WorldWideScience

Sample records for low-dose acth stimulation

  1. Multidrug-Resistant Tuberculosis and Its Association with Adrenal Insufficiency: Assessment with the Low-Dose ACTH Stimulation Test

    Directory of Open Access Journals (Sweden)

    René Rodríguez-Gutiérrez

    2016-01-01

    Full Text Available Background. Multidrug-resistant tuberculosis (MDR-TB is a major public health care concern that affects the life of millions of people around the world. The association of tuberculosis and adrenal insufficiency is well known; however, it is thought to be less prevalent every time. A spike in TB incidence and a lack of evidence of this association in patients with MDR-TB call for reassessment of an illness (adrenal dysfunction that if not diagnosed could seriously jeopardize patients’ health. Objective. To determine the prevalence of adrenocortical insufficiency in patients with MDR-TB using the low-dose (1 μg ACTH stimulation test at baseline and at 6–12 months of follow-up after antituberculosis treatment and culture conversion. Methods. A total of 48 men or women, aged ≥18 years (HIV-negative patients diagnosed with pulmonary MDR-TB were included in this prospective observational study. Blood samples for serum cortisol were taken at baseline and 30 and 60 minutes after 1 μg ACTH stimulation at our tertiary level university hospital before and after antituberculosis treatment. Results. Forty-seven percent of subjects had primary MDR-TB; 43.8% had type 2 diabetes; none were HIV-positive. We found at enrollment 2 cases (4.2% of adrenal insufficiency taking 500 nmol/L as the standard cutoff point value and 4 cases (8.3% alternatively, using 550 nmol/L. After antituberculosis intensive phase drug-treatment and a negative mycobacterial culture (10.2±3.6 months adrenocortical function was restored in all cases. Conclusions. In patients with MDR-TB, using the low-dose ACTH stimulation test, a low prevalence of mild adrenal insufficiency was observed. After antituberculosis treatment adrenal function was restored in all cases. Given the increasing and worrying epidemic of MDR-TB these findings have important clinical implications that may help clinicians and patients make better decisions when deciding to test for adrenocortical

  2. Stimulation of seeds by low dose irradiation

    International Nuclear Information System (INIS)

    Lawson, Helen

    1976-05-01

    The first section of the bibliography lists materials on the stimulation of seeds by low dose irradiation, with particular reference to stimulation of germination and yield. The second section contains a small number of selected references on seed irradiation facilities. (author)

  3. Stimulation of corticosterone secretion in vitro by brief ACTH exposure

    International Nuclear Information System (INIS)

    Keith, L.D.; Tam, B.; Greer, M.A.

    1986-01-01

    The authors examined the relationship between ACTH concentration and exposure duration on stimulation of corticosterone (B) secretion in vitro using perifused enzymatically dispersed rat adrenocortical cells. A modular perifusion apparatus was used that permitted evaluation of 20-24 cell chambers per experimental session. In expt 1,20-1000 pg/ml concentrations of synthetic ACTH-(1-24) were presented to cells for 1 min. In expt 2, 100 pg ACTH-(1-24) was presented to adrenal cells in five dose-duration regimens ranging from 5 pg/min for 20 min to 100 pg/min for 1 min. Perifusal rate was 1 ml/min in all sessions. B was determined by radioimmunoassay. In expt 1 (constant-duration paradigm), 1-min presentation of ACTH-(1-24) produced log-linear dose-response effects across these concentrations. In expt 2 (constant-mass paradigm), identical masses administered in different dose-duration regimens had different steroidogenic efficacies: low-dose long-duration regimens provoked greater total release than high-dose short-duration regimens. Overall, every dose-duration regimen was associated with stimulation of B secretion. These results indicate that 1) very brief exposure to physiological concentrations of ACTH-(1-24) is a significant stimulus for corticosteroid secretion; 2) variations in the dose-duration regimen over the physiological range modifies both the maximum rate of secretion and the duration of secretion, but not the response latency; and 3) ACTH-(1-24) presentation mass is not the sole determinant of B secretion

  4. Brain sites mediating corticosteroid feedback inhibition of stimulated ACTH secretion

    International Nuclear Information System (INIS)

    Jacobson, L.

    1989-01-01

    There is substantial evidence that the brain mediates stress-induced and circadian increases in ACTH secretion and that corticosteroid concentrations which normalize basal plasma ACTH are insufficient to normalize ACTH responses to circadian or stressful stimuli in adrenalectomized rats. To identify brain sites mediating corticosteroid inhibition of stimulated ACTH secretion, two approaches were used. The first compared brain [ 14 C]-2-deoxyglucose uptake in rats with differential ACTH responses to stress. Relative to sham-adrenalectomized (SHAM) rats, adrenalectomized rats replaced with low, constant corticosterone levels via a subcutaneous corticosterone pellet (B-PELLET) exhibited elevated and prolonged ACTH responses to a variety of stimuli. Adrenalectomized rate given a circadian corticosterone rhythm via corticosterone in their drinking water exhibited elevated ACTH levels immediately after stress, but unlike B-PELLET rats, terminated stress induced ACTH secretion normally relative to SHAMS. Therefore, the abnormal ACTH responses to stress in B-PELLET rats were due to the lack of both circadian variations and stress-induced increases in corticosterone. Hypoxia was selected as a standardized stimulus for correlating brain [ 14 C]-2-deoxyglucose uptake with ACTH secretion. In intact rats, increases in plasma ACTH and decreases in arterial PO 2 correlated with the severity of hypoxia at arterial PCO 2 below 60 mm Hg. Hypoxia PELLET vs. SHAM rats. However, in preliminary experiments, although hypoxia increased brain 2-deoxyglucose uptake in most brain regions, plasma ACTH correlated poorly with 2-deoxyglucose uptake at 12% and 10% O 2

  5. Low dose stimulation in foeniculum vulgare

    International Nuclear Information System (INIS)

    Jahagirdar, H.A.; Khalatkar, A.W.; Dnyansagar, V.R.

