in deriving risk estimates, the controversies surrounding the linear no-threshold model and the potential future challenges facing clinicians and policy-makers with regards to diagnostic medical radiation and cancer risk, most notably the uncertainties regarding deriving risk estimates from epidemiological data at low doses. PMID:23175483

Shah, D J; Sachs, R K; Wilson, D J



Brachial plexus block in a parturient.  


We report a novel circumstance of brachial plexus anesthesia in a parturient. A 25-year-old woman at 34 weeks of gestation presented with a pathologic proximal right humerus fracture from an intramedullary mass. She was scheduled for tumor biopsy which was performed using a two-site ultrasound-guided brachial plexus block to maximize odds of complete anesthesia while minimizing the risk of phrenic nerve paresis. After a supraclavicular block with 0.5% ropivacaine 20 mL, we translated our ultrasound probe cephalad, inferior to the root of C7 where the divisions of the superior trunk could be seen in a tightly compact arrangement. An additional injection of 0.5% ropivacaine 20 mL was administered at this site, and the patient subsequently underwent successful biopsy without sedatives or analgesics, aside from local anesthetics. In the post-anesthesia care unit, she had normal respirations and oxygen saturations breathing room air, denied any shortness of breath or difficulty breathing, and was discharged shortly after her arrival. While we did not pursue radiologic examination to rule out hemidiaphragm paralysis, we assumed, as evidenced in a previous case report, that unlike most healthy patients, a parturient would demonstrate some clinical signs and/or symptoms of hemidiaphragm paralysis, given that the diaphragm is almost totally responsible for inspiration in the term parturient. This represents only the second brachial plexus block in a parturient reported in the literature; the first using ultrasound guidance and without respiratory embarrassment. PMID:24631059

Patzkowski, M; Scheiner, J



Delayed Radiation-Induced Vasculitic Leukoencephalopathy  

SciTech Connect

Purpose: Recently, single-fraction, high-dosed focused radiation therapy such as that administered by Gamma Knife radiosurgery has been used increasingly for the treatment of metastatic brain cancer. Radiation therapy to the brain can cause delayed leukoencephalopathy, which carries its own significant morbidity and mortality. While radiosurgery-induced leukoencephalopathy is known to be clinically different from that following fractionated radiation, pathological differences are not well characterized. In this study, we aimed to integrate novel radiographic and histopathologic observations to gain a conceptual understanding of radiosurgery-induced leukoencephalopathy. Methods and Materials: We examined resected tissues of 10 patients treated at Yale New Haven Hospital between January 1, 2009, and June 30, 2010, for brain metastases that had been previously treated with Gamma Knife radiosurgery, who subsequently required surgical management of a symptomatic regrowing lesion. None of the patients showed pathological evidence of tumor recurrence. Clinical and magnetic resonance imaging data for each of the 10 patients were then studied retrospectively. Results: We provide evidence to show that radiosurgery-induced leukoencephalopathy may present as an advancing process that extends beyond the original high-dose radiation field. Neuropathologic examination of the resected tissue revealed traditionally known leukoencephalopathic changes including demyelination, coagulation necrosis, and vascular sclerosis. Unexpectedly, small and medium-sized vessels revealed transmural T-cell infiltration indicative of active vasculitis. Conclusions: We propose that the presence of a vasculitic component in association with radiation-induced leukoencephalopathy may facilitate the progressive nature of the condition. It may also explain the resemblance of delayed leukoencephalopathy with recurring tumor on virtually all imaging modalities used for posttreatment follow-up.

Rauch, Philipp J. [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States); Faculty of Medicine, University of Heidelberg, Heidelberg (Germany); Park, Henry S. [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States); Knisely, Jonathan P.S. [Department of Radiation Medicine, North Shore University Hospital, Manhasset, New York (United States); Chiang, Veronica L. [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States); Vortmeyer, Alexander O., E-mail: [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States)



Treatment of radiation-induced cystitis with hyperbaric oxygen  

SciTech Connect

The effects of hyperbaric oxygen on radiation cystitis have been documented in 3 patients with radiation-induced hemorrhagic cystitis refractory to conventional therapy. Cessation of gross hematuria and reversal of cystoscopic bladder changes were seen in response to a series of hyperbaric oxygen treatments of 2 atmosphere absolute pressure for 2 hours. To our knowledge this is the first report of cystoscopically documented healing of radiation-induced bladder injury.

Weiss, J.P.; Boland, F.P.; Mori, H.; Gallagher, M.; Brereton, H.; Preate, D.L.; Neville, E.C.



MRI of the brachial plexus: A pictorial review  

Microsoft Academic Search

Magnetic resonance imaging (MRI) of the brachial plexus is the imaging modality of first choice for depicting anatomy and pathology of the brachial plexus. The anatomy of the roots, trunks, divisions and cords is very well depicted due to the inherent contrast differences between the nerves and the surrounding fat. In this pictorial review the technique and the anatomy will

Hendrik W. van Es; Thomas L. Bollen; Hans P. M. van Heesewijk



Radiation-induced malignant and atypical peripheral nerve sheath tumors  

Microsoft Academic Search

The reported peripheral nerve complications of therapeutic irradiation in humans include brachial and lumbar plexus fibrosis and cranial and peripheral nerve atrophy. We have encountered 9 patients with malignant (7) and atypical (2) peripheral nerve tumors occurring in an irradiated site suggesting that such tumors represent another delayed effect of radiation treatment on peripheral nerve. In all instances the radio-theray

Kathleen M. Foley; James M. Woodruff; Frank T. Ellis; Jerome B. Posner



Nerve transfer in brachial plexus traction injuries.  


Brachial plexus palsy due to traction injury, especially spinal nerve-root avulsion, represents a severe handicap for the patient. Despite recent progress in diagnosis and microsurgical repair, the prognosis in such cases remains unfavorable. Nerve transfer is the only possibility for repair in cases of spinal nerve-root avulsion. This technique was analyzed in 37 patients with 64 reinnervation procedures of the musculocutaneous and/or axillary nerve using upper intercostal, spinal accessory, and regional nerves as donors. The most favorable results, with an 83.8% overall rate of useful functional recovery, were obtained in patients with upper brachial plexus palsy in which regional donor nerves, such as the medial pectoral, thoracodorsal, long thoracic, and subscapular nerves, had been used. The overall rates of recovery for the spinal accessory and upper intercostal nerves were 64.3% and 55.5%, respectively, which are significantly lower. The authors evaluate the results of nerve transfer and analyze different donor nerves as factors influencing the prognosis of surgical repair. PMID:1730947

Samardzic, M; Grujicic, D; Antunovic, V



Motor Cortex Neuroplasticity Following Brachial Plexus Transfer  

PubMed Central

In the past decade, research has demonstrated that cortical plasticity, once thought only to exist in the early stages of life, does indeed continue on into adulthood. Brain plasticity is now acknowledged as a core principle of brain function and describes the ability of the central nervous system to adapt and modify its structural organization and function as an adaptive response to functional demand. In this clinical case study we describe how we used neuroimaging techniques to observe the functional topographical expansion of a patch of cortex along the sensorimotor cortex of a 27-year-old woman following brachial plexus transfer surgery to re-innervate her left arm. We found bilateral activations present in the thalamus, caudate, insula as well as across the sensorimotor cortex during an elbow flex motor task. In contrast we found less activity in the sensorimotor cortex for a finger tap motor task in addition to activations lateralized to the left inferior frontal gyrus and thalamus and bilaterally for the insula. From a pain perspective the patient who had experienced extensive phantom limb pain (PLP) before surgery found these sensations were markedly reduced following transfer of the right brachial plexus to the intact left arm. Within the context of this clinical case the results suggest that functional improvements in limb mobility are associated with increased activation in the sensorimotor cortex as well as reduced PLP. PMID:23966938

Dimou, Stefan; Biggs, Michael; Tonkin, Michael; Hickie, Ian B.; Lagopoulos, Jim



Radiation-induced myeloid leukemia in murine models.  


The use of radiation therapy is a cornerstone of modern cancer treatment. The number of patients that undergo radiation as a part of their therapy regimen is only increasing every year, but this does not come without cost. As this number increases, so too does the incidence of secondary, radiation-induced neoplasias, creating a need for therapeutic agents targeted specifically towards incidence reduction and treatment of these cancers. Development and efficacy testing of these agents requires not only extensive in vitro testing but also a set of reliable animal models to accurately recreate the complex situations of radiation-induced carcinogenesis. As radiation-induced leukemic progression often involves genomic changes such as rearrangements, deletions, and changes in methylation, the laboratory mouse Mus musculus, with its fully sequenced genome, is a powerful tool in cancer research. This fact, combined with the molecular and physiological similarities it shares with man and its small size and high rate of breeding in captivity, makes it the most relevant model to use in radiation-induced leukemia research. In this work, we review relevant M. musculus inbred and F1 hybrid animal models, as well as methods of induction of radiation-induced myeloid leukemia. Associated molecular pathologies are also included. PMID:25062865

Rivina, Leena; Davoren, Michael; Schiestl, Robert H



Radiation-induced myeloid leukemia in murine models  

PubMed Central

The use of radiation therapy is a cornerstone of modern cancer treatment. The number of patients that undergo radiation as a part of their therapy regimen is only increasing every year, but this does not come without cost. As this number increases, so too does the incidence of secondary, radiation-induced neoplasias, creating a need for therapeutic agents targeted specifically towards incidence reduction and treatment of these cancers. Development and efficacy testing of these agents requires not only extensive in vitro testing but also a set of reliable animal models to accurately recreate the complex situations of radiation-induced carcinogenesis. As radiation-induced leukemic progression often involves genomic changes such as rearrangements, deletions, and changes in methylation, the laboratory mouse Mus musculus, with its fully sequenced genome, is a powerful tool in cancer research. This fact, combined with the molecular and physiological similarities it shares with man and its small size and high rate of breeding in captivity, makes it the most relevant model to use in radiation-induced leukemia research. In this work, we review relevant M. musculus inbred and F1 hybrid animal models, as well as methods of induction of radiation-induced myeloid leukemia. Associated molecular pathologies are also included. PMID:25062865



Electroacupuncture attenuates neuropathic pain after brachial plexus injury.  


Electroacupuncture has traditionally been used to treat pain, but its effect on pain following brachial plexus injury is still unknown. In this study, rat models of an avulsion injury to the left brachial plexus root (associated with upper-limb chronic neuropathic pain) were given electroacupuncture stimulation at bilateral Quchi (LI11), Hegu (LI04), Zusanli (ST36) and Yanglingquan (GB34). After electroacupuncture therapy, chronic neuropathic pain in the rats' upper limbs was significantly attenuated. Immunofluorescence staining showed that the expression of ?-endorphins in the arcuate nucleus was significantly increased after therapy. Thus, experimental findings indicate that electroacupuncture can attenuate neuropathic pain after brachial plexus injury through upregulating ?-endorphin expression. PMID:25221593

Zhang, Shenyu; Tang, Hailiang; Zhou, Junming; Gu, Yudong



Brachial Plexus Injuries in Adults: Evaluation and Diagnostic Approach  

PubMed Central

The increased incidence of motor vehicle accidents during the past century has been associated with a significant increase in brachial plexus injuries. New imaging studies are currently available for the evaluation of brachial plexus injuries. Myelography, CT myelography, and magnetic resonance imaging (MRI) are indicated in the evaluation of brachial plexus. Moreover, a series of specialized electrodiagnostic and nerve conduction studies in association with the clinical findings during the neurologic examination can provide information regarding the location of the lesion, the severity of trauma, and expected clinical outcome. Improvements in diagnostic approaches and microsurgical techniques have dramatically changed the prognosis and functional outcome of these types of injuries. PMID:24967130

Sakellariou, Vasileios I.; Badilas, Nikolaos K.; Mazis, George A.; Stavropoulos, Nikolaos A.; Kotoulas, Helias K.; Kyriakopoulos, Stamatios; Tagkalegkas, Ioannis; Sofianos, Ioannis P.



Ankle-brachial index in HIV infection.  


Prognosis for patients with the human immunodeficiency virus (HIV) has improved with the introduction of highly active antiretroviral therapy (HAART). Evidence over recent years suggests that the incidence of cardiovascular disease is increasing in HIV patients. The ankle-brachial index (ABI) is a cheap and easy test that has been validated in the general population. Abnormal ABI values are associated with increased cardiovascular mortality. To date, six series of ABI values in persons with HIV have been published, but none was a prospective study. No agreement exists concerning the risk factors for an abnormal ABI, though its prevalence is clearly higher in these patients than in the general population. Whether this higher prevalence of an abnormal ABI is associated with a higher incidence of vascular events remains to be determined. PMID:19397788

Olalla, Julián; Salas, Daniel; de la Torre, Javier; Del Arco, Alfonso; Prada, José Luis; Martos, Francisco; Perea-Milla, Emilio; García-Alegría, Javier



Ankle-brachial index in HIV infection  

PubMed Central

Prognosis for patients with the human immunodeficiency virus (HIV) has improved with the introduction of highly active antiretroviral therapy (HAART). Evidence over recent years suggests that the incidence of cardiovascular disease is increasing in HIV patients. The ankle-brachial index (ABI) is a cheap and easy test that has been validated in the general population. Abnormal ABI values are associated with increased cardiovascular mortality. To date, six series of ABI values in persons with HIV have been published, but none was a prospective study. No agreement exists concerning the risk factors for an abnormal ABI, though its prevalence is clearly higher in these patients than in the general population. Whether this higher prevalence of an abnormal ABI is associated with a higher incidence of vascular events remains to be determined. PMID:19397788

Olalla, Julian; Salas, Daniel; de la Torre, Javier; del Arco, Alfonso; Prada, Jose Luis; Martos, Francisco; Perea-Milla, Emilio; Garcia-Alegria, Javier



Radiation induces senescence and a bystander effect through metabolic alterations.  


Cellular senescence is a state of irreversible growth arrest; however, the metabolic processes of senescent cells remain active. Our previous studies have shown that radiation induces senescence of human breast cancer cells that display low expression of securin, a protein involved in control of the metaphase-anaphase transition and anaphase onset. In this study, the protein expression profile of senescent cells was resolved by two-dimensional gel electrophoresis to investigate associated metabolic alterations. We found that radiation induced the expression and activation of glyceraldehyde-3-phosphate dehydrogenase that has an important role in glycolysis. The activity of lactate dehydrogenase A, which is involved in the conversion of pyruvate to lactate, the release of lactate and the acidification of the extracellular environment, was also induced. Inhibition of glycolysis by dichloroacetate attenuated radiation-induced senescence. In addition, radiation also induced activation of the 5'-adenosine monophosphate-activated protein kinase (AMPK) and nuclear factor kappa B (NF-?B) pathways to promote senescence. We also found that radiation increased the expression of monocarboxylate transporter 1 (MCT1) that facilitates the export of lactate into the extracellular environment. Inhibition of glycolysis or the AMPK/NF-?B signalling pathways reduced MCT1 expression and rescued the acidification of the extracellular environment. Interestingly, these metabolic-altering signalling pathways were also involved in radiation-induced invasion of the surrounding, non-irradiated breast cancer and normal endothelial cells. Taken together, radiation can induce the senescence of human breast cancer cells through metabolic alterations. PMID:24853433

Liao, E-C; Hsu, Y-T; Chuah, Q-Y; Lee, Y-J; Hu, J-Y; Huang, T-C; Yang, P-M; Chiu, S-J



Plasma prostaglandin levels in radiation-induced enteritis  

Microsoft Academic Search

Increased prostaglandin synthesis has been implicated as a causative factor in the production of radiation induced enteritis. Seventeen patients selected to begin pelvic irradiation for treatment of gynecological cancer had plasma Prostaglandin E, Prostaglandin F, and 13, 14 dihydro 15 keto PGF\\/sub 2..cap alpha..\\/ metabolite determined by radioimmunoassay, prior to initiation of radiotherapy, at weekly intervals during treatment and at

Samuel Lifshitz; John E. Savage; Kevin A. Taylor; Hamed H. Tewfik; Dianna E. Van Orden



Halofuginone Mediated Protection against Radiation-Induced Leg Contracture  

PubMed Central

Fibrosis of normal tissues often accompanies radiation treatment of cancer. Activation of the transforming growth factor-? (TGF-?) signaling pathway is thought to play a major role in radiation-induced fibrosis and has prompted the development and assessment of low molecular weight inhibitors of the pathway. Previous studies with halofuginone have shown it to inhibit TGF-? signaling in vitro and protect mice from radiation-induced leg contraction (a model for soft tissue fibrosis). The current study confirms these findings for HaCaT cells stimulated with exogenous TGF-? treatment. Reducing the halifuginone treatment from 7 days/week (used previously) to 5 days/week post-radiation exposure provided significant protection against radiation-induced leg contraction in mice 3 and 4 months post-radiation treatment. Halofuginone treatment was shown to attenuate TGF-? signaling molecules taken from irradiated skin including TGF-?RII, pSmad3, Smad7, and TSP1. The latter, TSP1, a co-activator of TGF-? may serve as a suitable biomarker for monitoring the efficacy of halofuginone should it be evaluated in a clinical setting for protection against radiation-induced fibrosis. PMID:19578745

Ishii, Hisanari; Choudhuri, Rajani; Mathias, Askale; Sowers, Anastasia L.; Flanders, Kathleen C.; Cook, John A.; Mitchell, James B.



SPHINX Measurements of Radiation Induced Conductivity of Foam  

SciTech Connect

Experiments on the SPHINX accelerator studying radiation-induced conductivity (RIC) in foam indicate that a field-exclusion boundary layer model better describes foam than a Maxwell-Garnett model that treats the conducting gas bubbles in the foam as modifying the dielectric constant. In both cases, wall attachment effects could be important but were neglected.

Ballard, W.P.; Beutler, D.E.; Burt, M.; Dudley, K.J.; Stringer, T.A.



Radiation-induced nonlinear optical response of quartz fibers  

NASA Astrophysics Data System (ADS)

The intensity of radiation-induced luminescence and transient optical losses in KU-1 (Russia) and K-3 (Japan) quartz glass optical tibers irradiated in a fast pulsed fission reactor (a pulse duration of 80 ?s and a neutron flux up to 7 × 1016 cm 2 s 2) has been measured in the visible range. The intensity of the fast luminescence component nonlinearly depends on the neutron flux. The luminescence intensity and the transient optical losses depend on the probe light intensity. Suppression of radiation-induced luminescence is observed at wavelengths that are longer or shorter than the probe light wavelength. Light probing leads to an increase in transient optical losses and a more rapid recovery of transparency. A model of two photon fluxes is proposed to analyze the relationship of the effects of suppression of radiation-induced luminescence and the increase in optical losses upon light probing. The effect of suppression of radiation-induced luminescence can be used to control the optical properties of fibers in radiation fields.

Plaksin, O. A.



Cosmology for grand unified theories with radiatively induced symmetry breaking  

Microsoft Academic Search

The treatment of first-order phase transitions for standard grand unified theories is shown to break down for models with radiatively induced spontaneous symmetry breaking. It is argued that proper analysis of these transitions which would take place in the early history of the universe can lead to an explanation of the cosmological homogeneity, flatness, and monopole puzzles.

Andreas Albrecht; P. J. Steinhardt




EPA Science Inventory

Determination of dose-response relationships for radiation-induced cancer in segments of the population with high susceptibility is critical for understanding the risks of low dose and low dose rates to humans. Clean-up levels for radionuclides will depend upon the fraction of t...


Radiation-induced instability and its relation to radiation carcinogenesis  

NASA Technical Reports Server (NTRS)

PURPOSE: A model that identifies radiation-induced genetic instability as the earliest cellular event in the multi-step sequence leading to radiation-induced cancer was previously proposed. In this paper ongoing experiments are discussed which are designed to test this model and its predictions in mouse mammary epithelial cells. RESULTS: Several lines of evidence are presented that appear to support this model: first, the development of delayed mutations in p53 following irradiation in altered growth variants; secondly, the high frequencies for the induction of both instability and transformation following irradiation in mammary epithelial cells; and finally, the demonstration that susceptibility to the induction of cytogenetic instability is a heritable trait that correlates with susceptibility to transformation and radiation-induced mammary cancer. Mice resistant to transformation and mammary cancer development are also resistant to the development of instability after irradiation. In contrast, mice sensitive to transformation and cancer are also sensitive to the development of cytogenetic instability. CONCLUSIONS: Data from this laboratory and from the studies cited above suggest a specific, and perhaps unique, role for radiation-induced instability as a critical early event associated with initiation of the carcinogenic process.

Ullrich, R. L.; Ponnaiya, B.



Hyperbaric Oxygen Therapy for Radiation-induced Optic Neuropathy  

Microsoft Academic Search

Introduction: Radiation-induced optic neuropathy (RON) is an infrequent but devastating consequence of radiation exposure to the visual pathways, usually following months to years after the treatment of paranasal or intracranial tumours. Hyperbaric oxygen (HBO) therapy is one of several therapies that have been tried for this condition. The purpose of this review is to describe the clinical characteristics of RON,

Richard L Levy; Neil R Miller


Modeling radiation-induced mixing at interfaces between low solubility metals  

E-print Network

This thesis studies radiation-induced mixing at interfaces between low solubility metals using molecular dynamics (MD) computer simulations. It provides original contributions on the fundamental mechanisms of radiation-induced ...

Zhang, Liang, Ph. D. Massachusetts Institute of Technology



Automated analysis of brachial ultrasound time series  

NASA Astrophysics Data System (ADS)

Atherosclerosis begins in childhood with the accumulation of lipid in the intima of arteries to form fatty streaks, advances through adult life when occlusive vascular disease may result in coronary heart disease, stroke and peripheral vascular disease. Non-invasive B-mode ultrasound has been found useful in studying risk factors in the symptom-free population. Large amount of data is acquired from continuous imaging of the vessels in a large study population. A high quality brachial vessel diameter measurement method is necessary such that accurate diameters can be measured consistently in all frames in a sequence, across different observers. Though human expert has the advantage over automated computer methods in recognizing noise during diameter measurement, manual measurement suffers from inter- and intra-observer variability. It is also time-consuming. An automated measurement method is presented in this paper which utilizes quality assurance approaches to adapt to specific image features, to recognize and minimize the noise effect. Experimental results showed the method's potential for clinical usage in the epidemiological studies.

Liang, Weidong; Browning, Roger L.; Lauer, Ronald M.; Sonka, Milan



Irradiated Esophageal Cells are Protected from Radiation-Induced Recombination by MnSOD Gene Therapy  

E-print Network

Irradiated Esophageal Cells are Protected from Radiation-Induced Recombination by MnSOD Gene. Irradiated Esophageal Cells are Protected from Radiation- Induced Recombination by MnSOD Gene Therapy. Radiat in esophageal cells. These results demonstrate the efficacy of MnSOD-PL for suppressing radiation-induced HR

Engelward, Bevin


Radiation-induced decomposition of explosives under extreme conditions  

SciTech Connect

We present high-pressure and high temperature studies of the synchrotron radiation-induced decomposition of powder secondary high explosives pentaerythritol tetranitrate (PETN) and 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) using white beam synchrotron radiation at the 16 BM-B and 16 BM-D sectors of the HP-CAT beamline at the Advanced Photon Source. The radiation-induced decomposition rate TATB showed dramatic slowing with pressure up to 26.6 GPa (the highest pressure studied), implying a positive activation volume of the activated complex. The decomposition rate of PETN varied little with pressure up to 15.7 GPa (the highest pressure studied). Diffraction line intensities were measured as a function of time using energy-dispersive methods. By measuring the decomposition rate as a function of pressure and temperature, kinetic and other constants associated with the decomposition reactions were extracted.

Giefers, Hubertus; Pravica, Michael; Yang, Wenge; Liermann, Peter (UNLV); (CIW)



Caffeine Markedly Enhanced Radiation-Induced Bystander Effects  

NASA Astrophysics Data System (ADS)

In this paper it is shown that incubation with 2 mM caffeine enhanced significantly the MN (micronucleus) formation in both the 1 cGy ?-particle irradiated and non-irradiated bystander regions. Moreover, caffeine treatment made the non-irradiated bystander cells more sensitive to damage signals. Treated by c-PTIO(2-(4-carboxy-phenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide), a nitric oxide (NO) scavenger, the MN frequencies were effectively inhibited, showing that nitric oxide might be very important in mediating the enhanced damage. These results indicated that caffeine enhanced the low dose ?-particle radiation-induced damage in irradiated and non-irradiated bystander regions, and therefore it is important to investigate the relationship between the radiosensitizer and radiation-induced bystander effects (RIBE).

Jiang, Erkang; Wu, Lijun



Heavy-ion radiation induced bystander effect in mice  

NASA Astrophysics Data System (ADS)

Radiation-induced bystander effect is defined as the induction of damage in neighboring non-hit cells by signals released from directly-irradiated cells. Recently, Low dose of high LET radiation induced bystander effects in vivo have been reported more and more. It has been indicated that radiation induced bystander effect was localized not only in bystander tissues but also in distant organs. Genomic, epigenetic, metabolomics and proteomics play significant roles in regulating heavy-ion radiation stress responses in mice. To identify the molecular mechanism that underlies bystander effects of heavy-ion radiation, the male mice head were exposed to 2000mGy dose of 12C heavy-ion radiation and the distant organ liver was detected on 1h, 6h, 12h and 24h after radiation, respectively. MSAP was used to monitor the level of polymorphic DNA methylation changes. The results show that heavy-ion irradiate mouse head can induce liver DNA methylation changes significantly. The percent of DNA methylation changes are time-dependent and highest at 6h after radiation. We also prove that the hypo-methylation changes on 1h and 6h after irradiation. But the expression level of DNA methyltransferase DNMT3a is not changed. UPLC/Synapt HDMS G2 was employed to detect the proteomics of bystander liver 1h after irradiation. 64 proteins are found significantly different between treatment and control group. GO process show that six of 64 which were unique in irradiation group are associated with apoptosis and DNA damage response. The results suggest that mice head exposed to heavy-ion radiation can induce damage and methylation pattern changed in distant organ liver. Moreover, our findings are important to understand the molecular mechanism of radiation induced bystander effects in vivo.

Liang, Shujian; Sun, Yeqing; Zhang, Meng; Wang, Wei; Cui, Changna



Process and Radiation Induced Defects in Electronic Materials and Devices  

NASA Technical Reports Server (NTRS)

Process and radiation induced defects are characterized by a variety of electrical techniques, including capacitance-voltage measurements and charge pumping. Separation of defect type into stacking faults, displacement damage, oxide traps, interface states, etc. and their related causes are discussed. The defects are then related to effects on device parameters. Silicon MOS technology is emphasized. Several reviews of radiation effects and silicon processing exist.

Washington, Kenneth; Fogarty, T. N.



Pulsed radiation-induced attenuation in certain optical fibers  

Microsoft Academic Search

Using the X-ray pulse from the HERMES II simulation machine at Sandia National Laboratories, the pulsed radiation-induced attenuation was measured in two optical fibers considered to be 'nonrad-hard': the 50-micron-core, graded-index fiber from Corning and the plastic (PMMA) fiber from the Mitsubishi Rayon Company. These fibers were exposed to radiation up to doses of 19.5 and 28 krad(Si), respectively. In

Jonathan D. Weiss



Pulsed radiation-induced attenuation in certain optical fibers  

Microsoft Academic Search

Using the X-ray pulse from the HERMES II simulation machine at Sandia National Laboratories, the author measured the pulsed radiation-induced attenuation in two optical fibers considered to be `non-rad-hard': the 50 ?m core graded-index fiber from Corning and the plastic (PMMA) fiber from the Mitsubishi Rayon Company. These fibers were exposed to radiation up to doses of 19.5 and 28

J. D. Weiss



Radiation Induced DNA-Damage\\/Repair and Associated Signaling Pathways  

Microsoft Academic Search

Radiation-induced DNA damage and related repair mechanisms are described in this chapter. The emerging connection with growth\\u000a factor induced signal transduction is described, with important implications for radiotherapy. The prospect of developing\\u000a targeting agents, which selectively deliver radioactivity to the tumor and at the same time radiosensitize the tumor cells\\u000a is discussed in some detail.

Bo Stenerlöw; Lina Ekerljung; Jörgen Carlsson; Johan Lennartsson


Morphology and pathology of radiation-induced esophagitis  

Microsoft Academic Search

Radiation-induced esophagitis can cause substantial morbidity. Experiments in lab animals have shown that pretreatment with indomethacin protects the esophagus from radiation damage. We conducted a prospective, double-blind, randomized trial of naproxen vs placebo in patients undergoing thoracic radiation therapy for lung cancer. Twenty-eight patients were enrolled, of which 26 completed the study. Sixteen patients were given a short course of

Edy E. Soffer; Frank Mitros; J. Fred Doornbos; Jay Friedland; Janice Launspach; Robert W. Summers



Rehabilitation of brachial plexus injuries in adults and children.  


Management of brachial plexus injury sequelae is a challenging issue in neurorehabilitation. In the last decades great strides have been made in the areas of early diagnosis and surgical techniques. Conversely, rehabilitation of brachial plexus injury is a relatively unexplored field. Some critical aspects regarding brachial plexus injury rehabilitation have to be acknowledged. First, brachial plexus injury may result in severe and chronic impairments in both adults and children, thus requiring an early and long-lasting treatment. Second, nerve damage causes a multifaceted clinical picture consisting of sensorimotor disturbances (pain, muscle atrophy, muscle weakness, secondary deformities) as well as reorganization of the Central Nervous System that may be associated with upper limb underuse, even in case of peripheral injured nerves repair. Finally, psychological problems and a lack of cooperation by the patient may limit rehabilitation effects and increase disability. In the present paper the literature concerning brachial plexus injury deficits and rehabilitation in both adults and children was reviewed and discussed. Although further research in this field is recommended, current evidence supports the potential role of rehabilitation in reducing both early and long-lasting disability. Furthermore, the complexity of the functional impairment necessitates an interdisciplinary approach incorporating various health professionals in order to optimizing outcomes. PMID:23075907

Smania, N; Berto, G; La Marchina, E; Melotti, C; Midiri, A; Roncari, L; Zenorini, A; Ianes, P; Picelli, A; Waldner, A; Faccioli, S; Gandolfi, M



Radiation-induced grain boundary segregation in austenitic stainless steels  

SciTech Connect

Radiation-induced segregation (RIS) to grain boundaries in Fe-Ni-Cr-Si stainless alloys has been measured as a function of irradiation temperature and dose. Heavy-ion irradiation was used to produce damage levels from 1 to 20 displacements per atom (dpa) at temperatures from 175 to 550{degrees}C. Measured Fe, Ni, and Cr segregation increased sharply with irradiation dose (from G to 5 dpa) and temperature (from 175 to about 350{degrees}C). However, grain boundary concentrations did not change significantly as dose or temperatures were further increased. Although interfacial compositions were similar, the width of radiation-induced enrichment or depletion profiles increased consistently with increasing dose or temperature. Impurity segregation (Si and P) was also measured, but only Si enrichment appeared to be radiation-induced. Grain boundary Si peaked at levels approaching 10 at% after irradiation doses to 10 dpa at an intermediate temperature of 325{degrees}C. No evidence of grain boundary silicide precipitation was detected after irradiation at any temperature. Equilibrium segregation of P was measured in the high-P alloys, but interfacial concentration did not increase with irradiation exposure. Comparisons to reported RIS in neutron-irradiated stainless steels revealed similar grain boundary compositional changes for both major alloying and impurity elements.

Bruemmer, S.M.; Charlot, L.A.; Vetrano, J.S.; Simonen, E.P.



Radiation-induced products of peptides and their enzymatic digestibility  

SciTech Connect

Chemical characterization of radiation-induced products of peptides and proteins is essential for understanding the effect of ionizing radiation on peptides and proteins. Furthermore, peptides containing radiation-altered amino acid residues might not be completely digestible by proteolytic enzymes. In this work, small homopeptides of Ala, Phe and Met were chosen as model peptides. Lysozyme was used to investigate the effect of ionizing radiation on a small protein. All peptides and lysozyme were irradiated in diluted, oxygen free, N/sub 2/O-saturated aqueous solutions, using a /sup 60/Co-..gamma..-source. HPLC, capillary GC and GC-MS were applied to isolate and characterize the radiation-induced products. The enzymatic digestibility of the products was investigated using aminopeptidase M, leucine aminopeptidase, carboxypeptidase A and carboxypeptidase Y. It was found that irradiation of peptides examined in this work leads to racemization and alteration of amino acid residues and crosslinks between the peptide chains. In addition, it was established that exopeptidases act differently on radiation-induced dimers of peptides composed of aliphatic, aromatic and sulfur-containing amino acids.

Gajewski, E.



Respiratory arrest in patients undergoing arteriovenous graft placement with supraclavicular brachial plexus block: a case series.  


Supraclavicular brachial plexus block is commonly used for upper extremity surgery. Respiratory arrest in three patients with end-stage renal disease after ultrasound-guided supraclavicular brachial plexus block for creation of an arteriovenous graft over a 6-month period is presented. Patients with renal failure may represent a group at particular risk for respiratory failure following supraclavicular brachial plexus block. PMID:23830847

Afonso, Anoushka; Beilin, Yaakov



3 T MR tomography of the brachial plexus: Structural and microstructural evaluation  

Microsoft Academic Search

Magnetic resonance (MR) neurography comprises an evolving group of techniques with the potential to allow optimal noninvasive evaluation of many abnormalities of the brachial plexus. MR neurography is clinically useful in the evaluation of suspected brachial plexus traumatic injuries, intrinsic and extrinsic tumors, and post-radiogenic inflammation, and can be particularly beneficial in pediatric patients with obstetric trauma to the brachial

Ammar Mallouhi; Wolfgang Marik; Daniela Prayer; Franz Kainberger; Gerd Bodner; Gregor Kasprian


Quantifying Local Radiation-Induced Lung Damage From Computed Tomography  

SciTech Connect

Purpose: Optimal implementation of new radiotherapy techniques requires accurate predictive models for normal tissue complications. Since clinically used dose distributions are nonuniform, local tissue damage needs to be measured and related to local tissue dose. In lung, radiation-induced damage results in density changes that have been measured by computed tomography (CT) imaging noninvasively, but not yet on a localized scale. Therefore, the aim of the present study was to develop a method for quantification of local radiation-induced lung tissue damage using CT. Methods and Materials: CT images of the thorax were made 8 and 26 weeks after irradiation of 100%, 75%, 50%, and 25% lung volume of rats. Local lung tissue structure (S{sub L}) was quantified from local mean and local standard deviation of the CT density in Hounsfield units in 1-mm{sup 3} subvolumes. The relation of changes in S{sub L} (DELTAS{sub L}) to histologic changes and breathing rate was investigated. Feasibility for clinical application was tested by applying the method to CT images of a patient with non-small-cell lung carcinoma and investigating the local dose-effect relationship of DELTAS{sub L}. Results: In rats, a clear dose-response relationship of DELTAS{sub L} was observed at different time points after radiation. Furthermore, DELTAS{sub L} correlated strongly to histologic endpoints (infiltrates and inflammatory cells) and breathing rate. In the patient, progressive local dose-dependent increases in DELTAS{sub L} were observed. Conclusion: We developed a method to quantify local radiation-induced tissue damage in the lung using CT. This method can be used in the development of more accurate predictive models for normal tissue complications.

Ghobadi, Ghazaleh; Hogeweg, Laurens E. [Department of Radiation Oncology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands); Faber, Hette [Department of Radiation Oncology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands); Department of Cell Biology, Section of Radiation and Stress Cell Biology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands); Tukker, Wim G.J. [Department of Radiology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands); Schippers, Jacobus M. [Department of Radiation Oncology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands); Accelerator Department, Paul Scherrer Institut, Villigen (Switzerland); Brandenburg, Sytze [Kernfysisch Versneller Instituut, Groningen (Netherlands); Langendijk, Johannes A. [Department of Radiation Oncology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands); Coppes, Robert P. [Department of Radiation Oncology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands); Department of Cell Biology, Section of Radiation and Stress Cell Biology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands); Luijk, Peter van, E-mail: p.van.luijk@rt.umcg.n [Department of Radiation Oncology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands)



MRI of axillary brachial plexus blocks  

PubMed Central

BACKGROUND Axillary plexus blocks are usually guided by ultrasound, but alternative methods may be used when ultrasound equipment is lacking. For a nonultrasound-guided axillary block, the need for three injections has been questioned. OBJECTIVES Could differences in block success between single, double and triple deposits methods be explained by differences in local anaesthetic distribution as observed by MRI? DESIGN A blinded and randomised controlled study. SETTING Conducted at Oslo University Hospital, Rikshospitalet, Norway from 2009 to 2011. PATIENTS Forty-five ASA 1 to 2 patients scheduled for surgery were randomised to three equally sized groups. All patients completed the study. INTERVENTIONS Patients in the single-deposit group had an injection through a catheter parallel to the median nerve. In the double-deposit group the patients received a transarterial block. In the triple-deposit group the injections of the two other groups were combined. Upon completion of local anaesthetic injection the patients were scanned by MRI, before clinical block assessment. The distribution of local anaesthetic was scored by its closeness to terminal nerves and cords of the brachial plexus, as seen by MRI. The clinical effect was scored by the degree of sensory block in terminal nerve innervation areas. MAIN OUTCOME MEASURES Sensory block effect and MRI distribution pattern. RESULTS The triple-deposit method had a higher success rate (100%) than the single-deposit method (67%) and the double-deposit method (67%) in blocking all cutaneous nerves distal to the elbow (P?=?0.04). The patients in the triple-deposit group most often had the best MRI scores. For any nerve or cord, at least one of the single-deposit or double-deposit groups had a similarly high MRI score as the triple-deposit group. CONCLUSION Distal to the elbow, the triple-deposit method had the highest sensory block success rate. This could be explained to some extent by analysis of the magnetic resonance images. TRIAL REGISTRATION identifier: NCT01033006. PMID:25051144

Kjelstrup, Trygve; Hol, Per K.; Courivaud, Frederic; Smith, Hans-J?rgen; R?kkum, Magne; Klaastad, ?ivind



Radiation-induced morphoea treated with UVA-1 phototherapy.  


Morphoea is a localized inflammatory disorder of the dermis and subcutaneous fat and radiotherapy is a rarely reported cause (estimated incidence of 2 per 1000). Morphoea is commonly mistaken for an inflammatory recurrence of breast cancer, resulting in unnecessary investigations and treatment. We report the case of a 40-year-old woman who developed radiation-induced morphoea of the breast 7 months following adjuvant radiotherapy. She was treated with topical and systemic steroids as well as psoralen plus ultraviolet (UV)A before proceeding to UVA1 phototherapy. We also review the literature and discuss other management options. PMID:24890985

Lim, D; Johnston, S; Novakovic, L; Fearfield, L



Transient radiation-induced absorption in laser materials  

SciTech Connect

Transient radiation-induced absorption losses in laser materials have been measured using a pulsed nuclear reactor. Reactor pulse widths of 70 to 90 {mu}s and absorbed doses of 1 to 7.5 krad have been used. Transmission recovery times and peak absorption coefficients are given. Materials tested include LiNbO{sub 3}, GSGG, silica substrates, and filter glasses used in the laser cavity. The filter glasses are tested at discrete wavelengths in the range 440--750 nm. Lithium niobate , MgO doped LiNbO{sub 3}, GSGG, and the silica substrates are tested at 1061 nm.

Brannon, P.J.



Measurements of prompt radiation induced conductivity in Teflon (PTFE).  

SciTech Connect

We performed measurements of the prompt radiation induced conductivity (RIC) in thin samples of Teflon (PTFE) at the Little Mountain Medusa LINAC facility in Ogden, UT. Three mil (76.2 microns) samples were irradiated with a 0.5 %CE%BCs pulse of 20 MeV electrons, yielding dose rates of 1E9 to 1E11 rad/s. We applied variable potentials up to 2 kV across the samples and measured the prompt conduction current. Details of the experimental apparatus and analysis are reported in this report on prompt RIC in Teflon.

Hartman, E. Frederick; Zarick, Thomas Andrew; Sheridan, Timothy J.; Preston, E. [ITT Exelis Mission Systems, Colorado Springs, CO



Radiation-induced apoptosis in the eye structures: a review  

NASA Astrophysics Data System (ADS)

Apoptosis plays a crucial role in tissue homeostasis and in the removal of damaged cells from tissues. Both increased and insufficient cell death can lead to human diseases. Apoptotic process is under the control of physiological metabolism as well as a panel of genes. After exposure to radiation, membrane damages induce the membrane pathway signal transduction for cell apoptosis. The importance of the radiation-induced apoptosis in the different ocular tissues and its relationship to the radiation parameters are reviewed in this article. This topic of ocular research has not been addressed in detail in the literature.

Belkacémi, Yazid; Huchet, Aymeri; Baudouin, Christophe; Lartigau, Éric



Kinetics and mechanisms of radiation-induced degradation of acetochlor.  


The radiation-induced degradation of acetochlor was investigated in this work. In a mixed solvent composed of acetonitrile and water at a ratio of 20/80 in volume, the acetochlor degradation rate was proportional to the radiation dose rate and acetochlor concentration. The acetochlor degradation efficiency was higher under alkali conditions and lower under acidic conditions. The contribution to the acetochlor degradation by the radicals was in the order of: e(aq)->.OH>H.. The quantum efficiency ratios of .OH, e(aq)- and H. for the degradation of acetochlor were calculated as 1:3:1. PMID:15698639

Liu, Shao-Yang; Chen, You-Peng; Yu, Han-Qing; Zhang, Shu-Juan



Postanesthetic brachial triceps myonecrosis in a Spanish-bred horse  

PubMed Central

This report describes a case of postanesthetic brachial triceps myonecrosis affecting only the left forelimb of a horse. A fatal unilateral postanesthetic myonecrosis has not been previously reported in the horse. This article describes the factors in the horse’s history, the anesthetic protocol, and the treatment that may have led to this condition. PMID:19412400

Ayala, Ignacio; Rodriguez, M. Jesus; Aguirre, Carla; Buendia, Antonio J.; Belda, Eliseo; Laredo, Francisco G.



Supraclavicular brachial plexus blocks: review and current practice.  


This article reviews the possible revival of the supraclavicular brachial plexus blockade due to the use of ultrasound guidance. The brachial plexus is a complex network of nerves, extending from the neck to the axilla, which supplies motor and sensory fibers to the upper extremity. Understanding the complexities of the formation and structure of the brachial plexus remains a cornerstone for effective regional anaesthesia. On the level of the supraclavicular fossa, the plexus is most compactly arranged. The supraclavicular approach of the brachial plexus has a high success rate including blockade of the ulnar and musculocutaneous nerve, which can be missed respectively with the interscalene and axillary approach. However, because of the proximity of the pleura, most anaesthesiologists have been reluctant to perform this supraclavicular approach. The introduction of ultrasound guidance techniques not only reduces the possible risk of pneumothorax but also allows a faster onset time of the block with a reduction of the local anaesthetic dose. This makes the supraclavicular approach a valuable alternative to the axillary, interscalene and infraclavicular approach for upper limb surgery. PMID:22783706

Vermeylen, K; Engelen, S; Sermeus, L; Soetens, F; Van de Velde, M



Learn the Brachial Plexus in Five Minutes or Less  

E-print Network

is the result of work supported with resources and the use of facilities at the VA Gulf Coast Veterans Health and Rehabilitation Department of Veterans Affairs, Biloxi, Mississippi and Dennis A. Chu, M.D. This material view of the Department of Veterans Affairs of the U.S. Government. #12;The brachial plexus contains

Finley Jr., Russell L.


Should Cancer Survivors Fear Radiation-Induced Sarcomas?  

PubMed Central

Purpose/Results. Ionizing radiation is carcinogenic and the induction of a second malignancy is a serious potential long-term complication of radiotherapy. The incidence of radiation-induced sarcomas was evaluated from many large epidemiological surveys of long-term cancer survivors reported in the literature over the past 30 years and only one case was found for every 1000 patients irradiated. Discussion. Although greater numbers of cancer patients are receiving radical radiotherapy and surviving free of disease for longer intervals, cases of radiation-induced sarcomas are rare and should not deter patients from accepting radiotherapy as treatment for curable cancers. With improvements in the administration of radiotherapy over the past two decades which are resulting in less damage to bone and soft tissues, it is likely that fewer cases of this condition will be seen in the future. If these sarcomas are diagnosed early, long-term survival can be achieved with surgical excision and possibly re-irradiation, as occurs in other types of sarcomas. PMID:18521195



Radiation induced corrosion of copper for spent nuclear fuel storage  

NASA Astrophysics Data System (ADS)

The long term safety of repositories for radioactive waste is one of the main concerns for countries utilizing nuclear power. The integrity of engineered and natural barriers in such repositories must be carefully evaluated in order to minimize the release of radionuclides to the biosphere. One of the most developed concepts of long term storage of spent nuclear fuel is the Swedish KBS-3 method. According to this method, the spent fuel will be sealed inside copper canisters surrounded by bentonite clay and placed 500 m down in stable bedrock. Despite the importance of the process of radiation induced corrosion of copper, relatively few studies have been reported. In this work the effect of the total gamma dose on radiation induced corrosion of copper in anoxic pure water has been studied experimentally. Copper samples submerged in water were exposed to a series of total doses using three different dose rates. Unirradiated samples were used as reference samples throughout. The copper surfaces were examined qualitatively using IRAS and XPS and quantitatively using cathodic reduction. The concentration of copper in solution after irradiation was measured using ICP-AES. The influence of aqueous radiation chemistry on the corrosion process was evaluated based on numerical simulations. The experiments show that the dissolution as well as the oxide layer thickness increase upon radiation. Interestingly, the evaluation using numerical simulations indicates that aqueous radiation chemistry is not the only process driving the corrosion of copper in these systems.

Björkbacka, Åsa; Hosseinpour, Saman; Johnson, Magnus; Leygraf, Christofer; Jonsson, Mats



Swelling and radiation-induced segregation in austentic alloys  

NASA Astrophysics Data System (ADS)

To elucidate the relationship between radiation-induced segregation and swelling in austenitic stainless steels, a series of alloys were irradiated with 3.2 MeV protons to doses of 0.5 and 1.0 dpa at 400 °C. Three alloy series were irradiated, the first to examine the effect of bulk nickel in Fe-16-18Cr- xNi, the second to determine the effect of Mo and P in an Fe-16Cr-13Ni base alloy, and the third to examine the effect of oversized solute Zr addition to an Fe-18Cr-0.5Ni alloy. The addition of nickel in Fe-16-18Cr- xNi caused a significant decrease in swelling and increase in segregation. The addition of Mo+P to Fe-16Cr-13Ni eliminated swelling and reduced segregation. The addition of Zr to Fe-18Cr-9.5Ni decreased swelling and altered the segregation. Comparison of swelling with changes in lattice parameter and shear modulus caused by the segregation showed that swelling correlates well with the decreases in lattice parameter caused by radiation-induced segregation. Those alloys whose segregation decreased the lattice parameter the greatest showed the lowest swelling. These results are consistent with theoretical predictions made by Wolfer.

Allen, T. R.; Cole, J. I.; Gan, J.; Was, G. S.; Dropek, R.; Kenik, E. A.



Simvastatin attenuates radiation-induced tissue damage in mice  

PubMed Central

The aim of this study was to investigate the protective effect of simvastatin against radiation-induced tissue injury in mice. Mice were radiated with 4 Gy or 8 Gy after 20 mg/kg/d simvastatin treatment over 2 weeks. Morphological changes were observed in the jejunum and bone marrow, and apoptotic cells were determined in both tissues. Peripheral blood cells were counted, and the superoxide dismutase (SOD) activity and the malondialdehyde (MDA) level in tissues of both thymus and spleen were measured. Compared with the radiation-only group, 20 mg/kg/d simvastatin administration significantly increased the mean villi height and decreased apoptotic cells in jejunum tissue, and stimulated regeneration and reduced apoptotic cells in bone marrow. Peripheral blood cell analysis revealed that simvastatin treatment induced a larger number of red blood cells and increased the hemoglobin level present after 4 Gy of radiation. Interestingly, it was also found that the number of peripheral endothelial progenitor cells was markedly increased following simvastatin administration. Antioxidant determination for tissues displayed that simvastatin therapy increased the SOD activity after both 4 and 8 Gy of radiation, but only decreased the MDA level after 4 Gy. Simvastatin ameliorated radiation-induced tissue damage in mice. The radioprotective effect of simvastatin was possibly related to inhibition of apoptosis and improvement of oxygen-carrying and antioxidant activities. PMID:24105712

Zhao, Xinbin; Yang, Hong; Jiang, Guojun; Ni, Min; Deng, Yaping; Cai, Jian; Li, Zhangpeng; Shen, Fuming; Tao, Xia



Radiation-induced genomic instability in Caenorhabditis elegans.  


