Science.gov

Sample records for model rat irradiated

  1. Role of the bradykinin B2 receptor in a rat model of local heart irradiation

    PubMed Central

    Lieblong, Benjamin J.; Sridharan, Vijayalakshmi; Srivastava, Anup K.; Moros, Eduardo G.; Sharma, Sunil K.; Boerma, Marjan

    2016-01-01

    Purpose Radiation-induced heart disease (RIHD) is a delayed effect of radiotherapy for cancers of the chest, such as breast, esophageal, and lung. Kinins are small peptides with cardioprotective properties. We previously used a rat model that lacks the precursor kininogen to demonstrate that kinins are involved in RIHD. Here, we examined the role of the kinin B2 receptor (B2R) in early radiation-induced signaling in the heart. Materials and methods Male Brown Norway rats received the B2R-selective antagonist HOE-140 (icatibant) via osmotic minipump from 5 days before until 4 weeks after 21 Gy local heart irradiation. At 4 weeks, signaling events were measured in left ventricular homogenates and nuclear extracts using western blotting and real-time polymerase chain reaction. Numbers of CD68-positive (monocytes/macrophages), CD2-positive (T-lymphocytes), and mast cells were measured using immunohistochemistry. Results Radiation-induced c-Jun phosphorylation and nuclear translocation were enhanced by HOE-140. HOE-140 did not modify endothelial nitric oxide synthase (eNOS) phosphorylation or alter numbers of CD2-positive or mast cells, but enhanced CD68-positive cell counts in irradiated hearts. Conclusions B2R signaling may regulate monocyte/macrophage infiltration and c-Jun signals in the irradiated heart. Although eNOS is a main target for kinins, the B2R may not regulate eNOS phosphorylation in response to radiation. PMID:25955317

  2. Gamma Knife Irradiation of Injured Sciatic Nerve Induces Histological and Behavioral Improvement in the Rat Neuropathic Pain Model

    PubMed Central

    Yagasaki, Yuki; Hayashi, Motohiro; Tamura, Noriko; Kawakami, Yoriko

    2013-01-01

    We examined the effects of gamma knife (GK) irradiation on injured nerves using a rat partial sciatic nerve ligation (PSL) model. GK irradiation was performed at one week after ligation and nerve preparations were made three weeks after ligation. GK irradiation is known to induce immune responses such as glial cell activation in the central nervous system. Thus, we determined the effects of GK irradiation on macrophages using immunoblot and histochemical analyses. Expression of Iba-1 protein, a macrophage marker, was further increased in GK-treated injured nerves as compared with non-irradiated injured nerves. Immunohistochemical study of Iba-1 in GK-irradiated injured sciatic nerves demonstrated Iba-1 positive macrophage accumulation to be enhanced in areas distal to the ligation point. In the same area, myelin debris was also more efficiently removed by GK-irradiation. Myelin debris clearance by macrophages is thought to contribute to a permissive environment for axon growth. In the immunoblot study, GK irradiation significantly increased expressions of βIII-tubulin protein and myelin protein zero, which are markers of axon regeneration and re-myelination, respectively. Toluidine blue staining revealed the re-myelinated fiber diameter to be larger at proximal sites and that the re-myelinated fiber number was increased at distal sites in GK-irradiated injured nerves as compared with non-irradiated injured nerves. These results suggest that GK irradiation of injured nerves facilitates regeneration and re-myelination. In a behavior study, early alleviation of allodynia was observed with GK irradiation in PSL rats. When GK-induced alleviation of allodynia was initially detected, the expression of glial cell line-derived neurotrophic factor (GDNF), a potent analgesic factor, was significantly increased by GK irradiation. These results suggested that GK irradiation alleviates allodynia via increased GDNF. This study provides novel evidence that GK irradiation of

  3. Induction of Lipocalin2 in a Rat Model of Lung Irradiation.

    PubMed

    Sultan, Sadaf; Ahmad, Shakil; Rave-Fränk, Margret; Malik, Ihtzaz Ahmed; Hess, Clemens F; Christiansen, Hans; Cameron, Silke

    2016-01-01

    Previously, we showed that lipocalin2 (LCN2) serum levels increased after liver irradiation and during acute-phase conditions. Here, we evaluate LCN2 expression and serum levels after single-dose lung irradiation with 25 Gy, percutaneously administered to the lung of randomly-paired male Wistar rats. Due to the concave anatomy of the lung recesses, the irradiation field included the upper part of the liver. No rat died due to irradiation. In control tissue, lung immunohistochemistry showed a high constitutive expression of LCN2+ granulocytes. LCN2 mRNA levels in lung tissue increased up to 24 h (9 ± 2.3-fold) after irradiation. However, serum LCN2 levels remained undetectable after lung irradiation. LCN2 expression in the upper part of the liver increased up to 4.2-fold after lung irradiation, but the lower liver showed an early decrease. Acute-phase cytokines (IL-1β and TNF-α) showed a significant increase on transcript level in both lung and upper liver, whilst the lower liver did not show any considerable increase. In conclusion, constitutive expression of LCN2 in local immune cells demonstrates its local role during stress conditions in the lung. The absence of LCN2 in the serum strengthens our previous findings that the liver is the key player in secreting LCN2 during stress conditions with liver involvement. PMID:27136530

  4. Induction of Lipocalin2 in a Rat Model of Lung Irradiation

    PubMed Central

    Sultan, Sadaf; Ahmad, Shakil; Rave-Fränk, Margret; Malik, Ihtzaz Ahmed; Hess, Clemens F.; Christiansen, Hans; Cameron, Silke

    2016-01-01

    Previously, we showed that lipocalin2 (LCN2) serum levels increased after liver irradiation and during acute-phase conditions. Here, we evaluate LCN2 expression and serum levels after single-dose lung irradiation with 25 Gy, percutaneously administered to the lung of randomly-paired male Wistar rats. Due to the concave anatomy of the lung recesses, the irradiation field included the upper part of the liver. No rat died due to irradiation. In control tissue, lung immunohistochemistry showed a high constitutive expression of LCN2+ granulocytes. LCN2 mRNA levels in lung tissue increased up to 24 h (9 ± 2.3-fold) after irradiation. However, serum LCN2 levels remained undetectable after lung irradiation. LCN2 expression in the upper part of the liver increased up to 4.2-fold after lung irradiation, but the lower liver showed an early decrease. Acute-phase cytokines (IL-1β and TNF-α) showed a significant increase on transcript level in both lung and upper liver, whilst the lower liver did not show any considerable increase. In conclusion, constitutive expression of LCN2 in local immune cells demonstrates its local role during stress conditions in the lung. The absence of LCN2 in the serum strengthens our previous findings that the liver is the key player in secreting LCN2 during stress conditions with liver involvement. PMID:27136530

  5. Low-level laser irradiation improves functional recovery and nerve regeneration in sciatic nerve crush rat injury model.

    PubMed

    Wang, Chau-Zen; Chen, Yi-Jen; Wang, Yan-Hsiung; Yeh, Ming-Long; Huang, Mao-Hsiung; Ho, Mei-Ling; Liang, Jen-I; Chen, Chia-Hsin

    2014-01-01

    The development of noninvasive approaches to facilitate the regeneration of post-traumatic nerve injury is important for clinical rehabilitation. In this study, we investigated the effective dose of noninvasive 808-nm low-level laser therapy (LLLT) on sciatic nerve crush rat injury model. Thirty-six male Sprague Dawley rats were divided into 6 experimental groups: a normal group with or without 808-nm LLLT at 8 J/cm(2) and a sciatic nerve crush injury group with or without 808-nm LLLT at 3, 8 or 15 J/cm(2). Rats were given consecutive transcutaneous LLLT at the crush site and sacrificed 20 days after the crush injury. Functional assessments of nerve regeneration were analyzed using the sciatic functional index (SFI) and hindlimb range of motion (ROM). Nerve regeneration was investigated by measuring the myelin sheath thickness of the sciatic nerve using transmission electron microscopy (TEM) and by analyzing the expression of growth-associated protein 43 (GAP43) in sciatic nerve using western blot and immunofluorescence staining. We found that sciatic-injured rats that were irradiated with LLLT at both 3 and 8 J/cm(2) had significantly improved SFI but that a significant improvement of ROM was only found in rats with LLLT at 8 J/cm(2). Furthermore, the myelin sheath thickness and GAP43 expression levels were significantly enhanced in sciatic nerve-crushed rats receiving 808-nm LLLT at 3 and 8 J/cm(2). Taken together, these results suggest that 808-nm LLLT at a low energy density (3 J/cm(2) and 8 J/cm(2)) is capable of enhancing sciatic nerve regeneration following a crush injury. PMID:25119457

  6. Calculations of dose distributions in the lungs of a rat model irradiated in the thermal column of the TRIGA reactor in Pavia.

    PubMed

    Protti, N; Bortolussi, S; Stella, S; Gadan, M A; De Bari, A; Ballarini, F; Bruschi, P; Ferrari, C; Clerici, A M; Zonta, C; Bakeine, J G; Dionigi, P; Zonta, A; Altieri, S

    2009-07-01

    To test the possibility to apply boron neutron capture therapy (BNCT) to lung tumors, some rats are planned to be irradiated in the thermal column of the TRIGA reactor of the University of Pavia. Before the irradiation, lung metastases will be induced in BDIX rats, which will be subsequently infused with boronophenylalanine (BPA). During the irradiation, the rats will be positioned in a box designed to shield the whole animal except the thorax area. In order to optimize the irradiation set-up and to design a suitable shielding box, a set of calculations were performed with the MCNP Monte Carlo transport code. A rat model was constructed using the MCNP geometry capabilities and was positioned in a box with walls filled with lithium carbonate. A window was opened in front of the lung region. Different shapes of the holder and of the window were tested and analyzed in terms of the dose distribution obtained in the lungs and of the dose absorbed by the radiosensitive organs in the rat. The best configuration of the holder ensures an almost uniform thermal neutron flux inside the lungs (Phi(max)/Phi(min)=1.5), an irradiation time about 10 min long, to deliver at least 40 Gy(w) to the tumor, a mean lung dose of 5.9+/-0.4 Gy(w), and doses absorbed by all the other healthy tissues below the tolerance limits. PMID:19406647

  7. Retroductal Submandibular Gland Instillation and Localized Fractionated Irradiation in a Rat Model of Salivary Hypofunction.

    PubMed

    Nair, Renjith Parameswaran; Zheng, Changyu; Sunavala-Dossabhoy, Gulshan

    2016-01-01

    Normal tissues that lie within the portals of radiation are inadvertently damaged. Salivary glands are often injured during head and neck radiotherapy. Irreparable cell damage results in a chronic loss of salivary function that impairs basic oral activities, and increases the risk of oral infections and dental caries. Salivary hypofunction and its complications gravely impact a patient's comfort. Current symptomatic management of the condition is ineffective, and newer therapies to assuage the condition are needed. Salivary glands are exocrine glands, which expel their secretions into the mouth via excretory ducts. Cannulation of these ducts provides direct access to the glands. Retroductal delivery of a contrast agent to major salivary glands is a routine out-patient procedure for diagnostic imaging. Using a similar procedure, localized treatment of the glands is feasible. However, performing this technique in preclinical studies with small animals poses unique challenges. In this study we describe the technique of retroductal administration in rat submandibular glands, a procedure that was refined in Dr. Bruce Baum's laboratory (NIH)(1), and lay out a procedure for local gland irradiation. PMID:27168158

  8. The treatment of peripheral nerve injuries using irradiated allografts and temporary host immunosuppression (in a rat model)

    SciTech Connect

    Easterling, K.J.; Trumble, T.E. )

    1990-10-01

    Irradiation of allografts prior to transplantation and host immunosuppression with cyclosporin-A were studied separately and in combination as means of lessening the rejection of transplanted peripheral nerve tissue. Lewis and Brown Norway rats were used in the animal model, as they differ at both major and minor histocompatibility loci. Sciatic nerve grafts (2.5 cm) were used and the animals were followed for 16 weeks after nerve grafting. The outcome was studied by functional measurements (sensory testing, gait analysis, joint flexion contracture, and muscle weight), as well as by measurements of biochemical and histologic parameters (hydroxyproline concentration and axon counts, respectively). Sensory testing was not reliable because of crossover innervation by the saphenous nerve. Evaluation by standard gait-testing techniques was found to be unsatisfactory. However, the allografted animals receiving cyclosporin-A had significantly smaller flexion contractures, compared to the allografted animals without immunosuppression (17 degrees +/- 12 degrees vs. 44 degrees +/- 13 degrees and 51 degrees +/- 13 degrees, p less than 0.005). Allografted animals receiving short-term cyclosporin-A had contractures that were not significantly different from those seen in isografted control animals (17 degrees +/- 12 degrees vs. 22 degrees +/- 15 degrees, NS). Muscle hydroxyproline concentration analysis revealed a lower hydroxyproline concentration among the allografted groups that received irradiated allografts, compared to groups receiving nonirradiated allogeneic grafts. The studies of muscle hydroxyproline concentration and muscle weight both showed substantial reinnervation, even in allografted animals without pretreatment of the grafts or immunosuppression of the recipient animal.

  9. Anti-tumor response induced by immunologically modified carbon nanotubes and laser irradiation using rat mammary tumor model

    NASA Astrophysics Data System (ADS)

    Acquaviva, Joseph T.; Hasanjee, Aamr M.; Bahavar, Cody F.; Zhou, Fefian; Liu, Hong; Howard, Eric W.; Bullen, Liz C.; Silvy, Ricardo P.; Chen, Wei R.

    2015-03-01

    Laser immunotherapy (LIT) is being developed as a treatment modality for metastatic cancer which can destroy primary tumors and induce effective systemic anti-tumor responses by using a targeted treatment approach in conjunction with the use of a novel immunoadjuvant, glycated chitosan (GC). In this study, Non-invasive Laser Immunotherapy (NLIT) was used as the primary treatment mode. We incorporated single-walled carbon nanotubes (SWNTs) into the treatment regimen to boost the tumor-killing effect of LIT. SWNTs and GC were conjugated to create a completely novel, immunologically modified carbon nanotube (SWNT-GC). To determine the efficacy of different laser irradiation durations, 5 minutes or 10 minutes, a series of experiments were performed. Rats were inoculated with DMBA-4 cancer cells, a highly aggressive metastatic cancer cell line. Half of the treatment group of rats receiving laser irradiation for 10 minutes survived without primary or metastatic tumors. The treatment group of rats receiving laser irradiation for 5 minutes had no survivors. Thus, Laser+SWNT-GC treatment with 10 minutes of laser irradiation proved to be effective at reducing tumor size and inducing long-term anti-tumor immunity.

  10. A Bilayer Engineered Skin Substitute for Wound Repair in an Irradiation-Impeded Healing Model on Rat

    PubMed Central

    Mohd Hilmi, A.B.; Hassan, Asma; Halim, Ahmad Sukari

    2015-01-01

    Objective: An engineered skin substitute is produced to accelerate wound healing by increasing the mechanical strength of the skin wound via high production of collagen bundles. During the remodeling stage of wound healing, collagen deposition is the most important event. The collagen deposition process may be altered by nutritional deficiency, diabetes mellitus, microbial infection, or radiation exposure, leading to impaired healing. This study describes the fabrication of an engineered bilayer skin substitute and evaluates its effectiveness for the production of collagen bundles in an impaired healing model. Approach: Rats were exposed to 10 Gy of radiation. Two months postirradiation, the wounds were excised and treated with one of three skin replacement products: bilayer engineered skin substitutes, chitosan skin templates, or duoderm©. The collagen deposition was analyzed by hematoxylin and eosin staining. Results: On day 21 postwound, the irradiated wounds displayed increased collagen bundle deposition after treatment using bilayer engineered skin substitutes (3.4±0.25) and chitosan skin templates (3.2±0.58) compared with duoderm (2.0±0.63). Innovation: We provide the first report on the fabrication of bilayer engineered skin substitutes using high density human dermal fibroblasts cocultured with HFSCs on chitosan skin templates. Conclusion: The high density of fibroblasts significantly increases the penetration of cells into chitosan skin templates, contributing to the fabrication of bilayer engineered skin substitute. PMID:26005597

  11. A new steroid-induced cataract model in the rat: long-term prednisolone applications with a minimum of X-irradiation.

    PubMed

    Shui, Y B; Kojima, M; Sasaki, K

    1996-01-01

    In order to induce experimental steroid cataracts in rat eyes similar morphologically to those seen in human eyes, prednisolone acetate was administered either topically or systemically for 12 months with a low dose of X-irradiation as a cocataractogenic factor. Twenty-seven Brown-Norway rats were randomly divided into a control group (group I) with no steroid administration; an eyedrop group (group II) with a daily 1% prednisolone acetate instillation of a total volume of 1.0 mg/kg in both eyes, and a systemic group (group III) with a daily intramuscular injection of 0.8-1.0 mg/kg prednisolone acetate. The right eyes of animals in each group were X-irradiated with a single dose of 2 Gy. Topical and systemic steroid administrations started 2 weeks after X-irradiation. Anterior segment changes were documented with a slitlamp microscope and an anterior eye segment analysis system once a month. Body weight and blood glucose levels were examined every week and every 2 weeks, respectively. The mortality rates in groups I, II and III were 0, 11 (1/9) and 25% (3/12), respectively. The both lenses in group I showed a gradual increase in light-scattering intensity in the nuclear and supranuclear regions over time. Initial lens changes in both steroid-treated groups were Y-suture dissociation and a slight increase in light-scattering intensity in the posterior supranuclear region 3 months after prednisolone administration. Opacification of the anterior shallow cortex and the posterior subcapsular layer was observed after 10 months. X-irradiated eyes showed more prominent lens opacification as compared with nonirradiated eyes after 10 months in both group II and group III. Either topical or systemic administrations of prednisolone acetate over a long term successfully induced morphological lenticular changes in the rat similar to those found in human steroid-induced cataracts. A low dose of X-irradiation effectively accelerated opacification as a cocataractogenic risk. This

  12. Hepatic injury after whole-liver irradiation in the rat

    SciTech Connect

    Geraci, J.P.; Jackson, K.L.; Mariano, M.S.; Leitch, J.M.

    1985-03-01

    Radiation-induced hepatic injury in rats, which is characterized by marked ascites accompanied by liver necrosis, fibrosis, and vein lesions, is described in this study. These adverse sequelae are produced within 30 days after irradiation if there is surgical removal of two-thirds of the liver immediately after whole-liver irradiation. The LD/sub 50/30/ day and median survival time after liver irradiation and two-thirds partial hepatectomy is 24 Gy and 17 days, respectively. Death is preceded by reduction in liver function as measured by (/sup 131/I)-labeled rose bengal clearance. Prior to death, liver sepsis and endotoxemia were detected in most irradiated, partially hepatectomized animals. Pretreatment of the animals with endotoxin and/or antibiotic decontamination of the GI tract resulted in increased survival time, but no irradiated, partially hepatectomized animal survived beyond 63 days. This suggests that sepsis and endotoxemia resulting from the bacteria in the intestine are the immediate cause of death after 30-Gy liver irradiation and partial hepatectomy. It is concluded that the hepatectomized rat model is an economical and scientifically manageable experimental system to study a form of radiation hepatitis that occurs in compromised human livers.

  13. Neuroprotective effect of EGb761® and low-dose whole-body γ-irradiation in a rat model of Parkinson's disease.

    PubMed

    El-Ghazaly, Mona A; Sadik, Nermin A H; Rashed, Engy R; Abd-El-Fattah, Amal A

    2015-12-01

    Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease. The present study was undertaken to investigate the pretreatment effects of standardized Ginkgo biloba extract (EGb761(®)) and low-dose whole-body γ-irradiation on the neurological dysfunction in the reserpine model of PD. Male Wistar rats were pretreated orally with EGb761 or fractionated low-dose whole-body γ-irradiation or their combination, then subjected to intraperitoneal injection of reserpine (5 mg/kg body weight) 24 h after the final dose of EGb761 or radiation. Reserpine injection resulted in the depletion of striatal dopamine (DA) level, increased catalepsy score, increased oxidative stress indicated via depletion of glutathione (GSH), increased malondialdehyde (MDA) and iron levels, decreased DA metabolites metabolizing enzymes; indicated by inhibition by glutathione-S-transferase, and nicotinamide adenine dinucleotide phosphate (NADPH)-quinone oxidoreductase (NQO) activities, mitochondrial dysfunction; indicated by declined complex I activity, and adenosine triphosphate (ATP) level and increased apoptosis; indicated by decreased mitochondrial B cell lymphoma-2 (Bcl-2) protein level and by transmission electron microscope. EGb761 and low-dose γ-radiation ameliorated the reserpine-induced state of oxidative stress, mitochondrial dysfunction, and apoptosis in brain. It can be concluded that EGb761, a widely used herbal medicine and low dose of γ-irradiation have protective effects for combating Parkinsonism possibly via replenishment of GSH levels. PMID:23696346

  14. Assessment of the effect of laser irradiations at different wavelengths (660, 810, 980, and 1064 nm) on autophagy in a rat model of mucositis.

    PubMed

    Bostanciklioglu, Mehmet; Demiryürek, Şeniz; Cengiz, Beyhan; Demir, Tuncer; Öztuzcu, Serdar; Aras, Mutan Hamdi; Özsevik, Semih; Usumez, Aslihan; Ergün, Sercan; Özbal, Halime Kübra; Bagci, Cahit

    2015-05-01

    It is known that high-dose radiation has an effect on tissue healing, but tissue healing does not occur when low dose radiation is applied. To clarify this issue, we compare the treatment success of low dose radiation with programmed cell death mechanisms on wounded tissue. In this study, we aimed to investigate the interactions of low and high-dose radiation using an autophagic mechanism. We included 35 adult Wistar-Albino rats in this study. All animals were injected with 100 mg/kg of 5-fluorouracil (5-FU) on the first day and 65 mg/kg of 5-FU on the third day. The tips of 18-gauge needles were used to develop a superficial scratching on the left cheek pouch mucosa by dragging in a linear movement on third and fifth days. After mucositis formation was clinically detected, animals were divided into five groups (n = 7). Different wavelengths of laser irradiations (1064 nm, Fidelis Plus, Fotona, Slovenia; 980 nm, FOX laser, A.R.C., Germany; 810 nm, Fotona XD, Fotona, Slovenia; 660 nm, HELBO, Medizintechnik GmbH, Wels, Austria) were performed on four groups once daily for 4 days. The laser irradiation was not performed on the control group. To get the tissue from the left cheek at the end of fourth day from all animals, oval excisional biopsy was performed. Molecular analysis assessments of pathological and normal tissue taken were performed. For this purpose, the expression analysis of autophagy genes was performed. The results were evaluated by normalization and statistics analysis. We found that Ulk1, Beclin1, and Atg5 expression levels were increased in the rats when the Nd:YAG laser was applied. This increase showed that a 1064-nm laser is needed to activate the autophagic mechanism. However, in the diode applications, we found that Beclin1, Atg10, Atg5, and Atg7 expressions numerically decreased. Atg5 is responsible for the elongation of autophagosome. Becn1 is a control gene in the control mechanism of autophagy. The reduction of the expression of these

  15. Altered ovarian responsiveness to gonadotropins in neonatally irradiated immature rats

    SciTech Connect

    Freud, A.; Sod-Moriah, U.A.

    1988-01-01

    Female rats which were exposed to a single low dose of gamma irradiation (6R or 15R) at the age of 8 days produce smaller litters when mature than untreated controls. In order to study the possibility that such an impaired reproductive performance could result from a reduced ovulation rate, neonatally irradiated females were treated with PMSG (12 iu/rat) at the age of 26 days. Another group of rats, similarly treated, was further injected with hCG (5 iu/rat) 48 hours later. Animals were killed 48, 55, 60 and 72 hours after PMSG treatment or 72 and 120 after hCG injection. The results indicated that PMSG treatment increased the ovarian weight of non-irradiated controls as well as of irradiated rats and in all animals induced a proestrus like profile of LH. Only a combined treatment of PMSG and hCG resulted in ovulation and corpora lutea formation with significantly increased numbers of corpora lutea in the ovaries of the irradiated rats. The latter was associated with higher progesterone plasma levels not correlated to the number of corpora lutea. The gradual decrease in the number of ovarian binding sites for hCG with increased radiation dose and the increased association constant in the 15R group could not explain the increased sensitivity of the ovary to exogenous gonadotropins which results from neonatal exposure to low doses of gamma irradiation.

  16. Physiologic consequences of local heart irradiation in rats

    SciTech Connect

    Geist, B.J.; Lauk, S.; Bornhausen, M.; Trott, K.R. )

    1990-05-01

    Noninvasive methods have been used to study the long-term cardiovascular and pulmonary functional changes at rest and after exercise in adult rats following local heart irradiation with single x-ray doses of 15, 17.5 or 20 Gy, and in non-irradiated control animals. Rats that had undergone a chronic exercise program were compared with untrained cohorts. The earliest dysfunction detected was an increased respiratory rate (f) at 10 weeks after irradiation in the highest dose group. In contrast, both telemetric heart-rate (HR) and rhythm and indirect systolic blood pressure measurements performed at rest only revealed changes starting at 43 weeks after irradiation with 20 Gy, up to which point the rats showed no clinical signs of heart failure. However, the number of minutes required for the recovery of the HR to pre-exercise levels following the implementation of a standardized exercise challenge was elevated in untrained rats compared with their trained cohorts at 18 weeks after irradiation with 20 Gy. Increases in recovery times were required in the two lowest dose groups, starting at 26 weeks after irradiation. It was concluded that the reserve capacity of the cardiopulmonary system masks functional decrements at rest for many months following local heart irradiation, necessitating the use of techniques which reveal reductions in reserve capacities. Further, the influence of local irradiation to the heart and lungs deserves closer scrutiny due to mutual interactions.

  17. Effect of irradiation and endogenous nucleases on rat liver chromatin

    SciTech Connect

    Gelderblom, D.; Smit, B.J.; Boehm, L.

    1984-08-01

    The assessment of the consequences of irradiation on chromatin is complicated by endogenous nucleases. Isolation and prolonged storage of rat liver nuclei in buffers containing divalent metal ions activates these enzymes and promotes the degradation of chromatin. Irradiation of rat liver nuclei to dose levels of 20,000 rad under conditions in which endogenous nucleases are inhibited and analysis of the irradiated chromatin by sucrose density gradient centrifugation gave no evidence for monosomes or oligosomes. When chromatin from irradiated nuclei was digested with micrococcal nuclease, the levels of monosomes and oligosomes were identical to those of micrococcal nuclease digests of unirradiated control nuclei. These results suggest that irradiation results in neither a direct fragmentation of linkers nor the sensitization of linkers for subsequent cleavage by micrococcal nuclease.

  18. The Effect of Photoluminescence of Bioceramic Irradiation on Middle Cerebral Arterial Occlusion in Rats.

    PubMed

    Zhang, Lei; Chan, Paul; Liu, Zhong-Min; Hwang, Ling-Ling; Lin, Kuo-Chi; Chan, Wing P; Leung, Ting-Kai; Choy, Cheuk Sing

    2016-01-01

    The purpose of this study is to determine the possible effect of photoluminescence of bioceramic (PLB) on ischemic cerebral infarction (stroke), by using an animal model of transient middle cerebral artery occlusion (MCAO). Sprague-Dawley rats were used to induce MCAO to block the origin of the left MCAO; three months later, the positive chronic stroke rats were selected by running tunnel maze; the MCAO rats with significant chronic stroke and neurological defects were used for treadmill experiments with varying speed settings to test their capability for restoration after muscular fatigue under conditions of with and without PLB irradiation. As a result, PLB irradiation could improve exercise completion rate and average running speed during slow and fast treadmill settings. After PLB irradiation, the selected MCAO rats successfully completed all the second-round treadmill exercises at the maximum speed setting, and they had better restoration from muscular fatigue. An in vitro cell study on astrocytes of rats by bioceramic irradiation further demonstrated increased intracellular nitric oxide. To explain these results, we suggest that cortical brain stimulation of microcirculation and enhancement of peripheral muscular activity are the main causes of the improved exercise performance in MCAO rats by PLB. PMID:27375765

  19. The Effect of Photoluminescence of Bioceramic Irradiation on Middle Cerebral Arterial Occlusion in Rats

    PubMed Central

    Zhang, Lei; Chan, Paul; Liu, Zhong-Min; Hwang, Ling-Ling; Lin, Kuo-Chi; Chan, Wing P.; Leung, Ting-Kai; Choy, Cheuk Sing

    2016-01-01

    The purpose of this study is to determine the possible effect of photoluminescence of bioceramic (PLB) on ischemic cerebral infarction (stroke), by using an animal model of transient middle cerebral artery occlusion (MCAO). Sprague-Dawley rats were used to induce MCAO to block the origin of the left MCAO; three months later, the positive chronic stroke rats were selected by running tunnel maze; the MCAO rats with significant chronic stroke and neurological defects were used for treadmill experiments with varying speed settings to test their capability for restoration after muscular fatigue under conditions of with and without PLB irradiation. As a result, PLB irradiation could improve exercise completion rate and average running speed during slow and fast treadmill settings. After PLB irradiation, the selected MCAO rats successfully completed all the second-round treadmill exercises at the maximum speed setting, and they had better restoration from muscular fatigue. An in vitro cell study on astrocytes of rats by bioceramic irradiation further demonstrated increased intracellular nitric oxide. To explain these results, we suggest that cortical brain stimulation of microcirculation and enhancement of peripheral muscular activity are the main causes of the improved exercise performance in MCAO rats by PLB. PMID:27375765

  20. Effects of low intensity laser acupoint irradiation on inhibiting islet beta-cell apoptosis in rats with type 2 diabetes

    NASA Astrophysics Data System (ADS)

    Xiong, Guoxin; Xiong, Leilei; Li, Xinzhong

    2016-09-01

    To investigate the effects of low intensity semiconductor laser acupoint irradiation on inhibiting islet beta-cell apoptosis in rats with type 2 diabetes, a method using a high-fat diet and low-dose intraperitoneal injections of streptozotocin established a type 2 diabetes mellitus rat model. Model rats were randomly divided into a laser acupoint irradiation group, rosiglitazone control group, and placebo group; each group had 10 rats. In addition, 10 normal male rats were selected for the normal control group. The Housanli, Neiting and Yishu acupoints of the rats in the laser acupoint irradiation group were irradiated with a 10 mW semiconductor laser; each point was irradiated for 15 min, once every 2 d over 28 d, for a total of 14 episodes of irradiation. The rosiglitazone group rats were given rosiglitazone (0.2 mg kg‑1) intragastrically; the placebo group rats were given 0.9% brine (0.2 mg kg‑1) intragastrically, once daily, for four consecutive weeks. The change of fasting blood glucose was determined before and after each treatment. The islet beta-cell apoptosis was determined. The islet beta-cell apoptosis rates of the laser acupoint irradiation group and the rosiglitazone group were significantly lower than the rate of the placebo group. Even though the rate was lower in the laser acupoint irradiation group than in the rosiglitazone group, there was no significant difference between them. It is shown that acupoint irradiation with a semiconductor laser can effectively inhibit islet beta-cell apoptosis in rats with type 2 diabetes.

  1. Influence of a single gamma-irradiation on rat microflora.

    PubMed

    Benová, K; Falis, M; Toropila, M; Sehnalková, H; Pastvová, L

    2002-01-01

    Changes in leukocyte counts and in the gut microflora of laboratory rats irradiated with single whole-body dose of gamma rays (5.0 Gy) were determined. The number of leukocytes was lower especially 1 and 2 weeks after irradiation. A significant decrease in lymphocytes was observed 1 week and in monocytes 1 and 2 weeks after irradiation. In parallel with these changes, an increase in common microflora was observed; some microorganisms, which normally are not present in duodenum, liver and mouth cavity, were detected in these organs. PMID:12422530

  2. A novel technique for image-guided local heart irradiation in the rat.

    PubMed

    Sharma, Sunil; Moros, Eduardo G; Boerma, Marjan; Sridharan, Vijayalakshmi; Han, Eun Young; Clarkson, Richard; Hauer-Jensen, Martin; Corry, Peter M

    2014-12-01

    In radiotherapy treatment of thoracic, breast and chest wall tumors, the heart may be included (partially or fully) in the radiation field. As a result, patients may develop radiation-induced heart disease (RIHD) several years after exposure to radiation. There are few methods available to prevent or reverse RIHD and the biological mechanisms remain poorly understood. In order to further study the effects of radiation on the heart, we developed a model of local heart irradiation in rats using an image-guided small animal conformal radiation therapy device (SACRTD) developed at our institution. First, Monte Carlo based simulations were used to design an appropriate collimator. EBT-2 films were used to measure relative dosimetry, and the absolute dose rate at the isocenter was measured using the AAPM protocol TG-61. The hearts of adult male Sprague-Dawley rats were irradiated with a total dose of 21 Gy. For this purpose, rats were anesthetized with isoflurane and placed in a custom-made vertical rat holder. Each heart was irradiated with a 3-beam technique (one AP field and 2 lateral fields), with each beam delivering 7 Gy. For each field, the heart was visualized with a digital flat panel X-ray imager and placed at the isocenter of the 1.8 cm diameter beam. In biological analysis of radiation exposure, immunohistochemistry showed γH2Ax foci and nitrotyrosine throughout the irradiated hearts but not in the lungs. Long-term follow-up of animals revealed histopathological manifestations of RIHD, including myocardial degeneration and fibrosis. The results demonstrate that the rat heart irradiation technique using the SACRTD was successful and that surrounding untargeted tissues were spared, making this approach a powerful tool for in vivo radiobiological studies of RIHD. Functional and structural changes in the rat heart after local irradiation are ongoing. PMID:24000983

  3. A Novel Technique for Image-Guided Local Heart Irradiation in the Rat

    PubMed Central

    Sharma, Sunil; Moros, Eduardo G.; Boerma, Marjan; Sridharan, Vijayalakshmi; Han, Eun Young; Clarkson, Richard; Hauer-Jensen, Martin; Corry, Peter M.

    2014-01-01

    In radiotherapy treatment of thoracic, breast and chest wall tumors, the heart may be included (partially or fully) in the radiation field. As a result, patients may develop radiation-induced heart disease (RIHD) several years after exposure to radiation. There are few methods available to prevent or reverse RIHD and the biological mechanisms remain poorly understood. In order to further study the effects of radiation on the heart, we developed a model of local heart irradiation in rats using an image-guided small animal conformal radiation therapy device (SACRTD) developed at our institution. First, Monte Carlo based simulations were used to design an appropriate collimator. EBT-2 films were used to measure relative dosimetry, and the absolute dose rate at the isocenter was measured using the AAPM protocol TG-61. The hearts of adult male Sprague-Dawley rats were irradiated with a total dose of 21 Gy. For this purpose, rats were anesthetized with isoflurane and placed in a custom-made vertical rat holder. Each heart was irradiated with a 3-beam technique (one AP field and 2 lateral fields), with each beam delivering 7 Gy. For each field, the heart was visualized with a digital flat panel X-ray imager and placed at the isocenter of the 1.8 cm diameter beam. In biological analysis of radiation exposure, immunohistochemistry showed γH2Ax foci and nitrotyrosine throughout the irradiated hearts but not in the lungs. Long-term follow-up of animals revealed histopathological manifestations of RIHD, including myocardial degeneration and fibrosis. The results demonstrate that the rat heart irradiation technique using the SACRTD was successful and that surrounding untargeted tissues were spared, making this approach a powerful tool for in vivo radiobiological studies of RIHD. Functional and structural changes in the rat heart after local irradiation are ongoing. PMID:24000983

  4. Modeling Solar Lyman Alpha Irradiance

    NASA Technical Reports Server (NTRS)

    Pap, J.; Hudson, H. S.; Rottman, G. J.; Willson, R. C.; Donnelly, R. F.; London, J.

    1990-01-01

    Solar Lyman alpha irradiance is estimated from various solar indices using linear regression analyses. Models developed with multiple linear regression analysis, including daily values and 81-day running means of solar indices, predict reasonably well both the short- and long-term variations observed in Lyman alpha. It is shown that the full disk equivalent width of the He line at 1083 nm offers the best proxy for Lyman alpha, and that the total irradiance corrected for sunspot effect also has a high correlation with Lyman alpha.

  5. Rat Endovascular Perforation Model

    PubMed Central

    Sehba, Fatima A.

    2014-01-01

    Experimental animal models of aneurysmal subarachnoid hemorrhage (SAH) have provided a wealth of information on the mechanisms of brain injury. The Rat endovascular perforation model (EVP) replicates the early pathophysiology of SAH and hence is frequently used to study early brain injury following SAH. This paper presents a brief review of historical development of the EVP model, details the technique used to create SAH and considerations necessary to overcome technical challenges. PMID:25213427

  6. Gastroprotective effect of kefir on ulcer induced in irradiated rats.

    PubMed

    Fahmy, Hanan A; Ismail, Amel F M

    2015-03-01

    The current study was designed to investigate the protective effect of kefir milk on ethanol-induced gastric ulcers in γ-irradiated rats. The results of the present study revealed that treatment with γ-irradiation and/or ethanol showed a significant increase in ulcers number, total acidity, peptic, H(+)K(+)ATPase, MMP-2 and MMP-9 activities and MDA level, which were accompanied by a significant decrease in the mucus content, the stomach GSH level, the GSH-Px activity and DNA damage. Pre-treatment with kefir milk exert significant improvement in all the tested parameters. Kefir milk exerts comparable effect to that of the antiulcer drug ranitidine. In conclusion, the present study revealed that oral administration of kefir milk prevents ethanol-induced gastric ulcer in γ-irradiated rats that could attribute to its antioxidant, anti-apoptotic and radio-protective activities. PMID:25728227

  7. Fetal hypothalamic transplants into brain irradiated rats: Graft morphometry and host behavioral responses

    SciTech Connect

    Pearlman, S.H.; Rubin, P.; White, H.C.; Wiegand, S.J.; Gash, D.M. )

    1990-08-01

    This study was designed to test the hypothesis that neural implants can ameliorate or prevent some of the long-term changes associated with CNS irradiation. Using a rat model, the initial study focused on establishing motor, regulatory, and morphological changes associated with brain radiation treatments. Secondly, fetal hypothalamic tissue grafts were placed into the third ventricle of rats which had been previously irradiated. Adult male Long Evans rats received one of three radiation doses (15, 22.5, 30 Gy) or no radiation. Three days after irradiation, 7 animals in each dose group received an embryonic day 17 hypothalamic graft into the third ventricle while the remaining 8-9 animals in each group received injections of vehicle solution (sham). Few changes were observed in the 15 and 22.5 Gy animals, however rats in the 30 Gy treatment group showed stereotypic and ambulatory behavioral hyperactivity 32 weeks after irradiation. Regulatory changes in the high dose group included decreased growth rate and decreased urine osmolalities, but these measures were extremely variable among animals. Morphological results demonstrated that 30 Gy irradiated animals showed extensive necrosis primarily in the fimbria, which extended into the internal capsule, optic nerve, hippocampus, and thalamus. Hemorrhages were found in the hippocampus, thalamus, and fimbria. Defects in the blood-brain barrier also were evident by entry of intravascularly injected horseradish peroxidase into the parenchyma of the brain. Animals in the 30 Gy grafted group showed fewer behavioral changes and less brain damage than their sham grafted counterparts. Specifically, activity measures were comparable to normal levels, and a dilute urine was not found in the 30 Gy implanted rats. Morphological changes support these behavioral results since only two 30 Gy implanted rats showed necrosis.

  8. MRI-guided 3D conformal arc micro-irradiation of a F98 glioblastoma rat model using the Small Animal Radiation Research Platform (SARRP).

    PubMed

    Bolcaen, Julie; Descamps, Benedicte; Deblaere, Karel; Boterberg, Tom; Hallaert, Giorgio; Van den Broecke, Caroline; Decrock, Elke; Vral, Anne; Leybaert, Luc; Vanhove, Christian; Goethals, Ingeborg

    2014-11-01

    Current glioblastoma (GB) small animal models for cranial radiation therapy (RT) use simple single beam technologies, which differ from the advanced conformal image-guided radiation techniques used in clinical practice. This technological disparity presents a major disadvantage for the development of new therapeutic approaches. Hence, we established a F98 GB rat model using magnetic resonance imaging (MRI)-guided three-dimensional (3D)-conformal arc RT with the Small Animal Radiation Research Platform (SARRP). Ten Fischer rats were inoculated with F98 tumor cells. When the tumor reached a volume of approximately 27 mm(3) on T2-weighted MR images, the animals were randomized into a treatment group (n = 5) receiving RT and concomitant temozolomide, and a sham group (n = 5) receiving control injections. For the treated animals, contrast-enhanced T1-weighted MR images were acquired followed by a cone-beam computed tomography (CBCT) on the SARRP system. Both scans were co-registered; MRI was used to define the target whereas CBCT was used for calculating a dose plan (20 Gy, three non-coplanar arc beams, 3 × 3 mm collimator). Tumor volumes were evaluated on follow-up contrast-enhanced T1-weighted MR images. Verification of treatment accuracy with γH2AX immunohistochemical staining was performed. Tumors in the control animals showed rapid proliferation during follow-up, encompassing almost the entire right cerebral hemisphere at day 12-15. Treated animals showed no significant tumor growth from 2 to 9 days post RT. γH2AX results confirmed the accuracy of dose delivery. This model, which is quite similar to the approach in the clinic, is valid for combined RT and chemotherapy of GB in rats. PMID:25069566

  9. Effect of X-irradiation on the stomach of the rat

    SciTech Connect

    Breiter, N.; Trott, K.R.; Sassy, T. )

    1989-10-01

    A model for localized 300 kV X-irradiation of the rat stomach was developed. After irradiation with single doses, three distinct gastric disorders were observed which occurred at different latency times. Acute death 2-3 weeks after irradiation was caused by an erosive and ulcerative gastritis and occurred in all animals given 28.5 Gy without diet, in 17% of the animals given 28.5 Gy plus diet, and in 13% of the animals given 23 Gy. Subacute to chronic fatal disorders 4 weeks to 7 months after irradiation were seen as stomach dilatation and gastroparesis, associated with the replacement of the normal gastric mucosa by a hyperkeratinized multilayered squamous epithelium. These disorders occurred in 40-100% of the animals after doses between 16 Gy and 28.5 Gy (+diet). An ED 50 value of 19.2 Gy (16.5-21.2 Gy, 95% confidence interval) was calculated for this gastroparesis. Late gastric obstruction exceeding 7 months after irradiation was seen in the rats because of profound changes in the gastric wall in 13-18% of the animals after doses between 23 Gy and 14 Gy. In animals surviving these three periods, an atrophic mucosa and intestinal metaplasia developed. From functional and morphohistological studies, it can be concluded that there are differences in the pathogenesis of the fatal radiation damage for each of these periods after irradiation.

