Sample records for radiation-induced brachial plexopathy

  1. Brachial plexopathy

    MedlinePLUS

    Neuropathy - brachial plexus; Brachial plexus dysfunction; Parsonage Turner syndrome; Pancoast syndrome ... Brachial plexus dysfunction (brachial plexopathy) is a form of peripheral neuropathy . It occurs when there is damage to ...

  2. Distinction between neoplastic and radiation-induced brachial plexopathy, with emphasis on the role of EMG

    SciTech Connect

    Harper, C.M. Jr.; Thomas, J.E.; Cascino, T.L.; Litchy, W.J.

    1989-04-01

    The results of clinical, radiologic, and electrophysiologic studies are retrospectively reviewed for 55 patients with neoplastic and 35 patients with radiation-induced brachial plexopathy. The presence or absence of pain as the presenting symptom, temporal profile of the illness, presence of a discrete mass on CT of the plexus, and presence of myokymic discharges on EMG contributed significantly to the prediction of the underlying cause of the brachial plexopathy. The distribution of weakness and the results of nerve conduction studies were of no help in distinguishing neoplastic from radiation-induced brachial plexopathy.

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

    Microsoft Academic Search

    Niels Kjær Olsen; Per Pfeiffer; Lis Johannsen; H. Schroder; Carsten Rose

    1993-01-01

    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

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

    SciTech Connect

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

    1993-04-30

    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.

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

    SciTech Connect

    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: jwelsh@mdanderson.org [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States)

    2012-03-01

    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.

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

    PubMed Central

    Amini, Arya; Yang, Jinzhong; Williamson, Ryan; McBurney, Michelle L.; Erasmus, Jeremy; Allen, Pamela K.; Karhade, Mandar; Komaki, Ritsuko; Liao, Zhongxing; Gomez, Daniel; Cox, James; Dong, Lei; Welsh, James

    2013-01-01

    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 tolerated dose to 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 multi-atlas segmentation method combined with deformable image registration to delineate the brachial plexuson the original planning CT scans and scoredplexopathy according to the Common Terminology Criteria for Adverse Events v4.03. Results The 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 had had brachial plexopathy (16%) (8 [9%] grade 1 and 6 [7%] grade ?2); median time to symptom onset was 6.5 months (range 1.4-37.4 months). On multivariate analysis, receipt of median brachial plexus dose >69 Gy(odds ratio [OR] 10.091, 95% confidence interval [CI] 1.512-67.331, P=0.005), maximum dose >75 Gy to 2 cm3 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 which allowed 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 trialswithhigh dose radiation therapy for unresectable lung cancer. PMID:22284035

  7. Brachial plexopathy: recurrent cancer or radiation

    SciTech Connect

    Lederman, R.J.; Wilbourn, A.J.

    1984-10-01

    We reviewed clinical and electrodiagnostic features of 16 patients with neoplastic brachial plexopathy (NBP) and 17 patients with radiation-induced plexopathy (RBP). The groups were similar in symptom-free interval after cancer diagnosis and location of the plexus lesions. NBP patients had pain and Horner's syndrome; RBP patients had paresthesias, but rarely Horner's. NBP patients presented earlier after symptom onset and had a shorter course. RBP patients more frequently had abnormal sensory and normal motor nerve conduction studies and characteristically had fasciculations or myokymia on EMG.

  8. Malignant brachial plexopathy: A pictorial essay of MRI findings

    PubMed Central

    Iyer, Veena R; Sanghvi, Darshana A; Merchant, Nikhil

    2010-01-01

    For imaging, the brachial plexus is a technically and anatomically challenging region of the peripheral nervous system. MRI has a central role in the identification and accurate characterization of malignant lesions arising here, as also in defining their extent and the status of the adjacent structures. The purpose of this pictorial essay is to describe the MRI features of primary and secondary malignant brachial plexopathies and radiation-induced brachial nerve damage. PMID:21423902

  9. Delayed brachial plexopathy in clavicular fracture with tri-cord neurapraxia and complete recovery

    Microsoft Academic Search

    T. W. L. Chapman; N. M. Harris; M. Rogers; P. Wilson; J. McDiarmid

    2007-01-01

    Brachial plexopathy after clavicular fracture is a rare and sparsely reported phenomenon. The symptoms are usually delayed\\u000a and caused by compression by hypertrophic callus, non-union, or a subclavian pseudoaneurysm. We describe the first reported\\u000a case of near complete plexopathy with a delayed presentation. This appeared to be a result of impingement by excess callus\\u000a poorly tolerated due to the reduced

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

    PubMed Central

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

    2014-01-01

    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 PMID:25360196

  11. Hereditary Neuropathy with Liability to Pressure Palsy Presenting as an Acute Brachial Plexopathy: A Lover's Palsy

    PubMed Central

    Wedderburn, Sarah; Pateria, Puraskar; Panegyres, Peter K.

    2014-01-01

    It is generally regarded that patients with hereditary neuropathy to pressure palsies, due to a deletion in the PMP22 gene, show recurrent pressure palsy and generalised peripheral neuropathy (pes cavus and hammer toes sometimes develop). Brachial plexopathy is rarely identified as a first presentation of hereditary neuropathy to pressure palsies. We describe a young man who developed a painless flail upper limb with a clinical diagnosis of a brachial plexopathy after his partner slept on his arm – a PMP22 deletion was found. His father, who had a symmetrical polyneuropathy without recurrent mononeuropathies, shared the PMP22 deletion. PMID:25685136

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

    PubMed

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

    2013-02-01

    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

  13. Characteristic features of hereditary neuropathy with liability to pressure palsy (HNPP) presenting with brachial plexopathy in soldiers.

    PubMed

    Kim, Kyoung-Eun

    2014-11-15

    A brachial plexus lesion is not common in hereditary neuropathy with liability to pressure palsy (HNPP). We report the clinical and electrodiagnostic features of young soldiers with HNPP presenting with brachial plexopathy. By reviewing 2year medical records from Korean military hospitals, we identified soldiers with brachial plexus lesions. Among them, patients diagnosed with HNPP were determined and clinical and electrophysiological findings were compared between HNPP and non-HNPP patients with a brachial plexus lesion. Thirteen patients (6.8%) were diagnosed with HNPP among 189 patients with a brachial plexus lesion. Push-ups, as either a punishment or an exercise, was the most frequent preceding event in HNPP patients (76.9%), whereas it was rare in non-HNPP patients. The distal motor latency of the median nerve showed the highest sensitivity (90.9%) and specificity (100%) for HNPP in patients with a brachial plexus lesion. In conclusion, HNPP should be suspected in patients with brachial plexopathy if brachial plexopathy develops after push-ups or if the distal motor latency of median nerves is prolonged. PMID:25175852

  14. Complete Recovery of Spinal Cord Injury without Radiographic Abnormality and Traumatic Brachial Plexopathy in a Young Infant Falling from a 30-Feet-High Window

    Microsoft Academic Search

    Chien-Chang Lee; Sie-Huei Lee; Chia-Hung Yo; Wang-Tso Lee; Shyr-Chyr Chen

    2006-01-01

    The laxity and elasticity of the infant or child spine may predispose him to cervical spine injury without bony disruption. The term ‘SCIWORA’ syndrome (Spinal Cord Injury Without Radiographic Abnormalities) is commonly used to characterize this condition. We report a 14-month-old infant who fell from a fourth-story window, with delayed onset of SCIWORA and brachial plexopathy. The infant initially presented

  15. Lumbosacral plexus delineation, dose distribution, and its correlation with radiation-induced lumbosacral plexopathy in cervical cancer patients

    PubMed Central

    Tunio, Mutahir; Al Asiri, Mushabbab; Bayoumi, Yasser; Abdullah O Balbaid, Ali; AlHameed, Majid; Gabriela, Stanciu Laura; Amir O Ali, Ahmad

    2015-01-01

    Background To evaluate the dose distribution to the lumbosacral plexus (LSP) and its correlation with radiation-induced lumbosacral plexopathy (RILSP) in patients with cervical cancer treated with intensity-modulated radiotherapy (IMRT) and high-dose-rate brachytherapy. Materials and methods After meeting eligibility criteria, 50 patients with cervical cancer were selected who were treated with IMRT and high-dose-rate brachytherapy, and the LSP was contoured. Mean volume; percentages of LSP volume absorbing 40, 50, 55, and 60 Gy (V30, V40, V50, V55, and V60) and point doses (P1, P2, P3, P4, P5, P6, P7, P8, P9, and P10); and RILSP incidence were calculated. Results At 60 months of follow-up, four patients (8%) were found to have grade 2/3 RILSP. The mean maximal LSP dose in patients with RILSP was 59.6 Gy compared with 53.9 Gy in patients without RILSP (control; P=0.04). The mean values of V40, V50, V55, and V60 in patients with RILSP versus control were 61.8% versus 52.8%, 44.4% versus 27.7%, 8.0% versus 0.3% and 1.8% versus 0%, respectively (P=0.01, 0.001, 0.001, and 0.001, respectively). Conclusion The delineation of the LSP during IMRT planning may reduce the risk for RILSP. The mean values of V40, V50, V55, and V60 for LSP should be less than 55%, 30%, 5%, and 0.5%, respectively; however, further studies are warranted. PMID:25565862

  16. Brachial plexus

    MedlinePLUS

    The brachial plexus is a group of nerves that run from the lower neck through the upper shoulder area. These ... Damage to the brachial plexus nerves can cause muscle and sensation problems that are often associated with pain in the same area. Symptoms may ...

  17. Brachial plexus lesions after backpack carriage in young adults.

    PubMed

    Mäkelä, Jyrki P; Ramstad, Raimo; Mattila, Ville; Pihlajamäki, Harri

    2006-11-01

    Carrying a heavy backpack exerts compression on shoulders, with the potential to cause brachial plexopathy. We evaluated the incidence and predisposing factors of compression plexopathy of the shoulder region in 152,095 military conscripts, hypothesizing that a low body mass index and poor physical fitness predispose to the plexus lesion. Reports of conscripts with neural lesions of the upper arm associated with load carriage were reviewed retrospectively for details associated with the condition onset, symptoms, signs, nerve conduction studies, and electromyographic examinations. Height, weight, and physical fitness scores were obtained from their military training data. The incidence of neural compression after shoulder load carriage in Finnish soldiers was 53.7 (95% confidence interval, 39.5-67.8) per 100,000 conscripts per year. The long thoracic nerve was affected in 19, the axillary nerve in 13, the suprascapular nerve in seven, and the musculocutaneous nerve in six patients. Four patients (7%) had hereditary neuropathy with susceptibility to pressure palsies (HNPP). Symptoms were induced by lighter loads in patients with HNPP. Vulnerability to brachial plexopathy was not predictable from body structure or physical fitness level. To prevent these lesions, awareness of the condition and its symptoms should be increased and backpack designs should be improved. PMID:16906084

  18. CT of the brachial plexus in patients with cancer

    SciTech Connect

    Cascino, T.L.; Kori, S.; Krol, G.; Foley, K.M.

    1983-12-01

    To assess the usefulness of CT, we reviewed 51 patients with clinically diagnosed brachial plexopathy who were seen between 1977 and 1981. The established etiology was metastatic tumor in 46 and radiation fibrosis in 5. CT was abnormal in 89% of tumor patients. Myelography, bone scan, and plain cervical spine radiographs were less useful. In four of five patients with radiation fibrosis, CT showed distortion of normal tissue planes without a discrete mass, but was not always distinguishable from tumor infiltration. CT of the brachial plexus provides the best two-dimensional view of tumor infiltration and detects bony changes earlier than standard radiographs. CT is a useful guide for surgical exploration of the brachial plexus, but does not differentiate tumor infiltration from radiation fibrosis.

  19. Brachial Plexus Injuries

    MedlinePLUS

    NINDS Brachial Plexus Injuries Information Page Synonym(s): Erb's Palsy Table of Contents (click to jump to sections) What are Brachial ... is being done? Clinical Trials Organizations What are Brachial Plexus Injuries? The brachial plexus is a network of ...

  20. Imaging of the non-traumatic brachial plexus.

    PubMed

    Boulanger, X; Ledoux, J-B; Brun, A-L; Beigelman, C

    2013-10-01

    The first line imaging of the non-traumatic brachial plexus is by MRI. Knowledge of the anatomy and commonest variants is essential. Three Tesla imaging offers the possibility of 3D isotropic sequences with excellent spatial and contrast enhancement resolutions, which leads to time saving and quality boosting. The most commonly seen conditions are benign tumor lesions and radiation damage. Gadolinium is required to assess inflammatory or tumour plexopathy. MRI data should be correlated with FDG-PET if tumor recurrence is suspected. PMID:23891030

  1. Brachial plexus lesions in patients with cancer: 100 cases

    SciTech Connect

    Kori, S.H.; Foley, K.M.; Posner, J.B.

    1981-01-01

    In patients with cancer, brachial plexus signs are usually caused by tumor infiltration or injury from radiation therapy (RT). We analyzed 100 cases of brachial plexopathy to determine which clinical criteria helped differentiate tumor from radiation injury. Seventy-eight patients had tumor and 22 had radiation injury. Severe pain occurred in 80% of tumor patients but in only 19% of patients with radiation injury. The lower trunk was involved in 72% of the tumors. Seventy-eight percent of the radiation injuries affected the upper plexus (C5-6). Horner syndrome was more common in tumor, and lymphedema in radiation injury. The time from RT to onset of plexus symptoms, and the dose of RT, also differed.

  2. Brachial Plexus Injuries

    MedlinePLUS

    ... Videos Infographics Hand Anatomy Find a Hand Surgeon Brachial Plexus Injury Email to a friend * required fields From * ... to name and customize your collection. DESCRIPTION The brachial plexus is a group of nerves that come from ...

  3. Brachial plexus (image)

    MedlinePLUS

    The brachial plexus is a group of nerves that originate from the neck region and branch off to give rise ... movement in the upper limb. Injuries to the brachial plexus are common and can be debilitating. If the ...

  4. Transient unilateral brachial plexopathy and partial Horner's syndrome following spinal anesthesia for cesarean section

    PubMed Central

    Anson, Jonathan A; McQuillan, Patrick M

    2014-01-01

    A healthy 21-year-old primigravida presented for elective cesarean section. At 45 min after intrathecal (IT) injection of bupivacaine, morphine and fentanyl she developed dysphagia, right sided facial droop, ptosis and ulnar nerve weakness. This constellation of signs and symptoms resolved 2 h later. Based on the time course and laterality of her symptoms, as well as the pharmacologic properties of spinal opioids, we believe her symptoms can be attributed to the IT administration of fentanyl. PMID:24803773

  5. Transient unilateral brachial plexopathy and partial Horner's syndrome following spinal anesthesia for cesarean section.

    PubMed

    Anson, Jonathan A; McQuillan, Patrick M

    2014-04-01

    A healthy 21-year-old primigravida presented for elective cesarean section. At 45 min after intrathecal (IT) injection of bupivacaine, morphine and fentanyl she developed dysphagia, right sided facial droop, ptosis and ulnar nerve weakness. This constellation of signs and symptoms resolved 2 h later. Based on the time course and laterality of her symptoms, as well as the pharmacologic properties of spinal opioids, we believe her symptoms can be attributed to the IT administration of fentanyl. PMID:24803773

  6. Cervical spinal cord stimulation treatment of deafferentation pain from brachial plexus avulsion injury complicated by complex regional pain syndrome.

    PubMed

    Chang Chien, George C; Candido, Kenneth D; Saeed, Kashif; Knezevic, Nebojsa Nick

    2014-08-01

    Brachial plexus avulsion is a rare and debilitating condition frequently associated with severe, intractable neuropathic pain. Interventional treatment modalities include dorsal root entry zone lesioning, stellate ganglion blockade, and neuromodulation such as spinal cord stimulation. We present a case of a 42-year-old woman with a traumatic left upper extremity brachial plexus avulsion injury after a motor vehicle accident and treatment of deafferentation pain complicated by complex regional pain syndrome type II. Previous unsuccessful interventions included repeated stellate ganglion blocks, transcutaneous electrical nerve stimulation, and opioid medication. After a successful trial of cervical spinal cord stimulator lead placement, she went on to an uneventful permanent implantation procedure. Spinal cord stimulation is an effective treatment for deafferentation pain and complex regional pain syndrome type II secondary to brachial plexopathy refractory to pharmacotherapy and conventional interventional attempts to modulate pain. PMID:25611136

  7. The Brachial Plexus

    NSDL National Science Digital Library

    Mr. Samuel J Schwarzlose (Amarillo College Biology)

    2010-08-20

    This project is designed to instruct students on the basic anatomy and physiology of the brachial plexus. Through exercises such as matching, coloring and labeling, students are introduced to the brachial plexus and its role in controlling the cutaneous sensation and movement of the upper limbs.

  8. Radiation-induced malignant and atypical peripheral nerve sheath tumors

    SciTech Connect

    Foley, K.M.; Woodruff, J.M.; Ellis, F.T.; Posner, J.B.

    1980-04-01

    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 was within an acceptable radiation dosage, yet 3 patients developed local radiation-induced skin and bony abnormalities. The malignant peripheral nerve sheath tumors developed only in the radiation port. Animal studies support the clinical observation that malignant peripheral nerve sheath tumors can occur as a delayed effect of irradiation.

  9. Radiation-Induced Bioradicals

    NASA Astrophysics Data System (ADS)

    Lahorte, Philippe; Mondelaers, Wim

    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.

  10. Brachial artery pseudoaneurysm.

    PubMed

    Kemp, Katie; Radwan, Rami; Shingler, Guy; Davies, Chris

    2014-01-01

    We describe a case of an elderly man who presented with an upper arm swelling that had developed following a humeral fracture 8?months previously. The swelling was painless but associated with significantly diminished motor function of his right hand and concurrent paraesthaesia. On examination, a large pulsatile mass was identified and CT angiography confirmed the presence of an 11×7?cm brachial artery pseudoaneurysm. The patient underwent surgical repair in which a fragment of the humerus was found to have punctured the brachial artery resulting in a pseudoaneurysm. The patient had an uncomplicated postoperative period and was discharged 2?days later having regained some motor function in his right hand. PMID:24859555

  11. Radiation-induced genomic instability

    NASA Technical Reports Server (NTRS)

    Kronenberg, A.

    1994-01-01

    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.

  12. Acquired brachial cutaneous dyschromatosis.

    PubMed

    Hu, Stephanie W; Chu, Julie; Meehan, Shane; Kamino, Hideko; Pomeranz, Miriam Keltz

    2011-01-01

    Acquired brachial cutaneous dyschromatosis (ABCD) is a newly described disorder of pigmentary change that occurs on the dorsal aspects of the forearms in post-menopausal women. We report a case of a 62-year-old woman who developed an asymptomatic, reticulated, gray-brown eruption on the dorsal aspects of the forearms of gradual onset that is clinically and histopathologically consistent with ABCD. Whereas the original report found an association between hypertension and/or the use of anti-hypertensive medications in the original cohort, we propose that this entity may, in fact, be associated more closely with cumulative sun damage and may be related to such acquired disorders of the skin as poikiloderma of Civatte. Treatment of these lesions may prove to be a challenge, with an emphasis on rigorous sun protection and adjunctive measures with depigmentating agents, chemical peels, and lasers. PMID:22031642

  13. BROOKHAVEN SCIENCE ASSOCIATES Radiation Induced Demagnetization of

    E-print Network

    Ohta, Shigemi

    BROOKHAVEN SCIENCE ASSOCIATES Radiation Induced Demagnetization of Nd-Fe-B Permanent Magnets P.K. Job Radiation Physicist NSLS II #12;BROOKHAVEN SCIENCE ASSOCIATES Radiation Induced Demagnetization Irradiation of Sample Magnets MCNPX Calculations for Comparison #12;BROOKHAVEN SCIENCE ASSOCIATES Radiation

  14. Lumbosacral plexopathy from iliopsoas haematoma after combined general-epidural anaesthesia for abdominal aneurysmectomy

    Microsoft Academic Search

    Edward T. Crosby; Dennis R. Reid; Gina DiPrimio; Steven Grahovac

    1998-01-01

    Purpose  To report a case of iliopsoas haematoma after resection of an abdominal aortic aneurysm which resulted in a lumbosacral plexopathy.\\u000a \\u000a \\u000a \\u000a Clinical features  An 81-yr-old man presented with an abdominal aortic aneurysm for aneurysmectomy and tube grafting. An epidural catheter was\\u000a placed at the L1?2 spinal level and combined epidural-general anaesthesia was provided for surgery. The surgery was complex and a suprarenal

  15. Lumbar Plexopathy Caused by Metastatic Tumor, Which Was Mistaken for Postoperative Femoral Neuropathy

    PubMed Central

    Lee, Ki Hwa; Choe, Ji Hyun; Lee, Sang Eun; Park, Jae Hong; Bang, Si Ra; Kim, Yong Han

    2011-01-01

    Surgical excision was performed on a 30-years old woman with a painful mass on her left thigh. The pathologic findings on the mass indicated fibromatosis. After the operation, she complained of allodynia and spontaneous pain at the operation site and ipsilateral lower leg. We treated her based on postoperative femoral neuropathy, but symptom was aggravated. We found a large liposarcoma in her left iliopsoas muscle which compressed the lumbar plexus. In conclusion, the cause of pain was lumbar plexopathy related to a mass in the left iliopsoas muscle. Prompt diagnosis of acute neuropathic pain after an operation is important and management must be based on exact causes. PMID:22220245

  16. Radiation-induced parotid cancer

    SciTech Connect

    Walker, M.J.; Chaudhuri, P.K.; Wood, D.C.; Das Gupta, T.K.

    1981-03-01

    A retrospective analysis of 72 cases of primary malignant tumors of the parotid gland treated at the University of Illinois Hospital, Chicago, from 1950 through 1978 revealed that six of these had developed from two to 24 years after irradiation of the head or neck for various benign and malignant neoplastic conditions. At the time of irradiation, ages ranged from 7 to 73 years; the sex distribution was equal. From our findings and those in 26 cases reported by various other authors, the following criteria are proposed for the designation of a parotid tumor as being radiation induced: (1) well-documented radiation exposure; (2) part of irradiation must incorporate the gland in which the cancer subseqently arises; (3) exposure to a minimum of 300 rads; and (4) minimum latent period of two years. In view of the widespread use in the past of heat and neck irradiation of benign neoplastic disease, the surgeon should be aware of this possible link with parotid gland tumor.

  17. [Management tactics in brachial plexus injuries].

    PubMed

    Harat, M; Radek, A

    1993-01-01

    The authors present their own experience in the management of brachial plexus injuries. Conservative treatment as well as the results of surgical brachial plexus repair are described. Clinical material includes 114 patients operated on the last 9 years. The principles of qualification of the patients for surgery, various surgical procedures employed and outcomes are analysed. The authors' experience in the management of brachial plexus injuries is compared with the other found in the literature. The approach to the management of brachial plexus injuries is suggested and recommended. PMID:8164778

  18. Neuromuscular hamartoma arising in the brachial plexus.

    PubMed

    Lai, P H; Ho, J T; Lin, S L; Hsu, S S; Chen, C; Yeh, L R; Pan, H B

    2004-03-01

    We report a case brachial plexus neuromuscular hamartoma (choristoma) in a 28-year-old man who complained of numbness of the left hand and forearm for several years. MRI revealed a circumscribed, rounded mass in the left brachial plexus. The patient is well 2 years after surgery, with no neurological deficit. PMID:14991257

  19. Ultrasound-Guided Supraclavicular Brachial Plexus Block

    Microsoft Academic Search

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

    2003-01-01

    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

  20. Radiation Induced Bystander Effect in vivo

    PubMed Central

    Chai, Yunfei; Hei, Tom K.

    2010-01-01

    Radiation-induced bystander effect is defined as the induction of biological effects in cells that are not directly traversed by radiation, but merely in the presence of cells that are. Although radiation induced bystander effects have been well defined in a variety of in vitro models using a range of endpoints including clonogenic survival, mutations, neoplastic transformation, apoptosis, micronucleus, chromosomal aberrations and DNA double strand beaks, the mechanism(s) as well as the presence of such an effect in vivo are not well described. In this review, we summarize the evidence of radiation induced bystander effect in various in vivo systems including rodents, fish and plants. Many biological endpoints such as epigenetic changes, DNA damage, miRNA, apoptosis, cell proliferation, gene expression and tumorgenesis have been demonstrated in the non-targeted regions in vivo. Although the bystander effect is evolutionarily conserved in rodent systems, the bystander response depends on gender, tissue and strain. However, the studies about mechanism of radiation induced bystander effect in vivo are still limited. PMID:20634916

  1. Nuclear Radiation Induced Noise in Infrared Detectors

    Microsoft Academic Search

    J. C. Pickel; M. D. Petroff

    1975-01-01

    A model for calculating the rate and amplitude of gamma ionization events in infrared detectors is presented. Several simplifying approximations to the actual, complex physical situation are applied in the model, thereby allowing an exact analytical formulation of the problem. Experimental measurements of nuclear-radiation induced noise pulse-height distributions and event rates are compared to predictions made using the model. Comparisons

  2. Nuclear radiation induced noise in infrared detectors

    Microsoft Academic Search

    J. C. Pickel; M. D. Petroff

    1975-01-01

    A model for calculating the rate and amplitude of gamma ionization events in infrared detectors is presented. Several simplifying approximations to the actual, complex physical situation are applied in the model, thereby allowing an exact analytical formulation of the problem. Experimental measurements of nuclear-radiation induced noise pulse-height distributions and event rates are compared to predictions made using the model. Comparisons

  3. Radiation Induced Bystander Effect in vivo.

    PubMed

    Chai, Yunfei; Hei, Tom K

    2008-01-01

    Radiation-induced bystander effect is defined as the induction of biological effects in cells that are not directly traversed by radiation, but merely in the presence of cells that are. Although radiation induced bystander effects have been well defined in a variety of in vitro models using a range of endpoints including clonogenic survival, mutations, neoplastic transformation, apoptosis, micronucleus, chromosomal aberrations and DNA double strand beaks, the mechanism(s) as well as the presence of such an effect in vivo are not well described. In this review, we summarize the evidence of radiation induced bystander effect in various in vivo systems including rodents, fish and plants. Many biological endpoints such as epigenetic changes, DNA damage, miRNA, apoptosis, cell proliferation, gene expression and tumorgenesis have been demonstrated in the non-targeted regions in vivo. Although the bystander effect is evolutionarily conserved in rodent systems, the bystander response depends on gender, tissue and strain. However, the studies about mechanism of radiation induced bystander effect in vivo are still limited. PMID:20634916

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

    SciTech Connect

    Truong, Minh Tam, E-mail: mitruong@bu.edu [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)

    2012-09-01

    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.

  5. Radiation-induced meningiomas in pediatric patients

    SciTech Connect

    Moss, S.D.; Rockswold, G.L.; Chou, S.N.; Yock, D.; Berger, M.S.

    1988-04-01

    Radiation-induced meningiomas rarely have latency periods short enough from the time of irradiation to the clinical presentation of the tumor to present in the pediatric patient. Three cases of radiation-induced intracranial meningiomas in pediatric patients are presented. The first involved a meningioma of the right frontal region in a 10-year-old boy 6 years after the resection and irradiation of a 4th ventricular medulloblastoma. Review of our pediatric tumor cases produced a second case of a left temporal fossa meningioma presenting in a 15-year-old boy with a history of irradiation for retinoblastoma at age 3 years and a third case of a right frontoparietal meningioma in a 15-year-old girl after irradiation for acute lymphoblastic leukemia. Only three cases of meningiomas presenting in the pediatric age group after radiation therapy to the head were detected in our review of the literature.

  6. Radiation induced fracture of the scapula

    SciTech Connect

    Riggs, J.H. III; Schultz, G.D.; Hanes, S.A. (Los Angeles College of Chiropractic, Whittier, CA (USA))

    1990-10-01

    A case of radiation induced osteonecrosis resulting in a fracture of the scapula in a 76-yr-old female patient with a history of breast carcinoma is presented. Diagnostic imaging, laboratory recommendations and clinical findings are discussed along with an algorithm for the safe management of patients with a history of cancer and musculoskeletal complaints. This case demonstrates the necessity of a thorough investigation of musculoskeletal complaints in patients with previous bone-seeking carcinomas.

  7. Modeling radiation-induced cell cycle delays

    Microsoft Academic Search

    Anna Ochab-Marcinek; Ewa Gudowska-Nowak; Elena Nasonova; Sylvia Ritter

    2009-01-01

    Ionizing radiation is known to delay the cell cycle progression. In particular after particle exposure significant delays\\u000a have been observed and it has been shown that the extent of delay affects the expression of damage, such as chromosome aberrations.\\u000a Thus, to predict how cells respond to ionizing radiation and to derive reliable estimates of radiation risks, information\\u000a about radiation-induced cell

  8. Prostate cancer with perineural spread and dural extension causing bilateral lumbosacral plexopathy: case report.

    PubMed

    Capek, Stepan; Howe, Benjamin M; Tracy, Jennifer A; García, Joaquín J; Amrami, Kimberly K; Spinner, Robert J

    2015-04-01

    Perineural tumor spread in prostate cancer is emerging as a mechanism to explain select cases of neurological dysfunction and as a cause of morbidity and tumor recurrence. Perineural spread has been shown to extend from the prostate bed to the lumbosacral plexus and then distally to the sciatic nerve or proximally to the sacral and lumbar nerves and even intradurally. The authors present a case of a bilateral neoplastic lumbosacral plexopathy that can be explained anatomically as an extension of the same process: from one lumbosacral plexus to the contralateral one utilizing the dural sac as a bridge between the opposite sacral nerve roots. Their theory is supported by sequential progression of symptoms and findings on clinical examinations as well as high-resolution imaging (MRI and PET/CT scans). The neoplastic nature of the process was confirmed by a sciatic nerve fascicular biopsy. The authors believe that transmedian dural spread allows continuity of a neoplastic process from one side of the body to the other. PMID:25658791

  9. Neurinomas of the brachial plexus: case report.

    PubMed

    Forte, A; Gallinaro, L S; Bertagni, A; Montesano, G; Prece, V; Illuminati, G

    1999-01-01

    Neurinomas, also referred to as neurilemmomas and schwannomas, are rare benign tumours of the peripheral nerves, a low proportion of which arise from the brachial plexus. Authors report a case of an ancient schwannoma arising from the brachial plexus. The tumour, usually asymptomatic, may cause sensory radicular symptoms, or rarely motor deficits in the involved arm. Enucleation of the tumour from the nerve without damage to any of the fascicles is the correct treatment. PMID:10710825

  10. Acute brachial neuritis following influenza vaccination.

    PubMed

    Shaikh, Maliha Farhana; Baqai, Tanya Jane; Tahir, Hasan

    2012-01-01

    Brachial neuritis following vaccination is an uncommon but clinically important presentation of severe shoulder and arm pain associated with globally reduced range of movement. It may be confused with the more common diagnoses of rotator cuff pathology, adhesive capsulitis (frozen shoulder), shoulder arthritis or cervical spondylosis. We present a case of acute brachial neuritis, which posed a clinical diagnostic challenge to emergency, acute medical and rheumatology clinicians. PMID:23192585

  11. Idiopathic Brachial Plexitis After Total Shoulder Replacement with Interscalene Brachial Plexus Block

    Microsoft Academic Search

    JOHN E. TETZLAFF; JOHN DILGER; ENGLOK YAP; JOHN BREMS

    1998-01-01

    e describe a case of idiopathic brachial plexitis (IBP) that occurred after total shoulder re- placement with an interscalene brachial plexus block. A unique aspect of the case was full recovery of neurological function before release from the postanesthesia care unit (PACU) with the onset of new neurological symptoms 12-18 h later. Case Report A 65-year old woman was scheduled

  12. Radiation-induced intracranial malignant fibrous histiocytoma.

    PubMed

    Gonzalez-Vitale, J C; Slavin, R E; McQueen, J D

    1976-06-01

    An autopsy case of radiation-induced intracranial malignant fibrous histiocytoma (fibroxanthosarcoma) is reported. The tumor developed in the region of the sella turcica 11 years after high dose radiotherapy of a chromophobe adenoma of the pituitary. The tumor had infiltrated the base of the brain as well as the base of the skull. Metastases were not found. The tumor was composed of an admixture of bizarre fibroblasts, histiocytes and giant cells, xanthoma cells and siderophages, with a storiform fibrous stroma. This appears to be the first documented instance of a malignant fibrous histiocytoma occurring intracranially after local x-irradiation. PMID:181126

  13. Dermatoglyphs and brachial plexus palsy.

    PubMed

    Polovina, Svetislav; Cvjeticanin, Miljenko; Milici?, Jasna; Prolosci?, Tajana Polovina

    2006-09-01

    Perinatal brachial plexus palsy (PBPP) is a handicap quite commonly encountered in daily routine. Although birth trauma is considered to be the major cause of the defect, it has been observed that PBPP occurs only in some infants born under identical or nearly identical conditions. The aim of this study was to test the hypothesis of genetic predisposition for PBPP. It is well known that digito-palmar dermatoglyphs can be used to determine hereditary roots of some diseases. Thus, we found it meaningful to do a study analysis of digito-palmar dermatoglyphs in this disease as well, conducting it on 140 subjects (70 males and 70 females) diagnosed with PBPP. The control group was composed of fingerprints obtained from 400 adult and phenotypically healthy subjects (200 males and 200 females) from the Zagreb area. The results of multivariate and univariate analysis of variance have shown statistically significant differences between the groups observed. In spite of lower percentage of accurately classified female subjects by discriminant analysis, the results of quantitative analysis of digito-palmar dermatoglyphs appeared to suggest a genetic predisposition for the occurrence of PBPP. PMID:17058524

  14. Learn the Brachial Plexus in Five Minutes or Less

    E-print Network

    Finley Jr., Russell L.

    Learn the Brachial Plexus in Five Minutes or Less By Daniel S. Romm, M.D. Chief, Physical Medicine view of the Department of Veterans Affairs of the U.S. Government. #12;The brachial plexus contains the diagram of the brachial plexus. #12;Draw two headless arrows to the right. #12;Add a headless arrow

  15. Upper trunk brachial plexus injuries in contact sports

    Microsoft Academic Search

    William G. Clancy; Robert L. Brand; John A. Bergfield

    1977-01-01

    Cervical nerve pinch syndrome, a neura praxia of the brachial plexus, is a common occurrence in contact football. The incidence at two universities was approximately 49%. The more serious injury, brachial plexus ax onotmesis, has received little attention in the literature. We are reporting 13 cases of brachial plexus axonotmesis. Ten were docu mented by electromyography. All involved the upper

  16. Brachial Artery Injury Accompanying Closed Elbow Dislocations

    PubMed Central

    Harnarayan, Patrick; Cawich, Shamir O.; Harnanan, Dave; Budhooram, Steve

    2014-01-01

    Introduction Brachial artery injuries from elbow dislocations are uncommon, but they may lead to disastrous consequences if the diagnosis is delayed. Presentation of case We report a case of a patient who sustained a fall onto the elbow, with dislocation and brachial artery injury, despite an ipsilateral radial pulse being palpable. Discussion Clinicians should maintain a high index of suspicion for brachial injury when patients present with a fall onto the elbow coupled with signs suggestive of fracture-dislocation, nerve injury and/or signs of limb ischemia. Frank ischamia, however, is uncommon as there is a rich collateral anastomosis in the upper limb. Conclusion A high index of suspicion should be maintained in order to make the diagnosis early. Exploration with excision of the injured segment and reverse vein interposition grafting is the treatment of choice in these cases. PMID:25644552

  17. Radiation induced carcinoma of the larynx

    SciTech Connect

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

    1985-07-01

    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.

  18. Cathodoluminescence of radiation-induced zircon

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Y.; Nishido, H.; Kayama, M.; Noumi, Y.

    2013-12-01

    Zircon occurs as a common accessory mineral in igneous, metamorphic and sedimentary rocks, and maintains much information on thermal history, metamorphic process and natural radiation dose accumulated in the mineral. U-Pb zircon dating (e.g., SHRIMP) is an important tool to interpret a history of the minerals at a micrometer-scale, where cathodoluminescence (CL) image has been used for identification of internal zones and domains having different chemical compositions and/or structures with a high spatial resolution. The CL of zircon is derived from various types of emission centers, which are derived from impurities such as rare earth elements (REE) and structural defects. In fact, the CL features of zircon are closely related to metamorphic process and radiation from contained radionuclides as well as geochemical condition of its formation. Most zircon has yellow emission, which seems to be assigned to UO2 centers or radiation-induced defect during metamictization of the lattice by alpha particles from the decay of U and Th. In this study, the radiation effects on zircon CL have been studied for He+ ion-implanted samples annealed at various temperatures to clarify radiation-induced defect centers involved with the yellow CL emission in zircon. Single crystals of zircon from Malawi (MZ), Takidani granodiorite (TZ) and Kurobegawa granite (KZ) were selected for He+ ion implantation experiments. The polished plates of the samples were implanted by He+ ion 4.0 MeV corresponding to energy of alpha particle from 238 U and 232Th. CL spectra in the range from 300 to 800 nm with 1 nm step were measured by a scanning electron microscopy-cathodoluminescence (SEM-CL). CL spectra of untreated and annealed zircon show emission bands at ~370 nm assigned to intrinsic defect centers and at ~480, ~580 and ~760 nm to trivalent Dy impurity centers (Cesbron et al., 1995; Gaft et al, 2005). CL emissions in the yellow-region were observed in untreated zircon. The TZ and KZ indicate youngest formation ages of 1.93-1.20 Ma and 1.7-0.9 Ma, respectively (Harayama,1994; Harayama et al., 2010) in the world. In this case, it is hardly to detect yellow CL emissions derived from radiation-induced defect center, suggesting low radiation dose of alpha radiation from 238U and 232Th on them. CL spectra of MZ, TZ and KZ showed an increase in the intensities of yellow emissions with an increase in radiation dose of He+ ion implantation, though He+ ion implantation reduces the intensities of their impurity centers. CL intensity in the yellow region depends on radiation dose of He+ ion implantation. Therefore, if the component of yellow emission could be deconvoluted from the CL spectra in zircon, its intensity will be used for an indicator to evaluate total exposure doses on it during geological age.

  19. [Late manifestation of radiation injury to the plexus brachialis and plexus lumbosacralis].

    PubMed

    Strub, M; Fuhr, P; Kappos, L

    2000-10-01

    Radiotherapy of breast cancer, cervical cancer, testicular tumours and lymphoma is one of the most effective therapy options. Damage to the nervous system, in particular the brachial and lumbar plexus, is rare and typically leads to development of progressive sensory disturbances and motor weakness after years-long latency. We present two cases exemplifying the diagnostic problems in differentiating between radiation-induced injury and recurrence of the primary tumour. A clinical course with sensorimotor symptoms and signs progressing over months, electomyographic recording of myokymic discharges, and absence of a space-occupying mass suggest late-onset radiation-induced plexopathy. The literature on pathogenesis and incidence of radiation-induced plexopathy is reviewed. PMID:11059032

  20. Radiation-induced morphea - a literature review.

    PubMed

    Spalek, M; Jonska-Gmyrek, J; Ga?ecki, J

    2015-02-01

    Radiation-induced morphea (RIM) is a rare and under-recognized skin complication of radiotherapy. It is commonly wrongly diagnosed as other dermatological conditions or malignancy because of similar clinical characteristics. This literature review analyses 66 cases that have been reported in the literature since 1989. The clinical appearance often includes pain and disfiguration of affected area, which may influence the patient's quality of life. There is no clear connection between the radiotherapy dose, the fractionation scheme, the use of a boost, age, the presence of other dermatological conditions or other connective tissue diseases and the occurrence of RIM. Its pathogenesis is still unclear, but several theories are proposed to explain this phenomenon. The available data suggest that the abnormally high secretion of some cytokines (interleukin 4, interleukin 5, transforming growth factor) induced by radiation causes an extensive fibrosis after an activation of fibroblasts. Histological confirmation is crucial in distinguishing RIM from similar-looking diseases, such as chronic radiation dermatitis, cancer recurrence, radiation, recall dermatitis, new carcinoma or cellulitis. There is no clear treatment regimen for this condition. Clinical outcome after therapy is often unsatisfactory. The commonly used methods and agents include: topical and systemic steroids, calcineurin inhibitors, systemic immunosuppressants including methotrexate, tacrolimus, heparin, hyaluronidase, phototherapy (UVA, UVA1, UVB, PUVA), systemic antibiotics, imiquimod, mycophenolate mofetil, photophoresis. The differential diagnosis is challenging and requires a multidisciplinary approach to avoid misdiagnosis and to plan appropriate treatment. PMID:25174551

  1. Delayed Radiation-Induced Vasculitic Leukoencephalopathy

    SciTech Connect

    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: alexander.vortmeyer@yale.edu [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States)

    2012-05-01

    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.

  2. Radiation-induced xerostomia: pathophysiology, clinical course and supportive treatment

    Microsoft Academic Search

    H.-J. Guchelaar; A. Vermes; J. H. Meerwaldt

    1997-01-01

    Xerostomia, or oral dryness, is one of the most common complaints experienced by patients who have had radiotherapy of the\\u000a oral cavity and neck region. The hallmarks of radiation-induced damage are acinar atrophy and chronic inflammation of the\\u000a salivary glands. The early response, resulting in atrophy of the secretory cells without inflammation might be due to radiation-induced\\u000a apoptosis. In contrast,

  3. Treatment of radiation-induced cystitis with hyperbaric oxygen

    SciTech Connect

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

    1985-08-01

    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.

  4. Protection from radiation-induced pneumonitis using cerium oxide nanoparticles

    Microsoft Academic Search

    Jimmie Colon; Luis Herrera; Joshua Smith; Swanand Patil; Chris Komanski; Patrick Kupelian; Sudipta Seal; D. Wayne Jenkins; Cheryl H. Baker

    2009-01-01

    In an effort to combat the harmful effects of radiation exposure, we propose that rare-earth cerium oxide (CeO2) nanoparticles (free-radical scavengers) protect normal tissue from radiation-induced damage. Preliminary studies suggest that these nanoparticles may be a therapeutic regenerative nanomedicine that will scavenge reactive oxygen species, which are responsible for radiation-induced cell damage. The effectiveness of CeO2 nanoparticles in radiation protection

  5. Bilateral brachial plexus compressive neuropathy (crutch palsy).

    PubMed

    Raikin, S; Froimson, M I

    1997-01-01

    Brachial plexus compressive neuropathy following the use of axillary crutches (crutch palsy) is a rare but well-recognized entity. Most reported cases involve the posterior cord of the brachial plexus in children and have resolved spontaneously within 8-12 weeks. We recently treated a 36-year-old man who was using axillary crutches for mobilization after a supracondylar femoral fracture. Bilateral posterior cord (predominantly radial nerve) compressive neuropathy subsequently developed, with lesser involvement of the ulnar and median nerves. The patient had little to no improvement clinically 8 weeks after the estimated onset of the palsy, and an electromyogram at that time confirmed the presence of a severe axonotmesis lesion of the radial, median, and ulnar nerves bilaterally. The patient was treated with static cock-up wrist splinting and discontinuation of the axillary crutches. Return of sensory and motor function was delayed but occurred within 9 months. PMID:9057152

  6. Qualitative dermatoglyphic traits in brachial plexus palsy.

    PubMed

    Polovina, Svetislav; Milici?, Jasna; Cvjeticanin, Miljenko; Prolosci?, Tajana Polovina

    2007-12-01

    It has been considered for many years that the cause of perinatal brachial plexus palsy (PBPP) is excessive lateral traction applied to the fetal head at delivery, in association with anterior shoulder dystocia, but this do not explain all cases of brachial plexus palsy. The incidence found in several family members could be suggestive for inheritance with variable expression. The aim of this study was to prove early found confirmations of genetic predisposition for PBPP In the previous studies, the quantitative dermatoglyphic analysis showed some differences in digito-palmar dermatoglyphs between patients with PBPP and healthy controls. Now this qualitative analysis will try to determine hereditary of those diseases. We analyzed digito-palmar dermatoglyphics from 140 subjects (70 males and 70 females) diagnosed with PBPP and 400 phenotypically healthy adults (200 males and 200 females) from Zagreb area as control group. The results of Chi-square test showed statistically significant differences for frequencies of patterns on fingers in females between the groups observed. Statistically significant differences were found on palms in III and IV interdigital areas in both males and females and in thenar and I interdigital area only in females. As it was found in previous researches on quantitative dermatoglyphic traits, more differences are found between females with PBPP and control group, than between males. The fact, that the main presumed cause of PBPP is obstetrical trauma, it could be associated with congenital variability in formation of brachial plexus. PMID:18217462

  7. Radiation-induced myeloid leukemia in murine models

    PubMed Central

    2014-01-01

    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

  8. Associated factors in 1611 cases of brachial plexus injury

    Microsoft Academic Search

    William M Gilbert; Thomas S Nesbitt; Beate Danielsen

    1999-01-01

    Objective: To identify risk factors associated with brachial plexus injury in a large population.Methods: A computerized data set containing records from hospital discharge summaries of mothers and infants and birth certificates was examined. The deliveries took place in more than 300 civilian acute care hospitals in California between January 1, 1994, and December 31, 1995. Cases of brachial plexus injury

  9. Three-dimensional MR imaging of the brachial plexus.

    PubMed

    Vargas, Maria Isabel; Gariani, Joanna; Delattre, Benedicte A; Dietemann, Jean-Louis; Lovblad, Karl; Becker, Minerva

    2015-04-01

    Pathologic conditions of the brachial plexus often result in serious and disabling complications. With the increasing availability and use of new and powerful MRI sequences and coils, understanding and assessment of the complex anatomy and pathology of the brachial plexus have been greatly facilitated. These new technical developments have led to an improved assessment of brachial plexus lesions, thereby improving patient care. In this article we describe various MRI techniques for the evaluation of the brachial plexus obtained at 1.5 T and 3 T, and we explain differences and similarities between sequences and protocols performed on MRI equipment from different vendors. The main characteristics of pathologic conditions affecting the brachial plexus are discussed and illustrated, as well as their differential diagnoses, with an emphasis on key imaging findings and relevance for patient management. Pitfalls related to suboptimal technique and image interpretation are also addressed. PMID:25764238

  10. [Radiation-induced cavernoma of the central nervous system].

    PubMed

    Melot, A; Laquerrière, A; Hanzen, S; Fréger, P; Proust, F

    2007-12-01

    Central nervous system radiation-induced cavernoma (RIC) is a rare entity. We report one case with a review of the literature. This case illustrates the following features: mean age of 11.7 years at time of radiation and mean latency period of nine years for these RIC, which are often numerous (38%), and located in the field of the craniospinal radiation therapy. This nosological entity belongs to the spectrum of radiation-induced lesions, and requires a long-term MRI follow up in patients who underwent cranial radiation therapy. PMID:18061632

  11. The mechanisms of radiation-induced bystander effect.

    PubMed

    Najafi, M; Fardid, R; Hadadi, Gh; Fardid, M

    2014-12-01

    The radiation-induced bystander effect is the phenomenon which non-irradiated cells exhibit effects along with their different levels as a result of signals received from nearby irradiated cells. Responses of non-irradiated cells may include changes in process of translation, gene expression, cell proliferation, apoptosis and cells death. These changes are confirmed by results of some In-Vivo studies. Most well-known important factors affecting radiation-induced bystander effect include free radicals, immune system factors, expression changes of some genes involved in inflammation pathway and epigenetic factors. PMID:25599062

  12. Panretinal photocoagulation for radiation-induced ocular ischemia

    SciTech Connect

    Augsburger, J.J.; Roth, S.E.; Magargal, L.E.; Shields, J.A.

    1987-08-01

    We present preliminary findings on the effectiveness of panretinal photocoagulation in preventing neovascular glaucoma in eyes with radiation-induced ocular ischemia. Our study group consisted of 20 patients who developed radiation-induced ocular ischemia following cobalt-60 plaque radiotherapy for a choroidal or ciliary body melanoma. Eleven of the 20 patients were treated by panretinal photocoagulation shortly after the diagnosis of ocular ischemia, but nine patients were left untreated. In this non-randomized study, the rate of development of neovascular glaucoma was significantly lower (p = 0.024) for the 11 photocoagulated patients than for the nine who were left untreated.

  13. The Mechanisms of Radiation-Induced Bystander Effect

    PubMed Central

    Najafi, M; Fardid, R; Hadadi, Gh; Fardid, M

    2014-01-01

    The radiation-induced bystander effect is the phenomenon which non-irradiated cells exhibit effects along with their different levels as a result of signals received from nearby irradiated cells. Responses of non-irradiated cells may include changes in process of translation, gene expression, cell proliferation, apoptosis and cells death. These changes are confirmed by results of some In-Vivo studies. Most well-known important factors affecting radiation-induced bystander effect include free radicals, immune system factors, expression changes of some genes involved in inflammation pathway and epigenetic factors. PMID:25599062

  14. Introduction Mammals suffering from radiation-induced anemia or

    E-print Network

    Zandstra, Peter W.

    that distinguish the stem cell niche of the BM versus skeletal muscle microenvironments. Key words: Hematopoietic to endogenous muscle- derived satellite-stem-cells, this repair process was affected by a small numberIntroduction Mammals suffering from radiation-induced anemia or neutropenia can be rescued

  15. Radiation induces senescence and a bystander effect through metabolic alterations

    PubMed Central

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

    2014-01-01

    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

  16. Radiation Induced Absorption in Rare Earth Doped Optical Fibers

    Microsoft Academic Search

    M. Lezius; K. Predehl; W. Stower; A. Turler; M. Greiter; Ch. Hoeschen; P. Thirolf; W. Assmann; D. Habs; A. Prokofiev; C. Ekstrom; T. W. Hansch; R. Holzwarth

    2012-01-01

    We have investigated the radiation induced absorption (RIA) of optical fibers with high active ion concentration. Comparing our results to the literature leads us to the conclusion that RIA appears to be only weakly dependent on the rare earth dopant concentration. Instead, co-dopants like Al, Ge, or P and manufacturing processes seem to play the major role for the radiation

  17. Hyperbaric Oxygen Therapy for Radiation-induced Optic Neuropathy

    Microsoft Academic Search

    Richard L Levy; Neil R Miller

    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,

  18. Radiation induces senescence and a bystander effect through metabolic alterations.

    PubMed

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

    2014-01-01

    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

  19. SENSITIVITY TO RADIATION-INDUCED CANCER IN HEMOCHROMATOSIS

    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...

  20. Obstructive jaundice due to radiation-induced hepatic duct stricture

    SciTech Connect

    Chandrasekhara, K.L.; Iyer, S.K.

    1984-10-01

    A case of obstructive jaundice due to radiation-induced hepatic duct stricture is reported. The patient received postoperative radiation for left adrenal carcinoma, seven years prior to this admission. The sequelae of hepatobiliary radiation and their management are discussed briefly.

  1. Radiation-induced instability and its relation to radiation carcinogenesis

    NASA Technical Reports Server (NTRS)

    Ullrich, R. L.; Ponnaiya, B.

    1998-01-01

    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.

  2. Radiation-induced soft errors in advanced semiconductor technologies

    Microsoft Academic Search

    Robert C. Baumann

    2005-01-01

    The once-ephemeral radiation-induced soft error has become a key threat to advanced commercial electronic components and systems. Left unchallenged, soft errors have the potential for inducing the highest failure rate of all other reliability mechanisms combined. This article briefly reviews the types of failure modes for soft errors, the three dominant radiation mechanisms responsible for creating soft errors in terrestrial

  3. Radiation Induced Carcinogenesis; Epidemiology and Mechanisms: A Review

    Microsoft Academic Search

    Stuart Anderson

    Exposure to ionizing radiation has been proven to cause cancer and initiate mutagenesis in human and animal cells. This paper reviews some of the epide- miological data collected over the past 60 years and literature describing the current search for a genetic link to radiation induced carcinogenesis. Increased incidences of Leukemia, Breast Cancer, Lung Cancer, Skin Cancer and Bone Can-

  4. Electroacupuncture attenuates neuropathic pain after brachial plexus injury

    PubMed Central

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

    2014-01-01

    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

  5. Pseudo-paralysie du biceps brachial dans les paralysies obstétricales du plexus brachial (POPB) – À propos de l'« optimisme » de l'EMG

    Microsoft Academic Search

    J. L Benaim; J. L Jouve; J Bardot; D Casanova; G Magalon; G Bollini

    1999-01-01

    Pseudo-paralysis of the brachial biceps in obstetrical brachial plexus lesions (OBPL): concerning the `overly optimistic' EMG in OBPL.In birth palsy of the brachial plexus, the mixed interference pattern recorded for the brachial biceps on the electromyogram often conflicts with the muscle's inability to flex the elbow. We report our observations of a six-month-old infant who presented paralysis of the upper

  6. Experimental study: brachial motion artifact reduction in the ECG

    Microsoft Academic Search

    Shen Luo; W. J. Tompkins

    1995-01-01

    This study focuses on a dual-input adaptive noise reduction technique by investigation of brachial motion artifact in the ECG under a special experimental protocol. The ECG and motion artifact signals are acquired from a three-electrode system. Primary input is obtained from the standard EGG lead II. Because limbs function like fixed resistors in ECG measurement, we obtain EGG-free brachial motion

  7. Radiation-induced decomposition of explosives under extreme conditions

    SciTech Connect

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

    2008-11-03

    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.

