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1

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

SciTech Connect

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

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

1993-04-30

2

Brachial plexopathy  

MedlinePLUS

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

3

Atypical brachial plexopathy with pseudotumor cerebri.  

PubMed

A 24-year-old woman with previously known pseudotumor cerebri syndrome (PTCS) presented with severe pain in the neck and shoulders followed by the classical symptoms and signs of bilateral brachial neuritis. At the same time, there was a recurrence of the PTCS which had been in remission for more than one-and-a-half years. Despite treatment with high doses of methylprednisolone, intravenous immunoglobulins and repeated cerebrospinal fluid drainage, both brachial plexopathy and the PTCS continued to worsen. Both lumbosacral plexuses became involved and the visual acuity deteriorated to a level such that a lumboperitoneal shunt had to be inserted. The neurological condition started to improve progressively after 8 weeks. This case is, to our knowledge, the first where brachial plexopathy has been described in association with a PTCS. Although the pathogenesis of this association is not clear, there are enough data to suggest the existence of a continuum between extended brachial plexopathy and Guillain Barre syndrome, with which PTCS has been associated in some instances. PMID:10209359

Awada, A; Obeid, T; Al Jumah, M; Al Ghanmi, H

1999-01-01

4

Shoulder pain and isolated brachial plexopathy.  

PubMed

Pancoast syndrome, classically considered as a constellation of (1) pain along the C8-T2 dermatomes, (2) weakness and atrophy of the hand and (3) Horner's syndrome, often presents a diagnostic challenge. In fact, it may manifest as a singular orthopaedic complaint, prompting a futile barrage of tests and referrals. The authors present the case of an elderly man who initially presented with severe shoulder pain. Due to progressive pain and weakness, he was referred to rheumatology and was treated with corticosteroid injections for a presumed musculoskeletal lesion. Ultimately, he manifested gross muscular atrophy and worsening pain, prompting a referral to neurology. An electromyogram (EMG) suggested a lower brachial plexopathy, and a follow-up brachial plexus MRI identified a large Pancoast tumour. Unfortunately, his disease was rapidly progressive, and he passed away within 2 months. While the MRI remains the gold standard for diagnosing Pancoast syndrome, an EMG can facilitate diagnosis in difficult cases such as this one. PMID:22744250

Kishan, Amar U; Syed, Sana; Fiorito-Torres, Franchesca; Thakore-James, Manisha

2012-06-28

5

Upper and middle trunk brachial plexopathy after robotic prostatectomy.  

PubMed

We describe 3 patients who developed injury of upper and middle brachial plexus trunks during robotic-assisted prostatectomy, and review factors potentially associated with this type of injury. Three patients underwent robotic-assisted prostatectomy. Surgical exposure was facilitated by steep head-down tilt position. To secure patients and prevent sliding on the operating table, shoulders were supported with moldable beanbags. In all 3 cases, the left arm was abducted to approximately 90°, and the right arm was adducted. Postoperatively, all patients were diagnosed with left arm upper and middle trunk brachial plexopathies. The combination of arm abduction, extreme head-down position, and shoulder immobilization with beanbags resulted in several mechanistic forces that may have contributed to the development of brachial plexopathy in our patients. Steep head-down tilt may result in cephalad slide of the torso in relation to an abducted arm. When shoulder restraints are used to secure the patient, the compensatory movement of the shoulder girdle of an abducted arm is impeded. This may result in injurious stretching and compression of the brachial plexus, especially the upper and middle trunks. When steep head-down position is needed to facilitate surgical exposure, clinicians should consider adduction and tucking of both arms, and use of other methods to prevent sliding on the operating room table that do not require the use of restraints across the shoulder girdle. PMID:22798532

Devarajan, Jagan; Byrd, J Bryant; Gong, Michael C; Wood, Hadley M; O'Hara, Jerome; Weingarten, Toby N; Warner, Mark A; Warner, Mary Ellen; Sprung, Juraj

2012-07-13

6

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

PubMed

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

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

2012-07-02

7

Plexopathies  

Microsoft Academic Search

The neural plexuses are intricate networks of nerve fibers interposed be- tween the spinal cord or anterior primary rami (APR) proximally and the most proximal portions of peripheral nerves distally. (The term, plexus, means ''interweaving of strands.'') Depending on how they are defined, there are three or four neural plexuses: cervical, brachial, and lumbosacral (also known as pelvic) or lumbar

Asa J. Wilbourn

8

Paraneoplastic rhombencephalitis and brachial plexopathy in two cases of amphiphysin auto-immunity.  

PubMed

Amphiphysin, a synaptic vesicle protein, is an auto-immune target in rare cases of paraneoplastic neurological disorders. We report two additional cases with distinct neurological syndromes and paraneoplastic anti-amphiphysin antibodies. The first patient, a 59-year-old man, presented with cerebellar and cranial nerve dysfunction and small cell lung carcinoma. The second, a 77-year- old woman, presented with left brachial plexopathy followed by sensorimotor neuropathy and breast carcinoma. PMID:16567945

Coppens, T; Van den Bergh, P; Duprez, T J; Jeanjean, A; De Ridder, F; Sindic, C J M

2006-03-24

9

Paraneoplastic Rhombencephalitis and Brachial Plexopathy in Two Cases of Amphiphysin AutoImmunity  

Microsoft Academic Search

Amphiphysin, a synaptic vesicle protein, is an auto-immune target in rare cases of paraneoplastic neurological disorders. We report two additional cases with distinct neurological syndromes and paraneoplastic anti-amphiphysin antibodies. The first patient, a 59-year-old man, presented with cerebellar and cranial nerve dysfunction and small cell lung carcinoma. The second, a 77-year- old woman, presented with left brachial plexopathy followed by

T. Coppens; P. Van den Bergh; T. J. Duprez; A. Jeanjean; F. De Ridder; C. J. M. Sindic

2006-01-01

10

Painful brachial plexopathy: an unusual presentation of polyarteritis nodosa  

PubMed Central

An elderly man was admitted to hospital with an unusual painful bilateral brachial neuropathy, which progressed in spite of high dose corticosteroid therapy. Polyarteritis nodosa, characterized by widespread arteriolar involvement, was shown at post-mortem.

Allan, S. G.; Smith, C. C.; Towla, H. M. A.; Downie, A. W.; Clark, J. C.

1982-01-01

11

Delayed diagnosis of concomitant rotator cuff tear and brachial plexopathy in a patient with traumatic brain injury: A case report  

Microsoft Academic Search

Mukand JA, Blackinton DD, VanDyck WR. Delayed diagnosis of concomitant rotator cuff tear and brachial plexopathy in a patient with traumatic brain injury: a case report. Arch Phys Med Rehabil 2001;82:1729-32. Traumatic brain injury (TBI) is often accompanied by additional trauma that can be obscured by cognitive dysfunction or multiple injuries in the same region of the body. This report

Jon A. Mukand; Dilshad D. Blackinton; Walter R. VanDyck

2001-01-01

12

A report of hereditary neuropathy with liability to pressure palsy (HNPP) presenting with brachial plexopathy: the value of complete electrodiagnostic testing.  

PubMed

Patients with hereditary neuropathy with liability to pressure palsy (HNPP) typically present with a mononeuropathy (particularly peroneal or ulnar palsy) or a brachial plexopathy. Careful electrodiagnostic testing has an important role in establishing the diagnosis of HNPP differentiating this condition from other inherited or acquired neuropathies as well as obviating the need for unnecessary surgeries. We present a case of a patient who presented with a painless brachial plexopathy who was found to have multiple sites of segmental demyelination on nerve conduction studies, consistent with HNPP. We review the clinical and electrodiagnostic features of HNPP including the key electrodiagnostic findings to screen for this disorder. PMID:21988036

Bulusu, Srinivas; McMillan, Hugh J

2011-09-01

13

Carcinomatous versus radiation-induced brachial plexus neuropathy in breast cancer  

Microsoft Academic Search

A retrospective study was performed of 18 women in whom ipsilateral brachial plexus neuropathy developed after treatment for carcinoma of the breast. In the absence of metastatic tumor elsewhere, the only distinguishing feature between carcinomatous neuropathy and radiation-induced neuropathy was the symptom-free interval after mastectomy and radiation therapy. Women with an interval of less than a year have radiation-induced neuropathy.

Frederick H. Bagley; John W. Walsh; Blake Cady; Ferdinand A. Salzman; Richard A. Oberfield; Artemis G. Pazianos

1978-01-01

14

Radiation-induced neuropathy in cancer survivors.  

PubMed

Radiation-induced peripheral neuropathy is a chronic handicap, frightening because progressive and usually irreversible, usually appearing several years after radiotherapy. Its occurrence is rare but increasing with improved long-term cancer survival. The pathophysiological mechanisms are not yet fully understood. Nerve compression by indirect extensive radiation-induced fibrosis plays a central role, in addition to direct injury to nerves through axonal damage and demyelination and injury to blood vessels by ischaemia following capillary network failure. There is great clinical heterogeneity in neurological presentation since various anatomic sites are irradiated. The well-known frequent form is radiation-induced brachial plexopathy (RIBP) following breast cancer irradiation, while tumour recurrence is easier to discount today with the help of magnetic resonance imaging and positron emission tomography. RIBP incidence is in accordance with the irradiation technique, and ranges from 66% RIBP with 60Gy in 5Gy fractions in the 1960s to less than 1% with 50Gy in 2Gy fractions today. Whereas a link with previous radiotherapy is forgotten or difficult to establish, this has recently been facilitated by a posteriori conformal radiotherapy with 3D-dosimetric reconstitution: lumbosacral radiculo-plexopathy following testicular seminoma or Hodgkin's disease misdiagnosed as amyotrophic lateral sclerosis. Promising treatments via the antioxidant pathway for radiation-induced fibrosis suggest a way to improve the everyday quality of life of these long-term cancer survivors. PMID:23245644

Delanian, Sylvie; Lefaix, Jean-Louis; Pradat, Pierre-François

2012-12-01

15

Brachial plexus compression: a rare sequelae of malignant papillary thyroid carcinoma  

PubMed Central

Invasive papillary thyroid carcinoma (PTC) can rarely invade adjacent vital structures. There has been one report on secondary brachial plexopathy associated with locally invasive PTC. Here we report a patient with a large locally invasive PTC associated with secondary neoplastic brachial plexopathy. The case exhibits an extremely rare occurrence that has substantial impact on surgical planning and management.

Patel, Amit S; Carter, John M; Friedlander, Paul L; Kandil, Emad

2013-01-01

16

Inadvertent lumbosacral plexopathy due to temporary pacemaker implantation.  

PubMed Central

Reported here is a 70-year-old man who suffered from a lumbosacral plexopathy after a temporary pacemaker implantation. Drawing attention to the increased number of femoral catheterizations in cardiovascular practice, we have highlighted some neuromuscular complications pertaining to these type of interventions.

Ozcan, Firat; Guray, Yesim; Ozcakar, Levent; Korkmaz, Sule

2006-01-01

17

Electrodiagnosis in traumatic brachial plexus injury  

PubMed Central

Electrodiagnosis (EDX) is a useful test to accurately localize the site, determine the extent, identify the predominant pathophysiology, and objectively quantify the severity of brachial plexopathies. It can also be used to examine muscles not easily assessed clinically and recognize minimal defects. Post-operatively and on follow up studies, it is important for early detection of re-innervation. It can be used intra-operatively to assess conduction across a neuroma, which would help the surgeon to decide further course of action. Localization of the site of the lesion can be very challenging as there may be multiple sites of involvement and hence the electroneuromyographic evaluation must be adequate. The unaffected limb also needs to be examined for comparison. The final impression must be co-related with the type and severity of injury.

Mansukhani, K. A.

2013-01-01

18

Differential diagnosis between radiation and tumor plexopathy of the pelvis  

SciTech Connect

Twenty patients were studied with lumbosacral radiculoplexopathy from radiation treatment and 30 patients with plexus damage from pelvic malignancy. Indolent leg weakness occurred early in radiation disease, whereas pain marked the onset of tumor plexopathy. Eventually, all radiation cases had weakness, which was bilateral in most of them and painless in one-half of them. Tumor patients typically had unilateral weakness, which was painful in all of them. Radiation disease often resulted in serious neurologic disability. Of the tumor patients, 86% were dead within 3 1/2 years after onset of neurologic symptoms.

Thomas, J.E.; Cascino, T.L.; Earle, J.D.

1985-01-01

19

Radiation-induced proctosigmoiditis  

Microsoft Academic Search

In a prospective study, 37 consecutive patients with radiation-induced proctosigmoiditis were randomized to receive a four-week course of either 3.0 g oral sulfasalazine plus 20 mg twice daily rectal prednisolone enemas (group I,N=18) or 2.0 g twice daily rectal sucralfate enemas plus oral placebo (group II,N=19). The two groups were comparable with respect to demographic features, duration of symptoms, and

R. Kochhar; F. Patel; S. C. Sharma; S. Ayyagari; R. Aggarwal; M. K. Goenka; B. D. Gupta; S. K. Mehta

1991-01-01

20

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

PubMed

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

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

2013-07-18

21

The Brachial Plexus  

NSDL National Science Digital Library

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.

Mr. Samuel J Schwarzlose (Amarillo College Biology)

2010-08-20

22

Brachial Plexus Injury  

MedlinePLUS

... from that shoulder. Brachial plexus injuries are common in contact sports, but they frequently result from auto or motorcycle ... with no apparent shoulder injury. Risk factors Participating in contact sports, particularly football and wrestling, or being involved in ...

23

Brachial plexus neuropathy  

PubMed Central

Branchial plexus neuropathy is characterized by acute onset of intense pain in the shoulder or arm followed shortly by focal muscle weakness. This presentation may mislead the clinician into diagnosing shoulder or cervical spine pathology. Although brachial plexus neuropathy is not common, it should be considered in the differential diagnosis of pain and weakness of the arm. We present a patient with brachial plexus neuropathy who was originally misdiagnosed as having a cervical disc herniation. ImagesFigure 1Figure 2Figure 3

Hubka, Michael J; King, Laurie; Cassidy, J David; Donat, JR

1992-01-01

24

Radiation-induced optic neuropathy  

Microsoft Academic Search

Radiation-induced optic neuropathy (RION) is a devastating late complication of radiotherapy to the anterior visual pathway resulting in acute, profound, irreversible visual loss. It is thought to be a result of radiation necrosis of the anterior visual pathway. Visual loss may be unilateral or bilateral; simultaneous or sequential. RION occurs commonly between 10-20 months, with an average of 18 months

Helen V. Danesh-Meyer

2008-01-01

25

Obstetrical brachial plexus palsy.  

PubMed

Obstetrical brachial plexus palsy is considered to be the result of a trauma during the delivery, even if there remains some controversy surrounding the causes. Although most babies recover spontaneously in the first 3 months of life, a small number remains with poor recovery which requires surgical brachial plexus exploration. Surgical indications depend on the type of lesion (producing total or partial palsy) and particularly the nonrecovery of biceps function by the age of 3 months. In a global palsy, microsurgery will be mandatory and the strategy for restoration will focus first on hand reinnervation and secondarily on providing elbow flexion and shoulder stability. Further procedures may be necessary during growth in order to avoid fixed contractured deformities or to give or increase strength of important muscle functions like elbow flexion or wrist extension. The author reviews the history of obstetrical brachial plexus injury, epidemiology, and the specifics of descriptive and functional anatomy in babies and children. Clinical manifestations at birth are directly correlated with the anatomical lesion. Finally, operative procedures are considered, including strategies of reconstruction with nerve grafting in infants and secondary surgery to increase functional capacity at later ages. However, normal function is usually not recovered, particularly in total brachial plexus palsy. PMID:23622302

Romaña, M C; Rogier, A

2013-01-01

26

Brachial Plexus Injuries  

MedlinePLUS

... United Brachial Plexus Network 1610 Kent Street Kent, OH 44240 info@ubpn.org http://www.ubpn.org Tel: 866-877-7004 Fax: 866-877-7004 National Institute on Disability and Rehabilitation Research (NIDRR) U.S. Department of Education Office of Special Education and Rehabilitative Services 400 ...

27

Obstetric brachial plexus injury  

PubMed Central

Obstetric brachial plexus injury (OBPI), also known as birth brachial plexus injury (BBPI), is unfortunately a rather common injury in newborn children. Incidence varies between 0.15 and 3 per 1000 live births in various series and countries. Although spontaneous recovery is known, there is a large subset which does not recover and needs primary or secondary surgical intervention. An extensive review of peer-reviewed publications has been done in this study, including clinical papers, review articles and systematic review 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. Causes of OBPI, indications of primary nerve surgery and secondary reconstruction of shoulder, etc. are discussed in detail. Although all affected children do not require surgery in infancy, a substantial proportion of them, however, require it and are better off for it. Secondary surgery is needed for shoulder elbow and hand problems. Results of nerve surgery are very encouraging. Children with OBPI should be seen early by a hand surgeon dealing with brachial plexus injuries. Good results are possible with early and appropriate intervention even in severe cases.

Thatte, Mukund R.; Mehta, Rujuta

2011-01-01

28

Obstetric brachial plexus injury.  

PubMed

Obstetric brachial plexus injury (OBPI), also known as birth brachial plexus injury (BBPI), is unfortunately a rather common injury in newborn children. Incidence varies between 0.15 and 3 per 1000 live births in various series and countries. Although spontaneous recovery is known, there is a large subset which does not recover and needs primary or secondary surgical intervention. An extensive review of peer-reviewed publications has been done in this study, including clinical papers, review articles and systematic review 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. Causes of OBPI, indications of primary nerve surgery and secondary reconstruction of shoulder, etc. are discussed in detail. Although all affected children do not require surgery in infancy, a substantial proportion of them, however, require it and are better off for it. Secondary surgery is needed for shoulder elbow and hand problems. Results of nerve surgery are very encouraging. Children with OBPI should be seen early by a hand surgeon dealing with brachial plexus injuries. Good results are possible with early and appropriate intervention even in severe cases. PMID:22279269

Thatte, Mukund R; Mehta, Rujuta

2011-09-01

29

Radiation-induced leiomyosarcoma of the oropharynx  

PubMed Central

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

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

2006-01-01

30

Isolated latissimus dorsi transfer to restore shoulder external rotation in adults with brachial plexus injury.  

PubMed

In adults with brachial plexus injuries, lack of active external rotation at the shoulder is one of the most common residual deficits, significantly compromising upper limb function. There is a paucity of evidence to address this complex issue. We present our experience of isolated latissimus dorsi (LD) muscle transfer to achieve active external rotation. This is a retrospective review of 24 adult post-traumatic plexopathy patients who underwent isolated latissimus dorsi muscle transfer to restore external rotation of the shoulder between 1997 and 2010. All patients were male with a mean age of 34 years (21 to 57). All the patients underwent isolated LD muscle transfer using a standard technique to correct external rotational deficit. Outcome was assessed for improvement in active external rotation, arc of movement, muscle strength and return to work. The mean improvement in active external rotation from neutral was 24° (10° to 50°). The mean increase in arc of rotation was 52° (38° to 55°). Mean power of the external rotators was 3.5 Medical Research Council (MRC) grades (2 to 5). A total of 21 patients (88%) were back in work by the time of last follow up. Of these, 13 had returned to their pre-injury occupation. Isolated latissimus dorsi muscle transfer provides a simple and reliable method of restoring useful active external rotation in adults with brachial plexus injuries with internal rotational deformity. PMID:23632677

Ghosh, S; Singh, V K; Jeyaseelan, L; Sinisi, M; Fox, M

2013-05-01

31

[Radiation-induced cardiac disease].  

PubMed

Radiation-induced effects may damage various cardiac structures chronically and cause heart valve dysfunction as well as occlusive lesions of coronary and other arteries exposed to radiation. A 72-year-old woman with a history of radiation treatment after breast cancer was admitted 25 years later with symptoms of tachycardia and acute dyspnea. We found valvular thickening, medium to severe valvular dysfunction and high grade occlusive coronary artery disease in proximal portions. The left subclavian artery also was affected. Surgical treatment was required immediately. Long-term follow-up cardiac evaluation even in asymptomatic patients is mandatory to uncover cardiac injuries by radiation. To lower the risk and maximize the benefit, early intervention by valvular replacement and myocardial revascularization is indicated. Restrictive myopathy and chronic pericarditis increase risk and have to be clarified. Diagnosis in these radiation exposed patients can be made by typical findings. Echocardiography is of eminent relevancy. PMID:14634766

Andresen, H; Kaag, N; Meinhardt, A; Potratz, J

2003-11-01

32

Radiation-induced parotid cancer  

SciTech Connect

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.

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

1981-03-01

33

Brachial plexus injury in newborns  

MedlinePLUS

... brachial plexus injury: Breech delivery Larger-than-average newborn (such as an infant of a diabetic mother ) ... immediately or soon after birth, and may include: Newborn is not moving the upper or lower arm ...

34

Radiation-induced moyamoya syndrome  

SciTech Connect

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

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

2006-07-15

35

Radiation-induced accelerated coronary arteriosclerosis  

Microsoft Academic Search

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

B. Mittal; M. Deutsch; M. Thompson; H. Lee Dameshek

1986-01-01

36

Management of birth brachial plexus palsy  

Microsoft Academic Search

Introduction  The indications for surgical repair of congenital brachial plexus palsy are controversial. Our objective was to determine the results of early brachial plexus surgery following obstetric-induced brachial plexus palsy.Methods  We performed a retrospective analysis of the outcome of 58 cases of brachial plexus surgery. The indication for operation consisted of the presence of less than antigravity strength in the biceps, triceps,

Donncha F. O’Brien; T. S. Park; Michael J. Noetzel; Trisha Weatherly

2006-01-01

37

Radiation-induced solution chlorination of PVC  

NASA Astrophysics Data System (ADS)

The high solubility in the usual solvents makes the chlorinated PVC most suitable for laquers, adhesives and fibres. For this reason, the radiation-induced solution chlorination of PVC in methylene chloride was studied. The results of many experiments show that during the reaction between chlorine and PVC the solvent (methylene chloride) is chlorinated only in a small percentage to chloroform (9.5%) and finally to tetrachloromethane (0.1%). It was found that the radiation-induced chlorinated PVC has the same structure as the thermally chlorinated polymer, while the thermal stability and the rate of degradation of the radiation products show the better data for application purposes.

Friese, K.; Hösselbarth, B.; Reinhardt, J.; Newe, R.

1996-03-01

38

Radiation-induced leukemias in ankylosing spondylitis  

SciTech Connect

Three cases of leukemia occurred in patients with ankylosing spondylitis treated by radiotherapy. In each case, the leukemic process exhibited bizarre features suggesting that radiation is likely to induce atypical forms of leukemia possessing unusual attributes not shared by spontaneously developing leukemia. The likely distinctive aspects of radiation-induced leukemia are discussed.

Toolis, F. (Royal Infirmary, Edinburgh, UK); Potter, B.; Allan, N.C.; Langlands, A.O.

1981-10-01

39

Radiation Induces Acute Alterations in Neuronal Function  

Microsoft Academic Search

Every year, nearly 200,000 patients undergo radiation for brain tumors. For both patients and caregivers the most distressing adverse effect is impaired cognition. Efforts to protect against this debilitating effect have suffered from inadequate understanding of the cellular mechanisms of radiation damage. In the past it was accepted that radiation-induced normal tissue injury resulted from a progressive reduction in the

Peter H. Wu; Steven Coultrap; Chelsea Pinnix; Kurtis D. Davies; Ramesh Tailor; Kian K. Ang; Michael D. Browning; David R. Grosshans

2012-01-01

40

[Quantification of radiation-induced genetic risk].  

PubMed

Associated with technical advances of our civilization is a radiation- and chemically-induced increase in the germ cell mutation rate in man. This would result in an increase in the frequency of genetic diseases and would be detrimental to future generations. It is the duty of our generation to keep this risk as low as possible. The estimation of the radiation-induced genetic risk of human populations is based on the extrapolation of results from animal experiments. Radiation-induced mutations are stochastic events. The probability of the event depends on the dose; the degree of the damage does not. The different methods to estimate the radiation-induced genetic risk will be discussed. The accuracy of the predicted results will be evaluated by a comparison with the observed incidence of dominant mutations in offspring born to radiation exposed survivors of the Hiroshima and Nagasaki atomic bombings. These methods will be used to predict the genetic damage from the fallout of the reactor accident at Chernobyl. For the exposure dose we used the upper limits of the mean effective life time equivalent dose from the fallout values in the Munich region. According to the direct method for the risk estimation we will expect for each 100 to 500 spontaneous dominant mutations one radiation-induced mutation in the first generation. With the indirect method we estimate a ratio of 100 dominant spontaneous mutations to one radiation-induced dominant mutation. The possibilities and the limitations of the different methods to estimate the genetic risk will be discussed. The discrepancy between the high safety standards for radiation protection and the low level of knowledge for the toxicological evaluation of chemical mutagens will be emphasized. PMID:3589954

Ehling, U H

1987-05-01

41

Fluorodeoxyglucose and 11C-Choline positron emission tomography for distinction of metastatic plexopathy and neuritis: a case report  

PubMed Central

Introduction Fluorodeoxyglucose positron emission tomography scanning has an established role in the diagnostic work-up of many malignant diseases and also in the evaluation of cancer treatment response. Fluorodeoxyglucose positron emission tomography may, however be non-specific as infectious processes are depicted as well. Case presentation We present a patient with longstanding leg pain and weakness due to plexopathy developed a few years after treatment for prostate cancer. Prostate-specific antigen was raised and magnetic resonance imaging showed contrast uptake in thickened sacral nerves, suspicious for metastasis. While fluorodeoxyglucose positron emission tomography showed increased uptake in the plexus region, 11C-Choline- positron emission tomography did not show any uptake. It was concluded that the FDG uptake reflected plexus neuritis and no tumor. Treatment for pain relief was started. Conclusion 11C-Choline- positron emission tomography can be used to detect metastasis in patients with plexopathy suspicious for malignancy, while fluorodeoxyglucose positron emission tomography is more sensitive to inflammatory processes.

2009-01-01

42

Radiation-induced brain injury: A review  

PubMed Central

Approximately 100,000 primary and metastatic brain tumor patients/year in the US survive long enough (>6 months) to experience radiation-induced brain injury. Prior to 1970, the human brain was thought to be highly radioresistant; the acute CNS syndrome occurs after single doses >30 Gy; white matter necrosis occurs at fractionated doses >60 Gy. Although white matter necrosis is uncommon with modern techniques, functional deficits, including progressive impairments in memory, attention, and executive function have become important, because they have profound effects on quality of life. Preclinical studies have provided valuable insights into the pathogenesis of radiation-induced cognitive impairment. Given its central role in memory and neurogenesis, the majority of these studies have focused on the hippocampus. Irradiating pediatric and young adult rodent brains leads to several hippocampal changes including neuroinflammation and a marked reduction in neurogenesis. These data have been interpreted to suggest that shielding the hippocampus will prevent clinical radiation-induced cognitive impairment. However, this interpretation may be overly simplistic. Studies using older rodents, that more closely match the adult human brain tumor population, indicate that, unlike pediatric and young adult rats, older rats fail to show a radiation-induced decrease in neurogenesis or a loss of mature neurons. Nevertheless, older rats still exhibit cognitive impairment. This occurs in the absence of demyelination and/or white matter necrosis similar to what is observed clinically, suggesting that more subtle molecular, cellular and/or microanatomic modifications are involved in this radiation-induced brain injury. Given that radiation-induced cognitive impairment likely reflects damage to both hippocampal- and non-hippocampal-dependent domains, there is a critical need to investigate the microanatomic and functional effects of radiation in various brain regions as well as their integration at clinically relevant doses and schedules. Recently developed techniques in neuroscience and neuroimaging provide not only an opportunity to accomplish this, but they also offer the opportunity to identify new biomarkers and new targets for interventions to prevent or ameliorate these late effects.

Greene-Schloesser, Dana; Robbins, Mike E.; Peiffer, Ann M.; Shaw, Edward G.; Wheeler, Kenneth T.; Chan, Michael D.

2012-01-01

43

RADIATION-INDUCED DEGRADATION OF WATER  

Microsoft Academic Search

Abstract--The radiation-induced decomposition,of biological resistant pollutants in drinking as well as in wastewater is briefly reviewed. First, some important units, definitions etc., radiation sources, as well as dose-depth curves in water as functions of the electron energy and 6°Co-y-rays are mentioned. Following is a schematical presentation of water radiolysis and of characteristics of primary,free radicals. Then the degradation,of some,aliphatic and

Nikola Getoff

44

Radiation-induced clastogenic plasma factors  

Microsoft Academic Search

Ionizing irradiation induces chromosomal aberrations in directly exposed cells and is known to have mutagenic and carcinogenic potential for the exposed host. Under controlled conditions, we examined whether such clastogenic effects of irradiation might be due in part to radiation-induced plasma factors. Irradiated cells and sera from CF-Nelson rats were used at 15 min, and 1, 7, 14, and 56-70

G. B. Faguet; S. M. Reichard; D. A. Welter

1984-01-01

45

Modeling radiation-induced cell cycle delays  

Microsoft Academic Search

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

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

2009-01-01

46

Imaging radiation-induced normal tissue injury.  

PubMed

Technological developments in radiation therapy and other cancer therapies have led to a progressive increase in five-year survival rates over the last few decades. Although acute effects have been largely minimized by both technical advances and medical interventions, late effects remain a concern. Indeed, the need to identify those individuals who will develop radiation-induced late effects, and to develop interventions to prevent or ameliorate these late effects is a critical area of radiobiology research. In the last two decades, preclinical studies have clearly established that late radiation injury can be prevented/ameliorated by pharmacological therapies aimed at modulating the cascade of events leading to the clinical expression of radiation-induced late effects. These insights have been accompanied by significant technological advances in imaging that are moving radiation oncology and normal tissue radiobiology from disciplines driven by anatomy and macrostructure to ones in which important quantitative functional, microstructural, and metabolic data can be noninvasively and serially determined. In the current article, we review use of positron emission tomography (PET), single photon emission tomography (SPECT), magnetic resonance (MR) imaging and MR spectroscopy to generate pathophysiological and functional data in the central nervous system, lung, and heart that offer the promise of, (1) identifying individuals who are at risk of developing radiation-induced late effects, and (2) monitoring the efficacy of interventions to prevent/ameliorate them. PMID:22348250

Robbins, Mike E; Brunso-Bechtold, Judy K; Peiffer, Ann M; Tsien, Christina I; Bailey, Janet E; Marks, Lawrence B

2012-02-21

47

Primary brachial plexus neoplasia in cats.  

PubMed

Conditions affecting the brachial plexus and its branches can cause lameness and/or neurological deficits. There are few reports of schwannomas in cats. In reported cases, the tumours arose from the dermis or subcutis of the limbs, head and neck and thorax, but there are no reports of primary tumours that arose from the brachial plexus itself. The purpose of this study is to present the clinical, radiological, ultrasonographical and pathological findings of primary brachial plexus tumour in three cats. PMID:23197498

Hanna, Fikry Younan

2012-11-29

48

Brachial plexus neuritis following HPV vaccination  

Microsoft Academic Search

We present a 19-year-old girl who developed a left brachial plexus neuritis following vaccination with a quadrivalent human papillomavirus (HPV) vaccine. Post-vaccination brachial plexus neuritis is a rare event. Nevertheless, this first case warrants careful attention in view of the large vaccination campaigns in young adolescents being launched all over the world.

Ph. Debeer; P. De Munter; F. Bruyninckx; R. Devlieger

2008-01-01

49

Radiation-induced injury of the esophagus  

SciTech Connect

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

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

1983-08-01

50

A report on radiation-induced gliomas  

SciTech Connect

Radiation-induced gliomas are uncommon, with only 73 cases on record to date. The disease that most frequently occasioned radiation therapy has been acute lymphoblastic leukemia (ALL). Three more cases are added here, two after irradiation for ALL and one after irradiation for tinea capitis. In a review of the relevant literature, the authors stress the possibility that the ALL-glioma and the retinoblastoma-glioma links point to syndromes in their own right that may occur without radiation therapy.56 references.

Salvati, M.; Artico, M.; Caruso, R.; Rocchi, G.; Orlando, E.R.; Nucci, F. (Univ. of Rome La Sapienza (Italy))

1991-01-15

51

Radiation-Induced Effects on Microstructure  

SciTech Connect

Irradiation of materials with particles that are sufficiently energetic to create atomic displacements can induce significant microstructural alteration, ranging from crystalline-to-amorphous phase transitions to the generation of large concentrations of point defect or solute aggregates in crystalline lattices. These microstructural changes typically cause significant changes in the physical and mechanical properties of the irradiated material. A variety of advanced microstructural characterization tools are available to examine the microstructural changes induced by particle irradiation, including electron microscopy, atom probe field ion microscopy, X-ray scattering and spectrometry, Rutherford backscattering spectrometry, nuclear reaction analysis, and neutron scattering and spectrometry. Numerous reviews, which summarize the microstructural changes in materials associated with electron and heavy ion or neutron irradiation, have been published. These reviews have focused on pure metals as well as model alloys, steels, and ceramic materials. In this chapter, the commonly observed defect cluster morphologies produced by particle irradiation are summarized and an overview is presented on some of the key physical parameters that have a major influence on microstructural evolution of irradiated materials. The relationship between microstructural changes and evolution of physical and mechanical properties is then summarized, with particular emphasis on eight key radiation-induced property degradation phenomena. Typical examples of irradiated microstructures of metals and ceramic materials are presented. Radiation-induced changes in the microstructure of organic materials such as polymers are not discussed in this overview.

Zinkle, Steven J [ORNL

2012-01-01

52

Brachial plexus trauma: the morbidity of hemidiaphragmatic paralysis  

Microsoft Academic Search

Phrenic nerve palsy has previously been associated with brachial plexus root avulsion; severe unilateral phrenic nerve injury is not uncommonly associated with brachial plexus injury. Brachial plexus injuries can be traumatic (gunshot wounds, lacerations, stretch\\/contusion and avulsion injuries) or non-traumatic in aetiology (supraclavicular brachial plexus nerve block, subclavian vein catheterisation, cardiac surgeries, or obstetric complications such as birth palsy). Despite

O I Franko; Z Khalpey; J Gates

2008-01-01

53

Role of neurotensin in radiation-induced hypothermia in rats  

SciTech Connect

The role of neurotensin in radiation-induced hypothermia was examined. Intracerebroventricular (ICV) administration of neurotensin produced dose-dependent hypothermia. Histamine appears to mediate neurotensin-induced hypothermia because the mast cell stabilizer disodium cromoglycate and antihistamines blocked the hypothermic effects of neurotensin. An ICV pretreatment with neurotensin antibody attenuated neurotensin-induced hypothermia, but did not attenuate radiation-induced hypothermia, suggesting that radiation-induced hypothermia was not mediated by neurotensin.

Kandasamy, S.B.; Hunt, W.A.; Harris, A.H. (Armed Forces Radiobiology Research Institute, Bethesda, MD (USA))

1991-05-01

54

Radiation-induced intracranial meningioma and multiple cavernomas.  

PubMed

Brain irradiation has several well-known long-term side effects, including radiation-induced neoplasms and vasculopathy. In this case report, we describe an extremely rare case of meningioma and 15 cavernomas developing in a 29-year-old man, 19 years after cranial irradiation for posterior cranial fossa medulloblastoma. To our knowledge, this is the first case of a radiation-induced meningioma accompanied by this many radiation-induced cavernous angiomas. PMID:24051144

Chourmouzi, Danai; Papadopoulou, Elissavet; Kontopoulos, Athanasios; Drevelegas, Antonios

2013-09-19

55

Management of radiation-induced rectal bleeding.  

PubMed

Pelvic radiation disease is one of the major complication after radiotherapy for pelvic cancers. The most commonly reported symptom is rectal bleeding which affects patients' quality of life. Therapeutic strategies for rectal bleeding are generally ignored and include medical, endoscopic, and hyperbaric oxygen treatments. Most cases of radiation-induced bleeding are mild and self-limiting, and treatment is normally not indicated. In cases of clinically significant bleeding (i.e. anaemia), medical therapies, including stool softeners, sucralfate enemas, and metronidazole, should be considered as first-line treatment options. In cases of failure, endoscopic therapy, mainly represented by argon plasma coagulation and hyperbaric oxygen treatments, are valid and complementary second-line treatment strategies. Although current treatment options are not always supported by high-quality studies, patients should be reassured that treatment options exist and success is achieved in most cases if the patient is referred to a dedicated centre. PMID:24101202

Laterza, Liboria; Cecinato, Paolo; Guido, Alessandra; Mussetto, Alessandro; Fuccio, Lorenzo

2013-11-01

56

Radiation induced carcinoma of the larynx  

SciTech Connect

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

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

1985-07-01

57

Radiation-induced electron migration along DNA  

SciTech Connect

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

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

1994-04-01

58

Ionizing Radiation Induces Stemness in Cancer Cells  

PubMed Central

The cancer stem cell (CSC) model posits the presence of a small number of CSCs in the heterogeneous cancer cell population that are ultimately responsible for tumor initiation, as well as cancer recurrence and metastasis. CSCs have been isolated from a variety of human cancers and are able to generate a hierarchical and heterogeneous cancer cell population. CSCs are also resistant to conventional chemo- and radio-therapies. Here we report that ionizing radiation can induce stem cell-like properties in heterogeneous cancer cells. Exposure of non-stem cancer cells to ionizing radiation enhanced spherogenesis, and this was accompanied by upregulation of the pluripotency genes Sox2 and Oct3/4. Knockdown of Sox2 or Oct3/4 inhibited radiation–induced spherogenesis and increased cellular sensitivity to radiation. These data demonstrate that ionizing radiation can activate stemness pathways in heterogeneous cancer cells, resulting in the enrichment of a CSC subpopulation with higher resistance to radiotherapy.

Ghisolfi, Laura; Keates, Andrew C.; Hu, Xingwang; Lee, Dong-ki; Li, Chiang J.

2012-01-01

59

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

SciTech Connect

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

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

2002-07-01

60

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

Microsoft Academic Search

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

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

61

Ionizing Radiation Induces Delayed Hyperrecombination in Mammalian Cells  

Microsoft Academic Search

Exposure to ionizing radiation can result in delayed effects that can be detected in the progeny of an irradiated cell multiple generations after the initial exposure. These effects are described under the rubric of radiation-induced genomic instability and encompass multiple genotoxic endpoints. We have developed a green fluorescence protein (GFP)-based assay and demonstrated that ionizing radiation induces genomic instability in

Lei Huang; Suzanne Grim; Leslie E. Smith; Perry M. Kim; Jac A. Nickoloff; Olga G. Goloubeva; William F. Morgan

2004-01-01

62

Radiation-induced osteosarcoma of the sphenoid bone  

SciTech Connect

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

Tanaka, S.; Nishio, S.; Morioka, T.; Fukui, M.; Kitamura, K.; Hikita, K. (Kyushui Univ., Fukuoka (Japan))

1989-10-01

63

Erb's Palsy (Brachial Plexus Birth Palsy)  

MedlinePLUS

... infant cannot move the arm effectively. (Courtesy of Texas Scottish Rite Hospital for Children) Anatomy The brachial ... overhead when reaching for an object. (Courtesy of Texas Scottish Rite Hospital for Children) A pediatrician is ...

64

Management of brachial artery aneurisms in infants  

Microsoft Academic Search

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

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

2008-01-01

65

Radiation induced collapse of the crystalline structure  

NASA Astrophysics Data System (ADS)

A theory of irradiation-induced amorphization of ordered intermetallic compounds, based on the destabilization of the crystalline structure by excess defect accumulation, has been developed recently. The theory is reviewed starting with its phenomenological basis, where the microstructural evolution of intermetallic compounds that are turned amorphous by irradiation is emphasized. Next, the analysis of defect buildup that suggests the formation of a stable complex defect consisting of a vacancy-interstitial pair, called a complex, is reviewed. The possibility of a radiation induced microstructure such as interstitial clusters, in addition to complexes, in intermetallics that undergo the crystalline-to-amorphous transition is incorporated into the theory. A comparison of radiation effects in NiTi and in Zr3Al is made using a rate theory approach. In the case of the aluminide, it is found that cluster development can hinder the amorphous transition when the material is irradiated with electrons. On the other hand, enhancement of complex production in the collision cascade, explains the occurrence of the transition during ion combardment.

