Dose-response study of the hematological toxicity induced by vectorized radionuclides in a mouse model

International Nuclear Information System (INIS)

Rousseau-Poivet, J.; Sas, N.; Nguyen, F.; Abadie, J.; Chouin, N.; Barbet, J.

2015-01-01

studied progenitor and blood cells. As compared to 0.8 Gy, one more week was necessary at 1.4 Gy. A mild anemia (21% erythrocyte depletion) was noticed only at this higher absorbed dose between D3 and D10. Conclusion: absorbed doses to the BM between 0.8 and 1.4 Gy induced hematological toxicity expressed by transient BM aplasia, neutropenia, thrombocytopenia and inconsistent anemia. These depletions and time to recovery were both dose-dependent. Higher absorbed doses will be achieved to better investigate the dose-response relationship and to further develop our compartmental model for platelets. Neutrophils and erythrocytes kinetics are also under investigation to generate satisfying simulations with the model. (authors)

Sun-Induced Changes in Stratum Corneum Function Are Gender and Dose Dependent in a Chinese Population

Science.gov (United States)

Liu, Z.; Fluhr, J.W.; Song, S.P.; Sun, Z.; Wang, H.; Shi, Y.J.; Elias, P.M.; Man, M.-Q.

2010-01-01

Previous studies have demonstrated that UVB radiation changes the epidermal permeability barrier and stratum corneum (SC) hydration. It is well known that sun exposure causes erythema, sunburn and melanoma. However, whether daily sun exposure alters SC integrity and epidermal permeability barrier function is largely unknown, especially in Chinese subjects. In the present study, we assess the SC integrity, SC hydration and epidermal permeability barrier function following various doses of sun exposure. A total of 258 subjects (124 males and 134 females) aged 18–50 years were enrolled. A multifunctional skin physiology monitor (Courage & Khazaka MPA5) was used to measure SC hydration and transepidermal water loss (TEWL) on the forearms. In males, basal TEWL was higher with higher doses of sun exposure than with lower doses and control, whereas in females, basal TEWL was higher with lower doses of sun exposure than with higher doses and control. In the group with higher doses of sun exposure, TEWL in females was significantly lower than that in males. The barrier recovery was faster in females than in males in both control and lower-dose groups. In both males and females, barrier recovery was delayed with higher doses of sun exposure. In males, sun exposure did not alter SC hydration, while in females SC hydration was lower with lower doses of sun exposure as compared with control and higher doses of sun exposure. These results demonstrated that sun-induced changes in SC function and SC hydration vary with gender and the extent of sun exposure. PMID:20571289

Intestinal recovery in pigs irradiated at high doses. Enzymological, histological and functional data

International Nuclear Information System (INIS)

Daburon, F.; Remy, J.; Villiers, P.-A.; Gregond, J.-C.; Tricaud, Y.; Sevignac, M.; Haag, J.

1975-01-01

The kinetics of appearance and possible recovery of intestinal injuries were studied in pigs following 60 Co γ exposure of the hind part, in the dose range between 800 and 1,250rd; histological, enzymological and functional aspects were investigated successively. Following 800-950rd exposure, good recovery occured within less than a month as to histology and enzymology of the intestinal mucosa, but malabsorption of lipids and calcium was long lasting. Following 1,250rd exposure, incipient recovery led to permanently atrophic and non-functional mucosa impairing enteral nutrition [fr

Study on a 4-Week Recovery Test of Sweet Bee Venom after a 13-Week, Repeated, Intramuscular Dose Toxicity Test in Sprague-Dawley Rats

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Chungsan Lim

2014-06-01

Full Text Available Objectives:This study was performed to check for reversibility in the changes induced by a 13-week, repeated, dose toxicity test of Sweet Bee Venom (SBV in Sprague-Dawley (SD rats. Methods:Fifteen male and 15 female SD rats were treated with 0.28 mg/kg of SBV (high-dosage group and the same numbers of male and female SD rats were treated with 0.2 mL/kg of normal saline (control group for 13 weeks. We selected five male and five female SD rats from the high-dosage group and the same numbers of male and female SD rats from the control group, and we observed these rats for four weeks. We conducted body-weight measurements, ophthalmic examinations, urinalyses and hematology, biochemistry, histology tests. Results:(1 Hyperemia and movement disorder were observed in the 13-week, repeated, dose toxicity test, but these symptoms were not observed during the recovery period. (2 The rats in the high-dose group showed no significant changes in weight compared to the control group. (3 No significant differences in the ophthalmic parameters, urine analyses, complete blood cell counts (CBCs, and biochemistry were observed among the recovery groups. (4 No changes in organ weights were observed during the recovery period. (5 Histological examination of the thigh muscle indicated cell infiltration, inflammation, degeneration, necrosis of muscle fiber, and fibrosis during the treatment period, but these changes were not observed during the recovery period. The fatty liver change that was observed during the toxicity test was not observed during the recovery period. No other organ abnormalities were observed. Conclusion:The changes that occurred during the 13-week, repeated, dose toxicity test are reversible, and SBV can be safely used as a treatment modality.

Recovery time from radiation-induced xerostomia and impairment of salivary secretion

International Nuclear Information System (INIS)

Fukutomi, Yukimi; Kawakami, Toshiaki; Murase, Kenya; Fujii, Takashi; Ikezoe, Junpei

2000-01-01

Between June 1995 and August 1997, we treated 23 patients with head and neck malignancies using an x-ray beam and then interviewed the patients to determine the degree of subjective salivary secretion and xerostomia after long-term radiation therapy. Interviews were continued for a maximum 179 weeks (mean, 76.3 weeks) after irradiation. We scored the results as the degree of subjective salivary secretion, then noted the recovery time for salivary secretion and xerostomia. When salivary glands had been irradiated to a total dose of 30 to 60 Gy, salivary secretion and oral dryness recovered within three years in 72% (13/18) and 67% (13/18) of the patients, respectively. However, these symptoms never recovered to their original levels when the total dose was more than 60 Gy. The acute and late effects of radiation therapy may induce a risk of dental caries, oral dryness, and osteoradionecrosis as well as taste impairment. Therefore, education as to dental and oral care is mandatory for patients who will be or who have been treated with radiotherapy. (author)

Recovery during radiation mutagenesis

International Nuclear Information System (INIS)

Deen, D.F.; Shaw, E.I.

1976-01-01

Many variables (e.g. cell inoculum size, mutagen dose, expression time, and concentration of the selective agent) are known to affect the induced mutation frequency obtained in cultured mammalian cells. The authors have studied the effects of several parameters on the frequency of radiation-induced resistance to 8-azaguanine in asynchronous V79-171B hamster cells. Inoculation with 10 5 cells was followed by graded doses of radiation, expression times were optimized to maximize mutation frequency, and then the treated cells were challenged with 8-azaguanine for ten days. The optimal expression times which maximized mutation frequency were dose dependent and are in the range of 14-24, 24, and 24-36 hours respectively for doses of 250, 40 and 800 rads. A time interval of 24 hours between two 250-rad fractions resulted in a mutation frequency smaller than that obtained from administration of a single 500-rad dose. With 36 hours between halves of the dose, the induced mutation frequency was an order of magnitude lower than that produced by a single dose and actually below the unirradiated (spontaneous) frequency. Maintenance of cells after irradation first at 18 0 C for 24 hours, and then allowance of expression at 37 0 C for 24 hours, increased both the spontaneous and induced mutation frequency. A one-hour postirradiation balanced salt-solution treatment did not affect the number of spontaneous mutants that arose, but reduced the number of induced mutants. Thus, the balanced salt treatment lowers the induced mutation frequency about a factor of two. The possible significance of these results are discussed with respect to the role of radiation repair mechanisms during mutagenesis, and to recovery at low dose rates. A working hypothesis is advanced to explain the possible mechanism which causes expression time to vary as a function of the dose of mutagen. (author)

Motion-induced dose artifacts in helical tomotherapy

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Kim, Bryan; Chen, Jeff; Battista, Jerry [London Regional Cancer Program, London Health Sciences Centre, London, ON (Canada); Kron, Tomas [Peter MacCallum Cancer Center, Melbourne (Australia)], E-mail: bryan.kim@lhsc.on.ca

2009-10-07

Tumor motion is a particular concern for a complex treatment modality such as helical tomotherapy, where couch position, gantry rotation and MLC leaf opening all change with time. In the present study, we have investigated the impact of tumor motion for helical tomotherapy, which could result in three distinct motion-induced dose artifacts, namely (1) dose rounding, (2) dose rippling and (3) IMRT leaf opening asynchronization effect. Dose rounding and dose rippling effects have been previously described, while the IMRT leaf opening asynchronization effect is a newly discovered motion-induced dose artifact. Dose rounding is the penumbral widening of a delivered dose distribution near the edges of a target volume along the direction of tumor motion. Dose rippling is a series of periodic dose peaks and valleys observed within the target region along the direction of couch motion, due to an asynchronous interplay between the couch motion and the longitudinal component of tumor motion. The IMRT leaf opening asynchronization effect is caused by an asynchronous interplay between the temporal patterns of leaf openings and tumor motion. The characteristics of each dose artifact were investigated individually as functions of target motion amplitude and period for both non-IMRT and IMRT helical tomotherapy cases, through computer simulation modeling and experimental verification. The longitudinal dose profiles generated by the simulation program agreed with the experimental data within {+-}0.5% and {+-}1.5% inside the PTV region for the non-IMRT and IMRT cases, respectively. The dose rounding effect produced a penumbral increase up to 20.5 mm for peak-to-peak target motion amplitudes ranging from 1.0 cm to 5.0 cm. Maximum dose rippling magnitude of 25% was calculated, when the target motion period approached an unusually high value of 10 s. The IMRT leaf opening asynchronization effect produced dose differences ranging from -29% to 7% inside the PTV region. This information

Cardiovascular effects, induction and recovery characteristics and alfaxalone dose assessment in alfaxalone versus alfaxalone-fentanyl total intravenous anaesthesia in dogs.

Science.gov (United States)

Dehuisser, Virginie; Bosmans, Tim; Kitshoff, Adriaan; Duchateau, Luc; de Rooster, Hilde; Polis, Ingeborgh

2017-11-01

To compare cardiovascular effects and anaesthetic quality of alfaxalone alone or in combination with a fentanyl constant rate infusion (CRI) when used for total intravenous anaesthesia (TIVA) in dogs. Prospective, blinded, randomized, experimental study. A group of 12 intact female dogs. Following intramuscular dexmedetomidine (10 μg kg -1 ) and methadone (0.1 mg kg -1 ) administration, anaesthesia was induced intravenously with alfaxalone (2 mg kg -1 ) (group AP) or alfaxalone (2 mg kg -1 ) preceded by fentanyl (2 μg kg -1 ) (group AF). Anaesthetic maintenance was obtained with an alfaxalone variable rate infusion (VRI) started at 0.15 mg kg -1 minute -1 (group AP) or an alfaxalone VRI (same starting rate) combined with a CRI of fentanyl (10 μg kg -1 hour -1 ) (group AF). The alfaxalone VRI was adjusted every 5 minutes, based on clinical assessment. Cardiovascular parameters (recorded every 5 minutes) and recovery characteristics (using a numerical rating scale) were compared between groups. A mixed model statistical approach was used to compare the mean VRI alfaxalone dose and cardiovascular parameters between groups; recovery scores were analysed using the Wilcoxon rank-sum test (α = 0.05). The mean CRI alfaxalone dose for anaesthetic maintenance differed significantly between treatments [0.16 ± 0.01 mg kg -1 minute -1 (group AP) versus 0.13 ± 0.01 mg kg -1 minute -1 (group AF)]. Overall heart rate, systolic, mean and diastolic arterial pressures were lower in group AF than in group AP (p < 0.0001, p = 0.0058, p < 0.0001 and p < 0.0001, respectively. Recovery quality scores did not differ significantly and were poor in both groups. In combination with a fentanyl CRI, an alfaxalone TIVA provides a cardiovascular stable anaesthesia in dogs. The addition of fentanyl results in a significant dose reduction. The quality of anaesthetic recovery remains poor. Copyright © 2017 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia

Limits of recovery against slip-induced falls while walking.

Science.gov (United States)

Yang, Feng; Bhatt, Tanvi; Pai, Yi-Chung

2011-10-13

Slip-induced falls in gait often have devastating consequences. The purposes of this study were 1) to select the determinants that can best discriminate the outcomes (recoveries or falls) of an unannounced slip induced in gait (and to find their corresponding threshold, i.e., the limits of recovery, which can clearly separate these two outcomes), and 2) to verify these results in a subset of repeated-slip trials. Based on the data collected from 69 young subjects during a slip induced in gait, nine different ways of combining the center of mass (COM) stability, the hip height, and its vertical velocity were investigated with the aid of logistic regression. The results revealed that the COM stability (s) and limb support (represented by the quotient of hip vertical velocity to hip height, S(hip)) recorded at the instant immediately prior to the recovery step touchdown were sufficiently sensitive to account for all (100%) variance in falls, and specific enough to account for nearly all (98.3%) variability in recoveries. This boundary (S(hip)=-0.22s-0.25), which quantifies the risk of falls in the stability-limb support quotient (s-S(hip)) domain, was fully verified using second-slip and third-slip trials (n=76) with classification of falls at 100% and recoveries at 98.6%. The severity of an actual fall is likely to be greater further below the boundary, while the likelihood of a fall diminishes above it. Finally, the slope of the boundary also indicates the tradeoff between the stability and limb support, whereby high stability can compensate for the insufficiency in limb support, or vice versa. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of low dose rate irradiation on doped silica core optical fibers

International Nuclear Information System (INIS)

Friebele, E.J.; Askins, C.G.; Gingerich, M.E.

1984-01-01

The optical attenuation induced in multimode doped silica core optical fiber waveguides by a year's exposure to low dose rate (1 rad/day) ionizing radiation was studied, allowing a characterization of fibers deployed in these environments and a determination of the permanent induced loss in the waveguides. Variations in the induced attenuation at 0.85 μm have been observed with changes in the dose rate between 1 rad/day and 9000 rads/min. These dose rate dependences have been found to derive directly from the recovery that occurs during the exposure; the recovery data predict little or no dose rate dependence of the damage at 1.3 μm. The low dose rate exposure has been found to induce significant permanent attenuation in the 0.7-1.7-μm spectral region in all fibers containing P in the core, whether doped uniformly across the diameter or constrained to a narrow spike on the centerline. Whereas permanent loss was induced at 0.85 μm in a P-free binary Ge-doped silica core fiber by the year's exposure, virtually no damage was observed at 1.3 μm

Therapeutic Effect of Low Doses of Acenocoumarol in the Course of Ischemia/Reperfusion-Induced Acute Pancreatitis in Rats

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Zygmunt Warzecha

2017-04-01

Full Text Available Intravascular activation of coagulation is observed in acute pancreatitis and is related to the severity of this inflammation. The aim of our study was to evaluate the impact of acenocoumarol therapy on the course of acute pancreatitis induced in male rats by pancreatic ischemia followed by reperfusion. Acenocoumarol at a dose of 50, 100, or 150 µg/kg/dose was administered intragastrically once a day, starting the first dose 24 h after the initiation of pancreatic reperfusion. Results: Histological examination showed that treatment with acenocoumarol reduces pancreatic edema, necrosis, and hemorrhages in rats with pancreatitis. Moreover, the administration of acenocoumarol decreased pancreatic inflammatory infiltration and vacuolization of pancreatic acinar cells. These findings were accompanied with a reduction in the serum activity of lipase and amylase, concentration of interleukin-1β, and plasma d-Dimer concentration. Moreover, the administration of acenocoumarol improved pancreatic blood flow and pancreatic DNA synthesis. Acenocoumarol given at a dose of 150 µg/kg/dose was the most effective in the treatment of early phase acute pancreatitis. However later, acenocoumarol given at the highest dose failed to exhibit any therapeutic effect; whereas lower doses of acenocoumarol were still effective in the treatment of acute pancreatitis. Conclusion: Treatment with acenocoumarol accelerates the recovery of ischemia/reperfusion-induced acute pancreatitis in rats.

Role for p53 in the Recovery of Transcription and Protection Against Apoptosis Induced by Ultraviolet Light

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Bruce C. McKay

1999-08-01

Full Text Available We have previously suggested that the inhibition of RNA polymerase II-mediated transcription after exposure to UV light promotes the accumulation of p53 and the induction of apoptosis (Oncogene 13, 823–831. However, it was not clear whether p53 induction was contributing to apoptosis. Here we report that apoptosis is triggered at lower UV doses in p53-deficient Li-Fraumeni syndrome (LFS and human papillomavirus (HPV E6 expressing fibroblasts than in normal cells, suggesting that p53 can be protective against UVinduced apoptosis. There is no significant difference in the effect of UV-irradiation on the cell cycle distribution of normal and primary LFS fibroblasts. Importantly, the recovery of nascent mRNA synthesis in all p53-deficient fibroblasts is significantly impaired compared with control cells after exposure to relevant doses of UV light. Taken together, our results suggest that wild-type p53 can protect cells against UV-induced apoptosis by facilitating the recovery of transcription. Furthermore, we suggest that the capacity of cells to recover transcription after genotoxic damage is an important determinant of sensitivity to apoptosis.

Structural alterations in rat liver proteins due to streptozotocin-induced diabetes and the recovery effect of selenium: Fourier transform infrared microspectroscopy and neural network study

Science.gov (United States)

Bozkurt, Ozlem; Haman Bayari, Sevgi; Severcan, Mete; Krafft, Christoph; Popp, Jürgen; Severcan, Feride

2012-07-01

The relation between protein structural alterations and tissue dysfunction is a major concern as protein fibrillation and/or aggregation due to structural alterations has been reported in many disease states. In the current study, Fourier transform infrared microspectroscopic imaging has been used to investigate diabetes-induced changes on protein secondary structure and macromolecular content in streptozotocin-induced diabetic rat liver. Protein secondary structural alterations were predicted using neural network approach utilizing the amide I region. Moreover, the role of selenium in the recovery of diabetes-induced alterations on macromolecular content and protein secondary structure was also studied. The results revealed that diabetes induced a decrease in lipid to protein and glycogen to protein ratios in diabetic livers. Significant alterations in protein secondary structure were observed with a decrease in α-helical and an increase in β-sheet content. Both doses of selenium restored diabetes-induced changes in lipid to protein and glycogen to protein ratios. However, low-dose selenium supplementation was not sufficient to recover the effects of diabetes on protein secondary structure, while a higher dose of selenium fully restored diabetes-induced alterations in protein structure.

Different effects of high- and low-dose phenobarbital on post-stroke seizure suppression and recovery in immature CD1 mice

Science.gov (United States)

Markowitz, Geoffrey J.; Kadam, Shilpa D.; Smith, Dani R.; Johnston, Michael V.; Comi, Anne M.

2011-01-01

Neonatal stroke presents with seizures that are usually treated with phenobarbital. We hypothesized that anticonvulsants would attenuate ischemic injury, but that the dose-dependent effects of standard anticonvulsants would impact important age-dependent and injury-dependent consequences. In this study, ischemia induced by unilateral carotid ligation in postnatal day 12 (P12) CD1 mice was immediately followed by an i.p. dose of vehicle, low-dose or high-dose phenobarbital. Severity of acute behavioral seizures was scored. 5-bromo-2’-deoxyuridine (BrdU) was administered from P18-P20, behavioral testing performed, and mice perfused at P40. Atrophy quantification and counts of BrdU/NeuN-labeled cells in the dentate gyrus were performed. Blood phenobarbital concentrations were measured. 30 mg/kg phenobarbital reduced acute seizures and chronic brain injury, and restored normal weight gain and exploratory behavior. By comparison, 60 mg/kg was a less efficacious anticonvulsant, was not neuroprotective, did not restore normal weight gain, and impaired behavioral and cognitive recovery. Hippocampal neurogenesis was not different between treatment groups. These results suggest a protective effect of lower-dose phenobarbital, but a lack of this effect at higher concentrations after stroke in P12 mice. PMID:21481568

A low-dose mindfulness intervention and recovery from work: effects on psychological detachment, sleep quality, and sleep duration

NARCIS (Netherlands)

Hüslheger, U.R.; Feinholdt, A.; Nübold, A.

2015-01-01

Although playing a crucial role for the prevention of long-term health impairment, interventions aiming at the improvement of employees' recovery processes are still scarce. In this study, we therefore investigated the effectiveness of a low-dose mindfulness intervention for recovery from work. In

Single dose systemic acetaminophen to improve patient reported quality of recovery after ambulatory segmental mastectomy: A prospective, randomized, double-blinded, placebo controlled, clinical trial.

Science.gov (United States)

De Oliveira, Gildasio S; Rodes, Meghan E; Bialek, Jane; Kendall, Mark C; McCarthy, Robert J

2017-11-15

Few systemic drug interventions are efficacious to improve patient reported quality of recovery after ambulatory surgery. We aimed to evaluate whether a single dose systemic acetaminophen improve quality of recovery in female patients undergoing ambulatory breast surgery. We hypothesized that patients receiving a single dose systemic acetaminophen at the end of the surgical procedure would have a better global quality of postsurgical recovery compared to the ones receiving saline. The study was a prospective randomized double blinded, placebo controlled, clinical trial. Healthy female subjects were randomized to receive 1 g single dose systemic acetaminophen at the end of the surgery or the same volume of saline. The primary outcome was the Quality of Recovery 40 (QOR-40) questionnaire at 24 hours after surgery. Other data collected included opioid consumption and pain scores. Data were analyzed using group t tests and the Wilcoxon exact test. The association between opioid consumption and quality of recovery was evaluated using Spearman rho. P quality of recovery, P = .007. A single dose of systemic acetaminophen improves patient reported quality of recovery after ambulatory breast surgery. The use of systemic acetaminophen is an efficacious strategy to improve patient perceived quality of postsurgical recovery and analgesic outcomes after hospital discharge for ambulatory breast surgery. © 2017 Wiley Periodicals, Inc.

Implications of tissue target-cell survival-curve shape for values of split-dose recovery doses: late versus early effects

International Nuclear Information System (INIS)

Redpath, J.L.; Peel, D.M.; Hopewell, J.W.

1984-01-01

Recent data from this laboratory on split-dose recovery for early and late effects in pig skin are consistent with the linear-quadratic model for cell survival, and with relative cell survival-curve shapes for early- and late-effect target cells where the early-effect cells have an intially steeper and straighter survival-curve than the late-effect cells. (author)

Low doses of neutrons induce changes in gene expression

International Nuclear Information System (INIS)

Woloschak, G.E.; Chang-Liu, C.M.; Panozzo, J.; Libertin, C.R.

1993-01-01

Studies were designed to identify genes induced following low-dose neutron but not following γ-ray exposure in fibroblasts. Our past work had shown differences in the expression of β-protein kinase C and c-fos genes, both being induced following γ-ray but not neutron exposure. We have identified two genes that are induced following neutron, but not γ-ray, exposure: Rp-8 (a gene induced by apoptosis) and the long terminal repeat (LTR) of the human immunodeficiency (HIV). Rp-8 mRNA induction was demonstrated in Syrian hamster embryo fibroblasts and was found to be induced in cells exposed to neutrons administered at low (0.5 cGy/min) and at high dose rate (12 cGy/min). The induction of transcription from the LTR of HIV was demonstrated in HeLa cells bearing a transfected construct of the chloramphenicol acetyl transferase (CAT) gene driven by the HIV-LTR promoter. Measures of CAT activity and CAT transcripts following irradiation demonstrated an unresponsiveness to γ rays over a broad range of doses. Twofold induction of the HIV-LTR was detected following neutron exposure (48 cGy) administered at low (0.5 cGy/min) but not high (12 cGy/min) dose rates. Ultraviolet-mediated HIV-LTR induction was inhibited by low-dose-rate neutron exposure

Sci—Fri PM: Topics — 06: The influence of regional dose sensitivity on salivary loss and recovery in the parotid gland

Energy Technology Data Exchange (ETDEWEB)

Clark, H [University of British Columbia, Vancouver, B.C. (Canada); BC Cancer Agency, Surrey, B.C. (Canada); BC Cancer Agency, Vancouver, B.C. (Canada); Thomas, S [BC Cancer Agency, Surrey, B.C. (Canada); Moiseenko, V [University of California San Diego, La Jolla, Ca (United States); Hovan, A; Wu, J [BC Cancer Agency, Vancouver, B.C. (Canada)

2014-08-15

Purpose: The Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC 2010) survey of radiation dose-volume effects on salivary gland function has called for improved understanding of intragland dose sensitivity and the effectiveness of partial sparing in salivary glands. Regional dose susceptibility of sagittally- and coronally-sub-segmented parotid gland has been studied. Specifically, we examine whether individual consideration of sub-segments leads to improved prediction of xerostomia compared with whole parotid mean dose. Methods: Data from 102 patients treated for head-and-neck cancers at the BC Cancer Agency were used in this study. Whole mouth stimulated saliva was collected before (baseline), three months, and one year after cessation of radiotherapy. Organ volumes were contoured using treatment planning CT images and sub-segmented into regional portions. Both non-parametric (local regression) and parametric (mean dose exponential fitting) methods were employed. A bootstrap technique was used for reliability estimation and cross-comparison. Results: Salivary loss is described well using non-parametric and mean dose models. Parametric fits suggest a significant distinction in dose response between medial-lateral and anterior-posterior aspects of the parotid (p<0.01). Least-squares and least-median squares estimates differ significantly (p<0.00001), indicating fits may be skewed by noise or outliers. Salivary recovery exhibits a weakly arched dose response: the highest recovery is seen at intermediate doses. Conclusions: Salivary function loss is strongly dose dependent. In contrast no useful dose dependence was observed for function recovery. Regional dose dependence was observed, but may have resulted from a bias in dose distributions.

Evaluation of amino acids changes in liver and serum during the recovery from gamma-irradiation in rats

International Nuclear Information System (INIS)

Elkashef, H.S.; Saada, H.N.; Roushdy, H.M.; Abdelsamie, M.A.

1989-01-01

Recovery from radiation induced changes in glutamic and aspartic acids in both liver and serum was evaluated in rats treated with a mixture of testosterone and vitamin E and subjected to whole body gamma irradiation of 5.5 Gy. The intraperitoneal injection of the mixture 10 days before exposing the rat gamma radiation improved the recovery process from radiation induced changes in the level of aspartic and glutamic acid. The recovery occurred in liver two weeks after irradiation in injected irradiated rats, while in irradiated rats self recovery was noticed on the third week after irradiation for aspartic acid but this mixture has no protective effect on the radiation induced changes in the liver glutamic acid. With respect to changes in blood serum, recovery was recorded in the first week after irradiation in the case of aspartic acid while recovery in glutamic acid was attained latter, in the second week. The results suggested that blood serum is more sensitive to the radiation dose 5.5 Gy than the liver of whole body gamma-irradiated rats. Also, it could be suggested that glutamic acid and aspartic acid have different susceptibility to this radiation dose.2 tab

Time-dependent recovery of in vivo binding sites after drug dosing: A method for radiotracer evaluation

International Nuclear Information System (INIS)

Kilbourn, Michael R.

1997-01-01

The recovery of in vivo binding sites for (±)-α-[ 11 C]methoxytetrabenazine, a radioligand for the monoamine vesicular transporter (VMAT2), was determined in mouse brain at various times following a pharmacological dose of tetrabenazine. Concentrations of in vivo radioligand binding sites progressively increased and had reached control values by 8.5 h, and this recovery was consistent with the pharmacokinetics of the competing drug tetrabenazine and its active metabolite, dihydrotetrabenazine. This study demonstrates a simple experimental protocol of using a single dose of a reversible competing drug and time-dependent measurements of in vivo binding of a radioligand. This protocol is suitable for testing the sensitivity of an in vivo radiotracer for measurement of varying concentrations of in vivo binding sites

Split dose recovery studies using homologous recombination deficient gene knockout chicken B lymphocyte cells

International Nuclear Information System (INIS)

Rao, B.S.S.; Tano, Kaori; Utsumi, Hiroshi; Takeda, Shunichi

2007-01-01

To understand the role of proteins involved in double strand breaks (DSB) repair modulating sublethal damage (SLD) recovery, chicken B lymphoma (DT 40) cell lines either proficient or deficient in RAD52, XRCC2, XRCC3, RAD51C and RAD51D were subjected to fractionated irradiation and their survival curves charted. Survival curves of both WT DT40 and RAD52 -/- cells had a big shoulder while all the other cells exhibited small shoulders. However, at the higher doses of radiation, RAD51C -/- cells displayed hypersensitivity comparable to the data obtained for the homologous recombination deficient RAD54 -/- cells. Repair of SLD was measured as an increase in survival after a split dose irradiation with an interval of incubation between the radiation doses. All the cell lines (parental DT40 and genetic knockout cell lines viz., RAD52 -/- , XRCC2 -/- XRCC3 -/- RAD51C -/- and RAD51D -/- ) used in this study demonstrated a typical split-dose recovery capacity with a specific peak, which varied depending on the cell type. The maximum survival of WT DT40 and RAD52 -/- was reached at about 1-2 hours after the first dose of radiation and then decreased to a minimum thereafter (5 h). The increase in the survival peaked once again by about 8 hours. The survival trends observed in XRCC2 -/- , XRCC3 -/- , RAD51C -/- and RAD51D -/- knockout cells were also similar, except for the difference in the initial delay of a peak survival for RAD51D -/- and lower survival ratios. The second phase of increase in the survival in these cell lines was much slower in XRCC2 -/- , XRCC3 -/- , RAD51C -/- nd RAD51D -/- and further delayed when compared with that of RAD52 -/- and parental DT40 cells suggesting a dependence on their cell cycle kinetics. This study demonstrates that the participation of RAD52, XRCC2, XRCC3, RAD51C and RAD51D in the DSB repair via homologous recombination is of less importance in comparison to RAD54, as RAD54 deficient cells demonstrated complete absence of SLD recovery

The Impact of Timing and Dose of Rehabilitation Delivery on Functional Recovery of Stroke Patients

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Hsiu-Chen Huang

2009-05-01

Conclusion: There is a dose-dependent effect of rehabilitation on functional improvement of stroke patients for the first 6 months post-stroke, and earlier delivery of rehabilitation has lasting effects on the functional recovery of stroke patients up to 1 year.

Daptomycin-Induced Acute Eosinophilic Pneumonia: Late Onset and Quick Recovery

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Mohamad Rachid

2017-01-01

Full Text Available Background. Daptomycin is a cyclic lipopeptide antibiotic that provides great coverage for gram positive cocci. From the early years of daptomycin use, concerns were raised regarding the pulmonary side effects of daptomycin and potential development of acute eosinophilic pneumonia (AEP secondary to daptomycin therapy. Discussion. AEP could be idiopathic or induced by drugs or toxins. It is a distinct entity from atopic diseases and autoimmune, parasitic, or fungal infections that can also cause pulmonary eosinophilia. Multiple medications are associated with acute eosinophilic pneumonia. Multiple cases of daptomycin-induced AEP have been reported in the literature. Diagnosis of AEP is based on clinical history, laboratory tests, and radiographic studies. Obtaining bronchoalveolar lavage or lung biopsy is needed to confirm the diagnosis. Timing of the drug use and clinical presentation is crucial in the diagnosis of drug-induced AEP. Discontinuation of the offending drug and systemic corticosteroids are the mainstay treatment with great outcomes and recovery. Conclusion. We present a case of AEP caused by daptomycin, with complete recovery after discontinuation of daptomycin and administration of steroids. The patient had AEP after almost 6 weeks of daptomycin therapy which has never been reported in literature and our patient achieved complete recovery with appropriate management.

Beta induced Bremsstrahlung dose rate in concrete shielding

International Nuclear Information System (INIS)

Manjunatha, H.C.

2013-01-01

Dosimetric study of beta-induced Bremsstrahlung in concrete is importance in the field of radiation protection. The efficiency, intensity and dose rate of beta induced Bremsstrahlung by 113 pure beta nuclides in concrete shielding is computed. The Bremsstrahlung dosimetric parameters such as the efficiency (yield), Intensity and dose rate of Bremsstrahlung are low for 199 Au and high for 104 Tc in concrete. The efficiency, Intensity and dose rate of Bremsstrahlung increases with maximum energy of beta nuclide (Emax) and modified atomic number (Zmod) of the target. The estimated Bremsstrahlung efficiency, Intensity and dose rate are useful in the calculations photon track-length distributions. These parameters are useful to determine the quality and quantity of the radiation (known as the source term). Precise estimation of this source term is very important in planning of radiation shielding. (author)

Long-term divergent tidal flat benthic community recovery following hypoxia-induced mortality

NARCIS (Netherlands)

Colen, van C.; Montserrat, F.; Vincx, M.; Herman, P.M.J.; Ysebaert, T.; Degraer, S.

2010-01-01

Macrobenthos recovery after hypoxia-induced mass mortality was assessed in an estuarine tidal mudflat during 3 years. During the first 2 years, a Pearson-Rosenberg type of community recovery took place along with the improving bottom water oxygen conditions. After 3 months, spionid polychaetes

Recovery of reticulocytes and prevention of radiation-induced weight loss in mice by γ-tocotrienol: possible application to cancer therapy

International Nuclear Information System (INIS)

Kumar, K.S.; Srinivasan, V.; Toles, R.E.; Miner, V.L.; Seed, T.M.

2003-01-01

Gamma-tocotrienol (GT), an alpha-tocopherol (AT, vitamin E) isomer was found to be better than AT against radiation-induced lethality. CD2F1 male mice (LD 50/30 radiation dose 9 Gy) were injected subcutaneously with 10 mg/mouse each of GT or AT. After 24 hrs, mice were given 11 Gy 60 Cobalt radiation. All mice treated with AT survived; only 50% of the mice treated with GT survived. The mechanism of protection may not involve apoptotic pathway since GT did not affect caspase-3 activity whereas AT suppressed radiation-induced increase in activity. Recovery profiles of blood cells and weight loss were also evaluated. Mice were treated with AT, GT, or vehicle prior to sublethal whole-body gamma irradiation. In the AT- and GT-treated mice, the recovery rates of neutrophils, platelets, erythrocytes, and reticulocytes were greater than in vehicle-treated controls. The highest level (265% of the normal) of reticulocytes in GT or AT treated mice was reached in 15 days postirradiation; the highest level (450% of the normal) in vehicle-treated controls was reached 20 days after irradiation. Recovery profile of erythrocytes suggested that reticulocytes in the irradiated controls matured slowly into erythrocytes; reticulocytes in GT or AT treated mice matured at a faster rate. Radiation-induced weight loss was studied at a supralethal dose of 10.5 Gy. All animals, irrespective of the treatments lost up to 20% weight in 5 days. After a transient increase, irradiated controls and AT-treated mice continued to decline in weight (13 to 17%) till day 16 after irradiation. GT-treated mice lost only 1% to 9% after the initial loss in 5 days. These studies indicate that GT may be preferable than AT not only as a non-toxic radiation protective agent but also as an ideal adjuvant in alleviating anemia and weight loss accompanying radiotherapy or chemotherapy of cancer

Theophylline-induced respiratory recovery following cervical spinal cord hemisection is augmented by serotonin 2 receptor stimulation.

Science.gov (United States)

Basura, Gregory J; Nantwi, Kwaku D; Goshgarian, Harry G

2002-11-22

Cervical spinal cord hemisection leads to a disruption of bulbospinal innervation of phrenic motoneurons resulting in paralysis of the ipsilateral hemidiaphragm. We have previously demonstrated separate therapeutic roles for theophylline, and more recently serotonin (5-HT) as modulators to phrenic nerve motor recovery; mechanisms that likely occur via adenosine A1 and 5-HT2 receptors, respectively. The present study was designed to specifically determine if concurrent stimulation of 5-HT2 receptors may enhance motor recovery induced by theophylline alone. Adult female rats (250-350 g; n=7 per group) received a left cervical (C2) hemisection that resulted in paralysis of the ipsilateral hemidiaphragm. Twenty-four hours later rats were given systemic theophylline (15 mg/kg, i.v.), resulting in burst recovery in the ipsilateral phrenic nerve. Theophylline-induced recovery was enhanced with the 5-HT2A/2C receptor agonist, (+/-)-2,5-dimethoxy-4-iodoamphetamine hydrochloride (DOI; 1.0 mg/kg). DOI-evoked augmentation of theophylline-induced recovery was attenuated following subsequent injection of the 5-HT2 receptor antagonist, ketanserin (2.0 mg/kg). In a separate group, rats were pretreated with ketanserin, which did not prevent subsequent theophylline-induced respiratory recovery. However, pretreatment with ketanserin did prevent DOI-induced augmentation of the theophylline-evoked phrenic nerve burst recovery. Lastly, using immunocytochemistry and in situ hybridization, we showed for the first time a positive co-localization of adenosine A1 receptor mRNA and immunoreactivity with phrenic motoneurons of the cervical ventral horns. Taken together, the results of the present study suggest that theophylline may induce motor recovery likely at adenosine A1 receptors located at the level of the spinal cord, and the concurrent stimulation of converging 5-HT2 receptors may augment the response.

Summary of radiation-induced transient absorption and recovery in fiber optic waveguides. [Pulsed electrons and x-rays

Energy Technology Data Exchange (ETDEWEB)

Skoog, C.D.

1976-11-01

The absorption induced in fiber optic waveguides by pulsed electron and X-ray radiation has been measured as a function of optical wavelength from 450 to 950 nm, irradiation temperature from -54 to 71/sup 0/C, and dose from 1 to 500 krads. The fibers studied are Ge-doped silica core fibers (Corning Low Loss), ''pure'' vitreous silica core fibers (Schott, Bell Laboratories, Fiberoptic Cable Corp., and Valtec Fiberoptics), polymethyl-methacrylate core fibers (DuPont CROFON and PFX), and polystyrene core fibers (International Fiber Optics and Polyoptics). Models that have been developed to account for the observed absorption recovery are also summarized.

Dose rate effectiveness in radiation-induced teratogenesis in mice

International Nuclear Information System (INIS)

Kato, F.; Ootsuyama, A.; Norimura, T.

2000-01-01

To investigate the role of p53 gene in tissue repair of teratogenic injury, we compared incidence of radiation-induced malformations in homozygous p53(-/-) mice, heterozygous p53(+/-) mice and wild-type p53(+/+) mice. After X-irradiation with 2 Gy at high dose rate on 9.5 days of gestation, p53(-/-) mice showed higher incidences of anomalies and higher resistance to prenatal deaths than p53(+/+) mice. This reciprocal relationship of radiosensitivity to anomalies and deaths supports the notion that embryos or fetuses have a p53-dependent 'guardian' that aborts cells bearing radiation-induced teratogenic DNA damage. In fact, after X-irradiation, the number of apoptotic cells was greatly increased in p53(+/+) fetuses but not in p53(-/-) fetuses. The same dose of γ-ray exposure at low dose rate on 9.5-10.5 day of gestation produced significant reduction of radiation-induced malformation in p53(+/+) and p53(+/-) mice, remained teratogenic for p53(-/-) mice. These results suggest that complete elimination of teratogenic damage from irradiated tissues requires the concerted cooperation of two mechanisms; proficient DNA repair and the p53-dependent apoptotic tissue repair. When concerted DNA repair and apoptosis functions efficiently, there is a threshold dose-rate for radiation-induced malformations. (author)

Carcinogenesis induced by low-dose radiation

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Piotrowski Igor

2017-11-01

Full Text Available Although the effects of high dose radiation on human cells and tissues are relatively well defined, there is no consensus regarding the effects of low and very low radiation doses on the organism. Ionizing radiation has been shown to induce gene mutations and chromosome aberrations which are known to be involved in the process of carcinogenesis. The induction of secondary cancers is a challenging long-term side effect in oncologic patients treated with radiation. Medical sources of radiation like intensity modulated radiotherapy used in cancer treatment and computed tomography used in diagnostics, deliver very low doses of radiation to large volumes of healthy tissue, which might contribute to increased cancer rates in long surviving patients and in the general population. Research shows that because of the phenomena characteristic for low dose radiation the risk of cancer induction from exposure of healthy tissues to low dose radiation can be greater than the risk calculated from linear no-threshold model. Epidemiological data collected from radiation workers and atomic bomb survivors confirms that exposure to low dose radiation can contribute to increased cancer risk and also that the risk might correlate with the age at exposure.

Studies on adaptive response of lymphocyte transformation induced by low-dose irradiation

International Nuclear Information System (INIS)

Du Zeji; Su Liaoyuan; Tian Hailin; Zou Huawei

1995-10-01

Human peripheral blood lymphocytes stimulated by mitogen in vitro for 24 h were exposed to low-dose γ-ray irradiation (0.5∼4.0 cGy, adaptive dose). They showed an adaptive response to the inhibition of 3 H-TdR incorporation by subsequent higher acute doses of γ-ray (challenge dose). At the interval of 24 h between adaptive dose and challenge dose, the strongest adaptive response induced by low-dose irradiation was found. It is also found that the response induced by 1.0 cGy of adaptive dose was more obvious than that by other doses and that 3.0 Gy of challenge dose produced the strongest adaptive response. As the challenge doses increased, the adaptive response reduced. (2 figs., 2 tabs.)

Quinine-induced tinnitus in rats.

Science.gov (United States)

Jastreboff, P J; Brennan, J F; Sasaki, C T

1991-10-01

Quinine ingestion reportedly induces tinnitus in humans. To expand our salicylate-based animal model of tinnitus, a series of conditioned suppression experiments was performed on 54 male-pigmented rats using quinine injections to induce tinnitus. Quinine induced changes in both the extent of suppression and recovery of licking, which followed a pattern that paralleled those produced after salicylate injections, and which may be interpreted as the result of tinnitus perception in animals. These changes depended on the dose and time schedule of quinine administration. Additionally, the calcium channel blocker, nimodipine, abolished the quinine-induced effect in a dose-dependent manner.

Estimation of the Radon-induced Dose for Russia's Population: Methods and Results

International Nuclear Information System (INIS)

Marenny, A.M.; Savkin, M.N.; Shinkarev, S.M.

2000-01-01

A model is proposed for inferring the radon-induced annual average collective and personal doses, as well as the dose distribution of the population, all over Russia from selective radon monitoring in some regions of Russia. The model assumptions and the selective radon monitoring results that underlie the numerical estimates obtained for different population groups are presented. The current estimate of the collective radon-induced dose received by the population of Russia (148,100,000 as of 1996) is about 130,000 man Sv, of which 55,000 man Sv is for the rural population (27% of the total population) and 75,000 man Sv for the urban population (73% of the total). The average radon-induced personal dose in Russia is estimated to be about 0.87 mSv. About 1,000,000 people receive annual doses above 10 mSv, including some 200,000 people who receive doses above 20 mSv annually. The ways of making the current estimates more accurate are outlined. (author)

Effect and adaptive response of lymphocytes DNA induced by low dose irradiation

International Nuclear Information System (INIS)

Du Zeji; Su Liaoyuan; Tian Hailin

1994-09-01

Fluorometric analysis of DNA unwinding (FADU) was conducted and was proved to be an optimal method for studying DNA strand breaks induced by low dose irradiation. The linear dose response curve was obtained. The minimum detected dose was 0.3 Gy. There was no effect of low dose γ-rays (0.5∼8.0 cGy) on DNA strand breaks of quiescent and mitogen-induced lymphocytes. The 0.5∼4.0 cGy γ-rats could induce adaptive response of lymphocytes' DNA strand breaks, especially, at the doses of 2.0 and 4.0 cGy. The challenge doses of 5∼20 Gy could make the adaptive response appearance, and the 15 Gy was the best one. The 3-AB could powerfully inhibit the adaptive response. The repair of DNA strand breaks (37 degree C, 15∼60 min) caused by 15 Gy γ-rays could be promoted by the low dose γ-ray irradiation (2.0 cGy), but no difference was found at 37 degree C, 120 min

Very low dose and dose-rate X-ray induced adaptive response in human lymphocytes at various cell cycle stages against bleomycin induced chromatid aberrations

International Nuclear Information System (INIS)

Hossein Mozdarani; Moghadam, R.N.

2007-01-01

Complete text of publication follows. Objective: To study the adaptive response induced by very low doses of X-rays at very low dose rate in human lymphocytes at different cell cycle stages followed by a challenge dose of bleomycin sulphate at G2 phase. Materials and Methods: Human peripheral blood lymphocytes before (G0) and after PHA stimulation (G1 and G2) were exposed to 1 and 5 cGy X-rays generated by a fluoroscopy unit with a dose rate of 5.56 mGy/min and challenged with 5 μg/ml bleomycin sulphate (BLM) 48 hours after culture initiation. Mitotic cells were arrested at metaphase by addition of colcemid in cultures 1.5 h before harvesting. Harvesting and slide preparation was performed using standard method. 100 well spread metaphases were analyzed for the presence of chromatid type aberrations for each sample. Results: Results obtained indicate that there is a linear relationship between the dose of BLM and chromatid aberrations below 5 μg/ml (R=0.93, p<0.0001). The results also show that pretreatment of lymphocytes with low dose X-rays at G0, G1 and G2 phases of the cell cycle significantly reduced the sensitivity of lymphocytes to the clastogenic effects of BLM in G2. Much lower frequencies of chromatid aberrations were observed in X-ray irradiated lymphocytes following BLM treatment (p<0.05). The magnitudes of adaptation induced at different phases of the cell cycle were not significantly different. Furthermore, there was no a significant difference in the magnitude of adaptive response induced by either 1 or 5 cGy X-rays. Conclusion: These observations might indicate that resistance of pre-exposure of lymphocytes to very low doses of X-rays protects them from clastogenic effects of BLM. This effect might be due to initial DNA damage induced in these cells leading to provocation of an active DNA repair mechanism independent of cell cycle stage.

Radiation-induced cell mutations as a function of dose rate

International Nuclear Information System (INIS)

Kiefer, J.

1987-01-01

A brief review of the data in the literature is presented and forms the background of the experimental data given by the author obtained with exponential long-term cultures of V79 hamster cells exposed over a period of up to 35 days to different dose rates of gamma radiation. The experimental results show that at a dose rate of 40 mGy/hour the number of induced mutations is reduced, - which is in agreement with literature data - , but a dose rate of less than 30 mGy/hour makes the induced mutations leap to a value clearly higher than those induced by acute irradiation. As in addition to the mutations recombination is a significant factor of the radiation risk, experiments with a heterozygotic yeast strain have been made, as there is to date no reliable mammalian cell system available for this kind of research. Long-term radiation exposure of the yeast cells over a period of six weeks drastically increased the rate of recombinations, to a value higher by a factor of about 4 than that induced by acute irradiation. (orig.) [de

Dose-effect relationship of apoptosis induced by fission-neutron in murine thymocytes

International Nuclear Information System (INIS)

Yuan Bin; Li Liang; Xue Wencheng; Sun Jianmin; Wang Baoqin

2000-01-01

Objective: To investigate the effectiveness of high LET fission-neutron to induce apoptosis in murine thymocytes and to compare it with that of low LET 60 Co γ-ray. Methods: Apoptosis induction was studied qualitatively by light and transmission electron microscopy and DNA gel electrophoresis,also quantitatively by flow cytometry(FCM) and diphenylamine (DPA)methods. Results: DNA ladders of murine thymocytes were detectable, the typical apoptosis of thymocytes could be observed morphologically by means of light and electron microscopy at 6 h after fission-neutron irradiation with doses ranging from 0.5 to 5.0 Gy, meanwhile the percentages of apoptosis increased with increasing doses. After exposure to γ-rays with doses ranging from 1.0 to 30 Gy, the experimental results were similar to those from neutron radiation. The incidence of apoptosis peaked at about 20 Gy, the percentages did not increase further when doses increased. Conclusion: Apoptosis of murine thymocytes can be induced when mice are exposed to either fission-neutron (0.5-5.0 Gy) or to γ-ray (1-30 Gy). Although the relationship between apoptosis and radiation doses is similar, the percentage of apoptosis induced by neutron irradiation is higher than that induced by γ-irradiation. The RBE values of fission-neutron for inducing apoptosis murine thymocytes are 2.09 (by FCM method) and 2.37 (by DPA method), respectively. These results also suggest that fission-neutron-induced murine immune tissue is more severe than that induced by γ-rays at several hours post-irradiation and this might be the basis for heavy damage to immune tissues induced by fission-neutron-irradiation in later period

Dose-response study of thimerosal-induced murine systemic autoimmunity

International Nuclear Information System (INIS)

Havarinasab, S.; Lambertsson, L.; Qvarnstroem, J.; Hultman, P.

2004-01-01

The organic compound ethylmercurithiosalicylate (thimerosal), which is primarily present in the tissues as ethylmercury, has caused illness and several deaths due to erroneous handling when used as a disinfectant or as a preservative in medical preparations. Lately, possible health effects of thimerosal in childhood vaccines have been much discussed. Thimerosal is a well-known sensitizing agent, although usually of no clinical relevance. In rare cases, thimerosal has caused systemic immune reactions including acrodynia. We have studied if thimerosal might induce the systemic autoimmune condition observed in genetically susceptible mice after exposure to inorganic mercury. A.SW mice were exposed to 1.25-40 mg thimerosal/l drinking water for 70 days. Antinucleolar antibodies, targeting the 34-kDa protein fibrillarin, developed in a dose-related pattern and first appeared after 10 days in the two highest dose groups. The lowest observed adverse effect level (LOAEL) for antifibrillarin antibodies was 2.5 mg thimerosal/l, corresponding to an absorbed dose of 147 μg Hg/kg bw and a concentration of 21 and 1.9 μg Hg/g in the kidney and lymph nodes, respectively. The same LOAEL was found for tissue immune-complex deposits. The total serum concentration of IgE, IgG1, and IgG2a showed a significant dose-related increase in thimerosal-treated mice, with a LOAEL of 5 mg thimerosal/l for IgG1 and IgE, and 20 mg thimerosal/l for IgG2a. The polyclonal B-cell activation showed a significant dose-response relationship with a LOAEL of 10 mg thimerosal/l. Therefore, thimerosal induces in genetically susceptible mice a systemic autoimmune syndrome very similar to that seen after treatment with inorganic mercury, although a higher absorbed dose of Hg is needed using thimerosal. The autoimmune syndrome induced by thimerosal is different from the weaker and more restricted autoimmune reaction observed after treatment with an equipotent dose of methylmercury

Multilineage hematopoietic recovery with concomitant antitumor effects using low dose Interleukin-12 in myelosuppressed tumor-bearing mice

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Miller Joseph D

2008-05-01

Full Text Available Abstract Background Interleukin-12 (IL-12 is a cytokine well known for its role in immunity. A lesser known function of IL-12 is its role in hematopoiesis. The promising data obtained in the preclinical models of antitumor immunotherapy raised hope that IL-12 could be a powerful therapeutic agent against cancer. However, excessive clinical toxicity, largely due to repeat dose regimens, and modest clinical response observed in the clinical trials have pointed to the necessity to design protocols that minimize toxicity without affecting the anti-tumor effect of IL-12. We have focused on the lesser known role of IL-12 in hematopoiesis and hypothesized that an important clinical role for IL-12 in cancer may be as an adjuvant hematological cancer therapy. In this putative clinical function, IL-12 is utilized for the prevention of cancer therapy-related cytopenias, while providing concomitant anti-tumor responses over and above responses observed with the primary therapy alone. This putative clinical function of IL-12 focuses on the dual role of IL-12 in hematopoiesis and immunity. Methods We assessed the ability of IL-12 to facilitate hematopoietic recovery from radiation (625 rad and chemotherapy (cyclophosphamide in two tumor-bearing murine models, namely the EL4 lymphoma and the Lewis lung cancer models. Antitumor effects and changes in bone marrow cellularity were also assessed. Results We show herein that carefully designed protocols, in mice, utilizing IL-12 as an adjuvant to radiation or chemotherapy yield facile and consistent, multilineage hematopoietic recovery from cancer therapy-induced cytopenias, as compared to vehicle and the clinically-utilized cytokine granulocyte colony-stimulating factor (G-CSF (positive control, while still providing concomitant antitumor responses over and above the effects of the primary therapy alone. Moreover, our protocol design utilizes single, low doses of IL-12 that did not yield any apparent toxicity

Low-dose radiation-induced adaptive response in bone marrow cells of mice

International Nuclear Information System (INIS)

Farooqi, Zeba; Kesavan, P.C.

1993-01-01

Using bone marrow cells of whole body irradiated mice, the cytogenetic adaptive response induced by low conditioning doses of gamma-rays was investigated. The conditioning doses (0.025 and 0.05 Gy) were given at a dose-rate of 1.67 Gy/min. The challenging dose of 1 Gy was given at a dose-rate of 0.045 Gy/s. The challenging dose was given at different time intervals after the conditioning dose. The time intervals between the conditioning dose and challenging dose were 2, 7.5, 13, 18.5 and 24 h. When the time interval between the conditioning dose and the challenging dose was 2 h, both conditioning doses (0.025 and 0.05 Gy) reduced the frequency of MNPCEs and chromosomal aberrations in the bone marrow cells. The data collected at different time intervals (7.5, 13, 18.5 h) reveal that the radioadaptive response persisted for a longer time when the lower conditioning dose (0.025 Gy) was given. With the higher conditioning dose (0.05 Gy), the radioadaptive response disappeared after a time interval of 13 h. When the time interval between the conditioning dose and the challenging doses was 18.5 or 24 h, only the lower conditioning dose appeared effective in inducing the radioadaptive response

Extent and kinetics of recovery of occult spinal cord injury

International Nuclear Information System (INIS)

Ang, K. Kian; Jiang, G.-L.; Feng Yan; Stephens, L. Clifton; Tucker, Susan L.; Price, Roger E.

2001-01-01

Purpose: To obtain clinically useful quantitative data on the extent and kinetics of recovery of occult radiation injury in primate spinal cord, after a commonly administered elective radiation dose of 44 Gy, given in about 2 Gy per fraction. Methods and Materials: A group of 56 rhesus monkeys was assigned to receive two radiation courses to the cervical and upper thoracic spinal cord, given in 2.2 Gy per fraction. The dose of the initial course was 44 Gy in all monkeys. Reirradiation dose was 57.2 Gy, given after 1-year (n 16) or 2-year (n = 20) intervals, or 66 Gy, given after 2-year (n = 4) or 3-year (n = 14) intervals. Two animals developed intramedullary tumors before reirradiation and, therefore, did not receive a second course. The study endpoint was myeloparesis, manifesting predominantly as lower extremity weakness and decrease in balance, occurring within 2.5 years after reirradiation, complemented by histologic examination of the spinal cord. The data obtained were analyzed along with data from a previous study addressing single-course tolerance, and data from a preliminary study of reirradiation tolerance. Results: Only 4 of 45 monkeys completing the required observation period (2-2.5 years after reirradiation, 3-5.5 years total) developed myeloparesis. The data revealed a substantial recovery of occult injury induced by 44 Gy within the first year, and suggested additional recovery between 1 and 3 years. Fitting the data with a model, assuming that all (single course and reirradiation) dose-response curves were parallel, yielded recovery estimates of 33.6 Gy (76%), 37.6 Gy (85%), and 44.6 Gy (101%) of the initial dose, after 1, 2, and 3 years, respectively, at the 5% incidence (D 5 ) level. The most conservative estimate, using a model in which it was assumed that there was no recovery between 1 and 3 years following initial irradiation and that the combined reirradiation curve was not necessarily parallel to the single-course curve, still showed an

Optimization of induced crystallization reaction in a novel process of nutrients removal coupled with phosphorus recovery from domestic wastewater

Directory of Open Access Journals (Sweden)

Zou Haiming

2017-12-01

Full Text Available Phosphorus removal and recovery from domestic wastewater is urgent nowadays. A novel process of nutrients removal coupled with phosphorus recovery from domestic sewage was proposed and optimization of induced crystallization reaction was performed in this study. The results showed that 92.3% of phosphorus recovery via induced Hydroxyapatite crystallization was achieved at the optimum process parameters: reaction time of 80 min, seed crystal loads of 60 g/L, pH of 8.5, Ca/P mole ratio of 2.0 and 4.0 L/min aeration rate when the PO43--P concentration was 10 mg/L in the influent, displaying an excellent phosphorus recovery performance. Importantly, it was found that the effect of reaction temperature on induced Hydroxyapatite crystallization was slight, thus favoring practical application of phosphorus recovery method described in this study. From these results, the proposed method of induced HAP crystallization to recover phosphorus combined with nutrients removal can be an economical and effective technology, probably favoring the water pollution control and phosphate rock recycle.

Radiobiological responses for two cell lines following continuous low dose-rate (CLDR) and pulsed dose rate (PDR) brachytherapy

International Nuclear Information System (INIS)

Hanisch, Per Henrik; Furre, Torbjoern; Olsen, Dag Rune; Pettersen, Erik O.

2007-01-01

The iso-effective irradiation of continuous low-dose-rate (CLDR) irradiation was compared with that of various schedules of pulsed dose rate (PDR) irradiation for cells of two established human lines, T-47D and NHIK 3025. Complete single-dose response curves were obtained for determination of parameters α and β by fitting of the linear quadratic formula. Sublethal damage repair constants μ and T 1/2 were determined by split-dose recovery experiments. On basis of the acquired parameters of each cell type the relative effectiveness of the two regimens of irradiation (CLDR and PDR) was calculated by use of Fowler's radiobiological model for iso-effect irradiation for repeated fractions of dose delivered at medium dose rates. For both cell types the predicted and observed relative effectiveness was compared at low and high iso-effect levels. The results indicate that the effect of PDR irradiation predicted by Fowler's model is equal to that of CLDR irradiation for both small and large doses with T-47D cells. With NHIK 3025 cells PDR irradiation induces a larger effect than predicted by the model for small doses, while it induces the predicted effect for high doses. The underlying cause of this difference is unclear, but cell-cycle parameters, like G2-accumulation is tested and found to be the same for the two cell lines

Modeling of Salivary Production Recovery After Radiotherapy Using Mixed Models: Determination of Optimal Dose Constraint for IMRT Planning and Construction of Convenient Tools to Predict Salivary Function

International Nuclear Information System (INIS)

Ortholan, Cecile; Chamorey, Emmanuel Phar; Benezery, Karen; Thariat, Juliette; Dassonville, Olivier; Poissonnet, Gilles; Bozec, Alexandre; Follana, Philippe; Peyrade, Frederique; Sudaka, Anne; Gerard, Jean Pierre; Bensadoun, Rene Jean

2009-01-01

Purpose: The mathematical relationship between the dose to the parotid glands and salivary gland production needs to be elucidated. This study, which included data from patients included in a French prospective study assessing the benefit of intensity-modulated radiotherapy (RT), sought to elaborate a convenient and original model of salivary recovery. Methods and Materials: Between January 2001 and December 2004, 44 patients were included (35 with oropharyngeal and 9 with nasopharyngeal cancer). Of the 44 patients, 24 were treated with intensity-modulated RT, 17 with three-dimensional conformal RT, and 2 with two-dimensional RT. Stimulated salivary production was collected for ≤24 months after RT. The data of salivary production, time of follow-up, and dose to parotid gland were modeled using a mixed model. Several models were developed to assess the best-fitting variable for the dose level to the parotid gland. Results: Models developed with the dose to the contralateral parotid fit the data slightly better than those with the dose to both parotids, suggesting that contralateral and ipsilateral parotid glands are not functionally equivalent even with the same dose level to the glands. The best predictive dose-value variable for salivary flow recovery was the volume of the contralateral parotid gland receiving >40 Gy. Conclusion: The results of this study show that the recommendation of a dose constraint for intensity-modulated RT planning should be established at the volume of the contralateral parotid gland receiving >40 Gy rather than the mean dose. For complete salivary production recovery after 24 months, the volume of the contralateral parotid gland receiving >40 Gy should be <33%. Our results permitted us to establish two convenient tools to predict the saliva production recovery function according to the dose received by the contralateral parotid gland

Low-Dose Radiation Induces Genes Promoting Cell Survival

International Nuclear Information System (INIS)

Liu, Shu-Zheng; Chen, Dong; Mu, Ying

1999-01-01

Apoptosis is an important process controlling homeostasis of the body. It is influenced by stimuli constantly arising from the external and internal environment of the organism. It is well known that radiation could induce apoptosis of cells in vitro and in vivo. However, the dose-effect relationship of apoptosis extending to the low-dose range has scarcely been studied. Here, the molecular basis of the phenomenon is explored by examining the changes in expression of some of the proapoptotic and antiapoptotic genes

Induction of somatic mutations by low-dose X-rays: the challenge in recognizing radiation-induced events.

Science.gov (United States)

Nagashima, Haruki; Shiraishi, Kumiko; Ohkawa, Saori; Sakamoto, Yuki; Komatsu, Kenshi; Matsuura, Shinya; Tachibana, Akira; Tauchi, Hiroshi

2017-10-19

It is difficult to distinguish radiation-induced events from spontaneous events during induction of stochastic effects, especially in the case of low-dose or low-dose-rate exposures. By using a hypersensitive system for detecting somatic mutations at the HPRT1 locus, we investigated the frequency and spectrum of mutations induced by low-dose X-rays. The mutant frequencies induced by doses of >0.15 Gy were statistically significant when compared with the spontaneous frequency, and a clear dose dependency was also observed for mutant frequencies at doses of >0.15 Gy. In contrast, mutant frequencies at doses of 0.2 Gy. Our observations suggest that there could be a critical dose for mutation induction at between 0.1 Gy and 0.2 Gy, where mutagenic events are induced by multiple DNA double-strand breaks (DSBs). These observations also suggest that low-dose radiation delivered at doses of <0.1 Gy may not result in DSB-induced mutations but may enhance spontaneous mutagenesis events. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

A blinded, randomized, controlled trial of three doses of high-dose insulin in poison-induced cardiogenic shock.

Science.gov (United States)

Cole, J B; Stellpflug, S J; Ellsworth, H; Anderson, C P; Adams, A B; Engebretsen, K M; Holger, J S

2013-05-01

High dose insulin (HDI) has proven superior to glucagon and catecholamines in the treatment of poison-induced cardiogenic shock (PICS) in previous animal studies. Standard recommendations for dosing of insulin vary and the optimal dose of HDI in PICS has not been established. Our hypothesis was a dose of 10 U/kg/hr of HDI would be superior to 1 U/kg/hr with cardiac output (CO) as our primary outcome measure in pigs with propranolol-induced PICS. This was a blinded, prospective, randomized trial with 4 arms consisting of 4 pigs in each arm. The arms were as follows: placebo (P), 1 U/kg/hr (HDI-1), 5 U/kg/hr (HDI-5), and 10 U/kg/hr (HDI-10). Cardiogenic shock was induced with a bolus of 0.5 mg/kg of propranolol followed by an infusion of 0.25 mg/kg/min until the point of toxicity, defined as 0.75 x (HR x MAP) was reached. At this point the propranolol infusion was decreased to 0.125 mg/kg/min and a 20 mL/kg bolus of normal saline (NS) was administered. The protocol was continued for 6 hours or until the animals died. 2 pigs died in the P arm, 1 pig died each in the HDI-1 and HDI-5 arms, and all pigs lived in the HDI-10 arm. There was a statistically significant difference in dose by time interaction on CO of 1.13 L/min over the 6 hr study period (p = < 0.001). There was also a statistically significant difference in dose by time interaction on MAP, HR, and systemic vascular resistance (SVR). No statistically significant difference was found between any of the arms regarding glucose utilization. HDI was statistically and clinically significantly superior to placebo in this propranolol model of PICS. Furthermore a dose response over time was found where CO increased corresponding to increases in doses of HDI.

Promotive effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on recovery from neutropenia induced by fractionated irradiation in mice

Energy Technology Data Exchange (ETDEWEB)

Kabaya, Koji; Watanabe, Masahiko; Kusaka, Masaru; Seki, Masatoshi (Kirin Brewery Co., Ltd., Gunma (Japan). Pharmaceutical Research Laboratory); Fushiki, Masato

1994-08-01

The effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on the recovery from neutropenia induced by fractionated whole-body irradiation was investigated in mice. Male 7-week old C3H/HeN mice received a total of ten exposures of 0.25 Gy/day from day 1 to 5 and from day 8 to 12. Peripheral neutropenia with a nadir on day 17 was caused by the fractionated irradiation. Daily subcutaneous injections of rhG-CSF at 0.25 and 2.5 [mu]g/body/day from day from day 1 to 21 promoted the recovery of neutrophils in a dose-dependent manner. The kinetics of morphologically identifiable bone marrow cells were studied to clarify the mechanism behind the promotive effect of this factor. A slight decrease in mitotic immature granulocytes, such as myeloblasts, promyelocytes and myelocytes on day 5, and a drastic decrease in metamyelocytes and marrow neutrophils on days 5, 9, and 17 were seen in the femur of irradiated mice. Treatment using rhG-CSF caused an increase in immature granulocytes of all differential stages in the femur. Microscopic findings of the femurs and spleens also reveals an increase in immature granulocytes in these organs in mice injected with rhG-CSF. These results indicate that rhG-CSF accelerates granulopoiesis in the femur and spleen, thereby promoting recovery from neutropenia induced by fractionated irradiation. (author).

Promotive effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on recovery from neutropenia induced by fractionated irradiation in mice

International Nuclear Information System (INIS)

Kabaya, Koji; Watanabe, Masahiko; Kusaka, Masaru; Seki, Masatoshi; Fushiki, Masato.