  8. Using Imaging Methods to Interrogate Radiation-Induced Cell Signaling

    SciTech Connect

    Shankaran, Harish; Weber, Thomas J.; Freiin von Neubeck, Claere H.; Sowa, Marianne B.

    2012-04-01

    There is increasing emphasis on the use of systems biology approaches to define radiation induced responses in cells and tissues. Such approaches frequently rely on global screening using various high throughput 'omics' platforms. Although these methods are ideal for obtaining an unbiased overview of cellular responses, they often cannot reflect the inherent heterogeneity of the system or provide detailed spatial information. Additionally, performing such studies with multiple sampling time points can be prohibitively expensive. Imaging provides a complementary method with high spatial and temporal resolution capable of following the dynamics of signaling processes. In this review, we utilize specific examples to illustrate how imaging approaches have furthered our understanding of radiation induced cellular signaling. Particular emphasis is placed on protein co-localization, and oscillatory and transient signaling dynamics.

  9. The radiation-induced chemistry in solid xenon matrices

    NASA Astrophysics Data System (ADS)

    Feldman, V. I.; Kobzarenko, A. V.; Orlov, A. Y.; Sukhov, F. F.

    2012-08-01

    The paper presents an overview of recent studies of the radiation-chemical transformations of guest molecules in solid xenon induced by fast electrons and x-ray irradiation. Specific features of the experimental approach based on the combination of matrix isolation IR and EPR spectroscopy are briefly outlined (with a particular emphasis on monoisotopic and isotopically enriched xenon matrices). The results reveal rich and diverse radiation-induced chemistry in solid xenon, which is considered in the following major aspects: (1) matrix-induced and matrix-assisted transformations of the primary guest radical cations; (2) production and dynamics of hydrogen atoms; (3) formation of xenon hydrides. Finally, preliminary results on the radiation-induced generation of oxygen atoms and ions in solid xenon are presented.

  10. Caffeine Markedly Enhanced Radiation-Induced Bystander Effects

    NASA Astrophysics Data System (ADS)

    Jiang, Erkang; Wu, Lijun

    2009-04-01

    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).

  11. Aspergillus parasellar abscess mimicking radiation-induced neuropathy

    Microsoft Academic Search

    Toshiki Endo; Yoshihiro Numagami; Hidefumi Jokura; Hidetoshi Ikeda; Reizo Shirane; Takashi Yoshimoto

    2001-01-01

    BACKGROUNDTranssphenoidal surgery is a safe procedure for treatment of pituitary adenomas. However, several complications, including post-surgical infection, are known. We describe a case of Aspergillus parasellar abscess that presented with cranial neuropathies following transsphenoidal surgery and radiosurgery. We initially diagnosed the case as radiation-induced neuropathies, which delayed the detection of Aspergillus.CASE DESCRIPTIONA 55-year-old man underwent transsphenoidal surgery for a pituitary

  12. Radiation-induced effects in acousto-optic devices

    Microsoft Academic Search

    Edward W. Taylor; Anthony D. Sanchez; Steve A. Dewalt; Richard J. Padden; S. P. Chapman; Tim W. Monarski; Douglas M. Craig; Daniel J. Page

    1993-01-01

    A brief report on an ongoing study concerned with the responses of acousto-optic modulators (AOMs) and deflectors (AODs) exposed to linearly accelerated electrons, gamma rays, and X rays is presented. The diffracted spatial intensities of PbMoO4, TeO2, and InP devices were observed to undergo displacements and attenuation. Discussions of radiation- induced temperature gradients and color center formation believed to be

  13. Radiation induced degradation of fluorine containing elastomers at various temperatures

    Microsoft Academic Search

    Masayuki Ito

    1996-01-01

    This article studied the effect of temperature on the radiation induced degradation of fluorine containing elastomers, i.e. AFLAS type (Asahi glass Co. Ltd) and VITON type (Du pont). The temperature range is from 90 to 200°C. The irradiation was performed by 60Co ?-ray in air oven. Dose rate was 2.5 kGy\\/h. The weight loss by irradiation increases with increasing temperatures.

  14. Radiation-induced cataract in astronauts and cosmonauts

    Microsoft Academic Search

    Zahra Noushin Rastegar; Peter Eckart; Manfred Mertz

    2002-01-01

    Background. Opacification of the ocular lens is an important effect of exposure to ionizing radiation. Astronauts and cosmonauts are exposed to relatively high doses of all types of radiation in space, including high-energy particle radiation. A study was initiated to examine the lenses of the eyes of astronauts\\/cosmonauts to detect signs of radiation-induced cataracts. The aim of this study was

  15. Heavy-ion radiation induced bystander effect in mice

    NASA Astrophysics Data System (ADS)

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

    2012-07-01

    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.

  16. Modulation of Radiation-Induced Apoptosis by Thiolamines

    NASA Technical Reports Server (NTRS)

    Warters, R. L.; Roberts, J. C.; Wilmore, B. H.; Kelley, L. L.

    1997-01-01

    Exposure to the thiolamine radioprotector N-(2-mercaptoethyl)-1,3-propanediamine (WR-1065) induced apoptosis in the mouse TB8-3 hybridoma after 60-minute (LD(sub50) = 4.5mM) or during a 20-hour (LD(sub50) = 0.15 mM) exposure. In contrast, a 20-hour exposure to 17 mM L-cysteine or 10 mM cysteamine was required to induce 50 percent apoptosis within 20 hours. Apoptosis was not induced by either a 60-minute or 20-hour exposure to 10 mM of the thiazolidime prodrugs ribose-cysteine (RibCys) or ribose-cysteamine (RibCyst). Thiolamine-induced apoptosis appeared to be a p53-independent process since it was induced by WR-1065 exposure in human HL60 cells. Exposure to WR-1065 (4mM for 15 minutes) or cysteine (10mM for 60 minutes) before and during irradiation protected cells against the induction of both DNA double-strand breaks and apoptosis, while exposure to RibCys (10 mM for 3 hours) did not. Treatment with either WR-1065, cysteine, RibCys or RibCyst for 60 minutes beginning 60 minutes after irradiation did not affect the level of radiation-induced apoptosis. In contrast, treatment with either cysteine, cysteamine or RibCys for 20 hours beginning 60 minutes after irradiation enhanced radiation-induced apoptosis. Similar experiments could not be conducted with WR-1065 because of its extreme toxicity. Our results indicate that thiolamine enhancement of radiation-induced apoptosis is not involved in their previously reported capacity to reduce radiation-induced mutations.

  17. Protection from radiation-induced pneumonitis using cerium oxide nanoparticles.

    PubMed

    Colon, Jimmie; Herrera, Luis; Smith, Joshua; Patil, Swanand; Komanski, Chris; Kupelian, Patrick; Seal, Sudipta; Jenkins, D Wayne; Baker, Cheryl H

    2009-06-01

    In an effort to combat the harmful effects of radiation exposure, we propose that rare-earth cerium oxide (CeO(2)) nanoparticles (free-radical scavengers) protect normal tissue from radiation-induced damage. Preliminary studies suggest that these nanoparticles may be a therapeutic regenerative nanomedicine that will scavenge reactive oxygen species, which are responsible for radiation-induced cell damage. The effectiveness of CeO(2) nanoparticles in radiation protection in murine models during high-dose radiation exposure is investigated, with the ultimate goal of offering a new approach to radiation protection, using nanotechnology. We show that CeO(2) nanoparticles are well tolerated by live animals, and they prevent the onset of radiation-induced pneumonitis when delivered to live animals exposed to high doses of radiation. In the end, these studies provide a tremendous potential for radioprotection and can lead to significant benefits for the preservation of human health and the quality of life for humans receiving radiation therapy. PMID:19285453

  18. Clarithromycin Attenuates Radiation-Induced Lung Injury in Mice

    PubMed Central

    Lee, Seung Jun; Yi, Chin-ok; Heo, Rok Won; Song, Dae Hyun; Cho, Yu Ji; Jeong, Yi Yeong; Kang, Ki Mun; Roh, Gu Seob; Lee, Jong Deog

    2015-01-01

    Radiation-induced lung injury (RILI) is a common and unavoidable complication of thoracic radiotherapy. The current study was conducted to evaluate the ability of clarithromycin (CLA) to prevent radiation-induced pneumonitis, oxidative stress, and lung fibrosis in an animal model. C57BL/6J mice were assigned to control, irradiation only, irradiation plus CLA, and CLA only groups. Test mice received single thoracic exposures to radiation and/or oral CLA (100 mg/kg/day). Histopathologic findings and markers of inflammation, fibrosis, and oxidative stress were compared by group. On a microscopic level, CLA inhibited macrophage influx, alveolar fibrosis, parenchymal collapse, consolidation, and epithelial cell changes. The concentration of collagen in lung tissue was lower in irradiation plus CLA mice. Radiation-induced expression of tumor necrosis factor (TNF)-?, TNF receptor 1, acetylated nuclear factor kappa B, cyclooxygenase 2, vascular cell adhesion molecule 1, and matrix metallopeptidase 9 were also attenuated by CLA. Expression levels of nuclear factor erythroid 2-related factor 2 and heme oxygenase 1, transforming growth factor-?1, connective tissue growth factor, and type I collagen in radiation-treated lungs were also attenuated by CLA. These findings indicate that CLA ameliorates the deleterious effects of thoracic irradiation in mice by reducing pulmonary inflammation, oxidative damage, and fibrosis. PMID:26114656

  19. Mini-invasive robot-assisted surgery of the brachial plexus: a case of intraneural perineurioma.

    PubMed

    Lequint, Thierry; Naito, Kiyohito; Chaigne, Dominique; Facca, Sybille; Liverneaux, Philippe

    2012-09-01

    Brachial plexus surgery requires extensive incisions. They are esthetically unsightly and compromise the quality of recovery after nerve repair surgery. We present a new approach to brachial plexus surgery using mini-invasive robot-assisted surgery to perform a biopsy of an intraneural perineurioma of the right brachial plexus in a 12-year-old girl. PMID:22638873

  20. Quantifying Local Radiation-Induced Lung Damage From Computed Tomography

    SciTech Connect

    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)

    2010-02-01

    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.

  1. Measurements of prompt radiation induced conductivity of Kapton.

    SciTech Connect

    Preston, Eric F. (ITT Corporation, Colorado Springs, CO); Zarick, Thomas Andrew; Sheridan, Timothy J.; Hartman, E. Frederick; Stringer, Thomas Arthur (ITT Corporation, Colorado Springs, CO)

    2010-10-01

    We performed measurements of the prompt radiation induced conductivity in thin samples of Kapton (polyimide) at the Little Mountain Medusa LINAC facility in Ogden, UT. Three mil samples were irradiated with a 0.5 {mu}s pulse of 20 MeV electrons, yielding dose rates of 1E9 to 1E10 rad/s. We applied variable potentials up to 2 kV across the samples and measured the prompt conduction current. Analysis rendered prompt conductivity coefficients between 6E-17 and 2E-16 mhos/m per rad/s, depending on the dose rate and the pulse width.

  2. Radiation-Induced Premelting of Ice at Silica Interfaces

    SciTech Connect

    Schoeder, S. [Max-Planck-Institut fuer Metallforschung, Heisenbergstrasse 3, 70569 Stuttgart (Germany); European Synchrotron Radiation Facility (ESRF), 38043 Grenoble (France); Reichert, H.; Schroeder, H.; Mezger, M.; Okasinski, J. S.; Dosch, H. [Max-Planck-Institut fuer Metallforschung, Heisenbergstrasse 3, 70569 Stuttgart (Germany); Honkimaeki, V. [European Synchrotron Radiation Facility (ESRF), 38043 Grenoble (France); Bilgram, J. [Laboratorium fuer Festkoerperphysik, ETH Zuerich, 8093 Zuerich (Switzerland)

    2009-08-28

    The existence of surface and interfacial melting of ice below 0 deg. C has been confirmed by many different experimental techniques. Here we present a high-energy x-ray reflectivity study of the interfacial melting of ice as a function of both temperature and x-ray irradiation dose. We found a clear increase of the thickness of the quasiliquid layer with the irradiation dose. By a systematic x-ray study, we have been able to unambiguously disentangle thermal and radiation-induced premelting phenomena. We also confirm the previously announced very high water density (1.25 g/cm{sup 3}) within the emerging quasiliquid layer.

  3. Radiation-induced bystander signalling in cancer therapy

    PubMed Central

    Prise, Kevin M.; O'Sullivan, Joe M.

    2010-01-01

    Our understanding of how radiation kills normal and tumour cells has been based on an intimate knowledge of the direct induction of DNA damage and its cellular consequences. What has become clear is that, as well as responses to direct DNA damage, cell–cell signalling — known as the bystander effect — mediated through gap junctions and inflammatory responses may have an important role in the response of cells and tissues to radiation exposure and also chemotherapy agents. This Review outlines the key aspects of radiation-induced intercellular signalling and assesses its relevance for existing and future radiation-based therapies. PMID:19377507

  4. Facial reconstruction for radiation-induced skin cancer

    SciTech Connect

    Panje, W.R.; Dobleman, T.J. (Univ. of Chicago, IL (USA))

    1990-04-01

    Radiation-induced skin cancers can be difficult to diagnose and treat. Typically, a patient who has received orthovoltage radiotherapy for disorders such as acne, eczema, tinea capitis, skin tuberculosis, and skin cancer can expect that aggressive skin cancers and chronic radiodermatitis may develop subsequently. Cryptic facial cancers can lead to metastases and death. Prophylactic widefield excision of previously irradiated facial skin that has been subject to multiple recurrent skin cancers is suggested as a method of deterring future cutaneous malignancy and metastases. The use of tissue expanders and full-thickness skin grafts offers an expedient and successful method of subsequent reconstruction.

  5. Radiation-induced morphoea treated with UVA-1 phototherapy.

    PubMed

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

    2014-07-01

    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

  6. Radiation induced segregation in candidate fusion reactor alloys

    NASA Astrophysics Data System (ADS)

    Brimhall, J. L.; Baer, D. R.; Jones, R. H.

    The effect of radiation on surface segregation of minor and impurity elements has been studied in four candidate fusion reactor alloys. Radiation induced surface segregation of phosphorus was found in both 316 type stainless steel and in Nimonic PE-16. Segregation and depletion of the other alloying elements in 316 stainless steel agreed with that reported by other investigators. Segregation of nitrogen in ferritic HT-9 was enhanced by radiation but no phosphorus segregation was detected. No significant radiation enhanced or induced segregation was observed in a Ti-6Al-4V alloy. The results indicate that radiation enhanced grain boundary segregation could contribute to the embrittlement of 316 SS and PE-16.

  7. Radiation-induced segregation in candidate fusion-reactor alloys

    SciTech Connect

    Brimhall, J.L.; Baer, D.R.; Jones, R.H.

    1981-07-01

    The effect of radiation on surface segregation of minor and impurity elements has been studied in four candidate fusion reactor alloys. Radiation induced surface segregation of phosphorus was found in both 316 type stainless steel and in Nimonic PE-16. Segregation and depletion of the other alloying elements in 316 stainless steel agreed with that reported by other investigators. Segregation of nitrogen in ferritic HT-9 was enhanced by radiation but no phosphorus segregation was detected. No significant radiation enhanced or induced segregation was observed in a Ti-6Al-4V alloy. The results indicate that radiaton enhanced grain boundary segregation could contribute to the embrittlement of 316 SS and PE-16.

  8. Brachial Artery Access for Percutaneous Renal Artery Interventions

    SciTech Connect

    Kaukanen, Erkki T.; Manninen, Hannu I.; Matsi, Pekka J.; Soeder, Heini K. [Department of Clinical Radiology, Kuopio University Hospital, SF-70211 Kuopio (Finland)

    1997-09-15

    Purpose: To evaluate the suitability of transbrachial access for endovascular renal artery interventions. Methods: During 37 consecutive endovascular renal artery interventions, the transbrachial approach was used on nine patients (mean age 63 years; range 41-76 years) for 11 renal artery procedures on native kidneys and one percutaneous transluminal angioplasty (PTA) on a transplanted kidney. The reason for using transbrachial access was a steep aorta-renal angle in five, and severe aorta-iliac atherosclerosis in the remaining patients. In addition to the intervention catheter in the left brachial artery, an additional nonselective catheter for controlling the procedure was inserted transfemorally (six patients) or via the contralateral brachial artery. Results: Eleven interventions (six PTAs, five stents) were successfully completed. The one failure resulted from impenetrable subclavian artery stenosis. The only major complication was a brachial artery pseudoaneurysm requiring surgical treatment. Conclusion: Transbrachial access is an effective and relatively safe technique for renal artery interventions when transfemoral access is not possible.

  9. Radiation-induced electron migration in nucleic acids.

    PubMed

    Fuciarelli, A F; Sisk, E C; Miller, J H; Zimbrick, J D

    1994-11-01

    Radiation-induced electron migration along DNA is a mechanism by which randomly produced stochastic energy deposition events can lead to non-random types of damage along DNA manifested distal to the sites of the initial energy deposition. Radiation-induced electron migration in nucleic acids has been examined using oligonucleotides containing 5-bromouracil (5-BrU). Interaction of 5-BrU with solvated electrons results in release of bromide ions and formation or uracil-5-yl radicals. Monitoring either bromide ion release or uracil formation provides an opportunity to study electron migration processes in model nucleic acid systems. Using this approach we have discovered that electron migration along oligonucleotides is significantly influenced by the base sequence and strandedness. Migration along 7 base pairs in oligonucleotides containing guanine bases was observed for oligonucleotides irradiated in solution, which compares with mean migration distances of 6-10 bp for Escherichia coli DNA irradiated in solution and 5.5 bp for E. coli DNA irradiated in cells. Evidence also suggests that electron migration can occur preferentially in the 5' to 3' direction along a double-stranded oligonucleotide containing a region of purine bases adjacent to the 5-BrU moiety. 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. PMID:7983438

  10. Mechanisms of radiation-induced defect generation in fused silica

    NASA Astrophysics Data System (ADS)

    Natura, Ute; Sohr, Oliver; Martin, Rolf; Kahlke, Michael; Fasold, Gabriele

    2004-06-01

    Excimer laser radiation changes the optical properties of fused silica. These changes include radiation induced absorption and changes of the index of refraction, which in turn determine the expected lifetime of silica lenses used in optical microlithography. A fully automated experimental setup designed for the marathon exposure of samples at low energy densities was employed. Measurements of the induced absorption, of the H2 content using Raman spectroscopy as well as wavefront measurements were performed. A model to predict the aging behavior of silica in optical microlithography systems due to defect generation has been developed for both ArF laser irradiation and KrF laser irradiation. The model includes linear and nonlinear defect generation, relaxation processes and the consumption of hydrogen and describes the radiation induced changes of the index of refraction, the increase as well as the decrease. The model calculations were derived by analytical and numerical methods. A very good agreement in the range of parameters used in the experiments is observed.

  11. Radiation-induced skin carcinomas of the head and neck

    SciTech Connect

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

    1991-03-01

    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.

  12. DNA damage in cells exhibiting radiation-induced genomic instability.

    PubMed

    Keszenman, Deborah J; Kolodiuk, Lucia; Baulch, Janet E

    2015-05-01

    Cells exhibiting radiation-induced genomic instability exhibit varied spectra of genetic and chromosomal aberrations. Even so, oxidative stress remains a common theme in the initiation and/or perpetuation of this phenomenon. Isolated oxidatively modified bases, abasic sites, DNA single strand breaks and clustered DNA damage are induced in normal mammalian cultured cells and tissues due to endogenous reactive oxygen species generated during normal cellular metabolism in an aerobic environment. While sparse DNA damage may be easily repaired, clustered DNA damage may lead to persistent cytotoxic or mutagenic events that can lead to genomic instability. In this study, we tested the hypothesis that DNA damage signatures characterised by altered levels of endogenous, potentially mutagenic, types of DNA damage and chromosomal breakage are related to radiation-induced genomic instability and persistent oxidative stress phenotypes observed in the chromosomally unstable progeny of irradiated cells. The measurement of oxypurine, oxypyrimidine and abasic site endogenous DNA damage showed differences in non-double-strand breaks (DSB) clusters among the three of the four unstable clones evaluated as compared to genomically stable clones and the parental cell line. These three unstable clones also had increased levels of DSB clusters. The results of this study demonstrate that each unstable cell line has a unique spectrum of persistent damage and lead us to speculate that alterations in DNA damage signaling and repair may be related to the perpetuation of genomic instability. PMID:25711497

  13. Radiation-induced transmissable chromosomal instability in haemopoietic stem cells

    NASA Astrophysics Data System (ADS)

    Kadhim, M. A.; Wright, E. G.

    Heritable radiation-induced genetic alterations have long been assumed to be ``fixed'' within the first cell division. However, there is a growing body of evidence that a considerable fraction of cells surviving radiation exposure appear normal, but a variety of mutational changes arise in their progeny due to a transmissible genomic instability. In our investigations of G-banded metaphases, non-clonal cytogenetic aberrations, predominantly chromatid-type aberrations, have been observed in the clonal descendants of murine and human haemopoietic stem cells surviving low doses (~1 track per cell) of alpha-particle irradiations. The data are consistent with a transmissible genetic instability induced in a stem cell resulting in a diversity of chromosomal aberrations in its clonal progeny many cell divisions later. Recent studies have demonstrated that the instability phenotype persists in vivo and that the expression of chromosomal instability has a strong dependence on the genetic characteristics of the irradiated cell. At the time when cytogenetic aberrations are detected, an increased incidence of hprt mutations and apoptotic cells have been observed in the clonal descendants of alpha-irradiated murine haemopoietic stem cells. Thus, delayed chromosomal abnormalities, delayed cell death by apoptosis and late-arising specific gene mutations may reflect diverse consequences of radiation-induced genomic instability. The relationship, if any, between these effects is not established. Current studies suggest that expression of these delayed heritable effects is determined by the type of radiation exposure, type of cell and a variety of genetic factors.

  14. Radiation-induced dural fibrosarcoma with unusually short latent period

    SciTech Connect

    Ghatak, N.R.; Aydin, F.; Leshner, R.T. (Medical College of Virginia, Richmond (United States) Tulane Univ., New Orleans, LA (United States))

    1993-05-01

    Although rare, the occurrence of radiation-induced intracranial neoplasms of various types is well known. Among these tumors, fibrosarcomas, especially in the region of seila turcica, seem to be the most common type. These tumors characteristically occur after a long latent period, usually several years, following radiation therapy. The authors now report a case of apparently radiation-induced fibrosarcoma with some unusual features in a 10-year-old boy who was treated with radiation for medulloblastoma. He received a total dose of 53.2 Gy radiation delivered at 1.8 per fraction with 6 MV acceleration using the standard craniospinal technique. An MRI at 15 months after the completion of radiotherapy showed a mass over the cerebral convexity, which increased two-fold in size within a period of 4 months. A well circumscribed tumor was removed from the fronto-parietal convexity. The tumor measured 5x4.5x1.5 cm and was attached to the dura with invasion of the overlying bone. Histologically, it displayed the characteristic features of a low-grade fibrosarcoma. The patient remains free of tumor 18 months after the surgery. This case emphasizes the potential risk for the development of a second neoplasm following therapeutic radiation and also documents, to the authors' knowledge, the shortest latent period reported so far between administration of radiotherapy and development of an intracranial tumor.

  15. Delayed Diagnosis of Probable Radiation Induced Spinal Cord Vascular Disorders

    PubMed Central

    Won, Young Il; Chung, Chun Kee; Yun, Tae Jin

    2015-01-01

    Occasionally, unexpected neurological deficits occur after lumbar spinal surgery. We report a case of monoparesis after lumbar decompressive surgery. A 63-year-old man, who had undergone decompression of L4-5 for spinal stenosis 4 days previously in the other hospital, visted the emergency department with progressive weakness in the left leg and hypoesthesia below sensory level T7 on the right side. He had been cured of lung cancer with chemotherapy and radiation therapy 10 years previously, but detailed information of radiotherapy was not available. Whole spine magnetic resonance (MR) imaging showed fatty marrow change from T1 to T8, most likely due to previous irradiation. The T2-weighted MR image showed a high-signal T4-5 spinal cord lesion surrounded by a low signal rim, and the T1-weighted MR image showed focal high signal intensity with focal enhancement. The radiological diagnosis was vascular disorders with suspicious bleeding. Surgical removal was refused by the patient. With rehabilitation, the patient could walk independently without assistance 2 months later. Considering radiation induced change at thoracic vertebrae, vascular disorders may be induced by irradiation. If the spinal cord was previously irradiated, radiation induced vascular disorders needs to be considered. PMID:25810864

  16. A mechanistic model for radiation-induced crystallization and amorphization in U 3Si

    Microsoft Academic Search

    J. Rest

    1995-01-01

    Of concern for the proposed Advanced Neutron Source and Research Reactors, which would use intermetallic fuels, are potential radiation-induced phenomena that could affect the physical and mechanical properties of intermetallic aluminum dispersion fuels. For this reason and because of observations of radiation-induced amorphization of U3Si during ion irradiation, the phenomenology of radiation-induced amorphization is assessed. A rate theory model is

  17. Protection of T cells from radiation-induced apoptosis by Cepharanthin®

    Microsoft Academic Search

    Haruki Oyaizu; Yasushi Adachi; Ryoji Yasumizu; Minoru Ono; Kazuya Ikebukuro; Shirou Fukuhara; Susumu Ikehara

    2001-01-01

    Cepharanthin® (CE) is a medicine that contains several biscoclaurine alkaloids. We examined the effects of CE on radiation-induced T cell apoptosis. Radiation induced apoptosis on T cells in a dose-dependent manner, while CE inhibited radiation-induced apoptosis. CE also attenuated the cytotoxic effects of radiation on the proliferative response of T cells. CE inhibited not only the loss of mitochondrial transmembrane

  18. Posterior subscapular dissection: An improved approach to the brachial plexus for human anatomy students.

    PubMed

    Hager, Shaun; Backus, Timothy Charles; Futterman, Bennett; Solounias, Nikos; Mihlbachler, Matthew C

    2014-05-01

    Students of human anatomy are required to understand the brachial plexus, from the proximal roots extending from spinal nerves C5 through T1, to the distal-most branches that innervate the shoulder and upper limb. However, in human cadaver dissection labs, students are often instructed to dissect the brachial plexus using an antero-axillary approach that incompletely exposes the brachial plexus. This approach readily exposes the distal segments of the brachial plexus but exposure of proximal and posterior segments require extensive dissection of neck and shoulder structures. Therefore, the proximal and posterior segments of the brachial plexus, including the roots, trunks, divisions, posterior cord and proximally branching peripheral nerves often remain unobserved during study of the cadaveric shoulder and brachial plexus. Here we introduce a subscapular approach that exposes the entire brachial plexus, with minimal amount of dissection or destruction of surrounding structures. Lateral retraction of the scapula reveals the entire length of the brachial plexus in the subscapular space, exposing the brachial plexus roots and other proximal segments. Combining the subscapular approach with the traditional antero-axillary approach allows students to observe the cadaveric brachial plexus in its entirety. Exposure of the brachial dissection in the subscapular space requires little time and is easily incorporated into a preexisting anatomy lab curriculum without scheduling additional time for dissection. PMID:24698357

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

    NASA Astrophysics Data System (ADS)

    Matsumoto, H.; Ohnishi, T.

    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

  20. Radiation induced genome instability: multiscale modelling and data analysis

    NASA Astrophysics Data System (ADS)

    Andreev, Sergey; Eidelman, Yuri

    2012-07-01

    Genome instability (GI) is thought to be an important step in cancer induction and progression. Radiation induced GI is usually defined as genome alterations in the progeny of irradiated cells. The aim of this report is to demonstrate an opportunity for integrative analysis of radiation induced GI on the basis of multiscale modelling. Integrative, systems level modelling is necessary to assess different pathways resulting in GI in which a variety of genetic and epigenetic processes are involved. The multilevel modelling includes the Monte Carlo based simulation of several key processes involved in GI: DNA double strand breaks (DSBs) generation in cells initially irradiated as well as in descendants of irradiated cells, damage transmission through mitosis. Taking the cell-cycle-dependent generation of DNA/chromosome breakage into account ensures an advantage in estimating the contribution of different DNA damage response pathways to GI, as to nonhomologous vs homologous recombination repair mechanisms, the role of DSBs at telomeres or interstitial chromosomal sites, etc. The preliminary estimates show that both telomeric and non-telomeric DSB interactions are involved in delayed effects of radiation although differentially for different cell types. The computational experiments provide the data on the wide spectrum of GI endpoints (dicentrics, micronuclei, nonclonal translocations, chromatid exchanges, chromosome fragments) similar to those obtained experimentally for various cell lines under various experimental conditions. The modelling based analysis of experimental data demonstrates that radiation induced GI may be viewed as processes of delayed DSB induction/interaction/transmission being a key for quantification of GI. On the other hand, this conclusion is not sufficient to understand GI as a whole because factors of DNA non-damaging origin can also induce GI. Additionally, new data on induced pluripotent stem cells reveal that GI is acquired in normal mature cells during genome reprogramming by the oncogene c-myc and three additional transcription factors. These and other data reveal the need for generalisation of current model of GI. One can expect that different early events of both DNA damaging and non-damaging origins merge in a single late pathway. To search for a deeper view we propose to redefine GI as genome destabilisation manifested in erosion of genome states and altered transitions between states. This changing view on GI may help to integrate the inducing factors of various origins in the single basic model of GI.

  1. Characterization of the brachial artery shear stress following walking exercise

    Microsoft Academic Search

    Jaume Padilla; Ryan A Harris; Lawrence D Rink; Janet P Wallace

    Habitual exercise provides repeated episodes of elevated vascular shear stress (SS), which may be a mechanism for repair of endothelial dysfunction in dis- ease. Our aim was to determine the brachial artery SS during the 3-hour period fol- lowing single bouts of low, moderate, and high-intensity walking exercise. In a ran- domized crossover design, 14 men walked for 45 minutes

  2. Pain, muscle spasms and twitching fingers following brachial plexus avulsion

    Microsoft Academic Search

    Carlo Alberto Pagni; Sergio Canavero

    1993-01-01

    Three patients who, following partial brachial plexus avulsion, experienced pain, involuntary finger twitching and muscular spasms are reported. Two exhibited cutaneous trigger zones, stimulation of which exacerbated their pain; changes in emotional tone aggravated both the pain and the spasms. Pain would appear to be due not only to deafferentation and scarring of the dorsal horn, but also to an

  3. Brachial artery reconstruction for occlusive disease: A 12-year experience

    Microsoft Academic Search

    Sean P. Roddy; R. Clement Darling; Benjamin B. Chang; Paul B. Kreienberg; Philip S. K. Paty; William E. Lloyd; Dhiraj M. Shah

    2001-01-01

    Objective: Symptomatic arterial disease of the upper extremity is an uncommon problem. In this study, we evaluate our results with brachial artery reconstruction in patients who present with symptomatic atherosclerotic occlusive disease and compare this cohort's demographics with a similar group with lower extremity ischemia. Methods: From 1986 to 1998, all patients presenting for upper extremity revascularization with chronic ischemia

  4. Ultrasonographic Findings of the Axillary Part of the Brachial Plexus

    Microsoft Academic Search

    Gerald Retzl; Stephan Kapral; Manfred Greher; Walter Mauritz

    2001-01-01

    In this prospective study we sought to determine ana- tomic variations of the main brachial plexus nerves in the axilla and upper arm via high-resolution ultra- sonography (US) examination. Positions of nerves were studied via US in three sectional levels of the upper arm in 69 healthy volunteers (31 men and 38 women, me- dian age 28 yr). Analysis was

  5. Axillary Brachial Plexus Blockade for the Reflex Sympathetic Dystrophy Syndrome.

    ERIC Educational Resources Information Center

    Ribbers, G. M.; Geurts, A. C. H.; Rijken, R. A. J.; Kerkkamp, H. E. M.

    1997-01-01

    Reflex sympathetic dystrophy syndrome (RSD) is a neurogenic pain syndrome characterized by pain, vasomotor and dystrophic changes, and often motor impairments. This study evaluated the effectiveness of brachial plexus blockade with local anaesthetic drugs as a treatment for this condition. Three patients responded well; three did not. (DB)

  6. Comparison of two neurostimulation techniques for axillary brachial plexus blockade

    Microsoft Academic Search

    D. M. Coventry; K. F. Barker; M. Thomson

    2001-01-01

    This prospective, randomized, double-blind study compared two techniques of axillary brachial plexus block using a peripheral nerve stimulator. Both groups received initial musculo- cutaneous nerve block followed by either a single injection on median nerve stimulation (group 1) or a double injection divided between median and radial nerves (group 2). All 60 patients received a total of 30 ml of

  7. Brachial artery hyperaemic blood flow velocity and left ventricular geometry

    Microsoft Academic Search

    S J Järhult; J Sundström; L Lind

    2012-01-01

    Cardiovascular risk factors and carotid atherosclerosis relate to blood flow velocity in the brachial artery during induced hyperaemia. This relation proved to be particularly strong when using the hyperaemic systolic to diastolic blood flow velocity (SDFV) ratio. In this study, we further investigated this ratio in relation to the left ventricular (LV) geometry in a cross-sectional analysis. In the Prospective

  8. MRI of axillary brachial plexus blocks

    PubMed Central

    Kjelstrup, Trygve; Hol, Per K.; Courivaud, Frédéric; Smith, Hans-Jørgen; Røkkum, Magne; Klaastad, Øivind

    2014-01-01

    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 ClinicalTrials.gov identifier: NCT01033006. PMID:25051144

  9. Experimental Radiation-Induced Heart Disease: Past, Present, and Future

    PubMed Central

    Boerma, Marjan

    2012-01-01

    Radiation-induced heart disease (RIHD) is a serious side effect of radiotherapy for intrathoracic and chest wall tumors. The threshold dose for development of clinically significant RIHD is believed to be lower than previously assumed. Therefore, research into mechanisms of RIHD has gained substantial momentum. RIHD becomes clinically apparent ten to fifteen years after radiation exposure. Chronic manifestations of RIHD include accelerated atherosclerosis, cardiomyopathy, and valve abnormalities. Reducing exposure of the heart during radiotherapy is the only known method of preventing RIHD, and there are no approaches to reverse RIHD once it occurs. We use a combination of pharmacological and genetic animal models to determine biological mechanisms of RIHD. Major technological advances in small animal research have made this type of study more valuable. The long-term goal of this work is to identify targets for intervention in RIHD, thereby enhancing the efficacy and safety of thoracic radiotherapy. PMID:22663150

  10. Radiation Induced Incorporation of CO in Pure and Aqueous Methanol

    NASA Astrophysics Data System (ADS)

    Jung, Hak-Jin; Getoff, Nikola; Lorbeer, Eberhard

    1994-05-01

    Pure and aqueous methanol were used for radiation induced incorporation of CO at elevated pressure (up to 15 bar). The initial yields (Gi) of the main products in pure methanol under 15 bar CO and 1 bar N2O were found to be: Gi(formaldehyde) = 3.80 and Gi(glycolic aldehyde) = 2.0. For aqueous (10-2 mol · dm-3) methanol under 15 bar CO (dose: 0.557 kGy, pH = 2): the yields were G(formaldehyde) = 5.44, G(glycolic aldehyde) = 4.0 and G(oxalic acid) = 7.7. At pH = 7 the yields were essentially lower, namely: G(formaldehyde) = 3.2, G(glycolic aldehyde) = 2.0, G(formate) = 3.8 and G(oxalate) = 5.0. Probable reaction-mechanisms for the product formation are discussed.

  11. Radiation-induced transient attenuation of PCS fiber

    SciTech Connect

    Lyons, P.B.; Looney, L.D.; Ogle, J.W.

    1983-01-01

    Some applications of optical fibers require their exposure to intense radiation fields. This exposure can potentially degrade performance of a fiber data link. Research at Los Alamos National Laboratory has recently concentrated on development of an understanding of such radiation effects at short times, less than 100 ns. In previous papers we have identified a particular type of fiber, ITT plastic-clad-silica (PCS) with Suprasil core as optimum for short time radiation-induced attenuation, but that work used very large doses of ionizing radiation, close to 1 Mrad. For these high dose exposures, moderate success in understanding the transient nature of the attenuation was realized with a geminate recombination model. In this paper, we report further studies with ITT PCS fiber over a range of doses and wavelengths. Data on other PCS fibers is included that provide performance comparable to the ITT product. Comparison to several fluorsilicate fibers is also included.

  12. Probabilistic methodology for estimating radiation-induced cancer risk

    SciTech Connect

    Dunning, D.E. Jr.; Leggett, R.W.; Williams, L.R.

    1981-01-01

    The RICRAC computer code was developed at Oak Ridge National Laboratory to provide a versatile and convenient methodology for radiation risk assessment. The code allows as input essentially any dose pattern commonly encountered in risk assessments for either acute or chronic exposures, and it includes consideration of the age structure of the exposed population. Results produced by the analysis include the probability of one or more radiation-induced cancer deaths in a specified population, expected numbers of deaths, and expected years of life lost as a result of premature fatalities. These calculatons include consideration of competing risks of death from all other causes. The program also generates a probability frequency distribution of the expected number of cancers in any specified cohort resulting from a given radiation dose. The methods may be applied to any specified population and dose scenario.

  13. Dose-dependent radiation-induced hypotension in the canine

    SciTech Connect

    Cockerham, L.G.; Hampton, J.D.; Doyle, T.F.

    1986-01-01

    Radiation-induced early transient incapacitation (ETI) is often accompanied by severe systemic hypotension. However, postradiation hypotension does not occur with equal frequency in all species and is not reported with consistency in the canine. In an attempt to clarify the differences in reported canine post-radiation blood pressures, canine systemic blood pressures were determined both before and after exposure to gamma radiation of either 80 or 100 Gy. Data obtained from six sham-radiated beagles and 12 radiated beagles indicated that 100-Gy, whole-body, gamma radiation produced a decrease in systemic mean blood pressure while 80-Gy, whole-body, gamma radiation did not. Analysis of this data could be consistent with a quantal response to a gamma radiation dose between 80 Gy and 100 Gy.

  14. Factors that modify risks of radiation-induced cancer

    SciTech Connect

    Fabrikant, J.I.

    1988-11-01

    The collective influence of biologic and physical factors that modify risks of radiation-induced cancer introduces uncertainties sufficient to deny precision of estimates of human cancer risk that can be calculated for low-dose radiation in exposed populations. The important biologic characteristics include the tissue sites and cell types, baseline cancer incidence, minimum latent period, time-to-tumor recognition, and the influence of individual host (age and sex) and competing etiologic influences. Physical factors include radiation dose, dose rate, and radiation quality. Statistical factors include time-response projection models, risk coefficients, and dose-response relationships. Other modifying factors include other carcinogens, and other biological sources (hormonal status, immune status, hereditary factors).

  15. Factors that modify risks of radiation-induced cancer

    SciTech Connect

    Fabrikant, J.I. (Univ. of California, Berkeley (USA))

    1990-07-01

    The collective influence of biologic, physical, and other factors that modify risks of radiation-induced cancer introduces uncertainties and assumptions that limit precision of estimates of human cancer risk that can be calculated for populations exposed to low-dose radiation. The important biologic characteristics include the tissue sites and cell types, baseline cancer incidence, latent periods, time-to-tumor recognition, and individual host (e.g., age and sex) and competing etiologic influences. Physical factors include radiation dose, dose rate, and radiation quality. Statistical factors include time-response projection models, risk coefficients, and dose-response relationships. Sources that modify risk also include other carcinogens and biologic factors (e.g., hormonal conditions, immune status, hereditary factors). Discussion includes examples of known influences that modify radiation-associated cancer risks and how they have been dealt with in the risk-estimation process, including extrapolation to low doses, use of relative risk models, and other uncertainties.

  16. Non-radiation induced signals in TL dosimetry.

    PubMed

    German, U; Weinstein, M

    2002-01-01

    One source of background signals, which are non-radiation related, is the reader system and it includes dark current, external contaminants and electronic spikes. These factors can induce signals equivalent to several hundredths of mSv. Mostly, the effects are minimised by proper design of the TLD reader, but some effects are dependent on proper operation of the system. The other main group of background signals originates in the TL crystal and is due to tribothermoluminescence, dirt, chemical reactions and stimulation by visible or UV light. These factors can have a significant contribution, equivalent to over several mSv, depending on whether the crystal is bare or protected by PTFE. Working in clean environments, monitoring continuously the glow curves and performing glow curve deconvolution are suggested to minimise non-radiation induced spurious signals. PMID:12382710

  17. Radioprotectors and Mitigators of Radiation-Induced Normal Tissue Injury

    PubMed Central

    Cotrim, Ana P.; Hyodo, Fuminori; Baum, Bruce J.; Krishna, Murali C.; Mitchell, James B.

    2010-01-01

    Radiation is used in the treatment of a broad range of malignancies. Exposure of normal tissue to radiation may result in both acute and chronic toxicities that can result in an inability to deliver the intended therapy, a range of symptoms, and a decrease in quality of life. Radioprotectors are compounds that are designed to reduce the damage in normal tissues caused by radiation. These compounds are often antioxidants and must be present before or at the time of radiation for effectiveness. Other agents, termed mitigators, may be used to minimize toxicity even after radiation has been delivered. Herein, we review agents in clinical use or in development as radioprotectors and mitigators of radiation-induced normal tissue injury. Few agents are approved for clinical use, but many new compounds show promising results in preclinical testing. PMID:20413641

  18. A model of radiation-induced myelopoiesis in space.

    PubMed

    Esposito, R D; Durante, M; Gialanella, G; Grossi, G; Pugliese, M; Scampoli, P; Jones, T D

    2001-01-01

    Astronauts' radiation exposure limits are based on experimental and epidemiological data obtained on Earth. It is assumed that radiation sensitivity remains the same in the extraterrestrial space. However, human radiosensitivity is dependent upon the response of the hematopoietic tissue to the radiation insult. It is well known that the immune system is affected by microgravity. We have developed a mathematical model of radiation-induced myelopoiesis which includes the effect of microgravity on bone marrow kinetics. It is assumed that cellular radiosensitivity is not modified by the space environment, but repopulation rates of stem and stromal cells are reduced as a function of time in weightlessness. A realistic model of the space radiation environment, including the HZE component, is used to simulate the radiation damage. A dedicated computer code was written and applied to solar particle events and to the mission to Mars. The results suggest that altered myelopoiesis and lymphopoiesis in microgravity might increase human radiosensitivity in space. PMID:11771552

  19. Radiation-induced bystander effect: early process and rapid assessment.

    PubMed

    Wang, Hongzhi; Yu, K N; Hou, Jue; Liu, Qian; Han, Wei

    2015-01-01

    Radiation-induced bystander effect (RIBE) is a biological process that has received attention over the past two decades. RIBE refers to a plethora of biological effects in non-irradiated cells, including induction of genetic damages, gene expression, cell transformation, proliferation and cell death, which are initiated by receiving bystander signals released from irradiated cells. RIBE brings potential hazards to normal tissues in radiotherapy, and imparts a higher risk from low-dose radiation than we previously thought. Detection with proteins related to DNA damage and repair, cell cycle control, proliferation, etc. have enabled rapid assessment of RIBE in a number of research systems such as cultured cells, three-dimensional tissue models and animal models. Accumulated experimental data have suggested that RIBE may be initiated rapidly within a time frame as short as several minutes after radiation. These have led to the requirement of techniques capable of rapidly assessing RIBE itself as well as assessing the early processes involved. PMID:24139967

  20. An amino acid mixture mitigates radiation-induced gastrointestinal toxicity.

    PubMed

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

    2014-06-01

    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

  1. Environmental applications of radiation-induced defects in clay minerals

    NASA Astrophysics Data System (ADS)

    Allard, T.

    2011-12-01

    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.

  2. Bystander effects in radiation-induced genomic instability

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  3. Ion beam induced luminescence: Relevance to radiation induced bystander effects

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    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.

  4. TransDifferentiation of Neural Stem Cells: A Therapeutic Mechanism Against the Radiation Induced Brain Damage

    Microsoft Academic Search

    Kyeung Min Joo; Juyoun Jin; Bong Gu Kang; Se Jeong Lee; Kang Ho Kim; Heekyoung Yang; Young-Ae Lee; Yu Jin Cho; Yong-Seok Im; Dong-Sup Lee; Do-Hoon Lim; Dong Hyun Kim; Hong-Duck Um; Sang-Hun Lee; Jung-II Lee; Do-Hyun Nam

    2012-01-01

    Radiation therapy is an indispensable therapeutic modality for various brain diseases. Though endogenous neural stem cells (NSCs) would provide regenerative potential, many patients nevertheless suffer from radiation-induced brain damage. Accordingly, we tested beneficial effects of exogenous NSC supplementation using in vivo mouse models that received whole brain irradiation. Systemic supplementation of primarily cultured mouse fetal NSCs inhibited radiation-induced brain atrophy

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

    Microsoft Academic Search

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

    2005-01-01

    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%.

  6. The Development of Countermeasures for Space Radiation Induced Adverse Health Effects

    Microsoft Academic Search

    Ann Kennedy

    2010-01-01

    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

  7. Radiation-induced defects in clay minerals: A review

    NASA Astrophysics Data System (ADS)

    Allard, Th.; Balan, E.; Calas, G.; Fourdrin, C.; Morichon, E.; Sorieul, S.

    2012-04-01

    Extensive information has been collected on radiation effects on clay minerals over the last 35 years, providing a wealth of information on environmental and geological processes. The fields of applications include the reconstruction of past radioelement migrations, the dating of clay minerals or the evolution of the physico-chemical properties under irradiation. The investigation of several clay minerals, namely kaolinite, dickite, montmorillonite, illite and sudoite, by Electron Paramagnetic Resonance Spectroscopy has shown the presence of defects produced by natural or artificial radiations. These defects consist mostly of electron holes located on oxygen atoms of the structure. The various radiation-induced defects are differentiated through their nature and their thermal stability. Most of them are associated with a ? orbital on a Si-O bond. The most abundant defect in clay minerals is oriented perpendicular to the silicate layer. Thermal annealing indicates this defect in kaolinite (A-center) to be stable over geological periods at ambient temperature. Besides, electron or heavy ion irradiation easily leads to an amorphization in smectites, depending on the type of interlayer cation. The amorphization dose exhibits a bell-shaped variation as a function of temperature, with a decreasing part that indicates the influence of thermal dehydroxylation. Two main applications of the knowledge of radiation-induced defects in clay minerals are derived: (i) The use of defects as tracers of past radioactivity. In geological systems where the age of the clay can be constrained, ancient migrations of radioelements can be reconstructed in natural analogues 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 fault gouges or laterites of the Amazon basin. (ii) The influence of irradiation over physico-chemical properties of clay minerals. An environmental application concerns the performance assessment of the engineered barrier of nuclear waste disposals. In case of a leakage of transuranic elements from the radioactive waste form, alpha recoil nuclei can amorphize smectite after periods of the order of 1000 years according to a worst case scenario, whereas amorphization from ionizing radiation is unlikely. As amorphization greatly enhances the dissolution kinetics of smectite, the sensitivity of the smectites must be taken into account in the prediction of the long term behavior of engineered barriers.

  8. Hyperbaric Oxygen Therapy for Radiation-Induced Cystitis and Proctitis

    SciTech Connect

    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: lydia.komarnicky-kocher@drexelmed.edu [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States)

    2012-11-01

    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.

  9. Reoperation for failed shoulder reconstruction following brachial plexus birth injury

    PubMed Central

    2013-01-01

    Background Various approaches have been developed to treat the progressive shoulder deformity in patients with brachial plexus birth palsy. Reconstructive surgery for this condition consists of complex procedures with a risk for failure. Case presentations This is a retrospective case review of the outcome in eight cases referred to us for reoperation for failed shoulder reconstructions. In each case, we describe the initial attempt(s) at surgical correction, the underlying causes of failure, and the procedures performed to rectify the problem. Results were assessed using pre- and post-operative Mallet shoulder scores. All eight patients realized improvement in shoulder function from reoperation. Conclusions This case review identifies several aspects of reconstructive shoulder surgery for brachial plexus birth injury that may cause failure of the index procedure(s) and outlines critical steps in the evaluation and execution of shoulder reconstruction. PMID:23883413

  10. Radiation-induced chromosome damage in astronauts' lymphocytes.

    PubMed

    Testard, I; Ricoul, M; Hoffschir, F; Flury-Herard, A; Dutrillaux, B; Fedorenko, B; Gerasimenko, V; Sabatier, L

    1996-10-01

    The increased number of manned space missions has made it important to estimate the biological risks encountered by astronauts. As they are exposed to cosmic rays, especially ions with high linear energy transfer (LET), it is necessary to estimate the doses they receive. The most sensitive biological dosimetry used is based on the quantification of radiation-induced chromosome damage to human lymphocytes. After the space missions ANTARES (1992) and ALTAIR (1993), we performed cytogenetic analysis of blood samples from seven astronauts who had spent from 2 weeks to 6 months in space. After 2 or 3 weeks, the X-ray equivalent dose was found to be below the cytogenetic detection level of 20 mGy. After 6 months, the biological dose greatly varied among the astronauts, from 95 to 455 mGy equivalent dose. These doses are in the same range as those estimated by physical dosimetry (90 mGy absorbed dose and 180 mSv equivalent dose). Some blood cells exhibited the same cytogenetic pattern as the 'rogue cells' occasionally observed in controls, but with a higher frequency. We suggest that rogue cells might result from irradiation with high-LET particles of cosmic origin. However, the responsibility of such cells for the long-term effects of cosmic irradiation remains unknown and must be investigated. PMID:8862451

  11. Radiation-induced optic neuropathy: A magnetic resonance imaging study

    SciTech Connect

    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))

    1991-03-01

    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.

  12. Radiation-induced conductivity control in polyaniline blends/composites

    NASA Astrophysics Data System (ADS)

    Güven, Olgun

    2007-08-01

    Polyaniline (PANI) blends with chlorine-containing polymers and copolymers and composites with HCl-releasing compounds were prepared to investigate their radiation response in terms of induced conductivities. Blends of non-conductive PANI with poly(vinyl chloride) (PVC), poly(vinylidene chloride- co-vinyl acetate), [P(VDC- co-VAc)], poly(vinylidene chloride- co-vinyl chloride), [P(VDC- co-VC)] were prepared in the form of as-cast films. A number of blends which are different in composition were exposed to gamma radiation and accelerated electrons to various doses, and the effects of irradiation type and composition of polymers on the conductivity of films were investigated by using conductivity measurements and UV-vis and FT-IR spectroscopy. The results clearly showed that ionizing radiation is an effective tool to induce and control conductivity in the blends of PANI-base with chlorine-carrying polymers as well as its composites prepared from HCl-releasing compounds such as chloral hydrate. The main mechanism behind this radiation-induced conductivity is in situ doping of PANI-base with HCl released from partner polymers and low molecular weight compounds by the effect of radiation.

  13. Radiation induced copolymerization reactivity of different allyl monomers with styrene

    NASA Astrophysics Data System (ADS)

    Yildirim, Yeliz; Balcan, Mehmet

    2012-07-01

    Radiation induced copolymerizations of electron donating such as allyl phenol (AP) and electron withdrawing such as allyl isothiocyanate (AITC) monomers with styrene (Sty) as a comonomer were studied in order to correlate the electronic behavior with copolymerization yield and molecular weight. The allyl monomers and comonomer were mixed in the same mol ratios under Ar atmosphere and copolymerized by using gamma radiation in various absorbed doses (55, 110, 165 kGy) obtained from a Co-60 source. Poly(AP-co-Sty), and poly(AITC-co-Sty) could have been prepared at all of the absorbed doses. The maximum copolymerization yields were calculated as a 16.35 and 6.52 percent for poly(AP-co-Sty) and poly(AITC-co-Sty), respectively. The molecular weights of poly(AP-co-Sty) copolymers are found to be higher in comparison to those of poly(AITC-co-Sty). Both results indicate that, under the same irradiation conditions, AP is more reactive on styrene than AITC is. Thus, the monomers having electron withdrawing (EW) substituents attached to allyl group may result in better copolymerization yield and molecular weight than those with electron donating (ED) substituents. Thermal stabilities of the poly(AP-co-Sty) copolymers are also higher than those of poly(AITC-co-Sty).