Pedraza, D. F.

1987-08-01

66

Radiation-induced amorphization of crystalline ice  

NASA Astrophysics Data System (ADS)

We study radiation-induced amorphization of crystalline ice, analyzing the results of three decades of experiments with a variety of projectiles, irradiation energy, and ice temperature, finding a similar trend of increasing resistance of amorphization with temperature and inconsistencies in results from different laboratories. We discuss the temperature dependence of amorphization in terms of the 'thermal spike' model. We then discuss the common use of the 1.65 ?m infrared absorption band of water as a measure of degree of crystallinity, an increasingly common procedure to analyze remote sensing data of astronomical icy bodies. The discussion is based on new, high quality near-infrared reflectance absorption spectra measured between 1.4 and 2.2 ?m for amorphous and crystalline ices irradiated with 225 keV protons at 80 K. We found that, after irradiation with 10 15 protons cm -2, crystalline ice films thinner than the ion range become fully amorphous, and that the infrared absorption spectra show no significant changes upon further irradiation. The complete amorphization suggests that crystalline ice observed in the outer Solar System, including trans-neptunian objects, may results from heat from internal sources or from the impact of icy meteorites or comets.

Famá, M.; Loeffler, M. J.; Raut, U.; Baragiola, R. A.

2010-05-01

67

Radiation-Induced Amorphization of Crystalline Ice  

NASA Astrophysics Data System (ADS)

Crystalline ice has been unambiguously identified on the surface of most of the Jovian, Saturnian and Uranian satellites, and on the surface of some trans-Neptunian objects such as Quaoar, and 2003 EL61. This result is surprising, as the low surface temperatures of these objects should cause the ice condensed on them to be amorphous. Moreover, the surface of these bodies is constantly exposed to UV photons, solar wind, cosmic rays or energetic charged particles trapped by the planetary magnetic fields, which are known to amorphize crystalline ice. Here, we review 30 years of experimental studies of radiation-induced amorphization of crystalline ice analyzing the differences found between light and heavy ions, electrons and photons. We also present high quality near-infrared absorption spectra for amorphous and crystalline ice before and after we irradiated them with 225 keV protons. After irradiation at 80 K, the crystalline ice spectrum is altered so that it is indistinguishable from the spectrum of amorphous ice, indicating that irradiation can fully amorphize crystalline ice. We will compare these results with previous studies and discuss the astrophysical implication for planetary bodies.

Fama, Marcelo A.; Loeffler, M. J.; Raut, U.; Baragiola, R. A.

2008-09-01

68

Overview of Radiation-Induced Interface Traps in MOS Structures  

National Technical Information Service (NTIS)

We focus on radiation-induced interface traps, describing first how they fit into the overall radiation response of metal-oxide semiconductor (MOS) structures. Detailed measurements of the time-, field-, and temperature-dependences of the buildup of radia...

F. B. McLean H. E. Boesch J. M. McGarrity T. R. Oldham

1989-01-01

69

Magnetic resonance neurography diagnosed brachial plexitis: a case report.  

PubMed

Idiopathic brachial plexitis is a rare disorder presenting with pain and weakness in the shoulder girdle and upper extremity. Idiopathic brachial plexitis can mimic other conditions that cause acute pain and weakness around the shoulder, and its diagnosis can be challenging. There is no special test for the diagnosis of idiopathic brachial plexitis, although electromyography may be useful. In this case of idiopathic brachial plexitis, we present magnetic resonance neurography findings for the first time. PMID:15895358

Sarikaya, Selda; Sumer, Murat; Ozdolap, Senay; Erdem, C Zuhal

2005-05-01

70

Delayed brachial plexus paralysis due to subclavian after clavicular fracture  

Microsoft Academic Search

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

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

71

Brachial plexus injury after anterior shoulder dislocation : A case report  

Microsoft Academic Search

Brachial plexus injury is a rare complication of ante- rior dislocation of the shoulder : nine cases have been reported in the literature. We report a unique case of anterior dislocation of the shoulder with associated brachial plexus palsy involving the posterior and medial cords. This is the first reported case of such an injury. Previous case reports of brachial

Emma SHEARS; Dakshinamurthy SUNDERAMOORTHY; Seyed ASHGAR ALI

2005-01-01

72

Brachial vascular reactivity in blacks.  

PubMed

Endothelial function was studied ultrasonographically in a healthy subset of African Americans (blacks) because they have an increased risk of hypertension and vascular disease. Twenty-four healthy black and 28 well-matched white subjects were investigated. Ischemia was induced by inflating a cuff over the forearm to 40 mm Hg higher than systolic pressure for 5 minutes. Brachial artery diameter and blood flow velocity were measured at baseline and at 15, 45, and 60 seconds after deflation by use of an Acuson 128XP10 ultrasonograph with a 7.5 MHz transducer. Mean postischemic dilatation, an index of endothelial function, was 1.76+/-0.56% in blacks and 8.79+/-1.22% in whites (P<0.001). Median postischemic vasodilatation in black men [0% (0% to 2.86%)] was not significantly different to that in black women [0.82% (0% to 3.14%)], whereas white women [11.48% (8.70% to 14.29%)] dilated significantly more than white men [4.20% (2.13% to 5.56%)] (P<0.05). Both groups dilated significantly over baseline diameter to sublingual nitroglycerin administration 18.7+/-2.5% (blacks) and 20.2+/-3.2% (whites; P=NS). Mean hyperemic responses did not differ significantly between the 2 subject groups, nor did they differ between men and women of both ethnic groups. We conclude that endothelium-dependent vasodilatation is significantly impaired in healthy, young blacks compared with whites and that gender differences are not seen in blacks with regard to this phenomenon. An impairment in endothelium-dependent NO generation may be a contributing factor to future hypertension and vascular disease in healthy blacks. PMID:11082158

Perregaux, D; Chaudhuri, A; Rao, S; Airen, A; Wilson, M; Sung, B H; Dandona, P

2000-11-01

73

Brachial plexus variations during the fetal period.  

PubMed

The brachial plexus is an important nervous system structure. It can be injured during the perinatal period and by postnatal damage. The goal of this study was to assess human fetal brachial plexus variability. A total of 220 brachial plexuses were surgically prepared from 110 human fetuses aged 14-32 weeks of fetal life (50 females and 60 males) ranging in CRL from 80 to 233 mm. The study incorporated the following methods: dissectional and anthropological, digital image acquisition, digital image processing using Image J and GIMP software, and statistical methods (Statistica 9.0). Symmetry and sexual dimorphism were examined. Anomalies of the brachial plexuses were observed in 117 (53.18 %) cases. No sexual dimorphism was found. It was observed that cord variations occurred more often on the left side. Division variants (33.64 %) occurred most often, but also cords (18.18 %) as well as root nerves and terminal ramifications (15.90 %) were found. Trunk anomalies were rare and occurred in only 5.45 % of plexuses. Three height types of median nerve roots in combination with the nerve were distinguished. In one-third of cases, median nerve root connections were found below the axillary fossa and even half in the proximal part of the humerus. In conclusion, the brachial plexus was characterized for anatomical structural variability. Most often division and cord variations were observed. Anomalies occurred regardless of sex or body side except for cord variants. Brachial plexus variation recognition is significant from the neurosurgical and traumatological point of view. PMID:22945314

Wo?niak, Jowita; K?dzia, Alicja; Dudek, Krzysztof

2012-09-04

74

Radiation-induced reactions in polymer films  

NASA Astrophysics Data System (ADS)

Since the 1950's, there has been a considerable interest in the effects of ionizing radiation on the physical properties of polymer systems. Radiation induced chemical changes that were found to be helpful in producing specialty polymers, but also potentially harmful by degrading the physical performance of the material. Therefore, solute molecules, which act as excited state quenchers, and free radical scavengers, have been incorporated into the polymers in order to regulate the crosslinking, scission and desaturation reactions. This work is focused on using spectroscopic techniques to characterize the physical properties of polymeric media and the reactions occurring within them following pulsed radiolysis. This is done primarily by using arene doped polymer films which have highly absorbing excited states and radical ions that are easily monitored by transient studies. The probes are used to characterize the polymeric microenvironment, to monitor reaction rates, and to interfere in the radical reactions. Photophysical and photochemical characterization of partially crystalline polyethylene complements data previously obtained by conventional physical techniques for polymer characterization. Probe molecules are excluded from crystalline zones and distributed in a networked structure of amorphous zones. Upon high energy radiolysis, it is found that polyolefin systems efficiently donate all radical ions and excited states to the solute molecules, even when the energy is absorbed within the polymer crystalline zones. Studies of the subsequent reactions of the solute excited states and radical ions reveal information about their long term effectiveness as protectants. It is found that highly excited states formed by the recombination of solute radical ions are energetic enough to cause dissociation of halo-arenes. Also, arenes are found to become attached to the polymer chain through a polymer-aryl radical intermediate. These intermediates have been isolated and photophysically characterized so that they can be easily identified in future experiments where they may be important reactants. Alternatively, photophysical probes are attached to polymer chains by radical copolymerization of pyrene acrylic acid and methyl acrylate with the underivatized monomer. These probes did not inhibit the polymerization reaction, and were found to be useful in monitoring polymerization rates during the early stages of polymerization.

Biscoglio, Michael Benedict

75

Electrodiagnostic assessment of the brachial plexus.  

PubMed

The brachial plexus is one of the largest and most complex structures of the peripheral nervous system and, as such, cannot be studied by a single nerve conduction study (NCS) or muscle sampled by needle electrode examination (NEE). Typically, the screening sensory NCS is used and expanded to identify the region of involvement, the motor NCS is applied to determine the severity of the process, and the NEE is used to further characterize the lesion. Our approach to the electrodiagnostic assessment of the brachial plexus is the focus of this article; 3 electrodiagnostic cases with discussion follow this article. PMID:22361374

Ferrante, Mark A

2011-12-30

76

What has changed in brachial plexus surgery?  

PubMed Central

Brachial plexus injuries, in all their severity and complexity, have been extensively studied. Although brachial plexus injuries are associated with serious and often definitive sequelae, many concepts have changed since the 1950s, when this pathological condition began to be treated more aggressively. Looking back over the last 20 years, it can be seen that the entire approach, from diagnosis to treatment, has changed significantly. Some concepts have become better established, while others have been introduced; thus, it can be said that currently, something can always be offered in terms of functional recovery, regardless of the degree of injury. Advances in microsurgical techniques have enabled improved results after neurolysis and have made it possible to perform neurotization, which has undoubtedly become the greatest differential in treating brachial plexus injuries. Improvements in imaging devices and electrical studies have allowed quick decisions that are reflected in better surgical outcomes. In this review, we intend to show the many developments in brachial plexus surgery that have significantly changed the results and have provided hope to the victims of this serious injury.

de Rezende, Marcelo Rosa; Silva, Gustavo Bersani; de Paula, Emygdio Jose Leomil; Junior, Rames Mattar; de Camargo, Olavo Pires

2013-01-01

77

Case report. Bee sting brachial block  

Microsoft Academic Search

A case of brachial plexus block is presented, following a bee sting in the posterior triangle of the neck. The onset of neurological symptoms was rapid as was their subsequent resolution. Delayed peripheral neurological symptoms believed to have an immunological basis have been reported in response to stings from bees and other Hymenoptera both in the central and peripheral nervous

S M Hay; F A Hay; D H Austwick

1992-01-01

78

Hypopharyngeal carcinoma after radiation for tuberculosis: radiation-induced carcinoma.  

PubMed

Radiation may cause radiation-induced cancers after a long latency period. In a group of 111 patients surgically treated for hypopharyngeal carcinoma, patients previously treated with radiotherapy for tuberculosis in the neck were compared to patients without previous radiotherapy. Seven patients (7.4%) underwent radiotherapy (median age 15 years) and developed a hypopharyngeal carcinoma (median age 70 years, median latency period 54.4 year). Considering this long latency period and the localisation in the previous radiation field these tumours can be classified as potentially radiation-induced carcinomas. Patients with potentially radiation-induced carcinomas were significantly older when the hypopharyngeal carcinoma was diagnosed (p=0.048), were more frequently females (p=0.05) and had a worse 5-year regional control rate (p=0.048). When radiotherapy is considered in young patients the risk of induction of tumours has to be kept in mind. PMID:20656544

van der Putten, Lisa; de Bree, Remco; Kuik, Dirk J; Rietveld, Derek H F; Langendijk, Johannes A; Leemans, C René

2010-07-24

79

Metal oxides immobilized fabrics by radiation induced graft polymerization  

NASA Astrophysics Data System (ADS)

Radiation induced graft polymerization is effective for adding a new functionality to various forms of existing polymers. Ion-exchange nonwoven fabrics by gamma radiation induced graft polymerization have been used as filters in air and liquid. However, these materials have no capability for removing non-ionic species, such as volatile organic compound and ozone. Manganese oxides immobilized fabrics were developed for removing ozone. In addition, these materials were capable of removing formaldehyde and arsenic. Fine particles of manganese oxides were observed on the fibers. New materials produced by radiation induced graft polymerization and metal immobilization were applicable for purification of contaminants in environment. Manufacturing process is applicable for immobilization of the other metal oxides.

Fujiwara, K.; Masubuchi, T.; Miyata, K.; Shiozawa, M.; Takato, T.; Harakawa, H.

2010-03-01

80

Hyperbaric oxygen: Primary treatment of radiation-induced hemorrhagic cystitis  

SciTech Connect

Of 8 patients with symptoms of advanced cystitis due to pelvic radiation treated with hyperbaric oxygen 7 are persistently improved during followup. All 6 patients treated for gross hematuria requiring hospitalization have been free of symptoms for an average of 24 months (range 6 to 43 months). One patient treated for stress incontinence currently is dry despite little change in bladder capacity, implying salutary effect from hyperbaric oxygen on the sphincter mechanism. One patient with radiation-induced prostatitis failed to respond. This experience suggests that hyperbaric oxygen should be considered the primary treatment for patients with symptomatic radiation-induced hemorrhagic cystitis.

Weiss, J.P.; Neville, E.C.

1989-07-01

81

What mechanisms/processes underlie radiation-induced genomic instability?  

PubMed

Radiation-induced genomic instability is a modification of the cell genome found in the progeny of irradiated somatic and germ cells but that is not confined on the initial radiation-induced damage and may occur de novo many generations after irradiation. Genomic instability in the germ line does not follow Mendelian segregation and may have unpredictable outcomes in every succeeding generation. This phenomenon, for which there is extensive experimental data and some evidence in human populations exposed to ionising radiation, is not taken into account in health risk assessments. It poses an unknown morbidity/mortality burden. Based on experimental data derived over the last 20 years (up to January 2012) six mechanistic explanations for the phenomenon have been proposed in the peer-reviewed literature. This article compares these hypotheses with the empirical data to test their fitness to explain the phenomenon. As a conclusion, the most convincing explanation of radiation-induced genomic instability attributes it to an irreversible regulatory change in the dynamic interaction network of the cellular gene products, as a response to non-specific molecular damage, thus entailing the rejection of the machine metaphor for the cell in favour of one appropriate to a complex dissipative dynamic system, such as a whirlpool. It is concluded that in order to evaluate the likely morbidity/mortality associated with radiation-induced genomic instability, it will be necessary to study the damage to processes by radiation rather than damage to molecules. PMID:22955377

Karotki, Andrei V; Baverstock, Keith

2012-09-06

82

Radiation-induced segregation in alloy X-750  

SciTech Connect

Microstructural and microchemical evolution of an Alloy X-750 heat under neutron irradiation was studied in order to understand the origin of irradiation-assisted stress corrosion cracking. Both clustering of point defects and radiation-induced segregation at interfaces were observed. Although no significant changes in the precipitate structure were observed, boundaries exhibited additional depletion of Cr and Fe and enrichment of Ni.

Kenik, E.A.

1996-12-31

83

Cosmology for grand unified theories with radiatively induced symmetry breaking  

Microsoft Academic Search

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

Andreas Albrecht; P. J. Steinhardt

1982-01-01

84

Dose rate radiation induced linear CCD functional failure  

Microsoft Academic Search

The experiments of different dose rate radiation induced Charge Coupled Devices (CCD) functional failure are presented. The CCDs are divided into three groups with no shielding, shielding the output amplifiers, and shielding the photo sensing and the shift register areas with Pb during 60Co ? tests. The radiation tolerance depend on the dose rates whether the linear CCDs are shielded

Zujun Wang; Bengqi Tang; Zhigang Xiao; Minbo Liu; Yong Zhang; Shaoyan Huang

2011-01-01

85

Photo- and radiation-induced coordination defects in amorphous chalcogenides  

NASA Astrophysics Data System (ADS)

Photo- and radiation-induced destruction-polymerization transformations in amorphous As2S3 associated with coordination defects formation processes have been studied by differential IR Fourier spectroscopy method in the 400 - 100 cm-1 region. All topological variants of these processes, statistically possible in the investigated samples, have been taken into account for physical consideration of the real structural transformations.

Shpotyuk, Oleg I.

1997-02-01

86

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...

87

Radiation-induced cognitive impairment-from bench to bedside  

PubMed Central

Approximately 100 000 patients per year in the United States with primary and metastatic brain tumor survive long enough (>6 months) to develop radiation-induced brain injury. Before 1970, the human brain was thought to be radioresistant; the acute central nervous system (CNS) syndrome occurs after single doses of ?30 Gy, and white matter necrosis can occur at fractionated doses of ?60 Gy. Although white matter necrosis is uncommon with modern radiation therapy techniques, functional deficits, including progressive impairments in memory, attention, and executive function have become increasingly important, having profound effects on quality of life. Preclinical studies have provided valuable insights into the pathogenic mechanisms involved in radiation-induced cognitive impairment. Although reductions in hippocampal neurogenesis and hippocampal-dependent cognitive function have been observed in rodent models, it is important to recognize that other brain regions are affected; non–hippocampal-dependent reductions in cognitive function occur. Neuroinflammation is viewed as playing a major role in radiation-induced cognitive impairment. During the past 5 years, several preclinical studies have demonstrated that interventional therapies aimed at modulating neuroinflammation can prevent/ameliorate radiation-induced cognitive impairment independent of changes in neurogenesis. Translating these exciting preclinical findings to the clinic offers the promise of improving the quality of life in patients with brain tumors who receive radiation therapy.

Greene-Schloesser, Dana; Robbins, Mike E.

2012-01-01

88

Possible Repair of Radiation-Induced Nondisjunction in Mouse Oocytes  

Microsoft Academic Search

There are some data from human epidemiological studies which suggest that radiation has a small but significant effect in causing aneuploid gametes. Alberman et al. (1972) suggested that much of this radiation occurred more than ten years before the conception of the abnormal child. Mice have been used to study experimentally radiation effects on chromosome segregation. Radiation induces nondisjunction in

Barbara Gayle Brennan

1984-01-01

89

Possible repair of radiation-induced nondisjunction in mouse oocytes  

Microsoft Academic Search

There are some data human epidemiological studies which suggest that radiation has a small but significant effect in causing aneuploid gametes. Alberman et al. (1972) suggested that much of this radiation occurred more than ten years before the conception of the abnormal child. Mice have been used to study experimentally radiation effects on chromosome segregation. Radiation induces nondisjunction in several

Barbara Gayle Brennan

1984-01-01

90

Radiation Induced Carcinogenesis; Epidemiology and Mechanisms: A Review  

Microsoft Academic Search

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-

Stuart Anderson

91

Desmoid Tumour of the Brachial Plexus  

PubMed Central

Desmoid tumours of the brachial plexus are rare and may occur in extra-abdominal sites. The tumours are of fibroblastic origin and, although benign, are locally aggressive. Their relationship to critical neurovascular structures in their anatomic locations presents a challenge to the operating surgeons trying to adhere to the principles of surgery. Surprisingly little neurosurgical literature exists which was devoted to this topic despite the challenge these lesions present in surgery both at surgery and in choosing adjuvant therapies. We report a case of a large brachial plexus tumour in a patient which was diagnosed radiologically and histopathologically and the patient underwent surgical excision with good outcome. Desmoid tumours histologically are benign and are usually composed of proliferating, benign fibroblasts in an abundant matrix of collagen. They do not transform into malignant tumours or metastasize. Surgery is the mainstay of treatment; however, adjuvant radiation and chemotherapy remain controversial.

Juliette, Orege; Florentius, Koech; Francis, Ndiangui; Macharia, Benson Ndegwa; Neema, Mbaruku

2013-01-01

92

Management of infant brachial plexus injuries.  

PubMed

Management of brachial plexus injuries is geared toward normalization of limb function, primarily through optimization of nerve regeneration and mechanical increase in elbow flexion and shoulder stabilization. Changes in the skeletal muscles and the osteous structures of the upper extremity are ongoing throughout the course of treatment, mandating continual assessment and aggressive rehabilitation. In patients who present too late for microsurgical intervention, irreversible changes take place in skeletal muscles, highlighting the importance of early referral. However, secondary procedures have been shown to be beneficial in older patients and in those whose primary procedures failed. Further advances in bionics and stem cell therapy may help replace the dynamic functional deficits of obstetric brachial plexus palsy. PMID:15636767

Shenaq, Saleh M; Bullocks, Jamal M; Dhillon, Gupreet; Lee, Rita T; Laurent, John P

2005-01-01

93

Brachial neuritis involving the bilateral phrenic nerves.  

PubMed

Brachial neuritis with bilateral hemidiaphragmatic paralysis has been reported in two previous cases in the literature. We report a patient who experienced severe right shoulder discomfort three weeks prior to hospital admission which evolved to include both shoulders. Two weeks prior to admission he noticed the onset of discomfort in breathing in the supine position and shortness of breath with minor exertion. The admitting diagnoses were myocardial infarction due to significant ECG changes and idiopathic elevated bilateral hemidiaphragms. The patient had findings significant for tachypnea, dyspnea, decreased breath sounds at the bases bilaterally, impaired motion of the bilateral lung bases on inspiration and paradoxical respirations. Comprehensive medical testing and evaluation revealed bilateral elevated hemidiaphragms and vital capacity 40% of normal. Weakness of the proximal shoulder girdle and bicep musculature bilaterally was noted. Electromyography was significant for reduced recruitment pattern in the bilateral shoulder girdle musculature. Nerve conduction studies suggested bilateral phrenic neuropathy. This case is an unusual presentation of brachial neuritis affecting the bilateral shoulder girdle with phrenic nerve involvement. The differential diagnosis of acute shoulder pain associated with respiratory symptomatology should therefore include brachial neuritis. PMID:3800625

Walsh, N E; Dumitru, D; Kalantri, A; Roman, A M

1987-01-01

94

Immobilization of Yeast Cells with Various Porous Carriers by Radiation-Induced Polymerization.  

National Technical Information Service (NTIS)

Yeast cells were immobilized by radiation-induced polymerization in twice. Various kinds of porous polymer carriers were prepared by radiation-induced polymerization of glass-forming monomers at a low temperature. Precultured yeast cells were incubated ae...

T. Fujimura I. Kaetsu

1982-01-01

95

A Study of Radiation-Induced Cerebral Vascular Injury in Nasopharyngeal Carcinoma Patients with Radiation-Induced Temporal Lobe Necrosis  

PubMed Central

Purpose To investigate radiation-induced carotid and cerebral vascular injury and its relationship with radiation-induced temporal lobe necrosis in nasopharyngeal carcinoma (NPC) patients. Methods and Materials Fifty eight NPC patients with radiation-induced temporal lobe necrosis (TLN) were recruited in the study. Duplex ultrasonography was used to scan bilateral carotid arterials to evaluate the intima-media thickness (IMT) and occurrence of plaque formation. Flow velocities of bilateral middle cerebral arteries (MCAs), internal carotid arteries (ICAs) and basal artery (BA) were estimated through Transcranial Color Doppler (TCD). The results were compared with data from 33 patients who were free from radiation-induced temporal lobe necrosis after radiotherapy and 29 healthy individuals. Results Significant differences in IMT, occurrence of plaques of ICAs and flow velocities of both MCAs and ICAs were found between patients after radiotherapy and healthy individuals (p<0.05). IMT had positive correlation with post radiation interval (p?=?0.049). Compared with results from patients without radiation-induced TLN, the mean IMT was significantly thicker in patients with TLN (p<0.001). Plaques were more common in patients with TLN than patients without TLN (p?=?0.038). In addition, flow velocities of MCAs and ICAs in patients with TLN were much faster (p<0.001, p<0.001). Among patients with unilateral TLN, flow velocity of MCAs was significantly different between ipsilateral and contralateral sides to the lesion (p?=?0.001). Conclusion Thickening of IMT, occurrence of plaque formation and hemodynamic abnormality are more common in patients after radiotherapy, especially in those with TLN, compared with healthy individuals.

Xiang, Yanqun; Xing, Yigang; Tang, Yamei

2012-01-01

96

Caffeine Markedly Enhanced Radiation-Induced Bystander Effects  

NASA Astrophysics Data System (ADS)

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

Jiang, Erkang; Wu, Lijun

2009-04-01

97

Effects from birth brachial plexus injury and postural control.  

PubMed

Of 32 children with birth brachial plexus injury, 31 had postural control deficits, including asymmetrical posture and atypical movements. Management of children with birth brachial plexus injury should address motor development of the entire body, not merely the affected extremity. PMID:23394776

Ridgway, Elizabeth; Valicenti-McDermott, Maria; Kornhaber, Lillian; Kathirithamby, Dona Rani; Wieder, Harriet

2013-02-07

98

Does the tumor microenvironment influence radiation-induced apoptosis?  

Microsoft Academic Search

Cytotoxic anti-cancer agents induce apoptosis in tumor and normal tissues. Therefore, it is important to investigate which\\u000a factors determine these apoptotic processes and hence their likely impact on therapeutic gain. Radiation-induced apoptosis\\u000a in tumors may be inhibited due to mutations of apoptotic elements or to tumor microenvironmental conditions arising from vascular\\u000a insufficiency. Tumors typically contain regions of hypoxia, low glucose

Alistair Hunter; Andre Hendrikse; Michael Renan; Raymond Abratt

2006-01-01

99

Radiation-induced space charge in polymer film capacitors  

Microsoft Academic Search

A space-charge mapping technique was used to observe the formation of x-ray-induced space charge in poly(ethylene terephthalate) and polystyrene capacitor structures. Electronic transport processes, responsible for radiation-induced conductivity in these insulators, produced trapped space charge adjacent to the electrodes. These results were consistent with the conclusions of earlier photoconductivity measurements and revealed injection processes that limit the buildup of space

S. R. Kurtz; R. A. Anderson

1986-01-01

100

Fiber enriched diets and radiation induced injury of the gut  

Microsoft Academic Search

The aim of this study was to evaluate the effect of fiber-enriched defined formula diets (DFDs) on radiation-induced enteropathy. Forty-five male Sprague-Dawley rats were assigned randomly after abdominal irradiation to one of three groups (15 in each group): a fiber-free DFD group, a non-soluble fiber-enriched DFD group, and a soluble fiber-enriched DFD group. They kept their diets respectively for seven

Murat Kapkac; Mehmet Erikoglu; Pars Tuncyurek; Sinan Ersin; Mustafa Esassolak; Murat Alkanat; Oguz Sipahioglu

2003-01-01

101

Pulsed radiation-induced attenuation in certain optical fibers  

Microsoft Academic Search

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

Jonathan D. Weiss

1992-01-01

102

Pulsed radiation-induced attenuation in certain optical fibers  

Microsoft Academic Search

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

J. D. Weiss

1992-01-01

103

Heavy-ion radiation induced bystander effect in mice  

NASA Astrophysics Data System (ADS)

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

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

2012-07-01

104

Tristetraprolin Mediates Radiation-Induced TNF-? Production in Lung Macrophages  

PubMed Central

The efficacy of radiation therapy for lung cancer is limited by radiation-induced lung toxicity (RILT). Although tumor necrosis factor-alpha (TNF-?) signaling plays a critical role in RILT, the molecular regulators of radiation-induced TNF-? production remain unknown. We investigated the role of a major TNF-? regulator, Tristetraprolin (TTP), in radiation-induced TNF-? production by macrophages. For in vitro studies we irradiated (4 Gy) either a mouse lung macrophage cell line, MH-S or macrophages isolated from TTP knockout mice, and studied the effects of radiation on TTP and TNF-? levels. To study the in vivo relevance, mouse lungs were irradiated with a single dose (15 Gy) and assessed at varying times for TTP alterations. Irradiation of MH-S cells caused TTP to undergo an inhibitory phosphorylation at Ser-178 and proteasome-mediated degradation, which resulted in increased TNF-? mRNA stabilization and secretion. Similarly, MH-S cells treated with TTP siRNA or macrophages isolated from ttp (?/?) mice had higher basal levels of TNF-?, which was increased minimally after irradiation. Conversely, cells overexpressing TTP mutants defective in undergoing phosphorylation released significantly lower levels of TNF-?. Inhibition of p38, a known kinase for TTP, by either siRNA or a small molecule inhibitor abrogated radiation-induced TNF-? release by MH-S cells. Lung irradiation induced TTPSer178 phosphorylation and protein degradation and a simultaneous increase in TNF-? production in C57BL/6 mice starting 24 h post-radiation. In conclusion, irradiation of lung macrophages causes TTP inactivation via p38-mediated phosphorylation and proteasome-mediated degradation, leading to TNF-? production. These findings suggest that agents capable of blocking TTP phosphorylation or stabilizing TTP after irradiation could decrease RILT.

Ray, Dipankar; Shukla, Shirish; Allam, Uday Sankar; Helman, Abigail; Ramanand, Susmita Gurjar; Tran, Linda; Bassetti, Michael; Krishnamurthy, Pranathi Meda; Rumschlag, Matthew; Paulsen, Michelle; Sun, Lei; Shanley, Thomas P.; Ljungman, Mats; Nyati, Mukesh K.; Zhang, Ming; Lawrence, Theodore S.

2013-01-01

105

Radiation-induced apoptosis in microvascular endothelial cells.  

PubMed

The response of the microvasculature to ionizing radiation is thought to be an important factor in the overall response of both normal tissues and tumours. It has recently been reported that basic fibroblast growth factor (bFGF), a potent mitogen for endothelial cells, protects large vessel endothelial cells from radiation-induced apoptosis in vitro. Microvessel cells are phenotypically distinct from large vessel cells. We studied the apoptotic response of confluent monolayers of capillary endothelial cells (ECs) to ionizing radiation and bFGF. Apoptosis was assessed by identifying changes in nuclear morphology, recording cell detachment rates and by detecting internucleosomal DNA fragmentation. Withdrawal of bFGF alone induces apoptosis in these monolayers. The magnitude of this apoptotic response depends upon the duration of bFGF withdrawal. Irradiation (2-10 Gy) induces apoptosis in a dose-dependent manner. Radiation-induced apoptosis occurs in a discrete wave 6-10 h after irradiation, and radiation-induced apoptosis is enhanced in cultures that are simultaneously deprived of bFGF. For example, 6 h after 10 Gy, 44.3% (s.e. 6.3%) of cells in the monolayer simultaneously deprived of bFGF exhibit apoptotic morphology compared with 19.8% (s.e. 3.8%) in the presence of bFGF. These studies show that either bFGF withdrawal or ionizing radiation can induce apoptosis in confluent monolayers of capillary endothelial cells and that radiation-induced apoptosis can be modified by the presence of bFGF. PMID:9043022

Langley, R E; Bump, E A; Quartuccio, S G; Medeiros, D; Braunhut, S J

1997-01-01

106

Thermal and radiation-induced interface traps in MOS devices  

Microsoft Academic Search

The interface trap build-up mechanisms during post-irradiation thermal annealing and radiation-induced charge neutralisation (RICN) are experimentally investigated. The role of substrate electrons is shown to be significant in post-irradiation interface trap build-up. The RICN is found to be incapable to replace a standard thermal annealing test in terms of conservative low dose rate response estimation

A. V. Sogoyan; S. V. Cherepko; V. S. Pershenkov; V. I. Rogov; V. N. Ulimov; V. V. Emelianov

1997-01-01

107

Use of probiotics for prevention of radiation-induced diarrhea  

Microsoft Academic Search

AIM: To investigate the efficacy of a high-potency probiotic preparation on prevention of radiation-induced diarrhea in cancer patients. METHODS: This was a double-blind, placebo-controlled trial. Four hundred and ninety patients who underwent adjuvant postoperative radiation therapy after surgery for sigmoid, rectal, or cervical cancer were assigned to either the high-potency probiotic preparation VSL#3 (one sachet t.i.d. ,) or placebo starting

P Deli; G Sansotta; V Donato; P Frosina; G Messina; C De Renzis; G Famularo

2007-01-01

108

Radiation induced CNS toxicity - molecular and cellular mechanisms  

PubMed Central

Radiotherapy of tumours proximal to normal CNS structures is limited by the sensitivity of the normal tissue. Prior to the development of prophylactic strategies or treatment protocols a detailed understanding of the mechanisms of radiation induced CNS toxicity is mandatory. Histological analysis of irradiated CNS specimens defines possible target structures prior to a delineation of cellular and molecular mechanisms. Several lesions can be distinguished: Demyelination, proliferative and degenerative glial reactions, endothelial cell loss and capillary occlusion. All changes are likely to result from complex alterations within several functional CNS compartments. Thus, a single mechanism responsible cannot be separated. At least four factors contribute to the development of CNS toxicity: (1) damage to vessel structures; (2) deletion of oligodendrocyte-2 astrocyte progenitors (O-2A) and mature oligodendrocytes; (3) deletion of neural stem cell populations in the hippocampus, cerebellum and cortex; (4) generalized alterations of cytokine expression. Several underlying cellular and molecular mechanisms involved in radiation induced CNS toxicity have been identified. The article reviews the currently available data on the cellular and molecular basis of radiation induced CNS side effects. ??http://www.bjcancer.com © 2001 Cancer Research Campaign

Belka, C; Budach, W; Kortmann, R D; Bamberg, M

2001-01-01

109

Radiation-induced products of peptides and their enzymatic digestibility  

SciTech Connect

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

Gajewski, E.

1983-01-01

110

A Comparison between Brachial and Echocardiographic Systolic Time Intervals  

PubMed Central

Systolic time interval (STI) is an established noninvasive technique for the assessment of cardiac function. Brachial STIs can be automatically determined by an ankle-brachial index (ABI)-form device. The aims of this study are to evaluate whether the STIs measured from ABI-form device can represent those measured from echocardiography and to compare the diagnostic values of brachial and echocardiographic STIs in the prediction of left ventricular ejection fraction (LVEF) <50%. A total of 849 patients were included in the study. Brachial pre-ejection period (bPEP) and brachial ejection time (bET) were measured using an ABI-form device and pre-ejection period (PEP) and ejection time (ET) were measured from echocardiography. Agreement was assessed by correlation coefficient and Bland-Altman plot. Brachial STIs had a significant correlation with echocardiographic STIs (r?=?0.644, P<0.001 for bPEP and PEP; r ?=?0.850, P<0.001 for bET and ET; r?=?0.708, P<0.001 for bPEP/bET and PEP/ET). The disagreement between brachial and echocardiographic STIs (brachial STIs minus echocardiographic STIs) was 28.55 ms for bPEP and PEP, -4.15 ms for bET and ET and -0.11 for bPEP/bET and PEP/ET. The areas under the curve for bPEP/bET and PEP/ET in the prediction of LVEF <50% were 0.771 and 0.765, respectively. Brachial STIs were good alternatives to STIs obtained from echocardiography and also helpful in prediction of LVEF <50%. Brachial STIs automatically obtained from an ABI-form device may be helpful for evaluation of left ventricular systolic dysfunction.

Su, Ho-Ming; Lin, Tsung-Hsien; Hsu, Po-Chao; Chu, Chun-Yuan; Lee, Wen-Hsien; Chen, Szu-Chia; Lee, Chee-Siong; Voon, Wen-Chol; Lai, Wen-Ter; Sheu, Sheng-Hsiung

2013-01-01

111

Quantifying Local Radiation-Induced Lung Damage From Computed Tomography  

SciTech Connect

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

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

2010-02-01

112

Facial reconstruction for radiation-induced skin cancer  

SciTech Connect

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.

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

1990-04-01

113

Functionalization of carbon nanotubes by radiation-induced graft polymerization.  

PubMed

Multi-walled carbon nanotubes (MWCNTs) were functionalized by radiation-induced graft polymerization of acrylic acid onto the surface of MWCNTs in order to improve their dispersibility in water. 1H NMR, Raman spectroscopy, TEM, and TGA techniques were used to characterize the resulting functionalized MWCNTs. The grafting degree was dependent on the grafting conditions such as the absorbed dose and the monomer concentration. The experimental results confirmed that poly(acrylic acid) chains were successfully grafted onto the surface of the MWCNTs. The poly(acrylic acid)-grafted MWCNTs showed a much better water dispersibility than the pristine MWCNTs. PMID:19908742

Jung, Chan-Hee; Kim, Dong-Ki; Choi, Jae-Hak; Shin, Kwanwoo; Nho, Young-Chang; Suh, Dong-Hack

2009-12-01

114

Radiation-induced apoptosis in the eye structures: a review  

NASA Astrophysics Data System (ADS)

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

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

2005-02-01

115

Quantitative analysis of radiation-induced disorder in spinel crystals  

NASA Astrophysics Data System (ADS)

Structural defects in the surface region of magnesium aluminate spinel (MgAl2O4) crystals irradiated with 450 MeV Xe ions were analyzed by using 4He backscattering in channeling geometry (RBS/C). Monte-Carlo simulations applied for the interpretation of channeling spectra permitted to determine the concentration of radiation-induced defects. They showed that the defect distributions are depth dependent, likely due to annihilation of defects at the surface of the crystals. The cross-section for the formation of defects by swift Xe ions, and consequently the diameter of an ion track, were estimated using single-impact-model calculations.

Thomé, L.; Jagielski, J.; Gentils, A.; Nowicki, L.; Garrido, F.

2006-01-01

116

Management of radiation-induced accelerated carotid atherosclerosis  

SciTech Connect

Patients with long survival following cervical irradiation are at risk for accelerated carotid atherosclerosis. The neurologic presentation in these patients mimics naturally occurring atheromatous disease, but patients often present at younger ages and with less concurrent coronary or systemic vascular disease. Hypercholesterolemia also contributes to this accelerated arteriosclerosis. Angiographic findings in this disorder include disproportionate involvement of the distal common carotid artery and unusually long carotid lesions. Pathologic findings include destruction of the internal elastic lamina and replacement of the normal intima and media with fibrous tissue. This article describes two surgical patients with radiation-induced accelerated carotid atherosclerosis who typify the presentation and characteristics of this disease.

Loftus, C.M.; Biller, J.; Hart, M.N.; Cornell, S.H.; Hiratzka, L.F.

1987-07-01

117

Measurements of prompt radiation induced conductivity of Kapton.  

SciTech Connect

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.

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

118

Transient radiation-induced absorption in laser materials  

SciTech Connect

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

Brannon, P.J.

1994-12-31

119

Radiation-induced segregation in candidate fusion-reactor alloys  

SciTech Connect

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.

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

1981-07-01

120

Sensitivity to Radiation-Induced Cancer in Hemochromatosis  

SciTech Connect

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

Bull. Richard J.; Anderson, Larry E.