  10. Solar Irradiance: Observations, Proxies, and Models (Invited)

    NASA Astrophysics Data System (ADS)

    Lean, J.

    2013-12-01

    Solar irradiance has been measured from space for more than thirty years. Variations in total (spectrally integrated) solar irradiance associated with the Sun's 11-year activity cycle and 27-day rotation are now well characterized. But the magnitude, and even the sign, of spectral irradiance changes at near ultraviolet, visible and near infrared wavelengths, remain uncertain on time scales longer than a few months. Drifts in the calibration of the instruments that measure solar irradiance and incomplete understanding of the causes of irradiance variations preclude specification of multi-decadal solar irradiance variations with any confidence, including whether, or not, irradiance levels were lower during the 2008-2009 anomalously low solar activity minimum than in prior minima. The ultimate cause of solar irradiance variations is the Sun's changing activity, driven by a sub-surface dynamo that generates magnetic features called sunspots and faculae, which respectively deplete and enhance the net radiative output. Solar activity also alters parameters that have been measured from the ground for longer periods and with greater stability than the solar irradiance datasets. The longest and most stable such record is the Sun's irradiance at 10.7 cm in the radio spectrum, which is used frequently as a proxy indicator of solar irradiance variability. Models have been developed that relate the solar irradiance changes - both total and spectral - evident in extant databases to proxies chosen to best represent the sunspot darkening and facular brightening influences. The proxy models are then used to reconstruct solar irradiance variations at all wavelengths on multi-decadal time scales, for input to climate and atmospheric model simulations that seek to quantity the Sun's contribution to Earth's changing environment. This talk provides an overview of solar total and spectral irradiance observations and their relevant proxies, describes the formulation and construction of

  11. The expression of aquaporins 1 and 5 in rat lung after thoracic irradiation

    PubMed Central

    Sun, Cheng-Ying; Zhao, Yu-Xia; Zhong, Wen; Liu, Da-Wei; Chen, Yan-Zhi; Qin, Li-Li; Bai, Lu; Liu, Dan

    2014-01-01

    Radiation-induced lung toxicity (RILT), leading to radiation pneumonia or fibrosis, is a primary problem of radiation therapy. The pathogenesis of RILT remains unclear. In this study, we used a rat model of RILT to examine the expression of aquaporins (AQPs) after radiation injury. Sprague Dawley rats were given a single dose of 17 Gy (dose rate of 3.0 Gy/min) of X-irradiation to the thorax. Rats that survived acute pneumonitis (at 1–4 weeks) were evaluated weekly for the expression of AQP1 and AQP5 in the lung by immunohistochemical and reverse transcription polymerase chain reaction (RT-PCR) analyses. Immunohistochemical analysis showed that AQP1 protein was expressed in the capillary endothelium, and its level was significantly decreased after irradiation. AQP5 protein was expressed in the alveolar epithelium, and its level was increased between Days 7 and 14 after irradiation but decreased at Day 28, compared with the sham group. The RT-PCR results were consistent with the immunohistochemical analysis results. In summary, this study provides the first report of AQP1 and AQP5 expression in a model of radiation-induced pulmonary inflammation and edema. Decreased levels of AQP1 and AQP5 after irradiation suggest that these proteins play a role in the pathogenesis of RILT. PMID:24570172

  12. Liver irradiation causes distal bystander effects in the rat brain and affects animal behaviour

    PubMed Central

    Kovalchuk, Anna; Mychasiuk, Richelle; Muhammad, Arif; Hossain, Shakhawat; Ilnytskyy, Slava; Ghose, Abhijit; Kirkby, Charles; Ghasroddashti, Esmaeel; Kovalchuk, Olga; Kolb, Bryan

    2016-01-01

    Radiation therapy can not only produce effects on targeted organs, but can also influence shielded bystander organs, such as the brain in targeted liver irradiation. The brain is sensitive to radiation exposure, and irradiation causes significant neuro-cognitive deficits, including deficits in attention, concentration, memory, and executive and visuospatial functions. The mechanisms of their occurrence are not understood, although they may be related to the bystander effects. We analyzed the induction, mechanisms, and behavioural repercussions of bystander effects in the brain upon liver irradiation in a well-established rat model. Here, we show for the first time that bystander effects occur in the prefrontal cortex and hippocampus regions upon liver irradiation, where they manifest as altered gene expression and somewhat increased levels of γH2AX. We also report that bystander effects in the brain are associated with neuroanatomical and behavioural changes, and are more pronounced in females than in males. PMID:26678032

  13. Cytoprotective effect of prostaglandin E2 in irradiated rat ileum

    SciTech Connect

    Tomas-de la Vega, J.E.; Banner, B.F.; Hubbard, M.; Boston, D.L.; Thomas, C.W.; Straus, A.K.; Roseman, D.L.

    1984-01-01

    Radiation injury to the gastrointestinal tract is an infrequent but major clinical problem. Results of previous studies have shown that prostaglandins provide cytoprotection of the gastrointestinal mucosa against a variety of noxious agents, although, prior to this study, the protection against radiation exposure had not been documented. Exteriorized segment of Sprague-Dawley rat ileum was radiated with 10 and 15 Gy (/sup 137/Cs). One group of rats was pretreated with prostaglandin E2 one hour before and 24 hours after radiation injury. The rats were sacrificed three and five days following radiation injury. Morphometric measurement of mucosal thickness, villous height, crypt of Lieberkuehn height and number of mitoses per square millimeter swath of tissue were analyzed. Also, /sup 125/IUdR and /sup 3/HTdR were injected in a group of rats radiated with 15 Gy (/sup 137/Cs). /sup 125/IUdR counts per minute per milligram of dry weight and /sup 3/HTdR labeled cells were counted and analyzed. The morphometric measurements and radioactive labeled tissue counts suggest that prostaglandin E2 has a cytoprotective effect upon irradiated rat ileum. Speculations about the possible mechanism and usefulness of this observation are included.

  14. Schwann cell myelination of the myelin deficient rat spinal cord following X-irradiation

    SciTech Connect

    Duncan, I.D.; Hammang, J.P.; Gilmore, S.A.

    1988-01-01

    The myelin-deficient (md) rat is an X-linked myelin mutant that has an abnormality of oligodendrocytes and a severe paucity of myelin throughout the CNS. This lack of myelin makes it an ideal model in which to study the cellular interactions that occur when foreign myelinating cells are induced in the milieu of this nonmyelinated CNS. In this study, Schwann cells were induced in the lumbosacral spinal cord by exposing it to radiation, a technique demonstrated repeatedly in other nonmutant strains of rats. Md rats and their age-matched littermates were irradiated (3,000 to 4,000 R) at 3 days of age and perfused 16-22 days later after pulse labeling with tritiated thymidine. In the md rat, Schwann cell invasion progressed from the area of the spinal cord-nerve root junction and extended into the dorsal columns and adjacent gray matter. Autoradiographic evidence revealed that many of these cells incorporated 3H-thymidine, indicating that they were undergoing proliferation. Ultrastructural observations showed that there was an integration of these intraspinal Schwann cells with the cells normally occurring in this environment, i.e., oligodendrocytes and astrocytes. The extent of migration and division of Schwann cells, as well as their interactions with glial cells, were similar to those seen in the nonmutant irradiated littermates. These studies provide conclusive evidence that md rat axons are normal with respect to their ability to provide trophic and mitogenic signals to myelinating cells.

  15. Head and neck tumors after energetic proton irradiation in rats

    NASA Astrophysics Data System (ADS)

    Wood, D.; Cox, A.; Hardy, K.; Salmon, Y.; Trotter, R.

    1994-10-01

    This is a two-year progress report on a life span dose-response study of brain tumor risk at moderate to high doses of energetic protons. It was initiated because a joint NASA/USAF life span study of rhesus monkeys that were irradiated with 55-MeV protons (average surface dose, 3.5 Gy) indicated that the incidence of brain tumors per unit surface absorbed dose was over 19 times that of the human tinea capitis patients whose heads were exposed to 100 kv x-rays. Examination of those rats that died in the two-year interval after irradiation of the head revealed a linear dose-response for total head and neck tumor incidence in the dose range of 0-8.5 Gy. The exposed rats had a greater incidence of pituitary chromophobe adenomas, epithelial and mesothelial cell tumors than the unexposed controls but the excessive occurrence of malignant gliomas that was observed in the monkeys was absent in the rats. The estimated dose required to double the number of all types of head and neck tumors was 5.2 Gy. The highest dose, 18 Gy, resulted in high mortality due to obstructive squamous metaplasia at less than 50 weeks, prompting a new study of the relative bological effectiveness of high energy protons in producing this lesion.

  16. Irradiation and responsiveness to pain stimuli in rats

    SciTech Connect

    Rutten, E.H.J.M.; Oosterveld, B.J.; Dirksen, R.; Crul, B.J.P.; Egmond, J. van )

    1994-01-01

    This study evaluates whether irradiation inhibits responses to pain in an animal model. The authors found that irradiation with doses of 10 Gy, 15 Gy and 17.5 Gy of the lumbar enlargement of the spinal cord inhibits behavioural responses to the stimulus of the hot-plate. These doses were otherwise without effects. This data is discussed in view of the effects of irradiation of living cells, and the authors propose that a modification of pain signal processing is accomplished. Similar considerations apply to the human condition.

  17. Proinflammatory effects of local abdominal irradiation on rat gastrointestinal tract

    SciTech Connect

    Buell, M.G.; Harding, R.K.

    1989-03-01

    Although the role of inflammatory processes in the genesis of late changes in the gastrointestinal tract following exposure to ionizing irradiation has been extensively studied, few studies have concentrated on the presence of an acute inflammatory response in the period immediately following radiation. We therefore examined, in rats, whether the local application of 10 Gy cobalt-60 irradiation to the abdomen led to changes in the gut within the first 24 hr that were consistent with an acute inflammatory response. In stomach, small intestine, and colon, local irradiation led to a significant increase in the accumulation of plasma within the tissue by 4-8 hr following irradiation. This increase in tissue plasma volume, indicative of an increased microvascular permeability, was then sustained until the end of the 24-hr assessment period in all tissues examined. Concurrent with this was a consistent transient increase in tissue red blood cell volume, suggestive of vasodilation. Of particular note, a significant increase in the number of mucosal neutrophils was also observed between 2 and 12 hr following irradiation. This elevation in mucosal neutrophils was particularly marked in the pericryptal or deep mucosal regions of small intestine and colon and consistently preceded the vasodilation and enhanced permeability. Furthermore these pathophysiological alterations occurred at a time when histological changes in the mucosa consistent with an impaired mucosal microcirculation (ie, edema of the lamina propria and subepithelial bleb formation) were present. These results support the hypothesis that an inflammatory response occurs in the gut during the first 24 hr following abdominal irradiation. Such changes may then further exacerbate the damage initiated by the ionizing radiation.

  18. The Impact of Heart Irradiation on Dose-Volume Effects in the Rat Lung

    SciTech Connect

    Luijk, Peter van Faber, Hette; Meertens, Harm; Schippers, Jacobus M.; Langendijk, Johannes A.; Brandenburg, Sytze; Kampinga, Harm H.; Coppes, Robert P. Ph.D.

    2007-10-01

    Purpose: To test the hypothesis that heart irradiation increases the risk of a symptomatic radiation-induced loss of lung function (SRILF) and that this can be well-described as a modulation of the functional reserve of the lung. Methods and Materials: Rats were irradiated with 150-MeV protons. Dose-response curves were obtained for a significant increase in breathing frequency after irradiation of 100%, 75%, 50%, or 25% of the total lung volume, either including or excluding the heart from the irradiation field. A significant increase in the mean respiratory rate after 6-12 weeks compared with 0-4 weeks was defined as SRILF, based on biweekly measurements of the respiratory rate. The critical volume (CV) model was used to describe the risk of SRILF. Fits were done using a maximum likelihood method. Consistency between model and data was tested using a previously developed goodness-of-fit test. Results: The CV model could be fitted consistently to the data for lung irradiation only. However, this fitted model failed to predict the data that also included heart irradiation. Even refitting the model to all data resulted in a significant difference between model and data. These results imply that, although the CV model describes the risk of SRILF when the heart is spared, the model needs to be modified to account for the impact of dose to the heart on the risk of SRILF. Finally, a modified CV model is described that is consistent to all data. Conclusions: The detrimental effect of dose to the heart on the incidence of SRILF can be described by a dose dependent decrease in functional reserve of the lung.

  19. Morphological changes in cultures of hippocampus following prenatal irradiation in the rat

    SciTech Connect

    Hamdorf, G.; Shahar, A.; Cervos-Navarro, J.; Scheffler, A.; Sparenberg, A.; Skoberla, A. )

    1990-07-01

    The effect of prenatal irradiation was studied in organotypic cultures of hippocampus, prepared from newborn rats that had been exposed to whole-body irradiation of 1 Gy from a {sup 60}Co-source at day 13 of pregnancy. Light and electron microscopic observations showed remarkable damage to neuronal mitochondria accompanied by extensive swelling, vacuolation of the Golgi complex, and formation of multilamellar bodies and vesicles of the lysosomal type. In contrast to neuronal alterations, no delay in synaptogenesis or onset of myelination was observed based upon the absence of significant morphological changes in synapses and myelin sheaths. Using this tissue culture model it could be confirmed that prenatal exposure to irradiation, even at low doses, induces specific morphological changes in the brain.

  20. Effects of heavy particle irradiation and diet on object recognition memory in rats

    NASA Astrophysics Data System (ADS)

    Rabin, Bernard M.; Carrihill-Knoll, Kirsty; Hinchman, Marie; Shukitt-Hale, Barbara; Joseph, James A.; Foster, Brian C.

    2009-04-01

    On long-duration missions to other planets astronauts will be exposed to types and doses of radiation that are not experienced in low earth orbit. Previous research using a ground-based model for exposure to cosmic rays has shown that exposure to heavy particles, such as 56Fe, disrupts spatial learning and memory measured using the Morris water maze. Maintaining rats on diets containing antioxidant phytochemicals for 2 weeks prior to irradiation ameliorated this deficit. The present experiments were designed to determine: (1) the generality of the particle-induced disruption of memory by examining the effects of exposure to 56Fe particles on object recognition memory; and (2) whether maintaining rats on these antioxidant diets for 2 weeks prior to irradiation would also ameliorate any potential deficit. The results showed that exposure to low doses of 56Fe particles does disrupt recognition memory and that maintaining rats on antioxidant diets containing blueberry and strawberry extract for only 2 weeks was effective in ameliorating the disruptive effects of irradiation. The results are discussed in terms of the mechanisms by which exposure to these particles may produce effects on neurocognitive performance.

  1. Vascular Injury After Whole Thoracic X-Ray Irradiation in the Rat

    SciTech Connect

    Ghosh, S.N. Wu, Q. M.S.; Maeder, M.; Fish, B.L.; Moulder, J.E.; Jacobs, E.R.; Medhora, M.; Molthen, R.C.

    2009-05-01

    Purpose: To study vascular injury after whole thoracic irradiation with single sublethal doses of X-rays in the rat and to develop markers that might predict the severity of injury. Methods and Materials: Rats that received 5- or 10-Gy thorax-only irradiation and age-matched controls were studied at 3 days, 2 weeks, and 1, 2, 5, and 12 months. Several pulmonary vascular parameters were evaluated, including hemodynamics, vessel density, total lung angiotensin-converting enzyme activity, and right ventricular hypertrophy. Results: By 1 month, the rats in the 10-Gy group had pulmonary vascular dropout, right ventricular hypertrophy, increased pulmonary vascular resistance, increased dry lung weights, and decreases in total lung angiotensin-converting enzyme activity, as well as pulmonary artery distensibility. In contrast, irradiation with 5 Gy resulted in only a modest increase in right ventricular weight and a reduction in lung angiotensin-converting enzyme activity. Conclusion: In a previous investigation using the same model, we observed that recovery from radiation-induced attenuation of pulmonary vascular reactivity occurred. In the present study, we report that deterioration results in several vascular parameters for {<=}1 year after 10 Gy, suggesting sustained remodeling of the pulmonary vasculature. Our data support clinically relevant injuries that appear in a time- and dose-related manner after exposure to relatively low radiation doses.

  2. Irradiation of Varying Volumes of Rat Lung to Same Mean Lung Dose: a Little to a Lot or a Lot to a Little?

    SciTech Connect

    Semenenko, Vladimir A. Molthen, Robert C.; Li Chunrong; Morrow, Natalya V.; Li Rongshan; Ghosh, Swarajit N.; Medhora, Meetha M.; Li, X. Allen

    2008-07-01

    Purpose: To investigate whether irradiating small lung volumes with a large dose or irradiating large lung volumes with a small dose, given the same mean lung dose (MLD), has a different effect on pulmonary function in laboratory animals. Methods and Materials: WAG/Rij/MCW male rats were exposed to single fractions of 300 kVp X-rays. Four treatments, in decreasing order of irradiated lung volume, were administered: (1) whole lung irradiation, (2) right lung irradiation, (3) left lung irradiation, and (4) irradiation of a small lung volume with four narrow beams. The irradiation times were chosen to accumulate the same MLD of 10, 12.5, or 15 Gy with each irradiated lung volume. The development of radiation-induced lung injury for {<=}20 weeks was evaluated as increased breathing frequency, mortality, and histopathologic changes in the irradiated and control rats. Results: A significant elevation of respiratory rate, which correlated with the lung volume exposed to single small doses ({>=}5 Gy), but not with the MLD, was observed. The survival of the rats in the whole-lung-irradiated group was MLD dependent, with all events occurring between 4.5 and 9 weeks after irradiation. No mortality was observed in the partial-volume irradiated rats. Conclusions: The lung volume irradiated to small doses might be the dominant factor influencing the loss of pulmonary function in the rat model of radiation-induced lung injury. Caution should be used when new radiotherapy techniques that result in irradiation of large volumes of normal tissue are used for the treatment of lung cancer and other tumors in the thorax.

  3. Elevation of serum 25-hydroxycalciferol levels in androgen-treated and ultraviolet-irradiated rats.

    PubMed

    Ohata, M; Sakagami, Y; Fujita, T

    1977-10-01

    Administration of 4-8 mg testosterone propionate significantly raised 25-hydroxycalciferol levels in the ultraviolet irradiated rats compared to the ultraviolet irradiated controls, but failed to influence serum 25-hydroxycalciferol levels in the non-irradiated animals. Estradiol benzoate and progesterone did not influence serum 25-hydroxycalciferol levels regardless of the ultraviolet irradiation. These findings implicate that testosterone enhances vitamin D biosynthesis induced by ultraviolet irradiation in rats, in accordance with the clinical observation that males often show higher levels of serum 25-hydroxycalciferol than females. PMID:303993

  4. Modeling of Irradiation Hardening of Polycrystalline Materials

    SciTech Connect

    Li, Dongsheng; Zbib, Hussein M.; Garmestani, Hamid; Sun, Xin; Khaleel, Mohammad A.

    2011-09-14

    High energy particle irradiation of structural polycrystalline materials usually produces irradiation hardening and embrittlement. The development of predict capability for the influence of irradiation on mechanical behavior is very important in materials design for next generation reactors. In this work a multiscale approach was implemented to predict irradiation hardening of body centered cubic (bcc) alpha-iron. The effect of defect density, texture and grain boundary was investigated. In the microscale, dislocation dynamics models were used to predict the critical resolved shear stress from the evolution of local dislocation and defects. In the macroscale, a viscoplastic self-consistent model was applied to predict the irradiation hardening in samples with changes in texture and grain boundary. This multiscale modeling can guide performance evaluation of structural materials used in next generation nuclear reactors.

  5. Royal jelly modulates oxidative stress and tissue injury in gamma irradiated male Wister Albino rats

    PubMed Central

    Azab, Khaled Shaaban; Bashandy, Mohamed; Salem, Mahmoud; Ahmed, Osama; Tawfik, Zaki; Helal, Hamed

    2011-01-01

    Background: Royal jelly is a nutritive secretion produced by the worker bees, rich in proteins, carbohydrates, vitamins and minerals. Aim: The present study was designed to determine the possible protective effects of royal jelly against radiation induced oxidative stress, hematological, biochemical and histological alterations in male Wister albino rats. Materials and Methods: Male Wister albino rats were exposed to a fractionated dose of gamma radiation (2 Gy every 3 days up to 8 Gy total doses). Royal jelly was administrated (g/Kg/day) by gavages 14 days before exposure to the 1st radiation fraction and the treatment was continued for 15 days after the 1st irradiation fraction till the end of the experiment. The rats were sacrificed 3rd, equivalent to 3rd post 2nd irradiation fraction, and equivalent to 3rd day post last irradiation fraction. Results: In the present study, gamma- irradiation induced hematological, biochemical and histological effects in male Wister albino rats. In royal jelly treated irradiated group, there was a noticeable decrease recorded in thiobarbituric reactive substances concentration when compared to γ-irradiated group. Also, the serum nitric oxide concentration was significantly improved. The administration of royal jelly to irradiated rats according to the current experimental design significantly ameliorates the changes induced in serum lipid profile. Moreover, in royal jelly treated irradiated group, there was a noticeable amelioration recorded in all hematological parameters along the three experimental intervals. The microscopic examination of cardiac muscle of royal jelly treated irradiated rats demonstrated structural amelioration, improved nuclei and normal features of capillaries and veins in endomysium when compared to gamma-irradiated rats. Conclusion: It was suggested that the biochemical, hematological and histological amelioration observed in royal jelly (g/Kg/day) treated irradiated rats might be due to the antioxidant

  6. SU-E-T-492: Implementing a Method for Brain Irradiation in Rats Utilizing a Commercially Available Radiosurgery Irradiator

    SciTech Connect

    Cates, J; Drzymala, R

    2014-06-01

    Purpose: The purpose of the study was to implement a method for accurate rat brain irradiation using the Gamma Knife Perfexion unit. The system needed to be repeatable, efficient, and dosimetrically and spatially accurate. Methods: A platform (“rat holder”) was made such that it is attachable to the Leskell Gamma Knife G Frame. The rat holder utilizes two ear bars contacting bony anatomy and a front tooth bar to secure the rat. The rat holder fits inside of the Leskell localizer box, which utilizes fiducial markers to register with the GammaPlan planning system. This method allows for accurate, repeatable setup.A cylindrical phantom was made so that film can be placed axially in the phantom. We then acquired CT image sets of the rat holder and localizer box with both a rat and the phantom. Three treatment plans were created: a plan on the rat CT dataset, a phantom plan with the same prescription dose as the rat plan, and a phantom plan with the same delivery time as the rat plan. Results: Film analysis from the phantom showed that our setup is spatially accurate and repeatable. It is also dosimetrically accurate, with an difference between predicted and measured dose of 2.9%. Film analysis with prescription dose equal between rat and phantom plans showed a difference of 3.8%, showing that our phantom is a good representation of the rat for dosimetry purposes, allowing for +/- 3mm diameter variation. Film analysis with treatment time equal showed an error of 2.6%, which means we can deliver a prescription dose within 3% accuracy. Conclusion: Our method for irradiation of rat brain has been shown to be repeatable, efficient, and accurate, both dosimetrically and spatially. We can treat a large number of rats efficiently while delivering prescription doses within 3% at millimeter level accuracy.

  7. Effects of single-dose and fractionated cranial irradiation on rat brain accumulation of methotrexate

    SciTech Connect

    Kamen, B.A.; Moulder, J.E.; Kun, L.E.; Ring, B.J.; Adams, S.M.; Fish, B.L.; Holcenberg, J.S.

    1984-11-01

    The effects of single-dose and fractionated whole-brain irradiation on brain methotrexate (MTX) has been studied in a rat model. The amount of MTX present in the brain 24 hr after a single i.p. dose (100 mg/kg) was the same whether animals were sham irradiated or given a single dose of 2000 rads 6 or 48 hr prior to the drug (6.9, 8.3, and 6.8 pmol MTX/g, wet weight, respectively). Animals sham irradiated or given 2000 rads in 10 fractions over 11 days and treated with an average dose of 1.2 mg MTX/kg i.p. twice a week for 24 weeks did not differ significantly in their brain MTX concentration (7.9 and 8.3 pmol MTX/g, wet weight, respectively). Chronically MTX-treated animals became folate deficient whether they were irradiated or not (450 and 670 pmol folate/g, wet weight, brain in MTX-treated and control animals). Thus, MTX accumulates in the brain with acute or chronic administration, and this accumulation is not altered by this amount of brain irradiation.

  8. Appearance of cell fragments in thymus after a whole-body X-irradiation of rat

    SciTech Connect

    Ohyama, H.; Yamada, T.

    1983-01-01

    Changes in surface architecture and three dimensional structure of rat thymus cortex were examined by scanning electron microscopy (SEM) after a whole-body X-irradiation. The samples of thymus prepared from rats 4 to 8 hr after a 400 R irradiation were observed by SEM. Normal thymocytes, having tiny microvilli and shallow ridges, decreased in number after irradiation, with a corresponding increase in radiation damaged round shaped cells with occasional protrusions and pores. With time after irradiation, smaller spherical fragments of cells having smooth or porous surfaces increased in number.

  9. Rat mammary cell survival following irradiation with 14. 3-MeV neutrons

    SciTech Connect

    Mahler, P.A.; Gould, M.N.; DeLuca, P.M. Jr.; Pearson, D.W.; Clifton, K.H.

    1982-08-01

    The survival of rat mammary gland cells irradiated in situ with either single or split doses of 14.3-MeV neutrons was determined by an in vivo transplantation assay. The single-dose data are best fit to the multitarget single-hit model by the parameters D/sub o/ = 97 cGy and n = 0.6 while the split-dose data are best fit by the parameters D/sub o/ = 100 cGy and n = 1.2.Analysis of the combined data sets suggests that the two survival curves are not identical. Comparison of these data with previously published results following irradiation with 250-kVp X rays is reported.

  10. Rat mammary-cell survival following irradiation with 14. 3-MeV neutrons

    SciTech Connect

    Mahler, P.A.; Gould, M.N.; DeLuca, P.M. Jr.; Pearson, D.W.; Clifton, K.H.

    1982-01-01

    The survival of rat mammary gland cells irradiated in situ with either single or split doses of 14.3-MeV neutrons was determined by an in vivo transplantation assay. The single-dose data are best fit to the multitarget single-hit model by the parameters D/sub 0/ = 97 cGy and n = 0.6 while the split-dose data are best fit by the parameters D/sub 0/ = 100 cGy and n = 1.2. Analysis of the combined data sets suggests that the two survival curves are not identical. Comparison of these data with previously published results following irradiation with 250-kVp x-rays is reported.

  11. Effects of He-Ne laser irradiation on chronic atrophic gastritis in rats

    PubMed Central

    Shao, Xue-Hui; Yang, Yue-Ping; Dai, Jie; Wu, Jing-Fang; Bo, Ai-Hua

    2005-01-01

    AIM: To study the effects of He-Ne laser irradiation on experimental chronic atrophic gastritis (CAG) in rats. METHODS: Sixty-three male adult Wistar rats were randomly divided into five groups including normal control group, model control group and three different dosages He-Ne laser groups. The chronic atrophic gastritis (CAG) model in rats was made by pouring medicine which was a kind of mixed liquor including 2% sodium salicylate and 30% alcohol down the throat for 8 wk to stimulate rat gastric mucosa, combining with irregular fasting and compulsive sporting as pathogenic factors; 3.36, 4.80, and 6.24 J/cm2 doses of He-Ne laser were used, respectively for three different treatment groups, once a day for 20 d. The pH value of diluted gastric acid was determined by acidimeter, the histopathological changes such as the inflammatory degrees in gastric mucosa, the morphology and structure of parietal cells were observed, and the thickness of mucosa was measured by micrometer under optical microscope. RESULTS: In model control group, the secretion of gastric acid was little, pathologic morphological changes in gastric mucosa such as thinner mucous, atrophic glands, notable inflammatory infiltration were found. After 3.36 J/cm2 dose of He-Ne laser treatment for 20 d, the secretion of gastric acid was increased (P < 0.05), the thickness of gastric mucosa was significantly thicker than that in model control group (P < 0.01), the gastric mucosal inflammation cells were decreased (P < 0.05). Morphology, structure and volume of the parietal cells all recuperated or were closed to normal. CONCLUSION: 3.36 J/cm2 dose of He-Ne laser has a significant effect on CAG in rats. PMID:15991302

  12. [Sequencing of low-molecular-weight DNA in blood plasma of irradiated rats].

    PubMed

    Vasilieva, I N; Bespalov, V G; Zinkin, V N; Podgornaya, O I

    2015-01-01

    Extracellular low-molecular-weight DNA in blood of irradiated rats was sequenced for the first time. The screening of sequences in the DDBJ database displayed homology of various parts of the rodent genome. Sequences of low-molecular-weight DNA in rat's plasma are enriched with G/C pairs and long interspersed elements relative to rat genome. DNA sequences in blood of rats irradiated at the doses of 8 and 100 Gy have marked distinctions. Data of sequencing of extracellular DNA from normal humans and with pathology were analyzed. DNA sequences of irradiated rats differ from the human ones by a wealth of long interspersed elements. This new knowledge lays the foundation for development of minimally invasive technologies of diagnosing the probability of pathology and controlling the adaptive resources of people in extreme environments. PMID:25958466

  13. Time course of lipolytic activity and lipid peroxidation after whole-body gamma irradiation of rats

    SciTech Connect

    Rejholcova, M.; Wilhelm, J.

    1989-01-01

    The content of fluorescing products of lipid peroxidation (LFP) and hormone-stimulated lipolytic activity were determined in rat epididymal adipose tissue during a 29-day interval after whole-body gamma irradiation. An increase in LFP was accompanied by a decrease in lipolytic activity. It is suggested that these effects are interrelated and that the decrease in lipolysis in irradiated, semi fasting rats is an additional deteriorating factor leading to death in some animals.

  14. The solar irradiance: observations and modelling

    NASA Astrophysics Data System (ADS)

    Cessateur, Gaël; Schmutz, Werner; Shapiro, Alexander

    2015-04-01

    The knowledge of the solar spectral irradiance (SSI) and its variability is an essential parameter for space weather and space climate studies. Many observations of the SSI have been performed in a recent past, but the level of confidence is rather low when considering long time scales, since space instruments are often suffering from degradation problems. Many SSI models have been also developed, and some of them are excellent inputs for many space climate models. We will then review the different data sets available of the SSI for the short term time-scales as well as for the long term, including both observations and models. We will also emphasize about our new irradiance model, COSIR for Code of Solar Irradiance Reconstruction, which is successful at reproducing the solar rotational modulation as seen in the PREMOS, Virgo and SORCE data.

  15. Biophotonic effect of diode laser irradiance on tensile strength of diabetic rats.

    PubMed

    Lau, Pik Suan; Bidin, Noriah; Krishnan, Ganesan; Nassir, Zaleha; Bahktiar, Hazri

    2015-04-01

    Low-energy laser irradiance at certain wavelengths is able to stimulate the tissue bio-reaction and enhance the healing process. Collagen deposition is one of the important aspects in healing process because it can increase the strength of the skin. This study was designed to examine the biophotonic effect of irradiance on collagen production of diabetic wound in rat model. The tensile strength of skin was employed as a parameter to describe the wound. Diabetic rat models were induced by streptozotocin via intravenous injection. Skin-breaking strength was measured using an Instron tensile test machine. The experimental animals were treated with 808-nm diode laser at two different powers-0.1 and 0.5 W/cm(2)-and 30, 60, and 120 s for each session. The tensile strength was optimized after treated with high-power diode laser. The photostimulation effect was revealed by accelerated healing process and enhanced tensile strength of wound. Laser photostimulation on tensile strength in diabetic wound suggests that such therapy facilitates collagen production in diabetic wound healing. PMID:25260140

  16. Modelling total solar irradiance using a flux transport model

    NASA Astrophysics Data System (ADS)

    Dasi Espuig, Maria; Jiang, Jie; Krivova, Natalie; Solanki, Sami

    2014-05-01

    Reconstructions of solar irradiance into the past are of considerable interest for studies of solar influence on climate. Models based on the assumption that irradiance changes are caused by the evolution of the photospheric magnetic field have been the most successful in reproducing the measured irradiance variations. Our SATIRE-S model is one of these. It uses solar full-disc magnetograms as an input, and these are available for less than four decades. Thus, to reconstruct the irradiance back to times when no observed magnetograms are available, we combine the SATIRE-S model with synthetic magnetograms, produced using a surface flux transport model. The model is fed with daily, observed or modelled statistically, records of sunspot positions, areas, and tilt angles. To describe the secular change in the irradiance, we used the concept of overlapping ephemeral region cycles. With this technique TSI can be reconstructed back to 1700.

  17. Modeling nicotine addiction in rats.

    PubMed

    Caille, Stephanie; Clemens, Kelly; Stinus, Luis; Cador, Martine

    2012-01-01

    Among the human population, 15% of drug users develop a pathological drug addiction. This figure increases substantially with nicotine, whereby more than 30% of those who try smoking develop a nicotine addiction. Drug addiction is characterized by compulsive drug-seeking and drug-taking behaviors (craving), and loss of control over intake despite impairment in health, social, and occupational functions. This behavior can be accurately modeled in the rat using an intravenous self-administration (IVSA) paradigm. Initial attempts at establishing nicotine self-administration had been problematic, yet in recent times increasingly reliable models of nicotine self-administration have been developed. The present article reviews different characteristics of the nicotine IVSA model that has been developed to examine nicotine reinforcing and motivational properties in rats. PMID:22231818

  18. Advanced Numerical Model for Irradiated Concrete

    SciTech Connect

    Giorla, Alain B.

    2015-03-01

    In this report, we establish a numerical model for concrete exposed to irradiation to address these three critical points. The model accounts for creep in the cement paste and its coupling with damage, temperature and relative humidity. The shift in failure mode with the loading rate is also properly represented. The numerical model for creep has been validated and calibrated against different experiments in the literature [Wittmann, 1970, Le Roy, 1995]. Results from a simplified model are shown to showcase the ability of numerical homogenization to simulate irradiation effects in concrete. In future works, the complete model will be applied to the analysis of the irradiation experiments of Elleuch et al. [1972] and Kelly et al. [1969]. This requires a careful examination of the experimental environmental conditions as in both cases certain critical information are missing, including the relative humidity history. A sensitivity analysis will be conducted to provide lower and upper bounds of the concrete expansion under irradiation, and check if the scatter in the simulated results matches the one found in experiments. The numerical and experimental results will be compared in terms of expansion and loss of mechanical stiffness and strength. Both effects should be captured accordingly by the model to validate it. Once the model has been validated on these two experiments, it can be applied to simulate concrete from nuclear power plants. To do so, the materials used in these concrete must be as well characterized as possible. The main parameters required are the mechanical properties of each constituent in the concrete (aggregates, cement paste), namely the elastic modulus, the creep properties, the tensile and compressive strength, the thermal expansion coefficient, and the drying shrinkage. These can be either measured experimentally, estimated from the initial composition in the case of cement paste, or back-calculated from mechanical tests on concrete. If some

  19. Irradiated lymphocytes do not adoptively transfer diabetes or prevent spontaneous disease in the BB/W rat

    SciTech Connect

    Mordes, J.P.; Handler, E.S.; Like, A.A.; Nakano, K.; Rossini, A.A.

    1986-06-01

    Diabetes in the BB/W rat is autoimmune in origin, and lymphocytes from acutely diabetic animals activated by concanavalin A (con A) induce the disease in adoptive recipients. We report that irradiation of these cells prevents adoptive transfer of diabetes. Through 60 days of age, diabetes occurred in none of 47 BB/W rats given irradiated con A cells, but in 21 of 36 (58%) given nonirradiated cells. Between 60 and 130 days of age, however, spontaneous diabetes occurred in 18 of 34 untreated control rats (53%) and 16 of 32 rats (50%) given two injections of irradiated con A activated spleen cells. We conclude that irradiation prevents adoptive transfer of BB/W rat diabetes and that irradiated con A activated lymphocytes from acutely diabetic rats do not protect against spontaneous disease in susceptible recipients.

  20. Relationship between oxidative damage and colon carcinogenesis in irradiated rats: influence of dietary countermeasures

    NASA Astrophysics Data System (ADS)

    Turner, Nancy; Sanders, Lisa; Wu, Guoyao; Davidson, Laurie; Ford, John; Braby, Leslie; Carroll, Raymond; Chapkin, Robert; Lupton, Joanne

    Galactic cosmic radiation not only kills colon epithelial cells, it also generates a cellular environment that can lead to oxidative DNA damage. We previously demonstrated that a diet containing fish oil and pectin protects against initiation of colon cancer by enhancing apoptotic removal of cells with oxidative DNA adducts (8-OHdG), and that apoptosis was highly correlated with colon cancer suppression. We hypothesized this diet combination will mitigate the oxidative damage occurring from radiation and thus reduce colon cancer. The experiment tested the effect of radiation (± 1 Gy, 1 GeV/n Fe ions) on redox balance, apoptosis, and 8-OHdG levels at initiation and colon tumor incidence. Diets contained fish oil or corn oil, and cellulose or pectin (2x2 factorial design). Rats received the diets 3 wk before irradiation (half of the rats), followed by azoxymethane (AOM) injections 10 and 17 d later (all rats). Just prior to AOM injection, irradiated fish oil/pectin rats had a more reduced redox state in colonocytes (lower GSSG, P < 0.05; higher GSH/GSSG ratio), which was not observed in irradiated corn oil/cellulose rats. A shift to a more oxidative state (lower GSH and GSH/GSSG ratio, P < 0.05) occurred between 6 and 12 h after AOM in the fish oil/pectin irradiated rats. Changes in redox balance likely contributed to lower 8-OHdG levels in colonocytes from rats consuming the fish oil diets. Dietary pectin enhanced (P < 0.04) apoptosis induction 12 h after AOM injection in irradiated rats. Similar to the 8-OHdG results, colon tumor incidence was 42% higher (P < 0.05) in rats fed corn oil vs fish oil diets. In summary, fish oil/pectin diets created a more reduced colon environment in irradiated rats that was evident 10 d after irradiation. The ensuing oxidative shift in those rats after AOM injection may have enhanced apoptosis; effectively eliminating more DNA damaged cells. Thus, inclusion of fish oil and pectin in diets for long-duration space flights should help

  1. Protective effect of ginseng against gamma-irradiation-induced oxidative stress and endothelial dysfunction in rats

    PubMed Central

    Mansour, Heba Hosny

    2013-01-01

    This study investigated the potential protective effects of ginseng on gamma-irradiation-induced oxidative stress and endothelial dysfunction in rats. Twenty four male albino rats were divided into four groups. In the control group, rats were administered vehicle by tube for 7 consecutive days. The second group was administered ginseng extract (100 mg/kg, by gavage) for 7 consecutive days. Animals in the third group were administered vehicle by tube for 7 consecutive days, then exposed to single dose gamma-irradiation (6 Gy). The Fourth group received ginseng extract for 7 consecutive days, one hour later rats were exposed to gamma-irradiation. Oral administration of ginseng extract prior to irradiation produced a significant protection which was evidenced by a significant reduction in serum creatine kinase (CPK) and lactate dehydrogenase (LDH) activities and asymmetric dimethylarginine (ADMA), urea and creatinine levels with significant increase in serum total nitrate/nitrite (NO(x)) level. Moreover, ginseng significantly increased cardiac and renal superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) activities, and reduced glutathione (GSH) content, associated with a significant depletion in malondialdehyde (MDA) and NO(x) levels compared to irradiated group. This study suggests that ginseng may serve as a potential protective agent against gamma-irradiation-induced cardio-nephrotoxicity via enhancing the antioxidant activity and inhibition of endothelial dysfunction. PMID:26622217

  2. Mechanical properties of UV irradiated rat tail tendon (RTT) collagen.

    PubMed

    Sionkowska, Alina; Wess, Tim

    2004-04-01

    The mechanical properties of RTT collagen tendon before and after UV irradiation have been investigated by mechanical testing (Instron). Air-dried tendon were submitted to treatment with UV irradiation (wavelength 254 nm) for different time intervals. The changes in such mechanical properties as breaking strength and percentage elongation have been investigated. The results have shown, that the mechanical properties of the tendon were greatly affected by time of UV irradiation. Ultimate tensile strength and ultimate percentage elongation decreased after UV irradiation of the tendon. Increasing UV irradiation leads to a decrease in Young's modulus of the tendon. PMID:15178003

  3. Boswellic acids extract attenuates pulmonary fibrosis induced by bleomycin and oxidative stress from gamma irradiation in rats

    PubMed Central

    2011-01-01

    Background Interstitial pulmonary fibrosis is characterized by an altered cellular composition of the alveolar region with excessive deposition of collagen. Lung inflammation is also common in pulmonary fibrosis. This study aims to test the inhibition of 5-lipooxygenase (5-LOX) by boswellic acid (BA) extract in an experimental model of pulmonary fibrosis using bleomycin (BL). Methods Boswellic acid extract (1 g/kg) was force-fed to rats seven days prior to administration of BL or gamma irradiation or both. BL (0.15 U/rat) in 25 μl of 0.9% normal saline (NS) or 0.9% NS alone was administered intratracheally. Rats were exposed to two fractionated doses of gamma irradiation (0.5 Gy/dose/week) with a gamma cell-40 (Cesium-137 irradiation units, Canada) during the last two weeks of the experiment. BA was administered during BL or irradiation treatment or both. After the animals were sacrificed, bronchoalveolar lavage was performed; lungs were weighed and processed separately for biochemical and histological studies. Results In rats treated with BL, levels of transforming growth factor-β1 (TGF-β1) and tumor necrosis factor-α (TNF-α) were significantly elevated (P = 0.05 and P = 0.005). Hydroxyproline was highly and extensively expressed. Immunoreactive compounds were abundantly expressed, represented in the levels of macrophages infiltrate, accumulation of eosinophils and neutrophils in the lung as well as the aggregation of fibroblasts in the fibrotic area. The levels of lipoxygenase enzyme activity were significantly increased (P = 0.005). Antioxidant activities measured in BL-treated rats deteriorated, coupled with the elevation of both levels of plasma lipid peroxide (LP) content and bronchoalveolar lavage lactate dehydrogenase activity. BA-treated rats had reduced number of macrophages, (P = 0.01), neutrophils in bronchoalveolar lavage (P = 0.01) and protein (P = 0.0001). Moreover, the hydroxyproline content was significantly lowered in BA-treated rats (P = 0

  4. Advances on genetic rat models of epilepsy

    PubMed Central

    Serikawa, Tadao; Mashimo, Tomoji; Kuramoto, Takashi; Voigt, Birger; Ohno, Yukihiro; Sasa, Masashi

    2014-01-01

    Considering the suitability of laboratory rats in epilepsy research, we and other groups have been developing genetic models of epilepsy in this species. After epileptic rats or seizure-susceptible rats were sporadically found in outbred stocks, the epileptic traits were usually genetically-fixed by selective breeding. So far, the absence seizure models GAERS and WAG/Rij, audiogenic seizure models GEPR-3 and GEPR-9, generalized tonic-clonic seizure models IER, NER and WER, and Canavan-disease related epileptic models TRM and SER have been established. Dissection of the genetic bases including causative genes in these epileptic rat models would be a significant step toward understanding epileptogenesis. N-ethyl-N-nitrosourea (ENU) mutagenesis provides a systematic approach which allowed us to develop two novel epileptic rat models: heat-induced seizure susceptible (Hiss) rats with an Scn1a missense mutation and autosomal dominant lateral temporal epilepsy (ADLTE) model rats with an Lgi1 missense mutation. In addition, we have established episodic ataxia type 1 (EA1) model rats with a Kcna1 missense mutation derived from the ENU-induced rat mutant stock, and identified a Cacna1a missense mutation in a N-Methyl-N-nitrosourea (MNU)-induced mutant rat strain GRY, resulting in the discovery of episodic ataxia type 2 (EA2) model rats. Thus, epileptic rat models have been established on the two paths: ‘phenotype to gene’ and ‘gene to phenotype’. In the near future, development of novel epileptic rat models will be extensively promoted by the use of sophisticated genome editing technologies. PMID:25312505

  5. Advances on genetic rat models of epilepsy.

    PubMed

    Serikawa, Tadao; Mashimo, Tomoji; Kuramoro, Takashi; Voigt, Birger; Ohno, Yukihiro; Sasa, Masashi

    2015-01-01

    Considering the suitability of laboratory rats in epilepsy research, we and other groups have been developing genetic models of epilepsy in this species. After epileptic rats or seizure-susceptible rats were sporadically found in outbred stocks, the epileptic traits were usually genetically-fixed by selective breeding. So far, the absence seizure models GAERS and WAG/Rij, audiogenic seizure models GEPR-3 and GEPR-9, generalized tonic-clonic seizure models IER, NER and WER, and Canavan-disease related epileptic models TRM and SER have been established. Dissection of the genetic bases including causative genes in these epileptic rat models would be a significant step toward understanding epileptogenesis. N-ethyl-N-nitrosourea (ENU) mutagenesis provides a systematic approach which allowed us to develop two novel epileptic rat models: heat-induced seizure susceptible (Hiss) rats with an Scn1a missense mutation and autosomal dominant lateral temporal epilepsy (ADLTE) model rats with an Lgi1 missense mutation. In addition, we have established episodic ataxia type 1 (EA1) model rats with a Kcna1 missense mutation derived from the ENU-induced rat mutant stock, and identified a Cacna1a missense mutation in a N-Methyl-N-nitrosourea (MNU)-induced mutant rat strain GRY, resulting in the discovery of episodic ataxia type 2 (EA2) model rats. Thus, epileptic rat models have been established on the two paths: 'phenotype to gene' and 'gene to phenotype'. In the near future, development of novel epileptic rat models will be extensively promoted by the use of sophisticated genome editing technologies. PMID:25312505

  6. Modeled soft X-ray solar irradiances

    NASA Technical Reports Server (NTRS)

    Tobiska, W. Kent

    1994-01-01

    Solar soft X-rays have historically been inaccurately modeled in both relative variations and absolute magnitudes by empirical solar extreme ultraviolet (EUV) irradiance models. This is a result of the use of a limited number of rocket data sets which were primarily associated with the calibration of the AE-E satellite EUV data set. In this work, the EUV91 solar EUV irradiance model has been upgraded to improve the accuracy of the 3.0 to 5.0 nm relative irradiance variations. The absolute magnitude estimate of the flux in this wavelength range has also been revised upwards. The upgrade was accomplished by first digitizing the SOLRAD 11 satellite 4.4 to 6.0 nm measured energy flux data set, then extracting and extrapolating a derived 3.0 to 5.0 nm photon flux from these data, and finally by performing a correlation between these derived data and the daily and 81-day mean 10.7 cm radio flux emission using a multiple linear regression technique. A correlation coefficient of greater than 0.9 was obtained between the dependent and independent data sets. The derived and modeled 3.0 to 5.0 nm flux varies by more than an order of magnitude over a solar cycle, ranging from a flux below 1 x 10(exp 8) to a flux greater than 1 x 10(exp 9) photons per sq cm per sec. Solar rotational (27-day) variations in the flux magnitude are a factor of 2. The derived and modeled irradiance absolute values are an order of magnitude greater than previous values from rocket data sets related to the calibration of the AE-E satellite.