Radiation-induced genomic instability has been well documented, particularly in vitro. However, the understanding of its mechanisms and their consequences in vivo is still limited. In this study, Caenorhabditis elegans (C. elegans; strain CB665) nematodes were exposed to X-rays at doses of 0.1, 1, 3 or 10Gy. The endpoints were measured several generations after exposure and included mutations in the movement-related gene unc-58, alterations in gene expression analysed with oligoarrays containing the entire C. elegans genome, and micro-satellite mutations measured by capillary electrophoresis. The progeny of the irradiated nematodes showed an increased mutation frequency in the unc-58 gene, with a maximum response observed at 1Gy. Significant differences were also found in gene expression between the irradiated (1Gy) and non-irradiated nematode lines. Differences in gene expression did not show clear clustering into certain gene categories, suggesting that the instability might be a chaotic process rather than a result of changes in the function of few specific genes such as, e.g., those responsible for DNA repair. Increased heterogeneity in gene expression, which has previously been described in irradiated cultured human lymphocytes, was also observed in the present study in C. elegans, the coefficient of variation of gene expression being higher in the progeny of irradiated nematodes than in control nematodes. To the best of our knowledge, this is the first publication reporting radiation-induced genomic instability in C. elegans. PMID:22796420

Huumonen, Katriina; Immonen, Hanna-Kaisa; Baverstock, Keith; Hiltunen, Mikko; Korkalainen, Merja; Lahtinen, Tapani; Parviainen, Juha; Viluksela, Matti; Wong, Garry; Naarala, Jonne; Juutilainen, Jukka



Mechanisms of the formation of radiation-induced chromosomal aberrations.  


Although much is now known about the mechanisms of radiation-induction of DNA double-strand breaks (DSB), there is less known about the conversion of DSB into chromosomal aberrations. In particular the induction and 'rejoining' of chromatid breaks has been a controversial topic for many years. However, its importance becomes clear in the light of the wide variation in the chromatid break response of human peripheral blood lymphocytes from different individuals when exposed to ionizing radiation, and the elevation of the frequency of radiation-induced chromatid breaks in stimulated peripheral blood lymphocytes of around 40% of breast cancer cases. A common assumption has been that chromatid breaks are merely expansions of initiating DSB, although the classic 'breakage-first' hypothesis (Sax, Ref. 44) was already challenged in the 50's by Revell [30] who maintained that chromatid breaks were formed as a result of an incomplete exchange process initiated by two interacting lesions of an unspecified nature. Here we argue that both these models of chromatid break formation are flawed and we suggest an alternative hypothesis, namely that a radiation-induced DSB initiates an indirect mechanism leading to a chromatid break. This mechanism we suggest involves the nuclear enzyme topoisomerase IIalpha and we present evidence from topoisomerase IIalpha expression variant human cell lines and from siRNA treatment of human cells that supports this hypothesis. PMID:20348019

Bryant, Peter E; Riches, Andrew C; Terry, Samantha Y A



Sensitivity to Radiation-Induced Cancer in Hemochromatosis  

SciTech Connect

The objectives of this pilot project using HFE-knockout homozygotes and heterozygotes are to (1) determine whether the knock-out mice have greater sensitivity to radiation-induced cancer of the colon, liver and breast, (2) establish the dependence of this sensitivity on the accumulation of iron, (3) determine the extent to which cell replication and apoptosis occur in these target tissues with varying iron load, and (4) correlate the increases in sensitivity with changes in insulin-related signaling in tumors and normal tissue from each target organ. Three experimental designs will be used in the pilot project. The sequence of experiments is designed to first explore the influence of iron load on the response and demonstrate that HFE knockout mice are more sensitive than the wild type to radiation-induced cancer in one or more of three target tissues (liver, colon and breast). The dose response relationships with a broader set of radiation doses will be explored in the second experiment. The final experiment is designed to explore the extent to which heterozygotes display the increased susceptibility to cancer induction and to independently assess the importance of iron load to the initiation versus promotion of tumors.

Bull. Richard J.; Anderson, Larry E.



Radiation-induced skin carcinomas of the head and neck  

SciTech Connect

Radiation exposures to the scalp during childhood for tinea capitis were associated with a fourfold increase in skin cancer, primarily basal cell carcinomas, and a threefold increase in benign skin tumors. Malignant melanoma, however, was not significantly elevated. Overall, 80 neoplasms were identified from an extensive search of the pathology logs of all major hospitals in Israel and computer linkage with the national cancer registry. Radiation dose to the scalp was computed for over 10,000 persons irradiated for ringworm (mean 7 Gy), and incidence rates were contrasted with those observed in 16,000 matched comparison subjects. The relative risk of radiogenic skin cancer did not differ significantly between men or women or by time since exposure; however, risk was greatest following exposures in early childhood. After adjusting for sex, ethnic origin, and attained age, the estimated excess relative risk was 0.7 per Gy and the average excess risk over the current follow-up was 0.31/10(4) PY-Gy. The risk per Gy of radiation-induced skin cancer was intermediate between the high risk found among whites and no risk found among blacks in a similar study conducted in New York City. This finding suggests the role that subsequent exposure to uv radiation likely plays in the expression of a potential radiation-induced skin malignancy.

Ron, E.; Modan, B.; Preston, D.; Alfandary, E.; Stovall, M.; Boice, J.D. Jr. (National Cancer Institute, Bethesda, MD (USA))



Radiation-induced chromatid breaks as a predictor of breast cancer risk  

Microsoft Academic Search

Purpose: In in vivo models, radiation-induced genomic instability correlates with the risk of breast cancer development. In addition, homozygous mutations in tumor suppressor genes associated with breast cancer development adversely affects the processing and repair of radiation-induced DNA damage. We performed a case-control study to determine whether an assay measuring radiation-induced chromatid breaks correlated with the risk of having bilateral

Thomas A Buchholz; Xifeng Wu



Contribution of radiation-induced, nitric oxide-mediated bystander effect to radiation-induced adaptive response.  

NASA Astrophysics Data System (ADS)

There has been a recent upsurge of interest in radiation-induced adaptive response and bystander effect which are specific modes in stress response to low-dose low-dose rate radiation Recently we found that the accumulation of inducible nitric oxide NO synthase iNOS in wt p53 cells was induced by chronic irradiation with gamma rays followed by acute irradiation with X-rays but not by each one resulting in an increase in nitrite concentrations of medium It is suggested that the accumulation of iNOS may be due to the depression of acute irradiation-induced p53 functions by pre-chronic irradiation In addition we found that the radiosensitivity of wt p53 cells against acute irradiation with X-rays was reduced after chronic irradiation with gamma rays This reduction of radiosensitivity of wt p53 cells was nearly completely suppressed by the addition of NO scavenger carboxy-PTIO to the medium This reduction of radiosensitivity of wt p53 cells is just radiation-induced adaptive response suggesting that NO-mediated bystander effect may considerably contribute to adaptive response induced by radiation

Matsumoto, H.; Ohnishi, T.


Pyridoxamine protects intestinal epithelium from ionizing radiation-induced apoptosis  

PubMed Central

Reactive oxygen species (ROS) and reactive carbonyl species (RCS) are the major cause of biological tissue damage during the exposure to ionizing radiation (IR). The existing strategies to protect normal tissues from detrimental effects of IR suffer from several shortcomings including high toxic side effects, unfavorable administration routs or low efficacy. These shortcomings emphasize a need for radioprotective treatments that combine effectiveness with safety and ease of use. In this paper, we demonstrate that pyridoxamine, a ROS and RCS scavenger with a very favorable safety profile, can inhibit IR-induced gastrointestinal endothelial apoptosis in cell culture and in animal model. Pyridoxamine was more effective at protecting from radiation-induced apoptosis compared to Amifostine, a synthetic thiol compound and the only FDA approved radioprotector. We suggest that PM has a potential as an effective and safe radioprotective agent. PMID:19540915

Thotala, Dinesh; Chetyrkin, Sergei; Hudson, Billy; Hallahan, Dennis; Voziyan, Paul; Yazlovitskaya, Eugenia



Radiation-induced cerebral meningioma: a recognizable entity  

SciTech Connect

The authors retrospectively analyzed the clinical and histopathological findings in 201 patients with intracranial meningiomas operated on in the period 1978 to 1982. Forty-three of the patients (21.4%) had at some previous time received radiation treatment to their scalp, the majority for tinea capitis. The findings in these 43 irradiated patients were compared with those in the 158 non-irradiated patients. Several distinctive clinical and histological features were identified in the irradiated group, which suggest that radiation-induced meningiomas can be defined as a separate nosological subgroup. The use of irradiation in large numbers of children with tinea capitis in the era prior to the availability of griseofulvin may be responsible for a significantly increased incidence of intracranial meningiomas.

Rubinstein, A.B.; Shalit, M.N.; Cohen, M.L.; Zandbank, U.; Reichenthal, E.



Radiation induced grafting of acrylic acid onto extruded polystyrene surface  

NASA Astrophysics Data System (ADS)

Polystyrene materials with good solubility in liquid scintillation cocktails are used to wipe off different types of surfaces in order to determine the tritium removable contamination with the help of a liquid scintillation counter. This paper analyses hydrophilic surface modifications by radiation induced grafting of acrylic groups onto extruded polystyrene plates. Two grafting methods were used: (a) exposure of extruded polystyrene plates, immersed in aqueous acrylic acid solution, to a gamma radiation of a Co-60 source, and (b) exposure of extruded polystyrene plates to a Co-60 source, followed by the immersion of extruded polystyrene plates in aqueous acrylic acid solution. The grafting of acrylic was proved by IR spectrometry and by radiometric methods using acrylic acid labelled with tritium.

Fugaru, Viorel; Bubueanu, George; Tuta, Catalin



Solar radiation induced rotational bursting of interplanetary particles  

NASA Technical Reports Server (NTRS)

It is suggested that the magnitudes of the two radiation-induced rotational bursting mechanisms (Radzieskii effect and windmill effect) have been overestimated and that they do not work significantly faster than the Poynting-Robertson effect in removing interplanetary particles. These two mechanisms are described, and serious doubts are raised regarding the derivation of their radiation pressure-torque proportionality constants, which are required for calculating their magnitudes. It is shown that both mechanisms will cause the alignment of elongated particles and, consequently, the polarization of zodiacal light. Since no positive polarization has been measured at the antisolar point, it is concluded that the magnitudes of the rotational bursting mechanisms are smaller than that of the Poynting-Robertson effect.

Sparrow, J. G.



Intercellular Adhesion Molecule 1 Knockout Abrogates Radiation Induced Pulmonary Inflammation  

NASA Astrophysics Data System (ADS)

Increased expression of intercellular adhesion molecule 1 (ICAM-1; CD54) is induced by exposure to ionizing radiation. The lung was used as a model to study the role of ICAM-1 in the pathogenesis of the radiation-induced inflammation-like response. ICAM-1 expression increased in the pulmonary microvascular endothelium and not in the endothelium of larger pulmonary vessels following treatment of mice with thoracic irradiation. To quantify radiation-induced ICAM-1 expression, we utilized fluorescence-activated cell sorting analysis of anti-ICAM-1 antibody labeling of pulmonary microvascular endothelial cells from human cadaver donors (HMVEC-L cells). Fluorochrome conjugates and UV microscopy were used to quantify the fluorescence intensity of ICAM in the irradiated lung. These studies showed a dose- and time-dependent increase in ICAM-1 expression in the pulmonary microvascular endothelium. Peak expression occurred at 24 h, while threshold dose was as low as 2 Gy. To determine whether ICAM-1 is required for inflammatory cell infiltration into the irradiated lung, the anti-ICAM-1 blocking antibody was administered by tail vein injection to mice following thoracic irradiation. Inflammatory cells were quantified by immunofluorescence for leukocyte common antigen (CD45). Mice treated with the anti-ICAM-1 blocking antibody showed attenuation of inflammatory cell infiltration into the lung in response to ionizing radiation exposure. To verify the requirement of ICAM-1 in the inflammation-like radiation response, we utilized the ICAM-1 knockout mouse. ICAM-1 was not expressed in the lungs of ICAM-1-deficient mice following treatment with thoracic irradiation. ICAM-1 knockout mice had no increase in the inflammatory cell infiltration into the lung in response to thoracic irradiation. These studies demonstrate a radiation dose-dependent increase in ICAM-1 expression in the pulmonary microvascular endothelium, and show that ICAM-1 is required for inflammatory cell infiltration into the irradiated lung.

Hallahan, Dennis E.; Virudachalam, Subbulakshmi



An amino acid mixture mitigates radiation-induced gastrointestinal toxicity.  


Electrolyte and nutrient absorption occur in villous epithelial cells. Radiation often results in reduced electrolyte and nutrient absorption, which leads to gastrointestinal toxicity. Therefore, the authors studied: (1) radiation-induced changes in glucose and amino acid absorption across ileal tissues and (2) the effect of amino acid mixtures on absorptive capacity. NIH Swiss mice were irradiated (0, 1, 3, 5, or 7 Gy) using a ¹³?Cs source at 0.9 Gy min?¹. Transepithelial short circuit current (I(sc)), dilution potential, and isotope flux determinations were made in Ussing chamber studies and correlated to plasma endotoxin and IL-1? levels. Amino acids that increased electrolyte absorption and improved mucosal barrier functions were used to create a mitigating amino acid mixture (MAAM). The MAAM was given to mice via gastric gavage; thereafter, body weight and survival were recorded. A significant decrease in basal and glucose-stimulated sodium absorption occurred after 0, 1, 3, 5, and 7 Gy irradiation. Ussing chamber studies showed that paracellular permeability increased following irradiation and that the addition of glucose resulted in a further increase in permeability. Following irradiation, certain amino acids manifested decreased absorption, whereas others were associated with increased absorption. Lysine, aspartic acid, glycine, isoleucine, threonine, tyrosine, valine, tryptophan, and serine decreased plasma endotoxins were selected for the MAAM. Mice treated with the MAAM showed increased electrolyte absorption and decreased paracellular permeability, IL-1? levels, and plasma endotoxin levels. Mice treated with MAAM also had increased weight gain and better survival following irradiation. The MAAM has immediate potential for use in mitigating radiation-induced acute gastrointestinal syndrome. PMID:24776907

Yin, Liangjie; Vijaygopal, Pooja; Menon, Rejeesh; Vaught, Lauren A; Zhang, Mei; Zhang, Lurong; Okunieff, Paul; Vidyasagar, Sadasivan



Ion beam induced luminescence: Relevance to radiation induced bystander effects  

NASA Astrophysics Data System (ADS)

The aim of this work is quantify the light emitted as a result of charged particle interaction in materials which may be of relevance to radiation induced "bystander effects" studies. We have developed a system which employs single photon counting to measure the light emitted from samples irradiated under vacuum by a charged particle beam. The system uses a fast photomultiplier tube with a peak cathode response at 420 nm. It has been tested in a proof-of-principle experiment using polystyrene targets. Light output, as a result of irradiation, was measured. The luminescence yield appears to have a non-linear behavior with the incident ion fluence: it rises exponentially to an asymptotic value. The target was irradiated with beam energies varying from 1 to 2 MeV and showed saturation at or before an incident fluence rate of 3 × 1013 H+/cm2 s. The average saturation value for the photon output was found to be 40 × 106 cps. Some measurements were performed using filters to study the emission at specific wavelengths. In the case of filtered light measurements, the photon output was found to saturate at 28 × 103, 10 × 106, and 35 × 106 cps for wavelengths of 280 ± 5 nm, 320 ± 5 nm and 340 ± 5 nm respectively. The light output reaches a maximum value because of damage induced in the polymer. Our measurements indicate a "damage cross section" of the order of 10-14 cm2. The average radiant intensity was found to increase at wavelengths of 280 and 320 nm when the proton energy was increased. This was not found to occur at 340 nm. In conclusion, the light emission at specific wavelengths was found to depend upon the incident proton fluence and the proton energy. The wavelengths of the emitted light measured in this study have significance for the understanding of radiation induced bystander effects.

Ahmad, S. B.; McNeill, F. E.; Byun, S. H.; Prestwich, W. V.; Seymour, C.; Mothersill, C. E.



Bystander effects in radiation-induced genomic instability  

NASA Technical Reports Server (NTRS)

Exposure of GM10115 hamster-human hybrid cells to X-rays can result in the induction of chromosomal instability in the progeny of surviving cells. This instability manifests as the dynamic production of novel sub-populations of cells with unique cytogenetic rearrangements involving the "marker" human chromosome. We have used the comet assay to investigate whether there was an elevated level of endogenous DNA breaks in chromosomally unstable clones that could provide a source for the chromosomal rearrangements and thus account for the persistent instability observed. Our results indicate no significant difference in comet tail measurement between non-irradiated and radiation-induced chromosomally unstable clones. Using two-color fluorescence in situ hybridization we also investigated whether recombinational events involving the interstitial telomere repeat-like sequences in GM10115 cells were involved at frequencies higher than random processes would otherwise predict. Nine of 11 clones demonstrated a significantly higher than expected involvement of these interstitial telomere repeat-like sequences at the recombination junction between the human and hamster chromosomes. Since elevated levels of endogenous breaks were not detected in unstable clones we propose that epigenetic or bystander effects (BSEs) lead to the activation of recombinational pathways that perpetuate the unstable phenotype. Specifically, we expand upon the hypothesis that radiation induces conditions and/or factors that stimulate the production of reactive oxygen species (ROS). These reactive intermediates then contribute to a chronic pro-oxidant environment that cycles over multiple generations, promoting chromosomal recombination and other phenotypes associated with genomic instability.

Morgan, William F.; Hartmann, Andreas; Limoli, Charles L.; Nagar, Shruti; Ponnaiya, Brian



[Radiation-induced cancers: state of the art in 1997].  


Scientists now have available a large amount of data dealing with radiation-induced neoplasms. These data went back to anecdotal observations which were made in the very first years of utilization of X-rays and radioactive elements. In fact, it is essentially the strict follow-up of the Japanese populations irradiated by the Hiroshima and Nagasaki bombing which allowed a more precise evaluation of the carcinogenicity of ionizing radiations. Further refinements came from therapeutical irradiations: it is now possible to study large cohorts of patients given well-known doses in well-defined volumes and followed for more than 20 years. Last but not least, a significant increase in the incidence and mortality of thyroid cancer has been detected in children contaminated by iodine radioisotopes after the Tchernobyl accident. Recently, some data suggested the emergence of "clusters" of leukemias close to some nuclear facilities, but this question remains highly polemical, both in France and in the UK. Other questions are still waiting for a precise answer; of course, the extrapolation of our available data to very low doses delivered at very low dose rates, but also the carcinogenic risk at high doses. For these "high" doses (about 30 to 70 Gy), a competition between mutagenesis and cell killing was expected, so that these dose levels were expected to be less carcinogenic than lower (a few sieverts) doses. Actually, recent data suggest that the carcinogenic risk goes on increasing up to relatively important doses. In addition, carcinogenic factors, such as tabacco, anticancer chemotherapy and individual susceptibility, are found more and more to be closely intricated with ionizing radiation in the genesis of a given cancer. Even if a number of questions are still pending, the already available data allow specialists, both in medicine and radioprotection, to edict strict rules which can be reasonably expected to have significantly reduced the risk of radiation-induced neoplasms in most situations. PMID:9614902

Cosset, J M



Environmental applications of radiation-induced defects in clay minerals  

NASA Astrophysics Data System (ADS)

Radiation effects on clay minerals have been studied over the last 35 years, providing a wealth of information on environmental and geological processes. They have been applied to the reconstruction of past radioelement migrations in the geosphere, the dating of clay minerals from soils or the evolution of the physico-chemical properties under irradiation. All known radiation-induced point defects in clay minerals are detected using Electron Paramagnetic Resonance Spectroscopy. They mostly consist in electron holes located on oxygen atoms of the structure, and can be differentiated through their nature and their thermal stability. For instance, several are associated to a ? orbital on a Si-O bond. One defect, namely the A-center, is stable over geological periods at ambiant temperature. These point defects are produced mainly by ionizing radiations. By contrast to point defects, it was shown that electron or heavy ion irradiation easily produces amorphization in smectites. Two main applications of radiation-induced defects in clay minerals are derived : (i) the use of defects as tracers of past radioactivity. In geosystems where the age of the clay can be constrained, migrations of radioelements can be reconstructed in natural analogues of the far field of high level nuclear waste repositories. When the dose rate may be assumed constant over time, the paleodose is used to date clay populations, an approach applied to laterites of the Amazon basin. (ii) The influence of radiation on clay mineral properties that remains poorly documented, although it is an important issue in various domains such as the safety assessment of the high level nuclear waste repositories. In case of a leakage of transuranic elements from the radioactive wasteform, alpha recoil nuclei would amorphize smectite after a period much lower than the disposal lifetime. By contrast, amorphisation from ionizing radiation is unlikely over 1 million years. Furthermore, it was shown that amorphization greatly enhances the dissolution kinetics of smectite, a result that must be taken into account in the safety assessment of engineered barriers.

Allard, T.



Gene expression profiles for radiation-induced thyroid cancer.  


The question whether radiation-induced thyroid cancer differs by its molecular biology from sporadic disease still remains. Studies on tissue from patients who developed thyroid cancer after the Chernobyl accident have provided a unique opportunity to look for biological consequences of low-dose irradiation by comparing the gene expression profile of sporadic papillary thyroid cancer (PTC), whose aetiology is unknown, and PTC induced by internal radiation. So far, four transcriptomic studies comparing radiation-induced and sporadic thyroid cancer have been reported. However, no final conclusion has been drawn regarding the presence of a radiation signature, as either no difference was noted or the reported differences were not sufficiently convincing due to the low number of cases analysed or to the presence of confounding factors. The list of putative biological and clinical factors that may influence the PTC gene expression profile is long, but there are sufficient data reported in the literature to link expression profiles with differing pathological variants of PTC. The comparison of expression profiles in the tumour samples allows the search for a radiation signature, whereas the comparison of expression profiles of the normal contralateral tissues offers a substantial opportunity for assessing the existence of a susceptibility to radiation that could be responsible for tumour development. We have undertaken this analysis as part of a European Union-funded project, GENRISK-T. Gene expression profiles were investigated in tumours that have arisen in the population exposed to fallout from Chernobyl (i.e. born before 26 April 1986) and were compared with profiles of tumours of similar pathology arising in an age-matched population, residing in the same geographical area (same ethnicity) and born after 1 January 1987. RNA samples from these tumours and their contralateral normal tissues were obtained from the Chernobyl Tissue Bank. Several lines of evidence suggest that the predisposition to developing cancer after radiation exposure is variable in the general population and may be measurable from gene expression. PMID:21411301

Maenhaut, C; Detours, V; Dom, G; Handkiewicz-Junak, D; Oczko-Wojciechowska, M; Jarzab, B



Bystander effects in radiation-induced genomic instability.  


Exposure of GM10115 hamster-human hybrid cells to X-rays can result in the induction of chromosomal instability in the progeny of surviving cells. This instability manifests as the dynamic production of novel sub-populations of cells with unique cytogenetic rearrangements involving the "marker" human chromosome. We have used the comet assay to investigate whether there was an elevated level of endogenous DNA breaks in chromosomally unstable clones that could provide a source for the chromosomal rearrangements and thus account for the persistent instability observed. Our results indicate no significant difference in comet tail measurement between non-irradiated and radiation-induced chromosomally unstable clones. Using two-color fluorescence in situ hybridization we also investigated whether recombinational events involving the interstitial telomere repeat-like sequences in GM10115 cells were involved at frequencies higher than random processes would otherwise predict. Nine of 11 clones demonstrated a significantly higher than expected involvement of these interstitial telomere repeat-like sequences at the recombination junction between the human and hamster chromosomes. Since elevated levels of endogenous breaks were not detected in unstable clones we propose that epigenetic or bystander effects (BSEs) lead to the activation of recombinational pathways that perpetuate the unstable phenotype. Specifically, we expand upon the hypothesis that radiation induces conditions and/or factors that stimulate the production of reactive oxygen species (ROS). These reactive intermediates then contribute to a chronic pro-oxidant environment that cycles over multiple generations, promoting chromosomal recombination and other phenotypes associated with genomic instability. PMID:12106650

Morgan, William F; Hartmann, Andreas; Limoli, Charles L; Nagar, Shruti; Ponnaiya, Brian



Radiation-induced cell death: importance of lysosomal destabilization  

PubMed Central

The mechanisms involved in radiation-induced cellular injury and death remain incompletely understood. In addition to the direct formation of highly reactive hydroxyl radicals (HO·) by radiolysis of water, oxidative stress events in the cytoplasm due to formation of H2O2 may also be important. Since the major pool of low-mass redox-active intracellular iron seems to reside within lysosomes, arising from the continuous intralysosomal autophagocytotic degradation of ferruginous materials, formation of H2O2 inside and outside these organelles may cause lysosomal labilization with release to the cytosol of lytic enzymes and low-mass iron. If of limited magnitude, such release may induce ‘reparative autophagocytosis’, causing additional accumulation of redox-active iron within the lysosomal compartment. We have used radio-resistant histiocytic lymphoma (J774) cells to assess the importance of intralysosomal iron and lysosomal rupture in radiation-induced cellular injury. We found that a 40 Gy radiation dose increased the ‘loose’ iron content of the (still viable) cells approx. 5-fold when assayed 24 h later. Cytochemical staining revealed that most redox-active iron was within the lysosomes. The increase of intralysosomal iron was associated with ‘reparative autophagocytosis’, and sensitized cells to lysosomal rupture and consequent apoptotic/necrotic death following a second, much lower dose of radiation (20 Gy) 24 h after the first one. A high-molecular-mass derivative of desferrioxamine, which specifically localizes intralysosomally following endocytic uptake, added to the culture medium before either the first or the second dose of radiation, stabilized lysosomes and largely prevented cell death. These observations may provide a biological rationale for fractionated radiation. PMID:15813701



Molecular Genetic Alterations in Radiation-Induced Astrocytomas  

PubMed Central

Astrocytic tumors occasionally arise in the central nervous system following radiotherapy. It is not clear if these gliomas represent a unique molecular genetic subset. We identified nine cases in which an astrocytoma arose within ports of previous radiation therapy, with total doses ranging from 2400 to 5500 cGy. Irradiated primary lesions included craniopharyngioma, pituitary adenoma, Hodgkin’s lymphoma, ependymoma, pineal neoplasm, rhabdomyosarcoma, and three cases of lymphoblastic malignancies. Patients ranged from 9 to 60 years of age and developed secondary tumors 5 to 23 years after radiotherapy. The 9 postradiation neoplasms presented as either anaplastic astrocytoma (3 cases) or glioblastoma multiforme (6 cases). Two of the latter contained malignant mesenchymal components. We performed DNA sequence analysis, differential polymerase chain reaction (PCR), and quantitative PCR on DNA from formalin-fixed, paraffin-embedded tumors to evaluate possible alterations of p53, PTEN, K-ras, EGFR, MTAP, and p16 (MTS1/CDKN2) genes. By quantitative PCR, we found EGFR gene amplification in 2 of 8 tumors. One of these demonstrated strong immunoreactivity for EGFR. Quantitative PCR showed chromosome 9p deletions including p16 tumor suppressor gene (2 of 7 tumors) and MTAP gene (3 of 7). Five of 9 tumors demonstrated diffuse nuclear immunoreactivity for p53 protein. Sequencing of the p53 gene in these 9 cases revealed a mutation in only one of these cases, a G-to-A substitution in codon 285 (exon 8). Somewhat unexpectedly, no mutations were identified in PTEN, a commonly altered tumor suppressor gene in de novo glioblastoma multiformes. Unlike some radiation-induced tumors, no activating point mutations of the K-ras proto-oncogene or base pair deletions of tumor suppressor genes were noted. These radiation-induced tumors are distinctive in their high histological grade at clinical presentation. The spectrum of molecular genetic alterations appears to be similar to that described in spontaneous high grade astrocytomas, especially those of the de novo type. PMID:10329596

Brat, Daniel J.; James, C. David; Jedlicka, Anne E.; Connolly, Denise C.; Chang, Ed; Castellani, Rudy J.; Schmid, Mathias; Schiller, Martin; Carson, Dennis A.; Burger, Peter C.



Radiation-induced leukemia: Comparative studies in mouse and man  

SciTech Connect

We now have a clear understanding of the mechanism by which radiation-induced (T-cell) leukemia occurs. In irradiated mice (radiation-induced thymic leukemia) and in man (acute lymphoblastic T-cell leukemia, T-ALL) the mechanism of leukemogenesis is surprisingly similar. Expressed in the most elementary terms, T-cell leukemia occurs when T-cell differentiation is inhibited by a mutation, and pre-T cells attempt but fail to differentiate in the thymus. Instead of leaving the thymus for the periphery as functional T-cells they continue to proliferate in the thymus. The proliferating pre- (pro-) T-cells constitute the (early) acute T-cell leukemia (A-TCL). This model for the mechanism of T-cell leukemogenesis accounts for all the properties of both murine and human A-TCL. Important support for the model has recently come from work by Ilan Kirsch and others, who have shown that mutations/deletions in the genes SCL (TAL), SIL, and LCK constitute primary events in the development of T-ALL, by inhibiting differentiation of thymic pre- (pro-) T-cells. This mechanism of T-cell leukemogenesis brings several specific questions into focus: How do early A-TCL cells progress to become potently tumorigenic and poorly treatable Is it feasible to genetically suppress early and/or progressed A-TCL cells What is the mechanism by which the differentiation-inhibited (leukemic) pre-T cells proliferate During the first grant year we have worked on aspects of all three questions.

Haas, M.



Brachial Plexus Impingement: An Unusual Complication of Bilateral Breast Augmentation  

Microsoft Academic Search

Breast augmentation is one of the most commonly performed aesthetic procedures, with many studies documenting the early and\\u000a long-term complications that might be expected. This report describes the case of an active young woman who experienced severe\\u000a pain, particularly with movement. Surgical exploration showed the cause of this pain to be impingement of the patient’s lower\\u000a brachial plexus by the

MG Berry; J. J. Stanek



Scapular deformity in obstetric brachial plexus palsy: a new finding  

Microsoft Academic Search

While most obstetric brachial plexus palsy patients recover arm and hand function, the residual nerve weakness leads to muscle\\u000a imbalances about the shoulder which may cause bony deformities. In this paper we describe abnormalities in the developing\\u000a scapula and the glenohumeral joint. We introduce a classification for the deformity which we term Scapular Hypoplasia, Elevation\\u000a and Rotation. Multiple anatomic parameters

Rahul K. Nath; Melia Paizi



Surgical treatment of brachial plexus injuries in adults  

Microsoft Academic Search

We carried out a retrospective review of 32 consecutive patients (30 adults and two children) with total or partial lesions\\u000a of the brachial plexus who had surgical repair using nerve grafting, neurotisation, and neurolysis between January 1991 and\\u000a December 2003. The outcome measures of muscular strength were correlated with the type of lesion, age, preoperative time,\\u000a length and number of

Monreal Ricardo



Brachial-jugular Expanded PTFE Grafts for Dialysis  

Microsoft Academic Search

  The objective of this study was to analyze the long-term outcome of 51 patients with brachial-jugular grafts for dialysis.\\u000a Age, presence of diabetic nephropathy, complications of the angio-access, and therapeutic methods of treating complications\\u000a were analyzed. All surgical procedures were performed under local anesthesia in an ambulatory surgical setting. The duration\\u000a of angio-access was analyzed using the life-table method. Our

Daniel Vega; José R. Polo; Jorge Polo; Jose A. López Baena; David Pacheco; Rosario García-Pajares



Method for surgical access to the brachial plexus.  


Problem of brachial plexus injuries is deemed one of the most topical in contemporary surgery. Irrespective of the newest achievements in medical science and technique, outcomes of treatment of brachial plexus injuries are yet incapable to be estimated as satisfactory. Quality of technical performance in many respects depends on convenience of access to the structures to be operated. The deficiency of the offered methods is that they are incapable to ensure sufficiently wide access to indicated structures, thus making operation more complicated and long and depressing functional and esthetical outcomes of the surgical treatment. The method, offered by us, is deemed to be solution of the above-mentioned problems. The core of the method is making of additional incision along lateral side of the horizontal wound, cutting out collarbone segment along the sides of wound and peeling up the formed rectangular clout, ensuring the wide access to the appropriate structures. We have examined and operated 59 patients with pathologies of brachial plexus and nearby structures. In 22 cases, where we applied the methodology offered by us, the above-mentioned complications did not arise: wide access facilitated technical aspect of the operation, reducing the duration of corresponding operation by in average 13-20%. Healing of wounds in both cases -- singularity-free. Controlling X-ray have shown successful coalescence of cut-off segments of collarbone without any deformation along axis. Method for ensuring access to brachial plexus, offered by us, provides more extensive and easier mobilization of plexus elements and nearby structures, facilitates technical side of the operation, shortens duration of surgical operation, and, finally, improves outcomes of treatment. PMID:16510901

Pheradze, I; Pheradze, T; Baratashvili, M



The Development of Countermeasures for Space Radiation Induced Adverse Health Effects  

Microsoft Academic Search

The Development of Countermeasures for Space Radiation Induced Adverse Health Effects Ann R. Kennedy Department of Radiation Oncology, University of Pennsylvania School of Medicine, 195 John Morgan Building, 3620 Hamilton Walk, Philadelphia, PA, United States 19104-6072 The development of countermeasures for radiation induced adverse health effects is a lengthy process, particularly when the countermeasure\\/drug has not yet been evaluated in

Ann Kennedy



Deep Level Transient Spectroscopy Technique to Analyze Radiation Induced Defects in Power Transistors  

SciTech Connect

Deep Level Transient Spectroscopy (DLTS) technique is useful tool to study process and radiation induced defects in semiconductor materials and devices. The different types of radiation induced trap levels in the collector-base depletion region of the transistors were studied by DLTS technique.

Prakash, A. P. Gnana [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore, Karnataka-570006 (India)



Radiation-induced stress change in polymers during irradiation by electrons  

Microsoft Academic Search

The goal of this study is to experimentally validate equations previously used to describe a radiation-induced stress change (RSC) in polymers. Radiation-induced creep is due to the freeing of volumes of the material with the breakdown of a bond. With an increase in molecular mobility, the contribution of single defects to creep may be an appreciable fraction of the contribution

E. A. Barbashev; V. A. Bogatov; V. I. Kozin; B. I. Panshin



New principles of radiation damage and recovery based on the radiation induced emission of Schottky defects  

Microsoft Academic Search

New concept of radiation-induced emission of Schottky defects from extended defects is proposed, which acts in the opposite direction compared with Frenkel pair production, and it results in the radiation-induced recovery processes. The vacancy emission from a void surface results in a shrinkage of the void which is analogous to the thermal void shrinkage at high temperatures, but it is

Vladimir I. Dubinko



Prevalence of minisatellite and microsatellite instability in radiation-induced post-Chernobyl pediatric thyroid carcinomas  

Microsoft Academic Search

Exposure to ionizing radiation induces different forms of genomic instability in cultured cells and experimental animals. A higher rate of germline mutations at human hypervariable minisatellite loci was reported in children born from parents exposed to radiation after Chernobyl, implicating genome destabilization as a possible mechanism responsible for late radiation effects in humans. To test if radiation-induced carcinogenesis in the

Yuri E Nikiforov; Marina Nikiforova; James A Fagin; A Fagin



Early hyperbaric oxygen therapy improves outcome for radiation-induced hemorrhagic cystitis  

Microsoft Academic Search

ObjectivesTo assess the clinical factors that affect the efficacy of hyperbaric oxygen (HBO2) therapy in treating radiation-induced hemorrhagic cystitis. HBO2 therapy is an effective treatment for radiation-induced hemorrhagic cystitis, with reported response rates ranging from 76% to 100%.

Kian Tai Chong; Neil B. Hampson; John M. Corman



Scapular deformity in obstetric brachial plexus palsy: a new finding.  


While most obstetric brachial plexus palsy patients recover arm and hand function, the residual nerve weakness leads to muscle imbalances about the shoulder which may cause bony deformities. In this paper we describe abnormalities in the developing scapula and the glenohumeral joint. We introduce a classification for the deformity which we term Scapular Hypoplasia, Elevation and Rotation. Multiple anatomic parameters were measured in bilateral CT images and three-dimensional CT reconstruction of the shoulder girdle of 30 obstetric brachial plexus palsy patients (age range 10 months-10.6 years). The affected scapulae were found to be hypoplastic by an average of 14% while the ratio of the height to the width of the body of scapula (excluding acromion) were not significantly changed, the acromion was significantly elongated by an average of 19%. These parameters as well as subluxation of the humeral head (average 14%) and downward rotation in the scapular plane were found to correlate with the area of scapula visible over the clavicle. This finding provides a classification tool for diagnosis and objective evaluation of the bony deformity and its severity in obstetric brachial plexus palsy patients. PMID:17262175

Nath, Rahul K; Paizi, Melia



Thoracic Outlet Syndrome Caused by Schwannoma of Brachial Plexus  

PubMed Central

Schwannomas are benign, usually slow-growing tumors that originate from Schwann cells surrounding peripheral, cranial, or autonomic nerves. The most common form of these tumors is acoustic neuroma. Schwannomas of the brachial plexus are quite rare, and symptomatic schwannomas of the brachial plexus are even rarer. A 47-year-old woman presented with a 1-year history of dysesthesia, neuropathic pain, and mild weakness of the right upper limb. Results of physical examination and electrodiagnostic studies supported a diagnosis as thoracic outlet syndrome. Conservative treatment did not relieve her symptoms. After 9 months, a soft mass was found at the upper margin of the right clavicle. Magnetic resonance imaging showed a 3.0×1.8×1.7 cm ovoid mass between the inferior trunk and the anterior division of the brachial plexus. Surgical mass excision and biopsy were performed. Pathological findings revealed the presence of schwannoma. After schwannoma removal, the right hand weakness did not progress any further and neuropathic pain gradually reduced. However, dysesthesia at the right C8 and T1 dermatome did not improve. PMID:24466527

Yun, Dong Hwan; Kim, Hee-Sang; Chon, Jinmann; Jung, Pil Kyo



Radiation-induced segregation and phase stability in ferritic-martensitic alloy T 91  

NASA Astrophysics Data System (ADS)

Radiation-induced segregation in ferritic-martensitic alloy T 91 was studied to understand the behavior of solutes as a function of dose and temperature. Irradiations were conducted using 2 MeV protons to doses of 1, 3, 7 and 10 dpa at 400 °C. Radiation-induced segregation at prior austenite grain boundaries was measured, and various features of the irradiated microstructure were characterized, including grain boundary carbide coverage, the dislocation microstructure, radiation-induced precipitation and irradiation hardening. Results showed that Cr, Ni and Si segregate to prior austenite grain boundaries at low dose, but segregation ceases and redistribution occurs above 3 dpa. Grain boundary carbide coverage mirrors radiation-induced segregation. Irradiation induces formation of Ni-Si-Mn and Cu-rich precipitates that account for the majority of irradiation hardening. Radiation-induced segregation behavior is likely linked to the evolution of the precipitate and dislocation microstructures.

Wharry, Janelle P.; Jiao, Zhijie; Shankar, Vani; Busby, Jeremy T.; Was, Gary S.



Nuclear scintigraphic assessment of radiation-induced intestinal dysfunction.  


Radiation-induced damage to the intestine can be measured by abnormalities in the absorption of various nutrients. Changes in intestinal absorption occur after irradiation because of loss of the intestinal absorptive surface and a consequent decrease in active transport. In our study, the jejunal absorption of (99m)Tc-pertechnetate, an actively transported gamma-ray emitter, was assessed in C3H/Kam mice given total-body irradiation with doses of 4, 6, 8 and 12.5 Gy and correlated with morphological changes in the intestinal epithelium. The absorption of (99m)Tc-pertechnetate from the intestinal lumen into the circulation was studied with a dynamic gamma-ray-scintigraphy assay combined with a multichannel analyzer to record the radiometry data automatically in a time-dependent regimen. The resulting radioactivity-time curves obtained for irradiated animals were compared to those for control animals. A dose-dependent decrease in absorptive function was observed 3.5 days after irradiation. The mean absorption rate was reduced to 78.8 +/- 9.3% of control levels in response to 4 Gy total-body irradiation (mean +/- SEM tracer absorption lifetime was 237 +/- 23 s compared to 187 +/- 12 s in nonirradiated controls) and to 28.3 +/- 3.7% in response to 12.5 Gy (660 +/- 76 s). The decrease in absorption of (99m)Tc-pertechnetate at 3.5 days after irradiation correlated strongly (P < 0.001) with TBI dose, with the number of cells per villus, and with the percentage of cells in the crypt compartment that were apoptotic or mitotic. A jejunal microcolony assay showed no loss of crypts and hence no measured dose-response effects after 4, 6 or 8 Gy TBI. These results show that dynamic enteroscintigraphy with sodium (99m)Tc-pertechnetate is a sensitive functional assay for rapid evaluation of radiation-induced intestinal damage in the clinically relevant dose range and has a cellular basis. PMID:10629615

Kirichenko, A V; Mason, K A; Straume, M; Teates, C D; Rich, T A



Hyperbaric Oxygen Therapy for Radiation-Induced Cystitis and Proctitis  

SciTech Connect

Purpose: To provide a retrospective analysis of the efficacy of hyperbaric oxygen therapy (HBOT) for treating hemorrhagic cystitis (HC) and proctitis secondary to pelvic- and prostate-only radiotherapy. Methods and Materials: Nineteen patients were treated with HBOT for radiation-induced HC and proctitis. The median age at treatment was 66 years (range, 15-84 years). The range of external-beam radiation delivered was 50.0-75.6 Gy. Bleeding must have been refractory to other therapies. Patients received 100% oxygen at 2.0 atmospheres absolute pressure for 90-120 min per treatment in a monoplace chamber. Symptoms were retrospectively scored according to the Late Effects of Normal Tissues-Subjective, Objective, Management, Analytic (LENT-SOMA) scale to evaluate short-term efficacy. Recurrence of hematuria/hematochezia was used to assess long-term efficacy. Results: Four of the 19 patients were lost to follow-up. Fifteen patients were evaluated and received a mean of 29.8 dives: 11 developed HC and 4 proctitis. All patients experienced a reduction in their LENT-SOMA score. After completion of HBOT, the mean LENT-SOMA score was reduced from 0.78 to 0.20 in patients with HC and from 0.66 to 0.26 in patients with proctitis. Median follow-up was 39 months (range, 7-70 months). No cases of hematuria were refractory to HBOT. Complete resolution of hematuria was seen in 81% (n = 9) and partial response in 18% (n = 2). Recurrence of hematuria occurred in 36% (n = 4) after a median of 10 months. Complete resolution of hematochezia was seen in 50% (n = 2), partial response in 25% (n = 1), and refractory bleeding in 25% (n = 1). Conclusions: Hyperbaric oxygen therapy is appropriate for radiation-induced HC once less time-consuming therapies have failed to resolve the bleeding. In these conditions, HBOT is efficacious in the short and long term, with minimal side effects.

Oliai, Caspian; Fisher, Brandon; Jani, Ashish; Wong, Michael; Poli, Jaganmohan; Brady, Luther W. [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States)] [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States); Komarnicky, Lydia T., E-mail: [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States)



Determination of Spread of Injectate After Ultrasound-guided Interscalene and Supraclavicular Brachial Plexus Block: A Fresh Cadaveric Study  

Microsoft Academic Search

ObjectiveThe aim of this anatomical study was to establish the likely spread of local anesthetics in vivo and the segmental nerve involvement resulting from ultrasound-guided interscalene brachial plexus blocks and supraclavicular brachial plexus blocks.

Jimmy Ong; Hsien-Yong Lai; Li-Fu Cheng; Pei-Chin Lin; Chia-Ling Lee; Tsung-Ying Chen; Po-Kai Wang



Space-radiation-induced photon luminescence of the Moon  

NASA Astrophysics Data System (ADS)

We report on the results of a continuing study of the photon luminescence of the Moon induced by Galactic Cosmic Rays (GCRs) and space radiation from the Sun, using the Monte Carlo program FLUKA. Understanding the space radiation environment is critical to future exploration of the Moon, and this includes photons. The model of the lunar surface is taken to be the chemical composition of soils found at various landing sites during the Apollo and Luna programs, averaged over all such sites to define a generic regolith for the present analysis. This surface model then becomes the target that is bombarded by Galactic Cosmic Rays (GCRs) and Solar Energetic Particles (SEPs) or Solar Particle Events (SPEs) above 1 keV in FLUKA to determine the photon fluence albedo produced by the Moon's surface when there is no sunlight and Earthshine. The result is to be distinguished from the gamma-ray spectrum produced by the radioactive decay of radiogenic constituents lying in the surface and interior of the Moon. From the photon fluence we derive the spectrum which can be utilized to examine existing lunar spectral data and to aid future orbiting instrumentation in the measurement of various components of the space-radiation-induced photon luminescence present on the Moon.

Lee, K. T.; Wilson, T. L.



Space-Radiation-Induced Photon Luminescence of the Moon  

NASA Astrophysics Data System (ADS)

We report on the results of a study of the photon luminescence of the Moon induced by Galactic Cosmic Rays (GCRs) and space radiation from the Sun, using the Monte Carlo program FLUKA. The model of the lunar surface is taken to be the chemical composition of soils found at various landing sites during the Apollo and Luna programs, averaged over all such sites to define a generic regolith for the present analysis. This then becomes the target that is bombarded by Galactic Cosmic Rays (GCRs) and Solar Energetic Particles (SEPs) above 1 keV in FLUKA to determine the photon fluence albedo produced by the Moon's surface when there is no sunlight and Earthshine. This is to be distinguished from the gamma-ray spectrum produced by the radioactive decay of radiogenic constituents lying in the surface and interior of the Moon. From the photon fluence we derive the spectrum which can be utilized to examine existing lunar spectral data and to design orbiting instrumentation for measuring various components of the space-radiation-induced photon luminescence present on the Moon.

Wilson, Thomas


Radiation induced thyroid neoplasms 1920 to 1987: A vanishing problem  

SciTech Connect

Radiation for benign diseases has been implicated as an etiologic factor in thyroid cancer. From 1930-60, over 2 million children may have been exposed to therapeutic radiation and it is estimated that up to 7% may develop thyroid cancer after a 5-40 year latency. Thyroid stimulating hormone, secondary to radioinduced hypothyroidism, has been implicated as causative in animals. Such data has led to expensive screening programs in high risk patients. Because of a decline in irradiation for benign diseases in children over the last 2 decades, we questioned whether the incidence of radiation induced thyroid neoplasms (RITN) was also decreasing. Twenty-six of 227 patients (11%) with thyroid malignancies seen at our institution from 1974-87 had a history of previous head and neck irradiation. These included 13 papillary, 3 follicular, and 7 mixed carcinomas as well as 2 lymphomas and 1 synovial cell sarcoma. None of these 26 patients had abnormal thyroid function tests at presentation. Mean latency from irradiation to the diagnosis of thyroid cancer was 25.4 years (6-55 year range). Compared to the reported increasing incidence of RITN from 1940-70, there appears to be a significant decrease since 1970. Based on our analysis, the use of expensive screening programs in high risk populations may no longer be warranted. Additionally, the routine use of thyroid replacement in previously irradiated chemically hypothyroid patients is not recommended.30 references.

Mehta, M.P.; Goetowski, P.G.; Kinsella, T.J.



Radiation-Induced Bystander Response: Mechanism and Clinical Implications  

PubMed Central

Significance: Absorption of energy from ionizing radiation (IR) to the genetic material in the cell gives rise to damage to DNA in a dose-dependent manner. There are two types of DNA damage; by a high dose (causing acute or deterministic effects) and by a low dose (related to chronic or stochastic effects), both of which induce different health effects. Among radiation effects, acute cutaneous radiation syndrome results from cell killing as a consequence of high-dose exposure. Recent advances: Recent advances in radiation biology and oncology have demonstrated that bystander effects, which are emerged in cells that have never been exposed, but neighboring irradiated cells, are also involved in radiation effects. Bystander effects are now recognized as an indispensable component of tissue response related to deleterious effects of IR. Critical issues: Evidence has indicated that nonapoptotic premature senescence is commonly observed in various tissues and organs. Senesced cells were found to secrete various proteins, including cytokines, chemokines, and growth factors, most of which are equivalent to those identified as bystander factors. Secreted factors could trigger cell proliferation, angiogenesis, cell migration, inflammatory response, etc., which provide a tissue microenvironment assisting tissue repair and remodeling. Future directions: Understandings of the mechanisms and physiological relevance of radiation-induced bystander effects are quite essential for the beneficial control of wound healing and care. Further studies should extend our knowledge of the mechanisms of bystander effects and mode of cell death in response to IR. PMID:24761341

Suzuki, Keiji; Yamashita, Shunichi



Radiation-induced edema after Gamma Knife treatment for meningiomas.  


A retrospective study was performed to analyze some parameters in a consecutive series of 35 Gamma Knife treatments in 34 patients with benign meningiomas. The minimum dose to the tumors was never less than 12 Gy. The follow-up period was from 1 to 3 years. A semiquantitative method of tumor volume assessment was used to measure the tumor response to treatment. The presence and clinical significance of postradiation edema were noted. Even in this short follow-up period, 11 of the 35 tumors were reduced in volume. No tumors increased in size. Edema developed preferentially in nonbasal tumors, especially those around the midline and sagittal sinus. In all but one case where radiation-induced edema was observed was the margin tumor dose 18 Gy or more. It is suggested that doses of 18 Gy or more should probably be avoided in the Gamma Knife treatment of meningiomas and that the greatest care should be taken in selecting non-skull base tumors for this form of treatment. PMID:9032853

Ganz, J C; Schröttner, O; Pendl, G



Molecular Mechanisms and Treatment of Radiation-Induced Lung Fibrosis  

PubMed Central

Radiation-induced lung fibrosis (RILF) is a severe side effect of radiotherapy in lung cancer patients that presents as a progressive pulmonary injury combined with chronic inflammation and exaggerated organ repair. RILF is a major barrier to improving the cure rate and well-being of lung cancer patients because it limits the radiation dose that is required to effectively kill tumor cells and diminishes normal lung function. Although the exact mechanism is unclear, accumulating evidence suggests that various cells, cytokines and regulatory molecules are involved in the tissue reorganization and immune response modulation that occur in RILF. In this review, we will summarize the general symptoms, diagnostics, and current understanding of the cells and molecular factors that are linked to the signaling networks implicated in RILF. Potential approaches for the treatment of RILF will also be discussed. Elucidating the key molecular mediators that initiate and control the extent of RILF in response to therapeutic radiation may reveal additional targets for RILF treatment to significantly improve the efficacy of radiotherapy for lung cancer patients.