1994-01-01

The effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on the recovery from neutropenia induced by fractionated whole-body irradiation was investigated in mice. Male 7-week old C3H/HeN mice received a total of ten exposures of 0.25 Gy/day from day 1 to 5 and from day 8 to 12. Peripheral neutropenia with a nadir on day 17 was caused by the fractionated irradiation. Daily subcutaneous injections of rhG-CSF at 0.25 and 2.5 μg/body/day from day from day 1 to 21 promoted the recovery of neutrophils in a dose-dependent manner. The kinetics of morphologically identifiable bone marrow cells were studied to clarify the mechanism behind the promotive effect of this factor. A slight decrease in mitotic immature granulocytes, such as myeloblasts, promyelocytes and myelocytes on day 5, and a drastic decrease in metamyelocytes and marrow neutrophils on days 5, 9, and 17 were seen in the femur of irradiated mice. Treatment using rhG-CSF caused an increase in immature granulocytes of all differential stages in the femur. Microscopic findings of the femurs and spleens also reveals an increase in immature granulocytes in these organs in mice injected with rhG-CSF. These results indicate that rhG-CSF accelerates granulopoiesis in the femur and spleen, thereby promoting recovery from neutropenia induced by fractionated irradiation. (author)

Effect of low doses of cannabidiolic acid and ondansetron on LiCl-induced conditioned gaping (a model of nausea-induced behaviour) in rats.

Science.gov (United States)

Rock, E M; Parker, L A

2013-06-01

To determine the minimally effective dose of cannabidiolic acid (CBDA) that effectively reduces lithium chloride (LiCl)-induced conditioned gaping reactions (nausea-induced behaviour) in rats and to determine if these low systemic doses of CBDA (5-0.1 μg·kg⁻¹) relative to those of CBD could potentiate the anti-nausea effects of the classic 5-hydroxytryptamine 3 (5-HT₃) receptor antagonist, ondansetron (OND). We investigated the efficacy of low doses of CBDA to suppress acute nausea, assessed by the establishment of conditioned gaping to a LiCl-paired flavour in rats. The potential of threshold and subthreshold doses of CBDA to enhance the reduction of nausea-induced conditioned gaping by OND were then determined. CBDA (at doses as low as 0.5 μg·kg⁻¹) suppressed nausea-induced conditioned gaping to a flavour. A low dose of OND (1.0 μg·kg⁻¹) alone reduced nausea-induced conditioned gaping, but when it was combined with a subthreshold dose of CBDA (0.1 μg·kg⁻¹) there was an enhancement in the suppression of LiCl-induced conditioned gaping. CBDA potently reduced conditioned gaping in rats, even at low doses and enhanced the anti-nausea effect of a low dose of OND. These findings suggest that combining low doses of CBDA and OND will more effectively treat acute nausea in chemotherapy patients. © 2013 The Authors. British Journal of Pharmacology © 2013 The British Pharmacological Society.

Okadaic acid for radiation dose estimation using drug-induced premature chromosome condensation

International Nuclear Information System (INIS)

Wang Chunyan; Zhang Wei; Su Xu

2005-01-01

Objective: To establish simple biological method for high irradiation dose estimation using drug-induced prematurely condensed chromosomes (PCC) aberrations. Methods: Peripheral blood was taken from healthy adults and irradiated by 0, 1, 2, 5, 10, 15, 20 and 25 Gy 60 Co γ-rays. Then the blood samples were cultured for 48 hrs. One hr before the end of culture , okadaic acid was added into culture medium to induce PCC rings, which were counted for each dose point. Results: The yield of PCC rings was increased with the dose of radiation until 20 Gy. Within the range of 1 to 20 Gy, there was a good dose-response relationship between the yield of PCC rings and radiation dose. Conclusion: Compared with the analysis of frequency of dicentrics, the yield of PCC rings could be a good biodosimetry indicator for estimation of high dose irradiation. (authors)

Recovery of the proliferative and functional integrity of mouse bone marrow in long-term cultures established after whole-body irradiation at different doses and dose rates

International Nuclear Information System (INIS)

Bierkens, J.G.; Hendry, J.H.; Testa, N.G.

1991-01-01

Injury inflicted upon the bone marrow stroma following whole-body irradiation and its repair over a 1-year period has been assessed in murine long-term bone marrow cultures established at increasing time intervals after irradiation. Different doses at different dose rates (10 Gy at 0.05 cGy/min, 4.5 Gy and 10 Gy at 1.6 cGy/min, and 4 x 4.5 Gy [3 weeks between doses] at 60 cGy/min) were chosen so as to maximize differences in effect in the stroma. The cellularity of the adherent layer in long-term cultures established 1 month after irradiation was reduced by 40%-90% depending on the dose and dose rate. Simultaneous with the poor ability of the marrow to form adherent layers, the cumulative spleen colony-forming unit (CFU-S) and granulocyte-macrophage colony-forming cell (GM-CFC) production over a 7-week period was reduced to 0% and 30% of control cultures, respectively. The slow recovery of the adherent layer was paralleled by an increase in the numbers of CFU-S and GM-CFC in the supernatant. Cultures established from repeatedly irradiated mice performed poorly over the entire 1-year period. Whereas the regeneration of the stroma was near complete 1 year after irradiation, the CFU-S and GM-CFC levels reached only between 50% and 80% of control cultures, respectively. Also, the concentration of CFU-S and GM-CFC in the supernatant remained persistently lower in cultures established from irradiated mice as compared to control cultures. The levels of sulfated glycosaminoglycans, which have been implicated in the establishment of the functional integrity of the microenvironment, were not reduced in the adherent layers at any time after irradiation. These results indicate that the regeneration of the stroma is accompanied by an incomplete recovery of active hemopoiesis in vitro

Morphology-dependent photo-induced polarization recovery in ferroelectric thin films

Science.gov (United States)

Wang, J. Y.; Liu, G.; Sando, D.; Nagarajan, V.; Seidel, J.

2017-08-01

We investigate photo-induced ferroelectric domain switching in a series of Pb(Zr0.2Ti0.8)O3/La0.7Sr0.3MnO3 (PZT/LSMO) bilayer thin films with varying surface morphologies by piezoresponse force microscopy under light illumination. We demonstrate that reverse poled ferroelectric regions can be almost fully recovered under laser irradiation of the PZT layer and that the recovery process is dependent on the surface morphology on the nanometer scale. The recovery process is well described by the Kolmogorov-Avrami-Ishibashi model, and the evolution speed is controlled by light intensity, sample thickness, and initial write voltage. Our findings shed light on optical control of the domain structure in ferroelectric thin films with different surface morphologies.

Recovery during radiation and chemical mutagenesis

International Nuclear Information System (INIS)

Deen, D.F.

1975-01-01

These investigations were directed toward the study of recovery in radiation and chemical mutagenesis in cultured mammalian cells. A mutagenesis system was established in which mutation of V79-17lb Chinese hamster cells to 8-azaguanine resistance was tested. The effects of split dose and postirradiation treatments upon both x-ray and EMS induced mutagenesis were determined. Increasing the cell inoculum by a factor of 5 (from 10 5 to 5 x 10 5 ) decreased both the spontaneous and x-ray induced mutation frequencies by two orders of magnitude. The x-ray induced mutation frequency was found to be higher for those cells allowed to attach for 5 hours before irradiation, in comparison to those allowed to attach for 2 hours. The uv spectrum of 8-azaguanine changes as a function of storage time at low temperature, but not when diluted to either 10 μg/ml or 30 μg/ml and maintained at 37 0 C. The optimal expression time required after irradiation is dose dependent and can be determined from the relationship: E.T. = 1.93(10 -2 )D + 15.5. (E.T. = hours; D = rads). The duration of the optimal expression time can be estimated by summing the cell cycle time and the radiation induced lag time

Transformation-Induced Creep and Creep Recovery of Shape Memory Alloy.

Science.gov (United States)

Takeda, Kohei; Tobushi, Hisaaki; Pieczyska, Elzbieta A

2012-05-22

If the shape memory alloy is subjected to the subloop loading under the stress-controlled condition, creep and creep recovery can appear based on the martensitic transformation. In the design of shape memory alloy elements, these deformation properties are important since the deflection of shape memory alloy elements can change under constant stress. The conditions for the progress of the martensitic transformation are discussed based on the kinetics of the martensitic transformation for the shape memory alloy. During loading under constant stress rate, temperature increases due to the stress-induced martensitic transformation. If stress is held constant during the martensitic transformation stage in the loading process, temperature decreases and the condition for the progress of the martensitic transformation is satisfied, resulting in the transformation-induced creep deformation. If stress is held constant during the reverse transformation stage in the unloading process, creep recovery appears due to the reverse transformation. The details for these thermomechanical properties are investigated experimentally for TiNi shape memory alloy, which is most widely used in practical applications. The volume fraction of the martensitic phase increases in proportion to an increase in creep strain.

In Vivo Imaging Reveals Significant Tumor Vascular Dysfunction and Increased Tumor Hypoxia-Inducible Factor-1α Expression Induced by High Single-Dose Irradiation in a Pancreatic Tumor Model

Energy Technology Data Exchange (ETDEWEB)

Maeda, Azusa [Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada); Chen, Yonghong; Bu, Jiachuan; Mujcic, Hilda [Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Wouters, Bradly G. [Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); DaCosta, Ralph S., E-mail: rdacosta@uhnres.utoronto.ca [Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada); Techna Institute, University Health Network, Toronto, Ontario (Canada)

2017-01-01

Purpose: To investigate the effect of high-dose irradiation on pancreatic tumor vasculature and microenvironment using in vivo imaging techniques. Methods and Materials: A BxPC3 pancreatic tumor xenograft was established in a dorsal skinfold window chamber model and a subcutaneous hind leg model. Tumors were irradiated with a single dose of 4, 12, or 24 Gy. The dorsal skinfold window chamber model was used to assess tumor response, vascular function and permeability, platelet and leukocyte adhesion to the vascular endothelium, and tumor hypoxia for up to 14 days after 24-Gy irradiation. The hind leg model was used to monitor tumor size, hypoxia, and vascularity for up to 65 days after 24-Gy irradiation. Tumors were assessed histologically to validate in vivo observations. Results: In vivo fluorescence imaging revealed temporary vascular dysfunction in tumors irradiated with a single dose of 4 to 24 Gy, but most significantly with a single dose of 24 Gy. Vascular functional recovery was observed by 14 days after irradiation in a dose-dependent manner. Furthermore, irradiation with 24 Gy caused platelet and leukocyte adhesion to the vascular endothelium within hours to days after irradiation. Vascular permeability was significantly higher in irradiated tumors compared with nonirradiated controls 14 days after irradiation. This observation corresponded with increased expression of hypoxia-inducible factor-1α in irradiated tumors. In the hind leg model, irradiation with a single dose of 24 Gy led to tumor growth delay, followed by tumor regrowth. Conclusions: Irradiation of the BxPC3 tumors with a single dose of 24 Gy caused transient vascular dysfunction and increased expression of hypoxia-inducible factor-1α. Such biological changes may impact tumor response to high single-dose and hypofractionated irradiation, and further investigations are needed to better understand the clinical outcomes of stereotactic body radiation therapy.

Search for the lowest irradiation dose from literatures on radiation-induced breast cancer

Energy Technology Data Exchange (ETDEWEB)

Yoshizawa, Y; Kusama, T [Tokyo Univ. (Japan). Faculty of Medicine

1975-12-01

A survey of past case reports concerning radiation-induced breast cancer was carried out in order to find the lowest irradiation dose. The search of literature published since 1951 revealed 10 cases of radiation-induced breast cancer. Only 5 cases had precise descriptions of the irradiation dose. The lowest irradiation dose was estimated at 1470 rads in the case of external X-ray irradiation for tuberous angioma. All of cases of radiation-induced breast cancer had received radiation for the treatment of nonmalignant tumors, such as pulmonary tuberculosis, mastitis, and tuberous angioma. There also were three statistical studies. The first concerned atomic bomb survivors, the second, pulmoanry tuberculous patients subjected to frequent fluoroscopies, and the third, patients of acute post partum mastitis. These statistical studies had revealed a significant increase in the incidence of breast cancer in the irradiated group, but there was little information about the lowest irradiation dose. It was noticed that radiation-induced breast cancer was more numerous in the upper inner quadrant of the breast. Most histopathological findings of radiation-induced breast cancer involved duct cell carcinoma. The latent period was about 15 years.

The potential benefits of nicaraven to protect against radiation-induced injury in hematopoietic stem/progenitor cells with relative low dose exposures

International Nuclear Information System (INIS)

Ali, Haytham; Galal, Omima; Urata, Yoshishige; Goto, Shinji; Guo, Chang-Ying; Luo, Lan; Abdelrahim, Eman; Ono, Yusuke; Mostafa, Emtethal; Li, Tao-Sheng

2014-01-01

Highlights: • Nicaraven mitigated the radiation-induced reduction of c-kit + stem cells. • Nicaraven enhanced the function of hematopoietic stem/progenitor cells. • Complex mechanisms involved in the protection of nicaraven to radiation injury. - Abstract: Nicaraven, a hydroxyl radical-specific scavenger has been demonstrated to attenuate radiation injury in hematopoietic stem cells with 5 Gy γ-ray exposures. We explored the effect and related mechanisms of nicaraven for protecting radiation injury induced by sequential exposures to a relatively lower dose γ-ray. C57BL/6 mice were given nicaraven or placebo within 30 min before exposure to 50 mGy γ-ray daily for 30 days in sequences (cumulative dose of 1.5 Gy). Mice were victimized 24 h after the last radiation exposure, and the number, function and oxidative stress of hematopoietic stem cells were quantitatively estimated. We also compared the gene expression in these purified stem cells from mice received nicaraven and placebo treatment. Nicaraven increased the number of c-kit + stem/progenitor cells in bone marrow and peripheral blood, with a recovery rate around 60–90% of age-matched non-irradiated healthy mice. The potency of colony forming from hematopoietic stem/progenitor cells as indicator of function was completely protected with nicaraven treatment. Furthermore, nicaraven treatment changed the expression of many genes associated to DNA repair, inflammatory response, and immunomodulation in c-kit + stem/progenitor cells. Nicaraven effectively protected against damages of hematopoietic stem/progenitor cells induced by sequential exposures to a relatively low dose radiation, via complex mechanisms

The potential benefits of nicaraven to protect against radiation-induced injury in hematopoietic stem/progenitor cells with relative low dose exposures

Energy Technology Data Exchange (ETDEWEB)

Ali, Haytham [Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523 (Japan); Department of Medical Physiology and Cell Biology, Qena Faculty of Medicine, South Valley University (Egypt); Galal, Omima [Department of Medical Physiology and Cell Biology, Qena Faculty of Medicine, South Valley University (Egypt); Urata, Yoshishige; Goto, Shinji; Guo, Chang-Ying; Luo, Lan [Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523 (Japan); Abdelrahim, Eman [Department of Medical Histology, Qena Faculty of Medicine, South Valley University (Egypt); Ono, Yusuke [Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523 (Japan); Mostafa, Emtethal [Department of Medical Physiology and Cell Biology, Qena Faculty of Medicine, South Valley University (Egypt); Li, Tao-Sheng, E-mail: litaoshe@nagasaki-u.ac.jp [Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523 (Japan)

2014-09-26

Highlights: • Nicaraven mitigated the radiation-induced reduction of c-kit{sup +} stem cells. • Nicaraven enhanced the function of hematopoietic stem/progenitor cells. • Complex mechanisms involved in the protection of nicaraven to radiation injury. - Abstract: Nicaraven, a hydroxyl radical-specific scavenger has been demonstrated to attenuate radiation injury in hematopoietic stem cells with 5 Gy γ-ray exposures. We explored the effect and related mechanisms of nicaraven for protecting radiation injury induced by sequential exposures to a relatively lower dose γ-ray. C57BL/6 mice were given nicaraven or placebo within 30 min before exposure to 50 mGy γ-ray daily for 30 days in sequences (cumulative dose of 1.5 Gy). Mice were victimized 24 h after the last radiation exposure, and the number, function and oxidative stress of hematopoietic stem cells were quantitatively estimated. We also compared the gene expression in these purified stem cells from mice received nicaraven and placebo treatment. Nicaraven increased the number of c-kit{sup +} stem/progenitor cells in bone marrow and peripheral blood, with a recovery rate around 60–90% of age-matched non-irradiated healthy mice. The potency of colony forming from hematopoietic stem/progenitor cells as indicator of function was completely protected with nicaraven treatment. Furthermore, nicaraven treatment changed the expression of many genes associated to DNA repair, inflammatory response, and immunomodulation in c-kit{sup +} stem/progenitor cells. Nicaraven effectively protected against damages of hematopoietic stem/progenitor cells induced by sequential exposures to a relatively low dose radiation, via complex mechanisms.

Repair in schizosaccharomyces pombe as measured by recovery from caffeine enhancement of radiation-induced lethality

International Nuclear Information System (INIS)

Gentner, N.E.; Werner, M.M.

1975-01-01

Inhibition of DNA repair by caffeine is manifested in Schizosaccharomyces pombe wild-type cells as an enhancement of UV- or γ-irradiation-induced lethality. The progress of DNA repair processes involving one or more caffeine-sensitive steps may be conveniently followed by measuring the concomitant decrease of this lethal enhancement effect. By measuring, during post-irradiation incubation, the ability of cells to overcome susceptibility to repair inhibition by caffeine, we have determined the time course and requirements for repair in S. pombe. Recovery began immediately and took 150-200 min after γ-irradiation and more than 500 min after UV-irradiation, for exposures which gave about 10% survival in the absence of caffeine. An incubation medium capable of supporting growth was required for caffeine-sensitive repair; no recovery occurred under liquid holding conditions. Survival curves after various recovery times indicated that a logarithmic phase cell population was homogeneous with respect to caffeine-sensitive repair of both UV- and γ-ray-induced damage. Recovery from caffeine inhibition was compared for cells of different physiological states (logarithmic and stationary phase); although the importance of the physiological state was not the same for the two types of radiation, recovery was found to occur more rapidly in the more radiation-resistant state, in each case. (orig.) [de

Recovery Profiles of T-Cell Subsets Following Low-Dose Total Body Irradiation and Improvement With Cinnamon

International Nuclear Information System (INIS)

Zheng, Xiaodan; Guo, Yuqi; Wang, Lei; Zhang, Honghai; Wang, Shaobo; Wang, Li; An, Lei; Zhou, Xianbin; Li, Xia; Yao, Chengfang

2015-01-01

Purpose: Inefficient T-cell reconstitution from x-ray–induced immune damage reduces antitumor response. To understand the profile of T-cell reconstitution after irradiation will overcome the barrier of antitumor immunity. This study aimed to identify the recovery profile of T-cell subsets following x-ray irradiation and to highlight the role of cinnamon on efficient T-cell restoration postexposure in the antitumor response. Methods and Materials: CD3"+, CD8"+, and CD4"+ T cells and Th1, Th2, Th17, and regulatory T (Treg) cells were evaluated at different time points after single low-dose total body irradiation (SLTBI) with or without cinnamon treatments. T-bet, GATA3, RORγt, and Foxp3 signaling specific for Th1, Th2, Th17, and Treg were also analyzed by RT-PCR assay. The effects of cinnamon on efficient T-cell subset reconstitution was confirmed in a lung melanoma model in irradiated mice. Results: Reconstitution of CD4"+ T cells was delayed more than that of CD8"+ T cells in T-cell restoration after SLTBI. The production of IFNγ by Th1 or Tc1 cells was sharply decreased and was accompanied by reduced T-bet mRNA, even when total T-cell numbers had recovered; the frequencies of Th17 and Treg cells and their specific transcription factors (RORγt and Foxp3, respectively) were obviously increased. Irradiation-induced inefficient T-cell reconstitution impaired the antitumor capacities in the lung melanoma model. Pretreatment with cinnamon in irradiated mice accelerated the generation of Th1 and reduced the differentiation of Treg cells by activating T-bet and limiting transcriptions of Foxp3. Improvement resulting from cinnamon pretreatment on the efficient T-cell recovery profile from SLTBI promoted antitumor immunity in the lung melanoma model. Conclusions: T-cell reconstitution from SLTBI was characterized by impaired Th1 and elevated Th17 and Treg cells. Cinnamon effectively improved the imbalance of T-cell subsets by promoting the proliferation of Th1 and

Recovery Profiles of T-Cell Subsets Following Low-Dose Total Body Irradiation and Improvement With Cinnamon

Energy Technology Data Exchange (ETDEWEB)

Zheng, Xiaodan [Key Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan (China); School of Medicine and Life Science, University of Jinan-Shandong Academy of Medical Science, Jinan (China); Guo, Yuqi [Key Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan (China); Wang, Lei [Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan (China); Zhang, Honghai [Key Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan (China); Wang, Shaobo [Shandong University, Jinan (China); Wang, Li [Key Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan (China); An, Lei [Key Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan (China); School of Medicine and Life Science, University of Jinan-Shandong Academy of Medical Science, Jinan (China); Zhou, Xianbin; Li, Xia [Key Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan (China); Yao, Chengfang, E-mail: yaocf9941@163.com [Key Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan (China)

2015-12-01

Purpose: Inefficient T-cell reconstitution from x-ray–induced immune damage reduces antitumor response. To understand the profile of T-cell reconstitution after irradiation will overcome the barrier of antitumor immunity. This study aimed to identify the recovery profile of T-cell subsets following x-ray irradiation and to highlight the role of cinnamon on efficient T-cell restoration postexposure in the antitumor response. Methods and Materials: CD3{sup +}, CD8{sup +}, and CD4{sup +} T cells and Th1, Th2, Th17, and regulatory T (Treg) cells were evaluated at different time points after single low-dose total body irradiation (SLTBI) with or without cinnamon treatments. T-bet, GATA3, RORγt, and Foxp3 signaling specific for Th1, Th2, Th17, and Treg were also analyzed by RT-PCR assay. The effects of cinnamon on efficient T-cell subset reconstitution was confirmed in a lung melanoma model in irradiated mice. Results: Reconstitution of CD4{sup +} T cells was delayed more than that of CD8{sup +} T cells in T-cell restoration after SLTBI. The production of IFNγ by Th1 or Tc1 cells was sharply decreased and was accompanied by reduced T-bet mRNA, even when total T-cell numbers had recovered; the frequencies of Th17 and Treg cells and their specific transcription factors (RORγt and Foxp3, respectively) were obviously increased. Irradiation-induced inefficient T-cell reconstitution impaired the antitumor capacities in the lung melanoma model. Pretreatment with cinnamon in irradiated mice accelerated the generation of Th1 and reduced the differentiation of Treg cells by activating T-bet and limiting transcriptions of Foxp3. Improvement resulting from cinnamon pretreatment on the efficient T-cell recovery profile from SLTBI promoted antitumor immunity in the lung melanoma model. Conclusions: T-cell reconstitution from SLTBI was characterized by impaired Th1 and elevated Th17 and Treg cells. Cinnamon effectively improved the imbalance of T-cell subsets by promoting the

Recovery of stream communities from experimental selenium exposure

Energy Technology Data Exchange (ETDEWEB)

Swift, M.C.; Kuklinskal, B.; Ferkull, K. [Univ. of Minnesota, Monticello, MN (United States); Allen, K.N.; Hermanutz, R.O.; Roush, T.H.; Hedtke, S.F. [Environmental Protection Agency, Duluth, MN (United States). Environmental Research Lab.

1994-12-31

The effects of selenium on stream communities and their recovery from those effects were studied at MERS from 1987--1991. Selenium was dosed into two replicate streams each at concentrations of 30, 10, 2.5 and 0 (control) {mu}g L{sup {minus}1} for 18, 30, and 12 months, respectively. Recovery was monitored for three (30) or two (1 0, 2.5) years following cessation of selenium dosing. Selenium rapidly accumulated in the sediment, plants, macroinvertebrates and fish during dosing. Selenium concentrations in sediment, macroinvertebrates, and plants were as high as 2X--4X, 2X--4X, and 1X--1OX the dosed concentration in the 30, 10, and 2.5 treatments, respectively. Selenium decreased relatively rapidly following cessation of dosing. By two years after dosing ceased, selenium concentrations in plants and macroinvertebrates were little different from the controls; selenium in sediment from the 30 and 10 streams was still higher than in the control streams two years after dosing ceased. The macroinvertebrate community changed little during the dosing and recovery period. Commonly used indices of community structure showed no effect of selenium dosing. The isopod Asellus and oligochaetes in the family Tubificidae decreased rapidly following the onset of selenium dosing; their recovery following cessation of dosing was slow.

Subeffective doses of dexketoprofen trometamol enhance the potency and duration of fentanyl antinociception

Science.gov (United States)

Gaitán, Gema; Herrero, Juan F

2002-01-01

The combination of classic non-steroidal antiinflammatory drugs (NSAIDs) with opiates induces more analgesia than the summed effect of each drug given separately. No studies have been performed using new generation NSAIDs and fentanyl nor on the duration of this effect. We have studied the analgesic effect of fentanyl alone and after the administration of subeffective doses of dexketoprofen trometamol in rat nociceptive responses. The responses were evoked by noxious mechanical stimulation and were recorded as single motor units in male Wistar rats anaesthetized with α-chloralose. The effective dose 50 (ED50) observed with fentanyl was 22.4±1.5 μg kg−1 and full recovery was apparent 20 min later. The administration of a total dose of 40 μg kg−1 of dexketoprofen trometamol did not induce any significant effect on the nociceptive responses. In the presence of dexketoprofen trometamol, the ED50 for fentanyl was 5 fold lower than before: 3.8±1.1 μg kg−1 and no significant recovery was observed 45 min later. The opioid antagonist naloxone (200 μg kg−1) did not reverse the effect, although in control experiments the same dose was able to prevent any action of fentanyl given alone. We conclude that the combination of fentanyl and subeffective doses of dexketoprofen trometamol induces a more potent and longer lasting analgesic effect than that observed with fentanyl alone, and that this is not an opioid mediated action. PMID:11815374

Low-Dose Adefovir-Induced Hypophosphatemic Osteomalacia on Whole-Body Bone Scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Kim, Sung Hoon; Won, Kyoung Sook; Song, Bongil; Jo, Il; Zeon, Seok Kil [Keimyung Univ., Daegu (Korea, Republic of)

2013-12-15

While adefovir dipivoxil (ADV) effectively suppresses the hepatitis B virus, it can cause proximal renal tubular dysfunction leading to phosphate wasting. The safety of low-dose ADV (a dose of 10 mg/day), which does not induce clinically significant nephrotoxicity, is well recognized, but a few cases of hypophosphatemic osteomalacia (HO) caused by low-dose ADV therapy have recently been reported. Although HO induced by low-dose ADV therapy is rare, the presence of bone pain in patients treated with ADV should be monitored. Bone scintigraphy can be performed to confirm the occurrence of osteomalacia and to determine the disease extent. Bone scintigraphic and radiological image findings with a brief review of the literature are presented in this article. We report two cases of HO induced by low-dose ADV therapy that showed multifocal increased radiotracer uptakes in the bilateral bony ribs, spines, pelvic bones and lower extremities on whole-body bone scintigraphy. Bone pain gradually improved after phosphate supplementation and by changing the antiviral agent. Whole-body bone scintigraphy is a highly sensitive imaging tool and can show disease extent at once in the setting of the wide range of the clinical spectrum with nonspecific radiological findings. Furthermore, frequent involvement of the lower extremities, as a result of maximum weight bearing, could be an additional scintigraphic clue for the diagnosis of HO. These cases could be helpful for both clinicians prescribing ADV and nuclear physicians to prevent delayed diagnosis and plan further appropriate treatment.

Low-Dose Adefovir-Induced Hypophosphatemic Osteomalacia on Whole-Body Bone Scintigraphy

International Nuclear Information System (INIS)

Kim, Sung Hoon; Won, Kyoung Sook; Song, Bongil; Jo, Il; Zeon, Seok Kil

2013-01-01

While adefovir dipivoxil (ADV) effectively suppresses the hepatitis B virus, it can cause proximal renal tubular dysfunction leading to phosphate wasting. The safety of low-dose ADV (a dose of 10 mg/day), which does not induce clinically significant nephrotoxicity, is well recognized, but a few cases of hypophosphatemic osteomalacia (HO) caused by low-dose ADV therapy have recently been reported. Although HO induced by low-dose ADV therapy is rare, the presence of bone pain in patients treated with ADV should be monitored. Bone scintigraphy can be performed to confirm the occurrence of osteomalacia and to determine the disease extent. Bone scintigraphic and radiological image findings with a brief review of the literature are presented in this article. We report two cases of HO induced by low-dose ADV therapy that showed multifocal increased radiotracer uptakes in the bilateral bony ribs, spines, pelvic bones and lower extremities on whole-body bone scintigraphy. Bone pain gradually improved after phosphate supplementation and by changing the antiviral agent. Whole-body bone scintigraphy is a highly sensitive imaging tool and can show disease extent at once in the setting of the wide range of the clinical spectrum with nonspecific radiological findings. Furthermore, frequent involvement of the lower extremities, as a result of maximum weight bearing, could be an additional scintigraphic clue for the diagnosis of HO. These cases could be helpful for both clinicians prescribing ADV and nuclear physicians to prevent delayed diagnosis and plan further appropriate treatment

Antioxidants enhance the recovery of three cycles of bleomycin, etoposide, and cisplatin-induced testicular dysfunction, pituitary-testicular axis, and fertility in rats.

Science.gov (United States)

Kilarkaje, Narayana; Mousa, Alyaa M; Al-Bader, Maie M; Khan, Khalid M

2013-10-01

To investigate the effects of an antioxidant cocktail (AC) on bleomycin, etoposide, and cisplatin (BEP)-induced testicular dysfunction. In vivo study. Research laboratory. Adult male and female Sprague-Dawley rats. The rats were treated with three cycles of 21 days each of therapeutically relevant dose levels of BEP (0.75, 7.5, and 1.5 mg/kg) with or without the AC (a mixture of α-tocopherol, L-ascorbic acid, Zn, and Se). Sperm parameters, fertility, serum hormone levels (ELISA), testicular histopathology, and expression of proliferating cell nuclear antigen (PCNA), and transferrin (Western blotting and immunohistochemistry) were evaluated at the end of treatment and a 63-day recovery period. At the end of treatment, the AC improved BEP-induced decrease in sperm motility and increase in abnormality but had no effect on reduced sperm count, fertility, and tubular atrophy, although it up-regulated germ cell proliferation. The AC normalized reduced inhibin B levels, but had no effect on decreased transferrin and testosterone and elevated LH levels. At the end of the recovery period, the AC enhanced the expression of PCNA and transferrin, repopulation of germ cells, LH-testosterone axis, and fertility, but had no effect on reduced FSH and elevated inhibin B levels. The antioxidants protect and then enhance the recovery of testicular and reproductive endocrine functions when administered concomitantly with BEP therapy. The AC may be beneficial to regain testicular functions after chemotherapy. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Influence of serial electrical stimulations of perifornical and posterior hypothalamic orexin-containing neurons on regulation of sleep homeostasis and sleep-wakefulness cycle recovery from experimental comatose state and anesthesia-induced deep sleep.

Science.gov (United States)

Chijavadze, E; Chkhartishvili, E; Babilodze, M; Maglakelidze, N; Nachkebia, N

2013-11-01

The work was aimed for the ascertainment of following question - whether Orexin-containing neurons of dorsal and lateral hypothalamic, and brain Orexinergic system in general, are those cellular targets which can speed up recovery of disturbed sleep homeostasis and accelerate restoration of sleep-wakefulness cycle phases during some pathological conditions - experimental comatose state and/or deep anesthesia-induced sleep. Study was carried out on white rats. Modeling of experimental comatose state was made by midbrain cytotoxic lesions at intra-collicular level.Animals were under artificial respiration and special care. Different doses of Sodium Ethaminal were used for deep anesthesia. 30 min after comatose state and/or deep anesthesia induced sleep serial electrical stimulations of posterior and/or perifornical hypothalamus were started. Stimulation period lasted for 1 hour with the 5 min intervals between subsequent stimulations applied by turn to the left and right side hypothalamic parts.EEG registration of cortical and hippocampal electrical activity was started immediately after experimental comatose state and deep anesthesia induced sleep and continued continuously during 72 hour. According to obtained new evidences, serial electrical stimulations of posterior and perifornical hypothalamic Orexin-containing neurons significantly accelerate recovery of sleep homeostasis, disturbed because of comatose state and/or deep anesthesia induced sleep. Speed up recovery of sleep homeostasis was manifested in acceleration of coming out from comatose state and deep anesthesia induced sleep and significant early restoration of sleep-wakefulness cycle behavioral states.

A ZnO nanowire-based photo-inverter with pulse-induced fast recovery.

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Raza, Syed Raza Ali; Lee, Young Tack; Hosseini Shokouh, Seyed Hossein; Ha, Ryong; Choi, Heon-Jin; Im, Seongil

2013-11-21

We demonstrate a fast response photo-inverter comprised of one transparent gated ZnO nanowire field-effect transistor (FET) and one opaque FET respectively as the driver and load. Under ultraviolet (UV) light the transfer curve of the transparent gate FET shifts to the negative side and so does the voltage transfer curve (VTC) of the inverter. After termination of UV exposure the recovery of photo-induced current takes a long time in general. This persistent photoconductivity (PPC) is due to hole trapping on the surface of ZnO NWs. Here, we used a positive voltage short pulse after UV exposure, for the first time resolving the PPC issue in nanowire-based photo-detectors by accumulating electrons at the ZnO/dielectric interface. We found that a pulse duration as small as 200 ns was sufficient to reach a full recovery to the dark state from the UV induced state, realizing a fast UV detector with a voltage output.

Influence of dosing times on cisplatin-induced peripheral neuropathy in rats

International Nuclear Information System (INIS)

Seto, Yoshihiro; Okazaki, Fumiyasu; Horikawa, Keiji; Zhang, Jing; Sasaki, Hitoshi; To, Hideto

2016-01-01

Although cis-diamminedichloro-platinum (CDDP) exhibits strong therapeutic effects in cancer chemotherapy, its adverse effects such as peripheral neuropathy, nephropathy, and vomiting are dose-limiting factors. Previous studies reported that chronotherapy decreased CDDP-induced nephropathy and vomiting. In the present study, we investigated the influence of dosing times on CDDP-induced peripheral neuropathy in rats. CDDP (4 mg/kg) was administered intravenously at 5:00 or 17:00 every 7 days for 4 weeks to male Sprague–Dawley rats, and saline was given to the control group. To assess the dosing time dependency of peripheral neuropathy, von-Frey test and hot-plate test were performed. In order to estimate hypoalgesia, the hot-plate test was performed in rats administered CDDP weekly for 4 weeks. On day 28, the withdrawal latency to thermal stimulation was significantly prolonged in the 17:00-treated group than in the control and 5:00-treated groups. When the von-Frey test was performed to assess mechanical allodynia, the withdrawal threshold was significantly lower in the 5:00 and 17:00-treated groups than in the control group on day 6 after the first CDDP dose. The 5:00-treated group maintained allodynia throughout the experiment with the repeated administration of CDDP, whereas the 17:00-treated group deteriorated from allodynia to hypoalgesia. It was revealed that the severe of CDDP-induced peripheral neuropathy was inhibited in the 5:00-treated group, whereas CDDP-treated groups exhibited mechanical allodynia. These results suggested that the selection of an optimal dosing time ameliorated CDDP-induced peripheral neuropathy. The online version of this article (doi:10.1186/s12885-016-2777-0) contains supplementary material, which is available to authorized users

Post-injury stretch promotes recovery in a rat model of muscle damage induced by lengthening contractions.

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Mori, Tomohiro; Agata, Nobuhide; Itoh, Yuta; Inoue-Miyazu, Masumi; Mizumura, Kazue; Sokabe, Masahiro; Taguchi, Toru; Kawakami, Keisuke

2017-06-30

We investigated the cellular mechanisms and therapeutic effect of post-injury stretch on the recovery process from muscle injury induced by lengthening contractions (LC). One day after LC, a single 15-min bout of muscle stretch was applied at an intensity of 3 mNm. The maximal isometric torque was measured before and at 2-21 days after LC. The myofiber size was analyzed at 21 days after LC. Developmental myosin heavy chain-immunoreactive (dMHC-ir) cells, a marker of regenerating myofibers, were observed in the early recovery stage (2-5 days after LC). We observed that LC-induced injury markedly decreased isometric torque and myofiber size, which recovered faster in rats that underwent stretch than in rats that did not. Regenerating myofiber with dMHC-ir cells was observed earlier in rats that underwent stretch. These results indicate that post-injury stretch may facilitate the regeneration and early formation of new myofibers, thereby promoting structural and functional recovery from LC-induced muscle injury.

Virtual nature environment with nature sound exposure induce stress recovery by enhanced parasympathetic activity

DEFF Research Database (Denmark)

Annerstedt, Matilda; Jönsson, Peter; Wallergård, Mattias

2013-01-01

. The group that recovered in virtual nature without sound and the control group displayed no particular autonomic activation or deactivation. The results demonstrate a potential mechanistic link between nature, the sounds of nature, and stress recovery, and suggest the potential importance of virtual reality......Experimental research on stress recovery in natural environments is limited, as is study of the effect of sounds of nature. After inducing stress by means of a virtual stress test, we explored physiological recovery in two different virtual natural environments (with and without exposure to sounds...... of nature) and in one control condition. Cardiovascular data and saliva cortisol were collected. Repeated ANOVA measurements indicated parasympathetic activation in the group subjected to sounds of nature in a virtual natural environment, suggesting enhanced stress recovery may occur in such surroundings...

Obestatin Accelerates the Recovery in the Course of Ischemia/Reperfusion-Induced Acute Pancreatitis in Rats.

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Jakub Bukowczan

pancreatic exocrine secretion. Administration of obestatin at doses used was without significant effect with regard to daily food intake or pancreatic exocrine secretion in sham-operated rats, as well as in rats with acute pancreatitis. On the other hand, obestatin abolished a statistical significance of difference in food intake between animals with AP and control animals without pancreatic fistula and induction of AP.Treatment with the exogenous obestatin reduces severity of ischemia/reperfusion-induced acute pancreatitis and accelerates recovery in this disease. The involved mechanisms are likely to be multifactorial, and are mediated, at least in part, by anti-inflammatory properties of obestatin.

Total dose induced latch in short channel NMOS/SOI transistors

International Nuclear Information System (INIS)

Ferlet-Cavrois, V.; Quoizola, S.; Musseau, O.; Flament, O.; Leray, J.L.; Pelloie, J.L.; Raynaud, C.; Faynot, O.

1998-01-01

A latch effect induced by total dose irradiation is observed in short channel SOI transistors. This effect appears on NMOS transistors with either a fully or a partially depleted structure. It is characterized by a hysteresis behavior of the Id-Vg characteristics at high drain bias for a given critical dose. Above this dose, the authors still observe a limited leakage current at low drain bias (0.1 V), but a high conduction current at high drain bias (2 V) as the transistor should be in the off-state. The critical dose above which the latch appears strongly depends on gate length, transistor structure (fully or partially depleted), buried oxide thickness and supply voltage. Two-dimensional (2D) numerical simulations indicate that the parasitic condition is due to the latch of the back gate transistor triggered by charge trapping in the buried oxide. To avoid the latch induced by the floating body effect, different techniques can be used: doping engineering, body contacts, etc. The study of the main parameters influencing the latch (gate length, supply voltage) shows that the scaling of technologies does not necessarily imply an increased latch sensitivity. Some technological parameters like the buried oxide hardness and thickness can be used to avoid latch, even at high cumulated dose, on highly integrated SOI technologies

Study on cellular survival adaptive response induced by low dose irradiation of 153Sm

International Nuclear Information System (INIS)

Zhu Shoupeng; Xiao Dong

1999-01-01

The present study engages in determining whether low dose irradiation of 153 Sm could cut down the responsiveness of cellular survival to subsequent high dose exposure of 153 Sm so as to make an inquiry into approach the protective action of adaptive response by second irradiation of 153 Sm. Experimental results indicate that for inductive low dose of radionuclide 153 Sm 3.7 kBq/ml irradiated beforehand to cells has obvious resistant effect in succession after high dose irradiation of 153 Sm 3.7 x 10 2 kBq/ml was observed. Cells exposed to low dose irradiation of 153 Sm become adapted and therefore the subsequent cellular survival rate induced by high dose of 153 Sm is sufficiently higher than high dose of 153 Sm merely. It is evident that cellular survival adaptive response could be induced by pure low dose irradiation of 153 Sm only

Low-dose tryptophan depletion in recovered depressed women induces impairments in autobiographical memory specificity.

Science.gov (United States)

Haddad, Anneke D M; Williams, J Mark G; McTavish, Sarah F B; Harmer, Catherine J

2009-12-01

Depressed patients perform poorly on tests of autobiographical memory specificity (AMS); this may have negative consequences for other important cognitive abilities, delays recovery from mood episodes, and, in recovered patients, may mediate vulnerability to future episodes. Although the cognitive mechanisms underlying AMS deficits are beginning to be understood, the neurobiological mechanisms remain unclear. Serotonin is implicated in both depression and long-term memory; therefore, temporary lowering of brain serotonin function via acute tryptophan depletion (ATD) offers a means of studying the role of serotonin in autobiographical memory specificity. In this study, 24 previously depressed women underwent low-dose ATD or sham depletion and completed tests of initial and delayed memory, recollection- and familiarity-based recognition, and AMS. ATD did not differentially affect state mood. Compared with sham depletion, ATD impaired immediate recall on the Auditory Verbal Learning Test. Although ATD did not differentially impair recollection- and familiarity-based recognition, it did slow recognition of positive words. ATD also reduced autobiographical memory specificity in response to negative cue words. The results confirm previous findings that low-dose ATD can reinstate depression-congruent biases in cognition without causing depressive mood in vulnerable populations. The ATD-induced reduction in memory specificity suggests that serotonergic dysfunction may mediate depressive deficits in autobiographical memory; the interaction of cognitive and neurobiological vulnerability mechanisms is discussed.

The Acute Effect of Local Vibration As a Recovery Modality from Exercise-Induced Increased Muscle Stiffness

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Hervé Pournot, Jérémy Tindel, Rodolphe Testa, Laure Mathevon, Thomas Lapole

2016-03-01

Full Text Available Exercise involving eccentric muscle contractions is known to decrease range of motion and increase passive muscle stiffness. This study aimed at using ultrasound shear wave elastography to investigate acute changes in biceps brachii passive stiffness following intense barbell curl exercise involving both concentric and eccentric contractions. The effect of local vibration (LV as a recovery modality from exercise-induced increased stiffness was further investigated. Eleven subjects performed 4 bouts of 10 bilateral barbell curl movements at 70% of the one-rep maximal flexion force. An arm-to-arm comparison model was then used with one arm randomly assigned to the passive recovery condition and the other arm assigned to the LV recovery condition (10 min of 55-Hz vibration frequency and 0.9-mm amplitude. Biceps brachii shear elastic modulus measurements were performed prior to exercise (PRE, immediately after exercise (POST-EX and 5 min after the recovery period (POST-REC. Biceps brachii shear elastic modulus was significantly increased at POST-EX (+53 ± 48%; p < 0.001 and POST-REC (+31 ± 46%; p = 0.025 when compared to PRE. No differences were found between passive and LV recovery (p = 0.210. LV as a recovery strategy from exercise-induced increased muscle stiffness was not beneficial, probably due to an insufficient mechanical action of vibrations.

Train-of-four recovery precedes twitch recovery during reversal with sugammadex in pediatric patients: A retrospective analysis.

Science.gov (United States)

Vieira Carlos, Ricardo; Luis Abramides Torres, Marcelo; de Boer, Hans Donald

2018-04-01

After reversal of a rocuronium-induced neuromuscular blockade with sugammadex, the recovery of train-of-four ratio to 0.9 is faster than recovery of first twitch of the train-of-four to 90% in adults. These findings after reversal of neuromuscular blockade with sugammadex have not yet been investigated in pediatric patients. The aim of this retrospective analysis was to investigate the relationship of the recovery of first twitch of the train-of-four height and train-of-four ratio after reversal of rocuronium-induced neuromuscular blockade with sugammadex in pediatric patients. Patients ASA I-III, aged 2-11 years, and who underwent abdominal and/or perineal surgery were included in the analysis. After extracting the necessary data from the hospital database, the patients were divided into 2 groups based on the dose of sugammadex received: group A: 2 mg.kg -1 for reversal of moderate neuromuscular blockade and group B: 4 mg.kg -1 for reversal of deep neuromuscular blockade. The relationship of the recovery of first twitch of the train-of-four height and train-of-four ratio in these 2 groups were analyzed. Data from 43 pediatric patients aged 2-11 years could be analyzed. The first twitch of the train-of-four height at the recovery of train-of-four ratio to 0.9 in group B was statistically significantly lower compared with group A. This height 3 and 5 minutes after the train-of-four ratio reached 0.9 showed no statistically significant differences between groups. The results were in line with the results found in adults and showed that the train-of-four ratio recovered to 0.9 was faster than first twitch of the train-of-four height recovered to the same level. © 2018 John Wiley & Sons Ltd.

Suppression of alkylating agent induced cell transformation and gastric ulceration by low-dose alkylating agent pretreatment

International Nuclear Information System (INIS)

Onodera, Akira; Kawai, Yuichi; Kashimura, Asako; Ogita, Fumiya; Tsutsumi, Yasuo; Itoh, Norio

2013-01-01

Highlights: •Low-dose MNNG pretreatment suppresses high-dose MNNG induced in vitro transformation. •Gastric ulcers induced by high-dose MNNG decreased after low-dose MNNG pretreatment. •Efficacy of low-dose MNNG related to resistance of mutation and oxidative stress. -- Abstract: Exposure to mild stress by chemicals and radiation causes DNA damage and leads to acquired stress resistance. Although the linear no-threshold (LNT) model of safety assessment assumes risk from any dose, evidence from radiological research demonstrates a conflicting hormetic phenomenon known as the hormesis effect. However, the mechanisms underlying radiation hormesis have not yet been clarified, and little is known about the effects of low doses of chemical carcinogens. We analyzed the efficacy of pretreatment with low doses of the alkylating agent N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) on the subsequent induction of cell transformation and gastric ulceration by high-dose MNNG. We used an in vitro Balb/3T3 A31-1-1 cell transformation test and monitored the formation of gastric ulcers in 5-week-old male ICR mice that were administered MNNG in drinking water. The treatment concentrations of MNNG were determined by the cell survival rate and past reports. For low-dose in vitro and in vivo experiments, MNNG was used at 0.028 μM, and 2.8 μg/mL, respectively. The frequency of cell transformation induced by 10 μm MNNG was decreased by low-dose MNNG pretreatment to levels similar to that of spontaneous transformation. In addition, reactive oxygen species (ROS) and mutation frequencies induced by 10 μm MNNG were decreased by low-dose MNNG pretreatment. Importantly, low-dose MNNG pretreatment had no effect on cell proliferation. In vivo studies showed that the number of gastric ulcers induced by 1 mg/mL MNNG decreased after low-dose MNNG pretreatment. These data indicate that low-dose pretreatment with carcinogens may play a beneficial role in the prevention of chemical toxicity

Suppression of alkylating agent induced cell transformation and gastric ulceration by low-dose alkylating agent pretreatment

Energy Technology Data Exchange (ETDEWEB)

Onodera, Akira, E-mail: onodera@pharm.kobegakuin.ac.jp [Department of Toxicology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Department of Pharmaceutical Sciences, Kobegakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe 650-8586 (Japan); Kawai, Yuichi [Department of Pharmaceutical Sciences, Kobegakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe 650-8586 (Japan); Kashimura, Asako; Ogita, Fumiya; Tsutsumi, Yasuo; Itoh, Norio [Department of Toxicology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871 (Japan)

2013-06-14

Highlights: •Low-dose MNNG pretreatment suppresses high-dose MNNG induced in vitro transformation. •Gastric ulcers induced by high-dose MNNG decreased after low-dose MNNG pretreatment. •Efficacy of low-dose MNNG related to resistance of mutation and oxidative stress. -- Abstract: Exposure to mild stress by chemicals and radiation causes DNA damage and leads to acquired stress resistance. Although the linear no-threshold (LNT) model of safety assessment assumes risk from any dose, evidence from radiological research demonstrates a conflicting hormetic phenomenon known as the hormesis effect. However, the mechanisms underlying radiation hormesis have not yet been clarified, and little is known about the effects of low doses of chemical carcinogens. We analyzed the efficacy of pretreatment with low doses of the alkylating agent N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) on the subsequent induction of cell transformation and gastric ulceration by high-dose MNNG. We used an in vitro Balb/3T3 A31-1-1 cell transformation test and monitored the formation of gastric ulcers in 5-week-old male ICR mice that were administered MNNG in drinking water. The treatment concentrations of MNNG were determined by the cell survival rate and past reports. For low-dose in vitro and in vivo experiments, MNNG was used at 0.028 μM, and 2.8 μg/mL, respectively. The frequency of cell transformation induced by 10 μm MNNG was decreased by low-dose MNNG pretreatment to levels similar to that of spontaneous transformation. In addition, reactive oxygen species (ROS) and mutation frequencies induced by 10 μm MNNG were decreased by low-dose MNNG pretreatment. Importantly, low-dose MNNG pretreatment had no effect on cell proliferation. In vivo studies showed that the number of gastric ulcers induced by 1 mg/mL MNNG decreased after low-dose MNNG pretreatment. These data indicate that low-dose pretreatment with carcinogens may play a beneficial role in the prevention of chemical toxicity

EFFECT OF MODIFIED CONSTRAINT INDUCED THERAPY ON UPPERLIMB FUNCTIONAL RECOVERY IN YOUNG STROKE SUBJECTS

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Kiran Prakash Pappala

2014-10-01

Full Text Available Background: The aim of this study is to evaluate the effect of modified constraint induced therapy on upper limb functional recovery in young stroke subjects. Most of the stroke rehabilitation units following conventional rehabilitation methods for treatment of the stroke patients where these methods have been proved to be less useful especially in the young stroke subjects. Hence the purpose of this study is to see the effect of modified constraint induced therapy which is a task specific training method for upperlimb in young stroke subjects. Methods: Total of 40 young stroke subjects who is having minimal motor criterion and met other inclusion criteria were recruited from department of physiotherapy, g.s.l.general hospital. Pre and post intervention measures were taken using Wolf motor function test and Jebsen Taylor hand function test. Results: In this study had shown significant improvements in the modified constraint induced therapy group when compared to the conventional rehabilitation alone. P value between groups was < 0.05. Conclusion: In this study concludes that addition of 15 minutes modified constraint induced movement therapy to conventional physiotherapy is a useful adjunct in functional recovery of upper limb among young stroke subjects

Low-dose radiation induces drosophila innate immunity through toll pathway activation

International Nuclear Information System (INIS)

Seong, Ki Moon; Kim, Cha Soon; Lee, Byung-Sub; Nam, Seon Young; Yang, Kwang Hee; Kim, Ji-Young; Jin, Young-Woo; Park, Joong-Jean; Min, Kyung-Jin

2012-01-01

Numerous studies report that exposing certain organisms to low-dose radiation induces beneficial effects on lifespan, tumorigenesis, and immunity. By analyzing survival after bacterial infection and antimicrobial peptide gene expression in irradiated flies, we demonstrate that low-dose irradiation of Drosophila enhances innate immunity. Low-dose irradiation of flies significantly increased resistance against gram-positive and gram-negative bacterial infections, as well as expression of several antimicrobial peptide genes. Additionally, low-dose irradiation also resulted in a specific increase in expression of key proteins of the Toll signaling pathway and phosphorylated forms of p38 and N-terminal kinase (JNK). These results indicate that innate immunity is activated after low-dose irradiation through Toll signaling pathway in Drosophila. (author)

Radiation-Induced Polymerization of Butyl Acrylate for Recovery of Organic Solvents

International Nuclear Information System (INIS)

Kattan, M.; Al-Kassiri, H.

2011-01-01

Radiation-induced polymerization of butyl acrylate using 60 Co gamma rays has been investigated under different conditions, such as irradiation dose (0-130 kGy), dose rate (10 kGy/h), and temperature (25-70 degree C). A linear relationship between conversion and temperature of irradiation was found. The activation energy (E) of 9.37 kJ/mol was obtained from kinetic analysis of the result from the polymerization at 10 kGy/h. Thermal properties were examined using differential scanning calorimetry and thermal gravimetric analysis. Efficient extraction of organic solvents including chloroform, chlorobenzene, carbon tetrachloride, benzene, styrene was revealed by the swelling and releasing measurements. These results indicate the feasibility of applying this polymer, which was prepared by radiation-induced polymerization, to management of organic wastes in the field of environment. (author)

Radiation-Induced Polymerization of Butyl Acrylate for Recovery of Organic Solvents

International Nuclear Information System (INIS)

Kattan, M.; Al-kassiri, H.

2010-01-01

Radiation-induced polymerization of butyl acrylate (BAc) using 60 Co gamma rays has been investigated under different conditions such as irradiation dose (0-130 kGy), dose rate (10 kGy/h) and temperature (25-70 C). A linear relationship between conversion and temperature of irradiation was found. The activation energy (E) of 9.37 kJ/mol was obtained from kinetic analysis of the result from the polymerization at 10 kGy/h. Thermal properties. were examined using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Efficient extraction of organic solvents including chloroform, chlorobenzene, carbon tetrachloride, benzene, styrene was revealed by the swelling and releasing measurements. These results indicate the feasibility of applying this polymer, which was prepared by radiation-induced polymerization, to management of organic wastes in the field of environment. (author)

Segregation of Spontaneous and Training Induced Recovery from Visual Field Defects in Subacute Stroke Patients

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Douwe P. Bergsma

2017-12-01

Full Text Available Whether rehabilitation after stroke profits from an early start is difficult to establish as the contributions of spontaneous recovery and treatment are difficult to tease apart. Here, we use a novel training design to dissociate these components for visual rehabilitation of subacute stroke patients with visual field defects such as hemianopia. Visual discrimination training was started within 6 weeks after stroke in 17 patients. Spontaneous and training-induced recoveries were distinguished by training one-half of the defect for 8 weeks, while monitoring spontaneous recovery in the other (control half of the defect. Next, trained and control regions were swapped, and training continued for another 8 weeks. The same paradigm was also applied to seven chronic patients for whom spontaneous recovery can be excluded and changes in the control half of the defect point to a spillover effect of training. In both groups, field stability was assessed during a no-intervention period. Defect reduction was significantly greater in the trained part of the defect than in the simultaneously untrained part of the defect irrespective of training onset (p = 0.001. In subacute patients, training contributed about twice as much to their defect reduction as the spontaneous recovery. Goal Attainment Scores were significantly and positively correlated with the total defect reduction (p = 0.01, percentage increase reading speed was significantly and positively correlated with the defect reduction induced by training (epoch 1: p = 0.0044; epoch 2: p = 0.023. Visual training adds significantly to the spontaneous recovery of visual field defects, both during training in the early and the chronic stroke phase. However, field recovery as a result of training in this subacute phase was as large as in the chronic phase. This suggests that patients benefited primarily of early onset training by gaining access to a larger visual field sooner.

MILDOS - a computer program for calculating environmental radiation doses from uranium recovery operations. Research report

International Nuclear Information System (INIS)

Strenge, D.L.; Bander, T.J.

1981-04-01

MILDOS is a Fortran Computer Code which calculates the dose commitments received by individuals and the general population within an 80 kilometer radius of an operating uranium recovery facility. In addition air and ground concentrations are presented for individual locations, as well as for a generalized population grid. Extra-regional population doses resulting from transport of radon and export of agricultural produce are also displayed. The transport of radiological emissions from point and area sources is predicted by using a sector-averaged Gaussian plume dispersion model. Mechanisms such as radioactive decay, plume depletion by deposition, ingrowth of daughter products and resuspension of deposited radionuclides are included in the transport model. Alterations in operation throughout the facility's lifetime can be accounted for in the input stream. The pathways considered are: inhalation; external exposure from ground shine and cloud immersion; and ingestion of vegetables, meat and milk. Dose commitments are calculated primarily on the basis of the recommendations of the International Commission on Radiological Protection (ICRP). Predictive 40 CFR 190 and 10 CFR 20 compliances are also performed. This computer code is designed primarily for uranium milling facilities and should not be used for operations with different radionuclides or processes

Radiation-induced hypopituitarism is dose-dependent

International Nuclear Information System (INIS)

Littley, M.D.; Shalet, S.M.; Beardwell, C.G.; Robinson, E.L.; Sutton, M.L.

1989-01-01

Radiation-induced hypopituitarism has been studies prospectively for up to 12 years in 251 adult patients treated for pituitary disease with external radiotherapy, ranging in dose from 20 Gy in eight fractions over 11 days to 45 Gy in 15 fractions over 21 days. Ten further patients were studied 2-4 years after whole-body irradiation for haematological malignancies using 12 Gy in six fractions over 3 days and seven patients were studied 3-11 years after whole-brain radiotherapy for a primary brain tumour (30 Gy, eight fractions, 11 days). Five years after treatment, patients who received 20 Gy had an incidence of TSH deficiency of 9% and in patients treated with 35-37 Gy, 40 Gy and 42-45 Gy, the incidence of TSH deficiency increased significantly with increasing dose. A similar relationship was observed for both ACTH and gonadotrophin deficiencies when the 20 Gy group was compared to patients treated with 35-45 Gy. Growth hormone deficiency was universal by 5 years over the dose range 35-45 Gy. In seven patients who were treated with 30 Gy in eight fractions over 11 days, deficiencies were observed at a similar frequency to the 40 Gy group (15 fractions, 21 days). No evidence of pituitary dysfunction was detected in the ten patients who received 12 Gy (six fractions, 3 days). (author)

Serotonin(2) receptors mediate respiratory recovery after cervical spinal cord hemisection in adult rats.

Science.gov (United States)

Zhou, S Y; Basura, G J; Goshgarian, H G

2001-12-01

The aim of the present study was to specifically investigate the involvement of serotonin [5-hydroxytryptamine (5-HT(2))] receptors in 5-HT-mediated respiratory recovery after cervical hemisection. Experiments were conducted on C(2) spinal cord-hemisected, anesthetized (chloral hydrate, 400 mg/kg ip), vagotomized, pancuronium- paralyzed, and artificially ventilated female Sprague-Dawley rats in which CO(2) levels were monitored and maintained. Twenty-four hours after spinal hemisection, the ipsilateral phrenic nerve displayed no respiratory-related activity indicative of a functionally complete hemisection. Intravenous administration of the 5-HT(2A/2C)-receptor agonist (+/-)-2,5-dimethoxy-4-iodoamphetamine hydrochloride (DOI) induced respiratory-related activity in the phrenic nerve ipsilateral to hemisection under conditions in which CO(2) was maintained at constant levels and augmented the activity induced under conditions of hypercapnia. The effects of DOI were found to be dose dependent, and the recovery of activity could be maintained for up to 2 h after a single injection. DOI-induced recovery was attenuated by the 5-HT(2)-receptor antagonist ketanserin but not with the 5-HT(2C)-receptor antagonist RS-102221, suggesting that 5-HT(2A) and not necessarily 5-HT(2C) receptors may be involved in the induction of respiratory recovery after cervical spinal cord injury.

Low-dose radiation-induced endothelial cell retraction

International Nuclear Information System (INIS)

Kantak, S.S.; Onoda, J.M.; Diglio, C.A.; Harper Hospital, Detroit, MI

1993-01-01

The data presented here are representative of a series of studies designed to characterize low-dose radiation effects on pulmonary microvascular endothelium. Data suggest that post-irradiation lung injuries (e.g. oedema) may be induced with only a single fraction of therapeutic radiation, and thus microscopic oedema may initiate prior to the lethal effects of radiation on the microvascular endothelium, and much earlier than would be suggested by the time course for clinically-detectable oedema. (author)

New way of dosing sugammadex for termination of vecuronium induced neuromuscular block

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Blaž Peček

2015-06-01

Full Text Available Background and Goal of Study: Sugammadex is a selective binding agent that bindsaminosteroid muscle relaxants. Each molecule of sugammadex binds one molecule of musclerelaxant. To produce the same depth of the neuromuscular block (NMB much less molecules ofvecuronium are needed than molecules of rocuronium. In theory less sugammadex would beneeded to neutralise the neuromuscular block if vecuronium was used to produce the neuromuscular block. Our aim was to compare reversal of vecuronium induced muscle relaxation between a new way of dosing sugammadex, which takes into account TOF value at the end of the surgery and the amount of vecuronium given during the surgery with neostigmine atropine combination. We also wanted to know how much this dosage regime can save compared to standard per kg dosage.Materials and Methods: 20 adult patients requiring a general anesthesia for surgery were analysed. The first group of 11 patients (SUG received sugammadex at the end of the surgery according to the table one for NMB reversal. The second group of 9 patients (NEO received neostigmine and atropine. Train of four (TOF value was recorded at the end of the surgery and then continuously until the TOF value reached more than 0.9 and the patient was extubated. The time required for the TOF value reaching 0.9 was compared between the groups. For economical evaluation we compared the amount of sugammadex used in the SUG group to standard sugammadex per kg dosage.Results and Discussion: Mean time to recovery to a TOF ratio of 0.9 with sugammadex was 5.12min versus 12.6 min with neostigmine atropine (P < 0.05. No sign of postoperative residual curarisation was observed in the SUG group. For patients in our study 530 mg of sugammadex were used to neutralise the NMB. If standard per kg sugammadex dosing had been used we would have used 2420 mg for the NMB reversal.Conclusion(s: New dosing for sugammadex was successful in neutralising the NMB regardlessof the TOF value

Sodium selenosulfate at an innocuous dose markedly prevents cisplatin-induced gastrointestinal toxicity

Energy Technology Data Exchange (ETDEWEB)

Li, Jun; Sun, Kang [School of Tea and Food Science, Anhui Agricultural University, Hefei 230036, Anhui (China); Ni, Lijuan; Wang, Xufang [School of Chemistry and Materials of Science, University of Science and Technology of China, Hefei 230052, Anhui (China); Wang, Dongxu [School of Tea and Food Science, Anhui Agricultural University, Hefei 230036, Anhui (China); Zhang, Jinsong, E-mail: zjs@ahau.edu.cn [School of Tea and Food Science, Anhui Agricultural University, Hefei 230036, Anhui (China)

2012-02-01

Our previous studies in mice revealed that two weeks short-term toxicity of sodium selenosulfate was significantly lower than that of sodium selenite, but selenium repletion efficacy of both compounds was equivalent. In addition, we showed that sodium selenosulfate reduced nephrotoxicity of cisplatin (CDDP) without compromising its anticancer activity, thus leading to a dramatic increase of cancer cure rate from 25% to 75%. Hydration has been used in clinical practice to reduce CDDP-induced nephrotoxicity, but it cannot mitigate CDDP-induced gastrointestinal toxicity. The present work investigated whether sodium selenosulfate is a potential preventive agent for the gastrointestinal toxicity. In tumor-bearing mice, sodium selenosulfate was administered at a dose of 9.5 μmol/kg daily for 11 days, CDDP alone resulted in diarrhea by 88% on day 12, whereas the co-administration of CDDP and sodium selenosulfate dramatically reduced diarrhea to 6% (p < 0.0001). Such a prominent protective effect promoted us to evaluate the safety potential of long-term sodium selenosulfate application. Mice were administered with sodium selenosulfate or sodium selenite for 55 days at the doses of 12.7 and 19 μmol/kg. The low-dose sodium selenite caused growth suppression and hepatotoxicity which were aggravated by the high-dose, leading to 40% mortality rate, but no toxic symptoms were observed in the two sodium selenosulfate groups. Altogether these results clearly show that sodium selenosulfate at an innocuous dose can markedly prevent CDDP-induced gastrointestinal toxicity. -- Highlights: ►Cisplatin resulted in diarrhea in mice by 88%. ►i.p. selenosulfate at 9.5 μmol/kg daily for 11 days reduced diarrhea to 6%. ►i.p. selenosulfate at 19 μmol/kg daily for 55 days was not toxic. ►i.p. selenite at 19 μmol/kg daily for 55 days was lethal. ►Innocuous dose of selenosulfate greatly prevents cisplatin-induced diarrhea.

Sodium selenosulfate at an innocuous dose markedly prevents cisplatin-induced gastrointestinal toxicity

International Nuclear Information System (INIS)

Li, Jun; Sun, Kang; Ni, Lijuan; Wang, Xufang; Wang, Dongxu; Zhang, Jinsong

2012-01-01

Our previous studies in mice revealed that two weeks short-term toxicity of sodium selenosulfate was significantly lower than that of sodium selenite, but selenium repletion efficacy of both compounds was equivalent. In addition, we showed that sodium selenosulfate reduced nephrotoxicity of cisplatin (CDDP) without compromising its anticancer activity, thus leading to a dramatic increase of cancer cure rate from 25% to 75%. Hydration has been used in clinical practice to reduce CDDP-induced nephrotoxicity, but it cannot mitigate CDDP-induced gastrointestinal toxicity. The present work investigated whether sodium selenosulfate is a potential preventive agent for the gastrointestinal toxicity. In tumor-bearing mice, sodium selenosulfate was administered at a dose of 9.5 μmol/kg daily for 11 days, CDDP alone resulted in diarrhea by 88% on day 12, whereas the co-administration of CDDP and sodium selenosulfate dramatically reduced diarrhea to 6% (p < 0.0001). Such a prominent protective effect promoted us to evaluate the safety potential of long-term sodium selenosulfate application. Mice were administered with sodium selenosulfate or sodium selenite for 55 days at the doses of 12.7 and 19 μmol/kg. The low-dose sodium selenite caused growth suppression and hepatotoxicity which were aggravated by the high-dose, leading to 40% mortality rate, but no toxic symptoms were observed in the two sodium selenosulfate groups. Altogether these results clearly show that sodium selenosulfate at an innocuous dose can markedly prevent CDDP-induced gastrointestinal toxicity. -- Highlights: ►Cisplatin resulted in diarrhea in mice by 88%. ►i.p. selenosulfate at 9.5 μmol/kg daily for 11 days reduced diarrhea to 6%. ►i.p. selenosulfate at 19 μmol/kg daily for 55 days was not toxic. ►i.p. selenite at 19 μmol/kg daily for 55 days was lethal. ►Innocuous dose of selenosulfate greatly prevents cisplatin-induced diarrhea.