    1974-01-01

    Genetically pure seeds with a moisture content of 12.5% were irradiated in a 60 Co γ-source at a dose rate of 1.1 KR/min, the radiation dose varying between 2 and 14 KR. Four days after irradiation the seeds were sown into the open field. Stimulation was determined on the basis of a lot of parameters e.g. height. The results indicated a significant stimulation after 10 KR as far as seed yield is concerned. (MG) [de

  6. ACTH stimulation test in the captive cheetah (Acinonyx jubatus

    Directory of Open Access Journals (Sweden)

    L.S. Koster

    2007-06-01

    Full Text Available Serum cortisol response was assessed in 8 captive cheetahs, of varying ages, after the intravenous administration of 500 µg of tetracosactide (Synacthen Depot(R, Novartis, Kempton Park while maintained under general anaesthesia. In addition, 8 cheetahs were anaesthetised and given an equal volume of saline in order to establish baseline cortisol concentrations at similar stages of anaesthesia. A significant difference in the median cortisol concentration measured over time was found following ACTH administration in the ACTH group (P < 0.001. There was no difference between the median cortisol concentrations in the ACTH group at time-points 120, 150 and 180 min after ACTH stimulation (P = 0.867. Thus it appears appropriate to collect serum 120 to 180 min after tetracosactide administration to assess maximal stimulation of the adrenal in the cheetah. No statistically significant rise was seen in the anaesthetised control group following the injection of saline (P = 0.238.

  7. The hormonal and radiological evaluation of adrenal glands, and the determination of the usefulness of low dose ACTH test in patients with renal amyloidosis.

    Science.gov (United States)

    Gündüz, Z; Keleştimur, F; Durak, A C; Utaş, C; Büyükberber, M; Düşünsel, R; Kurtoğlu, S; Poyrazoglu, M H

    2001-03-01

    Amyloidosis is a multisystem disease which may cause organ loss. Renal involvement is the most common clinical problem in amyloidosis, however involvement of endocrin organs is possible. In this study to assess adrenocortical function and to evaluate the usefulness of low dose ACTH test in patients with renal amyloidosis, we determined cortisol, 17-hydroxyprogesteron (17-OHP) and 11-deoxycortisol (11-DOC) responses to both 1 microg and 250 microg Synacthen. We also determined the size of adrenal glands radiologically by using computerized tomography. Twenty one patients with renal amyloidosis and 16 healthy subjects for hormonal evaluation, and 20 patients with renal amyloidosis and 22 healthy subjects for radiologic evaluation were included in the study. In four patients (19%) peak serum cortisol levels following stimulation with the low dose of Synacthen were less than 20 microg/dL (550 nmol/L). Two of them had also subnormal cortisol response to the 250 microg Synacthen stimulation test. Basal and stimulated levels of 11-DOC were lower than those of control values (p=0.000 and p<0.01 respectively). The mean 11-DOC responses to stimulation with 1 microg Synacthen were also significantly lower than the values obtained after the simulation with 250 microg Synacthen (p<0.01 and p=0.000). Cortisol responses to the stimulation with 250 microg Synacthen were also lower than the control responses (p<0.05). 17-OHP responses were similar to the control values in both tests. In the radiological evaluation the mean maximum width of right adrenal glands and the mean anterior and maximum width of left adrenal glands were significantly greater in the patient group (p<0.01). In conclusion, adrenal involvement and adrenal insufficiency is common in amyloidosis. Low 11-DOC levels in amyloidosis is a new finding and further detailed studies is required to explain its cause.

  8. Chronic ethanol consumption decreases adrenal responsiveness to adrenocorticotropin (ACTH) stimulation

    International Nuclear Information System (INIS)

    Nolan, C.J.; Bestervelt, L.L.; Cai, Y.; Maimansomsuk, P.; Coleman, L.; Piper, W.N.