2000-06-01

121

Radiation-induced skin carcinomas of the head and neck  

SciTech Connect

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

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

1991-03-01

122

Squamous cell carcinoma antigen suppresses radiation-induced cell death  

PubMed Central

Previous study has demonstrated that squamous cell carcinoma antigen (SCCA) 1 attenuates apoptosis induced by TNF?, NK cell or anticancer drug. In this study, we have examined the effect of SCCA2, which is highly homologous to SCCA1, but has different target specificity, against radiation-induced apoptosis, together with that of SCCA1. We demonstrated that cell death induced by radiation treatment was remarkably suppressed not only in SCCA1 cDNA-transfected cells, but also in SCCA2 cDNA-transfected cells. In these transfectants, caspase 3 activity and the expression of activated caspase 9 after radiation treatment were suppressed. Furthermore, the expression level of phosphorylated p38 mitogen-activated protein kinase (p38 MAPK) was suppressed compared to that of the control cells. The expression level of upstream stimulator of p38 MAPK, phosphorylated MKK3/MKK6, was also suppressed in the radiation-treated cells. Thus, both SCCA1 and SCCA2 may contribute to survival of the squamous cells from radiation-induced apoptosis by regulating p38 MAPK pathway. © 2001 Cancer Research Campaign http://www.bjcancer.com

Murakami, A; Suminami, Y; Hirakawa, H; Nawata, S; Numa, F; Kato, H

2001-01-01

123

Radiation-induced defect centers in glass ceramics  

SciTech Connect

Electron spin resonance (ESR) was used to characterize the radiation-induced defect centers in low-thermal-expansion glass ceramics, including two types of Zerodur and Astrositall. The observed ESR spectra can be associated with different types of defect centers: a Zn/sup +/ center, several types of oxygen hole centers (OHCs), an aluminum-oxygen hole center (Al-OHC), an Fe/sup 3 +/ center, Ti/sup 3 +/ and Zr/sup 3 +/ centers, and three types of As centers. An Sb/sup 4 +/ center, which is not observed in Zerodur, is tentatively identified in Astrositall. From the effect of crystallization on the observed defect concentrations in Zerodur and computer simulation of the spectral lines of some of the centers, we infer that among the nine defect centers observed in the Zerodurs, the As-associated centers are located in the glassy phase and/or at the interface between the glassy and crystalline phases, Zn/sup +/ and Al-OHC are in the crystalline phase, and the rest (including most of the OHCs) are in the glassy phase. Radiation-induced compaction in these materials appears to be related to the generation of OHCs in the glass phase.

Tsai, T.E.; Friebele, E.J.; Griscom, D.L.; Pannhorst, W.

1989-01-15

124

Radiation induced corrosion of copper for spent nuclear fuel storage  

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

125

Brachial plexus compression by an iatrogenic arteriovenous fistula  

Microsoft Academic Search

Summary  A case of left brachial plexus compression by an iatrogenic arteriovenous fistula was treated by detachable balloon technique\\u000a with immediate relief of pain. Good results on paresia were obtained in a few weeks.

J. G. Tebib; J. Bascoulergue; Ch. Dumontet; A. Paupert-Ravault; B. Prallet; F. Colson; M. Bouvier

1987-01-01

126

Brachial Plexus Injuries in Neonates: An Osteopathic Approach  

Microsoft Academic Search

Neonates and infants with brachial plexus injuries are typ- ically treated using splinting, range-of-motion exercise, and, in more severe cases, nerve reconstruction. However, myofas- cial release—a common osteopathic manipulative treatment technique that has been used to manage thoracic outlet syn- drome in adults—may provide effective, noninvasive man- agement of brachial plexus injuries in neonates and infants. While emphasizing the importance

David C. Mason; Carman A. Ciervo

2009-01-01

127

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

Microsoft Academic Search

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

J. Rest

1995-01-01

128

[Splints in birth-related brachial plexus injuries].  

PubMed

Most cases of obstetrical brachial plexus palsies are mild traction injuries which resolve under physical therapy within several weeks or months. Severe ruptures or avulsion injuries of the plexus can lead to lifelong impairment of the upper extremities. Hence, in severe brachial plexus injuries the indications for brachial plexus reconstruction should be evaluated, early. At the age of about 3 months, the infant should be presented in a centre specialised in obstetrical brachial plexus palsies. In almost all cases intensive physical therapy is performed. In addition, many patients require splinting in order to gain function as part of the conservative therapy or for postoperative fixation. Depending on the type of splint, different demands are made on design, material and strategy of adjustment. Many different natural and synthetic materials are available for orthopaedic constructions. Because of its good adjustment options, the use of low temperature thermoplastic is steadily increasing. This contribution presents an overview of our currently used splints, new technical developments in our experience with more than 200 patients with obstetrical brachial plexus palsy. We present our experience with the most common splints for the use in fixation after birth-related brachial plexus surgery, subscapularis release, trapezius muscle transfer and functional improvement of hands with a lack of wrist extension. PMID:21509702

Schenck, T L; Bayer, T; Enders, A; Marton, M-A; Machens, H-G; Müller-Felber, W; Giunta, R E

2011-04-20

129

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

NASA Astrophysics Data System (ADS)

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

Matsumoto, H.; Ohnishi, T.

130

Get the LEAD out: noninvasive assessment for lower extremity arterial disease using ankle brachial index and toe brachial index measurements.  

PubMed

Lower extremity arterial disease affects approximately one third of individuals 66 years of age and older and has a high risk for nonhealing wounds, infection, and limb loss. Much wound care is given by or under the direction of nurses. Therefore, the assessment and management of these patients presents many opportunities and challenges. Assessment is the cornerstone of effective care, but traditional methods of lower extremity arterial assessment, such as pulse palpation and pain history, are insufficient to determine the presence and extent of ischemia. Recently published national guidelines for assessment and management of patients with lower extremity wounds have recommended using noninvasive tests such as the ankle brachial index and toe brachial index to rule out lower extremity arterial disease, which complicates wound healing. However, the ankle brachial index can be falsely elevated in patients with diabetes and renal failure because of calcification of the arteries, which causes them to be incompressible. In these situations, it has been advised to obtain a toe pressure or toe brachial index because digital arteries are usually less affected by calcification. There is a paucity of data about the knowledge of principles and performance of the ankle brachial index/toe brachial index by nurses, particularly in the United States, using pocket-sized portable Doppler equipment. Therefore, the purpose of this article is to provide an overview and synthesis of relevant studies and published expert opinion regarding noninvasive arterial assessment using ankle brachial and toe brachial indexes as a basis for developing protocols for performing the tests and identifying gaps in research where further investigation is needed. PMID:16444101

Bonham, Phyllis A

131

Factors that modify risks of radiation-induced cancer  

SciTech Connect

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).

Fabrikant, J.I.

1988-11-01

132

Radiation induced grafting of acrylic acid onto extruded polystyrene surface  

NASA Astrophysics Data System (ADS)

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

Fugaru, Viorel; Bubueanu, George; Tuta, Catalin

2012-09-01

133

[Radiation-induced and therapy-related AML/MDS].  

PubMed

Radiation induced acute myeloid leukemia (AML) was recognized a century ago, soon after mankind found radiation. Atomic bomb survivors developed de novo AML with relatively short latency with very high frequency. By contrast, excess occurrence of myelodysplastic syndrome (MDS) as well as solid tumors was found decades late. This difference may be due to etiology that many de novo AML patients harbor chimeric leukemogenic genes caused by chromosomal translocations, while MDS patients rarely carry chimeras. In addition, epigenetic change would play important roles. Therapy related leukemia is mainly caused by topoisomerase II inhibitors that cause de novo AML with an 11q23 translocation or by alkyrating agents that induce MDS/AML with an AML1 point mutation and monosomy 7. PMID:19860183

Inaba, Toshiya

2009-10-01

134

Radiation-induced gas evolution from commercial lubricant base oil  

SciTech Connect

Radiation-induced evolved gases for 20 commercial lubricant base oils were measured at room temperature. Samples were irradiated under vacuum by /sup 60/Co gamma rays at a dose rate of 1 Mrad/h up to 1000 Mrad for mineral oils and ester lubricants, and 3000 Mrad for aromatic lubricants. The evolved gas was measured by means of gas chromatography. The G values (number of gas molecules liberated per absorbed energy of 100 eV) of total evolved gases are 2.8 for liquid paraffins, 1.4 for paraffinic neutral oils, 1.5 to 1.9 for esters, 0.26 to 0.56 for alkyl diphenyl ethers, and 0.005 for phenoxy-phenoxydiphenyl.

Kazuo, A.; Nashiro, H.

1983-06-01

135

Probabilistic methodology for estimating radiation-induced cancer risk  

SciTech Connect

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.

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

1981-01-01

136

Radiation-induced polymerization for the immobilization of penicillin acylase  

SciTech Connect

The immobilization of Escherichia coli penicillin acylase was investigated by radiation-induced polymerization of 2-hydroxyethyl methacrylate at low temperature. A leak-proof composite that does not swell in water was obtained by adding the cross-linking agent trimethylolpropane trimethacrylate to the monomer-aqueous enzyme mixture. Penicillin acylase, which was immobilized with greater than 70% yield, possessed a higher Km value toward the substrate 6-nitro-3-phenylacetamidobenzoic acid than the free enzyme form (Km = 1.7 X 10(-5) and 1 X 10(-5) M, respectively). The structural stability of immobilized penicillin acylase, as assessed by heat, guanidinium chloride, and pH denaturation profiles, was very similar to that of the free-enzyme form, thus suggesting that penicillin acylase was entrapped in its native state into aqueous free spaces of the polymer matrix.

Boccu, E.; Carenza, M.; Lora, S.; Palma, G.; Veronese, F.M.

1987-06-01

137

Non-radiation induced signals in TL dosimetry.  

PubMed

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

German, U; Weinstein, M

2002-01-01

138

Modulation of radiation-induced hemopoietic suppression by acute thrombocytopenia  

SciTech Connect

Modifications of radiation-induced hemopoietic suppression by acute thrombocytopenia were evaluated. Immediately before or after exposure to sublethal irradiation, mice were given a single injection of anti-mouse platelet serum (APS), normal heterologous serum, neuraminidase (N'ase), or saline, or no further treatment was provided. Hemopoiesis was evaluated by blood cell counts, hematocrits, and incorporation of (75Se)selenomethionine into platelets. APS and N'ase induced an acute thrombocytopenia from which there was partial recovery before the platelet count started to fall from the radiation. During the second post-treatment week, both thrombocytopoiesis and erythropoiesis were greater in mice that received APS or N'ase in addition to radiation than in control irradiated mice. Differences in leukopoiesis were not apparent. Therefore, both thrombocytopoiesis and erythropoiesis appeared to be responsive to a stimulus generated by acute thrombocytopenia in sublethally irradiated mice.

Ebbe, S.; Phalen, E.; Threatte, G.; Londe, H.

1985-01-01

139

Environmental applications of radiation-induced defects in clay minerals  

NASA Astrophysics Data System (ADS)

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

Allard, T.

2011-12-01

140

Ion beam induced luminescence: Relevance to radiation induced bystander effects  

NASA Astrophysics Data System (ADS)

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

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

2012-10-01

141

Radiation-induced leukemia: Comparative studies in mouse and man  

SciTech Connect

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

Haas, M.

1991-01-01

142

Radiation-induced cell death: importance of lysosomal destabilization.  

PubMed

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

Persson, H Lennart; Kurz, Tino; Eaton, John W; Brunk, Ulf T

2005-08-01

143

Attenuation of a Radiation-Induced Conditioned Taste Aversion after the Development of Ethanol Tolerance,  

National Technical Information Service (NTIS)

An attempt to reduce a radiation-induced conditioned taste aversion (CTA) was undertaken by rendering animals tolerant to ethanol. Ethanol tolerance, developed over 5 days, was sufficient to block a radiation-induced taste aversion, as well as an ethanol-...

B. M. Rabin W. A. Hunt

1988-01-01

144

Radiation-induced Cancer Risk from Annual Computed Tomography for Patients with Cystic Fibrosis  

Microsoft Academic Search

Rationale: Computed tomography (CT) is being considered as a tool for routine monitoring of lung damage in people with cystic fibrosis. Concern has been raised, however, about the associated risk of radiation-induced cancer. Objectives: To estimate the risk of radiation-induced cancer from lung CT for patients with cystic fibrosis, assuming annual monitoring start- ing at age 2 years. Methods: Radiation

Amy Berrington de Gonzalez; Kwang Pyo Kim; Jonathan M. Samet

2007-01-01

145

Involvement of Prostaglandins and Histamine in Radiation-Induced Temperature Responses in Rats.  

National Technical Information Service (NTIS)

Exposure of rats to Gy of gamma radiation induced hypothermia, whereas exposure to 20-150 Gy produced hypothermia. Since radiation exposure included the release of prostaglandins (PGs) and histamine, the role of PGs and histamine in radiation-induced temp...

S. B. Kandasamy W. A. Hunt

1990-01-01

146

Involvement of prostaglandins and histamine in radiation-induced temperature responses in rats  

SciTech Connect

Exposure of rats to 1-15 Gy of gamma radiation induced hyperthermia, whereas exposure to 20-150 Gy produced hypothermia. Since radiation exposure induced the release of prostaglandins (PGs) and histamine, the role of PGs and histamine in radiation-induced temperature changes was examined. Radiation-induced hyper- and hypothermia were antagonized by pretreatment with indomethacin, a cyclooxygenase inhibitor. Intracerebroventricular administration of PGE2 and PGD2 induced hyper- and hypothermia, respectively. Administration of SC-19220, a specific PGE2 antagonist, attenuated PGE2- and radiation-induced hyperthermia, but it did not antagonize PGD2- or radiation-induced hypothermia. Consistent with an apparent role of histamine in hypothermia, administration of disodium cromoglycate (a mast cell stabilizer), mepyramine (H1-receptor antagonist), or cimetidine (H2-receptor antagonist) attenuated PGD2- and radiation-induced hypothermia. These results suggest that radiation-induced hyperthermia is mediated via PGE2 and that radiation-induced hypothermia is mediated by another PG, possibly PGD2, via histamine.

Kandasamy, S.B.; Hunt, W.A. (Armed Forces Radiobiology Research Institute, Bethesda, MD (USA))

1990-01-01

147

Universal damage factor for radiation-induced dark current in silicon devices  

Microsoft Academic Search

A new damage factor formulation is presented for describing radiation-induced dark current in silicon devices. This damage factor, K dark, is the number of carriers thermally generated per unit volume per unit time in a depletion region per unit nonionizing dose deposited in that volume. Kdark appears to account successfully for the mean radiation-induced dark current for any silicon device

J. R. Srour; D. H. Lo

2000-01-01

148

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

SciTech Connect

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

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

2011-07-15

149

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

Microsoft Academic Search

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

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

150

Automated analysis of brachial ultrasound time series  

NASA Astrophysics Data System (ADS)

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

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

1998-07-01

151

Screening for Peripheral Artery Disease and Cardiovascular Disease Risk Assessment with Ankle Brachial Index in Adults  

MedlinePLUS

... Screening for Peripheral Artery Disease and Cardiovascular Disease Risk Assessment with Ankle Brachial Index in Adults The U.S. ... Peripheral Artery Disease (PAD) and Cardiovascular Disease (CVD) Risk Assessment with Ankle Brachial Index (ABI) in Adults . This ...

152

Countermeasures for Space Radiation Induced Malignancies and Acute Biological Effects  

NASA Astrophysics Data System (ADS)

The hypothesis being evaluated in this research program is that control of radiation induced oxidative stress will reduce the risk of radiation induced adverse biological effects occurring as a result of exposure to the types of radiation encountered during space travel. As part of this grant work, we have evaluated the protective effects of several antioxidants and dietary supplements and observed that a mixture of antioxidants (AOX), containing L-selenomethionine, N-acetyl cysteine (NAC), ascorbic acid, vitamin E succinate, and alpha-lipoic acid, is highly effective at reducing space radiation induced oxidative stress in both in vivo and in vitro systems, space radiation induced cytotoxicity and malignant transformation in vitro [1-7]. In studies designed to determine whether the AOX formulation could affect radiation induced mortality [8], it was observed that the AOX dietary supplement increased the 30-day survival of ICR male mice following exposure to a potentially lethal dose (8 Gy) of X-rays when given prior to or after animal irradiation. Pretreatment of animals with antioxidants resulted in significantly higher total white blood cell and neutrophil counts in peripheral blood at 4 and 24 hours following exposure to doses of 1 Gy and 8 Gy. Antioxidant treatment also resulted in increased bone marrow cell counts following irradiation, and prevented peripheral lymphopenia following 1 Gy irradiation. Supplementation with antioxidants in irradiated animals resulted in several gene expression changes: the antioxidant treatment was associated with increased Bcl-2, and decreased Bax, caspase-9 and TGF-?1 mRNA expression in the bone marrow following irradiation. These results suggest that modulation of apoptosis may be mechanistically involved in hematopoietic system radioprotection by antioxidants. Maintenance of the antioxidant diet was associated with improved recovery of the bone marrow following sub-lethal or potentially lethal irradiation. Taken together, oral supplementation with antioxidants appears to be an effective approach for the radioprotection of hematopoietic cells against the cell killing effects of radiation, and for improving survival in irradiated animals. Preliminary data suggest similar antioxidant protective effects for animals exposed to potentially lethal doses of proton radiation. Studies were also performed to determine whether dietary antioxidants could affect the incidence rates of malignancies in CBA mice exposed to 300 cGy proton (1 GeV/n) radiation or 50 cGy iron ion (1 GeV/n) radiation [9]. Two antioxidant formulations were utilized in these studies; an AOX formulation containing the mixture of antioxidant agents developed from our previous studies and an antioxidant dietary formulation containing the soybean-derived protease inhibitor known as the Bowman-Birk inhibitor (BBI). BBI was evaluated in the form of BBI Concentrate (BBIC), which is the form of BBI utilized in human trials. BBIC has been utilized in human trials since 1992, as described [10]. The major finding in the long-term animal studies was that there was a reduced risk of malignant lymphoma in mice exposed to space radiations and maintained on diets containing the antioxidant formulations. In addition, the two different dietary countermeasures also reduced the yields of a variety of different rare tumor types, arising from both epithelial and connective tissue cells, observed in the animals exposed to space radiation. REFERENCES [1] Guan J. et al (2004) Radiation Research 162, 572-579. [2] Wan X.S. et al (2005) Radiation Research 163, 364-368. [3] Wan X.S. et al (2005) Radiation Research 163, 232-240. [4] Guan J. et al (2006) Radiation Research 165, 373-378. [5] Wan X.S. et al (2006) International Journal of Radiation Oncology, Biology, Physics 64, 1475-1481. [6] Kennedy A.R. et al (2006) Radiation Research 166, 327-332. [7] Kennedy A.R. et al (2007) Radiation & Environmental Biophysics 46(2), 201-3. [8]Wambi, C., Sanzari, J., Wan, X.S., Nuth, M., Davis, J., Ko, Y.-H., Sayers, C.M., Baran, M., Ware, J.H. and Kennedy, A

Kennedy, Ann

153

Radiation-induced defects in clay minerals: A review  

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

154

Radiation-Induced Bystander Effects in Cultured Human Stem Cells  

PubMed Central

Background The radiation-induced “bystander effect” (RIBE) was shown to occur in a number of experimental systems both in vitro and in vivo as a result of exposure to ionizing radiation (IR). RIBE manifests itself by intercellular communication from irradiated cells to non-irradiated cells which may cause DNA damage and eventual death in these bystander cells. It is known that human stem cells (hSC) are ultimately involved in numerous crucial biological processes such as embryologic development; maintenance of normal homeostasis; aging; and aging-related pathologies such as cancerogenesis and other diseases. However, very little is known about radiation-induced bystander effect in hSC. To mechanistically interrogate RIBE responses and to gain novel insights into RIBE specifically in hSC compartment, both medium transfer and cell co-culture bystander protocols were employed. Methodology/Principal Findings Human bone-marrow mesenchymal stem cells (hMSC) and embryonic stem cells (hESC) were irradiated with doses 0.2 Gy, 2 Gy and 10 Gy of X-rays, allowed to recover either for 1 hr or 24 hr. Then conditioned medium was collected and transferred to non-irradiated hSC for time course studies. In addition, irradiated hMSC were labeled with a vital CMRA dye and co-cultured with non-irradiated bystander hMSC. The medium transfer data showed no evidence for RIBE either in hMSC and hESC by the criteria of induction of DNA damage and for apoptotic cell death compared to non-irradiated cells (p>0.05). A lack of robust RIBE was also demonstrated in hMSC co-cultured with irradiated cells (p>0.05). Conclusions/Significance These data indicate that hSC might not be susceptible to damaging effects of RIBE signaling compared to differentiated adult human somatic cells as shown previously. This finding could have profound implications in a field of radiation biology/oncology, in evaluating radiation risk of IR exposures, and for the safety and efficacy of hSC regenerative-based therapies.

Sokolov, Mykyta V.; Neumann, Ronald D.

2010-01-01

155

The Relationship between Multiple Health Behaviours and Brachial Artery Reactivity  

PubMed Central

Background. The effects of smoking, alcohol consumption, obesity, and a sedentary lifestyle on endothelial function (EF) have only been examined separately. The relative contributions of these behaviours on EF have therefore not been compared. Purpose. To compare the relative associations between these four risk factors and brachial artery reactivity in the same sample. Methods. 328 patients referred for single-photon emission computed tomography (SPECT) exercise stress tests completed a nuclear-medicine-based forearm hyperaemic reactivity test. Self-reported exercise behaviour, smoking habits, and alcohol consumption were collected and waist circumference was measured. Results. Adjusting for relevant covariates, logistic regression analyses revealed that waist circumference, abstinence from alcohol, and past smoking significantly predicted poor brachial artery reactivity while physical activity did not. Only waist circumference predicted continuous variations in EF. Conclusions. Central adiposity, alcohol consumption, and smoking habits but not physical activity are each independent predictors of poor brachial artery reactivity in patients with or at high risk for cardiovascular disease.

Gordon, Jennifer L.; Lavoie, Kim L.; Arsenault, Andre; Meloche, Bernard; Ditto, Blaine; Campbell, Tavis S.; Bacon, Simon L.

2012-01-01

156

Brachial Artery Access for Percutaneous Renal Artery Interventions  

SciTech Connect

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.

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

157

Molecular mechanisms and treatment of radiation-induced lung fibrosis.  

PubMed

Radiation-induced lung fibrosis (RILF) is a severe side effect of radiotherapy in lung cancer patients that presents as a progressive pulmonary injury combined with chronic inflammation and exaggerated organ repair. RILF is a major barrier to improving the cure rate and well-being of lung cancer patients because it limits the radiation dose that is required to effectively kill tumor cells and diminishes normal lung function. Although the exact mechanism is unclear, accumulating evidence suggests that various cells, cytokines and regulatory molecules are involved in the tissue reorganization and immune response modulation that occur in RILF. In this review, we will summarize the general symptoms, diagnostics, and current understanding of the cells and molecular factors that are linked to the signaling networks implicated in RILF. Potential approaches for the treatment of RILF will also be discussed. Elucidating the key molecular mediators that initiate and control the extent of RILF in response to therapeutic radiation may reveal additional targets for RILF treatment to significantly improve the efficacy of radiotherapy for lung cancer patients. PMID:23909719

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

2013-10-01

158

Mechanisms of radiation-induced neoplastic cell transformation  

SciTech Connect

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

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

1984-04-01

159

Radiation-induced neuroinflammation and radiation somnolence syndrome.  

PubMed

Cranial irradiation remains a standard treatment for malignant and benign brain diseases. Although this procedure helps to lengthen the life expectancy of the patient, the appearance of adverse effects related to radiation-induced injury is inevitable. Radiation somnolence syndrome (RSS) has been described as a delayed effect observed mainly after whole-brain radiotherapy in children. The RSS was first linked to demyelination, but more recently it has been proposed that the inflammatory response plays a primary role in the aforementioned syndrome. To evaluate the feasibility of this hypothesis, we explored previous work about RSS and reviewed published research that included measurements of the inflammatory response in models of brain exposure to ionizing radiation. Pro-inflammatory cytokines such as interleukin-1?, tumor necrosis factor-?, interleukin-6 and interleukin-18 as well as other inflammatory markers such as cyclooxygenase-2, prostaglandin E?, glial fibrillary acid protein, intercellular adhesion molecule-1 and nuclear factor-?B appear to be involved in the brain's response to radiation. However, certain publications have described the somnogenic effects of these cytokines and inflammatory markers. Although the radiation response is a complex phenomenon that involves several molecular and cellular processes, we propose that inflammation may be closely related to the adverse effects of brain irradiation and therefore to the etiology of RSS. PMID:22998139

Ballesteros-Zebadúa, Paola; Chavarria, Anahi; Celis, Miguel Angel; Paz, Carlos; Franco-Pérez, Javier

2012-11-01

160

Radiation induced degradation of dyes--an overview.  

PubMed

Synthetic dyes are a major part of our life. Products ranging from clothes to leather accessories to furniture all depend on extensive use of organic dyes. An unfortunate side effect of extensive use of these chemicals is that huge amounts of these potentially carcinogenic compounds enter our water supplies. Various advanced oxidation processes (AOPs) including the use of high-energy radiation have been developed to degrade these compounds. In this review, dye decoloration and degradation as a result of its exposure to high energy radiation such as gamma radiation and pulsed electron beam are discussed in detail. The role of various transient species such as H, OH and e(aq)(-) are taken into account as reported by various researchers. Literature citations in this area show that e(aq)(-) is very effective in decolorization but is less active in the further degradation of the products formed. The degradation of the dyes is initiated exclusively by OH attack on electron-rich sites of the dye molecules. Additionally, various parameters that affect the efficiency of radiation induced degradation of dyes, such as effect of radiation dose, oxygen, pH, hydrogen peroxide, added ions and dye classes are also reviewed and summarized. Lastly, pilot plant application of radiation for wastewater treatment is briefly discussed. PMID:19128875

Rauf, M A; Ashraf, S Salman

2008-11-24

161

Radiation-induced chromosomal instability in human mammary epithelial cells  

NASA Astrophysics Data System (ADS)

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

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

162

Radiation-induced sarcomas of the chest wall  

SciTech Connect

Sixteen patients are presented who had sarcomas of the chest wall at a site where a prior malignancy had been irradiated. The first malignancies included breast cancer (ten cases), Hodgkin's disease (four cases), and others (two cases). Radiation doses varied from 4200 to 5500 R (mean, 4900 R). The latency period ranged from 5 to 28 years (mean, 13 years). The histologic types of the radiation-induced sarcomas were as follows: malignant fibrous histiocytoma, nine cases; osteosarcoma, six cases; and malignant mesenchymoma, one case. The only long-term survivor is alive and well 12 years after resection of a clavicular chondroblastic osteosarcoma. Three cases were recently diagnosed. Despite aggressive multimodality treatment, the remaining 13 patients have all died from their sarcomas (mean survival, 13.5 months). All patients have apparently been cured of their first malignancies. Chemotherapy was ineffective. No treatment, including forequarter amputation, appeared to palliate the patients with supraclavicular soft tissue sarcomas. Major chest wall resection offered good palliation for seven of eight patients with sarcomas arising in the sternum or lateral chest wall. Close follow-up is needed to detect signs of these sarcomas in the ever-increasing number of patients receiving therapeutic irradiation.

Souba, W.W.; McKenna, R.J. Jr.; Meis, J.; Benjamin, R.; Raymond, A.K.; Mountain, C.F.

1986-02-01

163

Molecular Mechanisms and Treatment of Radiation-Induced Lung Fibrosis  

PubMed Central

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

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

2013-01-01

164

Radiation induced oxidation of liquid alkanes as a polymer model  

NASA Astrophysics Data System (ADS)

Radiation induced oxidation of liquid n-hexadecane (n-C16H34) and squalane (C30H62) as a polymer model has been investigated by the measurements of the gas evolution and O2 uptake, and analyses of the oxidation products. Low O2 uptake, [G(-O2)~6.0] in liquid alkanes, indicates that the oxidation reaction does not exhibit chain kinetics, which is a big contrast to the process observed in solid, G(-O2)>> 10. H2 is the main gas product. More than 90% of the consumed O2 are converted into the oxidation products in liquid phase, mainly carboxylic acids, which is also a big contrast to the results of the radiolysis of liquid cyclohexane in the presence of O2 and thermal oxidation of hexadecane at elevated temperatures, where ketones and alcohols are major products at the initial stage. In the presence of aromatic additives, energy and charge transfer to the additives taking place despite the presence of O2 reduce the H2 evolution and the acid formation in parallel. Although hydroaromatic compounds act as an energy and charge scavenger, they are selectively oxidized through the donation of hydrogen in cyclic alkyl part attached to the phenyl ring, leading to large O2 uptake and corresponding ketone formation. From the comparison of the G-values of the O2 uptake, it was found that the oxidation reactions of liquid alkanes reflect well the oxidation of amorphous part in polymers.

Soebianto, Yanti S.; Katsumura, Yosuke; Ishigure, Kenkichi; Kubo, Junichi; Hamakawa, Satoshi; Kudoh, Hisaaki; Seguchi, Tadao

1996-10-01

165

Radiation induced thyroid neoplasms 1920 to 1987: A vanishing problem  

SciTech Connect

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

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

1989-06-01

166

Interleukin-32 Positively Regulates Radiation-Induced Vascular Inflammation  

SciTech Connect

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.

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

167

Space-radiation-induced photon luminescence of the Moon  

NASA Astrophysics Data System (ADS)

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

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

2009-08-01

168

Space-Radiation-Induced Photon Luminescence of the Moon  

NASA Astrophysics Data System (ADS)

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

Wilson, Thomas

169

Radiation-induced Vascular Lesions of the Skin: An Overview.  

PubMed

Radiation-induced cutaneous vascular neoplasms occur infrequently and comprise benign, so-called atypical vascular lesions (AVL) and angiosarcomas (AS), often being high-grade malignant tumors. Both arise most frequently within previously irradiated skin in breast-conserving-treated mammary cancer patients. Because of the different clinical course and, consequently, different therapeutic approaches, histopathologic distinction of AVL and AS is essential but significant morphologic overlap has been documented. Furthermore, the coexistence of these lesions or progression of AVL into AS has rarely been reported. Whether AVL is a precursor of AS is much debated and unresolved to date. Recent interest has focused on genetic changes and their differences in AS and AVL. MYC amplification and expression of the corresponding protein has been identified in AS in comparison with AVL. Therefore, MYC fluorescent in situ hybridization and anti-MYC immunohistochemical analysis are diagnostically useful in difficult cases. Furthermore, advanced tailored treatment strategies in AS, one of the most aggressive type of sarcoma, rely on identifying genes and proteins involved in malignant angiogenesis. PMID:24113311

Flucke, Uta; Requena, Luis; Mentzel, Thomas

2013-11-01

170

Effect of radiation-induced amorphization on smectite dissolution.  

PubMed

Effects of radiation-induced amorphization of smectite were investigated using artificial irradiation. Beams of 925 MeV Xenon ions with radiation dose reaching 73 MGy were used to simulate the effects generated by alpha recoil nuclei or fission products in the context of high level nuclear waste repository. Amorphization was controlled by X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. An important coalescence of the smectite sheets was observed which lead to a loss of interparticle porosity. The amorphization is revealed by a loss of long-range structure and accompanied by dehydroxylation. The dissolution rate far-from-equilibrium shows that the amount of silica in solution is two times larger in the amorphous sample than in the reference clay, a value which may be enhanced by orders of magnitude when considering the relative surface area of the samples. Irradiation-induced amorphization thus facilitates dissolution of the clay-derived material. This has to be taken into account for the safety assessment of high level nuclear waste repository, particularly in a scenario of leakage of the waste package which would deliver alpha emitters able to amorphize smectite after a limited period of time. PMID:20225848

Fourdrin, C; Allard, T; Monnet, I; Menguy, N; Benedetti, M; Calas, G

2010-04-01

171

Radiation induced spent nuclear fuel dissolution under deep repository conditions.  

PubMed

The dynamics of spent nuclear fuel dissolution in groundwater is an important part of the safety assessment of a deep geological repository for high level nuclear waste. In this paperwe discussthe most important elementary processes and parameters involved in radiation induced oxidative dissolution of spent nuclear fuel. Based on these processes, we also present a new approach for simulation of spent nuclear fuel dissolution under deep repository conditions. This approach accounts for the effects of fuel age, burn up, noble metal nanoparticle contents, aqueous H2 and HCO3- concentration, water chemistry, and combinations thereof. The results clearly indicate that solutes consuming H202 and combined effects of noble metal nanoparticles and H2 have significant impact on the rate of spent nuclear fuel dissolution. Using data from the two possible repository sites in Sweden, we have employed the new approach to estimate the maximum rate of spent nuclear fuel dissolution. This estimate indicates that H2 produced from radiolysis of groundwater alone will be sufficient to inhibit the dissolution completely for spent nuclear fuel older than 100 years. PMID:17993152

Jonsson, Mats; Nielsen, Fredrik; Roth, Olivia; Ekeroth, Ella; Nilsson, Sara; Hossain, Mohammad Mohsin

2007-10-15

172

Radiation induced oxidative damage modification by cholesterol in liposomal membrane  

NASA Astrophysics Data System (ADS)

Ionizing radiation induced structural and chemical alterations in egg lecithin liposomal membrane have been studied by measurements of lipid peroxides, conjugated diene and fluorescence polarization. Predominantly unilamellar phospholipid vesicles prepared by sonication procedure were subjected to radiation doses of ?-rays from Co-60 in aerated, buffered aqueous suspensions. The oxidative damage in irradiated lipid molecules of liposomes has been determined spectrophotometrically by diene conjugate formation and thiobarbituric acid reactive (TBAR) method as a function of radiation dose. A correlation was found between the radiation dose applied (0.1-1 kGy) and the consequent lipid oxidation. The damage produced in irradiated liposomal membrane was measured by 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence decay and polarization. The observed decrease in DPH fluorescence and increase in polarization was found dependent on the radiation dose suggesting alterations in rigidity or organizational order in phospholipid bilayer after irradiation. Furthermore, irradiated liposome vesicles composed of cholesterol showed marked reduction in observed radiation mediated peroxide formation and significantly affected the DPH fluorescence parameters. The magnitude of these modifying effects were found dependent on the mole fraction of cholesterol. It is concluded that modulation of structural order in unilamellar vesicle membrane by variations in basic molecular components controlled the magnitude of lipid peroxidation and diene conjugate formation. These observations contribute to our understanding of mechanism of radical reaction mediated damage caused by ionizing radiation in phospholipid membrane.

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

1999-05-01

173

Radiation-induced optic neuropathy: A magnetic resonance imaging study  

SciTech Connect

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

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

1991-03-01

174

Influence of brachial plexus blockade on oxygen balance during surgery.  

PubMed

The combined effects of anesthesia, motor blockade, and chemically induced sympathectomy after brachial plexus blockade can have a beneficial impact, when applied in selected, isolated diseased states of the upper limb. With the aim of using the prolonged effects of brachial plexus blockade for a future therapeutic application, we demonstrated a dependable methodology of venous blood gas monitoring and confirmed an improved oxygen balance of the blocked versus nonblocked upper extremity in a controlled, prospective study in healthy patients undergoing elective hand surgery. PMID:21525181

Lumenta, David B; Haslik, Werner; Beck, Harald; Pollreisz, Andreas; Andel, Harald; Frey, Manfred

2011-04-27

175

p53 status in radiation-induced soft-tissue sarcomas  

Microsoft Academic Search

Background  Following therapeutic irradiation after a latency period of many years radiation-induced tumors, often sarcomas, can arise.\\u000a Results of radiation-induced DNA damage can be 1. p53 over-expression, inducing growth arrest or apoptosis, and 2. occurrence\\u000a of mutations, frequently including the p53 gene, as one molecular promotor for carcinogenesis. We were interested whether\\u000a radiation-induced sarcomas are associated with alterations of the p53

Helge Taubert; Axel Meye; Matthias Bache; Raoul Hinze; Hans-Jtirgen Holzhausen; Hannelore Schmidt; Friedrich-Wilhelm Rath; Jürgen Dunst; Peter Würl

1998-01-01

176

Low Estimated Glomerular Filtration Rate Is a Major Determinant of Low Ankle-Brachial Index and Toe-Brachial Index in Type 2 Diabetes  

Microsoft Academic Search

We enrolled 1461 Taiwanese type 2 diabetic outpatients with ankle-brachial index (ABI) and toe-brachial index (TBI) examinations, excluding participants with history of stroke, end-stage renal disease, malignancy, acute myocardial infarction, amputation, and overt calcification of the lower limbs (ABI >1.3). Ankle-brachial index values <0.9 were found in 2.8% of the patients and 5.7% had TBI <0.6. Estimated glomerular filtration rate

Yi-Jing Sheen; Jainn-Liang Lin; I-Te Lee; Yuan-Nian Hsu; Tsai-Chung Li; Wayne Huey-Herng Sheu

2012-01-01

177

Radiation-Induced Phase Transformations in Ilmenite-Group Minerals  

SciTech Connect

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

Mitchell, J. N.

1997-12-31

178

Ethnic differences in flow mediated dilation of the brachial artery  

Microsoft Academic Search

African Americans have a higher prevalence of cardiovascular disease than Whites. Several previous studies have demonstrated impaired flow mediated dilation of the brachial artery (FMD), a measure of endothelial function, in African Americans. Whether this ethnic difference in FMD is explained in part by decreased reactive hyperemia or attenuated vascular smooth muscle cell responsiveness to vasodilator stimuli is not well-established.

Alan L. Hinderliter; Karen M. Grewen; Kimberley A. Brownley; Susan S. Girdler; Kathleen C. Light

2005-01-01

179

Microsurgical repair and secondary surgery in obstetrical brachial plexus palsy  

Microsoft Academic Search

We present a personal experience with 750 children suffering from obstetrical brachial plexus palsy. The related surgery is described, including early microsurgical nerve reconstruction and secondary procedures including tendon and muscle transfers. The clinical examination, indications and timing for surgery, technical details of primary and secondary operations and the possible outcome are discussed. Both clinical and research work need an

Jörg Bahm; Hassan Noaman; Claudia Ocampo-Pavez

2005-01-01

180

Regular ingestion of black tea improves brachial artery vasodilator function.  

PubMed

A higher intake of black tea has been associated with lower cardiovascular disease risk. The antioxidant effects of tea polyphenols may enhance endothelial function and thereby reduce the risk of coronary events. The objective of the present study was to determine whether regular ingestion of black tea can improve brachial artery vasodilator function. The effects of regular ingestion of 5 cups per day of black tea for 4 weeks were compared with control conditions (hot water ingestion) in 21 subjects with mild elevations in serum cholesterol or triacylglycerol (triglyceride) concentrations in a parallel designed study. Endothelial function of the brachial artery was assessed ultrasonographically by measurement of post-ischaemic (endothelium-dependent) dilatation of the brachial artery. Endothelium-independent dilatation of the brachial artery was measured following administration of 400 microg of sublingual glyceryl trinitrate. Regular ingestion of black tea resulted in a significant and consistent increase in endothelium-dependent dilatation (2.3%; P=0.008) and in a significant increase in endothelium-independent dilatation (4.2%; P=0.03), compared with ingestion of hot water. These differences remained after adjustment for age, sex and body mass index. These results suggest that one mechanism by which black tea may reduce cardiovascular risk is via improved vasodilator function of conduit arteries. PMID:11834139

Hodgson, Jonathan M; Puddey, Ian B; Burke, Valerie; Watts, Gerald F; Beilin, Lawrence J

2002-02-01

181

Controversies surrounding the causes of brachial plexus injury  

Microsoft Academic Search

In the past decades, obstetric personnel have attempted to reduce the frequency of brachial plexus injury (BPI) by attempting to use less traction during the delivery of the fetal anterior shoulder. Clearly, these attempts have been unsuccessful in preventing or reducing the frequency of BPI. We conducted a nonsystematic literature review of the reported controversies regarding the mechanisms of BPI

Herbert F. Sandmire; Robert K. DeMott

2009-01-01

182

Predicting the radiation induced loss in Ge doped optical fibres at different temperatures  

Microsoft Academic Search

A new method is described for predicting radiation induced losses in Ge doped optical fibres at various temperatures. Some physical justification is given for the recovery model employed, and model calculations are compared with experimental results

R. H. West

1999-01-01

183

Renal and Adrenal Factors in Radiation-Induced Hypertension and Nephrosclerosis.  

National Technical Information Service (NTIS)

Experiments were conducted in order to investigate the effects of adrenalectomy on the incidence, severity, and rate of progression of radiation-induced hypertension and nephrosclerosis in male rats. Adrenalectomized and non-adrenalectomized rats received...

A. G. Lurie

1973-01-01

184

Mechanisms of Radiation-Induced Bone Loss and Effect on Prostate Cancer Bone Metastases.  

National Technical Information Service (NTIS)

Patients with tumors in the pelvic region frequently receive radiation therapy, and as a result, bystander bone may experience adverse effects. Earlier reports demonstrated that radiation-induced bone loss occurs via increased osteoclast activation in a m...

H. S. Kim

2012-01-01

185

Role of Neurotensin in Radiation-Induced Hypothermia in Rats. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

The role of neurotensin in radiation induced hypothermia was examined. Intracerebroventricular (ICV) administration of neurotensin produced dose-dependent hypothermia. Histamine appears to mediate neurotensin-induced hypothermia because the mast cell stab...