Effects of Respiration-Induced Density Variations on Dose Distributions in Radiotherapy of Lung Cancer

International Nuclear Information System (INIS)

Mexner, Vanessa; Wolthaus, Jochem W.H.; Herk, Marcel van; Damen, Eugene M.F.; Sonke, Jan-Jakob

2009-01-01

Purpose: To determine the effect of respiration-induced density variations on the estimated dose delivered to moving structures and, consequently, to evaluate the necessity of using full four-dimensional (4D) treatment plan optimization. Methods and Materials: In 10 patients with large tumor motion (median, 1.9 cm; range, 1.1-3.6 cm), the clinical treatment plan, designed using the mid-ventilation ([MidV]; i.e., the 4D-CT frame closest to the time-averaged mean position) CT scan, was recalculated on all 4D-CT frames. The cumulative dose was determined by transforming the doses in all breathing phases to the MidV geometry using deformable registration and then averaging the results. To determine the effect of density variations, this cumulative dose was compared with the accumulated dose after similarly deforming the planned (3D) MidV-dose in each respiratory phase using the same transformation (i.e., 'blurring the dose'). Results: The accumulated tumor doses, including and excluding density variations, were almost identical. Relative differences in the minimum gross tumor volume (GTV) dose were less than 2% for all patients. The relative differences were even smaller in the mean lung dose and the V20 (<0.5% and 1%, respectively). Conclusions: The effect of respiration-induced density variations on the dose accumulated over the respiratory cycle was very small, even in the presence of considerable respiratory motion. A full 4D-dose calculation for treatment planning that takes into account such density variations is therefore not required. Planning using the MidV-CT derived from 4D-CT with an appropriate margin for geometric uncertainties is an accurate and safe method to account for respiration-induced anatomy variations.

Sensitivity to Rocuronium-Induced Neuromuscular Block and Reversibility with Sugammadex in a Patient with Myotonic Dystrophy

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Akihiro Kashiwai

2012-01-01

Full Text Available We report a patient with myotonic dystrophy who showed prolonged rocuronium-induced neuromuscular blockade, although with a fast recovery with sugammadex. During general anesthesia with propofol and remifentanil, the times to spontaneous recovery of the first twitch (T1 of train of four to 10% of control values after an intubating dose of rocuronium 1 mg/kg and an additional dose of 0.2 mg/kg were 112 min and 62 min, respectively. Despite the high sensitivity to rocuronium, sugammadex 2 mg/kg administered at a T1 of 10% safely and effectively antagonized rocuronium-induced neuromuscular block in 90 s.

Radiation retinopathy caused by low dose irradiation and antithyroid drug-induced systemic vasculitis

International Nuclear Information System (INIS)

Sonoda, Koh-hei; Ishibashi, Tatsuro

2005-01-01

We report on a patient with Graves' disease with radiation retinopathy caused by low-dose irradiation and antithyroid drug-induced antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis. A 38-year-old woman with Graves' disease presented with bilateral blurred vision, micro-aneurysms, telangiectasia, and macular edema. The patient was examined by ophthalmoscopy and fluorescein angiography, and radiation retinopathy was diagnosed. The patient had been treated with low-dose irradiation for her Graves' ophthalmopathy a few years earlier. She also had ANCA-positive vasculitis induced by the antithyroid drug (propylthiouracil, PTU) that had been prescribed for her at that time. Because of multiple avascular areas on both retinas, she was treated by intensive retinal photocoagulation to control progressive retinopathy. The radiation doses used to treat Graves' disease ophthalmopathy are low. Nevertheless, there is still a risk of radiation retinopathy developing in patients with PTU-induced ANCA-positive vasculitis. (author)

Conjugated Linoleic Acid Administration Induces Amnesia in Male Sprague Dawley Rats and Exacerbates Recovery from Functional Deficits Induced by a Controlled Cortical Impact Injury.

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Rastafa I Geddes

Full Text Available Long-chain polyunsaturated fatty acids like conjugated linoleic acids (CLA are required for normal neural development and cognitive function and have been ascribed various beneficial functions. Recently, oral CLA also has been shown to increase testosterone (T biosynthesis, which is known to diminish traumatic brain injury (TBI-induced neuropathology and reduce deficits induced by stroke in adult rats. To test the impact of CLA on cognitive recovery following a TBI, 5-6 month old male Sprague Dawley rats received a focal injury (craniectomy + controlled cortical impact (CCI; n = 17 or Sham injury (craniectomy alone; n = 12 and were injected with 25 mg/kg body weight of Clarinol® G-80 (80% CLA in safflower oil; n = 16 or saline (n = 13 every 48 h for 4 weeks. Sham surgery decreased baseline plasma progesterone (P4 by 64.2% (from 9.5 ± 3.4 ng/mL to 3.4 ± 0.5 ng/mL; p = 0.068, T by 74.6% (from 5.9 ± 1.2 ng/mL to 1.5 ± 0.3 ng/mL; p 0.05 animals by post-injury day 29, but rapidly reversed by post-injury day 1 the hypoadrenalism in Sham (11-DOC: 372.6 ± 36.6 ng/mL; corticosterone: 202.6 ± 15.6 ng/mL and CCI-injured (11-DOC: 384.2 ± 101.3 ng/mL; corticosterone: 234.6 ± 43.8 ng/mL animals. In Sham surgery animals, CLA did not alter body weight, but did markedly increase latency to find the hidden Morris Water Maze platform (40.3 ± 13.0 s compared to saline treated Sham animals (8.8 ± 1.7 s. In CCI injured animals, CLA did not alter CCI-induced body weight loss, CCI-induced cystic infarct size, or deficits in rotarod performance. However, like Sham animals, CLA injections exacerbated the latency of CCI-injured rats to find the hidden MWM platform (66.8 ± 10.6 s compared to CCI-injured rats treated with saline (30.7 ± 5.5 s, p < 0.05. These results indicate that chronic treatment of CLA at a dose of 25 mg/kg body weight in adult male rats over 1-month 1 does not reverse craniectomy- and craniectomy + CCI-induced hypogonadism, but does reverse

Low dose radiation induced protein and its experimental and ophthalmic clinical research

International Nuclear Information System (INIS)

Shen Wei; Su Liaoyuan; Liu Fenju; Ding Jie; Li Longbiao; Pan Chengsi

2001-01-01

The protective effects of low dose radiation (LDR) induced protein on cellular impairments caused by some harmful chemical and physical factors were studied. Male Kunming mice were irradiated with LDR, then the spleen cells of the mice were broken with ultrasonic energy and then ultracentrifugalized. The supernatant solution contained with LDR induced protein. The newly emerging protein was detected by gel filtration and its molecular weight was determined by gel electrophoresis. The content of newly emerging protein (LDR induced protein) was determined by Lowry's method. The method of isotope incorporation was used to observe the biological activity and its influence factors, the protective effects of LDR induced protein on the cells impaired by irradiating with ultraviolet (UV), high doses of 60 Co γ-rays and exposed to heat respectively, and the stimulative effects of LDR induced protein on human peripheral blood lymphocytes. Newly emerging protein has been observed in the experiment. The molecular weight of the protein is in the region 76.9 KD+- - 110.0 KD+-, the yield of the protein was 613.33 +- 213.42 μg per 3 x 10 7 spleen cells. DPM values (isotope were incorporated) of normal and injured mice spleen cells increased significantly after stimulating with the solution contained LDR induced protein. It is concluded that LDR induced protein could be obtained from mice spleen cells exposed to 5 - 15 cGy radiation for 2 - 16 h. The protein had biological activity and was able to stimulate the transformation of the spleen cells in vitro. It had obvious protective effects on some impaired cells caused by high dose radiation, UV radiation, heat and so on. It also had stimulative effects on the transformation of peripheral blood T and B lymphocytes of healthy individual and patients with eye diseases. It indicates that LDR induced protein increased immune function of human

Potential role of coenzyme Q10 in facilitating recovery from statin-induced rhabdomyolysis.

Science.gov (United States)

Wang, L W; Jabbour, A; Hayward, C S; Furlong, T J; Girgis, L; Macdonald, P S; Keogh, A M

2015-04-01

Rhabdomyolysis is a rare, but serious complication of statin therapy, and represents the most severe end of the spectrum of statin-induced myotoxicity. We report a case where coenzyme Q10 facilitated recovery from statin-induced rhabdomyolysis and acute renal failure, which had initially persisted despite statin cessation and haemodialysis. This observation is biologically plausible due to the recognised importance of coenzyme Q10 in mitochondrial bioenergetics within myocytes, and the fact that statins inhibit farnesyl pyrophosphate production, a biochemical step crucial for coenzyme Q10 synthesis. Coenzyme Q10 is generally well tolerated, and may potentially benefit patients with statin-induced rhabdomyolysis. © 2015 Royal Australasian College of Physicians.

Relaxation behavior and dose dependence of radiation induced radicals in irradiated mango

International Nuclear Information System (INIS)

Kameya, Hiromi; Kakita, Daisuke; Kaimori, Yoshihiko; Ukai, Mitsuko; Kikuchi, Masahiro; Kobayashi, Yasuhiko; Shimoyama, Yuhei

2010-01-01

Mangoes are imported to Japan after treated with hot water. Recently, irradiated mangoes imported to U. S. are widely used. This paper reports on the ESR method for analyzing the radiation induced radicals of irradiated mangoes. Upon the γ ray irradiation, a strong single peak in the flesh and skin of mangoes was observed at g=2.004. This singlet peak may be attributed to organic free radicals. The ESR spectra of the flesh and skin of mangoes showed the radiation induced radicals due to cellulose by irradiation over 12 kGy. The relaxation times (T 1 and T 2 ) of the singlet signal were calculated. T 2 showed dose response according to increasing the irradiation dose levels, while T 1 was almost constant. The value of (T 1 T 2 ) 1/2 showed the dependence of irradiation dose level. (author)

Low dose radiation prevents doxorubicin-induced cardiotoxicity.

Science.gov (United States)

Jiang, Xin; Hong, Yaqiong; Zhao, Di; Meng, Xinxin; Zhao, Lijing; Du, Yanwei; Wang, Zan; Zheng, Yan; Cai, Lu; Jiang, Hongyu

2018-01-02

This study aimed to develop a novel and non-invasive approach, low-dose radiation (LDR, 75 mGy X-rays), to prevent doxorubicin (DOX)-induced cardiotoxicity. BALB/c mice were randomly divided into five groups, Control, LDR (a single exposure), Sham (treated same as LDR group except for irradiation), DOX (a single intraperitoneal injection of DOX at 7.5 mg/kg), and LDR/DOX (received LDR and 72 h later received DOX). Electrocardiogram analysis displayed several kinds of abnormal ECG profiles in DOX-treated mice, but less in LDR/DOX group. Cardiotoxicity indices included histopathological changes, oxidative stress markers, and measurements of mitochondrial membrane permeability. Pretreatment of DOX group with LDR reduced oxidative damages (reactive oxygen species formation, protein nitration, and lipid peroxidation) and increased the activities of antioxidants (superoxide dismutase and glutathione peroxidase) in the heart of LDR/DOX mice compared to DOX mice. Pretreatment of DOX-treated mice with LDR also decreased DOX-induced cardiac cell apoptosis (TUNEL staining and cleaved caspase-3) and mitochondrial apoptotic pathway (increased p53, Bax, and caspase-9 expression and decreased Bcl2 expression and ΔΨm dissipation). These results suggest that LDR could induce adaptation of the heart to DOX-induced toxicity. Cardiac protection by LDR may attribute to attenuate DOX-induced cell death via suppressing mitochondrial-dependent oxidative stress and apoptosis signaling.

Radiation-Induced Leukemia at Doses Relevant to Radiation Therapy: Modeling Mechanisms and Estimating Risks

Science.gov (United States)

Shuryak, Igor; Sachs, Rainer K.; Hlatky, Lynn; Mark P. Little; Hahnfeldt, Philip; Brenner, David J.

2006-01-01

Because many cancer patients are diagnosed earlier and live longer than in the past, second cancers induced by radiation therapy have become a clinically significant issue. An earlier biologically based model that was designed to estimate risks of high-dose radiation induced solid cancers included initiation of stem cells to a premalignant state, inactivation of stem cells at high radiation doses, and proliferation of stem cells during cellular repopulation after inactivation. This earlier model predicted the risks of solid tumors induced by radiation therapy but overestimated the corresponding leukemia risks. Methods: To extend the model to radiation-induced leukemias, we analyzed in addition to cellular initiation, inactivation, and proliferation a repopulation mechanism specific to the hematopoietic system: long-range migration through the blood stream of hematopoietic stem cells (HSCs) from distant locations. Parameters for the model were derived from HSC biologic data in the literature and from leukemia risks among atomic bomb survivors v^ ho were subjected to much lower radiation doses. Results: Proliferating HSCs that migrate from sites distant from the high-dose region include few preleukemic HSCs, thus decreasing the high-dose leukemia risk. The extended model for leukemia provides risk estimates that are consistent with epidemiologic data for leukemia risk associated with radiation therapy over a wide dose range. For example, when applied to an earlier case-control study of 110000 women undergoing radiotherapy for uterine cancer, the model predicted an excess relative risk (ERR) of 1.9 for leukemia among women who received a large inhomogeneous fractionated external beam dose to the bone marrow (mean = 14.9 Gy), consistent with the measured ERR (2.0, 95% confidence interval [CI] = 0.2 to 6.4; from 3.6 cases expected and 11 cases observed). As a corresponding example for brachytherapy, the predicted ERR of 0.80 among women who received an inhomogeneous low-dose

Recovery From Exercise-Induced Muscle Damage: Cold-Water Immersion Versus Whole-Body Cryotherapy.

Science.gov (United States)

Abaïdia, Abd-Elbasset; Lamblin, Julien; Delecroix, Barthélémy; Leduc, Cédric; McCall, Alan; Nédélec, Mathieu; Dawson, Brian; Baquet, Georges; Dupont, Grégory

2017-03-01

To compare the effects of cold-water immersion (CWI) and whole-body cryotherapy (WBC) on recovery kinetics after exercise-induced muscle damage. Ten physically active men performed single-leg hamstring eccentric exercise comprising 5 sets of 15 repetitions. Immediately postexercise, subjects were exposed in a randomized crossover design to CWI (10 min at 10°C) or WBC (3 min at -110°C) recovery. Creatine kinase concentrations, knee-flexor eccentric (60°/s) and posterior lower-limb isometric (60°) strength, single-leg and 2-leg countermovement jumps, muscle soreness, and perception of recovery were measured. The tests were performed before and immediately, 24, 48, and 72 h after exercise. Results showed a very likely moderate effect in favor of CWI for single-leg (effect size [ES] = 0.63; 90% confidence interval [CI] = -0.13 to 1.38) and 2-leg countermovement jump (ES = 0.68; 90% CI = -0.08 to 1.43) 72 h after exercise. Soreness was moderately lower 48 h after exercise after CWI (ES = -0.68; 90% CI = -1.44 to 0.07). Perception of recovery was moderately enhanced 24 h after exercise for CWI (ES = -0.62; 90% CI = -1.38 to 0.13). Trivial and small effects of condition were found for the other outcomes. CWI was more effective than WBC in accelerating recovery kinetics for countermovement-jump performance at 72 h postexercise. CWI also demonstrated lower soreness and higher perceived recovery levels across 24-48 h postexercise.

Influence of conditioned psychological stress on immunological recovery in mice exposed to low-dose x irradiation

International Nuclear Information System (INIS)

Sato, K.; Flood, J.F.; Makinodan, T.

1984-01-01

A study was initiated to determine the effects of psychological stress on the immune response in BALB/c mice recovering from exposure to a low dose of ionizing radiation. Mice were first subjected to conditioning training for 12 days, then exposed to 200 R, subjected to psychological stress for 14 days, and assessed for peak anti-sheep RBC response. The seven treatment groups included two unirradiated groups and five irradiated groups. Mice exposed to 200 R and then subjected to conditioned psychological stress responded less vigorously to antigenic stimulation than those of the other irradiated groups. The psychological stress imposed upon these mice did not influence the antibody-forming capacity of unirradiated mice. These results indicate that a psychological stress which did not affect the immunological activity of unirradiated mice can curtail the immunological recovery of mice exposed to low doses of ionizing radiation

Total-dose radiation-induced degradation of thin film ferroelectric capacitors

International Nuclear Information System (INIS)

Schwank, J.R.; Nasby, R.D.; Miller, S.L.; Rodgers, M.S.; Dressendorfer, P.V.

1990-01-01

Thin film PbZr y Ti 1-y O 3 (PZT) ferroelectric memories offer the potential for radiation-hardened, high-speed nonvolatile memories with good retention and fatigue properties. In this paper we explore in detail the radiation hardness of PZT ferroelectric capacitors. Ferroelectric capacitors were irradiated using x-ray and Co-60 sources to dose levels up to 16 Mrad(Si). The capacitors were characterized for their memory properties both before and after irradiation. The radiation hardness was process dependent. Three out of four processes resulted in capacitors that showed less than 30% radiation-induced degradation in retained polarization charge and remanent polarization after irradiating to 16 Mrad(Si). On the other hand, one of the processes showed significant radiation-induced degradation in retained polarization charge and remanent polarization at dose levels above 1 Mrad(Si). The decrease in retained polarization charge appears to be due to an alteration of the switching characteristics of the ferroelectric due to changes in the internal fields. The radiation-induced degradation is recoverable by a postirradiation biased anneal and can be prevented entirely if devices are cycled during irradiation. The authors have developed a model to simulate the observed degradation

Accumulation and Recovery of Disorder on Silicon and Carbon Sublattices in Ion-Irradiated 6H-SiC

International Nuclear Information System (INIS)

Jiang, Weilin; Weber, William J.; Thevuthasan, Suntharampillai; Shutthanandan, V.

2001-01-01

Irradiation experiments have been performed at 100, 170 and 300 K for 6H-SiC single crystals using Au and He+ ions over a range of fluences. The evolution of disorder on the both Si and C sublattices has been simultaneously investigated using 0.94 MeV D Rutherford backscattering spectrometry in combination with 12C(d,p) nuclear reaction analysis in a axial channeling geometry. The results show that the dependence of disorder on dose is consistent with a combined direct-impact / defect-stimulated model. At low doses, a slightly higher rate of C disordering is observed, which is consistent with molecular dynamics simulations that suggest a smaller threshold displacement energy on the C sublattice. At higher doses, the rate of C disordering decreases more rapidly than the rate of Si disordering, which suggests a higher rate of dynamical recovery on the C sublattice under the irradiation conditions. Three distinct recovery stages are observed on both the Si and C sublattices in the Au-irradiated 6H-SiC. However, complete recovery of irradiation-induced disorder does not occur during isochronal annealing at temperatures up to 970 K

Boosting recovery rather than buffering reactivity: Higher stress-induced oxytocin secretion is associated with increased cortisol reactivity and faster vagal recovery after acute psychosocial stress.

Science.gov (United States)

Engert, Veronika; Koester, Anna M; Riepenhausen, Antje; Singer, Tania

2016-12-01

Animal models and human studies using paradigms designed to stimulate endogenous oxytocin release suggest a stress-buffering role of oxytocin. We here examined the involvement of stress-induced peripheral oxytocin secretion in reactivity and recovery phases of the human psychosocial stress response. Healthy male and female participants (N=114) were subjected to a standardized laboratory stressor, the Trier Social Stress Test. In addition to plasma oxytocin, cortisol was assessed as a marker of hypothalamic-pituitary-adrenal (HPA-) axis activity, alpha-amylase and heart rate as markers of sympathetic activity, high frequency heart rate variability as a marker of vagal tone and self-rated anxiety as an indicator of subjective stress experience. On average, oxytocin levels increased by 51% following psychosocial stress. The stress-induced oxytocin secretion, however, did not reduce stress reactivity. To the contrary, higher oxytocin secretion was associated with greater cortisol reactivity and peak cortisol levels in both sexes. In the second phase of the stress response the opposite pattern was observed, with higher oxytocin secretion associated with faster vagal recovery. We suggest that after an early stage of oxytocin and HPA-axis co-activation, the stress-reducing action of oxytocin unfolds. Due to the time lag it manifests as a recovery-boosting rather than a reactivity-buffering effect. By reinforcing parasympathetic autonomic activity, specifically during stress recovery, oxytocin may provide an important protective function against the health-compromising effects of sustained stress. Copyright © 2016 Elsevier Ltd. All rights reserved.

Risk of radiation-induced cancer at low doses and low dose rates for radiation protection purposes

International Nuclear Information System (INIS)

1995-01-01

The aim of this report is to provide an updated, comprehensive review of the data available for assessing the risk of radiation-induced cancer for radiation protection purposes. Particular emphasis is placed on assessing risks at low doses and low dose rates. The review brings together the results of epidemiological investigations and fundamental studies on the molecular and cellular mechanisms involved in radiation damage. Additionally, this information is supplemented by studies with experimental animals which provide further guidance on the form of the dose-response relationship for cancer induction, as well as on the effect of dose rate on the tumour yield. The emphasis of the report is on cancer induction resulting from exposure to radiations with a low linear energy transfer (LET). The work was performed under contract for the Institut de Protection et de Surete Nucleaire, Fontenay-aux-Roses, Paris, France, whose agreement to publish is gratefully ackowledged. It extends the advice on radiation risks given in Documents of the NRPB, 4 No. 4 (1993). (Author)

Reinfusion of autologous lymphocytes with granulocyte-macrophage colony-stimulating factor induces rapid recovery of CD4+ and CD8+ T cells after high-dose chemotherapy for metastatic breast cancer

NARCIS (Netherlands)

de Gast, G. C.; Vyth-Dreese, F. A.; Nooijen, W.; van den Bogaard, C. J. C.; Sein, J.; Holtkamp, M. M. J.; Linthorst, G. A. M.; Baars, J. W.; Schornagel, J. H.; Rodenhuis, S.

2002-01-01

PURPOSE: Repeated high-dose chemotherapy (HDCT) followed by peripheral-blood progenitor cell (PBPC) transplantation can induce a complete remission in patients with metastatic breast cancer sensitive to standard chemotherapy (CT), but the majority of patients relapse within 1 to 2 years. The immune

Cystoid Macular Edema Induced by Low Doses of Nicotinic Acid

Directory of Open Access Journals (Sweden)

Daniela Domanico

2013-01-01

Full Text Available Cystoid macular edema (CME is a condition that involves the macula, causing painless vision loss. In this paper, we report a case of niacin-induced bilateral cystoid macular edema (CME in a middle-age woman taking low dose of niacin (18 mg of nicotinic acid. Optical coherence tomography (OCT showed retinal thickening and cystoid spaces in both eyes, whereas fluorescein angiography (FA; HRA 2, Heidelberg Engineering revealed the absence of fluorescein leakage also in later phases. Four weeks after discontinuation of therapy there were a complete disappearance of macular edema at funduscopic examination and an improvement of visual acuity in both eyes. Furthermore OCT showed a normal retinal profile in both eyes. In our opinion considering the wide availability of niacin, medical monitoring and periodical examination should be considered during niacin administration. To our knowledge, this is the first report in the literature that described the very low-dose niacin-induced bilateral niacin maculopathy.

High-dose 8% capsaicin patch in treatment of chemotherapy-induced peripheral neuropathy: single-center experience.

Science.gov (United States)

Filipczak-Bryniarska, Iwona; Krzyzewski, Roger M; Kucharz, Jakub; Michalowska-Kaczmarczyk, Anna; Kleja, Justyna; Woron, Jarosław; Strzepek, Katarzyna; Kazior, Lucyna; Wordliczek, Jerzy; Grodzicki, Tomasz; Krzemieniecki, Krzysztof

2017-08-17

High-dose capsaicin patch is effective in treatment of neuropathic pain in HIV-associated neuropathy and diabetic neuropathy. There are no studies assessing effectiveness of high-dose capsaicin patch in treatment of chemotherapy-induced peripheral neuropathy. We sought to determine the effectiveness of treatment of pain associated with chemotherapy-induced peripheral neuropathy with high-dose capsaicin patch. Our study group consisted of 18 patients with clinically confirmed oxaliplatin-induced neuropathy. Baseline characteristic including underling disease, received cumulative dose of neurotoxic agent, neuropathic symptoms, prior treatment and initial pain level were recorded. Pain was evaluated with Numeric Rating Scale prior to treatment with high-dose capsaicin and after 1.8 day and after 8 and 12 weeks after introducing treatment. Patients were divided into two groups accordingly to the amount of neurotoxic agent that caused neuropathy (high sensitivity and low sensitivity group). Most frequent symptoms of chemotherapy-induced neuropathy were: pain (88.89%), paresthesis (100%), sock and gloves sensation (100%) and hypoesthesis (100%). Initial pain level was 7.45 ± 1.14. Mean cumulative dose of oxaliplatin after which patients developed symptoms was 648.07 mg/m 2 . Mean pain level after 12 weeks of treatment was 0.20 ± 0.41. When examined according to high and low sensitivity to neurotoxic agent patients with low sensitivity had higher pain reduction, especially after 8 days after introducing treatment (69.55 ± 12.09 vs. 49.40 ± 20.34%; p = 0.02) and after 12 weeks (96.96 ± 5.56 vs. 83.93 ± 18.59%; p = 0.04). High-dose capsaicin patch is an effective treatment for pain associated with chemotherapy-induced neuropathy in patients treated with oxaliplatin. Patients with lower sensitivity to neurotoxic agents have better response to treatment and pain reduction.

Effect of high-dose preoperative methylprednisolone on recovery after total hip arthroplasty

DEFF Research Database (Denmark)

Lunn, T H; Andersen, Lasse Østergaard; Kristensen, B B

2013-01-01

(IQR) (95% CI), MP vs placebo]: 23.5 (23.3-23.7) (17.8-43.8) vs 23.5 (23.0-23.8) (20.0-46.8) h, the mean difference (95% CI) being -1.3 (-4.7 to 2.2) h, P=0.65. Overall pain for the first 24 h after surgery was significantly reduced in the MP vs the placebo group (PMP 125 mg i.v. before surgery added......BACKGROUND: /st>High-dose glucocorticoid may reduce postsurgical pain and improve recovery. We hypothesized that 125 mg methylprednisolone (MP) would reduce time to meet functional discharge criteria after total hip arthroplasty (THA). METHODS: /st>Forty-eight patients undergoing unilateral THA...... under spinal anaesthesia were consecutively included in this randomized, double-blind, placebo-controlled trial receiving preoperative i.v. MP or saline. All patients received a standardized, multimodal analgesic regime with paracetamol, celecoxib, and gabapentin. The primary outcome was time to meet...

Mono and sequential ion irradiation induced damage formation and damage recovery in oxide glasses: Stopping power dependence of the mechanical properties

International Nuclear Information System (INIS)

Mir, A.H.; Monnet, I.; Toulemonde, M.; Bouffard, S.; Jegou, C.; Peuget, S.

2016-01-01

Simple and complex borosilicate glasses were irradiated with single and double ion beams of light and heavy ions over a broad fluence and stopping power range. As a result of the heavy ion irradiation (U, Kr, Au), the hardness was observed to diminish and saturate after a decrease by 35 ± 1%. Unlike slow and swift heavy ion irradiation, irradiation with light ions (He,O) induced a saturation hardness decrease of 18 ± 1% only. During double ion beam irradiation; where glasses were first irradiated with a heavy ion (gold) and then by a light ion (helium), the light ion irradiation induced partial damage recovery. As a consequence of the recovery effect, the hardness of the pre-irradiated glasses increased by 10–15% depending on the chemical composition. These results highlight that the nuclear energy loss and high electronic energy loss (≥4 keV/nm) result in significant and similar modifications whereas light ions with low electronic energy loss (≤1 keV/nm) result in only mild damage formation in virgin glasses and recovery in highly pre-damaged glasses. These results are important to understand the damage formation and recovery in actinide bearing minerals and in glasses subjected to self-irradiation by alpha decays. - Highlights: • Behavior of glasses strongly depends on the electronic energy loss (Se) of the ions. • High Se (≥4 keV/nm) induces large changes in comparison to lower Se values. • Apart from mild damage formation, low Se causes recovery of pre-existing damage. • Alpha induced partial recovery of the damage would occur in nuclear waste glasses.

Intermittent fasting prompted recovery from dextran sulfate sodium-induced colitis in mice.

Science.gov (United States)

Okada, Toshihiko; Otsubo, Takeshi; Hagiwara, Teruki; Inazuka, Fumika; Kobayashi, Eiko; Fukuda, Shinji; Inoue, Takuya; Higuchi, Kazuhide; Kawamura, Yuki I; Dohi, Taeko

2017-09-01

Fasting-refeeding in mice induces transient hyperproliferation of colonic epithelial cells, which is dependent on the lactate produced as a metabolite of commensal bacteria. We attempted to manipulate colonic epithelial cell turnover with intermittent fasting to prompt recovery from acute colitis. Acute colitis was induced in C57BL/6 mice by administration of dextran sulfate sodium in the drinking water for 5 days. From day 6, mice were fasted for 36 h and refed normal bait, glucose powder, or lactylated high-amylose starch. On day 9, colon tissues were subjected to analysis of histology and cytokine expression. The effect of lactate on the proliferation of colonocytes was assessed by enema in vivo and primary culture in vitro . Intermittent fasting resulted in restored colonic crypts and less expression of interleukin-1β and interleukin-17 in the colon than in mice fed ad libitum . Administration of lactate in the colon at refeeding time by enema or by feeding lactylated high-amylose starch increased the number of regenerating crypts. Addition of lactate but not butyrate or acetate supported colony formation of colonocytes in vitro . In conclusion, intermittent fasting in the resolution phase of acute colitis resulted in better recovery of epithelial cells and reduced inflammation.

Pharmacological radionuclide ventriculography for detection of myocardial contractile reserve in patients after myocardial infarction: head-to-head comparison of low dose dobutamine and low dose dypiridamole

International Nuclear Information System (INIS)

Petrasinovic, Z.; Ostojic, M.; Beleslin, B.; Stojkovic, S.; Nedeljkovic, M.; Stankovic, G.; Dikic, A.; Pavlovic, S.; Sobic, D.

2002-01-01

%), whereas 32 segments were responders (36%, p=0.05 vs. dobutamine) during low dose dipyridamole. Positive predictive value of dobutamine and dipyridamole for predicting functional recovery was 72% and 75% (p=ns), respectively. Negative predictive value of dobutamine and dipyridamole was 48% and 69% (p=0.05), respectively. In the group of patients with most severe dyskinesia (regional ejection fraction <35%, 42 segments) positive predictive value was 73% and 82%, while negative predictive value was 42% and 64% for low dose dobutamine and low dose dipyridamole respectively (p=ns). Conclusion. Although low dose dobutamine induced higher rate of positive responses during radionuclide ventriculography imaging, dipyridamole radionuclide ventriculography has shown superior, particularly negative, prognostic value for predicting functional recovery of infarcted regions

Characterization of rapid recovery from γ-ray damage in plateau-phase human diploid fibroblasts

International Nuclear Information System (INIS)

Malcolm, A.W.; Tomkinson, K.N.; Little, J.B.

1982-01-01

Rapid recovery was investigated in density-inhibited, stationary-phase human diploid cells subcultured to low density at various times after a single dose of radiation. The influence of total dose, postirradiation temperature, and cell-to-cell contact on recovery was examined. The cultures were exposed to 60 Co γ rays at a dose rate of 50 rad per second. When the irradiation and postirradiation temperatures were maintained at 25 or 37 0 C, recovery, as manifested by an enhancement in survival, was similar during the first 30 min, whereas it was reduced at later times in the 25 0 C compared with the 37 0 C cultures. This result suggests the existence of different rapidly and slowly acting components to recovery. No recovery was noted at any time with incubation at 4 0 C. The recovery observed in density-inhibited cultures was consistently greater than that in less dense cultures, suggesting an effect of cell-to-cell contact and cell cycle distribution. Following single doses of 200 to 900 rad, progressive enhancement in relative recovery occurred with increasing doses over a period of 2 to 90 min, illustrating the importance of the relationship of the dose to the rapid recovery process

Transformation-Induced Relaxation and Stress Recovery of TiNi Shape Memory Alloy

Directory of Open Access Journals (Sweden)

Kohei Takeda

2014-03-01

Full Text Available The transformation-induced stress relaxation and stress recovery of TiNi shape memory alloy (SMA in stress-controlled subloop loading were investigated based on the local variation in temperature and transformation band on the surface of the tape in the tension test. The results obtained are summarized as follows. (1 In the loading process, temperature increases due to the exothermic martensitic transformation (MT until the holding strain and thereafter temperature decreases while holding the strain constant, resulting in stress relaxation due to the MT; (2 In the unloading process, temperature decreases due to the endothermic reverse transformation until the holding strain and thereafter temperature increases while holding the strain constant, resulting in stress recovery due to the reverse transformation; (3 Stress varies markedly in the initial stage followed by gradual change while holding the strain constant; (4 If the stress rate is high until the holding strain in the loading and unloading processes, both stress relaxation and stress recovery are large; (5 It is important to take into account this behavior in the design of SMA elements, since the force of SMA elements varies even if the atmospheric temperature is kept constant.

Evidence that progression of cells into S-phase is not a prerequisite for recovery between split doses of U.V.-light in synchronized and plateau phase cultures of Ehrlich ascites tumour cells

International Nuclear Information System (INIS)

Iliakis, G.; Nuesse, M.

1982-01-01

The ability of Ehrlich ascites tumour cells (EAT-cells) to perform split-dose recovery after U.V. exposure was studied with unfed plateau phase as well as with synchronized cells selected from exponentially growing cultures. The cells were kept in balanced salt solution which inhibited the progression of the cells through the cell cycle. The results indicated that split-dose recovery occurred in EAT-cells in all phases of the cell cycle and that progression of the cells into S-phase was not a prerequisite for this type of repair. The second-dose survival curves of G 1 -and S-phase cells showed, 24 hours after the first U.V. exposure, a shoulder width comparable to that of singly irradiated cells. Second-dose survival curves for G 2 -cells showed, after the same time interval, a shoulder width smaller than that for singly exposed cells, presumably due to some cell division. The recovery time constant (t 50 between 4 and 8 hours) increased with increasing U.V. exposure. (author)

Platelet count recovery and seroreversion in immune HIT despite continuation of heparin: further observations and literature review.

Science.gov (United States)

Shih, Andrew W; Sheppard, Jo-Ann I; Warkentin, Theodore E

2017-10-05

One of the standard distinctions between type 1 (non-immune) and type 2 (immune-mediated) heparin-induced thrombocytopenia (HIT) is the transience of thrombocytopenia: type 1 HIT is viewed as early-onset and transient thrombocytopenia, with platelet count recovery despite continuing heparin administration. In contrast, type 2 HIT is viewed as later-onset (i. e., 5 days or later) thrombocytopenia in which it is generally believed that platelet count recovery will not occur unless heparin is discontinued. However, older reports of type 2 HIT sometimes did include the unexpected observation that platelet counts could recover despite continued heparin administration, although without information provided regarding changes in HIT antibody levels in association with platelet count recovery. In recent years, some reports of type 2 HIT have confirmed the observation that platelet count recovery can occur despite continuing heparin administration, with serological evidence of waning levels of HIT antibodies ("seroreversion"). We now report two additional patient cases of type 2 HIT with platelet count recovery despite ongoing therapeutic-dose (1 case) or prophylactic-dose (1 case) heparin administration, in which we demonstrate concomitant waning of HIT antibody levels. We further review the literature describing this phenomenon of HIT antibody seroreversion and platelet count recovery despite continuing heparin administration. Our observations add to the concept that HIT represents a remarkably transient immune response, including sometimes even when heparin is continued.

Mechanisms and biological importance of photon-induced bystander responses. Do they have an impact on low-dose radiation responses

International Nuclear Information System (INIS)

Tomita, Masanori; Maeda, Munetoshi

2015-01-01

Elucidating the biological effect of low linear energy transfer (LET), low-dose and/or low-dose-rate ionizing radiation is essential in ensuring radiation safety. Over the past two decades, non-targeted effects, which are not only a direct consequence of radiation-induced initial lesions produced in cellular DNA but also of intra- and inter-cellular communications involving both targeted and non-targeted cells, have been reported and are currently defining a new paradigm in radiation biology. These effects include radiation-induced adaptive response, low-dose hypersensitivity, genomic instability, and radiation-induced bystander response (RIBR). RIBR is generally defined as a cellular response that is induced in non-irradiated cells that receive bystander signals from directly irradiated cells. RIBR could thus play an important biological role in low-dose irradiation conditions. However, this suggestion was mainly based on findings obtained using high-LET charged-particle radiations. The human population (especially the Japanese, who are exposed to lower doses of radon than the world average) is more frequently exposed to low-LET photons (X-rays or γ-rays) than to high-LET charged-particle radiation on a daily basis. There are currently a growing number of reports describing a distinguishing feature between photon-induced bystander response and high-LET RIBR. In particular, photon-induced by-stander response is strongly influenced by irradiation dose, the irradiated region of the targeted cells, and p53 status. The present review focuses on the photon-induced bystander response, and discusses its impact on the low-dose radiation effect. (author)

Metronidazole-induced encephalopathy in a patient with liver cirrhosis.

Science.gov (United States)

Cheong, Hyeong Cheol; Jeong, Taek Geun; Cho, Young Bum; Yang, Bong Joon; Kim, Tae Hyeon; Kim, Haak Cheoul; Cho, Eun-Young

2011-06-01

Encephalopathy is a disorder characterized by altered brain function, which can be attributed to various causes. Encephalopathy associated with metronidazole administration occurs rarely and depends on the cumulative metronidazole dose, and most patients with this condition recover rapidly after discontinuation of therapy. Because metronidazole is metabolized in the liver and can be transported by the cerebrospinal fluid and cross the blood-brain barrier, it may induce encephalopathy even at a low cumulative dose in patients with hepatic dysfunction. We experienced a patient who showed ataxic gait and dysarthric speech after receiving metronidazole for the treatment of hepatic encephalopathy that was not controlled by the administration of lactulose. The patient was diagnosed as metronidazole-induced encephalopathy, and stopping drug administration resulted in a complete recovery from encephalopathy. This case shows that caution should be exercised when administering metronidazole because even a low dose can induce encephalopathy in patients with liver cirrhosis.

Dose-rate effect of adaptive response of apoptosis and cell cycle progression induced by low-dose ionizing radiation in EL-4 lymphoma cells in vitro

International Nuclear Information System (INIS)

Liu Shuchun; Lu Zhe; Li Yanbo; Kang Shunai; Gong Shouliang; Zhao Wenju

2008-01-01

Objective: To observe the dose-rate effect of adaptive response of apoptosis and cell cycle progression induced by low-dose ionizing radiation in EL-4 lymphoma cells in vitro in order to reveal the possible mechanism of biological effect and adaptive response induced by low dose radiation. Methods: The experiment was divided into D2 (challenging dose), D1 (inductive dose) + D2 and sham-irradiation groups. EL-4 lymphoma cells were irradiated with D1 (75 mGy, 6.25-200.00 mGy·mm -1 ) and D2(1.5 Gy, 287 mGy·min -1 ), the time interval between D1 and D2 was 6 h. The percentage of apoptosis and each cell cycle phase were measured with flow cytometry. Results: When the dose rates of D1 were 6.25-50.00 mGy·min -1 , the percentages of apoptosis in the D1 + D2 group were significantly lower than those in the D2 group (P 0 /G 1 phase cells decreased significantly (P -1 , D2 is 1.5 Gy (287 mGy·min -1 ), and the time interval between D1 and D2 is 6 h, the adaptive response of apoptosis and cell cycle progression in EL-4 lymphoma cells in vitro could be induced. (authors)

Correlation between induced embryo toxicity and absorption dose of enriched uranium in testes

International Nuclear Information System (INIS)

Zhu Shoupeng; Lun Mingyue

1996-01-01

Doses of enriched uranium in testes inducing dominant lethality and skeletal abnormalities in offsprings are estimated. When intra-testicular injection dose is 0.4∼60 μg enriched uranium; from intake to insemination, testes could receive 9.14 x 10 -5 ∼1.38 x 10 -2 Gy radiation dose. Experimental results show that with the increase in the absorption dose, the number of living fetuses in a litter decreases, dominant lethality and skeletal abnormalities rise. It should be noted that relationship between the injected dose (I in μg) and the incidence of dominant skeletal abnormalities (S in %) in the offsprings can be represented by equation: S = 28.84 + 0.84I

Correlation between induced embryo toxicity and absorption dose of enriched uranium in testes

Energy Technology Data Exchange (ETDEWEB)

Shoupeng, Zhu; Mingyue, Lun [Suzhou Medical Coll., JS (China)

1996-08-01

Doses of enriched uranium in testes inducing dominant lethality and skeletal abnormalities in offsprings are estimated. When intra-testicular injection dose is 0.4{approx}60 {mu}g enriched uranium; from intake to insemination, testes could receive 9.14 x 10{sup -5}{approx}1.38 x 10{sup -2} Gy radiation dose. Experimental results show that with the increase in the absorption dose, the number of living fetuses in a litter decreases, dominant lethality and skeletal abnormalities rise. It should be noted that relationship between the injected dose (I in {mu}g) and the incidence of dominant skeletal abnormalities (S in %) in the offsprings can be represented by equation: S = 28.84 + 0.84I.

Extremely low-frequency magnetic fields can impair spermatogenesis recovery after reversible testicular damage induced by heat.

Science.gov (United States)

Tenorio, Bruno Mendes; Ferreira Filho, Moisés Bonifacio Alves; Jimenez, George Chaves; de Morais, Rosana Nogueira; Peixoto, Christina Alves; Nogueira, Romildo de Albuquerque; da Silva Junior, Valdemiro Amaro

2014-06-01

Male infertility is often related to reproductive age couples experiencing fertility-related issues. Men may have fertility problems associated with reversible testicular damage. Considering that men have been increasingly exposed to extremely low-frequency magnetic fields generated by the production, distribution and use of electricity, this study analyzed whether 60 Hz and 1 mT magnetic field exposure may impair spermatogenesis recovery after reversible testicular damage induced by heat shock using rats as an experimental model. Adult male rats were subjected to a single testicular heat shock (HS, 43 °C for 12 min) and then exposed to the magnetic field for 15, 30 and 60 d after HS. Magnetic field exposure during the spermatogenesis recovery induced changes in testis components volume, cell ultrastructure and histomorphometrical parameters. Control animals had a reestablished and active spermatogenesis at 60 d after heat shock, while animals exposed to magnetic field still showed extensive testicular degeneration. Magnetic field exposure did not change the plasma testosterone. In conclusion, extremely low-frequency magnetic field may be harmful to fertility recovery in males affected by reversible testicular damage.

Spontaneous recovery of locomotion induced by remaining fibers after spinal cord transection in adult rats.

Science.gov (United States)

You, Si-Wei; Chen, Bing-Yao; Liu, Hui-Ling; Lang, Bing; Xia, Jie-Lai; Jiao, Xi-Ying; Ju, Gong

2003-01-01

A major issue in analysis of experimental results after spinal cord injury is spontaneous functional recovery induced by remaining nerve fibers. The authors investigated the relationship between the degree of locomotor recovery and the percentage and location of the fibers that spared spinal cord transection. The spinal cords of 12 adult rats were transected at T9 with a razor blade, which often resulted in sparing of nerve fibers in the ventral spinal cord. The incompletely-transected animals were used to study the degree of spontaneous recovery of hindlimb locomotion, evaluated with the BBB rating scale, in correlation to the extent and location of the remaining fibers. Incomplete transection was found in the ventral spinal cord in 42% of the animals. The degree of locomotor recovery was highly correlated with the percentage of the remaining fibers in the ventral and ventrolateral funiculi. In one of the rats, 4.82% of remaining fibers in unilateral ventrolateral funiculus were able to sustain a certain recovery of locomotion. Less than 5% of remaining ventrolateral white matter is sufficient for an unequivocal motor recovery after incomplete spinal cord injury. Therefore, for studies with spinal cord transection, the completeness of sectioning should be carefully checked before any conclusion can be reached. The fact that the degree of locomotor recovery is correlated with the percentage of remaining fibers in the ventrolateral spinal cord, exclusive of most of the descending motor tracts, may imply an essential role of propriospinal connections in the initiation of spontaneous locomotor recovery.

Molecular hydrogen reduces LPS-induced neuroinflammation and promotes recovery from sickness behaviour in mice.

Directory of Open Access Journals (Sweden)

Stefan Spulber

Full Text Available Molecular hydrogen has been shown to have neuroprotective effects in mouse models of acute neurodegeneration. The effect was suggested to be mediated by its free-radical scavenger properties. However, it has been shown recently that molecular hydrogen alters gene expression and protein phosphorylation. The aim of this study was to test whether chronic ad libitum consumption of molecular hydrogen-enriched electrochemically reduced water (H-ERW improves the outcome of lipopolysaccharide (LPS-induced neuroinflammation. Seven days after the initiation of H-ERW treatment, C57Bl/6 mice received a single injection of LPS (0.33 mg/kg i.p. or an equivalent volume of vehicle. The LPS-induced sickness behaviour was assessed 2 h after the injection, and recovery was assessed by monitoring the spontaneous locomotor activity in the homecage for 72 h after the administration of LPS. The mice were killed in the acute or recovery phase, and the expression of pro- and antiinflammatory cytokines in the hippocampus was assessed by real-time PCR. We found that molecular hydrogen reduces the LPS-induced sickness behaviour and promotes recovery. These effects are associated with a shift towards anti-inflammatory gene expression profile at baseline (downregulation of TNF- α and upregulation of IL-10. In addition, molecular hydrogen increases the amplitude, but shortens the duration and promotes the extinction of neuroinflammation. Consistently, molecular hydrogen modulates the activation and gene expression in a similar fashion in immortalized murine microglia (BV-2 cell line, suggesting that the effects observed in vivo may involve the modulation of microglial activation. Taken together, our data point to the regulation of cytokine expression being an additional critical mechanism underlying the beneficial effects of molecular hydrogen.

Frequencies of aneuploidy and dominant lethal mutations in young female mice induced by low dose γ-rays

International Nuclear Information System (INIS)

Yao Suyan; Zhang Chaoyang; Dai Lianlian; Gao Changwen

1991-01-01

Relationship between aneuploidy, dominant lethal mutations and doses in young feral mice induced by low dose γ-rays was examined. The results suggest that the frequencies of aneuploidy of embryos increased at 0.15 Gy, but increases at over 0.50 Gy after irradiation in groups. The frequencies of aneuploidy and dominant lethal mutations increased with increasing doses and fitted linear relationship. This dose-response relationship of trisomic was not significant. The frequency of dominant lethal mutations induced by 60 Co γ irradiation is 5.59%. The effect of dominant lethal mutation is higher than that of the aneuploidy

Diethylene glycol-induced toxicities show marked threshold dose response in rats

Energy Technology Data Exchange (ETDEWEB)

Landry, Greg M., E-mail: Landry.Greg@mayo.edu [Department of Pharmacology, Toxicology, & Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA (United States); Dunning, Cody L., E-mail: cdunni@lsuhsc.edu [Department of Pharmacology, Toxicology, & Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA (United States); Abreo, Fleurette, E-mail: fabreo@lsuhsc.edu [Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, LA (United States); Latimer, Brian, E-mail: blatim@lsuhsc.edu [Department of Pharmacology, Toxicology, & Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA (United States); Orchard, Elysse, E-mail: eorcha@lsuhsc.edu [Department of Pharmacology, Toxicology, & Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA (United States); Division of Animal Resources, Louisiana State University Health Sciences Center, Shreveport, LA (United States); McMartin, Kenneth E., E-mail: kmcmar@lsuhsc.edu [Department of Pharmacology, Toxicology, & Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA (United States)

2015-02-01

Diethylene glycol (DEG) exposure poses risks to human health because of widespread industrial use and accidental exposures from contaminated products. To enhance the understanding of the mechanistic role of metabolites in DEG toxicity, this study used a dose response paradigm to determine a rat model that would best mimic DEG exposure in humans. Wistar and Fischer-344 (F-344) rats were treated by oral gavage with 0, 2, 5, or 10 g/kg DEG and blood, kidney and liver tissues were collected at 48 h. Both rat strains treated with 10 g/kg DEG had equivalent degrees of metabolic acidosis, renal toxicity (increased BUN and creatinine and cortical necrosis) and liver toxicity (increased serum enzyme levels, centrilobular necrosis and severe glycogen depletion). There was no liver or kidney toxicity at the lower DEG doses (2 and 5 g/kg) regardless of strain, demonstrating a steep threshold dose response. Kidney diglycolic acid (DGA), the presumed nephrotoxic metabolite of DEG, was markedly elevated in both rat strains administered 10 g/kg DEG, but no DGA was present at 2 or 5 g/kg, asserting its necessary role in DEG-induced toxicity. These results indicate that mechanistically in order to produce toxicity, metabolism to and significant target organ accumulation of DGA are required and that both strains would be useful for DEG risk assessments. - Highlights: • DEG produces a steep threshold dose response for kidney injury in rats. • Wistar and F-344 rats do not differ in response to DEG-induced renal injury. • The dose response for renal injury closely mirrors that for renal DGA accumulation. • Results demonstrate the importance of DGA accumulation in producing kidney injury.

Radiation effect and response of DNA synthesis in lymphocytes induced by low dose irradiation

International Nuclear Information System (INIS)

Zhao Yujie; Su Liaoyuan; Zou Huawei; Kong Xiangrong

1999-01-01

The ability of DNA synthesis in lymphocytes were measured by using 3 H-TdR incorporation method. This method was used to observe the damage of lymphocytes irradiated by several challenge doses (0.5-0.8 Gy) and adaptive response induced by previous low dose irradiation. The results show that DNA synthesis was inhibited by challenge dose of radiation and was adapted by previous 0.048 Gy irradiation

Progress in structure recovery from low dose exposures: Mixed molecular adsorption, exploitation of symmetry and reconstruction from the minimum signal level

Energy Technology Data Exchange (ETDEWEB)

Kramberger, C., E-mail: Christian.Kramberger-Kaplan@univie.ac.at; Meyer, J.C., E-mail: Jannik.Meyer@univie.ac.at

2016-11-15

We investigate the recovery of structures from large-area, low dose exposures that distribute the dose over many identical copies of an object. The reconstruction is done via a maximum likelihood approach that does neither require to identify nor align the individual particles. We also simulate small molecular adsorbates on graphene and demonstrate the retrieval of images with atomic resolution from large area and extremely low dose raw data. Doses as low as 5 e{sup −}/Å{sup 2} are sufficient if all symmetries (translations, rotations and mirrors) of the supporting membrane are exploited to retrieve the structure of individual adsorbed molecules. We compare different optimization schemes, consider mixed molecules and adsorption sites, and requirements on the amount of data. We further demonstrate that the maximum likelihood approach is only count limited by requiring at least three independent counts per entity. Finally, we demonstrate that the approach works with real experimental data and in the presence of aberrations.

Studies on chromosome aberrations induced in human lymphocytes by very low-dose exposure to tritium

International Nuclear Information System (INIS)

Hori, T.; Moriya, Junko; Nakai, Sayaka

1978-01-01

Assessment of potential hazard from environmental tritium to man becomes very important with increasing the development of nuclear-power industry. However, little data are available as to the determination on the genetic effect of tritium especially at the low levels. The object of the present study is to obtain quantitative data for chromosome aberrations in human lymphocytes, as an indicator for genetic risk estimation, induced by tritium at very low dose levels. Leukocyte cultures of human peripheral blood were chronically exposed for 48h to tritiated water and 3 H-thymidine using a wide range of tritium doses, and aberrations in lymphocyte chromosomes at the first metaphases were examined. In the experimental conditions, the types of aberrations induced by radiation emitted from both tritiated water and 3 H-thymidine were mostly chromatid types, such as chromatid gaps and deletions. The dose-response relations for chromatid breaks per cell exhibited unusual dose-dependency in both cases. It was demonstrated that at higher dose range the yields of chromatid breaks increased linearly with dose, while those at lower dose range were significantly higher than would be expected by a downward extraporation from the linear relation. Partial-hit or partial-target kinetics events appeared at very low dose exposure. (author)

Effects of Whole-Body Cryotherapy vs. Far-Infrared vs. Passive Modalities on Recovery from Exercise-Induced Muscle Damage in Highly-Trained Runners

Science.gov (United States)

Hausswirth, Christophe; Louis, Julien; Bieuzen, François; Pournot, Hervé; Fournier, Jean; Filliard, Jean-Robert; Brisswalter, Jeanick

2011-01-01

Enhanced recovery following physical activity and exercise-induced muscle damage (EIMD) has become a priority for athletes. Consequently, a number of post-exercise recovery strategies are used, often without scientific evidence of their benefits. Within this framework, the purpose of this study was to test the efficacy of whole body cryotherapy (WBC), far infrared (FIR) or passive (PAS) modalities in hastening muscular recovery within the 48 hours after a simulated trail running race. In 3 non-adjoining weeks, 9 well-trained runners performed 3 repetitions of a simulated trail run on a motorized treadmill, designed to induce muscle damage. Immediately (post), post 24 h, and post 48 h after exercise, all participants tested three different recovery modalities (WBC, FIR, PAS) in a random order over the three separate weeks. Markers of muscle damage (maximal isometric muscle strength, plasma creatine kinase [CK] activity and perceived sensations [i.e. pain, tiredness, well-being]) were recorded before, immediately after (post), post 1 h, post 24 h, and post 48 h after exercise. In all testing sessions, the simulated 48 min trail run induced a similar, significant amount of muscle damage. Maximal muscle strength and perceived sensations were recovered after the first WBC session (post 1 h), while recovery took 24 h with FIR, and was not attained through the PAS recovery modality. No differences in plasma CK activity were recorded between conditions. Three WBC sessions performed within the 48 hours after a damaging running exercise accelerate recovery from EIMD to a greater extent than FIR or PAS modalities. PMID:22163272

Effects of whole-body cryotherapy vs. far-infrared vs. passive modalities on recovery from exercise-induced muscle damage in highly-trained runners.

Directory of Open Access Journals (Sweden)

Christophe Hausswirth

Full Text Available Enhanced recovery following physical activity and exercise-induced muscle damage (EIMD has become a priority for athletes. Consequently, a number of post-exercise recovery strategies are used, often without scientific evidence of their benefits. Within this framework, the purpose of this study was to test the efficacy of whole body cryotherapy (WBC, far infrared (FIR or passive (PAS modalities in hastening muscular recovery within the 48 hours after a simulated trail running race. In 3 non-adjoining weeks, 9 well-trained runners performed 3 repetitions of a simulated trail run on a motorized treadmill, designed to induce muscle damage. Immediately (post, post 24 h, and post 48 h after exercise, all participants tested three different recovery modalities (WBC, FIR, PAS in a random order over the three separate weeks. Markers of muscle damage (maximal isometric muscle strength, plasma creatine kinase [CK] activity and perceived sensations [i.e. pain, tiredness, well-being] were recorded before, immediately after (post, post 1 h, post 24 h, and post 48 h after exercise. In all testing sessions, the simulated 48 min trail run induced a similar, significant amount of muscle damage. Maximal muscle strength and perceived sensations were recovered after the first WBC session (post 1 h, while recovery took 24 h with FIR, and was not attained through the PAS recovery modality. No differences in plasma CK activity were recorded between conditions. Three WBC sessions performed within the 48 hours after a damaging running exercise accelerate recovery from EIMD to a greater extent than FIR or PAS modalities.

Immunologic mechanism of the suppressive effect of low dose radiation on thymic lymphoma induced by radiation

International Nuclear Information System (INIS)

Li Xiujuan; Yang Ying; Li Xiuyi; Liu Shuzheng

1999-01-01

To study immunologic mechanism of the suppressive effect of low dose radiation (LDR) on thymic lymphoma (TL) induced by high dose radiation (HDR). The authors adopted the model that C57BL/6J mice were administered whole body irradiation with 1.75 Gy X-rays one time every week for 4 weeks to induce TL. It was examined that splenic NK cytotoxic activity, IL-2 and γ-IFN secretion activity, peritoneal macrophage phagocytosis and its TNF-α secretion activity in mice with different dose 1 month after irradiation. The results showed that all the immunologic functions mentioned above in mice given 75 mGy 12 h before 1.75 Gy every time were higher than that in mice given only 1.75 Gy, and approached to the sham-irradiation mice. It suggested that the suppressive effect of LDR on TL induced by HDR may be related to the adaptive response induced by LDR and decreasing immunological functions damage caused by HDR

Alzheimer ’s Disease: Possible Mechanisms Behind Neurohormesis Induced by Exposure to Low Doses of Ionizing Radiation

Science.gov (United States)

Bevelacqua, J.J.; Mortazavi, S.M.J.

2018-01-01

In 2016, scientists reported that human exposure to low doses of ionizing radiation (CT scans of the brain) might relieve symptoms of both Alzheimer’s disease (AD) and Parkinson disease (PD). The findings were unbelievable for those who were not familiar with neurohormesis. X-ray stimulation of the patient’s adaptive protection systems against neurodegenerative diseases was the mechanism proposed by those authors. Now, some more recent studies performed in the field of neurobiological research confirm that low levels of stress can produce protective responses against the pathogenic processes. This paper outlines possible protective consequences of LDR in preventing the pathogenesis of AD through mechanisms such as restoring the myelin sheath and preventing neurodegeneration caused by oxidative stress. Focal demyelination is frequently reported in the proximity of beta-amyloid plaques within neocortex. Extracellular accumulation of amyloid is among well-characterized pathological changes in AD. It should be noted that LDR has been shown to contribute to the regeneration and functional recovery after transverse peripheral nerve injury (through inducing increased production of VEGF and GAP-43), which advances both the axonal regeneration and myelination. Another mechanism which is possibly involved is preventing neurodegeneration caused by oxidative stress. While high doses can induce reactive oxygen species (ROS) formation, oxidative stress and neuro-inflammation, substantial evidence now indicates that LDR can mitigate tissue damage through antioxidant defenses. Although adult neurogenesis has been reported to be beneficial for the regeneration of nervous system, some studies demonstrate that neurogenesis increases in AD brains. In spite of these reports, cellular therapy is introduced as a promising strategy for AD, and hence, LDR can affect the proliferation and differentiation of neural stem cells. Although such mechanisms are not fully known yet, it is hoped

Study of the effect of dose-rate on radiation-induced damage to human erythrocytes

Energy Technology Data Exchange (ETDEWEB)

Krokosz, Anita [Department of Molecular Biophysics, University of Lodz, Banacha 12/16, Lodz (Poland)]. E-mail: krokosz@biol.uni.lodz.pl; Koziczak, Renata [Department of Molecular Biophysics, University of Lodz, Banacha 12/16, Lodz (Poland); Gonciarz, Marta [Department of Molecular Biophysics, University of Lodz, Banacha 12/16, Lodz (Poland); Szweda-Lewandowska, Zofia [Department of Molecular Biophysics, University of Lodz, Banacha 12/16, Lodz (Poland)

2006-01-15

Human erythrocytes suspended in an isotonic Na-phosphate buffer, pH 7.4 (hematocrit of 2%) were irradiated with {gamma}-rays at three dose-rates of 66.7, 36.7, 25 Gy min{sup -1} in order to investigate the influence of the dose-rate on radiation-induced membrane damage, hemoglobin oxidation and loss of reduced glutathione. The obtained results showed that such processes as erythrocyte hemolysis, lipid and protein destruction depend on the radiation dose-rate. The parameter values describing these processes showed an inverse dose-rate effect.

Study of the effect of dose-rate on radiation-induced damage to human erythrocytes

International Nuclear Information System (INIS)

Krokosz, Anita; Koziczak, Renata; Gonciarz, Marta; Szweda-Lewandowska, Zofia

2006-01-01

Human erythrocytes suspended in an isotonic Na-phosphate buffer, pH 7.4 (hematocrit of 2%) were irradiated with γ-rays at three dose-rates of 66.7, 36.7, 25 Gy min -1 in order to investigate the influence of the dose-rate on radiation-induced membrane damage, hemoglobin oxidation and loss of reduced glutathione. The obtained results showed that such processes as erythrocyte hemolysis, lipid and protein destruction depend on the radiation dose-rate. The parameter values describing these processes showed an inverse dose-rate effect

Mechanisms of Low Dose Radiation-induced T helper Cell Function

International Nuclear Information System (INIS)

Gridley, Daila S.

2008-01-01

Exposure to radiation above levels normally encountered on Earth can occur during wartime, accidents such as those at Three Mile Island and Chernobyl, and detonation of 'dirty bombs' by terrorists. Relatively high levels of radiation exposure can also occur in certain occupations (low-level waste sites, nuclear power plants, nuclear medicine facilities, airline industry, and space agencies). Depression or dysfunction of the highly radiosensitive cells of the immune system can lead to serious consequences, including increased risk for infections, cancer, hypersensitivity reactions, poor wound healing, and other pathologies. The focus of this research was on the T helper (Th) subset of lymphocytes that secrete cytokines (proteins), and thus control many actions and interactions of other cell types that make up what is collectively known as the immune system. The Department of Energy (DOE) Low Dose Radiation Program is concerned with mechanisms altered by exposure to high energy photons (x- and gamma-rays), protons and electrons. This study compared, for the first time, the low-dose effects of two of these radiation forms, photons and protons, on the response of Th cells, as well as other cell types with which they communicate. The research provided insights regarding gene expression patterns and capacity to secrete potent immunostimulatory and immunosuppressive cytokines, some of which are implicated in pathophysiological processes. Furthermore, the photon versus proton comparison was important not only to healthy individuals who may be exposed, but also to patients undergoing radiotherapy, since many medical centers in the United States, as well as worldwide, are now building proton accelerators. The overall hypothesis of this study was that whole-body exposure to low-dose photons (gamma-rays) will alter CD4+ Th cell function. We further proposed that exposure to low-dose proton radiation will induce a different pattern of gene and functional changes compared to

Endurance exercise induces mRNA expression of oxidative enzymes in human skeletal muscle late in recovery

DEFF Research Database (Denmark)

Leick, Lotte; Plomgaard, Peter S.; Grønløkke, L.

2010-01-01

exercise. To test the hypothesis that mRNA expression of many oxidative enzymes is up-regulated late in recovery (10-24 h) after exercise, male subjects (n=8) performed a 90-min cycling exercise (70% VO(2-max)), with muscle biopsies obtained before exercise (pre), and after 10, 18 and 24 h of recovery....... The mRNA expression of carnitine-palmitoyltransferase (CPT)I, CD36, 3-hydroxyacyl-CoA-dehydrogenase (HAD), cytochrome (Cyt)c, aminolevulinate-delta-synthase (ALAS)1 and GLUT4 was 100-200% higher at 10-24 h of recovery from exercise than in a control trial. Exercise induced a 100-300% increase...... in peroxisome proliferator-activated receptor gamma co-activator (PGC)-1alpha, citrate synthase (CS), CPTI, CD36, HAD and ALAS1 mRNA contents at 10-24 h of recovery relative to before exercise. No protein changes were detected in Cytc, ALAS1 or GLUT4. This shows that mRNA expression of several training...

The influence of non-equilibrium fluctuations on radiation damage and recovery of metals under irradiation

International Nuclear Information System (INIS)

Dubinko, V.I.; Klepikov, V.F.

2007-01-01

In the conventional theory of radiation damage, it is assumed that the main effect of irradiation is due to formation of Frenkel pairs of vacancies and self-interstitial atoms (SIAs) and their clusters. The difference in absorption of vacancies and SIAs by primary or radiation-induced extended defects (EDs) is thought to be the main reason of microstructural evolution under irradiation. On the other hand, the recovery of radiation damage is thought to be driven exclusively by thermal fluctuations resulting in the vacancy evaporation from voids (void annealing) or dislocations (thermal creep) and in the fluctuation-driven overcoming of obstacles by gliding dislocations (plastic strain). However, these recovery mechanisms can be efficient only at sufficiently high temperatures. At lower irradiation temperatures, the main driving force of the recovery processes may be due to nonequilibrium fluctuations of energy states of the atoms surrounding EDs arising as a result of scattering of radiation-induced excitations of atomic and electronic structure at EDs. In the present paper, the mechanisms of nonequilibrium fluctuations that result in such phenomena as the void shrinkage under irradiation at low temperatures (or high dose rates), irradiation creep and irradiation-induced increase of plasticity under sub-threshold irradiation was considered

Environmental enrichment induces behavioral recovery and enhanced hippocampal cell proliferation in an antidepressant-resistant animal model for PTSD.