    1991-01-01

    Increased alcohol consumption by adolescents and teenagers has heightened awareness of potential endocrine and developmental alterations. The current study was designed to determine whether chronic ethanol intake alters pituitary and adrenal function in the developing rat. One month old male Sprague Dawley rats were administered 6% ethanol in drinking water. After one month of treatment animals were sacrificed and blood, pituitary and adrenal glands collected. Plasma was assayed for ACTH and corticosterone (CS) by radioimmunossay (RIA). Five anterior pituitary glands per group were challenged with 100 μM corticotropin releasing factor (CRF) for 90 min at 37C under 95% air / 5% CO 2 . Media were analyzed for either ACTH (pituitary) or CS (adrenal) by RIA. Plasma ACTH and CS were unaffected by ethanol consumption. Pituitary response to CRF was not altered by ethanol. The lack of difference in ACTH release was not due to differences in pituitary content of ACTH. However, chronic ethanol consumption did decrease adrenal responsiveness to ACTH stimulation. In vitro corticosterone production was 1.21 ± 0.14 μg/adrenal in controls and 0.70 ± 0.06 μg/adrenal in ethanol consuming rats

  9. Effects of ACTH4–10 on self-stimulation behavior in the rat

    NARCIS (Netherlands)

    Nyakas, C.; Bohus, B.; Wied, D. de

    The threshold current evoking self-stimulation or multiples of this current was used to investigate the effect of ACTH4–10 on response performance for brain stimulation reward in the medial septum (MS) and the medial forebrain bundle (MFB). ACTH4–10 in a dose of 50 μg administered SC enhanced

  10. Cancer Control Related to Stimulation of Immunity by Low-Dose Radiation

    OpenAIRE

    Liu, Shu-Zheng

    2006-01-01

    Previous studies showed that low dose radiation (LDR) could stimulate the immune system in both animal and human populations. This paper reviews the present status of relevant research as support to the use of LDR in clinical practice for cancer prevention and treatment. It has been demonstrated that radiation-induced changes in immune activity follows an inverse J-shaped curve, i.e., low dose stimulation and high dose suppression. The stimulation of immunity by LDR concerns most anticancer p...

  11. Determination of the source of androgen excess in functionally atypical polycystic ovary syndrome by a short dexamethasone androgen-suppression test and a low-dose ACTH test.

    Science.gov (United States)

    Rosenfield, Robert L; Mortensen, Monica; Wroblewski, Kristen; Littlejohn, Elizabeth; Ehrmann, David A

    2011-11-01

    Polycystic ovary syndrome (PCOS) patients typically have 17-hydroxyprogesterone (17OHP) hyperresponsiveness to GnRH agonist (GnRHa) (PCOS-T). The objective of this study was to determine the source of androgen excess in the one-third of PCOS patients who atypically lack this type of ovarian dysfunction (PCOS-A). Aged-matched PCOS-T (n= 40), PCOS-A (n= 20) and controls (n= 39) were studied prospectively in a General Clinical Research Center. Short (4 h) and long (4-7 day) dexamethasone androgen-suppression tests (SDAST and LDAST, respectively) were compared in subsets of subjects. Responses to SDAST and low-dose adrenocorticotropic hormone (ACTH) were then evaluated in all. Testosterone post-SDAST correlated significantly with testosterone post-LDAST and 17OHP post-GnRHa (r = 0.671-0.672), indicating that all detect related aspects of ovarian dysfunction. An elevated dehydroepiandrosterone peak in response to ACTH, which defined functional adrenal hyperandrogenism, was similarly prevalent in PCOS-T (27.5%) and PCOS-A (30%) and correlated significantly with baseline dehydroepiandrosterone sulfate (DHEAS) (r = 0.708). Functional ovarian hyperandrogenism was detected by subnormal testosterone suppression by SDAST in most (92.5%) PCOS-T, but significantly fewer PCOS-A (60%, PPCOS-A, but present in 30% of PCOS-T (P PCOS-A cases with normal testosterone suppression in response to SDAST (5/8) lacked evidence of adrenal hyperandrogenism and were obese. Functional ovarian hyperandrogenism was not demonstrable by SDAST in 40% of PCOS-A. Most of these cases had no evidence of adrenal hyperandrogenism. Obesity may account for most hyperandrogenemic anovulation that lacks a glandular source of excess androgen, and the SDAST seems useful in making this distinction.

  12. ACTH stimulation test in the captive cheetah (Acinonyx jubatus).

    Science.gov (United States)

    Köster, L S; Schoeman, J P; Meltzer, D G A

    2007-09-01

    Serum cortisol response was assessed in 8 captive cheetahs, of varying ages, after the intravenous administration of 500 microg of tetracosactide (Synacthen Depot, Novartis, Kempton Park) while maintained under general anaesthesia. In addition, 8 cheetahs were anaesthetised and given an equal volume of saline in order to establish baseline cortisol concentrations at similar stages of anaesthesia. A significant difference in the median cortisol concentration measured over time was found following ACTH administration in the ACTH group (P cheetah. No statistically significant rise was seen in the anaesthetised control group following the injection of saline (P = 0.238).

  13. Emotional exhaustion and overcommitment to work are differentially associated with hypothalamus-pituitary-adrenal (HPA) axis responses to a low-dose ACTH1-24 (Synacthen) and dexamethasone-CRH test in healthy school teachers.