S. B. Kandasamy W. A. Hunt A. H. Harris

1991-01-01

186

Immobilization of Yeast Cells with Hydrophilic Carrier by Radiation-Induced Polymerization.  

National Technical Information Service (NTIS)

Radiation-induced polymerization method was applied to the immobilization of yeast cells. The effects of irradiation, cooling and monomer, which are necessary for polymerization, were recovered completely by subsequent aerobical incubation of yeast cells....

T. Fujimura I. Kaetsu

1981-01-01

187

Effect of Radiation-Induced Xerostomia on the Human Oral Microflora.  

National Technical Information Service (NTIS)

The caries-conducive impact of xerostomia was studied in 42 irradiated cancer patients. The radiation-induced xerostomia was paralleled by changes in the physical, microbial, biochemical, immunologic and dietary parameters of cariogenicity that collective...

S. Dreizen L. R. Brown

1976-01-01

188

Direct Assays of Radiation Induced DNA Base Lesions in Mammalian Cells: Technical Progress Report.  

National Technical Information Service (NTIS)

HPLC techniques were used to separate, detect, identify and quantitate radiation-induced damage products of adenine (A)-containing model compounds and eukaryotic DNA. A library of 7 pure synthetic or isolated major damage products has been established con...

K. T. Wheeler

1986-01-01

189

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

Microsoft Academic Search

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)

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

2003-01-01

190

Application of Formaldehyde for Treatment of Hemorrhagic Radiation-Induced Proctitis  

Microsoft Academic Search

. Radiation-induced proctitis with hemorrhage is not a common complication of radiotherapy to the pelvis for carcinoma.\\u000a In the most severe forms, massive hemorrhage may necessitate repeated transfusions and inpatient treatment. In severe cases\\u000a medical treatment has not been proved effective. Surgery may lead to serious complications and is technically difficult. Six\\u000a patients who showed a hemorrhagic radiation-induced proctitis have

B. Roche; R. Chautems; M. C. Marti

1996-01-01

191

Radiation-induced peripheral nerve neurofibromata in a patient receiving hypofractionated radiation therapy.  

PubMed

Radiation-induced peripheral nerve tumor, in particular a benign entity such as a neurofibroma, is rare, with only a few cases being reported so far. We demonstrate a case of radiation-induced neurofibromata along the left cervical nerve roots in a man with a background of localized targeted hypofractionated radiation therapy as adjuvant treatment for left cervical nodal metastasis complicating nasopharyngeal carcinoma. The toxicity of high-dose radiation in a hypofractionated regime is also stressed. PMID:18653682

Lai, V; Wong, Y C; Poon, W L; Fu, Y P; Lam, T C; Yuen, S C

2008-07-24

192

Radiation-induced osteosarcomas in the pediatric population  

SciTech Connect

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

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

193

Radiation-Induced Topological Disorder in Irradiated Network Structures  

SciTech Connect

This report summarizes results of a research program investigating the fundamental principles underlying the phenomenon of topological disordering in a radiation environment. This phenomenon is known popularly as amorphization, but is more formally described as a process of radiation-induced structural arrangement that leads in crystals to loss of long-range translational and orientational correlations and in glasses to analogous alteration of connectivity topologies. The program focus has been on a set compound ceramic solids with directed bonding exhibiting structures that can be described as networks. Such solids include SiO2, Si3N4, SiC, which are of interest to applications in fusion energy production, nuclear waste storage, and device manufacture involving ion implantation or use in radiation fields. The principal investigative tools comprise a combination of experimental diffraction-based techniques, topological modeling, and molecular-dynamics simulations that have proven a rich source of information in the preceding support period. The results from the present support period fall into three task areas. The first comprises enumeration of the rigidity constraints applying to (1) more complex ceramic structures (such as rutile, corundum, spinel and olivine structures) that exhibit multiply polytopic coordination units or multiple modes of connecting such units, (2) elemental solids (such as graphite, silicon and diamond) for which a correct choice of polytope is necessary to achieve correct representation of the constraints, and (3) compounds (such as spinel and silicon carbide) that exhibit chemical disorder on one or several sublattices. With correct identification of the topological constraints, a unique correlation is shown to exist between constraint and amorphizability which demonstrates that amorphization occurs at a critical constraint loss. The second task involves the application of molecular dynamics (MD) methods to topologically-generated models of amorphized network silicas. These methods are shown to generate fully connected topologically-disordered networks, equilibrated to achieve accurately-specified atomic coordinates that can be compared to correlation data derived from diffraction experiments. The MD equilibrations demonstrate the insensitivity of diffraction methods to substantial differences in intermediate-range topology, with the exception of the first diffraction peak which is shown to be uniquely sensitive to topological differences. The third task concerns application of MD simulations to amorphization of silicon carbide, which exhibits anomalous amorphizability. Amorphization of this compound is shown to derive from its facility for tolerating chemical disorder, and a critical homonuclear bond density threshold is established as a criterion for its amorphization.

Hobbs, Linn W.

2002-12-21

194

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

NASA Astrophysics Data System (ADS)

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

Kaplan, Mark Isaac

195

The mechanism of radiation induced densification in fused silica  

NASA Astrophysics Data System (ADS)

In this thesis, deep-UV (193nm) induced densification in fused silica is reviewed and some new compaction data are presented. UV-induced compaction in fused silica obeys a universal relation where, using the total energy absorbed from two-photon absorption as the dose parameter, density changes are equal to a material dependent constant times the dose parameter to a power of about 0.66 (2/3). With the exception of the two-photon damage excitation, this behavior is consistent with the compaction studies using electron beam and gamma radiation, suggesting like densification mechanisms. We have developed a two-phase model to describe the structure of vitreous silica. Low temperature phase A and high temperature phase B are connected by a solid state phase transition and the phase transition temperature should be higher than the glass transition temperature. This model is based on the observed volume change induced by hydrostatic pressure, fast neutron, ion, electron and photon irradiation etc. Using this structural model, we can understand the compaction-fluence behaviors for two distinct compaction phenomena; knock-on (atomic displacement) radiation-induced-compaction and ionization-induced-compaction. Generally, knock-on radiation triggers a A --> B phase transition in vitreous silica. For ionization-induced compaction, we propose a simple bridging-bond relaxation mechanism to explain the observed stretched power (2/3) dependence of compaction on deposited energy for ionization induced compaction in silica. We have used thermal annealing techniques to study the deep ultraviolet-induced compaction in fused silica, and found a strong correlation between the UV-compaction rates and thermal histories among various samples. Experimental observations agree with the predictions based on our compaction model. We have constructed a 193nm interferometer and measured the optical-pathlength difference (OPD) changes from compaction at the actinic wavelength. For the first time, we were able to directly observe the spatial variation of OPD, clearly showing the reduction in OPD outside the damaged region (because of the surface indentation) in contrast to the density-driven OPD increase inside the damaged area. The compaction-induced OPD decreased in thermal annealing and the reduction agreed with our stress-induced birefringence results.

Piao, Fan

1999-10-01

196

Image-based modeling of radiation-induced foci  

NASA Astrophysics Data System (ADS)

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

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

197

Statin therapy improves brachial artery endothelial function in nephrotic syndrome  

Microsoft Academic Search

Statin therapy improves brachial artery endothelial function in nephrotic syndrome.Background:Patients with nephrotic syndrome have impaired endothelial function probably related to dyslipidemia. This study evaluated the effects of statin therapy on dyslipidemia and endothelial function in patients with nephrotic syndrome.Methods:A sequential, open-label study of the effects of statins on endothelial dysfunction in 10 nephrotic patients treated with an angiotensin-converting enzyme (ACE)

Gursharan K Dogra; Gerald F Watts; Susan Herrmann; Mark A B Thomas; Ashley B Irish

2002-01-01

198

Entrapment neuropathy contributing to dysfunction after birth brachial plexus injuries.  

PubMed

Although surgical treatment of brachial plexus birth palsy has yielded encouraging results, persistent inability to abduct and elevate the shoulder is common even in children with excellent return of arm and hand function. The reason for deltoid weakness in the afflicted children is not completely understood and may be multifactorial. Clinical observations, including a pattern of position-dependent weakness, suggest that primary nerve damage may not be the sole cause. The authors performed a retrospective chart study to investigate the outcome of surgical treatment to augment shoulder function in a series of 10 children (ages 9 months to 8 years) with inadequate external rotation of the shoulder and inability to actively raise the arm beyond 90 degrees from a birth brachial plexus injury. At follow-up 6 months after surgery, increased shoulder range of motion was noticed in all, with significantly increased abduction/elevation in 8 of the 10 children. Analysis of data, including pre- and postoperative functional testing and intraoperative electrophysiologic monitoring, led to the conclusion that secondary compression of the axillary nerve in the quadrangular space is a separate and common reason for impairment in children with brachial plexus birth palsy and persistent weakness of the deltoid muscle and may provide an important reason for early intervention. PMID:16199937

Adelson, P David; Nystrom, N Ake; Sclabassi, Robert

199

Pseudoaneurysms of the brachial artery following venipuncture in infants.  

PubMed

Pediatric vascular injuries are increasing in frequency and represent a challenging problem in pediatric surgical practice. Increased survival of low birth weight infants and advances in invasive diagnostic procedures have resulted in a dramatic increase in the number of these injuries. Formation of pseudoaneurysm of the brachial artery in infants is a very rare complication of venipuncture, with only two cases reported in the literature. We report three cases of brachial artery pseudoaneurysm in infants following venipuncture who were operated upon in our institution, aged 43-64 days at the time of operation. The period from the injury to the operation ranged from 25 to 42 days. All three infants were referred from different institutions. In two infants, the pseudoaneurysms and the involved part of the artery were resected, and arterial continuity was restored with an end-to-end anastomosis; in the other infant, reconstruction was done using a venous interposition graft. All three infants were diagnosed with duplex ultrasonography, and the child requiring a more complex reconstructive procedure was also evaluated with helical contrast computed tomography. Brachial artery pseudoaneurysms are a rare but possible complication of multiple venipuncture in infants. Early diagnosis and microvascular reconstruction are key points in managing these injuries. PMID:15338170

Dzepina, Ivo; Unusic, Josip; Mijatovic, Davor; Bulic, Kresimir

2004-08-25

200

Aerobic run training improves brachial artery flow-mediated dilation.  

PubMed

The purpose of this study was to assess the relationship between aerobic exercise training and brachial artery flow-mediated dilation (FMD) in healthy subjects. Healthy controls (HC) and aerobically-trained (T) subjects were studied with high-resolution vascular ultrasound at baseline, and during a 5-minute period of hyperemia following forearm cuff occlusion. Training was defined by self-reported participation in recreational or competitive run training. Forearm cuff occlusion was held at 200 mm Hg for 5 minutes. At baseline, both brachial artery flow and diameter were greater in T than in HC (p < 0.05). Resting heart rate was lower in T than in HC (p < 0.05). Peak hyperemic flow (15 seconds postocclusion) was significantly greater in T than in HC (HC; 539 +/- 75 ml x min(-1) vs. T; 832 +/- 103 ml x min(-1), p < 0.05) and correlated well with V(.-)O2peak (r = 0.67, p = 0.008). Flow-mediated dilation was significantly greater in T vs. HC throughout the 5-minute postocclusion phase (p < 0.05). Maximal brachial artery dilation was greater in T than in HC (HC; 3 +/- 1% of baseline vs. T; 8 +/- 3% of baseline; p < 0.05) and moderately correlated with V(.-)O2peak (r = 0.55, p < 0.05). These data suggest that the greater FMD observed in trained subjects may be due, in part, to an augmentation of peak hyperemic flow. PMID:18076272

Libonati, Joseph R

2007-11-01

201

A Survey of Radiation-Induced Bronchiolitis Obliterans Organizing Pneumonia Syndrome After Breast-Conserving Therapy in Japan  

Microsoft Academic Search

Purpose: We observed a rare and unique occurrence of radiation-induced pulmonary injury outside the tangential field for early breast cancer treatment. The findings appeared to be idiopathic and were called radiation-induced bronchiolitis obliterans organizing pneumonia (BOOP) syndrome. We surveyed major hospitals in Japan to review their findings of radiation-induced BOOP, in particular the clinical and pictorial characteristics of the entity.

Etsuyo Ogo; Ritsuko Komaki; Kiminori Fujimoto; Masafumi Uchida; Toshi Abe; Katsumasa Nakamura; Michihide Mitsumori; Kenji Sekiguchi; Yuko Kaneyasu; Naofumi Hayabuchi

2008-01-01

202

Effect of solvents on radiation-induced ionic graft polymerization. [Gamma radiation  

SciTech Connect

The influence of various solvents on radiation-induced cationic (grafting of vinyl-n-butyl ether onto polyethylene) and anionic (grafting of 2-methyl-5-vinylpyridine onto polyethylene) graft polymerization was studied. This ionic grafting was performed in thoroughly dried systems at room temperature. It was established that electron-acceptor solvents promote cationic grafting but that electron-donor solvents promote the anionic. A clear correlation between the donor number of solvents and grafting value by the anionic mechanism was shown. There was no correlation between dielectric constants and grafting values. The reaction orders, according to monomer concentraton by 2-methyl-5-vinylpyridine grafting in various solvents, were equal to approximately 1.5 and 2 for the radical and anionic mechanisms, respectively. The effect of solvents on radiation-induced ionic graft polymerization is discussed. The results of this study indicate the correct choice of solvents for radiation-induced ionic grafting.

Kabanov, V.Ya.; Aliev, R.E.; Sidorova, L.P.

1980-03-01

203

Radioprotective effect of geraniin via the inhibition of apoptosis triggered by ?-radiation-induced oxidative stress.  

PubMed

The radioprotective effect of geraniin, a tannin compound isolated from Nymphaea tetragona Georgi var. (Nymphaeaceae), against ?-radiation-induced damage was investigated in Chinese hamster lung fibroblast (V79-4) cells. Geraniin recovered cell viability detected by MTT test and colony formation assay, which was compromised by ?-radiation, and reduced the ?-radiation-induced apoptosis by the inhibition of loss of the mitochondrial membrane potential. Geraniin protected cellular components (lipid membrane, cellular protein, and DNA) damaged by ?-radiation, which was detected by lipid peroxidation, protein carbonyl formation, and comet assay. Geraniin significantly reduced the level of intracellular reactive oxygen species generated by ?-radiation, which was detected using spectrofluorometer, flow cytometer, and confocal microscope after 2',7'-dichlorodihydrofluorescein diacetate staining. Geraniin normalized the superoxide dismutase and catalase activities, which were decreased by ?-radiation. These results suggest that geraniin protects cells against radiation-induced oxidative stress via enhancing of antioxidant enzyme activities and attenuating of cellular damage. PMID:20680428

Kang, Kyoung Ah; Lee, In Kyung; Zhang, Rui; Piao, Mei Jing; Kim, Ki Cheon; Kim, Sang Young; Shin, Taekyun; Kim, Bum Joon; Lee, Nam Ho; Hyun, Jin Won

2010-08-02

204

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

PubMed

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

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

2012-03-01

205

Non-problematic risks from low-dose radiation-induced DNA damage clusters.  

PubMed

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 precancerous and cancerous cells. PMID:18648573

Hayes, Daniel P

2008-01-16

206

Microwave polarization study of radiation-induced magneto-resistance oscillations  

NASA Astrophysics Data System (ADS)

Under microwave irradiation, high mobility GaAs/AlGaAs samples display radiation-induced magnetoresistance oscillations and zero resistance states. These novel phenomena have attracted significant theoretical and experimental efforts over the last few years. Here, we experimentally investigate the effect of polarization direction for linearly polarized microwaves on the radiation induced magnetoresistance oscillations. Previous investigations suggest the independence of the oscillations on the polarization direction in consistency with theoretical predictions (Jes'us Iñarrea and Gloria Platero, PRB 76, 073311 (2007)). Here, we present the results of our study and discuss the implications of the results for existing theoretical models.

Ghanem, Tarek; Mani, R. G.; Wegscheider, W.

2010-03-01

207

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

Microsoft Academic Search

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

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

1999-01-01

208

Plexus Irritation Caused by Interscalene Brachial Plexus Catheter for Shoulder Surgery  

Microsoft Academic Search

ontinuous interscalene brachial plexus block with bupivacaine has been used successfully in our hospital for most patients undergoing open or closed shoulder procedures, and especially for post- operative analgesia during shoulder physical therapy. The catheter is usually removed when analgesia for physical therapy is no longer required. We report two cases of possible nerve irritation associated with inter- scalene brachial

Flavio C. Ribeiro; Harris Georgousis; Rainer Bertram; Gerd Scheiber

1996-01-01

209

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

SciTech Connect

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

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

1996-05-15

210

Non invasive procedure to evaluate the viscoelastic behavior of the brachial artery by oscillometric repeated measurements  

Microsoft Academic Search

A non invasive methodology to evaluate the viscoelastic behavior of the brachial artery by oscillometric repeated blood pressure measurements is proposed. The methodology is based on the quantitative evaluation of the curve representing the arterial cross sectional area vs. transmural pressure function: repeated loading and unloading of the brachial artery produces modifications of the shape of the curve which have

G. Rosatella; S. Silvestri; P. Cappa

2003-01-01

211

Capnography as an aid in localizing the phrenic nerve in brachial plexus surgery. Technical note  

Microsoft Academic Search

BACKGROUND: To determine whether monitoring end- tidal Carbon Dioxide (capnography) can be used to reliably identify the phrenic nerve during the supraclavicular exploration for brachial plexus injury. METHODS: Three consecutive patients with traction pan-brachial plexus injuries scheduled for neurotization were evaluated under an anesthetic protocol to allow intraoperative electrophysiology. Muscle relaxants were avoided, anaesthesia was induced with propofol and fentanyl

Hemant Bhagat; Anil Agarwal; Manish S Sharma

2008-01-01

212

Brachial plexus palsy associated with cesarean section: An in utero injury?  

Microsoft Academic Search

Objective: Brachial plexus injury may be unrelated to manipulations performed at the time of delivery, occurring in the absence of shoulder dystocia and in the posterior arm of infants with anterior shoulder dystocia. To further support the hypothesis that some of these nerve injuries appear to be of intrauterine origin, we present a series of brachial plexus palsies associated with

Robert B. Gherman; T. Murphy Goodwin; Joseph G. Ouzounian; David A. Miller; Richard H. Paul

1997-01-01

213

Traumatic vertebral artery dissection in an adult with brachial plexus injury and cervical spinal fractures  

Microsoft Academic Search

We present a case of a 32 year-old right-hand dominant woman who sustained a right brachial plexus injury, ipsilateral fractures of the cervical spine transverse processes, and vertebral artery dissection. She presented to us four days following the initiating accident. Magnetic Resonance Imaging showed normal brachial plexus along with vertebral artery dissection with intramural thrombus and vascular lumen occlusion. The

Silas NS Motsitsi; Rian R Steyn

2007-01-01

214

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

Microsoft Academic Search

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

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

2001-01-01

215

Age-Related Progressive Brachial Artery Endothelial Dysfunction Precedes the Changed Carotid and Left Ventricular Geometry in Healthy Humans  

Microsoft Academic Search

In this study the authors evaluated correlation between aging and brachial endothelial and vascular smooth muscle dysfunction, changes in carotid geometry, and left ventric ular remodeling. Vasomotor influences of brachial endothelium and brachial smooth muscle function to reactive hyperemia and nitroglycerin (400 ?g, sublingual spray) were assessed by noninvasive ultrasound in 66 healthy subjects of different ages (20-82 years). Carotid

Dragan Djuric; Zoran Popovic; Jordan Petrovic; Milovan Bojic

1999-01-01

216

Development of an in vitro model for radiation-induced effects on oral keratinocytes  

Microsoft Academic Search

Changes in epithelial cell activity and the production of pro-inflammatory cytokines were examined utilizing an organotypic culture system as an in vitro model to study the effects of radiation on oral keratinocytes to simulate what is thought to occur in radiation-induced oral mucositis. Monolayer cultures of oral keratinocyte were irradiated by varying the dose. Cell injury was assessed using a

T. Tobita; K. Izumi; S. E. Feinberg

2010-01-01

217

Synchrotron radiation induced gas desorption from a Prototype Large Hadron Collider beam screen at cryogenic temperatures  

Microsoft Academic Search

The performance of the vacuum system of the Large Hadron Collider will depend critically on the synchrotron radiation induced gas desorption and on the readsorption of molecules on the cold surfaces. The present design of the system is based on a so-called beam screen inserted in the 1.9 K cold bore of the magnets. Gas molecules desorbed will therefore readsorb

R. Calder; O. Gröbner; A. G. Mathewson; V. V. Anashin; A. Dranichnikov; O. B. Malyshev

1996-01-01

218

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

SciTech Connect

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

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

1996-03-01

219

INTERRELATIONS OF NUCLEIC ACID AND PROTEIN SYNTHESES IN RADIATION INDUCED MUTATION INDUCTION IN BACTERIA  

Microsoft Academic Search

During the past decade evidence has accumulated that an appreciable ; portion of radiation-induced mutations are due to chemical effects of radiation ; on sensitive metabolites. The shape of induced mutation frequency curves ; suggests that intracellular radiation-sensitive material is modified by radiation. ; This material is probably both limited in quantity and destroyed by radiat high ; doses of

F. L. Haas; C. O. Doudney

1958-01-01

220

Study on Acetogenin against Radiation-induced Hepatic Biochemical Alterations in Mice  

Microsoft Academic Search

The aim of the present study was to evaluate the radioprotective effect of Acetogenin (AE) on Swiss albino mice against radiation induced hepatic biochemical alterations. Swiss albino mice (6-8 weeks) were divided into three groups. Group I (Normal) was without any treatment. Group II (Control) was only irradiated group (8 Gy). Group III (AE+Irradiated): Mice in this group received AE

A. L. Bhatia; Raka Kamal; Gulshan Verma; K. V. Sharma; Megha Jain; Sharad Vats

2008-01-01

221

Radiation-induced degradation of water pollutants: State of the art  

Microsoft Academic Search

The radiation induced decomposition of biological resistant pollutants in drinking as well as in wastewater is shortly reviewed. First, some important units, deffinitions etc., radiation sources as well as dose depth curves in water as function of the electron energy and 60Co-?-rays are mentioned. It follows schematical presentation of water rediolysis and of characteristics of primary free radicals. After that

Nikola Getoff

1995-01-01

222

Radiation-induced rectal cancer originating from a rectocutaneous fistula: report of a case.  

PubMed

This report describes a patient with radiation-induced rectal cancer with an unusual history. A 51-year-old man was admitted in 2000 because of ichorrhea of the skin on the left loin. The patient had received irradiation for a suspicious diagnosis of a malignant tumor in the pelvic cavity in 1975. A subcutaneous abscess in the right loin appeared in 1989, and rectocutaneous fistula was noted in 1992. Moreover, radiation-induced rectal cancer developed in 2000. Plain computed tomography and magnetic resonance imaging of the pelvis demonstrated a presacral mass and tumor in the rectum. Finally, we diagnosed the presacral mass to be an abscess attached to the center of the rectal cancer. The rectum was resected by Miles' operation and a colostomy of the sigmoid colon was also performed. Many cases of radiation-induced rectal cancer have been reported. However, this is a rare case of radiation-induced rectal cancer originating from a presacral abscess and rectocutaneous fistula. PMID:15290404

Yokoyama, Shozo; Takifuji, Katsunari; Arii, Kazuo; Tanaka, Hajime; Matsuda, Kenji; Higashiguchi, Takashi; Yamaue, Hiroki

2004-01-01

223

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

National Technical Information Service (NTIS)

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

J. Selow W. Winkler

1980-01-01

224

Radiation-induced otitis media—study of a new test, vestibular-evoked myogenic potential  

Microsoft Academic Search

PurposeExcluding the radiation history, current physical examination and audiovestibular function tests fail to differentiate radiation-induced otitis media (ROM) from chronic otitis media (COM). This study applied the newly developed vestibular-evoked myogenic potential (VEMP) test to investigate whether the VEMP test can be of help in differentiating between them.

Tsung-Lin Yang; Yi-Ho Young

2004-01-01

225

Radiation-induced defects and their annealing behavior in cadmium telluride  

SciTech Connect

Radiation-induced defects and their annealing behavior in p- and n-type CdTe irradiated with 2-MeV electrons, neutrons, and /sup 60/Co gamma rays have been investigated by means of photoluminescence, Hall, time-of-flight measurements, and the performance of CdTe gamma-ray detectors.

Taguchi, T.; Inuishi, Y.

1980-09-01

226

Experimental Study on Radiation Induced Boiling Enhancement for Stainless Steel Plate  

SciTech Connect

The Radiation Induced Boiling Enhancement phenomena (RIBE) were confirmed using the SUS304 foil. The SUS304 with plasma oxidized surface shows higher CHF, i.e., about 20% improvement. While, the natural and mixed gas oxidized surface does not show the boiling enhancement. The RIBE has been highly related to the surface conditions. (authors)

Koji Okamoto; Hiroshi Akiyama; Haruki Madarame [University of Tokyo (Japan); Tomoji Takamasa [Tokyo University of Mercantile Marine, 2-1-6 Etchu-jima, Koto-Ku, Tokyo 135-8533 (Japan)

2002-07-01

227

DETECTION OF LOW DOSE RADIATION INDUCED DNA DAMAGE USING TEMPERATURE DIFFERENNTIAL FLUORESENCE ASSAY  

EPA Science Inventory

A rapid and sensitive fluorescence assay for radiation-induced DNA damage is reported. Changes in temperature-induced strand separation in both calf thymus DNA and plasmid DNA (puc 19 plasmid from Escherichia coli) were measured after exposure to low doses of radiation. Exposures...

228

DETECTION OF LOW DOSE RADIATION INDUCED DNA DAMAGE USING TEMPERATURE DIFFERENTIAL FLUORESCENCE ASSAY  

EPA Science Inventory

A rapid and sensitive fluorescence assay for radiation-induced DNA damage is reported. Changes in temperature-induced strand separation in both calf thymus DNA and plasmid DNA (puc 19 plasmid from Escherichia coli) were measured after exposure to low doses of radiation. Exposur...

229

Experimental and theoretical investigations of electromagnetic radiation induced by rock fracture  

Microsoft Academic Search

Frid, V., Bahat, D., Goldbaum, J., Rabinovitch, A. 2000. Experimental and theoretical investigations of electromagnetic radiation induced by rock fracture. Isr. J. Earth Sci. 49: 9-19. There is a general agreement in the literature that the technique of measuring electro- magnetic radiation (EMR) emitted from cracked rock is a good candidate for forecast- ing of earthquakes. Our immediate objective in

Dov Bahat; Julia Goldbaum; Vladimir Frid; Avinoam Rabinovitcha; Avinoam Rabinovitch

2000-01-01

230

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

SciTech Connect

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.

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

231

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

PubMed Central

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.

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

232

Oxidative Lipidomics of ?-Radiation-Induced Lung Injury: Mass Spectrometric Characterization of Cardiolipin and Phosphatidylserine Peroxidation  

PubMed Central

Oxidative damage plays a significant role in the pathogenesis of ?-radiation-induced lung injury. Endothelium is a preferred target for early radiation-induced damage and apoptosis. Given the newly discovered role of oxidized phospholipids in apoptotic signaling, we performed oxidative lipidomics analysis of phospholipids in irradiated mouse lungs and cultured mouse lung endothelial cells. C57BL/6NHsd female mice were subjected to total-body irradiation (10 Gy, 15 Gy) and euthanized 24 h thereafter. Mouse lung endothelial cells were analyzed 48 h after ? irradiation (15 Gy). We found that radiation-induced apoptosis in vivo and in vitro was accompanied by non-random oxidation of phospholipids. Cardiolipin and phosphatidylserine were the major oxidized phospholipids, while more abundant phospholipids (phosphatidylcholine, phosphatidylethanolamine) remained non-oxidized. Electrospray ionization mass spectrometry analysis revealed the formation of cardiolipin and phosphatidylserine oxygenated molecular species in the irradiated lung and cells. Analysis of fatty acids after hydrolysis of cardiolipin and phosphatidylserine by phospholipase A2 revealed the presence of mono-hydroperoxy and/or mono-hydroxy/mono-epoxy, mono-hydroperoxy/mono-oxo molecular species of linoleic acid. We speculate that cyt c-driven oxidations of cardiolipin and phosphatidylserine associated with the execution of apoptosis in pulmonary endothelial cells are important contributors to endothelium dysfunction in ?-radiation-induced lung injury.

Tyurina, Yulia Y.; Tyurin, Vladimir A.; Kapralova, Valentyna I.; Wasserloos, Karla; Mosher, Mackenzie; Epperly, Michael W.; Greenberger, Joel S.; Pitt, Bruce R.; Kagan, Valerian E.

2011-01-01

233

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

Microsoft Academic Search

BACKGROUND: We have previously shown that small molecule PDGF receptor tyrosine kinase inhibitors (RTKI) can drastically attenuate radiation-induced pulmonary fibrosis if the drug administration starts at the time of radiation during acute inflammation with present but limited effects against acute inflammation. To rule out interactions of the drug with acute inflammation, we investigated here in an interventive trial if a

Minglun Li; Amir Abdollahi; Hermann-Josef Gröne; Kenneth E Lipson; Claus Belka; Peter E Huber

2009-01-01

234

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

SciTech Connect

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.

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

235

Effect of ozone oxidative preconditioning in preventing early radiation-induced lung injury in rats.  

PubMed

Ionizing radiation causes its biological effects mainly through oxidative damage induced by reactive oxygen species. Previous studies showed that ozone oxidative preconditioning attenuated pathophysiological events mediated by reactive oxygen species. As inhalation of ozone induces lung injury, the aim of this study was to examine whether ozone oxidative preconditioning potentiates or attenuates the effects of irradiation on the lung. Rats were subjected to total body irradiation, with or without treatment with ozone oxidative preconditioning (0.72 mg/kg). Serum proinflammatory cytokine levels, oxidative damage markers, and histopathological analysis were compared at 6 and 72 h after total body irradiation. Irradiation significantly increased lung malondialdehyde levels as an end-product of lipoperoxidation. Irradiation also significantly decreased lung superoxide dismutase activity, which is an indicator of the generation of oxidative stress and an early protective response to oxidative damage. Ozone oxidative preconditioning plus irradiation significantly decreased malondialdehyde levels and increased the activity of superoxide dismutase, which might indicate protection of the lung from radiation-induced lung injury. Serum tumor necrosis factor alpha and interleukin-1 beta levels, which increased significantly following total body irradiation, were decreased with ozone oxidative preconditioning. Moreover, ozone oxidative preconditioning was able to ameliorate radiation-induced lung injury assessed by histopathological evaluation. In conclusion, ozone oxidative preconditioning, repeated low-dose intraperitoneal administration of ozone, did not exacerbate radiation-induced lung injury, and, on the contrary, it provided protection against radiation-induced lung damage. PMID:23969972

Bakkal, B H; Gultekin, F A; Guven, B; Turkcu, U O; Bektas, S; Can, M

2013-09-27

236

Study of Radiation-Induced Defects in Platinum by Moessbauer Spectroscopy.  

National Technical Information Service (NTIS)

Investigation of annealing of radiation induced defects in platinum (with /sup 57/Co isotope addition) after 1.5 MeV proton irradiation up to the 1x10 /sup 18/ cm/sup -2/ dose at 85 K is carried out by the Moessbauer spectroscopy method. Analysis of the d...

V. V. Bogdanov V. V. Zakurkin Y. P. Pen'kov

1987-01-01

237

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

National Technical Information Service (NTIS)

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 ...

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

1993-01-01

238

AB INITIO DEFECT PROPERTIES FOR MODELING RADIATION-INDUCED SEGREGATION IN FE-NI-CR ALLOYS  

Microsoft Academic Search

Radiation-induced segregation (RIS) has been studied with experimental and theoretical methods for over 30 years and many models have been built in an attempt to understand the mechanisms involved. Input parameters for these models are often not available experimentally, limiting the model's predictive capabilities. In an effort to obtain more accurate input parameters we have calculated formation and migration energies

J. D. Tucker; T. R. Allen; D. Morgan

239

Chemical reactive filter paper prepared by radiation-induced graft polymerization—I  

Microsoft Academic Search

Chelating filter papers with chemically bonded amidoxime groups were synthesized by radiation-induced grafting of acrylonitrile onto filter paper (W3) followed by chemical treatment with hydroxylamine. The effect of grafting conditions such as absorbed dose, dose rate, monomer concentration and filter paper thickness on the grafting yield was studied. It was found that the degree of grafting increases with increasing absorbed

A. M. Dessouki; M. El-Tahawy; H. El-Boohy; S. A. El-Mongy; S. M. Badawy

1999-01-01

240

Chemical reactive filter paper prepared by radiation-induced graft polymerization-I  

Microsoft Academic Search

Chelating filter papers with chemically bonded amidoxime groups were synthesized by radiation-induced grafting of acrylonitrile onto filter paper (W3) followed by chemical treatment with hydroxylamine. The effect of grafting conditions such as absorbed dose, dose rate, monomer concentration and filter paper thickness on the grafting yield was studied. It was found that the degree of grafting increases with increasing absorbed

A. M. Dessouki; M. El-Tahawy; H. El-Boohy; S. A. El-Mongy; S. M. Badawy

1999-01-01

241

Predictive factors of radiation-induced skin toxicity in breast cancer patients  

Microsoft Academic Search

BACKGROUND: To assess the factors affecting the incidence of radiation-induced dermatitis in breast cancer patients treated with adjuvant 3 D conformal radiotherapy by the analysis of dosimetry and topical treatments. METHODS: Between September 2002 and July 2009, 158 breast cancer patients were treated with adjuvant 3 D conformal radiotherapy after undergoing surgery. Before November 2006, 90 patients were subjected to

Miao-Fen Chen; Wen-Cheng Chen; Chia-Hsuan Lai; Chao-hsiung Hung; Kuo-Chi Liu; Yin-Hsuan Cheng

2010-01-01

242

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

PubMed Central

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.

DU, SHASHA; YAO, QIWEI; TAN, PEIXIN; XIE, GUOZHU; REN, CHEN; SUN, QUANQUAN; ZHANG, XIAO; ZHENG, RONG; YANG, KAIJUN; YUAN, YAWEI; YUAN, QUAN

2013-01-01

243

Radiation-induced cytotoxicity, DNA damage and DNA repair: Implications for cell survival theory  

Microsoft Academic Search

Summary The radiosensitivities and the kinetics for removal of radiation-induced DNA damage were compared for proliferative (P) and quiescent (Q) cells of the lines 66 and 67 derived from a mouse mammary adenocarcinoma. As determined from cell survival assays, the 66 and 67 Q cells were more radiosensitive than their 66 and 67 P counterparts. The rank order of their

S. G. Swarts; G. B. Nelson; C. A. Wallen; K. T. Wheeler

1990-01-01

244

Finger movement at birth in brachial plexus birth palsy  

PubMed Central

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.

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

2013-01-01

245

Brachial plexus injury mimicking a spinal-cord injury  

PubMed Central

Objective:?High-energy impact to the head, neck, and shoulder can result in cervical spine as well as brachial plexus injuries. Because cervical spine injuries are more common, this tends to be the initial focus for management. We present a case in which the initial magnetic resonance imaging (MRI) was somewhat misleading and a detailed neurological exam lead to the correct diagnosis. Clinical presentation:?A 19-year-old man presented to the hospital following a shoulder injury during football practice. The patient immediately complained of significant pain in his neck, shoulder, and right arm and the inability to move his right arm. He was stabilized in the field for a presumed cervical-spine injury and transported to the emergency department. Intervention:?Initial radiographic assessment (C-spine CT, right shoulder x-ray) showed no bony abnormality. MRI of the cervical-spine showed T2 signal change and cord swelling thought to be consistent with a cord contusion. With adequate pain control, a detailed neurological examination was possible and was consistent with an upper brachial plexus avulsion injury that was confirmed by CT myelogram. The patient failed to make significant neurological recovery and he underwent spinal accessory nerve grafting to the suprascapular nerve to restore shoulder abduction and external rotation, while the phrenic nerve was grafted to the musculocutaneous nerve to restore elbow flexion. Conclusion:?Cervical spinal-cord injuries and brachial plexus injuries can occur by the same high energy mechanisms and can occur simultaneously. As in this case, MRI findings can be misleading and a detailed physical examination is the key to diagnosis. However, this can be difficult in polytrauma patients with upper extremity injuries, head injuries or concomitant spinal-cord injury. Finally, prompt diagnosis and early surgical renerveration have been associated with better long-term recovery with certain types of injury.

Macyszyn, Luke J.; Gonzalez-Giraldo, Ernesto; Aversano, Michael; Heuer, Gregory G.; Zager, Eric L.; Schuster, James M.

2010-01-01

246

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

PubMed Central

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.

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

247

Thoraco-cervico-brachial confined spaces an anatomic study.  

PubMed

A description is made on narrow spaces through which the brachial plexus and subclavian-axillary vessels run from the cervical spine up to the inferior border of the pectoralis major muscle. The spaces are: "Pleural suspensory Apparatus", interscalene spaces (vascular and neural), costo-clavicular, clavi-pectoral, retro-pectoralis minor, pre-humeral head, median nerve roots compass, pre-scalene space. Compressions with or without cervical rib, static or dynamic, are also described. Downward migration of shoulder girdle and muscle variations are analyzed. Forced positions which may produce compressions are also considered (downward pull, abduction + retraction, hyperabduction). PMID:3408287

Poitevin, L A

1988-01-01

248

In Utero Causation of Brachial Plexus Injury: Myth or Mystery?  

Microsoft Academic Search

\\u000a \\u000a In utero causation is a manufactured theory based on speculation that contradicts known anatomic and physiologic principles. Brachial\\u000a plexus injury (BPI) is a very-low-velocity and very-low-impact injury. Adult BPI is a high-velocity and high-impact injury.\\u000a Labor forces are compressive and expulsive, not traction or stretching. “Using a statistical model it is possible to identify\\u000a adverse combinations of factors that are

James A. O’Leary

249

Radiation-induced osteosarcomas after treatment for frontal gliomas: a report of two cases.  

PubMed

Most radiation-induced osteosarcomas of the skull are reported to arise in the facial bone or paranasal sinus after radiotherapy for retinoblastoma and/or pituitary adenoma. Here we report two cases of radiation-induced osteosarcoma in the paranasal sinus after treatment for frontal glioma. Case 1 was a 56-year-old woman who underwent surgical resection of a left frontal tumor in October 1990. The histological diagnosis was a low-grade glioma, and radiotherapy of 54 Gy was administered. Sixteen years later, in September 2006, the patient noted an enlarging subcutaneous mass in the right frontal region. CT showed an osteolytic mass in the right frontal sinus. An open biopsy established the histopathological diagnosis of osteosarcoma, and the patient subsequently died of rapid tumor regrowth. Case 2 was a 58-year-old man who underwent partial removal of a bifrontal tumor in May 1996. The histological diagnosis was anaplastic oligoastrocytoma, and radiotherapy of 56 Gy was administered. Twelve years later, in March 2008, the patient was readmitted to our hospital for reasons of marked deterioration in general physical condition. Tumor recurrence was suspected in the left frontal lobe, and CT demonstrated an osteolytic mass in the left frontal and ethmoid sinus. A secondary operation was performed, and the pathological specimens were diagnosed as osteosarcoma. Radiotherapy was readministered, but the subject died of rapid tumor regrowth. From these clinicopathological findings, both cases were diagnosed as radiation-induced osteosarcoma. Radiation-induced osteosarcomas appeared 16 and 12 years after radiotherapy in cases 1 and 2, respectively. As the prognosis of radiation-induced osteosarcoma is poorer than that of primary osteo-sarcoma, careful attention is required for consideration of the long-term survival of patients with glioma. PMID:21046312

Ito, Tamio; Ozaki, Yoshimaru; Sato, Ken-Ichi; Oikawa, Mitsuteru; Tanino, Mishie; Nakamura, Hirohiko; Tanaka, Shinya

2010-11-03

250

On the mechanism of radiation-induced emesis: The role of serotonin  

SciTech Connect

The aim of this study was to determine the mechanism of action of radiation-induced emesis by determining the incidence of radiation-induced emesis following hemibody irradiation; the effects of specific antiemetics especially ondansetron, a 5-hydroxytryptamine receptor antagonist, and to determine the relationship between radiation-induced emesis and serotonin (5-hydroxytryptamine) through its active metabolite, 5-hydroxyindoleacetic acid (5-HIAA). Forty-one patients received 53 hemibody treatments of 5-8 Gy following intravenous hydration. The patients were divided into three groups according to prehemibody irradiation treatment: Group A: no pretreatment antiemetics, 30 patients; Group B: nonondansetron antiemetics (metoclopramide, dexamethasone, prochlorperazine), ten patients; and Group C: ondansetron, 13 patient. The incidence of radiation-induced emesis was determined prehemibody irradiation or baseline and at 1 h posthemibody irradiation in 38 patients and the results expressed as the percent change in 5-HIAA (ng/ug creatinine). The incidence of radiation-induced emesis was 82% (14/17) following upper/mid hemibody irradiation and 15% (2/11) following lower hemibody irradiation in Group A; 50% (3/6) and 25% (1/4) following upper/mid and lower hemibody irradiation respectively, in Group B/; and 0% (p/13) after upper/mid hemibody irradiation in Group C. The incidence of emesis was significantly different (p<0.001) between the patients of Group A and C who received upper/mid hemibody irradiation. The percent change in 5-HIAA excretion following upper/mid hemibody irradiation were greatest in Group A and smallest in Group C (p<0.002). The degree of change following lower hemibody irradiation (15% incidence of emesis) in Group A was lower than upper/mid hemibody irradiation of the same group. 17 refs., 3 figs., 2 tabs.