Ding, Nian-Hua; Li, Jian Jian; Sun, Lun-Quan



Radiation-induced optic neuropathy: A magnetic resonance imaging study  

SciTech Connect

Optic neuropathy induced by radiation is an infrequent cause of delayed visual loss that may at times be difficult to differentiate from compression of the visual pathways by recurrent neoplasm. The authors describe six patients with this disorder who experienced loss of vision 6 to 36 months after neurological surgery and radiation therapy. Of the six patients in the series, two had a pituitary adenoma and one each had a metastatic melanoma, multiple myeloma, craniopharyngioma, and lymphoepithelioma. Visual acuity in the affected eyes ranged from 20/25 to no light perception. Magnetic resonance (MR) imaging showed sellar and parasellar recurrence of both pituitary adenomas, but the intrinsic lesions of the optic nerves and optic chiasm induced by radiation were enhanced after gadolinium-diethylenetriaminepenta-acetic acid (DTPA) administration and were clearly distinguishable from the suprasellar compression of tumor. Repeated MR imaging showed spontaneous resolution of gadolinium-DTPA enhancement of the optic nerve in a patient who was initially suspected of harboring recurrence of a metastatic malignant melanoma as the cause of visual loss. The authors found the presumptive diagnosis of radiation-induced optic neuropathy facilitated by MR imaging with gadolinium-DTPA. This neuro-imaging procedure may help avert exploratory surgery in some patients with recurrent neoplasm in whom the etiology of visual loss is uncertain.

Guy, J.; Mancuso, A.; Beck, R.; Moster, M.L.; Sedwick, L.A.; Quisling, R.G.; Rhoton, A.L. Jr.; Protzko, E.E.; Schiffman, J. (Univ. of Florida, Gainesville (USA))



Radiation-Induced Notch Signaling in Breast Cancer Stem Cells  

SciTech Connect

Purpose: To explore patterns of Notch receptor and ligand expression in response to radiation that could be crucial in defining optimal dosing schemes for ?-secretase inhibitors if combined with radiation. Methods and Materials: Using MCF-7 and T47D breast cancer cell lines, we used real-time reverse transcription–polymerase chain reaction to study the Notch pathway in response to radiation. Results: We show that Notch receptor and ligand expression during the first 48 hours after irradiation followed a complex radiation dose–dependent pattern and was most pronounced in mammospheres, enriched for breast cancer stem cells. Additionally, radiation activated the Notch pathway. Treatment with a ?-secretase inhibitor prevented radiation-induced Notch family gene expression and led to a significant reduction in the size of the breast cancer stem cell pool. Conclusions: Our results indicate that, if combined with radiation, ?-secretase inhibitors may prevent up-regulation of Notch receptor and ligand family members and thus reduce the number of surviving breast cancer stem cells.

Lagadec, Chann [Department of Radiation Oncology, David Geffen School of Medicine at University of California, Los Angeles (UCLA), Los Angeles, California (United States); Vlashi, Erina [Department of Radiation Oncology, David Geffen School of Medicine at University of California, Los Angeles (UCLA), Los Angeles, California (United States); Jonsson Comprehensive Cancer Center at UCLA, Los Angeles, California (United States); Alhiyari, Yazeed; Phillips, Tiffany M.; Bochkur Dratver, Milana [Department of Radiation Oncology, David Geffen School of Medicine at University of California, Los Angeles (UCLA), Los Angeles, California (United States); Pajonk, Frank, E-mail: [Department of Radiation Oncology, David Geffen School of Medicine at University of California, Los Angeles (UCLA), Los Angeles, California (United States); Jonsson Comprehensive Cancer Center at UCLA, Los Angeles, California (United States)



Radiation-induced chromosomal instability in human mammary epithelial cells  

NASA Technical Reports Server (NTRS)

Karyotypes of human cells surviving X- and alpha-irradiation have been studied. Human mammary epithelial cells of the immortal, non-tumorigenic cell line H184B5 F5-1 M/10 were irradiated and surviving clones isolated and expanded in culture. Cytogenetic analysis was performed using dedicated software with an image analyzer. We have found that both high- and low-LET radiation induced chromosomal instability in long-term cultures, but with different characteristics. Complex chromosomal rearrangements were observed after X-rays, while chromosome loss predominated after alpha-particles. Deletions were observed in both cases. In clones derived from cells exposed to alpha-particles, some cells showed extensive chromosome breaking and double minutes. Genomic instability was correlated to delayed reproductive death and neoplastic transformation. These results indicate that chromosomal instability is a radiation-quality-dependent effect which could determine late genetic effects, and should therefore be carefully considered in the evaluation of risk for space missions.

Durante, M.; Grossi, G. F.; Yang, T. C.



Mechanisms of radiation-induced neoplastic cell transformation  

SciTech Connect

Studies with cultured mammalian cells demonstrated clearly that radiation can transform cells directly and can enhance the cell transformation by oncogenic DNA viruses. In general, high-LET heavy-ion radiation can be more effective than X and gamma rays in inducing neoplastic cell transformation. Various experimental results indicate that radiation-induced DNA damage, most likely double-strand breaks, is important for both the initiation of cell transformation and for the enhancement of viral transformation. Some of the transformation and enhancement lesions can be repaired properly in the cell, and the amount of irrepairable lesions produced by a given dose depends on the quality of radiation. An inhibition of repair processes with chemical agents can increase the transformation frequency of cells exposed to radiation and/or oncogenic viruses, suggesting that repair mechanisms may play an important role in the radiation transformation. The progression of radiation-transformed cells appears to be a long and complicated process that can be modulated by some nonmutagenic chemical agents, e.g., DMSO. Normal cells can inhibit the expression of transforming properties of tumorigenic cells through an as yet unknown mechanism. The progression and expression of transformation may involve some epigenetic changes in the irradiated cells. 38 references, 15 figures, 1 table.

Yang, T.C.H.; Tobias, C.A.



Effect of Epicatechin against Radiation-Induced Oral Mucositis: In Vitro and In Vivo Study  

PubMed Central

Purpose Radiation-induced oral mucositis limits the delivery of high-dose radiation to head and neck cancer. This study investigated the effectiveness of epicatechin (EC), a component of green tea extracts, on radiation-induced oral mucositis in vitro and in vivo. Experimental Design The effect of EC on radiation-induced cytotoxicity was analyzed in the human keratinocyte line HaCaT. Radiation-induced apoptosis, change in mitochondrial membrane potential (MMP), reactive oxygen species (ROS) generation and changes in the signaling pathway were investigated. In vivo therapeutic effects of EC for oral mucositis were explored in a rat model. Rats were monitored by daily inspections of the oral cavity, amount of oral intake, weight change and survival rate. For histopathologic evaluation, hematoxylin-eosin staining and TUNEL staining were performed. Results EC significantly inhibited radiation-induced apoptosis, change of MMP, and intracellular ROS generation in HaCaT cells. EC treatment markedly attenuated the expression of p-JNK, p-38, and cleaved caspase-3 after irradiation in the HaCaT cells. Rats with radiation-induced oral mucositis showed decreased oral intake, weight and survival rate, but oral administration of EC significantly restored all three parameters. Histopathologic changes were significantly decreased in the EC-treated irradiated rats. TUNEL staining of rat oral mucosa revealed that EC treatment significantly decreased radiation-induced apoptotic cells. Conclusions This study suggests that EC significantly inhibited radiation-induced apoptosis in keratinocytes and rat oral mucosa and may be a safe and effective candidate treatment for the prevention of radiation-induced mucositis. PMID:23874895

Kang, Sung Un; Kim, Jang Hee; Oh, Young-Taek; Park, Keun Hyung; Kim, Chul-Ho



Penile erectile dysfunction after brachial plexus root avulsion injury in rats  

PubMed Central

Our previous studies have demonstrated that some male patients suffering from brachial plexus injury, particularly brachial plexus root avulsion, show erectile dysfunction to varying degrees. However, the underlying mechanism remains poorly understood. In this study, we evaluated the erectile function after establishing brachial plexus root avulsion models with or without spinal cord injury in rats. After these models were established, we administered apomorphine (via a subcutaneous injection in the neck) to observe changes in erectile function. Rats subjected to simple brachial plexus root avulsion or those subjected to brachial plexus root avulsion combined with spinal cord injury had significantly fewer erections than those subjected to the sham operation. Expression of neuronal nitric oxide synthase did not change in brachial plexus root avulsion rats. However, neuronal nitric oxide synthase expression was significantly decreased in brachial plexus root avulsion + spinal cord injury rats. These findings suggest that a decrease in neuronal nitric oxide synthase expression in the penis may play a role in erectile dysfunction caused by the combination of brachial plexus root avulsion and spinal cord injury.

Fu, Guo; Qin, Bengang; Jiang, Li; Huang, Xijun; Lu, Qinsen; Zhang, Dechun; Liu, Xiaolin; Zhu, Jiakai; Zheng, Jianwen; Li, Xuejia; Gu, Liqiang



Compromising abnormalities of the brachial plexus as displayed by magnetic resonance imaging  

Microsoft Academic Search

Magnetic resonance images (MRI) of brachial plexus anatomy bilaterally, not possible by plain radiographs or CT, were presented to the Vascular Surgery, Neurology, and the Neurosurgery departments. Patients were requested for MRI of their brachial plexus. They were referred for imaging and the imaging results were presented to the faculty and housestaff. Our technique was accepted and adopted to begin

James D. Collins; Marla L. Shaver; Anthony C. Disher; Theodore Q. Miller



Percutaneous Extraluminal (Subintimal) Recanalization of a Brachial Artery Occlusion Following Cardiac Catheterization  

SciTech Connect

A 47-year-old woman presented with disabling right arm claudication 10 weeks after Sones cardiac catheterization via a brachial artery cut-down. A technique of extraluminal recanalization of the brachial artery occlusion, used to treat this patient, is described.

Bolia, Amman [Department of Radiology, Clinical Sciences Building, Leicester Royal Infirmary, PO Box 65, Leicester LE2 7LX (United Kingdom); Nasim, Akhtar; Bell, Peter R.F. [Department of Surgery, Clinical Sciences Building, Leicester Royal Infirmary, PO Box 65, Leicester LE2 7LX (United Kingdom)



Schwannoma of the brachial plexus; report of two cases involving the C7 root  

PubMed Central

Brachial plexus schwannomas are rare tumors. They are benign nerve sheath tumors and only about 5% of Schwannoma arise from the brachial plexus. They pose a great challenge to surgeons due to their rare occurrence and complex anatomical location. We present two cases who presented with a supraclavicular swelling, that were proven to be schwannoma on histopathology. PMID:24180468



Brachial neuritis with bilateral diaphragmatic paralysis following herpes zoster: a case report.  


We present a case of supine respiratory failure due to a bilateral diaphragmatic paralysis associated with brachial neuritis secondary to thoracic herpes zoster. Fluoroscopy in both the standing and supine positions revealed bilateral diaphragmatic paralysis accentuated in the supine position. To our knowledge, this is the first case of thoracic herpes zoster associated with brachial neuritis and bilateral diaphragmatic paralysis. PMID:18525424

Hoque, Romy; Schwendimann, Robert N; Liendo, Cesar; Chesson, Andrew L



3T MR tomography of the brachial plexus: structural and microstructural evaluation.  


Magnetic resonance (MR) neurography comprises an evolving group of techniques with the potential to allow optimal noninvasive evaluation of many abnormalities of the brachial plexus. MR neurography is clinically useful in the evaluation of suspected brachial plexus traumatic injuries, intrinsic and extrinsic tumors, and post-radiogenic inflammation, and can be particularly beneficial in pediatric patients with obstetric trauma to the brachial plexus. The most common MR neurographic techniques for displaying the brachial plexus can be divided into two categories: structural MR neurography; and microstructural MR neurography. Structural MR neurography uses mainly the STIR sequence to image the nerves of the brachial plexus, can be performed in 2D or 3D mode, and the 2D sequence can be repeated in different planes. Microstructural MR neurography depends on the diffusion tensor imaging that provides quantitative information about the degree and direction of water diffusion within the nerves of the brachial plexus, as well as on tractography to visualize the white matter tracts and to characterize their integrity. The successful evaluation of the brachial plexus requires the implementation of appropriate techniques and familiarity with the pathologies that might involve the brachial plexus. PMID:21763092

Mallouhi, Ammar; Marik, Wolfgang; Prayer, Daniela; Kainberger, Franz; Bodner, Gerd; Kasprian, Gregor



A case of acute brachial artery occlusion after transradial coronary intervention  

PubMed Central

In 2010, a 49-year-old man was admitted to our hospital with chest pain. Angiography via the radial approach was performed. Acute brachial artery occlusion was present after the procedure. By transcatheter thrombolysis, brachial artery occlusion was recanalized. Transcatheter thrombolysis seemed to be effective and safe. PMID:24570715

Sang, Zhenchi; Jin, Huigen



Self-mutilation in young children following brachial plexus birth injury  

Microsoft Academic Search

Brachial plexus injury in adults commonly produces persistent pain. Pediatric textbooks and case series suggest that perinatal brachial plexus injury is very rarely associated with pain, though this is difficult to determine in preverbal infants. Some of these young children self-mutilate the affected extremity, which may or may not reflect pain. This study was designed to characterize the clinical presentation

Mary Ellen McCann; Peter Waters; Liliana C Goumnerova; Charles Berde



Transient radiation-induced absorption in the materials for a GSGG laser  

NASA Astrophysics Data System (ADS)

Materials used in the optical elements of a 1,061 m GSGG (gadolinium scandium gallium garnet) laser have been tested for transient radiation-induced absorption. The transient radiation-induced absorption in KK1, Schott S7005 and S7010, and M382 glasses have been determined for discrete wavelengths in the range 440-750 nm. Also, the transient radiation-induced absorption in 'pure' and MgO doped LiNbO3 has been measured at 1,061 nm. Mathematical expressions composed of exponentials are fitted to the data.

Brannon, P. J.



Transient radiation-induced absorption in the materials for a GSGG laser  

SciTech Connect

Materials used in the optical elements of a 1,061 m GSGG (gadolinium scandium gallium garnet) laser have been tested for transient radiation-induced absorption. The transient radiation-induced absorption in KK1, Schott S7005 and S7010, and M382 glasses have been determined for discrete wavelengths in the range 440--750 nm. Also, the transient radiation-induced absorption in {open_quotes}pure{close_quotes} and MgO doped LiNbO{sub 3} has been measured at 1,061 nm. Mathematical expressions composed of exponentials are fitted to the data.

Brannon, P.J.



Resolution of brachial plexus palsy due to hemangioma after intravenous corticosteroid therapy.  


The authors report a 7-day-old girl born with a hemangioma involving the right side of the scalp and neck who developed ipsilateral brachial plexus palsy at 5 days of age. Imaging studies confirmed the presence of a cavernous hemangioma in the vicinity of the brachial plexus. She was treated with intravenous corticosteroids and her palsy resolved in 5 days. Only 1 prior case of hemangioma producing brachial plexus palsy has been reported; this patient was not treated with corticosteroids and had a partial recovery. The authors believe that the quick recovery after initiating systemic steroids was due to relief of nerve compression (neuropraxia) resulting from shrinkage of the cavernous hemangioma. The purpose of this article is to describe an uncommon cause of neonatal brachial plexus palsy and to report the effectiveness of early intravenous corticosteroid treatment in a patient with brachial plexus palsy due to a cavernous hemangioma. PMID:18660479

Naqvi, Ali H; Alfonso, Daniel T; Flores, Patricia; Grossman, John A I; Restrepo, Ricardo; Alfonso, Israel



Brachial plexus blocks for upper extremity orthopaedic surgery.  


Regional anesthesia of the upper extremity has several clinical applications and is reported to have several advantages over general anesthesia for orthopaedic surgery. These advantages, such as improved postoperative pain, decreased postoperative opioid administration, and reduced recovery time, have led to widespread acceptance of a variety of regional nerve blocks. Interscalene block is the most commonly used block for shoulder surgery. Other brachial plexus nerve blocks used for orthopaedic surgery of the upper extremity are supraclavicular, infraclavicular, and axillary. Several practical and theoretical aspects of regional nerve blocks must be considered to optimize the beneficial effects and minimize the risk of complications. PMID:22207517

Bruce, Benjamin G; Green, Andrew; Blaine, Theodore A; Wesner, Lee V



Evaluation and management of brachial plexus birth palsy.  


Brachial plexus birth palsy can result in permanent lifelong deficits and unfortunately continues to be relatively common despite advancements in obstetric care. The diagnosis can be made shortly after birth by physical examination, noting a lack of movement in the affected upper extremity. Treatment begins with passive range-of-motion exercises to maintain flexibility and tactile stimulation to provide sensory reeducation. Primary surgery consists of microsurgical nerve surgery, whereas secondary surgery consists of alternative microsurgical procedures, tendon transfers, or osteotomies, all of which improve outcomes in the short term. However, the long-term outcomes of current treatment recommendations remain unknown. PMID:24684916

Abzug, Joshua M; Kozin, Scott H



Reinnervation of avulsed brachial plexus using the spinal accessory nerve.  


The use of the accessory nerve as a donor is one of the possibilities for the reinnervation of the brachial plexus in cases of paralysis due to root avulsion. In this paper, an analysis of the reinnervation of the musculocutaneous or axillary nerve using the spinal accessory nerve is made on 13 cases, 8 of total and 5 of upper partial avulsion. In all cases, Allieu's technique was used, but in seven cases reinnervation was supplemented by upper intercostal nerves when there was total avulsion and/or by the medial pectoral nerve when there was partial avulsion. The methods are discussed and compared with the intercostobrachial anastomosis. PMID:2154041

Samardzic, M; Grujicic, D; Antunovic, V; Joksimovic, M



Radiation-Induced Phase Transformations in Ilmenite-Group Minerals  

SciTech Connect

Transmission electron microscopy (TEM) is a powerful tool for characterizing and understanding radiation-induced structural changes in materials. We have irradiated single crystals of ilmenite (FeTiO{sub 3}) and geikielite (MgTiO{sub 3}) using ions and electrons to better understand the response of complex oxides to radiation. Ion irradiation experiments of bulk single crystals at 100 K show that ilmenite amorphized at doses of less than 1x10(exp15) Ar(2+)/sq cm and at a damage level in the peak damage region of 1 displacement per atom (dpa). Transmission electron microscopy and electron diffraction of a cross-sectioned portion of this crystal confirmed the formation of a 150 am thick amorphous layer. Geikielite proved to be more radiation resistant, requiring a flux of 2x10(exp 15) Xe(2+)/sq cm to induce amorphization at 100 K. This material did not amorphize at 470 K, despite a dose of 2.5 x10(exp 16) Xe(2+)/sq cm and a damage level as high as 25 dpa. Low temperature irradiations of electron- transparent crystals with 1 MeV Kr(+) also show that ilmenite amorphized after a damage level of 2.25 dpa at 175 K.Similar experiments on geikielite show that the microstructure is partially amorphous and partially crystalline after 10 dpa at 150 K. Concurrent ion and electron irradiation of both materials with 1 MeV Kr(+) and 0.9 MeV electrons produced dislocation loops in both materials, but no amorphous regions were formed. Differences in the radiation response of these isostructural oxides suggests that in systems with Mg-Fe solid solution, the Mg-rich compositions may be more resistant to structural changes.

Mitchell, J. N.



Radiation-induced grafting of acrylic acid onto polyethylene filaments  

NASA Astrophysics Data System (ADS)

Radiation-induced grafting of acrylic acid onto high density polyethylene (PE) filaments was carried out in order to raise softening temperature and impart flame retardance and hydrophilic properties. Mutual ?-irradiation method was employed for the grafting in a mixture of acrylic acid (AA), ethylene dichloride and water containing a small amount of ferrous ammonium sulfate. The rate of grafting was very low at room temperature. On the other hand, large percent grafts were obtained when the grafting was performed at an elevated temperature. Activation energy for the initial rate of grafting was found to be 17 {kcal}/{mol} between 20 and 60°C and 10 {kcal}/{mol} between 60 and 80°C. Original PE filament begins to shrink at 70°C, show maximum shrinkage of 50% at 130°C and then breaks off at 136°C. When a 34% AA graft is converted to metallic salt such as sodium and calcium, the graft filament retains its filament form even above 300°C and gives maximum shrinkage of 15%. Burning tests by a wire-netting basket method indicate that graft filaments and its metallic salts do not form melting drops upon burning and are self-extinguishing. Original PE filament shows no moisture absorption, however, that of AA-grafted PE increases with increasing graft percent. The sodium salt of 15% graft shows the same level of moisture regain as cotton. The AA-grafted PE filament and its metallic salts can be dyed with cationic dyes even at 1% graft. Tensile properties of PE filament is impaired neither by grafting nor by conversion to metallic salts.

Kaji, K.; Okada, T.; Sakurada, I.


Radiation-induced adaptive response in fish cell lines.  


There is considerable interest at present in low-dose radiation effects in non-human species. In this study gamma radiation-induced adaptive response, a low-dose radiation effect, was examined in three fish cell lines, (CHSE-214 (Chinook salmon), RTG-2 (rainbow trout) and ZEB-2J (zebrafish)). Cell survival after exposure to direct radiation with or without a 0.1 Gy priming dose, was determined using the colony forming assay for each cell line. Additionally, the occurrence of a bystander effect was examined by measuring the effect of irradiated cell culture medium from the fish cell lines on unexposed reporter cells. A non-linear dose response was observed for all cell lines. ZEB-2J cells were very sensitive to low doses and a hyper-radiosensitive (HRS) response was observed for doses <0.5 Gy. A typical protective adaptive response was not detected in any of the three fish cell lines tested. Rather, it was found that pre-exposure of these cells to 0.1 Gy radiation sensitized the cells to subsequent high doses. In CHSE-214 cells, increased sensitivity to subsequent high doses of radiation was observed when the priming and challenge doses were separated by 4 h; however, this sensitizing effect was no longer present when the interval between doses was greater than 8 h. Additionally, a "protective" bystander response was observed in these cell lines; exposure to irradiated medium from fish cells caused increased cloning efficiency in unirradiated reporter cells. The data confirm previous conclusions for mammalian cells that the adaptive response and bystander effect are inversely correlated and contrary to expectations probably have different underlying mechanisms. PMID:18054128

Ryan, Lorna A; Seymour, Colin B; O'Neill-Mehlenbacher, Alicia; Mothersill, Carmel E



Comparison of radiation-induced transmission degradation of borosilicate crown optical glass from four different manufacturers  

E-print Network

Comparison of radiation-induced transmission degradation of borosilicate crown optical glass from in optical glasses is often related with the presence of impurities, which are, intentionally or not, introduced during the manufacturing process. Glass manufacturers use proprietary fabrication processes

Glebov, Leon


Irradiated Esophageal Cells are Protected from Radiation-Induced Recombination by MnSOD Gene Therapy  

E-print Network

Radiation-induced DNA damage is a precursor to mutagenesis and cytotoxicity. During radiotherapy, exposure of healthy tissues can lead to severe side effects. We explored the potential of mitochondrial SOD (MnSOD) gene ...

Niu, Yunyun


Effect of bulk composition on swelling and radiation-induced segregation in austenitic alloys.  

National Technical Information Service (NTIS)

Changes in bulk composition are known to affect both radiation-induced segregation and microstructural development, including void swelling in austenitic stainless steels. In this work, three alloys have been studied: Fe-18Cr-8Ni alloy (bulk composition c...

T. R. Allen, J. I. Cole, N. L. Dietz, Y. Wang, G. S. Was, E. A. Kenik



Radiation-induced esophageal injury: A spectrum from esophagitis to cancer  

SciTech Connect

Radiation esophagitis is a common but frequently unrecognized complication of therapeutic radiation to the neck, chest, or mediastinum. The spectrum of injury ranges from acute self-limited esophagitis to life-threatening esophageal perforation. Complications such as stricture or primary esophageal cancer may occur many years after irradiation, and their linkage to radiation may not be considered. Five cases of radiation-induced injury are described, and the spectrum of radiation-induced esophageal injury is reviewed.

Vanagunas, A.; Jacob, P.; Olinger, E. (Northwestern Univ. Medical School, Chicago, IL (USA))



Radiation-induced absorption in high-purity silica fiber preforms  

Microsoft Academic Search

The effect of the preform fabrication procedure on the radiation-induced absorption in KU-1 and KS-4V high-purity silica glasses was investigated (these glasses are used in fiber preform fabrication via outside fluorosilicate glass deposition on substrate rods and in the rod-in-tube process). The results demonstrate that the deposition of a reflective cladding onto KU-1 rods drastically increases the radiation-induced UV absorption

M. O. Zabezhailov; A. L. Tomashuk; I. V. Nikolin; V. G. Plotnichenko



Layout-Related Stress Effects on Radiation-Induced Leakage Current  

Microsoft Academic Search

The effects of shallow-trench-isolation-induced mechanical stress on radiation-induced off-state leakage current are reported in 90-nm NMOS devices. The radiation-induced leakage current increases with increasing active device-to-isolation spacing. The leakage current also depends on channel width; narrow devices exhibit less leakage before irradiation, but more after irradiation. These geometrical factors affect the mechanical stress in the device, which impact the dopant

Nadia Rezzak; Ronald D. Schrimpf; Michael L. Alles; En Xia Zhang; Daniel M. Fleetwood; Yanfeng Albert Li



Potentiation of Radiation-induced Regrowth Delay in Murine Tumors by Fludarabine I  

Microsoft Academic Search

Fludarabine (9-\\/3-n-arabinofuranosyl-2-fluoroadenine-5'-monophos- phate), an adenine nucleoside analogue, has previously been shown to inhibit the repair of radiation-induced chromosome damage. Thus fludarabine may have therapeutic utility in combination with photon irradiation. The purpose of this study was to determine whether fludarabine could enhance radiation-induced murine tumor regrowth de- lay and to determine the most effective dose and schedule of the combi-

Vincent Gr; Nancy Hunter; Luka Milas; William A. Brock; William Plunkett; Walter N. Hittelman


Traumatic Pseudoaneurysm of Axillary Artery Combined with Brachial Plexus Injury  

PubMed Central

Traumatic pseudoaneurysm of the axillary artery combined with brachial plexus injury is extremely rare. The factors that influence the symptoms and functional recovery related to this condition are unclear. Nine patients who had sustained this trauma were surgically treated at our unit between June 1999 and November 2010. The cause of trauma, symptoms, signs and examinations of neurological and vascular deficits, and the surgical findings of the involved nerves and vessels were recorded in detail. The functional recovery of vessels and nerves, as well as the extent of pain, were evaluated, respectively. The average length of patient follow-up was 4.5 years (range, 24 months to 11.3 years). After vessel repair, whether by endovascular or operative treatment, the distending, constant, and pulsating pain was relieved in all patients. Furthermore, examination of the radial artery pulse on the repaired side appeared normal at last follow-up. All patients showed satisfactory sensory recovery, with motor recovery rated as good in five patients and fair in four patients. The symptom characteristics varied with the location of the damage to the axillary artery. Ultrasound examination and computed tomography angiography are useful to evaluate vascular injury and provide valuable information for operative planning. Surgical exploration is an effective therapy with results related to the nerve injury condition of the brachial plexus. PMID:25412426

Chen, Lin; Peng, Feng; Wang, Tao; Chen, Desong; Yang, Jianyun



Radiation-induced changes affecting polyester based polyurethane binder  

NASA Astrophysics Data System (ADS)

The application of thermoplastic polyurethane elastomers as binders in the high energy explosives particularly when used in weapons presents a significantly complex and challenging problem due to the impact of the aging of this polymer on the useful service life of the explosive. In this work, the effects of radiation on the aging of the polyester based polyurethane were investigated using both electron beam and gamma irradiation at various dose rates in the presence and absence of oxygen. It was found by means of GPC that, in the presence and absence of oxygen, the poly (ester urethane) primarily undergoes cross-linking, by means of a carbon-centered secondary alkyl radical. It was also concluded that the polymer partially undergoes scission of the backbone of the main chain at C-O, N-C, and C-C bonds. Substantial changes in the conditions of irradiation and in dose levels did not affect the cross-linking and scission yields. Experiments were also performed with EPR spectroscopy for the purpose of identifying the initial carbon-centered free radicals and for studying the decay mechanisms of these radicals. It was found that the carbon-centered radical which is produced via C-C scission (primary alkyl radical) is rapidly converted to a long-lived allylic species at higher temperatures; more than 80% radicals are converted to allyl species in 2.5 hours. In the presence of oxygen, the allyl radical undergoes a fast reaction to produce a peroxyl radical; this radical decays with a 1.7 hour half-life by pseudo first-order kinetics to negligible levels in 13 hours. FTIR measurements were conducted to identify the radiation-induced changes to the functional groups in the polyester polyurethane. These measurements show an increase in carbonyl, amine and carboxylic groups as a result of reaction of H atoms with R-C-O·, ·NH-R and R-COO·. The FTIR results also demonstrate the production of the unsaturation resulting from hydrogen atom transfer during intrachain conversion of the primary alkyl radical to the allyl species, prompt trans-vinylene production in tetramethylene units, and hydrogen atom abstraction by alkyl radicals on neighboring chains. The production of unsaturation is substantiated by the EPR studies. Finally, a free radical mechanism is proposed for the production of cross-linking in polyester polyurethane.

Pierpoint, Sujita Basi


Radiation-Induced Damage to Nucleic Acid Constituents  

NASA Astrophysics Data System (ADS)

The objective of this research was to identify the primary free radical species produced by ionizing radiation in DNA. The ultimate goal would be to use these data obtained from model compounds to analyze radiation-induced damage in DNA itself. The different single crystals were studied in detail. The first was the sodium salt of guanosine-3 ^':5^' -cyclic monophosphate (cyclic GMP). The results of studies on crystals irradiated at 4.2^ circK distinguished two species. One of these species exhibited a non-exchangeable proton coupling that was characterized by ENDOR spectroscopy and shown to be sigma proton. The spin density on C8 was deduced from the ENDOR hyperfine coupling tensor and found to be 0.15. The second species also exhibited a non-exchangeable sigma proton coupling and a beta proton coupling. The spin densities on C8 and N9 were deduced from ENDOR measurements to be 0.09 and 0.36. The former is attributed to the oxidation product and the latter to the primary reduction product. These products are respectively the guanine cation and anion. The second single crystal studied was a sodium salt of 2^'-deoxyguanosine -5^'-monophosphate tetrahydrate. The ESR and ENDOR spectra obtained from this crystal after x-irradiation at 4.2^circK were complex and the paramagnetic species were tentatively identified as ionic species. The third DNA model compound studied was thymidine. Single crystal of thymidine were irradiated at 1.6^ circK and at 4.2^circ K. The lower temperature preserved a more primitive stage of the radiation damage process. ENDOR measurements distinguished three paramagnetic species. The most interesting component of the paramagnetic absorption in crystals irradiated at 1.6^circK is attributed to trapped electron. These electrons are stabilized by the electrostatic fields generated by hydroxy dipoles. The hyperfine couplings between the trapped electron and the proton of these polar groups were deduced from ENDOR measurements. The ESR and ENDOR measurements described in this report were carried out DNA model compounds x-irradiated and measured at lower temperatures than reported previously. The experiments have demonstrated that an earlier stage of radiation damage can sometimes be stabilized and characterized in single crystals by maintaining the sample at 1.4 ^circK. (Abstract shortened with permission of author.).

Kim, Heasook


Targets for, and consequences of, radiation-induced chromosomal instability  

NASA Astrophysics Data System (ADS)

Chromosomal instability has been demonstrated in a human- hamster hybrid cell line, GM10115, after exposure to x- rays. Chromosomal instability in these cells is characterized by the appearance of novel chromosomal rearrangements multiple generations after exposure to ionizing radiation. To identify the cellular target(s) for radiation-induced chromosomal instability, cells were treated with 125I-labeled compounds. Labeling cells with 125I-iododeoxyuridine, which caused radiation damage to the DNA and associated nuclear structures, did induce chromosomal instability. While cell killing and first-division chromosomal rearrangements increased with increasing numbers of 125I decays, the frequency of chromosomal instability was independent of dose. Incorporation of an 125I-labeled protein, 125I-succinyl- concanavalin A, into either the plasma membrane or the cytoplasm, failed to elicit chromosomal instability. These results show that radiation damage to the nucleus, and not to extranuclear regions, contributes to the induction of chromosomal instability. To determine the role of DNA strand breaks as a molecular lesion responsible for initiating chromosomal instability, cells were treated with a variety of DNA strand breaking agents. Agents capable of producing complex DNA double strand breaks, including X-rays, Neocarzinostatin and bleomycin, were able to induce chromosomal instability. In contrast, double strand breaks produced by restriction endonucleases as well as DNA strand breaks produced by hydrogen peroxide failed to induce chromosomal instability. This demonstrates that the type of DNA breakage is important in the eventual manifestation of chromosomal instability. In order to understand the relationship between chromosomal instability and other end points of genomic instability, chromosomally stable and unstable clones were analyzed for sister chromatid exchange, delayed reproductive cell death, delayed mutation, mismatch repair and delayed gene amplification. Although individual clones within each group were significantly different from unirradiated clones for many of the endpoints, there was no significant correlation between chromosomal instability and the phenotypes of sister chromatid exchange, delayed mutation, and mismatch repair. Delayed gene amplification weakly correlated chromosomal instability (0.05 < p < 0.1) and delayed reproductive cell death correlated strongly (p < 0.05) with chromosomal instability. These data indicate that multiple pathways exist for inducing genomic instability in GM10115 cells after radiation exposure.

Kaplan, Mark Isaac


Radiation-induced osteosarcomas in the pediatric population  

SciTech Connect

Purpose: Radiation-induced osteosarcomas (R-OS) have historically been high-grade, locally invasive tumors with a poor prognosis. The purpose of this study was to perform a comprehensive literature review and analysis of reported cases dealing with R-OS in the pediatric population to identify the characteristics, prognostic factors, optimal treatment modalities, and overall survival of these patients. Methods and Materials: A MEDLINE/PubMed search of articles written in the English language dealing with OSs occurring after radiotherapy (RT) in the pediatric population yielded 30 studies from 1981 to 2004. Eligibility criteria included patients <21 years of age at the diagnosis of the primary cancer, cases satisfying the modified Cahan criteria, and information on treatment outcome. Factors analyzed included the type of primary cancer treated with RT, the radiation dose and beam energy, the latency period between RT and the development of R-OS, and the treatment, follow-up, and final outcome of R-OS. Results: The series included 109 patients with a median age at the diagnosis of primary cancer of 6 years (range, 0.08-21 years). The most common tumors treated with RT were Ewing's sarcoma (23.9%), rhabdomyosarcoma (17.4%), retinoblastoma (12.8%), Hodgkin's disease (9.2%), brain tumor (8.3%), and Wilms' tumor (6.4%). The median radiation dose was 47 Gy (range, 15-145 Gy). The median latency period from RT to the development of R-OS was 100 months (range, 36-636 months). The median follow-up after diagnosis of R-OS was 18 months (1-172 months). The 3- and 5-year cause-specific survival rate was 43.6% and 42.2%, respectively, and the 3- and 5-year overall survival rate was 41.7% and 40.2%, respectively. Variables, including age at RT, primary site, type of tumor treated with RT, total radiation dose, and latency period did not have a significant effect on survival. The 5-year cause-specific and overall survival rate for patients who received treatment for R-OS involving chemotherapy alone, surgery alone, and surgery plus chemotherapy was 17.3% and 17.3%, 56.6% and 50.3%, and 71.0% and 68.3%, respectively (p < 0.0001, log-rank test). Conclusion: The type of treatment for R-OS was the most significant factor for cause-specific and overall survival. Patients who develop R-OS should be aggressively treated, because the outcome is not as dismal as once thought.

Koshy, Matthew [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, and Texas Children's Hospital, Houston, TX (United States); Paulino, Arnold C. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, and Texas Children's Hospital, Houston, TX (United States)]. E-mail:; Mai, Wei Y. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, and Texas Children's Hospital, Houston, TX (United States); Teh, Bin S. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, and Texas Children's Hospital, Houston, TX (United States)



Radiation Induced Segregation in High Chromium Ferritic/Martensitic Steels  

NASA Astrophysics Data System (ADS)

High Cr ferritic/martensitic (F/M) steels including nano-featured oxide dispersion strengthened steels (NF-ODS) are a candidate material class for advanced fission and fusion nuclear reactor designs. F/M steels have excellent high temperature strength, low swelling rates and the recent developments in NF-ODS steels has improved their high temperature creep performance. A concern for F/M steels is their radiation induced segregation (RIS) response while in-service. RIS occurs when atomic fluxes preferentially couple to point defect fluxes to defect sinks such as grain boundaries (GBs). For F/M steels no conclusive trends or dependencies on the RIS response have been drawn. Interfaces, including grain boundaries and precipitate-matrix interfaces can alter the RIS response. The grain boundary structure could change the point defect interaction at the GB. Changes in the point defect kinetics at a grain boundary could therefore alter the RIS response at the boundary. Furthermore, oxide nanoclusters in NF-ODS steel act as sinks for point defects under irradiation. The surface area and number density of these nanoclusters in NF-ODS steels could alter the point defect fluxes to GBs. Analytical microscopy techniques were conducted to determine the role of grain boundary structure and nanocluster dispersion on the RIS response in irradiated F/M steels. Here, a 9 wt. % Cr model alloy which simulates the structure of commercially available steels and 14YWT NF-ODS alloy was irradiated under numerous conditions. Both alloys were investigated using STEM/EDS and GB misorientation analysis. Experimental results indicate a preferential segregation of Cr to specific GB misorientations in the model F/M steel. Findings in the NF-ODS alloy indicates the stability of nanoclusters within the alloy alters the concentration gradient of the point defects near irradiated GBs. Based on these results, new theories on the role of interfaces in irradiated F/M steels was developed including a rate theory model which accounts for the GB misorientation angle within the RIS model. These theories will stimulate the development of new F/M steels which are highly resistant to RIS while in-service.

Field, Kevin G.


Central blood pressure reflects left ventricular load, while brachial blood pressure reflects arterial damage.  


Abstract Objectives. The present study investigated whether brachial and central blood pressures have differential impact on the cardiovascular system in the general population. Methods. The study included 706 subjects (59 ± 10 years) who visited our hospital for a physical check-up. Brachial blood pressure and radial artery pressure waveforms were recorded using an automated device, and the pressure corresponding to the radial late systolic peak (SBP2) was taken as central blood pressure. The concentration of B-type natriuretic peptide and the intima-media thickness of the carotid artery were measured and a cross-sectional analysis was performed. Results. Brachial blood pressure was 128 ± 18/74 ± 12 (mean blood pressure, 92 ± 13) mmHg and SBP2 was 120 ± 19 mmHg. Although both brachial systolic blood pressure and SBP2 correlated with B-type natriuretic peptide in a univariate analysis, only SBP2 independently correlated with B-type natriuretic peptide after adjustment for possible factors. In contrast, brachial systolic blood pressure, but not SBP2, independently correlated with carotid artery intima-media thickness. Conclusions. Central blood pressure is more closely associated with left ventricular load than brachial blood pressure, while brachial blood pressure is more strongly associated with vascular damage than central blood pressure. PMID:24919682

Yamashita, Sumiyo; Dohi, Yasuaki; Takase, Hiroyuki; Sugiura, Tomonori; Ohte, Nobuyuki



[Prolonged blocking of the brachial plexus by axillary approach in children].  


Surgical interventions were carried out under combined total anesthesia with prolonged blocking of the brachial plexus via axillary approach in 40 children aged 4-14 years with surgical diseases of the arms. Prolonged axillary blockade maintained adequate analgesia in the lower third of the brachial bone, ulnar joint, forearm, and hand for 24-48 h. The proposed protocols of lidocaine and bupivacaine infusion into the axillary space of the brachial plexus caused no toxic reactions in children of this age group. The method can be used in children during and after surgery. PMID:10584368

Leshkevich, A I; Razhev, S V; Lukin, G I; Sidorov, V A



Synchrotron-Radiation Induced X-Ray Emission (SRIXE)  

SciTech Connect

Elemental analysis using emission of characteristic x rays is a well-established scientific method. The success of this analytical method is highly dependent on the properties of the source used to produce the x rays. X-ray tubes have long existed as a principal excitation source, but electron and proton beams have also been employed extensively. The development of the synchrotron radiation x-ray source that has taken place during the past 40 years has had a major impact on the general field of x-ray analysis. Even tier 40 years, science of x-ray analysis with synchrotron x-ray beams is by no means mature. Improvements being made to existing synchrotron facilities and the design and construction of new facilities promise to accelerate the development of the general scientific use of synchrotron x-ray sources for at least the next ten years. The effective use of the synchrotron source technology depends heavily on the use of high-performance computers for analysis and theoretical interpretation of the experimental data. Fortunately, computer technology has advanced at least as rapidly as the x-ray technology during the past 40 years and should continue to do so during the next decade. The combination of these technologies should bring about dramatic advances in many fields where synchrotron x-ray science is applied. It is interesting also to compare the growth and rate of acceptance of this particular research endeavor to the rates for other technological endeavors. Griibler [1997] cataloged the time required for introduction, diffusion,and acceptance of technological, economic, and social change and found mean values of 40 to 50 years. The introduction of the synchrotron source depends on both technical and non-technical factors, and the time scale at which this seems to be occurring is quite compatible with what is seen for other major innovations such as the railroad or the telegraph. It will be interesting to see how long the present rate of technological change and increase in scientific use can be maintained for the synchrotron x-ray source. A short summary of the present state of the synchrotron radiation-induced x-ray emission (SRIXE) method is presented here. Basically, SRIXE experiments can include any that depend on the detection. of characteristic x-rays produced by the incident x-ray beam born the synchrotron source as they interact with a sample. Thus, experiments done to measure elemental composition, chemical state, crystal, structure, and other sample parameters can be considered in a discussion of SRIXE. It is also clear that the experimentalist may well wish to use a variety of complementary techniques for study of a given sample. For this reason, discussion of computed microtomography (CMT) and x-ray diffraction is included here. It is hoped that this present discussion will serve as a succinct introduction to the basic ideas of SRIXE for those not working in the field and possibly help to stimulate new types of work by those starting in the field as well as by experienced practitioners of the art. The topics covered include short descriptions of (1) the properties of synchrotron radiation, (2) a description of facilities used for its production, (3) collimated microprobe, (4) focused microprobes, (5) continuum and monoenergetic excitation, (6) detection limits, (7) quantitation, (8) applications of SRIXE, (9) computed microtomography (CMT), and (10)chemical speciation using x-ray absorption near-edge structure (XANES) and extended x-ray absorption fine structure (EXAFS). An effort has been made to cite a wide variety of work from different laboratories to show the vital nature of the field.

Jones, Keith W.



Image-based modeling of radiation-induced foci  

NASA Astrophysics Data System (ADS)

Several proteins involved in the response to DNA double strand breaks (DSB) form microscopically visible nuclear domains, or foci, after exposure to ionizing radiation. Radiation-induced foci (RIF) are believed to be located where DNA damage occurs. To test this assumption, we used Monte Carlo simulations to predict the spatial distribution of DSB in human nuclei exposed to high or low-LET radiation. We then compared these predictions to the distribution patterns of three DNA damage sensing proteins, i.e. 53BP1, phosphorylated ATM and ?H2AX in human mammary epithelial. The probability to induce DSB can be derived from DNA fragment data measured experimentally by pulsed-field gel electrophoresis. We first used this probability in Monte Carlo simulations to predict DSB locations in synthetic nuclei geometrically described by a complete set of human chromosomes, taking into account microscope optics from real experiments. Simulations showed a very good agreement for high-LET, predicting 0.7 foci/µm along the path of a 1 GeV/amu Fe particle against measurement of 0.69 to 0.82 foci/µm for various RIF 5 min following exposure (LET 150 keV/µm). On the other hand, discrepancies were shown in foci frequency for low-LET, with measurements 20One drawback using a theoretical model for the nucleus is that it assumes a simplistic and static pattern for DNA densities. However DNA damage pattern is highly correlated to DNA density pattern (i.e. the more DNA, the more likely to have a break). Therefore, we generalized our Monte Carlo approach to real microscope images, assuming pixel intensity of DAPI in the nucleus was directly proportional to the amount of DNA in that pixel. With such approach we could predict DNA damage pattern in real images on a per nucleus basis. Since energy is randomly deposited along high-LET particle paths, RIF along these paths should also be randomly distributed. As expected, simulations produced DNA-weighted random (Poisson) distributions. In contrast, the distributions of RIF obtained as early as 5 min after exposure to high LET (1 GeV/amu Fe) were non-random. This deviation from the expected DNA-weighted random pattern was further characterized by "relative DNA image measurements". This novel imaging approach showed that RIF were located preferentially at the interface between high and low DNA density regions, and were more frequent than predicted in regions with lower DNA density. The same preferential nuclear location was also measured for RIF induced by 1 Gy of low-LET radiation. This deviation from random behavior was evident only 5 min after irradiation for phosphorylated ATM RIF, while ?H2AX and 53BP1 RIF showed pronounced deviations up to 30 min after exposure. These data suggest that RIF within a few minutes following exposure to radiation cluster into open regions of the nucleus (i.e. euchromatin). It is possible that DNA lesions are collected in these nuclear sub-domains for more efficient repair. If so, this would imply that DSB are actively transported within the nucleus, a phenomenon that has not yet been considered in modeling DNA misrepair following exposure to radiation. These results are thus critical for more accurate risk models of radiation and we are actively working on characterizing further RIF movement in human nuclei using live cell imaging.

Costes, Sylvain; Cucinotta, Francis A.; Ponomarev, Artem; Barcellos-Hoff, Mary Helen; Chen, James; Chou, William; Gascard, Philippe


Brachial plexus injury in adults: Diagnosis and surgical treatment strategies  

PubMed Central

Adult post traumatic Brachial plexus injury is unfortunately a rather common injury in young adults. In India the most common scenario is of a young man injured in a motorcycle accident. Exact incidence figures are not available but of the injuries presenting to us about 90% invole the above combination This article reviews peer-reviewed publications including clinical papers, review articles and Meta analysis of the subject. In addition, the authors? experience of several hundred cases over the last 15 years has been added and has influenced the ultimate text. Results have been discussed and analysed to get an idea of factors influencing final recovery. It appears that time from injury and number of roots involved are most crucial. PMID:23661959

Thatte, Mukund R.; Babhulkar, Sonali; Hiremath, Amita



Brachial plexus injury: a descriptive study of American football.  


A stinger is a common, yet understudied, injury that involves stretching or compression of the brachial plexus, often occurring during contact sports. Five football teams, including high school, collegiate, and professional teams, completed questionnaires. Questions were designed to obtain descriptive information regarding the nature and consequence of this injury and assess effectiveness of current preventive measures. Three hundred and four surveys were returned with 153 players reporting a stinger in their career (50.3%). The prevalence increased with years played and was most common in running backs (69%), defensive linemen (60%), linebackers (55%), and defensive secondary (54%). Current protective equipment and neck-strengthening programs did not provide protective benefits. Players at greatest risk of developing a stinger include those having played 3 or more years and players whose primary position is running back, defensive back, or defensive lineman. Further study is needed to better evaluate the effectiveness of current preventive measures. PMID:24875339

Starr, Harlan M; Anderson, Blake; Courson, Ron; Seiler, John G



Ultrasound Measurement of Brachial Artery Elasticity Before Hemodialysis Access Placement  

PubMed Central

Objectives Successful hemodialysis requires reliable vascular access that can deliver adequate blood flow. An arteriovenous fistula is preferred for access because of its longevity and low frequency of complications, but up to 60% of arteriovenous fistulas created surgically are never suitable for hemodialysis because of nonmaturation (insufficient vascular dilatation). Decreased arterial elasticity may impair dilatation, thereby affecting fistula maturation. This study evaluated the feasibility of brachial artery elasticity measurement in patients with chronic kidney disease obtained during routine preoperative mapping ultrasound (US) imaging before hemodialysis access placement and compared the measurements to those obtained in healthy volunteers. Methods Brachial artery functional US studies were collected from 75 patients undergoing routine preoperative mapping for hemodialysis access and 50 healthy volunteers. Vascular strain was calculated from the change in intima-media thickness between end systole and end diastole, and vascular stress was estimated from the pulse pressure. Assuming a linear elastic medium, the elastic modulus was estimated as the ratio of vascular stress to strain. Results Elastic modulus measurements were significantly higher in patients than in volunteers (130 versus 100 kPa; P = .01). With combined volunteer and patient data, there was a significant correlation between elasticity and systolic blood pressure (R2 = 0.23; P < .001). Elasticity was correlated with age in volunteers but not in patients (R2 = 0.14; P = .017; R2 < .001; P = .829, respectively). Conclusions This analysis of clinical arterial vessel biomechanics shows that a noninvasive US measurement can detect elastic modulus differences between patients with chronic kidney disease and healthy individuals. Future studies will correlate the elastic modulus with histologic characteristics and eventual arteriovenous fistula maturation, which may provide supplemental information on arterial biomechanical properties as a useful addition to current predictors of fistula success. PMID:23011621

Sorace, Anna G.; Robbin, Michelle L.; Umphrey, Heidi; Abts, Carl A.; Berry, Joel L.; Lockhart, Mark E.; Allon, Michael; Hoyt, Kenneth



Neonatal brachial plexus palsy: Incidence, prevalence, and temporal trends.  