  7. Incidence and nature of tumors induced in Sprague-Dawley rats by gamma-irradiation

    SciTech Connect

    Gross, L.; Dreyfuss, Y.; Faraggiana, T.

    1988-05-01

    In our previous studies carried out on inbred rats of the Sprague-Dawley strain, the tumor incidence was increased following irradiation (150 rads, 5 times, at weekly intervals), from 22 to 93% in females and from 5 to 59% in males. Experiments here reported suggest that 2 consecutive total-body gamma-irradiations of 150 rads each are sufficient to induce in rats the development of tumors, some malignant; 18 of 19 females (94.7%) developed tumors at an average age of 11.4 mo, and seven of the 14 males in this group (50%) developed tumors at an average age of 10.4 mo. In the second group, which received 3 consecutive gamma-irradiations, 20 of 23 females (86.9%) and 5 of 13 males (38.4%) developed tumors at average ages of 9.1 and 7.5 mo, respectively. In the third group, among rats which received 4 consecutive gamma-irradiations, 17 of 19 females (89.4%) and 4 of 12 males (33.3%) developed tumors at average ages of 9.4 and 10.5 mo, respectively. The etiology of tumors either developing spontaneously or induced by irradiation in rats remains to be clarified. Our attempts to detect virus particles by electron microscopy in such tumors or lymphomas have not been successful. As a working hypothesis, we are tempted to theorize that tumors or lymphomas developing spontaneously or induced by gamma irradiation in rats are caused by latent viral agents which are integrated into the cell genome and are cell associated, i.e., not separable from the rat tumor cells by conventional methods thus far used.

  8. Effect of gamma-ray irradiation on the unloaded animal model

    NASA Astrophysics Data System (ADS)

    Choi, Jong-Il; Yoon, Min-Chul; Sung, Nak-Yoon; Kim, Jae-Hun; Jong Lee, Yun; Lee, Ki-Soo; Choi, In-Ho; Nam, Gung Uk; Lee, Ju-Woon

    During the space flight, human beings encountered the extreme conditions such as the cosmic ray irradiation and microgravity. There have been developed the animal models to simulate the microgravity condition in laboratory, but no study was carried out to investigate the combined effect of microgravity and exposure to irradiation. In this study, it was examined the effect of gamma irradiation on the suspension model. Rats were divided into four groups, Group I was loaded and not exposed to gamma irradiation, Group 2 was unloaded and not exposed, Group 3 was loaded and exposed to gamma irradiation at the dose of 50 mSV, and Group 4 was unloaded and exposed to gamma irradiation at the same dose. It was measured body, muscles and tissues weights and the biological analysis and the hematological response in blood samples were conducted. Anti-gravity tissue weight was only changed between loading and un-loading condition. However, there was no difference between irradiation exposed and not exposed unloaded groups. To know the difference of protein expression in anti-gravity tissues, 2 dimensional electrophoresis was performed. It has been found that the expression levels of several proteins were different by unloading condition and by irradiation exposed condition, respectively. These results provided the information on the combined effect of irradiation and microgravity to simulate space flight, and could be useful to search the candidate material for the countermeasure against space environment.

  9. Inhibitory effects of 90Sr/90Y β-irradiation on alkali burn-induced corneal neovascularization in rats

    PubMed Central

    LIN, YUANQIANG; MA, QINGJIE; LIN, SHAN; ZHOU, HONGYAN; WEN, QIANG; GAO, SHI; CHENG, GUANGHUI

    2016-01-01

    The aim of the present study was to investigate the inhibitory effects of 90Sr-90Y β-irradiation in a rat model of alkali burn-induced corneal neovascularization (CNV). Alkali burn-induced CNV was induced in the right eyes of 30 female Wistar rats, which were randomly divided into the following three groups (n=10/group): i) The alkali burn control group, which received a balanced salt solution treatment; ii) group 1, which received treatment with angiogenesis inhibitors; and iii) group 2, which received 90Sr-90Y β-irradiation treatment. A further 10 female Wistar rats comprised a blank control group and received only balanced salt solution. Digital photographs of the corneas were acquired and the area of NV was calculated. In addition, the expression levels of matrix metalloproteinase (MMP)-9, vascular endothelial growth factor (VEGF), VEGF receptor (VEGFR)-1 and VEGFR-2 in alkali-burned rat corneas were determined using western blot analysis. The results suggested that the number of new vessels and the area of CNV were significantly decreased in groups 1 and 2, as compared with the alkali burn group at each time point (P<0.05). In addition, the number of inflammatory cells and the degree of edema were decreased in groups 1 and 2, as compared with the alkali burn group, with group 2 exhibiting the most marked reduction. Western blot analysis demonstrated that the expression levels of MMP-9, VEGF, VEGFR-1 and VEGFR-2 were significantly decreased in groups 1 and 2, as compared with the alkali burn control group, with group 2 exhibiting the most significant reduction (P<0.05). The results of the present study suggested that 90Sr-90Y β-irradiation and angiogenesis inhibitor treatments were able to inhibit alkali burn-induced CNV, although 90Sr-90Y β-irradiation may be more effective. PMID:26893623

  10. Prolongation of rat heart allografts by donor-specific blood transfusion treated with ultraviolet irradiation

    SciTech Connect

    Oluwole, S.F.; Iga, C.; Lau, H.; Hardy, M.A.

    1985-07-01

    The effect of donor-specific blood transfusion was compared to that of UVB-irradiated donor-specific blood transfusion on heart allograft survival in inbred rats with major histocompatibility differences. In one series ACI rats received heterotopic heart grafts from Lewis rats and 1 mL transfusion of donor-type blood at 1, 2, and 3 weeks prior to the transplantation. Fifty percent of the grafts were permanently accepted (survival greater than 200 days). Following UVB-irradiated donor-specific blood transfusion, 55% of the grafts survived indefinitely. In a mixed lymphocyte reaction ACI lymphocytes are weak responders to Lewis lymphocytes. In another series, Lewis rats received ACI hearts. Donor-specific transfusions at 1, 2, and 3 weeks prior to transplantation did not significantly alter the survival of heart allografts. Lewis lymphocytes react strongly to ACI stimulator cells in a mixed lymphocyte reaction. However, when the donor blood was UVB-irradiated prior to transfusion, the ACI allograft survival was significantly prolonged in this ACI-to-Lewis strain combination. When Lewis rats received W/F hearts following either donor-specific or UVB-irradiated donor-specific transfusions, the hearts' survival was similarly and significantly prolonged, but did not become permanent. Mixed lymphocyte reaction reveals that the stimulation index of Lewis lymphocytes against W/F lymphocytes is greater than that of ACI versus Lewis, but is less than that between Lewis responder cells against ACI stimulators.

  11. Allodynia-like effects in rat after ischaemic spinal cord injury photochemically induced by laser irradiation.

    PubMed

    Hao, J X; Xu, X J; Aldskogius, H; Seiger, A; Wiesenfeld-Hallin, Z

    1991-05-01

    We report behaviours suggesting the presence of allodynia elicited by non-noxious brushing and mechanical pressure following photochemically induced ischaemic spinal cord injury in the rat. Female rats were intravenously injected with Erythrosin B and the T10 vertebra was irradiated with a laser beam for 1, 5 or 10 min. These procedures initiated an intravascular photochemical reaction, resulting in ischaemic spinal cord injury. After irradiation a clear allodynia was observed in most rats. The animals vocalized intensely to light touch during gentle handling and were clearly agitated to light brushing of the flanks. The vocalization threshold in response to the mechanical pressure measured with von Frey hairs was markedly decreased during this period. In some animals the existence of spontaneous pain was suggested by spontaneous vocalization. The duration of the allodynia varied among animals from several hours to several days. The severity and duration of allodynia seemed not to be related to the duration of irradiation. In sham-operated rats a slight, transient allodynia was also noted around the wound within a few hours after surgery, which was effectively relieved by systemic morphine (2 mg/kg, i.p.). Morphine (2 mg/kg, i.p.) also partially relieved the allodynia in spinally injured rats 4 h after irradiation. However, morphine, even at a higher dose (5 mg/kg, i.p.), failed to alleviate the allodynia in spinally injured rats 24-48 h after the injury. Systemic injection of the GABAB agonist baclofen (0.01-0.1 mg/kg, i.p.), but not the GABAA agonist muscimol (1 mg/kg, i.p.), effectively relieved allodynia during this period. Pretreatment with guanethidine 24 h and just prior to the irradiation (20 mg/kg, s.c.) did not prevent the occurrence of allodynia in spinal cord injured rats. The present observation is the first to show that ischaemic spinal cord injury could result in cutaneous mechanical allodynia. This phenomenon is resistant to morphine and may not

  12. The effects of pre-emptive low-dose X-ray irradiation on MIA induced inflammatory pain in rats

    NASA Astrophysics Data System (ADS)

    Hahm, Suk-Chan; Lee, Go-Eun; Kim, Eun-Hye; Kim, Junesun; Lee, Taewoong; Lee, Wonho

    2013-07-01

    This study was performed to determine the effect of pre-emptive low-dose irradiation on the development of inflammatory pain and to characterize the potential mechanisms underlying this effect in osteoarthritis (OA) animal model. Whole-body X-irradiations with 0.1, 0.5, 1 Gy or sham irradiations were performed for 3 days before the induction of ostearthritis with monosodium iodoacetate (MIA) (40 µl, in saline) into the right knee joint in male Sprague Dawley rats. Behavioral tests for arthritic pain including evoked and non-evoked pain were conducted before and after MIA injection and inducible nitric-oxide synthase (iNOS) expression level was measured by western blot. Low-dose radiation significantly prevented the development of mechanical allodynia and thermal hyperalgesia and reduction in weight bearing that is regarded as a behavioral signs of non-evoked pain following MIA injection. Low-dose radiation significantly inhibited the increase in iNOS expression after MIA injection in spinal L3-5 segments in rat. These data suggest that low-dose X-irradiation is able to prevent the development of arthritic pain through modulation of iNOS expression in the spinal cord dorsal horn. Thus, low-dose radiotherapy could be substituted in part for treatment with drugs for patients with chronic inflammatory disease in clinical setting.

  13. Modeling precipitate evolution in zirconium alloys during irradiation

    NASA Astrophysics Data System (ADS)

    Robson, J. D.

    2016-08-01

    The second phase precipitates (SPPs) in zirconium alloys are critical in controlling their performance. During service, SPPs are subject to both thermal and irradiation effects that influence volume fraction, number, and size. In this paper, a model has been developed to capture the combined effect of thermal and irradiation exposure on the Zr(Fe,Cr)2 precipitates in Zircaloy. The model includes irradiation induced precipitate destabilization integrated into a classical size class model for nucleation, growth and coarsening. The model has been applied to predict the effect of temperature and irradiation on SPP evolution. Increasing irradiation displacement rate is predicted to strongly enhance the loss of particles that arises from coarsening alone. The effect of temperature is complex due to competition between coarsening and irradiation damage. As temperature increases, coarsening is predicted to become increasingly important compared to irradiation induced dissolution and may increase resistance to irradiation induced dissolution by increasing particle size.

  14. Increased EZH2 and decreased osteoblastogenesis during local irradiation-induced bone loss in rats.

    PubMed

    Guo, Changjun; Li, Changwei; Yang, Kai; Kang, Hui; Xu, Xiaoya; Xu, Xiangyang; Deng, Lianfu

    2016-01-01

    Radiation therapy is commonly used to treat cancer patients but exhibits adverse effects, including insufficiency fractures and bone loss. Epigenetic regulation plays an important role in osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Here, we reported local bone changes after single-dose exposure to (137)CS irradiation in rats. Femur bone mineral density (BMD) and trabecular bone volume in the tibia were significantly decreased at 12 weeks after irradiation. Micro-CT results showed that tBMD, Tb.h and Tb.N were also significantly reduced at 12 weeks after irradiation exposure. ALP-positive OB.S/BS was decreased by 42.3% at 2 weeks after irradiation and was decreased by 50.8% at 12 weeks after exposure. In contrast to the decreased expression of Runx2 and BMP2, we found EZH2 expression was significantly increased at 2 weeks after single-dose (137)CS irradiation in BMSCs. Together, our results demonstrated that single-dose (137)CS irradiation induces BMD loss and the deterioration of bone microarchitecture in the rat skeleton. Furthermore, EZH2 expression increased and osteoblastogenesis decreased after irradiation. The underlying mechanisms warrant further investigation. PMID:27499068

  15. Effects of low intensity laser irradiation during healing of infected skin lesions in the rat

    NASA Astrophysics Data System (ADS)

    Nussbaum, Ethne L.; Lilge, Lothar; Mazzulli, Tony; Pritzker, Kenneth P.

    2006-02-01

    Purpose: To determine the effect of low intensity laser therapy (LILT) on healing of infected skin wounds in the rat. Methods: Wounds on the dorsum of Sprague-Dawley rats (14 per group) were inoculated or sham-inoculated with P. aeruginosa. Wounds were irradiated or sham-irradiated three times weekly from Day 1-19 using 635nm or 808nm diode lasers at radiant exposure of 1 or 20 J/cm2 delivered in continuous wave (CW) or at an intensity modulation frequency of 3800Hz. Wound area and bacterial growth were evaluated three times weekly. Results: CW 808 nm (1 and 20 J/cm2) irradiation generally delayed healing in acute wounds. However, from Day 10 onwards CW 808 nm (1 J/cm2 and 20 J/cm2) and 808 nm 3800 Hz (1 J/cm2) irradiation improved healing in inoculated wounds. Healing in acute wounds improved using 635 nm irradiation at low radiant exposure (1 J/cm2); however, using 635 nm irradiation at high radiant exposure (20 J/cm2) delayed healing. Bacterial balance in wounds was significantly altered using 635 nm (20 J/cm2) and CW 808 nm irradiation (1 and 20 J/cm2). Conclusion: Clearing wounds of normal flora was not associated with improved healing. Proliferation of staphylococcal species in wounds was associated with delayed healing.

  16. Increased EZH2 and decreased osteoblastogenesis during local irradiation-induced bone loss in rats

    PubMed Central

    Guo, Changjun; Li, Changwei; Yang, Kai; Kang, Hui; Xu, Xiaoya; Xu, Xiangyang; Deng, Lianfu

    2016-01-01

    Radiation therapy is commonly used to treat cancer patients but exhibits adverse effects, including insufficiency fractures and bone loss. Epigenetic regulation plays an important role in osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Here, we reported local bone changes after single-dose exposure to 137CS irradiation in rats. Femur bone mineral density (BMD) and trabecular bone volume in the tibia were significantly decreased at 12 weeks after irradiation. Micro-CT results showed that tBMD, Tb.h and Tb.N were also significantly reduced at 12 weeks after irradiation exposure. ALP-positive OB.S/BS was decreased by 42.3% at 2 weeks after irradiation and was decreased by 50.8% at 12 weeks after exposure. In contrast to the decreased expression of Runx2 and BMP2, we found EZH2 expression was significantly increased at 2 weeks after single-dose 137CS irradiation in BMSCs. Together, our results demonstrated that single-dose 137CS irradiation induces BMD loss and the deterioration of bone microarchitecture in the rat skeleton. Furthermore, EZH2 expression increased and osteoblastogenesis decreased after irradiation. The underlying mechanisms warrant further investigation. PMID:27499068

  17. Irradiation effects on polymer-model compounds

    NASA Astrophysics Data System (ADS)

    Seguchi, Tadao; Katsumura, Yosuke; Hayashi, Nariyuki; Hayakawa, Naohiro; Tamura, Naoyuki; Tabata, Yoneho

    Irradiation effects on n-paraffins and squalane, used as models of polymers, were investigated by product analysis. Four n-paraffins, C 20H 42, C 21H 44, C 23H 48 and C 24H 50, and squalane (C 30H 62) were γ-irradiated under vacuum in liquid, crystalline and glassy states. The evolved gases were analyzed by gas chromatography and changes in molecular weight were analyzed by liquid chromatography and mass spectroscopy. G-values for crosslinking of n-paraffins were 1.2 for crystalline states (at 25°C) and 1.7 for liquid states (at 55°C), and showed no difference between odd and even carbon numbers. The G-value of liquid squalane was 1.7; it was 1.3 for the glassy state at low temperature (-77°C). Double bonds were common in the crosslinked products, especially after liquid-phase irradiation. The probability of chain scission was estimated as being negligible, though a small number of chain-scission products (which were products of scission at chain-ends or side chains) were observed by gas analysis.

  18. Focused Ultrasound Simultaneous Irradiation/MRI Imaging, and Two-Stage General Kinetic Model

    PubMed Central

    Huang, Sheng-Yao; Ko, Chia-En; Chen, Gin-Shin; Chung, I-Fang; Yang, Feng-Yi

    2014-01-01

    Many studies have investigated how to use focused ultrasound (FUS) to temporarily disrupt the blood-brain barrier (BBB) in order to facilitate the delivery of medication into lesion sites in the brain. In this study, through the setup of a real-time system, FUS irradiation and injections of ultrasound contrast agent (UCA) and Gadodiamide (Gd, an MRI contrast agent) can be conducted simultaneously during MRI scanning. By using this real-time system, we were able to investigate in detail how the general kinetic model (GKM) is used to estimate Gd penetration in the FUS irradiated area in a rat's brain resulting from UCA concentration changes after single FUS irradiation. Two-stage GKM was proposed to estimate the Gd penetration in the FUS irradiated area in a rat's brain under experimental conditions with repeated FUS irradiation combined with different UCA concentrations. The results showed that the focal increase in the transfer rate constant of Ktrans caused by BBB disruption was dependent on the doses of UCA. Moreover, the amount of in vivo penetration of Evans blue in the FUS irradiated area in a rat's brain under various FUS irradiation experimental conditions was assessed to show the positive correlation with the transfer rate constants. Compared to the GKM method, the Two-stage GKM is more suitable for estimating the transfer rate constants of the brain treated with repeated FUS irradiations. This study demonstrated that the entire process of BBB disrupted by FUS could be quantitatively monitored by real-time dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). PMID:24949997

  19. Mitochondrial activity assessed by cytofluorescence after in-vitro-irradiation of primary rat brain cultures

    SciTech Connect

    Cervos-Navarro, J.; Hamdorf, G. )

    1993-05-01

    Mitochondria play a key role in cell homeostasis and are the first cell organells affected by ionizing irradiation, as it was proved by previous electron microscopic investigations. In order to observe functional parameters of mitochondria after low-dose irradiation, primary rat brain cultures (prepared from 15-day-old rat fetuses) were irradiated from a [sup 60]Co-source with 0.5 and 1 Gy at the age of 2 or 7 days in vitro (div). Cytofluorescence measurement was made by a Cytofluor[sup [trademark]2350] using Rhodamine 123. This fluorescent dye is positively charged and accumulates specifically in the mitochondria of living cells without cytotoxic effect. Since its retention depends on the negative membrane potential as well as the proton gradient that exists across the inner mitochondrial membrane, Rhodamine 123 accumulation reflects the status of mitochondrial activity as a whole. After irradiation with 0.5 and 1 Gy on day 2 in culture there was a decrease in Rhodamine uptake in the irradiated cultures during the first week after the irradiation insult which reached minimum values after 3 days. Rhodamine uptake increased during the following period and finally reached the values of the control cultures. In the second experiment with irradiated cultures on day 7 and the same doses of 0.5 and 1 Gy the accumulation of Rhodamine decreased only initially then increased tremendously. After both doses values of Rhodamine-accumulation were higher than the control level. The results demonstrated that irradiation caused a change in mitochondrial activity depending on the time of irradiation. The dramatic increase over the control levels after irradiation on day 7 in vitro is attributed to the fact that at this time synapses have already developed. Deficiency of mitochondrial activity as well as hyperactivity and the consequent change in energy production may lead to changes in neuronal metabolism including an increase in production of free radicals.

  20. [Renal pathomorphology of rats fed irradiated food products over a long period].

    PubMed

    Levina, A I; Ivanov, A E

    1978-02-01

    Morphological changes were studied in the kidneys of albino rats and their progeny fed only with irradiated food for 20 months. Morphological signs of the autoimmune process in the form of the membraneous-proliferative glomerulonephritis in combination with characteristic disturbances of the blood vessels and extensive lymphoid-histiocyticeosinophilis infiltration of the stroma were revealed. PMID:630103

  1. The effects of Pycnogenol(®) on colon anastomotic healing in rats given preoperative irradiation.

    PubMed

    Değer, K Cumhur; Şeker, Ahmet; Özer, Ilter; Bostancı, E Birol; Dalgıç, Tahsin; Akmansu, Müge; Ekinci, Özgür; Erçin, Uğur; Bilgihan, Ayşe; Akoğlu, Musa

    2013-01-01

    Pycnogenol(®) has excellent radical scavenging properties and enhances the production of antioxidative enzymes which contributes to the anti-inflammatory effect of the extract. Irradiation delivered to the abdominal region, typically results in severe damage to the intestinal mucosa. The effects of ionizing radiation are mediated by the formation of free radicals through radiolysis. Irradiation has local effects on tissues. These local effects of irradiation on the bowel are believed to involve a two-stage process which includes both short and long term components. In our study we aimed to investigate the short term effects of Pycnogenol(®) on the healing of colon anastomoses in irradiated bowel. Sixty male Wistar-Albino rats were used in this study. There were three groups: Group I, control group (n = 20); group II which received preoperative irradiation (n = 20); group III which received per oral Pycnogenol(®) before irradiation (n = 20). Only segmeter colonic resection and anastomosis was performed to the control group (Group I). The other groups (Group II, III) underwent surgery on the 5th day after pelvic irradiation. On postoperative days 3 and 7, half of the rats in each group were sacrificed and then relaparotomy was performed. There was no statistical difference between groups with respect to biochemical parameters. Bursting pressure was significantly higher in the Control and Group III compared with the Group II. In conclusion, the present study showed that preoperative irradiation effect negatively on colonic anastomoses in rats by means of mechanical parameters and administration of Pycnogenol(®) preoperatively ameliorates this unfavorable effect. PMID:23791893

  2. Reversal of impaired wound healing in irradiated rats by platelet-derived growth factor-BB

    SciTech Connect

    Mustoe, T.A.; Purdy, J.; Gramates, P.; Deuel, T.F.; Thomason, A.; Pierce, G.F. )

    1989-10-01

    This study examined the potential influence of platelet-derived growth factor-BB homodimers (PDGF-BB) on surgical incisions in irradiated animals with depressed wound healing. Rats were irradiated with either 800 rads total body or 2,500 rads surface irradiation. Parallel dorsal skin incisions were made 2 days later, and PDGF-BB was applied topically a single time to one of two incisions. In total body-irradiated rats, bone marrow-derived elements were severely depressed, wound macrophages were virtually eliminated, and PDGF-BB treatment was ineffective. However, in surface-irradiated rats, PDGF-BB treatment recruited macrophages into wounds and partially reversed impaired healing on day 7 (p less than 0.005) and day 12 (p less than 0.001). PDGF-BB-treated wounds were 50 percent stronger than the paired control wounds. The results suggest PDGF requires bone marrow-derived cells, likely wound macrophages, for activity and that it may be useful as a topical agent in postirradiation surgical incisions.

  3. Kidney and lung injury in irradiated rats protected from acute death by partial-body shielding

    SciTech Connect

    Geraci, J.P.; Jackson, K.L.; Mariano, M.S.; Michieli, B.M. )

    1990-04-01

    Ninety-six CD-1 male rats were exposed to gamma-ray doses (0-25 Gy) in increments of 5 Gy. One femur, the surgically exteriorized GI tract, and the oral cavity were shielded during irradiation to protect against acute mortality from injury to the hematopoietic system, small intestine, and oral cavity. In addition, the thoraxes of half of the animals from each dose group were shielded. At approximately monthly intervals from 2 to 10 months after irradiation the hematocrit, plasma urea nitrogen (PUN), and {sup 51}Cr-EDTA clearance were measured. During the study 20 thorax-shielded and 19 thorax-irradiated animals died. All rats whose thoraxes received 25 Gy irradiation and three out of seven rats whose thoraxes received 20 Gy died 1 to 3 months postirradiation with massive pleural fluid accumulation. Shielding the thoraxes prevented this mode of death at these doses. Kidney injury was judged to be the primary cause of death of all thorax-shielded animals and 15- and 20-Gy thorax-irradiated animals. Animals with kidney damage had elevated PUN and reduced {sup 51}Cr-EDTA clearance and hematocrits. The relative merits of each of these end points in assessing radiation-induced kidney injury after total-body exposure are discussed.

  4. Dantrolene protects erythrocytes against oxidative stress during whole-body irradiation in rats.

    PubMed

    Emin Büyükokuroğlu, Mehmet; Taysi, Seyithan; Koç, Mehmet; Bakan, Nuri

    2003-06-01

    In our study, we examined the radioprotective effects of dantrolene against gamma irradiation-induced damage of blood cells after total body irradiation of rats. Rats were divided into three groups of eight rats each. The first group was the control group receiving no dantrolene or irradiation, the second group received total body irradiation (RT) with 5 Gy of gamma irradiation only, and the third group received dantrolene at a dose of 5 mg x kg(-1) plus RT. Dantrolene was given intraperitoneally 30 min before RT. All groups were sacrificed 2 h after RT, and blood samples were taken. Leukocyte, and thrombocyte counts and hemoglobin levels were measured. Furthermore, malondialdehyde (MDA) levels in plasma and erythrocytes and superoxide dismutase (SOD) and glutathione peroxidase activities (GSH-Px) in erythrocytes were determined. It was found that pretreatment with dantrolene at a dose of 5 mg x kg(-1) significantly reduced the MDA levels and increased the antioxidant SOD and GSH-Px activities, and prevented the decrease in leukocyte and thrombocyte counts. We conclude that dantrolene has clear antioxidant properties when given prior to radiation exposure and the protective effect of dantrolene against damage inflicted by radiation, depends, at least in part, on the decrease in lipid peroxidation and increase in the activity of antioxidant enzymes SOD and GSH-Px. PMID:12736901

  5. Re-assessment of chronic radio-induced tissue damage in a rat hindlimb model

    PubMed Central

    PHULPIN, BÉRENGÈRE; DOLIVET, GILLES; MARIE, PIERRE-YVES; POUSSIER, SYLVAIN; GALLET, PATRICE; LEROUX, AGNÈS; GRAFF, PIERRE; GROUBACH, FREDERIQUE; BRAVETTI, PIERRE; MERLIN, JEAN-LOUIS; TRAN, NGUYEN

    2010-01-01

    Radiotherapy is successfully used to treat neoplastic lesions, but may adversely affect normal tissues within the irradiated volume. However, additional clinical and para-clinical data are required for a comprehensive understanding of the pathogenesis of this damage. We assessed a rat model using clinical records and medical imaging to gain a better understanding of irradiation-induced tissue damage. The hindlimbs of the rats in this model were irradiated with a single dose of 30 or 50 Gy. Sequential analysis was based on observation records of stage and planar scintigraphy. Additional radiography, radiohistology and histology studies were performed to detect histological alterations. All animals developed acute and late effects, with an increased severity after a dose of 50 Gy. The bone uptake of 99mTc-HDP was significantly decreased in a dose- and time-dependent manner. Histologically, significant tissue damage was observed. After the 50 Gy irradiation, the animals developed lesions characteristic of osteoradionecrosis (ORN). Radiographic and histological studies provided evidence of lytic bone lesions. Our rat model developed tissue damage characteristic of radiation injury after a single 30 Gy irradiation and tissue degeneration similar to that which occurs during human ORN after a 50 Gy irradiation. The development of this animal model is an essential step in exploring the pathogenesis of irradiation-induced tissue damage, and may be used to test the efficacy of new treatments. PMID:22993575

  6. Glatiramer acetate reverses cognitive deficits from cranial-irradiated rat by inducing hippocampal neurogenesis.

    PubMed

    He, Fen; Zou, Jun-Tao; Zhou, Qiong-Fang; Niu, Dao-Li; Jia, Wei-Hua

    2014-06-15

    Patients received cranial-irradiation can be affected with cognitive deficits and decreasing hippocampal neurogenesis. In this work, we characterized the cognitive ability and immune-induced neurogenesis of the pre- and post-treated cranial-irradiated rats with Glatiramer acetate (GA), known as a weak CNS auto-antigen. The GA-treated rats displayed better cognitive abilities in Morris water maze (MWM). The numbers of Iba-I-positive microglia, BrdU(+)/DCX(+) cells and BrdU(+)/NeuN(+) cells in hippocampus increased, which are accompanied with increased IFN-γ and decreased IL-6, IL-4. Furthermore, GA reverted the Th1/Th2 balance. GA treatment can reverse the cognitive deficits caused by cranial irradiation through a mechanism that likely involves immunomodulation. PMID:24713401

  7. HZE ⁵⁶Fe-ion irradiation induces endothelial dysfunction in rat aorta: role of xanthine oxidase.

    PubMed

    Soucy, Kevin G; Lim, Hyun Kyo; Kim, Jae Hyung; Oh, Young; Attarzadeh, David O; Sevinc, Baris; Kuo, Maggie M; Shoukas, Artin A; Vazquez, Marcelo E; Berkowitz, Dan E

    2011-10-01

    Ionizing radiation has been implicated in the development of significant cardiovascular complications. Since radiation exposure is associated with space exploration, astronauts are potentially at increased risk of accelerated cardiovascular disease. This study investigated the effect of high atomic number, high-energy (HZE) iron-ion radiation on vascular and endothelial function as a model of space radiation. Rats were exposed to a single whole-body dose of iron-ion radiation at doses of 0, 0.5 or 1 Gy. In vivo aortic stiffness and ex vivo aortic tension responses were measured 6 and 8 months after exposure as indicators of chronic vascular injury. Rats exposed to 1 Gy iron ions demonstrated significantly increased aortic stiffness, as measured by pulse wave velocity. Aortic rings from irradiated rats exhibited impaired endothelial-dependent relaxation consistent with endothelial dysfunction. Acute xanthine oxidase (XO) inhibition or reactive oxygen species (ROS) scavenging restored endothelial-dependent responses to normal. In addition, XO activity was significantly elevated in rat aorta 4 months after whole-body irradiation. Furthermore, XO inhibition, initiated immediately after radiation exposure and continued until euthanasia, completely inhibited radiation-dependent XO activation. ROS production was elevated after 1 Gy irradiation while production of nitric oxide (NO) was significantly impaired. XO inhibition restored NO and ROS production. Finally, dietary XO inhibition preserved normal endothelial function and vascular stiffness after radiation exposure. These results demonstrate that radiation induced XO-dependent ROS production and nitroso-redox imbalance, leading to chronic vascular dysfunction. As a result, XO is a potential target for radioprotection. Enhancing the understanding of vascular radiation injury could lead to the development of effective methods to ameliorate radiation-induced vascular damage. PMID:21787183

  8. Effect of in vivo heart irradiation on the development of antioxidant defenses and cardiac functions in the rat

    SciTech Connect

    Benderitter, M.; Assem, M.; Maupoil, V.

    1995-10-01

    During radiotherapy of thoracic tumors, the heart is often included in the primary treatment volume, and chronic impairment of myocardial function occurs. The cellular biomolecules are altered directly by radiation or damaged indirectly by free radical production. The purpose of this investigation was to evaluate the biochemical and functional response of the rat heart to a single high dose of radiation. The effect of 20 Gy local X irradiation was determined in the heart of Wistar rats under general anesthesia. Mechanical performances were measured in vitro using an isolated perfused working heart model, and cardiac antioxidant defenses were also evaluated. Hearts were studied at 1 and 4 months after irradiation. This single dose of radiation induced a marked drop in the mechanical activity of the rat heart: aortic output was significantly reduced (18% less than control values) at 1 month postirradiation and remained depressed for the rest of the experimental period (21% less than control 4 months after treatment). This suggests the development of myocardial failure after irradiation. The decline of functional parameters was associated with changes in antioxidant defenses. The decrease in cardiac levels of vitamin E (-30%) was associated with an increase in the levels of Mn-SOD and glustathione peroxidase (+45.5% and +32%, respectively, at 4 months postirradiation). However, cardiac vitamin C and catalase levels remained constant. Since these antioxidant defenses were activated relatively long after irradiation, it is suggested that this was probable due to the production of free radical species associated with the development of inflammation. 49 refs., 8 figs., 1 tab.

  9. Effects of Irradiation on Brain Vasculature Using an In Situ Tumor Model

    SciTech Connect

    Zawaski, Janice A.; Gaber, M. Waleed; Sabek, Omaima M.; Wilson, Christy M.; Duntsch, Christopher D.; Merchant, Thomas E.

    2012-03-01

    Purpose: Damage to normal tissue is a limiting factor in clinical radiotherapy (RT). We tested the hypothesis that the presence of tumor alters the response of normal tissues to irradiation using a rat in situ brain tumor model. Methods and Materials: Intravital microscopy was used with a rat cranial window to assess the in situ effect of rat C6 glioma on peritumoral tissue with and without RT. The RT regimen included 40 Gy at 8 Gy/day starting Day 5 after tumor implant. Endpoints included blood-brain barrier permeability, clearance index, leukocyte-endothelial interactions and staining for vascular endothelial growth factor (VEGF) glial fibrillary acidic protein, and apoptosis. To characterize the system response to RT, animal survival and tumor surface area and volume were measured. Sham experiments were performed on similar animals implanted with basement membrane matrix absent of tumor cells. Results: The presence of tumor alone increases permeability but has little effect on leukocyte-endothelial interactions and astrogliosis. Radiation alone increases tissue permeability, leukocyte-endothelial interactions, and astrogliosis. The highest levels of permeability and cell adhesion were seen in the model that combined tumor and irradiation; however, the presence of tumor appeared to reduce the volume of rolling leukocytes. Unirradiated tumor and peritumoral tissue had poor clearance. Irradiated tumor and peritumoral tissue had a similar clearance index to irradiated and unirradiated sham-implanted animals. Radiation reduces the presence of VEGF in peritumoral normal tissues but did not affect the amount of apoptosis in the normal tissue. Apoptosis was identified in the tumor tissue with and without radiation. Conclusions: We developed a novel approach to demonstrate that the presence of the tumor in a rat intracranial model alters the response of normal tissues to irradiation.

  10. Effects of laser irradiation on immature olfactory neuroepithelial explants from the rat

    SciTech Connect

    Mester, A.F.; Snow, J.B. Jr.

    1988-07-01

    The photobiological effect of low-output laser irradiation on the maturation and regeneration of immature olfactory bipolar receptor cells of the rat was studied. The maturation and regeneration of the receptor cells of rat fetuses were quantified in neuroepithelial explants with morphometric analysis. The number of explants with outgrowth and the number and length of neuritic outgrowths were determined on a regular basis for 12 days. Explants in the experimental group were irradiated with a helium-neon laser using different incident energy densities (IED). Explants in the fluorescent light control group were exposed to fluorescent light for the same periods of time as those in the experimental group were exposed to laser irradiation. Explants in another control group were not exposed to laser or fluorescent light irradiation. The IED of 0.5 J/cm2 laser irradiation has been found to increase significantly the number of explants with outgrowth and the number and length of the outgrowths. Other laser IEDs or fluorescent light irradiation did not influence maturation or regeneration.

  11. A magnetic resonance imaging study on changes in rat mandibular bone marrow and pulp tissue after high-dose irradiation

    PubMed Central

    Lee, Wan; Lee, Byung-Do; Lee, Kang-Kyoo

    2014-01-01

    Purpose This study was designed to evaluate whether magnetic resonance imaging (MRI) is appropriate for detecting early changes in the mandibular bone marrow and pulp tissue of rats after high-dose irradiation. Materials and Methods The right mandibles of Sprague-Dawley rats were irradiated with 10 Gy (Group 1, n=5) and 20 Gy (Group 2, n=5). Five non-irradiated animals were used as controls. The MR images of rat mandibles were obtained before irradiation and once a week until week 4 after irradiation. From the MR images, the signal intensity (SI) of the mandibular bone marrow and pulp tissue of the incisor was interpreted. The MR images were compared with the histopathologic findings. Results The SI of the mandibular bone marrow had decreased on T2-weighted MR images. There was little difference between Groups 1 and 2. The SI of the irradiated groups appeared to be lower than that of the control group. The histopathologic findings showed that the trabecular bone in the irradiated group had increased. The SI of the irradiated pulp tissue had decreased on T2-weighted MR images. However, the SI of the MR images in Group 2 was high in the atrophic pulp of the incisor apex at week 2 after irradiation. Conclusion These patterns seen on MRI in rat bone marrow and pulp tissue were consistent with histopathologic findings. They may be useful to assess radiogenic sclerotic changes in rat mandibular bone marrow. PMID:24701458

  12. Effects of 0. 6-Gy prenatal X irradiation on postnatal neurophysiologic development in the Wistar rat

    SciTech Connect

    Jensh, R.P.; Brent, R.L.

    1986-04-01

    Forty-one pregnant Wistar strain rats were irradiated with 0.6-Gy X rays or were sham irradiated on the 9th or 17th days of gestation to determine if this dosage level would result in alterations in postnatal neurophysiologic development. Half of the mothers were sacrificed at term, and the developmental status of 221 newborns was evaluated. The remaining mothers delivered and raised their litters. The 161 offspring were observed for the age of attainment of the following physiologic parameters: pinna detachment, eye opening, testes opening. Offspring were also tested for the acquisition of the following selected reflexes: surface righting, negative geotaxis, auditory startle, air righting, and visual placing. Term fetal weight was lower than the controls in the group irradiated on the 9th day but was recuperable postnatally. None of the 9 developmental tests performed postnatally were abnormal in the animals irradiated on the 9th day. Thus, at least with regard to these measures, the surviving embryos exposed during the all-or-none period could not be differentiated from the controls. Offspring irradiated on the 17th day exhibited retarded growth which persisted during neonatal life. The three-day-mean neonatal weight was significantly lower in the group irradiated on the 17th day compared to controls. There were no significant maternal body weight or organ/weight differences between the groups. Rats exposed in utero on the 17th day had a significantly delayed acquisition of air righting. These results demonstrate that 0.6-Gy in utero irradiation on the 17th day of gestation can cause subtle alterations in growth and development of the Wistar strain rat during postnatal life.