  14. Radiation-induced sarcomas of the head and neck

    PubMed Central

    Thiagarajan, Anuradha; Iyer, N Gopalakrishna

    2014-01-01

    With improved outcomes associated with radiotherapy, radiation-induced sarcomas (RIS) are increasingly seen in long-term survivors of head and neck cancers, with an estimated risk of up to 0.3%. They exhibit no subsite predilection within the head and neck and can arise in any irradiated tissue of mesenchymal origin. Common histologic subtypes of RIS parallel their de novo counterparts and include osteosarcoma, chondrosarcoma, malignant fibrous histiocytoma/sarcoma nitricoxide synthase, and fibrosarcoma. While imaging features of RIS are not pathognomonic, large size, extensive local invasion with bony destruction, marked enhancement within a prior radiotherapy field, and an appropriate latency period are suggestive of a diagnosis of RIS. RIS development may be influenced by factors such as radiation dose, age at initial exposure, exposure to chemotherapeutic agents and genetic tendency. Precise pathogenetic mechanisms of RIS are poorly understood and both directly mutagenizing effects of radiotherapy as well as changes in microenvironments are thought to play a role. Management of RIS is challenging, entailing surgery in irradiated tissue and a limited scope for further radiotherapy and chemotherapy. RIS is associated with significantly poorer outcomes than stage-matched sarcomas that arise independent of irradiation and surgical resection with clear margins seems to offer the best chance for cure. PMID:25493233

  15. Interleukin-32 Positively Regulates Radiation-Induced Vascular Inflammation

    SciTech Connect

    Kobayashi, Hanako; Yazlovitskaya, Eugenia M. [Department of Radiation Oncology, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN (United States); Lin, P. Charles [Department of Radiation Oncology, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN (United States); Department of Cancer Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN (United States); Department of Cell and Development Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN (United States)], E-mail: Charles.lin@vanderbilt.edu

    2009-08-01

    Purpose: To study the role of interleukin-32 (IL-32), a novel protein only detected in human tissues, in ionizing radiation (IR)-induced vascular inflammation. Methods and Materials: Irradiated (0-6 Gy) human umbilical vein endothelial cells treated with or without various agents-a cytosolic phospholipase A2 (cPLA2) inhibitor, a cyclooxygenase-2 (Cox-2) inhibitor, or lysophosphatidylcholines (LPCs)-were used to assess IL-32 expression by Northern blot analysis and quantitative reverse transcriptase-polymerase chain reaction. Expression of cell adhesion molecules and leukocyte adhesion to endothelial cells using human acute monocytic leukemia cell line (THP-1) cells was also analyzed. Results: Ionizing radiation dramatically increased IL-32 expression in vascular endothelial cells through multiple pathways. Ionizing radiation induced IL-32 expression through nuclear factor {kappa}B activation, through induction of cPLA2 and LPC, as well as induction of Cox-2 and subsequent conversion of arachidonic acid to prostacyclin. Conversely, blocking nuclear factor {kappa}B, cPLA2, and Cox-2 activity impaired IR-induced IL-32 expression. Importantly, IL-32 significantly enhanced IR-induced expression of vascular cell adhesion molecules and leukocyte adhesion on endothelial cells. Conclusion: This study identifies IL-32 as a positive regulator in IR-induced vascular inflammation, and neutralization of IL-32 may be beneficial in protecting from IR-induced inflammation.

  16. Radiation-Induced Notch Signaling in Breast Cancer Stem Cells

    SciTech Connect

    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: fpajonk@mednet.ucla.edu [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)

    2013-11-01

    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.

  17. Radiation-Induced Bystander Response: Mechanism and Clinical Implications.

    PubMed

    Suzuki, Keiji; Yamashita, Shunichi

    2014-01-01

    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

  18. Radiation-induced alterations in cytokine production by skin cells.

    PubMed

    Müller, Kerstin; Meineke, Viktor

    2007-04-01

    Ionizing radiation exposure of skin results in a cutaneous radiation reaction comprising all pathophysiological reactions and clinical symptoms in irradiated skin. Biological responses of skin occur in a characteristic temporal pattern and mainly depend on radiation quality, dose rate, total dose, and cellular conditions. Immediately after irradiation, production of cytokines by skin cells is initiated and continues as a cascade during all stages of the cutaneous radiation syndrome leading to progressive late symptoms, the predominant of which is fibrosis. Cytokines are important signaling molecules mediating communicative interactions both locally between different cell types within dermal tissues and distantly between organs. Although during recent years much progress has been made in dissecting the complex cytokine network, the role of cytokines in the pathophysiology of the cutaneous radiation reaction is only beginning to be elucidated. Previous studies indicate that the major cytokines in the response of skin cells to ionizing radiation include IL (interleukin)-1, IL-6, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta, and the chemokines IL-8 and eotaxin. In this paper, existing data on the radiation-induced modulation of cytokine expression by skin cells are reviewed. PMID:17379094

  19. Radiation-induced bystander effects in vivo are sex specific.

    PubMed

    Koturbash, Igor; Kutanzi, Kristy; Hendrickson, Karl; Rodriguez-Juarez, Rocio; Kogosov, Dmitry; Kovalchuk, Olga

    2008-07-01

    Ionizing radiation (IR) effects span beyond the area of direct exposure and can be observed in neighboring and distant naïve cells and organs. This phenomenon is termed a 'bystander effect'. IR effects in directly exposed tissue in vivo are epigenetically mediated and distinct in males and females. Yet, IR-induced bystander effects have never been explored in a sex-specificity domain. We used an in vivo mouse model, whereby the bystander effects are studied in spleen of male and female animals subjected to head exposure when the rest of the body is protected by a medical-grade lead shield. We analyzed the induction of DNA damage and alterations in global DNA methylation. Molecular parameters were correlated with cellular proliferation and apoptosis levels. The changes observed in bystander organs are compared to the changes in unexposed animals and animals exposed to predicted and measured scatter doses. We have found the selective induction of DNA damage levels, global DNA methylation, cell proliferation and apoptosis in exposed and bystander spleen tissue of male and female mice. Sex differences were significantly diminished in animals subjected to a surgical removal of gonads. These data constitute the first evidence of sex differences in radiation-induced bystander effects in mouse spleen in vivo. We show the role of sex hormones in spleen bystander responses and discuss implications of the observed changes. PMID:18508093

  20. Radiation-Induced Bystander Response: Mechanism and Clinical Implications

    PubMed Central

    Suzuki, Keiji; Yamashita, Shunichi

    2014-01-01

    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

  1. Safe method of supraclavicular brachial-plexus anesthesia

    Microsoft Academic Search

    Yoshiki Yamano

    1983-01-01

    Summary  Using the needle direction we devised, we applied brachial-plexus anesthesia in the supraclavicular approach originated by\\u000a Kulenkampff to 561 patients 6 to 85 years of age. In this method, 20 ml of anesthetic was enough to obtain more than 95% anesthetic\\u000a effect without any complications such as pneumothorax. Moreover, by using a long-acting drug (bupivacaine), we could get an\\u000a effect

  2. Aortic-brachial stiffness mismatch and mortality in dialysis population.

    PubMed

    Fortier, Catherine; Mac-Way, Fabrice; Desmeules, Simon; Marquis, Karine; De Serres, Sacha A; Lebel, Marcel; Boutouyrie, Pierre; Agharazii, Mohsen

    2015-02-01

    We hypothesized that increased aortic stiffness (central elastic artery) combined with a decrease in brachial stiffness (peripheral muscular artery) leads to the reversal of the physiological stiffness gradient (ie, mismatch), promoting end-organ damages through increased forward pressure wave transmission into the microcirculation. We, therefore, examined the effect of aortic-brachial stiffness mismatch on mortality in patients in need of dialysis. In a prospective observational study, aortic-brachial arterial stiffness mismatch (pulse wave velocity ratio) was assessed using carotid-femoral pulse wave velocity divided by carotid-radial pulse wave velocity in 310 adult patients on dialysis. After a median follow-up of 29 months, 146 (47%) deaths occurred. The hazard ratio (HR) for mortality related to PWV ratio in a Cox regression analysis was 1.43 (95% confidence interval [CI], 1.24-1.64; P<0.001 per 1 SD) and was still significant after adjustments for confounding factors, such as age, dialysis vintage, sex, cardiovascular disease, diabetes mellitus, smoking status, and weight (HR, 1.23; 95% CI: 1.02-1.49). The HRs for changes in 1 SD of augmentation index (HR, 1.35; 95% CI, 1.12-1.63), carotid-femoral pulse wave velocity (HR, 1.29; 95% CI, 1.11-1.50), and carotid-radial pulse wave velocity (HR, 0.80; 95% CI, 0.67-0.95) were statistically significant in univariate analysis, but were no longer statistically significant after adjustment for age. In conclusion, aortic-brachial arterial stiffness mismatch was strongly and independently associated with increased mortality in this dialysis population. Further studies are required to confirm these finding in lower-risk groups. PMID:25452473

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

    PubMed Central

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

    2013-01-01

    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

  4. A Two Trunked Brachial Plexus: A Case Report

    PubMed Central

    Singla, Rajan Kumar; Sharma, Ravi Kant; Shree, Bhagya

    2013-01-01

    The brachial plexus is a major and a complicated plexus at the root of the neck. It is formed by the ventral primary rami of the C5, C6, C7, C8 and the T1 spinal nerves. During the routine under graduate dissection of the right upper limb of an adult female cadaver, a variant pattern of a two trunked brachial plexus was encountered. The upper trunk was formed by the fusion of the C5 and the C6 roots. The C7 root, instead of continuing as the middle trunk, joined with the roots of C8 and T1 to form the lower trunk. On the left side, the usual pattern of the brachial plexus was seen. The knowledge on such variations are of interest to anatomists, clinicians, anesthesiologists and especially, to surgeons. These are of immense importance during surgical explorations of the axilla and the arm region and also during nerve blocks. It also helps the clinicians in getting a proper understanding of some previously unexplained clinical symptoms. Further, the ontogeny and the phylogeny of this entity have been discussed in detail. PMID:23730651

  5. A Perplexing Presentation of Entrapment of the Brachial Artery

    PubMed Central

    Cevirme, Deniz; Aksoy, Eray; Adademir, Taylan; Sunar, Hasan

    2015-01-01

    A 45-year-old male being otherwise healthy presented acute onset of right upper extremity ischemia. On physical examination, axillary artery could be palpated whereas the brachial artery could not be palpated below the level of the antecubital fossa, including radial and ulnar artery pulses. Pulses were also inaudible with pocket-ultrasound below the level of the brachial artery bifurcation. The patient was initially diagnosed to have acute thromboembolic occlusion and given 5000?IU intravenous heparin. The patient was taken to the operating room. We noticed that the ischemic symptoms disappeared within a couple of minutes just before we began the operation. However, ischemic symptoms reappeared six hours later and computed tomography angiography showed lack of enhancement below the elbow crease. We were taking the patient to the operating room for the second time when the symptoms recovered in a few minutes, again. The operation was not canceled anymore. In the operation, the brachial artery was found anomalously perforating and it was entrapped by the bicipital aponeurosis. The artery was relieved by resecting the aponeurosis and there was no need for any other intervention. The patient had no more recurrence of symptoms postoperatively. PMID:26185707

  6. Dosimetric Analysis of Radiation-induced Gastric Bleeding

    SciTech Connect

    Feng, Mary, E-mail: maryfeng@umich.edu [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Normolle, Daniel [Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania (United States)] [Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Pan, Charlie C. [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Dawson, Laura A. [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada)] [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada); Amarnath, Sudha [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Ensminger, William D. [Department of Internal Medicine, Division of Hematology Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Internal Medicine, Division of Hematology Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Lawrence, Theodore S.; Ten Haken, Randall K. [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)

    2012-09-01

    Purpose: Radiation-induced gastric bleeding has been poorly understood. In this study, we described dosimetric predictors for gastric bleeding after fractionated radiation therapy. Methods and Materials: The records of 139 sequential patients treated with 3-dimensional conformal radiation therapy (3D-CRT) for intrahepatic malignancies were reviewed. Median follow-up was 7.4 months. The parameters of a Lyman normal tissue complication probability (NTCP) model for the occurrence of {>=}grade 3 gastric bleed, adjusted for cirrhosis, were fitted to the data. The principle of maximum likelihood was used to estimate parameters for NTCP models. Results: Sixteen of 116 evaluable patients (14%) developed gastric bleeds at a median time of 4.0 months (mean, 6.5 months; range, 2.1-28.3 months) following completion of RT. The median and mean maximum doses to the stomach were 61 and 63 Gy (range, 46-86 Gy), respectively, after biocorrection of each part of the 3D dose distributions to equivalent 2-Gy daily fractions. The Lyman NTCP model with parameters adjusted for cirrhosis predicted gastric bleed. Best-fit Lyman NTCP model parameters were n=0.10 and m=0.21 and with TD{sub 50} (normal) = 56 Gy and TD{sub 50} (cirrhosis) = 22 Gy. The low n value is consistent with the importance of maximum dose; a lower TD{sub 50} value for the cirrhosis patients points out their greater sensitivity. Conclusions: This study demonstrates that the Lyman NTCP model has utility for predicting gastric bleeding and that the presence of cirrhosis greatly increases this risk. These findings should facilitate the design of future clinical trials involving high-dose upper abdominal radiation.

  7. Molecular responses of radiation-induced liver damage in rats

    PubMed Central

    CHENG, WEI; XIAO, LEI; AINIWAER, AIMUDULA; WANG, YUNLIAN; WU, GE; MAO, RUI; YANG, YING; BAO, YONGXING

    2015-01-01

    The aim of the present study was to investigate the molecular responses involved in radiation-induced liver damage (RILD). Sprague-Dawley rats (6-weeks-old) were irradiated once at a dose of 20 Gy to the right upper quadrant of the abdomen. The rats were then sacrificed 3 days and 1, 2, 4, 8 and 12 weeks after irradiation and rats, which were not exposed to irradiation were used as controls. Weight measurements and blood was obtained from the rats and liver tissues were collected for histological and apoptotic analysis. Immunohistochemistry, reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis were performed to measure the expression levels of mRNAs and proteins, respectively. The serum levels of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase were increased significantly in the RILD rats. Histological investigation revealed the proliferation of collagen and the formation of fibrotic tissue 12 weeks after irradiation. Apoptotic cells were observed predominantly 2 and 4 weeks after irradiation. The immunohistochemistry, RT-qPCR and western blot analysis all revealed the same pattern of changes in the expression levels of the molecules assessed. The expression levels of transforming growth factor-?1 (TGF-?1), nuclear factor (NF)-?B65, mothers against decapentaplegic homolog 3 (Smad3) and Smad7 and connective tissue growth factor were increased during the recovery period following irradiation up to 12 weeks. The expression levels of tumor necrosis factor-?, Smad7 and Smad4 were only increased during the early phase (first 4 weeks) of recovery following irradiation. In the RILD rat model, the molecular responses indicated that the TGF-?1/Smads and NF-?B65 signaling pathways are involved in the mechanism of RILD recovery. PMID:25483171

  8. Radiation-induced epigenetic bystander effects demonstrated in Arabidopsis thaliana.

    PubMed

    Xu, Wei; Wang, Ting; Xu, Shuyan; Xu, Shaoxin; Wu, Lijun; Wu, Yuejin; Bian, Po

    2015-05-01

    Radiation-induced bystander effects (RIBE) in vivo in the higher plant Arabidopsis thaliana ( A. thaliana ) have been well demonstrated in terms of effects on development and genetics. However, there is not yet robust evidence regarding RIBE-mediated epigenetic changes in plants. To address this, in the current work the roots of A. thaliana seedlings were locally irradiated with 10 Gy of ? particles, after which DNA methylation in bystander aerial plants were detected using the methylation-sensitive amplification polymorphism (MSAP) and bisulfite sequencing PCR (BSP). Results showed that irradiation of the roots led to long-distance changes in DNA methylation patterns at some CCGG sites over the whole genome, specifically from hemi-methylation to non-methylation, and the methylation ratios, mainly at CG sites, strongly indicating the existence of RIBE-mediated epigenetic changes in higher plants. Root irradiation also influenced expressions of DNA methylation-related MET1, DRM2 and SUVH4 genes and demethylation-related DML3 gene in bystander aerial plants, suggesting a modulation of RIBE to the methylation machinery in plants. In addition, the multicopy P35S:GUS in A. thaliana line L5-1, which is silenced epigenetically by DNA methylation and histone modification, was transcriptionally activated through the RIBE. The transcriptional activation could be significantly inhibited by the treatment with reactive oxygen species (ROS) scavenger dimethyl sulfoxide (DMSO), indicative of a pivotal role of ROS in RIBE-mediated epigenetic changes. Time course analyses showed that the bystander signaling molecule(s) for transcriptional activation of multicopy P35S:GUS, although of unknown chemical nature, were generated in the root cells within 24 h postirradiation. PMID:25938771

  9. Radiation-Induced Phase Transformations in Ilmenite-Group Minerals

    SciTech Connect

    Mitchell, J. N.

    1997-12-31

    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.

  10. Dosimetric Analysis of Radiation-Induced Gastric Bleeding

    PubMed Central

    Feng, Mary; Normolle, Daniel; Pan, Charlie C.; Dawson, Laura A.; Amarnath, Sudha; Ensminger, William D.; Lawrence, Theodore S.; Ten Haken, Randall K.

    2012-01-01

    Purpose Radiation-induced gastric bleeding has been poorly understood. In this study, we describe dosimetric predictors for gastric bleeding after fractionated radiotherapy and compare several predictive models. Materials & Methods The records of 139 sequential patients treated with 3-dimensional conformal radiotherapy (3D-CRT) for intrahepatic malignancies between January 1999 and April 2002 were reviewed. Median follow-up was 7.4 months. Logistic regression and Lyman normal tissue complication probability (NTCP) models for the occurrence of ? grade 3 gastric bleed were fit to the data. The principle of maximum likelihood was used to estimate parameters for all models. Results Sixteen of 116 evaluable patients (14%) developed gastric bleeds, at a median time of 4.0 months (mean 6.5 months, range 2.1–28.3 months) following completion of RT. The median and mean of the maximum doses to the stomach were 61 and 63 Gy (range 46 Gy–86 Gy), respectively, after bio-correction to equivalent 2 Gy daily fractions. The Lyman NTCP model with parameters adjusted for cirrhosis was most predictive of gastric bleed (AUROC=0.92). Best fit Lyman NTCP model parameters were n =0.10, and m =0.21, with TD50(normal) =56 Gy and TD50(cirrhosis) = 22 Gy. The low n value is consistent with the importance of maximum dose; a lower TD50 value for the cirrhosis patients points out their greater sensitivity. Conclusion This study demonstrates that the Lyman NTCP model has utility for predicting gastric bleeding, and that the presence of cirrhosis greatly increases this risk. These findings should facilitate the design of future clinical trials involving high-dose upper abdominal radiation. PMID:22541965

  11. [DNA-signaling pathway mediating development of a radiation-induced bystander effect in human cells].

    PubMed

    Ermakov, A V; Kon'kova, M S; Kostiuk, S V; Ve?ko, N N

    2011-01-01

    Low doses of ionizing radiation induce the adaptive effect (AE) development in human cells which is followed by a number of cell responses. These responses can be transmitted from irradiated cells to non-irradiated ones (bystander effect, BE). The major role in radiation-induced BE is played by an oxidative stress (OS) and a DNA-signaling pathway, in which extracellular DNA fragments (ecDNA) are the factors of stress-signalization. We propose the following sequence of events in this signaling system: irradiation-OS-DNA modification-apoptosis of irradiated cells-ecDNA-signal acceptance by non-irradiated cells-OS-DNA modification, etc. We observed a radiation-induced BE which is accompanied by DNA-signaling pathway in differentiated and undifferentiated human cells forming monolayer or suspension cultures. Here we discuss several aspects of the radiation-induced BE mechanism and its persistence possibilities. PMID:22384714

  12. Sulfation of keratan sulfate proteoglycan reduces radiation-induced apoptosis in human Burkitt's lymphoma cell lines.

    PubMed

    Nakayama, Fumiaki; Umeda, Sachiko; Ichimiya, Tomomi; Kamiyama, Shin; Hazawa, Masaharu; Yasuda, Takeshi; Nishihara, Shoko; Imai, Takashi

    2013-01-16

    This study focuses on clarifying the contribution of sulfation to radiation-induced apoptosis in human Burkitt's lymphoma cell lines, using 3'-phosphoadenosine 5'-phosphosulfate transporters (PAPSTs). Overexpression of PAPST1 or PAPST2 reduced radiation-induced apoptosis in Namalwa cells, whereas the repression of PAPST1 expression enhanced apoptosis. Inhibition of PAPST slightly decreased keratan sulfate (KS) expression, so that depletion of KS significantly increased radiation-induced apoptosis. In addition, the repression of all three N-acetylglucosamine-6-O-sulfotransferases (CHST2, CHST6, and CHST7) increased apoptosis. In contrast, PAPST1 expression promoted the phosphorylation of p38 MAPK and Akt in irradiated Namalwa cells. These findings suggest that 6-O-sulfation of GlcNAc residues in KS reduces radiation-induced apoptosis of human Burkitt's lymphoma cells. PMID:23238079

  13. ORIGINAL PAPER Ionizing radiation induces DNA double-strand breaks in bystander primary

    E-print Network

    and Genetic Engineering, 148 Zabolotnogo St, Kiev 03143, Ukraine; 3 Center for Radiological Research, CollegeORIGINAL PAPER Ionizing radiation induces DNA double-strand breaks in bystander primary human

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

    E-print Network

    Niu, Yunyun

    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 ...

  15. Layout-Related Stress Effects on Radiation-Induced Leakage Current

    Microsoft Academic Search

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

    2010-01-01

    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

  16. Idiopathic and Radiation-Induced Ocular Telangiectasia: The Involvement of the ATM Gene

    Microsoft Academic Search

    Martine Mauget-Faysse; Michele Vuillaume; Maddalena Quaranta; Norman Moullan; Sandra Angele; Marlin D. Friesen; Janet Hall

    2003-01-01

    PURPOSE. To investigate whether individuals, with no family history of ataxia telangiectasia (AT), in whom idiopathic or radiation-induced ocular telangiectasia developed are carriers of ATM gene mutations. METHODS. The ATM cDNA from lymphoblastoid cell lines estab- lished from 16 patients with idiopathic retinal or choroidal telan- giectasia and 14 patients with radiation-induced telangiectasia after radiotherapy for age-related macular degeneration (AMD)

  17. Radiation-induced absorption in high-purity silica fiber preforms

    Microsoft Academic Search

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

    2005-01-01

    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

  18. Protection of cellular DNA from ?-radiation-induced damages and enhancement in DNA repair by troxerutin

    Microsoft Academic Search

    Dharmendra Kumar Maurya; Sreedevi Balakrishnan; Veena Prakash Salvi; Cherupally Krishnan Krishnan Nair

    2005-01-01

    The effect of troxerutin on ?-radiation-induced DNA strand breaks in different tissues of mice in vivo and formations of the micronuclei were studied in human peripheral blood lymphocytes ex vivo and mice blood reticulocytes in vivo. Treatments with 1 mM troxerutin significantly inhibited the micronuclei induction in the human lymphocytes. Troxerutin protected\\u000a the human peripheral blood leucocytes from radiation-induced DNA

  19. Comparison of endothelial function evaluated by strain gauge plethysmography and brachial artery ultrasound

    Microsoft Academic Search

    Concetta Irace; Roberto Ceravolo; Libero Notarangelo; Anna Crescenzo; Giorgio Ventura; Oscar Tamburrini; Francesco Perticone; Agostino Gnasso

    2001-01-01

    Strain gauge plethysmography and brachial artery ultrasound are widely used to study endothelial function. No data on correlation between these two procedures are reported. The present study compared these two methods and investigated the correlation between vasodilation and brachial wall shear stress. In six healthy subjects and ten patients with hypertension or obesity, strain gauge plethysmography was performed in resting

  20. The Brachial Plexus: Development and Assessment of a Computer Based Learning Tool

    Microsoft Academic Search

    Douglas J. Gould

    2001-01-01

    The objective of the present study is to evaluate the use of multimedia technology to simplify study of the brachial plexus. A combination of newly-rendered illustrations, animations, explanatory text, and a set of printable sample questions were combined into a program to provide a tutorial for the brachial plexus. One aspect of the program is an animation showing the devel-

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

    SciTech Connect

    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)

    1996-05-15

    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.

  2. Penile erectile dysfunction after brachial plexus root avulsion injury in rats

    PubMed Central

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

    2014-01-01

    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. PMID:25422647

  3. Tramadol Added to Mepivacaine Prolongs the Duration of an Axillary Brachial Plexus Blockade

    Microsoft Academic Search

    Stephan Kapral; Gabriele Gollmann; Barbara Waltl; Rudolf Likar; Robert N. Sladen; Christian Weinstabl; Franz Lehofer

    1999-01-01

    Tramadol is an analgesic drug that is antagonized by a2-adrenoceptor antagonists, as well as opioid antago- nists. We hypothesized that tramadol might produce effects on an axillary brachial plexus blockade similar to those of clonidine. We designed a prospective, con- trolled, double-blinded study to assess the impact of tramadol added to mepivacaine on the duration of an axillary brachial plexus

  4. Radiation-induced osteosarcomas in the pediatric population

    SciTech Connect

    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: apaulino@tmh.tmc.edu; 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)

    2005-11-15

    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.

  5. Radiation Induced Segregation in High Chromium Ferritic/Martensitic Steels

    NASA Astrophysics Data System (ADS)

    Field, Kevin G.

    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.

  6. Finger movement at birth in brachial plexus birth palsy

    PubMed Central

    Nath, Rahul K; Benyahia, Mohamed; Somasundaram, Chandra

    2013-01-01

    AIM: To investigate whether the finger movement at birth is a better predictor of the brachial plexus birth injury. METHODS: We conducted a retrospective study reviewing pre-surgical records of 87 patients with residual obstetric brachial plexus palsy in study 1. Posterior subluxation of the humeral head (PHHA), and glenoid retroversion were measured from computed tomography or Magnetic resonance imaging, and correlated with the finger movement at birth. The study 2 consisted of 141 obstetric brachial plexus injury patients, who underwent primary surgeries and/or secondary surgery at the Texas Nerve and Paralysis Institute. Information regarding finger movement was obtained from the patient’s parent or guardian during the initial evaluation. RESULTS: Among 87 patients, 9 (10.3%) patients who lacked finger movement at birth had a PHHA > 40%, and glenoid retroversion < -12°, whereas only 1 patient (1.1%) with finger movement had a PHHA > 40%, and retroversion < -8° in study 1. The improvement in glenohumeral deformity (PHHA, 31.8% ± 14.3%; and glenoid retroversion 22.0° ± 15.0°) was significantly higher in patients, who have not had any primary surgeries and had finger movement at birth (group 1), when compared to those patients, who had primary surgeries (nerve and muscle surgeries), and lacked finger movement at birth (group 2), (PHHA 10.7% ± 15.8%; Version -8.0° ± 8.4°, P = 0.005 and P = 0.030, respectively) in study 2. No finger movement at birth was observed in 55% of the patients in this study group. CONCLUSION: Posterior subluxation and glenoid retroversion measurements indicated significantly severe shoulder deformities in children with finger movement at birth, in comparison with those lacked finger movement. However, the improvement after triangle tilt surgery was higher in patients who had finger movement at birth. PMID:23362472

  7. Postirradiation lesions of the brachial plexus. Results of surgical treatment

    SciTech Connect

    LeQuang, C.

    1989-02-01

    In a series of 103 cases of postirradiation lesions of the brachial plexus operated on between 1978 and 1986--of which 60 patients have been reviewed with a follow up from 2 to 9 years--the surgical results are analyzed according to an anatomic classification, a clinical classification, and the surgical procedures. We conclude that the radiation plexitis should be treated surgically and at the earliest possible time after the onset of paresthesias. Also, the surgical procedure which gives the best results is neurolysis with pedicled omentoplasty.

  8. Ultrasound guidance improves success rate of axillary brachial plexus block

    Microsoft Academic Search

    Vincent W. S. Chan; Anahi Perlas; Colin J. L. McCartney; Richard Brull; Daquan Xu; Sherif Abbas

    2007-01-01

    Purpose  The purpose of this study is to determine if real time ultrasound guidance improves the success rate of axillary brachial\\u000a plexus blockade.\\u000a \\u000a \\u000a \\u000a Methods  Patients undergoing elective hand surgery were randomly assigned to one of three groups. Axillary blocks were performed using\\u000a three motor response endpoints in the nerve stimulator (NS) Group, real-time ultrasound guidance in the ultrasound (US) Group\\u000a and combined

  9. Role of inducible heat shock protein 70 in radiation-induced cell death

    PubMed Central

    Lee, Su-Jae; Choi, Sun-Ah; Lee, Kang-Hyun; Chung, Hee-Yong; Kim, Tae-Hwan; Cho, Chul-Koo; Lee, Yun-Sil

    2001-01-01

    We previously demonstrated the protective effect of inducible heat shock protein 70 (Hsp70) against gamma radiation. Herein, we extend our studies on the possible role of Hsp70 to ionizing radiation-induced cell cycle regulation. The growth rate of inducible hsp70-transfected cells was 2–3 hours slower than that of control cells. Flow cytometric analysis of cells at G1 phase synchronized by serum starvation also showed the growth delay in the Hsp70-overexpressing cells. In addition, reduced cyclin D1 and Cdc2 levels and increased dephosphorylated phosphoretinoblastoma (pRb) were observed in inducible hsp70-transfected cells, which were probably responsible for the reduction of cell growth. To find out if inducible Hsp70-mediated growth delay affected radiation-induced cell cycle regulation, flow cytometric and molecular analyses of cell cycle regulatory proteins and their kinase were performed. The radiation-induced G2/M arrest was found to be inhibited by Hsp70 overexpression and reduced p21Waf induction and its kinase activity by radiation in the Hsp70-transfected cells. In addition, radiation-induced cyclin A or B1 expressions together with their kinase activities were also inhibited by inducible Hsp70, which represented reduced mitotic cell death. Indeed, hsp70 transfectants showed less induction of radiation-induced apoptosis. When treated with nocodazole, radiation-induced mitotic arrest was inhibited by inducible Hsp70. These results strongly suggested that inducible Hsp70 modified growth delay (increased G1 phase) and reduced G2/M phase arrest, subsequently resulting in inhibition of radiation-induced cell death. PMID:11599569

  10. Image-based modeling of radiation-induced foci

    NASA Astrophysics Data System (ADS)

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

    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.

  11. Synchrotron-Radiation Induced X-Ray Emission (SRIXE)

    SciTech Connect

    Jones, Keith W.

    1999-09-01

    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.

  12. Traumatic Pseudoaneurysm of Axillary Artery Combined with Brachial Plexus Injury

    PubMed Central

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

    2014-01-01

    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

  13. Avulsion of the brachial plexus in a great horned owl (Bubo virginaus)

    USGS Publications Warehouse

    Moore, M.P.; Stauber, E.; Thomas, N.J.

    1989-01-01

    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 peripheral nerve involvement. A brachial plexus avulsion was suspected on the basis of clinical signs, presence of electromyographic abnormalities in all muscles supplied by the nerves of the brachial plexus and absence of median-ulnar motor nerve conduction velocities.

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

    PubMed

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

    2012-03-01

    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

  15. Non-Problematic Risks from Low-Dose Radiation-Induced DNA Damage Clusters

    PubMed Central

    Hayes, Daniel P.

    2008-01-01

    Radiation-induced DNA damage clusters have been proposed and are usually considered to pose the threat of serious biological damage. This has been attributed to DNA repair debilitation or cessation arising from the complexity of cluster damage. It will be shown here, contrary to both previous suggestions and perceived wisdom, that radiation induced damage clusters contribute to non-problematic risks in the low-dose, low-LET regime. The very complexity of cluster damage which inhibits and/or compromises DNA repair will ultimately be responsible for the elimination and/or diminution of precancer-ous and cancerous cells. PMID:18648573

  16. [A case of prednisolone therapy for radiation-induced hemorrhagic cystitis].

    PubMed

    Yanagi, Masato; Nishimura, Taiji; Kurita, Susumu; Lee, Chorsu; Kondo, Yukihiro; Yamazaki, Keiichi

    2011-05-01

    Hemorrhagic cystitis resulting from radiation to pelvic visceral malignant lesions often might be incurable and there have been no established definitive treatment. We experienced a case with severe radiation-induced hemorrhagic cystitis refractory to conventional therapy. The treatment with oral administration of prednisolone was performed and obtained a successful result. Gross hematuria disappeared in 2 weeks in this case. This experience suggested that oral administration of prednisolone could be considered the treatment for patients with radiation-induced hemorrhagic cystitis when usual treatments including transurethral electro-coagulation are unsuccessful. PMID:21846069

  17. Utility of automated brachial ankle pulse wave velocity measurements in hypertensive patients

    Microsoft Academic Search

    Masanori Munakata; Nobuhiko Ito; Tohru Nunokawa; Kaoru Yoshinaga

    2003-01-01

    BackgroundWe examined whether pulse wave velocity (PWV), determined by brachial ankle arterial pressure wave measurements, using a newly developed, fully automated device could be a surrogate measure for carotid femoral PWV.

  18. Investigation of brachial plexus traction lesions by peripheral and spinal somatosensory evoked potentials

    Microsoft Academic Search

    S J Jones

    1979-01-01

    Peripheral, spinal and cortical somatosensory evoked potentials were recorded in 26 patients with unilateral traction injuries of the brachial plexus ganglia. Of 10 cases explored surgically the recordings correctly anticipated the major site of the lesion in eight.

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

    SciTech Connect

    Shankar, Sridhar, E-mail: shankars@ummhc.org; 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)

    2005-06-15

    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.

  20. Temporal pattern of pulse wave velocity during brachial hyperemia reactivity

    NASA Astrophysics Data System (ADS)

    Graf, S.; Valero, M. J.; Craiem, D.; Torrado, J.; Farro, I.; Zócalo, Y.; Valls, G.; Bía, D.; Armentano, R. L.

    2011-09-01

    Endothelial function can be assessed non-invasively with ultrasound, analyzing the change of brachial diameter in response to transient forearm ischemia. We propose a new technique based in the same principle, but analyzing a continuous recording of carotid-radial pulse wave velocity (PWV) instead of diameter. PWV was measured on 10 healthy subjects of 22±2 years before and after 5 minutes forearm occlusion. After 59 ± 31 seconds of cuff release PWV decreased 21 ± 9% compared to baseline, reestablishing the same after 533 ± 65 seconds. There were no significant changes observed in blood pressure. When repeating the study one hour later in 5 subjects, we obtained a coefficient of repeatability of 4.8%. In conclusion, through analysis of beat to beat carotid-radial PWV it was possible to characterize the temporal profiles and analyze the acute changes in response to a reactive hyperemia. The results show that the technique has a high sensitivity and repeatability.

  1. Brachial plexus injury in adults: Diagnosis and surgical treatment strategies

    PubMed Central

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

    2013-01-01

    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

  2. Obstetrical brachial plexus palsy: electrodiagnostical study and functional outcome.

    PubMed

    Toupchizadeh, V; Abdavi, Y; Barzegar, M; Eftekharsadat, B; Tabrizi, I

    2010-12-15

    Obstetrical Brachial Plexus Palsy (OBPP) is a complication of difficult delivery and resulted from excessive traction on the brachial plexus during delivery. Erb palsy, klumpke paralysis and panplexus palsy reported in 46, 0.6 and 20% of patients, respectively. Unilateral injury is more common than bilateral injury. Risk factors include macrosomia, multiparity, prior delivery of a child with OBPP, breech delivery shoulder dystocia, vacium and forceps assisted delivery and excessive maternal weight gain. The recovery rate is usually reported to be between 80 and 90%. We evaluated 42 children with OBPP. Out of them, we could follow only 28 cases during two years. Poor to moderate recovery occurred in 13 cases. Good to complete (expected) recovery occurred in 15 cases. Most of the patients were females. Right side palsy was more prevalent than left side palsy. Vaginal delivery without forceps was the most mode of delivery. Vertex was the most common presentation. Most of the patients were term. The mean weight of the birth was 3.8 kg. Erb palsy and pan-plexus palsy consisted of 71.4 and 28.6% of lesions. In patients with Erb palsy, there were preganglionic palsy in 3 (15.8%) and postganglionic palsy in 16 (84.2%) cases, while all the patients with panplexus palsy had postganglionic palsy. All patients with complete recovery (9 of 15) had Erb palsy and postganglionic lesion. Erb palsy was present in 71.4% and panplexus palsy was present in 28.6% of cases. Also, 23.8% of cases had preganglionic and 76.2% of cases had postganglionic injures. PMID:21313897

  3. OCT/PS-OCT imaging of brachial plexus neurovascular structures

    NASA Astrophysics Data System (ADS)

    Raphael, David T.; Zhang, Jun; Zhang, Yaoping; Chen, Zhongping; Miller, Carol; Zhou, Li

    2004-07-01

    Introduction: Optical coherence tomography (OCT) allows high-resolution imaging (less than 10 microns) of tissue structures. A pilot study with OCT and polarization-sensitive OCT (PS-OCT) was undertaken to image ex-vivo neurovascular structures (vessels, nerves) of the canine brachial plexus. Methods: OCT is an interferometry-based optical analog of B-mode ultrasound, which can image through non-transparent biological tissues. With approval of the USC Animal Care and Use Committee, segments of the supra- and infraclavicular brachial plexus were excised from euthanized adult dogs, and the ex-vivo specimens were placed in cold pH-buffered physiologic solution. An OCT beam, in micrometer translational steps, scanned the fixed-position bisected specimens in transverse and longitudinal views. Two-dimensional images were obtained from identified arteries and nerves, with specific sections of interest stained with hematoxylin-eosin for later imaging through a surgical microscope. Results: with the beam scan direction transverse to arteries, the resulting OCT images showed an identifiable arterial lumen and arterial wall tissue layers. By comparison, transverse beam OCT images of nerves revealed a multitude of smaller nerve bundles contained within larger circular-shaped fascicles. PS-OCT imaging was helpful in showing the characteristic birefringence exhibited by arrayed neural structures. Discussion: High-resolution OCT imaging may be useful in the optical identification of neurovascular structures during attempted regional nerve blockade. If incorporated into a needle-shaped catheter endoscope, such a technology could prevent intraneural and intravascular injections immediately prior to local anesthetic injection. The major limitation of OCT is that it can form a coherent image of tissue structures only to a depth of 1.5 - 2 mm.

  4. Case series: Septa can influence local anesthetic spread during infraclavicular brachial plexus blocks

    Microsoft Academic Search

    Maki Morimoto; Jovan Popovic; Jung T. Kim; Harald Kiamzon; Andrew D. Rosenberg

    2007-01-01

    Purpose: To ultrasonically identify the presence of septae within the neurovascular sheath and to assess their effect on local anesthetic\\u000a spread when performing infraclavicular brachial plexus blocks.\\u000a \\u000a \\u000a Clinical features: Thirty ASA status I and II patients scheduled for minor hand surgeries were enrolled in the study. Ultrasound guided infraclavicular\\u000a brachial plexus blocks were performed on 28 patients. The images of

  5. Determination of ?-radiation induced proudcts in aqueous solutions of tryptophan and synthesis of 4-, 6- and 7-hydroxytryptophan

    Microsoft Academic Search

    Barbara van Wickern; Burkhardt Müller; Thomas Simat; Hans Steinhart

    1997-01-01

    A HPLC method with UV and fluorescence detection was developed to determine ?-radiation induced products in aqueous solutions of tryptophan. Therefore 4-, 6- and 7-hydroxytryptophan were synthesized in purities which allow their use as reference substances for analytical studies. Oxindolylalanine, N-formylkynurenine, 4-, 5, 6- and 7-hydroxytryptophan were determined as the main radiation induced products.

  6. Radiation-induced granulocyte transmigration predicts development of delayed structural changes in rat intestine.

    PubMed

    Richter, K K; Wang, J; Fagerhol, M K; Hauer-Jensen, M

    2001-04-01

    We examined whether early radiation-induced granulocyte transmigration (assessed by the fecal transferrin excretion ELISA assay) predicts subsequent development of (consequential) chronic radiation enteropathy. After accounting for the effect of radiation dose, transferrin excretion remained an independent predictor of overall tissue injury, intestinal fibrosis, and mucosal ulcers, but not TGF-beta immunoreactivity. PMID:11295210

  7. Base substitutions, frameshifts, and small deletions constitute ionizing radiation-induced point mutations in mammalian cells

    SciTech Connect

    Grosovsky, A.J.; de Boer, J.G.; de Jong, P.J.; Drobetsky, E.A.; Glickman, B.W.

    1988-01-01

    The relative role of point mutations and large genomic rearrangements in ionizing radiation-induced mutagenesis has been an issue of long-standing interest. Recent studies using Southern blotting analysis permit the partitioning of ionizing radiation-induced mutagenesis in mammalian cells into detectable deletions and major genomic rearrangements and into point mutations. The molecular nature of these point mutations has been left unresolved; they may include base substitutions as well as small deletions, insertions, and frame-shifts below the level of resolution of Southern blotting analysis. In this investigation, we have characterized a collection of ionizing radiation-induced point mutations at the endogenous adenine phosphoribosyltransferase (aprt) locus of Chinese hamster ovary cells at the DNA sequence level. Base substitutions represented approximately equal to 2/3 of the point mutations analyzed. Although the collection of mutants is relatively small, every possible type of base substitution event has been recovered. These mutations are well distributed throughout the coding sequence with only one multiple occurrence. Small deletions represented the remainder of characterized mutants; no insertions have been observed. Sequence-directed mechanisms mediated by direct repeats could account for some of the observed deletions, while others appear to be directly attributable to radiation-induced strand breakage.

  8. Noise characteristics of radiation-induced soft breakdown current in ultrathin gate oxides

    Microsoft Academic Search

    Andrea Cester; Leonardo Bandiera; Marco Ceschia; Gabriella Ghidini; Alessandro Paccagnella

    2001-01-01

    We have investigated new aspects of the gate leakage current due to radiation-induced soft breakdown (RSB) of thin oxides subjected to heavy-ion irradiation. Temperature and noise characteristics of RSB on MOS capacitors with 3- and 4- nm MOS oxides have been experimentally investigated. We have developed an empirical law to describe quantitatively the temperature dependence of the RSB current. A

  9. UV Radiation-Induced Immunosuppression Is Greater in Men and Prevented by Topical Nicotinamide

    Microsoft Academic Search

    Diona L Damian; Clare R S Patterson; Michael Stapelberg; Ross St C Barnetson; Gary M Halliday

    2008-01-01

    UV radiation-induced immunosuppression augments cutaneous carcinogenesis. The incidence of skin cancer continues to increase despite increased use of sunscreens, which are less effective at preventing immunosuppression than sunburn. Using the Mantoux reaction as a model of skin immunity, we investigated the effects of solar-simulated (ss) UV and its component UVA and UVB wavebands and tested the ability of topical nicotinamide

  10. Mechanism of radiation-induced degradation of poly(methyl methacrylate) — temperature effect

    Microsoft Academic Search

    Tsuneki Ichikawa

    1995-01-01

    ESR and gel permeation chromatographic measurements of poly(methyl methacrylate) ?-irradiated between 77 and 300 K have been carried out to elucidate the mechanism of radiation-induced degradation of the polymer. It is revealed that the scission of the main chain does not take place immediately after the absorption of radiation energy but is induced by the intramolecular radical conversion of the

  11. Mechanisms of Enhanced Radiation-Induced Degradation Due to Excess Molecular Hydrogen in Bipolar Oxides

    Microsoft Academic Search

    X. J. Chen; H. J. Barnaby; B. Vermeire; K. Holbert; D. Wright; R. L. Pease; G. Dunham; D.G. Platteter; J. Seiler; S. McClure; P. Adell

    2007-01-01

    Bipolar junction test structures packaged in hermetically sealed packages with excess molecular hydrogen (H2) showed enhanced degradation after radiation exposure. Using chemical kinetics, we propose a model that quantitatively establishes the relationship between excess H2 and radiation-induced interface trap formation. Using environments with different molecular hydrogen concentrations, radiation experiments were performed and the experimental data showed excellent agreement with the

  12. Radiation-Induced Demagnetization of Nd-Fe-B Permanent Magnets

    E-print Network

    Kemner, Ken

    Operations Division Advanced Photon Source Argonne National Laboratory R.C. Martin, C.M. Simmons, and G Source Argonne National Laboratory R.C. Martin, C.M. Simmons, and G. D. Owen Californium User FacilityLS-290 Radiation-Induced Demagnetization of Nd-Fe-B Permanent Magnets J. Alderman and P.K. Job APS

  13. On the mechanisms of the radiation-induced degradation of cellulosic substances

    NASA Astrophysics Data System (ADS)

    Tissot, Chanel; Grdanovska, Slavica; Barkatt, Aaron; Silverman, Joseph; Al-Sheikhly, Mohamad

    2013-03-01

    Much interest has been generated in utilizing ionizing radiation for the production of bio-fuels from cellulosic plant materials. It is well known that exposure of cellulose to ionizing radiation causes significant breakdown of the polysaccharide. Radiation-induced degradation of cellulose may reduce or replace ecologically hazardous chemical steps in addition to reducing the number of processing stages and decreasing energy consumption.

  14. The radiation-induced changes in rectal mucosa: Hyperfractionated vs. hypofractionated preoperative radiation for rectal cancer

    SciTech Connect

    Starzewski, Jacek J. [Department of General and Colorectal Surgery, Medical University of Silesia, Sosnowiec (Poland); Pajak, Jacek T. [Department of Pathology, Medical University of Silesia, Katowice (Poland); Pawelczyk, Iwona [Department of General and Colorectal Surgery, Medical University of Silesia, Sosnowiec (Poland); Lange, Dariusz [Department of Tumor Pathology, Comprehensive Cancer Center Division, Gliwice (Poland); Golka, Dariusz [Department of Pathology, Medical University of Silesia, Katowice (Poland)]. E-mail: dargolka@wp.pl; Brzeziska, Monika [Department of General and Colorectal Surgery, Medical University of Silesia, Sosnowiec (Poland); Lorenc, Zbigniew [Department of General and Colorectal Surgery, Medical University of Silesia, Sosnowiec (Poland)

    2006-03-01

    Purpose: The purpose of the study was the qualitative and quantitative evaluation of acute radiation-induced rectal changes in patients who underwent preoperative radiotherapy according to two different irradiation protocols. Patients and Methods: Sixty-eight patients with rectal adenocarcinoma underwent preoperative radiotherapy; 44 and 24 patients underwent hyperfractionated and hypofractionated protocol, respectively. Fifteen patients treated with surgery alone served as a control group. Five basic histopathologic features (meganucleosis, inflammatory infiltrations, eosinophils, mucus secretion, and erosions) and two additional features (mitotic figures and architectural glandular abnormalities) of radiation-induced changes were qualified and quantified. Results: Acute radiation-induced reactions were found in 66 patients. The most common were eosinophilic and plasma-cell inflammatory infiltrations (65 patients), erosions, and decreased mucus secretion (54 patients). Meganucleosis and mitotic figures were more common in patients who underwent hyperfractionated radiotherapy. The least common were the glandular architectural distortions, especially in patients treated with hypofractionated radiotherapy. Statistically significant differences in morphologic parameters studied between groups treated with different irradiation protocols were found. Conclusion: The system of assessment is a valuable tool in the evaluation of radiation-induced changes in the rectal mucosa. A greater intensity of regenerative changes was found in patients treated with hyperfractionated radiotherapy.

  15. Cell Cycle Dependence of Ionizing Radiation-Induced DNA Deletions and Antioxidant Radioprotection in Saccharomyces cerevisiae

    PubMed Central

    Hafer, Kurt; Rivina, Leena; Schiestl, Robert H.

    2013-01-01

    The yeast DEL assay is an effective method for measuring intrachromosomal recombination events resulting in DNA deletions that when occurring in mammalian cells are often associated with genomic instability and carcinogenesis. Here we used the DEL assay to measure ?-ray-induced DNA deletions throughout different phases of yeast culture growth. Whereas yeast survival differed by only up to twofold throughout the yeast growth phase, proliferating cells in lag and early exponential growth phases were tenfold more sensitive to ionizing radiation-induced DNA deletions than cells in stationary phase. Radiation-induced DNA deletion potential was found to correlate directly with the fraction of cells in S/G2 phase. The ability of the antioxidants l-ascorbic acid and DMSO to protect against radiation-induced DNA deletions was also measured within the different phases of yeast culture growth. Yeast cells in lag and early exponential growth phases were uniquely protected by antioxidant treatment, whereas nondividing cells in stationary phase could not be protected against the induction of DNA deletions. These results are compared with those from mammalian cell studies, and the implications for radiation-induced carcinogenesis and radioprotection are discussed. PMID:20518659

  16. Protective effect of tanshinone IIA against radiation-induced ototoxicity in HEI-OC1 cells.

    PubMed

    DU, Shasha; Yao, Qiwei; Tan, Peixin; Xie, Guozhu; Ren, Chen; Sun, Quanquan; Zhang, Xiao; Zheng, Rong; Yang, Kaijun; Yuan, Yawei; Yuan, Quan

    2013-10-01

    Radiotherapy is a highly efficient treatment method for nasopharyngeal carcinoma that is often accompanied by significant ototoxic side-effects. The inner ear hair cells are particularly prone to serious injury following radiotherapy. Tanshinone IIA is a transcription factor inhibitor that is extracted from the traditional herbal medicine, Salvia miltiorrhiza Bunge. The present study investigated the effects of tanshinone IIA treatment on radiation-induced toxicity in the HEI-OC1 hair cell line. Using an MTT assay and flow cytometry, the radiation-induced weakening of the cells was observed to be alleviated when the cells were pre-treated with tanshinone IIA. Radiation exposure promoted p65/nuclear factor (NF)-?B nuclear translocation and activated the p53/p21 pathway, two processes which play a significant role in radiation-induced cell apoptosis. However, pre-treatment of the cells with tanshinone IIA inhibited p65/NF-?B nuclear translocation and p53/p21 pathway activation. These results demonstrate that tanshinone IIA is capable of protecting cochlear cells from radiation-induced injury through the suppression of p65/NF-?B nuclear translocation and the p53/p21 signaling pathway. PMID:24137434

  17. Effect of radiation induced deep level traps on Si detector performance

    Microsoft Academic Search

    V. Eremin; E. Verbitskaya; Z. Li

    2002-01-01

    The main factor, which leads to semiconductor detector degradation in high-energy physics experiments, is the introduction of lattice defects in the detector material produced by radiation. Based on the spectrum of radiation induced defects in the silicon bulk, the overview of effects and mechanisms responsible for the changes in the main detector parameters such as effective concentration of the space

  18. Mitochondrial dysfunction resulting from loss of cytochrome c impairs radiation-induced bystander effect

    PubMed Central

    Yang, G; Wu, L; Chen, S; Zhu, L; Huang, P; Tong, L; Zhao, Y; Zhao, G; Wang, J; Mei, T; Xu, A; Wang, Y

    2009-01-01

    Cytochrome c is a pivotal protein that resides in mitochondria as component of mitochondria respiration and apoptosis initiator. Using murine cells lacking cytochrome c, we showed here that cytochrome c-deficient cells had attenuated reactive oxygen species/nitric oxide and micronuclei induction to radiation-induced bystander signals, indicating cytochrome c is essential for the bystander effect. PMID:19455142

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

    E-print Network

    Brenner, David Jonathan

    Radiation-Induced Carcinogenesis: Mechanistically Based Differences between Gamma-Rays and Neutrons effect). Densely ionizing radiation (e.g. neutrons) often produces downwardly curving dose responses exposed to high or low dose rates of c-rays and neutrons, either with or without pre

  20. Activating PTEN by COX-2 inhibitors antagonizes radiation-induced AKT activation contributing to radiosensitization.

    PubMed

    Meng, Zhen; Gan, Ye-Hua

    2015-05-01

    Radiotherapy is still one of the most effective nonsurgical treatments for many tumors. However, radioresistance remains a major impediment to radiotherapy. Although COX-2 inhibitors can induce radiosensitization, the underlying mechanism is not fully understood. In this study, we showed that COX-2 selective inhibitor celecoxib enhanced the radiation-induced inhibition of cell proliferation and apoptosis in HeLa and SACC-83 cells. Treatment with celecoxib alone dephosphorylated phosphatase and tensin homolog deleted on chromosome ten (PTEN), promoted PTEN membrane translocation or activation, and correspondingly dephosphorylated or inactivated protein kinase B (AKT). By contrast, treatment with radiation alone increased PTEN phosphorylation, inhibited PTEN membrane translocation and correspondingly activated AKT in the two cell lines. However, treatment with celecoxib or another COX-2 selective inhibitor (valdecoxib) completely blocked radiation-induced increase of PTEN phosphorylation, rescued radiation-induced decrease in PTEN membrane translocation, and correspondingly inactivated AKT. Moreover, celecoxib could also upregulate PTEN protein expression by downregulating Sp1 expression, thereby leading to the activation of PTEN transcription. Our results suggested that COX-2 inhibitors could enhance radiosensitization at least partially by activating PTEN to antagonize radiation-induced AKT activation. PMID:25770423

  1. At-wavelength characterization of UV-radiation-induced damage in fused silica

    E-print Network

    Bokor, Jeffrey

    At-wavelength characterization of UV-radiation-induced damage in fused silica Sang Hun Lee*1 ABSTRACT Fused silica is the optical material of choice for deep ultraviolet (DUV) lithographic systems report direct, at-wavelength, wavefront measurements of DUV-laser-damaged fused silica samples performed

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

    SciTech Connect

    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)

    1996-03-01

    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

  3. Colitis cystica profunda occurring in a radiation-induced colonic stricture

    SciTech Connect

    Gardiner, G.W.; McAuliffe, N.; Murray, D.