Epidemiological knowledge of the incidence, prevalence, and temporal changes of neonatal brachial plexuses palsy (NBPP) should assist the clinician, avert unnecessary interventions, and help formulate evidence-based health policies. A summary of 63 publications in the English language with over 17 million births and 24,000 NBPPs is notable for six things. First, the rate of NBPP in the US and other countries is comparable: 1.5 vs. 1.3 per 1000 total births, respectively. Second, the rate of NBPP may be decreasing: 0.9, 1.0 and 0.5 per 1,000 births for publications before 1990, 1990-2000, and after 2000, respectively. Third, the likelihood of not having concomitant shoulder dystocia with NBPP was 76% overall, though it varied by whether the publication was from the US (78%) vs. other countries (47%). Fourth, the likelihood of NBPP being permanent (lasting at least 12 months) was 10-18% in the US-based reports and 19-23% in other countries. Fifth, in studies from the US, the rate of permanent NBPP is 1.1-2.2 per 10,000 births and 2.9-3.7 per 10,000 births in other nations. Sixth, we estimate that approximately 5000 NBPPs occur every year in the US, of which over 580-1050 are permanent, and that since birth, 63,000 adults have been afflicted with persistent paresis of their brachial plexus. The exceedingly infrequent nature of permanent NBPP necessitates a multi-center study to improve our understanding of the antecedent factors and to abate the long-term sequela. PMID:24863027

Chauhan, Suneet P; Blackwell, Sean B; Ananth, Cande V



Sodium tanshinone IIA sulfonate attenuates radiation-induced fibrosis damage in cardiac fibroblasts.  


The main pathological change in radiation-induced heart disease is fibrosis. Emerging evidence has indicated that sodium tanshinone IIA sulfonate (STS) was used for treating ?brosis diseases. The present study was undertaken to characterize the effect of STS on radiation-induced cardiac fibrosis (RICF) on cultured cardiac fibroblasts (CFs). CFs were irradiated with 1 or 2 Gy X-rays, and the expression of TGF-?1 and collagen I (Col-1) increased, indicating that low-dose X-rays promoted fibrosis damage effect. The fibrosis damage was accompanied by morphologic changes in the endoplasmic reticulum (ER), as well as an increase in the expression of the ER stress-related molecules, GRP78 and CHOP. Administration of STS reduced ROS production and decreased the expression of Col-1, TGF-?1, p-Smad2/3, GRP78, and CHOP in irradiated CFs, thus weakening the radiation-induced fibrosis damage and ER stress. Radiation-induced fibrosis damage was observed on a cellular level. The involvement of ER stress in radiation-induced fibrosis damage was demonstrated for the first time. STS attenuated the fibrosis damage effect in CFs and this effect may be related to its antioxidant action, and also related to its inhibition of ER stress and TGF-?1-Smad pathway. These results suggest that STS shows a good prospect in clinical prevention and treatment of RICF. PMID:25135631

Gu, Jing; Li, Hai-Long; Wu, Hong-Yan; Gu, Mei; Li, Ying-Dong; Wang, Xiao-Gang; Ming, Hai-Xia; Dong, Xiao-Li; Liu, Kai



Brachial Plexus Injury from CT-Guided RF Ablation Under General Anesthesia  

SciTech Connect

Brachial plexus injury in a patient under general anesthesia (GA) is not uncommon, despite careful positioning and, particularly, awareness of the possibility. The mechanism of injury is stretching and compression of the brachial plexus over a prolonged period. Positioning the patient within the computed tomography (CT) gantry for abdominal or chest procedures can simulate a surgical procedure, particularly when GA is used. The potential for brachial plexus injury is increased if the case is prolonged and the patient's arms are raised above the head to avoid CT image degradation from streak artifacts. We report a case of profound brachial plexus palsy following a CT-guided radiofrequency ablation procedure under GA. Fortunately, the patient recovered completely. We emphasize the mechanism of injury and detail measures to combat this problem, such that radiologists are aware of this potentially serious complication.

Shankar, Sridhar, E-mail:; Sonnenberg, Eric van; Silverman, Stuart G.; Tuncali, Kemal [Brigham and Women's Hospital, Department of Radiology (United States); Flanagan, Hugh L. [Brigham and Women's Hospital, Department of Anesthesia (United States); Whang, Edward E. [Brigham and Women's Hospital, Department of Surgery (United States)



Restoration and protection of brachial plexus injury: hot topics in the last decade  

PubMed Central

Brachial plexus injury is frequently induced by injuries, accidents or birth trauma. Upper limb function may be partially or totally lost after injury, or left permanently disabled. With the development of various medical technologies, different types of interventions are used, but their effectiveness is wide ranging. Many repair methods have phasic characteristics, i.e., repairs are done in different phases. This study explored research progress and hot topic methods for protection after brachial plexus injury, by analyzing 1,797 articles concerning the repair of brachial plexus injuries, published between 2004 and 2013 and indexed by the Science Citation Index database. Results revealed that there are many methods used to repair brachial plexus injury, and their effects are varied. Intervention methods include nerve transfer surgery, electrical stimulation, cell transplantation, neurotrophic factor therapy and drug treatment. Therapeutic methods in this field change according to the hot topic of research. PMID:25374596

Zhang, Kaizhi; Lv, Zheng; Liu, Jun; Zhu, He; Li, Rui



Anatomical structure of the brachial plexus in the merlin (Falco columbarius).  


This study aimed to document the detailed features of the morphological structure and the innervation areas of the brachial plexus in Merlin (Falco columbarius). The skin and muscles of five adult male Merlins were dissected under the stereo microscope. The Merlin had two plexus trunks. The accessory brachial plexus consisted of ventral rami C10 and C11. C11 was divided into two branches: the cranial and caudal. The brachial plexus was composed of a rather complex network involving the ventral rami of C11-C13, T1 and T2. In addition, a thin branch from the last two cervical sympathetic nerves participated in the plexus formation. C12, C13 and T1 had rather thick trunk. C12, C13 and T1 were also involved in the formation of the brachial plexus emerging after 1 cm from the foramen inter-vertebrale as three trunk roots. PMID:23464686

Çevik-Demirkan, A



A Case of True Brachial Artery Aneurysm in an Elderly Male  

PubMed Central

Brachial artery aneurysms are relatively rare and are mostly pseudoaneurysms rather than true aneurysms, as true aneurysms are even rarer entities. Patients can be asymptomatic, or present with pulsatile masses, or ischemia due to associated thromboembolic complications. Distal embolism can occur with transient or minimal ischemic symptoms; however, aneurysm itself can thrombose entirely. The authors report a case of upper limb acute ischemia caused by true brachial artery aneurysm thrombosis in an elderly man, managed by reconstructive vascular surgery. PMID:24250977

A. Fakhree M., Bassir; Azhough, Ramin; Hafez Quran, Farnaz



Hemidiaphragmatic paresis can be avoided in ultrasound-guided supraclavicular brachial plexus block  

Microsoft Academic Search

BACKGROUND AND OBJECTIVES: Supraclavicular brachial plexus block is associated with 50% to 67% incidence of hemidiaphragmatic paresis as a result of phrenic nerve block. We examined whether ultrasound-guided compared with nerve stimulation supraclavicular brachial plexus block using 0.75% ropivacaine results in a lower incidence of hemidiaphragmatic paresis. METHODS: In a prospective randomized observer-blinded controlled trial, 60 patients scheduled for elective

Steven H. Renes; Hubertus H. Spoormans; Mathieu J. Gielen; Harald C. Rettig; Geert J. van Geffen



Color Doppler Ultrasound-guided Supraclavicular Brachial Plexus Block to Prevent Vascular Injection  

PubMed Central

Ultrasound-guided nerve blocks are quickly becoming integrated into emergency medicine practice for pain control and as an alternative to procedural sedation. Common, but potentially catastophic errors have not been reported outside of the anesthesiology literature. Evaluation of the brachial plexus with color Doppler should be standard for clinicians performing a supraclavicular brachial plexus block to determine ideal block location and prevention of inadvertant intravascular injection. PMID:25247047

Hahn, Christopher; Nagdev, Arun



Color Doppler Ultrasound-guided Supraclavicular Brachial Plexus Block to Prevent Vascular Injection.  


Ultrasound-guided nerve blocks are quickly becoming integrated into emergency medicine practice for pain control and as an alternative to procedural sedation. Common, but potentially catastophic errors have not been reported outside of the anesthesiology literature. Evaluation of the brachial plexus with color Doppler should be standard for clinicians performing a supraclavicular brachial plexus block to determine ideal block location and prevention of inadvertant intravascular injection. PMID:25247047

Hahn, Christopher; Nagdev, Arun



Ultrasound-guided supraclavicular brachial plexus block in pediatric patients -A report of four cases-  

PubMed Central

Supraclavicular brachial plexus blocks are not common in pediatric patients due to the risk of pneumothorax. Ultrasonography is an important tool for identifying nerves during regional anesthesia. Directly visualizing the target nerves and monitoring the distribution of the local anesthetic are potentially significant. In addition, ultrasound monitoring helps avoid complications, such as inadvertent intravascular injection or pneumothorax. This paper reports four cases of pediatric patients who received ultrasound-guided supraclavicular brachial plexus block for upper limb surgery. PMID:21286471

Yang, Chun Woo; Kwon, Hee Uk; Roh, Jae Young; Heo, Youn Moo; Ahn, Sung-Min



Amelioration of ionizing radiation induced lipid peroxidation in mouse liver by Moringa oleifera Lam. leaf extract.  


Protective effect of Moringa oleifera leaf extract (MoLE) against radiation-induced lipid peroxidation has been investigated. Swiss albino mice, selected from an inbred colony, were administered with MoLE (300 mg/kg body wt) for 15 days before exposing to a single dose of 5 Gy 60Co-gamma radiation. After treatments, animals were necropsied at different post irradiation intervals (days 1, 7 and 15) and hepatic lipid peroxidation and reduced glutathione (GSH) contents were estimated to observe the relative changes due to irradiation and its possible amelioration by MoLE. It was observed that, MoLE treatment restored GSH in liver and prevented radiation induced augmentation in hepatic lipid peroxidation. Phytochemical analysis showed that MoLE possess various phytochemicals such as ascorbic acid, phenolics (catechin, epicatechin, ferulic acid, ellagic acid, myricetin) etc., which may play the key role in prevention of hepatic lipid peroxidation by scavenging radiation induced free radicals. PMID:22439436

Sinha, Mahuya; Das, Dipesh Kr; Datta, Sanjukta; Ghosh, Santinath; Dey, Sanjit



Prevention of ?-radiation induced cellular genotoxicity by tempol: protection of hematopoietic system.  


Tempol (TPL) under in vitro conditions reduced the extent of gamma radiation induced membrane lipid peroxidation and disappearance of covalently closed circular form of plasmid pBR322. TPL protected cellular DNA from radiation-induced damage in various tissues under ex vivo and in vivo conditions as evidenced by comet assay. TPL also prevented radiation induced micronuclei formation (in peripheral blood leucocytes) and chromosomal aberrations (in bone marrow cells) in whole body irradiated mice. TPL enhanced the rate of repair of cellular DNA (blood leucocytes and bone marrow cells) damage when administered immediately after radiation exposure as revealed from the increased Cellular DNA Repair Index (CRI). The studies thus provided compelling evidence to reveal the effectiveness of TPL to protect hematopoietic system from radiation injury. PMID:22609778

Ramachandran, Lakshmy; Nair, Cherupally Krishnan Krishnan



Radiation-induced genomic instability and its implications for radiation carcinogenesis  

NASA Technical Reports Server (NTRS)

Radiation-induced genomic instability is characterized by an increased rate of genetic alterations including cytogenetic rearrangements, mutations, gene amplifications, transformation and cell death in the progeny of irradiated cells multiple generations after the initial insult. Chromosomal rearrangements are the best-characterized end point of radiation-induced genomic instability, and many of the rearrangements described are similar to those found in human cancers. Chromosome breakage syndromes are defined by chromosome instability, and individuals with these diseases are cancer prone. Consequently, chromosomal instability as a phenotype may underlie some fraction of those changes leading to cancer. Here we attempt to relate current knowledge regarding radiation-induced chromosome instability with the emerging molecular information on the chromosome breakage syndromes. The goal is to understand how genetic and epigenetic factors might influence the onset of chromosome instability and the role of chromosomal instability in carcinogenesis.

Huang, Lei; Snyder, Andrew R.; Morgan, William F.



Radiation-induced transmission loss in low water peak single mode fibers  

NASA Astrophysics Data System (ADS)

Radiation-induced transmission loss in Low Water Peak Single Mode (LWPSM) fiber has been investigated. Formation and conversion processes of defect centers also have been proposed using electron spin resonance in the fiber irradiated with gamma rays. When the irradiation dose is low, Germanium electron center (GEC) and self-trapped hole center (STH) occur. With the increase of dose, E' centers (Si and Ge) and nonbridge oxygen hole centers (NBOHCs) generate. With the help of thermal-bleaching or photo-bleaching, the radiation-induced loss of pre-irradiation optical fiber can be reduced effectively. The obtain results also have been analyzed in detail.

Wang, Tingyun; Xiao, Zhongyin; Luo, Wenyun; Wen, Jianxiang; Yin, Jianchong; Wu, Wenkai; Gong, Renxiang



Low-Dose Bevacizumab Is Effective in Radiation-Induced Necrosis  

PubMed Central

Background Radiation-induced necrosis is a complication of brain irradiation. Treatment options are limited. Methods The response to treatment with low-dose bevacizumab in 2 patients with radiation-induced necrosis was reported. Results Both patients with metastatic melanoma, aged 48 and 51 years, had significant symptomatic and radiological improvement with low-dose bevacizumab treatment. Doses as low as 5 mg/kg every 6 weeks and 7.5 mg/kg i.v. every 4 weeks were used and were highly effective. Conclusions Low-dose bevacizumab is a solid option in the management of edema associated with radiation necrosis. PMID:24474923

Alessandretti, Matheus; Buzaid, Antonio C.; Brandao, Raphael; Brandao, Erika P.



Antimicrobial fabric adsorbed iodine produced by radiation-induced graft polymerization  

NASA Astrophysics Data System (ADS)

Antimicrobial fabric was synthesized by radiation-induced graft polymerization of N-vinyl pyrrolidone onto polyolefine nonwoven fabric and subsequent adsorption of iodine. In response of the huge request for the antimicrobial material applied to face masks for swine flu in 2009, operation procedure of continuous radiation-induced graft polymerization apparatus was improved. The improved grafting production per week increased 3.8 times compared to the production by former operation procedure. Shipped antimicrobial fabric had reached 130,000 m2 from June until December, 2009.

Aoki, Shoji; Fujiwara, Kunio; Sugo, Takanobu; Suzuki, Koichi



Numerical analysis of cosmic radiation-induced failures in power diodes  

Microsoft Academic Search

Silicon power diodes can run into thermal destruction due to cosmic radiation-induced effects. We performed electro-thermal coupled device simulations in order to explain the failure mechanism. The results are compared to ion irradiation experiments. We find a strong heating located at the point where the incident ion deposits charge with a temperature rise which can explain melting of used materials.

Christoph Weis; Stefan Aschauer; Gerhard Wachutka; Andreas Hartl; Frank Hille; Frank Pfirsch



Radiation-Induced Carcinogenesis: Mechanistically Based Differences between Gamma-Rays and Neutrons, and  

E-print Network

Radiation-Induced Carcinogenesis: Mechanistically Based Differences between Gamma-Rays and Neutrons: Mechanistically Based Differences between Gamma-Rays and Neutrons, and Interactions with DMBA. PLoS ONE 6(12): e dose/dose rate. Sparsely ionizing radiation (e.g. c-rays) generally produces linear or upwardly curving

Brenner, David Jonathan


A Prospective Cohort Study on Radiation-induced Hypothyroidism: Development of an NTCP Model  

SciTech Connect

Purpose: To establish a multivariate normal tissue complication probability (NTCP) model for radiation-induced hypothyroidism. Methods and Materials: The thyroid-stimulating hormone (TSH) level of 105 patients treated with (chemo-) radiation therapy for head-and-neck cancer was prospectively measured during a median follow-up of 2.5 years. Hypothyroidism was defined as elevated serum TSH with decreased or normal free thyroxin (T4). A multivariate logistic regression model with bootstrapping was used to determine the most important prognostic variables for radiation-induced hypothyroidism. Results: Thirty-five patients (33%) developed primary hypothyroidism within 2 years after radiation therapy. An NTCP model based on 2 variables, including the mean thyroid gland dose and the thyroid gland volume, was most predictive for radiation-induced hypothyroidism. NTCP values increased with higher mean thyroid gland dose (odds ratio [OR]: 1.064/Gy) and decreased with higher thyroid gland volume (OR: 0.826/cm{sup 3}). Model performance was good with an area under the curve (AUC) of 0.85. Conclusions: This is the first prospective study resulting in an NTCP model for radiation-induced hypothyroidism. The probability of hypothyroidism rises with increasing dose to the thyroid gland, whereas it reduces with increasing thyroid gland volume.

Boomsma, Marjolein J.; Bijl, Hendrik P.; Christianen, Miranda E.M.C.; Beetz, Ivo; Chouvalova, Olga; Steenbakkers, Roel J.H.M. [Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Laan, Bernard F.A.M. van der [Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Wolffenbuttel, Bruce H.R. [Department of Endocrinology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands)] [Department of Endocrinology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Oosting, Sjoukje F. [Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands)] [Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Schilstra, Cornelis [Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands)] [Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Langendijk, Johannes A., E-mail: [Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands)



Radiation-induced absorption in a photo-thermo-refractive glass Leonid Glebov1  

E-print Network

. Holograms in borosilicate optical glass K-8 (BK-7) were stable at room temperature but the diffractionRadiation-induced absorption in a photo-thermo-refractive glass Leonid Glebov1 , Larissa Glebova1, Pleinlaan 2, B-1050 Brussel, Belgium ABSTRACT Photo-thermo-refractive (PTR) glass is a new photosensitive

Glebov, Leon


Dynamic testing for radiation induced failures in a standard CMOS submicron technology pixel front-end  

Microsoft Academic Search

A testing method for the detection of performance degradation induced by high-dose irradiation in high-energy experiments has been developed. This method was successfully applied for testing the analogue CMOS front-end of a silicon pixel detector. The major effects of radiation induced faults have been investigated with respect to the special layout used for the nMOS transistors

D. De Venuto; S. Corsi; M. J. Ohletz



3D ultrasound Nakagami imaging for radiation-induced vaginal fibrosis  

NASA Astrophysics Data System (ADS)

Radiation-induced vaginal fibrosis is a debilitating side-effect affecting up to 80% of women receiving radiotherapy for their gynecological (GYN) malignancies. Despite the significant incidence and severity, little research has been conducted to identify the pathophysiologic changes of vaginal toxicity. In a previous study, we have demonstrated that ultrasound Nakagami shape and PDF parameters can be used to quantify radiation-induced vaginal toxicity. These Nakagami parameters are derived from the statistics of ultrasound backscattered signals to capture the physical properties (e.g., arrangement and distribution) of the biological tissues. In this paper, we propose to expand this Nakagami imaging concept from 2D to 3D to fully characterize radiation-induced changes to the vaginal wall within the radiation treatment field. A pilot study with 5 post-radiotherapy GYN patients was conducted using a clinical ultrasound scanner (6 MHz) with a mechanical stepper. A serial of 2D ultrasound images, with radio-frequency (RF) signals, were acquired at 1 mm step size. The 2D Nakagami shape and PDF parameters were calculated from the RF signal envelope with a sliding window, and then 3D Nakagami parameter images were generated from the parallel 2D images. This imaging method may be useful as we try to monitor radiation-induced vaginal injury, and address vaginal toxicities and sexual dysfunction in women after radiotherapy for GYN malignancies.

Yang, Xiaofeng; Rossi, Peter; Shelton, Joseph; Bruner, Debrorah; Tridandapani, Srini; Liu, Tian



Radiation-Induced Apoptosis Varies Among Individuals and is Modified by Sex and Age  

PubMed Central

Purpose Although there are considerable data on mechanisms of radiation-induced apoptosis in vitro and in animal models, little is known about functional variation in these pathways in humans. We sought to develop a tractable system to evaluate this. Materials and methods Peripheral blood mononuclear cells were isolated from 90 healthy volunteers, divided into two aliquots, one irradiated with a 5 Gy dose and the other sham-treated (0 Gy), and assessed for damage-induced apoptosis after 24 hours. To investigate reproducibility, ten individuals spanning the entire radiation-induced apoptotic range were tested three times each, with 3–6 months between replicates. Results We observed surprising heterogeneity in apoptosis among individuals, ranging from 21–62%. Biological replicates from a single individual, however, were completely concordant, suggesting the variability observed across individuals is not the result of stochastic or short-term effects. We found significantly higher radiation-induced apoptosis in males than in females (Mean: 41.0% vs. 30.7%; p < 3.5 × 10?7). Moreover, advancing age was associated with decreasing radiation-induced apoptosis in males (p = 0.01) but not females (p = 0.82).a Conclusions Our results provide evidence that the function of cellular pathways crucial for stress-induced apoptosis varies by sex and could decline with age in humans. PMID:24882388

Applebaum, Mark A.; Skol, Andrew D.; Bond, Elisabeth E.; Overholtzer, Michael; Bond, Gareth L.; Onel, Kenan



Effects of triphenylsulfonium hexafluorophosphate in the radiation-induced cationic polymerization of styrene  

Microsoft Academic Search

Radiation-induced cationic polymerization of styrene was studied in methylene chloride in the presence of triphenylsulfonium hexafluorophosphate. Acceleration in polymerization and an increase in molecular weight at a low temperature (- 78°C) were observed in the presence of triphenylsulfonium salt. A study of pulse radiolysis revealed that both effects are due mainly to PFâ⁻, which forms ion pairs with the cationic

Soukil Mah; Yukio Yamamoto; Koichiro Hayashi



The genetics of radiation-induced and sporadic osteosarcoma: a unifying theory?  

Microsoft Academic Search

Cancer is a disease of the genome, with the neoplastic phenotype being passed from one cell generation to the other. Radiation-induced cancer has often been considered to represent a unique entity amongst neoplasia, with the energy deposition being held responsible for both direct (gene mutations) and indirect (bystander effects, induced instability etc) alterations to the cellular genome. However, radiogenic tumours

Michael Rosemann; Virginija Kuosaite; Michaela Nathrath; Michael J. Atkinson



Morphogenesis of the Radiation-Induced Mutant Limb Deformity (Ld) of the Common Mouse.  

National Technical Information Service (NTIS)

Findings obtained in the thoracic and pelvic extremities of mice of the incest strain C57B1/10; i.e. animals homozygous with regard to the radiation-induced mutation 'limb deformity', are summarized and compared with the findings in non-deformed mice. Fur...

J. Selow, W. Winkler



Monte Carlo simulation of diffusion and reaction in radiation-induced spurs. Comparisons with analytic models  

Microsoft Academic Search

Reaction in radiation-induced spurs, containing one type of radical, is simulated by using random walks on a cubic lattice. The simulations are shown to agree satisfactorily with analytical results for the evolution of a single-particle density function and for the reaction between two particles. For spurs containing more than two particles, no exact analytical treatments are available. Results of simulations

Peter Clifford; Nicholas J. B. Green; Michael J. Pilling



Radiation induces genomic instability and mammary ductal dysplasia in Atm heterozygous mice  

NASA Technical Reports Server (NTRS)

Ataxia-telangiectasia (AT) is a genetic syndrome resulting from the inheritance of two defective copies of the ATM gene that includes among its stigmata radiosensitivity and cancer susceptibility. Epidemiological studies have demonstrated that although women with a single defective copy of ATM (AT heterozygotes) appear clinically normal, they may never the less have an increased relative risk of developing breast cancer. Whether they are at increased risk for radiation-induced breast cancer from medical exposures to ionizing radiation is unknown. We have used a murine model of AT to investigate the effect of a single defective Atm allele, the murine homologue of ATM, on the susceptibility of mammary epithelial cells to radiation-induced transformation. Here we report that mammary epithelial cells from irradiated mice with one copy of Atm truncated in the PI-3 kinase domain were susceptible to radiation-induced genomic instability and generated a 10% incidence of dysplastic mammary ducts when transplanted into syngenic recipients, whereas cells from Atm(+/+) mice were stable and formed only normal ducts. Since radiation-induced ductal dysplasia is a precursor to mammary cancer, the results indicate that AT heterozygosity increases susceptibility to radiogenic breast cancer in this murine model system.

Weil, M. M.; Kittrell, F. S.; Yu, Y.; McCarthy, M.; Zabriskie, R. C.; Ullrich, R. L.



Curcumin Attenuates Radiation-Induced Inflammation and Fibrosis in Rat Lungs  

PubMed Central

A beneficial radioprotective agent has been used to treat the radiation-induced lung injury. This study was performed to investigate whether curcumin, which is known to have anti-inflammatory and antioxidant properties, could ameliorate radiation-induced pulmonary inflammation and fibrosis in irradiated lungs. Rats were given daily doses of intragastric curcumin (200 mg/kg) prior to a single irradiation and for 8 weeks after radiation. Histopathologic findings demonstrated that macrophage accumulation, interstitial edema, alveolar septal thickness, perivascular fibrosis, and collapse in radiation-treated lungs were inhibited by curcumin administration. Radiation-induced transforming growth factor-?1 (TGF-?1), connective tissue growth factor (CTGF) expression, and collagen accumulation were also inhibited by curcumin. Moreover, western blot analysis revealed that curcumin lowered radiation-induced increases of tumor necrosis factor-? (TNF-?), TNF receptor 1 (TNFR1), and cyclooxygenase-2 (COX-2). Curcumin also inhibited the nuclear translocation of nuclear factor-? B (NF-?B) p65 in radiation-treated lungs. These results indicate that long-term curcumin administration may reduce lung inflammation and fibrosis caused by radiation treatment. PMID:23946685

Cho, Yu Ji; Yi, Chin Ok; Jeon, Byeong Tak; Jeong, Yi Yeong; Kang, Gi Mun; Lee, Jung Eun



Use of iron colloid-enhanced MRI for study of acute radiation-induced hepatic injury  

SciTech Connect

We present a case with acute radiation-induced hepatic injury using chondroitin sulfate iron colloid (CSIC)-enhanced MRI. Uptake of CSIC was decreased in the irradiated portion of the liver. CSIC-enhanced MRI is useful for obtaining information on the function of the reticuloendothelial system and demarcates between irradiated and nonirradiated zones. 18 refs., 3 figs

Suto, Yuji; Ametani, Masaki; Kato, Takashi; Hashimoto, Masayuki; Kamba, Masayuki; Sugihara, Syuji; Ohta, Yoshio [Tottori Univ. School of Medicine, Yonago (Japan)] [Tottori Univ. School of Medicine, Yonago (Japan)



Radiatively induced Lorentz-violating operator of mass dimension five in QED  

E-print Network

The first higher derivative term of the photon sector of Lorentz-violating QED, with operator of mass dimension $d=5$, is radiatively induced from the fermion sector, in which contains a derivative term with the dimensionless coefficient $g^{\\lambda\\mu\

T. Mariz



Pharyngeal-cervical-brachial variant of Guillain-Barre syndrome.  


The pharyngeal-cervical-brachial (PCB) variant of Guillain-Barré syndrome is defined by rapidly progressive oropharyngeal and cervicobrachial weakness associated with areflexia in the upper limbs. Serial nerve conduction studies suggest that PCB represents a localised subtype of Guillain-Barré syndrome characterised by axonal rather than demyelinating neuropathy. Many neurologists are unfamiliar with PCB, which is often misdiagnosed as brainstem stroke, myasthenia gravis or botulism. The presence of additional ophthalmoplegia and ataxia indicates overlap with Fisher syndrome. Half of patients with PCB carry IgG anti-GT1a antibodies which often cross-react with GQ1b, whereas most patients with Fisher syndrome carry IgG anti-GQ1b antibodies which always cross-react with GT1a. Significant overlap between the clinical and serological profiles of these patients supports the view that PCB and Fisher syndrome form a continuous spectrum. In this review, we highlight the clinical features of PCB and outline new diagnostic criteria. PMID:23804237

Wakerley, Benjamin R; Yuki, Nobuhiro



Journal of Nuclear Materials - Radiation-induced segregation and phase stability in ferritic-martensitic alloy T 91  

SciTech Connect

Radiation-induced segregation in ferritic martensitic alloy T 91 was studied to understand the behavior of solutes as a function of dose and temperature. Irradiations were conducted using 2 MeV protons to doses of 1, 3, 7 and 10 dpa at 400 C. Radiation-induced segregation at prior austenite grain boundaries was measured, and various features of the irradiated microstructure were characterized, including grain boundary carbide coverage, the dislocation microstructure, radiation-induced precipitation and irradiation hardening. Results showed that Cr, Ni and Si segregate to prior austenite grain boundaries at low dose, but segregation ceases and redistribution occurs above 3 dpa. Grain boundary carbide coverage mirrors radiation-induced segregation. Irradiation induces formation of Ni Si Mn and Cu-rich precipitates that account for the majority of irradiation hardening. Radiation-induced segregation behavior is likely linked to the evolution of the precipitate and dislocation microstructures. 2010 Elsevier B.V. All rights reserved

Jiao, Zhijie [ORNL; Busby, Jeremy T [ORNL; Was, Gary S [ORNL; Jiao, Zhijie [University of Michigan



Gene expression profiling of alpha-radiation-induced rat osteosarcomas: identification of dysregulated genes involved in radiation-induced tumorigenesis of bone.  


To better understand the molecular basis of radiation-induced osteosarcoma (OS), we performed global gene expression profiling of rat OS tumors induced by the bone-seeking alpha emitter (238)Pu, and the expression profiles were compared with those of normal osteoblasts (OB). The expressions of 72 genes were significantly differentially expressed in the tumors related to OB. These included genes involved in the cell adhesion (e.g., Podxl, Col18a1, Cd93, Emcn and Vcl), differentiation, developmental processes (e.g., Hhex, Gata2, P2ry6, P2rx5, Cited2, Osmr and Igsf10), tumor-suppressor function (e.g., Nme3, Blcap and Rrm1), Src tyrosine kinase signaling (e.g., Hck, Shf, Arhgap29, Cttn and Akap12), and Wnt/beta-catenin signaling (e.g., Fzd6, Lzic, Dkk3 and Ctnna1) pathways. Expression changes of several genes were validated by quantitative real-time RT-PCR analysis. Notably, all of the identified genes involved in the Wnt/beta-catenin signaling pathway were known or proposed to be negative regulators of this pathway and were downregulated in the tumors, suggesting the activation of beta-catenin in radiation-induced OS. By using immunohistochemical and immunoblot analyses, constitutive activation of the Wnt/beta-catenin signaling pathway in the tumors was confirmed by observing nuclear and/or cytoplasmic localization of beta-catenin and a decrease in its inactive (phosphorylated) form. Furthermore, we found a significant reduction in the levels of glycogen synthase kinase 3beta (GSK-3beta) protein in the tumors relative to OB. Taken together, these findings provide new insights into the molecular basis of radiation-induced OS. PMID:19444910

Daino, Kazuhiro; Ugolin, Nicolas; Altmeyer-Morel, Sandrine; Guilly, Marie-Noëlle; Chevillard, Sylvie



Use of a Collagen-Based Device for Closure of Low Brachial Artery Punctures  

SciTech Connect

Purpose. To report our experience with the Angioseal vascular closure device for hemostasis of distal brachial artery puncture. Methods. Between September 2003 and August 2005, 64 Angioseal vascular closure devices were inserted in 64 patients (40 men, 24 women; mean age 65 years) immediately after diagnostic or therapeutic arterial angiographies performed through a 5 Fr to 7 Fr sheath via the distal brachial artery. Ultrasound examination of the brachial artery preceded the angiography in all cases and only arteries wider than 4 mm were closed by the Angioseal. In cases of a sonographically evident thin subcutaneous space of the cubital fossa, tissue tumescence, using 1% Lidocaine, was performed prior to the arterial closure. Results. The deployment success rate was 100%. No major complications were encountered; only 2 patients developed puncture site hematoma, and these were followed conservatively. Conclusions. Closure of low brachial artery punctures with the Angioseal is simple and safe. No additional manual compression is required. We recommend its use after brachial artery access interventions, through appropriately wide arteries, to improve early patient ambulation and potentially reduce possible puncture site complications.

Belenky, A. [Rabin Medical Center, Beilinson and Glolda Campuses, Petah Tiqwa, Sakler Faculty of Medicine, Tel Aviv University, Department of Interventional Radiology (Israel)], E-mail:; Aranovich, D.; Greif, F. [Rabin Medical Center, Beilinson and Glolda Campuses, Petah Tiqwa, Sakler Faculty of Medicine, Tel Aviv University, Department of Surgery (Israel); Bachar, G. [Rabin Medical Center, Beilinson and Glolda Campuses, Petah Tiqwa, Sakler Faculty of Medicine, Tel Aviv University, Department of Radiology (Israel); Bartal, G. [Hillel Yaffe Medical Center, Department of Radiology (Israel); Atar, E. [Rabin Medical Center, Beilinson and Glolda Campuses, Petah Tiqwa, Sakler Faculty of Medicine, Tel Aviv University, Department of Interventional Radiology (Israel)



Constraint-Induced Movement Therapy for Children with Obstetric Brachial Plexus Palsy: Two Single-Case Series  

ERIC Educational Resources Information Center

The objective of this pilot study was to investigate the feasibility of constraint-induced movement therapy (CIMT) in children with obstetric brachial plexus palsy and receive preliminary information about functional improvements. Two patients (age 12 years) with obstetric brachial plexus palsy were included for a 126-h home-based CIMT…

Buesch, Francisca Eugster



Advanced radiological work-up as an adjunct to decision in early reconstructive surgery in brachial plexus injuries  

Microsoft Academic Search

BACKGROUND: As neurophysiologic tests may not reveal the extent of brachial plexus injury at the early stage, the role of early radiological work-up has become increasingly important. The aim of the study was to evaluate the concordance between the radiological and clinical findings with the intraoperative findings in adult patients with brachial plexus injuries. METHODS: Seven consecutive male patients (median

Kasim Abul-Kasim; Clas Backman; Anders Björkman; Lars B Dahlin



Hand Function in Children with an Upper Brachial Plexus Birth Injury: Results of the Nine-Hole Peg Test  

ERIC Educational Resources Information Center

Aim: The aim of this study was to evaluate hand function in children with Erb upper brachial plexus palsy. Method: Hand function was evaluated in 25 children (eight males; 17 females) with a diagnosed upper (C5/C6) brachial plexus birth injury. Of these children, 22 had undergone primary nerve reconstruction and 13 of the 25 had undergone…

Immerman, Igor; Alfonso, Daniel T.; Ramos, Lorna E.; Grossman, Leslie A.; Alfonso, Israel; Ditaranto, Patricia; Grossman, John A. I.



Structural Characteristics of the Subscapularis Muscle in Children With Medial Rotation Contracture of the Shoulder After Obstetric Brachial Plexus Injury  

Microsoft Academic Search

The aim of this study was to obtain a better understanding of the cause of the medial rotation contracture of the shoulder after obstetric brachial plexus lesions by studying the morphology of the shortened subscapularis muscle. Muscle biopsy specimens were harvested from 13 children with obstetric brachial plexus palsy who underwent corrective surgery for the rotation contracture. The majority of

T. Hultgren; F. Einarsson; E. Runesson; C. Hemlin; J. Fridén; B.-O. Ljung



Different Learning Curves for Axillary Brachial Plexus Block: Ultrasound Guidance versus Nerve Stimulation.  


Little is known about the learning of the skills needed to perform ultrasound- or nerve stimulator-guided peripheral nerve blocks. The aim of this study was to compare the learning curves of residents trained in ultrasound guidance versus residents trained in nerve stimulation for axillary brachial plexus block. Ten residents with no previous experience with using ultrasound received ultrasound training and another ten residents with no previous experience with using nerve stimulation received nerve stimulation training. The novices' learning curves were generated by retrospective data analysis out of our electronic anaesthesia database. Individual success rates were pooled, and the institutional learning curve was calculated using a bootstrapping technique in combination with a Monte Carlo simulation procedure. The skills required to perform successful ultrasound-guided axillary brachial plexus block can be learnt faster and lead to a higher final success rate compared to nerve stimulator-guided axillary brachial plexus block. PMID:21318138

Luyet, C; Schüpfer, G; Wipfli, M; Greif, R; Luginbühl, M; Eichenberger, U



Different Learning Curves for Axillary Brachial Plexus Block: Ultrasound Guidance versus Nerve Stimulation  

PubMed Central

Little is known about the learning of the skills needed to perform ultrasound- or nerve stimulator-guided peripheral nerve blocks. The aim of this study was to compare the learning curves of residents trained in ultrasound guidance versus residents trained in nerve stimulation for axillary brachial plexus block. Ten residents with no previous experience with using ultrasound received ultrasound training and another ten residents with no previous experience with using nerve stimulation received nerve stimulation training. The novices' learning curves were generated by retrospective data analysis out of our electronic anaesthesia database. Individual success rates were pooled, and the institutional learning curve was calculated using a bootstrapping technique in combination with a Monte Carlo simulation procedure. The skills required to perform successful ultrasound-guided axillary brachial plexus block can be learnt faster and lead to a higher final success rate compared to nerve stimulator-guided axillary brachial plexus block. PMID:21318138

Luyet, C.; Schupfer, G.; Wipfli, M.; Greif, R.; Luginbuhl, M.; Eichenberger, U.



Neurolymphomatosis of Brachial Plexus in Patients with Non-Hodgkin's Lymphoma  

PubMed Central

Neurolymphomatosis (NL) is a rare clinical disease where neoplastic cells invade the cranial nerves and peripheral nerve roots, plexus, or other nerves in patients with hematologic malignancy. Most NL cases are caused by B-cell non-Hodgkin's lymphoma (NHL). Diagnosis can be made by imaging with positron emission tomography (PET) and magnetic resonance imaging (MRI). We experienced two cases of NL involving the brachial plexus in patients with NHL. One patient, who had NHL with central nervous system (CNS) involvement, experienced complete remission after 8 cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) chemotherapy but relapsed into NL of the brachial plexus 5 months later. The other patient, who suffered from primary central nervous system lymphoma (PCNSL), had been undergoing chemoradiotherapy but progressed to NL of the brachial plexus. PMID:24324902

Shin, Jung A.; Cho, Joong-Yang; Yi, Seong Yoon; Lee, Hye Ran



Brachial plexus palsy following a training run with a heavy backpack.  


A 23-year-old male British soldier developed a progressive sensory loss and weakness in his right arm during a 12?km training run with a load of approximately 70?kg. There was no recovery of his symptoms within 3?months and both MRI and USS did not demonstrate a site of compression within the brachial plexus. An infraclavicular brachial plexus exploration was performed 11?months after injury that indicated an ischaemic neuropathy with post-injury fibrosis. Injuries of the brachial plexus secondary to carrying a heavy backpack during prolonged periods of exercise are rare, particularly in the infraclavicular region. Cases such as this highlight that training regimens within the military population should be appraised due to the risk of similar injuries occurring. PMID:24125801

McCulloch, Robert; Sheena, Y; Simpson, C; Power, D



Outcome in adolescence of brachial plexus birth palsy.  


Background and purpose - The frequency and severity of a permanent lesion after brachial plexus birth palsy (BPBP) and its impact on activities of daily living are not well documented. We therefore investigated the outcome of BPBP in adolescents, regarding arm function and consequences for activity and participation. Participants and methods - Of 30,574 babies born at St. Olavs University Hospital in 1991-2000, 91 had BPBP (prevalence 3 per 1,000), and 69 of these individuals were examined at a median age of 14 (10-20) years. The examination included the modified Mallet classification, range of motion, shoulder rotation and grip strength, Assisting Hand Assessment, and Canadian Occupational Performance Measure. Of the 22 subjects who were not examined, 3 could not be traced and 19 reported having no problems in the affected arm. Results - At follow-up, 17 adolescents had a permanent lesion (i.e. individual Mallet subscore below 4) with a median Mallet total score of 15 (9-19), while 52 had good or normal shoulder function (median Mallet total score 25 (23-25)). All participants with a permanent lesion had reduced active shoulder rotation (? 15°), 16 had elbow extension deficit, and 10 had subnormal grip strength. External rotation was considerably weaker in the affected shoulder. In addition, they had ineffective use of the affected arm in bimanual activities. Even so, all except 1 were independent in activities of daily living, although 15 experienced minor difficulties. Interpretation - Every fourth to fifth child with BPBP had a permanent lesion as an adolescent. External rotation was the most impaired movement. Despite ineffective use of the affected arm in bimanual activities, all of the participants except one were independent in activities of daily living. PMID:25238434

Hulleberg, Gunn; Elvrum, Ann-Kristin G; Brandal, Merethe; Vik, Torstein



Modulation of radiation-induced apoptosis and G{sub 2}/M block in murine T-lymphoma cells  

SciTech Connect

Radiation-induced apoptosis in lymphocyte-derived cell lines is characterized by endonucleolytic cleavage of cellular DNA within hours after radiation exposure. We have studied this phenomenon qualitatively (DNA gel electrophoresis) and quantitatively (diphenylamine reagent assay) in murine EL4 T-lymphoma cells exposed to {sup 137}Cs {gamma} irradiation. Fragmentation was discernible within 18-24 h after exposure. It increased with time and dose and reached a plateau after 8 Gy of {gamma} radiation. We studied the effect of several pharmacological agents on the radiation-induced G{sub 2}/M block and DNA fragmentation. The agents which reduced the radiation-induced G{sub 2}/M-phase arrest (caffeine, theobromine, theophylline and 2-aminopurine) enhanced the degree of DNA fragmentation at 24 h. In contrast, the agents which sustained the radiation-induced G{sub 2}/M-phase arrest (TPA, DBcAMP, IBMX and 3-aminobenzamide) inhibited the DNA fragmentation at 24 h. These studies on EL4 lymphoma cells are consistent with the hypothesis that cells with radiation-induced genetic damage are eliminated by apoptosis subsequent to a G{sub 2}/M block. Furthermore, it may be possible to modulate the process of radiation-induced apoptosis in lymphoma cells with pharmacological agents that modify the radiation-induced G{sub 2}/M block, and to use this effect in the treatment of patients with malignant disease. 59 refs., 7 figs.

Palayoor, S.T.; Macklis, R.M.; Bump, E.A.; Coleman, C.N. [Harvard Medical School, Boston, MA (United States)



Brachial Plexus Tumors in a Consecutive Series of Twenty One Patients  

PubMed Central

Objective This is a retrospective review of 22 surgically treated benign and malignant tumors of brachial plexus region to describe clinical presentation, the characteristics of brachial plexus tumor and clinical outcomes with a literature review. Methods Twenty-one patients with consecutive 22 surgeries for primary brachial plexus tumors were enrolled between February 2002 and November 2011 were included in this study. The medical records of all patients were reviewed. Results Eleven male and 10 female patients were enrolled. Mean age was 39 years. Three patients had brachial plexus tumor associated with neurofibromatosis (13.6%). Presenting signs and symptoms included parenthesis and numbness (54.5%), radiating pain (22.7%), direct tenderness and pain (27.2%), palpable mass (77.3%). Twelve patients presented preoperative sensory deficit (54.5%) and 9 patients presented preoperative motor deficit (40.9%). Twenty tumors (90.9%) were benign and 2 tumors (9.1%) were malignant. Benign tumors included 15 schwannomas (68.2%), 4 neurofibromas (18.2%) and 1 granular cell tumor (4.5%). There were 1 malignant peripheral nerve sheath tumor (MPNST) and 1 malignant granular cell tumor. Gross total resection was achieved in 16 patients (72.7%), including all schwannomas, 1 neurofibroma. Subtotal resection was performed in 6 tumors (27.3%), including 3 neurofibromatosis associated with brachial plexus neurofibromas, 1 MPNST and 2 granular cell tumor in one patient. Conclusion Resection of tumor is the choice of tumor in the most of benign and malignant brachial plexus tumors. Postoperative outcomes are related to grade of resection at surgery and pathological features of tumor. PMID:23091673

Go, Myeong Hoon; Cho, Ki Hong



Relationship Between Brachial Flow - Mediated Dilation and Carotid Intima- Media Thickness in an Elderly Cohort: The Cardiovascular Health Study  

PubMed Central

Objective The aim of this study was to determine the relationship between brachial flow-mediated dilation (FMD) and carotid intima-media thickness (IMT) in a large multi-ethnic elderly cohort. Background Brachial flow-mediated dilation (FMD) is a physiologic measure and Carotid IMT is an anatomic structural measure of subclinical atherosclerosis. Both brachial FMD and carotid IMT have been associated with cardiovascular risk factors and cardiovascular events. The relationship between brachial FMD and carotid IMT is less clear especially in older adults. Methods Brachial FMD, carotid IMT and traditional cardiovascular risk factors were measured in 2338 adults, age 72–98 years who were participants in the Cardiovascular Health Study. The relationship between FMD and IMT was assessed both unadjusted and also after adjusting for age, gender, race/ethnicity. BMI, HDL, LDL, systolic and diastolic blood pressure, serum creatinine, current smoking, diabetes mellitus, hormone therapy and prior CVD. Results Both brachial FMD and carotid IMT correlated significantly with age, HDL levels, waist/hip ratio, serum cholesterol and number of CV risk factors. Brachial FMD was not associated with CCA IMT in this elderly cohort (Pearson partial correlation coefficient= ?0.0252, p=0.222). In the adjusted linear regression model with CCA IMT as the dependent variable, brachial FMD was also not associated with CCA IMT (beta coefficient= ?0.006, p=0.470) Conclusion Brachial FMD and CCA IMT are not related in population-based older adults. Brachial FMD and CCA IMT may be distinct and independent stages in the complex atherosclerotic process. PMID:17804000

Yeboah, Joseph; Burke, Gregory L; Crouse, John R; Herrington, David M



Brachial plexus injury in two red-tailed hawks (Buteo jamaicensis).  


Two red-tailed hawks (Buteo jamaicensis), found near Deltaville, Virginia (USA), were evaluated because of inability to use a wing. Results of needle electromyographic studies of the affected wing muscles in both hawks were compatible with denervation. On euthanasia, one hawk had extensive axon and myelin loss with multifocal perivascular lymphocytic inflammation of its brachial plexus and radial nerve. Demyelination and axon loss in the dorsal white matter of the spinal cord on the affected side also were found at the origin of the brachial plexus. The other hawk's wing had not returned to functional status > 2 yr after injury. PMID:8383253

Shell, L; Richards, M; Saunders, G



Can bilateral bronchospasm be a sign of unilateral phrenic nerve palsy after supraclavicular brachial plexus block?  


Ultrasound-guided peripheral nerve blocks facilitate ambulatory anesthesia for upper limb surgeries. Unilateral phrenic nerve blockade is a common complication after interscalene brachial plexus block, rather than the supraclavicular block. We report a case of severe respiratory distress and bilateral bronchospasm following ultrasound-guided supraclavicular brachial plexus block. Patient did not have clinical features of pneumothorax or drug allergy and was managed with oxygen therapy and salbutamol nebulization. Chest X-ray revealed elevated right hemidiaphragm confirming unilateral phrenic nerve paresis. PMID:22557755

Chaudhuri, Souvik; Gopalkrishna, Md; Paul, Cherish; Kundu, Ratul



Brachial Plexus Injury as a Complication after Nerve Block or Vessel Puncture  

PubMed Central

Brachial plexus injury is a potential complication of a brachial plexus block or vessel puncture. It results from direct needle trauma, neurotoxicity of injection agents and hematoma formation. The neurological presentation may range from minor transient pain to severe sensory disturbance or motor loss with poor recovery. The management includes conservative treatment and surgical exploration. Especially if a hematoma forms, it should be removed promptly. Comprehensive knowledge of anatomy and adept skills are crucial to avoid nerve injuries. Whenever possible, the patient should not be heavily sedated and should be encouraged to immediately inform the doctor of any experience of numbness/paresthesia during the nerve block or vessel puncture. PMID:25031806

Kim, Hyun Jung; Park, Sang Hyun; Shin, Hye Young



Severe stridor and marked respiratory difficulty after right-sided supraclavicular brachial plexus block  

Microsoft Academic Search

Brachial plexus block is commonly used for upper limb surgery. Although the procedure is safe, it may be associated with some\\u000a life-threatening complications. We performed right-sided supraclavicular brachial plexus block for below-elbow amputation\\u000a in a 45-year-old female. At completion of the block the patient developed marked respiratory difficulty with audible inspiratory\\u000a stridor. Although SpO2 decreased to 82% initially, it was

Sohan Lal Solanki; Amit Jain; Jeetinder Kaur Makkar; Sapna Annaji Nikhar



Magnetic resonance neurography in children with birth-related brachial plexus injury  

Microsoft Academic Search

Background  Magnetic resonance neurography (MRN) enables visualization of peripheral nerves. Clinical examination and electrodiagnostic\\u000a studies have been used in the evaluation of birth-related brachial plexus injury. These are limited in their demonstration\\u000a of anatomic detail and severity of injury.\\u000a \\u000a \\u000a \\u000a Objective  We investigated the utility of MRN in evaluating birth-related brachial plexus injury in pediatric patients, and assessed\\u000a the degree of correlation between

Alice B. Smith; Nalin Gupta; Jonathan Strober; Cynthia Chin



Compensation of fading effects of radiation-induced loss by multiple wavelengths measurements  

NASA Astrophysics Data System (ADS)

The radiation induced loss of multimode lead glass fibers is measured during and after irradiation by a Co-60 source in the temperature range from 10 degree(s)C to 50 degree(s)C. The measurements were performed at visible and infrared LED wavelengths using time multiplexing of the LED's. The radiation sensitivity and relaxation effects of this fiber depend on temperature and on the wavelength of the read-out light. The wavelength dependence allows estimation of the actual fiber temperature. Thus a method can be developed to compensate temperature and fading effects on radiation induced loss in situations where the fiber temperature is unknown. The application of multiple wavelength measurements of induced loss for radiation dosimetry with optical fibers is discussed.