  13. Shielding effect of mineral schungite during electromagnetic irradiation of rats.

    PubMed

    Kurotchenko, S P; Subbotina, T I; Tuktamyshev, I I; Tuktamyshev, I Sh; Khadartsev, A A; Yashin, A A

    2003-11-01

    We studied the effect of nonthermal 37-GHz radiation on hemopoiesis in schungite-shielded Wistar rats. Radiation with right-handed or left-handed rotation of the polarization plane of electromagnetic wave was used. Shielding with schungite decreased the severity of damage produced by high-frequency electromagnetic radiation. PMID:14968159

  14. Transplantation of mesenchymal stem cells, recombinant human BMP-2,and their combination in accelerating the union after osteotomy and increasing, the mechanical strength of extracorporeally irradiated femoral autograft in rat models

    PubMed Central

    Fauzi Kamal, Achmad; Hadisoebroto Dilogo, Ismail; Untung Hutagalung, Errol; Iskandriati, Diah; Susworo, R.; Chaerani Siregar, Nurjati; Aulia Yusuf, Achmad; Bachtiar, Adang

    2014-01-01

    Background: Delayed union, nonunion, and mechanical failure is still problems encountered in limb salvage surgery (LSS) using extracorporeal irradiation (ECI). This study aimed to determine whether bone marrow mesenchymal stem cells (MSC) and recombinant human bone morphogenetic protein-2 (rhBMP-2) improve hostgraft union after osteotomy and also increase its mechanical strength. Methods: Thirty Sprague Dawley rats were randomly divided into five groups. Group I (control) underwent LSS using ECI method with 150 Gy single doses. Similar procedures were applied to other groups. Group II received hydroxyapatite (HA) scaffold. Group III received HA scaffold and MSC. Group IV received HA scaffold and rhBMP-2. Group V received HA scaffolds, MSC, and rhBMP-2. Radiograph were taken at week-2, 4, 6, and 8; serum alkaline phosphatase and osteocalcin were measured at week-2 and 4. Histopathological evaluation and biomechanical study was done at week-8. Results: The highest radiological score was found in group IV and V Similar result was obtained in histological score and ultimate bending force. These results were found to be statistically significant. There was no significant difference among groups in serum alkaline phosphatase and osteocalcin level. Conclusion: Combination of MSC and rhBMP-2 was proven to accelerate union and improve mechanical strength of ECI autograft. PMID:25679008

  15. Total-Body Irradiation Produces Late Degenerative Joint Damage in Rats

    PubMed Central

    Hutchinson, Ian D.; Olson, John; Lindburg, Carl A.; Payne, Valerie; Collins, Boyce; Smith, Thomas L.; Munley, Michael T.; Wheeler, Kenneth T.; Willey, Jeffrey S.

    2014-01-01

    Purpose Premature musculoskeletal joint failure is a major source of morbidity among childhood cancer survivors. Radiation effects on synovial joint tissues of the skeleton are poorly understood. Our goal was to assess long-term changes in the knee joint from skeletally mature rats that received total-body irradiation while skeletal growth was ongoing. Materials and Methods 14 week-old rats were irradiated with 1, 3 or 7 Gy total-body doses of 18 MV x-rays. At 53 weeks of age, structural and compositional changes in knee joint tissues (articular cartilage, subchondral bone, and trabecular bone) were characterized using 7T MRI, nanocomputed tomography (nanoCT), microcomputed tomography (microCT), and histology. Results T2 relaxation times of the articular cartilage were lower after exposure to all doses. Likewise, calcifications were observed in the articular cartilage. Trabecular bone microarchitecture was compromised in the tibial metaphysis at 7 Gy. Mild to moderate cartilage erosion was scored in the 3 and 7 Gy rats. Conclusions Late degenerative changes in articular cartilage and bone were observed after total body irradiation in adult rats exposed prior to skeletal maturity. 7T MRI, microCT, nanoCT, and histology identified potential prognostic indicators of late radiation-induced joint damage. PMID:24885745

  16. PBPK MODELING OF DELTAMETHRIN IN RATS

    EPA Science Inventory

    The pyrethroid pesticide deltamethrin is cleared nearly twice as rapidly in human liver microsomes compared to rat liver microsomes. A species difference such as this could influence the toxic potency of deltamethrin between rats and humans. PBPK modeling is a tool that can be ut...

  17. Modelling rotational and cyclical spectral solar irradiance variations

    NASA Astrophysics Data System (ADS)

    Unruh, Yvonne

    Solar irradiance changes are highly wavelength dependent: solar-cycle variations in the UV can be on the order of tens of percent, while changes in the visible are typically only of the order of one or two permille. With the launch of a number of instruments to measure spectral solar irradiance, we are now for a first time in a good position to explore the changing solar irradiance over a large range of wavelengths and to test our irradiance models as well as some of their underlying assumptions. I will introduce some of the current modelling approaches and present model-data comparisons, using the SATIRE irradiance model and SORCE/SIM measurements as an example. I will conclude by highlighting a number of outstanding questions regarding the modelling of spectral irradiance and current approaches to address these.

  18. Gravitational Biology: The Rat Model

    NASA Technical Reports Server (NTRS)

    1997-01-01

    In this session, Session JP3, the discussion focuses on the following topics: Morphology of brain, pituitary and thyroid in the rats exposed to altered gravity; Biochemical Properties of B Adrenoceptors After Spaceflight (LMS-STS78) or Hindlimb Suspension in Rats; Influence of Hypergravity on the Development of Monoaminergic Systems in the Rat Spinal Cord; A Vestibular Evoked Potentials (VsEPs) Study of the Function of the Otolith Organs in Different Head Orientations with respect to Earth Gravity Vector in the Rat; Quantitative Observations on the Structure of Selected Proprioceptive Components in Adult Rats that Underwent About Half of their Fetal Development in Space; Effects of a Nine-Day Shuttle Mission on the Development of the Neonatal Rat Nervous System, A Behavioral Study; Muscle Atrophy Associated to Microgravity in Rat, Basic Data For Countermeasures; Simulated Weightlessness by Unloading in the Rat, Results of a Time Course Study of Biochemical Events Occurring During Unloading and Lack of Effect of a rhBNP-2 Treatment on Bone Formation and Bone Mineral Content in Unloading Rats; and Cytological Mechanism of the Osteogenesis Under Microgravity Conditions.

  19. U. v. -enhanced reactivation of u. v. -irradiated herpes virus by primary cultures of rat hepatocytes

    SciTech Connect

    Zurlo, J.; Yager, J.D. )

    1984-04-01

    Carcinogen treatment of cultured mammalian cells prior to infection with u.v.-irradiated virus results in enhanced virus survival and mutagenesis suggesting the induction of SOS-type processes. The development of a primary rat hepatocyte culture system is reported to investigate cellular responses to DNA damage which may be relevant to hepatocarcinogenesis in vivo. Enhanced reactivation of u.v.-irradiated Herpes simplex virus type 1 (HSV-1) occurred in hepatocytes irradiated with u.v. Cultured hepatocytes were pretreated with u.v. at the time of enhanced DNA synthesis. These treatments caused an inhibition followed by a recovery of DNA synthesis. At various times after pretreatment, the hepatocytes were infected with control or u.v.-irradiated HSV-1 at low multiplicity, and virus survival was measured. U.v.-irradiated HSV-1 exhibited the expected two-component survival curve in control or u.v. pretreated hepatocytes. The magnitude of enhanced reactivation of HSV-1 was dependent on the u.v. dose to the hepatocytes, the time of infection following u.v. pretreatment, and the level of DNA synthesis at the time of pretreatment. These results suggest that u.v. treatment of rat hepatocytes causes the induction of SOS-type functions tht may have a role in the initiation of hepatocarcinogenesis.

  20. Comparative Modeling Analysis of the Hematopoiesis Dynamics in Mammals Exposed to Nonuniform and Uniform Acute Irradiation.

    PubMed

    Smirnova, Olga A

    2015-09-01

    Biologically motivated mathematical models of the dynamics of the major hematopoietic lineages (the thrombopoietic, erythropoietic, granulopoietic, and lymphopoietic systems) in mammals (rodents) exposed to nonuniform acute irradiation are developed and thoroughly investigated. These models are based on earlier developed mathematical models, which are capable of predicting the dynamics of these systems in mammals (rodents) exposed to uniform acute/chronic irradiation. The developed models are the systems of nonlinear ordinary differential equations whose variables and constant parameters have clear biological meaning. It is found that these models are capable of reproducing a lesser depletion of the major hematopoietic lineages and faster recovery in rodents (rats, mice) after nonuniform acute irradiation than those after uniform acute irradiation at equal whole-body doses of such exposures. The nature of this phenomenon is elucidated in the framework of the models. Thorough comparative analysis of effects of nonuniform (partial) and uniform acute irradiation on the major hematopoietic lineages is performed. It is revealed that the lymphopoietic system is the most susceptible major hematopoietic lineage both to uniform and nonuniform (partial) acute irradiation. It is argued that the first-day level of the concentration of functional blood cells in this system (blood lymphocytes) after nonuniform (partial) acute irradiation can serve for early assessment of the risk of acute radiation syndrome. It is also shown that the modeling results on the first-day levels of the blood lymphocyte concentration after various partial acute exposures are in a very good agreement with the relevant experimental data. This agreement testifies to the applicability of the developed model of the lymphopoietic system to be used in the prognostic aims; in particular, for predicting the development of lymphocytopenia after partial acute irradiation. The modeling results imply that the

  1. State of the antioxidative enzymes of rat bone marrow cells after irradiation, fractures, and a combination of both

    SciTech Connect

    Bogdanova, I.A.; Ovchinnikov, K.G.; Torbenko, V.P.; Gerasimov, A.M.

    1987-11-01

    The authors study bone marrow levels of antioxidative (antiradical) defensive systems (ADS) enzymes, namely superoxide dismutase (SOD), glutathione peroxidase (GP), glutathione reductase (GR), and glutathione: dehydroascorbate oxidoreductase (GDAR), rats and changes in their activity in the bone marrow at various times after irradiation, mechanical trauma, and a combination of both. Development of acute radiation sickness as a result of a single irradiation was accompanied by marked changes in the enzymic antioxidative system of rat bone marrow cells.

  2. A new mouse model of impaired wound healing after irradiation.

    PubMed

    Tsumano, Tomoko; Kawai, Kenichiro; Ishise, Hisako; Nishimoto, Soh; Fukuda, Kenji; Fujiwara, Toshihiro; Kakibuchi, Masao

    2013-04-01

    Radiation has many benefits and is an important treatment for cancer therapy. However, it also has unfavourable side-effects. Among these side-effects, the impairment of wound healing in the skin is a major problem in clinics. Although many attempts have been made to overcome this shortcoming, there are few effective treatments for impaired wound healing after irradiation. One reason for this is that it is hard to obtain good animal models for researching this topic. In this study, two different models were created and investigated. In one model, rectangular flaps were created on the backs of mice and irradiated while the other parts of their bodies were covered with a lead board. In another model, the lower limbs were exposed to radiation. In each model, several doses of irradiation were tested. Skin ulcers were created in the irradiated area, and the wound healing process was observed. In order to verify the usefulness of the model, adipose derived stromal cells were injected into the wound and the healing rate was calculated. In the flap model, the flaps contracted and formed linear scars. On the other hand, in the thigh model, 15 Gy irradiation resulted in slow wound healing but no strong inflammation or necrosis. The transplantation of adipose tissue derived stromal cells into the irradiated thigh wound improved the wound healing. This study suggested that irradiation of the lower limb at ∼ 15 Gy might be an appropriate model for basic research into wound healing in irradiated skin. PMID:23406401

  3. A reconstruction of solar irradiance using a flux transport model

    NASA Astrophysics Data System (ADS)

    Dasi Espuig, Maria; Jiang, Jie; Krivova, Natalie; Solanki, Sami

    2013-04-01

    Reconstructions of solar irradiance into the past are of considerable interest for studies of solar influence on climate. Models based on the assumption that irradiance changes are caused by the evolution of the photospheric magnetic field have been the most successful in reproducing the measured irradiance variations. Our SATIRE-S model is one of these. It uses solar full-disc magnetograms as an input, and these are available for less than four decades. Thus, to reconstruct the irradiance back to times when no observed magnetograms are available, we combine the SATIRE-S model with synthetic magnetograms, produced using a surface flux transport model. The model is fed with daily, observed or modelled statistically, records of sunspot positions, areas, and tilt angles. To describe the secular change in the irradiance, we used the concept of overlapping ephemeral region cycles. With this technique TSI can be reconstructed back to 1610.

  4. A reconstruction of solar irradiance using a flux transport model

    NASA Astrophysics Data System (ADS)

    Dasi Espuig, Maria; Krivova, Natalie; Solanki, Sami K.; Jiang, Jie

    2012-07-01

    Solar irradiance is one of the important drivers of the Earth's global climate, but it has only been measured for the past 33 years. Its reconstructions are therefore crucial to study longer term variations relevant to climate timescales. Most successful in reproducing the measured irradiance variations have being the models that are based on the assumption that irradiance changes are caused by the evolution of the photospheric magnetic field. Our SATIRE-S model is one of these, which uses solar full-disc magnetograms as an input, and these are available for less than four decades. To reconstruct the irradiance back to times when no observed magnetograms are available, we combine the SATIRE-S model with synthetic magnetograms, produced using a surface flux transport model. The model is fed with daily, observed or modelled statistically, records of sunspot positions, areas, and tilt angles. The concept of overlapping ephemeral region cycles is used to describe the secular change in the irradiance.

  5. Increased activity of tyrosine hydroxylase in the cerebellum of the x-irradiated dystonic rat

    SciTech Connect

    Dopico, A.M.; Rios, H.; Mayo, J.; Zieher, L.M. )

    1990-08-01

    The exposure of the cephalic end of rats to repeated doses of x-irradiation (150 rad) immediately after birth induces a long-term increase in the noradrenaline (NA) content of cerebellum (CE) (+ 37.8%), and a decrease in cerebellar weight (65.2% of controls), which results in an increased NA concentration (+ 109%). This increase in the neurotransmitter level is accompanied by a dystonic syndrome and histological abnormalities: Purkinje cells (the target cells for NA afferents to CE) fail to arrange in a characteristic monolayer, and their primary dendritic tree appears randomly oriented. The injection of reserpine 0.9 and 1.2 mg/kg ip to adult rats for 18 h depletes cerebellar NA content in both controls (15.7 {plus minus} 4 ng/CE and 2.8 {plus minus} 1.5 ng/CE, respectively) and x-irradiated rats (17.1 {plus minus} 1 ng/CE and 8.3 {plus minus} 2 ng/CE, respectively). The activity of tyrosine hydroxylase (TH) in CE of adult rats, measured by an in vitro assay, is significantly increased in neonatally x-irradiated animals when compared to age-matched controls (16.4 {plus minus} 1.4 vs 6.32 {plus minus} 0.6 nmol CO2/h/mg prot., p less than 0.01). As observed for NA levels, a net increase in TH activity induced by the ionizing radiation is also measured: 308.9 {plus minus} 23.8 vs 408.2 {plus minus} 21.5 nmol CO2/h/CE, p less than 0.01 (controls and x-treated, respectively). These results suggest that x-irradiation at birth may induce an abnormal sprouting of noradrenergic afferents to CE. The possibility that these changes represent a response of the NA system to the dystonic syndrome is discussed.

  6. Photometric quantities for solar irradiance modeling

    NASA Astrophysics Data System (ADS)

    Preminger, D. G.; Walton, S. R.; Chapman, G. A.

    2002-11-01

    We analyze photometric quantities for the modeling of the total solar irradiance, S. These quantities are derived from full-disk solar images taken at the San Fernando Observatory. We introduce a new quantity, the photometric sum, Σ, which is the sum over an entire image of each pixel's contribution to the irradiance in that image. Σ combines both bright and dark features; and because the sum is over the entire image, it will include low contrast features that cannot be identified directly. Specifically, we examine Σr, Σb, and ΣK, the photometric sums over broadband red, broadband blue, and 1-nm bandpass Ca II K images, respectively. Σr and Σb measure the effects of solar features on the variability in S at two different continuum wavelengths. ΣK measures the variability in spectral lines due to solar features. We find that Σr and Σb have no long-term trend. ΣK, however, varies in phase with the solar cycle. We carry out several multiple linear regressions on the value of S from cycle 22; the best fit uses Σr and ΣK and reproduces the observed composite S with a multiple regression coefficient R = 0.96. We conclude that the long-term change in S over the solar cycle can be accounted for by the variability in the spectral lines as measured by ΣK, assuming no change in the quiet Sun; the contribution of the continuum to the variations in S is only on active region timescales.

  7. Gamma Knife irradiation method based on dosimetric controls to target small areas in rat brains

    SciTech Connect

    Constanzo, Julie; Paquette, Benoit; Charest, Gabriel; Masson-Côté, Laurence; Guillot, Mathieu

    2015-05-15

    Purpose: Targeted and whole-brain irradiation in humans can result in significant side effects causing decreased patient quality of life. To adequately investigate structural and functional alterations after stereotactic radiosurgery, preclinical studies are needed. The purpose of this work is to establish a robust standardized method of targeted irradiation on small regions of the rat brain. Methods: Euthanized male Fischer rats were imaged in a stereotactic bed, by computed tomography (CT), to estimate positioning variations relative to the bregma skull reference point. Using a rat brain atlas and the stereotactic bregma coordinates obtained from CT images, different regions of the brain were delimited and a treatment plan was generated. A single isocenter treatment plan delivering ≥100 Gy in 100% of the target volume was produced by Leksell GammaPlan using the 4 mm diameter collimator of sectors 4, 5, 7, and 8 of the Gamma Knife unit. Impact of positioning deviations of the rat brain on dose deposition was simulated by GammaPlan and validated with dosimetric measurements. Results: The authors’ results showed that 90% of the target volume received 100 ± 8 Gy and the maximum of deposited dose was 125 ± 0.7 Gy, which corresponds to an excellent relative standard deviation of 0.6%. This dose deposition calculated with GammaPlan was validated with dosimetric films resulting in a dose-profile agreement within 5%, both in X- and Z-axes. Conclusions: The authors’ results demonstrate the feasibility of standardizing the irradiation procedure of a small volume in the rat brain using a Gamma Knife.

  8. Phototherapeutic Effect of Low-Level Laser on Thyroid Gland of Gamma-Irradiated Rats.

    PubMed

    Morcos, Nadia; Omran, Manar; Ghanem, Hala; Elahdal, Mahmoud; Kamel, Nashwa; Attia, Elbatoul

    2015-01-01

    One inescapable feature of life on the earth is exposure to ionizing radiation. The thyroid gland is one of the most sensitive organs to gamma-radiation and endocrine disrupters. Low-level laser therapy (LLLT) has been used to stimulate tissue repair, and reduce inflammation. The aim of this study was to gauge the value of using Helium-Neon laser to repair the damaged tissues of thyroid gland after gamma-irradiation. Albino rats were used in this study (144 rats), divided into control, gamma, laser, and gamma plus laser-irradiated groups, each group was divided into six subgroups according to time of treatment (total six sessions). Rats were irradiated once with gamma radiation (6 Gy), and an external dose of laser (Wavelength 632.8 nm, 12 mW, CW, Illuminated area 5.73 cm(2), 2.1 mW cm(-2) 120 s, 1.4 J, 0.252 J cm(-2)) twice weekly localized on thyroid region of the neck, for a total of six sessions. Animals were sacrificed after each session. Analysis included thyroid function, oxidative stress markers, liver function and blood picture. Results revealed improvement in thyroid function, liver function and antioxidant levels, and the blood cells count after LLLT. PMID:25975382

  9. EFFECTS OF HEAVY PARTICLES IRRADIATION AND DIET ON AMPHETAMINE- AND LITHIUM CHLORIDE-INDUCED TASTE AVOIDANCE LEARNING IN RATS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rats were maintained on diets containing either 2% blueberry or strawberry extract or a control diet for 8 weeks prior to being exposed to 1.5 Gy of 56Fe particles in the Alternating Gradient Synchrotron at Brookhaven National Laboratory. Three days following irradiation, the rats were tested for t...

  10. Variation in cyclic nucleotide levels and lysosomal enzyme activities in the irradiated rat

    SciTech Connect

    Trocha, P.J.; Catravas, G.N.

    1980-09-01

    Whole-body irradiation of rats causes not only a release of hydrolases from the lysosomes but also fluctuations in the cyclic nucleotide levels in spleen and liver tissues. Significant increases in lysosomal enzyme activities were further observed in spleen following radiation treatment. At 3 to 6 hr after rats were exposed to ..gamma.. radiation, transient increases in both cGMP and cAMP levels were accompanied with the release of ..beta..-glucuronidase and acid phosphatase enzymes from lysosomes in liver and spleen tissues. A second transitory release and activation of lysosomal hydrolases and an increase in cAMP levels occurred between 2 and 5 days after irradiation in spleen but not in liver. On Days 7 and 8, there was a third release of lysosomal hydrolases and a slight increase in the spleen cAMP concentration before they returned to near-control values. Cyclic GMP levels in the spleen decreased on the third day after irradiation, remained suppressed until Day 9, and then increased to levels higher than normal physiological values. The liver cGMP concentration remained unchanged between 9 hr and 11 days after irradiation.

  11. Orally Active Multi-Functional Antioxidants Delay Cataract Formation in Streptozotocin (Type 1) Diabetic and Gamma-Irradiated Rats

    PubMed Central

    Randazzo, James; Zhang, Peng; Makita, Jun; Blessing, Karen; Kador, Peter F.

    2011-01-01

    Background Age-related cataract is a worldwide health care problem whose progression has been linked to oxidative stress and the accumulation of redox-active metals. Since there is no specific animal model for human age-related cataract, multiple animal models must be used to evaluate potential therapies that may delay and/or prevent cataract formation. Methods/Principal Findings Proof of concept studies were conducted to evaluate 4-(5-hydroxypyrimidin-2-yl)-N,N-dimethyl-3,5-dioxopiperazine-1-sulfonamide (compound 4) and 4-(5-hydroxy-4,6-dimethoxypyrimidin-2-yl)-N,N-dimethyl-3,5-dioxopiperazine-1-sulfonamide (compound 8), multi-functional antioxidants that can independently chelate redox metals and quench free radicals, on their ability to delay the progression of diabetic “sugar” cataracts and gamma radiation-induced cataracts. Prior to 15 Gy of whole head irradiation, select groups of Long Evans rats received either diet containing compound 4 or 8, or a single i.p. injection of panthethine, a radioprotective agent. Compared to untreated, irradiated rats, treatment with pantethine, 4 and 8 delayed initial lens changes by 4, 47, and 38 days, respectively, and the average formation of posterior subcapsular opacities by 23, 53 and 58 days, respectively. In the second study, select groups of diabetic Sprague Dawley rats were administered chow containing compounds 4, 8 or the aldose reductase inhibitor AL1576. As anticipated, treatment with AL1576 prevented cataract by inhibiting sorbitol formation in the lens. However, compared to untreated rats, compounds 4 and 8 delayed vacuole formation by 20 days and 12 days, respectively, and cortical cataract formation by 8 and 3 days, respectively, without reducing lenticular sorbitol. Using in vitro lens culture in 30 mM xylose to model diabetic “sugar” cataract formation, western blots confirmed that multi-functional antioxidants reduced endoplasmic reticulum stress. Conclusions/Significance Multi

  12. Monitoring the process of tissue healing of rat skin in vivo after laser irradiation based on optical coherence tomography

    NASA Astrophysics Data System (ADS)

    He, Youwu; Wu, Shulian; Li, Zhifang; Cai, Shoudong; Li, Hui

    2010-11-01

    It is imperative to evaluate the tissue wound healing response after laser irradiation so as to develop effective devices for this clinical indication, and evaluate the thermal damage degree to take appropriate treatment. In our research, we prepare 6 white rat (approximately 2 months old, weight :28+/-2g). Each rat was injected intraperitoneally a single dose of 2% pentobarbital sodium. After the rat was anesthetized, the two side of the rats' back were denuded and antisepsised a standardized. An Er:YAG laser (2940nm, 2.5J/cm2, single spot, 4 times) was irradiated on rat skin in vivo, and the skin which before irradiated and the process of renovating scathe that irradiated after Er:YAG laser were observed by an Optical coherence tomography (OCT). The tissue recovery is about a twelve -day period. The results indicate that the scattering coefficient of post- tissue has changed distinctly. The and flexibility fiber is the chief component of rat dermis and the collagen is the main scattering material. The normal tissue has a large scattering coefficient, after laser irradiated, the collagen became concreting and putrescence and caused the structure change. It became more uniform density distribution, which results in a reduced scattering coefficient. In a word, OCT can noninvasively monitor changes in collagen structure and the recover process in thermal damage through monitor the tissue scattering coefficient.

  13. Effects of High-Protein Diet and/or Resveratrol Supplementation on the Immune Response of Irradiated Rats

    PubMed Central

    Kim, Kyoung Ok; Park, Hyunjin; Kim, Hyun-Sook

    2014-01-01

    We investigated the effects of a high-protein diet and resveratrol supplementation on immune cells changes induced by abdominal irradiation in rats. Female Wistar rats were divided into 5 groups: 1) control diet, 2) control diet with irradiation 3) 30% high-protein diet with irradiation, 4) normal diet with resveratrol supplementation and irradiation, and 5) 30% high-protein diet with resveratrol supplementation and irradiation. We measured blood protein and albumin concentrations, lipid profiles, white blood cell (WBC) counts, proinflammatory cytokine production, and splenocyte proliferation in rats that had been treated with a 17.5 Gy dose of radiation 30 days prior. A high-protein diet affected plasma total cholesterol and very low density lipoprotein-cholesterol levels, which were increased by the radiation treatment. In addition, the lymphocyte percentage and immunoglobulin M (IgM) concentration were increased, and the neutrophil percentage was decreased in rats fed a high-protein diet. Resveratrol supplementation decreased the triglyceride (TG) level, but increased the IgM concentration and splenocyte proliferation. Proinflammatory cytokine production was lower in rats fed a high-protein diet supplemented with resveratrol than in rats fed a control diet. The results of the present study indicate that high-protein diets, with or without resveratrol supplementation, might assist with recovery from radiation-induced inflammation by modulating immune cell percentages and cytokine production. PMID:25320712

  14. Imaging radiation pneumonitis in a rat model of a radiological terrorism incident

    NASA Astrophysics Data System (ADS)

    Molthen, Robert; Wu, QingPing; Krenz, Gary; Medhora, Meetha; Jacobs, Elizabeth; Moulder, John E.

    2009-02-01

    We have developed a rat model of single, sub-lethal thoracic irradiation. Our irradiation protocol is considered representative of exposures near the detonation site of a dirty bomb or small nuclear device. The model is being used to investigate techniques for identifying, triaging and treating possible victims. In addition to physiological markers of right ventricular hypertrophy, pulmonary vascular resistance, and arterial distensibility, we present two methods for quantifying microvascular density. We used methods including microfocal X-ray imaging to investigate changes in lung structure/function resulting from radiation exposure. Radiation pneumonitis is a complication in subjects receiving thoracic irradiation. A radiographic hallmark of acute radiation pneumonitis is a diffuse infiltrate corresponding to the radiation treatment field. We describe two methods for quantifying small artery dropout that occurs in the model at the same time-period. Rats were examined 3-days, 2-weeks, 1-month (m), 2-m, 5-m, and 12-m post-irradiation and compared with aged-matched controls. Right ventricular hypertrophy and increases in pulmonary vascular resistance were present during the pneumonitis phase. Vascular injury was dependent on dose and post-irradiation duration. Rats irradiated with 5 Gy had few detectable changes, whereas 10 Gy resulted in a significant decrease in both microvascular density and arterial distensibility around 2- m, the decrease in each lessening, but extending through 12-m. In conclusion, rats irradiated with a 10 Gy dose had changes in vascular structure concurrent with the onset of radiation pneumonitis that were detectable with our imaging techniques and these structural changes persist after resolution of the pneumonitis.

  15. Irradiation-induced precipitation modelling of ferritic steels

    NASA Astrophysics Data System (ADS)

    Yin, You Fa; Faulkner, Roy G.; Lu, Zheng

    2009-06-01

    In high strength low alloy (HSLA) steels typically used in reactor pressure vessels (RPV), irradiation-induced microstructure changes affect the performance of the components. One such change is precipitation hardening due to the formation of solute clusters and/or precipitates which form as a result of irradiation-enhanced solute diffusion and thermodynamic stability changes. The other is irradiation-enhanced tempering which is a result of carbide coarsening due to irradiation-enhanced carbon diffusion. Both effects have been studied using a recently developed Monte Carlo based precipitation kinetics simulation technique and modelling results are compared with experimental measurements. Good agreements have been achieved.

  16. Inter-species extrapolation of skin heating resulting from millimeter wave irradiation: modeling and experimental results.

    PubMed

    Nelson, D A; Walters, T J; Ryan, K L; Emerton, K B; Hurt, W D; Ziriax, J M; Johnson, L R; Mason, P A

    2003-05-01

    This study reports measurements of the skin surface temperature elevations during localized irradiation (94 GHz) of three species: rat (irradiated on lower abdomen), rhesus monkey (posterior forelimb), and human (posterior forearm). Two exposure conditions were examined: prolonged, low power density microwaves (LPM) and short-term, high power density microwaves (HPM). Temperature histories were compared with calculations from a bio-heat transfer model. The mean peak surface temperature increase was approximately 7.0 degrees C for the short-term HPM exposures for all three species/locations, and 8.5 degrees C (monkey, human) to 10.5 degrees C (rat) for the longer-duration LPM exposures. The HPM temperature histories are in close agreement with a one-dimensional conduction heat transfer model with negligible blood flow. The LPM temperature histories were compared with calculations from the bio-heat model, evaluated for various (constant) blood flow rates. Results suggest a variable blood flow model, reflecting a dynamic thermoregulatory response, may be more suited to describing skin surface temperature response under long-duration MMW irradiation. PMID:12747480

  17. An ultrastructural study of the effects of x-irradiation on the oral epithelium of the rat: qualitative aspects.

    PubMed

    Liu, H M; Meyer, J; Waterhouse, J P

    1976-07-01

    Adult male rats of Simonsen strain were given a dose of 5000 r at 50 peak KV of x-irradiation directed at the lower lip, which was everted through a hole in a lead rubber cylinder shielding the head and body of the animal. Light and electron microscopic observations were made on specimens of lip oral mucosa from animals killed at 2, 6, 26 and 50 h and at 12 days after irradiation. The experimental model met the aim of permitting the study of the sequential effects of high dose of irradiation without causing ulceration of the mucosa. Widespread degenerative changes were noted in the basal cells as early as 2 h after x-irradiation, increasing in degree up to 50 h. They included inflation of the outer nuclear envelope and rough endoplasmic reticulum (RER) with loss of ribosomes, swelling of mitochondria and disarrangement of cristae evident at 2 h, followed at 6 h by swelling of nucleus and cytoplasm and 26 h by frank membrane breaks. Irreversible degrees of damage were noted in a small though growing minority of cells. Immediate mobilization of the Golgi-lysosomal system was evident as an increase in size of the zone, maximal at 2 h, and subsequent autophagic activity. Signs of recovery, beginning at 26 h, were noted in nuclear envelope, RER, intercellular space, and in mitotic activity by 50 h. Virtually complete recovery was seen at 12 days. It is held that the successful confinement of irradiation to a small tissue volume, the effective activity of the lysosomal system and the short epithelial turnover time were important factors in limiting the damage and in permitting recovery. PMID:820842

  18. Traumatic arteriogenic erectile dysfunction: a rat model.

    PubMed

    El-Sakka, A; Yen, T S; Lin, C S; Lue, T F

    2001-06-01

    We developed a rat model of traumatic arteriogenic erectile dysfunction (ED) for the study of vasculogenic ED. Bilateral ligation of the internal iliac artery was performed on 30 three-month old male Sprague-Dawley rats as an experimental group. The control group consisted of 12 rats which underwent dissection of the internal iliac artery without ligation. Before their euthanization at 3 days, 7 days, and 1 month (10 rats in the experimental group and four rats in the control group at each time point), erectile function was assessed by electrostimulation of the cavernous nerves. Penile tissues were collected for nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase staining, trichrome staining, electron microscopy and RT-PCR for transforming growth factor beta (TGF-beta1), insulin like growth factor-I (IGF-I) and fibroblast growth factors (FGF) mRNA expression. Electrostimulation of the cavernous nerves revealed a highly significant declining of the intracavernous pressure after 3 and 7 days. No significant recovery of erectile function was noted at 1 month. Histology showed degeneration of the dorsal nerve fibers in all experimental rats. There was little decrease in the bulk of intracavernous smooth muscle in the experimental rats euthanazed 7 and 30 days. NADPH diaphorase staining revealed a significant decrease in nitric oxide synthase (NOS) containing nerve fibers in the dorsal and intracavernosal nerves in all rats in the experimental group. Electron microscopy showed a variety of changes such as collapse of sinusoids, increased cell debris, fibroblast and myofibroblast loss, intracellular deposition of fat and collagen and fatty degeneration. RT-PCR revealed up-regulation of TGF-beta1 after 3 days but not after 7 days or 1 month. There is no significant difference in IGF-I or FGF expression between the experimental and control group. Bilateral ligation of internal iliac arteries produces a reliable animal model for traumatic arteriogenic ED. Further

  19. Radiation-Induced Oxidative Stress at Out-of-Field Lung Tissues after Pelvis Irradiation in Rats

    PubMed Central

    Najafi, Masoud; Fardid, Reza; Takhshid, Mohammad Ali; Mosleh-Shirazi, Mohammad Amin; Rezaeyan, Abol-Hassan; Salajegheh, Ashkan

    2016-01-01

    Objective The out-of-field/non-target effect is one of the most important phenomena of ionizing radiation that leads to molecular and cellular damage to distant non-irradiated tissues. The most important concern about this phenomenon is carcinogenesis many years after radiation treatment. In vivo mechanisms and consequences of this phenomenon are not known completely. Therefore, this study aimed to evaluate the oxidative damages to out-of-field lung tissues 24 and 72 hours after pelvic irradiation in rats. Materials and Methods In this experimentalinterventional study, Sprague-Dawleymale rats (n=49) were divided into seven groups (n=7/each group), including two groups of pelvis- exposed rats (out-of-field groups), two groups of whole bodyexposed rats (scatter groups), two groups of lung-exposed rats (direct irradiation groups), and one control sham group. Out- of-field groups were irradiated at a 2×2 cm area in the pelvis region with 3 Gy using 1.25 MeV cobalt-60 gamma-ray source, and subsequently, malondialdehyde (MDA) and glutathione (GSH) levels as well as superoxide dismutase (SOD) activity in out-of-field lung tissues were measured. Results were compared to direct irradiation, control and scatter groups at 24 and 72 hours after exposure. Data were analyzed using Mann-Whitney U test. Results SOD activity decreased in out-of-field lung tissue 24 and 72 hours after irradiation as compared with the controls and scatter groups. GSH level decreased 24 hours after exposure and increased 72 hours after exposure in the out-of-field groups as compared with the scatter groups. MDA level in out-of-field groups only increased 24 hours after irradiation. Conclusion Pelvis irradiation induced oxidative damage in distant lung tissue that led to a dramatic decrease in SOD activity. This oxidative stress was remarkable, but it was less durable as compared to direct irradiation. PMID:27602315

  20. Transmission of a Filterable Agent from Rat Leukaemia Induced by X-Ray Irradiation and Treatment with Methylcholanthrene

    SciTech Connect

    Sveg, F.; Hlavay, E.

    2004-07-01

    Leukemia was induced in rats by combination of x irradiation and oral application of methylcholanthrene. The rats were irradiated by a single dose of 800 r, and methylcholanthrene was applied 3 times a week by stomach tube in a dose of 1 mg for 9 months. From 60 rats, myelogenous leukemia developed in 2 and lymphatic leukemia in 1. The myelobiastic leukemia proved to be transplantable and was maintained as MR-leukemia. After irtravenous injection of 1 to 10 x 10/ sup 6/ leukemic cells, obtained from the liver and spleen, the disease developed in adult rats in 6 to 10 days. As early as the 2nd or 3rd day after inoculation, leukemic infiltration of organs, especially liver and spleen, were seen. The rats died exhibiting signs of generalized leukemia within 10 days. If cell-free filtrates from the liver and spleen of rats bearing MR leukemia were injected into newborn and 4-week-old rats, myelogenous leukemia developed in the newborn group in 24% after a latency period of 520 days and in 33% of the 4-week-old group after 570 days, on an average. The induced leukemias were transplantable into both suckling and adult rats. Many of the injected animals, which did not develop leukemia, died of cirrhosis of the liver. The results suggest that the leukemia induced by irradiation and chemical carcinogen might be caused by a submicroscopic virus-like agent.

  1. The action of a dietary retinoid on gene expression and cancer induction in electron-irradiated rat skin

    NASA Technical Reports Server (NTRS)

    Burns, Fredric J.; Chen, Shuaili; Xu, Guijuan; Wu, Feng; Tang, Moon-Shong

    2002-01-01

    Current models of radiation carcinogenesis generally assume that the DNA is damaged in a variety of ways by the radiation and that subsequent cell divisions contribute to the conversion of the damage to heritable mutations. Cancer may seem complex and intractable, but its complexity provides multiple opportunities for preventive interventions. Mitotic inhibitors are among the strongest cancer preventive agents, not only slowing the growth rate of preneoplasias but also increasing the fidelity of DNA repair processes. Ionizing radiation, including electrons, is a strong inducer of cancer in rat skin, and dietary retinoids have shown potent cancer preventive activity in the same system. A non-toxic dietary dose of retinyl acetate altered gene expression levels 24 hours after electron irradiation of rat skin. Of the 8740 genes on an Affymetrix rat expression array, the radiation significantly (5 fold or higher) altered 188, while the retinoid altered 231, including 16 radiation-altered genes that were reversely altered. While radiation strongly affected the expression of stress response, immune/inflammation and nucleic acid metabolism genes, the retinoid most strongly affected proliferation-related genes, including some significant reversals, such as, keratin 14, retinol binding protein, and calcium binding proteins. These results point to reversal of proliferation-relevant genes as a likely basis for the anti-radiogenic effects of dietary retinyl acetate.

  2. A synthetic superoxide dismutase/catalase mimetic EUK-207 mitigates radiation dermatitis and promotes wound healing in irradiated rat skin.

    PubMed

    Doctrow, Susan R; Lopez, Argelia; Schock, Ashley M; Duncan, Nathan E; Jourdan, Megan M; Olasz, Edit B; Moulder, John E; Fish, Brian L; Mäder, Marylou; Lazar, Jozef; Lazarova, Zelmira

    2013-04-01

    In the event of a radionuclear attack or nuclear accident, the skin would be the first barrier exposed to radiation, though skin injury can progress over days to years following exposure. Chronic oxidative stress has been implicated as being a potential contributor to the progression of delayed radiation-induced injury to skin and other organs. To examine the causative role of oxidative stress in delayed radiation-induced skin injury, including impaired wound healing, we tested a synthetic superoxide dismutase (SOD)/catalase mimetic, EUK-207, in a rat model of combined skin irradiation and wound injury. Administered systemically, beginning 48 hours after irradiation, EUK-207 mitigated radiation dermatitis, suppressed indicators of tissue oxidative stress, and enhanced wound healing. Evaluation of gene expression in irradiated skin at 30 days after exposure revealed a significant upregulation of several key genes involved in detoxication of reactive oxygen and nitrogen species. This gene expression pattern was primarily reversed by EUK-207 therapy. These results demonstrate that oxidative stress has a critical role in the progression of radiation-induced skin injury, and that the injury can be mitigated by appropriate antioxidant compounds administered 48 hours after exposure. PMID:23190879

  3. Pulmonary endothelial dysfunction induced by unilateral as compared to bilateral thoracic irradiation in rats

    SciTech Connect

    Ward, W.F.; Molteni, A.; Ts'Ao, C.H.; Solliday, N.H.

    1987-07-01

    Rats were sacrificed 2 months after a single dose of 10-30 Gy of /sup 60/Co gamma rays delivered to either a right unilateral or a bilateral thoracic port. Four indices of lung endothelial function were measured: the activities of angiotensin-converting enzyme (ACE) and plasminogen activator (PLA) and the production of prostacyclin (PGI2) and thromboxane (TXA2). The number of macrophages recovered by bronchoalveolar lavage (BAL) and the degree of right ventricular hypertrophy (an index of pulmonary hypertension) also were determined. Right lung ACE and PLA activity decreased linearly, and PGI2 and TXA2 production increased linearly with increasing radiation dose. The response curves for right unilateral and bilateral thoracic irradiation were not significantly different. In contrast, bilateral irradiation was more toxic than unilateral, since rats exposed to the former exhibited decreased body weight, an increased incidence of pleural effusions, an increase in the number of macrophages recovered by BAL, and right ventricular hypertrophy. These data demonstrate that pulmonary endothelial dysfunction induced by hemithorax irradiation represents a direct response of the endothelium to radiation injury and is not secondary to other phenomena such as shunting of function to the shielded lung.

  4. Induction of tolerance to cardiac allografts in lethally irradiated rats reconstituted with syngeneic bone marrow

    SciTech Connect

    Hartnett, L.C.

    1983-01-01

    Generally, organ grafts from one individual animal to another are rejected in one-two weeks. However, if the recipients are given Total Body Irradiation (TBI) just prior to grafting, followed by reconstitution of hemopoietic function with syngeneic (recipient-type) bone marrow cells, then vascularized organ grafts are permanently accepted. Initially after irradiation, it is possible to induce tolerance to many strain combinations in rats. This thesis examines the system of TBI as applied to the induction of tolerance in LEW recipients of WF cardiac allografts. These two rat strains are mismatched across the entire major histocompatibility complex. When the LEW recipient are given 860 rads, a WF cardiac allograft and LEW bone marrow on the same day, 60% of the grafts are accepted. Methods employed to improve the rate of graft acceptance include: treating either donor or recipient with small amounts of methotrexate, or waiting until two days after irradiation to repopulate with bone marrow. It seems from these investigations of some of the early events in the induction of tolerance to allografts following TBI and syngeneic marrow reconstitution that an immature cell population in the bone marrow interacts with a radioresistant cell population in the spleen to produce tolerance to completely MHC-mismatched allografts.