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Hendrikus Hendriksen

Full Text Available BACKGROUND: Post traumatic stress disorder (PTSD can be considered the result of a failure to recover after a traumatic experience. Here we studied possible protective and therapeutic aspects of environmental enrichment (with and without a running wheel in Sprague Dawley rats exposed to an inescapable foot shock procedure (IFS. METHODOLOGY/PRINCIPAL FINDINGS: IFS induced long-lasting contextual and non-contextual anxiety, modeling some aspects of PTSD. Even 10 weeks after IFS the rats showed reduced locomotion in an open field. The antidepressants imipramine and escitalopram did not improve anxiogenic behavior following IFS. Also the histone deacetylase (HDAC inhibitor sodium butyrate did not alleviate the IFS induced immobility. While environmental enrichment (EE starting two weeks before IFS did not protect the animals from the behavioral effects of the shocks, exposure to EE either immediately after the shock or one week later induced complete recovery three weeks after IFS. In the next set of experiments a running wheel was added to the EE to enable voluntary exercise (EE/VE. This also led to reduced anxiety. Importantly, this behavioral recovery was not due to a loss of memory for the traumatic experience. The behavioral recovery correlated with an increase in cell proliferation in hippocampus, a decrease in the tissue levels of noradrenalin and increased turnover of 5-HT in prefrontal cortex and hippocampus. CONCLUSIONS/SIGNIFICANCE: This animal study shows the importance of (physical exercise in the treatment of psychiatric diseases, including post-traumatic stress disorder and points out the possible role of EE in studying the mechanism of recovery from anxiety disorders.

Dose-dependent effects of celecoxib on CB-1 agonist-induced antinociception in the mice

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Mohammad Reza Zarrindast

2009-04-01

Full Text Available "nObjective: Endocannabinoid produce analgesia that is comparable which of opioids. The mechanism of antinociceptive effects of (∆ - 9 tetrahydrocannabinol (THC is suggested to be through cyclooxygenase (COX pathway. In the present work, the effect of two extreme dose ranges of celecoxib (mg/kg and ng/kg, a cyclooxygenase-2 (COX-2 antagonist, on arachidonylcyclopropylamide (ACPA, a selective CB1 agonist induced antinociception in mice was examined. "nMethods: We have investigated the interaction between celecoxib, at the doses of mg/kg (50, 100, 200 and 400 i.p.  and ultra low dose (ULD (25 and 50 ng/kg, i.p., on the antinociceptive effect of intracerebroventricular (i.c.v. administration of ACPA (0.004, 0.0625 and 1 μg/mice, using formalin test in mice. "nResults: I.C.V. administration of ACPA induced antinociception. Intraperitoneal administration of celecoxib (mg/kg and its ULD (ng/kg attenuated and potentiated, ACPA antinociceptive effects, respectively. "nConclusion: It is concluded that the mg/kg doses of COX-2 antagonist showed opposite effects compare to the ultra-low dose of the drug.

Early application of tail nerve electrical stimulation-induced walking training promotes locomotor recovery in rats with spinal cord injury.

Science.gov (United States)

Zhang, S-X; Huang, F; Gates, M; Shen, X; Holmberg, E G

2016-11-01

This is a randomized controlled prospective trial with two parallel groups. The objective of this study was to determine whether early application of tail nerve electrical stimulation (TANES)-induced walking training can improve the locomotor function. This study was conducted in SCS Research Center in Colorado, USA. A contusion injury to spinal cord T10 was produced using the New York University impactor device with a 25 -mm height setting in female, adult Long-Evans rats. Injured rats were randomly divided into two groups (n=12 per group). One group was subjected to TANES-induced walking training 2 weeks post injury, and the other group, as control, received no TANES-induced walking training. Restorations of behavior and conduction were assessed using the Basso, Beattie and Bresnahan open-field rating scale, horizontal ladder rung walking test and electrophysiological test (Hoffmann reflex). Early application of TANES-induced walking training significantly improved the recovery of locomotor function and benefited the restoration of Hoffmann reflex. TANES-induced walking training is a useful method to promote locomotor recovery in rats with spinal cord injury.

After low and high dose-rate interstitial brachytherapy followed by IMRT radiotherapy for intermediate and high risk prostate cancer

International Nuclear Information System (INIS)

Nakamura, Satoshi; Murakami, Naoya; Inaba, Koji; Wakita, Akihisa; Kobayashi, Kazuma; Takahashi, Kana; Okamoto, Hiroyuki; Umezawa, Rei; Morota, Madoka; Sumi, Minako; Igaki, Hiroshi; Ito, Yoshinori; Itami, Jun

2016-01-01

The study aimed to compare urinary symptoms in patients with clinically localized prostate cancer after a combination of either low-dose-rate or high-dose-rate interstitial brachytherapy along with intensity-modulated radiation therapy (LDR-ISBT + IMRT or HDR-ISBT + IMRT). From June 2009 to April 2014, 16 and 22 patients were treated with LDR-ISBT + IMRT and HDR-ISBT + IMRT, respectively. No patient from these groups was excluded from this study. The prescribed dose of LDR-ISBT, HDR-ISBT, and IMRT was 115 Gy, 20 Gy in 2 fractions, and 46 Gy in 23 fractions, respectively. Obstructive and irritative urinary symptoms were assessed by the International Prostate Symptom Score (IPSS) examined before and after treatments. After ISBT, IPSS was evaluated in the 1st and 4th weeks, then every 2–3 months for the 1st year, and every 6 months thereafter. The median follow-up of the patients treated with LDR-ISBT + IMRT and HDR-ISBT + IMRT was 1070.5 days and 1048.5 days, respectively (p = 0.321). The IPSS-increment in the LDR-ISBT + IMRT group was greater than that in the HDR-ISBT + IMRT between 91 and 180 days after ISBT (p = 0.015). In the LDR-ISBT + IMRT group, the IPSS took longer time to return to the initial level than in the HDR-ISBT + IMRT group (in LDR-ISBT + IMRT group, the recovery time was 90 days later). The dose to urethra showed a statistically significant association with the IPSS-increment in the irritative urinary symptoms (p = 0.011). Clinical outcomes were comparable between both the groups. Both therapeutic modalities are safe and well suited for patients with clinically localized prostate cancer; however, it took patients longer to recover from LDR-ISBT + IMRT than from HDR-ISBT + IMRT. It is possible that fast dose delivery induced early symptoms and early recovery, while gradual dose delivery induced late symptoms and late recovery. Urethral dose reductions were associated with small increments in IPSS

Impact-Induced Muscle Damage and Contact-Sport: Aetiology, Effects on Neuromuscular Function and Recovery, and the Modulating Effects of Adaptation and Recovery Strategies.

Science.gov (United States)

Naughton, Mitchell; Miller, Joanna; Slater, Gary J

2017-11-28

Athletes involved in contact-sports are habitually exposed to skeletal muscle damage as part of their training and performance environments. This often leads to exercise-induced muscle damage (EIMD) resulting from repeated eccentric and/or high-intensity exercise, and impact-induced muscle damage (IIMD) resulting from collisions with opponents and the playing surface. Whilst EIMD has been an area of extensive investigation, IIMD has received comparatively little research, with the magnitude and timeframe of alterations following IIMD not presently well understood. It is currently thought that EIMD occurs through an overload of mechanical stress causing ultrastructural damage to the cellular membrane constituents. Damage leads to compromised ability to produce force which manifest immediately and persist for up to 14 days following exercise exposure. IIMD has been implicated in attenuated neuromuscular performance and recovery with inflammatory process implicated, although the underlying time course remains unclear. Exposure to EIMD leads to an adaptation to subsequent exposures, a phenomenon known as the repeated-bout effect. An analogous adaptation has been suggested to occur following IIMD, however, to date this contention remains equivocal. Whilst a considerable body of research has explored the efficacy of recovery strategies following EIMD, strategies promoting recovery from IIMD are limited to investigations using animal contusion models. Strategies such as cryotherapy and antioxidant supplementation, which focus on attenuating the secondary inflammatory response may provide additional benefit in IIMD and are explored herein. Further research is required to firstly establish a model of generating IIMD and then explore broader areas around IIMD in athletic populations.

Search for the lowest irradiation dose from literatures on radiation-induced cancer in uterus

International Nuclear Information System (INIS)

Yoshizawa, Yasuo; Kusama, Tomoko

1975-01-01

A survey of past case reports on radiation-induced cancer of the uterus was carried out with the main object of finding the lowest irradiation dose. Search of literature published since 1912 revealed 548 cases of radiation-induced cancer of the uterus. All of these cases of radiation-induced cancer had received radiation for the treatment of non-malignant disease. The primary gynecological conditions which were the object of radiation therapy were functional bleeding, endometrial hyperplasia, myoma, endometritis, and polyps. The lowest irradiation dose was estimated at 1000-1450 rad in the case of external X-ray irradiation, and 100 mg.hr for intrauterine radium therapy, which corresponds to 100-1000 rad. It was noted that were more cases of corpus cancer than cervical cancer. Histopathological findings of radiation-induced uterine cancer were carcinoma, sarcoma, and mixed mesodermal tumors. The latent period was distributed in the range of 1 to 40 years, with the average of 10.1 years. (auth.)

Experimental Study of the Lead Tungstate Scintillator Proton-Induced Damage and Recovery

CERN Document Server

Auffray, Etiennette; Singovski , A

2011-01-01

Lead tungstate (PbWO4, or PWO) scintillating crystals are used by two of the four experiments at the Large Hadron Collider (LHC): 75848 in CMS and 17920 in ALICE. For the CMS electromagnetic calorimeter, one of the most important crystal properties is its radiation hardness. With the increase of luminosity, the radiation level will increase drastically, particularly in the high pseudorapidity regions of the calorimeter. Beside the effects of color-centre formation caused by gamma-radiation, additional measurable effect originated by hadron irradiation could appear, which will further deteriorate the optical transmission of the crystals and therefore their efficiency. In this paper, we will present results of the proton-induced damage in PWO and a study of optical transmission recovery at different temperatures and under different light-induced "bleaching" conditions for proton-irradiated crystals.

Dose-response relationship of γ-ray-induced reciprocal translocations at low doses in spermatogonia of the crab-eating monkey (Macaca fascicularis)

International Nuclear Information System (INIS)

Matsuda, Yoichi; Tobari, Izuo; Yamagiwa, Junji; Utsugi, Toyoko; Okamoto, Masanori; Nakai, Sayaka

1985-01-01

The yield of translocations induced by acute γ-irradiation at low doses in the crab-eating monkey's (Macaca fascicularis) spermatogonia was examined. Over the low dose range from 0 to 1 Gy, the dose-response relationship for translocation yield was a linear one. To estimate the sensitivity to the induction of translocations in the crab-eating monkey's spermatogonia, the slope of the regression line was compared with those in other mammalian species. Consequently, over the low dose range below 1 Gy, the sensitivity of the crab-eating monkey's spermatogonia to translocation induction was similar to several mammalian species, the mouse, Chinese hamster, and the rabbit, but significantly higher than that of the rhesus monkey and lower than that of the marmoset. (Auth.)

Low-Dose Ribavirin Treatments Attenuate Neuroinflammatory Activation of BV-2 Cells by Interfering with Inducible Nitric Oxide Synthase

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Iva Bozic

2015-01-01

Full Text Available Microglia play a key role in defending central nervous system from various internal and external threats. However, their excessive and/or chronic activation is associated with deleterious effects in a variety of neurodegenerative diseases. Previously, we have shown that ribavirin when applied in clinically relevant dosage (10 μM modulates activated microglia in complex fashion inducing both anti- and proinflammatory effects, simultaneously causing cytotoxicity. Here, we examined potential of low-dose ribavirin (0.1 and 1 μM to modulate activated BV-2 microglia. Morphological and functional activation of BV-2 cells was achieved with lipopolysaccharide (LPS stimulation. Our results demonstrated that low-dose ribavirin did not induce cell death, while 10 μM ribavirin promoted LPS induced apoptosis. We determined that 1 μM ribavirin was equally efficient in deactivation of LPS induced morphological changes as 10 μM ribavirin treatment. Ribavirin showed halfway success in reducing markers of functional activation of microglia. Namely, none of the doses had effect on LPS triggered production of proinflammatory cytokine tumor necrosis factor alpha. On the other hand, low-dose ribavirin proved its effectiveness in reduction of another inflammatory mediator, nitric oxide, by inhibiting inducible form of nitric oxide synthase. Our results imply that low-dose ribavirin may alleviate nitrosative stress during neuroinflammation.

Low-Dose Ribavirin Treatments Attenuate Neuroinflammatory Activation of BV-2 Cells by Interfering with Inducible Nitric Oxide Synthase

Science.gov (United States)

Bozic, Iva; Savic, Danijela; Jovanovic, Marija; Bjelobaba, Ivana; Laketa, Danijela; Nedeljkovic, Nadezda; Stojiljkovic, Mirjana; Pekovic, Sanja; Lavrnja, Irena

2015-01-01

Microglia play a key role in defending central nervous system from various internal and external threats. However, their excessive and/or chronic activation is associated with deleterious effects in a variety of neurodegenerative diseases. Previously, we have shown that ribavirin when applied in clinically relevant dosage (10 μM) modulates activated microglia in complex fashion inducing both anti- and proinflammatory effects, simultaneously causing cytotoxicity. Here, we examined potential of low-dose ribavirin (0.1 and 1 μM) to modulate activated BV-2 microglia. Morphological and functional activation of BV-2 cells was achieved with lipopolysaccharide (LPS) stimulation. Our results demonstrated that low-dose ribavirin did not induce cell death, while 10 μM ribavirin promoted LPS induced apoptosis. We determined that 1 μM ribavirin was equally efficient in deactivation of LPS induced morphological changes as 10 μM ribavirin treatment. Ribavirin showed halfway success in reducing markers of functional activation of microglia. Namely, none of the doses had effect on LPS triggered production of proinflammatory cytokine tumor necrosis factor alpha. On the other hand, low-dose ribavirin proved its effectiveness in reduction of another inflammatory mediator, nitric oxide, by inhibiting inducible form of nitric oxide synthase. Our results imply that low-dose ribavirin may alleviate nitrosative stress during neuroinflammation. PMID:26413464

Comparison of neostigmine induced reversal of vecuronium in normal weight, overweight and obese female patients

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Shilpa Bhimasen Joshi

2015-01-01

Full Text Available Background and Aims: Obese patients are more vulnerable to residual neuromuscular block (NMB and its associated complications in the post-operative period. This study was carried out to compare neostigmine induced reversal of vecuronium in normal weight, overweight and obese female patients, objectively using neuromuscular (NM monitoring. Methods: Twenty female patients each belonging to normal weight, overweight and obese, based on body mass index, requiring general anaesthesia were recruited for this prospective cross sectional study. NMB was induced with vecuronium (0.1 mg/kg dose based on patient′s real body weight (RBW and monitored using acceleromyographic train of four (TOF. All patients received neostigmine 40 μg/kg and glycopyrrolate 10 μg/kg at 25% of spontaneous recovery of first twitch height (T1 of TOF (DUR 25% and were allowed to recover to TOF ratio of 0.9. Statistical analysis was done using analysis of variance test. Results: Recovery of TOF ratio to 0.5 was comparable in all three groups. Recovery of TOF ratio to 0.7 was delayed in obese (9.82 ± 3.21 min compared with normal weight group (7.50 ± 2.52 min. Recovery of TOF to 0.9 was significantly delayed in both overweight (12.18 ± 4.29 min and obese patients (13.78 ± 4.30 min. DUR 25% was significantly longer in overweight (mean, standard deviation [range]; 30.10 [19-40 min] and obese (28.8 [12-45 min] compared with normal weight patients (22.75 [16-30 min]. Conclusion: In overweight and obese patients, when vecuronium induction dose is based on RBW, neostigmine induced recovery of NMB is delayed in late phases (TOF 0.7-0.9, which may result in vulnerability for associated complications of incomplete recovery. Ensuring safe recovery thus requires objective NM monitoring.

Sugammadex and neostigmine dose-finding study for reversal of residual neuromuscular block at a train-of-four ratio of 0.2 (SUNDRO20)†,.

Science.gov (United States)

Kaufhold, N; Schaller, S J; Stäuble, C G; Baumüller, E; Ulm, K; Blobner, M; Fink, H

2016-02-01

The aim of this dose-finding study was to evaluate the dose-response relationship of sugammadex and neostigmine to reverse a commonly observed level of incomplete recovery from rocuronium-induced neuromuscular block, that is, a train-of-four ratio (TOFR) ≥0.2. Ninety-nine anaesthetized patients received rocuronium 0.6 mg kg(-1) i.v. for tracheal intubation and, if necessary, incremental doses of 0.1-0.2 mg kg(-1). Neuromuscular monitoring was performed by calibrated electromyography. Once the TOFR recovered to 0.2, patients were randomized to receive sugammadex (0.25, 0.5, 0.75, 1.0, or 1.25 mg kg(-1) i.v.), neostigmine (10, 25, 40, 55, or 70 µg kg(-1) i.v.), or saline (n=9 per group). Primary and secondary end points were the doses necessary to restore neuromuscular function to a TOFR≥0.9 with an upper limit of 5 and 10 min for 95% of patients, respectively. Neostigmine was not able to fulfil the end points. Based on the best-fitting model, the sugammadex dose estimation for recovery to a TOFR≥0.9 for 95% of patients within 5 and 10 min was 0.49 and 0.26 mg kg(-1), respectively. A residual neuromuscular block of a TOFR of 0.2 cannot be reversed reliably with neostigmine within 10 min. In the conditions studied, substantially lower doses of sugammadex than the approved dose of 2.0 mg kg(-1) may be sufficient to reverse residual rocuronium-induced neuromuscular block at a recovery of TOFR≥0.2. NCT01006720. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The stimulatory effect of single-dose pre-irradiation administration of indomethacin and diclofenac on haemopoietic recovery in the spleen of gamma-irradiated mice

International Nuclear Information System (INIS)

Kozubik, A.; Pospisil, M.; Netikova, J.

1989-01-01

The aim of the work was to examine the effect of the single-dose pre-irradiation administration of non-steroid anti-inflammatory drugs, i.e. indomethacin (0.15 mg/mouse) and diclofenac (0.6 mg/mouse) on the recovery of haemopoiesis in the spleen of whole-body irradiated male mice (CBA x C57BL/10)F 1 . It was shown that the administation of these substances 1-24 h prior to sublethal irradiation stimulates the recovery of the proliferation activity of the spleen and the formation of endogenous spleen colonies. These results can be explained as the inhibitory effect of the substances administered on biosynthesis of prostaglandins. (author)

Adaptive repair induced by small doses of γ radiation in repair-defective human cells

International Nuclear Information System (INIS)

Zasukhina, G.D.; L'vova, G.N.; Vasil'eva, I.M.; Sinel'shchikova, T.A.; Semyachkina, A.N.

1993-01-01

Adaptive repair induced by small doses of gamma radiation was studied in repair-defective xeroderma pigmentosum, gout, and homocystinuria cells. The adaptation of cells induced by small doses of radiation was estimated after subsequent exposure to gamma radiation, 4-nitroquinoline-1-oxide, and N-methyl-N-nitro-N-nitrosoguanidine by three methods: (1) by the reduction in DNA breaks; (2) by induction of resistant DNA synthesis; and (3) by increased reactivation of vaccinia virus. The three cell types in response to the three different mutagens revealed differences in the mechanism of cell defense in excision repair, in the adaptive response, and in Weigl reactivation

Review of low dose-rate epidemiological studies and biological mechanisms of dose-rate effects on radiation induced carcinogenesis

International Nuclear Information System (INIS)

Iwasaki, Toshiyasu; Otsuka, Kensuke; Yoshida, Kazuo

2015-01-01

Radiation protection system adopts the linear non-threshold model with using dose and dose-rate effectiveness factor (DDREF). The dose-rate range where DDREF is applied is below 100 mGy per hour, and it is regarded that there are no dose-rate effects at very low dose rate, less than of the order of 10 mGy per year, even from the biological risk evaluation model based on cellular and molecular level mechanisms for maintenance of genetic integrity. Among low dose-rate epidemiological studies, studies of residents in high natural background areas showed no increase of cancer risks at less than about 10 mGy per year. On the other hand, some studies include a study of the Techa River cohort suggested the increase of cancer risks to the similar degree of Atomic bomb survivor data. The difference of those results was supposed due to the difference of dose rate. In 2014, International Commission on Radiological Protection opened a draft report on stem cell biology for public consultations. The report proposed a hypothesis based on the new idea of stem cell competition as a tissue level quality control mechanism, and suggested that it could explain the dose-rate effects around a few milligray per year. To verify this hypothesis, it would be needed to clarify the existence and the lowest dose of radiation-induced stem cell competition, and to elucidate the rate of stem cell turnover and radiation effects on it. As for the turnover, replenishment of damaged stem cells would be the important biological process. It would be meaningful to collect the information to show the difference of dose rates where the competition and the replenishment would be the predominant processes. (author)

Clustered DNA damages induced in human hematopoietic cells by low doses of ionizing radiation

Science.gov (United States)

Sutherland, Betsy M.; Bennett, Paula V.; Cintron-Torres, Nela; Hada, Megumi; Trunk, John; Monteleone, Denise; Sutherland, John C.; Laval, Jacques; Stanislaus, Marisha; Gewirtz, Alan

2002-01-01

Ionizing radiation induces clusters of DNA damages--oxidized bases, abasic sites and strand breaks--on opposing strands within a few helical turns. Such damages have been postulated to be difficult to repair, as are double strand breaks (one type of cluster). We have shown that low doses of low and high linear energy transfer (LET) radiation induce such damage clusters in human cells. In human cells, DSB are about 30% of the total of complex damages, and the levels of DSBs and oxidized pyrimidine clusters are similar. The dose responses for cluster induction in cells can be described by a linear relationship, implying that even low doses of ionizing radiation can produce clustered damages. Studies are in progress to determine whether clusters can be produced by mechanisms other than ionizing radiation, as well as the levels of various cluster types formed by low and high LET radiation.

Demonstration of a stimulating effect of natural ionizing radiation and of very low radiation doses on cell multiplication

International Nuclear Information System (INIS)

Planel, G.; Soleilhavoup, J.P.; Tixador, R.; Croute, F.; Richoilley, G.

1976-01-01

Experiments have been carried out to demonstrate a possible effect of natural ionizing radiation. Using lead shielding devices or an underground laboratory, it was shown that a decrease in background irradiation induces a decrease in cell growth rate (experiments carried out on Paramecia). On the other hand, the recovery of a normal irradiation level in shielding devices induces a quite normal cell proliferation. Moreover, small doses of γ rays from 60 Co exhibit a stimulating effect. Variations in cell radiosensitivity to these low doses are reported. Experiments carried out in the underground laboratory and at high altitude show that both telluric radioactivity and cosmic rays contribute to this stimulating effect on cell multiplication. (author)

Time dependence of Elkind-type recovery in class B oocytes of Drosophila melanogaster

International Nuclear Information System (INIS)

Steiner, T.; Wuergler, F.E.

1979-01-01

Recovery from X-ray-induced damage in class B oocytes of Drosophila melanogaster was studied by the dose-fractionation technique. A total dose of 5000 R was delivered either as a single exposure or as two fractions of 2000 R and 3000 R separated by increasing time intervals. The use of attached-X females made it possible to study simultaneously the induction of dominant lethals and of chromosome aberrations (detachments of the attached-X chromosome). The same repair kinetics were observed for sublethal damage and for the lesions leading to detachments. The time-response curves were of similar shape: a plateau was reached within 20 to 30 min and half of the repairable damage disappeared in 5 to 7 min. It is concluded that the same type of X-ray-induced primary lesion in chromosomes is responsible for the induction of detachments and for dominant lethals. As primary lesions actual chromosome breaks or lesions leading to breaks and chromosome rearrangements are assumed. (author)

Irradiation induced aerosol formation in flue gas: experiments on low doses

International Nuclear Information System (INIS)

Maekelae, J.M.

1992-01-01

Laboratory experiments on irradiation induced aerosol formation from gaseous sulphur dioxide in humid air are presented. This work is connected to the aerosol particle formation process in the electron beam technique for cleaning flue gas. As a partial process of this method primary products of the radiolysis of water vapour convert sulphur dioxide into gaseous sulphuric acid which then nucleates with water vapour forming small acid droplets. This experimental work has been performed on relatively low absorbed doses. Aerosol particle formation is strongly dependent on dose. In the experiments, the first aerosol particles were detected already on absorbed doses of 0.1-10 mGy. The particle size in these cases is in the so-called ultrafine size range (1-20 nm). In this article three experimental set-ups with some characteristic results are presented. (Author)

Dose dependence of radiation-induced segregation in Ni-1 at% Si

International Nuclear Information System (INIS)

Rehn, L.E.; Okamoto, P.R.; Wiedersich, H.

1979-01-01

Measurements have been made of alloy composition as a function of depth from the external surface in Ni-1 at% Si specimens after irradiation with 3-MeV 58 Ni + ions to several different doses at nominal temperatures of 525 and 600 0 C. Very rapid segregation of Si toward the external surface ocurred during irradiation. Surface concentrations of Si in excess of the 10 at% solubility limit were found at both irradiation temperatures after a dose of only approximately 0.05 dpa. The rate of segregation decreased markedly in the dose range from approximately 1-10 dpa. Qualitative agreement was found between the experimental observations and calculations made using a modified Johnson-Lam segregation mode (1976). The present investigation suggests that radiation-induced segregation may significantly alter the mechanical behavior of irradiated alloys long before the onset of void swelling. (Auth.)

Retinal and choroidal expression of BMP-2 in lens-induced myopia and recovery from myopia in guinea pigs.

Science.gov (United States)

Li, Honghui; Wu, Juan; Cui, Dongmei; Zeng, Junwen

2016-03-01

The present study investigated the retinal and choroidal expression of bone morphogenetic protein-2 (BMP-2) in myopia and in myopia recovery in a guinea pig model. For this investigation, two groups of guinea pigs, lens‑induced myopia and recovery from myopia, were used, and defocused myopia was induced the guinea pigs wearing ‑4.00 D lenses on the right eyes for 3 weeks, with the left eyes serving as the contralateral. In the following week, the lenses of the guinea pigs in the recovery group were removed, and the refractive power and axial length were measured. The expression of BMP‑2 in the eyeballs was observed using immunohistochemistry and analyzed using Western blot analysis. After 3 weeks, the eyes acquired relative myopia and longer axial lengths in the two groups of guinea pigs. After 1 week without lenses in the recovery group, the myopia and axial lengths regressed. Immunofluorescence staining showed that BMP‑2 was expressed in the posterior retina, RPE, choroid and sclera. The expression of BMP‑2 decreased in the myopic retina of the guinea pigs. Following the regression of myopia in the recovery group, no difference in the expression of BMP‑2 was observed between the recovered treated eyes and the contralateral eyes. The choroidal expression level of BMP‑2 in the treated eyes showed no significant changes in either group. Therefore, BMP‑2 may be involved in the development of myopia, however, it does not have a primary role in the retinal and choroidal signals regulating scleral remodeling.

Effect of a single dose of green tea polyphenols on the blood markers of exercise-induced oxidative stress in soccer players.

Science.gov (United States)

Jówko, Ewa; Sacharuk, Jaroslaw; Balasinska, Bozena; Wilczak, Jacek; Charmas, Malgorzata; Ostaszewski, Piotr; Charmas, Robert

2012-12-01

To evaluate the effect of acute ingestion of green tea polyphenols (GTP) on blood markers of oxidative stress and muscle damage in soccer players exposed to intense exercise. This randomized, double-blinded study was conducted on 16 players during a general preparation period, when all athletes participated in a strength-training program focused on the development of strength endurance. After ingestion of a single dose of GTP (640 mg) or placebo, all athletes performed an intense muscle-endurance test consisting of 3 sets of 2 strength exercises (bench press, back squat) performed to exhaustion, with a load at 60% 1-repetition maximum and 1-min rests between sets. Blood samples were collected preexercise, 5 min after the muscle-endurance test, and after 24 hr of recovery. Blood plasma was analyzed for the concentrations of thiobarbituric acid-reacting substances (TBARS), uric acid (UA), total catechins, total antioxidant status (TAS), and activity of creatine kinase (CK); at the same time, erythrocytes were assayed for the activity of superoxide dismutase (SOD). In both groups, plasma TBARS, UA, and TAS increased significantly postexercise and remained elevated after a 24-hr recovery period. SOD activity in erythrocytes did not change significantly in response to the muscle-endurance test, whereas in both groups plasma CK activity increased significantly after 24 hr of recovery. Acute intake of GTP cased a slight but significant increase in total plasma catechins. However, GTP was found not to exert a significant effect on measured parameters. Acute ingestion of GTP (640 mg) does not attenuate exercise-induced oxidative stress and muscle damage.

Low-dose ionizing radiation alleviates Aβ42-induced defective phenotypes in Drosophila Alzheimer's disease models

International Nuclear Information System (INIS)

Hwang, SooJin; Jeong, Hae Min; Nam, Seon Young

2017-01-01

Alzheimer's disease (AD) is the most common neurodegenerative disease that is characterized by amyloid plaques, progressive neuronal loss, and gradual deterioration of memory. Amyloid imaging using positron emission tomography (PET) radiotracers have been developed and approved for clinical use in the evaluation of suspected neurodegenerative disease, including AD. Particularly, previous studies involving low-dose ionizing radiation on Aβ 42-treated mouse hippocampal neurons have suggested a potential role for low-dose ionizing radiation in the treatment of AD. However, associated in vivo studies involving the therapy effects of low-dose ionizing radiation on AD are still insufficient. As a powerful cell biological system, Drosophila AD models have been generated and established a useful model organism for study on the etiology of human AD. In this study, we investigated the hormesis effects of low-dose ionizing radiation on Drosophila AD models. Our results suggest that low-dose ionizing radiation have the beneficial effects on not only the Aβ42-induced developmental defective phenotypes but also motor defects in Drosophila AD models. These results might be due to a regulation of apoptosis, and provide insight into the hormesis effects of low-dose ionizing radiation. Our results suggest that low-dose ionizing radiation have the beneficial effects on not only the Aβ42-induced developmental defective phenotypes but also motor defects in Drosophila AD models. These results might be due to a regulation of apoptosis, and provide insight into the hormesis effects of low-dose ionizing radiation.

Tests of the linearity assumption in the dose-effect relationship for radiation-induced cancer

International Nuclear Information System (INIS)

Cohen, A.F.; Cohen, B.L.

1978-01-01

The validity of the BEIR linear extrapolation to low doses of the dose-effect relationship for radiation induced cancer is tested by use of natural radiation making use of selectivity on type of cancer, sex, age group, geographic area, and time period. For lung cancer, a linear interpolation between zero dose-zero effect and the data from radon-induced cancers in miners over-estimates the total number of observed lung cancers in many countries in the early years of this century; the discrepancy is substantially increased if the 30-44 year age range and/or if only females are considered, and by the fact that many other causes of lung cancer are shown to have been important at that time. The degree to which changes of diagnostic efficiency with time can influence the analysis is considered at some length. It is concluded that the linear relationship substantially over-estimates effects of low radiation doses. A similar analysis is applied to leukemia induced by natural radiation, applying selectivity by age, sex, natural background level, and date, and considering other causes. It is concluded that effects substantially larger than those obtained from linear extrapolation are excluded. The use of the selectivities mentioned above is justified by the fact that the incidence of cancer or leukemia is an upper limit on the rate at which it is caused by radiation effects; in determining upper limits it is justifiable to select situations which minimize it. (author)

The genetic effects induced by an irradiation in low doses at Drosophila melanogaster

International Nuclear Information System (INIS)

Zajnullin, V.G.; Taskaev, A.I.; Moskalev, A.A.; Shaposhnikov, M.V.

2006-01-01

The review generalizes the results obtained in researches of genetic radiation effects for Drosophila melanogaster from contamination regions near the Chernobylsk NPP. The results of laboratory investigations of low dose irradiation effects on genotype variability and lifetime of Drosophila are presented too. It supposed that the main effect of low dose irradiation is caused by the induced genetic instability against the background of which the realization of different-directed radiobiological reactions is possible [ru

Persistent DNA Damage in Spermatogonial Stem Cells After Fractionated Low-Dose Irradiation of Testicular Tissue

International Nuclear Information System (INIS)

Grewenig, Angelika; Schuler, Nadine; Rübe, Claudia E.

2015-01-01

Purpose: Testicular spermatogenesis is extremely sensitive to radiation-induced damage, and even low scattered doses to testis from radiation therapy may pose reproductive risks with potential treatment-related infertility. Radiation-induced DNA double-strand breaks (DSBs) represent the greatest threat to the genomic integrity of spermatogonial stem cells (SSCs), which are essential to maintain spermatogenesis and prevent reproduction failure. Methods and Materials: During daily low-dose radiation with 100 mGy or 10 mGy, radiation-induced DSBs were monitored in mouse testis by quantifying 53 binding protein 1 (53BP-1) foci in SSCs within their stem cell niche. The accumulation of DSBs was correlated with proliferation, differentiation, and apoptosis of testicular germ cell populations. Results: Even very low doses of ionizing radiation arrested spermatogenesis, primarily by inducing apoptosis in spermatogonia. Eventual recovery of spermatogenesis depended on the survival of SSCs and their functional ability to proliferate and differentiate to provide adequate numbers of differentiating spermatogonia. Importantly, apoptosis-resistant SSCs resulted in increased 53BP-1 foci levels during, and even several months after, fractionated low-dose radiation, suggesting that surviving SSCs have accumulated an increased load of DNA damage. Conclusions: SSCs revealed elevated levels of DSBs for weeks after radiation, and if these DSBs persist through differentiation to spermatozoa, this may have severe consequences for the genomic integrity of the fertilizing sperm

Persistent DNA Damage in Spermatogonial Stem Cells After Fractionated Low-Dose Irradiation of Testicular Tissue

Energy Technology Data Exchange (ETDEWEB)

Grewenig, Angelika; Schuler, Nadine; Rübe, Claudia E., E-mail: claudia.ruebe@uks.eu

2015-08-01

Purpose: Testicular spermatogenesis is extremely sensitive to radiation-induced damage, and even low scattered doses to testis from radiation therapy may pose reproductive risks with potential treatment-related infertility. Radiation-induced DNA double-strand breaks (DSBs) represent the greatest threat to the genomic integrity of spermatogonial stem cells (SSCs), which are essential to maintain spermatogenesis and prevent reproduction failure. Methods and Materials: During daily low-dose radiation with 100 mGy or 10 mGy, radiation-induced DSBs were monitored in mouse testis by quantifying 53 binding protein 1 (53BP-1) foci in SSCs within their stem cell niche. The accumulation of DSBs was correlated with proliferation, differentiation, and apoptosis of testicular germ cell populations. Results: Even very low doses of ionizing radiation arrested spermatogenesis, primarily by inducing apoptosis in spermatogonia. Eventual recovery of spermatogenesis depended on the survival of SSCs and their functional ability to proliferate and differentiate to provide adequate numbers of differentiating spermatogonia. Importantly, apoptosis-resistant SSCs resulted in increased 53BP-1 foci levels during, and even several months after, fractionated low-dose radiation, suggesting that surviving SSCs have accumulated an increased load of DNA damage. Conclusions: SSCs revealed elevated levels of DSBs for weeks after radiation, and if these DSBs persist through differentiation to spermatozoa, this may have severe consequences for the genomic integrity of the fertilizing sperm.

The independent action of radiation and cisplatin on the survival or recovery of human normal or tumour cells in vitro or in vivo

International Nuclear Information System (INIS)

Basham, C.; Mills, J.; Roberts, J.J.

1989-01-01

Recovery from γ-radiation- or cisplatin-induced lethal damage was studied in euoxic normal human foetal lung fibroblasts (HFL cells). After 1 hour treatment with cisplatin the half-time of recovery was about 2 days. Recovery after radiation presented half-times of approximately 10 h, with further measurable recovery after 2 days. With either agent recovery ratios (RR) were dose-dependent but recovery (following treatment with equitoxic doses of both agents) was appreciably greater after cisplatin (RR ''approx.'' 123 after 40μm for 1 h) than after radiation (RR ''approx.'' 15 after 900 cGy). When radiation (900 cGy) was combined with cisplatin (40 μm for 1 h) the cell survival (measured at 5 days post-treatment or later) was not significantly less than that predicted by the additive, independent effects of both agents irrespective of whether cisplatin was given 1 h before, during or for 1 h after radiation. In euoxic, exponentially growing HFL or HeLa cells there was no evidence that combinations of cisplatin and radiation gave more than additive toxic effects. The combined effects of cisplatin or carboplatin and whole-body irradiation given 45 min later, on human melanoma cells were essentially the same as that predicted by the additive, independent effects of both agents. (author)

Effect of exogenous IAA on radiation-induced seedling growth in rice

International Nuclear Information System (INIS)

Bhattacharya, Shakuntala; Shama Rao, H.K.

1978-01-01

Rice seeds of var. D-6-2-2 were used to ascertain the interaction between exogenous IAA and low and high dose of γ-rays on seedling growth. Low doses of radiation (1,2 kR) and low concentrations of IAA(5,10 ppm) stimulated growth when applied independently. However, they proved inhibitory in combination, indicating the possibility of native IAA involvement at optimum level in radiation-induced stimulation. At a higher dose (5 kR), higher concentrations of exogenous IAA (50,100 ppm) resulted in a significant growth recovery over control. These results suggest that low doses of ionizing radiations probably accelerate the IAA synthesizing system leading to stimulation. (author)

Sodium fusidate ameliorates the course of diabetes induced in mice by multiple low doses of streptozotocin

DEFF Research Database (Denmark)

Nicoletti, F; Di Marco, R; Conget, I

2000-01-01

We studied the effects of the immunosuppressant sodium fusidate (fusidin) on murine immunoinflammatory diabetes mellitus (DM) induced by multiple low doses of streptozotocin (SZ). Fusidin was given by gavage to three strains of mice (C57KsJ, C57BL/6, CD1) at doses 10 or 100 mg/kg body weight every...... induced in vivo by ConA, reducing the levels of IFN-gamma, IL-2 and TNF-alpha and augmenting the level of IL-6. However, only the inhibitory effect of the drug on the synthesis/release of IFN-gamma seemed to be causally related to its capacity to counteract the SZ-induced DM. In fact, the disease...... other day. The drug was administered as an early or late prophylactic regime starting either 1 day prior to the first or after the fifth and last injection of SZ. In both situations the largest dose of fusidin successfully reduced the clinical, chemical and histological signs of DM, the treated mice...

The recovery of bladder epithelial hyperplasia caused by a melamine diet-induced bladder calculus in mice.

Science.gov (United States)

Sun, Ying; Jiang, Yi-Na; Xu, Chang-Fu; Du, Yun-Xia; Zhang, Jiao-Jiao; Yan, Yang; Gao, Xiao-Li

2014-02-01

Applying a model of bladder epithelial hyperplasia (BEH) caused by melamine-induced bladder calculus (BC), the recovery of BEH after melamine withdrawal was investigated. One experiment, comprising untreated, melamine and recovery groups, was conducted in Balb/c mice. Each group included 4 subgroups. Mice were fed normal-diet in untreated or a melamine-diet in other groups. The melamine-diet was then substituted with normal-diet in recovery group. Both of BC and BEH were observed after 14 and 56 days of melamine-diet. The BC is relatively uniform at the same melamine-diet durations. The BEH was diffuse with many mitotic figures, 4-7 rows of nuclei, and well-defined umbrella/intermediate cells. No marked differences in BEH degree were observed in the two different melamine-diet durations. On 4-42 days after melamine withdrawal, BC was not found, as the progressive regression with complete regression of BEH was observed, along with well-defined ageing/apoptotic cells in the superficial regions of BEH regression tissue. Conclusion, the melamine-induced BEH is relatively uniform, may be self-limiting in rows of nuclei, and can return to normal. Melamine withdrawal duration is critical for the BEH regression. Tissue of the BEH and its regression is ideal for exploring the renewal as well as growth biology of mammalian urothelium. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Activity of coenzyme Q 10 (Q-Ter multicomposite) on recovery time in noise-induced hearing loss.

Science.gov (United States)

Staffa, Paola; Cambi, Jacopo; Mezzedimi, Chiara; Passali, Desiderio; Bellussi, Luisa

2014-01-01

A potential consequence of exposure to noise is a temporary reduction in auditory sensitivity known as temporary threshold shift (TTS), which mainly depends on the intensity and duration of exposure to the noise. Recovery time is related to the amount of initial hearing loss, and the most recovery takes place during the first 15 min following exposure. This study evaluated the efficacy in otoprotection against noise-induced hearing loss of an orally administrated food supplement containing coenzyme Q 10 -Ter. This water-soluble formulation of coenzyme Q 10 shows better bioavailability than the native form and has been found to have a protective effect on outer hair cells after exposure to noise in animal models. Thirty volunteers were enrolled, and the right ear of each subject was exposed to a narrow-band noise centered at 3 kHz for 10 min at the intensity of 90 dB HL. In the 30 subjects enrolled, TTS was evaluated after 2, 15, and 30 min and the recovery time was recorded in each subject. The longest recovery time was 45 min. Among the 18 subjects who underwent a second test after treatment with Q-Ter, the mean recovery time was 31.43 min. The results of the present study show that 30 days' treatment with Q-Ter can aid faster recovery after exposure to noise (P < 0.0001). The reduction in the recovery time following treatment can be explained by Q-Ter-mediated improvement of the outer hair cells' response to oxidative stress.

Possible Protective Effect of Low-dose Gamma Irradiation and Certain Natural Products on Chemically Induced Hepatotoxicity in Rats

International Nuclear Information System (INIS)

Rashed, R.R.A.

2015-01-01

Liver, the largest organ in the human body, is a vital organ that performs more than 500 vital metabolic functions. More than a 1000 drugs of the modern pharmacopoeia can induce liver injury with different clinical presentations. In the most severe cases, drug-induced liver injury may require liver transplantation or lead to death of the patient. Acetaminophen (acetyl-para-amino-phenol, paracetamol, APAP) is safe at therapeutic doses, but accidental or intentional overdose can induce severe hepatotoxicity in both humans and experimental animals. APAP-induced hepatotoxicity is dose related and reproducible in animals, and is thus widely used as a model for experimentally induced hepatotoxicity. Many herbs have been used as natural remedies for the prevention and/or treatment of liver diseases. Herbal drugs gained importance and popularity in recent years because of their safety, efficacy and cost effectiveness. Interestingly, exposure to a small dose or dose rate of radiation was reported to induce stress, perturbing homeostasis. Organisms respond adaptively to such disturbances. The mechanisms by which low-dose radiation (LDR) protects the cells or tissue against subsequent radiation- or drug-induced toxicities have been attributed to its stimulation of various protective molecules such as antioxidants and anti apoptotic. In the light of the above mentioned information, this study was constructed in order to investigate the mechanism(s) of the hepato protective effects offered by each of garlic oil (GO), black seed oil (BO) and sesame oil (SO) each alone or combined with low dose total body gamma (γ)-irradiation against APAP-induced hepatotoxicity in male albino Wistar rats. Preliminary pilot studies were performed prior to the main experimental work; in order to select the effective irradiation dose, the hepato protective natural products and the duration of their administration to be used in the main study. To carry out the main study, 96 rats were randomly

Radiation-induced damage of membranes

International Nuclear Information System (INIS)

Yonei, Shuji

1977-01-01

An outline of membranous structure was stated, and radiation-induced damage of membranes were surveyed. By irradiation, permeability of membranes, especially passive transportation mechanism, was damaged, and glycoprotein in the surface layers of cells and the surface layer structures were changed. The intramembranous damage was induced by decrease of electrophoresis of nuclear mambranes and a quantitative change of cytochrome P450 of microsomal membranes of the liver, and peroxidation of membranous lipid and SH substitute damage of membranous protein were mentioned as the mechanism of membranous damage. Recovery of membranous damage depends on radiation dose and temperature, and membranous damage participates largely in proliferation death. (tsunoda, M.)

Long term low dose rate irradiation causes recovery from type II diabetes and suppression of aging in type II diabetes-prone mice

International Nuclear Information System (INIS)

Namura, T.; Oda, T.

2003-01-01

The effects of low dose rate gamma irradiation on model C57BL/KsJ-db/db mice with Type II diabetes mellitus was investigated. These mice develop Type II diabetes by 10 weeks of age, due to obesity, and are characterized by hyperinsulinemia. A group of 12 female 10-week old mice were irradiated at 0.65 mGy/hr in the low dose rate irradiation facility in the Low Dose Radiation Research Center. The urine glucose levels of all of the mice were strongly positive at the beginning of the irradiation. In the irradiated group, a decrease in the glucose level was observed in three mice, one in the 35th week, another in the 52nd week and the third in the 80th week. No recovery from the diabetes was observed in the 12 mice of non-irradiated control group. There was no systematic change of body weight or consumption of food and drinking water between the irradiated group and the non-irradiated group or between the recovered mice and the non-recovered mice. Survival was better in the irradiated group. The surviving fraction at the age of 90 weeks was 75 % in the irradiated group but only 40 % in the non-irradiated. A marked difference was also observed in the appearance of the coat hair, skin and tail. The irradiated group was in much better condition. Mortality was delayed and the healthy appearance was prolonged in the irradiated mice by about 20-30 weeks compared with the control mice. These results suggest that the low dose irradiation modified the condition of the diabetic mice, leading not only to recovery from diabetes, but also to suppression of the aging process

Improvement of dose determination using glass display of mobile phones for accident dosimetry

International Nuclear Information System (INIS)

Discher, M.; Woda, C.; Fiedler, I.

2013-01-01

Previous studies have demonstrated that mobile phones can be used as suitable emergency dosimeters in case of an accidental radiation overexposure. Glass samples extracted from displays of mobile phones are sensitive to ionizing radiation and can be measured using the thermoluminescence (TL) method. A non-radiation induced background signal (so-called zero dose signal) was observed which overlaps with the radiation induced signal and consequently limits the minimum detectable dose. Investigations of several glasses from different displays showed that it is possible to reduce the zero dose signal up to 90% by etching the glass surface with concentrated hydrofluoric acid. With this approach a reduction of the detection limit of a factor of four, corresponding to approximately 80 mGy, was achieved. Dosimetric properties of etched samples are presented and developed protocols validated by dose recovery tests under realistic conditions. With the improvements in sample preparation the proposed method of dose determination is a competitive alternative to OSL/TL measurements of electronic components and chip cards and provides a useful option for retrospective accident dosimetry. -- Highlights: ► Glass displays from mobile phones have good potential for emergency dosimetry. ► The background signal can be reduced by etching glass samples with hydrofluoric acid. ► The minimum detectable dose can be lowered to approximately 80 mGy

Low submetamorphic doses of dexamethasone and thyroxine induce complete metamorphosis in the axolotl (Ambystoma mexicanum) when injected together.

Science.gov (United States)

Kühn, Eduard R; De Groef, Bert; Grommen, Sylvia V H; Van der Geyten, Serge; Darras, Veerle M

2004-06-01

Entanglement of functions between the adrenal (or interrenal) and thyroid axis has been well described for all vertebrates and can be tracked down up to the level of gene expression. Both thyroid hormones and corticosteroids may induce morphological changes leading to metamorphosis climax in the neotenic Mexican axolotl (Ambystoma mexicanum). In a first series of experiments, metamorphosis was induced with an injection of 25 microg T(4) on three alternate days as judged by a decrease in body weight and tail height together with complete gill resorption. This injection also resulted in elevated plasma concentrations of T(3) and corticosterone. Previous results have indicated that the same dose of dexamethasone (DEX) is ineffective in this regard (Gen. Comp. Endocrinol. 127 (2002) 157). In a second series of experiments low doses of T(4) (0.5 microg) or DEX (5 microg) were ineffective to induce morphological changes. However, when these submetamorphic doses were injected together, morphological changes were observed within one week leading to complete metamorphosis. It is concluded that thyroid hormones combined with corticosteroids are essential for metamorphosis in the axolotl and that only high doses of either thyroid hormone or corticosteroid can induce morphological changes when injected separately.

Antidiabetic Effect of Fresh Nopal (Opuntia ficus-indica in Low-Dose Streptozotocin-Induced Diabetic Rats Fed a High-Fat Diet

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Seung Hwan Hwang

2017-01-01

Full Text Available The objective of the present study was to evaluate α-glucosidase inhibitory and antidiabetic effects of Nopal water extract (NPWE and Nopal dry power (NADP in low-dose streptozotocin- (STZ- induced diabetic rats fed a high-fat diet (HFD. The type 2 diabetic rat model was induced by HFD and low-dose STZ. The rats were divided into four groups as follows: (1 nondiabetic rats fed a regular diet (RD-Control; (2 low-dose STZ-induced diabetic rats fed HFD (HF-STZ-Control; (3 low-dose STZ-induced diabetic rats fed HFD and supplemented with NPWE (100 mg/kg body weight, HF-STZ-NPWE; and (4 low-dose STZ-induced diabetic rats fed HFD and supplemented with comparison medication (rosiglitazone, 10 mg/kg, body weight, HF-STZ-Rosiglitazone. In results, NPWE and NADP had IC50 values of 67.33 and 86.68 μg/mL, both of which exhibit inhibitory activities but lower than that of acarbose (38.05 μg/mL while NPWE group significantly decreased blood glucose levels compared to control and NPDP group on glucose tolerance in the high-fat diet fed rats model (P<0.05. Also, the blood glucose levels of HR-STZ-NPWE group were significantly lower (P<0.05 than HR-STZ-Control group on low-dose STZ-induced diabetic rats fed HFD. Based on these findings, we suggested that NPWE could be considered for the prevention and/or treatment of blood glucose and a potential use as a dietary supplement.

Antidiabetic Effect of Fresh Nopal (Opuntia ficus-indica) in Low-Dose Streptozotocin-Induced Diabetic Rats Fed a High-Fat Diet.

Science.gov (United States)

Hwang, Seung Hwan; Kang, Il-Jun; Lim, Soon Sung

2017-01-01

The objective of the present study was to evaluate α -glucosidase inhibitory and antidiabetic effects of Nopal water extract (NPWE) and Nopal dry power (NADP) in low-dose streptozotocin- (STZ-) induced diabetic rats fed a high-fat diet (HFD). The type 2 diabetic rat model was induced by HFD and low-dose STZ. The rats were divided into four groups as follows: (1) nondiabetic rats fed a regular diet (RD-Control); (2) low-dose STZ-induced diabetic rats fed HFD (HF-STZ-Control); (3) low-dose STZ-induced diabetic rats fed HFD and supplemented with NPWE (100 mg/kg body weight, HF-STZ-NPWE); and (4) low-dose STZ-induced diabetic rats fed HFD and supplemented with comparison medication (rosiglitazone, 10 mg/kg, body weight, HF-STZ-Rosiglitazone). In results, NPWE and NADP had IC 50 values of 67.33 and 86.68  μ g/mL, both of which exhibit inhibitory activities but lower than that of acarbose (38.05  μ g/mL) while NPWE group significantly decreased blood glucose levels compared to control and NPDP group on glucose tolerance in the high-fat diet fed rats model ( P < 0.05). Also, the blood glucose levels of HR-STZ-NPWE group were significantly lower ( P < 0.05) than HR-STZ-Control group on low-dose STZ-induced diabetic rats fed HFD. Based on these findings, we suggested that NPWE could be considered for the prevention and/or treatment of blood glucose and a potential use as a dietary supplement.

The role of radiation types and dose in induced genomic instability

International Nuclear Information System (INIS)

Kadhim Munira, A.

2007-01-01

Complete text of publication follows. Genomic Instability (GI) is defined as long-term alterations induced by low-dose exposure to a variety of genotoxic agents in mammalian cells that act to increase the 'apparent' spontaneous mutation frequency.GI is a hallmark of tumorigenic progression and is observed in the progeny of irradiated and bystander cells as the delayed and stochastic appearance of de novo chromosomal aberrations, gene mutations and delayed lethal mutations both in vitro and in vivo. It occurs at a frequency several orders of magnitude greater than would be expected for mutation in a single gene, implying that GI is a multigenic phenomenon. The expression of GI can be influenced by genotype, cell type and radiation quality; however the underlying mechanisms are not fully understood. While several studies have demonstrated GI induction by high and low LET radiation, our work on human and mouse primary cell systems has shown significant differences in the capacity to induce GI and the spectrum of alterations depending on LET. These differences might be attributed to differences in radiation track structure, radiation dose and radiation exposure regime (distribution of hit and un hit cells). In this presentation I shall review the role of radiation quality; describe the possible mechanisms underlining the observed differences between radiation type and present results of experiments demonstrating that the dose of low LET radiation might be the most significant factor in determining the role of radiation type in the induction of GI.

Search for the lowest irradiation dose from literatures on radiation-induced bone tumor

Energy Technology Data Exchange (ETDEWEB)

Yoshizawa, Y; Kusama, T; Morimoto, K [Tokyo Univ. (Japan). Faculty of Medicine

1977-04-01

A survey of past case reports of bone tumor induced by external radiation was carried out with the main object of finding the lowest irradiation dose. Search of the literature published since 1922 revealed 262 cases of radiation-induced bone tumor. These patients, except a patient with occupational exposure, had received radiation for treatment. The primary conditions as object of radiation therapy were nonmalignan bone diseases such as tuberclosis, giant cell tumor, fibrous dysplasia and bone cyst, and extra-skeletal diseases such as retinoblastoma, breast cancer and uterus cancer. The ratio of male to female patients with radiation-induced bone tumor was 1:1.3. The age of the patient ranged between 5 and 98 years, with an average of 37.6 years. Skeletal distribution of radiation-induced bone tumor was as follows: 20% the frontal and face bones, 17% the femur, 10% the humerus, 9% the vertebral column, and 44% other. The lowest absorbed dose reported was 800 rads in patients irradiated for the treatment of bone disease, but 1800 rads in patients with extra-skeletal disease. The latent period ranged between 2 and 42 years, with an average of 11.7 years. The histopathological findings were as follows: 60% osteosarcoma, 25% fibrosarcoma, 7% chondrosarcoma, and 8% other.

Blocking weight-induced spinal cord injury in rats: effects of TRH or naloxone on motor function recovery and spinal cord blood flow

International Nuclear Information System (INIS)

Holtz, A.; Nystroem, B.; Gerdin, B.

1989-01-01

The ability of thyotropin releasing hormone (TRH) or naloxone to reduce the motor function deficit and to improve the spinal cord blood flow (SCBF) was investigated in a rat spinal cord compression injury model. Spinal cord injury was induced by compression for 5 min with a load of 35 g on a 2.2 x 5.0 mm sized compression plate causing a transient paraparesis. One group of animals was given TRH, one group naloxone and one group saline alone. Each drug was administered intravenously as a bolus dose of 2 mg/kg 60 min after injury followed by a continuous infusion of 2 mg/kg/h for 4 h. The motor performance was assessed daily on the inclined plant until Day 4, when SCBF was measured with the 14 C-iodoantipyrine autoradiographic method. It was found that neither TRH nor naloxone had promoted motor function recovery or affected SCBF 4 days after spinal cord injury. (author)

MAGIK: a Monte Carlo system for computing induced residual activation dose rates

International Nuclear Information System (INIS)

Barish, J.; Gabriel, T.A.; Alsmiller, R.G. Jr.

1979-08-01

The photon dose rate from the induced activity produced by sustained bombardment of materials by neutrons and charged particles may present a significant radiation hazard. To minimize this hazard, the material configuration must be so designed that the photon dose rate decays to an acceptable level soon after the source beam is turned off. MAGIK calculates the time-independent photon dose rates that result from activities produced by nucleon-nucleus and meson-nucleus collisions over a wide range of energies. The system has been used both for high-energy accelerator studies and for fusion reactor studies. In the MAGIK system the lengthy photon transport calculations are carried out independent of time, and the time dependence is introduced in the final program, thereby permitting study of various operating scenarios with a minimum computing cost

Long-term treadmill exercise-induced neuroplasticity and associated memory recovery of streptozotocin-induced diabetic rats: an experimenter blind, randomized controlled study.

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You, Joshua Sung H; Kim, Chung-Ju; Kim, Mee Young; Byun, Yong Gwon; Ha, So Young; Han, Bong Suk; Yoon, Bum Chul

2009-01-01

We investigated a long-term exercise-induced neuroplasticity and spatial memory recovery in 15 rats in a treadmill as follows: normal control rats (NC), streptozotocin (STZ)-induced diabetic control rats (DC), and STZ-induced diabetic rats exercising in a treadmill (DE). As per the DE group, the running exercise in a treadmill was administered for 30 minutes a day for 6 weeks. Neuronal immediate-early gene (IEG) expression (c-Fos) in the hippocampus and radial arm maze (RAM) tests were measured and revealed that the c-Fos levels in DE were significantly higher than those in NC and DC (p memory performance scores, obtained from the RAM test, were significantly different among the three groups (p memory scores of NC and DE were higher than those of DC (p memory. This is the first experimental evidence in literature that supports the efficacy of exercise-induced neuroplasticity and spatial motor memory in diabetes care.

Optimal dose of rocuronium bromide undergoing adenotonsillectomy under 5% sevoflurane with fentanyl.

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Huh, Hyub; Park, Jeong Jun; Kim, Ji Yeong; Kim, Tae Hoon; Yoon, Seung Zhoo; Shin, Hye Won; Lee, Hye-Won; Lim, Hye-Ja; Cho, Jang Eun

2017-10-01

Adenotonsillectomy is a short surgical procedure under general anaesthesia in children. An ideal muscle relaxant for adenotonsillectomy would create an intense neuromuscular block while having a quick recovery time without postoperative morbidity. We compared the effect of different doses of rocuronium for the tracheal intubation in children under 5% sevoflurane and fentanyl. 75 children (aged 3-10 years, ASA I) scheduled for adenotonsillectomy were enrolled. Anaesthesia was induced with propofol 2.5 mg/kg, followed by fentanyl 2 μg/kg. After mask ventilation with 5 vol% sevoflurane in 100% oxygen for 2 min, 2 ml of study drug was administered intravenously, i.e., either normal saline (S Group) or one of two doses (0.15 or 0.3 mg/kg) of rocuronium. We assessed conditions during tracheal intubation and also recorded the surgical condition, the time from discontinuation of sevoflurane to extubation and PAED scale, pain scores in PACU. Rocuronium groups (96% and 100%, respectively; P rocuronium (80%) treatment clearly resulted in excellent intubating conditions compared with the 0.15 mg/kg group (44%; p = 0.028). There was no significant difference in the time to extubation and surgical condition, and in the postoperative measures of emergence delirium, pain, and recovery time among the three groups. A dose of 0.3 mg/kg rocuronium may provide optimal intubating conditions without delayed recovery in 5% sevoflurane anaesthesia with fentanyl in children undergoing adenotonsillectomy. NCT02467595. Copyright © 2017 Elsevier B.V. All rights reserved.

Impact of penile rehabilitation with low-dose vardenafil on recovery of erectile function in Japanese men following nerve-sparing radical prostatectomy

Directory of Open Access Journals (Sweden)

Yuzo Nakano

2014-12-01

Full Text Available Erectile dysfunction (ED is a major complication after radical prostatectomy (RP; however, debate continues regarding the efficacy of penile rehabilitation in the recovery of the postoperative erectile function (EF. This study included a total of 103 consecutive sexually active Japanese men with localized prostate cancer undergoing nerve-sparing RP, and analyzed the postoperative EF, focusing on the significance of penile rehabilitation. In this series, 24 and 79 patients underwent bilateral and unilateral nerve-sparing RPs, respectively, and 10 or 20 mg of vardenafil was administered to 35 patients at least once weekly, who agreed to undergo penile rehabilitation. Twelve months after RP, 48 (46.6% of the 103 patients were judged to have recovered EF sufficient for sexual intercourse without any assistance. The proportion of patients who recovered EF in those undergoing penile rehabilitation (60.0% was significantly greater than that in those without penile rehabilitation (38.2%. Of several parameters examined, the preoperative International Index of Erectile Function-5 (IIEF-5 score and nerve-sparing procedure were significantly associated with the postoperative EF recovery rates in patients with and without management by penile rehabilitation, respectively. Furthermore, univariate analysis identified the preoperative IIEF-5 score, nerve-sparing procedure and penile rehabilitation as significant predictors of EF recovery, among which the preoperative IIEF-5 score and nerve-sparing procedure appeared to be independently associated with EF recovery. Considering these findings, despite the lack of independent significance, penile rehabilitation with low-dose vardenafil could exert a beneficial effect on EF recovery in Japanese men following nerve-sparing RP.

Radioprotective effect of Rapana thomasiana hemocyanin in gamma induced acute radiation syndrome

International Nuclear Information System (INIS)

Kindekov, Ivan; Vassilieva, Vladimir; Aljakova, Mitko; Mileva, Milka; Krastev, Dimo; Raynova, Yuliana; Idakieva, Krassimira; Doumanov, Lyuba

2014-01-01

The radioprotective effect of Rapana thomasiana hemocyanin (RtH) against radiation-induced injuries (stomach ulcers, survival time and endogenous haemopoiesis) and post-radiation recovery was investigated in male albino mice (C3H strain). Radiation course was in a dose of 7.5 Gy (LD 100/30 - dose that kills 100% of the mice at 30 days) from "1"3"7Cs with a dose of 2.05 Gy/ min. Radiation injuries were manifested by inducing 2 hematopoietic form of acute radiation syndrome. RtH was administered intraperitoneally in a single dose of 50, 100, 150 and 200 mg/kg body weight (b. w.) once a day for five consecutive days before irradiation. The results obtained showed that radiation exposure led to (1) 100% mortality rate, (2) ulceration in the stomach mucosa and (3) decrease formation of spleen colonies as a marker of endogenous haemopoiesis. Administration of RtH at a dose of 200 mg/kg provided better protection against radiation-induced stomach ulceration, mitigated the lethal effects of radiation exposure and recovered endogenous haemopoiesis versus irradiated but not supplemented mice. It could be expected that RtH will find a use in mitigating radiation induced injury and enhanced radiorecovery. Keywords: Rapana thomasiana hemocyanin; acute radiation syndrome; radioprotective effect; spleen colony assay; stomach ulcerations

Low-dose cadmium exposure exacerbates polyhexamethylene guanidine-induced lung fibrosis in mice.

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Kim, Min-Seok; Kim, Sung-Hwan; Jeon, Doin; Kim, Hyeon-Young; Han, Jin-Young; Kim, Bumseok; Lee, Kyuhong

2018-01-01

Cadmium (Cd) is a toxic metal present in tobacco smoke, air, food, and water. Inhalation is an important route of Cd exposure, and lungs are one of the main target organs for metal-induced toxicity. Cd inhalation is associated with an increased risk of pulmonary diseases. The present study aimed to assess the effects of repeated exposure to low-dose Cd in a mouse model of polyhexamethylene guanidine (PHMG)-induced lung fibrosis. Mice were grouped into the following groups: vehicle control (VC), PHMG, cadmium chloride (CdCl 2 ), and PHMG + CdCl 2 . Animals in the PHMG group exhibited increased numbers of total cells and inflammatory cells in the bronchoalveolar lavage fluid (BALF) accompanied by inflammation and fibrosis in lung tissues. These parameters were exacerbated in mice in the PHMG + CdCl 2 group. In contrast, mice in the CdCl 2 group alone displayed only minimal inflammation in pulmonary tissue. Expression of inflammatory cytokines and fibrogenic mediators was significantly elevated in lungs of mice in the PHMG group compared with that VC. Further, expression of these cytokines and mediators was enhanced in pulmonary tissue in mice administered PHMG + CdCl 2 . Data demonstrate that repeated exposure to low-dose Cd may enhance the development of PHMG-induced pulmonary fibrosis.

LINKING GABAA RECEPTOR SUBUNITS TO ALCOHOL-INDUCED CONDITIONED TASTE AVERSION AND RECOVERY FROM ACUTE ALCOHOL INTOXICATION

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Blednov, Y.A.; Benavidez, J.M.; Black, M.; Chandra, D.; Homanics, G.E.; Rudolph, U.; Harris, R.A.

2012-01-01

GABA type A receptors (GABAA-R) are important for ethanol actions and it is of interest to link individual subunits with specific ethanol behaviors. We studied null mutant mice for six different GABAA-R subunits (α1, α2, α3, α4, α5 and δ). Only mice lacking the α2 subunit showed reduction of conditioned taste aversion (CTA) to ethanol. These results are in agreement with data from knock-in mice with mutation of the ethanol-sensitive site in the α2-subunit (Blednov et al., 2011) and indicate this aversive property of ethanol is dependent on ethanol action on α2-containing GABAA-R. Deletion of the α2-subunit led to faster recovery whereas absence of the α3-subunit slowed recovery from ethanol-induced incoordination (rotarod). Deletion of the other four subunits did not affect this behavior. Similar changes in this behavior for the α2 and α3 null mutants were found for flurazepam motor-incoordination. However, no differences in recovery were found in motor-incoordinating effects of an α1-selective modulator (zolpidem) or an α4-selective agonist (gaboxadol). Therefore, recovery of rotarod incoordination is under control of two GABAA-R subunits: α2 and α3. For motor activity, α3 null mice demonstrated higher activation by ethanol (1 g/kg) whereas both α2 and α3 (-/-) knockout mice were less sensitive to ethanol-induced reduction of motor activity (1.5 g/kg). These studies demonstrate that the effects of ethanol at GABAergic synapses containing α2 subunit are important for specific behavioral effects of ethanol which may be relevant to the genetic linkage of the α2 subunit with human alcoholism. PMID:23147414

Dose-dependent neuroprotective effect of enoxaparin on cold-induced traumatic brain injury.