    Science.gov (United States)

    Wolfram, Maren; Bellingrath, Silja; Feuerhahn, Nicolas; Kudielka, Brigitte M

    2013-01-01

    Evidence for a detrimental impact of chronic work stress on health has accumulated in epidemiological research. Recent studies indicate altered hypothalamus-pituitary-adrenal (HPA) axis regulation as a possible biological pathway underlying the link between stress and disease. However, the direction of dysregulation remains unclear, with reported HPA hyper- or hyporeactivity. To disentangle potential effects on different functional levels in the HPA axis, we examined responses using two pharmacological stimulation tests in 53 healthy teachers (31 females, 22 males; mean age: 49.3 years; age range: 30-64 years): a low-dose adrenocorticotrophic hormone (ACTH(1-24), Synacthen) test was used to assess adrenal cortex sensitivity and the combined dexamethasone-corticotropin releasing hormone (DEX-CRH) test to examine pituitary and adrenal cortex reactivity. Blood and saliva samples were collected at - 1,+15,+30,+45,+60,+90,+120 min. Emotional exhaustion (EE), the core dimension of burnout, was measured with the Maslach Burnout Inventory. Overcommitment (OC) was assessed according to Siegrist's effort-reward-imbalance model. We found a significant association between EE and higher plasma cortisol profiles after Synacthen (p = 0.045). By contrast, OC was significantly associated with attenuated ACTH (p = 0.045), plasma cortisol (p = 0.005), and salivary cortisol (p = 0.023) concentrations following DEX-CRH. Results support the notion of altered HPA axis regulation in chronically work-stressed teachers, with differential patterns of hyper- and hyporeactivity depending on individual stress condition and the tested functional level of the HPA axis.

  14. Low doses of ionizing radiation and hydrogen peroxide stimulate plant growth

    International Nuclear Information System (INIS)

    Korystov, Y.; Narimanov, A.

    1997-01-01

    The present study shows that low-dose oxidative stress induced by ionizing radiation (10-20 cGy) and hydrogen peroxide (1-100 pmol per litre) stimulates germination of seeds and growth of sprouts and roots. The growth of seedlings can be stimulated by treatment of seeds as well as seedlings but in the latter case it needs lower doses. The stimulation effect is observed in a narrow dose interval which is the same for the plant species studied: barley, wheat, pea, maize and melon

  15. Adrenocorticotrophic hormone (ACTH) stimulation of sheep fetal adrenal cortex can occur without increased expression of ACTH receptor (ACTH-R) mRNA

    DEFF Research Database (Denmark)

    Carter, A M; Petersen, Y M; Towstoless, M

    2002-01-01

    In the present study, it was hypothesized that the adrenocorticotrophin hormone receptor (ACTH-R) would be up-regulated in the adrenal gland of the sheep fetus following infusion of physiological amounts of ACTH, as shown for adrenal cortical cells in culture. In chronically catheterized sheep...

  16. Diagnostic value of ACTH stimulation test in determining the subtypes of primary aldosteronism.

    Science.gov (United States)

    Jiang, Yiran; Zhang, Cui; Wang, Weiqing; Su, Tingwei; Zhou, Weiwei; Jiang, Lei; Zhu, Wei; Xie, Jing; Ning, Guang

    2015-05-01

    Adrenal venous sampling is recommended as the golden standard for subtyping primary aldosteronism (PA). However, it is invasive and inconvenient, and seeking a better way to make differential diagnosis of PA is necessary. The objective of the study was to evaluate the diagnostic value of ACTH stimulation test under 1 mg dexamethasone suppression test (DST) in determining the subtypes of PA. Ninety-five patients with PA confirmed by saline infusion test were included in this study. According to adrenal venous sampling and histopathology, 39 patients were diagnosed as bilateral adrenal hyperplasia (BAH), 37 as aldosterone-producing adenoma (APA), and 19 as unilateral adrenal hyperplasia (UAH). An ACTH stimulation test under 1 mg DST was performed in all patients. Plasma aldosterone and cortisol levels were measured every 30 minutes until 120 minutes after the iv injection of 50 IU ACTH. During the ACTH stimulation test, aldosterone levels in APA and UAH were similar (P > .05) but higher than those in BAH (P APA and UAH) were significantly higher than bilateral PA (BAH) (P guide further treatment in PA patients.

  17. Avoiding OHSS: Controlled Ovarian Low-Dose Stimulation in Women with PCOS.

    Science.gov (United States)

    Fischer, D; Reisenbüchler, C; Rösner, S; Haussmann, J; Wimberger, P; Goeckenjan, M

    2016-06-01

    The polycystic ovary syndrome is a common endocrine disorder which influences outcome and potential risks involved with controlled ovarian stimulation for artificial reproductive techniques (ART). Concrete practical recommendations for the dosage of gonadotropins, the preferred protocol and preventive methods to avoid ovarian hyperstimulation syndrome (OHSS) are lacking. We present retrospective data of 235 individually calculated gonadotropin low-dose stimulations for ART in a single center from 2012 to 2014. Clinical data and outcome parameter of patients diagnosed with PCOS according to Rotterdam criteria (n = 39) were compared with patients without PCOS (n = 196). The starting dose of gonadotropins was individually calculated depending on patients' age, BMI, ovarian reserve, ovarian response in previous cycles, and diagnostic criteria of PCOS. Mean age and duration of infertility did not differ between the groups, whereas mean BMI (p = 0.007) and AMH (p PCOS-group. A lower mean FSH-starting and maximum dose was administered to women with PCOS (p PCOS-patients did not differ from those of the control group (42.2 % and 34.4 % respectively). Neither mild, nor moderate or severe manifestation of OHSS occurred significantly more often in patients with PCOS. Our study supports the use of a calculated low-dose FSH-stimulation strategy in ART for patients with PCOS. Further randomized clinical trials should confirm this strategy and lead to define individual risk factors for OHSS, which can be used for recommendation of safer ART-techniques like in vitro maturation.