    1984-03-01

    Localized colitis cystica profunda developed in a fibrotic radiation-induced colonic stricture 17 years after pelvic radiation for squamous carcinoma of cervix. This uncommon pathologic entity must be distinguished from invasive adenocarcinoma of colon, and colonic radiation injury should be included with other conditions associated with colitis cystica profunda.

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

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    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.

  5. EXTRAPOLATING RADIATION-INDUCED CANCER RISKS FROM LOW DOSES TO VERY LOW DOSES

    E-print Network

    Brenner, David Jonathan

    Paper EXTRAPOLATING RADIATION-INDUCED CANCER RISKS FROM LOW DOSES TO VERY LOW DOSES David J. Brenner* Abstract--There is strong evidence that ionizing radiation increases cancer risks at high doses are increased at low doses ( 10 mGy). Discussed here are the issues related to extrapolating radiation risks

  6. Glycerol as a chemical chaperone enhances radiation-induced apoptosis in anaplastic thyroid carcinoma cells

    Microsoft Academic Search

    Ken Ohnishi; Ichiro Ota; Katsunari Yane; Akihisa Takahashi; Kazue Yuki; Mie Emoto; Hiroshi Hosoi; Takeo Ohnishi

    2002-01-01

    INTRODUCTION: Anaplastic thyroid carcinoma, which is one of the most aggressive, malignant tumors in humans, results in an extremely poor prognosis despite chemotherapy and radiotherapy. The present study was designed to evaluate therapeutic effects of radiation by glycerol on p53-mutant anaplastic thyroid carcinoma cells (8305c cells). To examine the effectiveness of glycerol in radiation induced lethality for anaplastic thyroid carcinoma

  7. Pressure-sensitive blackbody point radiation induced by infrared diode laser irradiation

    E-print Network

    Cao, Wenwu

    Pressure-sensitive blackbody point radiation induced by infrared diode laser irradiation Feng Qin,1 of a 980 nm diode laser. The radiation was confirmed to be blackbody radiation, and it is sensitive with the widely used commercial 980 nm diode laser, which makes it an excellent sensitizing ion [5]. Third

  8. A Nonhuman Primate Model of Human Radiation-Induced Venocclusive Liver Disease and Hepatocyte Injury

    SciTech Connect

    Yannam, Govardhana Rao [Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska (United States); Han, Bing [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Department of Hepatobiliary Surgery, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi (China); Setoyama, Kentaro [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Yamamoto, Toshiyuki [Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska (United States); Ito, Ryotaro; Brooks, Jenna M. [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Guzman-Lepe, Jorge [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Department of Pathology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Galambos, Csaba [Department of Pathology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Fong, Jason V. [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Deutsch, Melvin; Quader, Mubina A. [Department of Radiation Oncology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Yamanouchi, Kosho [Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, New York (United States); Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York (United States); Kabarriti, Rafi; Mehta, Keyur [Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, New York (United States); Soto-Gutierrez, Alejandro [Department of Pathology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); and others

    2014-02-01

    Background: Human liver has an unusual sensitivity to radiation that limits its use in cancer therapy or in preconditioning for hepatocyte transplantation. Because the characteristic veno-occlusive lesions of radiation-induced liver disease do not occur in rodents, there has been no experimental model to investigate the limits of safe radiation therapy or explore the pathogenesis of hepatic veno-occlusive disease. Methods and Materials: We performed a dose-escalation study in a primate, the cynomolgus monkey, using hypofractionated stereotactic body radiotherapy in 13 animals. Results: At doses ?40 Gy, animals developed a systemic syndrome resembling human radiation-induced liver disease, consisting of decreased albumin, elevated alkaline phosphatase, loss of appetite, ascites, and normal bilirubin. Higher radiation doses were lethal, causing severe disease that required euthanasia approximately 10 weeks after radiation. Even at lower doses in which radiation-induced liver disease was mild or nonexistent, latent and significant injury to hepatocytes was demonstrated by asialoglycoprotein-mediated functional imaging. These monkeys developed hepatic failure with encephalopathy when they received parenteral nutrition containing high concentrations of glucose. Histologically, livers showed central obstruction via an unusual intimal swelling that progressed to central fibrosis. Conclusions: The cynomolgus monkey, as the first animal model of human veno-occlusive radiation-induced liver disease, provides a resource for characterizing the early changes and pathogenesis of venocclusion, for establishing nonlethal therapeutic dosages, and for examining experimental therapies to minimize radiation injury.

  9. Biologic susceptibility of hepatocellular carcinoma patients treated with radiotherapy to radiation-induced liver disease

    Microsoft Academic Search

    Jason Chia-Hsien Cheng; Jian-Kuen Wu; Patricia Chiao-Tzu Lee; Hua-Shan Liu; James Jer-Min Jian; Yu-Mong Lin; Juei-Low Sung; Gwo-Jen Jan

    2004-01-01

    Purpose:To identify the factors associated with radiation-induced liver disease (RILD) and to describe the difference in normal tissue complication probability (NTCP) between subgroups of hepatocellular carcinoma patients undergoing three-dimensional conformal radiotherapy (3D-CRT).

  10. Influence of Mast Cells on Structural and Functional Manifestations of Radiation-Induced Heart Disease

    Microsoft Academic Search

    Marjan Boerma; Junru Wang; Jan Wondergem; Jacob Joseph; Xiaohua Qiu; Richard H. Kennedy; Martin Hauer-Jensen

    2005-01-01

    Radiation-induced heart disease (RIHD), characterized by accelerated atherosclerosis and adverse tissue remodeling, is a serious sequelae after radiotherapy of thoracic and chest wall tumors. Adverse cardiac remodeling in RIHD and other cardiac disorders is frequently accompanied by mast cell hyperplasia, suggesting that mast cells may affect the development of cardiac fibrosis. This study used a mast cell- deficient rat model

  11. Oral glutamine to alleviate radiation-induced oral mucositis: a pilot randomized trial

    Microsoft Academic Search

    Eng-Yen Huang; Stephen Wan Leung; Chong-Jong Wang; Hui-Chun Chen; Li-Min Sun; Fu-Min Fang; Shyh-An Yeh; Hsuan-Chih Hsu; Ching-Yeh Hsiung

    2000-01-01

    Purpose: To evaluate the influence of oral glutamine on radiation-induced oral mucositis in the radiotherapy of head and neck cancer.Methods and Materials: From July 1997 through June 1998, 17 patients with head and neck cancer receiving primary or adjuvant irradiation were randomized to either glutamine suspension (16 g in 240 ml normal saline) (n = 8) or placebo (normal saline)

  12. Inactivation of Kupffer Cells by Gadolinium Chloride Protects Murine Liver From Radiation-Induced Apoptosis

    SciTech Connect

    Du Shisuo; Qiang Min [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Zeng Zhaochong, E-mail: zeng.zhaochong@zs-hospital.sh.c [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Ke Aiwu; Ji Yuan [Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai (China); Zhang Zhengyu [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Zeng Haiying [Department of Pathology, Zhongshan Hospital, Fudan University, Shanghai (China); Liu Zhongshan [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China)

    2010-03-15

    Purpose: To determine whether the inhibition of Kupffer cells before radiotherapy (RT) would protect hepatocytes from radiation-induced apoptosis. Materials and Methods: A single 30-Gy fraction was administered to the upper abdomen of Sprague-Dawley rats. The Kupffer cell inhibitor gadolinium chloride (GdCl3; 10 mg/kg body weight) was intravenously injected 24 h before RT. The rats were divided into four groups: group 1, sham RT plus saline (control group); group 2, sham RT plus GdCl3; group 3, RT plus saline; and group 4, RT plus GdCl3. Liver tissue was collected for measurement of apoptotic cytokine expression and evaluation of radiation-induced liver toxicity by analysis of liver enzyme activities, hepatocyte micronucleus formation, apoptosis, and histologic staining. Results: The expression of interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha was significantly attenuated in group 4 compared with group 3 at 2, 6, 24, and 48 h after injection (p <0.05). At early points after RT, the rats in group 4 exhibited significantly lower levels of liver enzyme activity, apoptotic response, and hepatocyte micronucleus formation compared with those in group 3. Conclusion: Selective inactivation of Kupffer cells with GdCl3 reduced radiation-induced cytokine production and protected the liver against acute radiation-induced damage.

  13. 3D ultrasound Nakagami imaging for radiation-induced vaginal fibrosis

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    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.

  14. Repression of ATR pathway by miR-185 enhances radiation-induced apoptosis and proliferation

    E-print Network

    Cai, Long

    of miR-34a expression may be responsible for important protective mechanisms counteracting radiationOPEN Repression of ATR pathway by miR-185 enhances radiation-induced apoptosis and proliferation and their downstream genes. Disruption of these signaling pathways leads to genome instability and cell death, and thus

  15. Prophylaxis and management of acute radiation-induced skin reactions: a systematic review of the literature

    PubMed Central

    Salvo, N.; Barnes, E.; van Draanen, J.; Stacey, E.; Mitera, G.; Breen, D.; Giotis, A.; Czarnota, G.; Pang, J.; De Angelis, C.

    2010-01-01

    Radiation therapy is a common treatment for cancer patients. One of the most common side effects of radiation is acute skin reaction (radiation dermatitis) that ranges from a mild rash to severe ulceration. Approximately 85% of patients treated with radiation therapy will experience a moderate-to-severe skin reaction. Acute radiation-induced skin reactions often lead to itching and pain, delays in treatment, and diminished aesthetic appearance—and subsequently to a decrease in quality of life. Surveys have demonstrated that a wide variety of topical, oral, and intravenous agents are used to prevent or to treat radiation-induced skin reactions. We conducted a literature review to identify trials that investigated products for the prophylaxis and management of acute radiation dermatitis. Thirty-nine studies met the pre-defined criteria, with thirty-three being categorized as prophylactic trials and six as management trials. For objective evaluation of skin reactions, the Radiation Therapy Oncology Group criteria and the U.S. National Cancer Institute Common Toxicity Criteria were the most commonly used tools (65% of the studies). Topical corticosteroid agents were found to significantly reduce the severity of skin reactions; however, the trials of corticosteroids evaluated various agents, and no clear indication about a preferred corticosteroid has emerged. Amifostine and oral enzymes were somewhat effective in preventing radiation-induced skin reactions in phase ii and phase iii trials respectively; further large randomized controlled trials should be undertaken to better investigate those products. Biafine cream (Ortho–McNeil Pharmaceuticals, Titusville, NJ, U.S.A.) was found not to be superior to standard regimes in the prevention of radiation-induced skin reactions (n = 6). In conclusion, the evidence is insufficient to support the use of a particular agent for the prevention and management of acute radiation-induced skin reactions. Future trials should focus on comparing agents and approaches that, in phase i and ii trials, suggest efficacy. These future phase iii randomized controlled trials must clearly distinguish between preventive and management strategies for radiation-induced dermatitis. Only then can evidence-based guidelines be developed, with the hope of standardizing the approach across centres and of improving the prevention and management of radiation-induced dermatitis. PMID:20697521

  16. Physiology of Hormone Autonomous Tissue Lines Derived From Radiation-Induced Tumors of Arabidopsis thaliana.

    PubMed

    Campell, B R; Town, C D

    1991-11-01

    gamma-Radiation-induced tumors of Arabidopsis thaliana L. have been produced as a novel approach to isolation of genes that regulate plant development. Tumors excised from irradiated plants are hormone autonomous in culture and have been maintained on hormone-free medium for up to 4 years. Five tumor tissue lines having different morphologies and growth rates were analyzed for auxin, cytokinin, and 1-aminocyclopropane-1-carboxylic acid (ACC) content, ethylene production, and response to exogenous growth regulators. Normal tissues and two crown gall tissue lines were analyzed for comparison. Rosettes and whole seedlings each contained approximately 30 nanograms. (gram fresh weight)(-1) free indoleacetic acid (IAA), 150 nanograms. (gram fresh weight)(-1) ester-conjugated IAA, and 10 to 20 micrograms. (gram fresh weight)(-1) amide-conjugated IAA. The crown gall lines contained similar amounts of free and ester-conjugated IAA but less amide conjugates. Whereas three of the radiation-induced tumor lines had IAA profiles similar to normal tissues, one line had 10- to 100-fold more free IAA and three- to 10-fold less amide-conjugated IAA. The fifth line had normal free IAA levels but more conjugated IAA than control tissues. Whole seedlings contained approximately 2 nanograms. (gram fresh weight)(-1) of both zeatin riboside and isopentenyladenosine. The crown gall lines had 100- to 1000-fold higher levels of each cytokinin. In contrast, the three radiation-induced tumor lines analyzed contained cytokinin levels similar to the control tissue. The radiation-induced tumor tissues produced very little ethylene, although each contained relatively high levels of ACC. Normal callus contained similar amounts of ACC but produced several times more ethylene than the radiation-induced tumor lines. Each of the radiation-induced tumor tissues displayed a unique set of responses to exogenously supplied growth regulators. Only one tumor line showed the same response as normal callus to both auxin and cytokinin feeding. In some cases, one or more tumor lines showed increased sensitivity to certain growth substances. In other cases, growth regulator feeding had no significant effect on tumor tissue growth. Morphology of the radiation-induced tumor tissues generally did not correlate with auxin to cytokinin ratio in the expected manner. The results suggest that a different primary genetic event led to the formation of each tumor and that growth and differentiation in the tumor tissue lines are uncoupled from the normal hormonal controls. PMID:16668504

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

    SciTech Connect

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

    2010-01-01

    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

  18. Brachial artery injury following opened elbow dislocation associated with accessory brachial artery: two rare entities in a 17-year –old girl: case report

    PubMed Central

    Hajji, Rita; Zrihni, Youssef; Naouli, Hamza; Bouarhroum, Abdellatif

    2015-01-01

    Elbow dislocations are the most frequently encountered after shoulder dislocations. In their vast majority, these injuries carry a good prognosis. Although, concomitant arterial injury is rare and make them more serious. In this paper, we report a case of a 17 year old woman with opened elbow dislocation with arterial injury associated to an artery variation: "accessory brachial artery"

  19. Radiation-induced bystander effects: what are they, and how relevant are they to human radiation exposures?

    PubMed

    Blyth, Benjamin J; Sykes, Pamela J

    2011-08-01

    The term radiation-induced bystander effect is used to describe radiation-induced biological changes that manifest in unirradiated cells remaining within an irradiated cell population. Despite their failure to fit into the framework of classical radiobiology, radiation-induced bystander effects have entered the mainstream and have become established in the radiobiology vocabulary as a bona fide radiation response. However, there is still no consensus on a precise definition of radiation-induced bystander effects, which currently encompasses a number of distinct signal-mediated effects. These effects are classified here into three classes: bystander effects, abscopal effects and cohort effects. In this review, the data have been evaluated to define, where possible, various features specific to radiation-induced bystander effects, including their timing, range, potency and dependence on dose, dose rate, radiation quality and cell type. The weight of evidence supporting these defining features is discussed in the context of bystander experimental systems that closely replicate realistic human exposure scenarios. Whether the manifestation of bystander effects in vivo is intrinsically limited to particular radiation exposure scenarios is considered. The conditions under which radiation-induced bystander effects are induced in vivo will ultimately determine their impact on radiation-induced carcinogenic risk. PMID:21631286

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

    SciTech Connect

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

    1995-03-01

    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.

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

    PubMed

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

    2014-03-01

    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

  2. The potential influence of radiation-induced microenvironments in neoplastic progression

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

    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.

  3. Radiation-induced magnetoresistance oscillations in two-dimensional electron systems

    NASA Astrophysics Data System (ADS)

    Lei, X. L.

    2007-04-01

    We carry out a systematic analysis on radiation induced magnetoresistance oscillations (RIMOs) in high-mobility two-dimensional electron gas (2DEG), based on the balance-equation approach to magnetotransport developed for high-carrier-density systems. The model covers regimes of both inter- and intra-Landau level processes, takes full account of multiphoton-assisted electron transitions as well as radiation-induced change of the electron distribution, and naturally includes electrodynamic damping. Electron scatterings by impurities, transverse and longitudinal acoustic phonons as well as polar optic phonons are considered in GaAs-based heterosystems with realistic scattering potentials. This theoretical model not only reproduces the main features of RIMOs, predicts the appearance of the measured zero resistance, but also explains the other prominent experimental observations.

  4. Hyperbaric oxygen in the treatment of radiation-induced optic neuropathy

    SciTech Connect

    Guy, J.; Schatz, N.J.

    1986-08-01

    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.

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

    PubMed

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

    2014-10-15

    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

  6. Differential protection by two sunscreens from UV radiation-induced immunosuppression.

    PubMed

    Reeve, V E; Bosnic, M; Boehm-Wilcox, C; Ley, R D

    1991-10-01

    A controversy has arisen concerning the ability of sunscreens to protect mice from the immunosuppressive effects of UV radiation. We have assessed the photoprotection in hairless mice of two sun protection factor (SPF)15 sunscreens containing different UVB (280-320-nm) absorbers, namely, octyl-N-dimethyl-p-aminobenzoate (o-PABA) or 2-ethylhexyl-p-methoxycinnamate (2-EHMC). Following three minimum erythemal exposures to UV radiation, both systemic suppression of contact hypersensitivity to 2,4-dinitrofluorobenzene and induction of susceptibility to transplanted UV radiation-induced tumor cells was established. Topically applied 2-EHMC sunscreen protected totally from both forms of immunosuppression, but the o-PABA sunscreen failed to protect, although both sunscreens were equally effective in protection from UV radiation-induced erythema and edema. PMID:1940432

  7. Radiation induced darkening of the optical elements in the Startracker camera

    SciTech Connect

    White, R.H.; Wirtenson, G.R.

    1993-03-01

    Optical glass flats that closely simulate the elements used in the Startracker lens designs were exposed to doses of ionizing radiation ranging from 0.44 to 1300 krad. Photometer traces determined the transmittance of the samples as a function of both wavelength and dose for wavelengths in the range 300 to 1200 nm. Cerium stabilized glasses used in the radiation stabilized Startracker system showed only a small amount of darkening for doses up to and exceeding 1 Mrad. Glasses used in the unstabilized Startracker design showed significant darkening to visible and ultra-violet spectra for doses as low as 5 krad. Plots of transmittance versus wavelength for various doses are given for each of the Startracker optical elements. Radiation induced absorption parameters that determine the radiation induced absorption coefficient are tabulated and plotted versus wavelength.

  8. Gamma radiation induced effects in floppy and rigid Ge-containing chalcogenide thin films

    SciTech Connect

    Ailavajhala, Mahesh S.; Mitkova, Maria [Department of Electrical Engineering, Boise State University, 1910 University Dr. Boise, Idaho 83725-2075 (United States); Gonzalez-Velo, Yago; Barnaby, Hugh; Kozicki, Michael N.; Holbert, Keith [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287-9309 (United States); Poweleit, Christian [Department of Physics, Arizona State University, Tempe, Arizona 85287-1504 (United States); Butt, Darryl P. [Department of Material Science and Engineering, Boise State University, 1910 University Dr. Boise, Idaho 83725-2090 (United States)

    2014-01-28

    We explore the radiation induced effects in thin films from the Ge-Se to Ge-Te systems accompanied with silver radiation induced diffusion within these films, emphasizing two distinctive compositional representatives from both systems containing a high concentration of chalcogen or high concentration of Ge. The studies are conducted on blanket chalcogenide films or on device structures containing also a silver source. Data about the electrical conductivity as a function of the radiation dose were collected and discussed based on material characterization analysis. Raman Spectroscopy, X-ray Diffraction Spectroscopy, and Energy Dispersive X-ray Spectroscopy provided us with data about the structure, structural changes occurring as a result of radiation, molecular formations after Ag diffusion into the chalcogenide films, Ag lateral diffusion as a function of radiation and the level of oxidation of the studied films. Analysis of the electrical testing suggests application possibilities of the studied devices for radiation sensing for various conditions.

  9. Radiation-induced lipid peroxidation and the fluidity of erythrocyte membrane lipids

    SciTech Connect

    Guille, J.; Raison, J.K.; Gebicki, J.M.

    1987-01-01

    The effect of radiation-induced peroxidation on the fluidity of the phospholipids of the erythrocyte membrane was studied using both erythrocyte ghosts and liposomes formed from the polar lipids of erythrocytes. In liposomes, the oxidation of the phospholipids increased with radiation dose, but there was no change in the fluidity of the lipids as measured by spin-label motion. Under the same conditions of irradiation, no oxidation of phospholipid was detected in erythrocyte ghosts, although changes occurred in the motion of spin labels intercalated with the membrane. These changes were attributed to radiation-induced alterations in the membrane proteins. It is concluded that alterations in motion of spin labels, observed with intact membranes after irradiation, are most likely the result of changes in the structure of membrane proteins rather than the lipids.

  10. Birth Weight and Incidence of Surgical Obstetric Brachial Plexus Injury

    PubMed Central

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

    2015-01-01

    Objectives: (1) To analyze the birth weight of obstetric brachial plexus injury (OBPI) patients requiring one or more reconstructive surgeries and (2) to analyze whether there is any difference in the severity of the injury, and the outcome of the surgery between the macrosomic and nonmacrosomic OBPI patients. Study Design: An observational cohort study was performed on 100 consecutive patients treated with surgery at the Texas Nerve and Paralysis Institute. Ninety of the 100 patients underwent the modified Quad surgery, which improves the shoulder abduction and overall shoulder function. All OBPI patients in our study were assessed preoperatively and postoperatively by evaluating video recordings of active shoulder abduction. Results: Using a 4000 g definition of macrosomia, 52% of patients would be considered macrosomic, and using a 4500 g definition of macrosomia, 18% of patients are considered macrosomic in our study. Permanent injury occurs also in average-birth-weight children. Conclusions: A significant percentage (48%-82% depending on definition of macrosomia) of OBPI patients requiring major reconstructive surgery had birth weights which would put them in the “normal” birth weight category. In addition, we found that there was no significant difference in the severity of the injury, and the outcome of the modified Quad surgical procedure between macrosomic and nonmacrosomic OBPI patients. However, there was a significant improvement in shoulder movement in both macrosomic and nonmacrosomic patients after modified Quad surgery. PMID:25987939

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

    SciTech Connect

    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: atareli@hotmail.com; 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)

    2007-04-15

    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.

  12. Trifurcation of superficial brachial artery: a rare case with its clinico-embryological implications.

    PubMed

    Gupta, N; Anshu, A; Dada, R

    2014-01-01

    Literatures on vasculature of upper limbs are crammed with reports of distinctly deviant version of normally prevalent vessels having modified origins, altered branching and odd courses. A unique anatomical variation in vascular pattern was observed during routine dissection of right upper limb in gross anatomy laboratory, AIIMS, New Delhi, India. The brachial artery was placed superficial to median nerve in the arm and therefore it was called superficial brachial artery. In the cubital fossa, 2.8 cm distal to intercondylar line of elbow joint, this superficial brachial artery terminated by trifurcation into radial, common interosseous and ulnar branches. Strikingly the ulnar branch, after its origin ran superficially over the median nerve and epitrochlear superficial flexor group of muscles of forearm in succession for the initial third of its course in the forearm, consequently it was addressed as superficial ulnar artery. The existence of superficial brachial artery in place of normal brachial artery, its termination by trifurcation into radial, common interosseous and superficial ulnar arteries with remarkably different courses, leads to confusing disposition of structures in the arm, cubital fossa and in the forearm and collectively makes this myriad of anatomical variations even rarer. The clinico-embryological revelations for combination of these unconventional observations, apprises and guides the specialized medical personnel attempting blind and invasive procedures in brachium and ante-brachium. This case report depicts the anatomical perspective and clinical implications on confronting a rare variant vasculature architecture pattern of upper limb. PMID:25366943

  13. Small Molecular Inhibitor of Transforming Growth Factor-? Protects Against Development of Radiation-Induced Lung Injury

    Microsoft Academic Search

    Mitchell S. Anscher; Bradley Thrasher; Larisa Zgonjanin; Zahid N. Rabbani; Michael J. Corbley; Kai Fu; Lihong Sun; Wen-Cherng Lee; Leona E. Ling; Zeljko Vujaskovic

    2008-01-01

    Purpose: To determine whether an anti-transforming growth factor- (TGF-) type 1 receptor inhibitor (SM16) can prevent radiation-induced lung injury. Methods and Materials: One fraction of 28 Gy or sham radiotherapy (RT) was administered to the right hemithorax of Sprague-Dawley rats. SM16 was administered in the rat chow (0.07 g\\/kg or 0.15 g\\/kg) beginning 7 days before RT. The rats were

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

    NASA Technical Reports Server (NTRS)

    Lo, R. H.

    1972-01-01

    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.

  15. Excision repair of UV radiation-induced DNA damage in Caenorhabditis elegans

    Microsoft Academic Search

    P. S. Hartman; J. Hevelone; V. Dwarakanath; D. L. Mitchell

    1989-01-01

    Radioimmunoassays were used to monitor the removal of antibody-binding sites associated with the two major UV radiation-induced DNA photoproducts (cyclobutane dimers and (6-4) photoproducts). Unlike with cultured human cells, where (6-4) photoproducts are removed more rapidly than cyclobutane dimers, the kinetics of repair were similar for both lesions. Repair capacity in wild type diminished throughout development. The radioimmunoassays were also

  16. [gamma]-radiation-induced changes in the chemical and physical structure of poly(ethylene terephthalate)

    Microsoft Academic Search

    Jin; Ho-Seon

    1992-01-01

    Poly(ethylene terephthalate) (PET) film was irradiated with [gamma]-rays in air at doses from 0 to 620 Mrad, and at the rate of 0l8 to 1.0 Mrad\\/hr. Radiation-induced physical structure changes were studied by DMA and DSC measurements. Tensile properties were measured to find interrelationships with chemical and physical structure changes. Below 100 Mrad, PET shows little change in NMR and

  17. Radiation-induced cardiomyopathy as a function of radiation beam gating to the cardiac cycle

    Microsoft Academic Search

    David J Gladstone; Michael F Flanagan; Jean B Southworth; Vaughn Hadley; Melissa Wei Thibualt; Eugen B Hug; P Jack Hoopes

    2004-01-01

    Portions of the heart are often unavoidably included in the primary treatment volume during thoracic radiotherapy, and radiation-induced heart disease has been observed as a treatment-related complication. Such complications have been observed in humans following radiation therapy for Hodgkin's disease and treatment of the left breast for carcinoma. Recent attempts have been made to prevent re-stenosis following angioplasty procedures using

  18. Effect of Temperature on the Relaxation of Radiation-Induced Coloration in Optical Glasses

    Microsoft Academic Search

    V. I. Arbuzov; M. G. Kurochkina

    2003-01-01

    Optical and radiation-resistant crown and flint glasses exposed to gamma irradiation at room temperature are investigated. The relaxation of radiation-induced absorption in irradiated glasses is examined prior to and after short-term or long-term heat treatment at different temperatures in the range 20–150°C. It is established that an increase in the heat treatment temperature by even several tens of degrees leads

  19. Factors influencing the rate of radiation-induced dissolution of spent nuclear fuel

    Microsoft Academic Search

    Olivia Roth; Martin Trummer; Mats Jonsson

    2009-01-01

    Several countries plan to store spent nuclear fuel in deep geological repositories. Accurate prediction of the spent fuel\\u000a dissolution rate is a key issue in the safety assessment of a future deep repository. A reliable quantitative model for radiation-induced\\u000a spent fuel dissolution must be based on an accurate description of the dose distribution around the spent fuel and fundamental\\u000a knowledge

  20. Radiation induced brainstem glioblastoma in a patient treated for glomus jugulare tumour.

    PubMed

    Na, Angelika F; Lai, Leon T; Kaye, Andrew H

    2015-01-01

    The intensive utilisation of cranial irradiation in young individuals with benign intracranial pathologies are of particular concern because of the potential for delayed development of radiation-induced neoplasms. We present a 48-year-old man who developed a second metachronous brainstem glioblastoma 10 years following adjuvant radiotherapy for a partially resected glomus jugulare tumour. The current patient highlights the importance of judicious and individualised consideration for irradiation treatment in benign pathologies that are associated with long-term survival. PMID:25085729

  1. Effects of Moisture on Radiation-Induced Degradation in CMOS SOI Transistors

    Microsoft Academic Search

    Marty R. Shaneyfelt; James R. Schwank; Paul E. Dodd; Tom A. Hill; Scott M. Dalton; Scot E. Swanson

    2010-01-01

    The effects of moisture on radiation-induced charge buildup in the oxides of a 0.35 ?m SOI technology are explored. Data show no observable effects of moisture-related aging on radiation hardness. These results are in contrast to those of previous work performed on bulk MOS technologies fabricated in the 1980s. The cause of these differences do not appear to be due

  2. Effect of gamma irradiation conditions on the radiation-induced degradation of isobutylene–isoprene rubber

    Microsoft Academic Search

    M. ?en; C. Uzun; Ö. Kantoglu; S. M. Erdo?an; V. Deniz; O. Güven

    2003-01-01

    The effect of gamma irradiation conditions on the radiation-induced degradation of uncrosslinked, commercial isobutylene–isoprene rubbers has been investigated in this study. Influence of dose rate and irradiation atmosphere on the degradation of butyl rubber has been followed by viscosimetric and chromatographic analyses. Limiting viscosity number of all butyl rubbers decreased sharply up to 100 kGy and leveled off at around

  3. Effect of G\\/M ratio on the radiation-induced degradation of sodium alginate

    Microsoft Academic Search

    Murat ?en; Stojan Rendevski; P?nar Akka? Kavakl?; Amir Sepehrianazar

    2010-01-01

    Radiation-induced degradation of sodium alginate (NaAlg) having different G\\/M ratios was investigated. NaAlg samples were irradiated with gamma rays in air at ambient temperature in the solid state at low dose rate. Change in their molecular weights was followed by size exclusion chromatography (SEC). Changes in their rheological properties and viscosity values as a function of temperature, shear rate and

  4. Thermal detector units for monitoring thin-film radiation-induced polymerization

    Microsoft Academic Search

    J. D. Wisnosky; R. M. Fantazier

    1981-01-01

    Detector cell units have been designed and fabricated to monitor radiation-induced polymerizations in neat, thin-film (4-10 mils) resin systems. The cells utilize rapid-response, thin-foil differential thermocouples to measure the heat evolved during a photopolymerization reaction. Analysis of reaction exotherm curves from the photopolymerization of common resin systems showed that the thermal response of the detector cells was comparable to that

  5. Protective effects of fucoidan against ?-radiation-induced damage of blood cells

    Microsoft Academic Search

    Ki Hyeong Rhee; Keyong Ho Lee

    2011-01-01

    Fucoidan, a sulfated polysaccharide purified from brown algae including Fucus vesiculosus and Laminaria japonica, has a variety of biological activities, including antioxidant and antitumor activities. Here, we investigated the radioprotective\\u000a effects of fucoidan on human monoblastic leukemia cell line U937. Further, animal tests were carried out using Balb\\/c mice\\u000a in order to determine the radiation-induced changes in the counts of

  6. Radiation-induced electrical degradation experiments in the Japan materials testing reactor

    Microsoft Academic Search

    Eugene H. Farnum; Tatsuo Shikama; Minoru Narui; Tsutomu Sagawa; Kent Scarborough

    1996-01-01

    An experiment to measure radiation-induced electrical degradation (RIED) in a sapphire sample and in three MgO-insulated cables was conducted at the JMTR light water reactor. The materials were irradiated at about 260°C to a fluence of 3 × 1024 n\\/m2 (E > 1 MeV) with an applied DC electric field between 100 kV\\/m and 500 kV\\/m. Even though the results

  7. Role of endovascular stenting in radiation-induced stenosis of lower extremity veins.

    PubMed

    Elias, Harold K; Jan, M Fuad; Allaqaband, Suhail Q

    2015-08-01

    Radiation-induced venous stenosis is rare with a few isolated cases reported in the medical literature involving the lower limb. Management options in such cases are thus not streamlined. We describe an unusual case of iliac vein stenosis in a patient with rectal carcinoma after combined chemoradiation therapy, managed with endovascular stenting. The possible mechanisms underlying the pathogenesis of venous stricture and their treatment options have been reviewed. © 2015 Wiley Periodicals, Inc. PMID:25256305

  8. Comparison of hot-carrier and radiation induced increases in base current in bipolar transistors

    Microsoft Academic Search

    R. L. Pease; S. L. Kosier; R. D. Schrimpf; W. E. Combs; M. Davey; M. Delaus; D. M. Fleetwood

    1994-01-01

    A comparison was made between hot-carrier stress induced and ionizing-radiation induced increases in the base current of bipolar linear microcircuit transistors from two process technologies. The comparison was made on the basis of a failure stress in seconds and a failure dose in rad(SiO2) for a failure criterion of ?I B=2 nA measured at an IC of 1 ?A and

  9. Epidermal growth factor receptor expression in radiation-induced dog lung tumors by immunocytochemical localization

    Microsoft Academic Search

    F. L. Leung; J. F. Park; G. E. Dagle

    1993-01-01

    In studies to determine the role of growth factors in radiation-induced lung cancer, epidermal growth factor (EGFR) expression was examined by immunocytochemistry in 51 lung tumors from beagle dogs exposed to inhaled plutonium; 21 of 51 (41%) tumors were positive for EGFR. The traction of tumors positive for EGFR and the histological type of EGFR-positive tumors in the plutonium-exposed dogs

  10. Melatonin protects human blood lymphocytes from radiation-induced chromosome damage

    Microsoft Academic Search

    Vijayalaxmi; Russel J. Reiter; Martin L. Meltz

    1995-01-01

    Cells in human peripheral blood were treated in vitro with increasing concentrations of melatonin (0.5 or 1.0 or 2.0 mM) for 20 min at 37 ± 1°C and then exposed to 150 cGy ?-radiation from a 137Cs source. The lymphocytes which were pre-treated with melatonin exhibited a significant and concentration-dependent decrease in the frequency of radiation-induced chromosome damage as compared

  11. Radiation-induced Breast Telangiectasias Treated with the Pulsed Dye Laser

    PubMed Central

    Rossi, Anthony M.; Nehal, Kishwer S.

    2014-01-01

    Background and objectives: Radiation dermatitis is a frequent sequela of adjuvant radiation therapy for breast cancer. Clinical manifestations include prominent telangiectasias that may be physically disfiguring and psychologically distressing for the patient. The objective of this study was to review cases of breast cancer patients with radiation-induced breast telangiectasias treated with the pulsed dye laser and assess clinical efficacy. The patient’s perception of treatment was also reviewed. Study design: A retrospective chart review of patients treated for radiation-induced telangiectasias was conducted at the Dermatology Division of Memorial Sloan-Kettering Cancer Center. Materials and methods: Pre- and post-clinical photos were used to assess clearance by two independent raters. Patient’s comments were assessed from visit notes and the treating physicians for the impact of treatment on the patient’s overall well-being. Results: All patients (n=11) experienced clinical improvement in the radiation-induced telangiectasias. The mean number of treatments was 4.3 (2–9) with an average fluence of 4.2J/cm2 (585nm platform) and 7.8J/cm2 (595nm) (4–8 J/cm2) used. The mean percent clearance was 72.7 percent (50–90%). Adverse effects were not encountered including those with breast implants or flap reconstruction. Patients reported an improvement in their well-being, including an improved sense of confidence. Limitations: Limitations include the small sample size, nonstandardized digital images, and nonsystematic collection of patient-reported outcomes. Conclusion: The pulsed dye laser is an efficacious treatment for radiation-induced breast telangiectasias. Multiple treatments are required for greater than 50-percent clearance and conservative treatment parameters are advised. Patients also reported an improved quality of life. PMID:25584136

  12. Effects of exogenous carbon monoxide on radiation-induced bystander effect in zebrafish embryos in vivo.

    PubMed

    Choi, V W Y; Wong, M Y P; Cheng, S H; Yu, K N

    2012-07-01

    In the present work, the influence of a low concentration of exogenous carbon monoxide (CO) liberated from tricarbonylchloro(glycinato)ruthenium (II) (CORM-3) on the radiation induced bystander effect (RIBE) in vivo between embryos of the zebrafish was studied. RIBE was assessed through the number of apoptotic signals revealed on embryos at 25 h post fertilization (hpf). A significant attenuation of apoptosis on the bystander embryos induced by RIBE in a CO concentration dependent manner was observed. PMID:22119559

  13. Photoreactivation reverses ultraviolet radiation induced premutagenic lesions leading to frameshift mutations in Escherichia coli

    Microsoft Academic Search

    Kazuo Yamamoto

    1985-01-01

    The effect of photoreactivation of the ultraviolet radiation induced reversion of a trpE9777 frameshift mutation was studied in a uvrA6 derivative of Escherichia coli K12. Two different photoreactivation treatments were used, one providing a single flash of photoreactivating light and another providing 10 min of light from fluorescent lamps. The reversion frequency of the trpE9777 frameshift mutation was strongly reduced

  14. Adenocarcinoma and colitis cystica profunda in a radiation-induced colonic stricture

    SciTech Connect

    Valiulis, A.P.; Gardiner, G.W.; Mahoney, L.J.

    1985-02-01

    A case of adenocarcinoma of the rectum occurring 17 years after pelvic irradiation for squamous carcinoma of the cervix is reported. Earlier colonic resection had shown localized colitis cystica profunda in a radiation-induced colonic stricture. Colorectal cancer is an infrequent sequel to radiotherapy, which may occur many years after treatment of the primary tumor. Prolonged follow-up of these patients is essential.

  15. Radiation induced depigmentation disorder in two patients with breast cancer: Exploring a rare accompaniment.

    PubMed

    Biswas, Ahitagni; Chaudhari, Pritee B; Julka, Pramod Kumar; Rath, Goura Kishor

    2015-06-01

    Radiation induced depigmentation disorder is a rare accompaniment. We herein report two patients of bilateral breast cancer developing depigmentation disorder, initially confined to the radiation portal with subsequent generalization within few months of completion of whole breast radiotherapy. Both these patients had no prior history of vitiligo or other autoimmune disorder. This brief report highlights the importance of awareness of this association in appropriate decision making in susceptible patients thereby preventing this morbidity and its psychological ramifications. PMID:25708302

  16. Radiation-induced liver disease after radiotherapy for hepatocellular carcinoma: clinical manifestation and dosimetric description

    Microsoft Academic Search

    Jason Chia-Hsien Cheng; Jian-Kuen Wu; Chao-Ming Huang; David Y. Huang; Skye H. Cheng; Yu-Mong Lin; James J. Jian; Po-Sheng Yang; Vincent P. Chuang; Andrew T. Huang

    2002-01-01

    Twelve patients with hepatocellular carcinoma and chronic hepatitis developed radiation-induced liver disease (RILD) after three-dimensional conformal radiotherapy. Six patients died of RILD and six recovered. Mean prescribed dose was 50.6±4.3Gy, in a daily fraction of 1.8–2.0Gy. Commonly used dosimetric parameters, such as fraction volume of normal liver with radiation dose >30Gy, prediction score, and normal tissue complication probability, failed to

  17. Impact of p53 status on heavy-ion radiation-induced micronuclei in circulating erythrocytes

    NASA Technical Reports Server (NTRS)

    Chang, P. Y.; Torous, D.; Lutze-Mann, L.; Winegar, R.

    2000-01-01

    Transgenic mice that differed in their p53 genetic status were exposed to an acute dose of highly charged and energetic (HZE) iron particle radiation. Micronuclei (MN) in two distinct populations of circulating peripheral blood erythrocytes, the immature reticulocytes (RETs) and the mature normochromatic erythrocytes (NCEs), were measured using a simple and efficient flow cytometric procedure. Our results show significant elevation in the frequency of micronucleated RETs (%MN-RETs) at 2 and 3 days post-radiation. At 3 days post-irradiation, the magnitude of the radiation-induced MN-RET was 2.3-fold higher in the irradiated p53 wild-type animals compared to the unirradiated controls, 2.5-fold higher in the p53 hemizygotes and 4.3-fold higher in the p53 nullizygotes. The persistence of this radiation-induced elevation of MN-RETs is dependent on the p53 genetic background of the animal. In the p53 wild-type and p53 hemizygotes, %MN-RETs returned to control levels by 9 days post-radiation. However, elevated levels of %MN-RETs in p53 nullizygous mice persisted beyond 56 days post-radiation. We also observed elevated MN-NCEs in the peripheral circulation after radiation, but the changes in radiation-induced levels of MN-NCEs appear dampened compared to those of the MN-RETs for all three strains of animals. These results suggest that the lack of p53 gene function may play a role in the iron particle radiation-induced genomic instability in stem cell populations in the hematopoietic system.

  18. Effects of Solvent on Gamma Radiation–Induced Graft Copolymerization of Acrylamide onto Poly (3-hydroxybutyrate)

    Microsoft Academic Search

    Maykel González-Torres; Arllene M. Perez-González; Manuel González-Perez; César Santiago-Tepantlán; Silvia G. Solís-Rosales; Aurelio H. Heredia-Jiménez

    2011-01-01

    In the present article the gamma radiation–induced graft copolymerization of acrylamide (AAm) onto poly (3-hydroxybutyrate) (PHB) has been carried out by the simultaneous irradiation method. The effect of different solvents on the graft reaction was investigated. The P(HB-g-AAm) thus synthesized were characterized by Fourier transform-infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron micrography (SEM), swelling behavior,

  19. Effect of structure in charge on radiation-induced reactions in micellar systems

    Microsoft Academic Search

    J. Kerry Thomas

    1977-01-01

    A study of radiation-induced reactions in micellar systems included the following topics: location of the probe molecule in the micelle, reaction of noncharged species in micelles, external quenching of pyrene fluorescence, reaction of e\\/sub aq\\/⁻, and photoionization. The effect of charge and structure on reactions induced by low or high-energy photons or fast electrons was ascertained. A comparison of the

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

    Microsoft Academic Search

    Eric J Hall; Cheng-Shie Wuu

    2003-01-01

    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

  1. Growth hormone and insulin-like growth factor I protect intestinal cells from radiation induced apoptosis

    Microsoft Academic Search

    Panagiotis G Mylonas; Panagiota T Matsouka; Eleni V Papandoniou; Constantine Vagianos; Fotis Kalfarentzos; Theodore K Alexandrides

    2000-01-01

    We studied whether programmed cell death (or apoptosis) is the predominant mechanism in radiation-induced cell damage to rat intestinal mucosa and investigated the mechanism of the protective effect of GH and IGF-I in the same model. Male albino Wistar rats were divided into four groups: controls, radiation, radiation plus GH and radiation plus IGF-I. Radiation was administered on the first

  2. Bone Marrow Stromal Cell Transplantation Mitigates Radiation-Induced Gastrointestinal Syndrome in Mice

    Microsoft Academic Search

    Subhrajit Saha; Payel Bhanja; Rafi Kabarriti; Laibin Liu; Alan A. Alfieri; Chandan Guha; Jan-Hendrik Niess

    2011-01-01

    BackgroundNuclear accidents and terrorism presents a serious threat for mass casualty. While bone-marrow transplantation might mitigate hematopoietic syndrome, currently there are no approved medical countermeasures to alleviate radiation-induced gastrointestinal syndrome (RIGS), resulting from direct cytocidal effects on intestinal stem cells (ISC) and crypt stromal cells. We examined whether bone marrow-derived adherent stromal cell transplantation (BMSCT) could restitute irradiated intestinal stem

  3. Mint oil (Mentha spicata Linn.) offers behavioral radioprotection: a radiation-induced conditioned taste aversion study.

    PubMed

    Haksar, A; Sharma, A; Chawla, R; Kumar, Raj; Lahiri, S S; Islam, F; Arora, M P; Sharma, R K; Tripathi, R P; Arora, Rajesh

    2009-02-01

    Mentha spicata Linn. (mint), a herb well known for its gastroprotective properties in the traditional system of medicine has been shown to protect against radiation-induced lethality, and recently its constituents have been found to possess calcium channel antagonizing properties. The present study examined the behavioral radioprotective efficacy of mint oil (obtained from Mentha spicata), particularly in mitigating radiation-induced conditioned taste aversion (CTA), which has been proposed as a behavioral endpoint that is mediated by the toxic effects of gamma radiation on peripheral systems, primarily the gastrointestinal system in the Sprague-Dawley rat model. Intraperitoneal administration of Mentha spicata oil 10% (v/v), 1 h before 2 Gy gamma radiation, was found to render significant radioprotection against CTA (p < 0.05), by blocking the saccharin avoidance response within 5 post-treatment observational days, with the highest saccharin intake being observed on day 5. This finding clearly demonstrates that gastroprotective and calcium channel antagonizing properties of Mentha spicata can be effectively utilized in preventing radiation-induced behavioral changes. PMID:18853399

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

    PubMed Central

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

    2012-01-01

    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

  5. Altered gastric emptying and prevention of radiation-induced vomiting in dogs. [Cobalt 60 irradiation

    SciTech Connect

    Dubois, A.; Jacobus, J.P.; Grissom, M.P.; Eng, R.R.; Conklin, J.J.

    1984-03-01

    The relation between radiation-induced vomiting and gastric emptying is unclear and the treatment of this condition is not established. We explored, therefore, (a) the effect of cobalt 60 irradiation on gastric emptying of solids and liquids and (b) the possibility of preventing radiation-induced vomiting with the dopamine antagonist, domperidone. Twenty dogs were studied on two separate days, blindly and in random order, after i.v. injection of either a placebo or 0.06 mg/kg domperidone. On a third day, they received 8 Gy (800 rads) whole body irradiation with cobalt 60 gamma-rays after either placebo (n . 10) or domperidone (n . 10). Before each study, each dog was fed chicken liver tagged in vivo with 99mTc-sulfur colloid (solid marker), and water containing 111In-diethylenetriamine pentaacetic acid (liquid marker). Dogs were placed in a Pavlov stand for the subsequent 3 h and radionuclide imaging was performed at 10-min intervals. Irradiation produced vomiting in 9 of 10 dogs given placebo but only in 1 of 10 dogs pretreated with domperidone (p less than 0.01). Gastric emptying of liquids and solids was significantly suppressed by irradiation (p less than 0.01) after both placebo and domperidone. These results demonstrate that radiation-induced vomiting is accompanied by suppression of gastric emptying. Furthermore, domperidone prevents vomiting produced by ionizing radiation but does not alter the accompanying delay of gastric emptying.

  6. The Mechanism of Zr and Hf in Reducing Radiation-Induced Segregation in 316 Stainless Steel

    SciTech Connect

    Hackett, Micah J. [University of Michigan; Busby, Jeremy T [ORNL; Was, Gary [University of Michigan

    2008-01-01

    The addition of oversized solutes has the potential to reduce the effects of radiation-induced segregation (RIS) in austenitic alloys. Radiation induced segregation has been implicated as one of several factors in enhancing stress corrosion cracking (SCC) under irradiation, so oversized solute additions could promote SCC resistance. Zr or Hf were added to 316-type stainless steel at levels between 0.05 at% and 0.37 at%. Samples were irradiated with 3 MeV protons to 3 dpa at 400 C, and analyzed in HR-STEM with EDS to measure the grain boundary composition. Zr additions substantially reduced the amount of RIS while Hf was much less effective. Despite similar sizes, first-principles calculations using VASP demonstrate that solute-vacancy binding for Zr is 1.05 eV vs. 0.69 eV for Hf. This difference results in a greater effectiveness of Zr in reducing radiation induced segregation as determined by kinetic rate theory calculations, in agreement with measured results.

  7. Protective effects of caffeic acid phenethyl ester against acute radiation-induced hepatic injury in rats.

    PubMed

    Chu, JianJun; Zhang, Xiaojun; Jin, Liugen; Chen, Junliang; Du, Bin; Pang, Qingfeng

    2015-03-01

    Caffeic acid phenyl ester (CAPE) is a potent anti-inflammatory agent and it can eliminate the free radicals. The current study was intended to evaluate the protective effect of CAPE against the acute radiation-induced liver damage in rats. Male Sprague-Dawley rats were intraperitoneally administered with CAPE (30 mg/kg) for 3 consecutive days before exposing them to a single dose of 30 Gy of ?-ray irradiation to upper abdomen. We found that pretreatment with CAPE significantly decreased the serum levels of alanine aminotransferase and aspartate aminotransferase and increased the activity of superoxide dismutase and glutathione. Histological evaluation further confirmed the protection of CAPE against radiation-induced hepatotoxicity. TUNEL assay showed that CAPE pretreatment inhibited hepatocyte apoptosis. Moreover, CAPE inhibited the nuclear transport of NF-?B p65 subunit, decreased the level of tumor necrosis factor-?, nitric oxide and inducible nitric oxide synthase. Taken together, these results suggest that pretreatment with CAPE offers protection against radiation-induced hepatic injury. PMID:25704035

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

    PubMed Central

    Jenrow, Kenneth A.; Brown, Stephen L.

    2014-01-01

    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. PMID:25324981

  9. Role of ferulic acid in the amelioration of ionizing radiation induced inflammation: a murine model.

    PubMed

    Das, Ujjal; Manna, Krishnendu; Sinha, Mahuya; Datta, Sanjukta; Das, Dipesh Kr; Chakraborty, Anindita; Ghosh, Mahua; Saha, Krishna Das; Dey, Sanjit

    2014-01-01

    Ionizing radiation is responsible for oxidative stress by generating reactive oxygen species (ROS), which alters the cellular redox potential. This change activates several redox sensitive enzymes which are crucial in activating signaling pathways at molecular level and can lead to oxidative stress induced inflammation. Therefore, the present study was intended to assess the anti-inflammatory role of ferulic acid (FA), a plant flavonoid, against radiation-induced oxidative stress with a novel mechanistic viewpoint. FA was administered (50 mg/kg body wt) to Swiss albino mice for five consecutive days prior to exposing them to a single dose of 10 Gy 60Co ?-irradiation. The dose of FA was optimized from the survival experiment and 50 mg/kg body wt dose showed optimum effect. FA significantly ameliorated the radiation induced inflammatory response such as phosphorylation of IKK?/? and I?B? and consequent nuclear translocation of nuclear factor kappa B (NF-?B). FA also prevented the increase of cycloxygenase-2 (Cox-2) protein, inducible nitric oxide synthase-2 (iNOS-2) gene expression, lipid peroxidation in liver and the increase of tumor necrosis factor-alpha (TNF-?) and interleukin-6 (IL-6) in serum. It was observed that exposure to radiation results in decreased activity of superoxide dismutase (SOD), catalase (CAT) and the pool of reduced glutathione (GSH) content. However, FA treatment prior to irradiation increased the activities of the same endogenous antioxidants. Thus, pretreatment with FA offers protection against gamma radiation induced inflammation. PMID:24854039

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

    ERIC Educational Resources Information Center

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

    2012-01-01

    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…

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

    ERIC Educational Resources Information Center

    Buesch, Francisca Eugster

    2010-01-01

    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…

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

    SciTech Connect

    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: akennedy@mail.med.upenn.edu

    2006-04-01

    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.