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Keskin, Ilknur; Gunal, M Yalcin; Ayturk, Nilufer; Kilic, Ulkan; Ozansoy, Mehmet; Kilic, Ertugrul

2017-05-01

Recent evidence exists that enoxaparin can reduce brain injury because of its anticoagulant activity. To investigate the potential therapeutic effect of enoxaparin on cold-induced traumatic brain injury, at 20 minutes after modeling, male BALB/c mouse models of cold-induced traumatic brain injury were intraperitoneally administered 3 and 10 mg/kg enoxaparin or isotonic saline solution. Twenty-four hours later, enoxaparin at 10 mg/kg greatly reduced infarct volume, decreased cell apoptosis in the cortex and obviously increased serum level of total antioxidant status. By contrast, administration of enoxaparin at 3 mg/kg did not lead to these changes. These findings suggest that enoxaparin exhibits neuroprotective effect on cold-induced traumatic brain injury in a dose-dependent manner.

Low dose radiation induced protein and its effect on expression of CD25 molecule in lymphocytes

International Nuclear Information System (INIS)

Lu Duicai; Su Liaoyuan

2001-01-01

Objective: To find the substantial basis for effects of low dose radiation, on development, extraction, and the biogical activity of the low-dose radiation-induced proteins, and the effects of LDR induced proteins on CD25 molecule expression of human lymphocytes. Methods: 1. Healthy Kumning male mice exposed to radiation of 226 Ra γ-rays at 5, 10 and 15 cGy respectively. The mice were killed 2 hours after exposure, the spleen cells were broken with ultrasonic energy and then ultra-centrifugalized at low temperature (4 degree C). The LDR-induced proteins were obtained in the supernatant solution. Then the changes of CD25 molecule was measured by flow cytometry (FCM) with immunofluorescence technique, which was used to reflect the effect of LDR induced proteins on CD25 molecule expression of human lymphocytes. Results: LDR induced proteins were obtained from spleen cells in mice exposed to 5-15 cGy whole body radiation. Conclusion: The expression of CD25 molecule of lymphocytes was increased significantly after use of LDR induced proteins. LDR induced proteins can enhance expression of CD25 molecule of lymphocytes slightly

Dose rate effect on the yield of radiation induced response with thermal fading

International Nuclear Information System (INIS)

Chernov, V.; Rogalev, B.; Barboza-Flores, M.

2005-01-01

A model describing the dependences of the accumulation of thermally unstable radiation induced defects on the dose and dose rate is proposed. The model directly takes into account the track nature of the ionizing radiation represented as accumulation processes of defects in tracks averaged over a crystal volume considering various degrees of overlapping in space and time. The accumulation of the defects in the tracks is phenomenologically described. General expressions are obtained that allows radiation yield simulation of defects involving known creation and transformation processes. The cases considered, of linear accumulation (constant increment of the defects in tracks) and accumulation with saturation (complete saturation of the defects in one track), lead to a set of linear dose dependences with saturation, which are routinely used in luminescence and ESR dating. The accumulation, with increase of sensitivity in regions overlapped by two or more tracks, gave a set of dose dependences, from linear-sublinear-linear-saturation, distinctive of quartz up to linear-supralinear-linear-saturation. It is shown that the effect of the dose rate on dose dependences is determined by a dimensionless parameter a=Pτ/D0, where P is the dose rate, τ is the defect lifetime and D0 is the track dose. At a-bar 1 the dose rate influences basically the accumulation of thermally unstable defects. In the reverse case the dose dependences did not seems to be influenced by the dose rate

High doses of bone morphogenetic protein 2 induce structurally abnormal bone and inflammation in vivo.

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Zara, Janette N; Siu, Ronald K; Zhang, Xinli; Shen, Jia; Ngo, Richard; Lee, Min; Li, Weiming; Chiang, Michael; Chung, Jonguk; Kwak, Jinny; Wu, Benjamin M; Ting, Kang; Soo, Chia

2011-05-01

The major Food and Drug Association-approved osteoinductive factors in wide clinical use are bone morphogenetic proteins (BMPs). Although BMPs can promote robust bone formation, they also induce adverse clinical effects, including cyst-like bone formation and significant soft tissue swelling. In this study, we evaluated multiple BMP2 doses in a rat femoral segmental defect model and in a minimally traumatic rat femoral onlay model to determine its dose-dependent effects. Results of our femoral segmental defect model established a low BMP2 concentration range (5 and 10 μg/mL, total dose 0.375 and 0.75 μg in 75 μg total volume) unable to induce defect fusion, a mid-range BMP2 concentration range able to fuse the defect without adverse effects (30 μg/mL, total dose 2.25 μg in 75 μg total volume), and a high BMP2 concentration range (150, 300, and 600 μg/mL, total dose 11.25, 22.5, and 45 μg in 75 μg total volume) able to fuse the defect, but with formation of cyst-like bony shells filled with histologically confirmed adipose tissue. In addition, compared to control, 4 mg/mL BMP2 also induced significant tissue inflammatory infiltrates and exudates in the femoral onlay model that was accompanied by increased numbers of osteoclast-like cells at 3, 7, and 14 days. Overall, we consistently reproduced BMP2 side effects of cyst-like bone and soft tissue swelling using high BMP2 concentration approaching the typical human 1500 μg/mL.

Beneficial effects of benzodiazepine diazepam on chronic stress-induced impairment of hippocampal structural plasticity and depression-like behavior in mice.

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Zhao, Yunan; Wang, Zhongli; Dai, Jianguo; Chen, Lin; Huang, Yufang; Zhan, Zhen

2012-03-17

Whether benzodiazepines (BZDs) have beneficial effects on the progress of chronic stress-induced impairment of hippocampal structural plasticity and major depression is uncertain. The present study designed four preclinical experiments to determine the effects of BZDs using chronic unpredictable stress model. In Experiment 1, several time course studies on behavior and hippocampus response to stress were conducted using the forced swim and tail suspension tests (FST and TST) as well as hippocampal structural plasticity markers. Chronic stress induced depression-like behavior in the FST and TST as well as decreased hippocampal structural plasticity that returned to normal within 3 wk. In Experiment 2, mice received p.o. administration of three diazepam dosages prior to each variate stress session for 4 wk. This treatment significantly antagonized the elevation of stress-induced corticosterone levels. Only low- (0.5mg/kg) and medium-dose (1mg/kg) diazepam blocked the detrimental effects of chronic stress. In Experiment 3, after 7 wk of stress sessions, daily p.o. diazepam administration during 1 wk recovery phase dose-dependently accelerated the recovery of stressed mice. In Experiment 4, 1 wk diazepam administration to control mice enhanced significantly hippocampal structural plasticity and induced an antidepressant-like behavioral effect, whereas 4 wk diazepam administration produced opposite effects. Hence, diazepam can slow the progress of chronic stress-induced detrimental consequences by normalizing glucocorticoid hormones. Considering the adverse effect of long-term diazepam administration on hippocampal plasticity, the preventive effects of diazepam may depend on the proper dose. Short-term diazepam treatment enhances hippocampal structural plasticity and is beneficial to recovery following chronic stress. Copyright © 2011 Elsevier B.V. All rights reserved.

Recovery response of dividing cells in the thymus of whole-body γ-irradiated mice

International Nuclear Information System (INIS)

Suciu, D.; Uray, Z.; Maniu, M.

1976-01-01

Mice were irradiated with different doses of γ-rays 30 min after the administration of 32 P-orthophosphate. The dose-response curves determined at 72 hours after exposure showed an inflection point in the total activity present in the DNA in thymus and spleen. In the low dose-range, the dose-response curves have D 0 = 55 rad(n = 2.5) for thymus and D 0 = 95 rad (n = 2.5) for the spleen. Thirty minutes after the administration of 32 P-orthophosphate, the dividing cells from thymus were partially synchronized by the administration of 80 mg per kg body-weight hydroxyurea. At different time-intervals, the mice were irradiated with 80 rad, and the total activity of DNA was determined at 72 hours after synchronization. A significant maximum of recovery was found at 5 hours (S phase) after the administration of hydroxyurea. In similar conditions, the dose-response curves corresponding to the G 1 , S and M phase of the division cycle were also determined. The synchronization of dividing cells induced by hydroxyurea failed in the spleen. (author)

Bestatin treatment enhances the recovery of radiation induced impairments of the immunological reactivity of the blood lymphocyte population in bladder cancer patients

International Nuclear Information System (INIS)

Blomgren, H.; Edsmyr, F.; Stedingk, L.V. von; Wasserman, J.

1986-01-01

Bestatin, an immunostimulating substance of microbial origin, was examined for its capacity to augment immune responses of blood lymphocytes in bladder cancer patients having received a full course of local irradiation (64 Gy). Following irradiation the patients became lymphopenic and the lymphocytes exhibited impaired mitogenic responses to phytohemagglutinin (PHA) and purified protein derivative of tuberculin (PPD) and reduced poke weed mitogen induced secretion of immunoglobulins in vitro. Patients who were randomized to receive daily oral Bestatin treatment exhibited enhanced recoveries of PHA- and PPD- responses and enhanced recovery of the IgM secreting capacity compared to irradiated patients who did not receive Bestatin. Repopulation of the blood lymphocyte population, however, was not enhanced by Bestatin treatment. It is concluded that Bestatin treatment may enhance the recovery of radiation induced functional defects of the immune system in cancer patients

Dose response of micronuclei induced by combination radiation of α-particles and γ-rays in human lymphoblast cells

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Ren, Ruiping; He, Mingyuan; Dong, Chen; Xie, Yuexia; Ye, Shuang; Yuan, Dexiao [Institute of Radiation Medicine, Fudan University, No. 2094 Xie-Tu Road, Shanghai 200032 (China); Shao, Chunlin, E-mail: clshao@shmu.edu.cn [Institute of Radiation Medicine, Fudan University, No. 2094 Xie-Tu Road, Shanghai 200032 (China)

2013-01-15

Highlights: ► α-Particle induced MN had a biphasic dose–response followed by a bystander model. ► MN dose–response of α- and γ-combination IR was similar to that of α-particle. ► α-Particles followed by γ-rays yielded a synergistic effect on MN induction. ► Low dose γ-rays triggered antagonistic and adaptive responses against α-particle. - Abstract: Combination radiation is a real situation of both nuclear accident exposure and space radiation environment, but its biological dosimetry is still not established. This study investigated the dose–response of micronuclei (MN) induction in lymphocyte by irradiating HMy2.CIR lymphoblast cells with α-particles, γ-rays, and their combinations. Results showed that the dose–response of MN induced by γ-rays was well-fitted with the linear-quadratic model. But for α-particle irradiation, the MN induction had a biphasic phenomenon containing a low dose hypersensitivity characteristic and its dose response could be well-stimulated with a state vector model where radiation-induced bystander effect (RIBE) was involved. For the combination exposure, the dose response of MN was similar to that of α-irradiation. However, the yield of MN was closely related to the sequence of irradiations. When the cells were irradiated with α-particles at first and then γ-rays, a synergistic effect of MN induction was observed. But when the cells were irradiated with γ-rays followed by α-particles, an antagonistic effect of MN was observed in the low dose range although this combination radiation also yielded a synergistic effect at high doses. When the interval between two irradiations was extended to 4 h, a cross-adaptive response against the other irradiation was induced by a low dose of γ-rays but not α-particles.

Low temperature recovery of radiation damage in vanadium

International Nuclear Information System (INIS)

Klabunde, C.E.; Coltman, R.R. Jr.; Williams, J.M.

1975-01-01

Some kind of order may emerge from the numerous anomalies in the low-temperature recovery of irradiated V if it is assumed that Stage I (first recovery by interstitial migration) occurs below 4 0 K. Present supporting evidence includes: from both thermal neutron and fission neutron damage studies (1) a continuous, nearly structureless recovery from 4 to 43 0 K independent of dose; (2) a nonlinear, decreasing damage rate at 4 0 K; and (3) from 6 0 K electron irradiations near threshold energy there is derived a Frenkel pair resistivity which is so small as to suggest significant loss of defects during irradiation. The assumption of a very low-lying Stage I also helps to explain several other unusual aspects of the data, especially those relating to the sharp recovery peak at 47 0 K. This is clearly a single first-order process (with a measured activation energy of 0.13 eV), but it has a strong positive dependence of population percentage upon dose, opposite to Stage II impurity detrapping peaks in several fcc metals. Also, the peak has a strong negative dependence upon irradiation temperature when equal doses put in at 4 and 31 0 K are compared

Inhibitory effects of prior low-dose X-ray irradiation on carbon tetrachloride-induced hepatopathy in acatalasemic mice

International Nuclear Information System (INIS)

Yamaoka, Kiyonori; Kataoka, Takahiro; Taguchi, Takehito; Wang, Da-Hong; Mori, Shuji; Hanamoto, Katsumi; Kira, Shohei; Nomura, Takaharu

2004-01-01

The catalase activities in blood and organs of the acatalasemic (C3H/AnLCs b Cs b ) mouse of C3H strain are lower than those of the normal (C3H/AnLCs a Cs a ) mouse. We examined the effects of prior low-dose (0.5 Gy) X-ray irradiation, which reduced the oxidative damage under carbon tetrachloride-induced hepatopathy in the acatalasemic or normal mice. The acatalasemic mice showed a significantly lower catalase activity and a significantly higher glutathione peroxidase activity compared with those in the normal mice. Moreover, low-dose irradiation increased the catalase activity in the acatalasemic mouse liver to a level similar to that of the normal mouse liver. Pathological examinations and analyses of blood glutamic oxaloacetic and glutamic pyruvic transaminase activity and lipid peroxide levels showed that carbon tetrachloride induced hepatopathy was inhibited by low-dose irradiation. These findings may indicate that the free radical reaction induced by the lack of catalase and the administration of carbon tetrachloride is more properly neutralized by high glutathione peroxidase activity and low-dose irradiation in the acatalasemic mouse liver. (author)

Overexpression of antioxidant enzymes in diaphragm muscle does not alter contraction-induced fatigue or recovery

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McClung, Joseph M.; DeRuisseau, Keith C.; Whidden, Melissa A.; Van Remmen, Holly; Richardson, Arlan; Song, Wook; Vrabas, Ioannis S.; Powers, Scott K.

2010-01-01

Low levels of reactive oxygen species (ROS) production are necessary to optimize muscle force production in unfatigued muscle. In contrast, sustained high levels of ROS production have been linked to impaired muscle force production and contraction-induced skeletal muscle fatigue. Using genetically engineered mice, we tested the hypothesis that the independent transgenic overexpression of catalase (CAT), copper/zinc superoxide dismutase (CuZnSOD; SOD1) or manganese superoxide dismutase (MnSOD; SOD2) antioxidant enzymes would negatively affect force production in unfatigued diaphragm muscle but would delay the development of muscle fatigue and enhance force recovery after fatiguing contractions. Diaphragm muscle from wild-type littermates (WT) and from CAT, SOD1 and SOD2 overexpressing mice were subjected to an in vitro contractile protocol to investigate the force–frequency characteristics, the fatigue properties and the time course of recovery from fatigue. The CAT, SOD1 and SOD2 overexpressors produced less specific force (in N cm−2) at stimulation frequencies of 20–300 Hz and produced lower maximal tetanic force than WT littermates. The relative development of muscle fatigue and recovery from fatigue were not influenced by transgenic overexpression of any antioxidant enzyme. Morphologically, the mean cross-sectional area (in μm2) of diaphragm myofibres expressing myosin heavy chain type IIA was decreased in both CAT and SOD2 transgenic animals, and the percentage of non-contractile tissue increased in diaphragms from all transgenic mice. In conclusion, our results do not support the hypothesis that overexpression of independent antioxidant enzymes protects diaphragm muscle from contraction-induced fatigue or improves recovery from fatigue. Moreover, our data are consistent with the concept that a basal level of ROS is important to optimize muscle force production, since transgenic overexpression of major cellular antioxidants is associated with

Vincristine-induced blindness: a case report and review of literature.

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Adhikari, Subodh; Dongol, Raj Man; Hewett, Yvonne; Shah, Binay Kumar

2014-11-01

Neurotoxicity is a dose-limiting side-effect of vincristine therapy. Blindness is a rare central neurotoxicity of vincristine with few case reports. In the present article, we report a rare case of vincristine-induced blindness in a patient with diffuse large B cell lymphoma. Literature search identified eleven published cases of vincristine-induced blindness. We reviewed patient characteristics, chemotherapy used and type of blindness. Vincristine-induced blindness is rare and unpredictable. Prompt recognition and discontinuation of vincristine may lead to recovery of vision. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Effects of air-pulsed cryotherapy on neuromuscular recovery subsequent to exercise-induced muscle damage.

Science.gov (United States)

Guilhem, Gaël; Hug, François; Couturier, Antoine; Regnault, Stéphanie; Bournat, Laure; Filliard, Jean-Robert; Dorel, Sylvain

2013-08-01

Localized cooling has been proposed as an effective strategy to limit the deleterious effects of exercise-induced muscle damage on neuromuscular function. However, the literature reports conflicting results. This randomized controlled trial aimed to determine the effects of a new treatment, localized air-pulsed cryotherapy (-30°C), on the recovery time-course of neuromuscular function following a strenuous eccentric exercise. Controlled laboratory study. A total of 24 participants were included in either a control group (CONT) or a cryotherapy group (CRYO). Immediately after 3 sets of 20 maximal isokinetic eccentric contractions of elbow flexors, and then 1, 2, and 3 days after exercise, the CRYO group received a cryotherapy treatment (3 × 4 minutes at -30°C separated by 1 minute). The day before and 1, 2, 3, 7, and 14 days after exercise, several parameters were quantified: maximal isometric torque and its associated maximal electromyographic activity recorded by a 64-channel electrode, delayed-onset muscle soreness (DOMS), biceps brachii transverse relaxation time (T2) measured using magnetic resonance imaging, creatine kinase activity, interleukin-6, and C-reactive protein. Maximal isometric torque decreased similarly for the CONT (-33% ± 4%) and CRYO groups (-31% ± 6%). No intergroup differences were found for DOMS, electromyographic activity, creatine kinase activity, and T2 level averaged across the whole biceps brachii. C-reactive protein significantly increased for CONT (+93% at 72 hours, P cryotherapy delayed the significant increase of T2 and the decrease of electromyographic activity level for CRYO compared with CONT (between day 1 and day 3) in the medio-distal part of the biceps brachii. Although some indicators of muscle damage after severe eccentric exercise were delayed (ie, local formation of edema and decrease of muscle activity) by repeated air-pulsed cryotherapy, we provide evidence that this cooling procedure failed to improve long

A UV-Induced Genetic Network Links the RSC Complex to Nucleotide Excision Repair and Shows Dose-Dependent Rewiring

Directory of Open Access Journals (Sweden)

Rohith Srivas

2013-12-01

Full Text Available Efficient repair of UV-induced DNA damage requires the precise coordination of nucleotide excision repair (NER with numerous other biological processes. To map this crosstalk, we generated a differential genetic interaction map centered on quantitative growth measurements of >45,000 double mutants before and after different doses of UV radiation. Integration of genetic data with physical interaction networks identified a global map of 89 UV-induced functional interactions among 62 protein complexes, including a number of links between the RSC complex and several NER factors. We show that RSC is recruited to both silenced and transcribed loci following UV damage where it facilitates efficient repair by promoting nucleosome remodeling. Finally, a comparison of the response to high versus low levels of UV shows that the degree of genetic rewiring correlates with dose of UV and reveals a network of dose-specific interactions. This study makes available a large resource of UV-induced interactions, and it illustrates a methodology for identifying dose-dependent interactions based on quantitative shifts in genetic networks.

Experimentally induced, synergistic late effects of a single dose of radiation and aging: significance in LKS fraction as compared with mature blood cells.

Science.gov (United States)

Hirabayashi, Yoko; Tsuboi, Isao; Nakachi, Kei; Kusunoki, Yoichiro; Inoue, Tohru

2015-03-01

The number of murine mature blood cells recovered within 6 weeks after 2-Gy whole-body irradiation at 6 weeks of age, whereas in the case of the undifferentiated hematopoietic stem/progenitor cell (HSC/HPC) compartment [cells in the lineage-negative, c-kit-positive and stem-cell-antigen-1-positive (LKS) fraction], the numerical differences between mice with and without irradiation remained more than a year, but conclusively the cells showed numerical recovery. When mice were exposed to radiation at 6 months of age, acute damages of mature blood cells were rather milder probably because of their maturation with age; but again, cells in the LKS fraction were specifically damaged, and their numerical recovery was significantly delayed probably as a result of LKS-specific cellular damages. Interestingly, in contrast to the recovery of the number of cells in the LKS fraction, their quality was not recovered, which was quantitatively assessed on the basis of oxidative-stress-related fluorescence intensity. To investigate why the recovery in the number of cells in the LKS fraction was delayed, expression levels of genes related to cellular proliferation and apoptosis of cells in the bone marrow and LKS fraction were analyzed by real-time polymerase chain reaction (RT-PCR). In the case of 21-month-old mice after radiation exposure, Ccnd1, PiK3r1 and Fyn were overexpressed solely in cells in the LKS fraction. Because Ccnd1and PiK3r1 upregulated by aging were further upregulated by radiation, single-dose radiation seemed to induce the acceleration of aging, which is related to the essential biological responses during aging based on a lifetime-dependent relationship between a living creature and xenobiotic materials. Copyright © 2014 John Wiley & Sons, Ltd.

Todralazine protects zebra fish from lethal doses of ionizing radiation: role of hematopoietic stem cell expansion

International Nuclear Information System (INIS)

Dimri, Manali; Joshi, Jaidev; Indracanti, Prem Kumar

2013-01-01

Radiation induced cell killing and hematopoietic stem cell depletion leads to compromised immune functions and opportunistic infections which significantly affect the recovery and survival upon irradiation. Any agent which can expand residual hematopoietic stem cells in irradiated organism can render protection from the effects of lethal doses of ionizing radiation. Johns Hopkins Clinical compound library (JHCCL) was screened for protection against lethal doses of ionizing radiation using developing zebra fish as a model organism. Modulation of radiation induced reactive oxygen species by the small molecules were done by DCFDA staining and for visual identification and quantification of apoptosis acridine orange assay, flow cytometry were employed respectively. Hematopoietic stem cell expansion potential was assessed by quantifying runx1 expression, a marker for definitive stem cells, were done by RT-PCR and by the kinetics of recovery from chemically induced anaemia. Todralazine hydrochloride from JHCCL exhibited promising results with potential anti radiation effects. A dose of 5μM was found to be the most effective and has rendered significant organ and whole body protection (100% survival advantage over a period of 6 days) against 20 Gy. However todralazine did not modulated radiation induced free radicals (monitored within 2 h of irradiation) and apoptosis in zebra fish embryos analysed at 8 and 24h post irradiation. Flow cytometric quantification of pre G1 population suggested the same. Chemoinformatics approaches were further carried out to elucidate possible targets which are contributing to its radioprotection potential. Structural similarity search suggested several targets and possible hematopoietic stem cell expanding potential. Treatment of zebra fish embryos with todralazine has lead to significant proliferation of hematopoietic stem cell as indicated by increase in expression of runx1. HSC expanding potential of todralazine was further supported by

Dose-response relationship for chromosomal aberrations induced in human lymphocytes by 18 MeV electron beam irradiation

International Nuclear Information System (INIS)

Lashin, E.A.; Elaasar, E.M.; Moustafa, H.F.; Bakir, Y.Y.; Al Zenki, S.D.

1990-01-01

Dose response curves for lymphocyte chromosome aberration frequencies using X- and gamma radiation became an important and reliable indicator as biological dosimeter especially in radiation accidents and occupational over exposures. Nowadays electron beam therapy is frequently used for their advantages in cases of tumours under or near to the body surface. Dose-response curves for these electron beams are rarely published. Human peripheral blood lymphocytes were in vitro irradiated with various low and high doses (0.1 Gy to 4.9 Gy) of 18 MeV electron beams to utilize such a dose-response curve using chromosomal aberration frequencies as a biological indicator. Then we compared the biological curve with physically obtained curves normally used in planning for radiotherapy treatment. It is interesting to find a significant difference between both of them. The biological curve is generally higher in value and the aberrations induced by 93% of a dose is significantly higher and deeper in site than those aberrations induced by the 100% dose calculated physically. If the above observation is confirmed by detailed studies, it would be of importance to the radiotherapist to plan for isodose curves according to biological determinations. (author)

Effect of L-glutamate on the metabolic recovery of the myocardium after K sup (+)- induced cardioplegic arrest. Die effek van L-glutamaat op die metaboliese herstel van die miokard na K sup (+)-geinduseerde kardioplegiese arres

Energy Technology Data Exchange (ETDEWEB)

Neethling, W M.L.

1984-01-01

A study was undertaken to determine the effect of L-glutamate on the metabolic recovery of the myocardium after K sup (+)-induced cardioplegic arrest. Isolated rat hearts and intact dog hearts were subjected to a K sup (+)-induced cardioplegic period of 60 minutes. Preservation temperature was kept constant at 26 degrees Celsius during the entire cardioplegic period. Different concentrations of L-glutamate were added to a dose of secondary cardioplegia. Several parameters, such as isotonic contraction, left ventricular function, enzymatic changes, coronary vascular resistance (coronary flow), oedema, re-animation time-interval and lactate-release were used to determine the above mentioned effect. Radioactive L-glutamate was used to determine the quantitative uptake and distribution of L-glutamate in the myocardium. Basic spectrophotometric methods were used to determine the concentrations of creatine phosphokinase, lactic dehydrogenase and lactate. Standard differential separation methods were used to divide myocardial samples into the different tissue and cytologic fractions. Biophysical methods were used to measure radioactivity in the respective tissue and cytologic fractions. Experimental results were statistically analyzed according to analysis of variance and at-test (Tukey's Test). Preliminary findings stress the important role of L-glutamate in the metabolic recovery of the myocardium after K sup (+)-induced arrest and consequently the positive contribution in the search for the best method of myocardial preservation during cardiac surgery.

Dose-Response Effects of Exercise Duration and Recovery on Cognitive Functioning.

Science.gov (United States)

Crush, Elizabeth A; Loprinzi, Paul D

2017-12-01

We examined the effects of different acute exercise durations and recovery periods on cognitive function in a counterbalanced, cross-over randomized controlled experiment. We placed 352 participants, aged 18 to 35 years into one of 16 experimental groups. Each participant visited the laboratory twice, separated by a 1-week washout period. Either Visit 1 or 2 consisted of an acute bout of moderate-intensity treadmill exercise (10, 20, 30, 45, or 60 minutes) followed by a period of rest (5, 15, or 30 minutes) before taking a set of five cognitive tests; the other visit consisted only of completing the cognitive tests (no exercise). Cognitive tests sampled multiple cognitive parameters, including reasoning, concentration, memory, attention, and planning. We found that a short recovery period (i.e., 5 minutes) may have a less favorable effect on planning ability but may be beneficial for memory. In addition, for various exercise durations and recovery periods, a Group × Time × Resting (nonexercise) A cognitive interaction effect was observed such that for both memory and inhibitory cognitive ability, acute exercise (vs. no exercise) had an enhancement effect for those with lower resting cognitive functioning. The length of the acute exercise recovery period and resting cognitive ability most influenced the association between exercise and cognitive function.

γ irradiation with different dose rates induces different DNA damage responses in Petunia x hybrida cells.

Science.gov (United States)

Donà, Mattia; Ventura, Lorenzo; Macovei, Anca; Confalonieri, Massimo; Savio, Monica; Giovannini, Annalisa; Carbonera, Daniela; Balestrazzi, Alma

2013-05-15

In plants, there is evidence that different dose rate exposures to gamma (γ) rays can cause different biological effects. The dynamics of DNA damage accumulation and molecular mechanisms that regulate recovery from radiation injury as a function of dose rate are poorly explored. To highlight dose-rate dependent differences in DNA damage, single cell gel electrophoresis was carried out on regenerating Petunia x hybrida leaf discs exposed to LDR (total dose 50 Gy, delivered at 0.33 Gy min(-1)) and HDR (total doses 50 and 100 Gy, delivered at 5.15 Gy min(-1)) γ-ray in the 0-24h time period after treatments. Significant fluctuations of double strand breaks and different repair capacities were observed between treatments in the 0-4h time period following irradiation. Dose-rate-dependent changes in the expression of the PhMT2 and PhAPX genes encoding a type 2 metallothionein and the cytosolic isoform of ascorbate peroxidase, respectively, were detected by Quantitative RealTime-Polymerase Chain Reaction. The PhMT2 and PhAPX genes were significantly up-regulated (3.0- and 0.7-fold) in response to HDR. The results are discussed in light of the potential practical applications of LDR-based treatments in mutation breeding. Copyright © 2013 Elsevier GmbH. All rights reserved.

Chronic Fluoxetine Induces Activity Changes in Recovery From Poststroke Anxiety, Depression, and Cognitive Impairment.

Science.gov (United States)

Vahid-Ansari, Faranak; Albert, Paul R

2018-01-01

Poststroke depression (PSD) is a common outcome of stroke that limits recovery and is only partially responsive to chronic antidepressant treatment. In order to elucidate changes in the cortical-limbic circuitry associated with PSD and its treatment, we examined a novel mouse model of persistent PSD. Focal endothelin-1-induced ischemia of the left medial prefrontal cortex (mPFC) in male C57BL6 mice resulted in a chronic anxiety and depression phenotype. Here, we show severe cognitive impairment in spatial learning and memory in the stroke mice. The behavioral and cognitive phenotypes were reversed by chronic (4-week) treatment with fluoxetine, alone or with voluntary exercise (free-running wheel), but not by exercise alone. To assess chronic cellular activation, FosB + cells were co-labeled for markers of glutamate/pyramidal (VGluT1-3/CaMKIIα), γ-aminobutyric acid (GAD67), and serotonin (TPH). At 6 weeks poststroke versus sham (or 4 days poststroke), left mPFC stroke induced widespread FosB activation, more on the right (contralesional) than on the left side. Stroke activated glutamate cells of the mPFC, nucleus accumbens, amygdala, hippocampus, and raphe serotonin neurons. Chronic fluoxetine balanced bilateral neuronal activity, reducing total FosB and FosB/CamKII + cells (mPFC, nucleus accumbens), and unlike exercise, increasing FosB/GAD67 + cells (septum, amygdala) or both (hippocampus, raphe). In summary, chronic antidepressant but not exercise mediates recovery in this unilateral ischemic PSD model that is associated with region-specific reversal of stroke-induced pyramidal cell hyperactivity and increase in γ-aminobutyric acidergic activity. Targeted brain stimulation to restore brain activity could provide a rational approach for treating clinical PSD.

Laser induced photoreceptor damage and recovery in the high numerical aperture eye of the garter snake.

Science.gov (United States)

Zwick, H; Edsall, P; Stuck, B E; Wood, E; Elliott, R; Cheramie, R; Hacker, H

2008-02-01

The garter snake provides a unique model for in-vivo imaging of photoreceptor damage induced by laser retinal exposure. Laser thermal/mechanical retinal injury induced alterations in photoreceptor structure and leukocyte cellular behavior. Photoreceptors turned white, lost mode structure, and swelled; leukocyte activity was observed in the vicinity of photoreceptor cells. Non-thermal alterations were identified with a bio-tag for oxidative stress. Mechanisms of photoreceptor recovery and replacement were observed and evaluated for active cytoskeletal systems by using an anti-actin tag that could detect the presence of active cytoskeletal systems resident in photoreceptors as well as other retinal systems.

Ultraviolet Radiation Induces Dose-Dependent Pigment Dispersion in Crustacean Chromatophores

OpenAIRE

Gouveia, Glauce Ribeiro; Lopes, Thaís Martins; Neves, Carla Amorim; Nery, Luiz Eduardo Maia; Trindade, Gilma Santos

2004-01-01

Pigment dispersion in chromatophores as a response to UV radiation was investigated in two species of crustaceans, the crab Chasmagnathus granulata and the shrimp Palaemonetes argentinus. Eyestalkless crabs and shrimps maintained on either a black or a white background were irradiated with different UV bands. In eyestalkless crabs the significant minimal effective dose inducing pigment dispersion was 0.42 J/cm2 for UVA and 2.15 J/cm2 for UVB. Maximal response was achieved with 10.0 J/cm...

Long-term recovery of spermatogenesis after radiotherapy in patient with testicular cancer

International Nuclear Information System (INIS)

Hansen, P.V.; Trykker, H.; Svennkjaer, I.L.; Hvolby, J.

1990-01-01

Gonadal function was evaluated before irradiation and by serial analyses after treatment in 27 patients with seminomas and 24 patients with nonseminomatous germ cell tumors of the testis. During subdiaphragmatic irradiation, a median testicular dose of 1.7 reached the remaining testis. Twenty nonseminoma patients were treated with adjuvant chemotherapy. After orchiectomy, 94% had spermatozoa in semen, 49% had a total sperm count exceeding the reference value, and in 67% serum follicle-stimulating hormone levels were normal. The corresponding estimated values 5 and 9 years after treatment were 61%, 13%, 14%, and 84%, 35%, 32%, respectively. A Cox regression analysis of recovery, with azoospermia used as an endpoint, showed that (1) recovery depended on the radiation dose, (2) adjuvant chemotherapy prolonged the recovery period, (3) recovery was decreased in patients with low pretreatment total sperm counts and in patients older than 25 years. A prognostic index was derived from the regression model and radiation dose-response curves were calculated. The authors conlude that a profound, dose-dependent impairment of spermatogenesis is caused by raiation scatter reaching the testis during subdiaphragmal irradiation. An effective gonadal shield should reduce the gonadal dose to a level low enough to preverse spermatogenesis in most patients. (authors). 36 refs.; 4 figs.; 3 tabs

cDNA cloning and transcriptional controlling of a novel low dose radiation-induced gene and its function analysis

International Nuclear Information System (INIS)

Zhou Pingkun; Sui Jianli

2002-01-01

Objective: To clone a novel low dose radiation-induced gene (LRIGx) and study its function as well as its transcriptional changes after irradiation. Methods: Its cDNA was obtained by DDRT-PCR and RACE techniques. Northern blot hybridization was used to investigate the gene transcription. Bioinformatics was employed to analysis structure and function of this gene. Results: LRIGx cDNA was cloned. The sequence of LRIGx was identical to a DNA clone located in human chromosome 20 q 11.2-12 Bioinformatics analysis predicted an encoded protein with a conserved helicase domain. Northern analysis revealed a ∼8.5 kb transcript which was induced after 0.2 Gy as well as 0.02 Gy irradiation, and the transcript level was increased 5 times at 4 h after 0.2 Gy irradiation. The induced level of LRIGx transcript by 2.0 Gy high dose was lower than by 0.2 Gy. Conclusion: A novel low dose radiation-induced gene has been cloned. It encodes a protein with a conserved helicase domain that could involve in DNA metabolism in the cellular process of radiation response

Recovery in soccer : part ii-recovery strategies.

Science.gov (United States)

Nédélec, Mathieu; McCall, Alan; Carling, Chris; Legall, Franck; Berthoin, Serge; Dupont, Gregory

2013-01-01

now do not significantly accelerate the return to initial levels of performance in comparison with a control condition. In conclusion, scientific evidence to support the use of strategies commonly used during recovery is lacking. Additional research is required in this area in order to help practitioners establish an efficient recovery protocol immediately after matchplay, but also for the following days. Future studies could focus on the chronic effects of recovery strategies, on combinations of recovery protocols and on the effects of recovery strategies inducing an anti-inflammatory or a pro-inflammatory response.

Reversal of rocuronium-induced neuromuscular block by the selective relaxant binding agent sugammadex: a dose-finding and safety study

DEFF Research Database (Denmark)

Sorgenfrei, Iben F; Norrild, Kathrine; Larsen, Per Bo

2006-01-01

Sugammadex (Org 25969) forms a complex with steroidal neuromuscular blocking agents, thereby reversing neuromuscular block. This study investigated the dose-response relation, safety, and pharmacokinetics of sugammadex to reverse rocuronium-induced block.......Sugammadex (Org 25969) forms a complex with steroidal neuromuscular blocking agents, thereby reversing neuromuscular block. This study investigated the dose-response relation, safety, and pharmacokinetics of sugammadex to reverse rocuronium-induced block....

Prospect of shale gas recovery enhancement by oxidation-induced rock burst

Directory of Open Access Journals (Sweden)

Lijun You

2017-11-01

Full Text Available By horizontal well multi-staged fracturing technology, shale rocks can be broken to form fracture networks via hydraulic force and increase the production rate of shale gas wells. Nonetheless, the fracturing stimulation effect may be offset by the water phase trapping damage caused by water retention. In this paper, a technique in transferring the negative factor of fracturing fluid retention into a positive factor of changing the gas existence state and facilitating shale cracking was discussed using the easy oxidation characteristics of organic matter, pyrite and other minerals in shale rocks. Furthermore, the prospect of this technique in tackling the challenges of large retention volume of hydraulic fracturing fluid in shale gas reservoirs, high reservoir damage risks, sharp production decline rate of gas wells and low gas recovery, was analyzed. The organic matter and pyrite in shale rocks can produce a large number of dissolved pores and seams to improve the gas deliverability of the matrix pore throats to the fracture systems. Meanwhile, in the oxidation process, released heat and increased pore pressure will make shale rock burst, inducing expansion and extension of shale micro-fractures, increasing the drainage area and shortening the gas flowing path in matrix, and ultimately, removing reservoir damage and improving gas recovery. To sum up, the technique discussed in the paper can be used to “break” shale rocks via hydraulic force and to “burst” shale rocks via chemical oxidation by adding oxidizing fluid to the hydraulic fracturing fluid. It can thus be concluded that this method can be a favorable supplementation for the conventional hydraulic fracturing of shale gas reservoirs. It has a broad application future in terms of reducing costs and increasing profits, maintaining plateau shale gas production and improving shale gas recovery.

Low dose β-emitter source induces sexual reproduction instead of fragmentation in an earthworm, Enchytraeus japonensis

International Nuclear Information System (INIS)

Miyachi, Yukihisa; Kanao, Tomoko; Okamoto, Takehito

2005-01-01

We examined whether background radiation, or radiation at a slightly higher level, plays a role in the reproduction of a terrestrial earthworm. Enchytraeus japonensis a recently described terrestrial oligochaete, reproduces asexually by fragmentation and subsequent regeneration. Following radiation exposure in which the worms were subjected to a 32 P β-emitter source at 15 times the background dose rate (4.5 μGy/h), a statistically significant decrease in the number of fragmentations was observed as compared with the sham controls. At that time, in a stained preparation with haematoxylin and eosin (HE), sexual reproduction occurred instead of asexual fragmentation, and mature oocytes were observed in the body of grown worms. However, increasing the radiation dose rate by 30 μGy/h resulted in the complete disappearance of the radiation-induced effects, i.e., fragmentation again occurred after 14 h. The results of this study indicate that a lower dose of radiation may be essential to achieve sexual reproduction, inducing an inhibition of fragmentation (asexual reproduction), but at higher, more cytotoxic doses of radiation these effects are negated

Skeletal muscle mass recovery from atrophy in IL-6 knockout mice.

Science.gov (United States)

Washington, T A; White, J P; Davis, J M; Wilson, L B; Lowe, L L; Sato, S; Carson, J A

2011-08-01

Skeletal muscle interleukin-6 (IL-6) expression is induced by continuous contraction, overload-induced hypertrophy and during muscle regeneration. The loss of IL-6 can alter skeletal muscle's growth and extracellular matrix remodelling response to overload-induced hypertrophy. Insulin-like growth factor-1 (IGF-1) gene expression and related signalling through Akt/mTOR is a critical regulator of muscle mass. The significance of IL-6 expression during the recovery from muscle atrophy is unclear. This study's purpose was to determine the effect of IL-6 loss on mouse gastrocnemius (GAS) muscle mass during recovery from hindlimb suspension (HS)-induced atrophy. Female C57BL/6 [wild type (WT)] and IL-6 knockout (IL-6 KO) mice at 10 weeks of age were assigned to control, HS or HS followed by normal cage ambulation groups. GAS muscle atrophy was induced by 10 days of HS. HS induced a 20% loss of GAS mass in both WT and IL-6 KO mice. HS+7 days of recovery restored WT GAS mass to cage-control values. GAS mass from IL-6 KO mice did not return to cage-control values until HS+14 days of recovery. Both IGF-1 mRNA expression and Akt/mTOR signalling were increased in WT muscle after 1 day of recovery. In IL-6 KO muscle, IGF-1 mRNA expression was decreased and Akt/mTOR signalling was not induced after 1 day of recovery. MyoD and myogenin mRNA expression were both induced in WT muscle after 1 day of recovery, but not in IL-6 KO muscle.   Muscle IL-6 expression appears important for the initial growth response during the recovery from disuse. © 2011 The Authors. Acta Physiologica © 2011 Scandinavian Physiological Society.

Benchmark studies of induced radioactivity and remanent dose rates produced in LHC materials

International Nuclear Information System (INIS)

Brugger, M.; Mayer, S.; Roesler, S.; Ulrici, L.; Khater, H.; Prinz, A.; Vincke, H.

2005-01-01

Samples of materials that will be used for elements of the LHC machine as well as for shielding and construction components were irradiated in the stray radiation field of the CERN-EU high-energy Reference Field facility. The materials included various types of steel, copper, titanium, concrete and marble as well as light materials such as carbon composites and boron nitride. Emphasis was put on an accurate recording of the irradiation conditions, such as irradiation profile and intensity, and on a detailed determination of the elemental composition of the samples. After the irradiation, the specific activity induced in the samples as well as the remanent dose rate were measured at different cooling times ranging from about 20 minutes to two months. Furthermore, the irradiation experiment was simulated using the FLUKA Monte Carlo code and specific activities. In addition, dose rates were calculated. The latter was based on a new method simulating the production of various isotopes and the electromagnetic cascade induced by radioactive decay at a certain cooling time. In general, solid agreement was found, which engenders confidence in the predictive power of the applied codes and tools for the estimation of the radioactive nuclide inventory of the LHC machine as well as the calculation of remanent doses to personnel during interventions. (authors)

Spectral Induced Polarization (SIP) monitoring during Microbial Enhanced Oil Recovery (MEOR)

Science.gov (United States)

Heenan, J. W.; Ntarlagiannis, D.; Slater, L. D.

2010-12-01

Jeffrey Heenan, Dimitrios Ntarlagiannis, Lee Slater Department of Earth and Environmental Sciences, Rutgers University, Newark NJ Microbial Enhanced Oil Recovery (MEOR) is an established, cost effective, method for enhancing tertiary oil recovery. Although not commonly used for shallow heavy oils, it could be a viable alternative since it can offer sustainable economic recovery and minimal environmental impact. A critical component of successful MEOR treatments is accurate, real time monitoring of the biodegradation processes resulting from the injection of microbial communities into the formation; results of recent biogeophysical research suggest that minimally-invasive geophysical methods could significantly contribute to such monitoring efforts. Here we present results of laboratory experiments, to assess the sensitivity of the spectral induced polarization method (SIP) to MEOR treatments. We used heavy oil, obtained from a shallow oilfield in SW Missouri, to saturate three sand columns. We then followed common industry procedures,and used a commercially available microbial consortia, to treat the oil columns. The active MEOR experiments were performed in duplicate while a control column maintained similar conditions, without promoting microbial activity and oil degradation. We monitored the SIP signatures, between 0.001 Hz and 1000 Hz, for a period of six months. To support the geophysical measurements we also monitored common geochemical parameters, including pH, Eh and fluid conductivity, and collected weekly fluid samples from the outflow and inflow for further analysis; fluid samples were analyzed to confirm that microbes actively degraded the heavy oils in the column while destructive analysis of the solid materials was performed upon termination of the experiment. Preliminary analysis of the results suggests that SIP is sensitive to MEOR processes. In both inoculated columns we recorded an increase in the low frequency polarization with time; measureable

Modeling long recovery early events (LOREs) produced by lightning-induced ionization of the nighttime upper mesosphere

Science.gov (United States)

Kotovsky, D. A.; Moore, R. C.

2017-07-01

We present results of a cylindrically symmetric, coupled electrodynamic, and photochemical model which simulates diffuse ionization of the middle atmosphere induced by strong lightning discharges (peak currents >150 kA). Scattering of subionospherically propagating, very low frequency radio waves is then evaluated using the Long-Wave Propagation Capability code. Some modeled sprite halos exhibit continued electron density growth up to timescales of seconds due to O- detachment, though it is not yet clear how this might relate to the slower onset durations (>20 ms) of some early VLF events. Modeled electron density enhancements in sprite halos, capable of strong VLF scattering, can persist for long periods of time (greater than hundreds of seconds) even at lower altitudes where their recovery is initially controlled by fast attachment processes. Consequently, our modeling results indicate that both typical recovery (20 to 240 s) and long recovery (LOREs, >300 s) VLF scattering events can be explained by scattering from conductivity changes associated with sprite halos. In contrast, modeled scattered fields resulting from elve-associated conductivity changes, though exhibiting long recovery times, are too weak to sufficiently explain typical LORE observations. Theoretical scattering from structured ionization events (e.g., sprites columns and gigantic jets) is not considered in this work.

Brain Tumor Therapy-Induced Changes in Normal-Appearing Brainstem Measured With Longitudinal Diffusion Tensor Imaging

International Nuclear Information System (INIS)

Hua Chiaho; Merchant, Thomas E.; Gajjar, Amar; Broniscer, Alberto; Zhang, Yong; Li Yimei; Glenn, George R.; Kun, Larry E.; Ogg, Robert J.

2012-01-01

Purpose: To characterize therapy-induced changes in normal-appearing brainstems of childhood brain tumor patients by serial diffusion tensor imaging (DTI). Methods and Materials: We analyzed 109 DTI studies from 20 brain tumor patients, aged 4 to 23 years, with normal-appearing brainstems included in the treatment fields. Those with medulloblastomas, supratentorial primitive neuroectodermal tumors, and atypical teratoid rhabdoid tumors (n = 10) received postoperative craniospinal irradiation (23.4–39.6 Gy) and a cumulative dose of 55.8 Gy to the primary site, followed by four cycles of high-dose chemotherapy. Patients with high-grade gliomas (n = 10) received erlotinib during and after irradiation (54–59.4 Gy). Parametric maps of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were computed and spatially registered to three-dimensional radiation dose data. Volumes of interest included corticospinal tracts, medial lemnisci, and the pons. Serving as an age-related benchmark for comparison, 37 DTI studies from 20 healthy volunteers, aged 6 to 25 years, were included in the analysis. Results: The median DTI follow-up time was 3.5 years (range, 1.6–5.0 years). The median mean dose to the pons was 56 Gy (range, 7–59 Gy). Three patterns were seen in longitudinal FA and apparent diffusion coefficient changes: (1) a stable or normal developing time trend, (2) initial deviation from normal with subsequent recovery, and (3) progressive deviation without evidence of complete recovery. The maximal decline in FA often occurred 1.5 to 3.5 years after the start of radiation therapy. A full recovery time trend could be observed within 4 years. Patients with incomplete recovery often had a larger decline in FA within the first year. Radiation dose alone did not predict long-term recovery patterns. Conclusions: Variations existed among individual patients after therapy in longitudinal evolution of brainstem white matter injury and recovery. Early response

"Interaction of different doses of Aspartame with Morphine-induced antinociception in the presence of MK-801, a NMDA antagonist "

Directory of Open Access Journals (Sweden)

Abdollahi M

2002-07-01

Full Text Available This study was designed to investigate the relative role of sweetness and comparative effects of different taste sensation of the non - caloric sweetener , aspartame on pain and its interaction with MK - 80] as a non - selective MMDA antagonist by formalin - test in mice. The formalin - test was chosen because it measures the response to a long - lasting nociceptive stimulus and closely resembles to the clinical pain. Morphine induced a dose dependent antinociception in the early and late phases of formalin test. Twelve days pretreatment of animals by aspartame ( 0.08% , 0.16% , 0.32% significantly potentiated morphine - induced (1.5-9 mg/kg analgesia in the early phase but significantly antagonized its analgesic effect in the late phase, dose dependently. Aspartame (0.16% alone showed a reduction in pain response . Naloxone (0.4 mg/kg significantly antagonized the antinociceptive effect of morphine in the presence of aspartame (0-0.32% in the early phase. Increasing the dose of aspartame decreased effects of naloxone. MK-801 (0.1 mg/kg as an N- Methyl - D - Aspartate (NMDA antagonist significantly potentiated the effect of aspartame on morphine - induced antinociception in the early phase. In the late phase, naloxone (0.4 mg/kg increased pain response but MK- 801 (0.1 mg/kg induced anti-inflammatory effect significantly. Treatment of animals with MK- 801 alone, significantly induced analgesia in both phases of formalin - test. This effect was potentiated with aspartame dose - dependently. Possible interaction of aspartame with NMDA receptors and its role to facilitate endogenous opioid system are proposed mechanisms of aspartame in modulating morphine - induced antinociception. Furthermore, the resulting association between morphine and aspartame chronic consumption may be explained as an interactive action rather than simple dose combination of both drugs.

Train-of-four ratio recovery often precedes twitch recovery when neuromuscular block is reversed by sugammadex

NARCIS (Netherlands)

Staals, L.M.; Driessen, J.J.; Egmond, J. van; Boer, H.D. de; Klimek, M.; Flockton, E.A.; Snoeck, M.M.J.

2011-01-01

BACKGROUND: Sugammadex reverses rocuronium-induced neuromuscular block (NMB). In all published studies investigating sugammadex, the primary outcome parameter was a train-of-four (TOF) ratio of 0.9. The recovery time of T1 was not described. This retrospective investigation describes the recovery of

Neuroprotection and mechanisms of atractylenolide III in preventing learning and memory impairment induced by chronic high-dose homocysteine administration in rats.

Science.gov (United States)

Zhao, H; Ji, Z-H; Liu, C; Yu, X-Y

2015-04-02

Studies demonstrated that chronic high-dose homocysteine administration induced learning and memory impairment in animals. Atractylenolide III (Aen-III), a neuroprotective constituent of Atractylodis macrocephalae Koidz, was isolated in our previous study. In this study, we investigated potential benefits of Aen-III in preventing learning and memory impairment following chronic high-dose homocysteine administration in rats. Results showed that administration of Aen-III significantly ameliorated learning and memory impairment induced by chronic high-dose homocysteine administration in rats, decreased homocysteine-induced reactive oxygen species (ROS) formation and restored homocysteine-induced decrease of phosphorylated protein kinase C expression level. Moreover, Aen-III protected primary cultured neurons from apoptotic death induced by homocysteine treatment. This study provides the first evidence for the neuroprotective effect of Aen-III in preventing learning and impairment induced by chronic administration of homocysteine. Aen-III may have therapeutic potential in treating homocysteine-mediated cognitive impairment and neuronal injury. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Radiation-induced rectal complications are not influenced by age: a dose fractionation study in the rat.

Science.gov (United States)

van den Aardweg, Gerard J M J; Olofsen-van Acht, Manouk J J; van Hooije, Christel M C; Levendag, Peter C

2003-05-01

Radiation-induced complications of the rectum are an important dose-limiting factor in radiotherapy of pelvic malignancies. In general, animal studies demonstrated no differences in acute and late normal tissue toxicity with age, but little is known about rectal complications in relation to age. For this purpose, an extensive histological and dose fractionation study was carried out on the rectum of young (12 weeks) and older (77-80 weeks) rats. In this paper, the results of dose fractionation are presented in relation to age at the time of irradiation. Young and older animals were irradiated with single and fractionated doses. After irradiation, rectal complications could lead to occlusion and stenosis, eventually resulting in the clinical symptoms of a megacolon and a possible fistula. For each dose group, cumulative survival rates were obtained with Kaplan-Meier analysis, from which dose-effect curves and the associated LD(50) values for a megacolon/fistula were calculated. The majority of responders died between 8 and 24 weeks after irradiation, irrespective of age. For both age groups, only the fractionation data showed a reduction in the mean latency with increasing dose. In the older age group, 39% of the responders developed a fistula compared to 26% for the younger animals. The LD(50) values increased from around 30 Gy after single doses to nearly 65 Gy after 10 fractions. The increases in LD(50) values with the number of fractions were independent of the age of the rats. For each of the dose fractionation schedules, log-rank testing indicated no significant differences in cumulative survival rates between younger and older animals (P > 0.10). The high alpha/beta ratios obtained for both the young and older animals strongly suggested that the late rectal complications were a consequence of early epithelial injury. Associated histological findings indicated that blood vessel damage, which was already evident at a high incidence at 4 weeks after irradiation

Dose dependency of time of onset of radiation-induced growth hormone deficiency

International Nuclear Information System (INIS)

Clayton, P.E.; Shalet, S.M.

1991-01-01

Growth hormone (GH) secretion during insulin-induced hypoglycemia was assessed on 133 occasions in 82 survivors of childhood malignant disease. All had received cranial irradiation with a dose range to the hypothalamic-pituitary axis of 27 to 47.5 Gy (estimated by a schedule of 16 fractions over 3 weeks) and had been tested on one or more occasions between 0.2 and 18.9 years after treatment. Results of one third of the GH tests were defined as normal (GH peak response, greater than 15 mU/L) within the first 5 years, in comparison with 16% after 5 years. Stepwise multiple linear regression analysis showed that dose (p = 0.007) and time from irradiation (p = 0.03), but not age at therapy, had a significant influence on peak GH responses. The late incidence of GH deficiency was similar over the whole dose range (4 of 26 GH test results normal for less than 30 Gy and 4 of 25 normal for greater than or equal to 30 Gy after 5 years), but the speed of onset over the first years was dependent on dose. We conclude that the requirement for GH replacement therapy and the timing of its introduction will be influenced by the dose of irradiation received by the hypothalamic-pituitary axis

Inhibition of the prostaglandin EP2 receptor is neuroprotective and accelerates functional recovery in a rat model of organophosphorus induced status epilepticus

Science.gov (United States)

Rojas, Asheebo; Ganesh, Thota; Lelutiu, Nadia; Gueorguieva, Paoula; Dingledine, Raymond

2015-01-01

Exposure to high levels of organophosphorus compounds (OP) can induce status epilepticus (SE) in humans and rodents via acute cholinergic toxicity, leading to neurodegeneration and brain inflammation. Currently there is no treatment to combat the neuropathologies associated with OP exposure. We recently demonstrated that inhibition of the EP2 receptor for PGE2 reduces neuronal injury in mice following pilocarpine-induced SE. Here, we investigated the therapeutic effects of an EP2 inhibitor (TG6-10-1) in a rat model of SE using diisopropyl fluorophosphate (DFP). We tested the hypothesis that EP2 receptor inhibition initiated well after the onset of DFP-induced SE reduces the associated neuropathologies. Adult male Sprague-Dawley rats were injected with pyridostigmine bromide (0.1 mg/kg, sc) and atropine methylbromide (20 mg/kg, sc) followed by DFP (9.5 mg/kg, ip) to induce SE. DFP administration resulted in prolonged upregulation of COX-2. The rats were administered TG6-10-1 or vehicle (ip) at various time points relative to DFP exposure. Treatment with TG6-10-1 or vehicle did not alter the observed behavioral seizures, however six doses of TG6-10-1 starting 80-150 min after the onset of DFP-induced SE significantly reduced neurodegeneration in the hippocampus, blunted the inflammatory cytokine burst, reduced microglial activation and decreased weight loss in the days after status epilepticus. By contrast, astrogliosis was unaffected by EP2 inhibition 4 d after DFP. Transient treatments with the EP2 antagonist 1 h before DFP, or beginning 4 h after DFP, were ineffective. Delayed mortality, which was low (10%) after DFP, was unaffected by TG6-10-1. Thus, selective inhibition of the EP2 receptor within a time window that coincides with the induction of cyclooxygenase-2 by DFP is neuroprotective and accelerates functional recovery of rats. PMID:25656476

Recovery Effect and Life Prolong Effect of Long Term Low-Dose Rate Irradiation on Type II Diabetes Model Mice

International Nuclear Information System (INIS)

Nomura, T.; Makino, N.; Oda, T.; Suzuki, I.; Sakai, K

2004-01-01

The effects of low-dose rate gamma-irradiation were investigated on model mice for type II diabetes mellitus, C57BL/KsJ-db/db. The mice develop the type II diabetes by 10 weeks of age due to obesity and are characterized by hyperinsulinemia. Female 10-week old mice, a group of 12 mice, were irradiated at 0.65 mGy/hr from 137-Cs (370 GBq). The urine glucose levels of all of the mice were strongly positive at the beginning of the irradiation. In the irradiated group, the decrease in the glucose level was observed in 3 mice. Such recovery from the diabetes was never observed in 12 mice of non-irradiated control group. There is no systematic difference in the change of body weight, food assumption, and amount of drinking water, between the irradiated group and the non-irradiated group or between the recovered mice and the non-recovered mice. The survival was better in the irradiated group: the surviving fraction at the age of 90 weeks was 75% in the irradiated group, while 40% in the non-irradiated. Marked difference was also observed in the appearance of the coat hair, skin, and tail; better condition was kept in the irradiated group. In the irradiated mice mortality was delayed and the healthy appearance was prolonged in the irradiated mice by about 20 ? 30 weeks compared with the non-irradiated mice. These results suggest that the low-dose irradiation modified the condition of the diabetic mice, which lead not only to the recovery of the diabetes, but also to the suppression of the aging process. (Author)

Single Low-Dose Radiation Induced Regulation of Keratinocyte Differentiation in Calcium-Induced HaCaT Cells

Science.gov (United States)

Hahn, Hyung Jin; Youn, Hae Jeong; Cha, Hwa Jun; Kim, Karam; An, Sungkwan

2016-01-01

Background We are continually exposed to low-dose radiation (LDR) in the range 0.1 Gy from natural sources, medical devices, nuclear energy plants, and other industrial sources of ionizing radiation. There are three models for the biological mechanism of LDR: the linear no-threshold model, the hormetic model, and the threshold model. Objective We used keratinocytes as a model system to investigate the molecular genetic effects of LDR on epidermal cell differentiation. Methods To identify keratinocyte differentiation, we performed western blots using a specific antibody for involucrin, which is a precursor protein of the keratinocyte cornified envelope and a marker for keratinocyte terminal differentiation. We also performed quantitative polymerase chain reaction. We examined whether LDR induces changes in involucrin messenger RNA (mRNA) and protein levels in calcium-induced keratinocyte differentiation. Results Exposure of HaCaT cells to LDR (0.1 Gy) induced p21 expression. p21 is a key regulator that induces growth arrest and represses stemness, which accelerates keratinocyte differentiation. We correlated involucrin expression with keratinocyte differentiation, and examined the effects of LDR on involucrin levels and keratinocyte development. LDR significantly increased involucrin mRNA and protein levels during calcium-induced keratinocyte differentiation. Conclusion These studies provide new evidence for the biological role of LDR, and identify the potential to utilize LDR to regulate or induce keratinocyte differentiation. PMID:27489424

Radioprotection by murine and human tumor-necrosis factor; Dose-dependent effects on hematopoiesis in the mouse

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Sloerdal, L; Muench, M O; Warren, D J; Moore, M A.S. [James Ewing Laboratory of Developmental Hematopoiesis, Memorial Sloan-Kettering Cancer Center, New York (USA)

1989-01-01

Tumor-necrosis factor (TNF) has been shown to confer significant radioprotection in murine models. Herein, we demonstrate a dose-dependent enhancement of hematological recovery when single doses of either murine or human recombinant TNF are administered prior to irradiation. In addition to its action upon leukocytes and erythocytes, TNF also alleviates radiation-induced thrombocytopenia in the mouse. These effects on circulating blood constituents are further reflected in increased numbers of both primitive (CFU-S) and more differentiated (CFU-GM, CFU-Mega) hematopoietic progenitors in TNF-treated animals. This suggests that TNF exerts it radioprotective effects on a pool of primitive multi-potential hematopoietic cells. (author).

Search for the lowest irradiation dose from literatures on radiation-induced cancer in gastrointestinal tract

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Yoshizawa, Y; Kusama, T [Tokyo Univ. (Japan). Faculty of Medicine

1976-05-01

A survey of past case reports about radiation-induced cancer in the gastrointestinal tract was carried out with the main object of finding the lowest irradiation dose. Search of the literature published since 1923 revealed 80 cases of radiation-induced large intestine cancer and one case of stomach cancer. The cases of radiation-induced cancer in the large intestine had received radiation for the treatment of non-malignant conditions, fibroma, ovarial cyste, myoma, endometritis and duodenal ulcer. The lowest irradiation dose was estimated at 460 rads. Adenocarcinoma was the histopathological finding in all cases of radiation-induced cancer in the caecum, colon and rectum, and squamous cell carcinoma in the cases of anal cancer. The latent period ranged from 1 to 31 years, with the average of 13.6 years. There were some reports of statistical studies of radiation-induced stomach cancer. Three groups were the subjects of these studies. The first group was composed of atomic bomb survivors, the second of patients who had undergone radiation treatment for ankylosing spondilitis, and the third of duodenal ulcer patients subjected to radiation treatment for the purpose of suppressing gastric acid secretion. These statistical studies showed no significant increase of the incidence of stomach cancer in the irradiated groups.

Search for the lowest irradiation dose from literatures on radiation-induced cancer in gastrointestinal tract

International Nuclear Information System (INIS)

Yoshizawa, Yasuo; Kusama, Tomoko

1976-01-01

A survey of past case reports about radiation-induced cancer in the gastrointestinal tract was carried out with the main object of finding the lowest irradiation dose. Search of the literature published since 1923 revealed 80 cases of radiation-induced large intestine cancer and one case of stomach cancer. The cases of radiation-induced cancer in the large intestine had received radiation for the treatment of non-malignant conditions, fibroma, ovarial cyste, myoma, endometritis and duodenal ulcer. The lowest irradiation dose was estimated at 460 rads. Adenocarcinoma was the histopathological finding in all cases of radiation-induced cancer in the caecum, colon and rectum, and squamous cell carcinoma in the cases of anal cancer. The latent period ranged from 1 to 31 years, with the average of 13.6 years. There were some reports of statistical studies of radiation-induced stomach cancer. Three groups were the subjects of these studies. The first group was composed of atomic bomb survivors, the second of patients who had undergone radiation treatment for ankylosing spondilitis, and the third of duodenal ulcer patients subjected to radiation treatment for the purpose of suppressing gastric acid secretion. These statistical studies showed no significant increase of the incidence of stomach cancer in the irradiated groups. (auth.)

Linking GABA(A) receptor subunits to alcohol-induced conditioned taste aversion and recovery from acute alcohol intoxication.

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Blednov, Y A; Benavidez, J M; Black, M; Chandra, D; Homanics, G E; Rudolph, U; Harris, R A

2013-04-01

GABA type A receptors (GABA(A)-R) are important for ethanol actions and it is of interest to link individual subunits with specific ethanol behaviors. We studied null mutant mice for six different GABA(A)-R subunits (α1, α2, α3, α4, α5 and δ). Only mice lacking the α2 subunit showed reduction of conditioned taste aversion (CTA) to ethanol. These results are in agreement with data from knock-in mice with mutation of the ethanol-sensitive site in the α2-subunit (Blednov et al., 2011). All together, they indicate that aversive property of ethanol is dependent on ethanol action on α2-containing GABA(A)-R. Deletion of the α2-subunit led to faster recovery whereas absence of the α3-subunit slowed recovery from ethanol-induced incoordination (rotarod). Deletion of the other four subunits did not affect this behavior. Similar changes in this behavior for the α2 and α3 null mutants were found for flurazepam motor incoordination. However, no differences in recovery were found in motor-incoordinating effects of an α1-selective modulator (zolpidem) or an α4-selective agonist (gaboxadol). Therefore, recovery of rotarod incoordination is under control of two GABA(A)-R subunits: α2 and α3. For motor activity, α3 null mice demonstrated higher activation by ethanol (1 g/kg) whereas both α2 (-/-) and α3 (-/Y) knockout mice were less sensitive to ethanol-induced reduction of motor activity (1.5 g/kg). These studies demonstrate that the effects of ethanol at GABAergic synapses containing α2 subunit are important for specific behavioral effects of ethanol which may be relevant to the genetic linkage of the α2 subunit with human alcoholism. Copyright © 2012 Elsevier Ltd. All rights reserved.

Low-dose ionizing radiation alleviates Aβ42-induced defective phenotypes in Drosophila Alzheimer's disease models

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Hwang, SooJin; Jeong, Hae Min; Nam, Seon Young [Low-dose Radiation Research Team, Radiation Health Institute, Korea Hydro & Nuclear Power Co. Ltd., Daejeon (Korea, Republic of)

2017-04-15

Alzheimer's disease (AD) is the most common neurodegenerative disease that is characterized by amyloid plaques, progressive neuronal loss, and gradual deterioration of memory. Amyloid imaging using positron emission tomography (PET) radiotracers have been developed and approved for clinical use in the evaluation of suspected neurodegenerative disease, including AD. Particularly, previous studies involving low-dose ionizing radiation on Aβ 42-treated mouse hippocampal neurons have suggested a potential role for low-dose ionizing radiation in the treatment of AD. However, associated in vivo studies involving the therapy effects of low-dose ionizing radiation on AD are still insufficient. As a powerful cell biological system, Drosophila AD models have been generated and established a useful model organism for study on the etiology of human AD. In this study, we investigated the hormesis effects of low-dose ionizing radiation on Drosophila AD models. Our results suggest that low-dose ionizing radiation have the beneficial effects on not only the Aβ42-induced developmental defective phenotypes but also motor defects in Drosophila AD models. These results might be due to a regulation of apoptosis, and provide insight into the hormesis effects of low-dose ionizing radiation. Our results suggest that low-dose ionizing radiation have the beneficial effects on not only the Aβ42-induced developmental defective phenotypes but also motor defects in Drosophila AD models. These results might be due to a regulation of apoptosis, and provide insight into the hormesis effects of low-dose ionizing radiation.