Scarantino, C.W.; Ornitz, R.D.; Hoffman, L.G. [Rex Cancer Center, Raleigh, NC (United States)] [and others

1994-11-15

251

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

SciTech Connect

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

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

1995-03-01

252

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

USGS Publications Warehouse

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.

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

1989-01-01

253

[Ipsilateral brachial plexus C7 root transfer. Presentation of a case and a literature review.  

PubMed

The C7 root in brachial plexus injuries has been used since 1986, since the first description by Gu at that time. This root can be used completely or partially in ipsilateral or contralateral lesions of the brachial plexus. A review of the literature and the case report of a 21-month-old girl with stab wounds to the neck and section of the C5 root of the right brachial plexus are presented. A transfer of the anterior fibres of the ipsilateral C7 root was performed. At 9 months there was complete recovery of abduction and external rotation of the shoulder. PMID:23474130

Vergara-Amador, Enrique; Ramírez, Alejandro

2013-03-01

254

A shuttle vector system for studying ionizing radiation-induced mutagenesis in mammalian cells.  

PubMed

A shuttle vector system was developed to quantitate and analyze ionizing radiation-induced mutation in mammalian host cells, COS-1 and CV-1. The shuttle vector pSV2-lacY, which was constructed to detect both point mutations and deletions, was irradiated in vitro with 60Co gamma rays before introduction into unirradiated host cells. The plasmid was then isolated and reintroduced into HB101 (lacY-) bacterial host cells for identification of mutated lacY marker genes. Gamma-irradiation produced a decrease of the survival (recovery) and an increase of mutation of the shuttle vector. The mutated shuttle vector molecules were examined for structural changes by means of restriction endonuclease digestion and agarose gel electrophoresis. A dose dependent increase was observed in the percentages of gross alteration events of total mutations in mammalian host. This system will be useful for studies of ionizing radiation-induced mutagenesis. PMID:8360857

Muraiso, C; Mudgett, J S; Matsudaira, H; Strniste, G F

1993-06-01

255

Spontaneous perseverative turning in rats with radiation-induced hippocampal damage  

SciTech Connect

This study found a new behavioral correlate of lesions specific to the dentate granule cell layer of the hippocampus: spontaneous perseverative turning. Irradiation of a portion of the neonatal rat cerebral hemispheres produced hypoplasia of the granule cell layer of the hippocampal dentate gyrus while sparing the rest of the brain. Radiation-induced damage to the hippocampal formation caused rats placed in bowls to spontaneously turn in long, slow bouts without reversals. Irradiated subjects also exhibited other behaviors characteristic of hippocampal damage (e.g., perseveration in spontaneous exploration of the arms of a T-maze, retarded acquisition of a passive avoidance task, and increased horizontal locomotion). These data extend previously reported behavioral correlates of fascia dentata lesions and suggest the usefulness of a bout analysis of spontaneous bowl turning as a measure of nondiscrete-trial spontaneous alternation and a sensitive additional indicator of radiation-induced hippocampal damage.

Mickley, G.A.; Ferguson, J.L.; Nemeth, T.J.; Mulvihill, M.A.; Alderks, C.E. (Armed Forces Radiobiology Research Institute, Bethesda, MD (USA))

1989-08-01

256

The effect of temperature on radiation-induced radicals in irradiated chicken drumstick bones  

NASA Astrophysics Data System (ADS)

The effect of temperature on the ESR spectra of well characterized unirradiated and irradiated samples of chicken drumstick bones under standardized experimental conditions has been investigated in detail over the temperature range 100-450 K. No significant changes in the linewidth and g factor of the endogenous signal were observed, but the signal intensity was found to decrease markedly in an irreversible way when the temperature was increased. The radiation-induced signal turned out to be the sum of a narrow and a broad line which were assigned to an inorganic and an organic radical, respectively. The thermal stability of the radiation-induced inorganic radical used in poultry irradiation dose determination and in dating was found to be much better than that of organic and endogenous radicals. The results of the present work highlight the need to define properly calibration factors which can be used in conjunction with pre- or post-irradiation thermal treatment of chicken drumstick bones.

Polat, M.; Korkmaz, M.; Korkmaz, Ö.

1997-04-01

257

Anti-apoptotic peptides protect against radiation-induced cell death  

SciTech Connect

The risk of terrorist attacks utilizing either nuclear or radiological weapons has raised concerns about the current lack of effective radioprotectants. Here it is demonstrated that the BH4 peptide domain of the anti-apoptotic protein Bcl-xL can be delivered to cells by covalent attachment to the TAT peptide transduction domain (TAT-BH4) and provide protection in vitro and in vivo from radiation-induced apoptotic cell death. Isolated human lymphocytes treated with TAT-BH4 were protected against apoptosis following exposure to 15 Gy radiation. In mice exposed to 5 Gy radiation, TAT-BH4 treatment protected splenocytes and thymocytes from radiation-induced apoptotic cell death. Most importantly, in vivo radiation protection was observed in mice whether TAT-BH4 treatment was given prior to or after irradiation. Thus, by targeting steps within the apoptosis signaling pathway it is possible to develop post-exposure treatments to protect radio-sensitive tissues.

McConnell, Kevin W. [Department of Surgery, Washington University School of Medicine, St. Louis, MO 63110 (United States); Muenzer, Jared T. [Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110 (United States); Chang, Kathy C. [Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Davis, Chris G. [Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); McDunn, Jonathan E. [Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Coopersmith, Craig M. [Department of Surgery, Washington University School of Medicine, St. Louis, MO 63110 (United States); Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Hilliard, Carolyn A. [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Hotchkiss, Richard S. [Department of Surgery, Washington University School of Medicine, St. Louis, MO 63110 (United States); Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Grigsby, Perry W. [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Hunt, Clayton R. [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO 63110 (United States)]. E-mail: chunt@radonc.wustl.edu

2007-04-06

258

A Kinetic-Based Model of Radiation-Induced Intercellular Signalling  

PubMed Central

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

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

2013-01-01

259

Radiation induced darkening of the optical elements in the Startracker camera  

SciTech Connect

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.

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

1993-03-01

260

Radiation-induced segregation and precipitation behaviours around cascade clusters under electron irradiation.  

PubMed

We have investigated the formation of cascade clusters and structural changes in them by means of electron irradiation following ion irradiation in an austenitic stainless steel. Almost all of the cascade clusters, which were introduced by the ion irradiation, grew to form interstitial-type dislocation loops or vacancy-type stacking fault tetrahedra after electron irradiation at 623 K, whereas a few of the dot-type clusters remained in the matrix. It was possible to recognize the concentration of Ni and Si by radiation-induced segregation around the dot-type clusters. After electron irradiation at 773 K, we found that some cascade clusters became precipitates (delta-Ni2Si) due to radiation-induced precipitation. This suggests that the cascade clusters could directly become precipitation sites during irradiation. PMID:12741490

Sueishi, Yuichiro; Sakaguchi, Norihito; Shibayama, Tamaki; Kinoshita, Hiroshi; Takahashi, Heishichiro

2003-01-01

261

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

SciTech Connect

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

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

1987-09-15

262

Modulation of radiation-induced protein kinase C activity by phenolics.  

PubMed

Natural phenolic compounds were tested in vitro for their effect on the activity of protein kinase C (PKC) isolated from the liver cytosol and the particulate fraction of unirradiated mice and mice irradiated at 5 Gy. Following irradiation, the PKC activity was found to be increased in both cytosolic and particulate fractions. Curcumin, ellagic acid and quercetin were effective in inhibiting radiation-induced PKC activity. Curcumin and ellagic acid were found to be more inhibitory towards radiation-induced PKC activity, while quercetin was the least effective. Curcumin was found to inhibit the activated cytosolic and particulate PKC at very low concentrations. Activation of PKC is one of the means of conferring radioresistance on a tumour cell. Suppression of PKC activity by phenolics may be one of the means of preventing the development of radioresistance following radiotherapy. PMID:11787891

Varadkar, P; Dubey, P; Krishna, M; Verma, N

2001-12-01

263

Radiation-Induced Glioblastoma Multiforme in a Remitted Acute Lymphocytic Leukemia Patient  

PubMed Central

Radiation therapy has been widely applied for cancer treatment. Childhood acute lymphocytic leukemia (ALL), characterized by frequent central nervous system involvement, is a well documented disease for the effect of prophylactic cranio-spinal irradiation. Irradiation, however, acts as an oncogenic factor as a delayed effect and it is rare that glioblastoma multiforme develops during the remission period of ALL. We experienced a pediatric radiation-induced GBM patient which developed during the remission period of ALL, who were primarily treated with chemotherapeutic agents and brain radiation therapy for the prevention of central nervous system (CNS) relapse. Additionally, we reviewed the related literature regarding on the effects of brain irradiation in childhood and on the prognosis of radiation induced GBM.

Joh, Daewon; Lim, Young Jin

2011-01-01

264

A kinetic-based model of radiation-induced intercellular signalling.  

PubMed

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

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

2013-01-22

265

Enzymatic and ultrastructural study of lysosomes in rats bearing radiation-induced thyroid follicular carcinoma  

SciTech Connect

Radiation-induced well-differentiated and poorly differentiated follicular thyroid cancers were transplanted into the intrascapular fat pads of male Fisher 144 rats. The tumors grew in the recipient rats and after a time interval were removed and studied along with normal rat thyroids for lysosomal activity and ultrastructural characteristics. Plasma from experimental and control rats was also studied for lysosomal activity. Rats with radiation-induced thyroid carcinoma had a decrease in growth rate compared with normal rats. There was no significant increase in plasma lysosomal enzymes in the experimental rats. Well-differentiated thyroid carcinomatous tissue showed increased total activities of lysosomal enzymes as well as a difference in subcellular distribution compared with normal and poorly differentiated carcinomatous tissue. Electron microscopy of normal and carcinomatous tissue demonstrated the greatest number of lysosomes in the well-differentiated carcinoma and the fewest in the poorly differentiated carcinoma.

Starling, J.R.; Clifton, K.H.; Norback, D.H.

1981-01-01

266

Radiation-induced segregation in FFTF-irradiated austenitic stainless steels  

NASA Astrophysics Data System (ADS)

Analytical electron microscopy has been applied to radiation-induced segragation (RIS) to defefct sinks in two austenitic stainless steels irradiated in the Fast Flux Test Facility to ?15 dpa at 520°C. RIS to faulted dislocation loops has been shown to be strongly dependent on loop size. Several mechanisms for this effect are discussed, including increased vacancy-driven RIS for large dislocation loop sizes. The spatial distribution of solutes near large dislocation loops is consistent with dominance of the inverse Kirkendall effect and not with an interstitial mechanism of RIS. In a manganese-stabilized austenite (EP838), manganese is the species strongly depleted at boundaries, resulting in little chromium depletion relative to that in USPCA. Therefore, EP838 should exhibit greater resistance to radiation-induced sensitization. Manganese depletion at grain boundaries in the EP838 may induce a loss of austenite stability, but that effect will be offset in part by an enrichment of nickel.

Kenik, E. A.; Hojou, K.

1992-09-01

267

Radiation-induced transient attenuation of optical fibers at 800 and 1300 nm  

SciTech Connect

Radiation-induced absorption in optical fibers has been a subject of considerable interest throughout the world. As availability and applications of fibers have evolved from ''first window'' systems operating near 850 nm to ''second window'' systems near 1300 nm, interest in wavelength dependence of radiation effects in optical fibers has similarly evolved. The present work summarizes second-window, radiation-induced transient absorption measurements in optical fibers for times shorter than 5 ..mu..s. Comparisons to first window data for these fibers are also presented. Only high purity silica fibers with low-OH concentrations were used in the present study to avoid the large OH absorption band in this region. This paper also collects first window data on several high-OH optical fibers.

Looney, L.D.; Lyons, P.B.

1987-01-01

268

Induction, repair and biological relevance of radiation-induced DNA lesions in eukaryotic cells  

Microsoft Academic Search

Summary This report summarizes data on the induction, repair and biological relevance of five types of radiation-induced DNA lesions for which repair kinetic studies have been performed in eukaryotic cells by various laboratories. These lesions are: DNA-protein crosslinks, base damage, single-strand breaks, double-strand breaks and bulky lesions (clustered base damage in the nm-range). The influence of various factors, such as

M. Frankenberg-Schwager

1990-01-01

269

BTK as a Mediator of Radiation-Induced Apoptosis in DT40 Lymphoma B Cells  

Microsoft Academic Search

Bruton's tyrosine kinase (BTK) is a member of the SRC-related TEC family of protein tyrosine kinases (PTKs). DT-40 lymphoma B cells, rendered BTK-deficient through targeted disruption of the btk gene by homologous recombination knockout, did not undergo radiation-induced apoptosis, but cells with disrupted lyn or syk genes did. Introduction of the wild-type, or a SRC homology 2 domain or a

Faith M. Uckun; Kevin G. Waddick; Sandeep Mahajan; Xiao Jun; Minoru Takata; Joseph Bolen; Tomohiro Kurosaki

1996-01-01

270

Radiation-induced conductivity of doped silicon in response to photon, proton and neutron irradiation  

Microsoft Academic Search

The opto-electronic performance of semiconductors during reactor operation is restricted by radiation-induced conductivity (RIC) and the synergistic effects of neutrons\\/ions and photons. The RICs of Si due to photons, protons and pulsed neutrons have been evaluated, aiming at radiation correlation. Protons of 17 MeV with an ionizing dose rate of 103 Gy\\/s and\\/or photons (h?=1.3eV) were used to irradiate impurity-doped

N. Kishimoto; H. Amekura; O. A. Plaksin; V. A. Stepanov

2000-01-01

271

Superoxide dismutase and radiation-induced haemolysis: no benefit of its increased content in red cells.  

PubMed

The sensitivity of human erythrocytes with normal and increased activity of superoxide dismutase (SOD) was compared under different types of oxidative stress. Red blood cells with increased SOD activity were more resistant to haemolysis induced by photoactivated riboflavin but no more resistant to radiation-induced haemolysis and acetylphenylhydrazine stress. These results indicate a negligible role of O(2) in mediation of the haemolytic action of ionizing radiation. PMID:6968737

Bartosz, G; Leyko, W; Kedziora, J; Jeske, J

1980-08-01

272

Gamma knife radiosurgery of radiation-induced intracranial tumors: Local control, outcomes, and complications  

SciTech Connect

Purpose: To determine local control (LC) and complication rates for patients who underwent radiosurgery for radiation-induced intracranial tumors. Methods and Materials: Review of a prospectively maintained database (2,714 patients) identified 16 patients (20 tumors) with radiation-induced tumors treated with radiosurgery between 1990 and 2004. Tumor types included typical meningioma (n = 17), atypical meningioma (n = 2), and schwannoma (n 1). Median patient age at radiosurgery was 47.5 years (range, 27-70 years). The median tumor margin dose was 16 Gy (range, 12-20 Gy). Median follow-up was 40.2 months (range, 10.8-146.2 months). Time-to-event outcomes were calculated with Kaplan-Meier estimates. Results: Three-year and 5-year LC rates were 100%. Three-year and 5-year overall survival rates were 92% and 80%, respectively. Cause-specific survival rates at 3 and 5 years were 100%. Three patients died: 1 had in-field progression 65.1 months after radiosurgery and later died of the tumor, 1 died of progression of a preexisting brain malignancy, and 1 died of an unrelated cause. One patient had increased seizure activity that correlated with development of edema seen on neuroimaging. Conclusions: LC, survival, and complication rates in our series are comparable to those in previous reports of radiosurgery for intracranial meningiomas. Also, LC rates with radiosurgery are at least comparable to those of surgical series for radiation-induced meningiomas. Radiosurgery is a safe and effective treatment option for radiation-induced intracranial tumors, most of which are typical meningiomas.

Jensen, Ashley W. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Brown, Paul D. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Pollock, Bruce E. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Department of Neurologic Surgery, Mayo Clinic, Rochester, MN (United States); Stafford, Scott L. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Link, Michael J. [Department of Neurologic Surgery, Mayo Clinic, Rochester, MN (United States); Garces, Yolanda I. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Foote, Robert L. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Gorman, Deborah A. [Department of Neurologic Surgery, Mayo Clinic, Rochester, MN (United States); Schomberg, Paula J. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States)

2005-05-01

273

Radiation-induced bilateral optic neuropathy in cancer of the nasopharynx  

Microsoft Academic Search

Case Report  A case history of unanticipated radiation-induced bilateral optic neuropathy, 18 months after induction chemotherapy and radiation\\u000a therapy for a locally advanced nasopharyngeal carcinoma, is presented. Retrospective reanalysis of the radiation therapy technique,\\u000a with emphasis on the doses received by the optic pathway structures, was performed. These re-calculations revealed unexpectedly\\u000a high doses in the range 79 to 82 Gy (cumulative

Oda B. Wijers; Peter C. Levendag; Gre P. M. Luyten; Bert A. Bakker; Nicole J. M. Freling; Julie Klesman-Bradley; Evert Woudstra

1999-01-01

274

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

Microsoft Academic Search

Purpose: To analyze the parameters that influence the risk of radiation-induced optic neuropathy (RION) after radiotherapy for head-and-neck tumors. Methods and Materials: Between 1964 and 2000, 273 patients with tumors of the nasopharynx, paranasal sinuses, nasal cavity, and hard palate adenoid cystic carcinomas were treated with curative intent and had radiation fields that included the optic nerves and\\/or chiasm. Patients

Niranjan Bhandare; Alan T. Monroe; Christopher G. Morris; M. Tariq Bhatti; William M.. Mendenhall

2005-01-01

275

Radiation-induced degradation of water pollutants—state of the art  

Microsoft Academic Search

The radiation-induced decomposition of biological resistant pollutants in drinking as well as in wastewater is briefly reviewed. First, some important units, definitions etc., radiation sources, as well as dose-depth curves in water as functions of the electron energy and 60Co-?-rays are mentioned. Following is a schematical presentation of water radiolysis and of characteristics of primary free radicals. Then the degradation

Nikola Getoff

1996-01-01

276

Radiation-induced formation of DNA intrastrand crosslinks between thymine and adenine bases: A theoretical approach.  

PubMed

The role of local geometric and stereo-electronic effects in tuning the radiation-induced formation of intrastrand crosslinks between adenine and thymine has been analyzed by a computational approach rooted in density functional theory. Our study points out that together with steric accessibility, stereo-electronic effects play a major role in determining the reaction mechanism and the observed predominance of the thymine-adenine lesion over the opposite sequence isomer. PMID:17047880

Xerri, Bertrand; Morell, Christophe; Grand, André; Cadet, Jean; Cimino, Paola; Barone, Vincenzo

2006-09-29

277

Analysis of ionizing radiation-induced foci of DNA damage repair proteins  

Microsoft Academic Search

Repair of DNA double-strand breaks by homologous recombination requires an extensive set of proteins. Among these proteins are Rad51 and Mre11, which are known to re-localize to sites of DNA damage into nuclear foci. Ionizing radiation-induced foci can be visualized by immuno-staining. Published data show a large variation in the number of foci-positive cells and number of foci per nucleus

Lieneke R. van Veelen; Tiziana Cervelli; Mandy W. M. M. van de Rakt; Arjan F. Theil; Jeroen Essers; Roland Kanaar

2005-01-01

278

Quercetin ameliorates gamma radiation-induced DNA damage and biochemical changes in human peripheral blood lymphocytes  

Microsoft Academic Search

We investigated the radioprotective efficacy of quercetin (QN), a naturally occurring flavonoid against gamma radiation-induced damage in human peripheral blood lymphocytes and plasmid DNA. In plasmid study, QN at different concentrations (3, 6, 12, 24 and 48?M) were pre-incubated with plasmid DNA for 1h followed by exposure of 6Gy radiation. Among all concentrations of QN used, 24?M showed optimum radioprotective

Nagarajan Devipriya; Adluri Ram Sudheer; Marimuthu Srinivasan; Venugopal P. Menon

2008-01-01

279

Serum amyloid P ameliorates radiation-induced oral mucositis and fibrosis  

Microsoft Academic Search

PURPOSE: To evaluate the effect of the anti-fibrotic protein serum amyloid P (SAP) on radiation-induced oral mucositis (OM) and fibrosis in a hamster cheek-pouch model. EXPERIMENTAL DESIGN: Hamsters received a single dose of radiation (40 Gy) to the left everted cheek pouch to induce significant OM. The protective therapeutic potential of SAP was evaluated using varying dosing regimens. The extent

Lynne A Murray; Michael S Kramer; David P Hesson; Brynmor A Watkins; Edward G Fey; Rochelle L Argentieri; Furquan Shaheen; Darryl A Knight; Stephen T Sonis

2010-01-01

280

Radiation-induced effects in chalcogenide glasses: Topological mechanisms and application  

NASA Astrophysics Data System (ADS)

Structural transformations in vitreous As2S3-based chalcogenide semiconducting glasses induced by ?-irradiation have been considered on the basis of IR Fourier spectroscopy results as destruction-polymerization changes of the covalent chemical bonds, associated with specific coordination defects formation. The whole variety of these processes has been taken into account in order to construct the physically real variants of the radiation-induced structural changes.

Shpotyuk, O. I.

2000-05-01

281

Giant Goos-Hänchen shifts and radiation-induced trapping of Helmholtz solitons at nonlinear interfaces.  

PubMed

Giant Goos-Hänchen shifts and radiation-induced trapping are studied at the planar boundary separating two focusing Kerr media within the framework of the Helmholtz theory. The analysis, valid for all angles of incidence, reveals that interfaces exhibiting linear external refraction can also accommodate both phenomena. Numerical evidence of these effects is provided, based on analytical predictions derived from a generalized Snell's law. PMID:21931405

Sánchez-Curto, Julio; Chamorro-Posada, Pedro; McDonald, Graham S

2011-09-15

282

Radiation-Induced Soft Error Rates of Advanced CMOS Bulk Devices  

Microsoft Academic Search

This work provides a comprehensive summary of radiation-induced soft error rate (SER) scaling trends of key CMOS bulk devices. Specifically we analyzed the SER per bit scaling trends of SRAMs, sequentials and static combinational logic. Our results show that for SRAMs the single-bit soft error rate continues to decrease whereas the multi-bit SER increases dramatically. While the total soft error

N. Seifert; P. Slankard; M. Kirsch; B. Narasimham; V. Zia; C. Brookreson; A. Vo; S. Mitra; B. Gill; J. Maiz

2006-01-01

283

On the mechanisms of radiation-induced curing of epoxy-fiber composites  

NASA Astrophysics Data System (ADS)

Depending on the monomer molecular structure, the mechanisms of radiation-induced polymerization proceed via either C-centered radical mechanisms or cationic polymerization. While polymerization via C-centered radicals can be impeded by the presence of oxygen and high dose-rate, polymerization through cationic polymerization is inhibited even by the presence of trace amounts of water. Synergy by the combination of radiation and thermal curing can help to achieve various desired properties of polymer-fiber composite materials.

Al-Sheikhly, Mohamad; McLaughlin, William L.

1996-08-01

284

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

SciTech Connect

Radiation-induced cationic polymerization of styrene was studied in methylene chloride in the presence of triphenylsulfonium hexafluorophosphate. Acceleration in polymerization and an increase in molecular weight at a low temperature (- 78/sup 0/C) were observed in the presence of triphenylsulfonium salt. A study of pulse radiolysis revealed that both effects are due mainly to PF/sub 6//sup -/, which forms ion pairs with the cationic species involved in the polymerization.

Mah, S.; Yamamoto, Y.; Hayashi, K.

1982-07-01

285

Radiation-induced apoptosis in different pH environments in vitro  

Microsoft Academic Search

Purpose: The effect of environmental pH on the radiation-induced apoptosis in tumor cells in vitro was investigated.Methods and Materials: Mammary adenocarcinoma cells of A\\/J mice (SCK cells) were irradiated with ?-rays using a 137Cs irradiator and incubated in media of different pHs. After incubation at 37°C for 24–120 h the extent of apoptosis was determined using agarose gel electrophoresis, TdT-mediated

Hyung-Sik Lee; Heon J. Park; John C. Lyons; Robert J. Griffin; Elizabeth A. Auger; Chang W. Song

1997-01-01

286

5-androstenediol improves survival in clinically unsupported rhesus monkeys with radiation-induced myelosuppression  

Microsoft Academic Search

We previously reported that five daily intramuscular doses of 5-androstenediol (AED), a naturally occurring adrenal steroid hormone, stimulated multilineage recovery of bone marrow in rhesus monkeys with radiation-induced myelosuppression after 4.0 Gy total body irradiation (TBI). Here we report the effect of AED on the survival of eighty rhesus macaques that received a 6.0 Gy dose of TBI in four sequential pilot

Dwight R. Stickney; Charles Dowding; Simon Authier; Armando Garsd; Nanette Onizuka-Handa; Christopher Reading; James M. Frincke

2007-01-01

287

Detection of radiation-induced hydrocarbons in baked sponged cake prepared with irradiated liquid egg  

Microsoft Academic Search

For identification of irradiated food, radiation-induced volatile hydrocarbons (HC) are determined by gas chromatography in the non-polar fraction of fat. However, in complex food matrices the detection is often disturbed by fat-associated compounds. On-line coupling of high performance liquid chromatography (LC) and gas chromatography (GC) is very efficient to remove such compounds from the HC fraction. The high sensitivity of

G. Schulzki; A. Spiegelberg; K. W. Bögl; G. A. Schreiber

1995-01-01

288

The impact of trastuzumab on radiation-induced pulmonary fibrosis: results of an experimental study  

Microsoft Academic Search

There are no data regarding the late toxicity of trastuzumab (T) administration with radiotherapy (RT). In this experimental\\u000a study, we aimed to asses if concurrent or sequential administration of T has any impact for the development of radiation-induced\\u000a pulmonary fibrosis in rats. Fifty-four female Wistar-albino rats were divided into 6 groups. First group of rats (Group 1;\\u000a concurrent T) had

N. S. Bese; C. Umay; S. Serdengecti; N. Kepil; N. Sut; T. Altug; A. Ober

2010-01-01

289

Chemical selectivity and energy transfer mechanisms in the radiation-induced modification of polyethersulphone  

Microsoft Academic Search

The mechanism of radiation-induced degradation of PES has been studied in a great detail by using XPS technique. PES films have been irradiated both with 6 keV Ar and 3 keV e? beams. The Ar irradiation is assumed to be representative of the processes which strictly depend on collisional energy loss, while the electron irradiation puts in evidence mainly the

G. Marletta; F. Iacona

1996-01-01

290

Radiation induced G 1-block and p53 status in six human cell lines  

Microsoft Academic Search

Considerable attention has recently been focused on the fact that the tumor suppressor protein p53 is involved in the cellular response to radiation. In its wild-type form the protein appears to control a cell cycle checkpoint, preventing entry into S-phase following DNA damage. A number of authors observed a radiation induced G1-block in cells expressing wild-type p53, but not in

F. Zölzer; S. Hillebrandt; C. Streffer

1995-01-01

291

Radiation-induced desulfurization of Arabian crude oil and straight-run diesel  

Microsoft Academic Search

Radiation-induced desulfurization of four types of Arabian crude oils (heavy, medium, light and extra light) and straight-run diesel (SRD) was investigated over the range of 10–200kGy. Results show that gamma radiation processing at absorbed doses up to 200kGy without further treatment is not sufficient for desulfurization. However, the combination of gamma-irradiation with other physical\\/chemical processes (i.e. L\\/L extraction, adsorption and

A. A. Basfar; K. A. Mohamed

2011-01-01

292

Analysis of radiation-induced liver disease using the Lyman NTCP model  

Microsoft Academic Search

Purpose: To describe the dose—volume tolerance for radiation-induced liver disease (RILD) using the Lyman—Kutcher—Burman (LKB) normal tissue complication probability (NTCP) model.Methods and Materials: A total of 203 patients treated with conformal liver radiotherapy and concurrent hepatic arterial chemotherapy were prospectively followed for RILD. Normal liver dose—volume histograms and RILD status for these patients were used as input data for determination

Laura A. Dawson; Daniel Normolle; James M. Balter; Cornelius J. McGinn; Theodore S. Lawrence; Randall K. Ten Haken

2002-01-01

293

Repression of PTEN phosphatase by Snail1 transcriptional factor during gamma radiation-induced apoptosis  

Microsoft Academic Search

The product of the Snail1 gene is a transcriptional repressor required for triggering the epithelial-to-mesenchymal transition. Furthermore, ectopic expression of Snail1 in epithelial cells promotes resistance to apoptosis. In this study, we demonstrate that this resistance to gamma radiation-induced apoptosis caused by Snail1 is associated with the inhibition of PTEN phosphatase. In MDCK cells, mRNA levels of the p53 target

Sandra Peiro; Nicolas Herranz; Patricia Villagrasa; Natalia Dave; Sentis B Montserrat; Stephen A. Murray; C. Franci; Thomas Gridley; Ismo Virtanen; de Herreros Garcia

2008-01-01

294

N- t-Butyl hydroxylamine regulates ionizing radiation-induced apoptosis in U937 cells  

Microsoft Academic Search

Ionizing radiation induces the production of reactive oxygen species, which play an important causative role in apoptotic cell death. Therefore, compounds that scavenge reactive oxygen species may confer regulatory effects on apoptosis. Recently, it has been shown that the decomposition product of the spin-trapping agent ?-phenyl-N-t-butylnitrone, N-t-butyl hydroxylamine (NtBHA), mimics ?-phenyl-N-t-butylnitrone and is much more potent in delaying reactive oxygen

Jin Hyup Lee; Jean Kyoung Tak; Kwon Moo Park; Jeen-Woo Park

2007-01-01

295

Radiation-induced defects in quartz. IV. Thermal properties and implications  

Microsoft Academic Search

The thermal stabilities and decay kinetics of three peroxy radicals (Centers #1, B and B?) and three other radiation-induced\\u000a defects (#3, C? and E1?) in natural quartz from the high-grade McArthur River uranium deposit (Athabasca basin, Canada) have been investigated by\\u000a isochronal and isothermal annealing experiments and electron paramagnetic resonance (EPR) spectroscopy. Single-crystal EPR\\u000a spectra of isochronally (2 h) annealed quartz

Yuanming Pan; Baoqun Hu

2009-01-01

296

Radiation-induced conductivity in electron-beam irradiated insulating polymer films  

Microsoft Academic Search

The radiation-induced conductivity (RIC) in polypropylene, polyethylene terephthalate, and polyimide due to electron-beam irradiation is measured with an external bias method and, in the case of polypropylene, also with a short-circuit method, as a function of dose rate and time of irradiation or total dose. The results substantiate the power-law dependence of the RIC on dose rate in all cases,

G. M. Yang; G. M. Sessler

1992-01-01

297

Amelioration of radiation-induced hematopoietic and gastrointestinal damage by Ex-RAD® in mice  

PubMed Central

The aim of the present study was to assess recovery from hematopoietic and gastrointestinal damage by Ex-RAD®, also known as ON01210.Na (4-carboxystyryl-4-chlorobenzylsulfone, sodium salt), after total body radiation. In our previous study, we reported that Ex-RAD, a small-molecule radioprotectant, enhances survival of mice exposed to gamma radiation, and prevents radiation-induced apoptosis as measured by the inhibition of radiation-induced protein 53 (p53) expression in cultured cells. We have expanded this study to determine best effective dose, dose-reduction factor (DRF), hematological and gastrointestinal protection, and in vivo inhibition of p53 signaling. A total of 500 mg/kg of Ex-RAD administered at 24 h and 15 min before radiation resulted in a DRF of 1.16. Ex-RAD ameliorated radiation-induced hematopoietic damage as monitored by the accelerated recovery of peripheral blood cells, and protection of granulocyte macrophage colony-forming units (GM-CFU) in bone marrow. Western blot analysis on spleen indicated that Ex-RAD treatment inhibited p53 phosphorylation. Ex-RAD treatment reduces terminal deoxynucleotidyl transferase mediated dUTP nick end labeling assay (TUNEL)-positive cells in jejunum compared with vehicle-treated mice after radiation injury. Finally, Ex-RAD preserved intestinal crypt cells compared with the vehicle control at 13 and 14 Gy. The results demonstrated that Ex-RAD ameliorates radiation-induced peripheral blood cell depletion, promotes bone marrow recovery, reduces p53 signaling in spleen and protects intestine from radiation injury.

Ghosh, Sanchita P.; Kulkarni, Shilpa; Perkins, Michael W.; Hieber, Kevin; Pessu, Roli L.; Gambles, Kristen; Maniar, Manoj; Kao, Tzu-Cheg; Seed, Thomas M.; Kumar, K. Sree

2012-01-01

298

Toward a better understanding of the hydrogen impact on the radiation induced growth of zirconium alloys  

NASA Astrophysics Data System (ADS)

Under neutron irradiation, recrystallized zirconium alloys, used as structural materials for Pressurized Water Reactor fuel assemblies, undergo stress-free growth which accelerates for high irradiation doses. This acceleration is correlated to the formation of c-component vacancy dislocation loops. Some feedbacks from neutron irradiations show that the in-service hydrogen pick-up could influence the fuel assembly radiation-induced elongation.

Tournadre, L.; Onimus, F.; Béchade, J.-L.; Gilbon, D.; Cloué, J.-M.; Mardon, J.-P.; Feaugas, X.

2013-10-01

299

Gamma radiation-induced heritable mutations at repetitive DNA loci in out-bred mice  

Microsoft Academic Search

Recent studies have shown that expanded-simple-tandem-repeat (ESTR) DNA loci are efficient genetic markers for detecting radiation-induced germline mutations in mice. Dose responses following irradiation, however, have only been characterized in a small number of inbred mouse strains, and no studies have applied ESTRs to examine potential modifiers of radiation risk, such as adaptive response. We gamma-irradiated groups of male out-bred

C. M. Somers; R. Sharma; J. S. Quinn; D. R. Boreham

2004-01-01

300

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

Microsoft Academic Search

Radiation therapy is widely used in the treatment of primary malignant brain tumors and metastatic tumors of the brain with\\u000a either curative or palliative intent. The limitation of cancer radiation therapy does not derive from the inability to ablate\\u000a tumor, but rather to do so without excessively damaging the patient. Among the varieties of radiation-induced brain toxicities,\\u000a it is the

Jae Ho Kim; Stephen L. Brown; Kenneth A. Jenrow; Samuel Ryu

2008-01-01

301

The Role of Platelet Factor 4 in Radiation-Induced Thrombocytopenia  

Microsoft Academic Search

Purpose: Factors affecting the severity of radiation-induced thrombocytopenia (RIT) are not well described. We address whether platelet factor 4 (PF4; a negative paracrine for megakaryopoiesis) affects platelet recovery postradiation. Methods and Materials: Using conditioned media from irradiated bone marrow (BM) cells from transgenic mice overexpressing human (h) PF4 (hPF4+), megakaryocyte colony formation was assessed in the presence of this conditioned

Michele P. Lambert; Liqing Xiao; Yvonne Nguyen; M. Anna Kowalska; Mortimer Poncz

2011-01-01

302

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

SciTech Connect

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

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

2005-07-01

303

A Radiation-Induced Meningioma "Cures" A Complex Dural Arteriovenous Fistula.  

PubMed

Objective We report a case of spontaneous thrombosis of an extremely complex dural arteriovenous fistula (DAVF), believed to be previously incurable, after the development of a radiation-induced meningioma resulting from prior attempts to treat the fistula with radiosurgery.Methods A very large DAVF was treated over the course of 3 decades with a combination of partial embolization and stereotactic radiosurgery with no angiographic or clinical treatment response at long-term follow-up. However, with the development of new neurologic symptoms 13 years after radiosurgery, a meningioma was found to have arisen in the previously irradiated field, and surprisingly, the fistula had spontaneously thrombosed. The meningioma was successfully removed.Results We discuss the unique pathophysiology of the radiation-induced meningioma causing this previously incurable DAVF progressing to obliteration. We also review the natural history of DAVFs, including reported rates of spontaneous occlusion, as well as the success of radiosurgery in their treatment. Finally, the incidence of radiosurgery-induced tumors, particularly meningiomas, is reviewed.Conclusion The relationship between the spontaneous thrombosis of a DAVF and the radiation-induced meningioma is unique and has not previously been reported. PMID:23765916

Copeland, William R; Link, Michael J

2013-06-13

304

Caffeic acid protects human peripheral blood lymphocytes against gamma radiation-induced cellular damage.  

PubMed

In the present study, we investigated in vitro radioprotective potential of caffeic acid (CA), a naturally occurring catecholic acid against gamma radiation-induced cellular changes. Different concentrations of CA (5.5, 11, 22, 44, 66, and 88 microM) were incubated with lymphocytes for 30 min prior to gamma-irradiation, and micronuclei (MN) scoring and comet assay were performed to fix the effective concentration of CA against gamma-irradiation. Among all concentrations, 66 microM of CA showed the optimum protection by effectively decreasing the MN frequencies and comet attributes. From the above-mentioned results, 66 microM of CA was selected as the effective concentration and was further used to investigate its radioprotective efficacy. For that purpose, a separate experiment was carried out on the lymphocytes in which lymphocytes were preincubated with CA (66 microM) and were exposed to different doses of radiation (1, 2, 3, and 4 Gy). Genetic damage (MN, dicentric aberration, and comet attributes) and biochemical changes were measured. Gamma-irradiated lymphocytes showed a dose-dependent increase in the genetic damage and thiobarbituric acid reactive substances, accompanied by the significant decrease in the antioxidant status, whereas CA pretreatment positively modulated all the radiation-induced changes through its antioxidant potential. The current study demonstrates that CA is effective in protecting lymphocytes against radiation-induced toxicity and encourages further in vivo study to evaluate radioprotective efficacy of CA. PMID:18561333

Devipriya, Nagarajan; Sudheer, Adluri Ram; Menon, Venugopal P

305

The efficacy of nardostachys jatamansi against the radiation induced haematological damage in rats.  