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

    PubMed

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

    2014-12-01

    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

  14. A new rat model of neuropathic pain: complete brachial plexus avulsion.

    PubMed

    Wang, Le; Yuzhou, Liu; Yingjie, Zhou; Jie, Lao; Xin, Zhao

    2015-03-01

    Brachial plexus avulsion (BPA) is one of the major injuries in motor vehicle accidents and may result in neuropathic pain. Accumulating evidence suggests that 30-80% of BPA developed neuropathic pain in human. In our study, complete brachial plexus avulsion (C5-T1) rats model leads to the results that 37.5% of rats had long-lasting (up to 6 months) mechanical allodynia and cold allodynia. We observed the activation of astrocyte and microglial in cervical spinal cord after BPA. Complete brachial plexus avulsion mimics human nerve root traction injury following traffic accidents. The complete BPA rat model approach human injuries and can be used for further investigations. PMID:25596440

  15. Effects of impurities on generation of radiation-induced defects in Si single crystals and space solar cells

    Microsoft Academic Search

    K. Nishimura; M. Yamaguchi; O. Anzawa; T. K. Vu; A. Khan; Y. Ohshita; T. Abe; M. Imaizumi; S. Matsuda; T. Ohshima; H. Itoh

    2003-01-01

    Anomalous degradation of Si space solar cells for the ETS-VI satellite suggests the importance of understanding the origins of radiation-induced defects in Si, because such defects are responsible for carrier removal, type conversion and reduction in minority-carrier lifetime. Effects of impurities on generation of radiation-induced defects in Si have been studied using measurements of DLTS and minority-carrier lifetime. Boron concentration

  16. Radiation-induced changes in peripheral nerve by stereotactic radiosurgery: a study on the sciatic nerve of rabbit

    Microsoft Academic Search

    Zhixiong LinVincent; Vincent W. C. Wu; Wenchui Ju; Yoshiya Yamada; Longhua Chen

    2011-01-01

    A large fractional dose in radiotherapy produces better radiobiological results, but there is always a concern of radiation-induced\\u000a damage to the normal tissues, especially peripheral nerves. This study was to evaluate the radiation-induced changes of sciatic\\u000a nerve treated by stereotactic radiosurgery (SRS) in rabbit. A localization test was performed on 3 rabbits to determine the\\u000a reference landmarks to the location

  17. Improved Protection Against Solar-Simulated Radiation-Induced Immunosuppression by a Sunscreen with Enhanced Ultraviolet A Protection

    Microsoft Academic Search

    Amy Fourtanier; Audrey Gueniche; Delphine Compan; Susan L. Walker; Antony R. Young

    2000-01-01

    Ultraviolet radiation-induced immunosuppression is thought to play a part in skin cancer. Several studies have indicated that sunscreens that are designed to protect against erythema failed to give comparable protection against ultraviolet radiation-induced immunosuppression. One possible reason for this discrepancy is inadequate ultraviolet A protection. This study evaluated the level of immunoprotection in mice afforded by two broad-spectrum sunscreens with

  18. Inhibitory effect of folinic acid on radiation-induced micronuclei and chromosomal aberrations in V79 cells

    Microsoft Academic Search

    C. Keshava; R. Nagalakshmi; T. Ong; J. Nath

    1996-01-01

    Folinic acid (FA), clinically called leucovorin, has been widely used as a nutrient supplement in dietary intake and is capable of inhibiting cytotoxicity and chromosomal damage induced by chemicals. However, data on its antigenotoxic effect on radiation-induced chromosomal damage are limited. The present study was, therefore, performed to investigate the effect of FA on radiation-induced (X-rays and UV radiation) micronuclei

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

    PubMed Central

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

    2014-01-01

    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

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

    PubMed Central

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

    2014-01-01

    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

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

    PubMed

    Shell, L; Richards, M; Saunders, G

    1993-01-01

    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

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

    Microsoft Academic Search

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

    2011-01-01

    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

  3. Femoral nerve transfer for treatment of brachial plexus root avulsion.

    PubMed

    Gu, Y D; Cheng, X M; Chen, D S; Zhang, G M; Xu, J G; Chen, L; Zhang, L Y; Cai, P Q

    1998-11-01

    Femoral nerve transfer to the muscular branches of the thenar and hypothenar muscles was performed to determine its protective effect on the hand intrinsic muscles. Seven cases of brachial plexus root avulsion treated from May of 1989 to October of 1991 were involved. The femoral nerve transfer to the muscular branches of the thenar and hypothenar muscles was done at the same stage of multiple neurotization. The muscular branches derived from the femoral nerve were isolated and coapted with the thenar muscle branch of the median nerve and the deep branch of the ulnar nerve. A groin flap was harvested simultaneously to form a skin-tube pedicle that covered the nerve bridge. At the second stage, when regeneration of the median and ulnar nerves was found to reach as far as the level of the wrist, the femoral nerve was divided and the muscular branches of the thenar and hypothenar muscles were anastomosed with the regenerated median and ulnar nerves. All the cases were followed up for more than 6 years. Six months after femoral nerve transfer, muscle power of the interosseous muscles and adductor pollicis recovered to MRC3, whereas that of the abductor pollicis brevis recovered to MRC1 to 2. Five cases underwent second-stage transfer. Four to five years of follow-up revealed that the muscle power of the interosseous muscles and adductor pollicis was MRC2 in one case, MRC1 in three cases, and MRC0 in one case. As for the donor area, muscle power of the quadriceps femoris reduced to M3 to 4 within 1 month after femoral nerve transfer and recovered to normal at 3 months. In conclusion, femoral nerve transfer to the muscular branches of the thenar and hypothenar muscles has some protective effect on the hand intrinsic muscles. The outcome of the second stage, however, is not satisfactory. PMID:9810993

  4. [gamma]-radiation-induced changes in the chemical and physical structure of poly(ethylene terephthalate)

    SciTech Connect

    Jin, Ho-Seon.

    1992-01-01

    Poly(ethylene terephthalate) (PET) film was irradiated with [gamma]-rays in air at doses from 0 to 620 Mrad, and at the rate of 0l8 to 1.0 Mrad/hr. Radiation-induced physical structure changes were studied by DMA and DSC measurements. Tensile properties were measured to find interrelationships with chemical and physical structure changes. Below 100 Mrad, PET shows little change in NMR and IR spectra. Fluorescence emission spectra, however, show the presence and increase of monohydroxy-substituted phenylene groups. This hydroxylation appears to stabilize the polymer. The phenylene group in PET also contributes to radiation-resistance. The amorphous-crystalline interfaces impede the penetration of oxygen and slow the oxidative chain scission. Between 100 and 215 Mrad, UV studies reveal that the rates of reaction begin to change rapidly. Chain scission appears to take place first in the interspherulitic amorphous regions and then in the intraspherulitic (interlamella) regions. [gamma]-Radiation-induced oxidative degradation shows aspects of both photolysis and of thermooxidative degradation (proton and carbon-13 NMR, and IR studies). It was concluded that the crystalline phase breaks down in to smaller crystallites, and these smaller crystallites grow in size by acting as nucleating sites. Tensile measurements show that throughout the range of irradiation studied the tensile strength at break and the percent elongation decrease. The tensile strength decreases uniformly and the percent elongation exhibits a more rapid decrease above 100 Mrad. The results of this study lead to the conclusion that [gamma]-radiation-induced oxidative degradation of PET involves products that are seen in both photolysis and thermooxidation.

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

    PubMed Central

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

    2013-01-01

    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

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

    SciTech Connect

    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: hidey@oita-u.ac.jp [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)

    2012-02-17

    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.

  7. Radiation-induced formation, annealing and ordering of voids in crystals: Theory and experiment

    NASA Astrophysics Data System (ADS)

    Dubinko, V. I.; Guglya, A. G.; Donnelly, S. E.

    2011-07-01

    Void ordering has been observed in very different radiation environments ranging from metals to ionic crystals bombarded with energetic particles. The void ordering is often accompanied by a saturation of the void swelling with increasing irradiation dose, which makes an understanding of the underlying mechanisms to be both of scientific significance and of practical importance for nuclear engineering. We show that both phenomena can be explained by the original mechanism based on the anisotropic energy transfer provided by self-focusing discrete breathers or quodons (energetic, mobile, highly localized lattice solitons that propagate great distances along close-packed crystal directions). The interaction of quodons with voids can result in radiation-induced “annealing” of selected voids, which results in the void ordering under special irradiation conditions. We observe experimentally radiation-induced void annealing by lowering the irradiation temperature of nickel and copper samples pre-irradiated to produce voids or gas bubbles. The bulk recombination of Frenkel pairs increases with decreasing temperature resulting in suppression of the production of freely migrating vacancies (the driving force of the void growth). On the other hand, the rate of radiation-induced vacancy emission from voids due to the void interaction with quodons remains essentially unchanged, which results in void dissolution. The experimental data on the void shrinkage and void lattice formation obtained for different metals and irradiating particles are explained by the present model assuming the quodon propagation length to be in the micron range, which is consistent with independent data on the irradiation-induced diffusion of interstitial ions in austenitic stainless steel.

  8. A Case of Radiation-Induced Generalized Morphea with Prominent Mucin Deposition and Tenderness

    PubMed Central

    Yanaba, Koichi; Umezawa, Yoshinori; Nakagawa, Hidemi

    2015-01-01

    Patient: Female, 67 Final Diagnosis: Dermatomyositis Symptoms: Muscle weakness • skin rash • subcutaneous nodules Medication: — Clinical Procedure: Drug administration Specialty: Dermatology Objective: Rare disease Background: Radiation-induced morphea is a rare complication of radiation therapy. The affected areas are generally restricted to the radiation field or to the nearby surrounding area. Case Report: A 67-year-old Japanese woman with a history of right breast cancer followed by adjuvant radiotherapy was referred our hospital because of 7-year history of symmetrical indurated erythematous plaques on her trunk. Three months after completion of irradiation, erythematous plaques developed on her right chest and gradually spread accompanied tenderness. She did not have a history of trauma to her right chest. Laboratory testing was positive for antinuclear antibody test at 1: 640 but negative for anti-SS-A/B, anti-U1-RNP, anti-DNA, anti-Sm, anticentromere, anti-topoisomerase I antibodies, and Borrelia and cytomegalovirus infection. She had no Raynaud’s phenomenon, sclerodactyly, or nail-fold bleeding. She did not have interstitial lung disease or other internal organ involvement. A biopsy specimen revealed reticular dermal fibrosis with thickened collagen bundles with superficial and deep perivascular infiltration of mononuclear cells. These findings were consistent with morphea. Furthermore, mucin deposition was present in the papillary dermis upon Alcian blue staining, which has been reported to be observed in generalized morphea. Consequently, a diagnosis of generalized morphea induced by radiotherapy was made. She had been treated with oral hydroxychloroquine sulfate, resulting in the resolution of tenderness but the erythematous plaques remained. Conclusions: To the best of our knowledge, this is the first report of radiation-induced generalized morphea with prominent mucin deposition. Hydroxychloroquine sulfate may be efficacious for radiation-induced morphea-associated tenderness. PMID:25958415

  9. Radiation induced defects in CVD-grown 3C-SiC

    Microsoft Academic Search

    Hisayoshi Itoh; Masahito Yoshikawa; Isamu Nashiyama; Shunji Misawa; Hajime Okumura; Sadafumi Yoshida

    1990-01-01

    Radiation-induced defects in 3C-SiC epitaxially grown by a chemical vapor deposition method were studied with the electron spin resonance (ESR) technique. A 15-line ESR spectrum was observed in 2-MeV proton and 1-MeV electron irradiated 3C-SiC when the magnetic field was applied parallel to the axis. This spectrum, T1, which has an isotropic g-value of 2.0029±0.0001, was interpreted by simultaneous hyperfine

  10. Microscopic mechanisms of radiation-induced proton density decay in SiO{sub 2} films

    SciTech Connect

    Karna, S.P.; Pugh, R.D.; Chavez, J.R.; Shedd, W.; Brothers, C.P.; Singaraju, B.K. [Air Force Research Lab., Kirtland AFB, NM (United States)] [Air Force Research Lab., Kirtland AFB, NM (United States); Vitiello, M.; Pacchioni, G. [Univ. di Milano (Italy). Dipt. di Scienza dei Materiali] [Univ. di Milano (Italy). Dipt. di Scienza dei Materiali; Devine, R.A.B. [French Telecom-CNET, Meylan (France)] [French Telecom-CNET, Meylan (France)

    1998-12-01

    In order to understand the physics of radiation-induced proton density decay in thin SiO{sub 2} films, the authors performed ab initio Hartree-Fock calculations of the potential energy curves for the interaction between model oxide clusters and H in two charge states. The calculated results led to two separate proposed mechanisms for proton density decay in thin SiO{sub 2} films: (1) electronic excitation involving hot phonon levels of the ground electronic state at low photon-energy radiation and (2) electron capture by protons at high photon-energy radiation. The proposed mechanisms qualitatively explain recent experimental observations.

  11. On the Radiatively Induced Lorentz and CPT Violating Chern-Simons Term

    E-print Network

    Yong-Liang Ma; Yue-Liang Wu

    2007-03-31

    The radiatively induced Lorentz and CPT violating Chern-Simons terms in QED is calculated based on the recently developed loop regularization method [Y.L. Wu, Int.J.Mod.Phys.A18 (2003) 5363, hep-th/0209021; Y.L. Wu, Mod.Phys.Lett.A19 (2004) 2191, hep-th/0311082] for quantum field theories. It enables us to make general comments on the various results in literature and obtain a consistent result when simultaneously combining the evaluation for the chiral anomaly which has a unique form once the vector current is kept conserved.

  12. Radiation induced dechlorination of some chlorinated hydrocarbons in aqueous suspensions of various solid particles

    NASA Astrophysics Data System (ADS)

    Mú?ka, V.; Bu?ata, M.; ?uba, V.; Silber, R.; Juha, L.

    2015-07-01

    Radiation induced dechlorination of trichloroethylene (TCE) and tetrachloroethylene (PCE) in aqueous solutions containing the active carbon (AC) or cupric oxide (CuO) as the modifiers was studied. The obtained results were compared to the previously studied dechlorination of polychlorinated biphenyls (PCBs). Both modifiers were found to decrease the efficiency of dechlorination. The AC modifier acts mainly via adsorption of the aliphatic (unlike the aromatic) hydrocarbons and the CuO oxide mainly inhibits the mineralization of the perchloroethylene. The results presented in this paper will be also helpful for the studies of the impact of chlorinated hydrocarbons on the membrane permeability of living cells.

  13. Accumulation of radiation-induced charge in MNOS structures with different oxide thicknesses

    SciTech Connect

    Gurtov, V.A.; Evdokimov, V.D.; Nazarov, A.I.; Khrustalev, V.A.

    1986-05-01

    The authors attempt to answer questions regarding the dosimetry of x-ray radiation sources, especially in the region of high exposure doses, using silicon nitride. SiO/sub 2/ was obtained by thermal oxidation in dry oxygen or in a mixture of oxygen and argon. Silicon nitride was obtained by ammonolysis of silicon tetrachloride. Aluminum was used for the gate. The magnitude of the radiation-induced space charge was determined from the shift in the flat-band voltage on the high-frequency volt-faraday curves.

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

    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.

  15. Transient radiation-induced absorption in materials for the DOI laser

    SciTech Connect

    Brannon, P.J.

    1995-01-01

    This is the final report on a series of experiments concerned with transient radiation-induced absorption in materials for a Cr,Nd:GSGG laser. Both the Sandia National Laboratories SPR III pulsed reactor and the Hermes III pulsed X-ray machine are used as radiation sources. The time dependence and the magnitude of the induced absorption in filter glasses and in doped and undoped LiNbO{sub 3} Q-switch materials have been measured. Gain has been observed in Cr,Nd:GSGG, the laser medium, when it is irradiated by X-rays.

  16. Protective effects of L-selenomethionine on space radiation induced changes in gene expression.

    PubMed

    Stewart, J; Ko, Y-H; Kennedy, A R

    2007-06-01

    Ionizing radiation can produce adverse biological effects in astronauts during space travel. Of particular concern are the types of radiation from highly energetic, heavy, charged particles known as HZE particles. The aims of our studies are to characterize HZE particle radiation induced biological effects and evaluate the effects of L-selenomethionine (SeM) on these adverse biological effects. In this study, microarray technology was used to measure HZE radiation induced changes in gene expression, as well as to evaluate modulation of these changes by SeM. Human thyroid epithelial cells (HTori-3) were irradiated (1 GeV/n iron ions) in the presence or in the absence of 5 microM SeM. At 6 h post-irradiation, all cells were harvested for RNA isolation. Gene Chip U133Av2 from Affymetrix was used for the analysis of gene expression, and ANOVA and EASE were used for a determination of the genes and biological processes whose differential expression is statistically significant. Results of this microarray study indicate that exposure to small doses of radiation from HZE particles, 10 and 20 cGy from iron ions, induces statistically significant differential expression of 196 and 610 genes, respectively. In the presence of SeM, differential expression of 77 out of 196 genes (exposure to 10 cGy) and 336 out of 610 genes (exposure to 20 cGy) is abolished. In the presence or in the absence of SeM, radiation from HZE particles induces differential expression of genes whose products have roles in the induction of G1/S arrest during the mitotic cell cycle, as well as heat shock proteins. Some of the genes, whose expressions were affected by radiation from HZE particles and were unchanged in irradiated cells treated with SeM, have been shown to have altered expression levels in cancer cells. The conclusions of this report are that radiation from HZE particles can induce differential expression of many genes, some of which are known to play roles in the same processes that have been shown to be activated in cells exposed to radiation from photons (like cell cycle arrest in G1/S), and that supplementation with SeM abolishes HZE particle-induced differential expression of many genes. Understanding the roles that these genes play in the radiation-induced transformation of cells may help to decipher the origins of radiation-induced cancer. PMID:17265150

  17. Modification of radiation-induced oxidative damage in liposomal and microsomal membrane by eugenol

    NASA Astrophysics Data System (ADS)

    Pandey, B. N.; Lathika, K. M.; Mishra, K. P.

    2006-03-01

    Radiation-induced membrane oxidative damage, and their modification by eugenol, a natural antioxidant, was investigated in liposomes and microsomes. Liposomes prepared with DPH showed decrease in fluorescence after ?-irradiation, which was prevented significantly by eugenol and correlated with magnitude of oxidation of phospholipids. Presence of eugenol resulted in substantial inhibition in MDA formation in irradiated liposomes/microsomes, which was less effective when added after irradiation. Similarly, the increase in phospholipase C activity observed after irradiation in microsomes was inhibited in samples pre-treated with eugenol. Results suggest association of radio- oxidative membrane damage with alterations in signaling molecules, and eugenol significantly prevented these membrane damaging events.

  18. Design of terahertz detector based on radiation-induced magnetoresistance oscillations

    NASA Astrophysics Data System (ADS)

    Zhou, Q. S.; Cao, J. C.; Qi, M.

    2010-06-01

    We have investigated the longitudinal resistivity of two-dimensional (2D) electron gas driven by microwave and magnetic field by using the balance-equation theory. Radiation-induced magnetoresistance oscillations have been reproduced. The period-in-the-inverse-magnetic-field is determined by radiation frequency. This property can be used to design a terahertz detector. The detection is realized by applying a time-varying magnetic field on a 2D electron device and then measuring the difference of longitudinal resistivity with and without radiation. This kind of detector has high sensitivity and high immunity.

  19. Radiation-induced electron paramagnetic resonance signal and soybean isoflavones content

    NASA Astrophysics Data System (ADS)

    de Oliveira, Marcos R. R.; Mandarino, José M. G.; del Mastro, Nelida L.

    2012-09-01

    Electron Paramagnetic Resonance (EPR) is a well-known spectroscopic technique that detects paramagnetic centers and can detect free radicals with high sensitivity. In food, free radicals can be generated by several commonly used industrial processes, such as radiosterilization or heat treatment. EPR spectroscopy is used to detect radioinduced free radicals in food. In this work the relation between EPR signal induced by gamma irradiation treatment and soybean isoflavones content was investigated. Present results did not show correlation between total isoflavones content and the EPR signal. Nevertheless, some isoflavone contents had a negative correlation with the radiation-induced EPR signal.

  20. Radiation-induced electrical breakdown of helium in fusion reactor superconducting magnet systems

    SciTech Connect

    Perkins, L.J.

    1983-12-02

    A comprehensive theoretical study has been performed on the reduction of the electrical breakdown potential of liquid and gaseous helium under neutron and gamma radiation. Extension of the conventional Townsend breakdown theory indicates that radiation fields at the superconducting magnets of a typical fusion reactor are potentially capable of significantly reducing currently established (i.e., unirradiated) helium breakdown voltages. Emphasis is given to the implications of these results including future deployment choices of magnet cryogenic methods (e.g., pool-boiling versus forced-flow), the possible impact on magnet shielding requirements and the analogous situation for radiation-induced electrical breakdown in fusion RF transmission systems.

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

    PubMed

    Shi, Junren; Xie, X C

    2003-08-22

    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

  2. Simple method to demonstrate radiation-inducible radiation resistance in microbial cells

    SciTech Connect

    Tan, S.T.; Maxcy, R.B.

    1986-01-01

    A simple method for detection of radiation-inducible radiation resistance was developed by irradiating aliquots (0.01 ml) of cell suspension on agar plates. Part of each experimental plate was subjected to an induction treatment, and subsequent radiation resistance was compared with that of untreated cells on the same plate. The UV radiation resistance of a Micrococcus sp. was increased approximately 1.6 times by an induction treatment. This simple procedure of irradiating cells in a fixed position on agar avoided washing, centrifugation, and cell enumeration required in traditional methods.

  3. Late-onset radiation-induced vasculopathy and stroke in a child with medulloblastoma.

    PubMed

    Bansal, Lalit R; Belair, Jeffrey; Cummings, Dana; Zuccoli, Giulio

    2015-05-01

    We report a case of a 15-year-old boy who presented to our institution with left-sided weakness and slurred speech. He had a history of medulloblastoma diagnosed at 3 years of age, status postsurgical resection and craniospinal radiation. Magnetic resonance imaging (MRI) of brain revealed a right paramedian pontine infarction, suspected secondary to late-onset radiation-induced vasculopathy of the vertebrobasilar system. Radiation to the brain is associated with increased incidence of ischemic stroke. Clinicians should have a high index of suspicion for stroke when these patients present with new neurologic symptoms. PMID:25015672

  4. AVULSION OF THE BRACHIAL PLEXUS IN A GREAT HORNED OWL (Bubo virginianus)

    Microsoft Academic Search

    MICHAEL P. MOORE; FRIK STAUBER; NANCY THOMAS

    1989-01-01

    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

  5. Supranormal ankle brachial index is associated with a favorable exercise blood pressure response

    Microsoft Academic Search

    Gardar Sigurdsson; Daniel A. Duprez; Alan T. Hirsch; Natalia Florea; Lynn Hoke; Jay N. Cohn

    2003-01-01

    The Ankle Brachial Index (ABI) is an established diagnostic test for peripheral arterial disease. Howerver, the significance of an ABI greater than 1.0 has been controversial, specifically in patients with diabetes mellitus or individuals evaluated in a primary cardiovascular prevention cohort. We hypothesized that high ABI values, usually considered to represent a noncompliant arterial circulation, would be associated with an

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

    PubMed Central

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

    2014-01-01

    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

  7. Brachial plexus compression due to subclavian pseudoaneurysm from cannulation of jugular vein hemodialysis catheter

    Microsoft Academic Search

    DC Tarng; TP Huang; KP Lin

    1998-01-01

    Jugular venous cannulation is generally safer than subclavian cannulation. The traumatic complications associated with jugular vein hemodialysis catheters are rare. A jugular vein, therefore, has become the preferred site for hemodialysis catheter insertion. We describe the first case of brachial plexus compression attributable to delayed recognition of a right subclavian pseudoaneurysm as a complication of jugular venous cannulation of hemodialysis

  8. Large brachial artery diameter is associated with angiographic coronary artery disease in women

    Microsoft Academic Search

    Richard Holubkov; Richard H. Karas; Carl J. Pepine; Cheryl R. Rickens; Nathaniel Reichek; William J. Rogers; Barry L. Sharaf; George Sopko; C. Noel Bairey Merz; Sheryl F. Kelsey; Susan P. McGorray; Steven E. Reis

    2002-01-01

    Background Noninvasive methods are needed for the identification of women at highest risk for coronary artery disease (CAD) who might benefit most from aggressive preventive therapy. Identification of brachial artery atherosclerosis, which correlates with coronary artery atherosclerosis, may be useful to estimate or stratify CAD risk. Because atherosclerosis disrupts the arterial architecture that regulates vessel size, we hypothesized that noninvasively

  9. The effect of perinatal brachial plexus lesion on upper limb development

    PubMed Central

    2014-01-01

    Background Deficiency in upper limb development is a sequel of the perinatal brachial plexus palsy. The purpose of this study was to evaluate the effect of brachial plexus birth lesion on upper limb development. Methods Forty-four patients with unilateral obstetric brachial plexus palsy underwent measurements of both upper extremities. The average age at the time of evaluation was 6.8 years. Active motion was assessed using Gilbert-Raimondi, the modified MRC, and Al-Qattan scales. Paired t test was used for statistical analysis. Correlation between limb length / circumference discrepancy and age / time of surgery was assessed using Pearson correlation coefficient. Results A decrease in the circumference and length was observed in all limbs with brachial plexus lesion. We found a statistically significant difference between degree of hand length and width decrease and its useful and useless function. We observed a statistically significant difference in measurement: forearm length, hand length and width dependent on the type of surgical procedure (neurolysis, reconstruction). We observed no correlation between age and limb length / circumference discrepancy. We also observed no correlation between time of surgery and limb length / circumference discrepancy. Conclusions The decrease in dimensions of the affected limbs occurred predominantly during the period of early childhood. Disparities in dimensions are observed in both cases of deficiency of useful function of upper limb and cases in which functional efficiency appears. PMID:24694070

  10. Validity of a new method to estimate mean arterial pressure at brachial level.

    PubMed

    Graf, Sebastian; Craiem, Damian; Armentano, Ricardo L

    2010-01-01

    The value of mean arterial pressure (MBP) is of clinical importance, and is required for peripheral resistance calculation as well as for central blood pressure calibration procedures. MBP is usually estimated at the upper arm using systolic and diastolic sphygmomanometers pressure values, as 33% of pulse pressure (PP) above diastolic pressure. In a previous work, we proposed to use 38%. The aim of this study was to investigate the validity of the proposed formula to calculate MBP, when assessing subjects with a wide range of blood pressure and pulse wave velocity (PWV) levels. In 73 volunteers (56 ± 10 years, range: 27-82; pulse pressure: 59 ± 12 mmHg, range: 43-86; PWV: 10 ± 2 m/s, range: 8-17) arterial pressure waveforms were obtained at the left brachial artery by applanation tonometry. Diastolic (DBP) and systolic (SBP) brachial pressure were obtained with oscillometric device. Brachial-radial PWV was obtained at the same arm using mechano-transducers. MBP computed as 38% of PP above diastolic pressure, introduces an error of only 0.1% in brachial MBP estimation, independent of pressure and PWV levels. PMID:21095973

  11. Robot-assisted surgery of the shoulder girdle and brachial plexus.

    PubMed

    Facca, Sybille; Hendriks, Sarah; Mantovani, Gustavo; Selber, Jesse C; Liverneaux, Philippe

    2014-02-01

    New developments in the surgery of the brachial plexus include the use of less invasive surgical approaches and more precise techniques. The theoretical advantages of the use of robotics versus endoscopy are the disappearance of physiological tremor, three-dimensional vision, high definition, magnification, and superior ergonomics. On a fresh cadaver, a dissection space was created and maintained by insufflation of CO2. The supraclavicular brachial plexus was dissected using the da Vinci robot (Intuitive Surgical, Sunnyvale, CA). A segment of the C5 nerve root was grafted robotically. A series of eight clinical cases of nerve damage around the shoulder girdle were operated on using the da Vinci robot. The ability to perform successful microneural repair was confirmed in both the authors' clinical and experimental studies, but the entire potential of robotically assisted microneural surgery was not realized during these initial cases because an open incision was still required. Robotic-assisted surgery of the shoulder girdle and brachial plexus is still in its early stages. It would be ideal to have even finer and more suitable instruments to apply fibrin glue or electrostimulation in nerve surgery. Nevertheless, the prospects of minimally invasive techniques would allow acute and subacute surgical approach of traumatic brachial plexus palsy safely, without significant and cicatricial morbidity. PMID:24872778

  12. The Association of Homocysteine and Related Factors to Brachial Artery Diameter and Flow-Mediated Dilation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brachial artery flow-mediated dilation (BAFMD) has been proposed as a measurement of the degree and severity of cardiovascular disease. The purpose of this study was to (1) evaluate the associations between BAFMD and homocysteine, folate, vitamin B12, vitamin B6, (2) examine the influence of 5,10-me...

  13. Buprenorphine added to the local anesthetic for brachial plexus block to provide postoperative analgesia in outpatients

    Microsoft Academic Search

    Kenneth D. Candido; Carlo D. Franco; Mohammad A. Khan; Alon P. Winnie; Durre S. Raja

    2001-01-01

    Background and Objectives: Over the past 10 years, several studies have suggested that the addition of certain opiates to the local anesthetic used for brachial block may provide effective, long-lasting postoperative analgesia. One of these studies indicated that the agonist-antagonist, buprenorphine, added to bupivacaine provided a longer period of postoperative analgesia than the traditional opiates, but in this study, it

  14. Brachial artery flow velocity variation: another victory for hand-carried ultrasound?

    PubMed Central

    2009-01-01

    Dynamic predictors are clearly superior to static pressures in predicting whether a patient will respond to a fluid bolus. Hand-carried ultrasound (HCUS) can measure changes in blood flow velocity in the brachial artery that parallel arterial pulse pressure variation. The potential for HCUS to guide fluid therapy non-invasively must overcome problems of sensitivity and applicability. PMID:19849818

  15. Robot-Assisted Surgery of the Shoulder Girdle and Brachial Plexus

    PubMed Central

    Facca, Sybille; Hendriks, Sarah; Mantovani, Gustavo; Selber, Jesse C.; Liverneaux, Philippe

    2014-01-01

    New developments in the surgery of the brachial plexus include the use of less invasive surgical approaches and more precise techniques. The theoretical advantages of the use of robotics versus endoscopy are the disappearance of physiological tremor, three-dimensional vision, high definition, magnification, and superior ergonomics. On a fresh cadaver, a dissection space was created and maintained by insufflation of CO2. The supraclavicular brachial plexus was dissected using the da Vinci robot (Intuitive Surgical, Sunnyvale, CA). A segment of the C5 nerve root was grafted robotically. A series of eight clinical cases of nerve damage around the shoulder girdle were operated on using the da Vinci robot. The ability to perform successful microneural repair was confirmed in both the authors' clinical and experimental studies, but the entire potential of robotically assisted microneural surgery was not realized during these initial cases because an open incision was still required. Robotic-assisted surgery of the shoulder girdle and brachial plexus is still in its early stages. It would be ideal to have even finer and more suitable instruments to apply fibrin glue or electrostimulation in nerve surgery. Nevertheless, the prospects of minimally invasive techniques would allow acute and subacute surgical approach of traumatic brachial plexus palsy safely, without significant and cicatricial morbidity. PMID:24872778

  16. Inflammation predicts accelerated brachial arterial wall changes in patients with recent-onset rheumatoid arthritis

    PubMed Central

    Hannawi, Suad; Marwick, Thomas H; Thomas, Ranjeny

    2009-01-01

    Introduction Patients with recent-onset rheumatoid arthritis (RA) have impaired brachial artery endothelial function compared with controls matched for age, sex and cardiovascular risk factors. The present study examined endothelium-dependent (flow-mediated dilatation (FMD)) and independent (glyceryl trinitrate (GTN)-mediated dilatation (GMD)) structural responses in early RA patients, and determined progress over one year. Methods Brachial artery FMD and GMD and carotid intima media thickness (cIMT) were studied using ultrasound in 20 patients diagnosed with early RA in whom symptoms had been present for less than 12 months, and in 20 control subjects matched for age, sex and established cardiovascular risk factors. FMD and GMD were re-assessed after 12 months in RA patients and the change in each parameter was calculated. Data were analysed by univariate regression. Results Mean FMD and GMD were significantly lower in early RA patients at baseline than in controls, but each parameter significantly improved in one year. FMD and GMD responses were positively associated with each other. Patients' age, C-reactive protein (CRP) level and cIMT at baseline and CRP level at one year, were negatively associated with change in brachial responses in one year. Conclusions Patients with recent-onset RA have altered brachial artery responses signifying both functional and structural abnormalities. However, early control of inflammation may reduce arterial dysfunction and thus the tendency for atherosclerotic progression. PMID:19344530

  17. Time course of brachial artery diameter responses to rhythmic handgrip exercise in humans

    Microsoft Academic Search

    J. K. Shoemaker; M. J. MacDonald; R. L. Hughson

    1997-01-01

    Objective: Whether the dimensions of conduit arteries contribute to the time course of change in blood flow during voluntary rhythmic exercise, and the mechanisms governing such a response in humans, are not known. Methods: The time course of change in the vascular and blood flow dynamics in the brachial artery during the transition between rest and 5 min of rhythmic

  18. Combined nerve transfers for repair of the upper brachial plexus injuries through a posterior approach.

    PubMed

    Lu, Jiuzhou; Xu, Jianguang; Xu, Wendong; Xu, Lei; Fang, Yousheng; Chen, Liang; Gu, Yudong

    2012-02-01

    The upper brachial plexus injury leads to paralysis of muscles innervated by C5 and C6 nerve roots. In this report, we present our experience on the use of the combined nerve transfers for reconstruction of the upper brachial plexus injury. Nine male patients with the upper brachial plexus injury were treated with combined nerve transfers. The time interval between injury and surgery ranged from 3 to 11 months (average, 7 months). The combined nerve transfers include fascicles of the ulnar nerve and/or the median nerve transfer to the biceps and/or the brachialis motor branch, and the spinal accessory nerve (SAN) to the suprascapular nerve (SSN) and triceps branches to the axillary nerve through a posterior approach. At an average of 33 months of follow-up, all patients recovered the full range of the elbow flexion. Six out of nine patients were able to perform the normal range of shoulder abduction with the strength degraded to M3 or M4. These results showed that the technique of the combined nerve transfers, specifically the SAN to the SSN and triceps branches to the axillary nerve through a posterior approach, may be a valuable alternative in the repair of the upper brachial plexus injury. Further evaluations of this technique are necessary. PMID:22002897

  19. Brachial plexus injury management in military casualties: who, what, when, why, and how.

    PubMed

    Chambers, James A; Hiles, Claire L; Keene, Brian P

    2014-06-01

    The Global War on Terrorism has achieved an unprecedented 90% casualty survival rate because of far forward surgical support, rapid transport, and body armor. Despite the remarkable protection body armor affords, peripheral nerve injuries continue to occur. The brachial plexus in particular is still susceptible to penetrating trauma through the axilla as well as blunt mechanisms. We report 1,818 individuals with reported cases of peripheral nerve injury, 97 of which had brachial plexus injury incident from Operation Iraqi Freedom and Operation Enduring Freedom. We suspect that true prevalence is higher as initial focus on vascular and orthopedic reconstruction in complex shoulder injuries may overlook brachial plexus lesions. Accordingly, emergency physicians, general and orthopedic trauma surgeons, and vascular surgeons should all consider the possibility of brachial plexus and other peripheral nerve injury for early and appropriate referral to surgeons (plastic, orthopedic, or neurosurgical) for further evaluation and reconstruction. The latter group should be familiar with appropriate modern diagnostic and initial as well as salvage therapeutic options. PMID:24902131

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

    ERIC Educational Resources Information Center

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

    2004-01-01

    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…

  1. Successful use of the Cardiva Boomerang™ vascular closure device to close a brachial artery puncture site after emergency PTCA.

    PubMed

    Cirillo, Plinio; Petrillo, Gianluca; D'Ascoli, Greta Luana; Piscione, Federico; Chiariello, Massimo

    2010-11-01

    Brachial artery access is a good alternative for performing percutaneous transluminal angioplasty when femoral access is contraindicated or not feasible. Although several closure devices are available for femoral access, haemostasis for brachial artery access is still achieved by manual compression with several potential complications, such as bleeding, pseudo-aneurysm formation, especially in patients in which heparin is administered, or thrombotic vessel occlusion. This first-in-human report describes the off-label brachial use of the Cardiva Boomerang™, a novel vascular closure device, which provides haemostasis using a temporary intravascular tampon, thus permitting the easier physiological closure of the puncture site without any important complications. PMID:20878167

  2. Correlative ultrasound anatomy of the feline brachial plexus and major nerves of the thoracic limb.

    PubMed

    Ansón, Agustina; Gil, Francisco; Laredo, Francisco G; Soler, Marta; Belda, Eliseo; Ayala, Maria D; Agut, Amalia

    2013-01-01

    Brachial plexus avulsions commonly occur in cats due to traumatic injuries involving the shoulder. Ultrasound may be an effective method for detecting injured nerves. Additional applications may include characterization of brachial plexus neoplasms and guidance of anesthetic nerve blocks. Aims of this study were to describe ultrasonographic approaches and the normal appearance of this plexus and other major nerves of the thoracic limb in cats. Eight feline cadavers were used to determine anatomic landmarks, obtain cross-sectional anatomic images of the target nerves, and compare these with ultrasound images. An ultrasonographic study was performed in five fresh feline cadavers to assess the brachial plexus and its major components at the levels of the axilla and proximal, middle and distal (lateral and medial approaches) humeral regions. Five healthy adult cats were recruited for an in vivo ultrasonographic study using the same protocol described for the cadaver ultrasonographic study. The roots of the brachial plexus appeared as a cluster of small, round hypoechoic structures surrounded by a hyperechoic rim in the axillary approach. The radialis, medianus, and ulnaris nerves were individually visualized on proximal and middle humeral approaches. The medianus and ulnaris nerves were easily identified on the medial aspect of the humerus in the distal approach. The superficial branch of radialis nerve was seen on the lateral aspect of the distal humerus approach. The nerves appeared as oval-to-round hypoechogenic structures with a hyperechogenic rim. Future studies are needed to compare findings from this study with those in cats with confirmed brachial plexus injuries or other lesions. PMID:23363032

  3. Automatic contouring of brachial plexus using a multi-atlas approach for lung cancer radiotherapy

    PubMed Central

    Yang, Jinzhong; Amini, Arya; Williamson, Ryan; Zhang, Lifei; Zhang, Yongbin; Komaki, Ritsuko; Liao, Zhongxing; Cox, James; Welsh, James; Court, Laurence; Dong, Lei

    2013-01-01

    Purpose To demonstrate a multi-atlas segmentation approach to facilitating accurate and consistent delineation of low-contrast brachial plexuses on CT images for lung cancer radiotherapy. Materials and Methods We retrospectively identified 90 lung cancer patients with treatment volumes near the brachial plexus. Ten representative patients were selected to form an atlas group, and their brachial plexuses were delineated manually. We used deformable image registration to map each atlas brachial plexus to the remaining 80 patients. In each patient, a composite contour was created from 10 individual segmentations using the Simultaneous Truth and Performance Level Estimation (STAPLE) algorithm. This auto-delineated contour was reviewed and modified appropriately for each patient. We also performed 10 leave-one-out tests using the 10 atlases to validate the segmentation accuracy and demonstrate the contouring consistency using multi-atlas segmentation. Results The multi-atlas segmentation took less than 2 minutes to complete. Contour modification took 5 minutes compared with 20 minutes for manual contouring from scratch. The multi-atlas segmentation from the 10 leave-one-out tests had a mean 3D volume overlap of 59.2% ± 8.2% and a mean 3D surface distance of 2.4 mm ± 0.5 mm. The distances between the individual and average contours in the 10 leave-one-out tests demonstrated much better contouring consistency for modified contours than for manual contours. The auto-segmented contours did not require substantial modification, demonstrated by the good agreement between the modified and auto-segmented contours in the 80 patients. Dose volume histograms of auto-segmented and modified contours were also in good agreement, showing that editing auto-segmented contours is clinically acceptable in view of the dosimetric impact. Conclusions Multi-atlas segmentation greatly reduced contouring time and improved contouring consistency. Editing auto-segmented contours to delineate the brachial plexus proved to be a better clinical practice than manually contouring from scratch. PMID:24273627

  4. [Nerve reconstruction techniques in traumatic brachial plexus surgery. Part 2: intraplexal nerve transfers].

    PubMed

    Robla-Costales, J; Socolovsky, M; Di Masi, G; Robla-Costales, D; Domitrovic, L; Campero, A; Fernández-Fernández, J; Ibáñez-Plágaro, J; García-Cosamalón, J

    2011-12-01

    After the great enthusiasm generated in the '70s and '80s in brachial plexus surgery as a result of the incorporation of microsurgical techniques and other advances, brachial plexus surgery has been shaken in the last two decades by the emergence of nerve transfer techniques or neurotizations. This technique consists in sectioning a donor nerve, sacrificing its original function, to connect it with the distal stump of a receptor nerve, whose function was lost during the trauma. Neurotizations are indicated when direct repair is not possible, i.e. when a cervical root is avulsed at its origin in the spinal cord. In recent years, due to the positive results of some of these nerve transfer techniques, they have been widely used even in some cases where the roots of the plexus were preserved. In complete brachial plexus injuries, it is mandatory to determine the exact number of roots available (not avulsed) to perform a direct reconstruction. In case of absence of available roots, extraplexual nerve transfers are employed, such as the spinal accessory nerve, the phrenic nerve, the intercostal nerves, etc., to increase the amount of axons transferred to the injured plexus. In cases of avulsion of all the roots, extraplexal neurotizations are the only reinnervation option available to limit the long-term devastating effects of this injury. Given the large amount of reports that has been published in recent years regarding brachial plexus traumatic injuries, the present article has been written in order to clarify the concerned readers the indications, results and techniques available in the surgical armamentarium for this condition. Since the choice of either surgical technique is usually taken during the course of the procedure, all this knowledge should be perfectly embodied by the surgical team before the procedure. In a previous paper extraplexual nerve transfers were analyzed; this literature review complements the preceding paper analyzing intraplexual nerve transfers, and thus completing the analysis of the nerve transfers available in brachial plexus surgery. PMID:22167282

  5. Inactivation of NADPH oxidases NOX4 and NOX5 protects human primary fibroblasts from ionizing radiation-induced DNA damage.

    PubMed

    Weyemi, Urbain; Redon, Christophe E; Aziz, Towqir; Choudhuri, Rohini; Maeda, Daisuke; Parekh, Palak R; Bonner, Michael Y; Arbiser, Jack L; Bonner, William M

    2015-03-01

    Human exposure to ionizing radiation from medical procedures has increased sharply in the last three decades. Recent epidemiological studies suggest a direct relationship between exposure to ionizing radiation and health problems, including cancer incidence. Therefore, minimizing the impact of radiation exposure in patients has become a priority in the development of future clinical practices. Crucial players in radiation-induced DNA damage include reactive oxygen species (ROS), but the sources of these have remained elusive. To the best of our knowledge, we show here for the first time that two members of the ROS-generating NADPH oxidase family (NOXs), NOX4 and NOX5, are involved in radiation-induced DNA damage. Depleting these two NOXs in human primary fibroblasts resulted in reduced levels of DNA damage as measured by levels of radiation-induced foci, a marker of DNA double-strand breaks (DSBs) and the comet assay coupled with increased cell survival. NOX involvement was substantiated with fulvene-5, a NOXs-specific inhibitor. Moreover, fulvene-5 mitigated radiation-induced DNA damage in human peripheral blood mononuclear cells ex vivo. Our results provide evidence that the inactivation of NOXs protects cells from radiation-induced DNA damage and cell death. These findings suggest that NOXs inhibition may be considered as a future pharmacological target to help minimize the negative effects of radiation exposure for millions of patients each year. PMID:25706776

  6. Considerations for comparing radiation-induced chromosome aberration data with predictions from biophysical models

    NASA Astrophysics Data System (ADS)

    Wu, H.; Furusawa, Y.; George, K.; Kawata, T.; Cucinotta, F.

    Biophysical models addressing the formation of radiation-induced chromosome aberrations are usually based on the assumption that chromosome aberrations are formed by DNA double strand break (DSB) misrejoining, via either the homologous or the non-homologous repair pathway. However, comparing chromosome aberration data with model predictions is not always straightforward. In this paper we discuss some of the aspects that must be considered to make these comparisons meaningful. Firstly, biophysical models are usually applied to DSB rejoining and misrejoining in the G0/G1 phase of the cell cycle, while most chromosome aberration data reported in the literature are analyzed in metaphase. Since cells must progress through the cell cycle check points in order to reach mitosis, model predictions that differ from the metaphase chromosome analysis may actually agree with the aberration data in chromosomes collected in interphase. Secondly, high- LET radiation generally produces more complex aberrations involving exchanges between three or more DSB. While some models have successfully provided quantitative predictions of high-LET radiation induced complex aberrations in human lymphocytes, applying such models to other cell types requires special considerations due to the lack of geometric symmetry of the nucleus. Chromosome aberration data for non-spherical human fibroblast cells bombarded from various directions by high-LET charged particles will be presented, and their implication on physical modeling will be discussed.

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

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

    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.

  8. Desalination by electrodialysis with the ion-exchange membrane prepared by radiation-induced graft polymerization

    NASA Astrophysics Data System (ADS)

    Choi, Seong-Ho; Han Jeong, Young; Jeong Ryoo, Jae; Lee, Kwang-Pill

    2001-01-01

    Ion-exchange membranes modified with the triethylamine [-N(CH 2CH 3) 3] and phosphoric acid (-PO 3 H) groups were prepared by radiation-induced grafting of glycidyl methacrylate (GMA) onto the polyolefin nonwavon fabric (PNF) and subsequent chemical modification of poly(GMA) graft chains. The physical and chemical properties of the GMA-grafted PNF and the PNF modified with ion-exchange groups were investigated by SEM, XPS, TGA, and DSC. Furthermore, electrochemical properties such as specific electric resistance, transport number of K +, and desalination were examined. The grafting yield increased with increasing reaction time and reaction temperature. The maximum grafting yield was obtained with 40% (vol.%) monomer concentration in dioxane at 60°C. The content of the cation- and anion-exchange group increased with increasing grafting yield. Electrical resistance of the PNF modified with TEA and -PO 3 H group decreased, while the water uptake (%) increased with increasing ion-exchange group capacities. Transport number of the PNF modified with ion-exchange group were the range of ca. 0.82-0.92. The graft-type ion-exchange membranes prepared by radiation-induced graft copolymerization were successfully applied as separators for electrodialysis.

  9. MRI findings of radiation-induced changes of masticatory muscles: a systematic review

    PubMed Central

    2013-01-01

    Background Radiotherapy to the head and neck regions can result in serious consequences to the temporomandibular joint (TMJ) and chewing muscles. Magnetic resonance imaging (MRI) demonstrates soft-tissue alterations after radiotherapy, such as morphology and signal intensity. Objective The purpose of this review is to critically and systematically analyse the available evidence regarding the masticatory muscles alterations, as demonstrated on MRI, after radiotherapy for head and neck cancer. Data sources Electronic search of MEDLINE, EMBASE, EBM reviews and Scopus. Inclusion criteria Reports of any study design investigating radiation-induced changes in masticatory muscles after radiotherapy in patients with head and neck cancer were included. Results and synthesis methods An electronic database search resulted in 162 papers. Sixteen papers were initially selected as potentially relevant studies; however, only four papers satisfied all inclusion criteria. The included papers focused on the MRI appearance of masticatory muscles following radiotherapy protocol. Two papers reported outcome based on retrospective clinical and imaging records, whereas the remaining two papers were case reports. Irradiated muscles frequently show diffuse increase in T2 signal and post-gadolinium enhancement post-irradiation. Also, muscle size changes were reported based on subjective comparison with the contralateral side. The quality of all included papers was considered poor with high risk of bias. Conclusion There is no evidence that MRI interpretations indicate specific radiation-induced changes in masticatory muscles. There is a clear need for a cohort study comparing patients with pre- and post-radiotherapy MRI. PMID:23663414

  10. Radiation-induced cognitive dysfunction: An experimental model in the old rat

    SciTech Connect

    Lamproglou, I. [Laboratoire de Biophysique, Paris (France)] [Laboratoire de Biophysique, Paris (France); Chen, Q.M.; Poisson, M. [Hopital de la Salpetriere, Paris (France)] [and others] [Hopital de la Salpetriere, Paris (France); and others

    1995-01-01

    To develop a model of radiation-induced behavioral dysfunction. A course of whole brain radiation therapy (30 Gy/10 fractions/12 days) was administered to 26 Wistar rats ages 16-27 months, while 26 control rats received sham irradiation. Sequential behavioral studies including one-way avoidance, two-way avoidance, and a standard operant conditioning method (press-lever avoidance) were undertaken. In addition, rats were studied in a water maze 7 months postradiation therapy. Prior to radiation therapy, both groups were similar. No difference was found 1 and 3 months postradiation therapy. At 6-7 months postradiation therapy, irradiated rats had a much lower percentage of avoidance than controls for one-way avoidance (23% vs. 55%, p {le} 0.001) and two-way avoidance (18% vs. 40%, p {le} 0.01). Seven months postradiation therapy the reaction time was increased (press-lever avoidance, 11.20 s vs. 8.43 s, p {le} 0.05) and the percentage of correct response was lower (water maze, 53% vs. 82%) in irradiated rats compared with controls. Pathological examination did not demonstrate abnormalities of the irradiated brains at the light microscopic level. Behavioral dysfunction affecting mainly memory can be demonstrated following conventional radiation therapy in old rats. This model can be used to study the pathogenesis of radiation-induced cognitive changes. 15 refs., 3 figs., 1 tab.

  11. The study of radiation induced DNA-protein crosslinks by electrospray ionization mass spectrometry

    SciTech Connect

    Lipton, M.S.; Fuciarelli, A.F.; Springer, D.L.; Edmonds, C.G. [Pacific Northwest Lab., Richland, WA (United States)

    1995-12-31

    The authors have used peptide-thymine and histone-thymine solutions to model protein-DNA cross-linking chemistry induced in intact chromatin by low dosage of g-irradiation. Induced thymine crosslinking to model peptide systems has been evaluated by on-line liquid chromatography-electrospray ionization mass spectrometry (ESI-MS) and tandem mass spectrometry (MS-MS) with sensitivity comparable or superior to conventional GC-MS determinations. Radiation damage at doses as low as 0.1 Gy can be detected by this method. Additionally, thymine modified H2B can also be examined by ESI-MS and tandem-MS of the intact protein and proteinase digests. Limited information on the sites of thymine crosslinking can be obtained by tandem mass spectrometry on the intact multiply charged molecular species. More detailed information on the sites of thymine-protein crosslinking is obtained by on-line LC-ESI-MS of selective proteolysis products of the modified histones. Further MS-MS experiments on the selective proteolysis products will reveal specific modified amino acids and their sequence location. These methods reveal the nature, extent and site of radiation induced modification of the oligopeptides. Studies are being extended to the examination of the radiation induced covalent interactions between histones and oligonucleotides in higher states of organization. The eventual object is to study DNA-protein crosslinking interactions in model and native genomic nucleosome systems.

  12. Effects of inhibitors of radiation-induced potentially lethal damage repair on chemotherapy in murine tumors

    SciTech Connect

    Nakatsugawa, S.; Sugahara, T.

    1982-09-01

    Enhancement of various antitumor drugs effects by inhibitors of radiation-induced potentially lethal damage (PLD) repair was studied in three murine tumors (EMT-6, RIF-1 and SQ-1). In EMT-6 tumors, PLD repair inhibitors, 3'-deoxyguanosine (3'dG) and 7904 (a derivative of 3'-deoxyadenosine) showed a marked enhancement of tumor growth inhibition by anticancerous drugs (FT-207 (a derivative of 5-FU), bleomycin, Ara-C, ACNU). However, the effects of mitomycin-C and vincristine were not potentiated by the inhibitors. In SQ-1 carcinomas, another repair inhibitor, ara-A (1-..beta..-D-arabinofuranosyladenine) (32 mg/kg) potentiated the effect of ACNU. In RIF-1 sarcomas, in which a low PLD repair function has been reported after ionizing radiation exposure, the potentiation was not so marked as in EMT-6 or SQ-1 tumors. Thus, as a possibility, the potentiation by inhibitors of radiation-induced PLD repair might be a result of the inhibition of chemical-induced PLD repair. The study of this field may contribute to the improvement of cancer treatment not only by radiotherapy but also by chemotherapy.

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

    SciTech Connect

    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: paul_okunieff@urmc.rochester.edu

    2006-07-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

    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.

  15. Radiation-induced transient effects in HgCdTe IR focal plane arrays

    NASA Astrophysics Data System (ADS)

    Pickel, Jim C.; Reed, Robert A.; Marshall, Paul W.; Waczynski, Augustyn; Polidan, Elizabeth J.; Johnson, Scott; McMurray, Robert; McKelvey, Mark; Ennico, Kimberly; Johnson, Roy; Gee, George

    2004-10-01

    The operability requirements of NASA's James Webb Space Telescope (JWST) impose specific challenges on radiation effects mitigation and analysis. For example, the NIRSpec Instrument has the following requirements: "The percentage of pixels defined as operable for target acquisition shall not be less than 97% (TBR) (goal 99%) of the total number of pixels... An inoperable pixel is: ? A dead pixel: a pixel with no radiometric response o A noisy pixel: a pixel with a total noise greater than 21 e-, per Fowler 8 exposure "The percentage of pixels defined as operable for science observations shall not be less than 92% (TBR) (goal 98%) of the total number of pixels... An inoperable pixel is: ? A dead/low-DQE pixel: a pixel deviating by >30% from the DQE mean value ? A noisy pixel: a pixel with a total noise greater than 12 e- (goal 9e-). With these performance requirements and operation in space, the radiation environment from galactic cosmic rays (GCR), energetic solar particles, and activation of spacecraft materials can contribute significantly to the number of inoperable pixels. The two most important issues to date are radiation-induced transient effects and hot pixels. This paper focuses on the methods used to assess the impact of ionizing radiation induced transients on the HgCdTe SCA selected by JWST. Hot pixel effects in these detectors has been previously presented. Both effects are currently under investigation.

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

    SciTech Connect

    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

    1997-08-01

    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.

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

    SciTech Connect

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

    2007-01-01

    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.

  18. Gene expression and hormone autonomy in radiation-induced tumors of Arabidopsis thaliana

    SciTech Connect

    Persinger, S.M.; Town, C.D. (Case Western Reserve Univ., Cleveland, OH (USA))

    1989-04-01

    In order to study the molecular genetics of factor controlling plant cell growth, we have isolated a group of radiation-induced tumors from Arabidopsis thaliana. Tumors appeared on plants derived from {sup 60}Co gamma-irradiated seed or seedlings, and are capable of hormone-autonomous growth in culture. We have used vertebrate oncogene probes to explore the hypothesis that the tumors arose by the radiation-induced activation of growth-regulating plant oncogenes. One probe, int-2, was used to isolate cDNA clones representing an mRNA differentially expressed between tumors and hormone-dependent callus tissue. The genomic organization and function of this and other differentially expressed Arabidopsis sequences are being further characterized. A second area of study concerns the hormonal status of individual tumors. Tumor tissue varies in color, texture, and degree of differentiation: while some tumors appear undifferentiated, one consistently produces roots, and others occasionally develop shoots or leaflets. The tumors have characteristic growth rates on hormone-free medium, and growth in response to exogenous hormones differs among the tumors themselves and from wild-type. Characterization of the relationships between hormonal status, morphogenesis, and gene expression should yield valuable insights into the mechanisms regulating plant growth and development.