  5. Radiation response of the rat cervical spinal cord after irradiation at different ages: Tolerance, latency and pathology

    SciTech Connect

    Ruifrok, A.C.C.; Van Der Kogel, A.J. ); Stephens, L.C. )

    1994-04-30

    Investigation of the age dependent single-dose radiation tolerance, latency to radiation myelopathy, and the histopathological changes after irradiation of the rat cervical spinal cord is presented. Rats were irradiated with graded single doses of 4 MV photons to the cervical spinal cord. When the rats showed definite signs of paresis of the forelegs, they were killed and processed for histological examination. The radiation dose resulting in paresis due to white matter damage in 50% of the animals (ED[sub 50]) after single dose irradiation was about 21.5 Gy at all ages [ge] 2 weeks. Only the Ed[sub 50] at 1 week was significantly lower. The latency to the development of paresis clearly changed with the age at irradiation, from about 2 weeks after irradiation at 1 week to 6-8 months after irradiation at age [ge] 8 weeks. The white matter damage was similar in all symptomatic animals studied. The most prominent were areas with diffuse demyelination and swollen axons, often with focal necrosis, accompanied by glial reaction. This was observed in all symptomatic animals, irrespective of the age at irradiation. Expression of vascular damage appeared to depend on the age at irradiation. Although the latency to myelopathy is clearly age dependent, single dose tolerance is not age dependent at age [ge] 2 weeks in the rat cervical spinal cord. The white matter damage is similar in all symptomatic animals studied, but the vasculopathies appear to be influenced by the age at irradiation. It is concluded that white matter damage and vascular damage are separate phenomena contributing to the development of radiation myelopathy, expression of which may depend on the radiation dose applied and the age at irradiation. 28 refs., 5 figs., 3 tabs.

  6. Solar spectral irradiance model validation using Solar Spectral Irradiance and Solar Radius measurements

    NASA Astrophysics Data System (ADS)

    Thuillier, Gérard; Zhu, Ping; Shapiro, Alexander; Sofia, Sabatino; Tagirov, Rinat; Van Ruymbeke, Michel; Schmutz, Werner

    2016-04-01

    The importance of the reliable solar spectral irradiance (SSI) data for solar and climate physics is now well acknowledged. In particular, the irradiance time series are necessary for most of the current studies concerning climate evolution. However, space instruments are vulnerable to the degradation due to the environment while ground based measurements are limited in wavelength range and need atmospheric effects corrections. This is why SSI modeling is necessary to understand the mechanism of the solar irradiance variability and to provide long and uninterrupted irradiance records to climate and Earth atmosphere scientists. Here we present COSI (COde for Solar Irradiance) model of the SSI variability. The COSI model is based on the Non local thermodynamic Equilibrium Spectral SYnthesis Code (NESSY). We validate NESSY by two independent datasets: - The SSI at solar minimum occurring in 2008, - The radius variation with wavelength and absolute values determined from PREMOS and BOS instruments onboard the PICARD spacecraft. Comparisons between modeling and measured SSI will be shown. However, since SSI measurements have an accuracy estimated between 2 to 3%, the comparison with the solar radius data provides a very important additional constrains on model. For that, 17 partial solar occultations by the Moon are used providing solar radii clearly showing the dependence of the solar radius with wavelength. These results are compared with the NESSY predictions. The agreement between NESSY and observations is within the model and measurements accuracy.

  7. Consensus Modeling of Oral Rat Acute Toxicity

    EPA Science Inventory

    An acute toxicity dataset (oral rat LD50) with about 7400 compounds was compiled from the ChemIDplus database. This dataset was divided into a modeling set and a prediction set. The compounds in the prediction set were selected so that they were present in the modeling set used...

  8. Fasciola hepatica: development of the tegument of normal and gamma-irradiated flukes during infection in rats and mice.

    PubMed

    Burden, D J; Bland, A P; Hughes, D L; Hammet, N C

    1983-02-01

    Rats and mice were infected with either normal metacercariae or metacercariae gamma-irradiated at 3 krad. or 4 krad. Flukes were recovered at various times after infection and their teguments examined using a transmission electron microscope. In normal flukes, the secretory granules T0, T1 and T2 were all seen during tegumental development. The teguments of flukes from mice developed faster than the corresponding teguments in rats. T0 granules were present from day 0 to day 10 post-infection (p.i.) in mouse flukes and from day 0 to day 14 p.i. in rat flukes. T1 granules first appeared in mouse flukes by day 4 p.i. but not until day 8 p.i. in rat flukes. T2 granules were seen in mouse flukes 2 days p.i. but not before 6 days p.i. in rat flukes. gamma-Irradiation at 4 krad prevented normal tegumental development in flukes from both rats and mice. T0 granules were present at all times in flukes from either host. T1 granules were produced in mouse flukes but their appearance was delayed until day 6 p.i. No significant production of T2 granules occurred in flukes from either host. Parasite survival was also affected by gamma-irradiation and none of the flukes reached maturity. Flukes from rats died between 10 and 21 days p.i. and flukes from mice died between 14 and 28 days p.i. gamma-Irradiation of metacercariae at 3 krad. had an extremely variable effect on subsequent tegumental development in both rats and mice. Some flukes developed normally, some showed development associated with gamma-irradiation at 4 krad, whilst some showed intermediate development. PMID:6835695

  9. Efficacy of Polaprezinc for Acute Radiation Proctitis in a Rat Model

    SciTech Connect

    Doi, Hiroshi; Kamikonya, Norihiko; Takada, Yasuhiro; Fujiwara, Masayuki; Tsuboi, Keita; Inoue, Hiroyuki; Tanooka, Masao; Nakamura, Takeshi; Shikata, Toshiyuki; Tsujimura, Tohru; Hirota, Shozo

    2011-07-01

    Purpose: The purpose of the present study was to standardize the experimental rat model of radiation proctitis and to examine the efficacy of polaprezinc on radiation proctitis. Methods and Materials: A total of 54 female Wistar rats (5 weeks old) were used. The rats were divided into three groups: those treated with polaprezinc (PZ+), those treated with base alone, exclusive of polaprezinc (PZ-), and those treated without any medication (control). All the rats were irradiated to the rectum. Polaprezinc was prepared as an ointment. The ointment was administered rectally each day after irradiation. All rats were killed on the 10th day after irradiation. The mucosal changes were evaluated endoscopically and pathologically. The results were graded from 0 to 4 and compared according to milder or more severe status, as applicable. Results: According to the endoscopic findings, the proportion of mild changes in the PZ+, PZ-, and control group was 71.4%, 25.0%, and 14.3% respectively. On pathologic examination, the proportion of low-grade findings in the PZ+, PZ-, and control group was 80.0%, 58.3%, and 42.9% for mucosal damage, 85.0%, 41.7%, and 42.9% for a mild degree of inflammation, and 50.0%, 33.3%, and 4.8% for a shallow depth of inflammation, respectively. The PZ+ group tended to have milder mucosal damage than the other groups, according to all criteria used. In addition, significant differences were observed between the PZ+ and control groups regarding the endoscopic findings, degree of inflammation, and depth of inflammation. Conclusions: This model was confirmed to be a useful experimental rat model for radiation proctitis. The results of the present study have demonstrated the efficacy of polaprezinc against acute radiation-induced rectal disorders using the rat model.

  10. Rat parotid cell function in vitro following x irradiation in vivo

    SciTech Connect

    Bodner, L.; Kuyatt, B.L.; Hand, A.R.; Baum, B.J.

    1984-02-01

    The effect of X irradiation on rat parotid acinar cell function was evaluated in vitro 1, 3, and 7 days following in vivo exposure to 2000 R. Several cellular functions were followed: protein secretion (amylase release), ion movement (K/sup +/ efflux and reuptake), amino acid transport (..cap alpha..-amino(/sup 14/C)isobutyric acid), and an intermediary metabolic response ((/sup 14/C)glucose oxidation). In addition both the morphologic appearance and in vivo saliva secretory ability of parotid cells were assessed. Our results demonstrate that surviving rat parotid acinar cells, isolated and studied in vitro 1-7 days following 2000 R, remain functionally intact despite in vivo diminution of secretory function.

  11. Tumor xenotransplantation in Wistar rats after treatment with cyclophosphamide and total lymphoid irradiation. [X-ray

    SciTech Connect

    Hoogenhout, J.; Kazem, I.; Jerusalem, C.R.; Bakkeren, J.A.J.; de Jong, J.; Kal, H.B.; van Munster, P.J.J.

    1982-10-01

    Three-month-old male Wistar rats were treated with cyclophosphamide and total lymphoid irradiation, and C22LR mouse osteosarcoma was transplanted into the rats. The effects of immunosuppression were monitored by lymphocyte counts, serum IgG determinations, phytohemagglutinin (PHA) and concanavalin A (Con A) responses, measurement of the proportion of B cells, and histopathological studies of the lymphoid organs. At eight days after treatment, the lymphocyte counts, IgG levels, and PHA and Con A values were decreased. Mitotic activity started in the depleted B and T cell areas of the peripheral lymphatic organs two weeks after treatment. There was a 94% graft take of the osteosarcoma. It was determined that the optimum time for tumor xenograft transplantation is 4 days after treatment. The duration of growth was 11 days, and this was followed by regression up to day 21.

  12. Tumor xenotransplantation in Wistar rats after treatment with cyclophosphamide and total lymphoid irradiation

    SciTech Connect

    Hoogenhout, J.; Kazem, I.; Jerusalem, C.R.; Bakkeren, J.A.; de Jong, J.; Kal, H.B.; van Munster, P.J.

    1982-10-01

    Three-month-old male Wistar rats were treated with cyclophosphamide and total lymphoid irradiation, and C22LR mouse osteosarcoma was transplanted into the rats. The effects of immunosuppression were monitored by lymphocyte counts, serum IgG determinations, phytohemagglutinin (PHA) and concanavalin A (Con A) responses, measurement of the proportion of B cells, and histopathological studies of the lymphoid organs. At eight days after treatment, the lymphocyte counts, IgG levels, and PHA and Con A values were decreased. Mitotic activity started in the depleted B and T cell areas of the peripheral lymphatic organs two weeks after treatment. There was a 94% graft take of the osteosarcoma. It was determined that the optimum time for tumor xenograft transplantation is 4 days after treatment. The duration of growth was 11 days, and this was followed by regression up to day 21.

  13. Low level laser therapy on injured rat muscle: assessment of irradiation parameters

    NASA Astrophysics Data System (ADS)

    Mantineo, M.; Pinheiro, J. P.; Morgado, A. M.

    2013-11-01

    Although studies show the clinical effectiveness of low level laser therapy (LLLT) in facilitating the muscle healing process, scientific evidence is still required to prove the effectiveness of LLLT and to clarify the cellular and molecular mechanisms triggered by irradiation. Here we evaluate the effect of different LLLT wavelengths, using continuous coherent Laser illumination (830 nm and 980 nm) and non-coherent LED illumination (850 nm), in the treatment of inflammation induced in the gastrocnemius muscle of Wistar rats, through the quantification of cytokines in systemic blood. We verified that all applied doses of coherent radiation produce an effect on reducing the concentration of pro-inflammatory TNF-α and IL-1β cytokines, while no treatment effect was observed after irradiation with non-coherent radiation. The best results were obtained for 40 mW at 830 nm. The results may suggest an important role of coherence properties of laser in LLLT.

  14. Reactivity of rat abdominal aorta to U46619 following whole-body gamma irradiation

    SciTech Connect

    Warfield, M.E.; Schneidkraut, M.J.; Cunard, C.M.; Ramwell, P.W.; Kot, P.A.

    1989-03-01

    Rats exposed to 20 Gy whole-body irradiation demonstrated a depressed aortic responsiveness to the thromboxane mimic, U46619, 48 h postirradiation. The mechanism for this observed response was investigated. Shielding the abdominal aorta attenuated this altered vascular reactivity. Since this suggests that radiation exposure induces local changes in the aorta, vascular smooth muscle function was assessed with cumulative concentrations of KCl. Radiation-induced smooth muscle damage was insufficient to account for the decreased reactivity to U46619. Next, calcium availability for vascular smooth muscle function was evaluated and found not to be responsible for the radiation-induced depression in aortic responsiveness. Finally, the role that cyclooxygenase products play in the depressed contractile response was investigated. Indomethacin treatment prior to and for 48 h after irradiation attenuated the altered vascular reactivity to U46619. These data suggest that a radiation-induced increase in cyclooxygenase products may play a role in the decreased aortic reactivity to the thromboxane mimic.

  15. NSBRI Radiation Effects: Carcinogenesis in Sprague-Dawley Rats Irradiated with Iron Ions, Protons, or Photons

    NASA Technical Reports Server (NTRS)

    Dicello, J. F.; Cucinotta, F. A.; Gridley, D. S.; Howard, S. P.; Novak, G. R.; Ricart-Arbona, R.; Strandberg, J. D.; Vazquez, M. E.; Williams, J. R.; Zhang, Y.; Zhou, H.; Huso, D. L.

    1999-01-01

    Our ability to confidently develop appropriate countermeasures for radiations in space in terms of shielding and design of a spacecraft, the mission scenario, or chemoprevention is severely limited by the uncertainties in both the risk itself and the change in that risk with intervention. Despite the fact that the risk of carcinogenesis from exposures of personnel to radiations on long-term missions is considered one of the worst hazards in space, only a limited amount of in-vivo data exist for tumor induction from exposures to protons or energetic heavy ions (HZEs) at lower doses. The most extensive work remains the landmark study. for tumor development in the harderian gland of the mouse. The objective of this study is to characterize the level of risk for tumor induction in another relevant animal model. Subsequent experiments are designed to test the hypothesis that the level of risk can be reduced by pharmaceutical intervention in the promoting and progressing stages of the disease rather than in the initiating stage. The work presented here results from a cooperative effort on the part of investigators from two projects of the Radiation-Effects Team of the National Space Biomedical Research Institute (NSBRI). The collaborating projects are the Core Project which is investigating the risk of carcinogenesis in Sprague-Dawley rats and the Chemoprevention Project which is investigating the ability of Tamoxifen to reduce the number of malignant tumors in the irradiated animals. Research at the cellular and subcellular levels is being conducted in two other projects of the Radiation-Effects Team, Cytogenetics with J. R. Williams as Principal Investigator and Mutations from Repeated DNA Sequences. Results for these other projects also are being presented at this Workshop.

  16. Effects of X irradiation on the cytoskeleton of rat alveolar macrophages in vitro

    SciTech Connect

    Ladyman, S.J.; Townsend, K.M.S.; Edwards, C.

    1984-07-01

    The three-dimensional visualization of Triton X-100 resistant cytoskeletons has been used to demonstrate that an absorbed dose of 120 Gy from X rays causes a distinctive and reproducible alteration of the cytoskeleton of intact rat alveolar macrophages in vitro. The alteration has also been shown to be rapidly and completely ''repaired'' and to be apparently similar to alterations caused by colchicine but dissimilar to those caused by cytochalasin B. From these observations and those of other workers who have studied the irradiation of extracted microtubular proteins in vitro, the authors think it likely that microtubules rather than microfilaments are the radiosensitive component of the macrophage cytoskeleton.

  17. Effect of UV irradiation on expression of membrane IL 1 by rat macrophages

    SciTech Connect

    Lange-Wantzin, G.; Rothlein, R.; Kahn, J.; Faanes, R.B.

    1987-06-01

    The effect of UV-B irradiation on the expression of membrane-associated IL 1 (mIL 1) by rat pulmonary alveolar macrophages (PAM) was studied. We found that although there was an increase in secreted IL 1 by PAM exposed to UV-B, the expression of mIL 1 was inhibited in a dose-dependent manner. Furthermore, PAM that were allowed to express mIL 1 before UV-B irradiation had a faster decay of mIL 1 activity than unirradiated cells. These data suggested that mIL 1 expression is inhibited by UV-B irradiation, and that under normal circumstances, mIL 1 synthesis and degradation is at a steady state, with the half-life of mIL 1 activity being 24 hr when assayed in an IL 1-dependent cell line proliferation assay. These data indicate that secreted forms of IL 1 and mIL 1 are differentially regulated and that the therapeutic effects of UV irradiation may be due to its inhibition of mIL 1 activity.

  18. Thromboxane release from irradiated perfused rat lungs: role of oncotic agents

    SciTech Connect

    Heinz, T.R.; Kot, P.A.; Ramwell, P.W.; Schneidkraut, M.J.

    1987-07-27

    Isolated lungs from 20 Gray (Gy) whole body irradiated rats were perfused with Krebs-Ringer bicarbonate plus 3% bovine serum albumin (KRB-BSA). The pulmonary effluent showed a 99% (p < .05) increase in immunoassayable thromboxane B2 (iTXB2) release compared with non-irradiated lungs. Since both arachidonic acid and cyclooxygenase products bind to albumin, studies were performed to determine if omission or substitution of this protein oncotic agent would alter the radiation-induced increase in pulmonary iTXB2 release. Irradiated, isolated lungs perfused with media from which the BSA was omitted (KRB) did not demonstrate the radiation-induced increase in pulmonary iTXB2 release. Similarly, irradiated lungs perfused with media in which Dextran 70 (KRB plus 3% Dextran 70, KRB-Dextran 70) was substituted for BSA also did not show the radiation-induced increase in pulmonary effluent iTXB2 levels. These studies demonstrate the importance of including albumin as the oncotic agent in perfused organ systems when studying cyclooxygenase product release. 23 references, 2 tables.

  19. Effects of field orientation during 700-MHz radiofrequency irradiation of rats

    SciTech Connect

    Frei, M.R.; Jauchem, J.R.; Padilla, J.M. )

    1989-01-01

    Ketamine-anesthetized Sprague-Dawley rats were exposed to far-field 700-MHz continuous-wave radiofrequency radiation (RFR) in both E and H orientations. Irradiation was conducted at whole-body average specific absorption rates (SARs) of 9.2 and 13.0 W/kg (E and H, respectively) that resulted in approximately equivalent colonic specific heating rates (SHRs). Exposures were performed to repeatedly increase colonic temperature by 1 degree C (38.5 to 39.5 degrees C). Tympanic, tail, left and right subcutaneous (toward and away from RFR source), and colonic temperatures, arterial blood pressure, and respiratory rate were continuously recorded. In spite of equivalent colonic SHRs and the reduced E-orientation average SAR, the right subcutaneous, tympanic, and tail SARs, SHRs and absolute temperature increases were significantly greater in E than in H orientation. The cooling rate at all monitoring sites was also significantly greater in E than in H orientation. Heart rate and mean arterial blood pressure significantly increased during irradiation; however, changes between orientations were not different. Respiratory rate significantly increased during irradiation in H, but not in E orientation. These results indicate that during resonant frequency irradiation, differences occur in the pattern of heat deposition between E- and H-orientation exposure. When compared with previous investigations performed at supraresonant frequencies, the lower level of cardiovascular change in this study was probably related to the lower periphery-to-core thermal gradient.

  20. Effects of field orientation during 700-MHz radiofrequency irradiation of rats

    SciTech Connect

    Frei, M.R.; Jauchem, J.R.; Padilla, J.M.

    1989-01-01

    Ketamine-anesthetized Sprague-Dawley rats were exposed to far-field 700-MHz continuous-wave radiofrequency radiation (RFR) in both E and H orientations. Irradiation was conducted at whole-body average specific absorption rates (SARs) of 9.2 and 13.0 W/kg (E and H, respectively) that resulted in approximately equivalent colonic specific heating rates (SHRs). Exposures were performed to repeatedly increase colonic temperature by 1 deg C (38.5 to 39.5 deg C). Tympanic, tail, left and right subcutaneous (toward and away from RFR source), and colonic temperatures, arterial blood pressure, and respiratory rate were continuously recorded. In spite of equivalent colonic SHRs and the reduced E-orientation average SAR, the right subcutaneous, tympanic, and tail SARs, SHRs and absolute temperature increases were significantly greater in E than in H orientation. The cooling rate at all monitoring sites was also significantly greater in E than in H orientation. Heart rate and mean arterial blood pressure significantly increased during irradiation; however, changer between orientations were not different. Respiratory rate significantly increased during irradiation in H, but not in E orientation. These results indicate that during resonant frequency irradiation, differences occur in the pattern of heat deposition between E- and H-orientation exposure. When compared with previous investigations performed at supraresonant frequencies, the lower level of cardiovascular change in this study was probably related to the lower periphery-to-core thermal gradient.

  1. The megakaryocyte DNA content and platelet formation after the sublethal whole body irradiation of rats

    SciTech Connect

    Tanum, G.

    1984-04-01

    The DNA content of rat bone marrow megakaryocytes (MK) was studied by Feulgen photometry, following whole body irradiation with 2 Gy. The DNA measurements were preceded by acetylcholinesterase staining to avoid missing the smaller 2N-8N MK. The number of 2N-8N MK declined immediately following irradiation, whereas the number of 16N-64N MK remained normal for 4 days before decreasing. The number of 2N-8N and 16N-64N MK reached minimum around days 7 and 10, respectively, and thereafter increased to supranormal values at days 14 and 20, respectively. Platelet production, measured by /sup 35/S incorporation into platelets, increased during the first 4 days, then decreased to minimum about day 10. A rise to supranormal values was present at day 20. All values were about normal 30 days after exposure. The observed pattern may be explained as follows: Most of the 16N-64N MK survive the applied dose and maintain their ability to produce platelets. Some of the 2N-4N and 8N MK survive irradiation and transform into platelet-producing MK. No influx of cells from the MK stem cell compartment into the MK compartment can be observed before day 7 after irradiation. One explanation for this time lag may be that thrombocytopenia, which does not occur before then, is an essential stimulus for MK stem cell activation.

  2. A semiparametric spatio-temporal model for solar irradiance data

    DOE PAGESBeta

    Patrick, Joshua D.; Harvill, Jane L.; Hansen, Clifford W.

    2016-03-01

    Here, we evaluate semiparametric spatio-temporal models for global horizontal irradiance at high spatial and temporal resolution. These models represent the spatial domain as a lattice and are capable of predicting irradiance at lattice points, given data measured at other lattice points. Using data from a 1.2 MW PV plant located in Lanai, Hawaii, we show that a semiparametric model can be more accurate than simple interpolation between sensor locations. We investigate spatio-temporal models with separable and nonseparable covariance structures and find no evidence to support assuming a separable covariance structure. These results indicate a promising approach for modeling irradiance atmore » high spatial resolution consistent with available ground-based measurements. Moreover, this kind of modeling may find application in design, valuation, and operation of fleets of utility-scale photovoltaic power systems.« less

  3. Electron-microscopic studies on the effect of calcium pantothenate upon rat liver and locally irradiated epidermis.

    PubMed

    Craciun, C; Ghircoiasiu, M; Craciun, V

    1992-01-01

    Calcium pantothenate was administered to Wistar rats in a dose of 180 mg/day/rat for 42 days, in order to investigate its effect upon the ultrastructure of the epidermis locally irradiated with a dose of 600 rep and upon partly hepatectomized liver and locally irradiated epidermis, as compared to control. The resulting data have revealed that calcium pantothenate is metabolized without entailing ultrastructural changes. Both liver and epidermis appear to be protected by calcium pantothenate, which greatly diminishes or even cancels the display of irradiation-induced negative effects. The changes brought about by irradiation are throughly presented and the subcellular mechanisms providing the radioprotection of epidermis and liver are accurately defined. PMID:1365767

  4. The rat choledochojejunostomy model for microsurgical training

    PubMed Central

    Lee, Jun Suh

    2016-01-01

    Purpose The feasibility of a rat choledochojejunostomy (CJ) training model was investigated, as an introductory model to microsurgery for general surgeons. Methods Roux-en-Y CJ was performed on 20 rats. Interrupted 10-0 prolene sutures were used to perform CJ. The animals were observed for 7 days and sacrificed and examined. Results The rats were divided into 2 groups of 10 based on surgical order. The CJ time showed a significant decrease from 36.2 ± 5.6 minutes in group 1 to 29.4 ± 5.7 minutes in group 2 (P = 0.015). The bile leakage rate was 40% in group 1 and 10% in group 2. The survival time was 5.4 ± 2.2 days in group 1 and 7 days in group 2 (P = 0.049). Conclusion The rat CJ training model is a feasible introductory model for general surgeons with no previous experience in microsurgery. PMID:27186568

  5. Micro-CT evaluation of the radioprotective effect of resveratrol on the mandibular incisors of irradiated rats.

    PubMed

    Barbosa, Gabriella Lopes de Rezende; Pimenta, Luiz André; Almeida, Solange Maria de

    2016-01-01

    The purpose of this study was to perform a microcomputed tomographic evaluation of the radioprotective effect of resveratrol on the volume of mandibular incisors of irradiated rats. A second aim was to make a quantitative assessment of the effect of x-ray exposure on these dental tissues. Twenty adult male rats were divided into four groups: control, irradiated control, resveratrol, and irradiated resveratrol. The resveratrol groups received 100 mg/kg of resveratrol, whereas the irradiated groups were exposed to 15 Gy of irradiation. The animals were sacrificed 30 days after the irradiation procedure, and their mandibles were removed and scanned in a microcomputed tomography unit. The images were loaded into Mimics software to allow segmentation of the mandibular incisor and assessment of its volume. The results were compared by One-way ANOVA and Tukey's post hoc test, considering a 5% significance level. The irradiated groups showed significantly diminished volumes of the evaluated teeth, as compared with the control group (p < 0.05). The resveratrol group presented higher values than those of the irradiated groups, and volumes similar to those of the control group. High radiation doses significantly affected tooth formation, resulting in alterations in the dental structure, and thus lower volumes. Moreover, resveratrol showed no effective radioprotective impact on dental tissues. Future studies are needed to evaluate different concentrations of this substance, in an endeavor to verify its potential as a radioprotector for these dental tissues. PMID:26981750

  6. Protective Effects of Hong Shan Capsule against Lethal Total-Body Irradiation-Induced Damage in Wistar Rats.

    PubMed

    Li, Jianzhong; Xu, Jing; Xu, Weiheng; Qi, Yang; Lu, Yiming; Qiu, Lei; Hu, Zhenlin; Chu, Zhiyong; Chai, Yifeng; Zhang, Junping

    2015-01-01

    Hong Shan Capsule (HSC), a crude drug of 11 medicinal herbs, was used in clinical practice for the treatment of radiation injuries in China. In this study, we investigated its protection in rats against acute lethal total-body irradiation (TBI). Pre-administration of HSC reduced the radiation sickness characteristics, while increasing the 30-day survival of the irradiated rats. Administration of HSC also reduced the radiation sickness characteristics and increased the 30-day survival of mice after exposure to lethal TBI. Ultrastructural observation illustrated that the pretreatment of rats with HSC significantly attenuated the TBI-induced morphological changes in the different organs of irradiated rats. Gene expression profiles revealed the dramatic effect of HSC on alterations of gene expression caused by lethal TBI. Pretreatment with HSC prevented differential expression of 66% (1398 genes) of 2126 genes differentially expressed in response to TBI. Pathway enrichment analysis indicated that these genes were mainly involved in a total of 32 pathways, such as pathways in cancer and the mitogen-activated protein kinase (MAPK) signaling pathway. Our analysis indicated that the pretreatment of rats with HSC modulated these pathways induced by lethal TBI, such as multiple MAPK pathways, suggesting that pretreatment with HSC might provide protective effects on lethal TBI mainly or partially through the modulation of these pathways. Our data suggest that HSC has the potential to be used as an effective therapeutic or radio-protective agent to minimize irradiation damage. PMID:26274957

  7. Effects of heavy particle irradiation and diet on amphetamine- and lithium chloride-induced taste avoidance learning in rats

    NASA Technical Reports Server (NTRS)

    Rabin, Bernard M.; Shukitt-Hale, Barbara; Szprengiel, Aleksandra; Joseph, James A.

    2002-01-01

    Rats were maintained on diets containing either 2% blueberry or strawberry extract or a control diet for 8 weeks prior to being exposed to 1.5 Gy of 56Fe particles in the Alternating Gradient Synchrotron at Brookhaven National Laboratory. Three days following irradiation, the rats were tested for the effects of irradiation on the acquisition of an amphetamine- or lithium chloride-induced (LiCl) conditioned taste avoidance (CTA). The rats maintained on the control diet failed to show the acquisition of a CTA following injection of amphetamine. In contrast, the rats maintained on antioxidant diets (strawberry or blueberry extract) continued to show the development of an amphetamine-induced CTA following exposure to 56Fe particles. Neither irradiation nor diet had an effect on the acquisition of a LiCl-induced CTA. The results are interpreted as indicating that oxidative stress following exposure to 56Fe particles may be responsible for the disruption of the dopamine-mediated amphetamine-induced CTA in rats fed control diets; and that a reduction in oxidative stress produced by the antioxidant diets functions to reinstate the dopamine-mediated CTA. The failure of either irradiation or diet to influence LiCl-induced responding suggests that oxidative stress may not be involved in CTA learning following injection of LiCl.

  8. Protective Effects of Hong Shan Capsule against Lethal Total-Body Irradiation-Induced Damage in Wistar Rats

    PubMed Central

    Li, Jianzhong; Xu, Jing; Xu, Weiheng; Qi, Yang; Lu, Yiming; Qiu, Lei; Hu, Zhenlin; Chu, Zhiyong; Chai, Yifeng; Zhang, Junping

    2015-01-01

    Hong Shan Capsule (HSC), a crude drug of 11 medicinal herbs, was used in clinical practice for the treatment of radiation injuries in China. In this study, we investigated its protection in rats against acute lethal total-body irradiation (TBI). Pre-administration of HSC reduced the radiation sickness characteristics, while increasing the 30-day survival of the irradiated rats. Administration of HSC also reduced the radiation sickness characteristics and increased the 30-day survival of mice after exposure to lethal TBI. Ultrastructural observation illustrated that the pretreatment of rats with HSC significantly attenuated the TBI-induced morphological changes in the different organs of irradiated rats. Gene expression profiles revealed the dramatic effect of HSC on alterations of gene expression caused by lethal TBI. Pretreatment with HSC prevented differential expression of 66% (1398 genes) of 2126 genes differentially expressed in response to TBI. Pathway enrichment analysis indicated that these genes were mainly involved in a total of 32 pathways, such as pathways in cancer and the mitogen-activated protein kinase (MAPK) signaling pathway. Our analysis indicated that the pretreatment of rats with HSC modulated these pathways induced by lethal TBI, such as multiple MAPK pathways, suggesting that pretreatment with HSC might provide protective effects on lethal TBI mainly or partially through the modulation of these pathways. Our data suggest that HSC has the potential to be used as an effective therapeutic or radio-protective agent to minimize irradiation damage. PMID:26274957

  9. Periarteritis nodosa in rats treated with chronic excess sodium chloride (NaCl) after X-irradiation

    SciTech Connect

    Watanabe, H.; Nakagawa, Y.; Ito, A.; Kajihara, H.

    1987-07-01

    Five-week-old male Crj:CD (SD) rats were treated with excess sodium chloride after abdominal X-irradiation. The gastric regions of the rats were irradiated with a total dose of 20 Gy given in two equal fractions separated by 3 days. After X-irradiation, animals were fed a diet containing 10% sodium chloride. Red blood cell anemia appeared 22 weeks after the last irradiation. By gross observation, the mesenteric arteries became reddish in color, and bead- or lead pipe-like nodular thickenings were present. Microscopically, these nodularly thickened mesenteric arteries showed fibrinoid necrosis with massive inflammatory infiltration including eosinophils and neutrophils. In more advanced lesions, elastica interna and externa and medial smooth muscle cells disappeared completely and were replaced by granulation tissue. In old lesions, arterial walls were markedly thickened with fibrous or fibromuscular tissue. These findings were quite similar to those of the human periarteritis nodosa. These arterial lesions could not be found in the rats with X-irradiation only, sodium chloride only, or in nontreated animals. This study demonstrates X-ray-induced, NaCl-promoted periarteritis nodosa-like lesions in rats.

  10. Periarteritis nodosa in rats treated with chronic excess sodium chlorides (NaCl) after X-irradiation

    SciTech Connect

    Watanabe, H.; Nakagawa, Y.; Ito, A.; Kajihara, H.

    1987-07-01

    Five-week-old male Crj:CD (SD) rats were treated with excess sodium chloride after abdominal X-irradiation. The gastric regions of the rats were irradiated with a total dose of 20 Gy given in two equal fractions separated by 3 days. After X-irradiation, animals were fed a diet containing 10% sodium chloride. Red blood cell anemia appeared 22 weeks after the last irradiation. By gross observation, the mesenteric arteries became reddish in color, and bead- or lead pipe-like nodular thickenings were present. Microscopically these nodularly thickened mesenteric arteries showed fibrinoid necrosis with massive inflammatory infiltration including eosinophils and neutrophils. In more advanced lesions, elastica interna and externa and medial smooth muscle cells disappeared completely and were replaced by granulation tissue. In old lesions, arterial walls were markedly thickened with fibrous or fibromuscular tissue. These findings were quite similar to those of the human periarteritis nodosa. These arterial lesions could not be found in the rats with X-irradiation only, sodium chloride only, or in nontreated animals. This study demonstrates X-ray-induced, NaCl-promoted periarteritis nodosa-like lesions in rats.

  11. Effect of CO₂ laser irradiation on wound healing of exposed rat pulp.

    PubMed

    Suzuki, Masaya; Ogisu, Takahito; Kato, Chikage; Shinkai, Koichi; Katoh, Yoshiroh

    2011-01-01

    This study examined the effects of direct pulp capping treatment using super-pulsed CO₂ laser preirradiation on the wound healing process of exposed rat pulp on days 1, 3, 7, 14, and 28 postoperatively. Group 1 was irradiated with a CO₂ laser and directly capped with a self-etching adhesive system. The laser was operated in super-pulse mode (pulse duration, 200 μs; interval, 5800 μs; 0.003 J/pulse). The irradiation conditions were a power output of 0.5 W, an irradiation time of 3 s, and repeat mode (10 ms of irradiation at 10-ms intervals for a total beam exposure time of 1.5 s), defocused beam diameter of 0.74 mm (approximately 20 mm from the exposed pulp surface), energy density of 0.698 J/cm² per pulse, total applied energy of 0.75 J, and an activated air-cooling system. Group 2 was capped with the self-etching adhesive system. Group 3 was capped with commercially available calcium hydroxide, and the self-etching adhesive system was applied to the cavity. The following parameters were evaluated: pulp tissue disorganization, inflammatory cell infiltration, reparative dentin formation, and bacterial penetration. The results were statistically analyzed using the Kruskal-Wallis test for differences among the groups at each observation period (P < 0.05). There were no significant differences among the experimental groups in any parameters at any postoperative period (P > 0.05). CO₂ laser irradiation was effective in arresting hemorrhaging but showed a tendency to delay reparative dentin formation compared with the application of calcium hydroxide. PMID:21271324

  12. Ovarian toxicity of cyclophosphamide alone and in combination with ovarian irradiation in the rat

    SciTech Connect

    Jarrell, J.; Lai, E.V.; Barr, R.; McMahon, A.; Belbeck, L.; O'Connell, G.

    1987-05-01

    The effects of radiation and chemotherapy on gonadal function are relevant to the morbidity induced by such treatments. Cyclophosphamide given i.p. to rats on Day 30 of age delayed vaginal opening, prevented vaginal cyclicity, and caused a reduction in serum estradiol and progesterone. Antral follicular atresia increased in a dose-dependent fashion in response to cyclophosphamide (0 mg/kg, 53.5%; 1 mg/kg, 67.3%; 50 mg/kg, 65.7%; 100 mg/kg, 73.9%; 150 mg/kg, 92.2%). Despite such alterations in ovarian function, serum gonadotrophins did not rise. The concurrent administration of 0, 20, 30, 40, 50, and 60 Gy of radiation to the exteriorized ovaries in rats receiving 50 mg/kg cyclophosphamide induced widespread loss of primordial, preantral, and healthy antral follicles associated with reduction in serum progesterone and estradiol. Such irradiation induced dose-related increases in serum follicle-stimulating hormone and luteinizing hormone. Parenteral cyclophosphamide and local irradiation appear to induce ovarian toxicity by different mechanisms.

  13. Tetrahydropalmatine protects rat pulmonary endothelial cells from irradiation-induced apoptosis by inhibiting oxidative stress and the calcium sensing receptor/phospholipase C-γ1 pathway.

    PubMed

    Yu, J; Zhao, L; Liu, L; Yang, F; Zhu, X; Cao, B

    2016-06-01

    The aim of this study was to confirm the protective effect of tetrahydropalmatine (THP) against irradiation-induced rat pulmonary endothelial cell apoptosis and to explore the underlying mechanism, with a focus on the calcium-sensing receptor (CaSR)/phospholipase C-γ1 (PLC-γ1) pathway. We established a model of irradiation-induced primary rat pulmonary endothelial cell injury. Cell apoptosis and mitochondrial membrane potential (Δψm) were measured by flow cytometry. The expression of CaSR, cytochrome c, PLC-γ1, reactive oxygen species (ROS) and [Ca(2+)]i was also determined. Caspase-3 and caspase-9 activities were measured using commercial kits. Inositol triphosphate (IP3) and the production of inflammatory cytokines were detected by enzyme-linked immunosorbent assay. The results showed that THP significantly inhibited irradiation-induced cell apoptosis and intracellular accumulation of ROS. Pretreatment with THP significantly decreased the expression of CaSR, inhibited the CaSR/PLC-γ1 pathway and subsequent [Ca(2+)]i overload stimulated by irradiation. THP, NPS2390 (inhibitor of CaSR), U73122 (inhibitor of PLC-γ1) and 2-APB (inhibitor of IP3) further decreased cell apoptosis, along with down-regulation of cytochrome c, caspase-3 and caspase-9 activation, disruption of Δψm and the production of inflammatory cytokines. These findings suggest that THP protects primary rat pulmonary endothelial cells against irradiation-induced apoptosis by inhibiting oxidative stress and the CaSR/PLC-γ1 pathway. PMID:27134043

  14. Downregulation of toll-like receptor 4 and IL-6 following irradiation of the rat urinary bladder.

    PubMed

    Giglio, D; Wasén, C; Mölne, J; Suchy, D; Swanpalmer, J; Jabonero Valbuena, J; Tobin, G; Ny, L

    2016-07-01

    The pathophysiology behind radiation cystitis is poorly understood. Here we investigated whether bladder irradiation affects the immune system of the rat urinary bladder. Female rats were sedated and exposed to one single radiation dose of 20 Gy or only sedated (controls) and killed 16 h to 14 days later. Rats were placed in a metabolic cage at 16 h, 3 days, 7 days and 14 days following bladder irradiation. The urinary bladders were harvested and analysed with qPCR, immunohistochemistry and/or Western blot for the expression of interferon (IFN)-γ, interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-13, nitric oxide synthases (eNOS, iNOS and nNOS), tumour necrosis factor (TNF)-α and toll-like receptor 4 (TLR4). Urine was collected and analysed for IL-6 and nitrite (reflecting nitric oxide activity) with ELISA and the Griess reaction, respectively. Irradiation increased bladder frequency and decreased voiding volumes 14 days following bladder irradiation. Bladder irradiation increased the expression of IL-10 and collagen in the bladder, while TLR4 and IL-6 expressions were decreased in the urothelium concomitantly with a decrease in mast cells in the submucosa and urine levels of IL-6 and nitrite. The present findings show that bladder irradiation leads to urodynamic changes in the bladder and may suppress important immunoregulatory pathways in the urinary bladder. PMID:27117224

  15. Leydig cells contribute to the inhibition of spermatogonial differentiation after irradiation of the rat.

    PubMed

    Shetty, G; Zhou, W; Weng, C C Y; Shao, S H; Meistrich, M L

    2016-05-01

    Irradiation with 6 Gy produces a complete block of spermatogonial differentiation in LBNF1 rats that would be permanent without treatment. Subsequent suppression of gonadotropins and testosterone (T) restores differentiation to the spermatocyte stage; however, this process requires 6 weeks. We evaluated the role of Leydig cells (LCs) in maintenance of the block in spermatogonial differentiation after exposure to radiation by specifically eliminating functional LCs with ethane dimethane sulfonate (EDS). EDS (but not another alkylating agent), given at 10 weeks after irradiation, induced spermatogonial differentiation in 24% of seminiferous tubules 2 weeks later. However, differentiation became blocked again at 4 weeks as LCs recovered. When EDS was followed by treatment with GnRH antagonist and flutamide, sustained spermatogonial differentiation was induced in >70% of tubules within 2 weeks. When EDS was followed by GnRH antagonist plus exogenous T, which also inhibits LC recovery but restores follicle stimulating hormone (FSH) levels, the spermatogonial differentiation was again rapid but transient. These results confirm that the factors that block spermatogonial differentiation are indirectly regulated by T, and probably FSH, and that adult and possibly immature LCs contribute to the production of such inhibitory factors. We tested whether insulin-like 3 (INSL3), a LC-produced protein whose expression correlated with the block in spermatogonial differentiation, was indeed responsible for the block by injecting synthetic INSL3 into the testes and knocking down its expression in vivo with siRNA. Neither treatment had any effect on spermatogonial differentiation. The Leydig cell products that contribute to the inhibition of spermatogonial differentiation in irradiated rats remain to be elucidated. PMID:26991593

  16. Preventive and therapeutic effects of low level laser irradiation on gentamicin vestibulotoxicity in rat utricle

    NASA Astrophysics Data System (ADS)

    Rhee, Chung-Ku; Oh, Yang Hee; Ahn, Jin-Chul; Jung, Min-Sang; Kim, Yeong-Sik; Suh, Myung-Whan

    2009-02-01

    Purpose: To investigate the effects of low level laser (LLL) irradiation for the prevention and treatment of aminoglycoside-induced vestibular ototoxicity. Materials and Methods: An organotypic culture of 2 to 4 days old rat utricular maculae hair cells was used. The cultured utricular hair cells were divided into 6 groups. Group C: the hair cells were cultured for 14 days. Group G: cultured hair cells were treated with 1 mM gentamicin (GM) for 48 hours. Group L: LLL irradiation with 670 nm diode laser 3 mW/cm2 for 60 min (10.8 J/cm2)/day for 14 days. Group LG: LLL irradiation 10.8 J/ cm2/day for 2 days followed by GM insult. Group GL: treated with GM and followed by LLL irradiation 10.8 J/ cm2/day for 12 days. LGL group: LLL irradiation 10.8 J/ cm2/day for 2 days, then GM insulted, followed by the LLLT 10.8 J/ cm2/day for 10 days. The hair cells in each group were examined and counted by confocal laser scanning electron microscope on 7th and 14th days after FM1-43 staining and observed by scanning electron microscope (SEM). Results: The number of vestibular hair cells of group G was significantly less than those in group C. Group L showed no difference compared to group C. Significantly higher numbers of cells were seen in Group LG and GL comparing to group G. The cells were more in LG than group GL. Group LGL showed the most vestibular hair cells compared to the G, LG, and GL groups. SEM showed damaged hair cells in group G while they were well preserved in groups C, L, LG, GL, and LGL. Conclusion: LLL irradiation before and after GM insult on utricular hair cells were most effective to prevent and treat GM ototoxicity. This study indicates that LLL irradiation may have clinical implications to treat various vestibular and cochlear inner ear diseases.