Persistent DNA damage after high dose in vivo gamma exposure of minipig skin.

Directory of Open Access Journals (Sweden)

Emad A Ahmed

Full Text Available Exposure to high doses of ionizing radiation (IR can lead to localized radiation injury of the skin and exposed cells suffer dsDNA breaks that may elicit cell death or stochastic changes. Little is known about the DNA damage response after high-dose exposure of the skin. Here, we investigate the cellular and DNA damage response in acutely irradiated minipig skin.IR-induced DNA damage, repair and cellular survival were studied in 15 cm(2 of minipig skin exposed in vivo to ~50 Co-60 γ rays. Skin biopsies of control and 4 h up to 96 days post exposure were investigated for radiation-induced foci (RIF formation using γ-H2AX, 53BP1, and active ATM-p immunofluorescence. High-dose IR induced massive γ-H2AX phosphorylation and high 53BP1 RIF numbers 4 h, 20 h after IR. As time progressed RIF numbers dropped to a low of 3-fold elevated at all subsequent time points. Replicating basal cells (Ki67+ were reduced 3 days post IR followed by increased proliferation and recovery of epidermal cellularity after 28 days.Acute high dose irradiation of minipig epidermis impaired stem cell replication and induced elevated apoptosis from 3 days onward. DNA repair cleared the high numbers of DBSs in skin cells, while RIFs that persisted in <1% cells marked complex and potentially lethal DNA damage up to several weeks after exposure. An elevated frequency of keratinocytes with persistent RIFs may thus serve as indicator of previous acute radiation exposure, which may be useful in the follow up of nuclear or radiological accident scenarios.

Effects of chronic irradiation on spermatogenesis: recovery phase

International Nuclear Information System (INIS)

Day, P.A.; Shifrine, M.; Overstreet, J.W.

1984-01-01

Recovery of sperm production was not seen in four beagles rendered azoospermic or severely oligospermic by exposure to 183 R of gamma radiation given at a dose rate of 1 R/day. Two other dogs from the same group showed a partial recovery, but with very low sperm counts and many abnormal spermatozoa. 1 figure

Chronic UVA (365-nm) irradiation induced scratching in hairless mice: dose-time dependency and the effect of ketanserin

International Nuclear Information System (INIS)

Laat, J.M.T. de; Groenendijk, M.; Vloten, W.A. van; Gruijl, F.R. de; Seite, S.

1997-01-01

In a study on the dose-response relationship for longwave UVA (UVA1; 340-400 nm) carcinogenesis in hairless mice scratch marks appeared after months of daily exposure as an unwanted side effect. Tumor induction in the highest of the 4 tested dose groups (receiving a daily dose of 430 kJ/m 2 of 365-nm radiation) could not be determined because extensive scarification occurred prior to the development of any tumors. The induction of scratch marks could be scored and quantified in all 4 dose groups tested. The UVA1 dose-dependencies for the induction of tumors and scratch marks were compared. We found that the induction of scratch marks depended mainly on the cumulative UVA1 exposure, whereas tumor induction showed a lesser dose-dependency. An attempt was made to prevent the apparent pruritogenic effect of UVA1 irradiation and to understand its mechanism. The influence of ketanserin, a serotonin/histamine antagonist, on the UVA1 induction of scratch marks was tested in groups of 8 mice daily irradiated with 430 kJ/m 2 . No difference was found between treated and untreated animals. Histological examination of skin biopsies from irradiated mice from the 430-kJ/m 2 dose group from the UVA1 carcinogenic experiment, showed no changes in numbers of mast cells or other inflammatory features when compared to skin biopsies from unirradiated control mice. This indicated that UVA1-induced scratching is not mediated through mast cell release of serotonin and/or histamine. An adequate therapeutic treatment which can prevent UVA1-induced scratching would enable us to test tumor induction with UVA1 over a larger dose range, and may provide additional insight in how this radiation damages the skin. It remains conjectural whether there exists and analogous UVA-induced pruritus in human skin. (au)

A mixture of Lactobacillus species isolated from traditional fermented foods promote recovery from antibiotic-induced intestinal disruption in mice.

Science.gov (United States)

Shi, Y; Zhao, X; Zhao, J; Zhang, H; Zhai, Q; Narbad, A; Chen, W

2018-03-01

This study evaluated the antibiotic-induced changes in microbial ecology, intestinal dysbiosis and low-grade inflammation; and the combined effect of four different Lactobacillus species on recovery of microbiota composition and improvement of gut barrier function in mice. Administration of the antibiotic ampicillin for 2 weeks decreased microbial community diversity, induced caecum tumefaction and increased gut permeability in mice. Application of a probiotic cocktail of four Lactobacillus species (JUP-Y4) modulated the microbiota community structure and promoted the abundance of potentially beneficial bacteria such as Akkermansia. Ampicillin administration led to a decline in Bacteroidetes from 46·6 ± 3·91% to 0·264 ± 0·0362%; the addition of JUP-Y4 restored this to 41·4 ± 2·87%. This probiotic supplementation was more effective than natural restoration, where the levels of Bacteroidetes were only restored to 29·3 ± 2·07%. Interestingly, JUP-Y4 treatment was more effective in the restoration of microbiota in faecal samples than in caecal samples. JUP-Y4 also significantly reduced the levels of d-lactate and endotoxin (lipopolysaccharide, LPS) in the serum of mice, and increased the expression of tight-junction proteins while reducing the production of inflammatory cytokines (TNF-α, IL-6, MCP-1, IFN-γ and IL-1β) in the ileum and the colon of antibiotic-treated mice. JUP-Y4 not only promoted recovery from antibiotic-induced gut dysbiosis, but also enhanced the function of the gut barrier, reduced inflammation and lowered levels of circulating endotoxin in mice. Consumption of a mixture of Lactobacillus species may encourage faster recovery from antibiotic-induced gut dysbiosis and gut microbiota-related immune disturbance. © 2018 The Society for Applied Microbiology.

Radiation induced skeletal changes in beagle: dose rates, dose, and age effect analysis from 226Ra

International Nuclear Information System (INIS)

Momeni, M.H.; Williams, J.R.; Rosenblatt, L.S.

1976-01-01

Radiation-induced skeletal injury (E) and the rate of skeletal injury were studied as a function of time and dose in beagles administered 226 Ra Cl 2 in eight semimonthly iv injections starting at 2, 4, or 14 months of age. Skeletal changes were evaluated with a radiographic x-ray scoring system in 20 skeletal regions; each region was scored on a 0 to 6 scale. Bone changes in six regions of humeri were qualitatively analyzed for comparison with total skeletal changes. Skeletal changes were classified by endosteal or periosteal cortical sclerosis and thickening, fractures, osteolytic lesions, and trabecular coarsening

Dynamic change of global and local information processing in propofol-induced loss and recovery of consciousness.

Directory of Open Access Journals (Sweden)

Martin M Monti

Full Text Available Whether unique to humans or not, consciousness is a central aspect of our experience of the world. The neural fingerprint of this experience, however, remains one of the least understood aspects of the human brain. In this paper we employ graph-theoretic measures and support vector machine classification to assess, in 12 healthy volunteers, the dynamic reconfiguration of functional connectivity during wakefulness, propofol-induced sedation and loss of consciousness, and the recovery of wakefulness. Our main findings, based on resting-state fMRI, are three-fold. First, we find that propofol-induced anesthesia does not bear differently on long-range versus short-range connections. Second, our multi-stage design dissociated an initial phase of thalamo-cortical and cortico-cortical hyperconnectivity, present during sedation, from a phase of cortico-cortical hypoconnectivity, apparent during loss of consciousness. Finally, we show that while clustering is increased during loss of consciousness, as recently suggested, it also remains significantly elevated during wakefulness recovery. Conversely, the characteristic path length of brain networks (i.e., the average functional distance between any two regions of the brain appears significantly increased only during loss of consciousness, marking a decrease of global information-processing efficiency uniquely associated with unconsciousness. These findings suggest that propofol-induced loss of consciousness is mainly tied to cortico-cortical and not thalamo-cortical mechanisms, and that decreased efficiency of information flow is the main feature differentiating the conscious from the unconscious brain.

Galactic cosmic ray-induced radiation dose on terrestrial exoplanets.

Science.gov (United States)

Atri, Dimitra; Hariharan, B; Grießmeier, Jean-Mathias

2013-10-01

This past decade has seen tremendous advancements in the study of extrasolar planets. Observations are now made with increasing sophistication from both ground- and space-based instruments, and exoplanets are characterized with increasing precision. There is a class of particularly interesting exoplanets that reside in the habitable zone, which is defined as the area around a star where the planet is capable of supporting liquid water on its surface. Planetary systems around M dwarfs are considered to be prime candidates to search for life beyond the Solar System. Such planets are likely to be tidally locked and have close-in habitable zones. Theoretical calculations also suggest that close-in exoplanets are more likely to have weaker planetary magnetic fields, especially in the case of super-Earths. Such exoplanets are subjected to a high flux of galactic cosmic rays (GCRs) due to their weak magnetic moments. GCRs are energetic particles of astrophysical origin that strike the planetary atmosphere and produce secondary particles, including muons, which are highly penetrating. Some of these particles reach the planetary surface and contribute to the radiation dose. Along with the magnetic field, another factor governing the radiation dose is the depth of the planetary atmosphere. The higher the depth of the planetary atmosphere, the lower the flux of secondary particles will be on the surface. If the secondary particles are energetic enough, and their flux is sufficiently high, the radiation from muons can also impact the subsurface regions, such as in the case of Mars. If the radiation dose is too high, the chances of sustaining a long-term biosphere on the planet are very low. We have examined the dependence of the GCR-induced radiation dose on the strength of the planetary magnetic field and its atmospheric depth, and found that the latter is the decisive factor for the protection of a planetary biosphere.

An analysis of plasticity in the rat respiratory system following cervical spinal cord injury and the application of nanotechnology to induce or enhance recovery of diaphragm function

Science.gov (United States)

Walker, Janelle

Second cervical segment spinal cord hemisection (C2Hx) results in ipsilateral hemidiaphragm paralysis. However, the intact latent crossed phrenic pathway can restore function spontaneously over time or immediately following drug administration. WGA bound fluorochromes were administered to identify nuclei associated with diaphragm function in both the acute and chronic C2Hx models. WGA is unique in that it undergoes receptor mediated endocytosis and is transsynaptically transported across select physiologically active synapses. Comparison of labeling in the acutely injured to the chronically injured rat provided an anatomical map of spinal and supraspinal injury induced synaptic plasticity. The plasticity occurs over time in the chronic C2Hx model in an effort to adapt to the loss of hemidiaphragm function. Utilizing the selectivity of WGA, a nanoconjugate was developed to target drug delivery to nuclei involved in diaphragm function post C2Hx in an effort to restore lost function. Theophylline was selected due to its established history as a respiratory stimulant. Theophylline was attached to gold nanoparticles by a transient bond designed to degrade intracellularly. The gold nanoparticles were then permanently attached to WGA-HRP. Following intradiaphragmatic injection, the WGA portion was identified in the ipsilateral phrenic nuclei and bilaterally in the rVRGs. The location of WGA should reflect the location of the AuNP since the peptide bond between them is permanent. The effectiveness of the nanoconjugate was verified with EMG analysis of the diaphragm and recordings from the phrenic nerves. All doses administered in the acute C2Hx model resulted in resorted hemidiaphragm and phrenic nerve activity. A dose of 0.14mg/kg had a significantly higher percent recovery on day 3, whereas 0.03mg/kg was significantly higher on day 14. The change in most effective dose over time is likely due to the availability or concentration of the drug and location of drug release

Rat skin carcinogenesis as a basis for estimating risks at low doses and dose rates of various types of radiation

International Nuclear Information System (INIS)

Burns, F.J.; Vanderlaan, M.; Strickland, P.; Albert, R.E.

1976-01-01

The recovery rate, age dependence and latent period for tumor induction in rat skin were measured for single and split doses of radiation, and the data were analyzed in terms of a general model in an attempt to estimate the expected tumor response for various types of radiation given at low dose rates for long periods of time. The dorsal skin of male rats was exposed to electrons, x rays, or protons in either single or split doses for several doses and the tumor responses were compared during 80 weeks of observation. A two stage model incorporating a reversible or recoverable mode was developed and various parameters in the model, including recovery rate, dose-response coefficients, and indices of age sensitivity, were evaluated experimentally. The measured parameters were then utilized to calculate expected tumor responses for exposure periods extending for duration of life. The calculations indicated that low dose rates could be markedly ( 1 / 100 to 1 / 1000 ) less effective in producing tumors than the same dose given in a short or acute exposure, although the magnitude of the reduction in effectiveness declines as the dose declines

Determination of dose ranges of gamma rays to induce specific changes in three ornamental species

International Nuclear Information System (INIS)

Gonzalez J, J.

2011-11-01

In order to confirming the possibility of to settle a dose range that takes place directly and not at random, a specific effect independently of the species that is were produced several similar organisms to three ornamental species took place via meristems cultivation: Petunia hybrid, Impatiens walleriana and Sprekelia formosissima, same that were irradiated in an irradiator Gamma cell 220, to different dose: 0, 3.5, 5.0, 7.5, 10, 12.5, 15, 17.5 and 20 Gy. Later on, of the plants treated via in vitro the subsequent generations were obtained until the M 4 . To determine the DL 50 and the possible good doses, the survival parameters, development, morphogenesis and height were evaluated during 8 weeks, interpreting based on them, the possible physiologic and genetic alterations induced by the radiation. The established DL 50 were: 7.5 Gy (Petunia), 19.0 Gy (Impatiens) and 12.0 Gy (Sprekelia). Based on the DL 50 of each species, a range of coincident dose settled down that produces a similar effect in the three species: a range of DL 23 to the DL 50 induces and alteration in the cytokinins production affecting directly in the leaves number, buds and plants taken place by meristem, also a range of DL 32 - DL 50 impacts in the auxins production altering to the radicule system. However, when being superimposed the dose is considered that the investigation should continue. (Author)

High-dose radiation-induced meningioma following prophylactic cranial irradiation for acute lymphoblastic leukaemia

International Nuclear Information System (INIS)

Matsuda, Ryosuke; Nikaido, Yuji; Yamada, Tomonori; Mishima, Hideaki; Tamaki, Ryo

2005-01-01

A 12 year-old girl was treated with prophylactic cranial irradiation for acute lymphoblastic leukaemia (ALL). At the age of 39, she was admitted to our hospital for status epilepticus. Computed tomography demonstrated two, enhancing bilateral sided intracranial tumors. After surgery, this patient presented meningiomas which histologically, were of the meningothelial type. The high cure rate in childhood ALL, attributable to aggressive chemotherapy and prophylactic cranial irradiation, is capable of inducing secondary brain tumor. Twelve cases of high-dose radiation-induced meningioma following ALL are also reviewed. (author)

High-dose radiation-induced meningioma following prophylactic cranial irradiation for acute lymphoblastic leukaemia

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Matsuda, Ryosuke; Nikaido, Yuji; Yamada, Tomonori; Mishima, Hideaki; Tamaki, Ryo [National Hospital Organization Osaka Minami Medical Center, Kawachinagano (Japan)

2005-03-01

A 12 year-old girl was treated with prophylactic cranial irradiation for acute lymphoblastic leukaemia (ALL). At the age of 39, she was admitted to our hospital for status epilepticus. Computed tomography demonstrated two, enhancing bilateral sided intracranial tumors. After surgery, this patient presented meningiomas which histologically, were of the meningothelial type. The high cure rate in childhood ALL, attributable to aggressive chemotherapy and prophylactic cranial irradiation, is capable of inducing secondary brain tumor. Twelve cases of high-dose radiation-induced meningioma following ALL are also reviewed. (author)

Different effects of ursodeoxycholic acid on intrahepatic cholestasis in acute and recovery stages induced by alpha-naphthylisothiocyanate in mice.

Science.gov (United States)

Zhang, Linlin; Su, Huizong; Li, Yue; Fan, Yujuan; Wang, Qian; Jiang, Jian; Hu, Yiyang; Chen, Gaofeng; Tan, Bo; Qiu, Furong

2018-03-01

The aim of this study was to determine the effect of ursodeoxycholic acid (UDCA) on the alpha-naphthylisothiocyanate (ANIT)-induced acute and recovery stage of cholestasis model mice. In the acute stage of model mice, pretreatment with UDCA (25, 50, and 100 mg·kg -1 , ig) for 12 days prior to ANIT administration (50 mg·kg -1 , ig) resulted in the dramatic increase in serum biochemistry, with aggrevation of bile infarcts and hepatocyte necrosis. The elevation of beta-muricholic acid (β-MCA), cholic acid (CA), and taurocholic acid (TCA) in serum and liver, and reduction of these bile acids (BAs) in bile was observed. In contrast, in the recovery stage of model mice, treatment with UDCA (25, 50, and 100 mg·kg -1 , ig) for 7 days after ANIT administration (50 mg·kg -1 , ig) resulted in the significant decrease in levels of serum alanine aminotransferase (ALT) and total bile acid (TBA). Liver injury was attenuated, and the levels of TBA, CA, TCA, and β-MCA in the liver were significantly decreased. Additionally, UDCA can upregulate expression of BSEP, but it cannot upregulate expression of AE2. UDCA, which induced BSEP to increase bile acid-dependent bile flow, aggravated cholestasis and liver injury when the bile duct was obstructed in the acute stage of injury in model mice. In contrast, UDCA alleviated cholestasis and liver injury induced by ANIT when the obstruction was improved in the recovery stage. Copyright © 2018. Published by Elsevier Inc.

Long-term recovery of spermatogenesis after radiotherapy in patients with testicular cancer.

Science.gov (United States)

Hansen, P V; Trykker, H; Svennekjaer, I L; Hvolby, J

1990-06-01

Gonadal function was evaluated before irradiation and by serial analyses after treatment in 27 patients with seminomas and 24 patients with nonseminomatous germ cell tumors of the testis. During subdiaphragmatic irradiation, a median testicular dose of 1.7 Gy (range, 1.2 to 4.8 Gy) reached the remaining testis. Twenty nonseminoma patients were treated with adjuvant chemotherapy using vincristine and bleomycin (OB) or cisplatin/dactinomycin, vinblastine, and bleomycin (P/DVB). After orchiectomy, 94% had spermatozoa in semen, 49% had a total sperm count exceeding the reference value (80 x 10(6], and in 67% serum follicle-stimulating hormone levels were normal. The corresponding estimated values 5 and 9 years after treatment were 61%, 13%, 14%, and 84%, 35%, 32%, respectively. A Cox regression analysis of recovery, with azoospermia used as an endpoint, showed that (1) recovery depended on the radiation dose, (2) adjuvant chemotherapy prolonged the recovery period, (3) recovery was decreased in patients with low pretreatment total sperm counts and in patients older than 25 years. A prognostic index was derived from the regression model and radiation dose-response curves were calculated (+/- chemotherapy). We conclude that a profound, dose-dependent impairment of spermatogenesis is caused by radiation scatter reaching the testis during subdiaphragmal irradiation. An effective gonadal shield should reduce the gonadal dose to a level low enough to preserve spermatogenesis in most patients.

LET and dose rate effect on radiation-induced copolymerization of maleimide with styrene in 2-propanol solution

Energy Technology Data Exchange (ETDEWEB)

Nakagawa, Seiko, E-mail: Nakagawa.Seiko@iri-tokyo.jp [Tokyo Metropolitan Industrial Technology Research Institute, 2-4-10 Aoumi, Koto-ku, Tokyo 135-0064 (Japan); Taguchi, Mitsumasa; Kimura, Atsushi [Environmental Radiation Processing Group, Environment and Industrial Materials Research Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

2011-11-15

N{sub 2}-saturated 2-propanol solutions containing styrene and maleimide were irradiated by electron, proton, He and C-ion beams. The styrene-maleimide copolymer was produced by radical polymerization induced during irradiation. The effects of the radical distribution, which depends on the LET or dose rate, on the molecular weight and the polymer yield were discussed. - Highlights: > Maleimide with styrene in N{sub 2}-saturated 2-propanol was irradiated by electron and heavy ions. > LET and dose rate effects of radical polymerization induced by irradiation were studied. > Results have shown the relation between radical distribution and efficiency of polymerization.

Cellular recovery kinetic studies relevant to combined-modality research and therapy

International Nuclear Information System (INIS)

Dethlefsen, L.A.

1979-01-01

The relevance of cellular recovery kinetics to combined-modality therapy is evaluated within the framework of an idealized experimental flow chart and published adriamycin data. Within this context, limitations for both experimental design and data interpretations are discussed. The effects of adriamycin have been documented extensively at the molecular and cellular level and its interactions with x-irradiation have been studied, both in vitro and in vivo. The limited in vivo results suggest that the end results of a given protocol correlate with cellular recovery kinetics; however, definitive experiments simply have not been done. For example, no one has used single-dose drug and irradiation data to predict the outcome and then confirm or refute the prediction even in a relatively simple 2-dose drug + 2-dose drug + 2-dose x-ray protocol. Thus, at this time, the extent of the correlations between cellular recovery kinetics and clinical response for either normal or malignant tissues is not known and the possible relevance of such studies cannot be discounted

From personnel dose to personal dose

International Nuclear Information System (INIS)

Hoefert, M.; Raffnsoe, R.C.; Tuyn, J.W.N.; Wittekind, D.

1985-01-01

From following the development of personnel doses at CERN over the past six years it has become evident that work in areas of induced radioactivity is the principal cause of exposure. The results of photon dose measurements free-in-air and around a phantom are presented and discussed in the light of new quantities in individual monitoring. The importance of these results, with respect to the practical situation, is discussed and the problem of phantom size is mentioned. Finally, the results of dose measurements in the phantom are presented, since such information is important in cases where it becomes necessary to transform personnel doses into personal doses. (author)

Failure of antimony trioxide to induce micronuclei or chromosomal aberrations in rat bone-marrow after sub-chronic oral dosing.

Science.gov (United States)

Kirkland, David; Whitwell, James; Deyo, James; Serex, Tessa

2007-03-05

Antimony trioxide (Sb2O3, CAS 1309-64-4) is widely used as a flame retardant synergist in a number of household products, as a fining agent in glass manufacture, and as a catalyst in the manufacture of various types of polyester plastics. It does not induce point mutations in bacteria or mammalian cells, but is able to induce chromosomal aberrations (CA) in cultured cells in vitro. Although no CA or micronuclei (MN) have been induced after acute oral dosing of mice, repeated oral dosing for 14 or 21 days resulted in increased CA in one report, but did not result in increased MN in another. In order to further investigate its in vivo genotoxicity, Sb2O3 was dosed orally to groups of rats for 21 days at 250, 500 and 1000 mg/kg day. There were no clinical signs of toxicity in the Sb2O3-exposed animals except for some reductions in body-weight gain in the top dose group. Toxicokinetic measurements in a separate study confirmed bone-marrow exposure, and at higher levels than would have been achieved by single oral dosing. Large numbers of cells were scored for CA (600 metaphases/sex group) and MN (12,000 PCE/sex group) but frequencies of CA or MN in Sb2O3-treated rats were very similar to controls, and not biologically or statistically different, at all doses. These results provide further indication that Sb2O3 is not genotoxic to the bone marrow of rodents after 21 days of oral administration at high doses close to the maximum tolerated dose.

Low-dose acute vanillin is beneficial against harmaline-induced tremors in rats.

Science.gov (United States)

Abdulrahman, Al Asmari; Faisal, Kunnathodi; Meshref, Ali Al Amri; Arshaduddin, Mohammed

2017-03-01

To study the effect of pretreatment with low doses of vanillin, a flavoring agent used as a food additive, on harmaline-induced tremor in rats. Sprague Dawley rats (110 ± 5 g) were divided into groups of six animals each. Vanillin (6.25 mg, 12.5 mg, and 25 mg/kg) was administered by gavage to different groups of rats, 30 minutes before the induction of tremor. Harmaline (10 mg/kg, i.p.) was used for the induction of tremor. The latency of onset, duration, tremor intensity, tremor index, and spontaneous locomotor activity were recorded. A separate batch of animals was used for the determination of serotonin (5HT) and 5 hydroxyindole acetic acid (5HIAA) levels in the brain. Harmaline treatment resulted in characteristic tremor that lasted for more than 2 hours and decreased the locomotor activity of rats. Pre-treatment with vanillin significantly reduced the duration, intensity, and tremor index of harmaline-treated animals. Vanillin treatment also significantly attenuated harmaline-induced decrease in the locomotor activity. An increase in 5HT levels and the changes in 5HIAA/5HT ratio observed in harmaline treated rats were significantly corrected in vanillin pretreated animals. Vanillin in low doses reduces harmaline-induced tremor in rats, probably through its modulating effect on serotonin levels in the brain. These findings suggest a beneficial effect of vanillin in essential tremor.

The relation between work-induced neuroendocrine reactivity and recovery, subjective need for recovery, and health status

NARCIS (Netherlands)

Sluiter, JK; Frings-Dresen, MHW; van der Beek, AJ; Meijman, TF

Objectives: The purpose of this cross-sectional study with repeated measurements was to find out to what extent neuroendocrine reactivity during work and neuroendocrine recovery from work, and work characteristics, are related to subjective need for recovery and perceived health status. Methods:

Silicon carbide layer structure recovery after ion implantation

International Nuclear Information System (INIS)

Violin, Eh.E.; Demakov, K.D.; Kal'nin, A.A.; Nojbert, F.; Potapov, E.N.; Tairov, Yu.M.

1984-01-01

The process of recovery of polytype structure of SiC surface layers in the course of thermal annealing (TA) and laser annealing (LA) upon boron and aluminium implantation is studied. The 6H polytype silicon carbide C face (0001) has been exposed to ion radiation. The ion energies ranged from 80 to 100 keV, doses varied from 5x10 14 to 5x10 16 cm -2 . TA was performed in the 800-2000 K temperature range. It is shown that the recovery of the structure of silicon carbide layers after ion implantation takes place in several stages. Considerable effect on the structure of the annealed layers is exerted by the implantation dose and the type of implanted impurity. The recovery of polytype structure is possible only under the effect of laser pulses with duration not less than the time for the ordering of the polytype in question

Late recovery of damage in rat spinal cord and bone marrow observed in split dose irradiation with long time intervals for 300 kV X-rays and 15 MeV neutrons

International Nuclear Information System (INIS)

Kogel, A.J. van der; Sissingh, H.A.

The authors have performed an extended study on the capacity of the spinal cord for recovery of damage over long time intervals in split-dose experiments with 300 kV X-rays and 15 MeV neutrons, with time intervals of up to 30 weeks. The dose-response relationships for long term bone marrow depletion have been analysed and compared with those obtained for acute and late spinal cord damage. (Auth.)

The Effects of Pretreatment with Various Doses of L-Arginine on Cisplatin-Induced Nephropathy of Male Rats

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B Rasoulian

2016-09-01

Full Text Available Introduction: Cisplatin is a widely used anti-cancer drug, which its application is limited by nephrotoxicity. In this study, the effect of pretreatment with different l-arginine doses on Cisplatin-induced renal functional injury was investigated. Methods: 63 male rats were divided into 7 groups: In groups 3, 4, 5 and 6, 60 min before the Cisplatin injection (5mg/kg; L-Arginine with doses of 50,100,200 or 400mg/kg was injected, respectively. In group7, normal saline was injected before Cisplatin administration. In groups 1 and 2, normal saline was injected instead of Cisplatin. In group 2, 60min before normal saline injection, 400mg/kg L-Arginine was administered and in group1, instead of L-arginine, normal saline was injected too. Injections were intraperitoneal. 72h after Cisplatin injection, blood sampling and plasma separation were done. Urine sample was collected 24 hours before blood sampling by metabolic cage. The mean of plasma urea and creatinine levels and creatinine clearance (ml/day.kg and fractional excretion of Na (FENa, % were compared among different groups as renal functional parameters. Results: In comparison to group 7, L-arginine injection in a dose of 400mg/kg led to significant amelioration of all parameters. 200 mg/kg L-arginine administration led to significant decrease in plasma urea level and FENa. 100mg/kg L-arginine caused significant improvement in fractional excretion of sodium. L-arginine injection with 50mg/kg dose, significantly ameliorate all renal function tests instead of creatinine clearance. Conclusion: Pretreatment with L-arginine administration with 400 or 50 mg/kg doses, respectively, had the highest effect on reducing Cisplatin-induced nephropathy. L-arginine injection with intermediate doses i.e. 200 or 100 mg/kg had less effect in reducing Cisplatin-induced nephropathy and it needs more investigations.

Tests of the linearity assumption in the dose-effect relationship for radiation-induced cancer

International Nuclear Information System (INIS)

Cohen, A.F.; Cohen, B.L.

1980-01-01

The validity of the BEIR linear extrapolation to low doses of the dose-effect relationship for radiation induced cancer is tested by use of natural radiation making use of selectivity on type of cancer, smoking habits, sex, age group, geographic area and/or time period. For lung cancer, a linear interpolation between zero dose-zero effect and the data from radon-induced cancers in miners implies that the majority of all lung cancers among non-smokers are due to radon; since lung cancers in miners are mostly small-cell undifferentiated (SCU), a rather rare type in general, linearity over predicts the frequency of SCU lung cancers among non smokers by a factor of 10, and among non-smoking females age 25-44 by a factor of 24. Similarly, linearity predicts that the majority of all lung cancers early in this century were due to radon even after due consideration is given to cases missed by poor diagnostic efficiency (this matter is considered in some detail). For the 30-40 age range, linearity over predicts the total lung cancer rate at that time by a factor of 3-6; for SCU lung cancer, the over-prediction is by at least a factor of 10. Other causes of lung cancer are considered which further enhance the degree to which the linearity assumption over-estimates the effects of low level radiation. A similar analysis is applied to leukemia induced by natural radiation. It is concluded that the upper limit for this is not higher than estimates from the linearity hypothesis. (author)

Radiation Sialadenitis Induced by High-dose Radioactive Iodine Therapy

International Nuclear Information System (INIS)

Jeong, Shin Young; Lee, Jaetae

2010-01-01

Radioactive iodine ( 131 I) is accumulated in the thyroid tissue and plays an important role in the treatment of differentiated papillary and follicular cancers after thyroidectomy. Simultaneously, 131 I is concentrated in the salivary glands and secreted into the saliva. Dose-related damage to the salivary parenchyma results from the 131 I irradiation. Salivary gland swelling and pain, usually involving the parotid, can be seen. The symptoms may develop immediately after a therapeutic dose of 131 I and/or months later and progress in intensity with time. In conjunction with the radiation sialadenitis, secondary complications reported include xerostomia, taste alterations, infection, increases in caries, facial nerve involvement, candidiasis, and neoplasia. Prevention of 131 I sialadenitis may involve the use of sialogogic agents to hasten the transit time of the radioactive iodine through the salivary glands. However, studies are not available to delineate the efficacy of this approach. Treatment of the varied complications that may develop encompass numerous approaches and include gland massage, sialogogic agents, duct probing, antibiotics, mouthwashes, good oral hygiene, and adequate hydration. Recently interventional sialoendoscopy has been introduced an effective tool for the management of patients with 131 I-induced sialadenitis that is unresponsive to medical treatment.

Adaptive response of spermatogenic cell apoptosis selectively induced by low dose X-ray irradiation in mice

International Nuclear Information System (INIS)

Liu Guangwei; Dong Lihua; Liu Yang; Lv Zhe; Liu Shuchun; Gong Shouliang

2003-01-01

Objective: The adaptive response of spermatogenic cell apoptosis induced by whole-body X-ray irradiation at low doses was studied in mice. Methods: Kunming male mice were irradiated with an inductive dose (D1:75 mGy) and/or a challenging dose (D2:1.0, 2.0 or 3.0 Gy). Different kinds of spermatogenic cells were separated using density gradient centrifugation and their apoptotic percentages were analysed using flow cytometry (FCM). Results: When the mice were irradiated with D1 6 h before irradiation with D2, the apoptotic percentages of the spermatogonia and spermatocytes declined rapidly as compared with those in the groups irradiated with D2 only, and those of spermatids and spermatozoa showed no significant changes. When the interval times between D1 and D2 was 3, 6, 12 or 24 h, the apoptotic percentages in spermatogonia and spermatocytes reduced early, significantly and continued for a longer duration after smaller D2(1.0 and 2.0 Gy) irradiation, while the apoptotic percentages did not change after larger D2(3.0 Gy) irradiation. Conclusion: The adaptive response of apoptosis in spermatogonia and spermatocytes could be selectively induced by low dose X-ray irradiation. The adaptive response could be closely related to the D2 dose and interval time between D1 and D2

Sustained Low-Dose Treatment with the Histone Deacetylase Inhibitor LBH589 Induces Terminal Differentiation of Osteosarcoma Cells

Directory of Open Access Journals (Sweden)

Jason E. Cain

2013-01-01

Full Text Available Histone deacetylase inhibitors (HDACi were identified nearly four decades ago based on their ability to induce cellular differentiation. However, the clinical development of these compounds as cancer therapies has focused on their capacity to induce apoptosis in hematologic and lymphoid malignancies, often in combination with conventional cytotoxic agents. In many cases, HDACi doses necessary to induce these effects result in significant toxicity. Since osteosarcoma cells express markers of terminal osteoblast differentiation in response to DNA methyltransferase inhibitors, we reasoned that the epigenetic reprogramming capacity of HDACi might be exploited for therapeutic benefit. Here, we show that continuous exposure of osteosarcoma cells to low concentrations of HDACi LBH589 (Panobinostat over a three-week period induces terminal osteoblast differentiation and irreversible senescence without inducing cell death. Remarkably, transcriptional profiling revealed that HDACi therapy initiated gene signatures characteristic of chondrocyte and adipocyte lineages in addition to marked upregulation of mature osteoblast markers. In a mouse xenograft model, continuous low dose treatment with LBH589 induced a sustained cytostatic response accompanied by induction of mature osteoblast gene expression. These data suggest that the remarkable capacity of osteosarcoma cells to differentiate in response to HDACi therapy could be exploited for therapeutic benefit without inducing systemic toxicity.

Lansoprazole induces sensitivity to suboptimal doses of paclitaxel in human melanoma.

Science.gov (United States)

Azzarito, Tommaso; Venturi, Giulietta; Cesolini, Albino; Fais, Stefano

2015-01-28

Tumor acidity is now considered an important determinant of drug-resistance and tumor progression, and anti-acidic approaches, such as Proton Pump inhibitors (PPIs), have demonstrated promising antitumor and chemo-sensitizing efficacy. The main purpose of the present study was to evaluate the possible PPI-induced sensitization of human melanoma cells to Paclitaxel (PTX). Our results show that PTX and the PPI Lansoprazole (LAN) combination was extremely efficient against metastatic melanoma cells, as compared to the single treatments, both in vitro and in vivo. We also showed that acidity plays an important role on the anti-tumor activity of these drugs, being detrimental for PTX activity, while crucial for the synergistic effect of PTX following pretreatment with LAN, due to its nature of pro-drug needing protonation for a full activation. We obtained straightforward results in a human melanoma xenograft model combining well tolerated LAN doses with suboptimal and poorly toxic doses of PTX. With this study we provide a clear evidence that the PPI LAN may be included in new combined therapy of human melanoma together with low doses of PTX. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Possible radioprotective effect of folic acid supplementation on low dose ionizing radiation-induced genomic instability in vitro.

Science.gov (United States)

Padula, Gisel; Ponzinibbio, María Virginia; Seoane, Analia I

2016-08-01

Ionizing radiation (IR) induces DNA damage through production of single and double-strand breaks and reactive oxygen species (ROS). Folic acid (FA) prevents radiation-induced DNA damage by modification of DNA synthesis and/or repair and as a radical scavenger. We hypothesized that in vitro supplementation with FA will decrease the sensitivity of cells to genetic damage induced by low dose of ionizing radiation. Annexin V, comet and micronucleus assays were performed in cultured CHO cells. After 7 days of pre-treatment with 0, 100, 200 or 300 nM FA, cultures were exposed to radiation (100 mSv). Two un-irradiated controls were executed (0 and 100 nM FA). Data were statistically analyzed with X2-test and linear regression analysis (P 0.05). We observed a significantly decreased frequency of apoptotic cells with the increasing FA concentration (P <0.05). The same trend was observed when analyzing DNA damage and chromosomal instability (P <0.05 for 300 nM). Only micronuclei frequencies showed significant differences for linear regression analysis (R2=94.04; P <0.01). Our results have demonstrated the radioprotective effect of folic acid supplementation on low dose ionizing radiation-induced genomic instability in vitro; folate status should be taken into account when studying the effect of low dose radiation in environmental or occupational exposure.

Short-Term Sleep Disturbance-Induced Stress Does not Affect Basal Pain Perception, but Does Delay Postsurgical Pain Recovery.

Science.gov (United States)

Wang, Po-Kai; Cao, Jing; Wang, Hongzhen; Liang, Lingli; Zhang, Jun; Lutz, Brianna Marie; Shieh, Kun-Ruey; Bekker, Alex; Tao, Yuan-Xiang

2015-11-01

Chronic sleep disturbance-induced stress is known to increase basal pain sensitivity. However, most surgical patients frequently report short-term sleep disturbance/deprivation during the pre- and postoperation periods and have normal pain perception presurgery. Whether this short-term sleep disturbance affects postsurgical pain is elusive. Here, we report that pre- or postexposure to rapid eye movement sleep disturbance (REMSD) for 6 hours daily for 3 consecutive days did not alter basal responses to mechanical, heat, and cold stimuli, but did delay recovery in incision-induced reductions in paw withdrawal threshold to mechanical stimulation and paw withdrawal latencies to heat and cold stimuli on the ipsilateral side of male or female rats. This short-term REMSD led to stress shown by an increase in swim immobility time, a decrease in sucrose consumption, and an increase in the level of corticosterone in serum. Blocking this stress via intrathecal RU38486 or bilateral adrenalectomy abolished REMSD-caused delay in recovery of incision-induced reductions in behavioral responses to mechanical, heat, and cold stimuli. Moreover, this short-term REMSD produced significant reductions in the levels of mu opioid receptor and kappa opioid receptor, but not Kv1.2, in the ipsilateral L4/5 spinal cord and dorsal root ganglia on day 9 after incision (but not after sham surgery). Our findings show that short-term sleep disturbance either pre- or postsurgery does not alter basal pain perception, but does exacerbate postsurgical pain hypersensitivity. The latter may be related to the reductions of mu and kappa opioid receptors in the spinal cord and dorsal root ganglia caused by REMSD plus incision. Prevention of short-term sleep disturbance may help recovery from postsurgical pain in patients. Copyright © 2015 American Pain Society. Published by Elsevier Inc. All rights reserved.

Low-Dose Radiation-Induced Adaptive Response in Polychromatic Mice Erythrocyte as Measured by Acridine Orange Stained Micronuleus Assay

International Nuclear Information System (INIS)

Hee-Sun, K.; Kwang-Hee, Y.; Cha-Soom, K.; Jung-Mi, C.; Gu-Choul, S.; Suk-Young, P.; Kyoung-H, C.; Chong-Soom, K.; Young-Khi, L.; Jae-Ho, W.

2004-01-01

The effect of conditioning pretreatment with 0.01Gy of gamma rays on micronucleated polychromatic erythrocyte (MN-PCE) induction by 2Gy of g-rays was determined in peripheral blood of C3H/He mice. The timing of their administration of challenge doses was 6hr. The response was determined by scoring of Acridine orange dye stained MN-PCEs. The results indicate that low dose gamma ray pretreatment does protect against MN-PCE induction by the challenge g-ray dose. Introduction: An adaptive response induced by low doses of ionizing radiation in vivo reported. Some research team reports that a reduction on MN-PCE of mice caused by the pretreatment was observed [1- 4]. However, there was variability in the amount of the response depending on the time and adaptive dose [3]. This is important because the variation of MN-PCE frequency with time could lead to differences in the interpretation. In this study, differences in the biological effects within the priming dose ranges are discussed. Materials and Methods: Specific pathogen free 5-week-old C3H/He mice, purchased from Shizuoka Laboratory Center (Japan), were kept in clean and conventional environment. When 6 weeks old, the animal were whole body irradiated using irradiator of IBL-437 (137Cs, 0.8Gy/min). After various time intervals, the two groups were administrated to adaptation dose and challenge dose of 0.01Gy and 2Gy, respectively. For experiments, sham-irradiated, only adaptive and challenge dose irradiated groups were run concurrently. Smears were stained and scored using Acridine orange dye method [2]. Statistically significant differences in MN-PCE frequency were determined by comparing tie individual values at each group with the respective control values (challenge dose irradiated group) by using the paired ttest. Results and Discussions: Induced MN by the challenge dose (2Gy) after the pretreatment with 0.01Gy is low to the one induced by the challenge dose alone. In the present study, this estimation for the

Time- and dose-dependent changes in neuronal activity produced by X radiation in brain slices

International Nuclear Information System (INIS)

Pellmar, T.C.; Schauer, D.A.; Zeman, G.H.

1990-01-01

A new method of exposing tissues to X rays in a lead Faraday cage has made it possible to examine directly radiation damage to isolated neuronal tissue. Thin slices of hippocampus from brains of euthanized guinea pigs were exposed to 17.4 ke V X radiation. Electrophysiological recordings were made before, during, and after exposure to doses between 5 and 65 Gy at a dose rate of 1.54 Gy/min. Following exposure to doses of 40 Gy and greater, the synaptic potential was enhanced, reaching a steady level soon after exposure. The ability of the synaptic potential to generate a spike was reduced and damage progressed after termination of the radiation exposure. Recovery was not observed following termination of exposure. These results demonstrate that an isolated neuronal network can show complex changes in electrophysiological properties following moderate doses of ionizing radiation. An investigation of radiation damage directly to neurons in vitro will contribute to the understanding of the underlying mechanisms of radiation-induced nervous system dysfunction

Variability of in vivo recovery of factor IX after infusion of monoclonal antibody purified factor IX concentrates in patients with hemophilia B. The Mononine Study Group.

Science.gov (United States)

White, G C; Shapiro, A D; Kurczynski, E M; Kim, H C; Bergman, G E

1995-05-01

Monoclonal antibody purified factor IX concentrate, Mononine (Armour Pharmaceutical Company, Kankakee, Illinois, USA), is a recently developed replacement factor concentrate for the treatment of patients with hemophilia B. The pharmacokinetic properties of monoclonal antibody purified factor IX concentrate (MAb Factor IX concentrate) have been evaluated in only small samples of patients, and little is known about those factors that might influenced in vivo recovery of factor IX after infusion is a larger patient population. In vivo recovery of factor IX was therefore evaluated for 80 different indications in 72 patients who received MAb Factor IX concentrate for the management of spontaneous or trauma-induced bleeding, or as prophylaxis with surgery. The average recovery after infusions for presurgical pharmacokinetic analysis (mean +/- standard deviation) was 1.28 +/- 0.56 U/dl rise per U/kg infused (range 0.41-2.80), and the average recovery after all infusions for treatment was 1.23 +/- 0.49 U/dl rise per U/kg infused (range - 0.35-2.92). Recovery values for multiple MAb Factor IX doses in a given patient were also variable; the average recovery was 1.22 +/- 0.53 U/dl rise per U/kg given, and standard deviations ranged from 0.03 to 1.26. Patient age, weight, and MAb Factor IX concentrate dose minimally but significantly influenced factor IX recovery. There was no significant effect of either race, history of previous thrombotic complications during treatment with other replacement factor concentrates, or bleeding state on recovery. All of the patients treated with this preparation experienced excellent hemostasis, and no thrombotic complications were observed.

Radiation-Induced Noncancer Risks in Interventional Cardiology: Optimisation of Procedures and Staff and Patient Dose Reduction

Science.gov (United States)

Khairuddin Md Yusof, Ahmad

2013-01-01

Concerns about ionizing radiation during interventional cardiology have been increased in recent years as a result of rapid growth in interventional procedure volumes and the high radiation doses associated with some procedures. Noncancer radiation risks to cardiologists and medical staff in terms of radiation-induced cataracts and skin injuries for patients appear clear potential consequences of interventional cardiology procedures, while radiation-induced potential risk of developing cardiovascular effects remains less clear. This paper provides an overview of the evidence-based reviews of concerns about noncancer risks of radiation exposure in interventional cardiology. Strategies commonly undertaken to reduce radiation doses to both medical staff and patients during interventional cardiology procedures are discussed; optimisation of interventional cardiology procedures is highlighted. PMID:24027768

Single Low-Dose Ionizing Radiation Induces Genotoxicity in Adult Zebrafish and its Non-Irradiated Progeny.

Science.gov (United States)

Lemos, J; Neuparth, T; Trigo, M; Costa, P; Vieira, D; Cunha, L; Ponte, F; Costa, P S; Metello, L F; Carvalho, A P

2017-02-01

This study investigated to what extent a single exposure to low doses of ionizing radiation can induce genotoxic damage in irradiated adult zebrafish (Danio rerio) and its non-irradiated F1 progeny. Four groups of adult zebrafish were irradiated with a single dose of X-rays at 0 (control), 100, 500 and 1000 mGy, respectively, and couples of each group were allowed to reproduce following irradiation. Blood of parental fish and whole-body offspring were analysed by the comet assay for detection of DNA damage. The level of DNA damage in irradiated parental fish increased in a radiation dose-dependent manner at day 1 post-irradiation, but returned to the control level thereafter. The level of DNA damage in the progeny was directly correlated with the parental irradiation dose. Results highlight the genotoxic risk of a single exposure to low-dose ionizing radiation in irradiated individuals and also in its non-irradiated progeny.

Whey Proteins Are More Efficient than Casein in the Recovery of Muscle Functional Properties following a Casting Induced Muscle Atrophy

Science.gov (United States)

Martin, Vincent; Ratel, Sébastien; Siracusa, Julien; Le Ruyet, Pascale; Savary-Auzeloux, Isabelle; Combaret, Lydie; Guillet, Christelle; Dardevet, Dominique

2013-01-01

The purpose of this study was to investigate the effect of whey supplementation, as compared to the standard casein diet, on the recovery of muscle functional properties after a casting-induced immobilization period. After an initial (I0) evaluation of the contractile properties of the plantarflexors (isometric torque-frequency relationship, concentric power-velocity relationship and a fatigability test), the ankle of 20 male adult rats was immobilized by casting for 8 days. During this period, rats were fed a standard diet with 13% of casein (CAS). After cast removal, rats received either the same diet or a diet with 13% of whey proteins (WHEY). A control group (n = 10), non-immobilized but pair-fed to the two other experimental groups, was also studied and fed with the CAS diet. During the recovery period, contractile properties were evaluated 7 (R7), 21 (R21) and 42 days (R42) after cast removal. The immobilization procedure induced a homogeneous depression of average isometric force at R7 (CAS: − 19.0±8.2%; WHEY: − 21.7±8.4%; P<0.001) and concentric power (CAS: − 26.8±16.4%, P<0.001; WHEY: − 13.5±21.8%, P<0.05) as compared to I0. Conversely, no significant alteration of fatigability was observed. At R21, isometric force had fully recovered in WHEY, especially for frequencies above 50 Hz, whereas it was still significantly depressed in CAS, where complete recovery occurred only at R42. Similarly, recovery of concentric power was faster at R21 in the 500−700°/s range in the WHEY group. These results suggest that recovery kinetics varied between diets, the diet with the whey proteins promoting a faster recovery of isometric force and concentric power output as compared to the casein diet. These effects were more specifically observed at force level and movement velocities that are relevant for functional abilities, and thus natural locomotion. PMID:24069411

Recovery after whole-body radiation exposure

International Nuclear Information System (INIS)

Sattler, E.L.

A recovery formula recommended by commissions III and IV of the Federal Ministry of Internal Affairs was tested on goldhamsters. Two test schemes were studied: in the first one recovery took place after irradiating 5 times ''equivalent'' to 100 R at a distance of 20 d with a combined residual damage ''equivalent'' to 100 R, in the second one with ''equivalent'' doses of up to the residual damage of 100 R at a distance of 11 d, which corresponds to a particularly bad recovery phase of the hamster. In both events the residual damage proved to be below the anticipated values. It is being discussed whether these results can be transferred to humans. (MG) [de

Mechanics of vacuum-enhanced recovery of hydrocarbons

International Nuclear Information System (INIS)

Barnes, D.L.; McWhorter, D.B.

1995-01-01

A growing body of field data demonstrates the enhancement of product recovery that can be achieved by applying a partial vacuum to recovery wells. Typical explanations for the observed improvement in performance invoke an increased slope of the cone of depression created in the water-table surface. Explanations related to water-table slope do not consider the gradient induced in the hydrocarbon by virtue of the airflow. Also, the airflow may induce a gradient in the aqueous phase that is not reflected in a water-table drawdown. The equations for steady-state flow of three immiscible fluids elucidate the fundamental mechanics of vacuum-enhanced recovery or bioslurping. Airflow to the recovery well causes hydrocarbon to migrate toward the well, independent of any gravity effects that may be created. Also, the relative permeability to hydrocarbon is affected by both water and airflow in the vicinity of the recovery well. Two critical airflow rates delineate the conditions for which only air is recovered, air and hydrocarbon are recovered, and all three phases are recovered

Whole-body fluid distribution in humans during dehydration and recovery, before and after humid-heat acclimation induced using controlled hyperthermia.

Science.gov (United States)

Patterson, M J; Stocks, J M; Taylor, N A S

2014-04-01

This experiment was designed to test the hypothesis that the plasma volume is not selectively defended during exercise- and heat-induced dehydration following humid-heat acclimation. Eight physically active males were heat acclimated (39.8 °C, relative humidity 59.2%) using 17 days of controlled hyperthermia (core temperature: 38.5 °C). Inter-compartmental fluid losses and movements were tracked (radioisotopes and Evans blue dye) during progressive dehydration (cycling) in these same conditions and also during a resting recovery without fluid replacement (28 °C), before (day 1), during (day 8) and after heat acclimation (day 22). On days 8 and 22, there were significant increases in total body water, interstitial fluid and plasma volume (P 0.05). The baseline plasma volume remained expanded throughout: 43.4 [±2.6 (day 1)], 49.1 [±2.4 (day 8); P recovery, plasma volume restoration commenced, with the intracellular fluid contribution becoming more pronounced as acclimation progressed. It is concluded that the plasma volume was not defended more vigorously following humid-heat acclimation. Indeed, a greater fluid loss may well underlie the mechanisms for enhancing plasma volume recovery when heat acclimation is induced using the controlled-hyperthermia technique. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Carbon dioxide inhalation induces dose-dependent and age-related negative affectivity.

Directory of Open Access Journals (Sweden)

Eric J Griez

Full Text Available BACKGROUND: Carbon dioxide inhalation is known to induce an emotion similar to spontaneous panic in Panic Disorder patients. The affective response to carbon dioxide in healthy subjects was not clearly characterized yet. METHODOLOGY/PRINCIPAL FINDINGS: Sixty-four healthy subjects underwent a double inhalation of four mixtures containing respectively 0, 9, 17.5 and 35% CO(2 in compressed air, following a double blind, cross-over, randomized design. Affective responses were assessed according to DSM IV criteria for panic, using an Electronic Visual Analogue Scale and the Panic Symptom List. It was demonstrated that carbon dioxide challenges induced a dose dependent negative affect (p<0.0001. This affect was semantically identical to the DSM IV definition of panic. Older individuals were subjectively less sensitive to Carbon Dioxide (p<0.05. CONCLUSIONS/SIGNIFICANCE: CO(2 induced affectivity may lay on a continuum with pathological panic attacks. Consistent with earlier suggestions that panic is a false biological alarm, the affective response to CO(2 may be part of a protective system triggered by suffocation and acute metabolic distress.

Docosahexaenoic acid and other fatty acids induce a decrease in pHi in Jurkat T-cells

OpenAIRE

Aires, Virginie; Hichami, Aziz; Moutairou, Kabirou; Khan, Naim Akhtar

2003-01-01

Docosahexaenoic acid (DHA) induced rapid (t1/2=33 s) and dose-dependent decreases in pHi in BCECF-loaded human (Jurkat) T-cells. Addition of 5-(N,N-dimethyl)-amiloride, an inhibitor of Na+/H+ exchanger, prolonged DHA-induced acidification as a function of time, indicating that the exchanger is implicated in pHi recovery.Other fatty acids like oleic acid, arachidonic acid, eicosapentaenoic acid, but not palmitic acid, also induced a fall in pHi in these cells.To assess the role of calcium in t...

Reversal of neuromuscular blockade by sugammadex in laparoscopic bariatric surgery: In support of dose reduction.

Science.gov (United States)

Badaoui, Rachid; Cabaret, Aurélie; Alami, Youssef; Zogheib, Elie; Popov, Ivan; Lorne, Emmanuel; Dupont, Hervé

2016-02-01

Sugammadex is the first molecule able to antagonize steroidal muscle relaxants with few adverse effects. Doses are adjusted to body weight and the level of neuromuscular blockade. Sleeve gastrectomy is becoming a very popular form of bariatric surgery. It requires deep muscle relaxation followed by complete and rapid reversal to decrease postoperative and especially post-anaesthetic morbidity. Sugammadex is therefore particularly indicated in this setting. The objective of this study was to evaluate the deep neuromuscular blockade reversal time after administration of various doses of sugammadex (based on real weight or at lower doses). Secondary endpoints were the interval between the sugammadex injection and extubation and transfer from the operating room to the recovery room. We then investigated any complications observed in the recovery room. This pilot, prospective, observational, clinical practice evaluation study was conducted in the Amiens University Hospital. Neuromuscular blockade was induced by rocuronium. At the end of the operation, deep neuromuscular blockade was reversed by sugammadex at the dose of 4mg/kg. Sixty-four patients were included: 31 patients received sugammadex at a dosage based on their real weight (RW) and 33 patients received a lower dose (based on ideal weight [IW]). For identical rocuronium doses calculated based on IBW, sugammadex doses were significantly lower in the IW group: 349 (± 65) mg versus 508 (± 75) mg (Psugammadex and extubation (P=0.07) and transfer from the operating room to the recovery room (P=0.68) were also non-significantly longer in the IW group. The mean dose of sugammadex used by anaesthetists in the IW group was 4mg/kg of ideal weight increased by 35% to 50% (n=20; 351±34mg). No sugammadex adverse effects and no residual neuromuscular blockades were observed. Postoperative nausea and vomiting (PONV) was observed in 19.4% of patients in the real weight group versus 27.3% in the ideal weight group (P

A Single Sub-anesthetic Dose of Ketamine Relieves Depression-like Behaviors Induced by Neuropathic Pain in Rats

Science.gov (United States)

Wang, Jing; Goffer, Yossef; Xu, Duo; Tukey, David S.; Shamir, D. B.; Eberle, Sarah E.; Zou, Anthony H.; Blanck, Thomas J.J.; Ziff, Edward B.

2011-01-01

Background Chronic pain is associated with depression. In rodents, pain is often assessed by sensory hypersensitivity, which does not sufficiently measure affective responses. Low-dose ketamine has been used to treat both pain and depression, but it is not clear whether ketamine can relieve depression associated with chronic pain and whether this antidepressant effect depends on its anti-nociceptive properties. Methods We examined whether the spared nerve injury (SNI) model of neuropathic pain induces depressive behavior in rats, using sucrose preference test and forced swim test, and tested whether a subanesthetic dose of ketamine treats SNI-induced depression. Results SNI-treated rats, compared with control, showed decreased sucrose preference (0.719 ± 0.068 (mean ± SEM) vs. 0.946 ± 0.010) and enhanced immobility in the forced swim test (107.3 ± 14.6s vs. 56.2 ± 12.5s). Further, sham-operated rats demonstrated depressive behaviors in the acute postoperative period (0.790 ± 0.062 on postoperative day 2). A single subanesthetic dose of ketamine (10mg/kg) did not alter SNI-induced hypersensitivity; however, it treated SNI-associated depression-like behaviors (0.896 ± 0.020 for ketamine vs. 0.663 ± 0.080 for control 1 day after administration; 0.858 ± 0.017 for ketamine vs. 0.683 ± 0.077 for control 5 days after administration). Conclusions Chronic neuropathic pain leads to depression-like behaviors. The postoperative period also confers vulnerability to depression, possibly due to acute pain. Sucrose preference test and forced swim test may be used to compliment sensory tests for assessment of pain in animal studies. Low-dose ketamine can treat depression-like behaviors induced by chronic neuropathic pain. PMID:21934410

Prevention and Treatment of Vaginal Bleeding after Drug-induced Abortion by Yaoliuan Capsule and Its Effects on Menses Recovery

Institute of Scientific and Technical Information of China (English)

JIN Zhichun; HUANG Guangying

2005-01-01

Summary: In order to explore the effect of Yaoliuan capsule in the prevention and treatment of vaginal bleeding after drug-induced abortion and menses recovery after drug-induced abortion, 323 cases of gestation period ≤ 49 days and without contraindication, were divided randomly into study group (168 cases, taking Yaoliuan capsule) and control group (155 cases, taking placebo capsule). The results showed that in the study group, there were 161 cases (95.8 %) of complete abortion, 7 cases (4.2 %) of incomplete abortion; In the control group, there were 146 cases (94.2 %) of complete abortion, 6 cases (3.9 %) of incomplete abortion, 3 cases (1.9 %) of abortion failure. The vaginal bleeding time was 5-25 days (mean 10.8 days) in study group, while that was 6-62 days (mean 19.1 days) in control group. The menstrual cycle was 30.5±5.2 days and 33.8 d±8.6 days respectively in study and control groups. The menstrual period was 6.1±3.5 days and 9.9±5.1 days respectively in study and control groups. Yaoliuan capsule is an effective drug to prevent and treat vaginal bleeding following drug-induced abortion, promote menstruation recovery and prevent pelvic infection.

Damage of DNA by radiation and it's recovery, 3

International Nuclear Information System (INIS)

Narita, Noboru; Matsuura, Tomio; Sato, Hiroyuki.

1974-01-01

The damage and recovery of DNA was investigated by the incorporation of thymine derivatives (DHT, I trans, II trans, cis and glycol) into exponentially growing Tetrahymena cells. The strain employed was Tetrahymena pyriformis, Variety I, mating type IV. It is well known that these thymine derivatives are induced in vivo by radiation. The in vivo damage of DNA induced by radiation, and its recovery, were confirmed experimentally by means of gradient separation of sucrose density and by analytical ultra centrifugation (UVC). The recovery of DNA, its excision repair and its recombinational repair were compared with the recovery of Bacillus subtilis whose recovery kinetics were already known. 1) The damage of DNA was more sensitive to glycol than to II trans and cis. On the other hand, DHT is not sensitive for breaking DNA strand. 2) In its recovery damaged DNA was no more sensitive to glycol than to hhp as was true for Bacillus subtilis. (author)

Induced mitotic gynogenesis in common carp (Cyprinus carpio L.), optimizing irradiation dose of X- and gamma-ray

International Nuclear Information System (INIS)

Yousefian, M.; Amirinia, C.; Bercsenyi, M.; Horvath, L.

1997-01-01

Mitotic gynogenesis was induced in common carp, Cyprinus carpio L., in hatchery and laboratory conditions, using 60Co gamma-ray and X-ray for inactivation of sperm DNA and a subsequent heat shock for inducing endomitosis. The parameter examined was the dose of irradiation in the range of 70-140 Krad. Carp spermatozoa irradiated by 70-100 Krad doses showed higher motility and fertilization ability than the ones irradiated by 110-140 Krad. Sperm treated with doses of 70-90 Krad showed the same fertility rate, but lower survival rate at embryo stage compared with 100 Krad. The shock temperature and duration applied in these experiments for restoration of diploidy level were 40 degrees C plus/minus 0.1 and 2 min., respectively. The highest frequency of mitotic gynogenetic larvae was achieved by 100 Krad 60Co gamma ray at 34 min. after fertilization, - up to 12.2 percent (at 23 degrees C incubating temperature)

Inhibition and recovery of the replication of depurinated parvovirus DNA in mouse fibroblasts

International Nuclear Information System (INIS)

Vos, J.M.; Avalosse, B.; Su, Z.Z.; Rommelaere, J.

1984-01-01

Apurinic sites were introduced in the single-stranded DNA of parvovirus minute-virus-of-mice (MVM) and their effect on viral DNA synthesis was measured in mouse fibroblasts. Approximately one apurinic site per viral genome, is sufficient to block its replication in untreated cells. The exposure of host cells to a sublethal dose of UV-light 15 hours prior to virus infection, enhances their ability to support the replication of depurinated MVM. Cell preirradiation induces the apparent overcome of 10-15% of viral DNA replication blocks. These results indicate that apurinic sites prevent mammalian cells from replicating single-stranded DNA unless a recovery process is activated by cell UV-irradiation

Correlation between γ-ray-induced DNA double-strand breakage and cell killing after biologically relevant doses: analysis by pulsed-field gel electrophoresis

International Nuclear Information System (INIS)

Murray, D.

1994-01-01

We examined the degree of correlation between γ-ray-induced lethality and DNA double-strand breaks (dsbs) after biologically relevant doses of radiation. Radiation lethality was modified by treating 14 C-labelled Chinese hamster ovary cells with either of two aminothiols (WR-1065 or WR-255591) and the associated effect on dsb induction was determined by pulsed-field gel electrophoresis (PFGE). The use of phosphorimaging to analyse the distribution of 14 C-activity in the gel greatly improved the low-dose resolution of the PFGE assay. Both WR-1065 and WR-255591 protected against dsb induction and lethality to a similar extent after low doses of radiation. although this correlation broke down when supralethal doses were used to induce dsbs. Thus, the level of dsbs induced in these cells as measured by PFGE after survival-curve doses of γ-radiation is consistently predictive of the degree of lethality obtained, implying a cause-effect relationship between these two parameters and confirming previous results obtained using the neutral filter elution assay for dsbs. (author)

Radiation Sialadenitis Induced by High-dose Radioactive Iodine Therapy

Energy Technology Data Exchange (ETDEWEB)

Jeong, Shin Young; Lee, Jaetae [Kyungpook National University Hospital, Daegu (Korea, Republic of)

2010-06-15

Radioactive iodine ({sup 131}I) is accumulated in the thyroid tissue and plays an important role in the treatment of differentiated papillary and follicular cancers after thyroidectomy. Simultaneously, {sup 131}I is concentrated in the salivary glands and secreted into the saliva. Dose-related damage to the salivary parenchyma results from the {sup 131}I irradiation. Salivary gland swelling and pain, usually involving the parotid, can be seen. The symptoms may develop immediately after a therapeutic dose of {sup 131}I and/or months later and progress in intensity with time. In conjunction with the radiation sialadenitis, secondary complications reported include xerostomia, taste alterations, infection, increases in caries, facial nerve involvement, candidiasis, and neoplasia. Prevention of {sup 131}I sialadenitis may involve the use of sialogogic agents to hasten the transit time of the radioactive iodine through the salivary glands. However, studies are not available to delineate the efficacy of this approach. Treatment of the varied complications that may develop encompass numerous approaches and include gland massage, sialogogic agents, duct probing, antibiotics, mouthwashes, good oral hygiene, and adequate hydration. Recently interventional sialoendoscopy has been introduced an effective tool for the management of patients with {sup 131}I-induced sialadenitis that is unresponsive to medical treatment.

Research on dose setting for radiation sterilization of medical device

International Nuclear Information System (INIS)

Zhang Tongcheng; Liu Qingfang; Zhong Hongliang; Mi Zhisu; Wang Chunlei; Jiang Jianping

2002-01-01

Objective: To establish the radiation sterilization dose for medical devices using data of bioburden on the medical device. Methods: Firstly determination of recovery ratio and correction coefficient of the microbiological test method was used according to ISO11737 standard, then determination of bioburden on the products, finally the dose setting was completed based on the Method 1 in ISO11137 standard. Results: Fifteen kinds of medical devices were tested. Bioburden range was from 8.6-97271.2 CFU/device, recovery ration range 54.6%-100%, correction co-efficiency range 1.00-1.83, D 10 distribution from 1.40 to 2.82 kGy, verification dose (dose at SAL = 10 -2 ) range 5.1-17.6 kGy and sterilization dose (dose at SAL 10 -6 ) range 17.5-32.5 kGy. Conclusion: One hundred samples of each kind of product were exposed to the pre-determined verification dose and then the sterility test was performed. Each sterility test showed positive number was not greater than two. This indicated that the sterilization dose established for each kind of product was statistically acceptable

Stress and Recovery during Simulated Microgravity

Science.gov (United States)

Nicolas, Michel

The aim of this study was to determine the effects of a 60-day head-down tilt long-term bed rest (HDT) on stress and recovery in sixteen healthy female volunteers during the WISE-2005 study (Women International Space Simulation for Exploration). Participants were randomly assigned to either an exercise group (Exe) that followed a training program combining resistive and aerobic exercises, or to a no-exercise control group (Ctl). Psychological states were assessed using the Rest-Q, a validated questionnaire based on stress-recovery responses. A longitudinal analysis revealed significant changes in the general and specific stress scales for all participants throughout the experiment with a critical stage from supine to standing posture leading to a significant decrease in physical recovery. During HDT, Exe reported higher scores in stress subscales, as well as lower recovery scores compared to the Ctl. During the post HDT ambulatory recovery period, the exercisers still reported higher scores than the non-exercisers on the Lack of energy stress related scale, along with lower scores in general well-being and personal accomplishment. The present findings show that simulated weightlessness such as HDT may induce psychological stress and lead to subsequent alterations in perceived recovery. Exercise did not reduce HDT impaired effects on stress and recovery states. In the perspective of spaceflights of long-duration such as the future missions to Mars, there is a need for additional experiments to further investigate spaceflight-induced changes of stress and recovery parameters and the effects of exercise on these parameters. Further studies might determine and analyze the psychological factors involved, but also how to intervene concerning these factors with efficient psychological preparation which, although not yet fully investigated, may reduce stress, promote recovery and support adaptive responses to such extreme environments.