Bueker, Harald; Haesing, Friedrich W.; Gerhard, E.



A Kinetic-Based Model of Radiation-Induced Intercellular Signalling  

PubMed Central

It is now widely accepted that intercellular communication can cause significant variations in cellular responses to genotoxic stress. The radiation-induced bystander effect is a prime example of this effect, where cells shielded from radiation exposure see a significant reduction in survival when cultured with irradiated cells. However, there is a lack of robust, quantitative models of this effect which are widely applicable. In this work, we present a novel mathematical model of radiation-induced intercellular signalling which incorporates signal production and response kinetics together with the effects of direct irradiation, and test it against published data sets, including modulated field exposures. This model suggests that these so-called “bystander” effects play a significant role in determining cellular survival, even in directly irradiated populations, meaning that the inclusion of intercellular communication may be essential to produce robust models of radio-biological outcomes in clinically relevant in vivo situations. PMID:23349919

McMahon, Stephen J.; Butterworth, Karl T.; Trainor, Colman; McGarry, Conor K.; O'Sullivan, Joe M.; Schettino, Giuseppe; Hounsell, Alan R.; Prise, Kevin M.



Interplay between photo- and radiation-induced darkening in ytterbium-doped fibers.  


This Letter demonstrates a remarkable interplay between photo- and radiation-induced darkening of ytterbium-doped alumino-silica optical fibers operated in amplifying conditions and harsh environments (as, e.g., in space-based applications). Influences of the pump power, ionizing dose, and dose rate on this interaction are characterized. The pump is capable of accelerating or slowing down the radiation-induced darkening build-up depending on the ionizing dose. The steady-state photo-radio-darkening level is independent of the dose and at least equal to the equilibrium level of pure photo-darkening. This lower limit is notably reached at low dose rates, including those encountered in space. We, therefore, argue that photo-resistant ytterbium-doped fibers will resist against a space mission, whatever the dose. PMID:25361132

Duchez, Jean-Bernard; Mady, Franck; Mebrouk, Yasmine; Ollier, Nadège; Benabdesselam, Mourad



Radiation-induced leiomyosarcoma of the great vessels presenting as superior vena cava syndrome  

SciTech Connect

A patient with a pleomorphic intravascular leiomyosarcoma of the great vessels of the neck and mediastinum presented clinically with a superior vena cava syndrome. A latent period of 29 years elapsed between receiving orthovoltage radiation to the neck and right side of chest to treat recurrent ganglioneuroblastoma, and the appearance of a leiomyosarcoma and subsequent recurrences. The patient underwent partial resection of the tumor, received adjunct chemotherapy, and was shown to be free of disease by clinical tests and by magnetic resonance imaging (MRI) 17 months after completion of chemotherapy. The criteria for the diagnosis of radiation-induced sarcomas are reviewed in relation to the present case. The critical role of magnetic resonance imaging in both the diagnosis and continued follow-up of the patient is described. This would appear to be the first reported case of radiation-induced intravascular leiomyosarcoma of the great vessels of the neck and mediastinum presenting as a superior vena cava syndrome.

Weiss, K.S.; Zidar, B.L.; Wang, S.; Magovern, G.J. Sr.; Raju, R.N.; Lupetin, A.R.; Shackney, S.E.; Simon, S.R.; Singh, M.; Pugh, R.P.



The potential influence of radiation-induced microenvironments in neoplastic progression  

NASA Technical Reports Server (NTRS)

Ionizing radiation is a complete carcinogen, able both to initiate and promote neoplastic progression and is a known carcinogen of human and murine mammary gland. Tissue response to radiation is a composite of genetic damage, cell death and induction of new gene expression patterns. Although DNA damage is believed to initiate carcinogenesis, the contribution of these other aspects of radiation response are beginning to be explored. Our studies demonstrate that radiation elicits rapid and persistent global alterations in the mammary gland microenvironment. We postulate that radiation-induced microenvironments may affect epithelial cells neoplastic transformation by altering their number or susceptibility. Alternatively, radiation induced microenvironments may exert a selective force on initiated cells and/or be conducive to progression. A key impetus for these studies is the possibility that blocking these events could be a strategy to interrupt neoplastic progression.

Barcellos-Hoff, M. H.; Chatterjee, A. (Principal Investigator)



Evaluating radiation induced noise effects on pixelated sensors for the National Ignition Facility  

NASA Astrophysics Data System (ADS)

The National Ignition Facility (NIF) utilizes several different pixelated sensor technologies for various measurement systems that include alignment cameras, laser energy sensors, and high-speed framing cameras. These systems remain in the facility where they are exposed to 14MeV neutrons during a NIF shot. The image quality of the sensors degrades as a function of radiation-induced damage. This article reports on a figure-of-merit technique that aids in the tracking of the performance of pixelated sensors when exposed to neutron radiation from NIF. The sensor dark current growth can be displayed over time in a 2D visual representation for tracking radiation induced damage. Predictions of increased noise as a function of neutron fluence for future NIF shots allow simulation of reduced performance for each of the individual camera applications. This predicted longevity allows for proper management of the camera systems.

Datte, Philip; Manuel, Anastacia M.; Eckart, Mark; Jackson, Mark; Khater, Hesham; Newton, Mark



Hyperbaric oxygen in the treatment of radiation-induced optic neuropathy  

SciTech Connect

Four patients with radiation-induced optic neuropathies were treated with hyperbaric oxygen. They had received radiation therapy for treatment of pituitary tumors, reticulum cell sarcoma, and meningioma. Two presented with amaurosis fugax before the onset of unilateral visual loss and began hyperbaria within 72 hours after development of unilateral optic neuropathy. Both had return of visual function to baseline levels. The others initiated treatment two to six weeks after visual loss occurred in the second eye and had no significant improvement of vision. Treatment consisted of daily administration of 100% oxygen under 2.8 atmospheres of pressure for 14-28 days. There were no medical complications of hyperbaria. While hyperbaric oxygen is effective in the treatment of radiation-induced optic neuropathy, it must be instituted within several days of deterioration in vision for restoration of baseline function.

Guy, J.; Schatz, N.J.



Radiation-induced alterations in histone modification patterns and their potential impact on short-term radiation effects  

PubMed Central

Detection and repair of radiation-induced DNA damage occur in the context of chromatin. An intricate network of mechanisms defines chromatin structure, including DNA methylation, incorporation of histone variants, histone modifications, and chromatin remodeling. In the last years it became clear that the cellular response to radiation-induced DNA damage involves all of these mechanisms. Here we focus on the current knowledge on radiation-induced alterations in post-translational histone modification patterns and their effect on the chromatin accessibility, transcriptional regulation and chromosomal stability. PMID:23050241

Friedl, Anna A.; Mazurek, Belinda; Seiler, Doris M.



Radiation-induced gliomas in 2 pediatric patients with neurofibromatosis type 1: case study and summary of the literature.  


Neurofibromatosis type 1 (NF1) is a genetic disorder that predisposes patients to the formation of sporadic tumors and also increases the risk of radiation-induced malignancies. The most commonly described radiation-induced tumor in NF1 patients is a malignant peripheral nerve sheath tumor. We present 2 children with NF1 who received radiation therapy and subsequently developed high-grade gliomas. We then review the current literature on radiation-induced tumors in NF1 patients. Although radiation may be the most appropriate therapy in specific situations for children with NF1, the secondary tumor risk should be carefully considered. PMID:24136023

Madden, Jennifer R; Rush, Sarah Z; Stence, Nicholas; Foreman, Nicholas K; Liu, Arthur K



Interaction of water vapor with gamma-radiation-induced defects in proton conductive polymers  

Microsoft Academic Search

The correlation between protonic conduction and the amount of radiation-induced defects in gamma-ray-irradiated perfluorosulfonic acid (PFSA) polymers (Aciplex-SF-1004®) has been investigated using a direct-current resistance method, transmission spectroscopy for the ultraviolet (UV) and visible (Vis) wavelength ranges and Fourier transform infrared (FTIR) spectroscopy with the attenuated total refraction (ATR) technique. The proton conductivity of the polymers, which are irradiated with

B. Tsuchiya; Y. Konishi; S. Nagata; T. Shikama



C/EBP? Deficiency Sensitizes Mice to Ionizing Radiation-Induced Hematopoietic and Intestinal Injury  

PubMed Central

Knowledge of the mechanisms involved in the radiation response is critical for developing interventions to mitigate radiation-induced injury to normal tissues. Exposure to radiation leads to increased oxidative stress, DNA-damage, genomic instability and inflammation. The transcription factor CCAAT/enhancer binding protein delta (Cebpd; C/EBP? is implicated in regulation of these same processes, but its role in radiation response is not known. We investigated the role of C/EBP? in radiation-induced hematopoietic and intestinal injury using a Cebpd knockout mouse model. Cebpd?/? mice showed increased lethality at 7.4 and 8.5 Gy total-body irradiation (TBI), compared to Cebpd+/+ mice. Two weeks after a 6 Gy dose of TBI, Cebpd?/? mice showed decreased recovery of white blood cells, neutrophils, platelets, myeloid cells and bone marrow mononuclear cells, decreased colony-forming ability of bone marrow progenitor cells, and increased apoptosis of hematopoietic progenitor and stem cells compared to Cebpd+/+ controls. Cebpd?/? mice exhibited a significant dose-dependent decrease in intestinal crypt survival and in plasma citrulline levels compared to Cebpd+/+ mice after exposure to radiation. This was accompanied by significantly decreased expression of ?-H2AX in Cebpd?/? intestinal crypts and villi at 1 h post-TBI, increased mitotic index at 24 h post-TBI, and increase in apoptosis in intestinal crypts and stromal cells of Cebpd?/? compared to Cebpd+/+ mice at 4 h post-irradiation. This study uncovers a novel biological function for C/EBP? in promoting the response to radiation-induced DNA-damage and in protecting hematopoietic and intestinal tissues from radiation-induced injury. PMID:24747529

Chang, Jianhui; Wang, Wenze; Pathak, Rupak; Zhu, Xiaoyan; Wang, Junru; Hendrickson, Howard; Boerma, Marjan; Sterneck, Esta; Zhou, Daohong; Hauer-Jensen, Martin



Silencing of Cited2 and Akap12 genes in radiation-induced rat osteosarcomas  

Microsoft Academic Search

We have previously studied genomic copy number changes and global gene expression patterns in rat osteosarcomas (OS) induced by the bone-seeking alpha emitter 238Pu by comparative genomic hybridization (CGH) and oligonucleotide microarray analyses, respectively. Among the previously identified genes that were down-regulated in radiation-induced rat OS tumors, Cited2 (Cbp\\/p300-interacting transactivator, with Glu\\/Asp-rich carboxy-terminal domain, 2) and Akap12 (a kinase anchoring

Kazuhiro Daino; Sandrine Roch-Lefevre; Nicolas Ugolin; Sandrine Altmeyer-Morel; Marie-Noëlle Guilly; Sylvie Chevillard



The Self-Consistent Charge Method: A Numerical Approach to Radiation-Induced Charge Transport Phenomena  

Microsoft Academic Search

Reconsidering the numerous conceptions as they have been developed in atomic physics (self-consistent field), heat and charge transport theory (carrier-enhanced and radiation-induced conductivity) and many other related fields for iteratively solving the corresponding integro-differential equation systems we come now to propose a new approach to the subject addressed in the title. This method has been implemented in a FORTRAN code,

E. Hartmann; H.-R. Döring; J. Leonhardt



Influence of Radiation-Induced Grafting Process on mechanical Properties of ETFE Based Membranes  

Microsoft Academic Search

We investigated the influence of irradiation dose, crosslinker concentration, graft level or styrene\\/DVB content on the tensile strength, elongation at break, yield strength and modulus of elasticity, of poly(ethylene-alt-tetrafluoroethylene) (ETFE) based membranes. Grafted films were prepared by radiation-induced grafting and the membranes were obtained by subsequent sulfonation of the grafted films. It was found that the elongation at break decreases

H. Ben; S. Alkan Gürsel; A. Buisson; L. Gubler; A. Wokaun; G. G. Scherer


Radiatively induced Lorentz-violating operator of mass dimension five in QED  

SciTech Connect

The first higher derivative term of the photon sector of Lorentz-violating QED, with an operator of mass dimension d=5, is radiatively induced from the fermion sector, which contains a derivative term with the dimensionless coefficient g{sup {lambda}{mu}{nu}}. The calculation is performed perturbatively in the coefficient for Lorentz violation, and, due to the fact that the contributions are quadratically divergent, we adopt dimensional regularization.

Mariz, T. [Instituto de Fisica, Universidade Federal de Alagoas, 57072-270, Maceio, Alagoas (Brazil)



Selenoprotein P Inhibits Radiation-Induced Late Reactive Oxygen Species Accumulation and Normal Cell Injury  

SciTech Connect

Purpose: Radiation is a common mode of cancer therapy whose outcome is often limited because of normal tissue toxicity. We have shown previously that the accumulation of radiation-induced late reactive oxygen species (ROS) precedes cell death, suggesting that metabolic oxidative stress could regulate cellular radiation response. The purpose of this study was to investigate whether selenoprotein P (SEPP1), a major supplier of selenium to tissues and an antioxidant, regulates late ROS accumulation and toxicity in irradiated normal human fibroblasts (NHFs). Methods and Materials: Flow cytometry analysis of cell viability, cell cycle phase distribution, and dihydroethidium oxidation, along with clonogenic assays, were used to measure oxidative stress and toxicity. Human antioxidant mechanisms array and quantitative real-time polymerase chain reaction assays were used to measure gene expression during late ROS accumulation in irradiated NHFs. Sodium selenite addition and SEPP1 overexpression were used to determine the causality of SEPP1 regulating late ROS accumulation and toxicity in irradiated NHFs. Results: Irradiated NHFs showed late ROS accumulation (4.5-fold increase from control; P<.05) that occurs after activation of the cell cycle checkpoint pathways and precedes cell death. The mRNA levels of CuZn- and Mn-superoxide dismutase, catalase, peroxiredoxin 3, and thioredoxin reductase 1 increased approximately 2- to 3-fold, whereas mRNA levels of cold shock domain containing E1 and SEPP1 increased more than 6-fold (P<.05). The addition of sodium selenite before the radiation treatment suppressed toxicity (45%; P<.05). SEPP1 overexpression suppressed radiation-induced late ROS accumulation (35%; P<.05) and protected NHFs from radiation-induced toxicity (58%; P<.05). Conclusion: SEPP1 mitigates radiation-induced late ROS accumulation and normal cell injury.

Eckers, Jaimee C.; Kalen, Amanda L.; Xiao, Wusheng; Sarsour, Ehab H.; Goswami, Prabhat C., E-mail:



Energy Distribution of Electrons in Radiation Induced-Helium Plasmas. Ph.D. Thesis  

NASA Technical Reports Server (NTRS)

Energy distribution of high energy electrons as they slow down and thermalize in a gaseous medium is studied. The energy distribution in the entire energy range from source energies down is studied analytically. A helium medium in which primary electrons are created by the passage of heavy-charged particles from nuclear reactions is emphasized. A radiation-induced plasma is of interest in a variety of applications, such as radiation pumped lasers and gaseous core nuclear reactors.

Lo, R. H.



Effects of subdiaphragmatic vagotomy on the acquisition of a radiation-induced conditioned taste aversion  

SciTech Connect

The effect of subdiaphragmatic vagotomy on the acquisition of a radiation-induced taste aversion was examined to assess the importance of the vagus nerve in transmitting information on the peripheral toxicity of radiation to the brain. Vagotomy had no effect on taste aversion learning, consistent with reports using other toxins. The data support the involvement of a blood-borne factor in the acquisition of taste aversion induced by ionizing radiation.

Hunt, W.A.; Rabin, B.M.; Lee, J.



Biologically-based risk estimation for radiation-induced chronic myeloid leukemia  

Microsoft Academic Search

Radiation cancer risks are typically determined by the use of simple statistical descriptions of epidemiological data. It\\u000a is important in risk assessment in general, however, to attempt to incorporate as much biological information into the risk\\u000a models as possible. We illustrate this by presenting a biologically-based linear-quadratic-exponential (LQE) incidence rate\\u000a model for radiation-induced chronic myeloid leukemia (CML). The model consists

Tomas Radivoyevitch; David G. Hoel



Effect of sodium meclofenamate on radiation-induced esophagitis and cystitis  

SciTech Connect

Stumptailed monkeys (Macaca arctoides) received 2000 rad irradiation to the upper half of the esophagus and to the bladder by a 6-MeV linear accelerator. Endoscopy and biopsy was obtained from these organs weekly for 3 weeks. At the end of this period, the animals were autopsied and histopathologic examination undertaken. Sodium meclofenamate in doses of 5-20 mg/kg/day p.os was found effective in reducing or preventing radiation-induced esophagitis and cystitis.

Ambrus, J.L.; Ambrus, C.M.; Lillie, D.B.; Johnson, R.J.; Gastpar, H.; Kishel, S.



Radiation-induced esophageal injury: A spectrum from esophagitis to cancer  

Microsoft Academic Search

Radiation esophagitis is a common but frequently unrecognized complication of therapeutic radiation to the neck, chest, or mediastinum. The spectrum of injury ranges from acute self-limited esophagitis to life-threatening esophageal perforation. Complications such as stricture or primary esophageal cancer may occur many years after irradiation, and their linkage to radiation may not be considered. Five cases of radiation-induced injury are

A. Vanagunas; P. Jacob; E. Olinger



Functionalization of polymer surfaces by radiation-induced grafting for separation of heavy metal ions  

NASA Astrophysics Data System (ADS)

The reported investigations were focused on the elucidation of the most important factors influencing radiation-induced grafting, particularly on studying the relationship between layer structure formed via copolymerization and content of monomers in the initial solution. Sorption capacity of the prepared by radiation grafting adsorber was evaluated by gamma radiometer using 152Eu3+ as a marker monitoring depletion of the radioisotope from the feed solution.

Kornacka, E. M.; Przybytniak, G.; Fuks, L.; Walo, M.; ?yczko, K.



Radiation-induced thyroid cancer: What we have learned from Chernobyl  

Microsoft Academic Search

An increased incidence of thyroid cancer in the exposed children remains the most well-documented long-term effect of radioactive\\u000a contamination after the Chernobyl nuclear accident in April, 1986. Multiple studies on approx 4000 children and adolescents\\u000a with thyroid cancer have provided important new information about the epidemiological, clinical, pathological, and molecular\\u000a aspects of radiation-induced carcinogenesis in the thyroid gland. They revealed

Yuri E. Nikiforov



Radiation-induced second cancers: the impact of 3D-CRT and IMRT  

Microsoft Academic Search

Information concerning radiation-induced malignancies comes from the A-bomb survivors and from medically exposed individuals, including second cancers in radiation therapy patients. The A-bomb survivors show an excess incidence of carcinomas in tissues such as the gastrointestinal tract, breast, thyroid, and bladder, which is linear with dose up to about 2.5 Sv. There is great uncertainty concerning the dose–response relationship for

Eric J Hall; Cheng-Shie Wuu



Radiation-induced effects on special super large n-channel power MOSFETS for space applications  

Microsoft Academic Search

Outlines the design, manufacture, and special processing techniques used to attain a solution to radiation-induced effects on super large N-channel power MOSFET dies, sizes 9 and 11, which are approximately 500×690 mils and 772×1022 mils, and still meet the critical and unique requirements of the remote power controller (RPC), the remote bus isolator (RBI), and, above all, the DC-to-DC converter

H. M. Joseph



Stem cells and the repair of radiation-induced salivary gland damage.  


Hyposalivation underlying xerostomia after radiotherapy is still a major problem in the treatment of head and neck cancer. Stem cell therapy may provide a means to reduce radiation-induced hyposalivation and improve the quality of life of patients. This review discusses the current status in salivary gland stem cell research with respect to their potential to attenuate salivary gland dysfunction. Knowledge on the embryonic development, homeostasis and regeneration after atrophy of the salivary glands has provided important knowledge on the location of the salivary gland as well as on the factors that influence proliferation and differentiation. This knowledge has helped to locate, isolate and characterize cell populations that contain the salivary gland stem cell, although the exact tissue stem cell is still unidentified. The role that stem/progenitor cells play in the response to radiation and the factors that can influence stem/progenitor induced proliferation and differentiation are discussed. Finally, the mobilization and transplantation of stem cells and supportive cells and their potential to attenuate radiation-induced salivary gland damage are discussed. Based on the major advances made in the field of stem cell research, stem cell-based therapy has great potential to allow prevention or treatment of radiation-induced hyposalivation. PMID:20796229

Coppes, R P; Stokman, M A



Loss of Matrix Metalloproteinase-13 Attenuates Murine Radiation-Induced Pulmonary Fibrosis  

SciTech Connect

Purpose: Pulmonary fibrosis is a disorder of the lungs with limited treatment options. Matrix metalloproteinases (MMPs) constitute a family of proteases that degrade extracellular matrix with roles in fibrosis. Here we studied the role of MMP13 in a radiation-induced lung fibrosis model using a MMP13 knockout mouse. Methods and Materials: We investigated the role of MMP13 in lung fibrosis by investigating the effects of MMP13 deficiency in C57Bl/6 mice after 20-Gy thoracic irradiation (6-MV Linac). The morphologic results in histology were correlated with qualitative and quantitative results of volume computed tomography (VCT), magnetic resonance imaging (MRI), and clinical outcome. Results: We found that MMP13 deficient mice developed less pulmonary fibrosis than their wildtype counterparts, showed attenuated acute pulmonary inflammation (days after irradiation), and a reduction of inflammation during the later fibrogenic phase (5-6 months after irradiation). The reduced fibrosis in MMP13 deficient mice was evident in histology with reduced thickening of alveolar septi and reduced remodeling of the lung architecture in good correlation with reduced features of lung fibrosis in qualitative and quantitative VCT and MRI studies. The partial resistance of MMP13-deficient mice to fibrosis was associated with a tendency towards a prolonged mouse survival. Conclusions: Our data indicate that MMP13 has a role in the development of radiation-induced pulmonary fibrosis. Further, our findings suggest that MMP13 constitutes a potential drug target to attenuate radiation-induced lung fibrosis.

Flechsig, Paul [Department of Radiation Oncology, German Cancer Research Center and University Hospital Center Heidelberg, Heidelberg (Germany); Hartenstein, Bettina; Teurich, Sybille [Department of Signal Transduction, German Cancer Research Center, Heidelberg (Germany); Dadrich, Monika; Hauser, Kai; Abdollahi, Amir; Groene, Hermann-Josef [Department of Radiation Oncology, German Cancer Research Center and University Hospital Center Heidelberg, Heidelberg (Germany); Angel, Peter [Department of Signal Transduction, German Cancer Research Center, Heidelberg (Germany); Huber, Peter E., E-mail: p.huber@dkfz.d [Department of Molecular Pathology, German Cancer Research Center, Heidelberg (Germany)



Radiation-induced chromosomal instability and gene expression profiling: searching for clues to initiation and perpetuation.  


Radiation-induced genomic instability (RIGI) manifests in the progeny of cells surviving ionizing radiation (IR), and can be measured using such endpoints as delayed mutation, micronuclei formation, and chromosomal instability. The frequency of RIGI is relatively high, exceeding the gene mutation rate of IR by orders of magnitude, leading to conjecture that a gene mutation is not the cause of the phenotype. We have started to explore whether differential gene expression patterns are associated with the instability phenotype, in order to shed light on its initiation and perpetuation. Using GM10115 human-hamster hybrid-derived chromosomally stable and radiation-induced unstable clones, gene expression patterns were analyzed using microarray analysis. Two methods were used to find differentially expressed genes, and all candidate genes identified by these methods were under-expressed relative to the chromosomally stable reference sample. Among this set differentially expressed genes identified were two candidates with a relationship to the ubiquitin/proteasome pathway. While follow-up gene expression analyses have confirmed the under-expression of these two genes in some of our chromosomally unstable clones, preliminary functional studies have been unable to demonstrate a link to instability. It is anticipated that as we apply this technology to the study of radiation-induced genomic instability, clues to its onset will be revealed, ultimately contributing to a greater understanding of the mechanisms of radiation carcinogenesis. PMID:15530542

Snyder, Andrew R; Morgan, William F



Analysis of potential radiation-induced genetic and somatic effects to man from milling of uranium  

SciTech Connect

Potential mortality from natural causes and from radiation exposure conditions typical of those in the vicinity of uranium mills in the western USA was calculated. The exposure conditions were those assumed to exist in the vicinity of a hypothetical model mill. Dose rates to organs at risk were calculated as a function of time using the Uranium Dispersion and Dosimetry Code (Momeni et al. 1979). The changes in population size, birth rates, and radiation-induced and natural mortalities were calculated using the PRIM code (Momeni 1983). The population of the region within a radius of 80 km from the model mill is projected to increase from 57 428 to 75 638.6 during the 85 years of this analysis. Within the same period, the average birth rates for five-year periods increase from 5067.8 to 7436.1. The cumulative deaths within the five-year periods increase from 724 and 3501.8 from spontaneously induced neoplasms and all causes, respectively, to 1538.2 and 6718.2. In comparison to natural causes, radiation-induced mortality is negligible. The highest rate of death from radiation in any five-year period is only 0.2, compared with 1538.2 deaths attributable to spontaneous incidence. The total radiation-induced genetic disorders were much less than unity for the 85-year period of analysis, in contrast with the 10.7% natural incidence of these disorders.

Momeni, M.H.



A gene expression signature distinguishes normal tissues of sporadic and radiation-induced papillary thyroid carcinomas  

PubMed Central

Background: Papillary thyroid cancer (PTC) incidence increased dramatically in children after the Chernobyl accident, providing a unique opportunity to investigate the molecular features of radiation-induced thyroid cancer. In contrast to the previous studies that included age-related confounding factors, we investigated mRNA expression in PTC and in the normal contralateral tissues of patients exposed and non-exposed to the Chernobyl fallout, using age- and ethnicity-matched non-irradiated cohorts. Methods: Forty-five patients were analysed by full-genome mRNA microarrays. Twenty-two patients have been exposed to the Chernobyl fallout; 23 others were age-matched and resident in the same regions of Ukraine, but were born after 1 March 1987, that is, were not exposed to 131I. Results: A gene expression signature of 793 probes corresponding to 403 genes that permitted differentiation between normal tissues from patients exposed and from those who were not exposed to radiation was identified. The differences were confirmed by quantitative RT-PCR. Many deregulated pathways in the exposed normal tissues are related to cell proliferation. Conclusion: Our results suggest that a higher proliferation rate in normal thyroid could be related to radiation-induced cancer either as a predisposition or as a consequence of radiation. The signature allows the identification of radiation-induced thyroid cancers. PMID:22828612

Dom, G; Tarabichi, M; Unger, K; Thomas, G; Oczko-Wojciechowska, M; Bogdanova, T; Jarzab, B; Dumont, J E; Detours, V; Maenhaut, C



Mechanisms of radiation-induced normal tissue toxicity and implications for future clinical trials  

PubMed Central

To summarize current knowledge regarding mechanisms of radiation-induced normal tissue injury and medical countermeasures available to reduce its severity. Advances in radiation delivery using megavoltage and intensity-modulated radiation therapy have permitted delivery of higher doses of radiation to well-defined tumor target tissues. Injury to critical normal tissues and organs, however, poses substantial risks in the curative treatment of cancers, especially when radiation is administered in combination with chemotherapy. The principal pathogenesis is initiated by depletion of tissue stem cells and progenitor cells and damage to vascular endothelial microvessels. Emerging concepts of radiation-induced normal tissue toxicity suggest that the recovery and repopulation of stromal stem cells remain chronically impaired by long-lived free radicals, reactive oxygen species, and pro-inflammatory cytokines/chemokines resulting in progressive damage after radiation exposure. Better understanding the mechanisms mediating interactions among excessive generation of reactive oxygen species, production of pro-inflammatory cytokines and activated macrophages, and role of bone marrow-derived progenitor and stem cells may provide novel insight on the pathogenesis of radiation-induced injury of tissues. Further understanding the molecular signaling pathways of cytokines and chemokines would reveal novel targets for protecting or mitigating radiation injury of tissues and organs.

Jenrow, Kenneth A.; Brown, Stephen L.



p53 Functions in Endothelial Cells to Prevent Radiation-Induced Myocardial Injury in Mice  

PubMed Central

p53 functions in the heart to promote myocardial injury after multiple types of stress. However, how p53 regulates radiation-induced myocardial injury, which develops after radiation therapy, is not well understood. Here, we utilize the Cre-loxP system to demonstrate that p53 functioned in endothelial cells to protect mice from myocardial injury after whole-heart irradiation. Mice with an endothelial cell-specific deletion of p53 succumbed to heart failure after whole-heart irradiation due to myocardial necrosis, systolic dysfunction and cardiac hypertrophy. Moreover, the onset of cardiac dysfunction was preceded by alterations in myocardial vascular permeability and density, which resulted in cardiac ischemia and myocardial hypoxia. Mechanistic studies using primary cardiac endothelial cells irradiated in vitro indicated that p53 signaling caused mitotic arrest and protected cardiac endothelial cells against radiation-induced mitotic catastrophe. Furthermore, mice lacking the cyclin-dependent kinase inhibitor p21, which is a transcriptional target of p53, were also sensitized to myocardial injury after wholeheart irradiation. Together, our results demonstrate that the p53/p21 axis functions to prevent radiation-induced myocardial injury in mice. PMID:22827996

Lee, Chang-Lung; Moding, Everett J.; Cuneo, Kyle C.; Li, Yifan; Sullivan, Julie M.; Mao, Lan; Washington, Iman; Jeffords, Laura B.; Rodrigues, Rafaela C.; Ma, Yan; Das, Shiva; Kontos, Christopher D.; Kim, Yongbaek; Rockman, Howard A.; Kirsch, David G.



Radiation-induced off-state leakage current in commercial power MOSFETs.  

SciTech Connect

The total dose hardness of several commercial power MOSFET technologies is examined. After exposure to 20 krad(SiO{sub 2}) most of the n- and p-channel devices examined in this work show substantial (2 to 6 orders of magnitude) increases in off-state leakage current. For the n-channel devices, the increase in radiation-induced leakage current follows standard behavior for moderately thick gate oxides, i.e., the increase in leakage current is dominated by large negative threshold voltage shifts, which cause the transistor to be partially on even when no bias is applied to the gate electrode. N-channel devices biased during irradiation show a significantly larger leakage current increase than grounded devices. The increase in leakage current for the p-channel devices, however, was unexpected. For the p-channel devices, it is shown using electrical characterization and simulation that the radiation-induced leakage current increase is related to an increase in the reverse bias leakage characteristics of the gated diode which is formed by the drain epitaxial layer and the body. This mechanism does not significantly contribute to radiation-induced leakage current in typical p-channel MOS transistors. The p-channel leakage current increase is nearly identical for both biased and grounded irradiations and therefore has serious implications for long duration missions since even devices which are usually powered off could show significant degradation and potentially fail.

Dodd, Paul Emerson; Shaneyfelt, Marty Ray; Draper, Bruce Leroy; Felix, James Andrew; Schwank, James Ralph; Dalton, Scott Matthew



Failla Memorial Lecture. The prevalence of multilocus lesions in radiation-induced mutants.  


In L5178Y mouse lymphoblasts, ionizing radiation-induced mutant frequencies were dramatically higher when the genetic marker analyzed was heterozygous (tk+/tk-) than when hemizygous (tk+/tk0 or hprt+/hprt0). In contrast, base-change mutagens induced similar mutant frequencies at heterozygous and hemizygous loci. These results indicate that the majority of radiation-induced mutants harbor multilocus lesions, and that these mutants are poorly recovered when the target gene is in a hemizygous chromosomal region. Dose-rate dependence of radiation-induced mutant frequency was demonstrated at the heterozygous tk locus but not at the hemizygous hprt locus; in a cell line deficient in the rejoining of DNA double-strand breaks (DSBs), no dose-rate dependence was observed for either locus. The majority of TK-/- mutants, whether spontaneous or induced by X, alpha-particle or UV radiation, or by photosensitization, showed loss of the entire active tk allele. The percentage of TK-/- mutants exhibiting inactivation of galactokinase, encoded by the neighboring gk gene, was high in UV repair-deficient cells exposed to UV radiation and in DNA DSB repair-deficient lines exposed to X radiation. Thus the presence of unrepaired DNA lesions, whether DSBs or pyrimidine dimers, appears to result in an increase in the percentage of mutants harboring multilocus lesions. PMID:8134537

Evans, H H



Radiation-induced gliomas following radiotherapy for craniopharyngiomas: a case report and review of the literature.  


The aim of this study was to collect, describe and analyze the radiation-induced gliomas in craniopharyngioma patients reported in the literature up to date. Review of the relevant literature was performed. One personal illustrative case was added. Reports of 15 patients, including the presented illustrative case, were evaluated. The average age of the patients at the time of irradiation was 12.5 years. All patients underwent conventional fractionated radiotherapy with mean total radiation dose of 55Gy and an average latency period of 10.8 years. Glioma localization varied with the highest frequency of the temporal lobe involvement. All but one patient had high-grade gliomas on the histological exam. Although exceptionally rare, the radiation-induced gliomas in craniopharyngioma patients are potentially possible, long-term complications with devastating consequences in typically younger patients with long life-expectancy. The radiation-induced iatrogenic injury on one hand should provoke the research and elaboration of safer and at least, equally efficient alternative treatment modalities and on the other hand ought to prompt the investigation of the patients' risk factors predisposing the oncogenesis after irradiation. PMID:19447544

Enchev, Yavor; Ferdinandov, Dilian; Kounin, Georgi; Encheva, Elitsa; Bussarsky, Ventzeslav



The role of secretory granules in radiation-induced dysfunction of rat salivary glands  

SciTech Connect

To investigate the possible role of secretory granules in radiation-induced salivary gland dysfunction, rats were pretreated with isoproterenol (5 mg/kg intraperitoneally) to degranulate salivary gland acini. At maximal depletion, salivary glands were locally irradiated with a single dose of 15 Gy of X rays. Parotid and submandibular/sublingual saliva samples were collected before and 1-10 days after irradiation. The lag phase, flow rate, concentrations of potassium and sodium, and amylase secretion were determined. Sham-treated, isoproterenol-treated and irradiated animals provided reference data. In the parotid gland, but not in the submandibular gland, protection against radiation-induced changes in flow rate and composition of saliva occurred after pretreatment with isoproterenol. Combining morphological data from a previous study with data from the current study, it is suggested that improvement of parotid gland function is attributed predominantly to a proliferative stimulus on acinar cells by isoproterenol and not to its degranulation effect. After pretreatment with isoproterenol, an earlier expression of radiation-induced acinar cell damage leading to death was observed, followed by a faster tissue recovery. Thus the proliferative stimulus on acinar cells may accelerate the unmasking of latent lethal damage, resulting in the earlier replacement of dead cells by new, functionally intact cells. 33 refs., 2 figs.

Peter, B.; Van Waarde, M.A.W.H.; Konings, A.W.T. [Univ. of Groningen (Netherlands); Vissink, A. [Univ. of Groningen (Netherlands)]|[Univ. Hospital, Groningen (Netherlands); `s-Gravenmade, E.J. [Univ. Hospital, Groningen (Netherlands)



Origin of Medial and Lateral Pectoral Nerves from the Supraclavicular Part of Brachial Plexus and its Clinical Importance - A Case Report  

PubMed Central

Knowledge of normal and anomalous formation of brachial plexus and its branches is of utmost importance to anatomists, clinicians, anesthesiologists and surgeons. Possibility of variations in the origin, course and distribution of branches of brachial plexus must be kept in mind during anesthetizing the brachial plexus, mastectomy and plastic surgery procedures. In the current case, the medial pectoral nerve arose directly from the middle trunk of the brachial plexus and the lateral pectoral nerve arose from the anterior division of the upper trunk of the brachial plexus. The lateral pectoral nerve supplied the pectoralis major and the medial pectoral nerve supplied pectoralis major and pectoralis minor muscles through two separate branches. PMID:24701504

Shetty, Prakashchandra; Nayak, Satheesha B; Kumar, Naveen; Thangarajan, Rajesh; D'Souza, Melanie Rose



Epigenetic Analysis of Heavy-ion Radiation Induced Bystander Effects in Mice  

NASA Astrophysics Data System (ADS)

Abstract: Radiation-induced bystander effect was defined as the induction of damage in neighboring non-hit cells by signals released from directly-irradiated cells. Recently, low dose of high LET radiation induced bystander effects in vivo have been reported more and more. It has been indicated that radiation induced bystander effect was localized not only in bystander tissues but also in distant organs. Genomic, epigenetic and proteomics plays significant roles in regulating heavy-ion radiation stress responses in mice. To identify the molecular mechanism that underlies bystander effects of heavy-ion radiation, the male Balb/c and C57BL mice were exposed head-only to 40, 200, 2000mGy dose of (12) C heavy-ion radiation, while the rest of the animal body was shielded. Directly radiation organ ear and the distant organ liver were detected on 1h, 6h, 12h and 24h after radiation, respectively. Methylation-sensitive amplification polymorphism (MSAP) was used to monitor the level of polymorphic genomic DNA methylation changed with dose and time effects. The results show that heavy-ion irradiated mouse head could induce genomic DNA methylation changes significantly in both the directly radiation organ ear and the distant organ liver. The percent of DNA methylation changes were time-dependent and tissue-specific. Demethylation polymorphism rate was highest separately at 1 h in 200 mGy and 6 h in 2000 mGy after irradiation. The global DNA methylation changes tended to occur in the CG sites. The results illustrated that genomic methylation changes of heavy ion radiation-induced bystander effect in liver could be obvious 1 h after radiation and achieved the maximum at 6 h, while the changes could recover gradually at 12 h. The results suggest that mice head exposed to heavy-ion radiation can induce damage and methylation pattern changed in both directly radiation organ ear and distant organ liver. Moreover, our findings are important to understand the molecular mechanism of radiation induced bystander effects in vivo.

Zhang, Meng; Sun, Yeqing; Cui, Changna; Xue, Bei


Protection against radiation-induced oxidative stress in cultured human epithelial cells by treatment with antioxidant agents  

SciTech Connect

Purpose: To evaluate the protective effects of antioxidant agents against space radiation-induced oxidative stress in cultured human epithelial cells. Methods and Materials: The effects of selected concentrations of N-acetylcysteine, ascorbic acid, sodium ascorbate, co-enzyme Q10, {alpha}-lipoic acid, L-selenomethionine, and vitamin E succinate on radiation-induced oxidative stress were evaluated in MCF10 human breast epithelial cells exposed to radiation with X-rays, {gamma}-rays, protons, or high mass, high atomic number, and high energy particles using a dichlorofluorescein assay. Results: The results demonstrated that these antioxidants are effective in protecting against radiation-induced oxidative stress and complete or nearly complete protection was achieved by treating the cells with a combination of these agents before and during the radiation exposure. Conclusion: The combination of antioxidants evaluated in this study is likely be a promising countermeasure for protection against space radiation-induced adverse biologic effects.

Wan, X. Steven [Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States); Ware, Jeffrey H. [Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States); Zhou, Zhaozong [Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States); Donahue, Jeremiah J. [Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States); Guan, Jun [Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States); Kennedy, Ann R. [Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States)]. E-mail:



Effects of moisture exposure on radiation-induced MOS device degradation and its implications for long-term aging.  

SciTech Connect

Large and unexpected radiation-induced voltage shifts have been observed for some MOS technologies exposed to moisture. The mechanisms for these large voltage shifts and their implications for long-term aging are discussed.

Dasgupta, A. (Vanderbilt University); Lum, Gary K. (Lockheed Martin Space Systems); Zhou, X. J. (Vanderbilt University); Francis, S. A. (Vanderbilt University); Schrimpf, Ron D. (Vanderbilt University); Fleetwood, Daniel M. (Vanderbilt University); Schwank, James Ralph; Felix, James Andrew; Shaneyfelt, Marty Ray; Dodd, Paul Emerson; Pantelides, Sokrates T. (Vanderbilt University)



Radiation-induced versus endogenous DNA damage: possible effect of inducible protective responses in mitigating endogenous damage  

Microsoft Academic Search

Ionizing radiation (IR) causes damage to DNA that is apparently proportional to absorbed dose. The incidence of radiation-induced cancer in humans unequivocally rises with the value of absorbed doses above about 300 mGy, in a seemingly linear fashion. Extrapolation of this linear correlation down to zero-dose constitutes the linear-no-threshold (LNT) hypothesis of radiation-induced cancer incidence. The corresponding dose-risk correlation, however,

Myron Pollycove; Ludwig E Feinendegen



Amlodipine induces a flow and pressure-independent vasoactive effect on the brachial artery in hypertension.  

PubMed Central

1. The objectives of this study were to study the flow-dependent arterial reactivity and pressure-independent arterial compliance of the calcium antagonist amlodipine in hypertensive men. 2. Twenty-one hypertensive patients were randomized to receive 2 months treatment with placebo (n = 10) or 5-10 mg amlodipine (n = 11) once a day. Non-invasive measurement of brachial artery mean blood pressure, diameter and flow (pulsed Doppler) and compliance (arterial mechanography and logarithmic elastic model) were obtained before and after drug administration. Vasoreactivity was studied by means of response of the brachial artery during exclusion of the hand and hyperaemia post-ischaemia. 3. Compared with placebo, amlodipine reduced mean blood pressure (% change +/- s.e. mean 11 +/- 1% vs 4 +/- 3%, P < 0.05), and increased arterial compliance at prevailing pressure (44 +/- 13%, vs 1 +/- 8%, P < 0.05) and at isobaric pressure (26 +/- 10% vs -3 +/- 6%, P < 0.05). A significant % change increase from baseline in brachial artery diameter between placebo and amlodipine was observed at rest (-2 +/- 3 vs 8 +/- 3%; P < 0.05), after wrist occlusion (-3 +/- 3 vs 6 +/- 2%; P < 0.05) and during reactive hyperaemia (-5 +/- 3 vs 18 +/- 5%; P < 0.05). No significant differences between amlodipine and placebo groups were observed in blood velocity after forearm manoeuvres before and after treatment. 4. No differences were observed between groups in brachial flow-dependent vasodilation.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7654482

Megnien, J L; Levenson, J; Del-Pino, M; Simon, A



Changes in Spinal Cord Architecture after Brachial Plexus Injury in the Newborn  

ERIC Educational Resources Information Center

Obstetric brachial plexus palsy is a devastating birth injury. While many children recover spontaneously, 20-25% are left with a permanent impairment of the affected limb. So far, concepts of pathology and recovery have focused on the injury of the peripheral nerve. Proximal nerve injury at birth, however, leads to massive injury-induced…

Korak, Klaus J.; Tam, Siu Lin; Gordon, Tessa; Frey, Manfred; Aszmann, Oskar C.



[Ventricular fibrillation with tolonium chloride: axillary brachial plexus anesthesia led to cessation of circulation].  


A 22-year-old patient underwent surgery for a glass wound incision of the hand and anesthesia was carried out using an axillary brachial plexus block with prilocaine. Following surgery the patient developed methemoglobinemia which was treated with tolonium chloride. After administration of the drug the sinus rhythm changed into ventricular fibrillation. The current treatment options of methemoglobinemia will be discussed. PMID:21491141

Radke, O C; Hoffmann, C; Klut, I; Koch, T



Restricted infraclavicular distribution of the local anesthetic solution after infraclavicular brachial plexus block  

Microsoft Academic Search

Background and Objectives: The distribution of local anesthetic after different approaches for brachial plexus anesthesia could be responsible for the varying rates of side effects, such as phrenic block, hoarseness, and Horner's syndrome associated with each approach. We compared the distribution of local anesthetic within the neurovascular space in infraclavicular block with that of interscalene and supraclavicular block. Methods: In

Jaime Rodr??guez; Mar??a Bárcena; Julián Álvarez



Does the Addition of Tramadol and Ketamine to Ropivacaine Prolong the Axillary Brachial Plexus Block?  

PubMed Central

Background and Objectives. A prospective, randomized, controlled, double-blind clinical trial to assess the effect of tramadol and ketamine, 50?mg, added to ropivacaine in brachial plexus anesthesia. Methods. Thirty-six ASA physical statuses I and II patients, between 18 and 60 years of age, scheduled for forearm and hand surgery under axillary brachial plexus block, were allocated to 3 groups. Group R received 0.375% ropivacaine in 40?mL, group RT received 0.375% ropivacaine in 40?mL with 50?mg tramadol, and group RK received 0.375% ropivacaine in 40?mL with 50?mg ketamine for axillary brachial plexus block. The onset times and the duration of sensory and motor blocks, duration of analgesia, hemodynamic parameters, and adverse events (nausea, vomiting, and feeling uncomfortable) were recorded. Results. The onset time of sensorial block was the fastest in ropivacaine + tramadol group. Duration of sensorial and motor block was the shortest in the ropivacaine + tramadol group. Duration of analgesia was significantly longer in ropivacaine + tramadol group. Conclusion. We conclude that when added to brachial plexus analgesia at a dose of 50?mg, tramadol extends the onset and duration time of the block and improves the quality of postoperative analgesia without any side effects. PMID:24883319

Senel, Ahmet Can; Ukinc, Ozlem; Timurkaynak, Alper



Brachial plexus anesthesia: A review of the relevant anatomy, complications, and anatomical variations.  


The trend towards regional anesthesia began in the late 1800s when William Halsted and Richard Hall experimented with cocaine as a local anesthetic for upper and lower limb procedures. Regional anesthesia of the upper limb can be achieved by blocking the brachial plexus at varying stages along the course of the trunks, divisions, cords and terminal branches. The four most common techniques used in the clinical setting are the interscalene block, the supraclavicular block, the infraclavicular block, and the axillary block. Each approach has its own unique set of advantages and indications for use. The supraclavicular block is most effective for anesthesia of the mid-humerus and below. Infraclavicular blocks are useful for procedures requiring continuous anesthesia. Axillary blocks provide effective anesthesia distal to the elbow, and interscalene blocks are best suited for the shoulder and proximal upper limb. The two most common methods for localizing the appropriate nerves for brachial plexus blocks are nerve stimulation and ultrasound guidance. Recent literature on brachial plexus blocks has largely focused on these two techniques to determine which method has greater efficacy. Ultrasound guidance has allowed the operator to visualize the needle position within the musculature and has proven especially useful in patients with anatomical variations. The aim of this study is to provide a review of the literature on the different approaches to brachial plexus blocks, including the indications, techniques, and relevant anatomical variations associated with the nerves involved. PMID:23959836

Mian, Asma; Chaudhry, Irfan; Huang, Richard; Rizk, Elias; Tubbs, R Shane; Loukas, Marios



Pocket Doppler and vascular laboratory equipment yield comparable results for ankle brachial index measurement  

Microsoft Academic Search

BACKGROUND: The ankle brachial index (ABI) is a well-established tool for screening and diagnosis of peripheral arterial disease (PAD). In this study we assessed the validity of ABI determination using a pocket Doppler device compared with automatic vascular laboratory measurement in patients suspected of PAD. METHODS: Consecutive patients with symptoms of PAD referred for ABI measurement between December 2006 and

Saskia PA Nicolaï; Lotte M Kruidenier; Ellen V Rouwet; Liliane Wetzels-Gulpers; Constantijn AM Rozeman; Martin H Prins; Joep AW Teijink




Microsoft Academic Search

Avulsion of the brachial plexus was documented in a Great Horned Owl (Bubo virginianus). A fractured scapula was also present. Cause of these injuries was not known but was thought to be due to trauma. Differentiation of musculoskeletal injury from peripheral nerve damage can be difficult in raptors. Use of electromyography and motor nerve conduction velocity was helpful in demonstrating




Transposed brachial-basilic arteriovenous fistulas versus prosthetic upper limb grafts: A meta-analysis  

Microsoft Academic Search

BackgroundControversy exists regarding the best type of arteriovenous (AV) fistula to be formed in secondary and tertiary access procedures when primary fistulas have failed. This meta-analysis aimed to compare transposed brachial-basilic AV fistulas (BBAVFs) with upper limb AV prosthetic grafts.

M. K. Lazarides; G. S. Georgiadis; C. P. Papasideris; G. Trellopoulos; V. D. Tzilalis



Fenestrated brachial vein perforated by the lateral root of median nerve: a case report  

Microsoft Academic Search

Variations of venous pattern in the arm are common. In this case report, we present a variation of brachial vein (BV) and lat- eral root of median nerve (LRMN). During routine educational dissections of axillary region, it was observed that a fenes- trated BV was perforated by LRMN in the right arm of an old male cadaver. LRMN was not

Ahmet Songur; Ramazan Uygur; Sezer Akçer; Muhsin Toktafl



Protective effects of Korean red ginseng against radiation-induced apoptosis in human HaCaT keratinocytes.  