PubMed

Introduction: Radiation is increasingly being used for medical purposes and it is an established weapon in the diagnosis and the therapy of cancer. An exposure to 1-2 Gys causes the NVD (Nausea, vomiting, diarrhoea) syndrome, whereas an exposure to 2-6 Gys causes the haematopoietic syndrome. The aim of the present study was to investigate the protective effect of the Nardostachys jatamansi root extract (NJE) on the radiation induced haematological damage in rats. Materials and Methods: EBR was performed at the Microtron Centre, Mangalore University, India. Rats were treated with NJE once daily for 15 days before and after the irradiation. After the irradiation, blood was collected for determining the peripheral blood counts (RBC and WBC), haemoglobin, the platelet count and the packed cell volume (PCV) at 6 hours, 12 hours, 24 hours, 48 hours and 5, 10 and 15 days post irradiation. The data was analyzed by one way ANOVA, followed by the Tukey's test for multiple comparisons. Result: NJE provided protection against the radiation induced haematological disorders. The rats treated with NJE exhibited a time dependent significant elevation in all the haematological parameters which were studied and its modulation upto the near normal level was recorded. Conclusion: From this study, we concluded that, NJE provides protection by modulating the radiation induced damage on the haematopoietic system. PMID:23905085

Gowda, Damodara K M; Shetty, Lathika; A P, Krishna; Kumari, Suchetha N; Sanjeev, Ganesh; P, Naveen

2013-04-26

306

Radiation-induced spinal cord glioblastoma with cerebrospinal fluid dissemination subsequent to treatment of lymphoblastic lymphoma  

PubMed Central

Background: Radiation-induced glioma arising in the spinal cord is extremely rare. We report a case of radiation-induced spinal cord glioblastoma with cerebrospinal fluid (CSF) dissemination 10 years after radiotherapy for T-cell lymphoblastic lymphoma. Case Description: A 32-year-old male with a history of T-cell lymphoblastic lymphoma presented with progressive gait disturbance and sensory disturbance below the T4 dermatome 10 years after mediastinal irradiation. Gadolinium-enhanced magnetic resonance (MR) imaging revealed an intramedullary tumor extending from the C6 to the T6 level, corresponding to the previous radiation site, and periventricular enhanced lesions. In this case, the spinal lesion was not directly diagnosed because the patient refused any kind of spinal surgery to avoid worsening of neurological deficits. However, based on a biopsy of an intracranial disseminated lesion and repeated immmunocytochemical examination of CSF cytology, we diagnosed the spinal tumor as a radiation-induced glioblastoma. The patient was treated with radiotherapy plus concomitant and adjuvant temozolomide. Then, the spinal tumor was markedly reduced in size, and the dissemination disappeared. Conclusion: We describe our detailed diagnostic process and emphasize the diagnostic importance of immunocytochemical analysis of CSF cytology.

Kikkawa, Yuichiro; Suzuki, Satoshi O; Nakamizo, Akira; Tsuchimochi, Ryosuke; Murakami, Nobuya; Yoshitake, Tadamasa; Aishima, Shinichi; Okubo, Fumihiko; Hata, Nobuhiro; Amano, Toshiyuki; Yoshimoto, Koji; Mizoguchi, Masahiro; Iwaki, Toru; Sasaki, Tomio

2013-01-01

307

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

SciTech Connect

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

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

2010-06-01

308

Spinacia oleracea Modulates Radiation-Induced Biochemical Changes in Mice Testis  

PubMed Central

The present study is an attempt to investigate the radioprotective efficacy of spinach against radiation induced oxidative stress, since its leaves are rich in antioxidants like carotenoids (?-carotene, lutein and zeaxanthin) and high content of proteins, minerals, vitamin C. For the experimental study, healthy Swiss mice were selected from an inbred colony and divided into four groups. Group I (normal) it did not receive any treatment. Group II (drug treated) was orally supplemented with extract of spinach extract once daily at the dose of 1100 mg/kg for fifteen consecutive days. Group III (control) received distilled water orally equivalent to spinach extract for fifteen days than exposed to 5 Gy of gamma radiation. Group IV (experimental) was also administered orally with spinach extract for 15 consecutive days once daily. Thereafter, exposed to single dose of 5Gy of gamma radiation. After the exposure mice were than sacrificed at different autopsy intervals viz. 1, 3, 7, 15 and 30 days. Testis was removed for various biochemical estimations viz. LPO, protein, cholesterol and glycogen. Radiation induced augmentation in lipid peroxidation, glycogen and cholesterol values were significantly ameliorated by supplementation of SE extract, whereas radiation induced deficit in protein content could be elevated. This indicates that spinach extract pre - treatment renders protection against various biochemical changes in the mice testis to some extent if taken continuously which might be due to synergistic effect of antioxidant constituents present in the spinach.

Sisodia, Rashmi; Yadav, Ritu K.; Sharma, K. V.; Bhatia, A. L.

2008-01-01

309

Role of the area postrema in radiation-induced taste aversion learning and emesis in cats  

SciTech Connect

The role of the area postrema in radiation-induced emesis and taste aversion learning and the relationship between these behaviors were studied in cats. The potential involvement of neural factors which might be independent of the area postrema was minimized by using low levels of ionizing radiation (100 rads at a dose rate of 40 rads/min) to elicit a taste aversion, and by using body-only exposures (4500 and 6000 rads at 450 rads/min) to produce emesis. Lesions of the area postrema disrupted both taste aversion learning and emesis following irradiation. These results, which indicate that the area postrema is involved in the mediation of both radiation-induced emesis and taste aversion learning in cats under these experimental conditions, are interpreted as being consistent with the hypotheses that similar mechanisms mediate both responses to exposure to ionizing radiation, and that the taste aversion learning paradigm can therefore serve as a model system for studying radiation-induced emesis.

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

1986-01-01

310

Radiation Induced Non-targeted Response: Mechanism and Potential Clinical Implications  

PubMed Central

Generations of students in radiation biology have been taught that heritable biological effects require direct damage to DNA. Radiation-induced non-targeted/bystander effects represent a paradigm shift in our understanding of the radiobiological effects of ionizing radiation in that extranuclear and extracellular effects may also contribute to the biological consequences of exposure to low doses of radiation. Although radiation induced bystander effects have been well documented in a variety of biological systems, including 3D human tissue samples and whole organisms, the mechanism is not known. There is recent evidence that the NF-?B-dependent gene expression of interleukin 8, interleukin 6, cyclooxygenase-2, tumor necrosis factor and interleukin 33 in directly irradiated cells produced the cytokines and prostaglandin E2 with autocrine/paracrine functions, which further activated signaling pathways and induced NF-?B-dependent gene expression in bystander cells. The observations that heritable DNA alterations can be propagated to cells many generations after radiation exposure and that bystander cells exhibit genomic instability in ways similar to directly hit cells indicate that the low dose radiation response is a complex interplay of various modulating factors. The potential implication of the non-targeted response in radiation induced secondary cancer is discussed. A better understanding of the mechanism of the non-targeted effects will be invaluable to assess its clinical relevance and ways in which the bystander phenomenon can be manipulated to increase therapeutic gain in radiotherapy.

Hei, Tom K.; Zhou, Hongning; Chai, Yunfei; Ponnaiya, Brian; Ivanov, Vladimir N.

2012-01-01

311

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

SciTech Connect

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.

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

1984-03-01

312

Brachial plexus injury in adults: Diagnosis and surgical treatment strategies  

PubMed Central

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

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

2013-01-01

313

Temporal pattern of pulse wave velocity during brachial hyperemia reactivity  

NASA Astrophysics Data System (ADS)

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.

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

2011-09-01

314

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

SciTech Connect

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

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

2008-02-01

315

Contribution of Endogenous and Exogenous Damage to the Total Radiation-Induced Damage in the Bacterial Spore.  

National Technical Information Service (NTIS)

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 resul...

G. P. Jacobs A. Samuni G. Czapski

1980-01-01

316

Analysis of Radiation-Induced Embrittlement Gradients on Fracture Characteristics of Thick-Walled Pressure Vessel Steels.  

National Technical Information Service (NTIS)

The fracture behavior of thick-walled nuclear vessels is considered for the case of a radiation-induced toughness gradient through the wall which characteristically results from neutron attenuation by the wall material itself. Fracture-safe design analyse...

F. J. Loss J. R. Hawthorne C. Z. Serpan P. P. Puzak

1971-01-01

317

Neural sheath tumors of the brachial plexus: a multidisciplinary team-based approach.  

PubMed

Peripheral tumors of the brachial plexus, although rare, provide an opportunity for the plastic surgeon to coordinate a multidisciplinary team and achieve excellent outcomes. Most of the case series are reported from the neurosurgical literature. We report on the experience of the Kaiser Permanente Brachial Plexus Clinic over a recent 2-year period. A retrospective review was conducted to examine the medical records, radiographic images, operative reports, and pathologic findings of 13 consecutive patients with peripheral nerve sheath tumors of brachial plexus origin. Of the 10 patients requiring surgical exploration, 90% had significant improvement or resolution of pain, with sensory and motor recovery showing mixed results. Average follow-up consisted of 2 years with occupational therapy beginning shortly after operative intervention. Our results are similar to or better than those published in the literature. The plastic surgeon with subspecialty training can safely and successfully treat tumors of the brachial plexus by implementing a multidisciplinary approach. PMID:23392262

Soltani, Ali M; Francis, Cameron S; Kane, Justin T; Kazimiroff, Paul B; Edgerton, Bradford W

2013-07-01

318

Spectroscopic Study of ? Ray and Pulsed XRay Radiation-Induced Point Defects in Pure-Silica-Core Optical Fibers  

Microsoft Academic Search

We investigate the radiation-induced effects on pure-silica-core (PSC) optical fibers. For this, we measured the radiation-induced attenuation (RIA) growth and decay kinetics in four fibers with different hydroxyl and chorine contents. Our results show that PSC fibers exhibit different transient and continuous radiation responses depending of the silica-glass composition. Self-trapped charges [self-trapped excitons (STEs) and self-trapped holes (STHs)] seem mainly

S. Girard; Y. Ouerdane; B. Vincent; J. Baggio; K. Medjahdi; J. Bisutti; B. Brichard; A. Boukenter; A. Boudrioua; J.-P. Meunier

2007-01-01

319

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

Microsoft Academic Search

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

Myron Pollycove; Ludwig E Feinendegen

2003-01-01

320

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

Microsoft Academic Search

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

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

2000-01-01

321

Methylglyoxal-bis(guanylhydrazone), a polyamine analogue, sensitized ?-radiation-induced cell death in HL60 leukemia cells  

Microsoft Academic Search

Methylglyoxal-bis(guanylhydrazone) (MGBG), a polyamine analogue, has been known to inhibit the biosynthesis of polyamines, which are important in cell proliferation. We showed that MGBG treatment significantly affected ?-radiation-induced cell cycle transition (G1\\/G0?S?G2\\/M) and thus ?-radiation-induced cell death. As determined by micronuclei and comet assay, we showed that it sensitized the cytotoxic effect induced by ?-radiation. One of the reasons is

Jin Sik Kim; Jin Lee; Hai Won Chung; Han Choi; Sang Gi Paik; In Gyu Kim

2006-01-01

322

Radiation-Induced Acid Generation Reactions in Chemically Amplified Resists for Electron Beam and X-Ray Lithography  

Microsoft Academic Search

The radiation-induced reactions of onium salts in some kinds of solutions and model compound solutions of chemically amplified electron beam (EB) and X-ray resists have been studied by means of picosecond and nanosecond pulse radiolysis. The following reaction mechanisms of the chemically amplified EB and X-ray resists have been elucidated. The radiation-induced reaction mechanisms are complicated due to the presence

Takahiro Kozawa; Yoichi Yoshida; Mitsuru Uesaka; Seiichi Tagawa

1992-01-01

323

Impact of Metabolic Syndrome on Brachial-Ankle Pulse Wave Velocity in Japanese  

Microsoft Academic Search

The aim of this study was to determine the effect of metabolic syndrome on brachial-ankle pulse wave velocity (baPWV) by using the new guidelines for diagnosis of this syndrome in Japan. We examined 525 men and women without a history of cardiovascular disease or cancer, and an ankle-brachial index<0.9. The baPWV was measured using a device (Form PWV\\/ABI) that simultaneously

Akiko Tsubakimoto; Isao Saito; Toshifumi Mannami; Yoshihiko Naito; Shinobu Nakamura; Yoshiko Dohi; Kunio Yonemasu

2006-01-01

324

Brachial plexus injury as an unusual complication of coronary artery bypass graft surgery  

PubMed Central

Brachial plexus injury is an unusual and under-recognised complication of coronary artery bypass grafting especially when internal mammary artery harvesting takes place. It is believed to be due to sternal retraction resulting in compression of the brachial plexus. Although the majority of cases are transient, there are cases where the injury is permanent and may have severe implications as illustrated in the accompanying case history.

Chong, A; Clarke, C; Dimitri, W; Lip, G

2003-01-01

325

Ultrasound-guided posterior approach to brachial plexus for the treatment of upper phantom limb syndrome.  

PubMed

The purpose of the case is to report the clinical value of the ultrasound-guided posterior approach to the brachial plexus in the treatment of phantom limb syndrome after an upper extremity amputation. The author experienced ultrasound guidance as sole technique to localize the brachial plexus for the purpose of placing a catheter for continuous infusion of a local anesthetic in a patient where standard landmark-based nerve stimulation for placement of a continuous perineural block was not possible. PMID:21623340

Tognù, A; Borghi, B; Gullotta, S; White, P F

2011-05-30

326

Effects of mental stress on brachial artery flow-mediated vasodilation in healthy normal individuals  

Microsoft Academic Search

Background Mental stress is associated with increased risk for cardiovascular events, possibly because of acute increases in endogenous catecholamines. Recently, brachial artery flow-mediated vasodilation has been used for noninvasive assessment of macrovascular endothelial function. The effect of mental stress and its associated changes in sympathetic activation on brachial artery endothelium-dependent vasomotor tone in vivo remains unknown.Methods and Results Two-dimensional ultrasound

Charles W. Harris; Jennifer L. Edwards; Amy Baruch; Ward A. Riley; Benjamin E. Pusser; Walter J. Rejeski; David M. Herrington

2000-01-01

327

Pleural effusion and chest pain after continuous interscalene brachial plexus block  

Microsoft Academic Search

Objective: We describe a unique case of a patient who experienced atelectasis of the lower lobe of the left lung and pleural effusion manifested by chest pain after continuous interscalene brachial plexus block for postoperative analgesia.Case Report: A 45-year-old man with no respiratory disease was scheduled for left shoulder arthroscopy for rotator cuff repair under interscalene brachial plexus block and

Vincent Souron; Youri Reiland; Laurent Delaunay

2003-01-01

328

ANKLE-BRACHIAL INDEX AND LDL-RECEPTOR GENE IN ASYMPTOMATIC SEVERE HYPER CHOLESTEROLEMIA  

Microsoft Academic Search

The issue with the different levels of ankle-brachial index, as screening for LDL-receptor defective gene in newly detected asymptomatic severe hypercholesterolemia is less studied, but quite interesting. There have not been any studies on ankle-brachial index in patients with severe hypercholesterolemia in Bulgaria. Aim: To examine the difference between patients with severe hypercholesterolemia, who are carriers and non-carriers of LDL-R

L. Vladimirova-Kitova

2011-01-01

329

Axillary nerve neurotization with the anterior deltopectoral approach in brachial plexus injuries.  

PubMed

Combined neurotization of both axillary and suprascapular nerves in shoulder reanimation has been widely accepted in brachial plexus injuries, and the functional outcome is much superior to single nerve transfer. This study describes the surgical anatomy for axillary nerve relative to the available donor nerves and emphasize the salient technical aspects of anterior deltopectoral approach in brachial plexus injuries. Fifteen patients with brachial plexus injury who had axillary nerve neurotizations were evaluated. Five patients had complete avulsion, 9 patients had C5, six patients had brachial plexus injury pattern, and one patient had combined axillary and suprascapular nerve injury. The long head of triceps branch was the donor in C5,6 injuries; nerve to brachialis in combined nerve injury and intercostals for C5-T1 avulsion injuries. All these donors were identified through the anterior approach, and the nerve transfer was done. The recovery of deltoid was found excellent (M5) in C5,6 brachial plexus injuries with an average of 134.4° abduction at follow up of average 34.6 months. The shoulder recovery was good with 130° abduction in a case of combined axillary and suprascapular nerve injury. The deltoid recovery was good (M3) in C5-T1 avulsion injuries patients with an average of 64° shoulder abduction at follow up of 35 months. We believe that anterior approach is simple and easy for all axillary nerve transfers in brachial plexus injuries. PMID:22434572

Jerome, J Terrence Jose; Rajmohan, Bennet

2012-03-21

330

Study of sensory and motor fascicles in brachial plexus and establishment of a digital three-dimensional graphic model.  

PubMed

To investigate a 3-dimensional (3D) model of human brachial plexus including its topography of sensory and motor fascicles with the assistance of the computer technology, 2 brachial plexus were serially horizontally sliced. Each slice was stained by Karnovsky-Roots acetylcholinesterase histochemical method. The stained sections were scanned, and the image was put into the computer serially. At last, the 3D diagram of brachial plexus was made. The internal structure of the brachial plexus was found to be very complicated. The fascicles bifurcated and recombined with one another with no fixed rules. All fascicles were mixed sensory and motor fibers. Acetylcholinesterase histochemical staining from a serial tissue section is a useful technique to distinguish sensory fibers from motor ones. The 3D visualization of the brachial plexus may help to develop a computerized database of the fascicle topography to provide an anatomical reference in fascicular repair of brachial plexus. PMID:22123540

Chen, Zenggan; Zhang, Jian; Chen, Tongyi; Chen, Zhongwei; Li, Hua; Zhang, Elizabeth W; Lineaweaver, William C; Zhang, Feng

2011-12-01

331

Nicaraven attenuates radiation-induced injury in hematopoietic stem/progenitor cells in mice.  

PubMed

Nicaraven, a chemically synthesized hydroxyl radical-specific scavenger, has been demonstrated to protect against ischemia-reperfusion injury in various organs. We investigated whether nicaraven can attenuate radiation-induced injury in hematopoietic stem/progenitor cells, which is the conmen complication of radiotherapy and one of the major causes of death in sub-acute phase after accidental exposure to high dose radiation. C57BL/6 mice were exposed to 1 Gy ?-ray radiation daily for 5 days in succession (a total of 5 Gy), and given nicaraven or a placebo after each exposure. The mice were sacrificed 2 days after the last radiation treatment, and the protective effects and relevant mechanisms of nicaraven in hematopoietic stem/progenitor cells with radiation-induced damage were investigated by ex vivo examination. We found that post-radiation administration of nicaraven significantly increased the number, improved the colony-forming capacity, and decreased the DNA damage of hematopoietic stem/progenitor cells. The urinary levels of 8-oxo-2'-deoxyguanosine, a marker of DNA oxidation, were significantly lower in mice that were given nicaraven compared with those that received a placebo treatment, although the levels of intracellular and mitochondrial reactive oxygen species in the bone marrow cells did not differ significantly between the two groups. Interestingly, compared with the placebo treatment, the administration of nicaraven significantly decreased the levels of the inflammatory cytokines IL-6 and TNF-? in the plasma of mice. Our data suggest that nicaraven effectively diminished the effects of radiation-induced injury in hematopoietic stem/progenitor cells, which is likely associated with the anti-oxidative and anti-inflammatory properties of this compound. PMID:23555869

Kawakatsu, Miho; Urata, Yoshishige; Imai, Ryo; Goto, Shinji; Ono, Yusuke; Nishida, Noriyuki; Li, Tao-Sheng

2013-03-29

332

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

PubMed

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

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

2006-12-01

333

Effects of Berberine Against Radiation-Induced Intestinal Injury in Mice  

SciTech Connect

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

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

2010-08-01

334

Administration of interleukin-6 stimulates multilineage hematopoiesis and accelerates recovery from radiation-induced hematopoietic depression  

SciTech Connect

Hematopoietic depression and subsequent susceptibility to potentially lethal opportunistic infections are well-documented phenomena following radiotherapy. Methods to therapeutically mitigate radiation-induced myelosuppression could offer great clinical value. In vivo studies have demonstrated that interleukin-6 (IL-6) stimulates pluripotent hematopoietic stem cell (CFU-s), granulocyte-macrophage progenitor cell (GM-CFC), and erythroid progenitor cell (CFU-e) proliferation in normal mice. Based on these results, the ability of IL-6 to stimulate hematopoietic regeneration following radiation-induced hematopoietic injury was also evaluated. C3H/HeN female mice were exposed to 6.5 Gy 60Co radiation and subcutaneously administered either saline or IL-6 on days 1 through 3 or 1 through 6 postexposure. On days 7, 10, 14, 17, and 22, femoral and splenic CFU-s, GM-CFC, and CFU-e contents and peripheral blood white cell, red cell, and platelet counts were determined. Compared with saline treatment, both 3-day and 6-day IL-6 treatments accelerated hematopoietic recovery; 6-day treatment produced the greater effects. For example, compared with normal control values (N), femoral and splenic CFU-s numbers in IL-6-treated mice 17 days postirradiation were 27% N and 136% N versus 2% N and 10% N in saline-treated mice. At the same time, bone marrow and splenic GM-CFC values were 58% N and 473% N versus 6% N and 196% N in saline-treated mice; bone marrow and splenic CFU-e numbers were 91% N and 250% N versus 31% N and 130% N in saline-treated mice; and peripheral blood white cell, red cell, and platelet values were 210% N, 60% N, and 24% N versus 18% N, 39% N, and 7% N in saline-treated mice. These studies demonstrate that therapeutically administered IL-6 can effectively accelerate multilineage hematopoietic recovery following radiation-induced hematopoietic injury.

Patchen, M.L.; MacVittie, T.J.; Williams, J.L.; Schwartz, G.N.; Souza, L.M. (Armed Forces Radiobiology Research Institute, Bethesda, MD (USA))

1991-02-01

335

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

PubMed

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

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

2013-09-03

336

Radiation induced apoptosis and initial DNA damage are inversely related in locally advanced breast cancer patients  

PubMed Central

Background DNA-damage assays, quantifying the initial number of DNA double-strand breaks induced by radiation, have been proposed as a predictive test for radiation-induced toxicity. Determination of radiation-induced apoptosis in peripheral blood lymphocytes by flow cytometry analysis has also been proposed as an approach for predicting normal tissue responses following radiotherapy. The aim of the present study was to explore the association between initial DNA damage, estimated by the number of double-strand breaks induced by a given radiation dose, and the radio-induced apoptosis rates observed. Methods Peripheral blood lymphocytes were taken from 26 consecutive patients with locally advanced breast carcinoma. Radiosensitivity of lymphocytes was quantified as the initial number of DNA double-strand breaks induced per Gy and per DNA unit (200 Mbp). Radio-induced apoptosis at 1, 2 and 8 Gy was measured by flow cytometry using annexin V/propidium iodide. Results Radiation-induced apoptosis increased in order to radiation dose and data fitted to a semi logarithmic mathematical model. A positive correlation was found among radio-induced apoptosis values at different radiation doses: 1, 2 and 8 Gy (p < 0.0001 in all cases). Mean DSB/Gy/DNA unit obtained was 1.70 ± 0.83 (range 0.63-4.08; median, 1.46). A statistically significant inverse correlation was found between initial damage to DNA and radio-induced apoptosis at 1 Gy (p = 0.034). A trend toward 2 Gy (p = 0.057) and 8 Gy (p = 0.067) was observed after 24 hours of incubation. Conclusions An inverse association was observed for the first time between these variables, both considered as predictive factors to radiation toxicity.

2010-01-01

337

Low dose radiation induced adaptive response in human T and B lymphocyte cell lines  

SciTech Connect

Human peripheral blood lymphocytes can express a low dose radiation induced adaptive response to subsequent radiation or chemical challenge. We are screening human T and B cell lines for differential expression of this phenomenon. Such lines should facilitate the identification of the factors underlying this phenomenon, and the conditions required to observe it. Our initial studies have used the T cell lines Molt-3 and CEM-CM3 and the B cell lines WIL2-NS and TK6. Two exposure scenarios were used: (1) a single exposure to 0.05 GY of x-rays followed 6 hrs. later 1 Gy, or (2) three 0.05 Gy exposures with 24 hr. intervals followed by 1 Gy 4 hrs after the last low dose exposure. To date we have triplicate experiments for each line. Under these conditions, TK6 is the only line to show an effect near significance (1 Gy CE 0.19{+-}0.04 vs 0.05{+-}1 Gy CE 0.24{+-}0.05, p=0.08, two tailed paired t-test) which was limited to scenario 1. Recently, Rigaud et al. reported on low dose radiation induced adaptive response to HGPRT mutation in the AHH-1 B cell line. We exposed cells of the WIL2-NS line to a single 0.05 Gy X-ray exposure followed by 6 hrs. later by 3 Gy. To date we have performed 3 experiments. As with the above studies, there was no adaptive response for survival, however, there was a significant decrease in HGPRT mutation (73.2{+-}14.9 x 10{sup -6}for 3 Gy vs 45.8{+-}6.6 x 10{sup -6} for 0.05+3 Gy). These preliminary results suggest that the detection of low dose radiation induced adaptive responses will depend upon cell line, exposure conditions, and biological endpoint measured.

Shadley, J.D.; Pai, G. [Medical College of Wisconsin, Milwaukee, WI (United States)

1994-12-31

338

Radiation-Induced Gene Translation Profiles Reveal Tumor Type and Cancer-Specific Components  

PubMed Central

The microarray analysis of total cellular RNA is a common method used in the evaluation of radiation-induced gene expression. However, profiling the cellular transcriptome does not take into account posttranscriptional processes that affect gene expression. To better define the genes whose expression is influenced by ionizing radiation, we used polysome-bound RNA to generate gene translation profiles for a series of tumor and normal cell lines. Cell lines were exposed to 2 Gy, polysome-bound RNA isolated 6 hours later, and then subjected to microarray analysis. To identify the genes whose translation was affected by radiation, the polysome-bound RNA profiles were compared with their corresponding controls using significance analysis of microarrays (<1% false discovery rate). From the statistically significant genes identified for each cell line, hierarchical clustering was performed by average linkage measurement and Pearson’s correlation metric. Ingenuity Pathway Analysis was used for distributing genes into biological networks and for evaluation of functional significance. Radiation-induced gene translation profiles clustered according to tissue of origin; the cell lines corresponding to each tissue type contained a significant number of commonly affected genes. Network analyses suggested that the biological functions associated with the genes whose translation was affected by radiation were tumor type–specific. There was also a set of genes/networks that were unique to tumor or normal cells. These results indicate that radiation-induced gene translation profiles provide a unique data set for the analysis of cellular radioresponse and suggest a framework for identifying and targeting differences in the regulation of tumor and normal cell radiosensitivity.

Kumaraswamy, Sandhya; Chinnaiyan, Prakash; Shankavaram, Uma T.; Lu, Xing; Camphausen, Kevin; Tofilon, Philip J.

2008-01-01

339

Protection against radiation-induced damage of 6-propyl-2-thiouracil (PTU) in thyroid cells.  

PubMed

Many epidemiologic studies have shown that the exposure to high external radiation doses increases thyroid neoplastic frequency, especially when given during childhood or adolescence. The use of radioprotective drugs may decrease the damage caused by radiation therapy and therefore could be useful to prevent the development of thyroid tumors. The aim of this study was to investigate the possible application of 6-propyl-2-thiouracil (PTU) as a radioprotector in the thyroid gland. Rat thyroid epithelial cells (FRTL-5) were exposed to different doses of ? irradiation with or without the addition of PTU, methimazole (MMI), reduced glutathione (GSH) and perchlorate (KClO4). Radiation response was analyzed by clonogenic survival assay. Cyclic AMP (cAMP) levels were measured by radioimmunoassay (RIA). Apoptosis was quantified by nuclear cell morphology and caspase 3 activity assays. Intracellular reactive oxygen species (ROS) levels were measured using the fluorescent dye 2',7'-dichlorofluorescein-diacetate. Catalase, superoxide dismutase and glutathione peroxidase activities were also determined. Pretreatment with PTU, MMI and GSH prior to irradiation significantly increased the surviving cell fraction (SF) at 2 Gy (P < 0.05), while no effect was observed with KClO4. An increase in extracellular levels of cAMP was found only in PTU treated cells in a dose and time-dependent manner. Cells incubated with agents that stimulate cAMP (forskolin and dibutyril cAMP) mimicked the effect of PTU on SF. Moreover, pretreatment with the inhibitor of protein kinase A, H-89, abolished the radioprotective effect of PTU. PTU treatment diminished radiation-induced apoptosis and protected cells against radiation-induced ROS elevation and suppression of the antioxidant enzyme's activity. PTU was found to radioprotect normal thyroid cells through cAMP elevation and reduction in both apoptosis and radiation-induced oxidative stress damage. PMID:23398355

Perona, Marina; Dagrosa, María A; Pagotto, Romina; Casal, Mariana; Pignataro, Omar P; Pisarev, Mario A; Juvenal, Guillermo J

2013-02-11

340

Radiation-Induced Leiomyosarcoma after Breast Cancer Treatment and TRAM Flap Reconstruction  

PubMed Central

The development of a radiation-induced sarcoma (RIS) in the post mastectomy thoracic treatment volume is an infrequent, but recognized, event. Its frequency is rising in relation with increasing survival of breast cancer patients treated with adjuvant radiation therapy, and is associated with poor prognosis despite treatment. We present a case of leiomyosarcoma in a patient who underwent mastectomy followed by radiotherapy for invasive ductal carcinoma. A delayed TRAM flap reconstruction was performed 10 years after and a rapid growing mass under the reconstructed flap appeared, on routine follow-up, twenty years later. This report analyzes the diagnostic and therapeutic approach of patients with RIS.

Olcina, M.; Merck, B.; Gimenez-Climent, M. J.; Almenar, S.; Sancho-Merle, M. F.; Llopis, F.; Vazquez-Albadalejo, C.

2008-01-01

341

Measurement of dose rate dependence of radiation induced damage to the current gain in bipolar transistors  

SciTech Connect

The authors report the study of radiation induced change in the current gain of bipolar transistors for three different gamma dose rates. The dose rates differed by a factor of 60 with the lowest close to that anticipated for the LHC, and the highest at a rate they have been routinely using for radiation damage tests. The maximum dose attained was 200kRad, which is high enough to compare with other measurements. The importance of annealing high dose rate data is demonstrated.

Dorfan, D.; Dubbs, T.; Grillo, A.A. [and others

1999-12-01

342

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

PubMed

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

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

2007-01-31

343

Experiment on direct nn scattering — The radiation-induced outgassing complication  

NASA Astrophysics Data System (ADS)

The first direct neutron-neutron scattering experiment using the YAGUAR pulsed reactor has yielded initial results. They show a unforeseen significant thermal neutron background as a result of radiation-induced desorption within the scattering chamber. Thermal neutrons are mostly scattering not from other neutrons but instead from the desorbed gas molecules. Analysis of the obtained neutron time-of-flight spectra suggests neutron scattering from H2 molecules. The presented desorption model agrees with our experimental value of the desorption yield ??=0.02 molecules/gamma. Possible techniques to reduce the effect of the desorption background are presented.

Stephenson, S. L.; Crawford, B. E.; Furman, W. I.; Lychagin, E. V.; Muzichka, A. Yu.; Nekhaev, G. V.; Sharapov, E. I.; Shvetsov, V. N.; Strelkov, A. V.; Levakov, B. G.; Lyzhin, A. E.; Chernukhin, Yu. I.; Howell, C. R.; Mitchell, G. E.; Tornow, W.; Showalter-Bucher, R. A.

2012-12-01

344

A graphical method of estimating fatal radiation-induced cancers using the BEIR V method  

SciTech Connect

A method is presented that permits health physicists to estimate the risks of radiation-induced cancers in populations of males or females exposed to whole-body external irradiation at any age. Graphics are presented that may be used for either acute or chronic exposures. There is good agreement for chronic exposures when the cancer estimates determined here are compared with those prescribed in BEIR V. There are differences between the two when considering some acute exposures. In such circumstances, the method given here generally gives conservative results.

Maillie, H.D.; Jacobson, A.P. (Department of Biophysics, University of Rochester, NY (United States))

1992-09-01

345

Radiation-induced segregation in desensitized type 304 austenitic stainless steel  

NASA Astrophysics Data System (ADS)

Schematic representation of overall experimental and results, indicating attack, after the DL-EPR test, on grain boundaries, twin boundaries and pit-like features within grains at the depth of maximum attack. The sensitized specimen also showed severe attack on grain boundaries, however, attack on twin-boundaries and pit-like features were not noticed. Characterization of radiation-induced segregation done by EPR & AFM examination. Cr depletion adjacent to carbides due to RIS in irradiated desensitized 304 SS. Effectiveness as defect sink: twins > pit-like features > grain boundary.

Ahmedabadi, Parag; Kain, V.; Arora, K.; Samajdar, I.; Sharma, S. C.; Bhagwat, P.

2011-09-01

346

Risedronate Prevents Early Radiation-Induced Osteoporosis in Mice at Multiple Skeletal Locations  

PubMed Central

Introduction Irradiation of normal, non-malignant bone during cancer therapy can lead to atrophy and increased risk of fracture at several skeletal sites, particularly the hip. This bone loss has been largely attributed to damaged osteoblasts. Little attention has been given to increased bone resorption as a contributor to radiation-induced osteoporosis. Our aims were to identify if radiation increases bone resorption resulting in acute bone loss, and if bone loss could be prevented by administering risedronate. Methods Twenty-week old female C57BL/6 mice were either: not irradiated and treated with placebo (NR+PL); whole-body irradiated with 2 Gy X-rays and treated with placebo (IR+PL); or irradiated and treated with risedronate (IR+RIS; 30?g/kg every other day). Calcein injections were administered 7 and 2 days before sacrifice. Bones were collected 1, 2, and 3 weeks after exposure. MicroCT analysis was performed at 3 sites: proximal tibial metaphysis; distal femoral metaphysis; and the body of the 5th lumbar vertebra (L5). Osteoclasts were identified from TRAP-stained histological sections. Dynamic histomorphometry of cortical and trabecular bone was performed. Circulating TRAP5b and osteocalcin concentrations were quantified. Results In animals receiving IR+PL, significant (P < 0.05) reduction in trabecular volume fraction relative to non-irradiated controls was observed at all three skeletal sites and time points. Likewise, radiation-induced loss of connectivity and trabecular number relative to NR+PL were observed at all skeletal sites throughout the study. Bone loss primarily occurred during the first week post-exposure. Trabecular and endocortical bone formation was not reduced until Week 2. Loss of bone volume was absent in animals receiving IR+RIS. Histology indicated greater osteoclast numbers at Week 1 within IR+PL mice. Serum TRAP5b concentration was increased in IR+PL mice only at Week 1 compared to NR+PL (P = 0.05). Risedronate treatment prevented the radiation-induced increase in osteoclast number, surface, and TRAP5b. Conclusion This study demonstrated a rapid loss of trabecular bone at several skeletal sites after whole-body irradiation. Changes were accompanied by an increase in osteoclast number and serum markers of bone loss. Risedronate entirely prevented bone loss, providing further evidence that an increase in bone resorption likely caused this radiation-induced bone loss.

Willey, Jeffrey S.; Livingston, Eric W.; Robbins, Michael E.; Bourland, J. Daniel; Tirado-Lee, Leidamarie; Smith-Sielicki, Hope; Bateman, Ted A.

2009-01-01

347

Tumor-to-tumor metastasis from pituitary carcinoma to radiation-induced meningioma.  

PubMed

Radiation-induced meningioma and pituitary carcinoma are both uncommon. Tumor-to-tumor metastasis (TTM) from pituitary carcinoma to meningioma, to our knowledge, has not been previously reported. A 67-year old man presented with a previous history of transcranial subtotal resection of pituitary adenoma, at the age of 36, followed by radiotherapy. The follow-up was uneventful for the following 31 years. The patient presented with worsening sight and numbness of the right arm. Three separate lesions were found on MRI. Histological examinations revealed pituitary carcinomas and TTM from pituitary carcinoma to meningioma. A constant surveillance is necessary for patients with pituitary tumor, especially those followed by radiotherapy. PMID:22989053

Zhou, Quan; Chang, Hong; Gao, Ying; Cui, Lifang

2012-09-19

348

Stress-related phenomena in transient radiation-induced absorption in optical fibers  

SciTech Connect

The optical properties of materials can be modified by exposure to radiation and research to investigate these radiation-induced phenomena has intensified over the last several decades. The advent of optical fiber technology and the many applications of optical fiber for information transmission have sharply increased the interest in these investigations. Optical fibers present a long optical transmission path and that path may traverse different adverse environments, including radiation areas. The long tranmission path provides increased potential for interactions between the optical information signal and the optical medium. 10 refs., 10 figs.

Looney, L.D.; Lyons, P.B.; Kelly, R.E.

1988-01-01

349

The effects of hyper velocity impact phenomena on radiation induced defects  

NASA Astrophysics Data System (ADS)

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

Yamanaka, C.; Ikeya, M.

1994-06-01

350

Perturbed angular correlation study of radiation-induced defects in Rh metal  

NASA Astrophysics Data System (ADS)

Radiation-induced defects are studied in cubic rhodium metal, using the local probe technique 'Time differential perturbed angular correlation (TDPAC) at liquid N-2 temperature. Isochronal annealing was done at 300, 1073 and 1473 K temperatures. The irradiated sample showed two quadrupole interaction frequencies at 1150 and 93 MHz. The low frequency disappeared at room-temperature annealing, which was assigned to In trapped at a vacancy, whereas the higher frequency remained up to high temperatures and was attributed to In trapped at Rh-C complexes in the Rh matrix.

Chawda, M.; Patel, N.; Sebastian, K. C.; Somayajulu, D. R. S.; Sarkar, M.; Singh, R. P.; Murlithar, S.; Awasthi, D. K.

2006-06-01

351

Postfixed brachial plexus radiculopathy due to thoracic disc herniation in a collegiate wrestler: a case report.  

PubMed

Objective: To present the unique case of a collegiate wrestler with C7 neurologic symptoms due to T1-T2 disc herniation. Background: A 23-year-old male collegiate wrestler injured his neck in a wrestling tournament match and experienced pain, weakness, and numbness in his left upper extremity. He completed that match and 1 additional match that day with mild symptoms. Evaluation by a certified athletic trainer 6 days postinjury showed radiculopathy in the C7 distribution of his left upper extremity. He was evaluated further by the team physician, a primary care physician, and a neurosurgeon. Differential Diagnosis: Cervical spine injury, stinger/burner, peripheral nerve injury, spinal cord injury, thoracic outlet syndrome, brachial plexus radiculopathy. Treatment: The patient initially underwent nonoperative management with ice, heat, massage, electrical stimulation, shortwave diathermy, and nonsteroidal anti-inflammatory drugs without symptom resolution. Cervical spine radiographs were negative for bony pathologic conditions. Magnetic resonance imaging showed evidence of T1-T2 disc herniation. The patient underwent surgery to resolve the symptoms and enable him to participate for the remainder of the wrestling season. Uniqueness: Whereas brachial plexus radiculopathy commonly is seen in collision sports, a postfixed brachial plexus in which the T2 nerve root has substantial contribution to the innervation of the upper extremity is a rare anatomic variation with which many health care providers are unfamiliar. Conclusions: The injury sustained by the wrestler appeared to be C7 radiculopathy due to a brachial plexus traction injury. However, it ultimately was diagnosed as radiculopathy due to a T1-T2 thoracic intervertebral disc herniation causing impingement of a postfixed brachial plexus and required surgical intervention. Athletic trainers and physicians need to be aware of the anatomic variations of the brachial plexus when evaluating and caring for patients with suspected brachial plexus radiculopathies. PMID:23952042

Kuzma, Scott A; Doberstein, Scott T; Rushlow, David R

2013-08-16

352

Ankle Brachial Pressure Index (ABPI): An update for practitioners  

PubMed Central

Peripheral vascular disease affects some 12%–14% of the general population, and the majority of people with the disease are asymptomatic. The Ankle Brachial Pressure Index (ABPI) test is widely used by a diverse range of practitioners (in the community and hospital setting) in order to screen asymptomatic patients, diagnose patients with clinical symptoms, and to monitor patients who have had radiological or surgical intervention. This paper explains the theoretical basis of the ABPI test, as well as the relevance of the common modifications of the test. It explores the background to the quoted normal ranges for the ABPI test. It reviews the large body of literature that has developed on the association between ABPI and cardiovascular risk, as well as ABPI as a predictor for cardiovascular morbidity and mortality, highlighting the evidence that can inform practice. The review looks critically at the limitations of the ABPI test, providing practitioners with an evidence-based update on the importance and challenges of standardizing ABPI methodology. This paper highlights the influence of the key technical aspects of the ABPI test that all practitioners need to consider in order to be able to make more reliable and informed management decisions based on ABPI findings.