  19. PHD inhibition mitigates and protects against radiation-induced gastrointestinal toxicity via HIF2.

    PubMed

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

    2014-05-14

    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 (prolyl hydroxylase domain) isoforms by the small-molecule dimethyloxallyl glycine (DMOG) increases hypoxia-inducible factor (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 vascular endothelial growth factor (VEGF) expression contributes to the protective effects of HIF2, because inhibition of VEGF function reversed the radioprotection and radiomitigation afforded by DMOG. Additionally, mortality from abdominal or total body irradiation was reduced even when DMOG was given 24 hours after exposure. Thus, prolyl hydroxylase inhibition represents a treatment strategy to protect against and mitigate GI toxicity from both therapeutic radiation and potentially lethal radiation exposures. PMID:24828078

  20. Biological responses of human apurinic endonuclease to radiation-induced DNA damage

    SciTech Connect

    Chen, D.S.; Olkowski, Z.L. [Emory Univ. School of Medicine, Atlanta, GA (United States)

    1994-12-31

    Ionizing radiation produces a variety of DNA damage through active oxygen species such as the superoxide radical (O{sub 2}{sup -}), the hydroxyl radical (OH), and hydrogen peroxide (H{sub 2}O{sub 2}). Previous studies showed that human AP endonuclease, a counterpart of exonuclease III, can functionally replace E. coli exonuclease III to repair methyl methanesulfonate (MMS)-induced but not H{sub 2}O{sub 2}-induced DNA damage. Reduction of radiation-induced cytotoxicity by human AP endonuclease in a radiation-sensitive mutant of E. coli indicated that the AP site is one of the major forms of DNA damage produced by ionizing radiation. The removal of alkylation-induced AP sites and 3{prime}-blocking deoxyribose fragments by human AP endonuclease indicates that this enzyme is playing a pivotal role in the repair of oxidative DNA damage. In the current study, we examined the biological roles of AP endonuclease as being responsible for the repair of radiation-induced DNA damage in human cells.

  1. Blockade of TLR3 protects mice from lethal radiation-induced gastrointestinal syndrome

    PubMed Central

    Takemura, Naoki; Kawasaki, Takumi; Kunisawa, Jun; Sato, Shintaro; Lamichhane, Aayam; Kobiyama, Kouji; Aoshi, Taiki; Ito, Junichi; Mizuguchi, Kenji; Karuppuchamy, Thangaraj; Matsunaga, Kouta; Miyatake, Shoichiro; Mori, Nobuko; Tsujimura, Tohru; Satoh, Takashi; Kumagai, Yutaro; Kawai, Taro; Standley, Daron M.; Ishii, Ken J.; Kiyono, Hiroshi; Akira, Shizuo; Uematsu, Satoshi

    2014-01-01

    High-dose ionizing radiation induces severe DNA damage in the epithelial stem cells in small intestinal crypts and causes gastrointestinal syndrome (GIS). Although the tumour suppressor p53 is a primary factor inducing death of crypt cells with DNA damage, its essential role in maintaining genome stability means inhibiting p53 to prevent GIS is not a viable strategy. Here we show that the innate immune receptor Toll-like receptor 3 (TLR3) is critical for the pathogenesis of GIS. Tlr3?/? mice show substantial resistance to GIS owing to significantly reduced radiation-induced crypt cell death. Despite showing reduced crypt cell death, p53-dependent crypt cell death is not impaired in Tlr3?/? mice. p53-dependent crypt cell death causes leakage of cellular RNA, which induces extensive cell death via TLR3. An inhibitor of TLR3–RNA binding ameliorates GIS by reducing crypt cell death. Thus, we propose blocking TLR3 activation as a novel approach to treat GIS. PMID:24637670

  2. Protein Kinase C epsilon is involved in ionizing radiation induced bystander response in human cells

    PubMed Central

    Hu, Burong; Shen, Bo; Su, Yanrong; Geard, Charles R.; Balajee, Adayabalam S.

    2009-01-01

    Our earlier study demonstrated the induction of PKC isoforms (beta II, PKC-alpha/beta, PKC-theta) by ionizing radiation induced bystander response in human cells. In this study, we extended our investigation to yet another important member of PKC family, PKC epsilon (PKC?). PKC? functions both as an anti-apoptotic and pro-apoptotic protein and it is the only PKC isozyme implicated in oncogenesis. Given the importance of PKC? in oncogenesis, we wished to determine whether or not PKC? is involved in bystander response. Gene expression array analysis demonstrated a 2-3 fold increase in PKC? expression in the bystander human primary fibroblast cells that were co-cultured in double sided Mylar dishes for 3 h with human primary fibroblast cells irradiated with 5 Gy of ?-particles. The elevated PKC? expression in bystander cells was verified by quantitative real time PCR. Suppression of PKC? expression by small molecule inhibitor Bisindolylmaleimide IX (Ro 31-8220) considerably reduced the frequency of micronuclei (MN) induced both by 5 Gy of ?-rays (low LET) and ?-particles (high LET) in bystander cells. Similar cytoprotective effects were observed in bystander cells after siRNA mediated silencing of PKC? suggestive of its critical role in mediating some of the bystander effects (BE). Our novel study suggests the possibility that PKC signaling pathway may be a critical molecular target for suppression of ionizing radiation induced biological effects in bystander cells. PMID:19577658

  3. Ionizing radiation induces immediate protein acetylation changes in human cardiac microvascular endothelial cells

    PubMed Central

    Barjaktarovic, Zarko; Kempf, Stefan J.; Sriharshan, Arundhathi; Merl-Pham, Juliane; Atkinson, Michael J.; Tapio, Soile

    2015-01-01

    Reversible lysine acetylation is a highly regulated post-translational protein modification that is known to regulate several signaling pathways. However, little is known about the radiation-induced changes in the acetylome. In this study, we analyzed the acute post-translational acetylation changes in primary human cardiac microvascular endothelial cells 4 h after a gamma radiation dose of 2 Gy. The acetylated peptides were enriched using anti-acetyl conjugated agarose beads. A total of 54 proteins were found to be altered in their acetylation status, 23 of which were deacetylated and 31 acetylated. Pathway analyses showed three protein categories particularly affected by radiation-induced changes in the acetylation status: the proteins involved in the translation process, the proteins of stress response, and mitochondrial proteins. The activation of the canonical and non-canonical Wnt signaling pathways affecting actin cytoskeleton signaling and cell cycle progression was predicted. The protein expression levels of two nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases, sirtuin 1 and sirtuin 3, were significantly but transiently upregulated 4 but not 24 h after irradiation. The status of the p53 protein, a target of sirtuin 1, was found to be rapidly stabilized by acetylation after radiation exposure. These findings indicate that post-translational modification of proteins by acetylation and deacetylation is essentially affecting the radiation response of the endothelium. PMID:25840449

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

    PubMed Central

    2014-01-01

    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

  5. Radiofrequency radiation-induced calcium ion efflux enhancement from human and other neuroblastoma cells in culture

    SciTech Connect

    Dutta, S.K.; Ghosh, B.; Blackman, C.F.

    1989-01-01

    To test the generality of radiofrequency radiation-induced changes in /sup 45/Ca2+ efflux from avian and feline brain tissues, human neuroblastoma cells were exposed to electromagnetic radiation at 147 MHz, amplitude-modulated (AM) at 16 Hz, at specific absorption rates (SAR) of 0.1, 0.05, 0.01, 0.005, 0.001, and 0.0005 W/kg. Significant /sup 45/Ca2+ efflux was obtained at SAR values of 0.05 and 0.005 W/kg. Enhanced efflux at 0.05 W/kg peaked at the 13-16 Hz and at the 57.5-60 Hz modulation ranges. A Chinese hamster-mouse hybrid neuroblastoma was also shown to exhibit enhanced radiation-induced /sup 45/Ca2+ efflux at an SAR of 0.05 W/kg, using 147 MHz, AM at 16 Hz. These results confirm that amplitude-modulated radiofrequency radiation can induce responses in cells of nervous tissue origin from widely different animal species, including humans. The results are also consistent with the reports of similar findings in avian and feline brain tissues and indicate the general nature of the phenomenon.

  6. The Protective Effect of Curcumin on Ionizing Radiation-induced Cataractogenesis in Rats

    PubMed Central

    Özgen, Seher Çimen; Dökmeci, Dikmen; Akpolat, Meryem; Karada?, Çetin Hakan; Gündüz, Özgür; Erba?, Hakan; Benian, Ömer; Uzal, Cem; Turan, Fatma Nesrin

    2012-01-01

    Objective: The aim of the study was to determine the protective effect of curcumin against ionizing radiation-induced cataract in the lens of rats. Material and Methods: Rats were divided into six groups. Group 1: Control, Group 2: Dimethyl sulfoxide (DMSO), Group 3: DMSO+curcumin, Group 4: Irradiation, Group 5: Irradiation+DMSO, Group 6: Irradiation+DMSO+curcumin. A 15 Gy total dose was given to 4, 5, 6 groups for radiation damage. Curcumin (100 mg/kg) was dissolved in DMSO and given by intragastric intubation for 28 days. At the end of the experiment, lenses were graded and enucleated. The lenticular activity of the antioxidant enzymes, total antioxidant and glutathione peroxidase (GSH-Px), and the malondialdehyde (MDA) were measured. Results: 100% Cataract was seen in the irradiation group. Cataract rate fell to 40% and was limited at grade 1 and 2 in the curcumin group. In the irradiation group, antioxidant enzyme levels were decreased, MDA levels were increased. There was an increase in antioxidant enzyme levels and a significant decrease in MDA in the group which was given curcumin. Conclusion: Curcumin has antioxidant and radioprotective properties and is likely to be a valuable agent for protection against ionizing radiation. Hence, it may be used as an antioxidant and radioprotector against radiation-induced cataractogenesis. PMID:25207034

  7. Blockade of TLR3 protects mice from lethal radiation-induced gastrointestinal syndrome.

    PubMed

    Takemura, Naoki; Kawasaki, Takumi; Kunisawa, Jun; Sato, Shintaro; Lamichhane, Aayam; Kobiyama, Kouji; Aoshi, Taiki; Ito, Junichi; Mizuguchi, Kenji; Karuppuchamy, Thangaraj; Matsunaga, Kouta; Miyatake, Shoichiro; Mori, Nobuko; Tsujimura, Tohru; Satoh, Takashi; Kumagai, Yutaro; Kawai, Taro; Standley, Daron M; Ishii, Ken J; Kiyono, Hiroshi; Akira, Shizuo; Uematsu, Satoshi

    2014-01-01

    High-dose ionizing radiation induces severe DNA damage in the epithelial stem cells in small intestinal crypts and causes gastrointestinal syndrome (GIS). Although the tumour suppressor p53 is a primary factor inducing death of crypt cells with DNA damage, its essential role in maintaining genome stability means inhibiting p53 to prevent GIS is not a viable strategy. Here we show that the innate immune receptor Toll-like receptor 3 (TLR3) is critical for the pathogenesis of GIS. Tlr3(-/-) mice show substantial resistance to GIS owing to significantly reduced radiation-induced crypt cell death. Despite showing reduced crypt cell death, p53-dependent crypt cell death is not impaired in Tlr3(-/-) mice. p53-dependent crypt cell death causes leakage of cellular RNA, which induces extensive cell death via TLR3. An inhibitor of TLR3-RNA binding ameliorates GIS by reducing crypt cell death. Thus, we propose blocking TLR3 activation as a novel approach to treat GIS. PMID:24637670

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

    PubMed Central

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

    2014-01-01

    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

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

    PubMed Central

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

    2011-01-01

    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

  10. Hydrogen-rich saline protects immunocytes from radiation-induced apoptosis

    PubMed Central

    Yang, Yanyong; Li, Bailong; Liu, Cong; Chuai, Yunhai; Lei, Jixiao; Gao, Fu; Cui, Jianguo; Sun, Ding; Cheng, Ying; Zhou, Chuanfeng; Cai, Jianming

    2012-01-01

    Summary Background Radiation often causes depletion of immunocytes in tissues and blood, which results in immunosuppression. Molecular hydrogen (H2) has been shown in recent studies to have potential as a safe and effective radioprotective agent through scavenging free radicals. This study was designed to test the hypothesis that H2 could protect immunocytes from ionizing radiation (IR). Material/Methods H2 was dissolved in physiological saline or medium using an apparatus produced by our department. A 2-[6-(4?-hydroxy) phenoxy-3H-xanthen-3-on-9-yl] benzoate (HPF) probe was used to detect intracellular hydroxyl radicals (•OH). Cell apoptosis was evaluated by annexin V-FITC and Propidium iodide (PI) staining as well as the caspase 3 activity. Finally, we examined the hematological changes using an automatic Sysmex XE 2100 hematology analyzer. Results We demonstrated H2-rich medium pretreatment reduced •OH level in AHH-1 cells. We also showed H2 reduced radiation-induced apoptosis in thymocytes and splenocytes in living mice. Radiation-induced caspase 3 activation was also attenuated by H2 treatment. Finally, we found that H2 rescued the radiation-caused depletion of white blood cells (WBC) and platelets (PLT). Conclusions This study suggests that H2 protected the immune system and alleviated the hematological injury induced by IR. PMID:22460088

  11. Protection by polaprezinc against radiation-induced apoptosis in rat jejunal crypt cells.

    PubMed

    Matsuu-Matsuyama, Mutsumi; Shichijo, Kazuko; Okaichi, Kumio; Nakayama, Toshiyuki; Nakashima, Masahiro; Uemura, Takashi; Niino, Daisuke; Sekine, Ichiro

    2008-07-01

    Polaprezinc, an anti-ulcer drug, is a chelate compound consisting of zinc and L-carnosine. Polaprezinc has been shown to prevent gastric mucosal injury. The anti ulcer effects of polaprezinc have been ascribed to its antioxidative property. The effect of polaprezinc on ionizing radiation-induced apoptosis was studied in the jejunal epithelial crypt cells of rats. Seven-to eight week-old Wistar rats, which were treated with 100 mg/kg of polaprezinc orally 1h before irradiation or 2% carboxymethyl cellulose sodium in controls, were exposed to whole body X-ray irradiation at 2 Gy. The number of apoptotic cells per jejunum crypt was counted in haematoxylin and eosin stained sections at 0-6 h after irradiation. TUNEL positive cells and immunopositive cells for active caspase-3 per crypt were also counted. Accumulation of p53, p21(WAF1/CIP1) and Bax expression in the jejunum after irradiation were examined by Western blot analyses. Polaprezinc treatment given prior to radiation resulted in a significant reduction in numbers of apoptotic cells, TUNEL positive cells and active caspase-3 immunopositive cells in jejunal crypt cells. Polaprezinc treatment resulted in decreases of p53 accumulation, p21(WAF1/CIP1) and Bax expression after irradiation. Polaprezinc has a protective effect against ionizing radiation induced apoptosis in rat jejunal crypt cells. PMID:18413982

  12. Radiation-induced complications in prostate cancer patients treated with radiotherapy

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

    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.

  13. Measurement and modeling of radiation-induced grain boundary grain boundary segregation in stainless steels

    SciTech Connect

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

    1995-08-01

    Grain boundary radiation-induced segregation (RIS) in Fe-Ni-Cr stainless alloys has been measured and modelled 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 0 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. Impurity segregation (Si and P) was also measured, but only Si enrichment appeared to be radiation-induced. Grain boundary Si levels peaked at an intermediate temperature of {approximately}325{degrees}C reaching levels of {approximately}8 at. %. Equilibrium segregation of P was measured in the high-P alloys, but interfacial concentration did not increase with irradiation exposure. Examination of reported RIS in neutron-irradiated stainless steels revealed similar effects of irradiation dose on grain boundary compositional changes for both major alloying and impurity element`s. The Inverse Kirkendall model accurately predicted major alloying element RIS in ion- and neutron-irradiated alloys over the wide range of temperature and dose conditions. In addition, preliminary calculations indicate that the Johnson-Lam model can reasonably estimate grain boundary Si enrichment if back diffusion is enhanced.

  14. The Role of Alveolar Epithelium in Radiation-Induced Lung Injury

    PubMed Central

    Almeida, Celine; Nagarajan, Devipriya; Tian, Jian; Leal, Sofia Walder; Wheeler, Kenneth; Munley, Michael; Blackstock, William; Zhao, Weiling

    2013-01-01

    Pneumonitis and fibrosis are major lung complications of irradiating thoracic malignancies. In the current study, we determined the effect of thoracic irradiation on the lungs of FVB/N mice. Survival data showed a dose-dependent increase in morbidity following thoracic irradiation with single (11–13 Gy) and fractionated doses (24–36 Gy) of 137Cs ?-rays. Histological examination showed a thickening of vessel walls, accumulation of inflammatory cells, collagen deposition, and regional fibrosis in the lungs 14 weeks after a single 12 Gy dose and a fractionated 30 Gy dose; this damage was also seen 5 months after a fractionated 24 Gy dose. After both single and fractionated doses, i] aquaporin-5 was markedly decreased, ii] E-cadherin was reduced and iii] prosurfactant Protein C (pro-SP-c), the number of pro-SP-c+ cells and vimentin expression were increased in the lungs. Immunofluorescence analysis revealed co-localization of pro-SP-c and ?-smooth muscle actin in the alveoli after a single dose of 12 Gy. These data suggest that, i] the FVB/N mouse strain is sensitive to thoracic radiation ii] aquaporin-5, E-cadherin, and pro-SP-c may serve as sensitive indicators of radiation-induced lung injury; and iii] the epithelial-to-mesenchymal transition may play an important role in the development of radiation-induced lung fibrosis. PMID:23326473

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

    SciTech Connect

    Daino, Kazuhiro, E-mail: k_daino@nirs.go.jp [LCE/iRCM/DSV/CEA, route du Panorama, BP 6, 92265 Fontenay-aux-Roses Cedex (France)] [LCE/iRCM/DSV/CEA, route du Panorama, BP 6, 92265 Fontenay-aux-Roses Cedex (France); Roch-Lefevre, Sandrine [LDB/SRBE/DRPH/IRSN, 31, avenue de la Division Leclerc, BP 17, 92262 Fontenay-aux-Roses Cedex (France)] [LDB/SRBE/DRPH/IRSN, 31, avenue de la Division Leclerc, BP 17, 92262 Fontenay-aux-Roses Cedex (France); Ugolin, Nicolas; Altmeyer-Morel, Sandrine; Guilly, Marie-Noelle; Chevillard, Sylvie [LCE/iRCM/DSV/CEA, route du Panorama, BP 6, 92265 Fontenay-aux-Roses Cedex (France)] [LCE/iRCM/DSV/CEA, route du Panorama, BP 6, 92265 Fontenay-aux-Roses Cedex (France)

    2009-12-18

    We have previously studied genomic copy number changes and global gene expression patterns in rat osteosarcomas (OS) induced by the bone-seeking alpha emitter {sup 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.

  16. Decreased repair of radiation-induced DNA double-strand breaks with cellular differentiation.

    PubMed

    Bill, C A; Grochan, B M; Vrdoljak, E; Mendoza, E A; Tofilon, P J

    1992-11-01

    Although the majority of mammalian cells in situ are terminally differentiated, most DNA repair studies have used proliferating cells. In an attempt to understand better the relationship between differentiation and DNA repair, we have used the murine 3T3-T proadipocyte cell line. In this model system, proliferating (stem) cells undergo growth arrest (GD cells) and subsequently terminally differentiate into adipocytes when exposed to media containing platelet-depleted human plasma. Pulsed-field gel electrophoresis was used to evaluate the induction and repair of DNA double-strand breaks (DSBs) after ionizing radiation. The levels of radiation-induced DSBs in GD and terminally differentiated cells were similar, but in both cases greater than those found in stem cells at each radiation dose tested (0 to 40 Gy); these differences appear to be due to growth arrest in G1 phase. DNA DSBs were repaired with biphasic kinetics for each cell type. For terminally differentiated cells 25% of DNA DSBs remained unrejoined compared with < 10% for GD and stem cells after a repair time of 4 h. These data indicate that terminal differentiation of 3T3-T cells is associated with a reduction in the repair of ionizing radiation-induced DNA DSBs. PMID:1438708

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

    PubMed Central

    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.

    2013-01-01

    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

  18. Gene-modified mesenchymal stem cells protect against radiation-induced lung injury.

    PubMed

    Xue, Jianxin; Li, Xin; Lu, You; Gan, Lu; Zhou, Lin; Wang, Yongsheng; Lan, Jie; Liu, Shurui; Sun, Lan; Jia, Li; Mo, Xianming; Li, Jian

    2013-02-01

    Radiation-induced lung injury (RILI) presents a common and major obstacle in the radiotherapy of thoracic cancers. The aim of this study was to examine whether RILI could be alleviated by mesenchymal stem cells (MSCs) expressing soluble transforming growth factor-? (TGF-?) type II receptor via an adenovirus (Ad-sT?R). Here, we systemically administered male MSCs into female mice challenged with thoracic irradiation. The data showed that either MSCs or Ad-sT?R transduced MSCs (Ad-sT?R-MSCs) specifically migrated into radiation-injured lung. Ad-sT?R-MSCs obviously alleviated lung injury, as reflected by survival and histopathology data, as well as the assays of malondialdehyde (MDA), hydroxyproline, plasma cytokines, and the expression of connective tissue growth factor (CTGF) and ?-smooth muscle actin (?-SMA). Furthermore, MSCs and Ad-sT?R-MSCs could adopt the characteristics of alveolar type II (ATII) cells. However, the MSCs levels in the lungs were relatively low to account for the noted therapeutic effects, suggesting the presence of other mechanisms. In vivo, MSCs-conditioned medium (MSCs CM) significantly attenuated RILI. In vitro, MSCs CM protected ATII cells against radiation-induced apoptosis and DNA damage, and modulated the inflammatory response, indicating the beneficial effects of MSCs are largely due to its paracrine activity. Our results provide a novel insight for RILI therapy that currently lack efficient treatments. PMID:23299797

  19. Radiation dose to the brachial plexus in nasopharyngeal carcinoma treated with intensity-modulated radiation therapy: An increased risk of an excessive dose to the brachial plexus adjacent to gross nodal disease

    PubMed Central

    FENG, GUOSHENG; LU, HEMING; LIANG, YUAN; CHEN, HUASHENG; SHU, LIUYANG; LU, SHUI; ZHU, JIANFANG; GAO, WEIWEI

    2012-01-01

    This retrospective study aimed to evaluate the dose to the brachial plexus in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT). Twenty-eight patients were selected and the brachial plexus was delineated retrospectively. Brachial plexus adjacent/not adjacent to nodes were defined and abbreviated as BPAN and BPNAN, respectively. Dose distribution was recalculated and a dose-volume histogram was generated based on the original treatment plan. The maximum dose to the left brachial plexus was 59.12–78.47 Gy, and the percentage of patients receiving the maximum dose exceeding 60, 66 and 70 Gy was 96.4, 57.1 and 25.0%, respectively; the maximum dose to the right brachial plexus was 59.74–80.31 Gy, and the percentage of patients exposed to a maximum dose exceeding 60, 66 and 70 Gy was 96.4, 64.3 and 39.3%, respectively. For the left brachial plexus, the maximum doses to the BPANs and the BPNANs were 72.84±3.91 and 64.81±3.47 Gy, respectively (p<0.001). For the right brachial plexus, the maximum doses to the BPANs and the BPNANs were 72.91±4.74 and 64.91±3.52 Gy, respectively (p<0.001). The difference between the left BPANs and the left BPNANs was statistically significant not only for V60 (3.60 vs. 1.01 cm3, p=0.028) but also for V66 (1.26 vs. 0.11 cm3, p=0.046). There were significant differences in V60 (3.68 vs. 1.16 cm3, p<0.001) and V66 (1.83 vs. 1.23 cm3, p=0.012) between the right BPANs and the right BPNANs. In conclusion, a large proportion of patients were exposed to the maximum dose to the brachial plexus exceeding the Radiation Therapy Oncology Group-recommended restraints when the brachial plexus was not outlined. The BPANs are at a significantly higher risk of receiving an excessive radiation dose when compared to the BPNANs. A further study is underway to test whether brachial plexus contouring assists in the dose reduction to the brachial plexus for IMRT optimization. PMID:22970028

  20. Protection of radiation induced DNA and membrane damages by total triterpenes isolated from Ganoderma lucidum (Fr.) P. Karst.

    PubMed

    Smina, T P; Maurya, D K; Devasagayam, T P A; Janardhanan, K K

    2015-05-25

    The total triterpenes isolated from the fruiting bodies of Ganoderma lucidum was examined for its potential to prevent ?-radiation induced membrane damage in rat liver mitochondria and microsomes. The effects of total triterpenes on ?-radiation-induced DNA strand breaks in pBR 322 plasmid DNA in vitro and human peripheral blood lymphocytes ex vivo were evaluated. The protective effect of total triterpenes against ?-radiation-induced micronuclei formations in mice bone marrow cells in vivo were also evaluated. The results indicated the significant effectiveness of Ganoderma triterpenes in protecting the DNA and membrane damages consequent to the hazardous effects of radiation. The findings suggest the potential use of Ganoderma triterpenes in radio therapy. PMID:25824410

  1. Amelioration of radiation-induced skin injury by adenovirus-mediated heme oxygenase-1 (HO-1) overexpression in rats

    PubMed Central

    2012-01-01

    Objective Radiation-induced skin injury remains a serious concern for radiation therapy. Heme oxygenase-1 (HO-1), the rate-limiting enzyme in heme catabolism, has been reported to have potential antioxidant and anti-apoptotic properties. However, the role of HO-1 in radiation-induced skin damage remains unclear. This study aims to elucidate the effects of HO-1 on radiation-induced skin injury in rats. Methods A control adenovirus (Ad-EGFP) and a recombinant adenovirus (Ad-HO1-EGFP) were constructed. Rats were irradiated to the buttock skin with a single dose of 45 Gy followed by a subcutaneous injection of PBS, 5 × 109 genomic copies of Ad-EGFP or Ad-HO1-EGFP (n = 8). After treatment, the skin MDA concentration, SOD activity and apoptosis were measured. The expression of antioxidant and pro-apoptotic genes was determined by RT-PCR and real-time PCR. Skin reactions were measured at regular intervals using the semi-quantitative skin injury score. Results Subcutaneous injection of Ad-HO1-EGFP infected both epidermal and dermal cells and could spread to the surrounding regions. Radiation exposure upregulated the transcription of the antioxidant enzyme genes, including SOD-1, GPx2 and endogenous HO-1. HO-1 overexpression decreased lipid peroxidation and inhibited the induction of ROS scavenging proteins. Moreover, HO-1 exerted an anti-apoptotic effect by suppressing FAS and FASL expression. Subcutaneous injection of Ad-HO1-EGFP demonstrated significant improvement in radiation-induced skin injury. Conclusions The present study provides evidences for the protective role of HO-1 in alleviating radiation-induced skin damage in rats, which is helpful for the development of therapy for radiation-induced skin injury. PMID:22247972

  2. Higher Brachial-Ankle Pulse Wave Velocity Is Associated with More Advanced Carotid Atherosclerosis in End-Stage Renal Disease

    Microsoft Academic Search

    Masanori Munakata; Junko Sakuraba; Jun Tayama; Takashi Furuta; Akira Yusa; Tohru Nunokawa; Kaoru Yoshinaga; Takayoshi Toyota

    2005-01-01

    Brachial-ankle pulse wave velocity is a new measure of arterial stiffness. We examined whether higher brachial-ankle pulse wave velocity is associated with more advanced carotid atherosclerosis and left ventricular hypertrophy in patients with end-stage renal disease, and whether this effect would be mediated by the influence of wave reflection on central arterial pressure. In 68 patients with end stage renal

  3. Brachial plexus block with bupivacaine: effects of added alpha-adrenergic agonists: comparison between clonidine and epinephrine

    Microsoft Academic Search

    Jean J. Eledjam; Jacques Deschodtt; Eric J. Viel; Jean F. Lubrano; Pierre Charavel; Françoise d’Athis; Jacques du Cailar

    1991-01-01

    The effects of clonidine and epinephrine, administered into the brachial plexus sheath, were evaluated in 60 patients who\\u000a underwent surgery of the upper limb. All patients received 40 to 50 ml of 0.25% bupivacaine, injected into the brachial plexus\\u000a sheath, using the supraclavicular technique. The patients were randomly allocated to two groups so that 30 patients received\\u000a 150 ?g clonidine

  4. Susceptibility of peripheral lymphocytes of brain tumour patients to in vitro radiation-induced DNA damage, a preliminary study

    Microsoft Academic Search

    Guruprasad Kalthur; Prem Kumar; Uma Devi; Sabir Ali; Ramya Upadhya; Sailaja Pillai; Anjali Rao

    2008-01-01

    Objective  The present investigation aimed to study the susceptibility of lymphocytes collected from brain tumour patients to radiation-induced\\u000a DNA damage under in vitro conditions.\\u000a \\u000a \\u000a \\u000a Methods  The peripheral lymphocytes collected from brain tumour patients were exposed to 2-Gy gamma radiation. Susceptibility of lymphocytes\\u000a to radiation-induced DNA damage and their repair ability was assessed by alkaline comet assay.\\u000a \\u000a \\u000a \\u000a Results  Lymphocytes of patients with benign and

  5. Reduction of radiation-induced cell cycle blocks by caffeine does not necessarily lead to increased cell killing

    SciTech Connect

    Musk, S.R. (Institute of Cancer Research, Sutton, Surrey (England))

    1991-03-01

    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.

  6. Connecting radiation-induced bystander effects and senescence to improve radiation response prediction.

    PubMed

    Poleszczuk, Jan; Krzywon, Aleksandra; Forys, Urszula; Widel, Maria

    2015-05-01

    For the last two decades radiation-induced bystander effects (RIBEs) have attracted significant attention due to their possible implications for radiotherapy. However, despite extensive research, the molecular pathways associated with RIBEs are still not completely known. In the current study we investigated the role of senescence in the bystander response. Irradiated (2, 4, 6 and 8 Gy) human colorectal carcinoma cells (HCT116) with p53(+/+) (wild-type) or p53(-/-) (knockout) gene were co-incubated with nonirradiated cells of the same type. Clonogenic and senescence assays were used for both irradiated and co-incubated bystander cell populations. We also performed additional measurements on the number of remaining cells after the whole co-incubation period. For radiation doses larger than 2 Gy we observed much larger fractions of senescent cells in p53-positive populations compared to their p53-negative counterparts (15.81% vs. 3.63% in the irradiated population; 2.89% vs. 1.05% in the bystander population; 8 Gy; P < 0.05). Statistically significant differences between cell lines in the clonogenic cell surviving fraction were observed for doses higher than 4 Gy (1.61% for p53(+/+) vs. 0.19% for p53(-/-) in irradiated population; 3.57% for +/+ vs. 50.39% for -/- in bystander population; 8 Gy; P < 0.05). Our main finding was that the number of senescent cells in the irradiated population correlated strongly with the clonogenic cell surviving fraction (R = -0.98, P < 0.001) and the number of senescent cells (R = 0.97, P < 0.001) in the bystander population. We also extended the standard linear-quadratic radiation response model by incorporating the influence of the signals released by the senescent cells, which accurately described the radiation response in the bystander population. Our findings suggest that radiation-induced senescence might be a key player in RIBE, i.e., the strength of RIBE depends on the amount of radiation-induced senescence. PMID:25844948

  7. Alpha Lipoic Acid Attenuates Radiation-Induced Thyroid Injury in Rats

    PubMed Central

    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

    2014-01-01

    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

  8. The use of radiation-induced graft polymerization for modification of polymer track membranes

    NASA Astrophysics Data System (ADS)

    Shtanko, N. I.; Kabanov, V. Ya.; Apel, P. Yu.; Yoshida, M.

    1999-05-01

    Track membranes (TM) made of poly(ethylene terephtalate) (PET) and polypropylene (PP) films have a number of peculiarities as compared with other ones. They have high mechanical strength at a low thickness, narrow pore size distribution, low content of extractables. However, TM have some disadvantages such as low chemical resistance in alkaline media (PET TM), the low water flow rate due to the hydrophobic nature of their surface. The use of radiation-induced graft polymerization makes it possible to improve the basic characteristics of TM. In this communication our results on the modification of PET and PP TM are presented. The modified membranes were prepared by radiation-induced graft polymerization from the liquid phase. Three methods of grafting were used: (a) the direct method in argon atmosphere; (b) the pre-irradiation of TM in air followed by grafting in argon atmosphere; (c) pre-irradiation in vacuum followed by grafting in vacuum without contacting oxygen. The aim of the work was to investigate some properties of TM modified by grafted poly(methylvinyl pyridine) (PMVP) and poly(N-isopropylacrylamide) (PNIPAAM). It was shown that the modification of TM with hydrophilic polymer results in the growth of the water flow rate. In the past few years many works have been devoted to the synthesis of new polymers - the so-called "intelligent" materials - such as PNIPAAM. However, it is very difficult to make thin membranes of this polymer. Recently, it has been proposed to manufacture composite membranes by grafting stimulus-responsive polymers onto TM. Following this principle, we prepared thermosensitive membranes by the radiation-induced graft polymerization of N-isopropylacrylamide (NIPAAM) onto PET TM. PET TM with the pore size of about 1 ?m and pore density of 10 6 cm -2 were first inserted into a solution of NIPAAM containing inhibitor of homopolymerization (CuCl 2) and then exposed to the ?-rays from a 60Co source. The transport properties of the grafted TM were investigated. The permeation of water through the TM was controlled by temperature. The grafted TM exhibited almost the same transition temperature (about 33°C) as that of PNIPAAM.

  9. Brachial artery reactivity in patients with severe sepsis: an observational study

    PubMed Central

    2012-01-01

    Introduction Ultrasound measurements of brachial artery reactivity in response to stagnant ischemia provide estimates of microvascular function and conduit artery endothelial function. We hypothesized that brachial artery reactivity would independently predict severe sepsis and severe sepsis mortality. Methods This was a combined case-control and prospective cohort study. We measured brachial artery reactivity in 95 severe sepsis patients admitted to the medical and surgical intensive care units of an academic medical center and in 52 control subjects without acute illness. Measurements were compared in severe sepsis patients versus control subjects and in severe sepsis survivors versus nonsurvivors. Multivariable analyses were also conducted. Results Hyperemic velocity (centimeters per cardiac cycle) and flow-mediated dilation (percentage) were significantly lower in severe sepsis patients versus control subjects (hyperemic velocity: severe sepsis = 34 (25 to 48) versus controls = 63 (52 to 81), P < 0.001; flow-mediated dilation: severe sepsis = 2.65 (0.81 to 4.79) versus controls = 4.11 (3.06 to 6.78), P < 0.001; values expressed as median (interquartile range)). Hyperemic velocity, but not flow-mediated dilation, was significantly lower in hospital nonsurvivors versus survivors (hyperemic velocity: nonsurvivors = 25 (16 to 28) versus survivors = 39 (30 to 50), P < 0.001; flow-mediated dilation: nonsurvivors = 1.90 (0.68 to 3.41) versus survivors = 2.96 (0.91 to 4.86), P = 0.12). Lower hyperemic velocity was independently associated with hospital mortality in multivariable analysis (odds ratio = 1.11 (95% confidence interval = 1.04 to 1.19) per 1 cm/cardiac cycle decrease in hyperemic velocity; P = 0.003). Conclusions Brachial artery hyperemic blood velocity is a noninvasive index of microvascular function that independently predicts mortality in severe sepsis. In contrast, brachial artery flow-mediated dilation, reflecting conduit artery endothelial function, was not associated with mortality in our severe sepsis cohort. Brachial artery hyperemic velocity may be a useful measurement to identify patients who could benefit from novel therapies designed to reverse microvascular dysfunction in severe sepsis and to assess the physiologic efficacy of these treatments. PMID:22390813

  10. Molecular targets in radiation-induced blood-brain barrier disruption

    SciTech Connect

    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: shun.wang@sw.ca

    2005-05-01

    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.

  11. Resolution of radiation-induced acneform eruption following treatment with tretinoin and minocycline: a case report.

    PubMed

    Parr, Karina; Mahmoudizad, Rod; Grimwood, Ronald

    2013-07-01

    Postradiation comedogenesis is an uncommon side effect of radiation therapy, with few cases reported in the medical literature. The proposed etiology of this reaction is alteration of pilosebaceous unit secretions and retention of proliferating ductal keratinocytes due to stricture and scarring. We report a case of a 48-year-old woman who had been treated for infiltrating ductal carcinoma of the right breast with lumpectomy and radiation therapy. She subsequently developed open and closed comedones as well as tender inflammatory papules and papulopustules in the irradiated area. Our patient was treated with tretinoin cream and oral minocycline, with rapid improvement in symptoms and complete resolution of lesions after 2 months of therapy. We review the literature on the pathogenesis, clinical features, and treatment of postradiation acne, and discuss rapid resolution of a radiation-induced acneform eruption after combination treatment with tretinoin and minocycline. PMID:23961521

  12. Radiation Induced Surface Activity Phenomenon: 1. Report - Surface Wettability on Metal Oxides

    SciTech Connect

    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)

    2002-07-01

    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)

  13. Nuclear dynamics of radiation-induced foci in euchromatin and heterochromatin

    PubMed Central

    Chiolo, Irene; Tang, Jonathan; Georgescu, Walter; Costes, Sylvain V.

    2013-01-01

    Repair of double strand breaks (DSBs) is essential for cell survival and genome integrity. While much is known about the molecular mechanisms involved in DSB repair and checkpoint activation, the roles of nuclear dynamics of radiation-induced foci (RIF) in DNA repair are just beginning to emerge. Here, we summarize results from recent studies that point to distinct features of these dynamics in two different chromatin environments: heterochromatin and euchromatin. We also discuss how nuclear architecture and chromatin components might control these dynamics, and the need of novel quantification methods for a better description and interpretation of these phenomena. These studies are expected to provide new biomarkers for radiation risk and new strategies for cancer detection and treatment. PMID:23958412

  14. Ultrasound appearance of radiation-induced hepatic injury. Correlation with computed tomography and magnetic resonance imaging

    SciTech Connect

    Garra, B.S.; Shawker, T.H.; Chang, R.; Kaplan, K.; White, R.D.

    1988-11-01

    The ultrasound findings in three cases of radiation-induced hepatic injury are described and compared with computed tomography and magnetic resonance imaging findings. Fatty infiltration of the liver was present in two of the cases in which concurrent chemotherapy was being administered. On ultrasound B-scans, the regions of radiation injury were hypoechoic relative to the remainder of the liver. This finding was more obvious in the patients with fatty livers. CT scans on the patients with fatty infiltrated livers showed higher attenuation in the irradiated region than in unexposed liver. In the patient where no fatty infiltration was present, the radiated section of liver had lower attenuation consistent with previous reports. Magnetic resonance imaging showed decreased signal in the exposed areas on T1 weighted images.

  15. Radiation-induced biomarkers for the detection and assessment of absorbed radiation doses

    PubMed Central

    Rana, Sudha; Kumar, Raj; Sultana, Sarwat; Sharma, Rakesh Kumar

    2010-01-01

    Radiation incident involving living organisms is an uncommon but a very serious situation. The first step in medical management including triage is high-throughput assessment of the radiation dose received. Radiation exposure levels can be assessed from viability of cells, cellular organelles such as chromosome and different intermediate metabolites. Oxidative damages by ionizing radiation result in carcinogenesis, lowering of the immune response and, ultimately, damage to the hematopoietic system, gastrointestinal system and central nervous system. Biodosimetry is based on the measurement of the radiation-induced changes, which can correlate them with the absorbed dose. Radiation biomarkers such as chromosome aberration are most widely used. Serum enzymes such as serum amylase and diamine oxidase are the most promising biodosimeters. The level of gene expression and protein are also good biomarkers of radiation. PMID:21829314

  16. Radiation-induced effects on some common storage edible seeds in India infested with surface microflora

    NASA Astrophysics Data System (ADS)

    Maity, J. P.; Chakraborty, A.; Saha, A.; Santra, S. C.; Chanda, S.

    2004-12-01

    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.

  17. Radiation-Induced Decomposition of PETN and TATB under Extreme Conditions

    SciTech Connect

    Giefers, Hubertus; Pravica, Michael (UNLV)

    2008-11-03

    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.

  18. Characterization of Network Structure of Polyacrylamide Based Hydrogels Prepared By Radiation Induced Polymerization

    SciTech Connect

    Mahmudi, Naim [State University of Tetovo, Faculty of Natural Science and Mathematics, 1200 Tetovo (Macedonia, The Former Yugoslav Republic of); Sen, Murat; Gueven, Olgun [Hacettepe University, Department of Chemistry, Polymer Chemistry Division, 06532, Beytepe, Ankara (Turkey); Rendevski, Stojan [Institute of Physics, Faculty of Natural Science and Mathematics, University 'Ss Cyril and Methodius', Skopje (Macedonia, The Former Yugoslav Republic of)

    2007-04-23

    In this study network structure of polyacrylamide based hydrogels prepared by radiation induced polymerization has been investigated. Polyacrylamide based hydrogels in the rod form were prepared by copolymerization of acrylamide(AAm) with hydroxyl ethyl methacrylate(HEMA) and methyl acrylamide(MAAm) in the presence of cross-linking agent and water by gamma rays at ambient temperature. Molecular weight between cross-links and effective cross-link density of hydrogels were calculated from swelling as well as shear modulus data obtained from compression tests. The results have shown that simple compression analyses can be used for the determination of effective cross-link density of hydrogels without any need to some polymer-solvent based parameters as in the case of swelling based determinations. Diffusion of water into hydrogels was examined by analyzing water absorption kinetics and the effect of network, structure on the diffusion type and coefficient was discussed.

  19. A simulation study of the radiation-induced bystander effect: modeling with stochastically defined signal reemission.

    PubMed

    Sasaki, Kohei; Wakui, Kosuke; Tsutsumi, Kaori; Itoh, Akio; Date, Hiroyuki

    2012-01-01

    The radiation-induced bystander effect (RIBE) has been experimentally observed for different types of radiation, cell types, and cell culture conditions. However, the behavior of signal transmission between unirradiated and irradiated cells is not well known. In this study, we have developed a new model for RIBE based on the diffusion of soluble factors in cell cultures using a Monte Carlo technique. The model involves the signal emission probability from bystander cells following Poisson statistics. Simulations with this model show that the spatial configuration of the bystander cells agrees well with that of corresponding experiments, where the optimal emission probability is estimated through a large number of simulation runs. It was suggested that the most likely probability falls within 0.63-0.92 for mean number of the emission signals ranging from 1.0 to 2.5. PMID:23197991

  20. A Simulation Study of the Radiation-Induced Bystander Effect: Modeling with Stochastically Defined Signal Reemission

    PubMed Central

    Sasaki, Kohei; Wakui, Kosuke; Tsutsumi, Kaori; Itoh, Akio; Date, Hiroyuki

    2012-01-01

    The radiation-induced bystander effect (RIBE) has been experimentally observed for different types of radiation, cell types, and cell culture conditions. However, the behavior of signal transmission between unirradiated and irradiated cells is not well known. In this study, we have developed a new model for RIBE based on the diffusion of soluble factors in cell cultures using a Monte Carlo technique. The model involves the signal emission probability from bystander cells following Poisson statistics. Simulations with this model show that the spatial configuration of the bystander cells agrees well with that of corresponding experiments, where the optimal emission probability is estimated through a large number of simulation runs. It was suggested that the most likely probability falls within 0.63–0.92 for mean number of the emission signals ranging from 1.0 to 2.5. PMID:23197991

  1. Radiation induced damage and recovery in poly(3-hexyl thiophene) based polymer solar cells.

    PubMed

    Li, Gang; Yang, Yang; Devine, R A B; Mayberry, Clay

    2008-10-22

    Polymer solar cells have been characterized during and after x-ray irradiation. The open circuit voltage, dark current and power conversion efficiency show degradation consistent with the generation of defect states in the polymer semiconductor. The polymer solar cell device remained functional with exposure to a considerable dose (500 krad (SiO(2))) and showed clear signs of recovery upon removal of the irradiation source (degraded from 4.1% to 2.2% and recovered to 2.9%). Mobility-relaxation time variation, derived from J-V measurement, clearly demonstrates that radiation induced defect generation mechanisms in the organic semiconductor are active and need to be further studied. Optical transmission results ruled out the possibility of reduced light absorption and/or polymer crystallinity. The results suggest that organic solar cells are sufficiently radiation tolerant to be useful for space applications. PMID:21832674

  2. Modeling and optimization aspects of radiation induced grafting of 4-vinylpyridene onto partially fluorinated films

    NASA Astrophysics Data System (ADS)

    Nasef, Mohamed Mahmoud; Ahmad Ali, Amgad; Saidi, Hamdani; Ahmad, Arshad

    2014-01-01

    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.

  3. Radiation-induced surface degradation of GaAs and high electron mobility transistor structures

    SciTech Connect

    Bobyl, A. V.; Konnikov, S. G.; Ustinov, V. M.; Baidakova, M. V.; Maleev, N. A.; Sakseev, D. A. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Konakova, R. V., E-mail: konakova@isp.kiev.ua; Milenin, V. V.; Prokopenko, I. V. [National Academy of Sciences of Ukraine, Lashkaryov Institute of Semiconductor Physics (Ukraine)

    2012-06-15

    Transistor heterostructures with high-carrier-mobility have been studied. It is shown that, as the {gamma}-irradiation dose {Phi} increases, their degradation occurs in the following sequence. (i) At {Phi} < 10{sup 7} rad, the GaAs surface layer is damaged to a depth of 10 nm due to a >0.2-eV decrease in the diffusion energy of intrinsic defects and, probably, atmospheric oxygen. (ii) At {Phi} > 10{sup 7} rad, highly structurally disordered regions larger than 1 {mu}m are formed near microscopic defects or dislocations. (iii) At {Phi} > 10{sup 8} rad, there occurs degradation of the internal AlGaAs/InGaAs/GaAs interfaces and the working channel. An effective method for studying the degradation processes in heterostructures is to employ a set of structural diagnostic methods to analyze processes of radiation-induced and aging degradation, in combination with theoretical simulation of the occurring processes.

  4. A computational approach to the relationship between radiation induced double strand breaks and translocations

    NASA Technical Reports Server (NTRS)

    Holley, W. R.; Chatterjee, A.

    1994-01-01

    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.

  5. Radiation-induced degradation of an epoxy thermoset supported by hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Nowicki, Andrzej; Przybytniak, Gra?yna; Legocka, Izabella; Mirkowski, Krzysztof

    2014-01-01

    Epoxy resin was decomposed applying two complementary treatments, namely (1) soaking up with 30% aqueous solution of hydrogen peroxide and (2) exposure of the swelled material to ionizing radiation in air atmosphere over doses up to 1000 kGy. The phase transition characteristic determined by the DSC technique revealed that both factors, swelling with oxidizing agent and irradiation applied sequentially induce in the resin deep structural changes resulting in the rise of two new exothermic transitions assigned to hydrogen peroxide decomposition and resin oxidation. The flexural stress at break measurements confirmed significant influence of H2O2 on the mechanical properties of the irradiated material which, under applied conditions, is efficiently decayed via oxidative degradation. On the basis of results obtained by EPR spectroscopy chemical mechanism of the radiation induced degradation was proposed.

  6. Radiation-inducible Immunotherapy for Cancer: Senescent Tumor Cells as a Cancer Vaccine

    PubMed Central

    Meng, Yuru; Efimova, Elena V; Hamzeh, Khaled W; Darga, Thomas E; Mauceri, Helena J.; Fu, Yang-Xin; Kron, Stephen J; Weichselbaum, Ralph R

    2012-01-01

    Radiotherapy offers an effective treatment for advanced cancer but local and distant failures remain a significant challenge. Here, we treated melanoma and pancreatic carcinoma in syngeneic mice with ionizing radiation (IR) combined with the poly(ADP-ribose) polymerase inhibitor (PARPi) veliparib to inhibit DNA repair and promote accelerated senescence. Based on prior work implicating cytotoxic T lymphocytes (CTLs) as key mediators of radiation effects, we discovered that senescent tumor cells induced by radiation and veliparib express immunostimulatory cytokines to activate CTLs that mediate an effective antitumor response. When these senescent tumor cells were injected into tumor-bearing mice, an antitumor CTL response was induced which potentiated the effects of radiation, resulting in elimination of established tumors. Applied to human cancers, radiation-inducible immunotherapy may enhance radiotherapy responses to prevent local recurrence and distant metastasis. PMID:22334019

  7. Bioinformatics methods for learning radiation-induced lung inflammation from heterogeneous retrospective and prospective data.

    PubMed

    Spencer, Sarah J; Bonnin, Damian Almiron; Deasy, Joseph O; Bradley, Jeffrey D; El Naqa, Issam

    2009-01-01

    Radiotherapy outcomes are determined by complex interactions between physical and biological factors, reflecting both treatment conditions and underlying genetics. Recent advances in radiotherapy and biotechnology provide new opportunities and challenges for predicting radiation-induced toxicities, particularly radiation pneumonitis (RP), in lung cancer patients. In this work, we utilize datamining methods based on machine learning to build a predictive model of lung injury by retrospective analysis of treatment planning archives. In addition, biomarkers for this model are extracted from a prospective clinical trial that collects blood serum samples at multiple time points. We utilize a 3-way proteomics methodology to screen for differentially expressed proteins that are related to RP. Our preliminary results demonstrate that kernel methods can capture nonlinear dose-volume interactions, but fail to address missing biological factors. Our proteomics strategy yielded promising protein candidates, but their role in RP as well as their interactions with dose-volume metrics remain to be determined. PMID:19704920

  8. Bioinformatics Methods for Learning Radiation-Induced Lung Inflammation from Heterogeneous Retrospective and Prospective Data

    PubMed Central

    Spencer, Sarah J.; Almiron Bonnin, Damian; Deasy, Joseph O.; Bradley, Jeffrey D.; El Naqa, Issam

    2009-01-01

    Radiotherapy outcomes are determined by complex interactions between physical and biological factors, reflecting both treatment conditions and underlying genetics. Recent advances in radiotherapy and biotechnology provide new opportunities and challenges for predicting radiation-induced toxicities, particularly radiation pneumonitis (RP), in lung cancer patients. In this work, we utilize datamining methods based on machine learning to build a predictive model of lung injury by retrospective analysis of treatment planning archives. In addition, biomarkers for this model are extracted from a prospective clinical trial that collects blood serum samples at multiple time points. We utilize a 3-way proteomics methodology to screen for differentially expressed proteins that are related to RP. Our preliminary results demonstrate that kernel methods can capture nonlinear dose-volume interactions, but fail to address missing biological factors. Our proteomics strategy yielded promising protein candidates, but their role in RP as well as their interactions with dose-volume metrics remain to be determined. PMID:19704920

  9. ESR investigations on radiation-induced modifications of irradiated thin polymeric films

    NASA Astrophysics Data System (ADS)

    Chipara, Mircea; Edwards, David L.; Beezhold, Wendland; Chipara, Magdalena; Nehls, Mary

    2004-10-01

    A parallel analysis of radiation-induced and thermal-induced degradation of polyethyleneterephtalate (PET) films is presented. The complexity of the degradation process is analyzed as a first step in a better understanding of the effect of combined temperature and radiation on PET. electron spin resonance spectrometry, DC electrical measurements, differential scanning calorimetry, and mechanical tests were used to analysze the effect of different ioninzing radiation (such as gamma, electrons, and accelerated ions) on thin films of PET. Data on the thermal analysis of PET are presented and analyzed. This study aims to a better understanding and modeling of complex degradation processes, required for a more reliable assessment of the behavior of polymers subjected to the space environment.

  10. Radiatively induced symmetry breaking and the conformally coupled magnetic monopole in AdS space

    NASA Astrophysics Data System (ADS)

    Edery, Ariel; Graham, Noah

    2013-11-01

    We implement quantum corrections for a magnetic monopole in a classically conformally invariant theory containing gravity. This yields the trace (conformal) anomaly and introduces a length scale in a natural fashion via the process of renormalization. We evaluate the one-loop effective potential and extract the vacuum expectation value (VEV) from it; spontaneous symmetry breaking is radiatively induced. The VEV is set at the renormalization scale M and we exchange the dimensionless scalar coupling constant for the dimensionful VEV via dimensional transmutation. The asymptotic (background) spacetime is anti-de Sitter (AdS) and its Ricci scalar is determined entirely by the VEV. We obtain analytical asymptotic solutions to the coupled set of equations governing gravitational, gauge and scalar fields that yield the magnetic monopole in an AdS spacetime.

  11. [Radiation-induced cutaneous hamartoma in a patient with Cowden syndrome. Clinical evidence for heterozygosity].