Ultraviolet radiation induces dose-dependent pigment dispersion in crustacean chromatophores.

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Gouveia, Glauce Ribeiro; Lopes, Thaís Martins; Neves, Carla Amorim; Nery, Luiz Eduardo Maia; Trindade, Gilma Santos

2004-10-01

Pigment dispersion in chromatophores as a response to UV radiation was investigated in two species of crustaceans, the crab Chasmagnathus granulata and the shrimp Palaemonetes argentinus. Eyestalkless crabs and shrimps maintained on either a black or a white background were irradiated with different UV bands. In eyestalkless crabs the significant minimal effective dose inducing pigment dispersion was 0.42 J/cm(2) for UVA and 2.15 J/cm(2) for UVB. Maximal response was achieved with 10.0 J/cm(2) UVA and 8.6 J/cm(2) UVB. UVA was more effective than UVB in inducing pigment dispersion. Soon after UV exposure, melanophores once again reached the initial stage of pigment aggregation after 45 min. Aggregated erythrophores of shrimps adapted to a white background showed significant pigment dispersion with 2.5 J/cm(2) UVA and 0.29 J/cm(2) UVC. Dispersed erythrophores of shrimps adapted to a black background did not show any significant response to UVA, UVB or UVC radiation. UVB did not induce any significant pigment dispersion in shrimps adapted to either a white or a black background. As opposed to the tanning response, which only protects against future UV exposure, the pigment dispersion response could be an important agent protecting against the harmful effects of UV radiation exposure.

Dose-responsiveness and persistence of microRNA expression alterations induced by cigarette smoke in mouse lung

International Nuclear Information System (INIS)

Izzotti, Alberto; Larghero, Patrizia; Longobardi, Mariagrazia; Cartiglia, Cristina; Camoirano, Anna; Steele, Vernon E.; De Flora, Silvio

2011-01-01

Our previous studies demonstrated that exposure to cigarette smoke (CS), either mainstream or environmental, results in a remarkable downregulation of microRNA expression in the lung of both mice and rats. The goals of the present study were to evaluate the dose responsiveness to CS and the persistence of microRNA alterations after smoking cessation. ICR (CD-1) neonatal mice were exposed whole-body to mainstream CS, at the doses of 119, 292, 438, and 631 mg/m 3 of total particulate matter. Exposure started within 12 h after birth and continued daily for 4 weeks. The levels of bulky DNA adducts and 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodGuo) were measured by 32 P postlabeling procedures, and the expression of 697 mouse microRNAs was analyzed by microarray. The highest CS dose was lethal. Exposure to CS caused a dose-dependent increase of DNA alterations. DNA adducts and, even more sharply, 8-oxodGuo were reverted 1 and 4 weeks after smoking cessation. Exposure to CS resulted in an evident dysregulation of microRNA expression profiles, mainly in the sense of downregulation. The two lowest doses were not particularly effective, while the highest nonlethal dose produced extensive microRNA alterations. The expression of most downregulated microRNAs, including among others 7 members of the let-7 family, was restored one week after smoking cessation. However, the recovery was incomplete for a limited array of microRNAs, including mir-34b, mir-345, mir-421, mir-450b, mir-466, and mir-469. Thus, it appears that microRNAs mainly behave as biomarkers of effect and that exposure to high-dose, lasting for an adequate period of time, is needed to trigger the CS-related carcinogenesis process in the experimental animal model used.

Benazepril-Induced Agranulocytosis: A Case Report and Review of the Literature.

Science.gov (United States)

Hashmi, Hafiz Rizwan Talib; Jabbour, Rami; Schreiber, Zwi; Khaja, Misbahuddin

2016-06-23

Angiotensin-converting enzyme inhibitors are widely used drugs, and in appropriately selected patients, serious side effects are infrequent. Commonly seen side effects include cough, rash, hyperkalemia, renal dysfunction, and angioedema. Historically, dose-related agranulocytosis has been associated with captopril. Benazepril, a relatively more potent angiotensin-converting enzyme inhibitor, is rarely associated with agranulocytosis. Here, we report a case of drug-induced agranulocytosis due to benazepril, with complete recovery of white blood cell count upon discontinuation of the drug. All tests for other causes of agranulocytosis were unremarkable. This report highlights a serious and rare side effect associated with benazepril. Benazepril is a commonly employed anti-hypertensive medication, and we report an unusual condition associated with this medication in order to increase vigilance among caregivers. In such cases, prompt recognition and discontinuation of the causative drug can make the difference between a recovery and a fatal outcome associated with drug-induced agranulocytosis.

Blueberry effects on dark vision and recovery after photobleaching: placebo-controlled crossover studies.

Science.gov (United States)

Kalt, Wilhelmina; McDonald, Jane E; Fillmore, Sherry A E; Tremblay, Francois

2014-11-19

Clinical evidence for anthocyanin benefits in night vision is controversial. This paper presents two human trials investigating blueberry anthocyanin effects on dark adaptation, functional night vision, and vision recovery after retinal photobleaching. One trial, S2 (n = 72), employed a 3 week intervention and a 3 week washout, two anthocyanin doses (271 and 7.11 mg cyanidin 3-glucoside equivalents (C3g eq)), and placebo. The other trial, L1 (n = 59), employed a 12 week intervention and an 8 week washout and tested one dose (346 mg C3g eq) and placebo. In both S2 and L1 neither dark adaptation nor night vision was improved by anthocyanin intake. However, in both trials anthocyanin consumption hastened the recovery of visual acuity after photobleaching. In S2 both anthocyanin doses were effective (P = 0.014), and in L1 recovery was improved at 8 weeks (P = 0.027) and 12 weeks (P = 0.030). Although photobleaching recovery was hastened by anthocyanins, it is not known whether this improvement would have an impact on everyday vision.

Therapy induces widespread reorganization of motor cortex after complete spinal transection that supports motor recovery.

Science.gov (United States)

Ganzer, Patrick D; Manohar, Anitha; Shumsky, Jed S; Moxon, Karen A

2016-05-01

Reorganization of the somatosensory system and its relationship to functional recovery after spinal cord injury (SCI) has been well studied. However, little is known about the impact of SCI on organization of the motor system. Recent studies suggest that step-training paradigms in combination with spinal stimulation, either electrically or through pharmacology, are more effective than step training alone at inducing recovery and that reorganization of descending corticospinal circuits is necessary. However, simpler, passive exercise combined with pharmacotherapy has also shown functional improvement after SCI and reorganization of, at least, the sensory cortex. In this study we assessed the effect of passive exercise and serotonergic (5-HT) pharmacological therapies on behavioral recovery and organization of the motor cortex. We compared the effects of passive hindlimb bike exercise to bike exercise combined with daily injections of 5-HT agonists in a rat model of complete mid-thoracic transection. 5-HT pharmacotherapy combined with bike exercise allowed the animals to achieve unassisted weight support in the open field. This combination of therapies also produced extensive expansion of the axial trunk motor cortex into the deafferented hindlimb motor cortex and, surprisingly, reorganization within the caudal and even the rostral forelimb motor cortex areas. The extent of the axial trunk expansion was correlated to improvement in behavioral recovery of hindlimbs during open field locomotion, including weight support. From a translational perspective, these data suggest a rationale for developing and optimizing cost-effective, non-invasive, pharmacological and passive exercise regimes to promote plasticity that supports restoration of movement after spinal cord injury. Copyright © 2016. Published by Elsevier Inc.

Imaging Radiation-Induced Gastrointestinal, Bone Marrow Injury and Recovery Kinetics Using 18F-FDG PET.

Science.gov (United States)

Tang, Tien T; Rendon, David A; Zawaski, Janice A; Afshar, Solmaz F; Kaffes, Caterina K; Sabek, Omaima M; Gaber, M Waleed

2017-01-01

Positron emission tomography using 18F-Fluro-deoxy-glucose (18F-FDG) is a useful tool to detect regions of inflammation in patients. We utilized this imaging technique to investigate the kinetics of gastrointestinal recovery after radiation exposure and the role of bone marrow in the recovery process. Male Sprague-Dawley rats were either sham irradiated, irradiated with their upper half body shielded (UHBS) at a dose of 7.5 Gy, or whole body irradiated (WBI) with 4 or 7.5 Gy. Animals were imaged using 18F-FDG PET/CT at 5, 10 and 35 days post-radiation exposure. The gastrointestinal tract and bone marrow were analyzed for 18F-FDG uptake. Tissue was collected at all-time points for histological analysis. Following 7.5 Gy irradiation, there was a significant increase in inflammation in the gastrointestinal tract as indicated by the significantly higher 18F-FDG uptake compared to sham. UHBS animals had a significantly higher activity compared to 7.5 Gy WBI at 5 days post-exposure. Animals that received 4 Gy WBI did not show any significant increase in uptake compared to sham. Analysis of the bone marrow showed a significant decrease of uptake in the 7.5 Gy animals 5 days post-irradiation, albeit not observed in the 4 Gy group. Interestingly, as the metabolic activity of the gastrointestinal tract returned to sham levels in UHBS animals it was accompanied by an increase in metabolic activity in the bone marrow. At 35 days post-exposure both gastrointestinal tract and bone marrow 18F-FDG uptake returned to sham levels. 18F-FDG imaging is a tool that can be used to study the inflammatory response of the gastrointestinal tract and changes in bone marrow metabolism caused by radiation exposure. The recovery of the gastrointestinal tract coincides with an increase in bone marrow metabolism in partially shielded animals. These findings further demonstrate the relationship between the gastrointestinal syndrome and bone marrow recovery, and that this interaction can be studied

Imaging Radiation-Induced Gastrointestinal, Bone Marrow Injury and Recovery Kinetics Using 18F-FDG PET.

Directory of Open Access Journals (Sweden)

Tien T Tang

Full Text Available Positron emission tomography using 18F-Fluro-deoxy-glucose (18F-FDG is a useful tool to detect regions of inflammation in patients. We utilized this imaging technique to investigate the kinetics of gastrointestinal recovery after radiation exposure and the role of bone marrow in the recovery process. Male Sprague-Dawley rats were either sham irradiated, irradiated with their upper half body shielded (UHBS at a dose of 7.5 Gy, or whole body irradiated (WBI with 4 or 7.5 Gy. Animals were imaged using 18F-FDG PET/CT at 5, 10 and 35 days post-radiation exposure. The gastrointestinal tract and bone marrow were analyzed for 18F-FDG uptake. Tissue was collected at all-time points for histological analysis. Following 7.5 Gy irradiation, there was a significant increase in inflammation in the gastrointestinal tract as indicated by the significantly higher 18F-FDG uptake compared to sham. UHBS animals had a significantly higher activity compared to 7.5 Gy WBI at 5 days post-exposure. Animals that received 4 Gy WBI did not show any significant increase in uptake compared to sham. Analysis of the bone marrow showed a significant decrease of uptake in the 7.5 Gy animals 5 days post-irradiation, albeit not observed in the 4 Gy group. Interestingly, as the metabolic activity of the gastrointestinal tract returned to sham levels in UHBS animals it was accompanied by an increase in metabolic activity in the bone marrow. At 35 days post-exposure both gastrointestinal tract and bone marrow 18F-FDG uptake returned to sham levels. 18F-FDG imaging is a tool that can be used to study the inflammatory response of the gastrointestinal tract and changes in bone marrow metabolism caused by radiation exposure. The recovery of the gastrointestinal tract coincides with an increase in bone marrow metabolism in partially shielded animals. These findings further demonstrate the relationship between the gastrointestinal syndrome and bone marrow recovery, and that this

Radiation-induced rib fracture after stereotactic body radiotherapy with a total dose of 54-56 Gy given in 9-7 fractions for patients with peripheral lung tumor: impact of maximum dose and fraction size.

Science.gov (United States)

Aoki, Masahiko; Sato, Mariko; Hirose, Katsumi; Akimoto, Hiroyoshi; Kawaguchi, Hideo; Hatayama, Yoshiomi; Ono, Shuichi; Takai, Yoshihiro

2015-04-22

Radiation-induced rib fracture after stereotactic body radiotherapy (SBRT) for lung cancer has been recently reported. However, incidence of radiation-induced rib fracture after SBRT using moderate fraction sizes with a long-term follow-up time are not clarified. We examined incidence and risk factors of radiation-induced rib fracture after SBRT using moderate fraction sizes for the patients with peripherally located lung tumor. During 2003-2008, 41 patients with 42 lung tumors were treated with SBRT to 54-56 Gy in 9-7 fractions. The endpoint in the study was radiation-induced rib fracture detected by CT scan after the treatment. All ribs where the irradiated doses were more than 80% of prescribed dose were selected and contoured to build the dose-volume histograms (DVHs). Comparisons of the several factors obtained from the DVHs and the probabilities of rib fracture calculated by Kaplan-Meier method were performed in the study. Median follow-up time was 68 months. Among 75 contoured ribs, 23 rib fractures were observed in 34% of the patients during 16-48 months after SBRT, however, no patients complained of chest wall pain. The 4-year probabilities of rib fracture for maximum dose of ribs (Dmax) more than and less than 54 Gy were 47.7% and 12.9% (p = 0.0184), and for fraction size of 6, 7 and 8 Gy were 19.5%, 31.2% and 55.7% (p = 0.0458), respectively. Other factors, such as D2cc, mean dose of ribs, V10-55, age, sex, and planning target volume were not significantly different. The doses and fractionations used in this study resulted in no clinically significant rib fractures for this population, but that higher Dmax and dose per fraction treatments resulted in an increase in asymptomatic grade 1 rib fractures.

Resolution of methylphenidate osmotic release oral system-induced hair loss in two siblings after dose escalation.

Science.gov (United States)

Ardic, Ulku Akyol; Ercan, Eyup Sabri

2017-11-01

This report describes the cases of two siblings who experienced hair loss after treatment with methylphenidate (MPH) osmotic release oral system (OROS). Hair loss was resolved after discontinuation of the drug, but the children re-initiated treatment, after which hair loss again occurred, but they continued the treatment. After dose escalation, the hair loss resolved. This is the first report to describe resolution of OROS-MPH-induced hair loss after dose escalation. © 2017 Japan Pediatric Society.

MK-801, but not naloxone, attenuates high-dose dextromethorphan-induced convulsive behavior: Possible involvement of the GluN2B receptor.

Science.gov (United States)

Tran, Hai-Quyen; Chung, Yoon Hee; Shin, Eun-Joo; Tran, The-Vinh; Jeong, Ji Hoon; Jang, Choon-Gon; Nah, Seung-Yeol; Yamada, Kiyofumi; Nabeshima, Toshitaka; Kim, Hyoung-Chun

2017-11-01

Dextromethorphan (DM) is a dextrorotatory isomer of levorphanol, a typical morphine-like opioid. When administered at supra-antitussive doses, DM produces psychotoxic and neurotoxic effects in humans. Although DM abuse has been well-documented, few studies have examined the effects of high-dose DM. The present study aimed to explore the effects of a single high dose of DM on mortality and seizure occurrence. After intraperitoneal administration with a high dose of DM (80mg/kg), Sprague-Dawley rats showed increased seizure occurrence and intensity. Hippocampal expression levels of N-methyl-d-aspartate (NMDA) receptor subunits (GluN1induced ultrastructural degeneration in the hippocampus. A non-competitive NMDA receptor antagonist, MK-801, attenuated these effects of high-dose DM, whereas an opioid antagonist, naloxone, did not affect DM-induced neurotoxicity. Moreover, pretreatment with a highly specific GluN2B subunit inhibitor, traxoprodil, was selectively effective in preventing DM-induced c-Fos expression and apoptotic changes. These results suggest that high-dose DM produces convulsive behaviors by activating GluN2B/NMDA signaling that leads to pro-apoptotic changes. Copyright © 2017. Published by Elsevier Inc.

Chronic low-dose ultraviolet-induced mutagenesis in nucleotide excision repair-deficient cells.

Science.gov (United States)

Haruta, Nami; Kubota, Yoshino; Hishida, Takashi

2012-09-01

UV radiation induces two major types of DNA lesions, cyclobutane pyrimidine dimers (CPDs) and 6-4 pyrimidine-pyrimidine photoproducts, which are both primarily repaired by nucleotide excision repair (NER). Here, we investigated how chronic low-dose UV (CLUV)-induced mutagenesis occurs in rad14Δ NER-deficient yeast cells, which lack the yeast orthologue of human xeroderma pigmentosum A (XPA). The results show that rad14Δ cells have a marked increase in CLUV-induced mutations, most of which are C→T transitions in the template strand for transcription. Unexpectedly, many of the CLUV-induced C→T mutations in rad14Δ cells are dependent on translesion synthesis (TLS) DNA polymerase η, encoded by RAD30, despite its previously established role in error-free TLS. Furthermore, we demonstrate that deamination of cytosine-containing CPDs contributes to CLUV-induced mutagenesis. Taken together, these results uncover a novel role for Polη in the induction of C→T transitions through deamination of cytosine-containing CPDs in CLUV-exposed NER deficient cells. More generally, our data suggest that Polη can act as both an error-free and a mutagenic DNA polymerase, depending on whether the NER pathway is available to efficiently repair damaged templates.

c-Jun/AP-1 pathway-mediated cyclin D1 expression participates in low dose arsenite-induced transformation in mouse epidermal JB6 Cl41 cells

International Nuclear Information System (INIS)

Zhang Dongyun; Li Jingxia; Gao Jimin; Huang Chuanshu

2009-01-01

Arsenic is a well-documented human carcinogen associated with skin carcinogenesis. Our previous work reveals that arsenite exposure is able to induce cell transformation in mouse epidermal cell JB6 Cl41 through the activation of ERK, rather than JNK pathway. Our current studies further evaluate downstream pathway in low dose arsenite-induced cell transformation in JB6 Cl41 cells. Our results showed that treatment of cells with low dose arsenite induced activation of c-Jun/AP-1 pathway, and ectopic expression of dominant negative mutant of c-Jun (TAM67) blocked arsenite-induced transformation. Furthermore, our data indicated that cyclin D1 was an important downstream molecule involved in c-Jun/AP-1-mediated cell transformation upon low dose arsenite exposure, because inhibition of cyclin D1 expression by its specific siRNA in the JB6 Cl41 cells resulted in impairment of anchorage-independent growth of cells induced by low dose arsenite. Collectively, our results demonstrate that c-Jun/AP-1-mediated cyclin D1 expression is at least one of the key events implicated in cell transformation upon low dose arsenite exposure

Dynamic gene expression in fish muscle during recovery growth induced by a fasting-refeeding schedule

Directory of Open Access Journals (Sweden)

Esquerré Diane

2007-11-01

Full Text Available Abstract Background Recovery growth is a phase of rapid growth that is triggered by adequate refeeding of animals following a period of weight loss caused by starvation. In this study, to obtain more information on the system-wide integration of recovery growth in muscle, we undertook a time-course analysis of transcript expression in trout subjected to a food deprivation-refeeding sequence. For this purpose complex targets produced from muscle of trout fasted for one month and from muscle of trout fasted for one month and then refed for 4, 7, 11 and 36 days were hybridized to cDNA microarrays containing 9023 clones. Results Significance analysis of microarrays (SAM and temporal expression profiling led to the segregation of differentially expressed genes into four major clusters. One cluster comprising 1020 genes with high expression in muscle from fasted animals included a large set of genes involved in protein catabolism. A second cluster that included approximately 550 genes with transient induction 4 to 11 days post-refeeding was dominated by genes involved in transcription, ribosomal biogenesis, translation, chaperone activity, mitochondrial production of ATP and cell division. A third cluster that contained 480 genes that were up-regulated 7 to 36 days post-refeeding was enriched with genes involved in reticulum and Golgi dynamics and with genes indicative of myofiber and muscle remodelling such as genes encoding sarcomeric proteins and matrix compounds. Finally, a fourth cluster of 200 genes overexpressed only in 36-day refed trout muscle contained genes with function in carbohydrate metabolism and lipid biosynthesis. Remarkably, among the genes induced were several transcriptional regulators which might be important for the gene-specific transcriptional adaptations that underlie muscle recovery. Conclusion Our study is the first demonstration of a coordinated expression of functionally related genes during muscle recovery growth

Comparative response of dogs and monkeys to sublethal acute and continuous low dose-rate gamma-ray exposure

International Nuclear Information System (INIS)

Spalding, J.F.; Holland, L.M.; Johnson, O.S.; LaBauve, P.M.; London, J.E.; Prine, J.R.; Vigil, E.A.

1977-02-01

Monkeys (Macaca mulatta) and dogs (beagle) were given thirteen 100-rad gamma-ray doses at 28-day intervals. The comparative response (injury and recovery) of the hematopoietic system of the two species was observed at 7-day intervals during the exposure regime. At 84 days after the thirteenth gamma-ray dose, the 1300-rad conditioned and control dogs and monkeys were challenged continuously with 35 R/day until death to determine the amount of radiation-induced injury remaining in conditioned animals as a reduction in mean survival time. Dogs (50 percent) and monkeys (8 percent) died from injury incurred during the conditioning exposures. Thus, the comparative response of dogs and monkeys to dose protraction by acute dose fractionation was similar to what might be expected from a single acute dose. Mean survival times for nonconditioned dogs and monkeys during continuous exposure at 35 R/day were the same (approximately 1400 h). Thus, hematopoietic response of the two species by this method of dose protraction was not significantly different. Mean survival times of conditioned dogs and monkeys during the continuous 35 R/day gamma-ray challenge exposure were greater than for their control counterparts. Thus, the long-term radiation-induced injury was not measurable by this method. Conditioning doses of more than four times the acute LD 50 - 30 in dogs and approximately two times that of monkeys served only to increase both mean survival time and variance in a gamma-ray stress environment with a dose rate of 35 R/day

Dose Rate Effects in Linear Bipolar Transistors

Science.gov (United States)

Johnston, Allan; Swimm, Randall; Harris, R. D.; Thorbourn, Dennis

2011-01-01

Dose rate effects are examined in linear bipolar transistors at high and low dose rates. At high dose rates, approximately 50% of the damage anneals at room temperature, even though these devices exhibit enhanced damage at low dose rate. The unexpected recovery of a significant fraction of the damage after tests at high dose rate requires changes in existing test standards. Tests at low temperature with a one-second radiation pulse width show that damage continues to increase for more than 3000 seconds afterward, consistent with predictions of the CTRW model for oxides with a thickness of 700 nm.

Evaluation of induced activity, decay heat and dose rate distribution after shutdown in ITER

Energy Technology Data Exchange (ETDEWEB)

Maki, Koichi [Hitachi Ltd., Ibaraki (Japan). Hitachi Research Lab.; Satoh, Satoshi; Hayashi, Katsumi; Yamada, Koubun; Takatsu, Hideyuki; Iida, Hiromasa

1997-03-01

Induced activity, decay heat and dose rate distributions after shutdown were estimated for 1MWa/m{sup 2} operation in ITER. The activity in the inboard blanket one day after shutdown is 1.5x10{sup 11}Bq/cm{sup 3}, and the average decay heating rate 0.01w/cm{sup 3}. The dose rate outside the 120cm thick concrete biological shield is two order higher than the design criterion of 5{mu}Sv/h. This indicates that the biological shield thickness should be enhanced by 50cm in concrete, that is, total thickness 170cm for workers to enter the reactor room and to perform maintenance. (author)

A Voxel-Based Approach to Explore Local Dose Differences Associated With Radiation-Induced Lung Damage

Energy Technology Data Exchange (ETDEWEB)

Palma, Giuseppe [Institute of Biostructure and Bioimaging, National Research Council, Naples (Italy); Monti, Serena [IRCCS SDN, Naples (Italy); D' Avino, Vittoria [Institute of Biostructure and Bioimaging, National Research Council, Naples (Italy); Conson, Manuel [Institute of Biostructure and Bioimaging, National Research Council, Naples (Italy); Department of Advanced Biomedical Sciences, Federico II University School of Medicine, Naples (Italy); Liuzzi, Raffaele [Institute of Biostructure and Bioimaging, National Research Council, Naples (Italy); Pressello, Maria Cristina [Department of Health Physics, S. Camillo-Forlanini Hospital, Rome (Italy); Donato, Vittorio [Department of Radiation Oncology, S. Camillo-Forlanini Hospital, Rome (Italy); Deasy, Joseph O. [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY (United States); Quarantelli, Mario [Institute of Biostructure and Bioimaging, National Research Council, Naples (Italy); Pacelli, Roberto [Institute of Biostructure and Bioimaging, National Research Council, Naples (Italy); Department of Advanced Biomedical Sciences, Federico II University School of Medicine, Naples (Italy); Cella, Laura, E-mail: laura.cella@cnr.it [Institute of Biostructure and Bioimaging, National Research Council, Naples (Italy)

2016-09-01

Purpose: To apply a voxel-based (VB) approach aimed at exploring local dose differences associated with late radiation-induced lung damage (RILD). Methods and Materials: An interinstitutional database of 98 patients who were Hodgkin lymphoma (HL) survivors treated with postchemotherapy supradiaphragmatic radiation therapy was analyzed in the study. Eighteen patients experienced late RILD, classified according to the Radiation Therapy Oncology Group scoring system. Each patient's computed tomographic (CT) scan was normalized to a single reference case anatomy (common coordinate system, CCS) through a log-diffeomorphic approach. The obtained deformation fields were used to map the dose of each patient into the CCS. The coregistration robustness and the dose mapping accuracy were evaluated by geometric and dose scores. Two different statistical mapping schemes for nonparametric multiple permutation inference on dose maps were applied, and the corresponding P<.05 significance lung subregions were generated. A receiver operating characteristic (ROC)-based test was performed on the mean dose extracted from each subregion. Results: The coregistration process resulted in a geometrically robust and accurate dose warping. A significantly higher dose was consistently delivered to RILD patients in voxel clusters near the peripheral medial-basal portion of the lungs. The area under the ROC curves (AUC) from the mean dose of the voxel clusters was higher than the corresponding AUC derived from the total lung mean dose. Conclusions: We implemented a framework including a robust registration process and a VB approach accounting for the multiple comparison problem in dose-response modeling, and applied it to a cohort of HL survivors to explore a local dose–RILD relationship in the lungs. Patients with RILD received a significantly greater dose in parenchymal regions where low doses (∼6 Gy) were delivered. Interestingly, the relation between differences in the high-dose

Bisphenol A (BPA) aggravates multiple low-dose streptozotocin-induced Type 1 diabetes in C57BL/6 mice.

Science.gov (United States)

Cetkovic-Cvrlje, Marina; Thinamany, Sinduja; Bruner, Kylie A

2017-12-01

Type 1 diabetes (T1D) is a T-cell-mediated autoimmune disorder characterized by destruction of insulin-producing pancreatic β-cells. Whereas epidemiological data implicate environmental factors in the increasing incidence of T1D, their identity remains unknown. Though exposure to bisphenol A (BPA) has been associated with several disorders, no epidemiologic evidence has linked BPA exposure and T1D. The goal of this study was to elucidate diabetogenic potentials of BPA and underlying mechanisms in the context of T-cell immunity, in a multiple low-dose streptozotocin (MLDSTZ)-induced autoimmune mouse T1D model. C57BL/6 mice were orally exposed to 1 or 10 mg BPA/L starting at 4 wk of age; diabetes was induced at 9 wk of age with STZ. T-cell composition, function, and insulitis levels were studied at Days 11 and 50 during diabetes development (i.e. post-first STZ injection). Results showed both BPA doses increased diabetes incidence and affected T-cell immunity. However, mechanisms of diabetogenic action appeared divergent based on dose. Low-dose BPA fits a profile of an agent that exhibits pro-diabetogenic effects via T-cell immunomodulation in the early stages of disease development, i.e. decreases in splenic T-cell subpopulations [especially CD4 + T-cells] along with a trend in elevation of splenic T-cell formation of pro-inflammatory cytokines (IFN-γ, TNF-α, and IL-6). In contrast, high-dose BPA did not affect T-cell populations and led to decreased levels of IFN-γ and TNF-α. Both treatments did not affect insulitis levels at the disease early stage, but aggravated it later on. By the study end, besides decreasing T-cell proliferative capacity, low-dose BPA did not affect other T-cell-related parameters, including cytokine secretion, comparable to the effects of high-dose BPA. In conclusion, this study confirmed BPA as a potential diabetogenic compound with immunomodulatory mechanisms of action - in the context of T-cell immunity - that seemed to be dose

Adaptive response induced by low doses of ionizing radiation in human lymphocytes

International Nuclear Information System (INIS)

Frati, Diego Libkind; Bunge, Maria M.

2001-01-01

The term adaptive response (AR) applies to the phenomenon of protection or enhanced repair induced by a small dose of a mutagenic agent. In order to determine the existence of AR in human lymphocytes for two different irradiation schemes, microcultures of blood from 4 donors were irradiated. Samples were exposed 24 hours (hr) after phytohemagglutinin stimulation to an adapting dose of 0,01 Gy and to a challenging dose of 1,5 Gy either 6 or 24 hr later (irradiation scheme 24+30 or 24+48, respectively). Gamma radiation from a 2,5 MeV Linac was used in all experiments. A cytogenetic analysis of unstable chromosome aberrations was applied as the endpoint. High inter-individual variability was found for the first irradiation scheme: one expressed AR, two did not and the last showed an apparent synergistic response. For the second irradiation scheme, low mitotic indices (MI) were found, suggesting a G2 arrest. When a series of harvesting times were applied for the last donor, normal MI were obtained only harvesting after 58 hr. An AR was found when harvesting at 72 hr but not at 58 hr. (author)

On the mechanism of rapid postirradiation recovery of yeast

International Nuclear Information System (INIS)

Glazunov, A.V.; Kapul'tsevich, Yu.G.

1983-01-01

Rapid postirradiation recovery of diploid yeast Saccharomyces cerevisiae is equally effective both in water and in a liquid nutrition medium. In the haploid strains, rapid recovery occurs more readily in the log phase than in the stationary phase of growth. In the diploid strains, rapid recovery is more effective in the log phase than in the stationary phase. Rapid recovery of yeast does not require an additional protein synthesis. Damages induced by UV-light are not sub ected to rapid recovery

New model for assessing dose and dose rate sensitivity of Gamma ray radiation loss in polarization maintaining optical fibers

International Nuclear Information System (INIS)

Zhang Hongchen; Liu Hai; Qiao Wenqiang; Xue Huijie; He Shiyu

2012-01-01

Highlights: ► Building a new phenomenological theory model to investigate the relation about the irradiation induced loss with irradiation dose and dose rate. ► The Gamma ray irradiation induced loss of the “Capsule” type and “Panda” type polarization maintaining optical fibers at 1310 nm wavelength are investigated. ► The anti irradiation performance of the “Panda” type polarization maintaining optical fiber is better than that of the “Capsule” type polarization maintaining optical fiber, the reason is that the stress region doped by GeO 2 . - Abstract: The Gamma ray irradiation induced loss of the “Capsule” type and “Panda” type polarization maintaining optical fibers at 1310 nm wavelength are investigated. A phenomenological theory model is introduced and the influence of irradiation dose and dose rate on the irradiation induced loss is discussed. The phenomenological theoretical results are consistent with the experimental results of the irradiation induced loss for the two types of polarization maintaining optical fibers. The anti irradiation performance of the “Panda” type polarization maintaining optical fiber is better than that of the “Capsule” type polarization maintaining optical fiber, the reason is that the stress region dope with GeO 2 . Meanwhile, both of the polarization maintaining optical fiber irradiation induced loss increase with increasing the irradiation dose. In the case of same dose, the high dose rate Gamma ray irradiation induced optical fiber losses are higher than that of the low dose rate.

Taenia crassiceps Infection Attenuates Multiple Low-Dose Streptozotocin-Induced Diabetes

Directory of Open Access Journals (Sweden)

Arlett Espinoza-Jiménez

2010-01-01

Full Text Available Taenia crassiceps, like other helminths, can exert regulatory effects on the immune system of its host. This study investigates the effect of chronic T. crassiceps infection on the outcome of Multiple Low Dose Streptozotocin-Induced Diabetes (MLDS. Healthy or previously T. crassiceps-infected mice received MLDS and type 1 diabetes (T1D symptoms were evaluated for 6 weeks following the induction of MLDS. T. crassiceps-infected mice displayed lower blood glucose levels throughout the study. A significantly lower percentage of T. crassiceps-infected mice (40% developed T1D compared to the uninfected group (100%. Insulitis was remarkably absent in T. crassiceps-infected mice, which had normal pancreatic insulin content, whereas uninfected mice showed a dramatic reduction in pancreatic insulin. Infected mice that received MLDS did not show an increase in their regulatory T cell population, however, they had a greater number of alternatively activated macrophages, higher levels of the cytokine IL-4, and lower levels of TNF-α. Therefore, infection with T. crassiceps causes an immunomodulation that modifies the incidence and development of MLDS-induced autoimmune diabetes.

Exposure levels for persons involved in recovery operations following the Chernobyl accident in 1986-1987 and dosimetric data verification

International Nuclear Information System (INIS)

Il'in, L.A.; Kkyuchkov, V.P.; Osanov, D.P.; Pavlov, D.A.

1995-01-01

It is considered the organization of individual dosimetric monitoring (IDM) within 30-km zone around Chernobyl nuclear power plant (CNPP) in 1986 for different contingents of recovery workers: the CNPP personnel, Management for Construction 605 (MC-605), military recovery workers, persons assigned to 30-km zone. It is concluded that the quality of IDM had decreased in the following series: the MC-605 personnel, the CNPP personnel, the assigned persons, and military units. The method of dosimetric data verification for recovery workers in 1986 is presented. The results obtained by this method correspond to the results of the experts' estimation. Using the theory of hybrid lognormal distribution it was obtained, in our opinion, real external dose distribution for all the recovery workers. It was estimated that 7% of recovery workers received doses more than 0.25 Gy. Also, the data on values of mean and collective doses for different contingents, as well as for all persons involved in recovery operations is presented. 14 refs., 18 figs

Human lymphocytes exposed to low doses of ionizing radiations become refractory to high doses of radiation as well as to chemical mutagens that induce double-strand breaks in DNA

International Nuclear Information System (INIS)

Wolff, Sheldon; Afzal, Veena; Wiencke, J.K.; Olivieri, G.; Michaeli, A.

1988-01-01

The results indicate that prior exposure to 0.01 Gy of X-rays reduces the number of chromosome breaks induced by double-strand breaks, and perhaps even by cross-links, in DNA, but has the opposite effect on breaks induced by the alkylating agent MMS. The results also show that the induced repair mechanism is different from that observed in the adaptive reponse that follows exposure to low doses of alkylating agents. (author)

Bimodal cell death induced by high radiation doses in the radioresistant sf9 insect cell line

International Nuclear Information System (INIS)

Chandna, S.

2003-01-01

Full text: This study was conducted to investigate the mode(s) of cell death induced by high radiation doses in the highly radioresistant Sf9 insect ovarian cell line. Methods: Cells were exposed to γ-radiation doses 200Gy and 500Gy, harvested at various time intervals (6h-72h) following irradiation, and subjected to cell morphology assay, DNA agarose gel electrophoresis, single cell gel electrophoresis (SCGE; comet assay) and Annexin-V labeling for the detection of membrane phosphatidylserine externalization. Cell morphology was assessed in cells entrapped and fixed in agarose gel directly from the cell suspension, thus preventing the possible loss of fragments/ apoptotic bodies. Surviving fraction of Sf9 cells was 0.01 at 200Gy and 98%) undergoing extensive DNA fragmentation at 500Gy, whereas the frequency of cells with DNA fragmentation was considerably less (∼12%) at 200Gy. Conclusions: While the mode of cell death at 200Gy seems to be different from typical apoptosis, a dose of 500Gy induced bimodal cell death, with typical apoptotic as well as the atypical cell death observed at 200Gy

Time-effect relationship of immunological adaptive response induced by low dose X-irradiation in mice

International Nuclear Information System (INIS)

Zhao Yong; Gong Shouliang; Liu Shuzheng

1995-01-01

Kunming mice irradiated with whole-body X-rays were used to observe time-effect relationship of immunological adaptive response induced by ionizing radiation. The results showed that pre-irradiation dose of 75 mGy X-rays with the intervals of 6-48 h between pre-irradiation and challenge irradiation could induce immunological adaptive response in the spontaneous proliferation of thymocytes and the responses of splenocytes to Con A and LPS in mice at 18-24 h after challenge irradiation with 1.5-2.0 Gy X-rays

Plutonium dose-effect relationship

International Nuclear Information System (INIS)

Matsuoka, Osamu

1976-01-01

Dose in internal exposure to Pu was investigated, and dose-effect relationship was discussed. Dose-effect relationship in internal exposure was investigated by means of two methods, which were relationship between dose and its effect (relationship between μ Ci/Kg and its effect), and exposure dose and its effects (rad-effect), and merits and demerits of two methods were mentioned. Problems in a indication method such as mean dose were discussed with respect to the dose in skeleton, the liver and the lung. Pu-induced osteosarcoma in mice rats, and beagles was described, and differences in its induction between animals were discussed. Pulmonary neoplasma induced by 239 PuO 2 inhalation in beagles was reported, and description was made as to differences in induction of lung cancer between animals when Pu was inhaled and was taken into the lung. A theoretical and experimental study of a extrapolation of the results of the animal experiment using Pu to human cases is necessary. (Serizawa, K.)

Is the ipsilateral cortex surrounding the lesion or the non-injured contralateral cortex important for motor recovery in rats with photochemically induced cortical lesions?

Science.gov (United States)

Takata, Kotaro; Yamauchi, Hideki; Tatsuno, Hisashi; Hashimoto, Keiji; Abo, Masahiro

2006-01-01

To determine whether the ipsilateral cortex surrounding the lesion or the non-injured contralateral cortex is important for motor recovery after brain damage in the photochemically initiated thrombosis (PIT) model. We induced PIT in the sensorimotor cortex in rats and examined the recovery of motor function using the beam-walking test. In 24 rats, the right sensorimotor cortex was lesioned after 2 days of training for the beam-walking test (group 1). After 10 days, PIT was induced in the left sensorimotor cortex. Eight additional rats (group 2) received 2 days training in beam walking, then underwent the beam-walking test to evaluate function. After 10 days of testing, the left sensorimotor cortex was lesioned and recovery was monitored by the beam-walking test for 8 days. In group 1 animals, left hindlimb function caused by a right sensorimotor cortex lesion recovered within 10 days after the operation. Right hindlimb function caused by the left-side lesion recovered within 6 days. In group 2, right hindlimb function caused by induction of the left-side lesion after a total of 12 days of beam-walking training and testing recovered within 6 days as with the double PIT model. The training effect may be relevant to reorganization and neuromodulation. Motor recovery patterns did not indicate whether motor recovery was dependent on the ipsilateral cortex surrounding the lesion or the cortex of the contralateral side. The results emphasize the need for selection of appropriate programs tailored to the area of cortical damage in order to enhance motor functional recovery in this model. Copyright 2006 S. Karger AG, Basel.

Retrospective Cohort Study of Bronchial Doses and Radiation-Induced Atelectasis After Stereotactic Body Radiation Therapy of Lung Tumors Located Close to the Bronchial Tree

International Nuclear Information System (INIS)

Karlsson, Kristin; Nyman, Jan; Baumann, Pia; Wersäll, Peter; Drugge, Ninni; Gagliardi, Giovanna; Johansson, Karl-Axel; Persson, Jan-Olov; Rutkowska, Eva; Tullgren, Owe; Lax, Ingmar

2013-01-01

Purpose: To evaluate the dose–response relationship between radiation-induced atelectasis after stereotactic body radiation therapy (SBRT) and bronchial dose. Methods and Materials: Seventy-four patients treated with SBRT for tumors close to main, lobar, or segmental bronchi were selected. The association between incidence of atelectasis and bronchial dose parameters (maximum point-dose and minimum dose to the high-dose bronchial volume [ranging from 0.1 cm 3 up to 2.0 cm 3 ]) was statistically evaluated with survival analysis models. Results: Prescribed doses varied between 4 and 20 Gy per fraction in 2-5 fractions. Eighteen patients (24.3%) developed atelectasis considered to be radiation-induced. Statistical analysis showed a significant correlation between the incidence of radiation-induced atelectasis and minimum dose to the high-dose bronchial volumes, of which 0.1 cm 3 (D 0.1cm3 ) was used for further analysis. The median value of D 0.1cm3 (α/β = 3 Gy) was EQD 2,LQ = 147 Gy 3 (range, 20-293 Gy 3 ). For patients who developed atelectasis the median value was EQD 2,LQ = 210 Gy 3 , and for patients who did not develop atelectasis, EQD 2,LQ = 105 Gy 3 . Median time from treatment to development of atelectasis was 8.0 months (range, 1.1-30.1 months). Conclusion: In this retrospective study a significant dose–response relationship between the incidence of atelectasis and the dose to the high-dose volume of the bronchi is shown

Recovery of HPA Axis Function After Successful Gonadotropin-Induced Pregnancy and Delivery in a Woman With Panhypopituitarism: Case Report and Review.

Science.gov (United States)

Wang, Yi; Zhang, Qiongyue; Yang, Jianzhi; Zhao, Xiaolong; He, Min; Shou, Xuefei; Li, Shiqi; Li, Yiming; Wang, Yongfei; Ye, Hongying

2015-09-01

Hypopituitarism is defined as the partial or complete defect of anterior pituitary hormone secretion. Patients with hypopituitarism usually need life-long hormone replacement therapy. However, in this case, we report a patient with panhypopituitarism whose hypothalamus-pituitary-adrenal (HPA) axis function was completely recovered after pregnancy and delivery. In this case study, we reported the case management and conducted a review of literature to identify the possible mechanism of pituitary function recovery. The patient who suffered from secondary amenorrhea was found a nonfunctioning pituitary macroadenoma, and the hormone test showed serum cortisol, FT3, FT4, thyrotropic hormone, and prolactin were at normal range. After surgical removal of the tumor which invasion in the sellar region, the patient had panhypopituitarism confirmed by the routine hormone test. Though spontaneous pregnancy is impossible in female patients with panhypopituitarism, the patient was restored fertility by the help of artificial reproductive techniques. After the confirmation of the pregnancy, levothyroixine was increased to 75 μg daily and readjusted to 150 μg daily before delivery according to the monthly measurement thyroid function. Hydrocortisone 10 mg daily replaced cortisone acetate; the dose was increased according to the symptoms of morning sickness. A single stress dose of hydrocortisone (200 mg) was used before elective cesarean delivery and was tapered to the dose of 10 mg per day in 1 week. Levothyroixine was reduced to 75 μg daily after delivery. During follow-up, her hypothalamus-pituitary-adrenal (HPA) axis function was completely recovered. The peak serum cortisol level could increase to 19.08 μg/dL by insulin-induced hypoglycemia. However, growth hormone remained unresponsive to the insulin-tolerance test, and thyroid hormone still needed exogenous supplementation. Hormone replacement therapy needed closely followed by endocrinologist and multidisciplinary

Hand-foot syndrome in a patient with metastatic lung adenocarcinoma induced by high-dose icotinib: A case report and review of the literature.

Science.gov (United States)

Zheng, Yulong; Fang, Weijia; Xu, Nong

2012-12-01

Icotinib is a new oral epidermal growth factor tyrosine kinase inhibitor (EGFR-TKI). The most frequent side-effects of icotinib include rash and diarrhea. Hand-foot syndrome (HFS) induced by EGFR-TKI is rare. The present study describes, for the first time, HFS induced by high-dose icotinib in a 65-year old female with metastatic lung adenocarcinoma. The patient developed HFS during the first week of icotinib treatment with characteristic clinical presentation. HFS regressed after icotinib dose-reduction was initiated. HFS may occur with icotinib, especially when administered in high doses.

Prediction of functional recovery in patients with myocardial infarction after revascularization. Comparison of low-dose dobutamine stress echocardiography with fluorine-18 fluorodeoxyglucose positron emission tomography

International Nuclear Information System (INIS)

Tani, Tomoko; Teragaki, Masakazu; Watanabe, Hiroyuki; Muro, Takashi; Yamagishi, Hiroyuki; Akioka, Kaname; Takeuchi, Kazuhide; Yoshikawa, Junichi

2001-01-01

The present study investigated the agreement between low-dose dobutamine stress echocardiography (LDDSE) and fluorine-18 fluorodeoxyglusose positron emission tomography (FDG-PET) and compared each technique's ability to detect myocardial viability and predict functional recovery in 30 patients. All patients underwent revascularization, followed by echocardiography 5±3 months. Of the 390 segments analyzed by echocardiography before revascularization, 110 (28%) had abnormal wall motion. LDDSE showed viability in 66 sites of the 110 dyssynergic segments and 58 of these viable segments recovered their wall motion. With FDG-PET, 78 of the 110 dyssynergic segments were diagnosed as viable and 62 of these showed improvement of the wall motion. The sensitivities for LDDSE and FDG-PET to assess functional recovery were 84% and 90%, respectively; specificities were 80% and 64%, respectively. Positive predictive values for LDDSE and FDG-PET were 88% and 79%; negative predictive values were 75% and 78%, respectively. Both methods had good sensitivity for detecting improvement in regional function after revascularization, but LDDSE had a higher specificity for detecting viability and a better positive predictive value for left ventricular functional recovery. (author)

In vitro and in vivo effects of low dose HTO contamination modulated by dose rate

International Nuclear Information System (INIS)

Petcu, I.; Savu, D.; Moisoi, N.; Koeteles, G.J.

1997-01-01

The experiment performed in vitro intended to examine whether an adaptive response could be elicited on lymphocytes by low-level contamination of whole blood with tritiated water and if the modification of the dose rate has any influence on it. Lymphocytes pre-exposed to 3 HOH (0.2 - 6.6 MBq/ml) and subsequently irradiated with I Gy γ-rays showed micronuclei frequency significantly lower (40% - 45%) than the expected member (sum of the yields induced by 3 HOH and γ-rays separately). The degree of the radioresistance induced by HTO pre-treatments became higher with decreasing dose-rate for a rather similar total adapting dose. In vivo, the aim of the study was to investigate if different dose rates are inducing modulation of the lipid peroxidation level and of the thymidine uptake in different tissues of animals contaminated by HTO ingestion. The total doses varied between 5 and 20 cGy and were delivered as chronic (100 days) or acute contamination (5 days). It was observed that only doses about 20 cGy caused a dose-rate dependent increase of the lipid peroxidation level in the tissues of small intestine, kidney and spleen. Both chronic and acute contamination did produce reduced incorporation of thymidine in the cells of bone marrow. The most effective decrease of thymidine uptake was induced by the acute contamination in the lower dose domain (approx. 5 cGy). Our hypothesis is that in this dose domain the modification of thymidine uptake could be due to changes at the level of membrane transport. (author)

The need for recovery scale : Adaption to the Italian context

NARCIS (Netherlands)

Pace, F.; Lo Cascio, V.; Civilleri, A.; Guzzo, G.; Foddai, E.; van Veldhoven, M.J.P.M.

2013-01-01

Introduction Need for Recovery scale is one of the main scales used to assess work-induced fatigue and quality of workers’ recovery time. In fact, need for recovery is considered relevant as a precursor of prolonged fatigue or psychological distress, an indicator of work stress, and a mediating or

In an animal model nephrogenic systemic fibrosis cannot be induced by intraperitoneal injection of high-dose gadolinium based contrast agents

Energy Technology Data Exchange (ETDEWEB)

Langer, R.D., E-mail: rlanger@uaeu.ac.ae [Faculty of Medicine and Health Sciences (FMHS), United Arab Emirates University, Al Ain (United Arab Emirates); Lorke, D.E. [Florida International University, Miami, FL (United States); Neidl van Gorkom, K.F. [Faculty of Medicine and Health Sciences (FMHS), United Arab Emirates University, Al Ain (United Arab Emirates); Petroianu, G. [Florida International University, Miami, FL (United States); Azimullah, S.; Nurulain, S.M.; Singh, S. [Faculty of Medicine and Health Sciences (FMHS), United Arab Emirates University, Al Ain (United Arab Emirates); Fuchsjäger, M. [Al Ain Hospital, MUV-VAMED, Al Ain (United Arab Emirates)

2012-10-15

Aim and objective: Nephrogenic systemic fibrosis (NSF) has been reported in humans to be most likely induced by gadolinium based contrast agents (GBCA), namely by gadodiamide, gadopentetate dimeglumine, and gadoversetamide, rarely by other GBCA. The pathogenesis of NSF remains unclear; different hypotheses are under discussion. The objective of the study is to assess if in the animal model human-like NSF changes can be induced by high-dose, intraperitoneal GBCA injections over four weeks. Materials and methods: After approval by the institutional animal ethics committee, six rats each were randomly assigned to groups, and treated with seven different GBCA. Intraperitoneal (IP) injections – proven in the animal model to be effective – were chosen to prolong the animals’ exposure to the respective GBCA. GBCA doses of previous intravenous (IV) animal studies were applied. After five weeks all rats were sacrificed. Sham controls were treated with IP saline injections, employing the same regimen. Results: No findings comparable with human NSF were observed in all animals after IP treatment with all seven GBCA at daily doses of 2.5 and 5.0 mmol/kg body weight (BW). No histopathological abnormalities of all examined organs were noted. Weight loss was stated in weeks three and four with GBCA injections at doses of 5.0 mmol/kg BW, but rats regained weight after cessation of GBCA treatment. Conclusions: NSF-comparable pathological findings could not be induced by high dose intraperitoneal injection of seven GBCA.

In an animal model nephrogenic systemic fibrosis cannot be induced by intraperitoneal injection of high-dose gadolinium based contrast agents

International Nuclear Information System (INIS)

Langer, R.D.; Lorke, D.E.; Neidl van Gorkom, K.F.; Petroianu, G.; Azimullah, S.; Nurulain, S.M.; Singh, S.; Fuchsjäger, M.

2012-01-01

Aim and objective: Nephrogenic systemic fibrosis (NSF) has been reported in humans to be most likely induced by gadolinium based contrast agents (GBCA), namely by gadodiamide, gadopentetate dimeglumine, and gadoversetamide, rarely by other GBCA. The pathogenesis of NSF remains unclear; different hypotheses are under discussion. The objective of the study is to assess if in the animal model human-like NSF changes can be induced by high-dose, intraperitoneal GBCA injections over four weeks. Materials and methods: After approval by the institutional animal ethics committee, six rats each were randomly assigned to groups, and treated with seven different GBCA. Intraperitoneal (IP) injections – proven in the animal model to be effective – were chosen to prolong the animals’ exposure to the respective GBCA. GBCA doses of previous intravenous (IV) animal studies were applied. After five weeks all rats were sacrificed. Sham controls were treated with IP saline injections, employing the same regimen. Results: No findings comparable with human NSF were observed in all animals after IP treatment with all seven GBCA at daily doses of 2.5 and 5.0 mmol/kg body weight (BW). No histopathological abnormalities of all examined organs were noted. Weight loss was stated in weeks three and four with GBCA injections at doses of 5.0 mmol/kg BW, but rats regained weight after cessation of GBCA treatment. Conclusions: NSF-comparable pathological findings could not be induced by high dose intraperitoneal injection of seven GBCA

Early postradiation recovery of precursor cells of hemopoietic stroma

International Nuclear Information System (INIS)

Todriya, T.V.

1984-01-01

Ability of stroma precursor cells to early postradiation recovery was studied in male mices using the method of fraction irradiation of bone marrow. Donor mices of bone marrow were irradiated in vivo once by the total dose (nonfraction irradiation) and fractionally with 6 h interval between two irradiation doses. The cumulative irradiation doses equal to 10, 12, 14, 16 Gr were investigated. Irradiation was carried out using gamma facility. Bone marrow of the femur was implanted immediately after irradiation under kidney capsule of nonirradiated syngeneic recipient. The ability of stroma precursor cells to intracellular repair (repair index) was evaluated according to the ratio of the number of hemopoietic cells formed in heterotropic transplants in groups with fraction irradiation to the same one in groups with nonfraction irradiation. The obtained results testify to the fact that slowly regenerated highly radioresistant population of precursor cells of hemopoietic stroma is capable to early postradiation recovery

Preoperative methylprednisolone enhances recovery after endovascular aortic repair

DEFF Research Database (Denmark)

de la Motte, Louise; Kehlet, Henrik; Vogt, Katja

2014-01-01

OBJECTIVE: To evaluate effects of preoperative high-dose glucocorticoid on the inflammatory response and recovery after endovascular aortic aneurysm repair (EVAR). BACKGROUND: The postimplantation syndrome after EVAR may delay recovery due to the release of proinflammatory mediators....... Glucocorticoids may reduce postoperative inflammatory responses and enhance recovery, but with limited information on EVAR. METHODS: A single-center, randomized, double-blind, placebo-controlled trial of 153 patients undergoing elective EVAR between November 2009 and January 2013. Patients received 30 mg.......001) and fulfillment of discharge criteria was shorter [2 days (IQR = 2-4 days) vs 3 days (IQR = 3-4 days)] (P factor receptor were also reduced (P

Clustered DNA damages induced in isolated DNA and in human cells by low doses of ionizing radiation

Science.gov (United States)

Sutherland, B. M.; Bennett, P. V.; Sidorkina, O.; Laval, J.; Lowenstein, D. I. (Principal Investigator)

2000-01-01

Clustered DNA damages-two or more closely spaced damages (strand breaks, abasic sites, or oxidized bases) on opposing strands-are suspects as critical lesions producing lethal and mutagenic effects of ionizing radiation. However, as a result of the lack of methods for measuring damage clusters induced by ionizing radiation in genomic DNA, neither the frequencies of their production by physiological doses of radiation, nor their repairability, nor their biological effects are known. On the basis of methods that we developed for quantitating damages in large DNAs, we have devised and validated a way of measuring ionizing radiation-induced clustered lesions in genomic DNA, including DNA from human cells. DNA is treated with an endonuclease that induces a single-strand cleavage at an oxidized base or abasic site. If there are two closely spaced damages on opposing strands, such cleavage will reduce the size of the DNA on a nondenaturing gel. We show that ionizing radiation does induce clustered DNA damages containing abasic sites, oxidized purines, or oxidized pyrimidines. Further, the frequency of each of these cluster classes is comparable to that of frank double-strand breaks; among all complex damages induced by ionizing radiation, double-strand breaks are only about 20%, with other clustered damage constituting some 80%. We also show that even low doses (0.1-1 Gy) of high linear energy transfer ionizing radiation induce clustered damages in human cells.

Dose-dependent and gender-related radiation-induced transcription alterations of Gadd45a and Ier5 in human lymphocytes exposed to gamma ray emitted by 60Co

International Nuclear Information System (INIS)

Tavakoli, H.; Manoochehri, M.; Mosalla, S. M. M.; Ghafori, M.; Karimi, A. A.

2013-01-01

Growth arrest DNA damage-inducible 45a gene (Gadd45a) and immediate early response gene 5 (Ier5) have been emphasised as ideal radiation bio-markers in several reports. However, some aspects of radiation-induced transcriptional alterations of these genes are unknown. In this study, gender-dependency and dose-dependency as two factors that may affect radiation induced transcription of Gadd45a and Ier5 genes were investigated. Human lymphocyte cells from six healthy voluntary blood donors (three women and three men) were irradiated in vitro with doses of 0.5-4.0 Gy from a 60 Co source and RNA isolated 4 h later using the High Pure RNA Isolation Kit. Dose and gender dependency of radiation-induced transcriptional alterations of Gadd45a and Ier5 genes were studied by quantitative real-time polymerase chain reaction. The results showed that as a whole, Gadd45a and Ier5 gave responses to gamma rays, while the responses were independent of radiation doses. Therefore, regardless of radiation dose, Gadd45a and Ier5 can be considered potential radiation bio-markers. Besides, although radiation-induced transcriptional alterations of Gadd45a in female and male lymphocyte samples were insignificant at 0.5 Gy, at other doses, their quantities in female samples were at a significantly higher level than in male samples. Radiation induced transcription of Ier5 of females samples had a reduction in comparison with male samples at 1 and 2 Gy, but at doses of 0.5 and 4 Gy, females were significantly more susceptible to radiation-induced transcriptional alteration of Ier5. (authors)

Pretreatment of low dose radiation reduces radiation-induced apoptosis in mouse lymphoma (EL4) cells.

Science.gov (United States)

Kim, J H; Hyun, S J; Yoon, M Y; Ji, Y H; Cho, C K; Yoo, S Y

1997-06-01

Induction of an adaptive response to ionizing radiation in mouse lymphoma (EL4) cells was studied by using cell survival fraction and apoptotic nucleosomal DNA fragmentation as biological end points. Cells in early log phase were pre-exposed to low dose of gamma-rays (0.01 Gy) 4 or 20 hrs prior to high dose gamma-ray (4, 8 and 12 Gy for cell survival fraction analysis; 8 Gy for DNA fragmentation analysis) irradiation. Then cell survival fractions and the extent of DNA fragmentation were measured. Significant adaptive response, increase in cell survival fraction and decrease in the extent of DNA fragmentation were induced when low and high dose gamma-ray irradiation time interval was 4 hr. Addition of protein or RNA synthesis inhibitor, cycloheximide or 5,6-dichloro-1-beta-d-ribofuranosylbenzimidazole (DRFB), respectively during adaptation period, the period from low dose gamma-ray irradiation to high dose gamma-ray irradiation, was able to inhibit the induction of adaptive response, which is the reduction of the extent DNA fragmentation in irradiated EL4 cells. These data suggest that the induction of adaptive response to ionizing radiation in EL4 cells required both protein and RNA synthesis.

Characterizing dose response relationships: Chronic gamma radiation in Lemna minor induces oxidative stress and altered polyploidy level.

Science.gov (United States)

Van Hoeck, Arne; Horemans, Nele; Van Hees, May; Nauts, Robin; Knapen, Dries; Vandenhove, Hildegarde; Blust, Ronny

2015-12-01

The biological effects and interactions of different radiation types in plants are still far from understood. Among different radiation types, external gamma radiation treatments have been mostly studied to assess the biological impact of radiation toxicity in organisms. Upon exposure of plants to gamma radiation, ionisation events can cause, either directly or indirectly, severe biological damage to DNA and other biomolecules. However, the biological responses and oxidative stress related mechanisms under chronic radiation conditions are poorly understood in plant systems. In the following study, it was questioned if the Lemna minor growth inhibition test is a suitable approach to also assess the radiotoxicity of this freshwater plant. Therefore, L. minor plants were continuously exposed for seven days to 12 different dose rate levels covering almost six orders of magnitude starting from 80 μGy h(-1) up to 1.5 Gy h(-1). Subsequently, growth, antioxidative defence system and genomic responses of L. minor plants were evaluated. Although L. minor plants could survive the exposure treatment at environmental relevant exposure conditions, higher dose rate levels induced dose dependent growth inhibitions starting from approximately 27 mGy h(-1). A ten-percentage growth inhibition of frond area Effective Dose Rate (EDR10) was estimated at 95 ± 7 mGy h(-1), followed by 153 ± 13 mGy h(-1) and 169 ± 12 mGy h(-1) on fresh weight and frond number, respectively. Up to a dose rate of approximately 5 mGy h(-1), antioxidative enzymes and metabolites remained unaffected in plants. A significant change in catalase enzyme activity was found at 27 mGy h(-1) which was accompanied with significant increases of other antioxidative enzyme activities and shifts in ascorbate and glutathione content at higher dose rate levels, indicating an increase in oxidative stress in plants. Recent plant research hypothesized that environmental genotoxic stress conditions

Radiation-induced rib fracture after stereotactic body radiotherapy with a total dose of 54–56 Gy given in 9–7 fractions for patients with peripheral lung tumor: impact of maximum dose and fraction size

International Nuclear Information System (INIS)

Aoki, Masahiko; Sato, Mariko; Hirose, Katsumi; Akimoto, Hiroyoshi; Kawaguchi, Hideo; Hatayama, Yoshiomi; Ono, Shuichi; Takai, Yoshihiro

2015-01-01

Radiation-induced rib fracture after stereotactic body radiotherapy (SBRT) for lung cancer has been recently reported. However, incidence of radiation-induced rib fracture after SBRT using moderate fraction sizes with a long-term follow-up time are not clarified. We examined incidence and risk factors of radiation-induced rib fracture after SBRT using moderate fraction sizes for the patients with peripherally located lung tumor. During 2003–2008, 41 patients with 42 lung tumors were treated with SBRT to 54–56 Gy in 9–7 fractions. The endpoint in the study was radiation-induced rib fracture detected by CT scan after the treatment. All ribs where the irradiated doses were more than 80% of prescribed dose were selected and contoured to build the dose-volume histograms (DVHs). Comparisons of the several factors obtained from the DVHs and the probabilities of rib fracture calculated by Kaplan-Meier method were performed in the study. Median follow-up time was 68 months. Among 75 contoured ribs, 23 rib fractures were observed in 34% of the patients during 16–48 months after SBRT, however, no patients complained of chest wall pain. The 4-year probabilities of rib fracture for maximum dose of ribs (Dmax) more than and less than 54 Gy were 47.7% and 12.9% (p = 0.0184), and for fraction size of 6, 7 and 8 Gy were 19.5%, 31.2% and 55.7% (p = 0.0458), respectively. Other factors, such as D2cc, mean dose of ribs, V10–55, age, sex, and planning target volume were not significantly different. The doses and fractionations used in this study resulted in no clinically significant rib fractures for this population, but that higher Dmax and dose per fraction treatments resulted in an increase in asymptomatic grade 1 rib fractures

Drug-drug interaction of microdose and regular-dose omeprazole with a CYP2C19 inhibitor and inducer.

Science.gov (United States)

Park, Gab-Jin; Bae, Soo Hyeon; Park, Wan-Su; Han, Seunghoon; Park, Min-Ho; Shin, Seok-Ho; Shin, Young G; Yim, Dong-Seok

2017-01-01

A microdose drug-drug interaction (DDI) study may be a valuable tool for anticipating drug interaction at therapeutic doses. This study aimed to compare the magnitude of DDIs at microdoses and regular doses to explore the applicability of a microdose DDI study. Six healthy male volunteer subjects were enrolled into each DDI study of omeprazole (victim) and known perpetrators: fluconazole (inhibitor) and rifampin (inducer). For both studies, the microdose (100 μg, cold compound) and the regular dose (20 mg) of omeprazole were given at days 0 and 1, respectively. On days 2-9, the inhibitor or inducer was given daily, and the microdose and regular dose of omeprazole were repeated at days 8 and 9, respectively. Full omeprazole pharmacokinetic samplings were performed at days 0, 1, 8, and 9 of both studies for noncompartmental analysis. The magnitude of the DDI, the geometric mean ratios (with perpetrator/omeprazole only) of maximum concentration (C max ) and area under the curve to the last measurement (AUC t ) of the microdose and the regular dose were compared. The geometric mean ratios in the inhibition study were: 2.17 (micro) and 2.68 (regular) for C max , and 4.07 (micro), 4.33 (regular) for AUC t . For the induction study, they were 0.26 (micro) and 0.21 (regular) for C max , and 0.16 (micro) and 0.15 (regular) for AUC t . There were no significant statistical differences in the magnitudes of DDIs between microdose and regular-dose conditions, regardless of induction or inhibition. Our results may be used as partial evidence that microdose DDI studies may replace regular-dose studies, or at least be used for DDI-screening purposes.

Exposure to low infective doses of HCV induces cellular immune responses without consistently detectable viremia or seroconversion in chimpanzees

International Nuclear Information System (INIS)

Shata, Mohamed Tarek; Tricoche, Nancy; Perkus, Marion; Tom, Darley; Brotman, Betsy; McCormack, Patricia; Pfahler, Wolfram; Lee, Dong-Hun; Tobler, Leslie H.; Busch, Michael; Prince, Alfred M.