Radiation-induced oral mucositis is a dose-limiting toxic side effect for patients with head and neck cancer. Numerous attempts at improving radiation-induced oral mucositis have not produced a qualified treatment. Ginseng polysaccharide has multiple immunoprotective effects. Our aim was to investigate the effectiveness of Korean red ginseng (KRG) on radiation-induced damage in the human keratinocyte cell line HaCaT and in an in vivo zebrafish model. Radiation inhibited HaCaT cell proliferation and migration in a cell viability assay and wound healing assay, respectively. KRG protected against these effects. KRG attenuated the radiation-induced embryotoxicity in the zebrafish model. Irradiation of HaCaT cells caused apoptosis and changes in mitochondrial membrane potential (MMP). KRG inhibited the radiation-induced apoptosis and intracellular generation of reactive oxygen species (ROS), and stabilized the radiation-induced loss of MMP. Western blots revealed KRG-mediated reduced expression of ataxia telangiectasia mutated protein (ATM), p53, c-Jun N-terminal kinase (JNK), p38 and cleaved caspase-3, compared with their significant increase after radiation treatment. The collective results suggest that KRG protects HaCaT cells by blocking ROS generation, inhibiting changes in MMP, and inhibiting the caspase, ATM, p38 and JNK pathways. PMID:24078877

Chang, Jae Won; Park, Keun Hyung; Hwang, Hye Sook; Shin, Yoo Seob; Oh, Young-Taek; Kim, Chul-Ho



Late treatment with imatinib mesylate ameliorates radiation-induced lung fibrosis in a mouse model  

PubMed Central

Background We have previously shown that small molecule PDGF receptor tyrosine kinase inhibitors (RTKI) can drastically attenuate radiation-induced pulmonary fibrosis if the drug administration starts at the time of radiation during acute inflammation with present but limited effects against acute inflammation. To rule out interactions of the drug with acute inflammation, we investigated here in an interventive trial if a later drug administration start at a time when the acute inflammation has subsided - has also beneficial antifibrotic effects. Methods Whole thoraces of C57BL/6 mice were irradiated with 20 Gy and treated with the RTKI imatinib starting either 3 days after radiation (during acute inflammation) or two weeks after radiation (after the acute inflammation has subsided as demonstrated by leucocyte count). Lungs were monitored and analyzed by clinical, histological and in vivo non-invasive computed tomography as a quantitative measure for lung density and lung fibrosis. Results Irradiation induced severe lung fibrosis resulting in markedly reduced mouse survival vs. non-irradiated controls. Both early start of imatinib treatment during inflammation and late imatinib start markedly attenuated the development of pulmonary fibrosis as demonstrated by clinical, histological and qualitative and quantitative computed tomography results such as reduced lung density. Both administration schedules resulted in prolonged lifespans. The earlier drug treatment start resulted in slightly stronger beneficial antifibrotic effects along all measured endpoints than the later start. Conclusions Our findings show that imatinib, even when administered after the acute inflammation has subsided, attenuates radiation-induced lung fibrosis in mice. Our data also indicate that the fibrotic fate is not only determined by the early inflammatory events but rather a complex process in which secondary events at later time points are important. Because of the clinical availability of imatinib or similar compounds, a meaningful attenuation of radiation-induced lung fibrosis in patients seems possible. PMID:20025728



Radiation-induced alterations of histone post-translational modification levels in lymphoblastoid cell lines  

PubMed Central

Background Radiation-induced alterations in posttranslational histone modifications (PTMs) may affect the cellular response to radiation damage in the DNA. If not reverted appropriately, altered PTM patterns may cause long-term alterations in gene expression regulation and thus lead to cancer. It is therefore important to characterize radiation-induced alterations in PTM patterns and the factors affecting them. Methods A lymphoblastoid cell line established from a normal donor was used to screen for alterations in methylation levels at H3K4, H3K9, H3K27, and H4K20, as well as acetylation at H3K9, H3K56, H4K5, and H4K16, by quantitative Western Blot analysis at 15 min, 1 h and 24 h after irradiation with 2 Gy and 10 Gy. The variability of alterations in acetylation marks was in addition investigated in a panel of lymphoblastoid cell lines with differing radiosensitivity established from lung cancer patients. Results The screening procedure demonstrated consistent hypomethylation at H3K4me3 and hypoacetylation at all acetylation marks tested. In the panel of lymphoblastoid cell lines, however, a high degree of inter-individual variability became apparent. Radiosensitive cell lines showed more pronounced and longer lasting H4K16 hypoacetylation than radioresistant lines, which correlates with higher levels of residual ?-H2AX foci after 24 h. Conclusion So far, the factors affecting extent and duration of radiation-induced histone alterations are poorly defined. The present work hints at a high degree of inter-individual variability and a potential correlation of DNA damage repair capacity and alterations in PTM levels. PMID:24406105



Radiation induced bystander effect by GAP junction channels in human fibroblast cell  

NASA Astrophysics Data System (ADS)

The chemical factor involved in bystander effect and its transfer pathway were investigated in a confluent human fibroblast cell (AG1522) population. Micronuclei (MN) and G1-phase arrest were detected in cells irradiated by carbon (~100 keV/?m) ions at HIMAC. A very low dose irradiation showed a high effectiveness in producing MN, suggesting a bystander effect. This effectiveness was enhanced by 8-Br-cAMP treatment that increases gap junctional intercellular communication (GJIC). On the other hand, the effect was reduced by 5% DMSO treatment, which reduce the reactive oxygen species (ROS), and suppressed by 100 ?M lindane treatment, an inhibitor of GJIC. In addition, the radiation-induced G1-phase arrest was also enhanced by cAMP, and reduced or suppressed by DMSO or lindane. A microbeam device (JAERI) was also used for these studies. It was found that exposing one single cell in a confluent cell population to exactly one argon (~1260 keV/?m) or neon (~430 keV/ ?m) ion, additional MN could be detected in many other unirradiated cells. The yield of MN increased with the number of irradiated cells. However, there was no significant difference in the MN induction when the cells were irradiated by increasing number of particles. MN induction by bystander effect was partly reduced by DMSO, and effectively suppressed by lindane. Our results obtained from both random irradiation and precise numbered irradiation indicate that both GJIC and ROS contributed to the radiation-induced bystander effect, but the cell gap junction channels likely play an essential role in the release and transfer of radiation-induced chemical factors.

Furusawa, Y.; Shao, C.; Aoki, M.; Kobayashi, Y.; Funayama, T.; Ando, K.


Involvement of inducible nitric oxide synthase in radiation-induced vascular endothelial damage.  


The use of radiation therapy has been linked to an increased risk of cardiovascular disease. To understand the mechanisms underlying radiation-induced vascular dysfunction, we employed two models. First, we examined the effect of X-ray irradiation on vasodilation in rabbit carotid arteries. Carotid arterial rings were irradiated with 8 or 16 Gy using in vivo and ex vivo methods. We measured the effect of acetylcholine-induced relaxation after phenylephrine-induced contraction on the rings. In irradiated carotid arteries, vasodilation was significantly attenuated by both irradiation methods. The relaxation response was completely blocked by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, a potent inhibitor of soluble guanylate cyclase. Residual relaxation persisted after treatment with L-N(?)-nitroarginine (L-NA), a non-specific inhibitor of nitric oxide synthase (NOS), but disappeared following the addition of aminoguanidine (AG), a selective inhibitor of inducible NOS (iNOS). The relaxation response was also affected by tetraethylammonium, an inhibitor of endothelium-derived hyperpolarizing factor activity. In the second model, we investigated the biochemical events of nitrosative stress in human umbilical-vein endothelial cells (HUVECs). We measured iNOS and nitrotyrosine expression in HUVECs exposed to a dose of 4 Gy. The expression of iNOS and nitrotyrosine was greater in irradiated HUVECs than in untreated controls. Pretreatment with AG, L-N(6)-(1-iminoethyl) lysine hydrochloride (a selective inhibitor of iNOS), and L-NA attenuated nitrosative stress. While a selective target of radiation-induced vascular endothelial damage was not definitely determined, these results suggest that NO generated from iNOS could contribute to vasorelaxation. These studies highlight a potential role of iNOS inhibitors in ameliorating radiation-induced vascular endothelial damage. PMID:23704776

Hong, Chang-Won; Kim, Young-Mee; Pyo, Hongryull; Lee, Joon-Ho; Kim, Suwan; Lee, Sunyoung; Noh, Jae Myoung



Radiation-induced bowel injury: the impact of radiotherapy on survivorship after treatment for gynaecological cancers  

PubMed Central

Background: The number of women surviving cancer who live with symptoms of bowel toxicity affecting their quality of life continues to rise. In this retrospective study, we sought to describe and analyse the presenting clinical features in our cohort, and evaluate possible predictors of severity and chronicity in women with radiation-induced bowel injury after treatment for cervical and endometrial cancers. Methods: Review of records of 541 women treated within the North London Gynaecological Cancer Network between 2003 and 2010 with radiotherapy with or without chemotherapy for cervical and endometrial cancer identified 152 women who reported significant new bowel symptoms after pelvic radiation. Results: Factor analysis showed that the 14 most common and important presenting symptoms could be ‘clustered' into 3 groups with predictive significance for chronicity and severity of disease. Median follow-up for all patients was 60 months. Univariate analysis showed increasing age, smoking, extended field radiation, cervical cancer treatment and the need for surgical intervention to be significant predictors for severity of ongoing disease at last follow-up. On multivariate analysis, only age, cancer type (cervix) and symptom combinations/‘cluster' of (bloating, flatulence, urgency, rectal bleeding and per-rectal mucus) were found to be significant predictors of disease severity. Fifteen (19%) women in the cervical cancer group had radiation-induced bowel injury requiring surgical intervention compared with five (6.7%) in the endometrial cancer group. Conclusion: Women with cervical cancer are younger and appear to suffer more severe symptoms of late bowel toxicity, whereas women treated for endometrial cancer suffer milder more chronic disease. The impact of radiation-induced bowel injury and the effect on cancer survivorship warrants further research into investigation of predictors of severe late toxicity. There is a need for prospective trials to aid early diagnosis, while identifying the underlying patho-physiological process of the bowel injury. PMID:24002603

Kuku, S; Fragkos, C; McCormack, M; Forbes, A



Protection from radiation-induced mitochondrial and genomic DNA damage by an extract of Hippophae rhamnoides.  


Hippophae rhamnoides or seabuckthorn is used extensively in Indian and Tibetan traditional medicine for the treatment of circulatory disorders, ischemic heart disease, hepatic injury, and neoplasia. In the present study, we have evaluated the radioprotective potential of REC-1001, a fraction isolated from the berries of H. rhamnoides. Chemical analysis of the extract indicated that REC-1001 was approximately 68% by weight polyphenols, and contained kaempferol, isorhamnetin, and quercetin. The effect of REC-1001 on modulating radiation-induced DNA damage was determined in murine thymocytes by measuring nonspecific nuclear DNA damage at the whole genome level using the alkaline halo assay and by measuring sequence/gene-specific DNA damage both in nuclear DNA (beta-globin gene) and in mitochondrial DNA using a quantitative polymerase chain reaction. Treatment with 10 Gy resulted in a significant amount of DNA damage in the halo assay and reductions in the amplification of both the beta-globin gene and mitochondrial DNA. REC-1001 dose-dependently reduced the amount of damage detected in each assay, with the maximum protective effects observed at the highest REC-1001 dose evaluated (250 micro g/ml). Studies measuring the nicking of naked plasmid DNA further established the radioprotective effect of REC-1001. To elucidate possible mechanisms of action, the antioxidant properties and the free-radical scavenging activities of REC-1001 were evaluated. REC-1001 dose-dependently scavenged radiation-induced hydroxyl radicals, chemically-generated superoxide anions, stabilized DPPH radicals, and reduced Fe(3+) to Fe(2+). The results of the study indicate that the REC-1001 extract of H. rhamnoides protects mitochondrial and genomic DNA from radiation-induced damage. The polyphenols/flavonoids present in the extract might be responsible for the free radical scavenging and DNA protection afforded by REC-1001. PMID:16948057

Shukla, Sandeep Kumar; Chaudhary, Pankaj; Kumar, Indracanti Prem; Samanta, Namita; Afrin, Farhat; Gupta, Manju Lata; Sharma, Upendra Kumar; Sinha, Arun Kumar; Sharma, Yogendra Kumar; Sharma, Rakesh Kumar



Effects of Berberine Against Radiation-Induced Intestinal Injury in Mice  

SciTech Connect

Purpose: Radiation-induced intestinal injury is a significant clinical problem in patients undergoing abdominal radiotherapy (RT). Berberine has been used as an antimicrobial, anti-inflammatory, and antimotility agent. The present study investigated the protective effect of berberine against radiation-induced intestinal injury. Methods and Materials: The mice were administrated berberine or distilled water. A total of 144 mice underwent 0, 3, 6, 12, or 16 Gy single session whole-abdominal RT and 16 mice underwent 3 Gy/fraction/d for four fractions of fractionated abdominal RT. Tumor necrosis factor-{alpha}, interleukin-10, diamine oxidase, intestinal fatty acid-binding protein, malonaldehyde, and apoptosis were assayed in the mice after RT. The body weight and food intake of the mice receiving fractionated RT were recorded. Another 72 mice who had undergone 12, 16, or 20 Gy abdominal RT were monitored for mortality every 12 h. Results: The body weight and food intake of the mice administered with distilled water decreased significantly compared with before RT. After the same dose of abdominal RT, tumor necrosis factor-{alpha}, diamine oxidase, intestinal fatty acid-binding protein in plasma and malonalhehyde and apoptosis of the intestine were significantly greater in the control group than in the mice administered berberine (p < .05-.01). In contrast, interleukin-10 in the mice with berberine treatment was significantly greater than in the control group (p < .01). A similar result was found in the fractionated RT experiment and at different points after 16 Gy abdominal RT (p < .05-.01). Berberine treatment significantly delayed the point of death after 20 Gy, but not 16 Gy, abdominal RT (p < .01). Conclusion: Treatment with berberine can delay mortality and attenuated intestinal injury in mice undergoing whole abdominal RT. These findings could provide a useful therapeutic strategy for radiation-induced intestinal injury.

Li Guanghui [Institute for Cancer Research in People's Liberation Army, Xinqiao Hospital, Third Military Medical University, Chongqing (China); Zhang Yaping [Institute of Burn Research, Southwest Hospital, Third Military Medical University, Chongqing (China); Tang Jinliang [Department of Pathology, Xinqiao Hospital, Third Military Medical University, Chongqing (China); Chen Zhengtang; Hu Yide [Institute for Cancer Research in People's Liberation Army, Xinqiao Hospital, Third Military Medical University, Chongqing (China); Wei Hong [Department of Plastic Surgery, Southwest Hospital, Third Military Medical University, Chongqing (China); Li Dezhi; Hao Ping [Institute for Cancer Research in People's Liberation Army, Xinqiao Hospital, Third Military Medical University, Chongqing (China); Wang Donglin, E-mail: wdl_tmmu@yahoo.c [Institute for Cancer Research in People's Liberation Army, Xinqiao Hospital, Third Military Medical University, Chongqing (China)



Smad, but not MAPK, pathway mediates the expression of type I collagen in radiation induced fibrosis  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer We examine how radiation affects the expression level and signal pathway of collagen. Black-Right-Pointing-Pointer TGF-{beta}1 mRNA is elevated earlier than those of collagen genes after irradiation. Black-Right-Pointing-Pointer Smad pathway mediates the expression of collagen in radiation induced fibrosis. Black-Right-Pointing-Pointer MAPK pathways are not affected in the expression of collagen after irradiation. -- Abstract: Radiation induced fibrosis occurs following a therapeutic or accidental radiation exposure in normal tissues. Tissue fibrosis is the excessive accumulation of collagen and other extracellular matrix components. This study investigated how ionizing radiation affects the expression level and signal pathway of type I collagen. Real time RT-RCR showed that both {alpha}1and {alpha}2 chain of type I collagen mRNA were elevated from 48 h after irradiation with 10 Gy in NIH3T3 cells. The relative luciferase activities of both genes and type I collagen marker were elevated at 72 h. TGF-{beta}1 mRNA was elevated earlier than those of type I collagen genes. A Western blot analysis showed the elevation of Smad phosphorylation at 72 h. Conversely, treatment with TGF-{beta} receptor inhibitor inhibited the mRNA and relative luciferase activity of type I collagen. The phosphorylation of Smad was repressed with the inhibitor, and the luciferase activity was cancelled using a mutant construct of Smad binding site of {alpha}2(I) collagen gene. However, the MAPK pathways, p38, ERK1/2 and JNK, were not affected with specific inhibitors or siRNA. The data showed that the Smad pathway mediated the expression of type I collagen in radiation induced fibrosis.

Yano, Hiroyuki [Department of Matrix Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan) [Department of Matrix Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan); Division of Radioisotope Research, Department of Research Support, Research Promotion Project, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan); Hamanaka, Ryoji; Nakamura, Miki [Cell Biology, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan)] [Cell Biology, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan); Sumiyoshi, Hideaki; Matsuo, Noritaka [Department of Matrix Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan)] [Department of Matrix Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan); Yoshioka, Hidekatsu, E-mail: [Department of Matrix Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan)] [Department of Matrix Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan)



Theoretical Approach to Microwave-Radiation-Induced Zero-Resistance States in 2D Electron Systems  

NASA Astrophysics Data System (ADS)

We present a theoretical model in which the existence of radiation-induced zero-resistance states is analyzed. An exact solution for the harmonic oscillator wave function in the presence of radiation, and a perturbation treatment for elastic scattering due to randomly distributed charged impurities, form the foundations of our model. Following this model most experimental results are reproduced, including the formation of resistivity oscillations, their dependence on the intensity and frequency of the radiation, temperature effects, and the locations of the resistivity minima. The existence of zero-resistance states is thus explained in terms of the interplay of the electron microwave-driven orbit dynamics and the Pauli exclusion principle.

Iñarrea, J.; Platero, G.



A multi-scale approach to radiation-induced segregation at various grain boundaries  

NASA Astrophysics Data System (ADS)

We investigated the dependence of radiation-induced segregation (RIS) in austenitic stainless steels on grain boundary orientation by numerical calculations. A new rate equation model for RIS that incorporates the grain boundary sink strength for point defects was developed. The sink strength was determined as functions of misorientation angle and ? values using interaction energies of vacancy near grain boundaries as determined by molecular dynamics (MD) and statics (MS). It was shown that the calculated results can reproduce the experimental data obtained by electron and proton irradiation experiments. The good agreement supports the validity of the present model.

Sakaguchi, N.; Watanabe, S.; Takahashi, H.; Faulkner, R. G.



Hydrogels obtained by radiation-induced polymerization as delivery systems for peptide and protein drugs  

NASA Astrophysics Data System (ADS)

The controlled release of peptides and proteins from hydrogels obtained by radiation-induced polymerization of 2-hydroxyethyl methacrylate at a low temperature was studied. It was found that the extent of release progressively decreased as protein molecular weight increased until no further release occurred above a critical value of the latter. However, an increasing rate of protein release was found if the polymerization was carried out in the presence of poly(ethylene glycol), PEG. Moreover, only with high molecular weight PEGs were large proteins released. The release data as a function of swellability and porosity of polymer matrices were discussed.

Carenza, M.; Lora, S.; Caliceti, P.; Schiavon, O.; Veronese, F. M.



Study on slow release anti-cancer drugs prepared by radiation induced polymerization  

NASA Astrophysics Data System (ADS)

This paper reports the research results which the anticancer drugs Ara-C with controlled slow release were made by radiation induced polymerization of monomers such as methacrylates at room temperature. Our studies showed that not only hydrophilic synthetic polymers but also hydrophobic polymers such as hydrophobic methacrylates (including MMA, EMA, and BMA) could be used to the immobilization. In vitro the rate of drugs release was controlled by the many factors such as the content of drugs, the monomer material, the crosslinking agent, the irradiation dose and the water content, etc.

Huaijiang, Xie; Juzhong, Song; Tao, Peng



Role of sphingolipids in murine radiation-induced lung injury: protection by sphingosine 1-phosphate analogs  

PubMed Central

Clinically significant radiation-induced lung injury (RILI) is a common toxicity in patients administered thoracic radiotherapy. Although the molecular etiology is poorly understood, we previously characterized a murine model of RILI in which alterations in lung barrier integrity surfaced as a potentially important pathobiological event and genome-wide lung gene mRNA levels identified dysregulation of sphingolipid metabolic pathway genes. We hypothesized that sphingolipid signaling components serve as modulators and novel therapeutic targets of RILI. Sphingolipid involvement in murine RILI was confirmed by radiation-induced increases in lung expression of sphingosine kinase (SphK) isoforms 1 and 2 and increases in the ratio of ceramide to sphingosine 1-phosphate (S1P) and dihydro-S1P (DHS1P) levels in plasma, bronchoalveolar lavage fluid, and lung tissue. Mice with a targeted deletion of SphK1 (SphK1?/?) or with reduced expression of S1P receptors (S1PR1+/?, S1PR2?/?, and S1PR3?/?) exhibited marked RILI susceptibility. Finally, studies of 3 potent vascular barrier-protective S1P analogs, FTY720, (S)-FTY720-phosphonate (fTyS), and SEW-2871, identified significant RILI attenuation and radiation-induced gene dysregulation by the phosphonate analog, fTyS (0.1 and 1 mg/kg i.p., 2×/wk) and to a lesser degree by SEW-2871 (1 mg/kg i.p., 2×/wk), compared with those in controls. These results support the targeting of S1P signaling as a novel therapeutic strategy in RILI.—Mathew, B., Jacobson, J. R., Berdyshev, E., Huang, Y., Sun, X., Zhao, Y., Gerhold, L. M., Siegler, J., Evenoski, C., Wang, T., Zhou, T., Zaidi, R., Moreno-Vinasco, L., Bittman, R., Chen, C. T., LaRiviere, P. J., Sammani, S., Lussier, Y. A., Dudek, S. M., Natarajan, V., Weichselbaum, R. R., Garcia, J. G. N. Role of sphingolipids in murine radiation-induced lung injury: protection by sphingosine 1-phosphate analogs. PMID:21712494

Mathew, Biji; Jacobson, Jeffrey R.; Berdyshev, Evgeny; Huang, Yong; Sun, Xiaoguang; Zhao, Yutong; Gerhold, Lynnette M.; Siegler, Jessica; Evenoski, Carrie; Wang, Ting; Zhou, Tong; Zaidi, Rafe; Moreno-Vinasco, Liliana; Bittman, Robert; Chen, Chin Tu; LaRiviere, Patrick J.; Sammani, Saad; Lussier, Yves A.; Dudek, Steven M.; Natarajan, Viswanathan; Weichselbaum, Ralph R.; Garcia, Joe G. N.



Remote sensor response study in the regime of the microwave radiation-induced magnetoresistance oscillations  

NASA Astrophysics Data System (ADS)

A concurrent remote sensing and magneto-transport study of the microwave excited two dimensional electron system (2DES) at liquid helium temperatures has been carried out using a carbon detector to remotely sense the microwave activity of the 2D electron system in the GaAs/AlGaAs heterostructure during conventional magneto-transport measurements. Various correlations are observed and reported between the oscillatory magnetotransport and the remotely sensed reflection. In addition, the oscillatory remotely sensed signal is shown to exhibit a power law type variation in its amplitude, similar to the radiation-induced magnetoresistance oscillations.

Ye, Tianyu; Mani, R. G.; Wegscheider, W.



Radiation-induced "zero-resistance state" and the photon-assisted transport.  


We demonstrate that the radiation-induced "zero-resistance state" observed in a two-dimensional electron gas is a result of the nontrivial structure of the density of states of the systems and the photon-assisted transport. A toy model of a quantum tunneling junction with oscillatory density of states in leads catches most of the important features of the experiments. We present a generalized Kubo-Greenwood conductivity formula for the photon-assisted transport in a general system and show essentially the same nature of the transport anomaly in a uniform system. PMID:14525265

Shi, Junren; Xie, X C



The effects of hyper velocity impact phenomena on radiation induced defects  

NASA Astrophysics Data System (ADS)

Effects of high speed impacts on radiation-induced defects were investigated with a plasma rail-gun. Vitreous quartz targets irradiated by ?-ray were shocked with polycarbonate projectiles at a speed of 7 km/s, then the remaining destroyed pieces were examined by ESR spectroscopy to investigate the degree of "impact-annealing". The white substance from the impact point showed a trace of melting and no ESR signal, while the rest of the scattered pieces showed a decrease of E' center density to 50 ± 10% of the initial density. The defect production efficiency for the impacted silica was almost two-third of the original material.

Yamanaka, C.; Ikeya, M.



The application of radiation-induced processed copolymers to biocatalysis immobilisation  

NASA Astrophysics Data System (ADS)

In this paper, some of the work carried out at our laboratories on the immobilisation of biocatalysts onto graft copolymers prepared by radiation induced procedures is reported. The graft copolymers used were based either on hydrophilic natural polymer (agar) or on hydrophobic (polyethylene) supports. The comonomers grafted branches include poly(hydroxyethyl methacrylate) and poly(hydroxyethyl methacrylate) crosslinked with trimethylpropane triacrylata (TMPTA). The suitability of these graft copolymers for immobilising ?-chymotrypsin, glucose oxidase and trypsin was assessed by determining the amount of biocatalysts coupled to the support and its retention of activity. The Michaelis Mentan constants (K M) for some of the immobilised enzymes were determined.

de Silva, M. Alves; Beddows, C. G.; Gil, M. H.; Guthrie, J. T.; Guiomar, A. J.; Kotov, S.; Piedade, A. P.


Comparison of Brachial Artery Vasoreactivity in Elite Power Athletes and Age-Matched Controls  

PubMed Central

Elite endurance athletes typically have larger arteries contributing to greater skeletal muscle blood flow, oxygen and nutrient delivery and improved physical performance. Few studies have examined structural and functional properties of arteries in power athletes. Purpose To compare the size and vasoreactivity of the brachial artery of elite power athletes to age-matched controls. It was hypothesized brachial artery diameters of athletes would be larger, have less vasodilation in response to cuff occlusion, but more constriction after a cold pressor test than age-matched controls. Methods Eight elite power athletes (age?=?23±2 years) and ten controls (age?=?22±1 yrs) were studied. High-resolution ultrasonography was used to assess brachial artery diameters at rest and following 5 minutes of forearm occlusion (Brachial Artery Flow Mediated Dilation?=?BAFMD) and a cold pressor test (CPT). Basic fitness measures included a handgrip test and 3-minute step test. Results Brachial arteries of athletes were larger (Athletes 5.39±1.51 vs. Controls: 3.73±0.71 mm, p<0.05), had greater vasodilatory (BAFMD%: Athletes: 8.21±1.78 vs. Controls: 5.69±1.56%) and constrictor (CPT %: Athletes: -2.95±1.07 vs. Controls: ?1.20±0.48%) responses, compared to controls. Vascular operating range (VOR?=?Peak dilation+Peak Constriction) was also greater in athletes (VOR: Athletes: 0.55±0.15 vs. Controls: 0.25±0.18 mm, p<0.05). Athletes had superior handgrip strength (Athletes: 55.92±17.06 vs. Controls: 36.77±17.06 kg, p<0.05) but similar heart rate responses at peak (Athletes: 123±16 vs. Controls: 130±25 bpm, p>0.05) and 1 minute recovery (Athletes: 88±21 vs. Controls: 98±26 bpm, p>0.05) following the step test. Conclusion Elite power athletes have larger brachial arteries, and greater vasoreactivity (greater vasodilatory and constrictor responses) than age-matched controls, contributing to a significantly greater VOR. These data extend the existence of an ‘athlete’s artery’ as previously shown for elite endurance athletes to elite power athletes, and presents a hypothetical explanation for the functional significance of the ‘power athlete’s artery’. PMID:23359214

Welsch, Michael A.; Blalock, Paul; Credeur, Daniel P.; Parish, Tracie R.



Radiation-Induced Testicular Injury and Its Amelioration by Tinospora cordifolia (An Indian Medicinal Plant) Extract  

PubMed Central

The primary objective of this investigation is to determine the deleterious effects of sub lethal gamma radiation on testes and their possible inhibition by Tinospora cordifolia extract (TCE). For this purpose, one group of male Swiss albino mice was exposed to 7.5?Gy gamma radiation to serve as the irradiated control, while the other group received TCE (75?mg/kg?b.?wt./day) orally for 5 consecutive days half an hr before irradiation to serve as experimental. Exposure of animals to 7.5?Gy gamma radiation resulted into significant decrease in body weight, tissue weight, testes- body weight ratio and tubular diameter up to 15 days of irradiation. Cent percent mortality was recorded by day 17th in irradiated control, whereas all animals survived in experimental group. TCE pretreatment rendered significant increase in body weight, tissue weight, testes- body weight ratio and tubular diameter at various intervals as compared to irradiated group. Radiation induced histological lesions in testicular architecture were observed more severe in irradiated control then the experimental. TCE administration before irradiation significantly ameliorated radiation induced elevation in lipid peroxidation and decline in glutathione concentration in testes. These observations indicate the radio- protective potential of Tinospora cordifolia root extract in testicular constituents against gamma irradiation in mice. PMID:21350610

Sharma, Priyanka; Parmar, Jyoti; Sharma, Priyanka; Verma, Preeti; Goyal, P. K.



Neuroanatomical target theory as a predictive model for radiation-induced cognitive decline  

PubMed Central

Objective: In a retrospective review to assess neuroanatomical targets of radiation-induced cognitive decline, dose volume histogram (DVH) analyses of specific brain regions of interest (ROI) are correlated to neurocognitive performance in 57 primary brain tumor survivors. Methods: Neurocognitive assessment at baseline included Trail Making Tests A/B, a modified Rey-Osterreith Complex Figure, California or Hopkins Verbal Learning Test, Digit Span, and Controlled Oral Word Association. DVH analysis was performed for multiple neuroanatomical targets considered to be involved in cognition. The %v10 (percent of ROI receiving 10 Gy), %v40, and %v60 were calculated for each ROI. Factor analysis was used to estimate global cognition based on a summary of performance on individual cognitive tests. Stepwise regression was used to determine which dose volume predicted performance on global factors and individual neurocognitive tests for each ROI. Results: Regions that predicted global cognitive outcomes at doses <60 Gy included the corpus callosum, left frontal white matter, right temporal lobe, bilateral hippocampi, subventricular zone, and cerebellum. Regions of adult neurogenesis primarily predicted cognition at %v40 except for the right hippocampus which predicted at %v10. Regions that did not predict global cognitive outcomes at any dose include total brain volume, frontal pole, anterior cingulate, right frontal white matter, and the right precentral gyrus. Conclusions: Modeling of radiation-induced cognitive decline using neuroanatomical target theory appears to be feasible. A prospective trial is necessary to validate these data. PMID:23390169

Leyrer, C. Marc; Greene-Schloesser, Dana M.; Shing, Elaine; Kearns, William T.; Hinson, William H.; Tatter, Stephen B.; Ip, Edward H.; Rapp, Stephen R.; Robbins, Mike E.; Shaw, Edward G.; Chan, Michael D.



Sorafenib Enhances Radiation-Induced Apoptosis in Hepatocellular Carcinoma by Inhibiting STAT3  

SciTech Connect

Purpose: Hepatocellular carcinoma (HCC) is one of the most common and lethal human malignancies. Lack of efficient therapy for advanced HCC is a pressing problem worldwide. This study aimed to determine the efficacy and mechanism of combined sorafenib and radiation therapy treatment for HCC. Methods and Materials: HCC cell lines (PLC5, Huh-7, Sk-Hep1, and Hep3B) were treated with sorafenib, radiation, or both, and apoptosis and signal transduction were analyzed. Results: All 4 HCC cell lines showed resistance to radiation-induced apoptosis; however, this resistance could be reversed in the presence of sorafenib. Inhibition of phospho-STAT3 was found in cells treated with sorafenib or sorafenib plus radiation and subsequently reduced the expression levels of STAT3-related proteins, Mcl-1, cyclin D1, and survivin. Silencing STAT3 by RNA interference overcame apoptotic resistance to radiation in HCC cells, and the ectopic expression of STAT3 in HCC cells abolished the radiosensitizing effect of sorafenib. Moreover, sorafenib plus radiation significantly suppressed PLC5 xenograft tumor growth. Conclusions: These results indicate that sorafenib sensitizes resistant HCC cells to radiation-induced apoptosis via downregulating phosphorylation of STAT3 in vitro and in vivo.

Huang, Chao-Yuan [Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (China) [Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (China); Department of Radiological Technology, Yuanpei University, Hsinchu, Taiwan (China); Lin, Chen-Si [School of Veterinary Medicine, National Taiwan University Hospital, Taipei, Taiwan (China)] [School of Veterinary Medicine, National Taiwan University Hospital, Taipei, Taiwan (China); Tai, Wei-Tien; Hsieh, Chi-Ying [Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan (China) [Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan (China); Shiau, Chung-Wai [Institute of Biopharmaceutical Sciences, National Yang-Ming University, Taipei, Taiwan (China)] [Institute of Biopharmaceutical Sciences, National Yang-Ming University, Taipei, Taiwan (China); Cheng, Ann-Lii [Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (China) [Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan (China); Chen, Kuen-Feng, E-mail: [Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan (China) [Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan (China)



Silencing of Cited2 and Akap12 genes in radiation-induced rat osteosarcomas.  


We have previously studied genomic copy number changes and global gene expression patterns in rat osteosarcomas (OS) induced by the bone-seeking alpha emitter (238)Pu by comparative genomic hybridization (CGH) and oligonucleotide microarray analyses, respectively. Among the previously identified genes that were down-regulated in radiation-induced rat OS tumors, Cited2 (Cbp/p300-interacting transactivator, with Glu/Asp-rich carboxy-terminal domain, 2) and Akap12 (a kinase anchoring protein, also known as src-suppressed C-kinase substrate, SSeCKS) genes mapped to the most frequently lost regions on chromosome 1p. In the present study, relative copy number losses of Cited2 and Akap12 genes were observed in 8 of 15 (53%) and 10 of 15 (67%) tumors by quantitative PCR analysis. Loss of Cited2 and Akap12 in the tumors was confirmed at the levels of mRNA and protein expression by quantitative RT-PCR and immunoblot analyses, respectively. These results indicate that Cited2 and Akap12 are silenced in radiation-induced OS, and therefore are novel candidate tumor-suppressor genes of this tumor. PMID:19825367

Daino, Kazuhiro; Roch-Lefevre, Sandrine; Ugolin, Nicolas; Altmeyer-Morel, Sandrine; Guilly, Marie-Noëlle; Chevillard, Sylvie



Radiation-induced cardiovascular diseases: Is the epidemiologic evidence compatible with the radiobiologic data?  

SciTech Connect

The Life Span Study of Japanese atomic bomb survivors demonstrates that radiation exposure significantly increased the risk of developing ischemic heart disease, in particular myocardial infarction. Similarly, epidemiologic investigations in very large populations of patients who had received postoperative radiotherapy for breast cancer or for peptic ulcer demonstrate that radiation exposure of the heart with an average equivalent single dose of approximately 2 Gy significantly increased the risk of developing ischemic heart disease more than 10 years after irradiation. These epidemiologic findings are compatible with radiobiologic data on the pathogenesis of radiation-induced heart disease in experimental animals. The critical target structure appears to be the endothelial lining of blood vessels, in particular arteries, leading to early functional alterations such as pro-inflammatory responses and other changes, which are slowly progressive. Research should concentrate on the interaction of these radiation-induced endothelial changes with the early stages of age-related atherosclerosis to develop criteria for optimizing treatment plans in radiotherapy and also potential interventional strategies.

Schultz-Hector, Susanne [Helmholtz-Gemeinschaft, Berlin (Germany)]. E-mail:; Trott, Klaus-Ruediger Prof. [Gray Cancer Institute, Northwood (United Kingdom)



Radiation-induced attenuation self-compensating effect in super-fluorescent fiber source  

NASA Astrophysics Data System (ADS)

The compact super-fluorescent fiber source (SFS) output spectra variations at different pump currents and under different dose of gamma-ray radiation were measured and compared respectively. The radiation-induced attenuation (RIA) self-compensating effect in SFS based on photo-bleaching was found and the general mathematic model of SFS output spectra variations was made. The radiation-induced background attenuation (RIBA) at the pump wavelength was identified to be the main cause of the total output power and spectra variations and the variations can then be compensated by active control of the pump power to enhance the self-compensating effect. With closed-loop feedback control of pump current, double-pass backward (DPB) configuration and spectrum re-shaping technology, an SFS prototype was made and tested. The mean-wavelength stability of about 87.4 ppm and output power instability of less than 5% were achieved under up to 200 krad (Si) gamma-ray irradiation.

Yang, Yuan-Hong; Suo, Xin-Xin; Yang, Wei



Preclinical evaluation of erythropoietin administration in a model of radiation-induced kidney dysfunction  

SciTech Connect

Purpose: To test whether the clinically available growth factor erythropoietin (EPO) influences radiation-induced normal-tissue damage in a model of kidney dysfunction. Methods: Animal experiments were conducted to test the role of EPO administration in a C3H mouse model of unilateral kidney irradiation with 6, 8, and 10 Gy and to assess the effects of 2 different dose levels of EPO. The kidney function was assessed before radiotherapy, as well as 19, 25, 31, and 37 weeks thereafter by means of {sup 99m}Tc-dimercaptosuccinat scans (static scintigraphy). Results: Concomitant EPO administration significantly increased the degree of radiation-induced kidney dysfunction. A dose of 2,000 IU/kg body weight per injection tended to cause more damage than the lower dose of 500 IU/kg. Conclusion: Administration of growth factors concomitant to radiotherapy might modify the development of kidney dysfunction. Although insulin-like growth factor-1 has previously been shown to protect the kidney, such an effect could not be demonstrated for EPO. The latter agent even increased the development of nephropathy.

Andratschke, Nicolaus [Department of Radiation Oncology, Klinikum rechts der Isar, Technical University of Munich, Munich (Germany); Schnaitera, Andrea [Department of Radiation Oncology, Klinikum rechts der Isar, Technical University of Munich, Munich (Germany); Weber, Wolfgang A. [Department of Molecular and Medical Pharmacology, Ahmanson Biological Imaging Center, The University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, CA (United States); Caia, Lu [Department of Radiation Oncology, Klinikum rechts der Isar, Technical University of Munich, Munich (Germany); Schill, Sabine [Department of Radiation Oncology, Klinikum rechts der Isar, Technical University of Munich, Munich (Germany); Wiedenmann, Nicole [Department of Experimental Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Schwaiger, Markus [Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich (Germany); Molls, Michael [Department of Radiation Oncology, Klinikum rechts der Isar, Technical University of Munich, Munich (Germany); Nieder, Carsten [Department of Radiation Oncology, Klinikum rechts der Isar, Technical University of Munich, Munich (Germany)]. E-mail:



Enhanced radiation-induced cell killing by Herbimycin A pre-treatment  

NASA Astrophysics Data System (ADS)

Herbimycin A (HA), as in Geldanamycin, binds to conserved pockets of heat shock protein 90 (Hsp90) and inhibits its chaperone functions. Hsp90 plays an integral role in cancer cell growth and survival, because it maintains the stability of several key proteins by its chaperone's activity. It is known that some of the proteins associated with radiation responses are functionally stabilized by Hsp90. In this study, we investigated the effect of HA on radiosensitivity in human cancer cells and the mechanism related to the sensitization. In order to gain a mechanistic insight of this sensitization, we examined repair of DNA double-strand breaks (DSBs) in irradiated human cancer cells pre-treated with HA, as unrepaired DSBs are thought to be the main cause of radiation-induced cell death. Cellular radiosensitivity was determined by clonogenic assay, and the DSB rejoining kinetics was examined by constant field gel electrophoresis. SQ-5, a lung squamous carcinoma cell line, showed synergistic increase in radiosensitivity when cells were pre-treated with HA. In addition, HA significantly inhibited repair of radiation-induced DSBs. These results suggest that the combination of HA and ionizing radiation may be a useful therapeutic strategy for treating certain cancer cells.

Noguchi, Miho; Hirayama, Ryoichi; Druzhinin, Sergey; Okayasu, Ryuichi



Cytokine profiling for prediction of symptomatic radiation-induced lung injury  

SciTech Connect

Purpose: To analyze plasma cytokine profiles before the initiation of radiation therapy to define a cytokine phenotype that correlates with risk of developing symptomatic radiation-induced lung injury (SRILI). Methods and Materials: Symptomatic radiation-induced lung injury was evaluated in 55 patients (22 with SRILI and 33 without SRILI), according to modified National Cancer Institute common toxicity criteria. These plasma samples were analyzed by the multiplex suspension bead array system (Bio-Rad Laboratories; Hercules, CA), which included the following cytokines: interleukin (IL)-1{beta}, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, IL-13, IL-17, granulocyte/macrophage colony-stimulating factor, interferon-{gamma}, monocyte chemotactic protein 1, macrophage inflammatory protein 1{beta}, tumor necrosis factor {alpha}, and granulocyte colony-stimulating factor. Results: Significant differences in the median values of IL-8 were observed between patients with and without SRILI. Patients who did not develop SRILI had approximately fourfold elevated levels of IL-8 as compared with patients who did subsequently develop SRILI. Significant correlations were not found for any other cytokine in this study, including transforming growth factor {beta}1. Conclusions: Patients with lower levels of plasma IL-8 before radiation therapy might be at increased risk for developing SRILI. Further studies are necessary to determine whether IL-8 levels are predictive of SRILI in a prospective trial and whether this marker might be used to determine patient eligibility for dose escalation.

Hart, Justin P. [Department of Pathology, Duke University Medical Center, Durham, NC (United States); Broadwater, Gloria [Cancer Center Biostatistics, Duke University Medical Center, Durham, NC (United States); Rabbani, Zahid [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Moeller, Benjamin J. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Clough, Robert [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Huang, Dale [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Sempowski, Gregory A. [Department of Medicine, Duke University Medical Center, Durham, NC (United States); Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC (United States); Dewhirst, Mark [Department of Pathology, Duke University Medical Center, Durham, NC (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Department of Biomedical Engineering, Duke University Medical Center, Durham, NC (United States); Pizzo, Salvatore V. [Department of Pathology, Duke University Medical Center, Durham, NC (United States); Vujaskovic, Zeljko [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Anscher, Mitchell S. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States)]. E-mail:



Radiation-induced malignant fibrous histiocytoma of the occipital: a case report.  


Malignant fibrous histiocytoma (MFH) is a rare neoplasm exhibiting a propensity for aggressive clinical behavior. Effective treatment modality is surgical resection with wide margins, but its rate of recurrence and metastasis is still high. Early detection and complete excision of the tumor is necessary. A MFH of the occipital developed in a 51-year-old woman eight years after surgery and radiation for medulloblastoma of the cerebellar vermis. The secondary neoplasm arose at the site of tumor resection within the irradiated field, and was resected. The development of sarcomas is a recognized complication of radiation therapy. The final diagnosis after the operation was MFH. Radiation-induced sarcoma (RIS) is well known, but radiation-induced MFH is relatively rare in the head and neck region, especially in the occipital. The imaging findings are not diagnosis specific, but strict follow-up within the radiation field by computerized tomography (CT) and magnetic resonance imaging (MRI) and appreciation of the expected latency period may help in providing the diagnosis of RIS. PMID:24742094

Zhang, Guo-Bin; Li, Jian; Zhang, Peng-Fei; Han, Li-Jiang; Zhang, Jun-Ting



Rejoining and misrejoining of radiation-induced chromatin breaks. III. Hypertonic treatment  

NASA Technical Reports Server (NTRS)

It has been shown that treatment in anisotonic medium modifies rejoining of radiation-induced breaks in interphase chromosomes. In previous work, we have demonstrated that formation of exchanges in human lymphocytes has a slow component (half-time of 1-2 h), but a fraction of exchanges are also observed in samples assayed soon after exposure. In this paper we studied the effect of hypertonic treatment on rejoining and misrejoining of radiation-induced breaks using fluorescence in situ hybridization of prematurely condensed chromosomes in human lymphocytes. Isolated lymphocytes were irradiated with 7 Gy gamma rays, fused to mitotic hamster cells and incubated in hypertonic solution (0.5 M NaCl) for the period normally allowed for interphase chromosome condensation to occur. The data from hypertonic treatment experiments indicate the presence of a class of interphase chromosome breaks that rejoin and misrejoin very quickly (half-time of 5-6 min). The fast misrejoining of these lesions is considered to be responsible for the initial level of exchanges which we reported previously. No significant effect of hypertonic treatment on the yield of chromosome aberrations scored at the first postirradiation mitosis was detected.

Durante, M.; George, K.; Wu, H. L.; Yang, T. C.



Radiation-induced sarcoma of bone: CT findings in 19 cases  

SciTech Connect

We reviewed the CT findings in 19 cases of radiation-induced sarcoma of bone. The latent period before development of the sarcoma ranged from 5 to 50 years (mean, 17 years). In all 19 lesions, a soft-tissue extraosseous component was seen on CT, and 18 of them had associated bone destruction. Expansion of the affected bone and tumor-matrix mineralization each were present in 10 patients, but occurred together in only five patients. Periosteal reaction was seen in five patients, one of whom had an associated fracture. Radiation osteitis could not be identified on CT scans in the affected bone of any of the patients when tumor was present, but it was present in contiguous bone in two patients and had been shown 6 years before tumor became apparent in the affected bone in one other patient. Radiation-induced sarcoma of bone should be considered when bone destruction and an associated soft-tissue mass are shown on CT, or when changes occur in the appearance of previously stable irradiated bone.

Lorigan, J.G.; Libshitz, H.I.; Peuchot, M. (Univ. of Texas M.D. Anderson Cancer Center, Houston (USA))



Genetic analysis of radiation-induced changes in human gene expression  

PubMed Central

Humans are exposed to radiation through the environment and in medical settings. To deal with radiation-induced damage, cells mount complex responses that rely on changes in gene expression. These gene expression responses differ greatly between individuals1 and contribute to individual differences in response to radiation2. Here we identify regulators that influence expression levels of radiation-responsive genes. We treated radiation-induced changes in gene expression as quantitative phenotypes3,4, and conducted genetic linkage and association studies to map their regulators. For more than 1,200 of these phenotypes there was significant evidence of linkage to specific chromosomal regions. Nearly all of the regulators act in trans to influence the expression of their target genes; there are very few cis-acting regulators. Some of the transacting regulators are transcription factors, but others are genes that were not known to have a regulatory function in radiation response. These results have implications for our basic and clinical understanding of how human cells respond to radiation. PMID:19349959

Smirnov, Denis A.; Morley, Michael; Shin, Eunice; Spielman, Richard S.; Cheung, Vivian G.



The nucleus is the target for radiation-induced chromosomal instability  

NASA Technical Reports Server (NTRS)

We have previously described chromosomal instability in cells of a human-hamster hybrid cell line after exposure to X rays. Chromosomal instability in these cells is characterized by the appearance of novel chromosomal rearrangements multiple generations after exposure to ionizing radiation. To identify the cellular target(s) for radiation-induced chromosomal instability, cells were treated with 125I-labeled compounds and frozen. Radioactive decays from 125I cause damage to the cell primarily at the site of their decay, and freezing the cells allows damage to accumulate in the absence of other cellular processes. We found that the decay of 125I-iododeoxyuridine, which is incorporated into the DNA, caused chromosomal instability. While cell killing and first-division chromosomal rearrangements increased with increasing numbers of 125I decays, the frequency of chromosomal instability was independent of dose. Chromosomal instability could also be induced from incorporation of 125I-iododeoxyuridine without freezing the cells for accumulation of decays. This indicates that DNA double-strand breaks in frozen cells resulting from 125I decays failed to lead to instability. Incorporation of an 125I-labeled protein (125I-succinyl-concanavalin A), which was internalized into the cell and/or bound to the plasma membrane, neither caused chromosomal instability nor potentiated chromosomal instability induced by 125I-iododeoxyuridine. These results show that the target for radiation-induced chromosomal instability in these cells is the nucleus.

Kaplan, M. I.; Morgan, W. F.



Does altered fractionation influence the risk of radiation-induced optic neuropathy?  

SciTech Connect

Purpose: To analyze the parameters that influence the risk of radiation-induced optic neuropathy (RION) after radiotherapy for head-and-neck tumors. Methods and Materials: Between 1964 and 2000, 273 patients with tumors of the nasopharynx, paranasal sinuses, nasal cavity, and hard palate adenoid cystic carcinomas were treated with curative intent and had radiation fields that included the optic nerves and/or chiasm. Patients were followed for at least 1 year after radiotherapy. Results: Radiation-induced optic neuropathy developed in 32 eyes of 24 patients (9%). The 5-year rates of freedom from RION according to the total dose and once- vs. twice-daily fractionation were as follows: {<=}63 Gy once daily, 95%; {<=}63 Gy twice daily, 98%; >63 Gy once daily, 78%; and >63 Gy twice daily, 91%. Multivariate analysis revealed that the total dose affected the risk of RION (p = 0.0047), with patient age (p = 0.0909), once-daily vs. twice-daily fractionation (p = 0.0684), and overall treatment time (p = 0.0972) were marginally significant. The use of adjuvant chemotherapy did not significantly influence the likelihood of developing RION. Conclusion: The likelihood of developing RION is primarily influenced by the total dose. Hyperfractionation may reduce the risk of experiencing this complication.