    PubMed

    Happle, R; Starink, T M

    2002-01-01

    A 56-year-old woman had typical features of Cowden syndrome in the form of hamartomas involving the skin, lips, and oral mucosa. At the age of 48, a mastectomy was performed for adenocarcinoma with a regional metastasis, and X-ray treatment was applied to the left axilla. Subsequently the patient developed approximately 30 skin-colored nodules surrounding the irradiated axillary region within several months. Histopathological examination of one of these lesions showed characteristic features of sclerotic fibroma. The multiple radiation-induced fibrous hamartomas observed may be best explained by multiple events of loss of heterozygosity (LOH), because molecular studies in other patients with Cowden syndrome have shown that both benign and malignant tumors originate from LOH. The X-ray treatment would have induced LOH in many cells, giving rise to either homo- or hemizygosity for the Cowden mutation. PMID:11963223

  12. Radiation-induced defects in Pr3+-activated LiYF4 laser host

    NASA Astrophysics Data System (ADS)

    Dhoble, S. J.; Deshpande, S. P.; Pode, R. B.; Dhoble, N. S.; Gundurao, T. K.

    2004-11-01

    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.

  13. Flow cytometric determination of radiation-induced chromosome damage and its correlation with cell survival

    SciTech Connect

    Welleweerd, J.; Wilder, M.E.; Carpenter, S.G.; Raju, M.R.

    1984-07-01

    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.

  14. A review on radiation-induced nucleation and growth of colloidal metallic nanoparticles

    PubMed Central

    2013-01-01

    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

  15. The complex interactions between radiation induced non-targeted effects and cancer.

    PubMed

    Campa, Alessandro; Balduzzi, Maria; Dini, Valentina; Esposito, Giuseppe; Tabocchini, Maria Antonella

    2015-01-01

    Radiation induced non-targeted effects have been widely investigated in the last two decades for their potential impact on low dose radiation risk. In this paper we will give an overview of the most relevant aspects related to these effects, starting from the definition of the low dose scenarios. We will underline the role of radiation quality, both in terms of mechanisms of interaction with the biological matter and for the importance of charged particles as powerful tools for low dose effects investigation. We will focus on cell communication, representing a common feature of non-targeted effects, giving also an overview of cancer models that have explicitly considered such effects. PMID:24139968

  16. Modeling of radiation-induced bystander effect using Monte Carlo methods

    NASA Astrophysics Data System (ADS)

    Xia, Junchao; Liu, Liteng; Xue, Jianming; Wang, Yugang; Wu, Lijun

    2009-03-01

    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.

  17. Graft polymerization using radiation-induced peroxides and application to textile dyeing

    NASA Astrophysics Data System (ADS)

    Enomoto, Ichiro; Katsumura, Yosuke; Kudo, Hisaaki; Soeda, Shin

    2011-02-01

    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.

  18. Maintenance of radiation-induced intestinal fibrosis: Cellular and molecular features

    PubMed Central

    Haydont, Valérie; Vozenin-Brotons, Marie-Catherine

    2007-01-01

    Recent advances in cell and molecular radiobiology clearly showed that tissue response to radiation injury cannot be restricted to a simple cell-killing process, but depends upon continuous and integrated pathogenic processes, involving cell differentiation and crosstalk between the various cellular components of the tissue within the extracellular matrix. Thus, the prior concept of primary cell target in which a single-cell type (whatever it’s epithelial or endothelial cells) dictates the whole tissue response to radiation injury has to be replaced by the occurrence of coordinated multicellular response that may either lead to tissue recovery or to sequel development. In this context, the present review will focus on the maintenance of the radiation-induced wound healing and fibrogenic signals triggered by and through the microenvironment toward the mesenchymal cell compartment, and will highlight how sequential and sustained modifications in cell phenotypes will in cascade modify cell-to-cell interactions and tissue composition. PMID:17569135

  19. The correlation between swelling and radiation-induced segregation in iron-chromium-nickel alloys.

    SciTech Connect

    Allen, T. R.; Busby, J. T.; Kenik, E. A.; Was, G. S.

    1998-03-05

    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.

  20. Proximity Within Interphase Chromosome Contributes to the Breakpoint Distribution in Radiation-Induced Intrachromosomal Exchanges

    NASA Technical Reports Server (NTRS)

    Zhang, Ye; Uhlemeyer, Jimmy; Hada, Megumi; Asaithamby, A.; Chen, David J.; Wu, Honglu

    2015-01-01

    Previously, we reported that breaks involved in chromosome aberrations were clustered in several regions of chromosome3 in human mammary epithelial cells after exposures to either low-or high-LET radiation. In particular, breaks in certain regions of the chromosome tended to rejoin with each other to form an intrachromosome exchange event. This study tests the hypothesis that proximity within a single chromosome in interphase cell nuclei contributes to the distribution of radiation-induced chromosome breaks. Chromosome 3 in G1 human mammary epithelial cells was hybridized with the multicolor banding in situ hybridization (mBAND) probes that distinguish the chromosome in six differently colored regions, and the location of these regions was measured with a laser confocal microscope. Results of the study indicated that, on a multi-mega base pair scale of the DNA, the arrangement of chromatin was non-random. Both telomere regions tended to be located towards the exterior of the chromosome domain, whereas the centromere region towards the interior. In addition, the interior of the chromosome domain was preferentially occupied by the p-arm of the chromatin, which is consistent with our previous finding of intrachromosome exchanges involving breaks on the p-arm and in the centromere region of chromosome3. Other factors, such as the fragile sites in the 3p21 band and gene regulation, may also contribute to the breakpoint distribution in radiation-induced chromosome aberrations. Further investigations suggest that the 3D chromosome folding is cell type and culture condition dependent.

  1. Whole Brain Radiation-Induced Cognitive Impairment: Pathophysiological Mechanisms and Therapeutic Targets

    PubMed Central

    Lee, Yong Woo; Cho, Hyung Joon; Lee, Won Hee; Sonntag, William E.

    2012-01-01

    Radiation therapy, the most commonly used for the treatment of brain tumors, has been shown to be of major significance in tu-mor control and survival rate of brain tumor patients. About 200,000 patients with brain tumor are treated with either partial large field or whole brain radiation every year in the United States. The use of radiation therapy for treatment of brain tumors, however, may lead to devastating functional deficits in brain several months to years after treatment. In particular, whole brain radiation therapy results in a significant reduction in learning and memory in brain tumor patients as long-term consequences of treatment. Although a number of in vitro and in vivo studies have demonstrated the pathogenesis of radiation-mediated brain injury, the cel-lular and molecular mechanisms by which radiation induces damage to normal tissue in brain remain largely unknown. Therefore, this review focuses on the pathophysiological mechanisms of whole brain radiation-induced cognitive impairment and the iden-tification of novel therapeutic targets. Specifically, we review the current knowledge about the effects of whole brain radiation on pro-oxidative and pro-inflammatory pathways, matrix metalloproteinases (MMPs)/tissue inhibitors of metalloproteinases (TIMPs) system and extracellular matrix (ECM), and physiological angiogenesis in brain. These studies may provide a foundation for defin-ing a new cellular and molecular basis related to the etiology of cognitive impairment that occurs among patients in response to whole brain radiation therapy. It may also lead to new opportunities for therapeutic interventions for brain tumor patients who are undergoing whole brain radiation therapy. PMID:24009822

  2. Radioprotective Effect of Melatonin on Radiation-Induced Lung Injury and Lipid Peroxidation in Rats

    PubMed Central

    Tahamtan, Raziyeh; Shabestani Monfared, Ali; Tahamtani, Yasser; Tavassoli, Alireza; Akmali, Maasoomeh; Mosleh-Shirazi, Mohammad Amin; Naghizadeh, Mohammad Mehdi; Ghasemi, Danial; Keshavarz, Mojtaba; Haddadi, Gholam Hassan

    2015-01-01

    Objective Free radicals generated by ionizing radiation attack various cellular components such as lipids. The lung is a very radiosensitive organ and its damage is a doselimiting factor in radiotherapy treatments. Melatonin (MLT), the major product of the pineal gland acts as a radioprotective agent. This study aims to investigate the radioprotective effects of MLT on malondialdehyde (MDA) levels and histopathological changes in irradiated lungs. Materials and Methods In this experimental study, a total of 62 rats were divided into five groups. Group 1 received no MLT and radiation (unT), group 2 received oral MLT (oM), group 3 received oral MLT and their thoracic areas were irradiated with 18 Gy (oMR), group 4 received MLT by intraperitoneal (i.p.) injection and their thoracic areas were irradiated with 18 Gy (ipM-R), group 5 received only 18 Gy radiation in the thoracic area (R). Following radiotherapy, half of the animals in each group were sacrificed at 48 hours for evaluation of lipid peroxidation and early phase lung injuries. Other animals were sacrificed in the eighth week of the experiment for evaluation of the presence of late phase radiation induced lung injuries. Results Pre-treatment of rats with either i.p injection (p<0.05) and oral administration of MLT (p<0.001) significantly reduced MDA levels in red blood cell (RBC) samples compared to the R group. Furthermore, i.p. injection of MLT decreased MDA levels in plasma and tissue (p<0.05). In the early phase of lung injury, both administration of MLT significantly increased lymphocyte (p<0.05) and macrophage frequency (p<0.001). MLT reduced the lung injury index in the lungs compared to the R group (p<0.05). Conclusion The result of this study confirms the radioprotective effect of MLT on lipid peroxidation, and in both early and late phases of radiation induced lung injuries in an animal model. PMID:25870840

  3. Persistence of Space Radiation Induced Cytogenetic Damage in the Blood Lymphocytes of Astronauts

    NASA Technical Reports Server (NTRS)

    George, Kerry; Cucinotta, Francis A.

    2008-01-01

    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.

  4. Exposure to Heavy Ion Radiation Induces Persistent Oxidative Stress in Mouse Intestine

    PubMed Central

    Datta, Kamal; Suman, Shubhankar; Kallakury, Bhaskar V. S.; Fornace, Albert J.

    2012-01-01

    Ionizing radiation-induced oxidative stress is attributed to generation of reactive oxygen species (ROS) due to radiolysis of water molecules and is short lived. Persistent oxidative stress has also been observed after radiation exposure and is implicated in the late effects of radiation. The goal of this study was to determine if long-term oxidative stress in freshly isolated mouse intestinal epithelial cells (IEC) is dependent on radiation quality at a dose relevant to fractionated radiotherapy. Mice (C57BL/6J; 6 to 8 weeks; female) were irradiated with 2 Gy of ?-rays, a low-linear energy transfer (LET) radiation, and intestinal tissues and IEC were collected 1 year after radiation exposure. Intracellular ROS, mitochondrial function, and antioxidant activity in IEC were studied by flow cytometry and biochemical assays. Oxidative DNA damage, cell death, and mitogenic activity in IEC were assessed by immunohistochemistry. Effects of ? radiation were compared to 56Fe radiation (iso-toxic dose: 1.6 Gy; energy: 1000 MeV/nucleon; LET: 148 keV/µm), we used as representative of high-LET radiation, since it's one of the important sources of high Z and high energy (HZE) radiation in cosmic rays. Radiation quality affected the level of persistent oxidative stress with higher elevation of intracellular ROS and mitochondrial superoxide in high-LET 56Fe radiation compared to unirradiated controls and ? radiation. NADPH oxidase activity, mitochondrial membrane damage, and loss of mitochondrial membrane potential were greater in 56Fe-irradiated mice. Compared to ? radiation oxidative DNA damage was higher, cell death ratio was unchanged, and mitotic activity was increased after 56Fe radiation. Taken together our results indicate that long-term functional dysregulation of mitochondria and increased NADPH oxidase activity are major contributing factors towards heavy ion radiation-induced persistent oxidative stress in IEC with potential for neoplastic transformation. PMID:22936983

  5. Dragon's blood and its extracts attenuate radiation-induced oxidative stress in mice

    PubMed Central

    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

    2014-01-01

    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 60Co-? 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

  6. Polaprezinc reduces the severity of radiation-induced mucositis in head and neck cancer patients

    PubMed Central

    DOI, HIROSHI; FUJIWARA, MASAYUKI; SUZUKI, HITOMI; NIWA, YASUE; NAKAYAMA, MASAHIRO; SHIKATA, TOSHIYUKI; ODAWARA, SOICHI; TAKADA, YASUHIRO; KIMURA, TAKESHI; KAMIKONYA, NORIHIKO; HIROTA, SHOZO

    2015-01-01

    Polaprezinc (PZ), an antiulcer drug, has been reported to have antioxidant properties. The aim of the present study was to assess the feasibility and efficacy of administering PZ for radiation-induced mucositis in head and neck cancer patients. Patients with newly diagnosed head and neck cancer were enrolled in this prospective study. PZ was prepared as an oral rinse. The PZ oral rinse was used four times per day during the course of radiotherapy. Sequential changes in radiation mucositis were assessed during and after radiotherapy according to the Common Terminology Criteria for Adverse Events, version 3.0. Furthermore, a retrospective comparison analysis was performed to assess the efficacy of PZ for radiation-induced mucositis. A total of 32 patients were enrolled in the prospective study of the PZ oral rinse. Radiotherapy was performed up to a total dose of 60–66 Gy using a conventional schedule combined with chemotherapy. Of the 32 patients, 30 (93.8%) reported no complaints due to the PZ oral rinse. In addition, PZ was not associated with severe adverse effects. Among the patients who received PZ, grade 3 mucositis was observed in 29.0% based on the mucosal findings and in 39.3% based on the symptoms. In the patients who did not receive PZ, the incidence of grade 3 mucositis was 40.0% based on the mucosal findings and 60.7% based on the symptoms. Moreover, PZ promoted the recovery from mucositis caused by chemoradiotherapy and was not associated with reduced tumor response to radiotherapy. Therefore, the PZ oral rinse was well tolerated and proved to be efficient for the treatment of radiotherapy-induced oral mucositis. PMID:25798271

  7. Effects of ozone oxidative preconditioning on radiation-induced organ damage in rats.

    PubMed

    Gultekin, Fatma Ayca; Bakkal, Bekir Hakan; Guven, Berrak; Tasdoven, Ilhan; Bektas, Sibel; Can, Murat; Comert, Mustafa

    2013-01-01

    Because radiation-induced cellular damage is attributed primarily to harmful effects of free radicals, molecules with direct free radical scavenging properties are particularly promising as radioprotectors. It has been demonstrated that controlled ozone administration may promote an adaptation to oxidative stress, preventing the damage induced by reactive oxygen species. Thus, we hypothesized that ozone would ameliorate oxidative damage caused by total body irradiation (TBI) with a single dose of 6 Gy in rat liver and ileum tissues. Rats were randomly divided into groups as follows: control group; saline-treated and irradiated (IR) groups; and ozone oxidative preconditioning (OOP) and IR groups. Animals were exposed to TBI after a 5-day intraperitoneal pretreatment with either saline or ozone (1 mg/kg/day). They were decapitated at either 6 h or 72 h after TBI. Plasma, liver and ileum samples were obtained. Serum AST, ALT and TNF-? levels were elevated in the IR groups compared with the control group and were decreased after treatment with OOP. TBI resulted in a significant increase in the levels of MDA in the liver and ileal tissues and a decrease of SOD activities. The results demonstrated that the levels of MDA liver and ileal tissues in irradiated rats that were pretreated with ozone were significantly decreased, while SOD activities were significantly increased. OOP reversed all histopathological alterations induced by irradiation. In conclusion, data obtained from this study indicated that ozone could increase the endogenous antioxidant defense mechanism in rats and there by protect the animals from radiation-induced organ toxicity. PMID:22915786

  8. Radiation-Induced Segregation and Phase Stability in Candidate Alloys for the Advanced Burner Reactor

    SciTech Connect

    Gary S. Was; Brian D. Wirth

    2011-05-29

    Major accomplishments of this project were the following: 1) Radiation induced depletion of Cr occurs in alloy D9, in agreement with that observed in austenitic alloys. 2) In F-M alloys, Cr enriches at PAG grain boundaries at low dose (<7 dpa) and at intermediate temperature (400°C) and the magnitude of the enrichment decreases with temperature. 3) Cr enrichment decreases with dose, remaining enriched in alloy T91 up to 10 dpa, but changing to depletion above 3 dpa in HT9 and HCM12A. 4) Cr has a higher diffusivity than Fe by a vacancy mechanism and the corresponding atomic flux of Cr is larger than Fe in the opposite direction to the vacancy flux. 5) Cr concentration at grain boundaries decreases as a result of vacancy transport during electron or proton irradiation, consistent with Inverse Kirkendall models. 6) Inclusion of other point defect sinks into the KLMC simulation of vacancy-mediated diffusion only influences the results in the low temperature, recombination dominated regime, but does not change the conclusion that Cr depletes as a result of vacancy transport to the sink. 7) Cr segregation behavior is independent of Frenkel pair versus cascade production, as simulated for electron versus proton irradiation conditions, for the temperatures investigated. 8) The amount of Cr depletion at a simulated planar boundary with vacancy-mediated diffusion reaches an apparent saturation value by about 1 dpa, with the precise saturation concentration dependent on the ratio of Cr to Fe diffusivity. 9) Cr diffuses faster than Fe by an interstitial transport mechanism, and the corresponding atomic flux of Cr is much larger than Fe in the same direction as the interstitial flux. 10) Observed experimental and computational results show that the radiation induced segregation behavior of Cr is consistent with an Inverse Kirkendall mechanism.

  9. Radiation-induced reactions of CO?H 2 gas mixtures over various solid catalysts

    NASA Astrophysics Data System (ADS)

    Nagai, S.; Arai, H.; Hatada, M.

    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.

  10. Protective effect of hydrogen-rich saline against radiation-induced immune dysfunction

    PubMed Central

    Zhao, Sanhu; Yang, Yanyong; Liu, Wen; Xuan, Zhiqiang; Wu, Shouming; Yu, Shunfei; Mei, Ke; Huang, Yijuan; Zhang, Pei; Cai, Jianming; Ni, Jin; Zhao, Yaoxian

    2014-01-01

    Recent studies showed that hydrogen can be used as an effective radioprotective agent through scavenging free radicals. This study was undertaken to evaluate the radioprotective effects of hydrogen on immune system in mice. H2 was dissolved in physiological saline using an apparatus produced by our department. Spleen index and histological analysis were used to evaluate the splenic structural damage. Spleen superoxide dismutase, GSH, MDA were measured to appraise the antioxidant capacity and a DCF assay for the measurement of radical oxygen species. Cell apoptosis was evaluated by an Annexin V-FITC and propidium iodide staining method as well as the apoptotic proteins such as Bcl-2, Bax, caspase-3 and c-caspase-3. CD4+ and CD8+ T cells subtypes were detected by flow cytometry with FITC-labelled antimouse CD4 and PE antimouse CD8 staining. Real-time PCR was utilized to determine the CD4+ T cell subtypes and related cytokines. Our study demonstrated that pre-treatment with H2 could increase the spleen index and attenuate the radiation damage on splenic structure. Radical oxygen species level was also reduced by H2 treatment. H2 also inhibited radiation-induced apoptosis in splenocytes and down-regulated pro-apoptotic proteins in living mice. Radiation-induced imbalance of T cells was attenuated by H2. Finally, we found that H2 could regulate the polarization of CD4+ T cells and the level of related cytokines. This study suggests H2 as an effective radioprotective agent on immune system by scavenging reactive oxygen species. PMID:24618260

  11. Inhibition of radiation induced dissolution of UO2 by sulfide - A comparison with the hydrogen effect

    NASA Astrophysics Data System (ADS)

    Yang, Miao; Barreiro Fidalgo, Alexandre; Sundin, Sara; Jonsson, Mats

    2013-03-01

    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.

  12. Obstetrical brachial plexus injuries: late functional results of the Steindler procedure.

    PubMed

    Gilbert, A; Valbuena, S; Posso, C

    2014-10-01

    We reviewed late functional results of a modified Steindler procedure in patients with obstetrical brachial plexus palsy and poor active elbow flexion. From 1982 to 2005, we reviewed final functional results and complications of 27 cases with flexion weakness of the elbow secondary to obstetrical brachial plexus injury, treated with a modified Steindler procedure. At the end of the follow-up, the mean active elbow flexion was 97° and the mean extensor lag was 10°. In the long-term follow-up, the modified Steindler procedure maintained good results in 67% of the cases in our series, and this percentage raised by 82% when the wrist extensor was present or restored before the Steindler procedure. There were poor results in 19% of the patients, but no major complications. PMID:24893931

  13. Multiple unilateral variations in medial and lateral cords of brachial plexus and their branches

    PubMed Central

    Goel, Shivi; Kumar, Ashwani; Mehta, Vandana; Suri, Rajesh Kumar

    2014-01-01

    During routine dissection of the upper extremity of an adult male cadaver, multiple variations in branches of medial and lateral cords of brachial plexus were encountered. Three unique findings were observed. First, intercordal neural communications between the lateral and medial cords were observed. Second, two lateral pectoral nerves and one medial pectoral nerve were seen to arise from the lateral and medial cord respectively. The musculocutaneous nerve did not pierce the coracobrachialis. Finally, the ulnar nerve arose by two roots from the medial cord. Knowledge of such variations is of interest to anatomists, radiologists, neurologists, anesthesiologists, and surgeons. The aim of our study is to provide additional information about abnormal brachial plexus and its clinical implications. PMID:24693486

  14. Nerve reconstruction: A cohort study of 93 cases of global brachial plexus palsy

    PubMed Central

    Bhatia, Anil; Shyam, Ashok K; Doshi, Piyush; Shah, Vitrag

    2011-01-01

    Introduction: Brachial plexus injury leading to flail upper limb is one of the most disabling injuries. Neglect of the injury and delay in surgeries may preclude reinnervation of the paralysed muscles. Currently for such injuries nerve transfers are the preferred procedures. We here present a series of 93 cases of global brachial plexus palsy treated with nerve transfers. Materials and Methods: Ninety-three cases of global palsies out of 384 cases of brachial plexus injury operated by the senior surgeon (AB) were selected. Age varied from 4 to 51 years with 63 patients in 20 to 40 age group and all patients having a minimum follow up of at least 1 year post surgery ranging up to 130 months. The delay before surgery ranged from 15 days to 16 months (mean 3.2 months). The aim of the surgery was to restore the elbow flexion, shoulder abduction, triceps function and wrist and finger flexion in that order of priority. The major nerve transfers used were spinal accessory to suprascapular nerve, intercostal to musculocutaneous nerve and pectoral nerves, contralateral C7 to median and radial nerves. Nerve stumps were used whenever available (30 patients). Results: Recovery of ? grade 3 power was noted in biceps in 73% (68/93) of patients, shoulder abduction in 89% (43/49), pectoralis major in 100% (8/8). Recovery of grade 2 triceps power was seen in 80% (12/16) patients with nerve transfer to radial nerve. Derotation osteotomies of humerus (n=13) and wrist fusion (n=14) were the most common secondary procedures performed to facilitate alignment and movements of the affected limb. Better results were noted in 59 cases where direct nerve transfers were done (without nerve graft). Conclusion: Acceptable function (restoration of biceps power ?3) can be obtained in more than two thirds (73%) of these global brachial plexus injuries by using the principles of early exploration and nerve transfer with rehabilitation. PMID:21430871

  15. Body vectoring technique with Radiesse® for tightening of the abdomen, thighs, and brachial zone

    PubMed Central

    Cogorno Wasylkowski, Valeria

    2015-01-01

    Background The objective of this study was to investigate the efficacy, safety, and subject satisfaction of the calcium hydroxylapatite-based dermal filler Radiesse® in a novel body vectoring technique to correct skin flaccidity in the thighs, abdomen, and brachial zones. Methods Female subjects with self-evaluated flaccidity scores ?3 on a 6-point scale (0, no flaccidity; 5, very severe flaccidity) in the zones of interest were included. Radiesse was injected according to predesigned vector maps (3 mL per thigh, 1.5 mL per hemiabdomen or brachial zone). Clinical assessments (skin density and thickness) were made by an independent reviewer at an exact position before and 5 weeks after treatment using a cutometer and an ultrascan. Subjects rated skin flaccidity before and 5 weeks after treatment on the 6-point scale and performed a pinch test to self-assess changes in skin thickness. All adverse events were recorded. Results Twenty females (aged 28–67 years) were enrolled, contributing 36 treatment zones. Across all zones, 78% of flaccidity measurements improved after treatment. Improvements in skin flaccidity were most common in the thighs (82% of cases). An improvement in skin density versus baseline was observed in the majority across all zones, most frequently in the abdomen (88% of cases). Skin thickness in each zone also improved versus baseline for the majority, most frequently in the thighs (88% of cases). Mean self-assessed flaccidity scores at baseline were 3.6 (thighs), 3.7 (abdomen), and 3.8 (brachial zone), and 2.6, 2.7, and 3.0, respectively, posttreatment. All subjects reported a positive pinch test. In total, 47.0% of subjects had bruising after treatment, which resolved within a week. No serious adverse events were reported. Conclusion Using this novel technique, Radiesse had notable results on skin flaccidity, density and thickness in the thighs, abdomen, and brachial zones, and was well tolerated.

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

    Microsoft Academic Search

    Kevin P. J. Armstrong; Richard A. Cherry

    2004-01-01

    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

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

    Microsoft Academic Search

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

    2002-01-01

    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

  18. Interscalene Brachial Plexus Block with a Continuous Catheter Insertion System and a Disposable Infusion Pump

    Microsoft Academic Search

    Stephen M. Klein; Stuart A. Grant; Roy A. Greengrass; Karen C. Nielsen; Kevin P. Speer; William White; David S. Warner; Susan M. Steele

    2000-01-01

    Continuous interscalene brachial plexus blockade tra- ditionally requires a hospital stay for local anesthetic infusion, and achieving consistent catheter insertion may be difficult. Incorporating long-acting pain relief from a continuous peripheral nerve block, with a reli- able method of catheter insertion, and a self-contained infusion system would be a valuable asset for short-stay care. We compared the efficacy of single

  19. Plasma concentrations of ropivacaine given with or without epinephrine for brachial plexus block

    Microsoft Academic Search

    Rosemary Hickey; Janna Blanchard; Joan Hoffman; Jan Sjovall; Somayaji Ramamurthy

    1990-01-01

    The purpose of this study was to determine the pharmacokinetic properties of the local anaesthetic ropivacaine used with or\\u000a without epinephrine for brachial plexus block. Seventeen ASA physical status I or II adult patients undergoing elective orthopaedic\\u000a surgery received a single injection of 33 ml ropivacaine for subclavian perivascular block and 5 ml to block the intercostobrachial\\u000a nerve in the

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

    ERIC Educational Resources Information Center

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

    2007-01-01

    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…

  1. [Nerve reconstruction techniques in traumatic brachial plexus surgery. Part 1: extraplexal nerve transfers].

    PubMed

    Robla-Costales, J; Socolovsky, M; Di Masi, G; Domitrovic A Campero J Fernández-Fernández J Ibáñez-Plágaro J García-Cosamalón, L; Campero, A; Fernández-Fernández, J; Ibáñez-Plágaro, J; García-Cosamalón, J

    2011-12-01

    After the great enthusiasm generated in the '70s and '80s in brachial plexus surgery as a result of the incorporation of microsurgical techniques and other advances, brachial plexus surgery has been shaken in the last two decades by the emergence of nerve transfer techniques or neurotizations. This technique consists in sectioning a donor nerve, sacrificing its original function, to connect it with the distal stump of a receptor nerve, whose function was lost during the trauma. Neurotizations are indicated when direct repair is not possible, i.e. when a cervical root is avulsed at its origin in the spinal cord. In recent years, due to the positive results of some of these nerve transfer techniques, they have been widely used even in some cases where the roots of the plexus were preserved. In complete brachial plexus injuries, it is mandatory to determine the exact number of roots available (not avulsed) to perform a direct reconstruction. In case of absence of available roots, extraplexual nerve transfers are employed, such as the spinal accessory nerve, the phrenic nerve, the intercostal nerves, etc., to increase the amount of axons transferred to the injured plexus. In cases of avulsion of all the roots, extraplexal neurotizations are the only reinnervation option available to limit the long-term devastating effects of this injury. Given the large amount of reports that has been published in recent years regarding brachial plexus traumatic injuries, the present article has been written in order to clarify the concerned readers the indications, results and techniques available in the surgical armamentarium for this condition. Since the choice of either surgical technique is usually taken during the course of the procedure, all this knowledge should be perfectly embodied by the surgical team before the procedure. In this first part extraplexual nerve transfers are analyzed, while intraplexual nerve transfers will be analyzed in the second part of this presentation. PMID:22167281

  2. Perspectives on glenohumeral joint contractures and shoulder dysfunction in children with perinatal brachial plexus palsy.

    PubMed

    Gharbaoui, Idris S; Gogola, Gloria R; Aaron, Dorit H; Kozin, Scott H

    2015-01-01

    Shoulder joint deformities continue to be a challenging aspect of treating upper plexus lesions in children with perinatal brachial plexus palsy (PBPP). It is increasingly recognized that PBPP affects the glenohumeral joint specifically, and that abnormal scapulothoracic movements are a compensatory development. The pathophysiology and assessment of glenohumeral joint contractures, the progression of scapular dyskinesia and skeletal dysplasia, and current shoulder imaging techniques are reviewed. PMID:25835253

  3. Radiation-induced immunogenic modulation of tumor enhances antigen processing and calreticulin exposure, resulting in enhanced T-cell killing.

    PubMed

    Gameiro, Sofia R; Jammeh, Momodou L; Wattenberg, Max M; Tsang, Kwong Y; Ferrone, Soldano; Hodge, James W

    2014-01-30

    Radiation therapy (RT) is used for local tumor control through direct killing of tumor cells. Radiation-induced cell death can trigger tumor antigen-specific immune responses, but these are often noncurative. Radiation has been demonstrated to induce immunogenic modulation (IM) in various tumor types by altering the biology of surviving cells to render them more susceptible to T cell-mediated killing. Little is known about the mechanism(s) underlying IM elicited by sub-lethal radiation dosing. We have examined the molecular and immunogenic consequences of radiation exposure in breast, lung, and prostate human carcinoma cells. Radiation induced secretion of ATP and HMGB1 in both dying and surviving tumor cells. In vitro and in vivo tumor irradiation induced significant upregulation of multiple components of the antigen-processing machinery and calreticulin cell-surface expression. Augmented CTL lysis specific for several tumor-associated antigens was largely dictated by the presence of calreticulin on the surface of tumor cells and constituted an adaptive response to endoplasmic reticulum stress, mediated by activation of the unfolded protein response. This study provides evidence that radiation induces a continuum of immunogenic alterations in tumor biology, from immunogenic modulation to immunogenic cell death. We also expand the concept of immunogenic modulation, where surviving tumor cells recovering from radiation-induced endoplasmic reticulum stress become more sensitive to CTL killing. These observations offer a rationale for the combined use of radiation with immunotherapy, including for patients failing RT alone. PMID:24480782

  4. Radiation-induced interaction of optical solitons in fibers with randomly varying birefringence V. V. Lebedev,2

    E-print Network

    Lebedev, Vladimir

    Radiation-induced interaction of optical solitons in fibers with randomly varying birefringence Y fibers with randomly varying birefringence which results in polarization mode dispersion. Due-speed fiber communications, the noise induced by opti- cal amplifiers and the birefringent disorder caused

  5. RADIOFREQUENCY RADIATION-INDUCED CALCIUM-ION-EFFLUX ENHANCEMENT FROM HUMAN AND OTHER NEUROBLASTOMA CELLS IN CULTURE

    EPA Science Inventory

    In order to test the generality of radiofrequency-radiation-induced change in alteration 45Ca2+ efflux from avian and feline brain tissues, human neuroblastoma cells were exposed to electromagnetic radiation at 147 MHz, amplitude modulated (AM) at 16 Hz, at specific absorption ra...

  6. A model of interactions between radiation-induced oxidative stress, protein and DNA damage in Deinococcus radiodurans

    E-print Network

    Brenner, David Jonathan

    A model of interactions between radiation-induced oxidative stress, protein and DNA damage 2009 Keywords: Mathematical model DNA repair Protein oxidation Dose response Clonogenic survival Bacteria Deinococcus radiodurans a b s t r a c t Ionizing radiation triggers oxidative stress, which can

  7. Ultraviolet Radiation-Induced Damage to Human Langerhans Cells In Vivo Is Not Reversed by Ultraviolet A or Visible Light

    Microsoft Academic Search

    Joseph Alcalay; Leonard H. Goldberg; John E. Wolf Jr.; Margaret L. Kripke

    1990-01-01

    Exposure of human skin in vivo to UVB radiation induces pyrimidine dimers in DNA and alters the morphology and function of epidermal Langerhans cells. Cells in human skin have been reported to contain a photoreactivation repair mechanism that, following exposure to UVA or visible light, repairs UVB-induced pyrimidine dimers. The purpose of this study was to determine whether exposure to

  8. Protective role of tea polyphenols in combination against radiation-induced haematopoietic and biochemical alterations in mice.

    PubMed

    Hu, Yuan; Cao, Jing-Jing; Liu, Ping; Guo, Dai-Hong; Wang, Ya-Ping; Yin, Jian; Zhu, Ying; Rahman, Khalid

    2011-12-01

    The purpose of this study was to investigate the radioprotective effects of tea polyphenols (TPs) in various combinations against radiation-induced damage in mice. Mice were divided into different groups: non-irradiated control, irradiated control, amifostine (43.6?mg/kg, i.v. 30?min before irradiation; positive control) and various combinations of tea polyphenols in different doses. The radioprotective effect on the haematopoietic system, serum cytokines and endogenous antioxidant enzymes were studied. TP50, containing approximately 50% of (-)-epigallochatechin-3-gallate in addition to other catechins, showed the greatest radioprotective effect against radiation-induced changes in haematological parameters (red blood cell count, white blood cell count and haemoglobin), and maintained the spleen and thymus indices unchanged (spleen or thymus weight/body weight?×?1000). Tea polyphenols also significantly decreased radiation-induced lipid peroxidation (malondialdehyde levels), elevated endogenous antioxidant enzymes (superoxide dismutase) and reduced the serum cytokines which were elevated in radiation-induced toxicity. This evidence shows the potential of tea polyphenols, particularly in the combination found in TP50, as radioprotectors in mice, especially regarding recovery of the haematopoietic system, antioxidant potential activity and reduction of inflammatory cytokines. PMID:21452375

  9. Statistical modeling of radiation-induced proton transport in silicon: deactivation of dopant acceptors in bipolar devices

    Microsoft Academic Search

    S. N. Rashkeev; D. M. Fleetwood; R. D. Schrimpf; S. T. Pantelides

    2003-01-01

    We show that radiation-induced dopant deactivation in MOS capacitors that simulate the base oxides of silicon bipolar transistors is due primarily to direct neutralization by protons. The strong dependence of the deactivation process on electric field is related to the transport of H+ in the depletion region. The probability of acceptor neutralization near the Si surface is higher for small

  10. Contribution of endogenous and exogenous damage to the total radiation-induced damage in the bacterial spore

    SciTech Connect

    Jacobs, G.P.; Samuni, A.; Czapski, G.

    1980-01-01

    Radical scavengers such as polyethylene glycol 4000 and bovine albumin have been used to define the contribution of exogenous and endogenous damage to the total radiation-induced damage in aqueous buffered suspensions of Bacillus pumilus spores. The results indicate that this damage in the bacterial spore is predominantly endogenous.

  11. The relationship between ionizing radiation-induced apoptosis and stem cells in the small and large intestine

    Microsoft Academic Search

    CS Potten; HK Grant

    1998-01-01

    Apoptosis is observed in the crypts of the small intestine of healthy animals and man (spontaneous apoptosis). The levels can be dramatically elevated 3-6 h following ionizing radiation exposure. Both the spontaneous and radiation-induced apoptosis in the small intestine crypts are most frequently observed at the positions in the crypt associated with stem cells (about four cell positions from the

  12. Acemannan-containing wound dressing gel reduces radiation-induced skin reactions in C3H mice

    Microsoft Academic Search

    Dianna B. Roberts; Elizabeth L. Travis

    1995-01-01

    To determine (a) whether a wound dressing gel that contains acemannan extracted from aloe leaves affects the severity of radiation-induced acute skin reactions in C3H mice; (b) if so, whether other commercially available gels such as a personal lubricating jelly and a healing ointment have similar effects; and (c) when the wound dressing gel should be applied for maximum effect.

  13. Brachial artery pseudoaneurysm arising from the stump of a ligated arteriovenous fistula.

    PubMed

    Cox, Nicola; Sahnan, Kapil; Yee, Chris Pui Yan; Sritharan, Kaji

    2015-01-01

    An 85-year-old man presented to A&E department with a bleeding, pulsatile mass within the left antecubital fossa. He reported a 3-month history of an increasing, painless swelling. He had a history of end-stage renal failure secondary to antiglomerular basement membrane disease. 14?years prior, he had a left brachiocephalic fistula created, which was ligated shortly after its creation due to Steal syndrome. Examination revealed a 10×15×10?cm pulsatile, non-tender mass with overlying ulceration in the left antecubital fossa. Arterial duplex demonstrated a pseudoaneurysm arising from the left distal brachial artery with a 9?mm neck. The patient underwent surgical exploration and repair. At surgery, a large brachial artery pseudoaneurysm at the site of the previous fistula ligation was found. The overlying ulcerated skin and pseudoaneurysm were excised en mass, and the arterial defect repaired by transection and end-to-end anastomosis. This is the first reported case of a brachial artery pseudoaneurysm occurring following arteriovenous fistula ligation. PMID:26063109

  14. Prediction of early and late preeclampsia by flow-mediated dilation of the brachial artery*

    PubMed Central

    Brandão, Augusto Henriques Fulgêncio; Evangelista, Aline Aarão; Martins, Raphaela Menin Franco; Leite, Henrique Vítor; Cabral, Antônio Carlos Vieira

    2014-01-01

    Objective To assess the accuracy in the prediction of both early and late preeclampsia by flow-mediated dilation of the brachial artery (FMD), a biophysical marker for endothelial dysfunction. Materials and Methods A total of 91 patients, considered at high risk for development of preeclampsia were submitted to brachial artery FMD between 24 and 28 weeks of gestation. Results Nineteen out of the selected patients developed preeclampsia, 8 in its early form and 11 in the late form. With a cut-off value of 6.5%, the FMD sensitivity for early preeclampsia prediction was 75.0%, with specificity of 73.3%, positive predictive value (PPV) of 32.4% and negative predictive value (NPV) of 91.9%. For the prediction of late preeclampsia, sensitivity = 83.3%, specificity = 73.2%, PPV = 34.4% and NPV = 96.2% were observed. And for the prediction of all associated forms of preeclampsia, sensitivity = 84.2%, specificity = 73.6%, PPV = 45.7% and NPV = 94.6% were observed. Conclusion FMD of the brachial artery is a test with good accuracy in the prediction of both early and late preeclampsia, which may represent a positive impact on the follow-up of pregnant women at high risk for developing this syndrome. PMID:25741086

  15. Gross anatomy of the brachial plexus in the giant Anteater (Myrmecophaga tridactyla).

    PubMed

    Souza, P R; Cardoso, J R; Araujo, L B M; Moreira, P C; Cruz, V S; Araujo, E G

    2014-10-01

    Ten forelimbs of five Myrmecophaga tridactyla were examined to study the anatomy of the brachial plexus. The brachial plexuses of the M. tridactyla observed in the present study were formed by the ventral rami of the last four cervical spinal nerves, C5 through C8, and the first thoracic spinal nerve, T1. These primary roots joined to form two trunks: a cranial trunk comprising ventral rami from C5-C7 and a caudal trunk receiving ventral rami from C8-T1. The nerves originated from these trunks and their most constant arrangement were as follows: suprascapular (C5-C7), subscapular (C5-C7), cranial pectoral (C5-C8), caudal pectoral (C8-T1), axillary (C5-C7), musculocutaneous (C5-C7), radial (C5-T1), median (C5-T1), ulnar (C5-T1), thoracodorsal (C5-C8), lateral thoracic (C7-T1) and long thoracic (C6-C7). In general, the brachial plexus in the M. tridactyla is similar to the plexuses in mammals, but the number of rami contributing to the formation of each nerve in the M. tridactyla was found to be larger than those of most mammals. This feature may be related to the very distinctive anatomical specializations of the forelimb of the anteaters. PMID:23952693

  16. Selective ultrasound guided pectoral nerve targeting in breast augmentation: How to spare the brachial plexus cords?

    PubMed

    Desroches, Jean; Grabs, Ursula; Grabs, Detlev

    2013-01-01

    Subpectoral breast augmentation surgery under regional anesthesia requires the selective neural blockade of the medial and lateral pectoral nerves to diminish postoperative pain syndromes. The purpose of this cadaver study is to demonstrate a reliable ultrasound guided approach to selectively target the pectoral nerves and their branches while sparing the brachial plexus cords. After evaluating the position and appearance of the pectoral nerves in 25 cadavers (50 sides), a portable ultrasound machine was used to guide the injection of 10 ml of 0.2% aqueous methylene blue solution in the pectoral region on both sides of three Thiel's embalmed cadavers using a single entry point-triple injection technique. This technique uses a medial to lateral approach with the entry point just medial to the pectoral minor muscle and three subsequent infiltrations: (1) deep lateral part of the pectoralis minor muscle, (2) between the pectoralis minor and major muscles, and (3) between the pectoralis major muscle and its posterior fascia under ultrasound visualization. Dissection demonstrates that the medial and lateral pectoral nerves were well stained while leaving the brachial plexus cords unstained. We show that 10 ml of an injected solution is sufficient to stain all the medial and lateral pectoral nerve branches without a proximal extension to the cords of the brachial plexus. PMID:22730005

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

    PubMed

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

    2011-04-01

    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

  18. A role for TRAIL/TRAIL-R2 in radiation-induced apoptosis and radiation-induced bystander response of human neural stem cells.

    PubMed

    Ivanov, Vladimir N; Hei, Tom K

    2014-03-01

    Adult neurons, which are terminally differentiated cells, demonstrate substantial radioresistance. In contrast, human neural stem cells (NSC), which have a significant proliferative capacity, are highly sensitive to ionizing radiation. Cranial irradiation that is widely used for treatment of brain tumors may induce death of NSC and further cause substantial cognitive deficits such as impairing learning and memory. The main goal of our study was to determine a mechanism of NSC radiosensitivity. We observed a constitutive high-level expression of TRAIL-R2 in human NSC. On the other hand, ionizing radiation through generation of reactive oxygen species targeted cell signaling pathways and dramatically changed the pattern of gene expression, including upregulation of TRAIL. A significant increase of endogenous expression and secretion of TRAIL could induce autocrine/paracrine stimulation of the TRAIL-R2-mediated signaling cascade with activation of caspase-3-driven apoptosis. Furthermore, paracrine stimulation could initiate bystander response of non-targeted NSC that is driven by death ligands produced by directly irradiated NSC. Experiments with media transfer from directly irradiated NSC to non-targeted (bystander) NSC confirmed a role of secreted TRAIL for induction of a death signaling cascade in non-targeted NSC. Subsequently, TRAIL production through elimination of bystander TRAIL-R-positive NSC might substantially restrict a final yield of differentiating young neurons. Radiation-induced TRAIL-mediated apoptosis could be partially suppressed by anti-TRAIL antibody added to the cell media. Interestingly, direct gamma-irradiation of SK-N-SH human neuroblastoma cells using clinical doses (2-5 Gy) resulted in low levels of apoptosis in cancer cells that was accompanied however by induction of a strong bystander response in non-targeted NSC. Numerous protective mechanisms were involved in the maintenance of radioresistance of neuroblastoma cells, including constitutive PI3K-AKT over-activation and endogenous synthesis of TGF?1. Specific blockage of these survival pathways was accompanied by a dramatic increase in radiosensitivity of neuroblastoma cells. Intercellular communication between cancer cells and NSC could potentially be involved in amplification of cancer pathology in the brain. PMID:24158598

  19. A role for TRAIL/TRAIL-R2 in radiation-induced apoptosis and radiation-induced bystander response of human neural stem cells

    PubMed Central

    Ivanov, Vladimir N.; Hei, Tom K.

    2013-01-01

    Adult neurons, which are terminally differentiated cells, demonstrate substantial radioresistance. In contrast, human neural stem cells (NSC), which have a significant proliferative capacity, are highly sensitive to ionizing radiation. Cranial irradiation that is widely used for treatment of brain tumors may induce death of NSC and further cause substantial cognitive deficits such as impairing learning and memory. The main goal of our study was to determine a mechanism of NSC radiosensitivity. We observed a constitutive high-level expression of TRAIL-R2 in human NSC. On the other hand, ionizing radiation through generation of reactive oxygen species targeted cell signaling pathways and dramatically changed the pattern of gene expression, including upregulation of TRAIL. A significant increase of endogenous expression and secretion of TRAIL could induce autocrine/paracrine stimulation of the TRAIL-R2-mediated signaling cascade with activation of caspase-3-driven apoptosis. Furthermore, paracrine stimulation could initiate bystander response of non-targeted NSC that is driven by death ligands produced by directly irradiated NSC. Experiments with media transfer from directly irradiated NSC to non-targeted (bystander) NSC confirmed a role of secreted TRAIL for induction of a death signaling cascade in non-targeted NSC. Subsequently, TRAIL production through elimination of bystander TRAIL-R-positive NSC might substantially restrict a final yield of differentiating young neurons. Radiation-induced TRAIL-mediated apoptosis could be partially suppressed by anti-TRAIL antibody added to the cell media. Interestingly, direct gamma-irradiation of SKN-SH human neuroblastoma cells using clinical doses (2–5 Gy) resulted in low levels of apoptosis in cancer cells that was accompanied however by induction of a strong bystander response in non-targeted NSC. Numerous protective mechanisms were involved in the maintenance of radioresistance of neuroblastoma cells, including constitutive PI3K-AKT over-activation and endogenous synthesis of TGF?1. Specific blockage of these survival pathways was accompanied by a dramatic increase in radiosensitivity of neuroblastoma cells. Intercellular communication between cancer cells and NSC could potentially be involved in amplification of cancer pathology in the brain. PMID:24158598

  20. Silymarin Protects Epidermal Keratinocytes from Ultraviolet Radiation-Induced Apoptosis and DNA Damage by Nucleotide Excision Repair Mechanism

    PubMed Central

    Katiyar, Santosh K.; Mantena, Sudheer K.; Meeran, Syed M.

    2011-01-01

    Solar ultraviolet (UV) radiation is a well recognized epidemiologic risk factor for melanoma and non-melanoma skin cancers. This observation has been linked to the accumulation of UVB radiation-induced DNA lesions in cells, and that finally lead to the development of skin cancers. Earlier, we have shown that topical treatment of skin with silymarin, a plant flavanoid from milk thistle (Silybum marianum), inhibits photocarcinogenesis in mice; however it is less understood whether chemopreventive effect of silymarin is mediated through the repair of DNA lesions in skin cells and that protect the cells from apoptosis. Here, we show that treatment of normal human epidermal keratinocytes (NHEK) with silymarin blocks UVB-induced apoptosis of NHEK in vitro. Silymarin reduces the amount of UVB radiation-induced DNA damage as demonstrated by reduced amounts of cyclobutane pyrimidine dimers (CPDs) and as measured by comet assay, and that ultimately may lead to reduced apoptosis of NHEK. The reduction of UV radiation-induced DNA damage by silymarin appears to be related with induction of nucleotide excision repair (NER) genes, because UV radiation-induced apoptosis was not blocked by silymarin in NER-deficient human fibroblasts. Cytostaining and dot-blot analysis revealed that silymarin repaired UV-induced CPDs in NER-proficient fibroblasts from a healthy individual but did not repair UV-induced CPD-positive cells in NER-deficient fibroblasts from patients suffering from xeroderma pigmentosum complementation-A disease. Similarly, immunohistochemical analysis revealed that silymarin did not reduce the number of UVB-induced sunburn/apoptotic cells in the skin of NER-deficient mice, but reduced the number of sunburn cells in their wild-type counterparts. Together, these results suggest that silymarin exert the capacity to reduce UV radiation-induced DNA damage and, thus, prevent the harmful effects of UV radiation on the genomic stability of epidermal cells. PMID:21731736

  1. Radiation-induced refraction artifacts in the optical CT readout of polymer gel dosimeters

    SciTech Connect

    Campbell, Warren G.; Jirasek, Andrew, E-mail: jirasek@uvic.ca [Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8P 5C2 (Canada); Wells, Derek M. [British Columbia Cancer Agency, Vancouver Island Centre, Victoria, British Columbia V8R 6V5 (Canada)

    2014-11-01

    Purpose: The objective of this work is to demonstrate imaging artifacts that can occur during the optical computed tomography (CT) scanning of polymer gel dosimeters due to radiation-induced refractive index (RI) changes in polyacrylamide gels. Methods: A 1 L cylindrical polyacrylamide gel dosimeter was irradiated with 3 × 3 cm{sup 2} square beams of 6 MV photons. A prototype fan-beam optical CT scanner was used to image the dosimeter. Investigative optical CT scans were performed to examine two types of rayline bending: (i) bending within the plane of the fan-beam and (ii) bending out the plane of the fan-beam. To address structured errors, an iterative Savitzky–Golay (ISG) filtering routine was designed to filter 2D projections in sinogram space. For comparison, 2D projections were alternatively filtered using an adaptive-mean (AM) filter. Results: In-plane rayline bending was most notably observed in optical CT projections where rays of the fan-beam confronted a sustained dose gradient that was perpendicular to their trajectory but within the fan-beam plane. These errors caused distinct streaking artifacts in image reconstructions due to the refraction of higher intensity rays toward more opaque regions of the dosimeter. Out-of-plane rayline bending was observed in slices of the dosimeter that featured dose gradients perpendicular to the plane of the fan-beam. These errors caused widespread, severe overestimations of dose in image reconstructions due to the higher-than-actual opacity that is perceived by the scanner when light is bent off of the detector array. The ISG filtering routine outperformed AM filtering for both in-plane and out-of-plane rayline errors caused by radiation-induced RI changes. For in-plane rayline errors, streaks in an irradiated region (>7 Gy) were as high as 49% for unfiltered data, 14% for AM, and 6% for ISG. For out-of-plane rayline errors, overestimations of dose in a low-dose region (?50 cGy) were as high as 13 Gy for unfiltered data, 10 Gy for AM, and 3.1 Gy for ISG. The ISG routine also addressed unrelated artifacts that previously needed to be manually removed in sinogram space. However, the ISG routine blurred reconstructions, causing losses in spatial resolution of ?5 mm in the plane of the fan-beam and ?8 mm perpendicular to the fan-beam. Conclusions: This paper reveals a new category of imaging artifacts that can affect the optical CT readout of polyacrylamide gel dosimeters. Investigative scans show that radiation-induced RI changes can cause significant rayline errors when rays confront a prolonged dose gradient that runs perpendicular to their trajectory. In fan-beam optical CT, these errors manifested in two ways: (1) distinct streaking artifacts caused by in-plane rayline bending and (2) severe overestimations of opacity caused by rays bending out of the fan-beam plane and missing the detector array. Although the ISG filtering routine mitigated these errors better than an adaptive-mean filtering routine, it caused unacceptable losses in spatial resolution.

  2. Radiation-Induced Leukemia at Doses Relevant to Radiation Therapy: Modeling Mechanisms and Estimating Risks

    NASA Technical Reports Server (NTRS)

    Shuryak, Igor; Sachs, Rainer K.; Hlatky, Lynn; Mark P. Little; Hahnfeldt, Philip; Brenner, David J.

    2006-01-01

    Because many cancer patients are diagnosed earlier and live longer than in the past, second cancers induced by radiation therapy have become a clinically significant issue. An earlier biologically based model that was designed to estimate risks of high-dose radiation induced solid cancers included initiation of stem cells to a premalignant state, inactivation of stem cells at high radiation doses, and proliferation of stem cells during cellular repopulation after inactivation. This earlier model predicted the risks of solid tumors induced by radiation therapy but overestimated the corresponding leukemia risks. Methods: To extend the model to radiation-induced leukemias, we analyzed in addition to cellular initiation, inactivation, and proliferation a repopulation mechanism specific to the hematopoietic system: long-range migration through the blood stream of hematopoietic stem cells (HSCs) from distant locations. Parameters for the model were derived from HSC biologic data in the literature and from leukemia risks among atomic bomb survivors v^ ho were subjected to much lower radiation doses. Results: Proliferating HSCs that migrate from sites distant from the high-dose region include few preleukemic HSCs, thus decreasing the high-dose leukemia risk. The extended model for leukemia provides risk estimates that are consistent with epidemiologic data for leukemia risk associated with radiation therapy over a wide dose range. For example, when applied to an earlier case-control study of 110000 women undergoing radiotherapy for uterine cancer, the model predicted an excess relative risk (ERR) of 1.9 for leukemia among women who received a large inhomogeneous fractionated external beam dose to the bone marrow (mean = 14.9 Gy), consistent with the measured ERR (2.0, 95% confidence interval [CI] = 0.2 to 6.4; from 3.6 cases expected and 11 cases observed). As a corresponding example for brachytherapy, the predicted ERR of 0.80 among women who received an inhomogeneous low-dose-rate dose to the bone marrow (mean = 2.5 Gy) was consistent with the measured ERR (0.62, 95% Cl =-0.2 to 1.9). Conclusions: An extended, biologically based model for leukemia that includes HSC initiation, inactivation, proliferation, and, uniquely for leukemia, long-range HSC migration predicts, %Kith reasonable accuracy, risks for radiationinduced leukemia associated with exposure to therapeutic doses of radiation.