  18. The low-dose combination preparation Vertigoheel activates cyclic nucleotide pathways and stimulates vasorelaxation.

    Science.gov (United States)

    Heinle, H; Tober, C; Zhang, D; Jäggi, R; Kuebler, W M

    2010-01-01

    Vertigo of various and often unknown aetiologies has been associated with and attributed to impaired microvascular perfusion in the inner ear or the vertebrobasilar system. Vertigoheel is a low-dose combination preparation of proven value in the symptomatic treatment of vertigo. In the present study we tested the hypothesis that Vertigoheel's anti-vertiginous properties may in part be due to a vasodilatory effect exerted via stimulation of the adenylate and/or guanylate cyclase pathways. Thus, the influence of Vertigoheel or its single constituents on synthesis and degradation of cyclic nucleotides was measured. Furthermore, vessel myography was used to observe the effect of Vertigoheel on the vasoreactivity of rat carotid arteries. Vertigoheel and one of its constituents, Anamirta cocculus, stimulated adenylate cyclase activity, while another constituent, Conium maculatum, inhibited phosphodiesterase 5, suggesting that the individual constituents of Vertigoheel contribute differentially to a synergistic stimulation of cyclic nucleotide signalling pathways. In rat carotid artery rings, Vertigoheel counteracted phenylephrine-induced tonic vasoconstriction. The present data demonstrate a vasorelaxant effect of Vertigoheel that goes along with a synergistic stimulation of cyclic nucleotide pathways and may provide a mechanistic basis for the documented anti-vertiginous effects of this combination preparation.

  19. Experimental study of low dose radiation stimulate the haematogenesis reconstitution of the recipient after bone marrow transplantation in mice

    International Nuclear Information System (INIS)

    Zhang Liyuan; Yang Shun; Zhang Ye; Zhang Mingzhi; Jiang Jiagui; Jiang Jianping

    2007-01-01

    Objective: To investigate if low dose radiation can stimulate the haematogenesis reconstitution of the recipient after bone marrow transplantation in mice. Methods: Bone marrow cells were irradiated in vitro by different low dose radiation and then cultured in vitro. 3 H-TdR incorporation was used to measure the reproductive activity of cells, and then the radiation dose with the best stimulating effect was determined. The donator myeloid cells were exposed to low dose radiation before the recipient mice received bone marrow transplantation; then the irradiated myeloid cells were infused to the recipient; and lastly, the counts of peripheral blood cells (PBC) and bone marrow mononuclear cells (BMMNC) were monitored in order to observe the effect of low dose radiation on haematogenesis reconstitution of the recipient animal after bone marrow transplantation. Results: The reproductive activity of the bone marrow cells irradiated by 6 and 8 cGy could be improved significantly in vitro. When the recipient mice received bone marrow transplantation of the myeloid cells after low dose radiation, the counts of BMMNC and PBC were higher than those in the control group (P<0.05). Conclusions: Low dose radiation can stimulate the haematogenesis reconstitution of the recipient after bone marrow transplantation. (authors)

  20. Studies on the stimulating effect of low dose irradiation on lymphocyte subsets

    International Nuclear Information System (INIS)

    Du Zeji; Su Liaoyuan

    1994-01-01

    In the study, three kinds of monoclonal antibody were used to separate subsets of lymphocyte, and then the functional changes of the separated subsets after low dose irradiation (LDI) were studied. McAb CD4, CD8 and B were used to obtain CD 4 + , CD8 + and B cells respectively with 'Panning' method, the cells were irradiated with X-ray machine (200 kV, 10 mA) for 0, 0.02, 0.05, 0.1, 0.2, 0.5 Gy. 3 H-TdR incorporation was used to reflect functional changes of subsets after LDI. The results indicated that (1) three kinds of subsets could be stimulated by LDI (within 0.2 Gy). The peak effect for CD 4 + and B cells was induced by 0.1 Gy irradiation for CD8 + cell, the peak effect dose was 0.05 Gy; (2) between 0.02 Gy and 0.2 Gy, for same dose, the stimulating effect of CD4 + was higher than that of CD8 + . This result has an important significance in demonstrating the immune mechanism of radiation hormesis. The past viewpoint suggested that immune hormesis was caused by the damage of radiosensitive T cell (Ts) after LDI. Recently, some authors proved that no change of the ratio of Ts to T H existed after LDI. In the study presented, It is found that the values of 3 H-TdR incorporation in CD4 + was bigger than that in CD8 + after LDI. Obvious stimulating effect could still be observed after 0.2 Gy irradiation, it indicated that subsets separated by McAb could have a wide stimulating dose range for LDI

  1. Effect of low-dose cyclophosphamide, ACTH, and IVIG combination immunotherapy on neuroinflammation in pediatric-onset OMS: A retrospective pilot study.