Al-Qaisi, Mo; Nott, David M; King, David H; Kaddoura, Sam

2009-01-01

353

Inflammation and neuropathic attacks in hereditary brachial plexus neuropathy  

PubMed Central

Objective: To study the role of mechanical, infectious, and inflammatory factors inducing neuropathic attacks in hereditary brachial plexus neuropathy (HBPN), an autosomal dominant disorder characterised by attacks of pain and weakness, atrophy, and sensory alterations of the shoulder girdle and upper limb muscles. Methods: Four patients from separate kindreds with HBPN were evaluated. Upper extremity nerve biopsies were obtained during attacks from a person of each kindred. In situ hybridisation for common viruses in nerve tissue and genetic testing for a hereditary tendency to pressure palsies (HNPP; tomaculous neuropathy) were undertaken. Two patients treated with intravenous methyl prednisolone had serial clinical and electrophysiological examinations. One patient was followed prospectively through pregnancy and during the development of a stereotypic attack after elective caesarean delivery. Results: Upper extremity nerve biopsies in two patients showed prominent perivascular inflammatory infiltrates with vessel wall disruption. Nerve in situ hybridisation for viruses was negative. There were no tomaculous nerve changes. In two patients intravenous methyl prednisolone ameliorated symptoms (largely pain), but with tapering of steroid dose, signs and symptoms worsened. Elective caesarean delivery did not prevent a typical postpartum attack. Conclusions: Inflammation, probably immune, appears pathogenic for some if not all attacks of HBPN. Immune modulation may be useful in preventing or reducing the neuropathic attacks, although controlled trials are needed to establish efficacy, as correction of the mutant gene is still not possible. The genes involved in immune regulation may be candidates for causing HBPN disorders.

Klein, C; Dyck, P; Friedenberg, S; Burns, T; Windebank, A; Dyck, P

2002-01-01

354

Radiation-induced vertebral compression fracture following spine stereotactic radiosurgery: clinicopathological correlation.  

PubMed

Spine stereotactic radiosurgery (SRS) is increasingly being used to treat metastatic spinal tumors. As the experience matures, high rates of vertebral compression fracture (VCF) are being observed. What is unknown is the mechanism of action; it has been postulated but not confirmed that radiation itself is a contributing factor. This case report describes 2 patients who were treated with spine SRS who subsequently developed signal changes on MRI consistent with tumor progression and VCF; however, biopsy confirmed a diagnosis of radiation-induced necrosis in 1 patient and fibrosis in the other. Radionecrosis is a rare and serious side effect of high-dose radiation therapy and represents a diagnostic challenge, as the authors have learned from years of experience with brain SRS. These cases highlight the issues in the new era of spine SRS with respect to relying on imaging alone as a means of determining true tumor progression. In those scenarios in which it is unclear based on imaging if true tumor progression has occurred, the authors recommend biopsy to rule out radiation-induced effects within the bone prior to initiating salvage therapies. PMID:23495889

Al-Omair, Ameen; Smith, Roger; Kiehl, Tim-Rasmus; Lao, Louis; Yu, Eugene; Massicotte, Eric M; Keith, Julia; Fehlings, Michael G; Sahgal, Arjun

2013-03-15

355

Radiation-induced acid ceramidase confers prostate cancer resistance and tumor relapse.  

PubMed

Escape of prostate cancer (PCa) cells from ionizing radiation-induced (IR-induced) killing leads to disease progression and cancer relapse. The influence of sphingolipids, such as ceramide and its metabolite sphingosine 1-phosphate, on signal transduction pathways under cell stress is important to survival adaptation responses. In this study, we demonstrate that ceramide-deacylating enzyme acid ceramidase (AC) was preferentially upregulated in irradiated PCa cells. Radiation-induced AC gene transactivation by activator protein 1 (AP-1) binding on the proximal promoter was sensitive to inhibition of de novo ceramide biosynthesis, as demonstrated by promoter reporter and ChIP-qPCR analyses. Our data indicate that a protective feedback mechanism mitigates the apoptotic effect of IR-induced ceramide generation. We found that deregulation of c-Jun induced marked radiosensitization in vivo and in vitro, which was rescued by ectopic AC overexpression. AC overexpression in PCa clonogens that survived a fractionated 80-Gy IR course was associated with increased radioresistance and proliferation, suggesting a role for AC in radiotherapy failure and relapse. Immunohistochemical analysis of human PCa tissues revealed higher levels of AC after radiotherapy failure than those in therapy-naive PCa, prostatic intraepithelial neoplasia, or benign tissues. Addition of an AC inhibitor to an animal model of xenograft irradiation produced radiosensitization and prevention of relapse. These data indicate that AC is a potentially tractable target for adjuvant radiotherapy. PMID:24091326

Cheng, Joseph C; Bai, Aiping; Beckham, Thomas H; Marrison, S Tucker; Yount, Caroline L; Young, Katherine; Lu, Ping; Bartlett, Anne M; Wu, Bill X; Keane, Barry J; Armeson, Kent E; Marshall, David T; Keane, Thomas E; Smith, Michael T; Jones, E Ellen; Drake, Richard R; Bielawska, Alicja; Norris, James S; Liu, Xiang

2013-09-16

356

Investigation of Radiation-Induced Free Radicals and Luminescence Properties in Fresh Pomegranate Fruits.  

PubMed

Radiation-induced free radicals and luminescence properties were investigated in ?-irradiated (0-3 kGy) pomegranate ( Punica granatum L.) fruits. Photostimulated luminescence (PSL) analysis showed limited applicability, and only 3 kGy-irradiated pomegranates showed positive PSL values (>5000 PCs). Thermoluminescence (TL) glow curve features, such as intensity and the presence of maximum glow peak in radiation-specific temperature range (150-250 °C), provided definite proof of irradiation, and the TL ratios (TL1/TL2) also confirmed the reliability of TL results. Scanning electron microscopy energy dispersive X-ray (SEM-EDX) analysis of the separated minerals showed that feldspar and quartz minerals were responsible for the luminescence properties. Radiation-induced cellulose radicals were detected in the seeds and rinds by ESR analysis. The ESR results were better in freeze-dried samples than in alcohol-extracted ones. A positive correlation was found between the ESR and TL signal intensities and irradiation doses; however, the most promising detection of the irradiation status was possible through TL analysis. PMID:23565691

Shahbaz, Hafiz M; Akram, Kashif; Ahn, Jae-Jun; Kwon, Joong-Ho

2013-04-18

357

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

SciTech Connect

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

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

1986-12-01

358

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

SciTech Connect

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.

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

1995-01-01

359

Relief of radiation-induced oral mucositis in head and neck cancer.  

PubMed

This study was a prospective, randomized clinical trial carried out to explore the efficacy of payayor in the prevention and relief of radiation-induced oral mucositis compared with benzydamine. Sixty patients with head and neck cancer, who have started to receive radiotherapy and met predetermined criteria, were randomly assigned into each group to use assigned products 3 times a day from the first to the last day of radiation. The first group used glycerin payayor, a Thai prepared herbal product, by dripping it into the mouth. Another group rinsed their mouths with benzydamine hydrochloride. The World Health Organization Mucositis Grading System was used to assess oral status every week and 2 weeks after radiation. Comparison of time to the onset, pain, severity, xerostomia, postponement of treatment, satisfaction of the solution, and body weight between the 2 groups was performed by t test. The average time to the onset of oral mucositis in the payayor group was significantly later, and its severity and pain score were less than those of the benzydamine group throughout the study period. Significantly higher satisfaction with the solution and higher body weight at the end of the study were shown in the payayor group. Payayor seemed to be superior to benzydamine for preventing and relieving radiation-induced oral mucositis. PMID:19104205

Putwatana, Panwadee; Sanmanowong, Phichanee; Oonprasertpong, Ladawal; Junda, Tiraporn; Pitiporn, Supaporn; Narkwong, Ladawan

360

Geraniin down regulates gamma radiation-induced apoptosis by suppressing DNA damage.  

PubMed

Gamma ray irradiation triggers DNA damage and apoptosis of proliferating stem cells and peripheral immune cells, resulting in the destruction of intestinal crypts and lymphoid system. Geraniin is a natural compound extracts from an aquatic plant Nymphaea tetragona and possesses good antioxidant property. In this study, we demonstrate that geraniin rescues radiosensitive splenocytes and jejunal crypt cells from radiation-induced DNA damage and apoptosis. Isolated splenocytes from C57BL/6 mice treated with geraniin were protected against radiation injury of 2 Gy irradiation through the enhancement of the proliferation and attenuation of DNA damage. Also, geraniin inhibited apoptosis in radiosensitive splenocytes by reducing the expression level and immunoreactivity of proapoptotic p53 and Bax and increasing those of anti-apoptotic Bcl-2. In mice exposed to radiation, geraniin treatment protected splenocytes and intestinal crypt cells from radiation-induced cell death. Our results suggest that geraniin presents radioprotective effects by regulating DNA damage on splenocytes, exerting immunostimulatory capacities and inhibiting apoptosis of radiosensitive immune cells and jejunal crypt cells. Therefore, geraniin can be a radioprotective agent against ?-irradiation exposure. PMID:23541438

Bing, So Jin; Ha, Danbee; Kim, Min Ju; Park, Eunjin; Ahn, Ginnae; Kim, Dae Seung; Ko, Ryeo Kyeong; Park, Jae Woo; Lee, Nam Ho; Jee, Youngheun

2013-03-26

361

Cytokine profiling for prediction of symptomatic radiation-induced lung injury  

SciTech Connect

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

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

2005-12-01

362

Radiation-induced pulmonary endothelial dysfunction in rats: modification by an inhibitor of angiotensin converting enzyme  

SciTech Connect

The ability of the angiotensin converting enzyme (ACE) inhibitor Captopril to modify radiation-induced pulmonary endothelial dysfunction was determined in male rats sacrificed 2 months after a single dose of 10-30 Gy of /sup 60/Co gamma rays to the right hemithorax. Half of each dose group consumed feed containing 0.12% w/w Captopril (60 mg/kg/day) continuously after irradiation, and half consumed control feed. Four markers of endothelial function were monitored: ACE activity, plasminogen activator (PLA) activity, and prostacyclin (PGI2) and thromboxane (TXA2) production. All data were plotted as dose-response curves, and subjected to linear regression analysis. The Captopril modifying effect was expressed as the ratio of isoeffective doses at a common intermediate response (DRF), or as the ratio of the response curve slopes. Right lung ACE and PLA activity decreased linearly, and PGI2 and TXA2 production increased linearly with increasing radiation dose. Captopril exhibited DRF values of 1.4-2.1, and slope ratios of 1.4-5.1 for all four functional markers (p less than 0.05). Thus, the ACE inhibitor Captopril ameliorates radiation-induced pulmonary endothelial dysfunction in rats sacrificed 2 months postirradiation. Although the mechanism of Captopril action is not clear at present, these data suggest a novel application for this class of compounds as injury-modifying agents in irradiated lung.

Ward, W.F.; Kim, Y.T.; Molteni, A.; Solliday, N.H.

1988-07-01

363

WR-1065, the Active Metabolite of Amifostine, Mitigates Radiation-Induced Delayed Genomic Instability  

PubMed Central

Compounds that can protect cells from the effects of radiation are important for clinical use, in the event of an accidental or terrorist-generated radiation event, and for astronauts traveling in space. One of the major concerns regarding the use of radio-protective agents is that they may protect cells initially, but predispose surviving cells to increased genomic instability later. In this study we used WR-1065, the active metabolite of amifostine, to determine how protection from direct effects of high and low-LET radiation exposure influences genomic stability. When added 30 minutes before irradiation and in high concentration, WR-1065 protected cells from immediate radiation-induced effects as well as from delayed genomic instability. Lower, non-toxic concentration of WR-1065 did not protect cells from death, however it was effective in significantly decreasing delayed genomic instability in the progeny of irradiated cells. The observed increase in manganese superoxide dismutase protein levels and activity may provide an explanation for this effect. These results confirm that WR-1065 is protective against both low- and high-LET radiation-induced genomic instability in surviving cells.

Dziegielewski, Jaroslaw; Baulch, Janet E.; Goetz, Wilfried; Coleman, Mitchell C.; Spitz, Douglas R.; Murley, Jeffrey S.; Grdina, David J.; Morgan, William F.

2009-01-01

364

WR-1065, the active metabolite of amifostine, mitigates radiation-induced delayed genomic instability.  

PubMed

Compounds that can protect cells from the effects of radiation are important for clinical use, in the event of an accidental or terrorist-generated radiation event, and for astronauts traveling in space. One of the major concerns regarding the use of radio-protective agents is that they may protect cells initially, but predispose surviving cells to increased genomic instability later. In this study we used WR-1065, the active metabolite of amifostine, to determine how protection from direct effects of high- and low-LET radiation exposure influences genomic stability. When added 30 min before irradiation and in high concentrations, WR-1065 protected cells from immediate radiation-induced effects as well as from delayed genomic instability. Lower, nontoxic concentrations of WR-1065 did not protect cells from death; however, it was effective in significantly decreasing delayed genomic instability in the progeny of irradiated cells. The observed increase in manganese superoxide dismutase protein levels and activity may provide an explanation for this effect. These results confirm that WR-1065 is protective against both low- and high-LET radiation-induced genomic instability in surviving cells. PMID:18845240

Dziegielewski, Jaroslaw; Baulch, Janet E; Goetz, Wilfried; Coleman, Mitchell C; Spitz, Douglas R; Murley, Jeffrey S; Grdina, David J; Morgan, William F

2008-09-18

365

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

NASA Astrophysics Data System (ADS)

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.

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

366

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

SciTech Connect

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

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

2006-04-01

367

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

NASA Astrophysics Data System (ADS)

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

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

2011-08-01

368

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

PubMed Central

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

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

2013-01-01

369

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

SciTech Connect

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

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

2007-01-01

370

Transient radiation-induced effects on solid core microstructured optical fibers.  

PubMed

We report transient radiation-induced effects on solid core microstructured optical fibers (MOFs). The kinetics and levels of radiation-induced attenuation (RIA) in the visible and near-infrared part of the spectrum (600 nm-2000 nm) were characterized. It is found that the two tested MOFs, fabricated by the stack-and-draw technique, present a good radiation tolerance. Both have similar geometry but one has been made with pure-silica tubes and the other one with Fluorine-doped silica tubes. We compared their pulsed X-ray radiation sensitivities to those of different classes of conventional optical fibers with pure-silica-cores or cores doped with Phosphorus or Germanium. The pulsed radiation sensitivity of MOFs seems to be mainly governed by the glass composition whereas their particular structure does not contribute significantly. Similarly for doped silica fibers, the measured spectral dependence of RIA for the MOFs cannot be correctly reproduced with the various absorption bands associated with the Si-related defects identified in the literature. However, our analysis confirms the preponderant role of self-trapped holes with their visible and infrared absorption bands in the transient behaviors of pure-silica of F-doped fibers. The results of this study showed that pure-silica or fluorine-doped MOFs, which offers specific advantages compared to conventional fibers, are promising for use in harsh environments due to their radiation tolerance. PMID:22109027

Girard, S; Ouerdane, Y; Bouazaoui, M; Marcandella, C; Boukenter, A; Bigot, L; Kudlinski, A

2011-10-24

371

Radiation-induced acid ceramidase confers prostate cancer resistance and tumor relapse  

PubMed Central

Escape of prostate cancer (PCa) cells from ionizing radiation–induced (IR-induced) killing leads to disease progression and cancer relapse. The influence of sphingolipids, such as ceramide and its metabolite sphingosine 1-phosphate, on signal transduction pathways under cell stress is important to survival adaptation responses. In this study, we demonstrate that ceramide-deacylating enzyme acid ceramidase (AC) was preferentially upregulated in irradiated PCa cells. Radiation-induced AC gene transactivation by activator protein 1 (AP-1) binding on the proximal promoter was sensitive to inhibition of de novo ceramide biosynthesis, as demonstrated by promoter reporter and ChIP-qPCR analyses. Our data indicate that a protective feedback mechanism mitigates the apoptotic effect of IR-induced ceramide generation. We found that deregulation of c-Jun induced marked radiosensitization in vivo and in vitro, which was rescued by ectopic AC overexpression. AC overexpression in PCa clonogens that survived a fractionated 80-Gy IR course was associated with increased radioresistance and proliferation, suggesting a role for AC in radiotherapy failure and relapse. Immunohistochemical analysis of human PCa tissues revealed higher levels of AC after radiotherapy failure than those in therapy-naive PCa, prostatic intraepithelial neoplasia, or benign tissues. Addition of an AC inhibitor to an animal model of xenograft irradiation produced radiosensitization and prevention of relapse. These data indicate that AC is a potentially tractable target for adjuvant radiotherapy.

Cheng, Joseph C.; Bai, Aiping; Beckham, Thomas H.; Marrison, S. Tucker; Yount, Caroline L.; Young, Katherine; Lu, Ping; Bartlett, Anne M.; Wu, Bill X.; Keane, Barry J.; Armeson, Kent E.; Marshall, David T.; Keane, Thomas E.; Smith, Michael T.; Jones, E. Ellen; Drake, Richard R.; Bielawska, Alicja; Norris, James S.; Liu, Xiang

2013-01-01

372

Vulnerability of rare-earth-doped fibers for space missions: origins of radiation-induced attenuation  

NASA Astrophysics Data System (ADS)

We characterized the responses of different types of rare-earth doped fibers (Yb, Er and Er/Yb) to various types of radiations like UV, gamma-rays, X-rays and protons. The understanding of the radiation-induced effects in this class of optical fibers is necessary as they are possible candidates for use as part of fiber-based systems like gyroscopes that will have to operate in space environment. For all types of irradiations, the main effect is an increase of the linear absorption of these waveguides due to the generation of point defects in the core and cladding. We characterize the growth and decay kinetics of the radiation-induced attenuation during and after irradiation for various compositions of optical fibers. In this paper, we particularly investigate the relative influence of the rare-earth ions (Er, Yb or Er/Yb) and of the glass matrix dopants (Al, P, ...) on the optical degradation induced by ultraviolet laser exposure at 5 eV. This has been done by using a set of five prototype optical fibers designed by iXFiber SAS to enlighten the role of these parameters. Additional spectroscopic tools like confocal microscopy of luminescence are also used to detect possible changes in the spectroscopy of the rare-earth ions and their consequence on the functionality of the active optical fibers.

Ouerdane, Y.; Girard, S.; Tortech, B.; Robin, T.; Marcandella, C.; Boukenter, A.; Cadier, B.; Meunier, J.-P.; Crochet, P.

2009-05-01

373

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

SciTech Connect

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.

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

1989-04-01

374

Radioprotector WR1065 reduces radiation-induced mutations at the hypoxanthine-guanine phosphoribosyl transferase locus in V79 cells  

SciTech Connect

N-(2-mercaptoethyl)-1,3-diaminopropane (WR1065) protects against radiation-induced cell killing and mutagenesis at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus in V79 Chinese hamster lung fibroblast cells. WR1065 (4 mm) was found to be effective in protecting against radiation-induced cell lethality only if present during irradiation. No protective effect was observed if the protector was added within 5 min after irradiation or 3 h later. The effect of WR1065 on radiation-induced mutation, expressed as resistance to the cytotoxic purine analogue 6-thioguanine (HGPRT), was also investigated. This agent was effective in reducing radiation-induced mutations regardless of when it was administered. Following 10 Gy of /sup 60/Co ..gamma..-rays, the mutation frequencies observed per 10/sup 6/ survivors were 77 +- 8, 27 +- 6, 42 +- 7, and 42 +- 7 for radiation only, and WR1065 present during, immediately after, or 3 h after irradiation. These data suggest that although a segment of radiation-induced damage leading to reproductive death cannot be modulated through the postirradiation action of WR1065, processes leading to the fixation of gross genetic damage and mutation induction in surviving cells can be effectively altered and interfered with leading to a marked reduction in mutation frequency.

Grdina, D.J.; Hill, C.K.; Peraino, C. (Argonne National Lab., IL (USA)); Biserka, N. (Central Inst. for Tumors and Allied Diseases, Zagreb (Yugoslavia)); Wells, R.L. (Colorado State Univ., Fort Collins (USA). Dept. of Radiology and Radiation Biology)

1985-06-01

375

Implication of prostaglandins and histamine h1 and h2 receptors in radiation-induced temperature responses of rats  

SciTech Connect

Exposure of rats to 1-15 Gy cobalt 60 gamma radiation induced hyperthermia, whereas 20-200 Gy induced hypothermia. Exposure either to the head or to the whole body to 10 Gy induced hyperthermia, while body-only exposure produced hypothermia. This observation indicates that radiation-induced fever is a result of a direct effect on the brain. The hyperthermia due to 10 Gy was significantly attenuated by the pre- or post-treatment with a cyclooxgenase inhibitor, indomethacin. Hyperthermia was also altered by the central administration of a mu receptor antagonist naloxone but only at low doses of radiation. These findings suggest that radiation-induced hyperthermia may be mediated through the synthesis and release of prostaglandins in the brain and to a lesser extent to the release of endogenous opioid peptides. The release of histamine acting on H(1) and H(2) receptors may be involved in radiation-induced hypothermia since both the H(1) receptor antagonist, mepyramine, and H(2) receptor antagonist, cimetidine, antagonized the hypothermia. The results of these studies suggested that the release of neurohumoral substances induced by exposure to ionizing radiation is dose dependent and has different consequences on physiological processes such as the regulation of body temperature. Furthermore, the antagonism of radiation-induced hyperthermia by indomethacin may have potential therapeutic implications in the treatment of fever resulting from accidental irradiations.

Kandasamy, S.B.; Hunt, W.A.; Mickley, G.A .

1988-01-01

376

Sialylation of Integrin beta1 is Involved in Radiation-Induced Adhesion and Migration in Human Colon Cancer Cells  

SciTech Connect

Purpose: Previously, we reported that radiation-induced ST6 Gal I gene expression was responsible for an increase of integrin beta1 sialylation. In this study, we have further investigated the function of radiation-mediated integrin beta1 sialylation in colon cancer cells. Methods and Materials: We performed Western blotting and lectin affinity assay to analyze the expression and level of sialylated integrin beta1. After exposure to ionizing radiation (IR), adhesion and migration of cells were measured by in vitro adhesion and migration assay. Results: IR increased sialylation of integrin beta1 responsible for its increased protein stability and adhesion and migration of colon cancer cells. However, for cells with an N-glycosylation site mutant of integrin beta1 located on the I-like domain (Mu3), these effects were dramatically inhibited. In addition, integrin beta1-mediated radioresistance was not observed in cells containing this mutant. When sialylation of integrin beta1 was targeted with a sulfonamide chalcone compound, inhibition of radiation-induced sialylation of integrin beta1 and inhibition of radiation-induced adhesion and migration occurred. Conclusion: The increase of integrin beta1 sialylation by ST6 Gal I is critically involved in radiation-mediated adhesion and migration of colon cancer cells. From these findings, integrin beta1 sialylation may be a novel target for overcoming radiation-induced survival, especially radiation-induced adhesion and migration.

Lee, Minyoung; Lee, Hae-June [Division of Radiation Effects, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Seo, Woo Duck [Department of Functional Corp, NICS, RDA, Miryang (Korea, Republic of); Park, Ki Hun [Division of Applied Life Science (BK21 program), EB-NCRC, Gyeongsang National University, Jinju (Korea, Republic of); Lee, Yun-Sil, E-mail: yslee@kcch.re.k [Division of Radiation Effects, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2010-04-15

377

Continuous brachial plexus blockade for digital replantations and toe-to-hand transfers.  

PubMed

Microsurgical operations of the hand are common procedures of reconstructive surgeons. Sympathetic blockade of the vessels provides increased blood flow to the injured extremity, which increases the success rate of the surgery. Moreover, postoperative pain management can be performed with continuous blockade of the nerves. In this article, the effect of continuous brachial plexus blockade on patients who underwent upper extremity microsurgical operation was evaluated.A total of 16 patients were operated on either for replantation or for toe-to-hand transfer. The first group (n = 9) received combined continuous brachial plexus blockade and general anesthesia, and postoperative pain management was performed with continuous brachial plexus blockade. The remaining 7 patients operated on general anesthesia and conventional pain management. All transplant and replants were followed by use of Doppler flowmeter. Pain was scored by visual analog scale every 4 hours postoperatively. Continuous brachial plexus blockade was found to be effective in both sympathetic blockade and postoperative pain management. Continuous brachial plexus blockade must be considered when microvascular anastomosis is performed at the upper extremity, especially at the digital vessels, which are very susceptible to vasospasm. PMID:15613878

Kurt, Ercan; Ozturk, Serdar; Isik, Selcuk; Zor, Fatih

2005-01-01

378

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

SciTech Connect

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

Belenky, A. [Rabin Medical Center, Beilinson and Glolda Campuses, Petah Tiqwa, Sakler Faculty of Medicine, Tel Aviv University, Department of Interventional Radiology (Israel)], E-mail: 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

379

Opposite effects of WR-2721 and WR-1065 on radiation-induced hypothermia: possible correlation with oxygen uptake. Scientific report  

SciTech Connect

Ionizing radiation induces hypothermia in guinea pigs. While systemic injection of the radioprotectant S-2-(3-aminopropylamimo)ethylphosphorothioic acid (WR-2721) did not block hypothermia induced by exposure to 10 Gy of gamma radiation, central administration did attenuate it. The dephosphorylated metabolite of WR-2721, N-(2-mercaptoethyl)-1,3-diaminopropane (WR-1065), accentuated radiation-induced hypothermia by both routes of administration. In brain homogenates, oxygen uptake was inhibited by WR-2721 but elevated by WR-1065. These results suggest that the antagonism of radiation-induced hypothermia found only after central administration of WR-2721 is due to its direct actions and not in its dephosphorylated metabolite, and that this effect may be correlated with the inhibition by WR-2721 of oxygen uptake.

Kandasamy, S.B.; Kumar, K.S.; Hunt, W.A.; Weiss, J.F.

1988-01-01

380

Opposite effects of WR-2721 and WR-1065 on radiation-induced hypothermia: possible correlation with oxygen uptake  

SciTech Connect

Ionizing radiation induces hypothermia in guinea pigs. While systemic injection of the radioprotectant S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR-2721) did not block hyperthermia induced by exposure to 10 Gy of gamma radiation, central administration did attenuate it. The dephosphorylated metabolite of WR-2721, N-(2-mercaptoethyl)-1,3-diaminopropane (WR-1065), accentuated radiation-induced hypothermia by both routes of administration. In brain homogenates, oxygen uptake was inhibited by WR-2721 but elevated by WR-1065. These results suggest that the antagonism of radiation-induced hypothermia found only after central administration of WR-2721 is due to its direct actions and not to its dephosphorylated metabolite and that this effect may be correlated with the inhibition by WR-2721 of oxygen uptake.

Kandasamy, S.B.; Kumar, K.S.; Hunt, W.A.; Weiss, J.F.

1988-05-01

381

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

NASA Astrophysics Data System (ADS)

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

Schnegg, Caroline Isabel

382

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

ERIC Educational Resources Information Center

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

Buesch, Francisca Eugster

2010-01-01

383

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

ERIC Educational Resources Information Center

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

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

2012-01-01

384

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

ERIC Educational Resources Information Center

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

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

2012-01-01

385

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

ERIC Educational Resources Information Center

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

Buesch, Francisca Eugster

2010-01-01

386

Phrenic nerve block caused by interscalene brachial plexus block: Effects of digital pressure and a low volume of local anesthetic  

Microsoft Academic Search

Background and Objectives. Interscalene brachial plexus block (ISB) is associated with phrenic block and diaphragmatic paralysis when high volumes (40–50 mL) of local anesthetic are injected. The goal of our study was to test if a low volume of local anesthetic administered while maintaining proximal digital pressure might more selectively block the brachial plexus and decrease the frequency of phrenic

X. Sala-Blanch; J. R. Lázaro; J. Correa; M. Gómez-Fernandez

1999-01-01

387

The Development of Countermeasures for Space Radiation Induced Adverse Health Effects  

NASA Astrophysics Data System (ADS)

The Development of Countermeasures for Space Radiation Induced Adverse Health Effects Ann R. Kennedy Department of Radiation Oncology, University of Pennsylvania School of Medicine, 195 John Morgan Building, 3620 Hamilton Walk, Philadelphia, PA, United States 19104-6072 The development of countermeasures for radiation induced adverse health effects is a lengthy process, particularly when the countermeasure/drug has not yet been evaluated in human trials. One example of a drug developed from the bench to the clinic is the soybean-derived Bowman-Birk inhibitor (BBI), which has been developed as a countermeasure for radiation induced cancer. It was originally identified as a compound/drug that could prevent the radiation induced carcinogenic process in an in vitro assay system in 1975. The first observation that BBI could inhibit carcinogenesis in animals was in 1985. BBI received Investigational New Drug (IND) Status with the U.S. Food and Drug Administration (FDA) in 1992 (after several years of negotiation with the FDA about the potential IND status of the drug), and human trials began at that time. Phase I, II and III human trials utilizing BBI have been performed under several INDs with the FDA, and an ongoing Phase III trial will be ending in the very near future. Thus, the drug has been in development for 35 years at this point, and it is still not a prescription drug on the market which is available for human use. A somewhat less time-consuming process is to evaluate compounds that are on the GRAS (Generally Recognized as Safe) list. These compounds would include some over-the-counter medications, such as antioxidant vitamins utilized in human trials at the levels for which Recommended Dietary Allowances (RDAs) have been established. To determine whether GRAS substances are able to have beneficial effects on radiation induced adverse health effects, it is still likely to be a lengthy process involving many years to potentially decades of human trial work. The human trials necessary to demonstrate "efficacy" for a beneficial effect on the long term adverse health effects of radiation, such as the development of cancer, cataracts, etc., is expected to take particularly long periods of time. To avoid the long time delay in the development of new drugs as countermeasures for radiation induced adverse health effects, the NSBRI Center for Acute Radiation Research (CARR) is currently focused on the use of drugs that have already been approved for human use by the FDA. Currently there are no approved countermeasures for external radiation exposure by the US Army or by NASA. The appropriate medications for symptoms of the Acute Radiation Syndrome (ARS) due to exposure to solar particle event (SPE) radiation are unknown, but there are medications appropriate for ARS symptoms caused by exposure to conventional ra-diation. The Armed Forces Radiobiology Research Institute (AFRRI) has medical guidelines for ARS medications (http://www.afrri.usuhs.mil/outreach/guidance.htm#policies), as does the US Dept. of Health and Human Services (the REMM (Radiation Event Medical Manage-ment) site (http://www.remm.nlm.gov). Supportive care when ARS symptoms develop include the administration of antimicrobial agents (which can include systemic antibiotics [especially those directed at gram-negative bacteria]), antiemetic agents, antidiarrheal agents, fluids, elec-trolytes, analgesic agents and topical burn creams (Waselenko, J.K. et al. Ann. Intern. Med. 140: 1037, 2004). For nausea and vomiting, serotonin receptor antagonists (5HT3 receptor antagonists) are very effective prophylaxis. There are two drugs that have been approved by the FDA (Zofran and Kytril) for radiation induced nausea and vomiting. Kytril (granisetron) is preferred by the US Army and is currently maintained in the US National Stockpile. Both of these drugs are known to stop retching and vomiting when given either before or after irradi-ation, even when vomiting and/or retching are occurring. Immune suppression can occur due to declines in white blood cells and infe

Kennedy, Ann

388

Brachial artery aneurysm rupture in a patient with neurofibromatosis: a case report.  

PubMed

Peripheral vascular manifestations of neurofibromatosis are rare but may result in fatal haemorrhaging when they rupture. Surgeons should be aware of this life-threatening condition. We report a case of 35-year-old woman with neurofibromatosis who presented with a swollen and tender mass around her right arm. Angiography revealed 2 aneurysms in the brachial artery. Surgical occlusion revealed a large amount of clotted blood within the subfascial space, and the bleeding point was identified as a pinpoint opening in the aneurysm. The brachial artery abutting the aneurysm and the surrounding soft tissues was extremely brittle and fragile, with massive oozing during dissection. The brachial artery was irreparable and was resected after ligation of the artery and surrounding soft tissues and the aneurysm. Despite an uneventful recovery, the patient died on day 4. PMID:18725682

Jeong, W K; Park, S W; Lee, S H; Kim, C W

2008-08-01

389

A novel technique of ultrasound-guided brachial plexus block in calves.  

PubMed

An interventional ultrasound technique to increase the safety of surgical treatment of the calf forelimb was tested. First, the brachial plexus was evaluated using ultrasonography and then 2% lidocaine was injected under ultrasound guidance. Ultrasonically, the brachial plexus appeared as multiple hypoechoic areas surrounded by a hyperechoic rim or a hyperechoic structure characterised by multiple discontinuous lines. It was located between the omotransverse muscle and axillary artery and vein. The sensitive effect in the forelimb was seen mainly in the area supplied by the musculocutaneous nerve, indicating successful blockage in the nerve plexus. Out of the eight forelimbs, the motor effect was observed in seven forelimbs. These results suggest the clinical feasibility of ultrasound-guided brachial plexus block in bovine medicine, although further studies are needed to examine various approaches, including the sites of needle insertion and the appropriate volume and dosage of anaesthetic. PMID:22682007

Iwamoto, Jiro; Yamagishi, Norio; Sasaki, Kouya; Kim, Danil; Devkota, Bhuminand; Furuhama, Kazuhisa

2012-06-07

390

The use of a catheter to provide brachial plexus block in dogs.  

PubMed Central

The objective of the study was to devise a method to facilitate catheter placement to perform brachial plexus block in the dog. Lidocaine plus epinephrine was injected through a 3.5 French feeding tube secured in proximity of the brachial plexus. Cutaneous areas for the nerves of the distal forelimb were tested for nociceptive sensation by pinching the skin with hemostats. Five out of the 7 dogs developed a full motor and sensory block. The onset time for a full block and duration of blockade were 54 min, s = 17.1 and 39 min, s = 37.6, respectively. A second blockade was successfully achieved in 2 dogs in which the catheter was not displaced. An indwelling feeding tube is an effective way to provide blockade of the brachial plexus in the dog. The placement and the fixation of the catheter were critical for the production of a full block.

Moens, N M; Caulkett, N A

2000-01-01

391

Bilateral single cord of the brachial plexus in an adult female cadaver of South Indian origin  

PubMed Central

The occurrence of a brachial plexus united into a single cord is very rare. During routine dissection of an elderly female cadaver, the brachial plexus united into a single cord was observed bilaterally. On the left side, C4, C5, and C6 roots combined to form the upper trunk, the C7 root continued as the middle trunk, and C8 and T1 united to form the lower trunk. All three trunks almost immediately fused to form a single cord. On the right side, C5 and C6 roots joined to form the upper trunk, which divided into anterior and posterior divisions. C7, C8, and T1 roots combined to form the lower trunk. The anterior and posterior divisions united with the lower trunk to form a single cord. On both sides, the subclavian artery was superior to the single cord. Supraclavicular brachial plexus injuries in such individuals may have serious clinical manifestations.

Viswanathan, Uma; Madhivadhany, Vigneswaran

2013-01-01

392

Brachial artery blood flow during submaximal isometric contraction of the biceps brachii and triceps brachii in humans: a preliminary observation.  

PubMed

The purpose of this study was to evaluate brachial artery blood flow changes during submaximal isometric contraction of the biceps and triceps brachii, in order to clarify the influence of the upper arm muscles activity on the local arterial flow. The brachial artery blood flow velocity and diameter were evaluated in twenty healthy men (mean age 29.6 years) at baseline (resting position) and during submaximal isometric contraction of the biceps and triceps brachii by means of ultrasonography (B-MODE and Doppler ultrasound methods). The brachial artery blood flow velocity was significantly higher than resting position during submaximal isometric contraction of the biceps (P < 0.001) and triceps brachii (P = 0.019). As to the brachial artery diameter, no significant change was observed during submaximal isometric contractions of the biceps and triceps brachii. Our preliminary findings suggest that the brachial artery blood flow velocity similarly increases during submaximal isometric contraction of the biceps and triceps brachii. PMID:23561862

Ledro, Giulia; Turrina, Andrea; Picelli, Alessandro; Stecco, Carla; Principe, Francesco; Cacciatori, Carlo; Smania, Nicola

2012-08-21

393

Gamma-radiation induced interstrand cross-links in PNA:DNA heteroduplexes.  

PubMed

Peptide nucleic acids (PNAs) efficiently hybridize with DNA and are promoted as versatile gene-targeting analytical tools and pharmaceuticals. However, PNAs have never been exploited as radiopharmaceuticals, and radiation-induced physicochemical modifications of PNA:DNA heteroduplexes have not been studied. Drug- and radiation-induced creation of covalent cross-links in DNA obstruct crucial cell survival processes such as transcription and replication and are thus considered genotoxic events with a high impact in anticancer therapies. Here we report that gamma-irradiation of complementary PNA:DNA heteroduplexes, wherein the PNA contains l-lysine, free amino, or N-methylmorpholinium N- and C-capping groups, results in the formation of irreversible interstrand cross-links (ICL). The number of detected ICL corresponds to the number of available amino functional groups on the PNA. The effect of DNA sequence on the formation of ICL was studied by modifying the terminal nucleotides of the DNA oligonucleotide to create deletions and overhangs. The involvement of abasic sites (ABS) on the DNA strand in the cross-linking reaction was confirmed by independent experiments with synthetic ABS-containing oligonucleotides. Molecular modeling and molecular dynamics (MD) simulations were applied to elucidate the conformation of the N- and C-capping groups of the PNA oligomer and their interactions with the proximal terminus of the DNA. Good agreement between experimental and modeling results was achieved. Modeling indicated that the presence of positively charged capping groups on the PNA increases the conformational flexibility of the PNA:DNA terminal base pairs and often leads to their melting. This disordered orientation of the duplex ends provides conditions for multiple encounters of the short (amino) and bulky (Lys) side chains with nucleobases and the DNA backbone up to the third base pair along the duplex stem. Dangling duplex ends offer favorable conditions for increased accessibility of the radiation-induced free radicals to terminal nucleotides and their damage. It is suggested that the ICL are produced by initial formation of Schiff base adducts between the PNA amino functions and the opposed DNA oxidation-damaged bases or abasic 2'-deoxyribose-derived aldehydic groups. The subsequent reduction by solvated electrons (e(-)(aq)) or other radiation-produced reducing species results in irreversible covalent interstrand cross-links. The simultaneous involvement of oxidizing, (*)OH, and reducing, e(-)(aq), radicals presents a case in which multiple ionization events along a gamma-particle path lead to DNA injuries that also encompass ICL as part of the multiply damaged sites (MDS). The obtained results may find applications in the development of a new generation of gene-targeted radiosensitizers based on PNA vectors. PMID:19469551

Gantchev, Tsvetan G; Girouard, Sonia; Dodd, David W; Wojciechowski, Filip; Hudson, Robert H E; Hunting, Darel J

2009-07-28

394

Selective inhibition of microglia-mediated neuroinflammation mitigates radiation-induced cognitive impairment.  

PubMed

Cognitive impairment precipitated by irradiation of normal brain tissue is commonly associated with radiation therapy for treatment of brain cancer, and typically manifests more than 6 months after radiation exposure. The risks of cognitive impairment are of particular concern for an increasing number of long-term cancer survivors. There is presently no effective means of preventing or mitigating this debilitating condition. Neuroinflammation mediated by activated microglial cytokines has been implicated in the pathogenesis of radiation-induced cognitive impairment in animal models, including the disruption of neurogenesis and activity-induced gene expression in the hippocampus. These pathologies evolve rapidly and are associated with relatively subtle cognitive impairment at 2 months postirradiation. However, recent reports suggest that more profound cognitive impairment develops at later post-irradiation time points, perhaps reflecting a gradual loss of responsiveness within the hippocampus by the disruption of neurogenesis. We hypothesized that inhibiting neuroinflammation using MW01-2-151SRM (MW-151), a selective inhibitor of proinflammatory cytokine production, might mitigate these deleterious radiation effects by preserving/restoring hippocampal neurogenesis. MW-151 therapy was initiated 24 h after 10 Gy whole-brain irradiation (WBI) administered as a single fraction and maintained for 28 days thereafter. Proinflammatory activated microglia in the dentate gyrus were assayed at 2 and 9 months post-WBI. Cell proliferation and neurogenesis in the dentate gyrus were assayed at 2 months post-WBI, whereas novel object recognition and long-term potentiation were assayed at 6 and 9 months post-WBI, respectively. MW-151 mitigated radiation-induced neuroinflammation at both early and late time points post-WBI, selectively mitigated the deleterious effects of irradiation on hippocampal neurogenesis, and potently mitigated radiation-induced deficits of novel object recognition consolidation and of long-term potentiation induction and maintenance. Our results suggest that transient administration of MW-151 is sufficient to partially preserve/restore neurogenesis within the subgranular zone and to maintain the functional integrity of the dentate gyrus long after MW-151 therapy withdrawal. PMID:23560629

Jenrow, Kenneth A; Brown, Stephen L; Lapanowski, Karen; Naei, Hoda; Kolozsvary, Andrew; Kim, Jae Ho

2013-04-05

395

Reduction of radiation-induced cell cycle blocks by caffeine does not necessarily lead to increased cell killing  

SciTech Connect

The effect of caffeine upon the radiosensitivities of three human tumor lines was examined and correlated with its action upon the radiation-induced S-phase and G2-phase blocks. Caffeine was found to reduce at least partially the S-phase and G2-phase blocks in all the cell lines examined but potentiated cytotoxicity in only one of the three tumor lines. That reductions have been demonstrated to occur in the absence of increased cell killing provides supporting evidence for the hypothesis that reductions may not be causal in those cases when potentiation of radiation-induced cytotoxicity is observed in the presence of caffeine.