  17. Radioprotective effects of lycopene and curcumin during local irradiation of parotid glands in Sprague Dawley rats.

    PubMed

    Lopez-Jornet, Pia; Gómez-García, Francisco; García Carrillo, Nuria; Valle-Rodríguez, Ezkai; Xerafin, Ana; Vicente-Ortega, Vicente

    2016-04-01

    Radiotherapy effectively treats cancers of the head and neck. We investigated the possible protective effects of lycopene and curcumin on the parotid glands of 40 female Sprague Dawley rats during irradiation. The study followed European Union regulations 86/609/EEC, 2010/63/EU for animal experimentation. The animals were divided into 4 groups: those treated with curcumin and radiation, those treated with lycopene and radiation, those treated with dimethyl sulphoxide (DMSO) and radiation, and those treated with radiation alone. All compounds were given intraperitoneally the day before irradiation. The total dose of radiation was 20Gy. Morphological and histopathological analyses showed less cell necrosis in the group treated with curcumin than in the other groups, but the difference was not significant. Analysis of structural damage to the parotid ducts and vacuolisation showed significant differences among all groups (p=0.023, p<0.01). Lycopene and curcumin given 24 hours before irradiation reduced the structural damage to the salivary glands. Further studies are needed to confirm these findings. PMID:26830066

  18. Effect of Alpha-Particle Irradiation on Brain Glycogen in the Rat

    NASA Technical Reports Server (NTRS)

    Wolfe, L. S.; Klatzo, Igor; Miquel, Jaime; Tobias, Cornelius; Haymaker, Webb

    1962-01-01

    The studies of Klatzo, Miquel, Tobias and Haymaker (1961) have shown that one of the earliest and most sensitive indications of the effects of alpha-particle irradiation on rat bran is the appearance of glycogen granules mainly in the neuroglia of the exposed area of the brain. Periodic acid-Schiff (PAS) positive, alpha-amylase soluble granules were demonstrated within 12 hr after irradiation, preceding by approximately 36 hr the first microscopically detectable vascular permeability disturbances, as shown by the fluorescein labeled serum protein technique. These studies suggested that the injurious effects of alpha-particle energy were on cellular elements primarily, according to the physical properties and distribution of the radiation in the tissue, and that the vascular permeability disturbances played a secondary role in pathogenesis. The purpose of this study was to correlate the histochemical observations on glycogen with a quantitative assessment of the glycogen in the irradiated brain tissue. It is felt that such a study may contribute to the understanding of radiation injury at the molecular level. A practical aspect of this problem is that the information on biological radiation effects due to accelerated particles from the cyclotron source, is employed in this study, is applicable to radiation from cosmic particles both in free space and entrapped in the Van Allen belts.

  19. Modeling monthly mean variation of the solar global irradiation

    NASA Astrophysics Data System (ADS)

    Vindel, J. M.; Polo, J.; Zarzalejo, L. F.

    2015-01-01

    The monthly mean variation of the solar global reaching the Earth's surface has been characterized at a global level by a regression model. This model considers the monthly variation itself (to different horizons and even the maximum annual variation) as the study variable, and it is applied without using data corresponding to measured meteorological variable. Two explicative variables have been used, the variation of the extraterrestrial irradiation and the variation of the clear sky global horizontal irradiation. The work has been carried out from datasets including average global daily solar irradiation for each month of the year measured on the ground. The model quality has been proven to be very dependent of the temporal variation considered, in such a way that higher variations, that is to say, higher distances between months, lead to an improvement in the model outcomes.

  20. On the rat model of human osteopenias and osteoporoses

    NASA Technical Reports Server (NTRS)

    Frost, Harold M.; Jee, Webster S. S.

    1992-01-01

    The idea that rats cannot model human osteopenias errs. The same mechanisms control gains in bone mass (longitudinal bone growth and modeling drifts) and losses (BMU-based remodeling), in young and aged rats and humans. Furthermore, they respond similarly in rats and man to mechanical influences, hormones, drugs and other agents.

  1. Meso-scale modeling of irradiated concrete in test reactor

    DOE PAGESBeta

    Giorla, Alain B.; Vaitová, M.; Le Pape, Yann; Štemberk, P.

    2015-10-18

    In this paper, we detail a numerical model accounting for the effects of neutron irradiation on concrete at the mesoscale. Irradiation experiments in test reactor (Elleuch et al.,1972), i.e., in accelerated conditions, are simulated. Concrete is considered as a two-phase material made of elastic inclusions (aggregate) subjected to thermal and irradiation-induced swelling and embedded in a cementitious matrix subjected to shrinkage and thermal expansion. The role of the hardened cement paste in the post-peak regime (brittle-ductile transition with decreasing loading rate), and creep effects are investigated. Radiation-induced volumetric expansion (RIVE) of the aggregate cause the development and propagation of damagemore » around the aggregate which further develops in bridging cracks across the hardened cement paste between the individual aggregate particles. The development of damage is aggravated when shrinkage occurs simultaneously with RIVE during the irradiation experiment. The post-irradiation expansion derived from the simulation is well correlated with the experimental data and, the obtained damage levels are fully consistent with previous estimations based on a micromechanical interpretation of the experimental post-irradiation elastic properties (Le Pape et al.,2015). In conclusion, the proposed modeling opens new perspectives for the interpretation of test reactor experiments in regards to the actual operation of light water reactors.« less

  2. Meso-scale modeling of irradiated concrete in test reactor

    SciTech Connect

    Giorla, Alain B.; Vaitová, M.; Le Pape, Yann; Štemberk, P.

    2015-10-18

    In this paper, we detail a numerical model accounting for the effects of neutron irradiation on concrete at the mesoscale. Irradiation experiments in test reactor (Elleuch et al.,1972), i.e., in accelerated conditions, are simulated. Concrete is considered as a two-phase material made of elastic inclusions (aggregate) subjected to thermal and irradiation-induced swelling and embedded in a cementitious matrix subjected to shrinkage and thermal expansion. The role of the hardened cement paste in the post-peak regime (brittle-ductile transition with decreasing loading rate), and creep effects are investigated. Radiation-induced volumetric expansion (RIVE) of the aggregate cause the development and propagation of damage around the aggregate which further develops in bridging cracks across the hardened cement paste between the individual aggregate particles. The development of damage is aggravated when shrinkage occurs simultaneously with RIVE during the irradiation experiment. The post-irradiation expansion derived from the simulation is well correlated with the experimental data and, the obtained damage levels are fully consistent with previous estimations based on a micromechanical interpretation of the experimental post-irradiation elastic properties (Le Pape et al.,2015). In conclusion, the proposed modeling opens new perspectives for the interpretation of test reactor experiments in regards to the actual operation of light water reactors.

  3. Modulation of gamma-irradiation and carbon tetrachloride induced oxidative stress in the brain of female rats by flaxseed oil.

    PubMed

    Ismail, Amel F M; Salem, Asmaa A M; Eassawy, Mamdouh M T

    2016-08-01

    The activity of flaxseed oil (FSO) on gamma-irradiation (7Gy) and/or carbon tetrachloride (CCl4) induced acute neurotoxicity in rats' brain was investigated. The results revealed a significant decrease (p<0.05) in superoxide dismutase (SOD), catalase (CAT), glutathione-peroxidase (GSH-Px) activities, reduced glutathione (GSH) and manganese (Mn) contents. Further, a significant elevation (p<0.05) in malondialdehyde, nitric oxide (NO), Tumor Necrosis Factor-alpha (TNF-α), Interleukin-1-beta (IL-1β), Interleukin-6 (IL-6), transforming growth factor-beta-1 (TGF-β1), iron (Fe), calcium (Ca), copper (Cu) and magnesium (Mg) levels were observed. Furthermore, the relative ratio of xanthine oxidase (XO) and inducible nitric-oxide synthase (iNOS) gene expression levels were elevated in the brain tissues of γ-irradiated and CCl4 intoxicated animals. Those effects were augmented due to the effect of CCl4-induced toxicity in γ-irradiated rats. The treatment of FSO displayed significant amendment of the studied parameters in the brain tissues of γ-irradiated and CCl4 intoxicated animals. FSO has a neuroprotective effect against CCl4-induced brain injury in gamma-irradiated rats. This effect is interrelated to the ability of FSO to scavenges the free radicals, enhances the antioxidant enzymes activity, increases GSH contents, down-regulates the inflammatory responses, ameliorates the iron, calcium, copper, magnesium, manganese levels and inhibiting the gene expression level of XO and iNOS in the brain tissues of intoxicated animals. In conclusion, this study demonstrated that the potent antioxidant and anti-inflammatory activities of FSO have the ability to improve the antioxidant status, suppress the inflammatory responses, and regulate the trace elements in the brain tissues of γ-irradiated, CCl4, and their combined effect in intoxicated animals. Consequently, FSO exhibited neuroprotective activity on γ-irradiated, CCl4, and their combined effect induced brain injury in

  4. Effects of gamma-irradiation on biosynthesis of different types of ribonucleic acids in normal and regenerating rat liver.

    PubMed Central

    Markov, G G; Dessev, G N; Russev, G C; Tsanev, R G

    1975-01-01

    1. The effect of gamma-irradiation (4000rd) on the synthesis of ribosomal (pre-rRNA) and heterogeneous nuclear RNA (pre-mRNA) in normal and in regenerating rat liver was studied by using 40 min labelling with [6(-14)C]orotic acid. 2. Partial hepatectomy caused a sharp transient increase in the specific radioactivity of the endogenous low-molecular-weight RNA precursors in the livers of both normal and irradiated rats. Irradiation of intact animals did not affect the pool. 3. Irradiation enhanced the synthesis of pre-rRNA for at least 12h. The synthesis of pre-mRNA was also enhanced, but only in the first 3h after irradiation. 4. Partial hepatectomy strongly stimulated the synthesis of both pre-rRNA and pre-mRNA. 5. The synthesis of pre-rRNA was enhanced also in regenerating liver of animals irradiated before or after the operation. The conclusion can be drawn that the early increase in the synthesis of ribosomal RNA is a non-specific cellular response to different injuring factors. 6. The only case where irradiation caused an early inhibition of RNA synthesis was that of pre-mRNA in regenerating liver. This supports the hypothesis that ionizing radiation does not suppress the transcription per se but affects the mechanisms of activation of new genes (cellular programming). PMID:1147904

  5. Evaluation of global horizontal irradiance to plane-of-array irradiance models at locations across the United States

    SciTech Connect

    Lave, Matthew; Hayes, William; Pohl, Andrew; Hansen, Clifford W.

    2015-02-02

    We report an evaluation of the accuracy of combinations of models that estimate plane-of-array (POA) irradiance from measured global horizontal irradiance (GHI). This estimation involves two steps: 1) decomposition of GHI into direct and diffuse horizontal components and 2) transposition of direct and diffuse horizontal irradiance (DHI) to POA irradiance. Measured GHI and coincident measured POA irradiance from a variety of climates within the United States were used to evaluate combinations of decomposition and transposition models. A few locations also had DHI measurements, allowing for decoupled analysis of either the decomposition or the transposition models alone. Results suggest that decomposition models had mean bias differences (modeled versus measured) that vary with climate. Transposition model mean bias differences depended more on the model than the location. Lastly, when only GHI measurements were available and combinations of decomposition and transposition models were considered, the smallest mean bias differences were typically found for combinations which included the Hay/Davies transposition model.

  6. Evaluation of solar irradiance models for climate studies

    NASA Astrophysics Data System (ADS)

    Ball, William; Yeo, Kok-Leng; Krivova, Natalie; Solanki, Sami; Unruh, Yvonne; Morrill, Jeff

    2015-04-01

    Instruments on satellites have been observing both Total Solar Irradiance (TSI) and Spectral Solar Irradiance (SSI), mainly in the ultraviolet (UV), since 1978. Models were developed to reproduce the observed variability and to compute the variability at wavelengths that were not observed or had an uncertainty too high to determine an accurate rotational or solar cycle variability. However, various models and measurements show different solar cycle SSI variability that lead to different modelled responses of ozone and temperature in the stratosphere, mainly due to the different UV variability in each model, and the global energy balance. The NRLSSI and SATIRE-S models are the most comprehensive reconstructions of solar irradiance variability for the period from 1978 to the present day. But while NRLSSI and SATIRE-S show similar solar cycle variability below 250 nm, between 250 and 400 nm SATIRE-S typically displays 50% larger variability, which is however, still significantly less then suggested by recent SORCE data. Due to large uncertainties and inconsistencies in some observational datasets, it is difficult to determine in a simple way which model is likely to be closer to the true solar variability. We review solar irradiance variability measurements and modelling and employ new analysis that sheds light on the causes of the discrepancies between the two models and with the observations.

  7. Field orientation effects during 5. 6-GHz radiofrequency irradiation of rats

    SciTech Connect

    Frei, M.R.; Jauchem, J.R.; Price, D.L.; Padilla, J.M. )

    1990-12-01

    Ketamine-anesthetized Sprague-Dawley rats were exposed in E and H orientations (long axis parallel to electric and magnetic fields, respectively) to far-field 5.6-GHz continuous-wave radio-frequency radiation (RFR). Power densities were used that resulted in equivalent whole-body average specific absorption rates of 14 W/kg in both orientations (90 mW/cm2 for E and 66 mW/cm2 for H). Irradiation was conducted to increase colonic temperature by 1 degree C (from 38.5 to 39.5 degrees C). During experimentation, arterial blood pressure and respiratory rate and colonic, tympanic, left and right subcutaneous (sides toward and away from RFR source), and tail temperatures were continuously recorded. Results showed no significant difference in the times required to cause a 1 degree C increase or to recover to the initial temperature when irradiation was stopped. Significant differences between E- and H-orientation exposure were seen in the patterns of localized heating. The tail and left subcutaneous temperature increases were significantly greater during E-orientation exposure, the tympanic site showed no difference, and the right subcutaneous temperature increase was significantly greater during H-orientation exposure. Under both exposure conditions, heart rate and mean arterial blood pressure significantly increased during irradiation; however, there were no significant differences between E and H orientation responses. These findings at 5.6 GHz are in contrast to the significant cardiovascular response differences between E- and H-orientation exposure noted during a previous study of irradiation at 2.45 GHz.

  8. Short Communication: Rheological properties of blood serum of rats after irradiation with different gamma radiation doses in vivo.

    PubMed

    Abdelhalim, Mohamed Anwar K; Moussa, Sherif Aa; Ms, Al-Ayed

    2016-01-01

    The blood serum rheological properties open the door to find suitable radio-protectors and convenient therapy for many cases of radiation exposure. The present study aimed to investigate the rheological properties of rat blood serum at wide range of shear rates after whole body irradiation with different gamma radiation doses in vivo. Healthy male rats were divided into five groups; one control group and 4 irradiated groups. The irradiation process was carried out using Co60 source with dose rate of 0.883cG/sec. Several rheological parameters were measured using Brookfield LVDV-III Programmable rheometer. A significant increase in viscosity and shear stress was observed with 25 and 50Gy corresponding to each shear rate compared with the control; while a significant decrease observed with 75 and 100Gy. The viscosity exhibited a Non-Newtonian behaviour with the shear rate while shear stress values were linearly related with shear rate. The decrease in blood viscosity might be attributed to changes in molecular weight, pH sensitivity and protein structure. The changes in rheological properties of irradiated rats' blood serum might be attributed to destruction changes in the haematological and dimensional properties of rats' blood products. PMID:27005501

  9. INTERACTION BETWEEN HEAVY PARTICLES IRRADIATION AND AGE IN THE DISRUPTION OF FIXED-RATION OPERANT RESPONDING IN RATS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exposing rats to heavy particle irradiation (56Fe) produces a disruption in the functioning of the dopaminergic system and in the behaviors that are mediated by the dopaminergic this system. To some extent the neurochemical and behavioral deficits observed following exposure to 56Fe particles are s...

  10. Modeling of microstructure evolution in austenitic stainless steels irradiated under light water reactor condition

    NASA Astrophysics Data System (ADS)

    Gan, J.; Was, G. S.; Stoller, R. E.

    2001-10-01

    A model for microstructure development in austenitic alloys under light water reactor irradiation conditions is described. The model is derived from the model developed by Stoller and Odette to describe microstructural evolution under fast neutron or fusion reactor irradiation conditions. The model is benchmarked against microstructure measurements in 304 and 316 SS irradiated in a boiling water reactor core using one material-dependent and three irradiation-based parameters. The model is also adapted for proton irradiation at higher dose rate and higher temperature and is calibrated against microstructure measurements for proton irradiation. The model calculations show that for both neutron and proton irradiations, in-cascade interstitial clustering is the driving mechanism for loop nucleation. The loss of interstitial clusters to sinks by interstitial cluster diffusion was found to be an important factor in determining the loop density. The model also explains how proton irradiation can produce an irradiated dislocation microstructure similar to that in neutron irradiation.

  11. Pre-exposure to low-power diode laser irradiation promotes cytoprotection in the rat retina.

    PubMed

    Sun, Yue; Zhang, Shisheng; Liao, Huaping; Wang, Jing; Wang, Ling

    2015-01-01

    The aim of this study was to investigate whether pre-exposure to low-power laser irradiation can provoke an effect on cellular protection in the rat retina. The right eyes of 40 rats were exposed to a 3-mm diode laser beam for 1 min in different light intensities and different experimental sets: group A low power of 60 mW (34.27 J/cm(2) on the retina in consideration of the energy losses along the optical pathway) prior to high power of 80 mW (44.88 J/cm(2) on the retina in consideration of the energy losses along the optical pathway), group B high power, group C low power, group D (the left eyes from the counterpart of group A) and group E (untreated rat eyes) as controls. Morphological retinal change retinas were assessed using light microscopy and/or transmission electron microscopy. Heat shock protein (Hsp) 70 and cleaved caspase 3 protein expression were analyzed by immunohistochemical staining and Western blot. Cellular injury was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay. Hsp 70 expression in the inner plexiform layer and the outer plexiform layer in group A were 73.09 ± 6.49 and 78.03 ± 3.05%, respectively, which was significantly higher (P < 0.05) than those observed in group B (59.07 ± 1.40 and 32.25 ± 4.26%, respectively). The Hsp70/β-actin ratio was 0.49 ± 0.06 in group C, which was significantly higher (P < 0.05) than that of group B (0.27 ± 0.04). Cleaved caspase 3 expression in group C both was significantly lower than that observed in group B. TUNEL staining showed that positive cells in the outer nuclear layer and inner nuclear layer in group A were significantly lower than those of group B. Pre-exposure to a 60-mW (34.27 J/cm(2) on the retina) power laser irradiation stimulates a hyperexpression of Hsp70 together with a hypoexpression of cleaved caspase 3 in rat retina, which may suggest a cellular protective effect. PMID:25048854

  12. Gamma irradiation or hydrocortisone treatment of rats increases the proteinase activity associated with histones of thymus nuclei

    SciTech Connect

    Kutsyi, M.P.; Gaziev, A.I.

    1994-11-01

    An increase in the activity of histone-associated rat thymus nucleus proteinases specific for histones H2A, H2B and H1 was shown after {gamma} irradiation or hydrocortisone treatment of animals. Histone H1-specific proteinase activity is dependent on DNA and increases in the presence of denatured DNA, whereas proteinases specific for core histones are inhibited in the presence of denatured DNA. The increase in the activity of histone-associated proteinases depends on the radiation dose and the time after irradiation or hydrocortisone injection. In the presence of dithiothreitol and sodium dodecyl sulfate, these proteinases dissociate from histones. It was found by gel electrophoresis that several proteinases of various molecular masses are closely associated with histones obtained from thymus nuclei of irradiated or hydrocortisone-treated rats. 43 refs., 7 figs.

  13. Dose-related cerebellar abnormality in rats with prenatal exposure to X-irradiation by magnetic resonance imaging volumetric analysis.

    PubMed

    Sawada, Kazuhiko; Saito, Shigeyoshi; Horiuchi-Hirose, Miwa; Mori, Yuki; Yoshioka, Yoshichika; Murase, Kenya

    2013-09-01

    Cerebellar abnormalities in 4-week-old rats with a single whole body X-irradiation at a dose of 0.5, 1.0, or 1.5 Gy on embryonic day (ED) 15 were examined by magnetic resonance imaging (MRI) volumetry. A 3D T2 W-MRI anatomical sequence with high-spatial resolution at 11.7-tesla was acquired from the fixed rat heads. By MRI volumetry, whole cerebellar volumes decreased dose-dependently. Multiple linear regression analysis revealed that the cortical volume (standardized β=0.901; P<0.001) was a major explanatory variable for the whole cerebellar volume, whereas both volumes of the white matter and deep cerebellar nuclei also decreased depending on the X-irradiation dose. The present MRI volumetric analysis revealed a dose-related cerebellar cortical hypoplasia by prenatal exposure to X-irradiation on E15. PMID:23998266

  14. Rat Model of Parkes Weber Syndrome.

    PubMed

    Bojakowski, Krzysztof; Janusz, Gabriela; Grabowska, Iwona; Zegrocka-Stendel, Oliwia; Surowiecka-Pastewka, Agnieszka; Kowalewska, Magdalena; Maciejko, Dorota; Koziak, Katarzyna

    2015-01-01

    The Parkes Weber syndrome is a congenital vascular malformation, characterized by varicose veins, arterio-venous fistulas and overgrown limbs. No broadly accepted animal model of Parkes Weber syndrome has been described. We created side-to-side arterio-venous fistula between common femoral vessels with proximal non-absorbable ligature on common femoral vein limiting the enlargement of the vein diameter in Wistar rats. Contralateral limb was sham operated. Invasive blood pressure measurements in both iliac and inferior cava veins were performed in rats 30 days after fistula creation. Tight circumference and femoral bone length were measured. Histopathology and morphology of soleus muscle, extensor digitorum longus muscle, and the common femoral vessel were analyzed. 30 days following arterio-venous fistula creation, a statistically significant elevation of blood pressure in common iliac vein and limb overgrowth was observed. Limb enlargement was caused by muscle overgrowth, varicose veins formation and bone elongation. Arterio-venous fistula with proximal outflow limitation led to significant increase of femoral vein circumference and venous wall thickness. Our study indicates that the described rat model mimics major clinical features characteristic for the human Parkes Weber syndrome: presence of arterio-venous fistula, venous hypertension and dilatation, varicose veins formation, and the limb hypertrophy. We reveal that limb overgrowth is caused by bone elongation, muscle hypertrophy, and venous dilatation. The newly established model will permit detailed studies on the mechanisms underlying the disease and on the efficacy of novel therapeutic strategies for the Parkes Weber syndrome treatment. PMID:26217941

  15. Rat Model of Parkes Weber Syndrome

    PubMed Central

    Bojakowski, Krzysztof; Janusz, Gabriela; Grabowska, Iwona; Zegrocka-Stendel, Oliwia; Surowiecka-Pastewka, Agnieszka; Kowalewska, Magdalena; Maciejko, Dorota; Koziak, Katarzyna

    2015-01-01

    The Parkes Weber syndrome is a congenital vascular malformation, characterized by varicose veins, arterio-venous fistulas and overgrown limbs. No broadly accepted animal model of Parkes Weber syndrome has been described. We created side-to-side arterio-venous fistula between common femoral vessels with proximal non-absorbable ligature on common femoral vein limiting the enlargement of the vein diameter in Wistar rats. Contralateral limb was sham operated. Invasive blood pressure measurements in both iliac and inferior cava veins were performed in rats 30 days after fistula creation. Tight circumference and femoral bone length were measured. Histopathology and morphology of soleus muscle, extensor digitorum longus muscle, and the common femoral vessel were analyzed. 30 days following arterio-venous fistula creation, a statistically significant elevation of blood pressure in common iliac vein and limb overgrowth was observed. Limb enlargement was caused by muscle overgrowth, varicose veins formation and bone elongation. Arterio-venous fistula with proximal outflow limitation led to significant increase of femoral vein circumference and venous wall thickness. Our study indicates that the described rat model mimics major clinical features characteristic for the human Parkes Weber syndrome: presence of arterio-venous fistula, venous hypertension and dilatation, varicose veins formation, and the limb hypertrophy. We reveal that limb overgrowth is caused by bone elongation, muscle hypertrophy, and venous dilatation. The newly established model will permit detailed studies on the mechanisms underlying the disease and on the efficacy of novel therapeutic strategies for the Parkes Weber syndrome treatment. PMID:26217941

  16. Effect of 710 nm visible light irradiation on neurite outgrowth in primary rat cortical neurons following ischemic insult

    SciTech Connect

    Choi, Dong-Hee; Lee, Kyoung-Hee; Kim, Ji-Hye; Kim, Moon Young; Lim, Jeong Hoon; Lee, Jongmin

    2012-06-01

    Highlights: Black-Right-Pointing-Pointer 710 nm wavelength light (LED) has a protective effect in the stroke animal model. Black-Right-Pointing-Pointer We determined the effects of LED irradiation in vitro stroke model. Black-Right-Pointing-Pointer LED treatment promotes the neurite outgrowth through MAPK activation. Black-Right-Pointing-Pointer The level of synaptic markers significantly increased with LED treatment. Black-Right-Pointing-Pointer LED treatment protects cell death in the in vitro stroke model. -- Abstract: Objective: We previously reported that 710 nm Light-emitting Diode (LED) has a protective effect through cellular immunity activation in the stroke animal model. However, whether LED directly protects neurons suffering from neurodegeneration was entirely unknown. Therefore, we sought to determine the effects of 710 nm visible light irradiation on neuronal protection and neuronal outgrowth in an in vitro stroke model. Materials and methods: Primary cultured rat cortical neurons were exposed to oxygen-glucose deprivation (OGD) and reoxygenation and normal conditions. An LED array with a peak wavelength of 710 nm was placed beneath the covered culture dishes with the room light turned off and were irradiated accordingly. LED treatments (4 min at 4 J/cm{sup 2} and 50 mW/cm{sup 2}) were given once to four times within 8 h at 2 h intervals for 7 days. Mean neurite density, mean neurite diameter, and total fiber length were also measured after microtubule associated protein 2 (MAP2) immunostaining using the Axio Vision program. Synaptic marker expression and MAPK activation were confirmed by Western blotting. Results: Images captured after MAP2 immunocytochemistry showed significant (p < 0.05) enhancement of post-ischemic neurite outgrowth with LED treatment once and twice a day. MAPK activation was enhanced by LED treatment in both OGD-exposed and normal cells. The levels of synaptic markers such as PSD 95, GAP 43, and synaptophysin significantly

  17. Steroid hormone production in testis, ovary, and adrenal gland of immature rats irradiated in utero with /sup 60/Co

    SciTech Connect

    Inano, H.; Suzuki, K.; Ishii-Ohba, H.; Imada, Y.; Kumagai, R.; Kurihara, S.; Sato, A.

    1989-02-01

    Pregnant rats received whole-body irradiation at 20 days of gestation with 2.6 Gy lambda rays from a 60Co source. Endocrinological effects before maturation were studied using testes and adrenal glands obtained from male offspring and ovaries from female offspring irradiated in utero. Seminiferous tubules of the irradiated male offspring were remarkably atrophied with free germinal epithelium and containing only Sertoli cells. Female offspring also had atrophied ovaries. Testicular tissue obtained from intact and 60Co-irradiated rats was incubated with 14C-labeled pregnenolone, progesterone, 17 alpha-hydroxyprogesterone, and androstenedione as a substrate. Intermediates for androgen production and catabolic metabolites were isolated after the incubation. The amounts of these metabolites produced by the irradiated testes were low in comparison with the control. The activities of delta 5-3 beta-hydroxysteroid dehydrogenase, 17 alpha-hydroxylase, C17,20-lyase, and delta 4-5 alpha-reductase in the irradiated testes were 30-40% of those in nonirradiated testes. Also, the activities of 17 beta- and 20 alpha-hydroxysteroid dehydrogenases were 72 and 52% of the control, respectively. In adrenal glands, the 21-hydroxylase activity of the irradiated animals was 38% of the control, but the delta 5-3 beta-hydroxysteroid dehydrogenase activity was comparable to that of the control. On the other hand, the activity of delta 5-3 beta-hydroxysteroid dehydrogenase of the irradiated ovary was only 19% of the control. These results suggest that 60Co irradiation of the fetus in utero markedly affects the production of steroid hormones in testes, ovaries, and adrenal glands after birth.

  18. The influence of antiorthostatic unloading and long gamma-irradiation on rat bone marrow (MSCs)

    NASA Astrophysics Data System (ADS)

    Roe, Maria; Bobyleva, Polina; Shtemberg, Andrey; Buravkova, Ludmila

    With the prospect of long interplanetary spaceflight becoming a real possibility there are some important questions that need to be answered regarding the combined effects of microgravity and long gamma-irradiation.The aim of this study was to evaluate the effects of synchronous antiorthostatic unloading and fractional gamma-irradiation on the functional characteristics of rat bone marrow multipotent stromal cells (MSCs).This experiment was carried out following all rules laid out by the Commission on Bioethics at the SSC RF - IBMP RAS. In this experiment the Wistar rats were kept in an unloaded position for a duration of 30 days. They were also subjected to 6 doses of gamma-radiation on the “GOBO-60” with a source of (137) Cs. The dose rate set to 1 meter 50 sGr / H (Total dose of 3 Gr).The study revealed a significant reduction in the number of colonies (CFU-F) in all cultures from the experimental groups when compared to the control groups. The most significant reduction was observed in the group, which had been subject to combined unloading, and radiation. This result was confirmed by examination of cell cultures during 10 days of growth.We found that the CD45 expression was increased in the groups exposed to radiation. At the same time a reduction in the expression of CD90 was observed during combination of radiation and unloading we found.The experimental groups also differed from the control group showing smaller lipid inclusions and decreased expression of alkaline phosphates in the MSCs. This experiment concluded that the bone marrow MSCs after a combination of unloading and multiple radiation sessions, showed a decrease in proliferation and differentiation potential which could reduce the adaption and reparative capacity of the organism.

  19. Evaluation of low level laser therapy irradiation parameters on rat muscle inflammation through systemic blood cytokines

    NASA Astrophysics Data System (ADS)

    Mantineo, Matias; Pinheiro, João. P.; Morgado, António M.

    2014-02-01

    Low level laser therapy (LLLT) has been used for inflammation treatment. Here, we evaluate the effect of different doses, using continuous (830 and 980 nm) and pulsed illumination (830 nm), in the treatment of inflammation induced in the gastrocnemius muscle of Wistar rats, through cytokines concentration in systemic blood and histological analysis of muscle tissue. Animals were randomly divided into five groups per wavelength (5 animals per group: 10, 20, 30, 40 and 50 mW) plus a control group. LLLT was applied during five days, with constant exposure time and irradiated area (3 minutes; 0.5026 cm2). Blood was collected on days 0, 3 and 6. TNF-α, IL-1β, IL-2 and IL-6 cytokines were quantified by ELISA. Rats were killed on day 6. Muscle inflammatory cells were counted using optical microscopy. Treatment effects occurred for all applied doses (largest effect at 40 mW: 7.2 J, 14 J/cm2 per irradiation), with reduction of proinflammatory TNF-α, IL-1β and IL-6 cytokines and lower number of inflammatory cells. Results were better for 830 nm. Identical methodology was used with pulsed illumination. Average power (40 mW) and duty cycle were kept constant (80%) at five frequencies (5, 25, 50, 100 and 200 Hz). Treatment effects were observed at higher frequencies, with no significant differences between them. However, the treatment effect was lower than for continuous illumination. LLLT effect on inflammation treatment can be monitored by measuring systemic blood cytokines. A larger treatment effect was observed with continuous illumination, where results seem to be compatible with a biphasic dose response.

  20. Suppressed histamine release from rat peritoneal mast cells by ultraviolet B irradiation: decreased diacylglycerol formation as a possible mechanism

    SciTech Connect

    Danno, K.; Fujii, K.; Tachibana, T.; Toda, K.; Horio, T.

    1988-06-01

    This study was designed to investigate the effect of ultraviolet B (UVB) irradiation on mast cell functions. Purified mast cells obtained from rat peritoneal cavity were irradiated with UVB and subsequently exposed to a degranulator, compound 48/80, or the calcium ionophore A-23187. The amount of histamine released from mast cells measured by the enzyme isotopic assay was significantly decreased by UVB irradiation (100-400 mJ/cm2). Within this dose range, UVB alone was not cytotoxic to the cells because it did not induce histamine release. The suppression was observed when mast cells were subjected to degranulation without intervals after UVB irradiation, and even after 5 h postirradiation. The wavelength of 300 nm from a monochromatic light source showed the maximum effect. When mast cells prelabeled with (/sup 3/H)arachidonate were irradiated and challenged by compound 48/80, label accumulation in diacylglycerol produced by the phosphatidylinositol cycle was considerably decreased by UVB irradiation. From these results, we hypothesize that, within an adequate irradiation dose, UVB irradiation suppresses histamine release from mast cells, probably by causing noncytotoxic damage to the membrane phospholipid metabolism, which is tied to the degranulation mechanisms.

  1. Anticarcinogenic effect of tetrachlorodecaoxide after total-body gamma irradiation in rats

    SciTech Connect

    Kempf, S.R.; Port, R.E.; Ivankovic, S.

    1994-08-01

    Tetrachlorodecaoxygen (TCDO) therapy of acute radiation syndrome was tested for a possible influence on the development of X-ray-induced malignancies. BD IX rats were exposed to total-body irradiation (TBI, {gamma} rays, 9 or 11 Gy) and received daily intravenous injections of either TCDO or physiological saline solution from days 4 through 11 after TBI. The short-term TCDO therapy reduced the acute death rate markedly, but survival rates after 4 months were similar with and without TCDO. The first malignancy after TBI occurred on day 103, and over the lifetime of the animals the tumor incidence in the group given TBI (11 Gy) without TCDO treatment was 73% vs 20% in animals with short-term TCDO therapy after TBI. In particular, there was a highly significant prevention of radiation-induced leukemia [P (one-sided) < 0.001] by TCDO, and a significantly reduced incidence of malignant epithelial tumors [P (one-sided) < 0.05]. The development of sarcomas was not affected by TCDO. Long-term survival was not enhanced by TCDO due to the occurrence of bronchopneumonial infections about 1 year after TBI. In conclusion, TCDO is not only a potent therapeutic agent in acute radiation syndrome, but it also significantly reduced the carcinogenic risk in rats after exposure to ionizing radiation. 18 refs., 3 figs., 4 tabs.

  2. Effect of low-level prenatal X-irradiation on postnatal development in the Wistar rat

    SciTech Connect

    Jensh, R.P.; Brent, R.L.

    1987-03-01

    The objective of this investigation was to determine the effect of low-dose prenatal X-irradiation on postnatal growth and neurobehavioral development, and whether alterations would manifest at dosages lower than those which produce anatomic malformations from exposure at the most sensitive period of organogenesis. Ninety-eight Wistar strain rats were exposed to 0.1, 0.2, or 0.4 Gy X-radiation of were sham irradiated on the 9th or 17th day of gestation. A conventional teratologic evaluation was completed on half of the animals (572 fetuses). The age of appearance of four physiologic markers and of acquisition of six reflexes was observed in 372 offspring. Exposure during early organogenesis at these levels had no effect on any of these parameters. Prenatal exposure to X-radiation on the 17th day of gestation at dosage levels greater than 0.1 Gy resulted in alterations in the appearance of three postnatal neurophysiologic parameters. Growth retardation throughout the postpartum period also was observed in the offspring. The induction of developmental and reflex alterations had a comparable threshold to the known threshold for anatomic malformations on the 9th day. These results indicate that all of the parameters studied had thresholds either at or above 0.2 Gy acute radiation, and that the postpartum developmental and reflex acquisition measures were not more sensitive indicators of exposure to X-radiation than growth parameters.

  3. Models of Solar Irradiance Variability and the Instrumental Temperature Record

    NASA Technical Reports Server (NTRS)

    Marcus, S. L.; Ghil, M.; Ide, K.

    1998-01-01

    The effects of decade-to-century (Dec-Cen) variations in total solar irradiance (TSI) on global mean surface temperature Ts during the pre-Pinatubo instrumental era (1854-1991) are studied by using two different proxies for TSI and a simplified version of the IPCC climate model.

  4. Irradiation Design for an Experimental Murine Model

    SciTech Connect

    Ballesteros-Zebadua, P.; Moreno-Jimenez, S.; Suarez-Campos, J. E.; Celis, M. A.; Larraga-Gutierrez, J. M.; Garcia-Garduno, O. A.; Rubio-Osornio, M. C.; Custodio-Ramirez, V.; Paz, C.

    2010-12-07

    In radiotherapy and stereotactic radiosurgery, small animal experimental models are frequently used, since there are still a lot of unsolved questions about the biological and biochemical effects of ionizing radiation. This work presents a method for small-animal brain radiotherapy compatible with a dedicated 6MV Linac. This rodent model is focused on the research of the inflammatory effects produced by ionizing radiation in the brain. In this work comparisons between Pencil Beam and Monte Carlo techniques, were used in order to evaluate accuracy of the calculated dose using a commercial planning system. Challenges in this murine model are discussed.

  5. Ideal Experimental Rat Models for Liver Diseases.

    PubMed

    Lee, Sang Woo; Kim, Sung Hoon; Min, Seon Ok; Kim, Kyung Sik

    2011-05-01

    There are many limitations for conducting liver disease research in human beings due to the high cost and potential ethical issues. For this reason, conducting a study that is difficult to perform in humans using appropriate animal models, can be beneficial in ascertaining the pathological physiology, and in developing new treatment modalities. However, it is difficult to determine the appropriate animal model which is suitable for research purposes, since every patient has different and diverse clinical symptoms, adverse reactions, and complications due to the pathological physiology. Also, it is not easy to reproduce identically various clinical situations in animal models. Recently, the Guide for the Care and Use of Laboratory Animals has tightened up the regulations, and therefore it is advisable to select the appropriate animals and decide upon the appropriate quantities through scientific and systemic considerations before conducting animal testing. Therefore, in this review article the authors examined various white rat animal testing models and determined the appropriate usable rat model, and the pros and cons of its application in liver disease research. The authors believe that this review will be beneficial in selecting proper laboratory animals for research purposes. PMID:26421020

  6. Effects of irradiation and semistarvation on rat thyrotropin beta subunit messenger ribonucleic acid, pituitary thyrotropin content, and thyroid hormone levels

    SciTech Connect

    Litten, R.Z. ); Carr, F.E. ); Fein, H.G.; Smallridge, R.C. )

    1990-01-01

    The effect of radiation-induced anorexia on serum thyrotropin (TSH), pituitary TSH-{beta} mRNA, pituitary TSH content, serum thyroxine (T{sub 4}), and serum 3,5,3{prime}-triiodothyronine (T{sub 3}) was investigated using feed-matched controls. Rats received 10 Gy gamma whole-body irradiation and were examined 1-3 days postirradiation. Feed-matched and untreated controls were also studied. The average food intake of the irradiated and feed-matched groups was approximately 18% of the untreated controls. Over the three day period both the irradiated and feed-matched groups lost a significant amount of body weight. The serum T{sub 4} levels of both the irradiated and feed-matched groups were not significantly different from each other, but were significantly depressed when compared to the untreated control group. The serum TSH and T{sub 3} were, however, significantly greater in the irradiated than the feed-matched groups at day 3 posttreatment. To determine if the difference in the serum TSH level between the two groups was due to a pretranslational alteration in TSH production, we measured the TSH-{beta} mRNA using an RNA blot hybridization assay. We found that the TSH-{beta} mRNA level was the same in the irradiated and feed-matched groups, suggesting that the mechanism responsible for the radiation-induced increase in the serum TSH level is posttranscriptional. Pituitary TSH content in the irradiated rats was significantly less than in pair-fed controls, suggesting that irradiation may permit enhanced secretion of stored hormone.

  7. Rat injury model of docetaxel extravasation

    PubMed Central

    ZHU, JING-JING; FU, JIAN-FEI; YANG, JIAO; HU, BING; ZHANG, HUI; YU, JIAN-HUA

    2014-01-01

    Docetaxel is a novel type of chemotherapy drug that actively treats a number of malignant tumors. The aim of the present study was to explore the severity and natural course of tissue damage induced by docetaxel extravasation and to confirm the vesicant potential of docetaxel. Rats were selected for the establishment of the ulcer model. Different volumes and concentrations were explored to induce the skin ulcer and to confirm the optimum rational injection model. The natural course of tissue injury and pathological changes produced by docetaxel extravasation were observed by comparing to vinorelbine extravasation. A 0.4 ml volume and a 6 mg/ml concentration were the optimum rational injection model for the induction of the skin ulcer. The docetaxel extravasation induced local tissue necrosis, followed by granuloma formation and hyperpigmentation or scar formation. The severity of the injury depended on the concentration of the extravasation used in the rat model. The injury occurred on the first day following extravasation and lasted 4–6 weeks. The damage from docetaxel was weaker than vinorelbine in association with the depth and extension of necrosis. In conclusion, docetaxel extravasation can induce tissue necrosis. However, the severity of necrosis was weaker than that of vinorelbine. Docetaxel has superficial vesicant properties. PMID:25054005

  8. Inability of donor total body irradiation to prolong survival of vascularized bone allografts: Experimental study in the rat

    SciTech Connect

    Gonzalez del Pino, J.; Benito, M.; Randolph, M.A.; Weiland, A.J. )

    1990-07-01

    At the present time, the toxic side effects of recipient immunosuppression cannot be justified for human non-vital organ transplantation. Total body irradiation has proven effective in ablating various bone-marrow-derived and endothelial immunocompetent cellular populations, which are responsible for immune rejection against donor tissues. Irradiation at a dose of 10 Gy was given to donor rats six days prior to heterotopic transplantation of vascularized bone allografts to host animals. Another group of recipient rats also received a short-term (sixth to fourteenth day after grafting), low dose of cyclosporine. Total body irradiation was able merely to delay rejection of grafts across a strong histocompatibility barrier for one to two weeks, when compared to nonirradiated allografts. The combination of donor irradiation plus cyclosporine did not delay the immune response, and the rejection score was similar to that observed for control allografts. Consequently, allograft viability was quickly impaired, leading to irreversible bone damage. This study suggest that 10 Gy of donor total body irradiation delivered six days prior to grafting cannot circumvent the immune rejection in a vascularized allograft of bone across a strong histocompatibility barrier.