    Science.gov (United States)

    Pranzatelli, Michael R; Allison, Tyler J; Tate, Elizabeth D

    2018-03-05

    Flow cytometric cerebrospinal fluid (CSF) lymphocyte subset analysis has improved the diagnosis of neuroinflammation and identified multiple markers of inflammation in opsoclonus-myoclonus syndrome (OMS). The aim of this exploratory, retrospective study was to analyze the effect of immunotherapy on these markers to determine which agents are disease modifying. Cross-sectional immunological observations were made in an IRB-approved case-control study, and patients were treated empirically. Ten different CSF lymphocyte subpopulations from 18 children with persistent OMS had been measured by flow cytometry before and after clinical treatment with cyclophosphamide/ACTH/IVIG combination (n = 7) or ACTH/IVIG alone (n = 11). Clinical severity of OMS was scored from videotapes by a blinded observer using the OMS Evaluation Scale. Only cyclophosphamide combination therapy (mean dose 26 ± 3 mg/kg or 922 ± 176 mg/m 2 x 6 cycles) significantly decreased the percentage of CSF B cells. The mean reduction was 65%, with CSF B cell frequency normalized at 7-8 months in 70%. Other abnormalities of the CSF immunophenotype, such as the low CD4/CD8 T cell ratio, persisted, and there were no therapeutic changes in T cell activation/maturation markers. Effects on relative and absolute size of PBMC subsets were similar. Clinical improvement was 70% and 55% in respective treatment groups. The relapse rates of the two groups did not significantly differ. The main effect of cyclophosphamide combination therapy on neuroinflammation in OMS was moderate reduction in CSF B cell expansion. Though exploratory, it may provide a steroid sparer option in partially-responsive OMS. Copyright © 2018 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  2. Differential stimulation of antioxidant defense in various organs of mice after whole body exposure to low-dose gamma radiation

    International Nuclear Information System (INIS)

    Pathak, C.M.; Avti, P.K.; Khanduja, K.L.; Sharma, S.C.

    2007-01-01

    It has been generally considered that any dose of ionizing radiation is detrimental to the living organisms, however low the radiation dose may be. The much relied upon 'Linear-No-Threshold' (LNT) hypothesis dose not have any convincing experimental evidence regarding the damaging effects at very low-doses and low-dose rates. Generally, the deleterious biological effects have been inferred theoretically by extrapolating the known effects of high radiation dose to low-dose range. Recently, it has been reported that the living organisms do not respond to ionizing radiations in a linear manner in the low-dose range 0.01-0.50 Gy and rather restore the homeostasis both in-vivo and in-vitro by normal physiological mechanisms such as, cellular and DNA repair processes, immune reactions, antioxidant defense, adaptive responses, activation of immune functions; stimulation of growth etc. In this study, we have attempted to find: (i) the critical radiation dose range and the post irradiation period during which the antioxidant defense systems in the lungs, liver and kidneys remain stimulated; and (ii) to evaluate the degree to which these defense mechanisms remain stimulated in these organs after whole body exposure of the animal to low-dose radiation

  3. Addition of low dose hCG to rFSh benefits older women during ovarian stimulation for IVF

    Directory of Open Access Journals (Sweden)

    Gomaa Hala

    2012-08-01

    Full Text Available Abstract Background To compare the outcome of IVF cycles in women receiving controlled ovarian stimulation with recFSH or recFSH plus low dose hCG. Methods A retrospective case control study, performed at a private practice affiliated with an academic institute. Patients were infertile women who were treated with IVF/ICSI and controlled ovarian stimulation in a long GnRH agonist protocol using either low dose hCG in addition to recFSH [N = 88] or recFSH alone [N = 99]. Primary outcomes were mean FSH dose, number of mature eggs, number of fertilized eggs, and serum levels of estradiol. Secondary outcomes were endometrial thickness, cycle cancellations and pregnancy rates. Results A significant increase in number of mature and fertilized eggs was observed in women over 40 years of age using low dose hCG in addition to recFSH. The estradiol level was significantly higher on the day of hCG administration and the serum level of FSH on cycle day 7 and on the day of hCG administration were lower. Conclusion Addition of low dose hCG to recFSH compared with recFSH alone significantly modified cycle characteristics in patients >/= 40 years and could be of potential benefit for IVF cycles in older infertile women.

  4. [Value of desmopressin stimulation test and high dose dexamethasone suppression testin the etiologic diagnosis of ACTH dependent Cushing's syndrome].

    Science.gov (United States)

    Zhang, Weiwei; Yu, Yerong; Tan, Huiwen; Wang, Chun; Li, Jianwei; An, Zhenmei; Liu, Yuping

    2016-03-22

    To investigate the value of desmopressin (DDAVP) stimulation test and high dose dexamethasone suppression test (HDDST) in establishing the cause of ACTH dependent Cushing's syndrome. The clinical data of patients with ACTH dependent Cushing's syndrome at West China Hospital from January 1, 2010 to September 30, 2015 was analyzed. The sensitivity and specificity of DDAVP stimulation test, HDDST, and the diagnostic accordance rate when the two tests were combined, were evaluated based on the diagnostic gold standard. A total of 85 patients with Cushing's disease and 10 patients with ectopic ACTH syndrome were included. The sensitivity and specificity of DDAVP stimulation test were 87% and 5/5, respectively, whereas those of HDDST were 79% and 8/10, respectively. The standard high dose dexamethasone suppression test showed a higher sensitivity than overnight 8 mg dexamethasone suppression test. When the two tests had consistent results, the diagnostic accordance rate was 100%. DDAVP stimulation test and HDDST are both efficient modalities for the diagnosis of Cushing's Disease and ectopic ACTH syndrome. The accuracy of diagnosis can be further improved by combining the two tests.