  3. Radiation-Induced Alterations of Osteogenic and Chondrogenic Differentiation of Human Mesenchymal Stem Cells

    PubMed Central

    Cruet-Hennequart, Séverine; Drougard, Carole; Shaw, Georgina; Legendre, Florence; Demoor, Magali; Barry, Frank; Lefaix, Jean-Louis; Galéra, Philippe

    2015-01-01

    While human mesenchymal stem cells (hMSCs), either in the bone marrow or in tumour microenvironment could be targeted by radiotherapy, their response is poorly understood. The oxic effects on radiosensitivity, cell cycle progression are largely unknown, and the radiation effects on hMSCs differentiation capacities remained unexplored. Here we analysed hMSCs viability and cell cycle progression in 21% O2 and 3% O2 conditions after medical X-rays irradiation. Differentiation towards osteogenesis and chondrogenesis after irradiation was evaluated through an analysis of differentiation specific genes. Finally, a 3D culture model in hypoxia was used to evaluate chondrogenesis in conditions mimicking the natural hMSCs microenvironment. The hMSCs radiosensitivity was not affected by O2 tension. A decreased number of cells in S phase and an increase in G2/M were observed in both O2 tensions after 16 hours but hMSCs released from the G2/M arrest and proliferated at day 7. Osteogenesis was increased after irradiation with an enhancement of mRNA expression of specific osteogenic genes (alkaline phosphatase, osteopontin). Osteoblastic differentiation was altered since matrix deposition was impaired with a decreased expression of collagen I, probably through an increase of its degradation by MMP-3. After induction in monolayers, chondrogenesis was altered after irradiation with an increase in COL1A1 and a decrease in both SOX9 and ACAN mRNA expression. After induction in a 3D culture in hypoxia, chondrogenesis was altered after irradiation with a decrease in COL2A1, ACAN and SOX9 mRNA amounts associated with a RUNX2 increase. Together with collagens I and II proteins decrease, associated to a MMP-13 expression increase, these data show a radiation-induced impairment of chondrogenesis. Finally, a radiation-induced impairment of both osteogenesis and chondrogenesis was characterised by a matrix composition alteration, through inhibition of synthesis and/or increased degradation. Alteration of osteogenesis and chondrogenesis in hMSCs could potentially explain bone/joints defects observed after radiotherapy. PMID:25837977

  4. Radiation-induced alterations of osteogenic and chondrogenic differentiation of human mesenchymal stem cells.

    PubMed

    Cruet-Hennequart, Séverine; Drougard, Carole; Shaw, Georgina; Legendre, Florence; Demoor, Magali; Barry, Frank; Lefaix, Jean-Louis; Galéra, Philippe

    2015-01-01

    While human mesenchymal stem cells (hMSCs), either in the bone marrow or in tumour microenvironment could be targeted by radiotherapy, their response is poorly understood. The oxic effects on radiosensitivity, cell cycle progression are largely unknown, and the radiation effects on hMSCs differentiation capacities remained unexplored. Here we analysed hMSCs viability and cell cycle progression in 21% O2 and 3% O2 conditions after medical X-rays irradiation. Differentiation towards osteogenesis and chondrogenesis after irradiation was evaluated through an analysis of differentiation specific genes. Finally, a 3D culture model in hypoxia was used to evaluate chondrogenesis in conditions mimicking the natural hMSCs microenvironment. The hMSCs radiosensitivity was not affected by O2 tension. A decreased number of cells in S phase and an increase in G2/M were observed in both O2 tensions after 16 hours but hMSCs released from the G2/M arrest and proliferated at day 7. Osteogenesis was increased after irradiation with an enhancement of mRNA expression of specific osteogenic genes (alkaline phosphatase, osteopontin). Osteoblastic differentiation was altered since matrix deposition was impaired with a decreased expression of collagen I, probably through an increase of its degradation by MMP-3. After induction in monolayers, chondrogenesis was altered after irradiation with an increase in COL1A1 and a decrease in both SOX9 and ACAN mRNA expression. After induction in a 3D culture in hypoxia, chondrogenesis was altered after irradiation with a decrease in COL2A1, ACAN and SOX9 mRNA amounts associated with a RUNX2 increase. Together with collagens I and II proteins decrease, associated to a MMP-13 expression increase, these data show a radiation-induced impairment of chondrogenesis. Finally, a radiation-induced impairment of both osteogenesis and chondrogenesis was characterised by a matrix composition alteration, through inhibition of synthesis and/or increased degradation. Alteration of osteogenesis and chondrogenesis in hMSCs could potentially explain bone/joints defects observed after radiotherapy. PMID:25837977

  5. On the morphology of the brachial plexus of the platypus (Ornithorhynchus anatinus) and the echidna (Tachyglossus aculeatus)

    PubMed Central

    KOIZUMI, MASAHIRO; SAKAI, TATSUO

    1997-01-01

    Four forelimbs of 3 platypuses and 3 forelimbs of 2 echidnas were examined to study the precise form of the brachial plexus and to clarify the structural characteristics of the brachial plexus in phylogeny. The spinal components contributing to the plexus (C4–T2) and the formation patterns of the 3 trunks of the plexus were the same as those generally observed in mammals. In the cranial half of the brachial plexus from C4, 5 and 6 in monotremes, division into the ventral bundle (lateral cord) and dorsal bundle (axillary nerve) is clear, as in other mammals. However, for monotremes, in the caudal half of the plexus from C7 and T1 (+T2) and the nerves arising from the caudal plexus there is no definite division into the ventral and dorsal bundles, which distribute to the flexor and extensor parts of the forelimbs, respectively. The lower trunk of the monotreme brachial plexus forms a cord which contains both ventral and dorsal components. This characteristic diverges from the generally accepted idea that the tetrapod limb plexus is divided clearly into 2 layers: a dorsal layer for extensors and a ventral layer for flexors of the limb. Considering the incomplete dorsoventral division of forelimb nerves in some reptiles and urodeles, the caudal half of the monotreme brachial plexus has characteristics in common with those of lower tetrapods. PMID:9147230

  6. The Effect of Motor Activity on the Onset and Progression of Brachial Plexus Block with Bupivacaine: A Randomized Prospective Study in Patients Undergoing Arthroscopic Shoulder Surgery

    Microsoft Academic Search

    Kenneth E. Langen; Kenneth D. Candido; Michael King; Guido Marra; Alon P. Winnie

    2008-01-01

    BACKGROUND: A decreased latency of onset of neural blockade has been noted when muscular exercise of the hand was performed after supraclavicular brachial plexus block using lidocaine. In this observational study, we examined the effect of repetitive muscle contraction of the hand on the speed of onset of interscalene brachial plexus block (ISB) using bupivacaine. METHODS: Forty patients were enrolled,

  7. Radiation induced conductivity of polycarbonate doped with different concentrations of aromatic hydrazone DEH

    NASA Astrophysics Data System (ADS)

    Vladimir, Saenko; Novikov, Lev; Tyutnev, Andrey

    Radiation induced conductivity (RIC) of polymers widely used on present-day spacecraft plays is an important factor affecting their charging by the hot plasma of the Earth’s magnetosphere. As a result, researchers pay special attention to laboratory investigations of RIC in polymers excited by 10 -100 keV electrons prevailing in the hot magnetospheric plasma, including auroral radiation. Due to fluctuating fluxes of plasma electrons and especially of auroral electrons, it is very important to know how RIC depends on time. In our report we present RIC results observed in polycarbonate (PC) molecularly doped with aromatic hydrazone DEH (10 to 30 mas. percent) under continuous irradiation with 50 keV electrons. It has been found that RIC behavior in this material differs markedly from what we observed earlier in most of the polymers. After beginning of the stepwise irradiation, the RIC of PC+DEH rises fast to the quasistationary level but unlike common polymers, does not fall by an order of magnitude, instead it starts to increase further thus causing the accumulating space charge to decrease. This fact combined with the confirmed high radiation and temperature tolerance allows us to recommend this material for application on the spacecraft outer surface and specifically, as a thermal blanket.

  8. Regulation of homologous recombinational repair by lamin B1 in radiation-induced DNA damage.

    PubMed

    Liu, Ning-Ang; Sun, Jiying; Kono, Kazuteru; Horikoshi, Yasunori; Ikura, Tsuyoshi; Tong, Xing; Haraguchi, Tokuko; Tashiro, Satoshi

    2015-06-01

    DNA double-strand breaks (DSBs) are the major lethal lesion induced by ionizing radiation (IR). RAD51-dependent homologous recombination (HR) is one of the most important pathways in DSB repair and genome integrity maintenance. However, the mechanism of HR regulation by RAD51 remains unclear. To understand the mechanism of RAD51-dependent HR, we searched for interacting partners of RAD51 by a proteomics analysis and identified lamin B1 in human cells. Lamins are nuclear lamina proteins that play important roles in the structural organization of the nucleus and the regulation of chromosome functions. Immunoblotting analyses revealed that siRNA-mediated lamin B1 depletion repressed the DNA damage-dependent increase of RAD51 after IR. The repression was abolished by the proteasome inhibitor MG132, suggesting that lamin B1 stabilizes RAD51 by preventing proteasome-mediated degradation in cells with IR-induced DNA damage. We also showed that lamin B1 depletion repressed RAD51 focus formation and decreased the survival rates after IR. On the basis of these results, we propose that lamin B1 promotes DSB repair and cell survival by maintaining the RAD51 protein levels for HR upon DSB induction after IR.-Liu, N.-A., Sun, J., Kono, K., Horikoshi, Y., Ikura, T., Tong, X., Haraguchi, T., Tashiro, S. Regulation of homologous recombinational repair by lamin B1 in radiation-induced DNA damage. PMID:25733566

  9. Radiation-Induced Changes in Serum Lipidome of Head and Neck Cancer Patients

    PubMed Central

    Jelonek, Karol; Pietrowska, Monika; Ros, Malgorzata; Zagdanski, Adam; Suchwalko, Agnieszka; Polanska, Joanna; Marczyk, Michal; Rutkowski, Tomasz; Skladowski, Krzysztof; Clench, Malcolm R.; Widlak, Piotr

    2014-01-01

    Cancer radiotherapy (RT) induces response of the whole patient’s body that could be detected at the blood level. We aimed to identify changes induced in serum lipidome during RT and characterize their association with doses and volumes of irradiated tissue. Sixty-six patients treated with conformal RT because of head and neck cancer were enrolled in the study. Blood samples were collected before, during and about one month after the end of RT. Lipid extracts were analyzed using MALDI-oa-ToF mass spectrometry in positive ionization mode. The major changes were observed when pre-treatment and within-treatment samples were compared. Levels of several identified phosphatidylcholines, including (PC34), (PC36) and (PC38) variants, and lysophosphatidylcholines, including (LPC16) and (LPC18) variants, were first significantly decreased and then increased in post-treatment samples. Intensities of changes were correlated with doses of radiation received by patients. Of note, such correlations were more frequent when low-to-medium doses of radiation delivered during conformal RT to large volumes of normal tissues were analyzed. Additionally, some radiation-induced changes in serum lipidome were associated with toxicity of the treatment. Obtained results indicated the involvement of choline-related signaling and potential biological importance of exposure to clinically low/medium doses of radiation in patient’s body response to radiation. PMID:24747595

  10. Activation of myc and ras oncogenes in radiation-induced rat skin carcinogenesis

    SciTech Connect

    Sawey, M.J.

    1987-01-01

    The radiation-induced rat skin carcinogenesis model system was used to examine oncogene activation from both the ras and myc complementation groups. Six of twelve tumors tested were positive in the NIH3T3 transfection assay and the rat K-ras oncogene was found to be activated in representative transformed foci. Southern analysis of the tumor DNAs revealed evidence for c-myc gene amplification and extensive restriction fragment polymorphisms in 9 of the 12 tumors. The appearance of several new c-myc restriction fragments was seen after digestion with Eco RI, Hind III, and Bam HI, and may represent gene rearrangement or activation of a c-myc homologous gene. Rehybridization of the filters with N-myc, K-ras, and H-ras probes failed to detect any differences compared to normal rat DNA. In addition, when probes from other oncogenes known to be activated by gene amplification and translocation mechanisms, were hybridized to these RAD tumor DNAs, no differences in either band intensity nor restriction fragment pattern were found.

  11. Amplification and rearrangement of c-myc in radiation-induced murine osteosarcomas

    SciTech Connect

    Sturm, S.A.; Strauss, P.G.; Adolph, S.; Hameister, H.; Erfle, V. (GSF-Abteilung fuer Molekulare Zellpathologie, Neuherberg (Germany, F.R.))

    1990-07-01

    Fifty-one radiation-induced murine osteosarcomas were investigated for alterations in c-myc gene structure and c-myc expression. Amplification of c-myc was found in 30% of BALB/c tumors and 13% of NMRI tumors. A region of common proviral integration, Mlvi-1, localized on the same region on chromosome 15, was amplified concomitantly. Multiple copies of both loci were localized on double minutes. Three of the tumors with c-myc amplification also showed rearrangements of the c-myc gene region. One of these rearrangements included the 5' and 3'-flanking sequences and the noncoding part of the third exon. Repetitive sequences were found in the 5' region of the c-myc gene, and the 3' flanking region was substituted by sequences normally present in a more distant part of chromosome 15. Increased levels of c-myc transcripts of apparently normal size were found in tumors carrying amplified c-myc sequences. Abnormally high expression of c-myc in some tumors was correlated with an early stage of osteogenic differentiation, suggesting the involvement of the c-myc gene in the control of the osteogenic differentiation of transformed cells.

  12. Amplification of oncogenes in early-stage, radiation-induced rat skin tumours

    SciTech Connect

    Ashkenazi-Kimmel, T.

    1989-10-01

    The effect of gene amplification on tumour size and growth was investigated in 39 samples collected from 23 radiation-induced rat skin tumours. The relationships of both the time from irradiation and the time from first appearance of the tumour to gene amplification were also examined. DNA from each tumour sample was extracted and probed for abl, fos, c-myc, N-myc, H-ras, and K-ras, and amplification of all but N-myc was detected. A single amplified gene was observed in 8 of 39 samples; multiple amplified genes were found in an additional 7. The amplification of c-myc, H-ras, or K-ras was found to be associated with increase in tumour size. c-myc amplification was also associated with an increase in growth rate. Amplification of c-myc was found to occur as a late-stage event in these tumours. The results suggest that both myc and ras genes play unique roles in the growth and development of radiation tumours, and they provide new information on the temporal aspects of c-myc activation. 77 refs., 26 figs., 11 tabs.

  13. Modeling radiation induced segregation in Ni-Cr model alloys from first principles

    NASA Astrophysics Data System (ADS)

    Barnard, L.; Tucker, J. D.; Choudhury, S.; Allen, T. R.; Morgan, D.

    2012-06-01

    In this paper, a rate theory model is employed to study radiation induced segregation (RIS) in Ni-Cr model alloys. In contrast with similar previous models, model parameters have been obtained from first principles via density functional theory (DFT) calculation. Qualitative model behavior is compared and contrasted with the physical mechanisms that underlie conventional RIS models, and the effects of Cr-Cr interstitial trapping and defect sink bias are investigated. It is concluded that: (1) the parameters required in this RIS model are too sensitive to be rigorously determined by present DFT approaches alone, and fitting to experimental RIS data is necessary to produce an accurate model. (2) In contrast with the emphasis of previous RIS models, the best fit DFT-based RIS model suggests that under radiation, the interstitial flux should drive Cr strongly toward enrichment near defect sinks, while the vacancy flux should drive Cr strongly toward depletion, and that the vacancy effect should be slightly stronger resulting in moderate Cr depletion. (3) The effects on RIS of Cr-Cr interstitial trapping and biased defect sinks are relatively small compared with the effects associated with variations in the species dependent diffusivities.

  14. A prediction study on radiation-induced second malignancies for IMRT treatment delivery.

    PubMed

    Stathakis, Sotirios; Roland, Teboh; Papanikolaou, Niko; Li, Jinseng; Ma, Charlie

    2009-04-01

    Low-level peripheral organ dose and its effect on second malignancies for patients undergoing radiation therapy have been reported in the literature. However, a comprehensive database outlining the treatment modalities, the tumor location, and a quantification of the overall relative risk of second malignancies is rather limited. In this work, we quantify the relative risks or percent likelihood of second malignancies for patients undergoing IMRT and conventional radiotherapy for four different tumor sites: breast, head and neck, lung, and prostate. We utilize Monte Carlo methods based on actual patient plans to compute the whole body effective dose equivalent for each plan and then deduce the percent likelihood of the occurrence of second malignancy. Based on an evaluation of over 30 actual patient plans and Monte Carlo simulations using 6, 10, and 18MV photon beam energies, we observed that the IMRT patients treated for head and neck cancer showed a 40% increase in risk for developing a second malignancy compared to those treated with conventional radiotherapy. The increase in risk for prostrate patients was 30% while the IMRT lung patients gave the highest relative risk almost tripling that observed in their conventionally treated counterparts. There was negligible difference in risk between breast patients undergoing IMRT treatment versus conventional therapy. The overall relative risk of radiation induced malignancy observed was below 6% in all treatment plans considered. PMID:19334795

  15. Dislocation dynamics simulations of interactions between gliding dislocations and radiation induced prismatic loops in zirconium

    NASA Astrophysics Data System (ADS)

    Drouet, Julie; Dupuy, Laurent; Onimus, Fabien; Mompiou, Frédéric; Perusin, Simon; Ambard, Antoine

    2014-06-01

    The mechanical behavior of Pressurized Water Reactor fuel cladding tubes made of zirconium alloys is strongly affected by neutron irradiation due to the high density of radiation induced dislocation loops. In order to investigate the interaction mechanisms between gliding dislocations and loops in zirconium, a new nodal dislocation dynamics code, adapted to Hexagonal Close Packed metals, has been used. Various configurations have been systematically computed considering different glide planes, basal or prismatic, and different characters, edge or screw, for gliding dislocations with -type Burgers vectors. Simulations show various interaction mechanisms such as (i) absorption of a loop on an edge dislocation leading to the formation of a double super-jog, (ii) creation of a helical turn, on a screw dislocation, that acts as a strong pinning point or (iii) sweeping of a loop by a gliding dislocation. It is shown that the clearing of loops is more favorable when the dislocation glides in the basal plane than in the prismatic plane explaining the easy dislocation channeling in the basal plane observed after neutron irradiation by transmission electron microscopy.

  16. Simulating and Detecting Radiation-Induced Errors for Onboard Machine Learning

    NASA Technical Reports Server (NTRS)

    Wagstaff, Kiri L.; Bornstein, Benjamin; Granat, Robert; Tang, Benyang; Turmon, Michael

    2009-01-01

    Spacecraft processors and memory are subjected to high radiation doses and therefore employ radiation-hardened components. However, these components are orders of magnitude more expensive than typical desktop components, and they lag years behind in terms of speed and size. We have integrated algorithm-based fault tolerance (ABFT) methods into onboard data analysis algorithms to detect radiation-induced errors, which ultimately may permit the use of spacecraft memory that need not be fully hardened, reducing cost and increasing capability at the same time. We have also developed a lightweight software radiation simulator, BITFLIPS, that permits evaluation of error detection strategies in a controlled fashion, including the specification of the radiation rate and selective exposure of individual data structures. Using BITFLIPS, we evaluated our error detection methods when using a support vector machine to analyze data collected by the Mars Odyssey spacecraft. We found ABFT error detection for matrix multiplication is very successful, while error detection for Gaussian kernel computation still has room for improvement.

  17. Prevention of Spontaneous and Radiation-Induced Tumors in Rats by Reduction of Food Intake

    NASA Astrophysics Data System (ADS)

    Gross, Ludwik; Dreyfuss, Yolande

    1990-09-01

    In our previous studies carried out on inbred Sprague-Dawley rats, we reported a striking increase in the incidence of tumors following total-body ?-irradiation [150 rads (1.5 Gy) five times at weekly intervals]. Subsequently, we observed that two or three irradiations, and to a lesser extent even a single irradiation, were sufficient to induce an impressive increase in the incidence of tumors, particularly in females. A significant reduction of the incidence of radiation-induced tumors resulted when the rats were placed on calorically restricted diet. In experiments reported here, we increased slightly the amount of food given to animals on restricted diet. In the new study, among 102 irradiated females on full diet, 91 (89%) developed tumors, as compared with 29 out of 128 female rats (23%) also irradiated but maintained on restricted diet and 43 out of 89 (48%) untreated control females. None of 77 nonirradiated females on restricted diet developed tumors. Among 65 irradiated male rats, 29 (45%) developed tumors, as compared with 5 out of 74 (7%) rats also irradiated but maintained on restricted diet. Of the 49 males in the nonirradiated groups, 2 (4%) developed tumors. There was a significant weight reduction in both females and males maintained on restricted diet; animals on restricted diet lived longer than those on full diet.

  18. A role for topoisomerase II? in the formation of radiation-induced chromatid breaks

    PubMed Central

    Terry, S Y A; Riches, A C; Bryant, P E

    2008-01-01

    Chromatid breaks in cells exposed to low dose irradiation are thought to be initiated by DNA double-strand breaks (DSB), and the frequency of chromatid breaks has been shown to increase in DSB rejoining deficient cells. However, the underlying causes of the wide variation in frequencies of G2 chromatid breaks (or chromatid ‘radiosensitivity') in irradiated T-lymphocytes from different normal individuals and cancer cases are as yet unclear. Here we report evidence that topoisomerase II? expression level is a factor determining chromatid radiosensitivity. We have exposed the promyelocytic leukaemic cell line (HL60) and two derived variant cell lines (MX1 and MX2) that have acquired resistance to mitoxantrone and low expression of topoisomerase II ?, to low doses of ?-radiation and scored the induced chromatid breaks. Chromatid break frequencies were found to be significantly lower in the variant cell lines, compared with their parental HL60 cell line. Rejoining of DSB in the variant cell lines was similar to that in the parental HL60 strain. Our results indicate the indirect involvement of topoisomerase II? in the formation of radiation-induced chromatid breaks from DSB, and suggest topoisomerase II? as a possible factor in the inter-individual variation in chromatid radiosensitivity. PMID:18665175

  19. Quercetin protects radiation-induced DNA damage and apoptosis in kidney and bladder tissues of rats.

    PubMed

    Özyurt, H; Çevik, Ö; Özgen, Z; Özden, A S; Çad?rc?, S; Elmas, M A; Ercan, F; Gören, M Z; ?ener, G

    2014-10-01

    Ionizing radiation (IR) can induce cell damage and cell death through the reactive oxygen species generated by radiolytic hydrolysis. The present study was aimed to determine the possible protective effects of quercetin, a well-known antioxidant agent, against IR-induced bladder and kidney damage in rats. Sprague-Dawley rats were exposed to 8-Gy whole-abdominal IR and given either vehicle or quercetin (20 mg/kg, ip). Rats were decapitated at either 36 h or 10 days following IR, where quercetin or vehicle injections were repeated once daily, and kidney and bladder samples were obtained for the determination of myeloperoxidase and caspase-3 activities, an index of tissue neutrophil infiltration and apoptosis, respectively. Radiation-induced inflammation was evaluated through tissue cytokine, TNF-? levels. In order to examine oxidative DNA damage, tissue 8-hydroxydeoxyguanosine (8-OHdG) levels were measured. All tissues were also examined microscopically. In the saline-treated irradiation groups, myeloperoxidase and caspase-3 activities, 8-OHdG and TNF-? levels were found to be increased in both tissues (p < 0.05). In the quercetin-treated-IR groups, all these oxidant responses were prevented significantly (p < 0.05). The present data demonstrate that quercetin, through its free radical scavenging and antioxidant properties, attenuates irradiation-induced oxidative organ injury, suggesting that quercetin may have a potential benefit in radiotherapy by minimizing the adverse effects and will improve patient care. PMID:25039564

  20. Radio frequency radiation-induced hyperthermia using Si nanoparticle-based sensitizers for mild cancer therapy

    NASA Astrophysics Data System (ADS)

    Tamarov, Konstantin P.; Osminkina, Liubov A.; Zinovyev, Sergey V.; Maximova, Ksenia A.; Kargina, Julia V.; Gongalsky, Maxim B.; Ryabchikov, Yury; Al-Kattan, Ahmed; Sviridov, Andrey P.; Sentis, Marc; Ivanov, Andrey V.; Nikiforov, Vladimir N.; Kabashin, Andrei V.; Timoshenko, Victor Yu

    2014-11-01

    Offering mild, non-invasive and deep cancer therapy modality, radio frequency (RF) radiation-induced hyperthermia lacks for efficient biodegradable RF sensitizers to selectively target cancer cells and thus avoid side effects. Here, we assess crystalline silicon (Si) based nanomaterials as sensitizers for the RF-induced therapy. Using nanoparticles produced by mechanical grinding of porous silicon and ultraclean laser-ablative synthesis, we report efficient RF-induced heating of aqueous suspensions of the nanoparticles to temperatures above 45-50°C under relatively low nanoparticle concentrations (<1 mg/mL) and RF radiation intensities (1-5 W/cm2). For both types of nanoparticles the heating rate was linearly dependent on nanoparticle concentration, while laser-ablated nanoparticles demonstrated a remarkably higher heating rate than porous silicon-based ones for the whole range of the used concentrations from 0.01 to 0.4 mg/mL. The observed effect is explained by the Joule heating due to the generation of electrical currents at the nanoparticle/water interface. Profiting from the nanoparticle-based hyperthermia, we demonstrate an efficient treatment of Lewis lung carcinoma in vivo. Combined with the possibility of involvement of parallel imaging and treatment channels based on unique optical properties of Si-based nanomaterials, the proposed method promises a new landmark in the development of new modalities for mild cancer therapy.

  1. Bystander effects may modulate ultraviolet A and B radiation-induced delayed mutagenesis.

    PubMed

    Dahle, Jostein; Kaalhus, Olav; Stokke, Trond; Kvam, Egil

    2005-03-01

    Ultraviolet irradiation of cells can induce a state of genomic instability that can persist for several cell generations after irradiation. However, questions regarding the time course of formation, relative abundance for different types of ultraviolet radiation, and mechanism of induction of delayed mutations remain to be answered. In this paper, we have tried to address these questions using the hypoxanthine phosphoribosyl transferase (HPRT) mutation assay in V79 Chinese hamster cells irradiated with ultraviolet A or B radiation. Delayed HPRT(-) mutations, which are indications of genomic instability, were detected by incubating the cells in medium containing aminopterin, selectively killing HPRT(-) mutants, and then treating the cells with medium containing 6-thioguanine, which selectively killed non-mutant cells. Remarkably, the delayed mutation frequencies found here were much higher than reported previously using a cloning method. Cloning of cells immediately after irradiation prevents contact between individual cell clones. In contrast, with the present method, the cells are in contact and are mixed several times during the experiment. Thus the higher delayed mutation frequency measured by the present method may be explained by a bystander effect. This hypothesis is supported by an experiment with an inhibitor of gap junctional intercellular communication, which reduced the delayed mutation frequency. In conclusion, the results suggest that a bystander effect is involved in ultraviolet-radiation-induced genomic instability and that it may be mediated in part by gap junctional intercellular communication. PMID:15733036

  2. Mechanisms of radiation-induced emesis. Technical report, 10 February 1984-1 March 1987

    SciTech Connect

    Carpenter, D.O.

    1988-08-31

    Nausea and vomiting following radiation exposure are factors which may seriously limit the ability of humans to perform in military situations and are side effects of such significance in radiation therapy that they may limit the patient's acceptance of treatment regimes (1). At doses of 1.5 Gy approximately 50% of humans experience nausea and vomiting, while at 3.0 Gy the figure approaches 100%. While irradiation almost anywhere may produce symptoms, the upper abdomen is the most-sensitive site. Dogs, cats, and monkeys also vomit on exposure to ionizing radiation, although cats and monkeys are considerably more resistant than dogs and man. These studies were designed to attempt to determine the roles of the area postrema and the vagus in radiation-induced emesis by ablation and electrophysiological studies, and to test the effects of some drugs on the emetic response. In addition, the authorrecorded from neurons in the dog area postrema, applying substances which may be emetic, in an attempt to determine which transmitters, peptides and hormones might function as chemical mediators of emesis. Finally, he have tested the emetic effects of some of these substances given intravenously in awake dogs, with particular emphasis on study of the mechanism of action of emetic agents on the area postrema neurons.

  3. Identification of novel radiation-induced p53-dependent transcripts extensively regulated during mouse brain development

    PubMed Central

    Quintens, Roel; Verreet, Tine; Janssen, Ann; Neefs, Mieke; Leysen, Liselotte; Michaux, Arlette; Verslegers, Mieke; Samari, Nada; Pani, Giuseppe; Verheyde, Joris; Baatout, Sarah; Benotmane, Mohammed A.

    2015-01-01

    ABSTRACT Ionizing radiation is a potent activator of the tumor suppressor gene p53, which itself regulates the transcription of genes involved in canonical pathways such as the cell cycle, DNA repair and apoptosis as well as other biological processes like metabolism, autophagy, differentiation and development. In this study, we performed a meta-analysis on gene expression data from different in vivo and in vitro experiments to identify a signature of early radiation-responsive genes which were predicted to be predominantly regulated by p53. Moreover, we found that several genes expressed different transcript isoforms after irradiation in a p53-dependent manner. Among this gene signature, we identified novel p53 targets, some of which have not yet been functionally characterized. Surprisingly, in contrast to genes from the canonical p53-regulated pathways, our gene signature was found to be highly enriched during embryonic and post-natal brain development and during in vitro neuronal differentiation. Furthermore, we could show that for a number of genes, radiation-responsive transcript variants were upregulated during development and differentiation, while radiation non-responsive variants were not. This suggests that radiation exposure of the developing brain and immature cortical neurons results in the p53-mediated activation of a neuronal differentiation program. Overall, our results further increase the knowledge of the radiation-induced p53 network of the embryonic brain and provide more evidence concerning the importance of p53 and its transcriptional targets during mouse brain development. PMID:25681390

  4. A human esophageal epithelial cell model for study of radiation induced cancer and DNA repair

    NASA Astrophysics Data System (ADS)

    Huff, Janice; Patel, Zarana; Hada, Megumi; Cucinotta, Francis A.

    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. Development of squamous cell carcinoma of the esophagus is associated with radiation exposure, as revealed by the significant enhanced in incidence rates for this type of cancer in the survivors of the atomic bomb detonations in Japan. It is also associated with poor nutritional status and micronutrient deficiencies, which are also important issues for long duration spaceflight. The possible synergies between nutritional issues and radiation exposure are unknown. Here we present the results of 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 gamma-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.

  5. Dose dependence of radiation induced segregation in proton irradiated austenitic alloys

    SciTech Connect

    Busby, J.T.; Allen, T.R.; Carter, R.D.; Was, G.S. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences; Kenik, E.A. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1997-11-01

    The dose dependence of radiation-induced segregation (RIS) is investigated for proton irradiated ultra high-purity (UHP) 304L stainless steel and Fe-20Cr-24Ni. Grain boundary compositions were measured in samples irradiated with 3.2 MeV protons at 400 C to doses ranging from 0.1 to 3.0 dpa. RIS measurements were made using scanning transmission electron microscopy with energy dispersive x-ray spectroscopy (STEM/EDS) and compared to results from Auger electron spectroscopy (AES). Comparison of the dose dependence for HP-304L and Fe-20Cr-24Ni shows that RIS is alloy specific. The approach to steady-state Cr depletion was observed to be more rapid in the alloy with higher Ni content. Fe-20Cr-24Ni reaches a steady-state Cr depletion level by 0.5 dpa, and the amount of Cr depletion in HP-304L SS is still increasing between 1.0 and 3.0 dpa. RIS in the stainless steel alloys irradiated with 3.2 MeV protons is comparable to that in neutron irradiated steels or similar composition.

  6. The role of mitochondria in the radiation-induced bystander effect in human lymphoblastoid cells.

    PubMed

    Rajendran, Sountharia; Harrison, Scott H; Thomas, Robert A; Tucker, James D

    2011-02-01

    Cells without intact mitochondrial DNA have been shown to lack the bystander effect, which is an energy-dependent process. We hypothesized that cells harboring mutations in mitochondrial genes responsible for ATP synthesis would show a decreased bystander effect compared to normal cells. Radiation-induced bystander effects were analyzed in two normal and four mitochondrial mutant human lymphoblastoid cells. Medium from previously irradiated cells (conditioned medium) was transferred to unirradiated cells from the respective cell lines and evaluated for the bystander effect using the cytokinesis-block micronucleus assay. Unlike normal cells that were used as a control, mitochondrial mutant cells neither generated nor responded to the bystander signals. The bystander effect was inhibited in normal cells by adding the mitochondrial inhibitors rotenone and oligomycin to the culture medium. Time-controlled blocking of the bystander effect by inhibitors was found to occur either for prolonged exposure to the inhibitor prior to irradiation with an immediate and subsequent removal of the inhibitors or immediate post-application of the inhibitor. Adding the inhibitors just prior to irradiation and removing them immediately after irradiation was uneventful. Fully functional mitochondrial metabolic capability may therefore be essential for the bystander effect. PMID:21268709

  7. Epidermal growth factor receptor expression in radiation-induced dog lung tumors by immunocytochemical localization

    SciTech Connect

    Leung, F.L.; Park, J.F.; Dagle, G.E.

    1993-06-01

    In studies to determine the role of growth factors in radiation-induced lung cancer, epidermal growth factor (EGFR) expression was examined by immunocytochemistry in 51 lung tumors from beagle dogs exposed to inhaled plutonium; 21 of 51 (41%) tumors were positive for EGFR. The traction of tumors positive for EGFR and the histological type of EGFR-positive tumors in the plutonium-exposed dogs were not different from spontaneous dog lung tumors, In which 36% were positive for EGFR. EGFR involvement in Pu-induced lung tumors appeared to be similar to that in spontaneous lung tumors. However, EGFR-positive staining was observed in only 1 of 16 tumors at the three lowest Pu exposure levels, compared to 20 of 35 tumors staining positive at the two highest Pu exposure levels. The results in dogs were in good agreement with the expression of EGFR reported in human non-small cell carcinoma of the lung, suggesting that Pu-induced lung tumors in the dog may be a suitable animal model to investigate the role of EGFR expression in lung carcinogenesis. In humans, EGFR expression in lung tumors has been primarily related to histological tumor types. In individual dogs with multiple primary lung tumors, the tumors were either all EGFR positive or EGFR negative, suggesting that EGFR expression may be related to the response of the individual dog as well as to the histological type of tumor.

  8. Quantitative evaluation of radiation-induced changes in sperm morphology and chromatin distribution

    SciTech Connect

    Aubele, M.; Juetting, U.R.; Rodenacker, K.; Gais, P.; Burger, G.; Hacker-Klom, U. (Institut fuer Strahlenschutz, Neuherberg (Germany, F.R.))

    1990-01-01

    Sperm head cytometry provides a useful assay for the detection of radiation-induced damage in mouse germ cells. Exposure of the gonads to radiation is known to lead to an increase of diploid and higher polyploid sperm and of sperm with head shape abnormalities. In the pilot studies reported here quantitative analysis of the total DNA content, the morphology, and the chromatin distribution of mouse sperm was performed. The goal was to evaluate the discriminative power of features derived by high resolution image cytometry in distinguishing sperm of control and irradiated mice. Our results suggest that besides the induction of the above mentioned variations in DNA content and shape of sperm head, changes of the nonhomogeneous chromatin distribution within the sperm may also be used to quantify the radiation effect on sperm cells. Whereas the chromatin distribution features show larger variations for sperm 21 days after exposure (dpr), the shape parameters seem to be more important to discriminate sperm 35 dpr. This may be explained by differentiation processes, which take place in different stages during mouse spermatogenesis.

  9. Mechanism of radiation-induced bystander effect: Role of the cyclooxygenase-2 signaling pathway

    PubMed Central

    Zhou, Hongning; Ivanov, Vladimir N.; Gillespie, Joseph; Geard, Charles R.; Amundson, Sally A.; Brenner, David J.; Yu, Zengliang; Lieberman, Howard B.; Hei, Tom K.

    2005-01-01

    The radiation-induced bystander effect is defined as “the induction of biological effects in cells that are not directly traversed by a charged particle but are in close proximity to cells that are.” Although these bystander effects have been demonstrated with a variety of biological endpoints in both human and rodent cell lines (as well as in 3D tissue samples), the mechanism of the phenomenon is not known. Although gap junction communication and the presence of soluble mediator(s) are both known to play important roles in the bystander response, the precise signaling molecules have yet to be identified. By using the Columbia University charged particle beam in conjunction with a strip dish design, we show here that the cyclooxygenase-2 (COX-2, also known as prostaglandin endoperoxide synthase-2) signaling cascade plays an essential role in the bystander process. Treatment of bystander cells with NS-398, which suppresses COX-2 activity, significantly reduced the bystander effect. Because the critical event of the COX-2 signaling is the activation of the mitogen-activated protein kinase pathways, our finding that inhibition of the extracellular signal-related kinase phosphorylation suppressed bystander response further confirmed the important role of mitogen-activated protein kinase signaling cascade in the bystander process. These results provide evidence that the COX-2-related pathway, which is essential in mediating cellular inflammatory response, is the critical signaling link for the bystander phenomenon. PMID:16203985

  10. UV radiation-induced immunosuppression is greater in men and prevented by topical nicotinamide.

    PubMed

    Damian, Diona L; Patterson, Clare R S; Stapelberg, Michael; Park, Joohong; Barnetson, Ross St C; Halliday, Gary M

    2008-02-01

    UV radiation-induced immunosuppression augments cutaneous carcinogenesis. The incidence of skin cancer continues to increase despite increased use of sunscreens, which are less effective at preventing immunosuppression than sunburn. Using the Mantoux reaction as a model of skin immunity, we investigated the effects of solar-simulated (ss) UV and its component UVA and UVB wavebands and tested the ability of topical nicotinamide to protect from UV-induced immunosuppression. Healthy, Mantoux-positive volunteers were UV-irradiated on their backs, with 5% nicotinamide or vehicle applied to different sites in a randomized, double-blinded manner. Subsequent Mantoux testing at irradiated and adjacent unirradiated sites enabled measurement of UV-induced immunosuppression with and without nicotinamide. Suberythemal ssUV caused significant immunosuppression, although component UVB and UVA doses delivered independently did not. Men were immunosuppressed by ssUV doses three times lower than those required to immunosuppress women. This may be an important cause of the higher skin cancer incidence and mortality observed in men. Topical nicotinamide prevented immunosuppression, with gene chip microarrays suggesting that the mechanisms of protection may include alterations in complement, energy metabolism and apoptosis pathways. Nicotinamide is a safe and inexpensive compound that could be added to sunscreens or after-sun lotions to improve protection from immunosuppression. immunosuppression.JID JOURNAL CLUB ARTICLE: For questions, answers, and open discussion about this article, please go to http://network.nature.com/group/jidclub PMID:17882270

  11. Radiation Induced Bystander Effects in Mice Given Low Doses of Radiation in Vivo

    PubMed Central

    Singh, Harleen; Saroya, Rohin; Smith, Richard; Mantha, Rebecca; Guindon, Lynda; Mitchel, Ron E.J.; Seymour, Colin; Mothersill, Carmel

    2010-01-01

    The ‘bystander effect’ phenomenon has challenged the traditional framework for assessing radiation damage by showing radiation induced changes in cells which have not been directly targeted, but are neighbors to or receive medium from directly hit cells. Our group performed a range of single and serial low dose irradiations on two genetically distinct strains of mice. Bladder explants established from these mice were incubated in culture medium, which was used to measure death responses in a keratinocyte reporter system. The study revealed that the medium harvested from bladder tissues’ (ITCM) from acutely irradiated C57BL6 but not Balb/c mice, was able to induce clonogenic death. Administration of a priming dose(s) before a challenge dose to both C57BL6 and Balb/c mice stimulated reporter cell survival irrespective of the time interval between dose(s) delivery. When ITCM corresponding to both strains of mice was measured for its calcium mobilization inducing ability, results showed an elevation in intracellular calcium levels that was strain dependent. This indicates that genotype determined the type of bystander signal/response that was produced after exposure to low and acute doses of radiation. However, serial exposure conditions modified bystander signal production to induce similar effects that were characterized by excessive growth. PMID:21731538

  12. Tight-binding molecular dynamics simulations of radiation-induced C60 fragmentation

    NASA Astrophysics Data System (ADS)

    Beu, Titus A.; Horváth, Lóránd; Ghi?oiu, Ioan

    2009-02-01

    The radiation-induced fragmentation of the C60 fullerene was investigated by tight-binding molecular dynamics simulations based on the parametrization of Papaconstantopoulos [Tight-Binding Approach to Computational Materials Science, edited by P.E.A. Turchi, A. Gonis, and L. Colombo, M.R.S. Symposia Proceedings No. 491 (Materials Research Society, Pittsburgh, 1998), p. 221] and employing novel models for nonadiabatic excitation and charge redistribution. The resulted fragment size and fragment charge distributions, averaged over large ensembles of trajectories corresponding to total ionization states up to +24e and excitation energies up to 1000 eV, have been used to analyze the fragmentation statistics in terms of several derived quantities. For moderate excitation energies, the fragment size profiles reproduce the experimentally observed U shape and bimodal dependence. Even though for high excitation energies and high total charges, predominantly multifragmentation occurs, a genuine power-law dependence sets in only beyond 1000 eV. A well-defined phase-transition region is found in the total charge-excitation energy plane, which appears to be delimited by a roughly parabolic critical line. The overall average critical excitation energy estimated from the simulations amounts to 55 eV and agrees with the experimental findings.

  13. Genistein prevents ultraviolet B radiation-induced nitrosative skin injury and promotes cell proliferation.

    PubMed

    Terra, V A; Souza-Neto, F P; Frade, M A C; Ramalho, L N Z; Andrade, T A M; Pasta, A A C; Conchon, A C; Guedes, F A; Luiz, R C; Cecchini, R; Cecchini, A L

    2015-03-01

    Nitric oxide (NO) levels increase considerably after 24h of exposure of skin to ultraviolet B (UVB) radiation, which leads to nitrosative skin injury. In addition, increased NO levels after exposure to UVB radiation are associated with inhibition of cell proliferation. Compared to the UV-control group, UV-genistein at 10 mg/kg (UV-GEN10) group showed tissue protection, decreased lipid peroxide and nitrotyrosine formation, and low CAT activity. Furthermore, NO levels and iNOS labeling remained high. In this group, the reduction in lipid peroxides and nitrotyrosine was accompanied by upregulation of cell proliferation factors (Ki67 and PCNA), which indicated that prevention of nitrosative skin injury promoted cell proliferation and DNA repair. Genistein also prevented nitrosative events, inhibited ONOO(-) formation, which leads to tissue protection and cell proliferation. The UV-GEN15 group did not result in a greater protective effect compared to that with UV-GEN10 group. In the UV-GEN15 group, histological examination of the epidermis showed morphological alterations without efficient protection against lipid peroxide formation, as well as inhibition of Ki67 and PCNA, and VEGF labeling, which suggested inhibition of cell proliferation. These results help to elucidate the mechanisms underlying the photoprotective effect of genistein and reveal the importance of UVB radiation-induced nitrosative damage. PMID:25668145

  14. Modulation of radiation induced lipid peroxidation by phospholipase A 2 and calmodulin antagonists: Relevance to detoxification

    NASA Astrophysics Data System (ADS)

    Varshney, Rajeev; Kale, R. K.

    1995-04-01

    Ghost membranes prepared from erythrocytes of Swiss albino mice were irradiated with 0.9 Gy s -1. Lipid peroxidation initiated by ionizing radiation was enhanced by phospholipase A 2, and required both phospholipase A 2 and GSH-peroxidase for consecutive action to convert fatty acid peroxides into corresponding alcohols. The ability of phospholipase A 2 to enhance lipid peroxidation was increased in presence of Ca 2+. However, in combination, phospholipase A 2 and GSH-peroxidase were effective in inhibiting lipid peroxidation. These findings show that free fatty acid peroxides considerably increase the peroxidation. Calmodulin antagonists inhibit lipid peroxidation and decrease the radiation induced release of Ca 2+ from the membranes. Our results suggest the importance of Ca 2+ dependent phospholipase A 2 in detoxification of fatty acid peroxides in the membranes. It is quite possible that scavenging of free radicals by calmodulin antagonists lower the formation of hydroperoxides, resulting in the decrease in activity of phospholipase A 2. Alternatively, decrease in Ca 2+ release due to the calmodulin antagonists might have affected the activity of phospholipase A 2. Our observations might be of considerable significance in the understanding of post irradiation effect on biological membranes.

  15. Zinc administration modulates radiation-induced oxidative injury in lens of rat

    PubMed Central

    Taysi, Seyithan; Okumus, Seydi; Akyuz, Mehmet; Uzun, Naim; Aksoy, Adnan; Demir, Elif; Orkmez, Mustafa; Tarakcioglu, Mehmet; Adli, Mustafa

    2012-01-01

    Background: The aim of this study was to evaluate the antioxidant role of zinc (Zn) against radiation-induced cataract in the rat lens after total cranial irradiation with a single 5 Gray (Gy) dose of gamma irradiation. Materials and Methods: Twenty-one Sprague-Dawley rats were used for the experiment. The control group did not receive Zn or irradiation but received 1-ml saline orally plus sham-irradiation. The irradiation (IR) group received 5 Gy gamma irradiation to the total cranium as a single dose plus 0.1 ml physiological saline intraperitoneally. The IR plus Zn group received irradiation to total cranium plus 10 mg/kg/day Zn intraperitoneally. Biochemical parameters measured in rat lenses were carried out using spectrophotometric techniques. Results: Lens total (enzymatic plus non-enzymatic) superoxide scavenger activity (TSSA), glutathione reductase (GRD), and glutathione-S-transferase (GST) activities significantly increased in the IR plus Zn groups when compared with the IR group. However, TSSA, GRD and GST activities were significantly lower in the IR group when compared with the control group. Lens non-enzymatic superoxide scavenger activity (NSSA) in the IR plus Zn group was significantly increased compared to that of the IR group. Lens xanthine oxidase (XO) activity in the IR group significantly increased compared to that of both the control and IR plus Zn groups. Conclusion: Zn has clear antioxidant properties and prevented oxidative stress by scavenging free radicals generated by ionizing radiation in rat lenses. PMID:24082625

  16. Radiation-induced phenomena in ethylene-co-tetrafluoroethylene polymer. Temperature and LET effects

    NASA Astrophysics Data System (ADS)

    Oshima, Akihiro; Washio, Masakazu

    2003-08-01

    Irradiation temperature and linear energy transfer (LET) dependency on radiation-induced reactions of ethylene-co-tetrafluoroethylene polymer (ETFE) were investigated precisely by using low and high LET beams, and in a wide range of irradiation temperatures from 77 to 573 K including its melting temperature, respectively. At various temperatures irradiation by low LET beam such as ?-rays or electron beams, significant changes were observed in the photo-absorption spectra in the wavelength region between 200 and 500 nm. The general tendency is that the absorption band shifts to longer wavelengths with higher irradiation temperatures. The enhancement of the photo-absorption at 200-500 nm is due to the formation of conjugated double bonds in ETFE by irradiation. By high LET beam irradiation at room temperature such as ion beams, the photo-absorption spectra was different from those of low LET beams, i.e. the new absorption bands around 250-450 nm was appeared. It could be suggested that the high LET beams induced the production of intermediate species in a localized area such as track structure. As a result, reaction kinetics are different from low LET beams.

  17. Measurements of the temperature dependence of radiation induced conductivity in polymeric dielectrics

    NASA Astrophysics Data System (ADS)

    Gillespie, Jodie

    This study measures Radiation Induced Conductivity (RIC) in five insulating polymeric materials over temperatures ranging from ~110 K to ~350 K: polyimide (PI or Kapton HN(TM) and Kapton E(TM)), polytetraflouroethylene (PTFE or Teflon(TM)), ethylene-tetraflouroethylene (ETFE or Tefzel(TM)), and Low Density Polyethylene (LDPE). RIC occurs when incident ionizing radiation deposits energy and excites electrons into the conduction band of insulators. Conductivity was measured when a voltage was applied across vacuum-baked, thin film polymer samples in a parallel plate geometry. RIC was calculated as the difference in sample conductivity under no incident radiation and under an incident ~4 MeV electron beam at low incident dose rates of 0.01 rad/sec to 10 rad/sec. The steady-state RIC was found to agree well with the standard power law relation, sigmaRIC(D?) = kRIC(T) D?Delta(T) between conductivity, sigmaRIC and adsorbed dose rate, D?. Both the proportionality constant, kRIC, and the power, Delta, were found to be temperature-dependent above ~250 K, with behavior consistent with photoconductivity models developed for localized trap states in disordered semiconductors. Below ~250 K, kRIC and Delta exhibited little change in any of the materials.

  18. Radiation-induced optical response of single-crystal and polycrystalline YAG.

    SciTech Connect

    Meister, Dorothy C.; Simmons-Potter, Kelly (University of Arizona, Tucson, AZ); Vaddigiri, Aruna (University of Arizona, Tucson, AZ); Thomes, William Joseph, Jr.

    2005-07-01

    Exposure of optical materials to transient-ionizing-radiation fields can give rise to transient and/or permanent photodarkening effects. In laser materials, such as YAG, such induced optical loss can result in significant degradation of the lasing characteristic of the material, making its selection for optical device applications in radiation environments unfeasible. In the present study, the effects of ionizing radiation on the optical response of undoped and 1.1% Nd-doped single-crystal and polycrystalline YAG have been investigated. In the undoped materials it is seen that both laser materials exhibit significant loss at the 1.06 ?m lasing wavelength following exposure to a 40 krad, 30 nsec pulse of gamma radiation. In the undoped single-crystal samples, the transmission loss is initially large but exhibits a rapid recovery. By contrast, the undoped polycrystalline YAG experiences an initial 100% loss in transmission, becoming totally opaque at 1.06 ?m following the radiation pulse. This loss is slow to recover and a large residual permanent photodarkening effect is observed. Nd-doping improves the optical response of the materials in that the radiation-induced optical loss is substantially smaller in both the polycrystalline and single-crystal YAG samples. Preliminary results on the radiation response of elevated-temperature samples will also be reported.

  19. Radiation-induced lower cranial nerve palsy in patients with head and neck carcinoma

    PubMed Central

    JANSSEN, STEFAN; GLANZMANN, CHRISTOPH; YOUSEFI, BITA; LOEWENICH, KARL; HUBER, GERHARD; SCHMID, STEPHAN; STUDER, GABRIELA

    2015-01-01

    Radiation-induced cranial nerve palsy (RICNP) is a severe long-term complication in patients with head and neck cancer following high-dose radiation therapy (RT). We present the case report of a patient with bilateral RICNP of the hypoglossal and vagus cranial nerves (XII/X) following postoperative RT in the era prior to the introduction of intensity-modulated RT (IMRT), and an analysis of our IMRT patient cohort at risk including the case of a XII RICNP. A total of 201 patients whose glosso-pharyngeal (IX), X and XII cranial nerves had been exposed to >65 Gy definitive IMRT in our institution between January, 2002 and December, 2012 with or without systemic therapy, were retrospectively identified. A total of 151 patients out of 201 fulfilling the following criteria were included in the analysis: Locoregionally controlled disease, with a follow-up (FU) of >24 months and >65 Gy exposure of the nerves of interest. So far, one of the assessed 151 IMRT patients at risk exhibited symptoms of RICNP after 6 years. The mean/median FU of the entire cohort was 71/68 months (range, 27–145). The results were compared with literature reports. In conclusion, RICNP appears to be a rare complication. However, a longer FU and a larger sample size are required to draw reliable conclusions on the incidence of RICNP in the era of IMRT.

  20. Low-dose radiation-induced senescent stromal fibroblasts render nearby breast cancer cells radioresistant.

    PubMed

    Tsai, Kelvin K C; Stuart, Jeremy; Chuang, Yao-Yu Eric; Little, John B; Yuan, Zhi-Min

    2009-09-01

    In addition to cell cycle arrest, DNA repair or/and apoptosis, ionizing radiation can also induce premature senescence, which could lead to very different biological consequences depending on the cell type. We show in this report that low-dose radiation-induced senescent stromal fibroblasts stimulate proliferation of cocultured breast carcinoma cells. Such effects of senescent fibroblasts appear to result from their ability to induce the expression in carcinoma cells of mitotic genes and subsequent mitotic division. The elevated proliferation of breast carcinoma cells correlates with resistance to radiation as well as to adriamycin. Of interest is the observation that exposure to lower doses (<20 cGy) augments the ability of senescent fibroblasts to promote the survival of cocultured breast carcinoma cells. The resistance appears to be mediated partially by the Akt pathway, because expression of a dominant negative Akt mutant in breast carcinoma cells results in a partial reversal of the radioresistance. The ability of fibroblasts to modulate the radiosensitivity of nearby carcinoma cells implicates the importance of targeting the stroma during therapy. PMID:19708779