  9. Total lymphoid irradiation in rat heart albgrafts: dose, fractionation, and combination with cyclosporin-A. [X-ray

    SciTech Connect

    Rynasiewicz, J.J.; Sutherland, D.E.R.; Kawahara, K.; Kim, T.; Najarian, J.S.

    1981-03-01

    The survival or organ allografts is prolonged in mice and rats treated with fractionated, high-dose total lymphoid irradiation (TLI). We have studied the effect of TLI, alone or in combination with donor bone marrow or pharmacologic immunosuppression (cyclosporin-A: CY-A), on the survival of heterotopic rat heart allografts. Specifically, we evaluated the generalized immunosuppressive effect of TLI as a function of accumulated dose and fractionation schedule. In addition, TLI and CY-A were used individually in schedules that by themselves gave only moderate graft prolongation and then subsequently in sequential combination.

  10. A polycrystal plasticity model of strain localization in irradiated iron

    NASA Astrophysics Data System (ADS)

    Barton, Nathan R.; Arsenlis, Athanasios; Marian, Jaime

    2013-02-01

    At low to intermediate homologous temperatures, the degradation of structural materials performance in nuclear environments is associated with high number densities of nanometric defects produced in irradiation cascades. In polycrystalline ferritic materials, self-interstitial dislocations loops are a principal signature of irradiation damage, leading to a mechanical response characterized by increased yield strengths, decreased total strain to failure, and decreased work hardening as compared to the unirradiated behavior. Above a critical defect concentration, the material deforms by plastic flow localization, giving rise to strain softening in terms of the engineering stress-strain response. Flow localization manifests itself in the form of defect-depleted crystallographic channels, through which all dislocation activity is concentrated. In this paper, we describe the formulation of a crystal plasticity model for pure Fe embedded in a finite element polycrystal simulator and present results of uniaxial tensile deformation tests up to 10% strain. We use a tensorial damage descriptor variable to capture the evolution of the irradiation damage loop subpopulation during deformation. The model is parameterized with detailed dislocation dynamics simulations of tensile tests up to 1.5% deformation of systems containing various initial densities of irradiation defects. The coarse-grained simulations are shown to capture the essential details of the experimental stress response observed in ferritic alloys and steels. Our methodology provides an effective linkage between the defect scale, of the order of one nanometer, and the continuum scale involving multiple grain orientations.

  11. Novel non-thermal atrial fibrillation treatment with photosensitization reaction: possibility of permanent electrical blockade in rat chronic model

    NASA Astrophysics Data System (ADS)

    Matsuo, Hiroki; Ito, Arisa; Miyoshi, Shunichiro; Soejima, Kyoko; Ogawa, Satoshi; Arai, Tsunenori

    2009-06-01

    We demonstrated a possibility of electrical conduction block by ex vivo and in vivo experiments using rat models to establish a non-thermal treatment for atrial fibrillation by photosensitization reaction (PR). One hour after the injection of 2 mg/kg Talaporfin sodium to Wistar rat, the right ventricle (1.4 mmT) was extracted. Paced with a stimulation electrode, this tissue was placed in a tissue bath and immersed in irrigated Tyrode's solution of 37°C with 8 μg/ml Talaporfin sodium and the gas mixture bubbling of 95% CO2 and 5% O2. The propagated electrical signal was measured by two bipolar electrodes. Exciting light of 670 nm in wavelength was irradiated to the tissue between the bipolar electrodes by the power density of 1 W/cm2. After this irradiation, propagation signal blockade was obtained and continued up to three hours. Rat atrioventricular (AV) node was employed as a target region for chronic model. The heart of Wistar rat was surgically exposed. External four-lead electrocardiogram of this rat was measured. Thirty minutes after the injection of 10 mg/kg Talaporfin sodium to the rat, exciting light of 663 nm in wavelength was irradiated to the AV node by the power density of 500 mW/cm2 for ten minutes. Acute AV block was obtained during the irradiation. Two weeks after this procedure, complete AV block was confirmed. The rat was sacrificed to obtain the tissue specimen. We found that the AV node was replaced by scarring tissue under the microscopic observation of the specimen. We verified possibility of permanent electrical conduction block using PR.

  12. Global horizontal irradiance clear sky models : implementation and analysis.

    SciTech Connect

    Stein, Joshua S.; Hansen, Clifford W.; Reno, Matthew J.

    2012-03-01

    Clear sky models estimate the terrestrial solar radiation under a cloudless sky as a function of the solar elevation angle, site altitude, aerosol concentration, water vapor, and various atmospheric conditions. This report provides an overview of a number of global horizontal irradiance (GHI) clear sky models from very simple to complex. Validation of clear-sky models requires comparison of model results to measured irradiance during clear-sky periods. To facilitate validation, we present a new algorithm for automatically identifying clear-sky periods in a time series of GHI measurements. We evaluate the performance of selected clear-sky models using measured data from 30 different sites, totaling about 300 site-years of data. We analyze the variation of these errors across time and location. In terms of error averaged over all locations and times, we found that complex models that correctly account for all the atmospheric parameters are slightly more accurate than other models, but, primarily at low elevations, comparable accuracy can be obtained from some simpler models. However, simpler models often exhibit errors that vary with time of day and season, whereas the errors for complex models vary less over time.

  13. Effective Rat Lung Tumor Model for Stereotactic Body Radiation Therapy.

    PubMed

    Zhang, Zhang; Wodzak, Michelle; Belzile, Olivier; Zhou, Heling; Sishc, Brock; Yan, Hao; Stojadinovic, Strahinja; Mason, Ralph P; Brekken, Rolf A; Chopra, Rajiv; Story, Michael D; Timmerman, Robert; Saha, Debabrata

    2016-06-01

    Stereotactic body radiation therapy (SBRT) has found an important role in the treatment of patients with non-small cell lung cancer, demonstrating improvements in dose distribution and even tumor cure rates, particularly for early-stage disease. Despite its emerging clinical efficacy, SBRT has primarily evolved due to advances in medical imaging and more accurate dose delivery, leaving a void in knowledge of the fundamental biological mechanisms underlying its activity. Thus, there is a critical need for the development of orthotropic animal models to further probe the biology associated with high-dose-per-fraction treatment typical of SBRT. We report here on an improved surgically based methodology for generating solitary intrapulmonary nodule tumors, which can be treated with simulated SBRT using the X-RAD 225Cx small animal irradiator and Small Animal RadioTherapy (SmART) Plan treatment system. Over 90% of rats developed solitary tumors in the right lung. Furthermore, the tumor response to radiation was monitored noninvasively via bioluminescence imaging (BLI), and complete ablation of tumor growth was achieved with 36 Gy (3 fractions of 12 Gy each). We report a reproducible, orthotopic, clinically relevant lung tumor model, which better mimics patient treatment regimens. This system can be utilized to further explore the underlying biological mechanisms relevant to SBRT and high-dose-per-fraction radiation exposure and to provide a useful model to explore the efficacy of radiation modifiers in the treatment of non-small cell lung cancer. PMID:27223828

  14. The effect of indomethacin on nucleic acids in blood, hemopoietic and lymphoid tissues in continuously irradiated rats.

    PubMed

    Misúrová, E; Kropácová, K; Chlebovský, O; Pado, D

    1989-01-01

    The effect of indomethacin--a nonsteroid antiinflammatory drug with potential antitumor activity--on the development of radiation-induced changes was followed in blood, bone marrow, spleen, thymus and testes of rats. Indomethacin administered in drinking water (0.7-1.0 mg/kg per day) during a continuous 7-day irradiation with gamma rays (dose rate of 2.055 Gy/day, total accumulated dose of 14.385 Gy) caused a higher and more rapid incorporation of 3H-thymidine into blood DNA, and an increase in blood RNA concentration. The results suggest some stimulation of hemopoiesis recovery by indomethacin treatment in continuously irradiated rats. PMID:2478902

  15. Androgen-mediated development of irradiation-induced thyroid tumors in rats: dependence on animal age during interval of androgen replacement in castrated males

    SciTech Connect

    Hofmann, C.; Oslapas, R.; Nayyar, R.; Paloyan, E.

    1986-07-01

    When male Long-Evans rats at age 8 weeks were radiation treated (40 microCi Na131I), thyroid follicular adenomas and carcinomas were observed at age 24 months with a high incidence of 94%. Castration of males prior to irradiation significantly reduced this tumor incidence to 60%. When testosterone (T) was replaced in castrated, irradiated male rats, differentially increased incidences of thyroid tumors occurred. Immediate (age 2-6 mo) or early (age 6-12 mo) T replacement at approximate physiologic levels led to thyroid follicular tumor incidences of 100 and 82%, respectively, whereas intermediate (12-18 mo) or late (18-24 mo) T treatment led to only 70 and 73% incidences, respectively. Continuous T replacement (2-24 mo) in castrated irradiated male rats raised thyroid tumor incidence to 100%. Since elevated thyroid-stimulating hormone (TSH) is a reported requisite for development of radiation-associated thyroid tumors, the effects of T on serum TSH levels were examined. Mean serum TSH values in all irradiated animal groups were significantly elevated above age-matched nonirradiated animals at 6, 12, 18, and 24 months. Serum TSH levels were higher in continuous T-replaced irradiated castrates than in intact, irradiated males, whereas such intact male TSH levels were greater than those for irradiated castrates without T treatment. Interval T replacement in castrated male rats was associated with increased serum TSH levels during the treatment interval and with lowered TSH levels after discontinuation of T treatment, particularly in irradiated rats. However, when irradiated, castrated males received late T replacement (age 18-24 mo), there was no elevation of TSH at the end of the treatment interval. An indirect effect of T via early stimulation of TSH may be partly responsible for the high incidence of irradiation-induced thyroid tumors in rats.

  16. Carbon Ion Irradiation of the Rat Spinal Cord: Dependence of the Relative Biological Effectiveness on Linear Energy Transfer

    SciTech Connect

    Saager, Maria; Glowa, Christin; Peschke, Peter; Brons, Stephan; Scholz, Michael; Huber, Peter E.; Debus, Jürgen; Karger, Christian P.

    2014-09-01

    Purpose: To measure the relative biological effectiveness (RBE) of carbon ions in the rat spinal cord as a function of linear energy transfer (LET). Methods and Materials: As an extension of a previous study, the cervical spinal cord of rats was irradiated with single doses of carbon ions at 6 positions of a 6-cm spread-out Bragg peak (16-99 keV/μm). The TD{sub 50} values (dose at 50% complication probability) were determined according to dose-response curves for the development of paresis grade 2 within an observation time of 300 days. The RBEs were calculated using TD{sub 50} for photons of our previous study. Results: Minimum latency time was found to be dose-dependent, but not significantly LET-dependent. The TD{sub 50} values for the onset of paresis grade 2 within 300 days were 19.5 ± 0.4 Gy (16 keV/μm), 18.4 ± 0.4 Gy (21 keV/μm), 17.7 ± 0.3 Gy (36 keV/μm), 16.1 ± 1.2 Gy (45 keV/μm), 14.6 ± 0.5 Gy (66 keV/μm), and 14.8 ± 0.5 Gy (99 keV/μm). The corresponding RBEs increased from 1.26 ± 0.05 (16 keV/μm) up to 1.68 ± 0.08 at 66 keV/μm. Unexpectedly, the RBE at 99 keV/μm was comparable to that at 66 keV/μm. Conclusions: The data suggest a linear relation between RBE and LET at high doses for late effects in the spinal cord. Together with additional data from ongoing fractionated irradiation experiments, these data will provide an extended database to systematically benchmark RBE models for further improvements of carbon ion treatment planning.

  17. Human Ghrelin Mitigates Intestinal Injury and Mortality after Whole Body Irradiation in Rats

    PubMed Central

    Wang, Zhimin; Yang, Weng Lang; Jacob, Asha; Aziz, Monowar; Wang, Ping

    2015-01-01

    Widespread use of ionizing radiation has led to the realization of the danger associated with radiation exposure. Although studies in radiation countermeasures were initiated a half century ago, an effective therapy for a radiomitigator has not been identified. Ghrelin is a gastrointestinal hormone, and administration of ghrelin is protective in animal models of injuries including radiation combined injury. To test whether ghrelin can be protective in whole body irradiaton (WBI) alone, male Sprague Dawley (SD) rats were treated with human ghrelin (20 nmol/rat) daily for 6 days starting at either 24 h or 48 h after 10 Gray (Gy) WBI and survival outcome was examined. The 10 Gy WBI produced a LD70/30 model in SD rats (30% survival in 30 days). The survival rate in rats treated with ghrelin starting at 24 h was significantly improved to 63% and when treatment was initiated at 48 h, the survival remained at 61%. At 7 days post WBI, plasma ghrelin was significantly reduced from the control value. Ghrelin treatment starting at 24 h after WBI daily for 6 days improved histological appearance of the intestine, reduced gut permeability, serum endotoxin levels and bacterial translocation to the liver by 38%, 42% and 61%, respectively at day 7 post WBI. Serum glucose and albumin were restored to near control levels with treatment. Ghrelin treatment also attenuated WBI-induced intestinal apoptosis by 62% as evidenced by TUNEL staining. The expression of anti-apoptotic cell regulator Bcl-xl was decreased by 38% in the vehicle and restored to 75% of the control with ghrelin treatment. Increased expression of intestinal CD73 and pAkt were observed with ghrelin treatment, indicating protection of the intestinal epithelium after WBI. These results indicate that human ghrelin attenuates intestinal injury and mortality after WBI. Thus, human ghrelin can be developed as a novel mitigator for radiation injury. PMID:25671547

  18. Regeneration of chromatin-bound and membrane lipids from liver and thymus of V-irradiated rats

    SciTech Connect

    Kaznacheev, Yu.S.; Kolomiitseva, I.K.; Kulagina, T.P.; Markevich, L.N.

    1985-06-20

    This paper compares the regeneration of nuclear and chromatin lipids from the liver and thymus of control and irradiated rats according to the criterion of the incorporation of (/sup 14/C) acetate. The chromatin-bound lipids were found to have high metabolic activity, which was sharply pronounced in thymus cells. The corresponding lipids of intact nuclei suggests that the chromatin lipids are structurally separate from the rest of the nuclear lipids.

  19. Hepatoprotective effect of grape seed oil against carbon tetrachloride induced oxidative stress in liver of γ-irradiated rat.

    PubMed

    Ismail, Amel F M; Salem, Asmaa A M; Eassawy, Mamdouh M T

    2016-07-01

    Carbon tetrachloride (CCl4) and ionizing radiation are well known environmental pollutants that generate free radicals and induce oxidative stress. The liver is the primary and major target organ responsible for the metabolism of drugs, toxic chemicals and affected by irradiation. This study investigated the effect of grape seed oil (GSO) on acute liver injury induced by carbon tetrachloride (CCl4) in γ-irradiated rats (7Gy). CCl4-intoxicated rats exhibited an elevation of ALT, AST activities, IL-6 and TNF-α level in the serum. Further, the levels of MDA, NO, NF-κB and the gene expression of CYP2E1, iNOS and Caspase-3 were increased, and SOD, CAT, GSH-Px, GST activities and GSH content were decreased. Furthermore, silent information regulator protein 1 (SIRT1) gene expression was markedly down-regulated. Additionally, alterations of the trace elements; copper, manganese, zinc and DNA fragmentation was observed in the hepatic tissues of the intoxicated group. These effects were augmented in CCl4-intoxicated-γ-irradiated rats. However, the administration of GSO ameliorated these parameters. GSO exhibit protective effects on CCl4 induced acute liver injury in γ-irradiated rats that could be attributed to its potent antioxidant, anti-inflammatory and anti-apoptotic activities. The induction of the antioxidant enzymes activities, down-regulation of the CYP2E1, iNOS, Caspase-3 and NF-κB expression, up-regulation of the trace elements concentration levels and activation of SIRT1 gene expression are responsible for the improvement of the antioxidant and anti-inflammatory status in the hepatic tissues and could be claimed to be the hepatoprotective mechanism of GSO. PMID:27085796

  20. Changes of lipofuscin-like pigments in erythrocytes and spleen after whole-body gamma irradiation of rats

    SciTech Connect

    Wilhelm, J.; Brzak, P.; Rejholcova, M. )

    1989-11-01

    Whole-body gamma irradiation of rats induced the formation of lipofuscin-like pigments in erythrocytes. Erythrocytes that were damaged by oxidation were scavenged in the spleen, and lipofuscin-like pigments were transferred from erythrocytes to the spleen during this process. The time course of lipofuscin-like pigments in erythrocytes and spleen indicates that the pigments were not induced by the action of free radicals produced by ionizing radiation but rather were a sequela of postirradiation metabolic changes.

  1. Effects of Prenatal Irradiation with an Accelerated Heavy-Ion Beam on Postnatal Development in Rats

    NASA Astrophysics Data System (ADS)

    Wang, B.; Murakami, M.; Eguchi-Kasai, K.; Nojima, K.; Shang, Y.; Tanaka, K.; Fujita, K.; Coffigny, H.; Hayata, I.

    Effects on postnatal neurophysiological development in offspring were studied following exposure of pregnant Wistar rats to accelerated neon-ion beams with a LET value of about 30 keV mu m at a dose range from 0 1 Gy to 2 0Gy on the 15th day of gestation The age at which four physiologic markers appeared and five reflexes were acquired was examined prior to weaning Gain in body weight was monitored until the offspring were 3 months old Male offspring were evaluated as young adults using two behavioral tests The effects of X-rays at 200 kVp measured for the same biological end points were studied for comparison Our previous study on carbon-ion beams with a LET value of about 13 keV mu m was also cited to elucidate a possible LET-related effect For most of the endpoints at early age significant alteration was even observed in offspring prenatally received 0 1 Gy of accelerated neon ions while neither X rays nor carbon-ions under the same dose resulted in such a significant alteration compared to that from the sham-irradiated dams All offspring whose mothers received 2 0 Gy died prior to weaning Offspring from dams irradiated with accelerated neon ions generally showed higher incidences of prenatal death and preweaning mortality markedly delayed accomplishment in their physiological markers and reflexes and gain in body weight compared to those exposed to X-rays or carbon ions at doses of 0 1 to 1 5 Gy Significantly reduced ratios of main organ weight to body weight at postnatal ages of 30 60 and 90 days were also observed

  2. Modeling the spectral solar irradiance in the SOTERIA Project Framework

    NASA Astrophysics Data System (ADS)

    Vieira, Luis Eduardo; Dudok de Wit, Thierry; Kretzschmar, Matthieu; Cessateur, Gaël

    The evolution of the radiative energy input is a key element to understand the variability of the Earth's neutral and ionized atmospheric components. However, reliable observations are limited to the last decades, when observations realized above the Earth's atmosphere became possible. These observations have provide insights about the variability of the spectral solar irradiance on time scales from days to years, but there is still large uncertainties on the evolu-tion on time scales from decades to centuries. Here we discuss the physics-based modeling of the ultraviolet solar irradiance under development in the Solar-Terrestrial Investigations and Archives (SOTERIA) project framework. In addition, we compare the modeled solar emission with variability observed by LYRA instrument onboard of Proba2 spacecraft.

  3. Rat Carotid Artery Balloon Injury Model

    PubMed Central

    Tulis, David Anthony

    2010-01-01

    i. Summary Numerous and diverse experimental animal models have been used over the years to examine reactions to various forms of blood vessel disease and/or injury across species and in multiple vascular beds in a cumulative effort to relate these findings to the human condition. In this context, the rat carotid artery balloon injury model is highly characterized and commonly used for investigating gross morphological, cellular, biochemical, and molecular components of the response to experimentally-induced arterial injury. The mechanical damage caused by the balloon catheter completely removes the intimal endothelial lining and creates a distending mural injury in the operated vessel. This elicits a reproducible remodeling response characterized by vascular smooth muscle cell (SMC) mitogenesis and migration (via phenotypic switching), SMC apoptosis, partial vascular endothelial cell regeneration, enhanced matrix synthesis, and establishment of an invasive neointima in time-dependent fashion. This multi-factorial process allows for investigation of these many important pathophysiological processes and can serve as a valuable “proof-of-concept” tool to verify and substantiate in vitro results; however, inherent anatomical and adaptive constraints of this in vivo model ration comparison to the diseased human system (see Note 1). In this chapter, brief overview of the materials needed and the methodologies commonly employed for successful routine performance of this important experimental animal model will be provided. Individual sub-sections will cover animal care and handling, pre- and post-operative procedures, and the surgery proper. Protocols for histopathology and morphometry and procedures for data management and interpretation pertinent to the rat carotid artery balloon injury model will be discussed in Chapter __ of this series. Notes will conclude with important caveats, limitations, and considerations for practical use of this technique. PMID:18287662

  4. Modelling solar irradiances using ground-based measurements

    NASA Technical Reports Server (NTRS)

    Pap, J. M.; Marquette, W. H.; Donnelly, R. F.

    1991-01-01

    The first results of photometric measurements of Ca-K plage remnants are presented. They show that during the fall of 1986 the remnants gave a significant contribution to the irradiance variations and that the averaged remnant component is less than assumed in the present UV models. The contribution of the plage remnants to the combined plage and remnant index was on average about 13 percent, and it changed with time.

  5. Lyman alpha solar spectral irradiance line profile observations and models

    NASA Astrophysics Data System (ADS)

    Snow, Martin; Machol, Janet; Quemerais, Eric; Curdt, Werner; Kretschmar, Matthieu; Haberreiter, Margit

    2016-04-01

    Solar lyman alpha solar spectral irradiance measurements are available on a daily basis, but only the 1-nm integrated flux is typically published. The International Space Science Institute (ISSI) in Bern, Switzerland has sponsored a team to make higher spectral resolution data available to the community. Using a combination of SORCE/SOLSTICE and SOHO/SUMER observations plus empirical and semi-empirical modeling, we will produce a dataset of the line profile. Our poster will describe progress towards this goal.

  6. Orazipone, a locally acting immunomodulator, ameliorates intestinal radiation injury: A preclinical study in a novel rat model

    SciTech Connect

    Boerma, Marjan; Wang, Junru; Richter, Konrad K.; Hauer-Jensen, Martin . E-mail: mhjensen@life.uams.edu

    2006-10-01

    Purpose: Intestinal radiation injury (radiation enteropathy) is relevant to cancer treatment, as well as to radiation accidents and radiation terrorism scenarios. This study assessed the protective efficacy of orazipone, a locally-acting small molecule immunomodulator. Methods and Materials: Male rats were orchiectomized, a 4-cm segment of small bowel was sutured to the inside of the scrotum, a proximal anteperistaltic ileostomy was created for intraluminal drug administration, and intestinal continuity was re-established by end-to-side anastomosis. After three weeks postoperative recovery, the intestine in the 'scrotal hernia' was exposed locally to single-dose or fractionated X-radiation. Orazipone (30 mg/kg/day) or vehicle was administered daily through the ileostomy, either during and after irradiation, or only after irradiation. Structural, cellular, and molecular aspects of intestinal radiation toxicity were assessed two weeks after irradiation. Results: Orazipone significantly ameliorated histologic injury and transforming growth factor-{beta} immunoreactivity levels, both after single-dose and fractionated irradiation. Intestinal wall thickness was significantly reduced after single-dose and nonsignificantly after fractionated irradiation. Mucosal surface area and numbers of mast cells were partially restored by orazipone after single-dose irradiation. Conclusions: This work (1) demonstrates the utility of the ileostomy rat model for intraluminal administration of response modifiers in single-dose and fractionated radiation studies; (2) shows that mucosal immunomodulation during and/or after irradiation ameliorates intestinal toxicity; and (3) highlights important differences between single-dose and fractionated radiation regimens.

  7. Thyroid tumors following /sup 131/I or localized x irradiation to the thyroid and pituitary glands in rats

    SciTech Connect

    Lee, W.; Chiacchierini, R.P.; Shleien, B.; Telles, N.C.

    1982-11-01

    Three thousand 6-week-old female Long-Evans rats were randomly assigned to 10 equal treatment groups. Three groups were injected intraperitoneally with 0.48, 1.9, and 5.4 ..mu..Ci of Na /sup 131/I yielding mean thyroid doses of 30, 330, and 850 rad, respectively. Three groups were irradiated with 94, 410, and 1060 rad from localized X ray to the thyroid. One group was irradiated with 410 rad to the pituitary, and another group was given 410 rad to both the thyroid and the pituitary with localized X rays. The remaining two groups of animals were used as separate sham-irradiated controls for the two types of radiation. All the surviving animals were killed 2 years later. Results derived from this study indicate that: (a) The proportion of animals with thyroid carcinoma is similar for /sup 131/I and X irradiation within the dose range of 0-1000 rad. (b) The thryoid carcinoma dose-response functions fitted by the least-squares method are nearly proportional to the square root of the thyroid dose. (c) Thyroid carcinoma induction appears to be independent of the dose rates resulting from the radiations used in this study. (d) A localized X-ray dose of 410 rad to the pituitary, whether the dose was administered concomitantly with thyroid irradiation or without thyroid irradiation, did not modify the risk of thyroid tumor.

  8. Chitosan Dermal Substitute and Chitosan Skin Substitute Contribute to Accelerated Full-Thickness Wound Healing in Irradiated Rats

    PubMed Central

    Mohd Hilmi, Abu Bakar; Halim, Ahmad Sukari; Jaafar, Hasnan; Asiah, Abu Bakar; Hassan, Asma

    2013-01-01

    Wounds with full-thickness skin loss are commonly managed by skin grafting. In the absence of a graft, reepithelialization is imperfect and leads to increased scar formation. Biomaterials can alter wound healing so that it produces more regenerative tissue and fewer scars. This current study use the new chitosan based biomaterial in full-thickness wound with impaired healing on rat model. Wounds were evaluated after being treated with a chitosan dermal substitute, a chitosan skin substitute, or duoderm CGF. Wounds treated with the chitosan skin substitute showed the most re-epithelialization (33.2 ± 2.8%), longest epithelial tongue (1.62 ± 0.13 mm), and shortest migratory tongue distance (7.11 ± 0.25 mm). The scar size of wounds treated with the chitosan dermal substitute (0.13 ± 0.02 cm) and chitosan skin substitute (0.16 ± 0.05 cm) were significantly decreased (P < 0.05) compared with duoderm (0.45 ± 0.11 cm). Human leukocyte antigen (HLA) expression on days 7, 14, and 21 revealed the presence of human hair follicle stem cells and fibroblasts that were incorporated into and surviving in the irradiated wound. We have proven that a chitosan dermal substitute and chitosan skin substitute are suitable for wound healing in full-thickness wounds that are impaired due to radiation. PMID:24324974

  9. Chitosan dermal substitute and chitosan skin substitute contribute to accelerated full-thickness wound healing in irradiated rats.

    PubMed

    Mohd Hilmi, Abu Bakar; Halim, Ahmad Sukari; Jaafar, Hasnan; Asiah, Abu Bakar; Hassan, Asma

    2013-01-01

    Wounds with full-thickness skin loss are commonly managed by skin grafting. In the absence of a graft, reepithelialization is imperfect and leads to increased scar formation. Biomaterials can alter wound healing so that it produces more regenerative tissue and fewer scars. This current study use the new chitosan based biomaterial in full-thickness wound with impaired healing on rat model. Wounds were evaluated after being treated with a chitosan dermal substitute, a chitosan skin substitute, or duoderm CGF. Wounds treated with the chitosan skin substitute showed the most re-epithelialization (33.2 ± 2.8%), longest epithelial tongue (1.62 ± 0.13 mm), and shortest migratory tongue distance (7.11 ± 0.25 mm). The scar size of wounds treated with the chitosan dermal substitute (0.13 ± 0.02 cm) and chitosan skin substitute (0.16 ± 0.05 cm) were significantly decreased (P < 0.05) compared with duoderm (0.45 ± 0.11 cm). Human leukocyte antigen (HLA) expression on days 7, 14, and 21 revealed the presence of human hair follicle stem cells and fibroblasts that were incorporated into and surviving in the irradiated wound. We have proven that a chitosan dermal substitute and chitosan skin substitute are suitable for wound healing in full-thickness wounds that are impaired due to radiation. PMID:24324974

  10. Immunization of Wistar female rats with 255-Gy-irradiated Toxoplasma gondii: preventing parasite load and maternofoetal transmission.

    PubMed

    Camossi, Lucilene Granuzzio; Fornazari, Felipe; Richini-Pereira, Virgínia Bodelão; da Silva, Rodrigo Costa; Cardia, Daniel Fontana Ferreira; Langoni, Helio

    2014-10-01

    Toxoplasmosis, caused by an obligate intracellular protozoan parasite, Toxoplasma gondii, is an worldwide parasitic disease, with significant importance for animal production and considerable impact to the public health. This study was aimed to evaluate the dynamic of the distribution of T.gondii in tissues of female Wistar rats and their puppies tissues, after the immunization by oral rote with irradiated tachyzoites. One week after pregnancy confirmation, rats was challenged by gavage with T. gondii bradyzoites, oocysts or tachyzoites of T. gondii. Forty-eight pregnant rats were grouped as follow: immunized and challenged with bradyzoites (BZ*); non-immunized and challenged with bradyzoites (BZ); immunized and challenged with oocysts (OC*); non-immunized and challenged with oocysts (OC); immunized and challenged with tachyzoites (TZ*); non-immunized and challenged with tachyzoites (TZ); only immunized (I); control group (C). After parturition the rats were sacrificed and the tissues were researched for the DNA of T. gondii by polymerase chain reaction (PCR) and the parasite load determined by the quantitative PCR (qPCR). It was verified that the immunization with irradiated tachyzoites of T. gondii induced the reduction of parasitic load in most organs analyzed, although not prevent the establishment of infection with the parasite. And also, the immunization showed a favorable effect on the birth rate and litter size. PMID:25169764

  11. Low power laser and LED irradiation effect on proliferation and differentiation of Wistar rats mesenchymal stem cells

    NASA Astrophysics Data System (ADS)

    Mancera, Diana; Solarte, Efrain; Fierro, Leonardo; Criollo, William

    2013-11-01

    It has been demonstrated that appropriately cultured and stimulated mesenchymal cells, can give rise to cells of all tissues of the body. We evaluate the cell proliferation and differentiation induced by low power light irradiation in cell cultures of mesenchymal cells, isolated and previously characterized, from Wistar rats. Roche® XTT and LDH tests were used to assess proliferation and cytotoxicity. Cellular differentiation was determined by optical microscopy and using specific fluorescent markers. We report laser cellular proliferation enhancement by 532 and 473 nm, and the best cell culture response by a dose of 2 Jcm-2. Although a three day irradiation protocol the cultures grown and no cytotoxicity was detected. Cellular differentiation occurred, and the production of cardiomyocytes was promoted by the cell proliferation stimulated by low power laser irradiation.

  12. [Effect of gamma-linolenic acid on microsomal oxidation in the rat liver following gamma-irradiation].

    PubMed

    Zavodnik, L B; Sushko, L I; Tarasov, Iu A; Ignatenko, K V; Chumachenko, S S; Ovchinnikov, V A; Brzosko, V; Buko, V U

    2001-01-01

    The antioxidant and radioprotector properties of gamma-linolenic acid isolated from the seeds of Borago officialis were studied on rats gamma-irradiated to a dose of 1 Gy. The irradiation caused an increase in the content of malonaldehyde in microsomal liver fraction and disturbed the metabolism of xenobiotics. The administration of gamma-linolenic acid in the form of a commercial drug Neoglandin (daily dose, 150 mg/kg, p.o.; over 1, 3, or 7 days after irradiation reduced the level of lipid peroxidation (for all treatment schedules), normalized the activity of NADPH-oxidase, NADH-oxidase, and NADPH-reductase, and increased the content of cytochromes P-450 and b5 as compared to bothirradiated and control animals. PMID:11589114

  13. Immunization of Wistar female rats with 255-Gy-irradiated Toxoplasma gondii: Tissue parasitic load and lactogenic quantification.

    PubMed

    Camossi, Lucilene Granuzzio; Fornazari, Felipe; Richini-Pereira, Virgínia Bodelão; Costa da Silva, Rodrigo; Cardia, Daniel Fontana Ferreira; Langoni, Helio

    2015-07-01

    Toxoplasma gondii is one of the most significant parasite, due its importance in veterinary medicine and in public health, considered a food-borne pathogens, there is no available drug treatments to eliminate it from animal tissue, this reinforce the search for a vaccine against this parasite. This study was aimed to evaluate the dynamic of the distribution of T. gondii in tissues of female Wistar rats and their milk, after the immunization by oral rote with irradiated tachyzoites. One week after pregnancy confirmation, rats was challenged by gavage with T. gondii bradyzoites, oocysts or tachyzoites of T. gondii. Forty-eight pregnant rats were grouped as follows: immunized and challenged with bradyzoites (BZ*); non-immunized and challenged with bradyzoites (BZ); immunized and challenged with oocysts (OC*); non-immunized and challenged with oocysts (OC); immunized and challenged with tachyzoites (TZ*); non-immunized and challenged with tachyzoites (TZ); only immunized (I); control group (C). After parturition, milk samples were collected for 3 weeks and then rats were sacrificed and the tissues and milk samples were researched for T. gondii parasite load determined by the quantitative PCR (qPCR). It was verified that the immunization with irradiated tachyzoites of T. gondii induced the reduction of parasitic load in muscle samples in rats challenged by bradyzoites and oocysts, although not enabled the development of sterile immunity. The detection of parasite DNA in milk was found throughout the lactation period, from immunized and non-immunized rats, however no differences were found in the parasite load caused by immunization. PMID:25936982

  14. Changes in the nuclear protein kinase activities in the regenerating liver of partially irradiated rat

    SciTech Connect

    Asami, K.; Kobayashi, H.; Fujiwara, A.; Yasumasu, I. )

    1989-09-01

    X rays (4.8 Gy) inhibit both DNA synthesis and phosphorylation of histone H1 in the regenerating liver of the rat. To determine the cause of the inhibition of histone H1 phosphorylation, changes in the nuclear protein kinase activities during the prereplicative phase of regeneration were measured. The cAMP-dependent protein kinase activity was low during regeneration, and the changes in the activity were not statistically significant. The cAMP-independent protein kinase activity increased at 15 h, decreased at 18 h, and increased again at 24 h after partial hepatectomy. X irradiation prior to partial hepatectomy did not inhibit the increase at 15 h, but it did inhibit the increase at 24 h. The activity was not inhibited by isoquinolinesulfonamide inhibitors such as H-7, and it was activated by a commercial preparation of an inhibitor protein of the cAMP-dependent kinase. It was also inhibited by quercetin. The possibility that the radiation-sensitive nuclear protein kinase is a nuclear cAMP-independent protein kinase specific for histone H1 is considered.

  15. Dose and time relationships in the endocrine response of the irradiated adult rat testis

    SciTech Connect

    Delic, J.I.; Hendry, J.H.; Morris, I.D.; Shalet, S.M.

    1986-01-01

    The dose- and time-dependent responses for the interstitial and tubular compartments in irradiated adult rat testes are described. Leydig cell dysfunction, as indicated by increased serum LH (to a maximum of 385% of control after 5 Gy) and decreased serum T (to a minimum of 30% of control after 10 Gy), was observed at 8 weeks postirradiation. Subsequent recovery of Leydig cell function was then observed, so that after 9 months serum T was normal but LH was still marginally elevated. The dysfunction, with a threshold of about 4 to 5 Gy, was associated with a loss of Leydig cells from the testis. Spermatogenic damage was observed; after doses of 3 Gy and above a marked dose-response was recorded as assessed by counts of tubule cross sections exhibiting spermatogenesis. Reduced serum levels of androgen binding protein indicated Sertoli cell dysfunction at 8 weeks after 3 Gy and above, with values of less than one half of those seen in the controls. Serum FSH also was elevated to between 150% and 200% of control, and after 9 months closely reflected androgen binding protein changes. Unlike the Leydig cell, no recovery with time was observed for this aspect of Sertoli cell function.

  16. Influence of temperature upon effects of crotoxin and gamma-irradiated crotoxin at rat neuromuscular transmission.

    PubMed

    Gallacci, M; Nascimento, N; Rogero, J R; Vassilieff, V S

    2000-04-01

    The influence of temperature upon the effects of crotoxin (CTX), from Crotalus durissus terrificus venom, and gamma-irradiated (60Co, 2000 Gy) crotoxin (iCTX) was studied in rat neuromuscular transmission 'in vitro'. Indirect twitches were evoked in the phrenic-diaphragm preparation by supramaximal strength pulses with a duration of 0.5 ms and frequency of 0.5 Hz. The phospholipase A(2) (PLA(2)) enzymatic activity of CTX and iCTX was assayed against phosphadityl choline in Triton X-100. At 27 degrees C, CTX (14 microg/ml) did not affect the amplitude of indirectly evoked twitches. However, at 37 degrees C, CTX induced a time-dependent blockade of the neuromuscular transmission that started at 90 min and was completed within 240 min. iCTX (14 microg/ml) was inneffective on the neuromuscular transmission either at 27 or 37 degrees C. The PLA(2) enzymatic activity of CTX at 37 degrees C was 84 and that at 27 degrees C was 27 micromol fatty acid released/min/mg protein, and that of the iCTX at 37 degrees C was 39 micromol fatty acid released/min/mg protein. Thus, it was concluded that the mechanism of detoxification of CTX by gamma radiation at the neuromuscular level relies on the loss of its PLA(2) enzymatic activity. PMID:10713471

  17. Evaluation of the Effect of a Gamma Irradiated DBM-Pluronic F127 Composite on Bone Regeneration in Wistar Rat

    PubMed Central

    Canciani, Barbara; Losi, Paola; Tripodi, Maria; Burchielli, Silvia; Ottoni, Priscilla; Salvadori, Piero Antonio; Soldani, Giorgio

    2015-01-01

    Demineralized bone matrix (DBM) is widely used for bone regeneration. Since DBM is prepared in powder form its handling properties are not optimal and limit the clinical use of this material. Various synthetic and biological carriers have been used to enhance the DBM handling. In this study we evaluated the effect of gamma irradiation on the physical-chemical properties of Pluronic and on bone morphogenetic proteins (BMPs) amount in DBM samples. In vivo studies were carried out to investigate the effect on bone regeneration of a gamma irradiated DBM-Pluronic F127 (DBM-PF127) composite implanted in the femur of rats. Gamma irradiation effects (25 kGy) on physical-chemical properties of Pluronic F127 were investigated by rheological and infrared analysis. The BMP-2/BMP-7 amount after DBM irradiation was evaluated by ELISA. Bone regeneration capacity of DBM-PF127 containing 40% (w/w) of DBM was investigated in transcortical holes created in the femoral diaphysis of Wistar rat. Bone porosity, repaired bone volume and tissue organization were evaluated at 15, 30 and 90 days by Micro-CT and histological analysis. The results showed that gamma irradiation did not induce significant modification on physical-chemical properties of Pluronic, while a decrease in BMP-2/BMP-7 amount was evidenced in sterilized DBM. Micro-CT and histological evaluation at day 15 post-implantation revealed an interconnected trabeculae network in medullar cavity and cellular infiltration and vascularization of DBM-PF127 residue. In contrast a large rate of not connected trabeculae was observed in Pluronic filled and unfilled defects. At 30 and 90 days the DBM-PF127 samples shown comparable results in term of density and thickness of the new formed tissue respect to unfilled defect. In conclusion a gamma irradiated DBM-PF127 composite, although it may have undergone a significant decrease in the concentration of BMPs, was able to maintains bone regeneration capability. PMID:25897753

  18. Continuum modeling of plastic flow localization in irradiated fcc metals

    NASA Astrophysics Data System (ADS)

    Po, Giacomo; Ghoniem, Nasr

    2013-11-01

    Under mechanical loading, neutron or ion irradiated metals may develop a mechanical instability characterized by the localization of plastic flow in narrow channels that are cleared of irradiation-induced defects. The resulting highly heterogeneous deformation can play a significant role in crack nucleation, fracture propagation, and premature failure of structural components used in nuclear applications. In this work, we develop a two-dimensional continuum model of plastic flow localization based on the continuum theory of dislocations. This framework allows a mechanism-based description of deformation in which plastic distortion is directly calculated from the evolution of dislocation density tensor fields on each slip system. The dislocation densities mutually interact through the self-consistent stress field derived from the deformation gradient and through back and flow stress corrections. The interaction between dislocation fields and irradiation-induced defects (mainly stacking fault tetrahedra (SFTs) in fcc metals) is twofold. First, the flow stress depends locally on the SFT density. Second, and based on existing molecular dynamics (MD) simulation results, dislocation fluxes are included as sink terms in the evolution equation of the SFT density. The model is implemented numerically using the finite element method (FEM) and simulation results for simple shear loading are presented. It is demonstrated here that small spatial fluctuations in the density of SFTs, coupled with their destruction by dislocation interaction, leads to plastic flow localization.

  19. Amifostine Protects Vascularity and Improves Unions in a Model of Irradiated Mandibular Fracture Healing

    PubMed Central

    Sarhaddi, Deniz; Tchanque-Fossuo, Catherine N.; Poushanchi, Behdod; Donneys, Alexis; Deshpande, Sagar S.; Weiss, Daniela M.; Buchman, Steven R.

    2013-01-01

    Background Pathologic fractures after irradiation (XRT) can be a devastating problem for cancer patients as XRT has a pernicious effect on bone healing in a large part due to impairment of vascularity. Our aim is to ascertain whether Amifostine (AMF), a radio-protective drug, will preserve the vascularity of the irradiated mandible, thereby improving bony healing and unions after exposure to a human equivalent dose of radiation (HEDR) in our murine model of mandibular fracture repair. Methods Rats were randomized into: Fx (n=9), XRT/Fx (n=5) and AMF/XRT/Fx (n=7). XRT/Fx and AMF/XRT/Fx underwent HEDR directed at the left hemimandible. AMF/XRT/Fx received AMF concomitantly with HEDR. All animals underwent unilateral left-mandibular osteotomy with external fixation set to a 2.1mm fracture gap. Fracture healing was allowed for 40 days prior to perfusion with Microfil. Vascular radiomorphometrics were quantified with micro-computed tomography. Results We observed a 100% rate of bony union in the non-irradiated Fx compared to 25% in XRT/Fx. Union rate in AMF/XRT/Fx more than doubled to 57%. We also saw substantial increase in Vessel Number (123%,p<0.05) and a corresponding decrease in Vessel Separation (55.5%,p<0.05) in AMF/XRT/Fx versus XRT/Fx and no differences between Fx and AMF/XRT/Fx. Conclusions We report that AMF prophylaxis maintains vascularity at levels seen in non-irradiated Fx specimens, correlating with a significant increase in bony unions after HEDR. Our results set the stage for exploration of this targeted therapy alone, and in combination with other treatments, to mitigate the harmful effects of XRT on fracture repair and bone healing in the clinical setting. PMID:24281582

  20. Tamoxifen induces regression of estradiol-induced mammary cancer in ACI.COP-Ept2 rat model

    PubMed Central

    Ruhlen, Rachel L.; Willbrand, Dana M.; Besch-Williford, Cynthia L.; Ma, Lixin; Shull, James D.; Sauter, Edward R.