  5. Stimulation effect of early growth in crops by low dose radiation

    International Nuclear Information System (INIS)

    Kim, J.S.; Song, H.S.; Kim, J.K.; Lee, Y.K.; Lee, Y.B.

    1998-01-01

    Germination rate and early growth in crop such as rice,soybean,and perilla were observed after irradiation of γ-ray (Co-60) in order to determine the effects of low does radiation. The low dose radiation was able to improve the early growth in crops and their agricultural characters. Germination rate of 2Gy-irradiatied rice seeds was high and also were seeding height and fresh weight of the 0.5 Gy-irradiated. Germination rate and early growth of soybean were high in 4Gy-irradiated group. Perilla gew of so promisingly after after low dose irradiation, however there slightly increasing effects on germination rate, seeding height and fresh weight at 2Gt-, 1Gy-, and 1Gy irradiated group, respectively. (author)

  6. Stimulation growth effect of Eriocheir sinensis treated with low-dose neutron

    International Nuclear Information System (INIS)

    Luo Keyong; Liu Chunquan; Xu Lixin; Peng Zhangji

    2006-01-01

    This paper was dealt with the relationship between biochemical indexes and different growth stages of Eriocheir sinensis megalopa treated with Low-dose Neutron at 55.24 to 73.66 mGy. It showed that some biochemical component indexes were increased, such as-SH group in protain (between 23.40% to 69.59%), albumen (between 4.99% to 22.6%) and Hyp compared with CK. However, free radical level (between 7.67% to 32.68%) and AKP were decreased. The carapace color was turned into darker than that of CK; Antibacterial immunity of younger crab during the growing stage was increased, the body size of treated Eriocheir sinensis megalopa became uniform and early sexual maturity was inhibited in a certain degree with a low dose neutron treatment. (authors)

  7. Pharmacological stimulation of p53 with low-dose doxorubicin ameliorates diet-induced nonalcoholic steatosis and steatohepatitis

    Directory of Open Access Journals (Sweden)

    Begoña Porteiro

    2018-02-01

    Full Text Available Objective: Recent reports have implicated the p53 tumor suppressor in the regulation of lipid metabolism. We hypothesized that the pharmacological activation of p53 with low-dose doxorubicin, which is widely used to treat several types of cancer, may have beneficial effects on nonalcoholic fatty liver disease (NAFLD and nonalcoholic steatohepatitis (NASH. Methods: We used long-term pharmacological activation of p53 by i.p. or oral administration of low-dose doxorubicin in different animal models of NAFLD (high fat diet containing 45% and 60% kcal fat and NASH (methionine- and choline-deficient diet and choline deficiency combined with high fat diet. We also administered doxorubicin in mice lacking p53 in the liver and in two human hepatic cells lines (HepG2 and THLE2. Results: The attenuation of liver damage was accompanied by the stimulation of fatty acid oxidation and decrease of lipogenesis, inflammation, and ER stress. The effects of doxorubicin were abrogated in mice with liver-specific ablation of p53. Finally, the effects of doxorubicin on lipid metabolism found in animal models were also present in two human hepatic cells lines, in which the drug stimulated fatty acid oxidation and inhibited de novo lipogenesis at doses that did not cause changes in apoptosis or cell viability. Conclusion: These data provide new evidence for targeting p53 as a strategy to treat liver disease. Keywords: Obesity, Lipid metabolism, Inflammation

  8. Is the growth stimulation by low doses of glyphosate sustained over time?

    International Nuclear Information System (INIS)

    Cedergreen, Nina

    2008-01-01

    The herbicide, glyphosate, has been shown to stimulate growth in a range of species when applied at doses of 5-60 g a.e. ha -1 , corresponding to realistic spray drift events. This study investigates growth of shoot parameters over time to detect whether the glyphosate induced growth increase was sustained and had a final effect on reproduction. The results showed that an actual biomass growth rate increase took place within the first week after spraying with glyphosate doses -1 . This initial growth boost kept treated plants larger than untreated plants for up to six weeks, but at harvest there was no significant difference between control plants and treated plants. Possible effects of glyphosate hormesis on the competitive ability of spray drift affected plants are discussed. - Glyphosate induced hormesis in barley is not sustained over time

  9. Is the growth stimulation by low doses of glyphosate sustained over time?

    Energy Technology Data Exchange (ETDEWEB)

    Cedergreen, Nina [Department of Agricultural Sciences, Faculty of Life Science, University of Copenhagen, Hojbakkegard Alle 13, 2630 Tastrup (Denmark)], E-mail: ncf@life.ku.dk

    2008-12-15

    The herbicide, glyphosate, has been shown to stimulate growth in a range of species when applied at doses of 5-60 g a.e. ha{sup -1}, corresponding to realistic spray drift events. This study investigates growth of shoot parameters over time to detect whether the glyphosate induced growth increase was sustained and had a final effect on reproduction. The results showed that an actual biomass growth rate increase took place within the first week after spraying with glyphosate doses <60 g a.e. ha{sup -1}. This initial growth boost kept treated plants larger than untreated plants for up to six weeks, but at harvest there was no significant difference between control plants and treated plants. Possible effects of glyphosate hormesis on the competitive ability of spray drift affected plants are discussed. - Glyphosate induced hormesis in barley is not sustained over time.