2003-01-01

In hepatitis C virus (HCV) infection, there is accumulating data suggesting the presence of cellular immune responses to HCV in exposed but seemingly uninfected populations. Some studies have suggested cross-reactive antigens rather than prior HCV exposure as the main reason for the immune responses. In this study we address this question by analyzing the immune response of chimpanzees that have been sequentially exposed to increasing doses of HCV virions. The level of viremia, as well as the immune responses to HCV at different times after virus inoculation, were examined. Our data indicate that HCV infective doses as low as 1-10 RNA (+) virions induce detectable cellular immune responses in chimpanzees without consistently detectable viremia or persistent seroconversion. However, increasing the infective doses of HCV to 100 RNA (+) virions overcame the low-inoculum-induced immune response and produced high-level viremia followed by seroconversion

Using LEDs to stimulate the recovery of radiation damage to plastic scintillators

Energy Technology Data Exchange (ETDEWEB)

Wetzel, J., E-mail: james-wetzel@uiowa.edu [The University of Iowa, Iowa City, IA (United States); Tiras, E. [The University of Iowa, Iowa City, IA (United States); Bilki, B. [The University of Iowa, Iowa City, IA (United States); Beykent University, Istanbul (Turkey); Onel, Y. [The University of Iowa, Iowa City, IA (United States); Winn, D. [Fairfield University, Fairfield, CT (United States)

2017-03-15

In this study, we consider using LEDs to stimulate the recovery of scintillators damaged from radiation in high radiation environments. We irradiated scintillating tiles of polyethylene naphthalate (PEN), Eljen brand EJ-260 (EJN), an overdoped EJ-260 (EJ2P), and a lab-produced elastomer scintillator (ES) composed of p-terphenyl (ptp) in epoxy. Two different high-dose irradiations took place, with PEN dosed to 100 kGy, and the others to 78 kGy. We found that the ‘blue’ scintillators (PEN and ES) recovered faster and maximally higher with LEDs than without. Conversely exposing the ‘green’ scintillators (EJ-260) to LED light had a nearly negligible effect on the recovery. We hypothesize that the ‘green’ scintillators require wavelengths that match their absorption and emission spectra for LED stimulated recovery.

Effects of chlorimuron ethyl on terrestrial and wetland plants: Levels of, and time to recovery following sublethal exposure

International Nuclear Information System (INIS)

Carpenter, David; Boutin, Céline; Allison, Jane E.

2013-01-01

Current pesticide registration guidelines call for short-term testing of plants; long-term effects on vegetative parts and reproduction remain untested. The aims of our study were to determine level of recovery and recovery times for plants exposed to the sulfonylurea herbicide chlorimuron ethyl using data collected from single species, dose–response greenhouse experiments. The nine terrestrial and eight wetland species tested showed variable levels of recovery and recovery timeframes. Many species (six terrestrial and five wetland) were vegetatively stunted at sublethal doses and were reproductively impaired. Full recovery did not occur at all doses and maximum recovery times varied from 3 to 15 weeks in this controlled environment. In a complex community, affected species may be displaced by tolerant species, through interspecific competition, before they fully recover. It is plausible that individual populations could be diminished or eliminated through reduced seedbank inputs (annuals and perennials) and asexual reproduction (perennials). - Highlights: ► Native terrestrial and wetland plants were used to assess the risks of herbicide drift. ► Vegetative and reproductive health endpoints were evaluated over time. ► Recovery rates were found to be both species and dose dependant. ► Reproductive recovery does not always equal vegetative recovery. ► Susceptible species may be displaced by resilient or resistant species. - Capsule: This study serves to bridge the gap between simplified short-term greenhouse tests and effects of herbicides on recovery of non-target plant species after sublethal exposures.

Effects of Sleep Deprivation on Hypoglycemia-Induced Cognitive Impairment and Recovery in Adults With Type 1 Diabetes.

Science.gov (United States)

Inkster, Berit E; Zammitt, Nicola N; Ritchie, Stuart J; Deary, Ian J; Morrison, Ian; Frier, Brian M

2016-05-01

To ascertain whether hypoglycemia in association with sleep deprivation causes greater cognitive dysfunction than hypoglycemia alone and protracts cognitive recovery after normoglycemia is restored. Fourteen adults with type 1 diabetes underwent a hyperinsulinemic, hypoglycemic clamp on two separate occasions. Before one glucose clamp, the participants stayed awake overnight to induce sleep deprivation. Participants were randomized and counterbalanced to the experimental condition. Cognitive function tests were performed before and during hypoglycemia and for 90 min after restoration of normoglycemia. Cognitive impairment during hypoglycemia did not differ significantly between the sleep-deprived and non-sleep-deprived conditions. However, in the sleep-deprived state, digit symbol substitution scores and choice reaction times were significantly poorer during recovery (P sleep deprivation, such as tiredness, were removed. Hypoglycemia per se produced a significant decrement in cognitive function; coexisting sleep deprivation did not have an additive effect. However, after restoration of normoglycemia, preceding sleep deprivation was associated with persistence of hypoglycemic symptoms and greater and more prolonged cognitive dysfunction during the recovery period. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Characterizing dose response relationships: Chronic gamma radiation in Lemna minor induces oxidative stress and altered polyploidy level

International Nuclear Information System (INIS)

Van Hoeck, Arne; Horemans, Nele; Van Hees, May; Nauts, Robin; Knapen, Dries; Vandenhove, Hildegarde; Blust, Ronny

2015-01-01

The biological effects and interactions of different radiation types in plants are still far from understood. Among different radiation types, external gamma radiation treatments have been mostly studied to assess the biological impact of radiation toxicity in organisms. Upon exposure of plants to gamma radiation, ionisation events can cause, either directly or indirectly, severe biological damage to DNA and other biomolecules. However, the biological responses and oxidative stress related mechanisms under chronic radiation conditions are poorly understood in plant systems. In the following study, it was questioned if the Lemna minor growth inhibition test is a suitable approach to also assess the radiotoxicity of this freshwater plant. Therefore, L. minor plants were continuously exposed for seven days to 12 different dose rate levels covering almost six orders of magnitude starting from 80 μGy h"−"1 up to 1.5 Gy h"−"1. Subsequently, growth, antioxidative defence system and genomic responses of L. minor plants were evaluated. Although L. minor plants could survive the exposure treatment at environmental relevant exposure conditions, higher dose rate levels induced dose dependent growth inhibitions starting from approximately 27 mGy h"−"1. A ten-percentage growth inhibition of frond area Effective Dose Rate (EDR_1_0) was estimated at 95 ± 7 mGy h"−"1, followed by 153 ± 13 mGy h"−"1 and 169 ± 12 mGy h"−"1 on fresh weight and frond number, respectively. Up to a dose rate of approximately 5 mGy h"−"1, antioxidative enzymes and metabolites remained unaffected in plants. A significant change in catalase enzyme activity was found at 27 mGy h"−"1 which was accompanied with significant increases of other antioxidative enzyme activities and shifts in ascorbate and glutathione content at higher dose rate levels, indicating an increase in oxidative stress in plants. Recent plant research hypothesized that environmental genotoxic

Recovery in stages I and II of thermal and fission neutron irradiated molybdenum

International Nuclear Information System (INIS)

Coltman, R.R. Jr.; Klabunde, C.E.; Redman, J.K.

1975-01-01

The influence of initial dose and irradiation doping upon the recovery of Mo was studied for the markedly different types of damage produced by thermal and fission neutrons. The features of the Stage I recovery commonly seen for several fcc metals can be identified, including a I/sub D/ peak at 40 0 K. The typical dose-dependent behavior of a I/sub E/ subpeak was observed at approximately 47 0 K, and evidence for free interstitial migration is further supported by irradiation doping results. Stage II shows a first-order peak at 120 0 K in which the population percentage increases with increasing initial dose in opposite fashion to fcc impurity detrapping peaks. (auth)

Evaluation of therapeutic effect of low dose naltrexone in experimentally-induced Crohn's disease in rats.

Science.gov (United States)

Tawfik, Dina Ibrahim; Osman, Afaf Sayed; Tolba, Hedayat Mahmoud; Khattab, Aida; Abdel-Salam, Lubna O; Kamel, Mahmoud M

2016-10-01

Crohn's disease is a relapsing inflammatory condition afflicting the digestive tract. Drugs used for treatment of Crohn's disease may be associated with serious side effects. Endogenous opioid peptides modulate inflammatory cytokine production. Opioid antagonists have been shown to play a role in healing and repair of tissues. This work was designed to detect the possible beneficial effects of opioid antagonist naltrexone in indomethacin-induced Crohn's disease in rats. Enteritis was induced in male albino rats by two subcutaneous injection of indomethacin in a dose of 7.5mg/kg 24h apart started on day one. Salfasalazine, naltrexone and their combination were administered orally from day one of induction of enteritis to day 10. Disease activity index, serum levels of C-reactive protein and tumor necrosis factor-α, macroscopic and microscopic pathological scores and in vitro motility studies were evaluated. Induction of enteritis resulted in significant increase of disease activity index, significant elevation of serum levels of C-reactive protein and tumor necrosis factor-α, significant deterioration of pathological scores and significant increase in the mean contractility response of the isolated ileal segments compared with normal untreated rats. Treatment with sulfasalazine, low dose of natrexone or their combination resulted in significant improvement of all measured parameters compared with enteritis group. The current finding could provide new interesting opportunity for developing new therapeutic approaches for treatment of Crohn's disease. Use of naltrexone, especially in small dose, has little side effects making it of interest for treatment of Crohn's disease. Also, it provides the possibility of reduced doses of other drugs if it is used as combined therapy. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dose and effect relationship of radiation induced cancer and its influencing factors in experimental animals, 1

International Nuclear Information System (INIS)

Sasaki, Shunsaku; Sato, Fumiaki; Eto, Hideo

1975-01-01

The data of risk evaluation of external irradiation were integrated with animal experiments from the aspects of qualitative generalizations of characteristics of radiation induced tumors. Studies covered competition of cause of death, figure of dose-to-effect relationship, characteristics of low dose rate of irradiation, relative biological effectiveness (RBE) of high LET radiation, effects of feactionated irradiation, complex actions with chemical substances, effects of protectional medium, differences of radiosensitivity by species and strains, and age dependency of sensitivities. Competition of cause of death by time length of latent period and degree of malignancy of the disease. Discussion on competition of death suggested the following idea: 1) incidence of tumor induction in the individual level did not correspond to transformation in the cellular level, and 2) relative incidence of tumor induction after a certain dose of whole body irradiation did not indicate the relative sensitivity of each tissue, for the relationship between tumor incidence and exposure dose was not a linear relationship. The dose-to-effect relationship of tumor induction was decided by following factors: i) sensitivity on transformation of cells, ii) sensitivity on the death of potential tumor cells, and iii) competition of the cause of death. Tumor induction by low dose rate irradiation was also studied by comparing qualitative and quantitative differences between high dose rate single irradiation and a series of low dose rate irradiation. (Serizawa, K.)

Some mechanisms of disturbances and recovery of T-lymphocyte migratory properties in irradiated mice

International Nuclear Information System (INIS)

Anokhin, G.N.; Yarilin, A.A.

1984-01-01

Migration of 51 Cr-labelled T cells from irradiated mice into lymph nodes of syngeneic unirradiated recipients decreased in a dose-dependent fashion. Influx of labelled T cells between 4 and 24 hr after injection (secondary migration) is more radiosensitive than lymph-node migration of T cells in the first 4 hr (primary migration). Treatment of T cells from irradiated mice in vitro with Con A or with trypsin does not enhance radiation-induced alteration of their migratory properties, but irradiation enhances the effects of Con A and trypsin on T-cell migration. Recovery of primary migration of irradiated T cells is completed 3 months after irradiation; it is probably caused by T-cell renewal. The defect of T-cell secondary migration is more stable: it remains 6 months after irradiation in a dose of 4 gy. Post-irradiation defects of the T-cell differentiation process as a cause of long-lasting alteration of T-cell secondary migration are discussed. (author)

Caffeine at a Moderate Dose Did Not Affect the Skeletal System of Rats with Streptozotocin-Induced Diabetes

Directory of Open Access Journals (Sweden)

Joanna Folwarczna

2017-10-01

Full Text Available Diabetes may lead to the development of osteoporosis. Coffee drinking, apart from its health benefits, is taken into consideration as an osteoporosis risk factor. Data from human and animal studies on coffee and caffeine bone effects are inconsistent. The aim of the study was to investigate effects of caffeine at a moderate dose on the skeletal system of rats in two models of experimental diabetes induced by streptozotocin. Effects of caffeine administered orally (20 mg/kg aily for four weeks were investigated in three-month-old female Wistar rats, which, two weeks before the start of caffeine administration, received streptozotocin (60 mg/kg, intraperitoneally alone or streptozotocin after nicotinamide (230 mg/kg, intraperitoneally. Bone turnover markers, mass, mineral density, histomorphometric parameters, and mechanical properties were examined. Streptozotocin induced diabetes, with profound changes in the skeletal system due to increased bone resorption and decreased bone formation. Although streptozotocin administered after nicotinamide induced slight increases in glucose levels at the beginning of the experiment only, slight, but significant unfavorable changes in the skeletal system were demonstrated. Administration of caffeine did not affect the investigated skeletal parameters of rats with streptozotocin-induced disorders. In conclusion, caffeine at a moderate dose did not exert a damaging effect on the skeletal system of diabetic rats.

Caffeine at a Moderate Dose Did Not Affect the Skeletal System of Rats with Streptozotocin-Induced Diabetes.

Science.gov (United States)

Folwarczna, Joanna; Janas, Aleksandra; Cegieła, Urszula; Pytlik, Maria; Śliwiński, Leszek; Matejczyk, Magdalena; Nowacka, Anna; Rudy, Karolina; Krivošíková, Zora; Štefíková, Kornélia; Gajdoš, Martin

2017-10-30

Diabetes may lead to the development of osteoporosis. Coffee drinking, apart from its health benefits, is taken into consideration as an osteoporosis risk factor. Data from human and animal studies on coffee and caffeine bone effects are inconsistent. The aim of the study was to investigate effects of caffeine at a moderate dose on the skeletal system of rats in two models of experimental diabetes induced by streptozotocin. Effects of caffeine administered orally (20 mg/kg aily for four weeks) were investigated in three-month-old female Wistar rats, which, two weeks before the start of caffeine administration, received streptozotocin (60 mg/kg, intraperitoneally) alone or streptozotocin after nicotinamide (230 mg/kg, intraperitoneally). Bone turnover markers, mass, mineral density, histomorphometric parameters, and mechanical properties were examined. Streptozotocin induced diabetes, with profound changes in the skeletal system due to increased bone resorption and decreased bone formation. Although streptozotocin administered after nicotinamide induced slight increases in glucose levels at the beginning of the experiment only, slight, but significant unfavorable changes in the skeletal system were demonstrated. Administration of caffeine did not affect the investigated skeletal parameters of rats with streptozotocin-induced disorders. In conclusion, caffeine at a moderate dose did not exert a damaging effect on the skeletal system of diabetic rats.

Developing a single-aliquot protocol for measuring equivalent dose in biogenic carbonates

International Nuclear Information System (INIS)

Stirling, R.J.; Duller, G.A.T.; Roberts, H.M.

2012-01-01

Exploiting biogenic carbonates as thermoluminescence dosimeters requires an understanding of trap kinetics and an appropriate sequence with which to measure equivalent dose. The trap kinetics of two high temperature peaks (peaks II and III) from calcitic snail opercula have been investigated resulting in the calculation of lifetimes of 7.4 × 10 7 and 1.4 × 10 11 years for the two peaks respectively. Two measurement sequences, based upon changes in the application and measurement of a test dose, have been applied to peaks II and III, and though both methods were equally successful in dose recovery and production of a dose response curve some differences were observed. Primarily, the use of method 1 lead to dose dependant sensitivity change implying competition effects occurring during irradiation; method 2 did not experience this phenomenon. As a consequence method 2 was chosen as the most appropriate protocol for single-aliquot dating of this material. When assessing the TL behaviour of the two peaks, peak II performed poorly in dose recovery experiments recovering a dose 60–100% larger than that applied. Disproportionate growth of peak II in response to a beta dose applied prior to measurement, compared to growth following regeneration doses indicated that peak II was not suitable for use in single-aliquot protocols. However, dose recovery results for peak III were all within errors of unity of the given dose, and peak III was therefore chosen as the most appropriate peak for TL dosimetry in these single-aliquot procedures. The lifetime of charge in peak III is sufficient to date over many millions of years, and furthermore using the chosen method 2 the dose response curve has a D 0 of 3,250 ± 163 Gy allowing dating to over 3 million years.

Cuminum cyminum extract attenuates scopolamine-induced memory loss and stress-induced urinary biochemical changes in rats: a noninvasive biochemical approach.

Science.gov (United States)

Koppula, Sushruta; Choi, Dong Kug

2011-07-01

Cuminum cyminum Linn. (Apiaceae), cumin, is a popular spice with a long history of medicinal use to treat various symptoms such as diarrhea, flatulence, gynecological, and respiratory diseases. To date, no scientific investigation was reported regarding memory-enhancing and antistress activity of cumin fruits. The present study deals with the memory-enhancing and antistress activities and further the antioxidant status via lipid peroxidation inhibition. Antistress activity was evaluated by inducing stress via forced swimming and the urinary vanillylmandelic acid (VMA) and ascorbic acid were estimated as biomarkers. Memory-enhancing activity was studied by conditioned avoidance response using Cook's pole climbing apparatus in normal and scopolamine-induced amnestic rats. Thiobarbituric acid reactive substances (TBARS) assay was used to evaluate the lipid peroxidation. Daily administration of cumin at doses of 100, 200, and 300 mg/kg body weight 1 h prior to induction of stress inhibited the stress-induced urinary biochemical changes in a dose-dependent manner without altering the levels in normal control groups. The cognition, as determined by the acquisition, retention, and recovery in rats, was observed to be dose-dependent. The extract also produced significant lipid peroxidation inhibition in comparison with known antioxidant ascorbic acid in both rat liver and brain. This study provides scientific support for the antistress, antioxidant, and memory-enhancing activities of cumin extract and substantiates that its traditional use as a culinary spice in foods is beneficial and scientific in combating stress and related disorders.

Relationship of DNA repair to chromosome aberrations, sister-chromatid exchanges and survival during liquid-holding recovery in X-irradiated mammalian cells

International Nuclear Information System (INIS)

Fornace, A.J. Jr.; Nagasawa, H.; Little, J.B.

1980-01-01

The repair of X-ray-induced DNA single strand breaks and DNA-protein cross-links was investigated in stationary phase, contact-inhibited mouse cells by the alkaline-elution technique. Approx. 90% of X-ray-induced single strand breaks were rejoined during the first hour of repair, whereas most of the remaining breaks were rejoined more slowly during the next 5 h. At early repair times, the number of residual non-rejoined sungle strand breaks was approx. proportional to the X-ray dose. DNA-protein cross-links were removed at a slower rate (Tsub(1/2) approx. 10-12 h). Cells were held in stationary growth for various periods of time after irradiation before subculture at low density to score for colony survival (potentially lethal damage repair), chromosome aberrations in the first mitosis, and sister-chromatid exchanges in the second mitosis. Both cell killing and the frequency of chromosome aberrations decreased during the first several hours of recovery, reaching a minimum level by 6 h; this decrease correlated temporally with the repair of the slowly rejoining DNA-strand breaks. Relatively few sister-chromatid exchanges were observed when the cells were subcultured immediately after X-ray. The exchange frequency rose to maximum levels after a 4-h recovery interval, and returned to control levels after 12 h of recovery. The possible relationship of DNA repair to these changes in survival, chromosome aberrations, and sister-chromatid exchanges during liquid-holding recovery is discussed. (orig.)

Neutropenia induced by high-dose intravenous benzylpenicillin in treating neurosyphilis: Does it really matter?

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Rui-Rui Peng

2017-03-01

Full Text Available Prompt therapy with high-dose intravenous benzylpenicillin for a prolonged period is critical for neurosyphilis patients to avoid irreversible sequelae. However, life-threatening neutropenia has been reported as a complication of prolonged therapy with high doses of benzylpenicillin when treating other diseases. This study aimed to investigate the incidence, presentation, management and prognosis of benzylpenicillin-induced neutropenia in treating neurosyphilis based on a large sample of syphilis patients in Shanghai.Between 1st January 2013 and 31st December 2015, 1367 patients with neurosyphilis were treated with benzylpenicillin, 578 of whom were eligible for recruitment to this study. Among patients without medical co-morbidities, the total incidence of benzylpenicillin-induced neutropenia and severe neutropenia was 2.42% (95% CI: 1.38-4.13% and 0.35% (95% CI: 0.06-1.39%, respectively. The treatment duration before onset of neutropenia ranged from 10 to 14 days, with a total cumulative dose of between 240 and 324 megaunits of benzylpenicillin. Neutropenia was accompanied by symptoms of chills and fever (5 patients, fatigue (2 patients, cough (1 patient, sore throat (1 patient, diarrhea (1 patient and erythematous rash (1 patient. The severity of neutropenia was not associated with age, gender or type of neurosyphilis (p>0.05. Neutropenia, even when severe, was often tolerated and normalized within one week. A more serious neutropenia did not occur when reinstituting benzylpenicillin in patients with mild or moderate neutropenia nor when ceftriaxone was used three months after patients had previously experienced severe neutropenia.Benzylpenicillin-induced neutropenia was uncommon in our cohort of patients. Continuation of therapy was possible with intensive surveillance for those with mild or moderate neutropenia. For severe neutropenia, it is not essential to aggressively use hematopoietic growth factors or broad-spectrum antibiotics for

Ringer's lactate improves liver recovery in a murine model of acetaminophen toxicity

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Yang Runkuan

2011-11-01

Full Text Available Abstract Background Acetaminophen (APAP overdose induces massive hepatocyte necrosis. Liver regeneration is a vital process for survival after a toxic insult. Since hepatocytes are mostly in a quiescent state (G0, the regeneration process requires the priming of hepatocytes by cytokines such as TNF-α and IL-6. Ringer's lactate solution (RLS has been shown to increase serum TNF-α and IL-6 in patients and experimental animals; in addition, RLS also provides lactate, which can be used as an alternative metabolic fuel to meet the higher energy demand by liver regeneration. Therefore, we tested whether RLS therapy improves liver recovery after APAP overdose. Methods C57BL/6 male mice were intraperitoneally injected with a single dose of APAP (300 mg/kg dissolved in 1 mL sterile saline. Following 2 hrs of APAP challenge, the mice were given 1 mL RLS or Saline treatment every 12 hours for a total of 72 hours. Results 72 hrs after APAP challenge, compared to saline-treated group, RLS treatment significantly lowered serum transaminases (ALT/AST and improved liver recovery seen in histopathology. This beneficial effect was associated with increased hepatic tissue TNF-α concentration, enhanced hepatic NF-κB DNA binding and increased expression of cell cycle protein cyclin D1, three important factors in liver regeneration. Conclusion RLS improves liver recovery from APAP hepatotoxicity.

Crystal growth and thermoluminescence response of NaZr2(PO4)3 at high gamma radiation doses

International Nuclear Information System (INIS)

Ordóñez-Regil, E.; Contreras-Ramírez, A.; Fernández-Valverde, S.M.; González-Martínez, P.R.; Carrasco-Ábrego, H.

2013-01-01

Graphical abstract: -- Highlights: •NaZr 2 (PO 4 ) 3 exposed to gamma doses of 10, 30 and 50 MGy. •Gamma radiation produced growth of the crystal size of the NZP. •Morphology changes were reversible by heating. •Linear relationship between the thermoluminescence and the applied gamma dose. •This property could be useful for high-level gamma dosimetry. -- Abstract: This work describes the synthesis and characterization of NaZr 2 (PO 4 ) 3 . The stability of this material under high doses of gamma radiation was investigated in the range of 10–50 MGy. Samples of unaltered and gamma irradiated NaZr 2 (PO 4 ) 3 were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and thermoluminescence. The results showed that while functional groups were not affected by the gamma irradiation, morphology changes were observed with increasing doses of gamma irradiation. The morphology of the non-irradiated compound is agglomerated flakes; however, irradiation at 10 MGy splits the flakes inducing the formation of well-defined cubes. Gamma irradiation induced the crystal size of the NaZr 2 (PO 4 ) 3 to grow. The heat treatment (973 K) of samples irradiated at 50 MGy resulted in the recovery of the original morphology. Furthermore, the thermoluminescence analysis of the irradiated compound is reported

Characteristics of myogenic response and ankle torque recovery after lengthening contraction-induced rat gastrocnemius injury

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Song Hongsun

2012-10-01

Full Text Available Abstract Background Although muscle dysfunction caused by unfamiliar lengthening contraction is one of most important issues in sports medicine, there is little known about the molecular events on regeneration process. The purpose of this study was to investigate the temporal and spatial expression patterns of myogenin, myoD, pax7, and myostatin after acute lengthening contraction (LC-induced injury in the rat hindlimb. Methods We employed our originally developed device with LC in rat gastrocnemius muscle (n = 24. Male Wistar rats were anesthetized with isoflurane (aspiration rate, 450 ml/min, concentration, 2.0%. The triceps surae muscle of the right hindlimb was then electrically stimulated with forced isokinetic dorsi-flexion (180°/sec and from 0 to 45°. Tissue contents of myoD, myogenin, pax7, myostatin were measured by western blotting and localizations of myoD and pax7 was measured by immunohistochemistry. After measuring isometric tetanic torque, a single bout of LC was performed in vivo. Results The torque was significantly decreased on days 2 and 5 as compared to the pre-treatment value, and recovered by day 7. The content of myoD and pax7 showed significant increases on day 2. Myogenin showed an increase from day 2 to 5. Myostatin on days 5 and 7 were significantly increased. Immunohistochemical analysis showed that myoD-positive/pax7-positive cells increased on day 2, suggesting that activated satellite cells play a role in the destruction and the early recovery phases. Conclusion We, thus, conclude that myogenic events associate with torque recovery after LC-induced injury.

Chromosomal aberrations induced by low-dose γ-irradiation: Study of R-banded chromosomes of human lymphocytes

International Nuclear Information System (INIS)

Al-Achkar, W.; Lefrancois, D.; Aurias, A.

1991-01-01

The effect of low-dose (0-0.5 Gy) γ-radiations was studied on R-banded chromosomes from lymphocytes of healthy donors of various ages. In cells from newborns, an increase of chromosome damage roughly proportional to the dose was found. In lymphocytes from young adults chromosomal aberrations were not detected at doses of 0.05 and 0.1 Gy, and in lymphocytes from old adults not even at 0.2 Gy. The difficulty in detecting aberrations in lymphocytes from adults is largely due to a considerable background of chromosomal anomalies which should be borne in mind in dosimetry studies. The rate of induction largely depends on the types of rearrangements. One-break terminal deletions are efficiently induced at 0.1 and 0.2 Gy and are the best indicators of exposure at these doses. At 0.5 Gy, the frequencies of 2-break lesions, i.e., dicentrics and reciprocal translocations, increase, whereas the of deletions decreases. (author). 6 refs., 3 figs., 2 tabs

The MARS15-based FermiCORD code system for calculation of the accelerator-induced residual dose

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Grebe, A.; Leveling, A.; Lu, T.; Mokhov, N.; Pronskikh, V.

2018-01-01

The FermiCORD code system, a set of codes based on MARS15 that calculates the accelerator-induced residual doses at experimental facilities of arbitrary configurations, has been developed. FermiCORD is written in C++ as an add-on to Fortran-based MARS15. The FermiCORD algorithm consists of two stages: 1) simulation of residual doses on contact with the surfaces surrounding the studied location and of radionuclide inventories in the structures surrounding those locations using MARS15, and 2) simulation of the emission of the nuclear decay gamma-quanta by the residuals in the activated structures and scoring the prompt doses of these gamma-quanta at arbitrary distances from those structures. The FermiCORD code system has been benchmarked against similar algorithms based on other code systems and showed a good agreement. The code system has been applied for calculation of the residual dose of the target station for the Mu2e experiment and the results have been compared to approximate dosimetric approaches.

Comparision the value of detecting myocardial viability between low dose dobutamine stress MRI and echocardiography

International Nuclear Information System (INIS)

He Yi; Zhang Zhaoqi; Yu Wei; Miao Cuilian; Zhao Yike; Yan Zixu

2006-01-01

Objective: To Compare the diagnostic value between low dose dobutamine stress transthrotic echocardiography and low dose dobutamine stress MRI in detecting myocardial viability of chronic myocardial infarction. Methods: Rest and low dose dobutamine (5, 10 μg·kg -1 ·min -1 ) stress transthrotic echocardiography and cine-MRI were performed in 30 patients with chronic myocardial infarction. 24 patients underwent successful revascularization and 10 of them underwent another rest cine-MRI study to assess segmental myocardial functional recovery. Left ventricular were divided into 16 segments, the criteria of viability in different techniques is: MRI: dobutamine induced systolic wall thickening was ≥2 mm in akinetic or diskinetic segments at rest; Echocardiography: wall motion score reduced at least 1 after dobutamine stress in akinetic or' diskinetic segments at rest. Results: One hundren and eight segments showed wall motion abnormalities of 30 patients, 65 and 56 segments shows positive reaction, 43 and 52 segments shows negativereaction in MRI and echocardiography after dobutamine stress respectively. Kappa value of the two techniques is 0.75, concordance in both techniques is 88%. Twenty-four segments showed functional recovery, 14 segments remained dysfunction 3-6 months after revascularization, the sensitivity, specificity and accuracy of detecting myocardial viability in chronic myocardial infarction in MRI and echocardiography is 95.8% vs 79.2% (P>0.05), 85.7% vs 85.7% (P>0.05), 92.1% vs 81.6% (P>0.05) respectively. The sensitivity and accuracy of MRI is a little higher. Conclusion: The ability of detecting myocardial viability by both low dose dobutamine stress transthrotic echocardiography and low dose dobutamine stress MRI is similer, the sensitivity and accuracy of MRI is a little higher. (authors)

Recovery profile-e comparison of isoflurane and propofol anesthesia for laparoscopic cholecystectomy

International Nuclear Information System (INIS)

Khalid, A.; Siddiqui, S.Z.; Aftab, S.; Sabbar, S.

2008-01-01

To compare the recovery profile in terms of time of extubation, eye opening, orientation and mobility and frequency of Postoperative Nausea and Vomiting (PONV) between propofol and isoflurane based anesthesia in patients undergoing laparoscopic cholecystectomy with prophylactic antiemetic. After informed consent, a total of 60 ASA I-II patients scheduled for laparoscopic cholecystectomy were divided in two equal groups I and P. Anesthesia in all patients were induced by Nalbuphine 0.15 mg/kg, Midazolam 0.03 mg/kg, Propofol 1.5 mg/kg and Rocuronium 0.6 mg/kg. Anesthesia was maintained with Isoflurane in group I and propofol infusion in group P, while ventilation was maintained with 50% N/sub 2/O/sub 2/ mixture in both the groups. All patients were given antiemetic prophylaxis. Hemodynamics were recorded throughout anesthesia and recovery period. At the end of surgery, times of extubation, eye opening, orientation (by modified Aldrete score) and mobility (recovery profile) were assessed. PONV was observed and recorded immediately after extubation, during early postoperative period (0-4 hours) and late period (4-24 hours). Antiemetic requirements were also recorded for the same periods in both the groups. Propofol provided faster recovery (extubation and eye opening times) and orientation in immediate postoperative period with statistically significant differences between the groups (p<0.0001). Recovery characteristics were comparably lower in group I. More patients achieved full points (8) on modified Aldrete score at different time until 30 minutes in group P. Postoperative nausea and vomiting in early and late periods were significantly reduced in group P. Moreover, requirement of rescue antiemetic doses were significantly lower in group P in 24 hours (p<0.0001). In this series, recovery was much faster with earlier gain of orientation with propofol anesthesia compared to isoflurane in the early recovery periods. Propofol is likely to be a better choice of

Recovery in stroke rehabilitation through the rotation of preferred directions induced by bimanual movements: a computational study.

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Ken Takiyama

Full Text Available Stroke patients recover more effectively when they are rehabilitated with bimanual movement rather than with unimanual movement; however, it remains unclear why bimanual movement is more effective for stroke recovery. Using a computational model of stroke recovery, this study suggests that bimanual movement facilitates the reorganization of a damaged motor cortex because this movement induces rotations in the preferred directions (PDs of motor cortex neurons. Although the tuning curves of these neurons differ during unimanual and bimanual movement, changes in PD, but not changes in modulation depth, facilitate such reorganization. In addition, this reorganization was facilitated only when encoding PDs are rotated, but decoding PDs are not rotated. Bimanual movement facilitates reorganization because this movement changes neural activities through inter-hemispheric inhibition without changing cortical-spinal-muscle connections. Furthermore, stronger inter-hemispheric inhibition between motor cortices results in more effective reorganization. Thus, this study suggests that bimanual movement is effective for stroke rehabilitation because this movement rotates the encoding PDs of motor cortex neurons.

Influence of irradiation dose on laser-induced surface nanostructures on silicon

Energy Technology Data Exchange (ETDEWEB)

Varlamova, Olga [Brandenburgische Technische Universität BTU Cottbus, Platz der Deutschen Einheit 1, 03046 Cottbus (Germany); Cottbus JointLab, Platz der Deutschen Einheit 1, 03046 Cottbus (Germany); Bounhalli, Mourad [Brandenburgische Technische Universität BTU Cottbus, Platz der Deutschen Einheit 1, 03046 Cottbus (Germany); Laboratoire Hubert Curien, Université St. Etienne, Bâtiment F 18 Rue du Professeur Benoît Lauras, 42000 Saint-Etienne (France); Reif, Juergen, E-mail: REIF@TU-COTTBUS.DE [Brandenburgische Technische Universität BTU Cottbus, Platz der Deutschen Einheit 1, 03046 Cottbus (Germany); Cottbus JointLab, Platz der Deutschen Einheit 1, 03046 Cottbus (Germany)

2013-08-01

We report on the dependence of femtosecond laser-induced periodic surface structures on an increase of incident pulse number. On silicon, the patterns evolve from linear, parallel sub-wavelength ripples, grossly perpendicular to the laser polarization, via coalesced wider features parallel to the polarization, to a crater with periodically structured, pillar-like walls. Closer inspection of the patterns indicates that the different features always continue to exhibit reminiscence to the preceding lower-dose patterns, suggesting that, indeed, all patterns can be created by ONE single GENERAL formation process, as in self-organized structure formation, and the different structures/feature sizes are NOT due to DIFFERENT mechanisms.

Influence of irradiation dose on laser-induced surface nanostructures on silicon

International Nuclear Information System (INIS)

Varlamova, Olga; Bounhalli, Mourad; Reif, Juergen

2013-01-01

We report on the dependence of femtosecond laser-induced periodic surface structures on an increase of incident pulse number. On silicon, the patterns evolve from linear, parallel sub-wavelength ripples, grossly perpendicular to the laser polarization, via coalesced wider features parallel to the polarization, to a crater with periodically structured, pillar-like walls. Closer inspection of the patterns indicates that the different features always continue to exhibit reminiscence to the preceding lower-dose patterns, suggesting that, indeed, all patterns can be created by ONE single GENERAL formation process, as in self-organized structure formation, and the different structures/feature sizes are NOT due to DIFFERENT mechanisms.

Annealing of radiation-induced defects in vanadium and vanadium-titanium alloys

International Nuclear Information System (INIS)

Leguey, T.

1996-01-01

The annealing of defects induced by electron irradiation up to a dose of 6.10 21 m -2 at T<293 K has been investigated in single-crystals of pure vanadium and in vanadium-titanium alloys with compositions 0.3, 1 and 5 at.% Ti using positron annihilation spectroscopy. The recovery of the positron annihilation parameters in V single-crystals indicates that the defect annealing takes place in the temperature range 410-470 K without formation of microvoids for the present irradiation conditions. For the alloys the recovery onset is shifted to 460 K, the width of the annealing stage is gradually broadened with increasing Ti content, and microvoids are formed for annealing temperatures at the end of the recovery stage. The results show that the vacancy release from vacancy-interstitial impurity pairs and subsequent recombination with interstitial loops is the mechanism of the recovery in pure V. For V-Ti alloys, vacancy-Ti-interstitial impurity complexes and vacancy-Ti pairs appear to be the defects responsible for the positron trapping. The broadening of the recovery stage with increasing Ti content indicates that solute Ti is a very effective trap for vacancies in V. (orig.)

Electrical Stimulation of the Ventral Tegmental Area Induces Reanimation from General Anesthesia

Science.gov (United States)

Solt, Ken; Van Dort, Christa J.; Chemali, Jessica J.; Taylor, Norman E.; Kenny, Jonathan D.; Brown, Emery N.

2014-01-01

BACKGROUND Methylphenidate or a D1 dopamine receptor agonist induce reanimation (active emergence) from general anesthesia. We tested whether electrical stimulation of dopaminergic nuclei also induces reanimation from general anesthesia. METHODS In adult rats, a bipolar insulated stainless steel electrode was placed in the ventral tegmental area (VTA, n = 5) or substantia nigra (SN, n = 5). After a minimum 7-day recovery period, the isoflurane dose sufficient to maintain loss of righting was established. Electrical stimulation was initiated and increased in intensity every 3 min to a maximum of 120μA. If stimulation restored the righting reflex, an additional experiment was performed at least 3 days later during continuous propofol anesthesia. Histological analysis was conducted to identify the location of the electrode tip. In separate experiments, stimulation was performed in the prone position during general anesthesia with isoflurane or propofol, and the electroencephalogram was recorded. RESULTS To maintain loss of righting, the dose of isoflurane was 0.9% ± 0.1 vol%, and the target plasma dose of propofol was 4.4 μg/ml ± 1.1 μg/ml (mean ± SD). In all rats with VTA electrodes, electrical stimulation induced a graded arousal response including righting that increased with current intensity. VTA stimulation induced a shift in electroencephalogram peak power from δ (anesthesia with isoflurane or propofol. These results are consistent with the hypothesis that dopamine release by VTA, but not SN, neurons induces reanimation from general anesthesia. PMID:24398816

Drug–drug interaction of microdose and regular-dose omeprazole with a CYP2C19 inhibitor and inducer

Science.gov (United States)

Park, Gab-jin; Bae, Soo Hyeon; Park, Wan-Su; Han, Seunghoon; Park, Min-Ho; Shin, Seok-Ho; Shin, Young G; Yim, Dong-Seok

2017-01-01

Purpose A microdose drug–drug interaction (DDI) study may be a valuable tool for anticipating drug interaction at therapeutic doses. This study aimed to compare the magnitude of DDIs at microdoses and regular doses to explore the applicability of a microdose DDI study. Patients and methods Six healthy male volunteer subjects were enrolled into each DDI study of omeprazole (victim) and known perpetrators: fluconazole (inhibitor) and rifampin (inducer). For both studies, the microdose (100 μg, cold compound) and the regular dose (20 mg) of omeprazole were given at days 0 and 1, respectively. On days 2–9, the inhibitor or inducer was given daily, and the microdose and regular dose of omeprazole were repeated at days 8 and 9, respectively. Full omeprazole pharmacokinetic samplings were performed at days 0, 1, 8, and 9 of both studies for noncompartmental analysis. Results The magnitude of the DDI, the geometric mean ratios (with perpetrator/omeprazole only) of maximum concentration (Cmax) and area under the curve to the last measurement (AUCt) of the microdose and the regular dose were compared. The geometric mean ratios in the inhibition study were: 2.17 (micro) and 2.68 (regular) for Cmax, and 4.07 (micro), 4.33 (regular) for AUCt. For the induction study, they were 0.26 (micro) and 0.21 (regular) for Cmax, and 0.16 (micro) and 0.15 (regular) for AUCt. There were no significant statistical differences in the magnitudes of DDIs between microdose and regular-dose conditions, regardless of induction or inhibition. Conclusion Our results may be used as partial evidence that microdose DDI studies may replace regular-dose studies, or at least be used for DDI-screening purposes. PMID:28408803

A combination of low-dose bevacizumab and imatinib enhances vascular normalisation without inducing extracellular matrix deposition.

Science.gov (United States)

Schiffmann, L M; Brunold, M; Liwschitz, M; Goede, V; Loges, S; Wroblewski, M; Quaas, A; Alakus, H; Stippel, D; Bruns, C J; Hallek, M; Kashkar, H; Hacker, U T; Coutelle, O

2017-02-28

Vascular endothelial growth factor (VEGF)-targeting drugs normalise the tumour vasculature and improve access for chemotherapy. However, excessive VEGF inhibition fails to improve clinical outcome, and successive treatment cycles lead to incremental extracellular matrix (ECM) deposition, which limits perfusion and drug delivery. We show here, that low-dose VEGF inhibition augmented with PDGF-R inhibition leads to superior vascular normalisation without incremental ECM deposition thus maintaining access for therapy. Collagen IV expression was analysed in response to VEGF inhibition in liver metastasis of colorectal cancer (CRC) patients, in syngeneic (Panc02) and xenograft tumours of human colorectal cancer cells (LS174T). The xenograft tumours were treated with low (0.5 mg kg -1 body weight) or high (5 mg kg -1 body weight) doses of the anti-VEGF antibody bevacizumab with or without the tyrosine kinase inhibitor imatinib. Changes in tumour growth, and vascular parameters, including microvessel density, pericyte coverage, leakiness, hypoxia, perfusion, fraction of vessels with an open lumen, and type IV collagen deposition were compared. ECM deposition was increased after standard VEGF inhibition in patients and tumour models. In contrast, treatment with low-dose bevacizumab and imatinib produced similar growth inhibition without inducing detrimental collagen IV deposition, leading to superior vascular normalisation, reduced leakiness, improved oxygenation, more open vessels that permit perfusion and access for therapy. Low-dose bevacizumab augmented by imatinib selects a mature, highly normalised and well perfused tumour vasculature without inducing incremental ECM deposition that normally limits the effectiveness of VEGF targeting drugs.

Characterization of the adaptive response to ionizing radiation induced by low doses of X-rays to Vibrio cholerae cells

International Nuclear Information System (INIS)

Basak, Jayasri

1996-01-01

Pretreatment with sublethal doses of X-rays induced an adaptive response in Vibrio cholerae cells as indicated by their greater resistance to the subsequent challenging doses of X-irradiation. The adaptive response was maximum following a pre-exposure dose of 1.7 Gy X-rays and an optimum incubation period of 40 min at 37C. Pre-exposure to a sublethal dose of 1.7 Gy X-rays made the Vibrio cholerae cells 3.38-fold more resistant to the subsequent challenge by X-rays. Pretreatment with a sublethal dose of hydrogen peroxide offered a similar degree of protection to the bacterial cells against subsequent treatment with challenging doses of X-ray radiation. However, exposure of Vibrio cholerae cells to mild heat (42C for 10 min) before X-ray irradiation decreased their survival following X-irradiation

Low dose transdermal estradiol induces breast density and heterogeneity changes comparable to those of raloxifene

DEFF Research Database (Denmark)

Nielsen, Mads; Raundahl, Jakob; Pettersen, Paola

2009-01-01

Objective: To investigate whether transdermal low dose estradiol treatment induces changes in mammographic density or heterogeneity compared to raloxifene. Secondarily, if these changes relate to changes in bone formation/resorption markers, and if these findings indicate elevation of breast canc...

Cholecalciferol (vitamin D₃ improves myelination and recovery after nerve injury.

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Jean-Francois Chabas

Full Text Available Previously, we demonstrated i that ergocalciferol (vitamin D2 increases axon diameter and potentiates nerve regeneration in a rat model of transected peripheral nerve and ii that cholecalciferol (vitamin D3 improves breathing and hyper-reflexia in a rat model of paraplegia. However, before bringing this molecule to the clinic, it was of prime importance i to assess which form - ergocalciferol versus cholecalciferol - and which dose were the most efficient and ii to identify the molecular pathways activated by this pleiotropic molecule. The rat left peroneal nerve was cut out on a length of 10 mm and autografted in an inverted position. Animals were treated with either cholecalciferol or ergocalciferol, at the dose of 100 or 500 IU/kg/day, or excipient (Vehicle, and compared to unlesioned rats (Control. Functional recovery of hindlimb was measured weekly, during 12 weeks, using the peroneal functional index. Ventilatory, motor and sensitive responses of the regenerated axons were recorded and histological analysis was performed. In parallel, to identify the genes regulated by vitamin D in dorsal root ganglia and/or Schwann cells, we performed an in vitro transcriptome study. We observed that cholecalciferol is more efficient than ergocalciferol and, when delivered at a high dose (500 IU/kg/day, cholecalciferol induces a significant locomotor and electrophysiological recovery. We also demonstrated that cholecalciferol increases i the number of preserved or newly formed axons in the proximal end, ii the mean axon diameter in the distal end, and iii neurite myelination in both distal and proximal ends. Finally, we found a modified expression of several genes involved in axogenesis and myelination, after 24 hours of vitamin supplementation. Our study is the first to demonstrate that vitamin D acts on myelination via the activation of several myelin-associated genes. It paves the way for future randomised controlled clinical trials for peripheral

Near-term and late biological effects of acute and low-dose-rate continuous gamma-ray exposure in dogs and monkeys

International Nuclear Information System (INIS)

Spalding, J.F.; Holland, L.M.

1979-07-01

Monkeys (Macaca mulatta) and dogs (beagle) were given thirteen 100-rad gamma-ray doses at 28-day intervals. The comparative response (inury and recovery) of the hematopoietic system of the two species was observed at 7-day intervals during the exposure regime. At 84 days after the thirteenth gamma-ray dose, the 1300-rad conditioned and control dogs and monkeys were challenged continuously with gamma rays at 35 r/day until death to determine the amount of radiation-induced injry remaining in conditioned animals as a reduction in mean survival time. Dogs (50%) and monkeys (8%) died from injury incurred during conditioning exposures. Thus, the comparative response (in terms of lethality) of dogs and monkeys to dose protraction by acute dose fractionation was similar to what we would expect from a single acute dose. The mean survival times for nonconditioned dogs and monkeys during continuous exposure at 35 R/day were the same (approx. 1400 h). Thus, the hematopoietic response of the two species by this method of dose protraction was not significantly different. Mean survival times of conditioned dogs and monkeys during the continuous 35-R/day gamma-ray challenge exposure were greater (significant in dogs but not in monkeys) than for their control counterparts. Thus, long-term radiation-induced injury was not measurable by this method. Conditioning doses of more than 4 times the acute LD 50 30 in dogs and approximately 2 times that in monkeys served only to increase both mean survival time and variance in a gamma-ray stress environment with a dose rate of 35 Rat/day

Advanced Computational Approaches for Characterizing Stochastic Cellular Responses to Low Dose, Low Dose Rate Exposures

Energy Technology Data Exchange (ETDEWEB)

Scott, Bobby, R., Ph.D.

2003-06-27

OAK - B135 This project final report summarizes modeling research conducted in the U.S. Department of Energy (DOE), Low Dose Radiation Research Program at the Lovelace Respiratory Research Institute from October 1998 through June 2003. The modeling research described involves critically evaluating the validity of the linear nonthreshold (LNT) risk model as it relates to stochastic effects induced in cells by low doses of ionizing radiation and genotoxic chemicals. The LNT model plays a central role in low-dose risk assessment for humans. With the LNT model, any radiation (or genotoxic chemical) exposure is assumed to increase one¡¯s risk of cancer. Based on the LNT model, others have predicted tens of thousands of cancer deaths related to environmental exposure to radioactive material from nuclear accidents (e.g., Chernobyl) and fallout from nuclear weapons testing. Our research has focused on developing biologically based models that explain the shape of dose-response curves for low-dose radiation and genotoxic chemical-induced stochastic effects in cells. Understanding the shape of the dose-response curve for radiation and genotoxic chemical-induced stochastic effects in cells helps to better understand the shape of the dose-response curve for cancer induction in humans. We have used a modeling approach that facilitated model revisions over time, allowing for timely incorporation of new knowledge gained related to the biological basis for low-dose-induced stochastic effects in cells. Both deleterious (e.g., genomic instability, mutations, and neoplastic transformation) and protective (e.g., DNA repair and apoptosis) effects have been included in our modeling. Our most advanced model, NEOTRANS2, involves differing levels of genomic instability. Persistent genomic instability is presumed to be associated with nonspecific, nonlethal mutations and to increase both the risk for neoplastic transformation and for cancer occurrence. Our research results, based on

Gamma dose rate effect on JFET transistors

International Nuclear Information System (INIS)

Assaf, J.

2011-04-01

The effect of Gamma dose rate on JFET transistors is presented. The irradiation was accomplished at the following available dose rates: 1, 2.38, 5, 10 , 17 and 19 kGy/h at a constant dose of 600 kGy. A non proportional relationship between the noise and dose rate in the medium range (between 2.38 and 5 kGy/h) was observed. While in the low and high ranges, the noise was proportional to the dose rate as the case of the dose effect. This may be explained as follows: the obtained result is considered as the yield of a competition between many reactions and events which are dependent on the dose rate. At a given values of that events parameters, a proportional or a non proportional dose rate effects are generated. No dependence effects between the dose rate and thermal annealing recovery after irradiation was observed . (author)

[Toxicity studies of landiolol hydrochloride (ONO-1101) (2). 4-week repeated dose intravenous toxicity study in rats with 4-week recovery test].

Science.gov (United States)

Yamaguchi, K; Yanagi, H; Shimizu, K; Sakai, M; Nishibata, K; Oida, H; Shinomiya, K; Suzuki, Y; Yonezawa, H; Fujita, T

1997-12-01

4-week repeated dose toxicity study with 4-week recovery test of landiolol hydrochloride (ONO-1101), a novel ultra short acting beta-blocker, was conducted in Sprague-Dawley (SD) rats. ONO-1101 was administered intravenously to rats of both sexes at a dose level of 0 (control), 12.5, 25, 50 or 100 mg/kg/day. In the 100 mg/kg/day group, bradypnea or dyspnea was seen in all animals, pale in ear, eye and foot, tremor, reddish lacrimation and loss of righting reflex were also observed in some animals right after administration, and then those signs disappeared within 1 min after administration. During the treatment period, 3/20 animals of each sex in the 100 mg/kg/day showed clonic convulsion and died within 2 min after administration. No clinical changes were seen in the 50 mg/kg/day group or lower. Histopathological findings showed atrophy of the submaxillary gland in females and vessel-wall thickening and perivascular fibrosis of the injection site (tail) in both sexes at 100 mg/kg/day, however those changes were reversible. ONO-1101 did not effect on body weight, food consumption, ophthalmology, urinalysis, hematology, blood chemistry, organ weights or necropsy at any doses. These results indicate that the no-adverse-effect level of ONO-1101 in rats is 50 mg/kg/day for both sexes in this study.

Dose-Related Effects of Acetylsalicylic acid (ASA) on Gamma Radiation-Induced Teratogenicity in Pregnant Albino Rats

International Nuclear Information System (INIS)

Ibrahim, M.F.

2013-01-01

Reviews of acetylsalicylic acid (ASA), a widely used nonsteroidal anti- inflammatory drug, has consistently suggested a possible association between prenatal ASA ingestion and adverse effects in the pregnant mothers and their developing fetuses. The objective of the current study was to comprehensively define the effect of relatively low and high doses of ASA (25 mg/kg body wt. and 200 mg/kg body wt. respectively) on gestating rats and their possible impact on the irradiated ones. Therefore 36 pregnant rats were randomly divided into 6 equal groups. Three rat groups were daily orally gavaged from the 7th to the 18th gestational days with: distilled water (Group 1), 25 mg/kg body wt. ASA (Group 2) and 200 mg/kg body wt. ASA (Group 3). The other three groups similarly received the same previous treatments besides 2 Gy whole body gamma irradiation of each, to serve as: Group 4 (distilled water + irradiation), Group 5 (25 mg/kg body wt. ASA + irradiation) and Group 6 (200 mg/kg body wt. ASA + irradiation). All rat groups were sacrificed on the 20th day of pregnancy and the uterine contents were examined. The lower ASA dose (25 mg/kg body wt.) treated group (Group 2) displayed healthy mothers and fetuses whereas that of the higher dose (200 mg/kg body wt.) (Group 3) despite not showing significant maternal or fetal mortalities, yet the intrauterine contents presented fetal developmental disorders including stunted growth and resorption together with some head and limb anomalies including plagiocephaly, marked acampsia and acrocontracture. Meanwhile, results have unexpectedly shown a radioprotective role of the lower ASA dose (25 mg/kg. body wt.) (Group 5) to pregnant rats and their fetuses as inspected by its efficacy in retrieving the radiation induced maternal weight loss together with its noticeable ameliorating effects on the intrauterine lethality of the affected fetuses and their externally detected abnormalities in addition toits effectiveness in retaining some

Corticosteroid effects on ventilator-induced diaphragm dysfunction in anesthetized rats depend on the dose administered

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Decramer Marc

2010-12-01

Full Text Available Abstract Background High dose of corticosteroids has been previously shown to protect against controlled mechanical ventilation (CMV-induced diaphragmatic dysfunction while inhibiting calpain activation. Because literature suggests that the calpain inhibiting effect of corticosteroid depends on the dose administered, we determined whether lower doses of corticosteroids would also provide protection of the diaphragm during CMV. This may be important for patients undergoing mechanical ventilation and receiving corticosteroids. Methods Rats were assigned to controls or to 24 hours of CMV while being treated at the start of mechanical ventilation with a single intramuscular administration of either saline, or 5 mg/kg (low MP or 30 mg/kg (high MP of methylprednisolone. Results Diaphragmatic force was decreased after CMV and this was exacerbated in the low MP group while high MP rescued this diaphragmatic dysfunction. Atrophy was more severe in the low MP group than after CMV while no atrophy was observed in the high MP group. A significant and similar increase in calpain activity was observed in both the low MP and CMV groups whereas the high dose prevented calpain activation. Expression of calpastatin, the endogenous inhibitor of calpain, was decreased in the CMV and low MP groups but its level was preserved to controls in the high MP group. Caspase-3 activity increased in all CMV groups but to a lesser extent in the low and high MP groups. The 20S proteasome activity was increased in CMV only. Conclusions Administration of 30 mg/kg methylprednisolone during CMV protected against CMV-induced diaphragm dysfunction while 5 mg/kg was more deleterious. The protective effect is due mainly to an inhibition of the calpain system through preservation of calpastatin levels and to a lesser extent to a caspase-3 inhibition.

Aerobic Interval Exercise Training Induces Greater Reduction in Cardiac Workload in the Recovery Period in Rats

International Nuclear Information System (INIS)

Borges, Juliana Pereira; Masson, Gustavo Santos; Tibiriçá, Eduardo; Lessa, Marcos Adriano

2014-01-01

Aerobic interval exercise training has greater benefits on cardiovascular function as compared with aerobic continuous exercise training. The present study aimed at analyzing the effects of both exercise modalities on acute and subacute hemodynamic responses of healthy rats. Thirty male rats were randomly assigned into three groups as follows: continuous exercise (CE, n = 10); interval exercise (IE, n = 10); and control (C, n = 10). Both IE and CE groups performed a 30-minute exercise session. The IE group session consisted of three successive 4-minute periods at 60% of maximal velocity (Max Vel), with 4-minute recovery intervals at 40% of Max Vel. The CE group ran continuously at 50% of Max Vel. Heart rate (HR), blood pressure(BP), and rate pressure product (RPP) were measured before, during and after the exercise session. The CE and IE groups showed an increase in systolic BP and RPP during exercise as compared with the baseline values. After the end of exercise, the CE group showed a lower response of systolic BP and RPP as compared with the baseline values, while the IE group showed lower systolic BP and mean BP values. However, only the IE group had a lower response of HR and RPP during recovery. In healthy rats, one interval exercise session, as compared with continuous exercise, induced similar hemodynamic responses during exercise. However, during recovery, the interval exercise caused greater reductions in cardiac workload than the continuous exercise

Aerobic Interval Exercise Training Induces Greater Reduction in Cardiac Workload in the Recovery Period in Rats

Science.gov (United States)

Borges, Juliana Pereira; Masson, Gustavo Santos; Tibiriçá, Eduardo; Lessa, Marcos Adriano

2014-01-01

Background Aerobic interval exercise training has greater benefits on cardiovascular function as compared with aerobic continuous exercise training. Objective The present study aimed at analyzing the effects of both exercise modalities on acute and subacute hemodynamic responses of healthy rats. Methods Thirty male rats were randomly assigned into three groups as follows: continuous exercise (CE, n = 10); interval exercise (IE, n = 10); and control (C, n = 10). Both IE and CE groups performed a 30-minute exercise session. The IE group session consisted of three successive 4-minute periods at 60% of maximal velocity (Max Vel), with 4-minute recovery intervals at 40% of Max Vel. The CE group ran continuously at 50% of Max Vel. Heart rate (HR), blood pressure(BP), and rate pressure product (RPP) were measured before, during and after the exercise session. Results The CE and IE groups showed an increase in systolic BP and RPP during exercise as compared with the baseline values. After the end of exercise, the CE group showed a lower response of systolic BP and RPP as compared with the baseline values, while the IE group showed lower systolic BP and mean BP values. However, only the IE group had a lower response of HR and RPP during recovery. Conclusion In healthy rats, one interval exercise session, as compared with continuous exercise, induced similar hemodynamic responses during exercise. However, during recovery, the interval exercise caused greater reductions in cardiac workload than the continuous exercise. PMID:24270864

Aerobic Interval Exercise Training Induces Greater Reduction in Cardiac Workload in the Recovery Period in Rats

Energy Technology Data Exchange (ETDEWEB)

Borges, Juliana Pereira, E-mail: julipborges@gmail.com; Masson, Gustavo Santos; Tibiriçá, Eduardo; Lessa, Marcos Adriano [Instituto Oswaldo Cruz - FIOCRUZ, Rio de Janeiro, RJ (Brazil)

2014-01-15

Aerobic interval exercise training has greater benefits on cardiovascular function as compared with aerobic continuous exercise training. The present study aimed at analyzing the effects of both exercise modalities on acute and subacute hemodynamic responses of healthy rats. Thirty male rats were randomly assigned into three groups as follows: continuous exercise (CE, n = 10); interval exercise (IE, n = 10); and control (C, n = 10). Both IE and CE groups performed a 30-minute exercise session. The IE group session consisted of three successive 4-minute periods at 60% of maximal velocity (Max Vel), with 4-minute recovery intervals at 40% of Max Vel. The CE group ran continuously at 50% of Max Vel. Heart rate (HR), blood pressure(BP), and rate pressure product (RPP) were measured before, during and after the exercise session. The CE and IE groups showed an increase in systolic BP and RPP during exercise as compared with the baseline values. After the end of exercise, the CE group showed a lower response of systolic BP and RPP as compared with the baseline values, while the IE group showed lower systolic BP and mean BP values. However, only the IE group had a lower response of HR and RPP during recovery. In healthy rats, one interval exercise session, as compared with continuous exercise, induced similar hemodynamic responses during exercise. However, during recovery, the interval exercise caused greater reductions in cardiac workload than the continuous exercise.

Low dose radiation enhance the anti-tumor effect of high dose radiation on human glioma cell U251

International Nuclear Information System (INIS)

Wang Chang; Wang Guanjun; Tan Yehui; Jiang Hongyu; Li Wei

2008-01-01

Objective: To detect the effect on the growth of human glioma cell U251 induced by low dose irradiation and low dose irradiation combined with large dose irradiation. Methods: Human glioma cell line U251 and nude mice carried with human glioma were used. The tumor cells and the mice were treated with low dose, high dose, and low dose combined high dose radiation. Cells growth curve, MTT and flow cytometry were used to detect the proliferation, cell cycle and apoptosis of the cells; and the tumor inhibition rate was used to assess the growth of tumor in vivo. Results: After low dose irradiation, there was no difference between experimental group and control group in cell count, MTT and flow cytometry. Single high dose group and low dose combined high dose group both show significantly the suppressing effect on tumor cells, the apoptosis increased and there was cell cycle blocked in G 2 period, but there was no difference between two groups. In vivo apparent anti-tumor effect in high dose radiation group and the combining group was observed, and that was more significant in the combining group; the prior low dose radiation alleviated the injury of hematological system. There was no difference between single low dose radiation group and control. Conclusions: There is no significant effect on human glioma cell induced by low dose radiation, and low dose radiation could not induce adaptive response. But in vivo experience, low dose radiation could enhance the anti-tumor effect of high dose radiation and alleviated the injury of hematological system. (authors)

Bayesian estimation of dose rate effectiveness

International Nuclear Information System (INIS)

Arnish, J.J.; Groer, P.G.

2000-01-01

A Bayesian statistical method was used to quantify the effectiveness of high dose rate 137 Cs gamma radiation at inducing fatal mammary tumours and increasing the overall mortality rate in BALB/c female mice. The Bayesian approach considers both the temporal and dose dependence of radiation carcinogenesis and total mortality. This paper provides the first direct estimation of dose rate effectiveness using Bayesian statistics. This statistical approach provides a quantitative description of the uncertainty of the factor characterising the dose rate in terms of a probability density function. The results show that a fixed dose from 137 Cs gamma radiation delivered at a high dose rate is more effective at inducing fatal mammary tumours and increasing the overall mortality rate in BALB/c female mice than the same dose delivered at a low dose rate. (author)

The Effect of Taurine on the Recovery from Eccentric Exercise-Induced Muscle Damage in Males

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Yanita McLeay

2017-10-01

daily for 72 h following eccentric exercise-induced muscle damage may help improve eccentric performance recovery of the biceps brachii.

Tumor sterilization dose and radiation induced change of the brain tissue in radiotherapy of brain tumors

International Nuclear Information System (INIS)

Yoshii, Yoshihiko; Maki, Yutaka; Takano, Shingo

1987-01-01

Ninety-seven patients with brain tumors (38 gliomas, 26 brain metastases, 18 sellar tumors, 15 others) were treated by cobalt gamma ray or proton radiotherapy. In this study, normal brain injury due to radiation was analysed in terms of time-dose-fractionation (TDF), nominal standard dose (NSD) by the Ellis formula and NeuNSD by a modification in which the N exponent was -0.44 and the T exponent was -0.06. Their calculated doses were analysed in relationship to the normal brain radiation induced change (RIC) and the tumor sterilization dose. All brain tumors with an exception of many patients with brain metastases were received a surgical extirpation subtotally or partially prior to radiotherapy. And all patients with glioma and brain metastasis received also immuno-chemotherapy in the usual manner during radiotherapy. The calculated dose expressed by NeuNSD and TDF showed a significant relationship between a therapeutic dose and a postradiation time in terms of the appearance of RIC. It was suggested that RIC was caused by a dose over 800 in NeuNSD and a dose over 70 in TDF. Furthermore, it was suggested that an aged patient and a patient who had the vulnerable brain tissue to radiation exposure in the irradiated field had the high risk of RIC. On the other hand, our results suggested that the tumor sterilization dose should be over 1,536 NeuNSD and the irradiated method should be further considered in addition to the radiobiological concepts for various brain tumors. (author)

Recovery of Nicotiana benthamiana plants from a necrotic response induced by a nepovirus is associated with RNA silencing but not with reduced virus titer.

Science.gov (United States)

Jovel, Juan; Walker, Melanie; Sanfaçon, Hélène

2007-11-01

Recovery of plants from virus-induced symptoms is often described as a consequence of RNA silencing, an antiviral defense mechanism. For example, recovery of Nicotiana clevelandii from a nepovirus (tomato black ring virus) is associated with a decreased viral RNA concentration and sequence-specific resistance to further virus infection. In this study, we have characterized the interaction of another nepovirus, tomato ringspot virus (ToRSV), with host defense responses during symptom induction and subsequent recovery. Early in infection, ToRSV induced a necrotic phenotype in Nicotiana benthamiana that showed characteristics typical of a hypersensitive response. RNA silencing was also activated during ToRSV infection, as evidenced by the presence of ToRSV-derived small interfering RNAs (siRNAs) that could direct degradation of ToRSV sequences introduced into sensor constructs. Surprisingly, disappearance of symptoms was not accompanied by a commensurate reduction in viral RNA levels. The stability of ToRSV RNA after recovery was also observed in N. clevelandii and Cucumis sativus and in N. benthamiana plants carrying a functional RNA-dependent RNA polymerase 1 ortholog from Medicago truncatula. In experiments with a reporter transgene (green fluorescent protein), ToRSV did not suppress the initiation or maintenance of transgene silencing, although the movement of the silencing signal was partially hindered. Our results demonstrate that although RNA silencing is active during recovery, reduction of virus titer is not required for the initiation of this phenotype. This scenario adds an unforeseen layer of complexity to the interaction of nepoviruses with the host RNA silencing machinery. The possibility that viral proteins, viral RNAs, and/or virus-derived siRNAs inactivate host defense responses is discussed.

A dose error evaluation study for 4D dose calculations

Science.gov (United States)

Milz, Stefan; Wilkens, Jan J.; Ullrich, Wolfgang

2014-10-01

Previous studies have shown that respiration induced motion is not negligible for Stereotactic Body Radiation Therapy. The intrafractional breathing induced motion influences the delivered dose distribution on the underlying patient geometry such as the lung or the abdomen. If a static geometry is used, a planning process for these indications does not represent the entire dynamic process. The quality of a full 4D dose calculation approach depends on the dose coordinate transformation process between deformable geometries. This article provides an evaluation study that introduces an advanced method to verify the quality of numerical dose transformation generated by four different algorithms. The used transformation metric value is based on the deviation of the dose mass histogram (DMH) and the mean dose throughout dose transformation. The study compares the results of four algorithms. In general, two elementary approaches are used: dose mapping and energy transformation. Dose interpolation (DIM) and an advanced concept, so called divergent dose mapping model (dDMM), are used for dose mapping. The algorithms are compared to the basic energy transformation model (bETM) and the energy mass congruent mapping (EMCM). For evaluation 900 small sample regions of interest (ROI) are generated inside an exemplary lung geometry (4DCT). A homogeneous fluence distribution is assumed for dose calculation inside the ROIs. The dose transformations are performed with the four different algorithms. The study investigates the DMH-metric and the mean dose metric for different scenarios (voxel sizes: 8 mm, 4 mm, 2 mm, 1 mm 9 different breathing phases). dDMM achieves the best transformation accuracy in all measured test cases with 3-5% lower errors than the other models. The results of dDMM are reasonable and most efficient in this study, although the model is simple and easy to implement. The EMCM model also achieved suitable results, but the approach requires a more complex