    2012-01-01

    The ACI rat is a unique model of human breast cancer in that mammary cancers are induced by estrogen without carcinogens, irradiation, xenografts or transgenic manipulations. We sought to characterize mammary cancers in a congenic variant of the ACI rat, the ACI.COP-Ept2. All rats with estradiol implants developed mammary cancers in 5–7 months. Rats bearing estradiol-induced mammary cancers were treated with tamoxifen for three weeks. Tamoxifen reduced tumor mass, measured by magnetic resonance imaging, by 89%. Tumors expressed estrogen receptors (ER), progesterone receptor (PR), and Erbb2. ERα and PR were overexpressed in tumor compared to adjacent non-tumor mammary gland. Thus, this model is highly relevant to hormone responsive human breast cancers. PMID:18830694

  1. Washout rate in rat brain irradiated by a 11C beam after acetazolamide loading using a small single-ring OpenPET prototype

    NASA Astrophysics Data System (ADS)

    Hirano, Yoshiyuki; Takuwa, Hiroyuki; Yoshida, Eiji; Nishikido, Fumihiko; Nakajima, Yasunori; Wakizaka, Hidekatsu; Yamaya, Taiga

    2016-03-01

    In dose verification techniques of particle therapies based on in-beam positron emission tomography (PET), the causes of washout of positron emitters by physiological effects should be clarified to correct washout for accurate verification. As well, the quantitative washout rate has a potential usefulness as a diagnostic index which should be explored. Therefore, we measured washout rates of rat brain after vasodilator acetazolamide loading to investigate the possible effects of blood flow on washout. Six rat brains were irradiated by a radioisotope 11C beam and time activity curves on the whole brains were obtained with a small single-ring OpenPET prototype. Then, washout rates were calculated with the Mizuno model, where two washout rates (k 2m and k 2s ) were assumed, and a two-compartment model including efflux from tissue to blood (k 2) and influx (k 3) and efflux (k 4) between the two tissue compartments. Before the irradiations, we used laser-Doppler flowmetry to confirm that acetazolamide increased cerebral blood flow (CBF) of a rat. We compared means of k 2m , k 2s and k 2, k 3 and k 4 without acetazolamide loading (Rest) and with acetazolamide loading (ACZ). For all k values, ACZ values were lower than Rest values. In other words, though CBF increased, washout rates were decreased. This may be attributed to the implanted 11C reacting to form 11CO2. Because acetazolamide increased the concentration of CO2 in brain, suppressed diffusion of 11CO2 and decomposition of 11CO2 into ions were prevented.

  2. Evaluation of global horizontal irradiance to plane-of-array irradiance models at locations across the United States

    DOE PAGESBeta

    Lave, Matthew; Hayes, William; Pohl, Andrew; Hansen, Clifford W.

    2015-02-02

    We report an evaluation of the accuracy of combinations of models that estimate plane-of-array (POA) irradiance from measured global horizontal irradiance (GHI). This estimation involves two steps: 1) decomposition of GHI into direct and diffuse horizontal components and 2) transposition of direct and diffuse horizontal irradiance (DHI) to POA irradiance. Measured GHI and coincident measured POA irradiance from a variety of climates within the United States were used to evaluate combinations of decomposition and transposition models. A few locations also had DHI measurements, allowing for decoupled analysis of either the decomposition or the transposition models alone. Results suggest that decompositionmore » models had mean bias differences (modeled versus measured) that vary with climate. Transposition model mean bias differences depended more on the model than the location. Lastly, when only GHI measurements were available and combinations of decomposition and transposition models were considered, the smallest mean bias differences were typically found for combinations which included the Hay/Davies transposition model.« less

  3. Evaluating the effect of laser irradiation on bone regeneration in midpalatal suture concurrent to rapid palatal expansion in rats

    PubMed Central

    Amini, Fariborz; Najaf Abadi, Maryam Pirmoradian; Mollaei, Mobina

    2015-01-01

    Background: Rapid palatal expansion is one of the most important orthopedic treatments that correct the dental and palatal constriction. Stability of the changes partly depend on the rapidity of new bone formation in affected sutures after expansion. The purpose of this study was to investigate the effect of laser irradiation on the healing of midpalatal suture concurrent to the expansion of midpalatal suture in rats. Materials and Methods: A total of 78 male Sprague rats in seven groups were evaluated: A control group of six rats without any treatments and three experimental groups of 24 which underwent palatal expansion for different time periods (7, 14, and 30 days), and each divided into two groups of with and without laser irradiation. Laser therapy was done by gallium-aluminum-arsenide diode laser with 810 nm wavelength and 4 J/cm2 irradiation in days 0, 2, 4, 6, 8, 10, 12, 14 in 4 points (1 labial and 3 palatal points). After sacrificing, the sections were evaluated by histomorphometric and quantitative analysis and results were statistically investigated by independent samples t-test. Results: The results in 7 days, 14 days, and 30 days show that laser therapy can increase the rate of osteogenesis in palatal suture during rapid palatal expansion but the differences in 7 days groups were not significant (P = 0.117) while in 14 days groups (P = 0.032) and 30 days groups were significant (P = 0.001). Most of effectiveness of low-power laser was seen between 14 and 30 days while the laser therapy was stopped. Conclusion: These findings suggest that low-level laser irradiation can increase and accelerate bone regeneration in the midpalatal suture after rapid palatal expansion, hence, reduce retention time. PMID:26229946

  4. Modelling total solar irradiance since 1878 from simulated magnetograms

    NASA Astrophysics Data System (ADS)

    Dasi-Espuig, M.; Jiang, J.; Krivova, N. A.; Solanki, S. K.

    2014-10-01

    Aims: We present a new model of total solar irradiance (TSI) based on magnetograms simulated with a surface flux transport model (SFTM) and the Spectral And Total Irradiance REconstructions (SATIRE) model. Our model provides daily maps of the distribution of the photospheric field and the TSI starting from 1878. Methods: The modelling is done in two main steps. We first calculate the magnetic flux on the solar surface emerging in active and ephemeral regions. The evolution of the magnetic flux in active regions (sunspots and faculae) is computed using a surface flux transport model fed with the observed record of sunspot group areas and positions. The magnetic flux in ephemeral regions is treated separately using the concept of overlapping cycles. We then use a version of the SATIRE model to compute the TSI. The area coverage and the distribution of different magnetic features as a function of time, which are required by SATIRE, are extracted from the simulated magnetograms and the modelled ephemeral region magnetic flux. Previously computed intensity spectra of the various types of magnetic features are employed. Results: Our model reproduces the PMOD composite of TSI measurements starting from 1978 at daily and rotational timescales more accurately than the previous version of the SATIRE model computing TSI over this period of time. The simulated magnetograms provide a more realistic representation of the evolution of the magnetic field on the photosphere and also allow us to make use of information on the spatial distribution of the magnetic fields before the times when observed magnetograms were available. We find that the secular increase in TSI since 1878 is fairly stable to modifications of the treatment of the ephemeral region magnetic flux.

  5. Effects of low level light irradiation on the migration of mesenchymal stem cells derived from rat bone marrow.

    PubMed

    Li, Wen-Tyng; Chen, Chih-Wei; Huang, Po-Ya

    2013-01-01

    Low level light irradiation (LLLI) was found to exert positive effects on various cells in vitro. The aim of this study was to investigate the effect of LLLI on the migration of rat bone marrow mesenchymal stem cells (rbMSCs). Light irradiation was applied at the energy density of 4 J/cm(2) using red (630 nm) and near infrared (NIR, 850 nm) light emitting diodes (LEDs). Wound healing assay showed both red and NIR light irradiation increased cell mobility. Red and NIR light enhanced transmembrane migration of rbMSCs up to 292.9% and 263.6% accordingly. This agreed with enzymatic activities of MMP-2 and MMP-9 enhanced by irradiation. F-actin accumulation and distribution correlated to increased migration in light-irradiated MSCs. Reactive oxygen species production as well as the expression of pFAK and pNF-кB were elevated after red and NIR LLLI. The study demonstrated that red and NIR LLLI increased rbMSCs migration and identified the phosphorylation of FAK and NF-кB as critical steps for the elevated cell migration upon LLLI. PMID:24110639

  6. Autoimmunity in type 1 diabetes mellitus: a rat model

    SciTech Connect

    Liu, Z.

    1987-01-01

    In this study, we have sought to isolate in vitro, from acutely diabetic BB rats, cytotoxic T lymphocytes, which exhibit specific cytotoxicity toward islet cells. Thoracic duct lymphocytes (TDL) from acutely diabetic BB rats cultured with irradiated MHC matched (RT1.u) islet cells and dendritic cells in vitro were shown to be specifically cytotoxic to MHC matched and mismatched allogeneic (RT1.1) and xenogeneic (hamster) islet target cells in a /sup 3/H-leucine release assay. Two cell lines (V1A8 and V1D11) derived from the TDL culture showed similar patterns of non-MHC restricted islet cell killing which could be blocked by islet cells and cultured rat insulinoma cells (RIN5mF) but not by non-islet cells of various tissue origins. Both V1A8 and V1D11 were not cytotoxic to Natural Killer (NK) sensitive target cells, G1TC and YAC-1. Conventional surface markers for rat helper and suppressor/cytotoxic T cells were not detectable on either cell lines. The V1D11 cell line was positive for W 3/13 (rat T/NK marker) on OX-19 (rat T/macrophage marker), whereas the V1A8 cell line was only positive for W 3/13.

  7. Simulation of Electron-Beam Irradiation of Skin Tissue Model

    SciTech Connect

    Miller, John H.; Suleiman, Atef; Chrisler, William B.; Sowa, Marianne B.

    2011-01-03

    Monte Carlo simulation of electrons stopping in liquid water was used to model the penetration and dose distribution of electron beams incident on the full-thickness EpiDermTM skin model (MatTek, Ashland, VA). This 3D tissue model has a fully developed basement membrane separating an epidermal layer of keratinocytes in various stages of differentiation from a dermal layer of fibroblast embedded in collagen. The simulations were motivated by a desire to selectively expose the epidermal layer to low linear-energy-transfer (LET) radiation in the presence of a non-irradiated dermal layer. Using the variable energy electron microbeam at the Pacific Northwest National Laboratory (PNNL) as a model of device characteristics and irradiation geometry, we find that at the highest beam energy available (90 keV), the estimated 90th percentile of penetration remains in the epidermal layer. To investigate the depth-dose distribution, we calculated lineal energy spectra for 10um thick layers near the 10th, 50th, and 90th percentile of penetration by the 90 keV electron beam. Biphasic spectra showed an increasing component of "stoppers" with increasing depth. Despite changes in the lineal energy spectra, the main effect on dose deposition with increasing depth is the screening effect of tissue above the layer of interest.

  8. A Rat Excised Larynx Model of Vocal Fold Scar

    ERIC Educational Resources Information Center

    Welham, Nathan V.; Montequin, Douglas W.; Tateya, Ichiro; Tateya, Tomoko; Choi, Seong Hee; Bless, Diane M.

    2009-01-01

    Purpose: To develop and evaluate a rat excised larynx model for the measurement of acoustic, aerodynamic, and vocal fold vibratory changes resulting from vocal fold scar. Method: Twenty-four 4-month-old male Sprague-Dawley rats were assigned to 1 of 4 experimental groups: chronic vocal fold scar, chronic vocal fold scar treated with 100-ng basic…

  9. A Rat Model to Study the Effects of Diet-Induced Obesity on Radiation-Induced Mammary Carcinogenesis.

    PubMed

    Imaoka, Tatsuhiko; Nishimura, Mayumi; Daino, Kazuhiro; Morioka, Takamitsu; Nishimura, Yukiko; Uemura, Hiroji; Akimoto, Kenta; Furukawa, Yuki; Fukushi, Masahiro; Wakabayashi, Keiji; Mutoh, Michihiro; Shimada, Yoshiya

    2016-05-01

    A detailed understanding of the relationship between radiation-induced breast cancer and obesity is needed for appropriate risk management and to prevent the development of a secondary cancer in patients who have been treated with radiation. Our goal was to develop an animal model to study the relationship by combining two existing Sprague-Dawley rat models of radiation-induced mammary carcinogenesis and diet-induced obesity. Female rats were fed a high-fat diet for 4 weeks and categorized as obesity prone or obesity resistant based on their body weight at 7 weeks of age, at which time the rats were irradiated with 4 Gy. Control rats were fed a standard diet and irradiated at the same time and in the same manner. All rats were maintained on their initial diets and assessed for palpable mammary cancers once a week for the next 30 weeks. The obesity-prone rats were heavier than those in the other groups. The obesity-prone rats were also younger than the other animals at the first detection of mammary carcinomas and their carcinoma weights were greater. A tendency toward higher insulin and leptin blood levels were observed in the obesity-prone rats compared to the other two groups. Blood angiotensin II levels were elevated in the obesity-prone and obesity-resistant rats. Genes related to translation and oxidative phosphorylation were upregulated in the carcinomas of obesity-prone rats. Expression profiles from human breast cancers were used to validate this animal model. As angiotensin is potentially an important factor in obesity-related morbidities and breast cancer, a second set of rats was fed in a similar manner, irradiated and then treated with an angiotensin-receptor blocker, losartan and candesartan. Neither blocker altered mammary carcinogenesis; analyses of losartan-treated animals indicated that expression of renin in the renal cortex and of Agtr1a (angiotensin II receptor, type 1) in cancer tissue was significantly upregulated, suggesting the presence of

  10. Evaluation of photon irradiation treatment upon calcium content of ribs of Wistar rats using micro-XRF

    SciTech Connect

    Parreiras Nogueira, Liebert; Barroso, Regina Cely; Pereira de Almeida, Andre; Braz, Delson; Almeida, Carlos Eduardo de; Salata, Camila; Andrade, Cherley Borba; Silva, Claudia Marcello da

    2012-05-17

    Therapeutic doses of radiation have been shown to have deleterious consequences on bone health. Among the treatment strategies used for breast cancer treatment, the most used are radiotherapy and chemotherapy. Radiotherapy may be given to destroy the cancer cells using high-dose x-rays. Protocols vary considerably, but generally whole body irradiation totals from 10 to 15 Gy, whereas local therapy totals from 40 to 70 Gy. In clinical practice, the quantitative evaluation of bone tissue relies on measurements of bone mineral density values, which are closely associated with the risk of osteoporotic fracture. Improved survivorship rates of cancer patients receiving radiotherapy increase the importance of understanding the mechanisms and long-term effects of radiation-induced bone loss. In this work, we investigated the variation on calcium distribution in ribs of female Wistar rats (Rattus norvegicus) submitted to photon irradiation with a single dose of 20 Gy. The determination of the calcium distribution was performed using synchrotron radiation microfluorescence (SR-{mu}XRF) at the X-ray Fluorescence beamline at Brazilian Synchrotron Light Laboratory (LNLS). Animals were irradiated using the linear accelerator Varian registered (CLINAC 2100) at the University Centre for Cancer Control of the State University of Rio de Janeiro (CUCC/UERJ). The total dose delivered was 20 Gy. The animals were about three months old and weighting about 200g. They were distributed into two groups (seven per group): control (did not receive any treatment) and irradiated (submitted to irradiation procedure) groups. Results showed that calcium content decreased within the dorsal ribs of rats submitted to radiotherapy in comparison to the control group.

  11. Evaluation of photon irradiation treatment upon calcium content of ribs of Wistar rats using micro-XRF

    NASA Astrophysics Data System (ADS)

    Nogueira, Liebert Parreiras; Barroso, Regina Cély; de Almeida, André Pereira; Braz, Delson; de Almeida, Carlos Eduardo; Salata, Camila; Andrade, Cherley Borba; da Silva, Claudia Marcello

    2012-05-01

    Therapeutic doses of radiation have been shown to have deleterious consequences on bone health. Among the treatment strategies used for breast cancer treatment, the most used are radiotherapy and chemotherapy. Radiotherapy may be given to destroy the cancer cells using high-dose x-rays. Protocols vary considerably, but generally whole body irradiation totals from 10 to 15 Gy, whereas local therapy totals from 40 to 70 Gy. In clinical practice, the quantitative evaluation of bone tissue relies on measurements of bone mineral density values, which are closely associated with the risk of osteoporotic fracture. Improved survivorship rates of cancer patients receiving radiotherapy increase the importance of understanding the mechanisms and long-term effects of radiation-induced bone loss. In this work, we investigated the variation on calcium distribution in ribs of female Wistar rats (Rattus norvegicus) submitted to photon irradiation with a single dose of 20 Gy. The determination of the calcium distribution was performed using synchrotron radiation microfluorescence (SR-μXRF) at the X-ray Fluorescence beamline at Brazilian Synchrotron Light Laboratory (LNLS). Animals were irradiated using the linear accelerator Varian® (CLINAC 2100) at the University Centre for Cancer Control of the State University of Rio de Janeiro (CUCC/UERJ). The total dose delivered was 20 Gy. The animals were about three months old and weighting about 200g. They were distributed into two groups (seven per group): control (did not receive any treatment) and irradiated (submitted to irradiation procedure) groups. Results showed that calcium content decreased within the dorsal ribs of rats submitted to radiotherapy in comparison to the control group.

  12. Comparison of histopathologic changes following X-irradiation of mid-thoracic and lumbosacral levels of neonatal rat spinal cord

    SciTech Connect

    Heard, J.K.; Gilmore, S.A.

    1985-02-01

    Light microscopic changes were studied in the dorsal funiculi of spinal cords from rats irradiated (4000 R) at 3 days of age and killed from 9-60 days postirradiation (P-I). The irradiated site was limited to a 5-mm length of mid-thoracic spinal cord (T only) in one group of rats, to a 5-mm length of lumbosacral spinal cord (L only) in a second group, and to 5-mm lengths of both mid-thoracic and lumbosacral spinal cord (T/L) in the third group. Changes in the lumbosacral regions were essentially the same in both L only and T/L irradiated groups. These changes included a decreased neuroglial population and a concurrent state of hypomyelination from 9-30 days P-I. In contrast, in the mid-thoracic regions of T only and T/L irradiated groups the decrease in the neuroglial population was obvious only through 13 days P-I, and by 30 days this population resembled that of the controls. The irradiated mid-thoracic areas were hypomyelinated, with the fasciculus gracilis showing a greater degree of hypomyelination than the fasciculus cuneatus. By 25 days P-I, myelination appeared to be normal in these areas. Scattered hemorrhages were noted in both lumbosacral and mid-thoracic regions, but necrotic areas occurred only at the lumbosacral level. In general, the mid-thoracic area appeared to be less sensitive to x-radiation at 3 days of age than the lumbosacral area. These data suggest that there may be marked differences in the developmental states of cells at these two levels at 3 days of age.

  13. Solar Spectral Proxy Irradiance from GOES (SSPRING): a model for solar EUV irradiance

    NASA Astrophysics Data System (ADS)

    Suess, Katherine; Snow, Martin; Viereck, Rodney; Machol, Janet

    2016-02-01

    Several currently operating instruments are able to measure the full EUV spectrum at sufficient wavelength resolution for use in upper-atmosphere modeling, the effects of space weather, and modeling satellite drag. However, no missions are planned at present to succeed the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) and Solar Dynamics Observatory (SDO) missions, which currently provide these data sources. To develop a suitable replacement for these measurements, we use two broadband EUV channels on the NOAA GOES satellites, the magnesium core-to-wing ratio (Mg II index) from the SOlar Radiation and Climate Experiment (SORCE) as well as EUV and Mg II time averages to model the EUV spectrum from 0.1 to 105 nm at 5-nm spectral resolution and daily time resolution. A Levenberg-Marquardt least squares fitting algorithm is used to determine a coefficient matrix that best reproduces a reference data set when multiplied by input data. The coefficient matrix is then applied to model data outside of the fitting interval. Three different fitting intervals are tested, with a variable fitting interval utilizing all days of data before the prediction date producing the best results. The correlation between the model results and the observed spectrum is found to be above 95% for the 0.1-50 nm range, and between 74% and 95% for the 50-105 nm range. We also find a favorable comparison between our results and the Flare Irradiance Spectral Model (FISM). These results provide a promising potential source for an empirical EUV spectral model after direct EUV measurements are no longer available, and utilize a similar EUV modeling technique as the upcoming GOES-R satellites.

  14. Influence of laser and LED irradiation on mast cells of cutaneous wounds of rats with iron deficiency anemia

    NASA Astrophysics Data System (ADS)

    Becher Rosa, Cristiane; Oliveira Sampaio, Susana C. P.; Monteiro, Juliana S. C.; Ferreira, Maria F. L.; Zanini, Fátima A. A.; Santos, Jean N.; Cangussú, Maria Cristina T.; Pinheiro, Antonio L. B.

    2011-03-01

    This work aimed to study histologically the effect of Laser or LED phototherapy on mast cells on cutaneous wounds of rats with iron deficiency. 18 rats were used and fed with special peleted iron-free diet. An excisional wound was created on the dorsum of each animal which were divided into: Group I - Control with anemia + no treatment; Group II - Anemia + Laser; Group III - Anemia + LED; Group IV - Healthy + no treatment; Group V - Healthy + Laser; Group VI - Healthy + LED. Irradiation was performed using a diode Laser (λ660nm, 40mW, CW, total dose of 10J/cm2, 4X2.5J/cm2) or a RED-LED ( λ700nm, 15mW, CW, total dose of 10J/cm2). Histological specimens were routinely processed, cut and stained with toluidine blue and mast cell counts performed. No significant statistic difference was found between groups as to the number of degranulated, non-degradulated or total mast cells. Greater mean values were found for degranulated mast cells in the Anemia + LED. LED irradiation on healthy specimens resulted in a smaller number of degranulated mast cells. Our results leads to conclude that there are no significant differences in the number of mast cells seven days after irradiation following Laser or LED phototherapy.

  15. Effects of split-dose X irradiation on rat salivary gland function

    SciTech Connect

    Vissink, A.; s-Gravenmade, E.J.; Ligeon, E.E.; Konings, A.W. )

    1991-07-01

    The effect of a single local dose of 15 Gy on salivary gland function in male Albino Wistar rats was compared with the effect of two doses of 7.5 Gy. The intervals chosen were 0-24 h and 1 week. Before and 1-30 days after the last radiation dose, samples of parotid and submandibular saliva were collected simultaneously after stimulation of the glands with pilocarpine. Irradiation with the single dose resulted in an increased lag phase and potassium concentration, and a decreased flow rate and sodium concentration. The rate of secretion of amylase was decreased during Days 1-6, increased at Day 10, and was decreased again at Day 30. With two dose fractions, substantial dose-sparing effects on lag phase, flow rate, and secretion of amylase were observed for both the very early (0-6 days postirradiation) and later (6-30 days postirradiation) effects. These effects were maximal when the interval between the fractions was 6 h. A significant dose-sparing effect on electrolytes was observed for the later effects only, again with a maximum for the 6-h interval. The dose-sparing observed for the very early effects cannot be explained satisfactorily by repair of sublethal damage (SLD), redistribution of cells over the cell cycle, or repopulation of salivary gland tissue between the doses. In contrast to the earlier dose-sparing effects, the split-dose recovery seen for later damage may be attributed, in part, to SLD repair in providing for greater reproductive survival of intercalated ductal cells and enhanced tissue regeneration.

  16. H-451 graphite irradiation creep design model; Revision 1

    SciTech Connect

    1988-07-01

    Available irradiation creep data on H-451 graphite area analyzed and fitted to the proposed creep model in a standard linear solid (a linear viscoelastic model). A creep equation is obtained and recommended for preliminary design use. It is found that the regression is significant and the creep equation is a good predictor. The standard error (SE) of the estimate is smaller than that used in the core graphite criteria development. This smaller SE shall be used in all future work related to criteria development. The creep coefficient and/or model can be further improved if additional creep data can be obtained. For this purpose several creep experiments are recommended. The immediate one is to capsule 87M-2A currently under design.

  17. Simultaneous bilateral laser therapy accelerates recovery after noise-induced hearing loss in a rat model

    PubMed Central

    Lee, Jae-Hun; Chang, So-Young; Moy, Wesley J.; Oh, Connie; Kim, Se-Hyung; Rhee, Chung-Ku; Ahn, Jin-Chul; Chung, Phil-Sang; Jung, Jae Yun

    2016-01-01

    Noise-induced hearing loss is a common type of hearing loss. The effects of laser therapy have been investigated from various perspectives, including in wound healing, inflammation reduction, and nerve regeneration, as well as in hearing research. A promising feature of the laser is its capability to penetrate soft tissue; depending on the wavelength, laser energy can penetrate into the deepest part of the body without damaging non-target soft tissues. Based on this idea, we developed bilateral transtympanic laser therapy, which uses simultaneous laser irradiation in both ears, and evaluated the effects of bilateral laser therapy on cochlear damage caused by noise overexposure. Thus, the purpose of this research was to assess the benefits of simultaneous bilateral laser therapy compared with unilateral laser therapy and a control. Eighteen Sprague-Dawley rats were exposed to narrow-band noise at 115 dB SPL for 6 h. Multiple auditory brainstem responses were measured after each laser irradiation, and cochlear hair cells were counted after the 15th such irradiation. The penetration depth of the 808 nm laser was also measured after sacrifice. Approximately 5% of the laser energy reached the contralateral cochlea. Both bilateral and unilateral laser therapy decreased the hearing threshold after noise overstimulation in the rat model. The bilateral laser therapy group showed faster functional recovery at all tested frequencies compared with the unilateral laser therapy group. However, there was no difference in the endpoint ABR results or final hair cell survival, which was analyzed histologically. PMID:27547558

  18. Simultaneous bilateral laser therapy accelerates recovery after noise-induced hearing loss in a rat model.

    PubMed

    Lee, Jae-Hun; Chang, So-Young; Moy, Wesley J; Oh, Connie; Kim, Se-Hyung; Rhee, Chung-Ku; Ahn, Jin-Chul; Chung, Phil-Sang; Jung, Jae Yun; Lee, Min Young

    2016-01-01

    Noise-induced hearing loss is a common type of hearing loss. The effects of laser therapy have been investigated from various perspectives, including in wound healing, inflammation reduction, and nerve regeneration, as well as in hearing research. A promising feature of the laser is its capability to penetrate soft tissue; depending on the wavelength, laser energy can penetrate into the deepest part of the body without damaging non-target soft tissues. Based on this idea, we developed bilateral transtympanic laser therapy, which uses simultaneous laser irradiation in both ears, and evaluated the effects of bilateral laser therapy on cochlear damage caused by noise overexposure. Thus, the purpose of this research was to assess the benefits of simultaneous bilateral laser therapy compared with unilateral laser therapy and a control. Eighteen Sprague-Dawley rats were exposed to narrow-band noise at 115 dB SPL for 6 h. Multiple auditory brainstem responses were measured after each laser irradiation, and cochlear hair cells were counted after the 15th such irradiation. The penetration depth of the 808 nm laser was also measured after sacrifice. Approximately 5% of the laser energy reached the contralateral cochlea. Both bilateral and unilateral laser therapy decreased the hearing threshold after noise overstimulation in the rat model. The bilateral laser therapy group showed faster functional recovery at all tested frequencies compared with the unilateral laser therapy group. However, there was no difference in the endpoint ABR results or final hair cell survival, which was analyzed histologically. PMID:27547558

  19. Cardiopulmonary bypass model in the rat: a new minimal invasive model with a low flow volume†

    PubMed Central

    Lebreton, Guillaume; Tamion, Fabienne; Bessou, Jean-Paul; Doguet, Fabien

    2012-01-01

    Numerous cardiopulmonary bypass (CPB) models in the rat have already been described, but these models often have an important mortality and differ a lot from human clinical conditions thus making them hardly usable. The CPB model in the rat we describe allows a femoro-femoral support CPB with a low priming volume, minimal surgical approach and excellent peroperative survival. This CPB model in the rat allows evaluating extracorporeal circulation effects. PMID:22345055

  20. Animal models of neurological deficits: how relevant is the rat?

    PubMed

    Cenci, M Angela; Whishaw, Ian Q; Schallert, Timothy

    2002-07-01

    Animal models of neurological deficits are essential for the assessment of new therapeutic options. It has been suggested that rats are not as appropriate as primates for the symptomatic modelling of disease, but a large body of data argues against this view. Comparative analyses of movements in rats and primates show homology of many motor patterns across species. Advances have been made in identifying rat equivalents of akinesia, tremor, postural deficits and dyskinesia, which are relevant to Parkinson's disease. Rat models of hemiplegia, neglect and tactile extinction are useful in assessing the outcome of ischaemic or traumatic brain injury, and in monitoring the effects of therapeutic interventions. Studies in rodents that emphasize careful behavioural analysis should continue to be developed as effective and inexpensive models that complement studies in primates. PMID:12094213

  1. Effect of He-Ne laser irradiation on spontaneous contractive activity and basal tone level of rat portal vein

    NASA Astrophysics Data System (ADS)

    Petrishchev, Nikolai N.; Barabanova, Valeria V.; Mikhailova, Irina A.; Chephu, Svetlana G.

    2000-11-01

    To study the effect of He-Ne irradiation (632.8 nm, 15 mW/cm2) on spontaneous contractive activity the fragments of rat portal vein weremounted isometrically in Krebs buffer. Irradiation of vessel fragments by He-Ne laser during 3,5 and 10 min caused the decrease of ton up to 50%, which lasted in postirradiation period (the observation time - 10 min). The frequency of phasic and tonic contractions did not change, but the amplitude increased up to 40% as compared to the initial level. The decreased basal tone level and the increased amplitude of phasic oscillations lasted in postirradiation period. Adding NO synthasa blocator (N - nitro-L-arginine) to Krebs solution before irradiation caused no significant changes mentioned above parameters. Irradiation and coputing of the same parameters of spontaneous contractive activity of vena porta caused no effects, mentioned in the absence of the blocator. From the results it is concluded that the decrease of tone is evoked by the increase of EDRF production and cGMP. The increase of amplitude of phasic and tonic contractions is connected with increase of Ca++ entry in every contraction cycle as a result of membrane Ca++ pool increase.

  2. Radiation induced cognitive impairment and altered diffusion tensor imaging in a juvenile rat model of cranial radiotherapy

    PubMed Central

    Peiffer, Ann M.; Creer, Rebecca M.; Linville, Constance; Olson, John; Kulkarni, Praveen; Brown, Jacquelyn Ann; Riddle, David R.; Robbins, Mike E.; Brunso-Bechtold, Judy E.

    2014-01-01

    Purpose Assess the long term effects of fractionated whole brain irradiation (fWBI) using diffusion tensor imaging (DTI) and behavior in a pediatric rodent model for the clinical presentation of adult pediatric cancer survivors. Materials and Methods Five week old, male F344xBN rats were randomized to receive 0, 5, or 6.5 Gy fractions biweekly for 3 weeks, resulting in Sham, Irradiated-30 (IR-30) and IR-39 Gy total dose groups. Magnetic Resonance Imaging occurred at 1, 3, 6 and 9 months with behavioral assessment at 10–11 months post-fWBI. Results Irradiation reduced brain size (p<0.001) and body weight (p<0.001) proportionate to dose. At 1 month post-fWBI and throughout follow-up, diffusion was reduced in IR-30 and IR-39 relative to shams (p<0.001). IR-30 but not IR-39 rats were impaired relative to Shams on the reversal trial of the Morris Water Maze (p<0.05), and IR-30 rats preferred a striatum-mediated strategy (p<0.06). Conclusions Hippocampal performance was impaired in IR-30 but not IR-39 animals. While gross size differences exist, white matter integrity is preserved in rats after fWBI at 5 weeks. This significant departure from childhood cancer survivors and single fraction rodent studies where white matter degradation is a prominent feature are discussed. PMID:24991879

  3. Geometrical MTF computation method based on the irradiance model

    NASA Astrophysics Data System (ADS)

    Lin, P.-D.; Liu, C.-S.

    2011-01-01

    The Modulation Transfer Function (MTF) is a measure of an optical system's ability to transfer contrast from the specimen to the image plane at a specific resolution. It can be computed either numerically by geometrical optics or measured experimentally by imaging a knife edge or a bar-target pattern of varying spatial frequency. Previously, MTF accuracy was generally affected by the size of the mesh on the image plane. This paper presents a new MTF computation method based on the irradiance model, without counting the number of rays hitting each grid. To verify the method, the MTF in the sagittal and meridional directions of an axis-symmetrical optical system is computed by both the ray-counting and the proposed methods. It is found that the grid size meshed on the image plane significantly affects the MTF of the ray-counting method, sometimes with significantly negative results. The proposed irradiance method is immune to issues of grid size. The CPU computation time for the two methods is approximately the same.

  4. Solar Irradiance Models and Measurements: A Comparison in the 220-240 nm wavelength band

    NASA Astrophysics Data System (ADS)

    Unruh, Yvonne C.; Ball, Will T.; Krivova, Natalie A.

    2012-07-01

    Solar irradiance models that assume solar irradiance variations to be due to changes in the solar surface magnetic flux have been successfully used to reconstruct total solar irradiance on rotational as well as cyclical and secular time scales. Modelling spectral solar irradiance is not yet as advanced, and also suffers from a lack of comparison data, in particular on solar cycle time scales. Here, we compare solar irradiance in the 220-240 nm band as modelled with SATIRE-S and measured by different instruments on the UARS and SORCE satellites. We find good agreement between the model and measurements on rotational time scales. The long-term trends, however, show significant differences. Both SORCE instruments, in particular, show a much steeper gradient over the decaying part of cycle 23 than the modelled irradiance or that measured by UARS/SUSIM.

  5. Modeling Alzheimer's disease with non-transgenic rat models

    PubMed Central

    2013-01-01

    Alzheimer's disease (AD), for which there is no cure, is the most common form of dementia in the elderly. Despite tremendous efforts by the scientific community, the AD drug development pipeline remains extremely limited. Animal models of disease are a cornerstone of any drug development program and should be as relevant as possible to the disease, recapitulating the disease phenotype with high fidelity, to meaningfully contribute to the development of a successful therapeutic agent. Over the past two decades, transgenic models of AD based on the known genetic origins of familial AD have significantly contributed to our understanding of the molecular mechanisms involved in the onset and progression of the disease. These models were extensively used in AD drug development. The numerous reported failures of new treatments for AD in clinical trials indicate that the use of genetic models of AD may not represent the complete picture of AD in humans and that other types of animal models relevant to the sporadic form of the disease, which represents 95% of AD cases, should be developed. In this review, we will discuss the evolution of non-transgenic rat models of AD and how these models may open new avenues for drug development. PMID:23634826

  6. Intravenous Injections of Human Mesenchymal Stromal Cells Modulated the Redox State in a Rat Model of Radiation Myelopathy

    PubMed Central

    Zhang, Jing; Li, Lian-Bing; Qiu, Zhu; Ren, Hong-Bo; Wu, Jia-Yan; Wang, Tao; Bao, Zhong-Hui; Yang, Ji-Fan; Zheng, Ke; Li, Shao-Lin; Wei, Li; You, Hua

    2015-01-01

    The main aim of the present study was to assess the antioxidative effects of human umbilical cord-derived mesenchymal stromal cells (UC-MSCs) in a rat model of radiation myelopathy. UC-MSCs were isolated from Wharton's jelly (WJ) of umbilical cords. An irradiated cervical spinal cord rat model (C2-T2 segment) was generated using a 60Co irradiator to deliver 30 Gy of radiation. UC-MSCs were injected through the tail vein at 90 days, 97 days, 104 days, and 111 days after-irradiation. Histological damage was examined by cresyl violet/Nissl staining. The activities of two antioxidant enzymes catalase (CAT) and glutathione peroxidase (GPX) in the spinal cord were measured by the biomedical assay. In addition, the levels of vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2) in the spinal cord were determined by ELISA methods. Multiple injections of UC-MSCs through the tail vein ameliorated neuronal damage in the spinal cord, increased the activities of the antioxidant enzymes CAT and GPX, and increased the levels of VEGF and Ang-2 in the spinal cord. Our results suggest that multiple injections of UC-MSCs via the tail vein in the rat model of radiation myelopathy could significantly improve the antioxidative microenvironment in vivo. PMID:26366180

  7. An experimental model to determine the level of antibiotics in irradiated tissues

    SciTech Connect

    Cruz, N.I.; Ariyan, S.; Miniter, P.; Andriole, V.T.

    1984-05-01

    An experimental study was designed using male Sprague-Dawley rats treated with a single dose of 1800 rads to an area of skin and soft tissue of the back measuring 2 X 3 cm. This dose was estimated to produce changes equivalent to 6000 rads in divided doses over 6 weeks. At intervals of 5, 10, and 15 weeks after irradiation, punch biopsies were taken from both irradiation, and nonirradiated skin areas of each animal 30 minutes after the intraperitoneal administration of gentamicin. Skin homogenates were prepared, and the antibiotic levels in these samples were determined by a bacterial growth inhibition assay. The antibiotic levels were found to be equal (16.1 +/- 6 micrograms/ml vs. 16.0 +/- 5 micrograms/ml) in both irradiated and nonirradiated skin at 5 weeks after radiation. However, at 10 and 15 weeks after radiation, the antibiotic levels had dropped to 9.9 +/- 3 micrograms/ml in irradiated skin compared with 14.1 +/- 4 micrograms/ml in normal skin (p less than 0.001) and with 5.4 micrograms/ml in irradiated skin vs. 11.8 +/- 5 micrograms/ml in nonirradiated skin (p less than 0.001), respectively. Results demonstrate that in spite of adequate gentamicin levels in the circulation and nonirradiated tissue in rats, gentamicin has a decreasing ability to diffuse into irradiated tissues with increasing intervals after therapeutic doses of radiation.

  8. The Carbohydrate Sensitive Rat as a Model of Obesity

    PubMed Central

    Nadkarni, Nachiket A.; Chaumontet, Catherine; Azzout-Marniche, Dalila; Piedcoq, Julien; Fromentin, Gilles; Tomé, Daniel; Even, Patrick C.

    2013-01-01

    Background Sensitivity to obesity is highly variable in humans, and rats fed a high fat diet (HFD) are used as a model of this inhomogeneity. Energy expenditure components (basal metabolism, thermic effect of feeding, activity) and variations in substrate partitioning are possible factors underlying the variability. Unfortunately, in rats as in humans, results have often been inconclusive and measurements usually made after obesity onset, obscuring if metabolism was a cause or consequence. Additionally, the role of high carbohydrate diet (HCD) has seldom been studied. Methodology/Findings Rats (n=24) were fed for 3 weeks on HCD and then 3 weeks on HFD. Body composition was tracked by MRI and compared to energy expenditure components measured prior to obesity. Results: 1) under HFD, as expected, by adiposity rats were variable enough to be separable into relatively fat resistant (FR) and sensitive (FS) groups, 2) under HCD, and again by adiposity, rats were also variable enough to be separable into carbohydrate resistant (CR) and sensitive (CS) groups, the normal body weight of CS rats hiding viscerally-biased fat accumulation, 3) HCD adiposity sensitivity was not related to that under HFD, and both HCD and HFD adiposity sensitivities were not related to energy expenditure components (BMR, TEF, activity cost), and 4) only carbohydrate to fat partitioning in response to an HCD test meal was related to HCD-induced adiposity. Conclusions/Significance The rat model of human obesity is based on substantial variance in adiposity gains under HFD (FR/FS model). Here, since we also found this phenomenon under HCD, where it was also linked to an identifiable metabolic difference, we should consider the existence of another model: the carbohydrate resistant (CR) or sensitive (CS) rat. This new model is potentially complementary to the FR/FS model due to relatively greater visceral fat accumulation on a low fat high carbohydrate diet. PMID:23935869

  9. A model for the diffuse attenuation coefficient of downwelling irradiance

    NASA Astrophysics Data System (ADS)

    Lee, Zhong-Ping; Du, Ke-Ping; Arnone, Robert

    2005-02-01

    The diffuse attenuation coefficient for downwelling irradiance (Kd) is an important parameter for ocean studies. For the vast ocean the only feasible means to get fine-scale measurements of Kd is by ocean color remote sensing. At present, values of Kd from remote sensing are estimated using empirical algorithms. Such an approach is insufficient to provide an understanding regarding the variation of Kd and contains large uncertainties in the derived values. In this study a semianalytical model for Kd is developed based on the radiative transfer equation, with values of the model parameters derived from Hydrolight simulations using the averaged particle phase function. The model is further tested with data simulated using significantly different particle phase functions, and the modeled Kd are found matching Hydrolight Kd very well (˜2% average error and ˜12% maximum error). Such a model provides an improved interpretation about the variation of Kd and a basis to more accurately determine Kd (especially using data from remote sensing).

  10. A Rat Model of Thrombosis in Common Carotid Artery Induced by Implantable Wireless Light-Emitting Diode Device

    PubMed Central

    Huang, Kuo-Lun; Hsiao, Yung-Chin; Lin, Yun-Han; Lou, Shyh-Liang; Lee, Tsong-Hai

    2014-01-01

    This work has developed a novel approach to form common carotid artery (CCA) thrombus in rats with a wireless implantable light-emitting diode (LED) device. The device mainly consists of an external controller and an internal LED assembly. The controller was responsible for wirelessly transmitting electrical power. The internal LED assembly served as an implant to receive the power and irradiate light on CCA. The thrombus formation was identified with animal sonography, 7T magnetic resonance imaging, and histopathologic examination. The present study showed that a LED assembly implanted on the outer surface of CCA could induce acute occlusion with single irradiation with 6 mW/cm2 LED for 4 h. If intermittent irradiation with 4.3–4.5 mW/cm2 LED for 2 h was shut off for 30 min, then irradiation for another 2 h was applied; the thrombus was observed to grow gradually and was totally occluded at 7 days. Compared with the contralateral CCA without LED irradiation, the arterial endothelium in the LED-irradiated artery was discontinued. Our study has shown that, by adjusting the duration of irradiation and the power intensity of LED, it is possible to produce acute occlusion and progressive thrombosis, which can be used as an animal model for antithrombotic drug development. PMID:25045695