Musk, S.R. (Institute of Cancer Research, Sutton, Surrey (England))

1991-03-01

396

Measurements of growth and decay of radiation induced attenuation during the irradiation and recovery of plastic optical fibres  

NASA Astrophysics Data System (ADS)

In this work, we present the experimental study of the radiation-induced attenuation in step-index polymethyl–methacrylate based plastic optical fibre by exposure to low dose rate ionizing radiation. The low dose exposure has been found to induce significant permanent attenuation in plastic optical fibres. Based on the experimental results, the formula between radiation-induced attenuation and radiation dose is obtained accordingly. The recovery properties of plastic optical fibre also were investigated. The fibre begins to recover immediately after irradiation, but it does not fully recover, i.e. the irradiation leads to permanent damage of polymer.

Kova?evi?, M. S.; Savovi?, S.; Djordjevich, A.; Baji?, J.; Stupar, D.; Kova?evi?, M.; Simi?, S.

2013-04-01

397

Effect of interscalene brachial plexus block on heart rate variability  

PubMed Central

Background Interscalene brachial plexus block (ISB) may be followed by cardiovascular instability. Until date, there is no clear picture available about the underlying mechanisms of ISB. In this study, we aimed to determine the changes in heart rate variability (HRV) parameters after ISB and the differences between right- and left-sided ISBs. Methods We prospectively studied 24 patients operated for shoulder surgery in sitting position and divided them into two respective groups: R (right-sided block = 14 pts) and L (left-sided block = 10 pts). HRV data were taken before and 30 min after the block. Ropivacaine without ephedrine was used for the ISB through an insulated block needle connected to a nerve stimulator. Statistical analysis implemented chi-square, Student's and t-paired tests. Skewed distributions were analyzed after logarithmic transformation. Results All the studied patients had successful blocks. Horner's syndrome signs were observed in 33.3% of the patients (R = 5/14, L = 3/10; [P = 0.769]). There were no significant differences in pre-block HRV between the groups. The application of ISB had differential effect on HRV variables: R-blocks increased QRS and QTc durations and InPNN50, while a statistical decrease was seen in InLF. L-blocks did not show any significant changes. These changes indicate a reduced sympathetic and an increased parasympathetic influence on the heart's autonomic flow after R-block. Conclusions Based on the obtained results we conclude that ISB, possibly through extension of block to the ipsilateral stellate ganglion, alters the autonomic outflow to the central circulatory system in a way depending on the block's side.

Simeoforidou, Marina; Chantzi, Eleni; Bareka, Metaxia; Tsiaka, Katerina; Iatrou, Christos; Karachalios, Theophilos

2013-01-01

398

Nitrogen tensions in brachial vein blood of Korean ama divers.  

PubMed

Intravascular bubble formation and symptoms of decompression sickness have been reported during repetitive deep breath-hold diving. Therefore we examined the pattern of blood N2 kinetics during and after repetitive breath-hold diving. To study muscle N2 uptake and release, we measured brachial venous N2 partial pressure (PN2) in nine professional Korean breath-hold divers (ama) during a 3-h diving shift at approximately 4 m seawater depth and up to 4 h after diving. PN2 was determined with the manometric Van Slyke method. Diving time and depth were recorded using a backpack computer-assisted dive longer that allowed calculating the surface-to-depth time ratio to derive the effective depth. With the assumption that forearm muscle N2 kinetics follow the general Haldanian principles of compression and decompression, i.e., forearm muscle is a single compartment with a uniform tissue PN2 equal to venous PN2, PN2 data were fitted to monoexponential functions of time. In the early phase of the diving shift, PN2 rapidly increased to 640 Torr (half time = 6 min) and then slowly declined to baseline levels (half time = 36 min) after the work shift. Peak PN2 levels approximated the alveolar PN2 derived from the effective depth. We conclude that forearm muscle N2 kinetics are well described by a Haldanian single-compartment model. Decompression sickness is theoretically possible in the ama; it did not occur because the absolute PN2 remained low due to the shallow working depth of the ama we studied. PMID:1490974

Radermacher, P; Falke, K J; Park, Y S; Ahn, D W; Hong, S K; Qvist, J; Zapol, W M

1992-12-01

399

Relation of Socioeconomic Position With Ankle-Brachial Index  

PubMed Central

Potential upstream determinants of coronary heart disease (CHD) include life-course socioeconomic position (e.g., childhood socioeconomic circumstances, own education and occupation); however, several plausible biological mechanisms by which socioeconomic position (SEP) may influence CHD are poorly understood. Several CHD risk factors appear to be more strongly associated with SEP in women than in men; little is known as to whether any CHD risk factors may be more strongly associated with SEP in men. Objectives were to evaluate whether cumulative life-course SEP is associated with a measurement of subclinical atherosclerosis, the ankle–brachial index (ABI), in men and women. This study was a prospective analysis of 1,454 participants from the Framingham Heart Study Offspring Cohort (mean age 57 years, 53.8% women). Cumulative SEP was calculated by summing tertile scores for father’s education, own education, and own occupation. ABI was dichotomized as low (? 1.1) and normal (> 1.1 to 1.4). After adjustment for age and CHD risk factors cumulative life-course SEP was associated with low ABI in men (odds ratio [OR] 2.04, 95% confidence interval [CI] 1.22 to 3.42, for low vs high cumulative SEP score) but not in women (OR 0.86, 95% CI 0.56 to 1.33). Associations with low ABI in men were substantially driven by their own education (OR 4.13, 95% CI 1.86 to 9.16, for lower vs higher than high school education). In conclusion, cumulative life-course SEP was associated with low ABI in men but not in women.

Agha, Golareh; Murabito, Joanne M.; Lynch, John W.; Abrahamowicz, Michal; Harper, Sam B.; Loucks, Eric B.

2013-01-01

400

Severe brachial plexus injury after retropubic radical prostatectomy -A case report-.  

PubMed

A 69-year-old man with prostate cancer underwent surgery for 16 h. Approximately 6 h after surgery, the patient developed severe pain and motor weakness in his right arm. After neurologic examinations that included a nerve conduction study and electromyography, the patient was diagnosed with a brachial plexus injury. The causes of the brachial plexus injury were thought to be abduction of both arms, direct compression of the shoulder brace, and prolonged surgery. Most of the postoperative peripheral nerve injuries due to patient position are preventable, and anesthetists and surgeons should be very careful in positioning the patient accurately. PMID:22870369

Song, Jaegyok

2012-07-24

401

Acute bilateral brachial plexus neuritis associated with hypersensitivity vasculitis. A case report and review of literature.  

PubMed

The occurrence of brachial plexus neuritis during the acute phase of vasculitis is uncommon. We describe a patient with a long history of rhinitis and a recent onset of asthma, who developed purpuric skin lesions, abdominal pain, eosinophilia and brachial neuritis along with evidence of sacral plexus neuropathy. High dose steroids and cyclophosphamide induced a remission. He stopped all medications after 3 years and after 6 years the patient has some fixed minimal residual neurological deficit. The importance of aggressive therapy in treating extensive polyneuropathy during the acute phase of hypersensitivity vasculitis is raised. A possible cytotoxic role of eosinophils in the pathological process is suggested. PMID:4032989

Raz, I; Leitersdorf, E; Kleinman, Y

1985-07-15

402

Percutaneous valve replacement in a young adult for radiation-induced aortic stenosis.  

PubMed

A 46-year-old woman known with relapsing Hodgkin's lymphoma diagnosed at age 5, treated with repeated cycles of radiotherapy and chemotherapy, presented with severe symptomatic radiation-induced aortic stenosis. She also had other late sequelae of radiotherapy including thyroid cancer, mediastinal fribrosis and left pulmonary fibrosis with severe restrictive lung disease and a newly diagnosed renal carcinoma. Due to the prohibitively high surgical risk and need for urgent treatment, she underwent successful transcatheter aortic valve replacement with transfemoral implantation of a 23 mm Edwards SAPIEN-XT prosthesis, which was performed without valvuloplasty of the noncalcified fibrotic valve. The final result was excellent with reduction of the transaortic gradient and no residual aortic regurgitation. PMID:22450861

Latib, Azeem; Montorfano, Matteo; Figini, Filippo; Maisano, Francesco; Chieffo, Alaide; Benussi, Stefano; Bellanca, Raimondo; Gerli, Chiara; Spagnolo, Pietro; Alfieri, Ottavio; Colombo, Antonio

2012-06-01

403

Asymmetric radiation-induced inclusion polymerization of 3-methyl-1,4-pentadiene in deoxycholic acid  

NASA Astrophysics Data System (ADS)

The radiation-induced polymerization of 3-methyl-1,3-pentadiene (3MPD) as an inclusion complex in deoxycholic acid (DOCA) has produced in good yield the optically active polymer poly(3-methyl-1,4-pentadiene) (P3MPD) whose structure and properties were studied by FT-IR spectroscopy and thermal analysis (TGA, DTG and DTA). The data show that the polymer is essentially trans-1,4-P3MPD as expected for the polymerization in constrained media. Trans-1,4-P3MPD is optically active with [?]D values comprised between +4.3 and +5.6. The optical rotatory dispersion curve of the P3MPD is completely different from that of DOCA as expected.

Cataldo, Franco; Ursini, Ornella; Angelini, Giancarlo

2010-01-01

404

mTOR inhibition prevents epithelial stem cell senescence and protects from radiation-induced mucositis  

PubMed Central

SUMMARY The integrity of the epidermis and mucosal epithelia is highly dependent on resident self-renewing stem cells, which makes them vulnerable to physical and chemical insults compromising the repopulating capacity of the epithelial stem cell compartment. This is frequently the case in cancer patients receiving radiation or chemotherapy, many of whom develop mucositis, a debilitating condition involving painful and deep mucosal ulcerations. Here, we show that inhibiting the mammalian target of rapamycin (mTOR) with rapamycin increases the clonogenic capacity of primary human oral keratinocytes and their resident self-renewing cells by preventing stem cell senescence. This protective effect of rapamycin is mediated by the increase expression of mitochondrial superoxide dismutase (MnSOD), and the consequent inhibition of ROS formation and oxidative stress. mTOR inhibition also protects from the loss of proliferative basal epithelial stem cells upon ionizing radiation in vivo, thereby preserving the integrity of the oral mucosa and protecting from radiation-induced mucositis.

Iglesias-Bartolome, Ramiro; Patel, Vyomesh; Cotrim, Ana; Leelahavanichkul, Kantima; Molinolo, Alfredo A.; Mitchell, James B.; Gutkind, J. Silvio

2012-01-01

405

On the mechanism of radiation-induced polymerization of vinyl monomers in ionic liquid  

NASA Astrophysics Data System (ADS)

An attempt was made to investigate the mechanism controlling the radiation-induced polymerization of vinyl monomers in room temperature ionic liquids. For that purpose, copolymerization of styrene (St) and methyl methacrylate (MMA) was initiated by 60Co gamma radiation in a moisture-stable ionic liquid, [choline chloride][ZnCl2], and its mixture with THF (4:1 v/v). By analyzing the product composition with FTIR for a series of poly(St-co-MMA) samples, it was found that the mole fraction of St in the copolymer is linearly proportional to the mole fraction of St in the feed. Therefore, radiation polymerization in ionic liquid and its mixture with organic solvent is suggested to be a radical propagating process.

Liu, Yaodong; Wu, Guozhong

2005-06-01

406

Endogenous retrovirus and radiation-induced leukemia in the RMF mouse  

SciTech Connect

The induction of myeloid leukemia in irradiated RFM/Un mice has been associated with retrovirus infection. However, two characteristics of this strain complicate efforts to define the role of the virus. This strain possesses only one inducible host range class of endogenous virus and a unique gene, in addition to the Fv-1/sup n/ locus, which specifically restricts exogenous infection by endogenous viruses. These characteristics possibly account for absence of recombinant viruses in this strain, even though virus is amply expressed during most of the animal's life span. We have examined further the distribution of retrovirus sequences and the chromosomal locus of the inducible virus in this strain. This report describes evidence for additional viral sequences in cells of a radiation-induced myeloid leukemia line and discusses the possible origin of these added copies.

Tennant, R.W.; Boone, L.R.; Lalley, P.; Yang, W.K.

1982-01-01

407

Flow cytometric determination of radiation-induced chromosome damage and its correlation with cell survival  

SciTech Connect

Chinese hamster M3-1 cells were irradiated with several doses of x rays or ..cap alpha.. particles from /sup 238/Pu. Propidium iodide-stained chromosome suspensions were prepared at different times after irradiation; cells were also assayed for survival. The DNA histograms of these chromosomes showed increased background counts with increased doses of radiation. This increase in background was cell-cycle dependent and was correlated with cell survival. The correlation between radiation-induced chromosome damage and cell survival was the same for X rays and ..cap alpha.. particles. Data are presented which indicate that flow cytometric analysis of chromosomes of irradiated cell populations can be a useful adjunct to classical cytogenic analysis of irradiation-induced chromosomal damage by virtue of its ability to express and measure chromosomal damage not seen by classical cytogenic methods.

Welleweerd, J.; Wilder, M.E.; Carpenter, S.G.; Raju, M.R.

1984-07-01

408

Thermal effusivity: a promising imaging biomarker to predict radiation-induced skin injuries.  

SciTech Connect

An effective screening technology is needed to triage individuals at the time of radiation incidents involving a large population. Three-dimensional thermal tomography is a relatively new development in active thermal imaging technology that produces cross-sectional images based on the subject's ability to transfer heat thermal effusivity at the voxel level. This noninvasive imaging modality has been used successfully in nondestructive examination of complex materials; also it has been shown to predict the severity of radiation-induced skin injuries several days before the manifestation of severe moist desquamations or blister formation symptoms in mice at 40 Gy. If these results are confirmed at lower dose levels in human subjects, a thermal tomography imaging device may be an ideal screening tool in radiation emergencies. This imaging method is non-invasive, relatively simple, easily adaptable for field use, and when properly deployed, it will enhance public emergency preparedness for incidents involving unexpected radiation exposure.

Chu, J. C. H.; Templeton, A.; Yao, R.; Griem, K. L.; Sun, J. G. (Nuclear Engineering Division); (Rush University)

2012-01-01

409

Revealing the impact of radiation-induced refractive index changes in polymer gel dosimeters  

NASA Astrophysics Data System (ADS)

This study examines effects of radiation-induced refractive index (RI) changes in polymer gel dosimeters. A prototype fan-beam optical computed tomography scanner was used to image a normoxic polymer gel dosimeter that was irradiated with two simple irradiation patterns-one single beam, one cross beam. A combed fan-beam was used for rayline tracing. Scans revealed that notable rayline errors occur when a steep, side-to-side dose gradient (i.e. RI gradient) is encountered. When the gradient occurs in the plane of the detector system, distinctive streaks in images are observed. When the gradient occurs perpendicular to the plane of the detector system, much more severe image errors are observed.

Campbell, W. G.; Jirasek, A.; Wells, D.

2013-06-01

410

Graft polymerization using radiation-induced peroxides and application to textile dyeing  

NASA Astrophysics Data System (ADS)

To improve the dyeing affinity of ultra high molecular weight polyethylene (UHMWPE) fiber, surface treatment by radiation-induced graft polymerization was performed. Methyl methacrylate (MMA), acrylic acid (AA) and styrene (St) were used as the monomers. The grafting yields as a function of storage time after irradiation were examined. Although the grafting yield of St after the sulfonation processing was quite low compared with those of MMA and AA, it was successfully dyed to a dark color with a cationic dye. Some acid dyes can dye the grafted fiber with AA. The acid dye is distributed to the amorphous domains of the AA grafted fiber. The dyeing concentration depended on the grafting yield, and the higher the grafting yield the darker the dye color.

Enomoto, Ichiro; Katsumura, Yosuke; Kudo, Hisaaki; Soeda, Shin

2011-02-01

411

Effect of nano-SiO2 films on the electron radiation induced conductivity of polyimide  

NASA Astrophysics Data System (ADS)

The radiation induced conductivity (RIC) behaviors in nano-SiO2 deposited polyimide (PI) were investigated using the in situ measurement technique. The results indicate that, by comparison with the case of virgin polyimide, the RIC in nano-SiO2 /polyimide shows low steady state values. Moreover, the steady state RIC is a power function of the dose rate with a power index of 0.659, lower than that of 0.76 in the virgin polyimide. The interfacial barrier and trapping effects are the main reasons for the change. Meanwhile, both of the interfacial effects also result in a unipolar carrier transportation mechanism in nano-SiO2 deposited PI from the dipolar one in the virgin PI. The mechanisms of the RIC behaviors are discussed in the paper.

Yue, Long; Wu, Yi-Yong; Sun, Cheng-Yue; Shi, Ya-Ping; Xiao, Jing-Dong; He, Shi-Yu

2013-07-01

412

Radiation-induced hemopoietic and immune dysfunction. Technical report, 16 Aug 86-31 Mar 90  

SciTech Connect

This work was aimed at investigating radiation-induced hemopoietic and immune dysfunction in the dog model. One project was to produce monoclonal antibodies directed against canine hemopoietic precursor cells and specific for pluripotent stem cells. Antibodies obtained reacted with different myeloid and erythroid precursor cells; unfortunately, none of the antibodies were specific for pluripotent hemopoietic stem cells. Positive selections for these cells were performed using magnetic beads and an antibody against class 2-antigen. Transplantation of class 2 positive marrow cells into otherwise lethally irradiated dogs led to sustained recovery in only 1 of 5 dogs. A second project established and investigated long-term marrow cultures in the dog. Culture conditions were studied and optimized, and marrow cells were transplanted into otherwise lethally irradiated dogs to investigate stem cell survival in long-term cultures. Engraftment was observed only with short-term marrow cultures.

Storb, R.; Schuening, F.

1991-06-01

413

Ionizing radiation induced helium release for hot pressed SiC  

NASA Astrophysics Data System (ADS)

Ionizing radiation induced helium release and diffusion in SiC has been assessed. Hot pressed SiC was pre-implanted with He+ ions at 45 keV, and then mounted in a special irradiation chamber in the beam line of a Van de Graaff electron accelerator. Release of the implanted helium was measured during 1.8 MeV electron irradiation as a function of temperature (15-450 °C) and irradiation time (dose), and compared with results obtained without irradiation. Ionizing radiation enhanced helium release from SiC has been clearly observed, and the relative change of He desorption as a function of ionizing radiation dose and temperature evaluated. The results are consistent with He release from discrete trapping centres.

Moroño, A.; Manzano, J.; Malo, M.; Hodgson, E. R.

2011-10-01

414

Modeling of radiation-induced bystander effect using Monte Carlo methods  

NASA Astrophysics Data System (ADS)

Experiments showed that the radiation-induced bystander effect exists in cells, or tissues, or even biological organisms when irradiated with energetic ions or X-rays. In this paper, a Monte Carlo model is developed to study the mechanisms of bystander effect under the cells sparsely populated conditions. This model, based on our previous experiment which made the cells sparsely located in a round dish, focuses mainly on the spatial characteristics. The simulation results successfully reach the agreement with the experimental data. Moreover, other bystander effect experiment is also computed by this model and finally the model succeeds in predicting the results. The comparison of simulations with the experimental results indicates the feasibility of the model and the validity of some vital mechanisms assumed.

Xia, Junchao; Liu, Liteng; Xue, Jianming; Wang, Yugang; Wu, Lijun

2009-03-01

415

A Simulation Study of the Radiation-Induced Bystander Effect: Modeling with Stochastically Defined Signal Reemission  

PubMed Central

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.

Sasaki, Kohei; Wakui, Kosuke; Tsutsumi, Kaori; Itoh, Akio; Date, Hiroyuki

2012-01-01

416

Computer simulation of radiation-induced nanostructure formation in amorphous materials  

NASA Astrophysics Data System (ADS)

In this study, 3D simulations based on a theoretical model were developed to investigate radiation-induced nanostructure formation in amorphous materials. Model variables include vacancy production and recombination rates, ion sputtering effects, and redeposition of sputtered atoms. In addition, a phase field model was developed to predict vacancy diffusion as a function of free energies of mixing and interfacial energies. The distribution profile of the vacancy production rate along the depth of an irradiated matrix was considered as a near Gaussian approximation according to Monte-Carlo TRIM code calculations. Dynamic processes responsible for nanostructure evolution were simulated by updating the vacancy concentration profile over time. Simulated morphologies include cellular nanoholes, nanowalls, nanovoids, and nanofibers, with the resultant morphology dependant upon the incident ion species and ion fluence. These simulated morphologies are consistent with experimental observations achieved under comparable experimental conditions. Our model provides a distinct numerical approach to accurately predicting morphological results for ion-irradiation-induced nanostructures.

Li, Kun-Dar; Perez-Bergquist, Alejandro; Wang, Lumin

2009-09-01

417

Radiation Induced Surface Activity Phenomenon: 1. Report - Surface Wettability on Metal Oxides  

SciTech Connect

Improving the limit of boiling heat transfer or critical heat flux requires that the cooling liquid can contact the heating surface, or a high-wettability, highly hydrophilic heating surface, even if a vapor bubble layer is generated on the surface. We investigated surface wettability using metal oxides irradiated by gamma rays in room condition. Contact angle, an indicator of macroscopic wettability, was measured by image processing of the images obtained by a CCD video camera. The results showed that the surface wettability on oxide metal pieces of titanium, zircaloy No. 4, SUS-304 and copper improved significantly by Radiation Induced Surface Activity (RISA) phenomenon. Highly hydrophilic conditions on the test pieces were achieved after 500 kGy irradiation of {sup 60}Co gamma ray. (authors)

Yasuyuki Imai; Tatsuya Koga; Tomoji Takamasa [Tokyo University of Mercantile Marine, 2-1-6 Etchu-jima, Koto-Ku, Tokyo 135-8533 (Japan); Koji Okamoto [University of Tokyo (Japan); Susumu Uematsu [Advanced Maritime Transport Technology Department, National Maritime Research Institute, Mitaka, Tokyo 181-0004 (Japan)

2002-07-01

418

Rb1 haploinsufficiency promotes telomere attrition and radiation-induced genomic instability.  

PubMed

Germline mutations of the retinoblastoma gene (RB1) predispose to both sporadic and radiation-induced osteosarcoma, tumors characterized by high levels of genomic instability, and activation of alternative lengthening of telomeres. Mice with haploinsufficiency of the Rb1 gene in the osteoblastic lineage reiterate the radiation susceptibility to osteosarcoma seen in patients with germline RB1 mutations. We show that the susceptibility is accompanied by an increase in genomic instability, resulting from Rb1-dependent telomere erosion. Radiation exposure did not accelerate the rate of telomere loss but amplified the genomic instability resulting from the dysfunctional telomeres. These findings suggest that telomere maintenance is a noncanonical caretaker function of the retinoblastoma protein, such that its deficiency in cancer may potentiate DNA damage-induced carcinogenesis by promoting formation of chromosomal aberrations, rather than simply by affecting cell-cycle control. PMID:23687339

Gonzalez-Vasconcellos, Iria; Anastasov, Natasa; Sanli-Bonazzi, Bahar; Klymenko, Olena; Atkinson, Michael J; Rosemann, Michael

2013-05-16

419

In vitro radiation induced alterations in heavy metals and metallothionein content in Plantago ovata Forsk.  

PubMed

Proton Induced X-ray emission (PIXE) and fluorescence-activated cell sorting (FACS) have been used to study the effects of gamma irradiation on heavy metal accumulation in callus tissue of Plantago ovata-an important cash crop of India. PIXE analysis revealed radiation-induced alteration in trace element profile during developmental stages of the callus of P. ovata. Subsequent experiments showed antagonism between Fe and Cu and also Cu and Zn and synergistic effect between Fe and Zn. FACS analysis showed significant induction of the metallothionein (MT) protein following gamma-irradiation, and maximum induction was noted at the 50-Gy absorbed dose. This indicated a progressive increment of MTs as a measure for protection against gamma-rays, to combat alteration in the homeostasis of heavy metals like Fe, Cu, Zn, and Mn. PMID:18493724

Saha, Priyanka; Mishra, Debadutta; Chakraborty, Anindita; Sudarshan, Mathummal; Raychaudhuri, Sarmistha Sen

2008-05-21

420

A Case of Radiation-Induced Multifocal Laryngeal Angiosarcoma Presenting as a Diagnostic Dilemma  

PubMed Central

Head and neck sarcomas are relatively rare tumors, with angiosarcomas representing a small subset. Angiosarcoma is a malignant endothelial neoplasm characterized by atypical, multilayered, or solid endothelial proliferation with vasoformative architecture. The global incidence of irradiation-associated sarcoma is estimated as between 0.03% and 0.08%. Here we reported the case of an elderly woman previously treated with radiation more than 20 years ago for an unknown primary of head and neck. This interesting case presented as a diagnostic challenge, and multiple biopsies were required to eventually establish the diagnosis of laryngeal angiosarcoma. We additionally have confirmation from our prior radiation records that the patient did, in fact, receive a substantial dose of radiation to the site previously. To our knowledge, this case represents the first report of a documented radiation-induced multifocal laryngeal angiosarcoma.

Dowdall, Jayme R.; Opfermann, Krisha J.; Kim, Harold; Lin, Ho-Sheng

2012-01-01

421

Radiation-induced segregation: A microchemical gauge to quantify fundamental defect parameters  

SciTech Connect

Defect Kinetic are evaluated for austenitic stainless alloys by comparing model predictions to measured responses for radiation-induced grain boundary segregation. Heavy-ions, neutrons and proton irradiations having substantial statistical bases are examined. The combined modeling and measurement approach is shown to be useful for quantifying fundamental defect parameters. The mechanism evaluation indicates vacancy, migration energies of 1.15 eV or less and a vacancy formation energy at grain boundaries of 1.5 eV. Damage efficiencies of about 0.03 were established for heavy-ions and for light-water reactor neutrons. Inferred proton damage efficiencies were about 0.15. Segregation measured in an advanced gas-cooled reactor component was much greater than expected using the above parameters.

Simonen, E.P.; Bruemmer, S.M.

1994-12-01

422

Determination of radiation-induced damage in lymphocytes using the micronucleus and microgel electrophoresis 'Comet' assays.  

PubMed

DNA damage assays may be useful as rapid predictors of normal tissue radiosensitivity in clinical samples. We measured in vitro radiation-induced (2 Gy) damage to lymphocytes from cancer patients and normal healthy donors using both the micronucleus and microgel electrophoresis (Comet) assays simultaneously. For damage assessment, there was a good correlation (P < 0.001) between the mean comet lengths and the fraction of cells with comets. There was no correlation with initial damage, determined as the proportion of cells within a sample that formed comets, in comparison with the mean frequency of micronuclei per binucleate cell. However, there appeared to be an association between the determination of repair proficiency in the Comet assay and the mean frequency of micronuclei per binucleate cell in lymphocytes from cancer patients. PMID:8652263

Malcolmson, A M; Davies, G; Hanson, J A; Deeley, J O; Gaffney, C C; McGregor, A D; Kerby, I J

1995-12-01

423

Ionizing radiation-induced fragmentation of plasmid DNA Atomic force microscopy and biophysical modeling  

NASA Astrophysics Data System (ADS)

It is widely accepted that DNA double-strand breaks (DSBs) are closely correlated with radiation-induced cell killing and are the most critical lesions related to cellular endpoints like mutagenesis and transformation. High linear energy transfer (LET) radiation produces more severe and complex damage due to the fact that induced DSBs are not randomly distributed but clustered at different levels of DNA organization. In this paper, direct visualization of DSBs induced in a plasmid supercoiled DNA by low- and high-LET radiation is presented. Resulting DNA fragments distributions obtained by use of atomic force microscopy (AFM) are shown. Moreover, a biophysical model of spatially correlated DSBs formation in the framework of the Local Effect Model (LEM) is introduced and its predictions on DNA fragment formation are discussed.

Psonka, K.; Gudowska-Nowak, E.; Brons, S.; Elsässer, Th.; Heiss, M.; Taucher-Scholz, G.

424

Microfabricated electrochemical sensor for the detection of radiation-induced DNA damage  

SciTech Connect

An electrochemical biosensor protocol for the detection of radiation-induced DNA damage is described. The procedure employs a dsDNA-coated screen-printed electrode and relies on changes in the guanine-DNA oxidation signal upon exposure to ultraviolet radiation. The decreased signal is ascribed primarily to conformational changes in the DNA and to the photoconversion of the guanine-DNA moiety to a nonelectroactive monomeric base product. Factors influencing the response of these microfabricated DNA sensors, such as irradiation time, wavelength, and distance, are explored, and future prospects are discussed. Similar results are given for the use of bare strip electrodes in connection with irradiated DNA solutions. 8 refs., 4 figs.

Wang, J.; Rivas, G.; Ozsoz, M.; Grant, D.H.; Cai, X.; Parrado, C. [New Mexico State Univ., Las Cruces, NM (United States)

1997-04-01

425

Molecular targets in radiation-induced blood-brain barrier disruption  

SciTech Connect

Disruption of the blood-brain barrier (BBB) is a key feature of radiation injury to the central nervous system. Studies suggest that endothelial cell apoptosis, gene expression changes, and alteration of the microenvironment are important in initiation and progression of injury. Although substantial effort has been directed at understanding the impact of radiation on endothelial cells and oligodendrocytes, growing evidence suggests that other cell types, including astrocytes, are important in responses that include induced gene expression and microenvironmental changes. Endothelial apoptosis is important in early BBB disruption. Hypoxia and oxidative stress in the later period that precedes tissue damage might lead to astrocytic responses that impact cell survival and cell interactions. Cell death, gene expression changes, and a toxic microenvironment can be viewed as interacting elements in a model of radiation-induced disruption of the BBB. These processes implicate particular genes and proteins as targets in potential strategies for neuroprotection.

Nordal, Robert A. [Departments of Radiation Oncology and Medical Biophysics, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Wong, C. Shun [Departments of Radiation Oncology and Medical Biophysics, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada)]. E-mail: shun.wang@sw.ca

2005-05-01

426

Characterization of Network Structure of Polyacrylamide Based Hydrogels Prepared By Radiation Induced Polymerization  

NASA Astrophysics Data System (ADS)

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.

Mahmudi, Naim; ?en, Murat; Güven, Olgun; Rendevski, Stojan

2007-04-01

427

The correlation between swelling and radiation-induced segregation in iron-chromium-nickel alloys.  

SciTech Connect

The magnitudes of both void swelling and radiation-induced segregation (RIS) in iron-chromium-nickel alloys are dependent on bulk alloy composition. Because the diffusivity of nickel via the vacancy flux is slow relative to chromium, nickel enriches and chromium depletes at void surfaces during irradiation. This local composition change reduces the subsequent vacancy flux to the void, thereby reducing void swelling. In this work, the resistance to swelling from major element segregation is estimated using diffusivities derived from grain boundary segregation measurements in irradiated iron-chromium-nickel alloys. The resistance to void swelling in iron- and nickel-base alloys correlates with the segregation and both are functions of bulk alloy composition. Alloys that display the greatest amount of nickel enrichment and chromium depletion are found to be most resistant to void swelling, as predicted. Additionally, swelling is shown to be greater in alloys in which the RIS profiles are slow to develop.

Allen, T. R.; Busby, J. T.; Kenik, E. A.; Was, G. S.

1998-03-05

428

Radiation-induced changes in the dielectric response of poly(vinylidene fluoride) type polymers  

NASA Astrophysics Data System (ADS)

High and dispersive dielectric response, characteristic of the relaxor state, was observed in ferroelectric P(VDF/TrFE)(50/50) copolymers irradiated with 1.0 MeV and 1.5 MeV electrons. Relaxor-like behaviour of the copolymer is a result of overlapping of the dielectric anomaly characteristic of the glass transition and that related to the Curie point, which is shifted downwards by electron irradiation. The results of ESR, IR and NIR Raman spectroscopy studies of the radiation damage to P(VDF/TrFE)(50/50) show that radiation-induced irreversible transformation of the ferroelectric copolymer to the relaxor state is related to the existence of polar clusters, consisting of a variety of short range coherence of trans-conformation, stabilized by random fields of C=C and conjugated C=C bonds.

Hilczer, B.; Smogor, H.; Goslar, J.; Warchol, S.

2003-01-01

429

Radiation-induced grafting of dimethylaminoethylmethacrylate onto PE/PP nonwoven fabric  

NASA Astrophysics Data System (ADS)

A new adsorbent was prepared by radiation-induced graft polymerization of dimethylaminoethylmethacrylate (DMAEMA) onto polyethylene/polypropylene (PE/PP) nonwoven fabric. The trunk polymer was irradiated by electron beam at a voltage of 2 MeV and a current of 3 mA in nitrogen atmosphere at dry-ice temperature to different doses. The degree of grafting was determined as a function of irradiation dose, monomer concentration, temperature and reaction time. Grafting conditions were optimized and about 150% grafted samples were used for further experiments. DMAEMA grafted polymer was later protonated in acid solution to prepare specialty adsorbent for the removal of phosphate. Adsorption experiments were performed in column mode for removal of phosphate. It was shown that 2000 bed volumes of phosphate-free water can be produced from 100 ppb phosphate (as P) solution at high space velocity.

Kavakl?, P?nar Akka?; Kavakl?, Cengiz; Seko, Noriaki; Tamada, Masao; Güven, Olgun

2007-12-01

430

Radiation-induced conductivity in alumina from 100 Hz to 10 MHz during proton irradiation  

NASA Astrophysics Data System (ADS)

Changes in the dielectric constant and loss tangent of alumina have been measured in situ during proton irradiation. In these experiments, single crystal sapphire specimens were irradiated with 3 MeV protons which passed through the sample and were stopped in a copper-block heat sink. Dielectric properties were measured between 100 Hz and 10 MHz using a guard-ring capacitor configuration. The proton irradiation caused an immediate increase in loss tangent from about 10-4 to more than 1.0. We have evaluated these changes at 300 and 373 K, vs irradiation time, flux and frequency. While the in situ radiation-induced conductivity (RIC) depends on these variables as well as on the history of previous irradiation, we believe that it is caused by a balance between the generation rate of electrons and holes, and their trapping and annihilation at displacement-type defects.

Farnum, E. H.; Kennedy, J. C.; Clinard, F. W.; Frost, H. M.

1992-09-01

431

X-ray microdiffraction analysis of radiation-induced defects in single grains of polycrystalline Fe  

SciTech Connect

Single-crystal diffuse X-ray scattering was analyzed to characterize radiation-induced defects in individual grains of a polycrystalline proton-irradiated Fe foil. The grains were probed with an intense submicron x-ray beam to demonstrated that both polycrystalline and micrometer-scale samples can be studied with single-crystal-like signal-to-noise. Scattering was measured with an x-ray sensitive area detector, which measures intensity over a surface in reciprocal space. By scanning the x-ray energy, intensity was measured over reciprocal-space volumes. Since the sample is not rotated, the real-space scattering volume does not change. We discuss methods to minimize experimental artifacts arising from the use of an area detector.

Specht, Eliot D [ORNL; Walker, Frederick J. [Yale University; Liu, W. [Argonne National Laboratory (ANL)

2010-01-01

432

Manganese Superoxide Dismutase-Mediated Gene Expression in Radiation-Induced Adaptive Responses  

PubMed Central

Antioxidant enzymes are critical in oxidative stress responses. Radioresistant variants isolated from MCF-7 human carcinoma cells following fractionated ionizing radiation (MCF+FIR cells) or overexpression of manganese superoxide dismutase (MCF+SOD cells) demonstrated dose-modifying factors at 10% isosurvival of 1.8 and 2.3, respectively. MCF+FIR and MCF-7 cells (exposed to single-dose radiation) demonstrated 5- to 10-fold increases in MnSOD activity, mRNA, and immunoreactive protein. Radioresistance in MCF+FIR and MCF+SOD cells was reduced following expression of antisense MnSOD. DNA microarray analysis and immunoblotting identified p21, Myc, 14-3-3 zeta, cyclin A, cyclin B1, and GADD153 as genes constitutively overexpressed (2- to 10-fold) in both MCF+FIR and MCF+SOD cells. Radiation-induced expression of these six genes was suppressed in fibroblasts from Sod2 knockout mice (?/?) as well as in MCF+FIR and MCF+SOD cells expressing antisense MnSOD. Inhibiting NF-?B transcriptional activity in MCF+FIR cells, by using mutant I?B?, inhibited radioresistance as well as reducing steady-state levels of MnSOD, 14-3-3 zeta, GADD153, cyclin A, and cyclin B1 mRNA. In contrast, mutant I?B? was unable to inhibit radioresistance or reduce 14-3-3 zeta, GADD153, cyclin A, and cyclin B1 mRNAs in MCF+SOD cells, where MnSOD overexpression was independent of NF-?B. These results support the hypothesis that NF-?B is capable of regulating the expression of MnSOD, which in turn is capable of increasing the expression of genes that participate in radiation-induced adaptive responses.

Guo, Guozheng; Yan-Sanders, Yan; Lyn-Cook, Beverly D.; Wang, Tieli; Tamae, Daniel; Ogi, Julie; Khaletskiy, Alexander; Li, Zhongkui; Weydert, Christine; Longmate, Jeffrey A.; Huang, Ting-Ting; Spitz, Douglas R.; Oberley, Larry W.; Li, Jian Jian

2003-01-01

433

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

PubMed Central

Background Nuclear 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 cells niche and mitigate radiation-induced gastrointestinal syndrome. Methodology/Principal Findings Autologous bone marrow was cultured in mesenchymal basal medium and adherent cells were harvested for transplantation to C57Bl6 mice, 24 and 72 hours after lethal whole body irradiation (10.4 Gy) or abdominal irradiation (16–20 Gy) in a single fraction. Mesenchymal, endothelial and myeloid population were characterized by flow cytometry. Intestinal crypt regeneration and absorptive function was assessed by histopathology and xylose absorption assay, respectively. In contrast to 100% mortality in irradiated controls, BMSCT mitigated RIGS and rescued mice from radiation lethality after 18 Gy of abdominal irradiation or 10.4 Gy whole body irradiation with 100% survival (p<0.0007 and p<0.0009 respectively) beyond 25 days. Transplantation of enriched myeloid and non-myeloid fractions failed to improve survival. BMASCT induced ISC regeneration, restitution of the ISC niche and xylose absorption. Serum levels of intestinal radioprotective factors, such as, R-Spondin1, KGF, PDGF and FGF2, and anti-inflammatory cytokines were elevated, while inflammatory cytokines were down regulated. Conclusion/Significance Mitigation of lethal intestinal injury, following high doses of irradiation, can be achieved by intravenous transplantation of marrow-derived stromal cells, including mesenchymal, endothelial and macrophage cell population. BMASCT increases blood levels of intestinal growth factors and induces regeneration of the irradiated host ISC niche, thus providing a platform to discover potential radiation mitigators and protectors for acute radiation syndromes and chemo-radiation therapy of abdominal malignancies.

Saha, Subhrajit; Bhanja, Payel; Kabarriti, Rafi; Liu, Laibin; Alfieri, Alan A.; Guha, Chandan

2011-01-01

434

Effects of ozone oxidative preconditioning on radiation-induced organ damage in rats.  

PubMed

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 signif