Bhandare, Niranjan [Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL (United States); Monroe, Alan T. [Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL (United States); Morris, Christopher G. [Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL (United States); Bhatti, M. Tariq [Department of Ophthalmology, Neurology, and Neurosurgery, University of Florida College of Medicine, Gainesville, FL (United States); Mendenhall, William M. [Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL (United States)]. E-mail:



Mitigating the risk of radiation-induced cancers: limitations and paradigms in drug development.  


The United States radiation medical countermeasures (MCM) programme for radiological and nuclear incidents has been focusing on developing mitigators for the acute radiation syndrome (ARS) and delayed effects of acute radiation exposure (DEARE), and biodosimetry technologies to provide radiation dose assessments for guiding treatment. Because a nuclear accident or terrorist incident could potentially expose a large number of people to low to moderate doses of ionising radiation, and thus increase their excess lifetime cancer risk, there is an interest in developing mitigators for this purpose. This article discusses the current status, issues, and challenges regarding development of mitigators against radiation-induced cancers. The challenges of developing mitigators for ARS include: the long latency between exposure and cancer manifestation, limitations of animal models, potential side effects of the mitigator itself, potential need for long-term use, the complexity of human trials to demonstrate effectiveness, and statistical power constraints for measuring health risks (and reduction of health risks after mitigation) following relatively low radiation doses (<0.75 Gy). Nevertheless, progress in the understanding of the molecular mechanisms resulting in radiation injury, along with parallel progress in dose assessment technologies, make this an opportune, if not critical, time to invest in research strategies that result in the development of agents to lower the risk of radiation-induced cancers for populations that survive a significant radiation exposure incident. PMID:24727460

Yoo, Stephen S; Jorgensen, Timothy J; Kennedy, Ann R; Boice, John D; Shapiro, Alla; Hu, Tom C-C; Moyer, Brian R; Grace, Marcy B; Kelloff, Gary J; Fenech, Michael; Prasanna, Pataje G S; Coleman, C Norman



Gamma radiation induced micronuclei and erythrocyte cellular abnormalities in the fish Catla catla.  


Ionizing radiation induced DNA damage in fishes is a scarcely studied topic and very few studies are available in fishes exposed to ionizing radiation using the erythrocyte micronucleus assay under laboratory conditions. Since radionuclides released accidentally or during a nuclear disaster can contaminate inland water bodies, biomonitoring methods are required for assessing the impacts of high and low levels of radiation that may ultimately result in ionizing radiation exposure to both humans and non-human biota. Fresh water fish, Catla catla were subjected to protracted (0.002 Gy/min) and acute (3.2 Gy/min) gamma radiation to a total dose of 5 Gy. Peripheral blood samples were collected at different intervals (days 3, 6, 12, 18, 30, 45, 90, 135, 202) and analyzed by the erythrocyte micronucleus assay. Nuclear anomalies observed were micronuclei (MN), deformed nuclei (DN), nuclear bud (NBu), nuclear bridge (NBr), vacuolated nucleus (VN), binucleated cell (BNC), apoptotic cells (AC) while cytoplasmic abnormalities detected were vacuolated cytoplasm (VC), anisochromasia (AN), echinocytes (EC) and enucleus (EN). Both exposures caused a statistically significant increase in nuclear and cytoplasmic abnormalities that correlated with micronucleus and other nuclear anomalies. However, the extent of damage is higher after an acute exposure lasting for a longer period leading to apoptosis. Nuclear and cytoplasmic abnormalities are the resultants of gamma radiation induced genotoxicity and cytotoxicity. PMID:22771702

Anbumani, S; Mohankumar, Mary N



A biological approach to the interspecies prediction of radiation-induced mortality risk  

SciTech Connect

Evolutionary explanations for why sexually reproducing organisms grow old suggest that the forces of natural selection affect the ages when diseases occur that are subject to a genetic influence (referred to here as intrinsic diseases). When extended to the population level for a species, this logic leads to the general prediction that age-specific death rates from intrinsic causes should begin to rise as the force of selection wanes once the characteristic age of sexual maturity is attained. Results consistent with these predictions have been found for laboratory mice, beagles, and humans where, after adjusting for differences in life span, it was demonstrated that these species share a common age pattern of mortality for intrinsic causes of death. In quantitative models used to predict radiation-induced mortality, risks are often expressed as multiples of those observed in a control population. A control population, however, is an aging population. As such, mortality risks related to exposure must be interpreted relative to the age-specific risk of death associated with aging. Given the previous success in making interspecies predictions of age-related mortality, the purpose of this study was to determine whether radiation-induced mortality observed in one species could also be predicted quantitatively from a model used to describe the mortality consequences of exposure to radiation in a different species. Mortality data for B6CF{sub 1} mice and beagles exposed to {sup 60}Co {gamma}-rays for the duration of life were used for analysis.

Carnes, B.A.; Grahn, D. [Argonne National Lab., IL (United States). Center for Mechanistic Biology and Biotechnology; Olshansky, S.J. [Univ. of Chicago, IL (United States). Dept. of Medicine



Radiation-induced complications in prostate cancer patients treated with radiotherapy  

NASA Astrophysics Data System (ADS)

The purpose of the study is to determine the relationship between radiation-induced complications with dosimetric and radiobiological parameters for prostate cancer patients that underwent the conformal radiotherapy treatment. 17 prostate cancer patients that have been treated with conformal radiotherapy were retrospectively analysed. The dosimetric data was retrieved in the form of dose-volume histogram (DVH) from Radiotherapy Treatment Planning System. The DVH was utilised to derived Normal Tissue Complication Probability (NTCP) in radiobiological data. Follow-up data from medical records were used to grade the occurrence of acute gastrointestinal (GI) and genitourinary (GU) complications using Radiation Therapy Oncology Group (RTOG) scoring system. The chi-square test was used to determine the relationship between radiation-induced complication with dosimetric and radiobiological parameters. 8 (47%) and 7 (41%) patients were having acute GI and GU complications respectively. The acute GI complication can be associated with V60rectum, rectal mean dose and NTCPrectum with p-value of 0.016, 0.038 and 0.049 respectively. There are no significant relationships of acute GU complication with dosimetric and radiobiological variables. Further study can be done by increase the sample size and follow up duration for deeper understanding of the factors that effecting the GU and GI complication in prostate cancer radiotherapy.

Azuddin, A. Yusof; Rahman, I. Abdul; Siah, N. J.; Mohamed, F.; Saadc, M.; Ismail, F.



Glucose transport by radiation-induced insulinoma and clonal pancreatic beta-cells  

SciTech Connect

Sugar uptake was measured in dispersed cells prepared from radiation-induced insulinomas transplantable in NEDH rats and in three clonal beta-cell lines maintained in continuous culture (RIN m5F, RIN 1046, HIT). Uptake of D-glucose and 3-O-methyl-D-glucose by insulinoma cells was rapid so that the intracellular concentration of D-hexoses approximated the concentration in the incubation medium by 15-30 s. L-Glucose was taken up only slowly. 3-O-methyl-D-glucose uptake by RIN m5F, RIN 1046, and HIT cells was slow; with 1 mM 3-O-methylglucose in the medium, equilibrium was attained at 20 min, but with 10 mM 3-O-methylglucose, equilibrium was not attained even at 20 min. In HIT cells incubated with D-glucose for 30 min, the intracellular concentration of glucose was less than the medium glucose concentration, indicating glucose transport is a nonequilibrium reaction in this cell line. These data indicate that radiation-induced insulinoma cells retain the capacity of normal beta-cells to transport sugar at high rates. RIN m5F, RIN 1046, and HIT cells transport sugar slowly, however, and thus differ from normal beta-cells. In RIN m5F, RIN 1046, and HIT cells, unlike in normal beta-cells, glucose transport may be the site regulating glucose metabolism.

Meglasson, M.D.; Manning, C.D.; Najafi, H.; Matschinsky, F.M.



Sivelestat sodium hydrate reduces radiation-induced lung injury in mice by inhibiting neutrophil elastase.  


The aim of this study was to investigate whether sivelestat, a neutrophil elastase (NE) inhibitor, mitigates radiation-induced lung injury in mice. C57BL/6J mice were administered a dose of 20 Gy to the bilateral whole lungs. Sivelestat was administered immediately before and 1 h after irradiation in group RE2, and immediately before and 1, 3 and 6 h after irradiation in group RE4. Group R received irradiation without sivelestat injection. Mice that did not receive sivelestat injection or irradiation were used as controls. NE activity was measured 24 and 48 h after irradiation, and the mice were sacrificed 24 h, 48 h and 15 weeks after irradiation for histopathological examination. In groups RE2 and RE4, NE activity was significantly suppressed until 48 h after irradiation compared to group R. The degree of lung damage in each group was scored during histopathological examination. Results showed that the scores of groups RE2 and RE4 were significantly lower compared to those of group R 15 weeks after irradiation. In conclusion, sivelestat reduced radiation?induced lung injury in the mice by suppressing NE activity and excessive inflammatory reactions. PMID:23404144

Yoshikawa, Nobuhiko; Inomata, Taisuke; Okada, Yoshikatsu; Shimbo, Taiju; Takahashi, Masatsugu; Akita, Kazuhiko; Uesugi, Yasuo; Narumi, Yoshifumi



Radiation-induced segregation in Cu-Au alloys. [1 at. % Au  

SciTech Connect

Radiation-induced segregation in a Cu-1 at. % Au alloy was investigated using in situ Rutherford Backscattering Spectrometry. Irradiation with 1.8-MeV He produced nonequilibrium Au atom depletion in the near surface region. The amount of segregation was measured as a function of dose, dose rate and temperature. Segregation was observed between 300 and 500/sup 0/C. For a calculated dose rate of 3.9 x 10/sup -5/ dpa/s, the radiation-induced segregation rate peaked near 400/sup 0/C. Theoretical analysis based on the Johnson-Lam model predicted that the amount of segregation would be directly proportional to dose at the early stage of irradiation, would deviate from linearity with a continuously decreasing slope at intermediate doses, and finally approach a constant value after high doses. The analysis also predicted that the segregation rate would vary as the -1/4th power of the dose rate at constant dose in the low temperature region. These predictions were all verified experimentally. A procedure for extracting relative defect production efficiencies from similar measurements is discussed.

Hashimoto, T.; Rehn, L.E.; Okamoto, P.R.



Effect of silica gel on radiation-induced reduction of dichromate ion in aqueous acidic solution  

NASA Astrophysics Data System (ADS)

Radiation-induced reduction of dichromate ion (Cr2O72-) in aqueous acidic solution containing silica gel was studied by ?-radiolysis to seek the characteristic reactions occurring in radiolysis of water-silica coexistent system. The addition of silica gel increased the reduction yield of Cr2O72- in aqueous solution containing 0.1 mol dm-3 perchloric acid (HClO4) and 1 mmol dm-3 potassium dichromate (K2Cr2O7). However, the addition of 0.1 mol dm-3t-butanol to the aqueous solution suppressed the effect of silica gel. Also the addition of silver(I) ion (Ag+) lowered the increase in the reduction yield by the addition of silica gel. Therefore it is suggested that the increase in the reduction yield of Cr2O72- was partially due to silica gel changing the reaction scheme of the radiation-induced reduction of Cr2O72-, in addition to the energy or charge transfer from excitation and ionization in silica gel to production of reactive species in aqueous solution. The inhibition of the oxidation of chromium(III) ion (Cr3+) and/or transient chromium species by hydroxyl radical (OH radical) is especially expected, since both t-butanol and Ag+ act as a scavenger of OH radical.

Kumagai, Yuta; Nagaishi, Ryuji; Yamada, Reiji; Katsumura, Yosuke



Protective effect of esculentoside A on radiation-induced dermatitis and fibrosis  

SciTech Connect

Purpose: To investigate the effect of esculentoside A (EsA) on radiation-induced cutaneous and fibrovascular toxicity and its possible molecular mechanisms, both in vivo and in vitro. Methods and Materials: Mice received drug intervention 18 hours before 30 Gy to the right hind leg. Alterations in several cytokines expressed in skin tissue 2 days after irradiation were determined by ELISA. Early skin toxicity was evaluated 3 to 4 weeks after irradiation by skin scoring, and both tissue contraction and expression of TGF-{beta}1 were determined for soft-tissue fibrosis 3 months after irradiation. In vitro, the effect of EsA on radiation-induced nitric oxide (NO) and cytokine production in different cell types was measured by application of 2, 4, and 8 Gy. Results: In vivo, EsA reduced levels of IL-1{alpha}, MCP-1, VEGF, and TGF-{beta}1 in cutaneous tissue and reduced soft-tissue toxicity. In vitro, EsA inhibited the IL-1{alpha} ordinarily produced after 4 Gy in A431 cells. In Raw264.7 cells, EsA reduced levels of IL-1{alpha}, IL-1{beta}, and NO production costimulated by radiation and lipopolysaccharide (LPS). In L-929 cells, EsA inhibited VEGF, TNF, and MCP-1 production at 2, 4, and 8 Gy. Conclusions: Esculentoside A protects soft tissues against radiation toxicity through inhibiting the production of several proinflammatory cytokines and inflammatory mediators in epithelial cells, macrophages, fibroblasts, and skin tissue.

Xiao Zhenyu [Department of Radiation Oncology, James P. Wilmot Cancer Center at the University of Rochester Medical Center, Rochester, NY (United States); Su Ying [Department of Radiation Oncology, James P. Wilmot Cancer Center at the University of Rochester Medical Center, Rochester, NY (United States); Yang Shanmin [Department of Radiation Oncology, James P. Wilmot Cancer Center at the University of Rochester Medical Center, Rochester, NY (United States); Yin Liangjie [Department of Radiation Oncology, James P. Wilmot Cancer Center at the University of Rochester Medical Center, Rochester, NY (United States); Wang Wei [Department of Radiation Oncology, James P. Wilmot Cancer Center at the University of Rochester Medical Center, Rochester, NY (United States); Yi Yanghua [Department of Radiation Oncology, James P. Wilmot Cancer Center at the University of Rochester Medical Center, Rochester, NY (United States); Fenton, Bruce M. [Department of Radiation Oncology, James P. Wilmot Cancer Center at the University of Rochester Medical Center, Rochester, NY (United States); Zhang Lurong [Department of Radiation Oncology, James P. Wilmot Cancer Center at the University of Rochester Medical Center, Rochester, NY (United States); Okunieff, Paul [Department of Radiation Oncology, James P. Wilmot Cancer Center at the University of Rochester Medical Center, Rochester, NY (United States)]. E-mail:



PHD Inhibition Mitigates and Protects Against Radiation-Induced Gastrointestinal Toxicity via HIF2  

PubMed Central

Radiation-induced gastrointestinal (GI) toxicity can be a major source of morbidity and mortality after radiation exposure. There is an unmet need for effective preventative or mitigative treatments against the potentially fatal diarrhea and water loss induced by radiation damage to the GI tract. We report that prolyl hydroxylase inhibition by genetic knockout or pharmacologic inhibition of all PHD isoforms by the small molecule dimethyloxyallylglycine (DMOG) increases HIF expression, improves epithelial integrity, reduces apoptosis, and increases intestinal angiogenesis, all of which are essential for radioprotection. HIF2, but not HIF1, is both necessary and sufficient to prevent radiation-induced GI toxicity and death. Increased VEGF expression contributes to the protective effects of HIF2, since inhibition of VEGF function reversed the radioprotection and radiomitigation afforded by DMOG. Additionally, mortality is reduced from abdominal or total body irradiation even when DMOG is given 24 hours after exposure. Thus, prolyl hydroxylase inhibition represents a new treatment strategy to protect against and mitigate GI toxicity from both therapeutic radiation and potentially lethal radiation exposures. PMID:24828078

Taniguchi, Cullen M.; Miao, Yu Rebecca; Diep, Anh N.; Wu, Colleen; Rankin, Erinn B.; Atwood, Todd F.; Xing, Lei; Giaccia, Amato J.



Radiation-induced malignant fibrous histiocytoma of the occipital: a case report  

PubMed Central

Malignant fibrous histiocytoma (MFH) is a rare neoplasm exhibiting a propensity for aggressive clinical behavior. Effective treatment modality is surgical resection with wide margins, but its rate of recurrence and metastasis is still high. Early detection and complete excision of the tumor is necessary. A MFH of the occipital developed in a 51-year-old woman eight years after surgery and radiation for medulloblastoma of the cerebellar vermis. The secondary neoplasm arose at the site of tumor resection within the irradiated field, and was resected. The development of sarcomas is a recognized complication of radiation therapy. The final diagnosis after the operation was MFH. Radiation-induced sarcoma (RIS) is well known, but radiation-induced MFH is relatively rare in the head and neck region, especially in the occipital. The imaging findings are not diagnosis specific, but strict follow-up within the radiation field by computerized tomography (CT) and magnetic resonance imaging (MRI) and appreciation of the expected latency period may help in providing the diagnosis of RIS. PMID:24742094



Preventive and therapeutic effects of Smad7 on radiation-induced oral mucositis  

PubMed Central

We report that K5.Smad7 mice, which express Smad7 transgene by a keratin-5 promoter, were resistant to radiation-induced oral mucositis, a painful oral ulceration. In addition to NF-?B activation known to contribute to oral mucositis, we found activated TGF-? signaling in oral mucositis. Smad7 dampened both pathways to attenuate inflammation, growth inhibition and apoptosis. Additionally, Smad7 promoted oral epithelial migration to close the wound. Further analyses revealed that TGF-? signaling Smads and their co-repressor CtBP1 transcriptionally repressed Rac1, and Smad7 abrogated this repression. Knocking down Rac1 in mouse keratinocytes abrogated Smad7-induced migration. Topically applying Smad7 protein with a cell permeable Tat-tag (Tat-Smad7) to oral mucosa showed preventive and therapeutic effects on radiation-induced oral mucositis in mice. Thus, we have identified novel molecular mechanisms involved in oral mucositis pathogenesis and our data suggest an alternative therapeutic strategy to block multiple pathological processes of oral mucositis. PMID:23475202

Han, Gangwen; Bian, Li; Li, Fulun; Cotrim, Ana; Wang, Donna; Lu, Jian Bo; Deng, Yu; Bird, Gregory; Sowers, Anastasia; Mitchell, James B.; Gutkind, J. Silvio; Zhao, Rui; Raben, David; Dijke, Peter ten; Refaeli, Yosef; Zhang, Qinghong; Wang, Xiao-Jing



Repeated Autologous Bone Marrow-Derived Mesenchymal Stem Cell Injections Improve Radiation-Induced Proctitis in Pigs  

PubMed Central

The management of proctitis in patients who have undergone very-high-dose conformal radiotherapy is extremely challenging. The fibrosis-necrosis, fistulae, and hemorrhage induced by pelvic overirradiation have an impact on morbidity. Augmenting tissue repair by the use of mesenchymal stem cells (MSCs) may be an important advance in treating radiation-induced toxicity. Using a preclinical pig model, we investigated the effect of autologous bone marrow-derived MSCs on high-dose radiation-induced proctitis. Irradiated pigs received repeated intravenous administrations of autologous bone marrow-derived MSCs. Immunostaining and real-time polymerase chain reaction analysis were used to assess the MSCs' effect on inflammation, extracellular matrix remodeling, and angiogenesis, in radiation-induced anorectal and colon damages. In humans, as in pigs, rectal overexposure induces mucosal damage (crypt depletion, macrophage infiltration, and fibrosis). In a pig model, repeated administrations of MSCs controlled systemic inflammation, reduced in situ both expression of inflammatory cytokines and macrophage recruitment, and augmented interleukin-10 expression in rectal mucosa. MSC injections limited radiation-induced fibrosis by reducing collagen deposition and expression of col1a2/col3a1 and transforming growth factor-?/connective tissue growth factor, and by modifying the matrix metalloproteinase/TIMP balance. In a pig model of proctitis, repeated injections of MSCs effectively reduced inflammation and fibrosis. This treatment represents a promising therapy for radiation-induced severe rectal damage. PMID:24068742

Busson, Elodie; Holler, Valerie; Strup-Perrot, Carine; Lacave-Lapalun, Jean-Victor; Lhomme, Bruno; Prat, Marie; Devauchelle, Patrick; Sabourin, Jean-Christophe; Simon, Jean-Marc; Bonneau, Michel; Lataillade, Jean-Jacques; Benderitter, Marc



A Case of Horner's Syndrome following Ultrasound-Guided Infraclavicular Brachial Plexus Block.  


Horner's syndrome results from paralysis of the ipsilateral sympathetic cervical chain (stellate ganglion) caused by surgery, drugs (mainly high concentrations of local anesthetics), local compression (hematoma or tumor), or inadequate perioperative positioning of the patient. It occurs in 100% of the patients with an interscalene block of the brachial plexus and can also occur in patients with other types of supraclavicular blocks.In this case report, we presented a case of Horner's syndrome after performing an ultrasound-guided infraclavicular brachial plexus block with 15?mL of bupivacaine 0.5%. It appeared 40 minutes after the block with specific triad (ptosis, miosis, and exophtalmia) and quickly disappears within 2 hours and a half without any sequelae. Horner's syndrome may be described as an unpleasant side effect because it has no clinical consequences in itself. For this reason anesthesiologists should be aware of this syndrome, and if it occurs patients should be reassured and monitored closely. PMID:22957277

Walid, Trabelsi; Mondher, Belhaj Amor; Mohamed Anis, Lebbi; Mustapha, Ferjani



Medial Antebrachial Cutaneous Nerve Injury After Brachial Plexus Block: Two Case Reports  

PubMed Central

Medial antebrachial cutaneous (MABC) nerve injury associated with iatrogenic causes has been rarely reported. Local anesthesia may be implicated in the etiology of such injury, but has not been reported. Two patients with numbness and painful paresthesia over the medial aspect of the unilateral forearm were referred for electrodiagnostic study, which revealed MABC nerve lesion in each case. The highly selective nature of the MABC nerve injuries strongly suggested that they were the result of direct nerve injury by an injection needle during previous brachial plexus block procedures. Electrodiagnostic studies can be helpful in evaluating cases of sensory disturbance after local anesthesia. To our knowledge, these are the first documented cases of isolated MABC nerve injury following ultrasound-guided axillary brachial plexus block. PMID:24466530

Jung, Mi Jin; Byun, Ha Young; Lee, Chang Hee; Moon, Seung Won; Oh, Min-Kyun



Effect of photobleaching on radiation-induced transmission loss of fused-silica-core optical fibres under gamma-ray and 14 MeV neutron irradiation  

Microsoft Academic Search

The effect of photobleaching on radiation-induced transmission loss of fused-silica-core optical fibres was examined under 60Co gamma-ray and 14 MeV neutron irradiation. In the visible wavelength range, the radiation-induced transmission loss could be reduced by photobleaching under both types of irradiation. It is considered that the number of radiation-induced defects such as E' centre and NBOHC that cause optical absorption

K. Toh; T. Shikama; S. Nagata; B. Tsuchiya; M. Yamauchi; T. Nishitani



Brachial Artery Diameter, Blood Flow and Flow-mediated Dilation in Sleep-Disordered Breathing  

PubMed Central

Clinic-based case-control studies linked sleep-disordered breathing (SDB) to markers of endothelial dysfunction. We attempted to validate this association in a large community-based sample, and evaluate the relation of SDB to arterial diameter and peripheral blood flow. This community-based cross-sectional observational study included 327 men and 355 women, age 42 to 83 years, from the Framingham Heart Study site of the Sleep Heart Health Study. Polysomnographically derived apnea-hypopnea index and hypoxemia index (percent sleep time with oxyhemoglobin saturation below 90%) were used to quantify the severity of SDB. Brachial artery ultrasound measurements included baseline diameter, percent flow-mediated dilation, and baseline and hyperemic flow velocity and volume. Baseline brachial artery diameter was significantly associated with both apnea-hypopnea index and hypoxemia index. The association was diminished by adjustment for body mass index, but remained significant for apnea-hypopnea index. Age-, sex-, race-and body mass index-adjusted mean diameters were 4.32, 4.33, 4.33, 4.56, 4.53 mm, respectively, for those with apnea-hypopnea index <1.5, 1.5–4.9, 5–14.9, 15–29.9, ?30; p=0.03. Baseline flow measures were associated with apnea-hypopnea index but this association was non-significant after adjusting for body mass index. No significant association was observed between measures of SDB and percent flow-mediated dilation or hyperemic flow in any model. In conclusion, this study supports a moderate association of SDB and larger baseline brachial artery diameter, which may reflect SDB-induced vascular remodeling. This study does not support a link between SDB and endothelial dysfunction as measured by brachial artery flow-mediated dilation. PMID:19808720

Chami, Hassan A.; Keyes, Michelle J.; Vita, Joseph A.; Mitchell, Gary F.; Larson, Martin G.; Fan, Shuxia; Vasan, Ramachandran S.; O'Connor, George T.; Benjamin, Emelia J.; Gottlieb, Daniel J.



Sensory Evaluation of the Hands in Children with Brachial Plexus Birth Injury  

ERIC Educational Resources Information Center

The aim of this study was to examine sensory changes of the hand in brachial plexus birth injury (BPBI). Ninety-five patients (43 females, 52 males) comprising two age groups, 6 to 8 years (mean age 7y 6mo) and 12 to 14 years (mean age 13y 2mo), were included. Sixty-four had upper (cervical [C] 5-6), 19 upper and middle (C5-7), and 12 had total…

Palmgren, Tove; Peltonen, Jari; Linder, Tove; Rautakorpi, Sanna; Nietosvaara, Yrjana



Late development of a brachial plexus lesion after fracture of the clavicle  

Microsoft Academic Search

Summary  \\u000a Neurological complications in clavicle fractures are rare. As a primary lesion, it is caused by the trauma itself. More often\\u000a however, the neurological symptoms develop later by large callus formation that encroach on the costoclavicular space. A case\\u000a report is presented of delayed injury to the brachial plexus due to clavicular fracture with non-union and callus formation.

W. Orljanski; H. Millesi; R. Schabus



Relation of Ankle Brachial Index to Left Ventricular Ejection Fraction in Non-Diabetic Individuals  

PubMed Central

Introduction Peripheral arterial disease is associated with an excessive risk for cardi-ovascular events and mortality. Peripheral arterial disease is usually measured with ankle brachial index (ABI). It is previously shown that the ABI would reflect LV systolic func-tion, as well as atherosclerosis; however, these results are not shown in non-diabetic indi-viduals. In this study, we aim to evaluate this relation in non-diabetic individuals. Methods In a prospective study, 73 non-diabetic individuals (38.4% male with mean age of 59.20±14.42 years) referred for ABI determination who had had the left ventricular ejection fraction determined using trans-thoracic echocardiography were studied. Participants were compared in normal and low ABI groups. Results The mean left ventricular ejection fraction (LVEF) was 52.34±7.69, mean ankle brachial index for the right leg was 1.08±0.13, and the mean ankle brachial index for the left leg was 1.07±0.12. Low ABI incidence was 12.32%. Individuals with low ABI significantly were older (p<0.001) and had lower left ventricular ejection fraction (p<0.001). ABI had significantly inverse corre-lation with LVEF (r=-0.53, p<0.001) and positive correlation with age (r=0.43, p<0.001). The ABI correlated inversely with LVEF in the patients with (r =-0.52, p=0.008) and without (r=-0.55, p<0.001) IHD. Conclusion Results showed that ankle brachial index would be influenced by left ventricular ejection fraction in non-diabetics and to evaluate and monitor cardiovascular risk in patients these should be considered together. PMID:24250966

Abbasnezhad, Mohsen; Aliasgarzadeh, Akbar; Aslanabadi, Hasan; Habibzadeh, Afshin; Zamani, Bejan



Management of obstetric brachial plexus lesions: state of the art and future developments  

Microsoft Academic Search

Despite improving perinatal care the incidence of obstetric brachial plexus lesions (OBPL) has not declined. Most babies recover\\u000a spontaneously. In 10–20% recovery is incomplete. To prevent lasting functional deficits early referral to specialized centers\\u000a is necessary. If the biceps shows no function at 3 months, standardized clinical assessment and additional investigations\\u000a must delineate the extent of a lesion. Detection of

W. J. R. van Ouwerkerk; J. A. van der Sluijs; F. Nollet; F. Barkhof; A. C. J. Slooff



Alcohol Consumption and Ankle-to-Brachial Index: Results from the Cardiovascular Risk Survey  

Microsoft Academic Search

Background and MethodologyA low ankle-to-brachial index (ABI) is a strong correlate of cardiovascular disease and subsequent mortality. The relationship between ABI and alcohol consumption remains unclear. Data are from the Cardiovascular Risk Survey (CRS), a multiple-ethnic, community-based, cross-sectional study of 14 618 Chinese people (5 757 Hans, 4 767 Uygurs, and 4 094 Kazakhs) aged 35 years and over at

Xiang Xie; Yi-Tong Ma; Yi-Ning Yang; Xiao-Mei Li; Fen Liu; Ding Huang; Zhen-Yan Fu; Xiang Ma; Bang-Dang Chen; Ying Huang; Gian Paolo Fadini



Brachial plexus anesthesia compared to general anesthesia when a block room is available  

Microsoft Academic Search

Purpose  Regional anesthesia is often felt to be beneficial to patient care but detrimental to operating room (OR) efficiency. In this\\u000a report we compare how a block room (BR) affects OR time (ORT) utilization for brachial plexus anesthesia (BPA) in a busy upper\\u000a limb practice. We also compare how anesthetic technique, BPA or general anesthesia (GA), impacts on the time to

Kevin P. J. Armstrong; Richard A. Cherry



Validity, Reproducibility, and Clinical Significance of Noninvasive Brachial-Ankle Pulse Wave Velocity Measurement  

Microsoft Academic Search

The present study was conducted to evaluate the validity and reproducibility of noninvasive brachial-ankle pulse wave velocity (baPWV) measurements and to examine the alteration of baPWV in patients with coro- nary artery disease (CAD). Simultaneous recordings of baPWV by a simple, noninvasive method and aortic pulse wave velosity (PWV) using a catheter tip with pressure manometer were performed in 41

Akira YAMASHINA; Hirofumi TOMIYAMA; Kazuhiro TAKEDA; Hideichi TSUDA; Tomio ARAI; Kenichi HIROSE; Yutaka KOJI; Saburoh HORI; Yoshio YAMAMOTO



Radiation-induced inflammatory markers of brain injury are modulated by PPARdelta activation in vitro and in vivo  

NASA Astrophysics Data System (ADS)

As a result of improvements in cancer therapy and health care, the population of long-term cancer survivors is growing. For these approximately 12 million long-term cancer survivors, brain metastases are a significant risk. Fractionated partial or whole-brain irradiation (fWBI) is often required to treat both primary and metastatic brain cancer. Radiation-induced normal tissue injury, including progressive cognitive impairment, however, can significantly affect the well-being of the approximately 200,000 patients who receive these treatments each year. Recent reports indicate that radiation-induced brain injury is associated with chronic inflammatory and oxidative stress responses, as well as increased microglial activation in the brain. Anti-inflammatory drugs may, therefore, be a beneficial therapy to mitigate radiation-induced brain injury. We hypothesized that activation of peroxisomal proliferator activated receptor delta (PPAR?) would prevent or ameliorate radiation-induced brain injury, including cognitive impairment, in part, by alleviating inflammatory responses in microglia. For our in vitro studies, we hypothesized that PPAR? activation would prevent the radiation-induced inflammatory response in microglia following irradiation. Incubating BV-2 murine microglial cells with the (PPAR)? agonist, L-165041, prevented the radiation-induced increase in: i) intracellular ROS generation, ii) Cox-2 and MCP-1 expression, and iii) IL-1? and TNF-? message levels. This occured, in part, through PPAR?-mediated modulation of stress activated kinases and proinflammatory transcription factors. PPAR? inhibited NF-?B via transrepression by physically interacting with the p65 subunit, and prevented activation of the PKC?/MEK1/2/ERK1/2/AP-1 pathway by inhibiting the radiation-induced increase in intracellular ROS generation. These data support the hypothesis that PPAR? activation can modulate the radiation-induced oxidative stress and inflammatory responses in microglia in vitro. To extend our in vitro findings in vivo, we investigated whether administration of the peroxisomal proliferator-activated receptor (PPAR)ä agonist, GW0742, prevented radiation-induced brain injury in C57Bl/6 WT mice. Our data demonstrate that GW0742 prevented the radiation-induced increase in the number of activated microglia (CD68+ cells) in wild-type (WT) mice 1 week following 10 Gy WBI. Furthermore, GW0742 inhibited the WBI-induced increase in IL-1? message levels and ERK phosphorylation observed 3 h post-irradiation. In contrast, GW0742 administration failed to modulate the radiation-induced decrease in hippocampal neurogenesis (NeuN+/BrdU+ cells) determined 2 months after irradiation, or mitigate hippocampal-dependent spatial memory impairment observed 3 months post-irradiation using the Barnes Maze task. We used PPAR? knockout (KO) mice to examine if the effects of GW0742 are PPAR?-dependent. Unexpectedly, PPAR? KO mice exhibited a differential response following WBI compared to WT mice; therefore, we were unable to make mechanistic conclusions about GW0742. KO mice do not exhibit a WBI-induced increase in activated microglia; however, they appeared to display a pronounced astrocytic response. In particular, PPAR? KO but not WT mice displayed increased GFAP message levels 2 months after WBI. Additionally, the number of GFAP+ cells was reduced significantly in the WT mice 2 months after WBI, but it was not in the PPAR? KO mice. These results demonstrate that: i) GW0742 prevents the radiation-induced increase in microglial activation and inflammatory markers, and ii) WT and PPAR? KO mice have a differential response to WBI.

Schnegg, Caroline Isabel


Severe stridor and marked respiratory difficulty after right-sided supraclavicular brachial plexus block.  


Brachial plexus block is commonly used for upper limb surgery. Although the procedure is safe, it may be associated with some life-threatening complications. We performed right-sided supraclavicular brachial plexus block for below-elbow amputation in a 45-year-old female. At completion of the block the patient developed marked respiratory difficulty with audible inspiratory stridor. Although SpO(2) decreased to 82% initially, it was increased to 100% by continuous positive airway pressure with a face mask. On conventional direct laryngoscopy, the left vocal cord was found to be in the midline position and the right vocal cord was in the paramedian position. The trachea was intubated and surgery proceeded without any other complication. Postoperative indirect laryngoscopy revealed that the left vocal cord was fixed, whereas the right vocal cord was mobile, and diagnosis of pre-existing incomplete left vocal cord paralysis was made. This clinical report is to emphasize the importance of thorough pre-operative evaluation of the vocal cord in patients who have undergone any surgical procedure or radiation treatment of the neck before planning for brachial plexus block. If such an evaluation cannot be obtained, an alternative technique, for example axillary approach, should be preferred. PMID:21212990

Solanki, Sohan Lal; Jain, Amit; Makkar, Jeetinder Kaur; Nikhar, Sapna Annaji



Risk Factors at Birth for Permanent Obstetric Brachial Plexus Injury and Associated Osseous Deformities  

PubMed Central

Purpose. To examine the most prevalent risk factors found in patients with permanent obstetric brachial plexus injury (OBPI) to identify better predictors of injury. Methods. A population-based study was performed on 241 OBPI patients who underwent surgical treatment at the Texas Nerve and Paralysis Institute. Results. Shoulder dystocia (97%) was the most prevalent risk factor. We found that 80% of the patients in this study were not macrosomic, and 43% weighed less than 4000?g at birth. The rate of instrument use was 41% , which is 4-fold higher than the 10% predicted for all vaginal deliveries in the United States. Posterior subluxation and glenoid version measurements in children with no finger movement at birth indicated a less severe shoulder deformity in comparison with those with finger movement. Conclusions. The average birth weight in this study was indistinguishable from the average birth weight reported for all brachial plexus injuries. Higher birth weight does not, therefore, affect the prognosis of brachial plexus injury. We found forceps/vacuum delivery to be an independent risk factor for OBPI, regardless of birth weight. Permanently injured patients with finger movement at birth develop more severe bony deformities of the shoulder than patients without finger movement. PMID:22518326

Nath, Rahul K.; Kumar, Nirupama; Avila, Meera B.; Nath, Devin K.; Melcher, Sonya E.; Eichhorn, Mitchell G.; Somasundaram, Chandra



[Transradial percutaneous approach for cardiac catheterization in patients with previous brachial artery cutdown].  


The percutaneous punction of the radial artery for catheterization procedures has gained acceptance lately. This was a consequence of achieving results similar to the femoral approach, with the benefits of a lower rate of complications and increased comfort for the patients post procedure. Recently it has gained an additional impulse with the better prognosis obtained in acute coronary syndromes. In this trial we have evaluated if the feasibility, results and advantages related with the use of the radial artery percutaneous approach to perform catheterization procedures, continues when used in patients who have had a previous brachial artery cutdown. Out of a total of 1356 percutaneous radial accesses, 53 were in patients with previous brachial artery cutdown. Through this access 71 catheterization procedures were performed, achieving access success in 96.2% (51/53) of the punctions. Once the access success was obtained, 93.6% (44/47) of the diagnostic procedures and 100% (24/24) of the therapeutics procedures were successful. During hospitalization, in this group of patients, no major adverse cardiac events occurred and there was a 1.4% (1/71) rate of minor events. At seven days follow up, no new complications were recorded. Although this is a small group, we believe that it is enough to show that percutaneous punctions of the radial artery to perform catheterization procedures, in patients with previous brachial artery cutdown, are feasible, allowing high access and procedure success rates, with a low frequency of complications. PMID:23335700

Magariños, Eduardo; Solioz, Germán; Cermesoni, Gabriel; Koretzky, Martín; Carnevalini, Mariana; González, Daniel



Gene expression differences in healthy brachial and femoral arteries of Rapacz familial hypercholesterolemic swine.  


The mechanisms underlying the unequal distribution of atherosclerotic disease in the peripheral arteries are currently unclear. Gene expression differences in healthy arteries may influence the heterogeneous distribution of atherosclerosis. Therefore, this investigation compares gene expression in healthy atheroprotected brachial and atherosusceptible femoral arteries of young and disease free Rapacz familial hypercholesterolemic (FHC) swine. We hypothesized that transcripts related to atherosusceptibility would be differentially expressed between these arteries prior to the onset of disease. Femoral and brachial arteries were harvested from four 13-day-old Rapacz FHC swine. No atherosclerotic disease was detected using Sudan IV, Verhoeff-van Gieson, and hematoxylin-eosin staining. Gene expression was quantified using Affymetrix GeneChip Porcine Genome Arrays. An average of 15,552 probe sets had detectable transcripts, while 430 probe sets showed a significant differential expression between arteries (false discovery rate < 0.05). The human orthologs of 63 probe sets with differential expression and a 1.5-fold or greater transcript abundance between arteries are associated with Wnt/?-catenin, lysophospholipid, and Ca-signaling, as well as apoptosis. This is the first investigation reporting that differences in relative abundance of gene expression exist between brachial and femoral arteries in young Rapacz FHC swine prior to the development of atherosclerotic lesions. PMID:21505098

Bahls, Martin; Bidwell, Christopher A; Hu, Juan; Krueger, Christian G; Reed, Jess D; Tellez, Armando; Kaluza, Greg L; Granada, Juan F; Van Alstine, William G; Newcomer, Sean C



The Development of Countermeasures for Space Radiation Induced Adverse Health Effects  

NASA Astrophysics Data System (ADS)

The Development of Countermeasures for Space Radiation Induced Adverse Health Effects Ann R. Kennedy Department of Radiation Oncology, University of Pennsylvania School of Medicine, 195 John Morgan Building, 3620 Hamilton Walk, Philadelphia, PA, United States 19104-6072 The development of countermeasures for radiation induced adverse health effects is a lengthy process, particularly when the countermeasure/drug has not yet been evaluated in human trials. One example of a drug developed from the bench to the clinic is the soybean-derived Bowman-Birk inhibitor (BBI), which has been developed as a countermeasure for radiation induced cancer. It was originally identified as a compound/drug that could prevent the radiation induced carcinogenic process in an in vitro assay system in 1975. The first observation that BBI could inhibit carcinogenesis in animals was in 1985. BBI received Investigational New Drug (IND) Status with the U.S. Food and Drug Administration (FDA) in 1992 (after several years of negotiation with the FDA about the potential IND status of the drug), and human trials began at that time. Phase I, II and III human trials utilizing BBI have been performed under several INDs with the FDA, and an ongoing Phase III trial will be ending in the very near future. Thus, the drug has been in development for 35 years at this point, and it is still not a prescription drug on the market which is available for human use. A somewhat less time-consuming process is to evaluate compounds that are on the GRAS (Generally Recognized as Safe) list. These compounds would include some over-the-counter medications, such as antioxidant vitamins utilized in human trials at the levels for which Recommended Dietary Allowances (RDAs) have been established. To determine whether GRAS substances are able to have beneficial effects on radiation induced adverse health effects, it is still likely to be a lengthy process involving many years to potentially decades of human trial work. The human trials necessary to demonstrate "efficacy" for a beneficial effect on the long term adverse health effects of radiation, such as the development of cancer, cataracts, etc., is expected to take particularly long periods of time. To avoid the long time delay in the development of new drugs as countermeasures for radiation induced adverse health effects, the NSBRI Center for Acute Radiation Research (CARR) is currently focused on the use of drugs that have already been approved for human use by the FDA. Currently there are no approved countermeasures for external radiation exposure by the US Army or by NASA. The appropriate medications for symptoms of the Acute Radiation Syndrome (ARS) due to exposure to solar particle event (SPE) radiation are unknown, but there are medications appropriate for ARS symptoms caused by exposure to conventional ra-diation. The Armed Forces Radiobiology Research Institute (AFRRI) has medical guidelines for ARS medications (, as does the US Dept. of Health and Human Services (the REMM (Radiation Event Medical Manage-ment) site ( Supportive care when ARS symptoms develop include the administration of antimicrobial agents (which can include systemic antibiotics [especially those directed at gram-negative bacteria]), antiemetic agents, antidiarrheal agents, fluids, elec-trolytes, analgesic agents and topical burn creams (Waselenko, J.K. et al. Ann. Intern. Med. 140: 1037, 2004). For nausea and vomiting, serotonin receptor antagonists (5HT3 receptor antagonists) are very effective prophylaxis. There are two drugs that have been approved by the FDA (Zofran and Kytril) for radiation induced nausea and vomiting. Kytril (granisetron) is preferred by the US Army and is currently maintained in the US National Stockpile. Both of these drugs are known to stop retching and vomiting when given either before or after irradi-ation, even when vomiting and/or retching are occurring. Immune suppression can occur due to declines in white blood cells and infe

Kennedy, Ann


Correlation between brachial-ankle pulse wave velocity, carotid artery intima-media thickness, ankle-brachial index, and the severity of coronary lesions.  


Coronary angiography is the gold standard for the diagnosis of coronary artery disease. Coronary artery Gensini scoring systems measure both the extent and the degree of stenosis of coronary artery and therefore, give clinicians a more accurate, objective, and comprehensive assessment of the severity of coronary artery disease. Using Gensini scoring systems in combination with statistical analysis, we found that five variables, namely, Brachial-ankle pulse wave velocity (PWV), ankle-brachial index (ABI), carotid artery intima-media thickness (IMT), blood sugar, and high density lipoprotein cholesterol (HDL-C), were all significantly different among groups of patients with different Gensini scores. All five variables can be used for early screening and assessment of coronary artery disease as independent prognostic factors for the morbidity and mortality from cardiovascular conditions. With the progression of coronary artery disease, the levels of PWV, IMT, and blood glucose are gradually increasing whereas the levels of ABI and HDL-C are gradually decreasing. These changes can be treated as warning signs and can also be helpful in evaluating the severity of coronary artery diseases. It is highly recommended to perform these five non-invasive tests as early as possible in order to identify high-risk patients at their subclinical stages. This would allow timely intervention and thereby lead to reduced morbidity and mortality from cardiovascular diseases. PMID:24906234

Zuo, Guoxing; Zhang, Minghui; Jia, Xiaogang; Zheng, Liuying; Li, Ying; Zhao, Hui; Wang, Cuancuan; Liang, Chunmei; Du, Xinping



Alpha Lipoic Acid Attenuates Radiation-Induced Thyroid Injury in Rats  

PubMed Central

Exposure of the thyroid to radiation during radiotherapy of the head and neck is often unavoidable. The present study aimed to investigate the protective effect of ?-lipoic acid (ALA) on radiation-induced thyroid injury in rats. Rats were randomly assigned to four groups: healthy controls (CTL), irradiated (RT), received ALA before irradiation (ALA + RT), and received ALA only (ALA, 100 mg/kg, i.p.). ALA was treated at 24 h and 30 minutes prior to irradiation. The neck area including the thyroid gland was evenly irradiated with 2 Gy per minute (total dose of 18 Gy) using a photon 6-MV linear accelerator. Greater numbers of abnormal and unusually small follicles in the irradiated thyroid tissues were observed compared to the controls and the ALA group on days 4 and 7 after irradiation. However, all pathologies were decreased by ALA pretreatment. The quantity of small follicles in the irradiated rats was greater on day 7 than day 4 after irradiation. However, in the ALA-treated irradiated rats, the numbers of small and medium follicles were significantly decreased to a similar degree as in the control and ALA-only groups. The PAS-positive density of the colloid in RT group was decreased significantly compared with all other groups and reversed by ALA pretreatment. The high activity index in the irradiated rats was lowered by ALA treatment. TGF-ß1 immunoreactivity was enhanced in irradiated rats and was more severe on the day 7 after radiation exposure than on day 4. Expression of TGF-ß1 was reduced in the thyroid that had undergone ALA pretreatment. Levels of serum pro-inflammatory cytokines (TNF-?, IL-1ß and IL-6) did not differ significantly between the all groups. This study provides that pretreatment with ALA decreased the severity of radiation-induced thyroid injury by reducing inflammation and fibrotic infiltration and lowering the activity index. Thus, ALA could be used to ameliorate radiation-induced thyroid injury. PMID:25401725

Jung, Jung Hwa; Jung, Jaehoon; Kim, Soo Kyoung; Woo, Seung Hoon; Kang, Ki Mun; Jeong, Bae-Kwon; Jung, Myeong Hee; Kim, Jin Hyun; Hahm, Jong Ryeal



Reduction of radiation-induced cell cycle blocks by caffeine does not necessarily lead to increased cell killing  

SciTech Connect

The effect of caffeine upon the radiosensitivities of three human tumor lines was examined and correlated with its action upon the radiation-induced S-phase and G2-phase blocks. Caffeine was found to reduce at least partially the S-phase and G2-phase blocks in all the cell lines examined but potentiated cytotoxicity in only one of the three tumor lines. That reductions have been demonstrated to occur in the absence of increased cell killing provides supporting evidence for the hypothesis that reductions may not be causal in those cases when potentiation of radiation-induced cytotoxicity is observed in the presence of caffeine.

Musk, S.R. (Institute of Cancer Research, Sutton, Surrey (England))



Biceps Brachii Long Head Overactivity Associated with Elbow Flexion Contracture in Brachial Plexus Birth Palsy  

PubMed Central

Background: The etiology of elbow flexion contracture in children with brachial plexus birth palsy remains unclear. We hypothesized that the long head of the biceps brachii muscle assists with shoulder stabilization in children with brachial plexus birth palsy and that overactivity of the long head during elbow and shoulder activity is associated with an elbow flexion contracture. Methods: Twenty-one patients with brachial plexus birth palsy-associated elbow flexion contracture underwent testing with surface electromyography. Twelve patients underwent repeat testing with fine-wire electromyography. Surface electrodes were placed on the muscle belly, and fine-wire electrodes were inserted bilaterally into the long and short heads of the biceps brachii. Patients were asked to perform four upper extremity tasks: elbow flexion-extension, hand to head, high reach, and overhead ball throw. The mean duration of muscle activity in the affected limb was compared with that in the contralateral, unaffected limb, which was used as a control. Three-dimensional motion analysis, surface dynamometry, and validated function measures were used to evaluate upper extremity kinematics, elbow flexor-extensor muscle imbalance, and function. Results: The mean activity duration of the long head of the biceps brachii muscle was significantly higher in the affected limb as compared with the contralateral, unaffected limb during hand-to-head tasks (p = 0.02) and high-reach tasks (p = 0.03). No significant differences in mean activity duration were observed for the short head of the biceps brachii muscle between the affected and unaffected limbs. Isometric strength of elbow flexion was not significantly higher than that of elbow extension in the affected limb (p = 0.11). Conclusions: Overactivity of the long head of the biceps brachii muscle is associated with and may contribute to the development of elbow flexion contracture in children with brachial plexus birth palsy. Elbow flexion contracture may not be associated with an elbow flexor-extensor muscle imbalance, as previously hypothesized. The negative impact of elbow flexion contracture on upper extremity function warrants future research in the development of preventive and therapeutic techniques to address elbow flexion contractures in children with brachial plexus birth palsy. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence. PMID:22336968

Sheffler, Lindsey C.; Lattanza, Lisa; Sison-Williamson, Mitell; James, Michelle A.



Microbiota and radiation-induced bowel toxicity: lessons from inflammatory bowel disease for the radiation oncologist.  


New gastrointestinal symptoms are frequent after pelvic radiotherapy and can greatly affect the quality of life of cancer survivors. The effect of radiation on the intestinal microbiota, and the clinical implications of a modified microbial balance after radiotherapy are now beginning to emerge. In this Personal View, we show the importance of the microbiota for intestinal homoeostasis, and discuss the similarity between inflammatory bowel disease, which has been extensively researched, and radiation-induced gastrointestinal toxicity. By use of microbiota profiles for risk assessment and manipulation of the intestinal flora for prevention and treatment of radiation, enteropathy could become a reality and would be of substantial relevance to the increasing numbers of long-term cancer survivors. PMID:24599929

Ferreira, Miguel R; Muls, Ann; Dearnaley, David P; Andreyev, H Jervoise N



Radiation-Induced Decomposition of PETN and TATB under Extreme Conditions  

SciTech Connect

We conducted a series of experiments investigating decomposition of secondary explosives PETN and TATB at varying static pressures and temperatures using synchrotron radiation. As seen in our earlier work, the decomposition rate of TATB at ambient temperature slows systematically with increasing pressure up to at least 26 GPa but varies little with pressure in PETN at ambient temperature up to 15.7 GPa, yielding important information pertaining to the activation complex volume in both cases. We also investigated the radiation-induced decomposition rate as a function of temperature at ambient pressure and 26 GPa for TATB up to 403 K, observing that the decomposition rate increases with increasing temperature as expected. The activation energy for the TATB reaction at ambient temperature was experimentally determined to be 16 {+-} 3 kJ/mol.

Giefers, Hubertus; Pravica, Michael (UNLV)



Modeling of radiation-induced bystander effect using Monte Carlo methods  

NASA Astrophysics Data System (ADS)

Experiments showed that the radiation-induced bystander effect exists in cells, or tissues, or even biological organisms when irradiated with energetic ions or X-rays. In this paper, a Monte Carlo model is developed to study the mechanisms of bystander effect under the cells sparsely populated conditions. This model, based on our previous experiment which made the cells sparsely located in a round dish, focuses mainly on the spatial characteristics. The simulation results successfully reach the agreement with the experimental data. Moreover, other bystander effect experiment is also computed by this model and finally the model succeeds in predicting the results. The comparison of simulations with the experimental results indicates the feasibility of the model and the validity of some vital mechanisms assumed.

Xia, Junchao; Liu, Liteng; Xue, Jianming; Wang, Yugang; Wu, Lijun



A review on radiation-induced nucleation and growth of colloidal metallic nanoparticles  

PubMed Central

This review presents an introduction to the synthesis of metallic nanoparticles by radiation-induced method, especially gamma irradiation. This method offers some benefits over the conventional methods because it provides fully reduced and highly pure nanoparticles free from by-products or chemical reducing agents, and is capable of controlling the particle size and structure. The nucleation and growth mechanism of metallic nanoparticles are also discussed. The competition between nucleation and growth process in the formation of nanoparticles can determine the size of nanoparticles which is influenced by certain parameters such as the choice of solvents and stabilizer, the precursor to stabilizer ratio, pH during synthesis, and absorbed dose. PMID:24225302



Radiation Induced Surface Activity Phenomenon: 1. Report - Surface Wettability on Metal Oxides  

SciTech Connect

Improving the limit of boiling heat transfer or critical heat flux requires that the cooling liquid can contact the heating surface, or a high-wettability, highly hydrophilic heating surface, even if a vapor bubble layer is generated on the surface. We investigated surface wettability using metal oxides irradiated by gamma rays in room condition. Contact angle, an indicator of macroscopic wettability, was measured by image processing of the images obtained by a CCD video camera. The results showed that the surface wettability on oxide metal pieces of titanium, zircaloy No. 4, SUS-304 and copper improved significantly by Radiation Induced Surface Activity (RISA) phenomenon. Highly hydrophilic conditions on the test pieces were achieved after 500 kGy irradiation of {sup 60}Co gamma ray. (authors)

Yasuyuki Imai; Tatsuya Koga; Tomoji Takamasa [Tokyo University of Mercantile Marine, 2-1-6 Etchu-jima, Koto-Ku, Tokyo 135-8533 (Japan); Koji Okamoto [University of Tokyo (Japan); Susumu Uematsu [Advanced Maritime Transport Technology Department, National Maritime Research Institute, Mitaka, Tokyo 181-0004 (Japan)



New era of radiotherapy: an update in radiation-induced lung disease  

PubMed Central

Over the last few decades, advances in radiotherapy (RT) technology have improved delivery of radiation therapy dramatically. Advances in treatment planning with the development of image-guided radiotherapy and in techniques such as proton therapy, allows the radiation therapist to direct high doses of radiation to the tumour. These advancements result in improved local regional control while reducing potentially damaging dosage to surrounding normal tissues. It is important for radiologists to be aware of the radiological findings from these advances in order to differentiate expected radiation-induced lung injury (RILD) from recurrence, infection, and other lung diseases. In order to understand these changes and correlate them with imaging, the radiologist should have access to the radiation therapy treatment plans. PMID:23473474

Benveniste, M. F. K.; Welsh, J.; Godoy, M. C. B.; Betancourt, S. L.; Mawlawi, O. R; Munden, R. F.



Functional properties of nisin-carbohydrate conjugates formed by radiation induced Maillard reaction  

NASA Astrophysics Data System (ADS)

Nisin-carbohydrate conjugates were prepared by irradiating nisin either with glucose or dextran. Increase in browning and formation of intermediate products was observed with a concomitant decrease in free amino and reducing sugar groups indicating occurrence of the Maillard reaction catalyzed by irradiation. Nisin-carbohydrate conjugates showed a broad spectrum antibacterial activity against Gram negative bacteria (Escherichia coli, Pseudomonas fluorescence) as well as Gram positive bacteria (Staphylococcus aureus, Bacillus cereus). Results of antioxidant assays, including that of DPPH radical-scavenging activity and reducing power, showed that the nisin-dextran conjugates possessed better antioxidant potential than nisin-glucose conjugate. These results suggested that it was possible to enhance the functional properties of nisin by preparing radiation induced conjugates suitable for application in food industry.

Muppalla, Shobita R.; Sonavale, Rahul; Chawla, Surinder P.; Sharma, Arun



On the mechanism of radiation-induced polymerization of vinyl monomers in ionic liquid  

NASA Astrophysics Data System (ADS)

An attempt was made to investigate the mechanism controlling the radiation-induced polymerization of vinyl monomers in room temperature ionic liquids. For that purpose, copolymerization of styrene (St) and methyl methacrylate (MMA) was initiated by 60Co gamma radiation in a moisture-stable ionic liquid, [choline chloride][ZnCl 2], and its mixture with THF (4:1 v/v). By analyzing the product composition with FTIR for a series of poly(St-co-MMA) samples, it was found that the mole fraction of St in the copolymer is linearly proportional to the mole fraction of St in the feed. Therefore, radiation polymerization in ionic liquid and its mixture with organic solvent is suggested to be a radical propagating process.

Liu, Yaodong; Wu, Guozhong



Molecular targets in radiation-induced blood-brain barrier disruption  

SciTech Connect

Disruption of the blood-brain barrier (BBB) is a key feature of radiation injury to the central nervous system. Studies suggest that endothelial cell apoptosis, gene expression changes, and alteration of the microenvironment are important in initiation and progression of injury. Although substantial effort has been directed at understanding the impact of radiation on endothelial cells and oligodendrocytes, growing evidence suggests that other cell types, including astrocytes, are important in responses that include induced gene expression and microenvironmental changes. Endothelial apoptosis is important in early BBB disruption. Hypoxia and oxidative stress in the later period that precedes tissue damage might lead to astrocytic responses that impact cell survival and cell interactions. Cell death, gene expression changes, and a toxic microenvironment can be viewed as interacting elements in a model of radiation-induced disruption of the BBB. These processes implicate particular genes and proteins as targets in potential strategies for neuroprotection.

Nordal, Robert A. [Departments of Radiation Oncology and Medical Biophysics, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Wong, C. Shun [Departments of Radiation Oncology and Medical Biophysics, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada)]. E-mail:



Radiation-induced effects on some common storage edible seeds in India infested with surface microflora  

NASA Astrophysics Data System (ADS)

The present work describes radiation-induced effects on surface microorganisms on some stored seeds widely used in India. Co-60 gamma source at 25°C emitting gamma ray at 1173 and 1332 keV energy was used for irradiating the rice ( Oryza sativa. Cv-2233 and Oryza sativa. Cv-Shankar) and pulse ( Cicer arietinum. Cv-local) having >10% moisture content. Dose of gamma irradiation up to 6 kGy (0.12 kGy/h) was applied for exposing the seeds. Significant depletion of the fungal population on seeds was noted with irradiation at 1-2 kGy, while complete inhibition of the contaminating fungi was observed above 4 kGy. Though the germinating potential of the treated grains did not alter significantly, loss in membrane permeability of the exposed seeds was significant.

Maity, J. P.; Chakraborty, A.; Saha, A.; Santra, S. C.; Chanda, S.



Flow cytometric determination of radiation-induced chromosome damage and its correlation with cell survival  

SciTech Connect

Chinese hamster M3-1 cells were irradiated with several doses of x rays or ..cap alpha.. particles from /sup 238/Pu. Propidium iodide-stained chromosome suspensions were prepared at different times after irradiation; cells were also assayed for survival. The DNA histograms of these chromosomes showed increased background counts with increased doses of radiation. This increase in background was cell-cycle dependent and was correlated with cell survival. The correlation between radiation-induced chromosome damage and cell survival was the same for X rays and ..cap alpha.. particles. Data are presented which indicate that flow cytometric analysis of chromosomes of irradiated cell populations can be a useful adjunct to classical cytogenic analysis of irradiation-induced chromosomal damage by virtue of its ability to express and measure chromosomal damage not seen by classical cytogenic methods.

Welleweerd, J.; Wilder, M.E.; Carpenter, S.G.; Raju, M.R.



Radiation-induced graft polymerization of N-vinylpyrrolidone onto segmented polyurethane based on isophorone diisocyanate  

NASA Astrophysics Data System (ADS)

A segmented polyurethane (PUR) sample based on isophorone diisocyante was modified by radiation induced-graft polymerization of N-vinylpyrrolidone. Radiation grafting was carried out by the mutual irradiation method to improve hydrophilicity of the matrix surface. Different parameters affecting the grafting yield, such as effect of dose, monomer and mineral salt concentration, were investigated. It was found that degree of grafting increased with increasing total dose and monomer concentration in the presence of small amount of homopolymer suppressor. Physicochemical properties of the control and grafted PUR were studied using infrared spectroscopy (ATR-FTIR), thermogravimetric analysis, atomic force microscopy and X-ray photoelectron spectroscopy. The wettability was evaluated by contact angle measurements.

Walo, Marta; Przybytniak, Gra?yna; Kavakl?, P?nar Akkas; Güven, Olgun



A Human Espophageal Epithelial Cell Model for Study of Radiation Induced Cancer and DNA Damage Repair  

NASA Technical Reports Server (NTRS)

For cancer risk assessment in astronauts and for countermeasure development, it is essential to understand the molecular mechanisms of radiation carcinogenesis and how these mechanisms are influenced by exposure to the types of radiation found in space. We are developing an in vitro model system for the study of radiation-induced initiation and progression of esophageal carcinoma, a type of cancer found to have a significant enhancement in incidence in the survivors of the atomic bomb detonations in Japan. Here we present the results of our preliminary characterization of both normal and hTERT immortalized esophageal epithelial cells grown in 2-dimensional culture. We analyzed DNA repair capacity by measuring the kinetics of formation and loss of - H2AX foci following radiation exposure. Additionally, we analyzed induction of chromosomal aberrations using 3-color fluorescence in situ hybridization (FISH). Data were generated using both low LET (gamma rays) and high LET ions (1000 MeV/nucleon iron).

Huff, Janice L.; Patel, Zarana S.; Hada, Megumi; Cucinotta, Francis A.



Radiation-induced conductivity in alumina from 100 Hz to 10 MHz during proton irradiation  

NASA Astrophysics Data System (ADS)

Changes in the dielectric constant and loss tangent of alumina have been measured in situ during proton irradiation. In these experiments, single crystal sapphire specimens were irradiated with 3 MeV protons which passed through the sample and were stopped in a copper-block heat sink. Dielectric properties were measured between 100 Hz and 10 MHz using a guard-ring capacitor configuration. The proton irradiation caused an immediate increase in loss tangent from about 10 -4 to more than 1.0. We have evaluated these changes at 300 and 373 K, vs irradiation time, flux and frequency. While the in situ radiation-induced conductivity (RIC) depends on these variables as well as on the history of previous irradiation, we believe that it is caused by a balance between the generation rate of electrons and holes, and their trapping and annihilation at displacement-type defects.

Farnum, E. H.; Kennedy, J. C.; Clinard, F. W.; Frost, H. M.



A mitochondria-targeted inhibitor of cytochrome c peroxidase mitigates radiation induced death  

PubMed Central

The risk of radionuclide release in terrorist acts or exposure of healthy tissue during radiotherapy demand potent radioprotectants/radiomitigators. Ionizing radiation induces cell death by initiating the selective peroxidation of cardiolipin in mitochondria by the peroxidase activity of its complex with cytochrome c leading to release of hemoprotein into the cytosol and commitment to the apoptotic program. Here we design and synthesize mitochondria-targeted triphenylphosphonium-conjugated imidazole-substituted oleic and stearic acids which blocked peroxidase activity of cytochrome c/cardiolipin complex by specifically binding to its heme-iron. We show that both compounds inhibit pro-apoptotic oxidative events, suppress cyt c release, prevent cell death, and protect mice against lethal doses of irradiation. Significant radioprotective/radiomitigative effects of imidazole-substituted oleic acid are observed after pretreatment of mice from 1 hr before through 24 hrs after the irradiation. PMID:21988913

Atkinson, Jeffrey; Kapralov, Alexandr A.; Yanamala, Naveena; Tyurina, Yulia Y.; Amoscato, Andrew A.; Pearce, Linda; Peterson, Jim; Huang, Zhentai; Jiang, Jianfei; Samhan-Arias, Alejandro K.; Maeda, Akihiro; Feng, Weihong; Wasserloos, Karla; Belikova, Natalia A.; Tyurin, Vladimir A.; Wang, Hong; Fletcher, Jackie; Wang, Yongsheng; Vlasova, Irina I.; Klein-Seetharaman, Judith; Stoyanovsky, Detcho A.; Bayir, Hulya; Pitt, Bruce R.; Epperly, Michael W.; Greenberger, Joel S.; Kagan, Valerian E.



Graft polymerization using radiation-induced peroxides and application to textile dyeing  

NASA Astrophysics Data System (ADS)

To improve the dyeing affinity of ultra high molecular weight polyethylene (UHMWPE) fiber, surface treatment by radiation-induced graft polymerization was performed. Methyl methacrylate (MMA), acrylic acid (AA) and styrene (St) were used as the monomers. The grafting yields as a function of storage time after irradiation were examined. Although the grafting yield of St after the sulfonation processing was quite low compared with those of MMA and AA, it was successfully dyed to a dark color with a cationic dye. Some acid dyes can dye the grafted fiber with AA. The acid dye is distributed to the amorphous domains of the AA grafted fiber. The dyeing concentration depended on the grafting yield, and the higher the grafting yield the darker the dye color.

Enomoto, Ichiro; Katsumura, Yosuke; Kudo, Hisaaki; Soeda, Shin



The correlation between swelling and radiation-induced segregation in iron-chromium-nickel alloys.  

SciTech Connect

The magnitudes of both void swelling and radiation-induced segregation (RIS) in iron-chromium-nickel alloys are dependent on bulk alloy composition. Because the diffusivity of nickel via the vacancy flux is slow relative to chromium, nickel enriches and chromium depletes at void surfaces during irradiation. This local composition change reduces the subsequent vacancy flux to the void, thereby reducing void swelling. In this work, the resistance to swelling from major element segregation is estimated using diffusivities derived from grain boundary segregation measurements in irradiated iron-chromium-nickel alloys. The resistance to void swelling in iron- and nickel-base alloys correlates with the segregation and both are functions of bulk alloy composition. Alloys that display the greatest amount of nickel enrichment and chromium depletion are found to be most resistant to void swelling, as predicted. Additionally, swelling is shown to be greater in alloys in which the RIS profiles are slow to develop.

Allen, T. R.; Busby, J. T.; Kenik, E. A.; Was, G. S.



Molecular mechanisms of radiation-induced genomic instability in human cells  

SciTech Connect

The overall strategy was to create a series of isogenic human cell lines that differ in key elements of cell cycle checkpoint, apoptosis, or DNA repair in response to radiation-induced damage. The goal then was to quantify the fractions of cells within a population that exhibit reduced telomere lengths and relate this to the genetic background of the cell, as well as to the response to ionizing radiation. Association between telomere length and degree of genomic instability in the population is being examined for seven closely related cell lines, that vary in p53 status, bcl-2 status, or ability to repair double strand breaks. Experiments utilize gamma rays at doses of 0, 10, and 200 cGy. During this time period the effort concentrated on generating data with two cell lines. Approximately one-third of the required clones were isolated, and analyses for mutagenesis and chromosome aberrations were undertaken.

Liber, Howard L.



Baicalein protects mice against radiation-induced DNA damages and genotoxicity.  


Baicalein is the major flavonoid extracted from the root of Scutellaria baicaleins. This flavonoid is used extensively in Chinese herbal medicine. In the present study baicalein is evaluated for its radioprotective properties. Human blood cells when exposed to the ?-radiation ex vivo in presence of baicalein underwent the reduced DNA damage compared to the control. Baicalein administration prior to the whole-body ?-radiation (4 Gy) exposure of mice resulted in protecting the damage to the DNA as measured in their blood cells by alkaline comet assay. Mice when exposed to the radiation (whole body; 1.7 Gy) resulted in damage to the bone marrow as measured by micronucleated reticulocyte (MNRET) formation. Baicalein pre-treatment reduces the radiation induced damage to the bone marrow cells, as there was decrease in the percentage MNRET formation. These findings indicate radio-protecting ability of baicalein. PMID:23606056

Gandhi, Nitin Motilal



New era of radiotherapy: an update in radiation-induced lung disease.  


Over the last few decades, advances in radiotherapy (RT) technology have improved delivery of radiation therapy dramatically. Advances in treatment planning with the development of image-guided radiotherapy and in techniques such as proton therapy, allows the radiation therapist to direct high doses of radiation to the tumour. These advancements result in improved local regional control while reducing potentially damaging dosage to surrounding normal tissues. It is important for radiologists to be aware of the radiological findings from these advances in order to differentiate expected radiation-induced lung injury (RILD) from recurrence, infection, and other lung diseases. In order to understand these changes and correlate them with imaging, the radiologist should have access to the radiation therapy treatment plans. PMID:23473474

Benveniste, M F K; Welsh, J; Godoy, M C B; Betancourt, S L; Mawlawi, O R; Munden, R F



X-ray microdiffraction analysis of radiation-induced defects in single grains of polycrystalline Fe  

SciTech Connect

Single-crystal diffuse X-ray scattering was analyzed to characterize radiation-induced defects in individual grains of a polycrystalline proton-irradiated Fe foil. The grains were probed with an intense submicron x-ray beam to demonstrated that both polycrystalline and micrometer-scale samples can be studied with single-crystal-like signal-to-noise. Scattering was measured with an x-ray sensitive area detector, which measures intensity over a surface in reciprocal space. By scanning the x-ray energy, intensity was measured over reciprocal-space volumes. Since the sample is not rotated, the real-space scattering volume does not change. We discuss methods to minimize experimental artifacts arising from the use of an area detector.

Specht, Eliot D [ORNL; Walker, Frederick J. [Yale University; Liu, W. [Argonne National Laboratory (ANL)



ESR study on radiation-induced radicals in carboxymethyl cellulose aqueous solution  

NASA Astrophysics Data System (ADS)

Carboxymethyl cellulose (CMC) at highly concentrated aqueous solution undergoes radiation crosslinking reaction by ionizing irradiation. It is assumed that this radiation-induced reaction takes place by the indirect effect of water radiolysis, especially through the OH radical. However, the reaction mechanism is not well known. In this topic, ESR spectra of CMC radicals formed by reaction with OH radicals were measured directly in aqueous solution to identify the initially formed radical site. The ESR spectra were observed successfully and were interpreted as the overlapping of two spectra; a Triplet×Doublet spectrum and a Doublet spectrum. Each spectrum was assigned to radicals located on carboxymethyl groups linked to C6 and C2/C3.

Saiki, Seiichi; Nagasawa, Naotsugu; Hiroki, Akihiro; Morishita, Norio; Tamada, Masao; Kudo, Hisaaki; Katsumura, Yosuke



Radiation-induced defects in Pr3+-activated LiYF4 laser host  

NASA Astrophysics Data System (ADS)

Rare earth doped fluorides have been used in laser applications. Not much is known about the effect of ionizing radiation on the lasing and other properties of fluorides. Therefore, in recent years much attention has been paid to the study of radiation-induced defects in laser materials, as they affect the optical and stimulated emission properties. The defect formation by gamma-ray irradiation in Pr3+ activated LiYF4, powder prepared by melt method, have been studied by thermoluminescence and electron spin resonance techniques and are reported in this paper. It is shown that LiYF4:Pr3+ is sensitive to gamma-ray radiation. Characterization of this laser material using ESR and photoluminescence techniques is also described.

Dhoble, S. J.; Deshpande, S. P.; Pode, R. B.; Dhoble, N. S.; Gundurao, T. K.



Modeling and optimization aspects of radiation induced grafting of 4-vinylpyridene onto partially fluorinated films  

NASA Astrophysics Data System (ADS)

Modeling and optimization aspects of radiation induced grafting (RIG) of 4-vinylpyridine (4-VP) onto partially fluorinated polymers such as poly(ethylene-co-tetrafluoroethene) (ETFE) and poly(vinylidene fluoride) (PVDF) films were comparatively investigated using response surface method (RSM). The effects of independent parameters: absorbed dose, monomer concentration, grafting time and reaction temperature on the response, grafting yield (GY) were correlated through two quadratic models. The results of this work confirm that RSM is a reliable tool not only for optimization of the reaction parameters and prediction of GY in RIG processes, but also for the reduction of the number of the experiments, monomer consumption and absorbed dose leading to an improvement of the overall reaction cost.

Nasef, Mohamed Mahmoud; Ahmad Ali, Amgad; Saidi, Hamdani; Ahmad, Arshad



Radiation-Induced Carotid Artery Stenosis: A Comprehensive Review of the Literature  

PubMed Central

In recent decades, with the improvement of radiotherapy (RT) technology and comprehensive treatment, the survival rate of head and neck malignancies has gained remarkable progress. Vascular injury and subsequent carotid stenosis following RT, as the backbone of treatment, have received increasing attention. Many investigations have demonstrated that radiation can result in the increase in carotid intima-media thickness, carotid stenosis and consequently lead to a higher risk of cerebrovascular events such as transient ischemic attack and stroke. In this review, we will examine the incidence of radiation-induced carotid artery stenosis, its morphological and histological characteristics, as well as its pathogenesis. The treatment and prevention methods, including follow-up strategies, will also be discussed at the end of the present review. PMID:25337087

Xu, Jiaping; Cao, Yongjun



A computational approach to the relationship between radiation induced double strand breaks and translocations  

NASA Technical Reports Server (NTRS)

A theoretical framework is presented which provides a quantitative analysis of radiation induced translocations between the ab1 oncogene on CH9q34 and a breakpoint cluster region, bcr, on CH 22q11. Such translocations are associated frequently with chronic myelogenous leukemia. The theory is based on the assumption that incorrect or unfaithful rejoining of initial double strand breaks produced concurrently within the 200 kbp intron region upstream of the second abl exon, and the 16.5 kbp region between bcr exon 2 and exon 6 interact with each other, resulting in a fusion gene. for an x-ray dose of 100 Gy, there is good agreement between the theoretical estimate and the one available experimental result. The theory has been extended to provide dose response curves for these types of translocations. These curves are quadratic at low doses and become linear at high doses.

Holley, W. R.; Chatterjee, A.



In situ studies of radiation induced crystallization in Fe/a-Y2O3 nanolayers  

NASA Astrophysics Data System (ADS)

Oxide dispersion strengthened ferritic alloys have superior radiation tolerance and thus become appealing candidates as fuel cladding materials for next generation nuclear reactors. In this study we constructed a model system, Fe/Y2O3 nanolayers with individual layer thicknesses of 10 and 50 nm, in order to understand their radiation response and corresponding damage mitigation mechanisms. These nanolayers were subjected to in situ Kr ion irradiation at room temperature up to ?8 displacements-per-atom. As-deposited Y2O3 layers had primarily amorphous structure. Radiation induced prominent nanocrystallization and grain growth in 50 nm thick Y2O3 layers. Conversely, little crystallization occurred in 10 nm thick Y2O3 layers implying size dependent enhancement of radiation tolerance. In situ video also captured grain growth in both Fe and Y2O3 and outstanding morphological stability of layer interfaces against Kr ion irradiation.

Chen, Y.; Jiao, L.; Sun, C.; Song, M.; Yu, K. Y.; Liu, Y.; Kirk, M.; Li, M.; Wang, H.; Zhang, X.



Mitigation of radiation-induced lung injury by Genistein and EUK-207  

PubMed Central

Purpose We examined the effects of genistein and/or Eukarion (EUK)-207 on radiation-induced lung damage and investigated whether treatment for 0–14 weeks (wks) post-irradiation (PI) would mitigate late lung injury. Materials and Methods The lungs of female Sprague-Dawley (SD) rats were irradiated with 10 Gy. EUK-207 was delivered by infusion and genistein was delivered as a dietary supplement starting immediately after irradiation (PI) and continuing until 14 wks PI. Rats were sacrificed at 0, 4, 8, 14 and 28 wks PI. Breathing rate was monitored and lung fibrosis assessed by lung hydroxyproline content at 28 wks. DNA damage was assessed by micronucleus (MN) assay and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels. The expression of the cytokines Interleukin (IL)-1?, IL-1?, IL-6, Tumor necrotic factor (TNF)-? and Transforming growth factor (TGF)-?1, and macrophage activation were analysed by immunohistochemistry. Results Increases in breathing rate observed in the irradiated rats were significantly reduced by both drug treatments during the pneumonitis phase and the later fibrosis phase. The drug treatments decreased micronuclei (MN) formation from 4–14 wks but by 28 wks the MN levels had increased again. The 8-OHdG levels were lower in the drug treated animals at all time points. Hydroxyproline content and levels of activated macrophages were decreased at 28 wks in all drug treated rats. The treatments had limited effects on the expression of the cytokines. Conclusion Genistein, and EUK-207 can provide partial mitigation of radiation-induced lung damage out to at least 28 wks PI even after cessation of treatment at 14 wks PI. PMID:21675818

Mahmood, J; Jelveh, S; Calveley, V; Zaidi, A; Doctrow, SR; Hill, RP



Radiation-induced blood-brain barrier damages: an in vitro study.  


A radiation-induced blood-brain barrier (BBB) breakdown has been supposed to explain the acute radiation syndrome and the delayed brain radiation injury, but it has been clearly demonstrated only at high doses. In a previous study (Diserbo et al., 2002), we showed that non-lethal total body irradiation produced an early transient increase in BBB permeability in rats but the underlying mechanisms of radiation-induced BBB breakdown remain unclear. In the present work, the effects of ionizing radiation were studied on an in vitro BBB model. Gamma irradiation induced an increase in [(14)C]-sucrose BBB permeability that can be detected 72 h after exposure at doses up to 4 Gy. This increase was more important 8 days after irradiation and could be limited by dexamethasone treatment. An increase in fluorescein and FITC-dextrans (4 kDa/70 kDa) permeability was also observed, which can be related to a substantial opening of endothelial cell tight-junctions but without massive modification of tight-junction protein (ZO-1, ZO-2, claudin-5, occludin) immunolabeling even 8 days after 25 Gy exposure. Formation of actin stress fibers occurred in endothelial cells 8 days after 25 Gy exposure. A progressive decrease in cellular density associated with a simultaneous spreading of the endothelial cells was also observed after irradiation. Anti-?H2AX immunolabeling was used to investigate both DNA double-strand break induction and repair rates in endothelial cells. It revealed long-lasting DNA double-strand breaks after gamma irradiation. A better understanding and awareness of these phenomena are essential for designing appropriate pharmacotherapy in radiation-therapy and treatment of accidental overexposure. PMID:22153623

Fauquette, William; Amourette, Christine; Dehouck, Marie-Pierre; Diserbo, Michel



Role of Radiation-induced TGF-beta Signaling in Cancer Therapy  

PubMed Central

TGF-? signaling regulates several different biological processes involving cell-growth, differentiation, apoptosis, motility, angiogenesis, epithelial mesenchymal transition and extracellular matrix production that affects embryonic development and pathogenesis of various diseases, including cancer, its effects depending on the cellular context and physiological environment. Growth suppression mediated by TGF-? signaling often associated with inhibition of c-myc, cdks and induction of p15, p27, Bax and p21. Despite its growth inhibitory effect, in certain conditions TGF-? may act as a promoter of cell proliferation and invasion. Loss of responsiveness to growth suppression by TGF-? due to mutation or loss of TGF-beta type II receptor (T?RII) and Smad4 in several different cancer cells are reported. In addition, TGF-? binding to its receptor activates many non-canonical signaling pathways. Radiation induced TGF-? is primarily involved in normal tissue injury and fibrosis. Seminal studies from our group have used radio-adjuvant therapies, involving classical components of the pathway such as T?RII and SMAD4 to overcome the growth promoting effects of TGF-?. The main impediment in the radiation-induced TGF-? signaling is the induction of SMAD7 that blocks TGF-? signaling in a negative feedback manner. It is well demonstrated from our studies that the use of neutralizing antibodies against TGF- ? can render a robust radio-resistant effect. Thus, understanding the functional interactions of TGF-? signaling components of the pathway with other molecules may help tailor appropriate adjuvant radio-therapeutic strategies for treatment of solid tumors. PMID:20336170

Dancea, Horatiu C.; Shareef, Mohammed M.; Ahmed, Mansoor M.



Quantitative Ultrasonic Evaluation of Radiation-Induced Late Tissue Toxicity: Pilot Study of Breast Cancer Radiotherapy  

SciTech Connect

Purpose: To investigate the use of advanced ultrasonic imaging to quantitatively evaluate normal-tissue toxicity in breast-cancer radiation treatment. Methods and Materials: Eighteen breast cancer patients who received radiation treatment were enrolled in an institutional review board-approved clinical study. Radiotherapy involved a radiation dose of 50.0 to 50.4 Gy delivered to the entire breast, followed by an electron boost of 10.0 to 16.0 Gy delivered to the tumor bed. Patients underwent scanning with ultrasound during follow-up, which ranged from 6 to 94 months (median, 22 months) postradiotherapy. Conventional ultrasound images and radio-frequency (RF) echo signals were acquired from treated and untreated breasts. Three ultrasound parameters, namely, skin thickness, Pearson coefficient, and spectral midband fit, were computed from RF signals to measure radiation-induced changes in dermis, hypodermis, and subcutaneous tissue, respectively. Ultrasound parameter values of the treated breast were compared with those of the untreated breast. Ultrasound findings were compared with clinical assessment using Radiation Therapy Oncology Group (RTOG) late-toxicity scores. Results: Significant changes were observed in ultrasonic parameter values of the treated vs. untreated breasts. Average skin thickness increased by 27.3%, from 2.05 {+-} 0.22mm to 2.61 {+-} 0.52mm; Pearson coefficient decreased by 31.7%, from 0.41 {+-} 0.07 to 0.28 {+-} 0.05; and midband fit increased by 94.6%, from -0.92 {+-} 7.35 dB to 0.87 {+-} 6.70 dB. Ultrasound evaluations were consistent with RTOG scores. Conclusions: Quantitative ultrasound provides a noninvasive, objective means of assessing radiation-induced changes to the skin and subcutaneous tissue. This imaging tool will become increasingly valuable as we continue to improve radiation therapy technique.

Liu Tian, E-mail: tliu34@emory.ed [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA (United States); Zhou Jun [Department of Radiation Oncology, Columbia University Medical Center, New York, NY (United States); Yoshida, Emi J. [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA (United States); Woodhouse, Shermian A. [Department of Radiation Oncology, Columbia University Medical Center, New York, NY (United States); Schiff, Peter B. [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA (United States); Wang, Tony J.C. [Department of Radiation Oncology, Columbia University Medical Center, New York, NY (United States); Lu Zhengfeng; Pile-Spellman, Eliza [Department of Radiology, Columbia University Medical Center, New York, NY (United States); Zhang Pengpeng [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Kutcher, Gerald J. [Department of History, Binghamton University, Binghamton, NY (United States)



The Role of Platelet Factor 4 in Radiation-Induced Thrombocytopenia  

SciTech Connect

Purpose: Factors affecting the severity of radiation-induced thrombocytopenia (RIT) are not well described. We address whether platelet factor 4 (PF4; a negative paracrine for megakaryopoiesis) affects platelet recovery postradiation. Methods and Materials: Using conditioned media from irradiated bone marrow (BM) cells from transgenic mice overexpressing human (h) PF4 (hPF4+), megakaryocyte colony formation was assessed in the presence of this conditioned media and PF4 blocking agents. In a model of radiation-induced thrombocytopenia, irradiated mice with varying PF4 expression levels were treated with anti-hPF4 and/or thrombopoietin (TPO), and platelet count recovery and survival were examined. Results: Conditioned media from irradiated BM from hPF4+ mice inhibited megakaryocyte colony formation, suggesting that PF4 is a negative paracrine released in RIT. Blocking with an anti-hPF4 antibody restored colony formation of BM grown in the presence of hPF4+ irradiated media, as did antibodies that block the megakaryocyte receptor for PF4, low-density lipoprotein receptor-related protein 1 (LRP1). Irradiated PF4 knockout mice had higher nadir platelet counts than irradiated hPF4+/knockout litter mates (651 vs. 328 x 106/mcL, p = 0.02) and recovered earlier (15 days vs. 22 days, respectively, p <0.02). When irradiated hPF4+ mice were treated with anti-hPF4 antibody and/or TPO, they showed less severe thrombocytopenia than untreated mice, with improved survival and time to platelet recovery, but no additive effect was seen. Conclusions: Our studies show that in RIT, damaged megakaryocytes release PF4 locally, inhibiting platelet recovery. Blocking PF4 enhances recovery while released PF4 from megakaryocytes limits TPO efficacy, potentially because of increased release of PF4 stimulated by TPO. The clinical value of blocking this negative paracrine pathway post-RIT remains to be determined.

Lambert, Michele P., E-mail: [Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA (United States); Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA (United States); Xiao Liqing; Nguyen, Yvonne [Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA (United States); Kowalska, M. Anna [Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA (United States); Center for Medical Biology, Polish Academy of Science, Lodz (Poland); Poncz, Mortimer [Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA (United States); Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA (United States)



Inhibition of radiation induced dissolution of UO2 by sulfide - A comparison with the hydrogen effect  

NASA Astrophysics Data System (ADS)

In this work we have studied the influence of H2S on radiation induced dissolution of spent nuclear fuel using simple model systems. The reaction between H2O2 and H2S/HS- has been studied experimentally as well as the effect of H2S/HS- on ?-radiation induced dissolution of a UO2 pellet. The experiments clearly show that the reaction of H2O2 and H2S/HS- is fairly rapid and that H2O2 and H2S/HS- stoichiometry is favorable for inhibition. Radiolysis experiments show that H2S/HS- can effectively protect UO2 from oxidative dissolution. The effect depends on sulfide concentration in combination with dose rate. Autoclave experiments were also conducted to study the role of H2S/HS- in the reduction of U(VI) in the presence and absence of H2 and Pd particles in anoxic aqueous solution. The aqueous solutions were pressurized with H2 or N2 and two different concentrations of H2S/HS- were used in the presence and absence of Pd. No catalytic effect of Pd on the U(VI) reduction by H2S/HS- could be found in N2 atmosphere. U(VI) reduction was found to be proportional to H2S/HS- concentration in H2 and N2 atmosphere. It is clearly shown the Pd catalyzed H2 effect is more powerful than the effect of H2S/HS-. H2S/HS- poisoning of the Pd catalyst is not observed under the present conditions.

Yang, Miao; Barreiro Fidalgo, Alexandre; Sundin, Sara; Jonsson, Mats



Radiation-induced defects in quartz. IV. Thermal properties and implications  

NASA Astrophysics Data System (ADS)

The thermal stabilities and decay kinetics of three peroxy radicals (Centers #1, B and B') and three other radiation-induced defects (#3, C' and E1') in natural quartz from the high-grade McArthur River uranium deposit (Athabasca basin, Canada) have been investigated by isochronal and isothermal annealing experiments and electron paramagnetic resonance (EPR) spectroscopy. Single-crystal EPR spectra of isochronally (2 h) annealed quartz show that these centers all grow in intensity to 280°C and then decay with further increase in temperature, but their disappearance temperatures differ markedly and depend on the initial concentrations (e.g., Center #1 in a dark smoky quartz is annealed out at 380°C, B and B' at 420°C and #3 and C' at 580°C). The isothermal decay processes of these centers are all of the second order type. The calculated activation energies for the peroxy radicals [#1 and B + B' at 0.36 (9) and 0.83 (8) eV, respectively] are smaller than those of Centers #3, C' and E1' [1.09 (8), 1.24 (8) and 1.45 (7) eV, respectively]. Gamma-ray irradiations of thermally bleached quartz restore a fraction of the peroxy radicals, suggesting that their diamagnetic precursors are stable up to at least 800°C. The unusual decay characteristics of “peroxy radicals” in quartz reported in the literature are shown to most likely arise from multiple radiation-induced defects. These results have implications for not only applications of peroxy radicals in quartz for EPR dating but also better understanding of thermoluminescence and cathodoluminescence spectra of this mineral.

Pan, Yuanming; Hu, Baoqun



Persistence of Space Radiation Induced Cytogenetic Damage in the Blood Lymphocytes of Astronauts  

NASA Technical Reports Server (NTRS)

Cytogenetic damage in astronaut's peripheral blood lymphocytes is a useful in vivo marker of space radiation induced damage. Moreover, if radiation induced chromosome translocations persist in peripheral blood lymphocytes for many years, as has been assumed, they could potentially be used to measure retrospective doses or prolonged low dose rate exposures. However, as more data becomes available, evidence suggests that the yield of translocations may decline with time after exposure, at least in the case of space radiation exposures. We present our latest follow-up measurements of chromosome aberrations in astronauts blood lymphocytes assessed by FISH painting and collected a various times beginning directly after return from space to several years after flight. For most individuals the analysis of individual time-courses for translocations revealed a temporal decline of yields with different half-lives. Since the level of stable aberrations depends on the interplay between natural loss of circulating T-lymphocytes and replenishment from the stem or progenitor cells, the differences in the rates of decay could be explained by inter-individual variation in lymphocyte turn over. Biodosimetry estimates derived from cytogenetic analysis of samples collected a few days after return to earth lie within the range expected from physical dosimetry. However, a temporal decline in yields may indicate complications with the use of stable aberrations for retrospective dose reconstruction, and the differences in the decay time may reflect individual variability in risk from space radiation exposure. In addition, limited data on multiple flights show a lack of correlation between time in space and translocation yields. Data from one crewmember who has participated in two separate long-duration space missions and has been followed up for over 10 years provides limited information on the effect of repeat flights and show a possible adaptive response to space radiation exposure.

George, Kerry; Cucinotta, Francis A.



Mitigation and Treatment of Radiation-Induced Thoracic Injury With a Cyclooxygenase-2 Inhibitor, Celecoxib  

SciTech Connect

Purpose: To test whether a cyclooxygenase-2 inhibitor (celecoxib) could reduce mortality resulting from radiation-induced pneumonitis. Methods and Materials: Celecoxib was given to mice twice daily for 40 consecutive days starting on the day of local thoracic irradiation (LTI) or 40 or 80 days later. C3Hf/KamLaw mice were observed for morbidity, and time to death was determined. Results were analyzed using the Cox proportional hazards model. Results: Timing of celecoxib relative to LTI determined efficacy. A significant reduction in time to death was achieved only when celecoxib was started 80 days after LTI, corresponding to the time when pneumonitis is expressed. For these mice the reduction in mortality was quantified as a hazard ratio for mortality of treated vs untreated of 0.36 (95% confidence interval [CI] 0.24-0.53), thus significantly less than 1.0. Correspondingly, the median lethal dose for treated mice (12.9 Gy; 95% CI 12.55-13.25 Gy) was significantly (P=.026) higher than for untreated mice (12.4 Gy; 95% CI 12.2-12.65 Gy). Conclusions: Celecoxib significantly reduced lung toxicity when administered months after LTI when the deleterious effects of radiation were expressed. The schedule-dependent reduction in fatal pneumonitis suggests that celecoxib could be clinically useful by reintroduction of treatment months after completion of radiation therapy. These findings may be important for designing clinical trials using cyclooxygenase-2 inhibitors to treat radiation-induced lung toxicity as a complement to concurrent radiation therapy of lung cancers.

Hunter, Nancy R.; Valdecanas, David [Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Liao Zhongxing [Division of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Division of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Milas, Luka [Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Thames, Howard D. [Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Mason, Kathy A., E-mail: [Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)



The radiation-induced fibroatrophic process: therapeutic perspective via the antioxidant pathway.  


The radiation-induced fibroatrophic process (RIF) constitutes a late, local and unavoidable sequela to high-dose radiotherapy, traditionally considered irreversible. Today, this process is partly reversible, thanks to recent progress in understanding the physiopathology of the lesions it causes and the results of recent clinical trials using antioxidant therapy. This review includes a synthetic description of the static and dynamic features of the RIF process, as reflected by its clinical, instrumental and histopathological characteristics, and by its cellular and molecular regulation. Schematically, three successive clinical and histopathological phases can be distinguished: a pre-fibrotic aspecific inflammatory phase, a constitutive fibrotic cellular phase, and a matrix densification and remodelling phase, possibly ending in terminal tissular necrosis. The respective roles of the chief actors in the RIF process are defined, as well as their development with time. A fibroblastic stromal hypothesis is suggested revolving around a 'gravitational effect' exerted by the couple ROS (reactive oxygen species)--fibroblasts, and partly mediated by TGF-beta1. A variety of strategies have been tested for the management of RIF. In the light of the mechanisms described, a curative procedure has been proposed via the antioxidant pathway. In particular, it was showed that superoxide dismutase and combined pentoxifylline-tocopherol treatment enables the process of established radiation-induced fibroatrophy to be greatly reduced or even reversed, both in clinical practice and animal experiments. The efficacy of combined pentoxifylline-tocopherol treatment in superficial RIF was confirmed in a randomised clinical trial, and then in successful phase II trials especially in uterine fibroatrophy and osteoradionecrosis. It is of critical importance to evaluate these new management approaches in larger clinical trials and to improve the recording of results for better outcome analysis. Mechanistic studies are always necessary to improve understanding of the RIF process and the antifibrotic drug action. PMID:15542158

Delanian, Sylvie; Lefaix, Jean-Louis



Radiation-induced reactions of CO?H 2 gas mixtures over various solid catalysts  

NASA Astrophysics Data System (ADS)

Studies have been carried out of radiation-induced reactions of CO?H 2 gas mixtures in the presence of various solid catalysts in order to find possibilities of synthesizing organic raw materials from CO?H 2 by radiation for the future. The solid catalysts studied include Fischer-Tropsch catalyst (Fe?Cu supported by diatomaceous earth), titania(TiO 2), and silica gel. Analysis of the reaction products over Fischer-Tropsch catalyst or semiconductors such as TiO 2 and ZnO?Cr 2O 3 reveals that these solid catalysts do not sensitize the radiation chemical reaction of CO?H 2 but show the secondary effects on the reaction so as to induce the hydrogenation of olefins produced by the catalytic reaction and of aldehydes produced in gas phase by radiation. On the other hand, silica gel and other insulators such as alumina have been found to exhibit high catalytic activity in the formation of hydrocarbons from CO?H 2 under electron beam irradiation at 300°C. It has been shown experimentally that secondary reactions between H 2 and carbonaceous solid produced from CO make a substantial contribution to the formation of hydrocarbons from CO?H 2 over silica gel. In an attempt to find the role of silica gel in the reaction to produce hydrocarbons, radiation-induced reactions have been studied of H 2 with the carbonaceous solid that had been produced by irradiation of CO in the absence of solid catalyst, over TiO 2, or over silica gel. The results indicate that silica gel not only enhances the yields of CO 2 and carbonaceous solid from CO but also promotes hydrogenation reactions of the carbonaceous solid under electron beam irradiation.

Nagai, S.; Arai, H.; Hatada, M.


Topical application of the synthetic triterpenoid RTA 408 protects mice from radiation-induced dermatitis.  


Free radicals produced during cancer radiotherapy often leads to dermatitis, with the insult ranging from mild erythema to moist desquamation and ulceration. This toxicity can be dose limiting and promote chronic complications, such as fibrosis and wound recurrence. The purpose of this study was to evaluate if RTA 408, a synthetic triterpenoid that potently activates the antioxidative transcription factor Nrf2 and inhibits the proinflammatory transcription factor nuclear factor-kappa b (NF-?B), could protect skin from radiation-induced dermatitis. Mice were irradiated (10 Gy/day) on days 0-2 and 5-7, and RTA 408 (0.01%, 0.1% and 1.0%) was topically applied once daily starting on day 5 or up to day 40. Dermatitis severity was evaluated using a scale ranging from 0 (normal) to 5 (frank ulceration), as well as histologically. The mRNA expression of Nrf2 and NF-?B target genes in skin was also evaluated. RTA 408 (0.01%, 0.1% and 1.0%) reduced the percentage of animal-days with scores ?2 by 11%, 31% and 55% and scores ?3 by 16%, 60% and 80%, respectively. Dose-dependent improvements in the appearance of skin were also manifestly visible, with RTA 408 at 1.0% eliciting a normal macroscopic appearance by the end of the treatment period on day 40, including substantial hair regrowth. Moreover, 1.0% RTA 408 markedly reduced epidermal and collagen thickening, prevented dermal necrosis and completely alleviated skin ulcers. These improvements were associated with significant increases in Nrf2 target genes and significant decreases in NF-?B target genes. Together, these data indicate that RTA 408 represents a potentially promising new therapy for the treatment of radiation-induced dermatitis. PMID:24720753

Reisman, Scott A; Lee, Chun-Yue I; Meyer, Colin J; Proksch, Joel W; Sonis, Stephen T; Ward, Keith W



Dragon's blood and its extracts attenuate radiation-induced oxidative stress in mice.  


Dragon's blood (DB) possesses great medicinal values due to the presence of several phenolic compounds. This study was designed to investigate the effects of DB and its extracts (DBEs) on oxidative stress in mice exposed to whole body (60)Co-? irradiation (4 Gy). DB and DBEs were intragastrically administered to mice for 5 d prior to radiation. The antioxidant activities, including malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels in liver and spleen were measured using kits. Furthermore, DB and DBE effects were determined by organ indices and histology of liver and spleen. Our results indicated that the DB and DBE-treated groups showed a significant decrease (P < 0.05) in levels of MDA in liver and spleen compared with the irradiation-only group. Moreover, the activity of SOD, CAT and the level of GSH in liver and spleen tissue were enhanced significantly (P < 0.05) in the DB and DBE groups. DB and DBE also had a significant effect on the recovery of thymus indices. The histological observations of groups having treatment with DB and DBE indicated significant reduction in the radiation-induced damage to the liver and spleen, together with improvement in the morphology of the liver and spleen. These results suggest that DB and DBE treatment prevents radiation-induced oxidative stress injury and restores antioxidant status and histopathological changes in the liver and spleen, but there is need for further study to explore the precise molecular mechanism and strategy for optimal practical application of DB and DBE. PMID:24634306

Ran, Yuanyuan; Wang, Ran; Gao, Qian; Jia, Qiutian; Hasan, Murtaza; Awan, Muhammad Umer Farooq; Tang, Bo; Zhou, Rui; Dong, Yiming; Wang, Xiao; Li, Qiang; Ma, Hong; Deng, Yulin; Qing, Hong



Abstract--As growing concerns on the potential side effect of radiation induced genetic, cancerous and other diseases, the  

E-print Network

Abstract--As growing concerns on the potential side effect of radiation induced genetic, cancerous that is working in conjunction with image-based database. It restores a low-dose image with modified non structures changes the database from image-based to patch-based that organized structure by structure

Mueller, Klaus


Nimotuzumab Enhances the Radiosensitivity of Cancer Cells In Vitro by Inhibiting Radiation-Induced DNA Damage Repair  

PubMed Central

Background Nimotuzumab is a humanized IgG1 monoclonal antibody specifically targeting EGFR. In this study, we aimed to investigate the molecular mechanisms of nimotuzumab in its effects of enhancing cancer cell radiosensitivity. Principal Finding Lung cancer A549 cells and breast cancer MCF-7 cells were pretreated with or without nimotuzumab for 24 h before radiation to perform the clonogenic survival assay and to analyze the cell apoptosis by flow ctyometry. ?-H2AX foci were detected by confocal microscopy to assess the effect of nimotuzumab on radiation induced DNA repair. EGFR activation was examined and the levels of DNA damage repair related proteins in A549 cells at different time point and at varying doses exposure after nimotuzumab and radiation treatment were examined by Western blot. Pretreatment with nimotuzumab reduced clonogenic survival after radiation, inhibited radiation-induced EGFR activation and increased the radiat