  10. Stimulating effect of low dose radiation expression of G-CSF receptors in bone marrow cells in mice

    International Nuclear Information System (INIS)

    Zhang Honglai; Liu Shuzheng; Zhang Ming

    1993-01-01

    The expression of G-CSF receptors in bone marrow cells (BMC) was studied by using 125 I labelled G-CSF ( 1 '2 5 I-G-CSF). The results showed that the reaction equilibrium of 125 I-G-CSF bound to BMC at 37 degree C was reached in 60 minutes, the maximum binding (Bmax) to 3 x 10 6 BMC being 15.1 pmol, the dissociation constant (Kd) being 78.6 pmol, and the estimated number of G-CSF receptors per cell being about 3100. The number of G-CSF receptors in BMC in mice 48 hours after whole body exposure to doses of 50, 75 and 100 mGy X-rays increased significantly to 161%, 169% and 342% of controls, respectively. The results suggested that the expression of G-CSF receptors in BMC was enhanced markedly following low dose radiation, which would lead to stimulation of BMC proliferation

  11. Stimulation of DNA synthesis in bacterial DNA-membrane complexes after low doses of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Watkins, D K [Hammersmith Hospital, London (UK). M.R.C. Experimental Radiopathology Unit

    1980-09-01

    DNA-membrane complexes from three strains of E. coli were irradiated and changes in the rates of DNA synthesis were observed. Doses from 1-10 krad to complexes from W3110 and pol A1 strains gave up to a 100 per cent increase in DNA synthesis; under the same conditions, no change was observed in Bsub(s-1). The degree of stimulation did not depend on the presence of oxygen during irradiation, and a post-irradiation incubation was necessary to achieve activation. The properties of all three complexes were similar when unirradiated. Irradiation of intact organisms under conditions which produced marked, oxygen-dependent inhibition of the Bsub(s-1) complex had no significant effect on those from W3110 and pol A1. Enhanced DNA synthesis is concluded to be due wholly to repair of pre-existing DNA. It is further postulated that DNA synthesis in untreated complexes (E.coli B's,W3110 and pol A1) is mainly of the repair-type and does not necessarily take place at the site of DNA-membrane attachment.

  12. ATR-101, a selective ACAT1 inhibitor, decreases ACTH-stimulated cortisol concentrations in dogs with naturally occurring Cushing's syndrome.

    Science.gov (United States)

    Langlois, Daniel K; Fritz, Michele C; Schall, William D; Bari Olivier, N; Smedley, Rebecca C; Pearson, Paul G; Bailie, Marc B; Hunt, Stephen W

    2018-05-02

    Cushing's syndrome in humans shares many similarities with its counterpart in dogs in terms of etiology (pituitary versus adrenal causes), clinical signs, and pathophysiologic sequelae. In both species, treatment of pituitary- and adrenal-dependent disease is met with limitations. ATR-101, a selective inhibitor of ACAT1 (acyl coenzyme A:cholesterol acyltransferase 1), is a novel small molecule therapeutic currently in clinical development for the treatment of adrenocortical carcinoma, congenital adrenal hyperplasia, and Cushing's syndrome in humans. Previous studies in healthy dogs have shown that ATR-101 treatment led to rapid, dose-dependent decreases in adrenocorticotropic hormone (ACTH) stimulated cortisol levels. The purpose of this clinical study was to investigate the effects of ATR-101 in dogs with Cushing's syndrome. ATR-101 pharmacokinetics and activity were assessed in 10 dogs with naturally-occurring Cushing's syndrome, including 7 dogs with pituitary-dependent disease and 3 dogs with adrenal-dependent disease. ATR-101 was administered at 3 mg/kg PO once daily for one week, followed by 30 mg/kg PO once daily for one (n = 4) or three (n = 6) weeks. Clinical, biochemical, adrenal hormonal, and pharmacokinetic data were obtained weekly for study duration. ATR-101 exposure increased with increasing dose. ACTH-stimulated cortisol concentrations, the primary endpoint for the study, were significantly decreased with responders (9 of 10 dogs) experiencing a mean ± standard deviation reduction in cortisol levels of 50 ± 17% at study completion. Decreases in pre-ACTH-stimulated cortisol concentrations were observed in some dogs although overall changes in pre-ACTH cortisol concentrations were not significant. The compound was well-tolerated and no serious drug-related adverse effects were reported. This study highlights the potential utility of naturally occurring canine Cushing's syndrome as a model for human disease and provides proof of

  13. Stimulating effect of low doses of ionizing radiation on the activity of chicken liver and spleen plasma membrane Ca+2 ATPase during different periods of development

    International Nuclear Information System (INIS)

    Islamov, T.M.

    1994-01-01

    Effect of pre incubative irradiation of chickens on the activity of chicken liver and spleen plasma membrane Ca +2 -ATPase in 13, 15, 17 day embryos and 1, 5, 10, 20, 30, 40, 50, 60 day chickens has been studied. Low doses of radiation are discovered to stimulate liver and spleen enzyme activity. On the basis of data obtained it is suggested that in the cells of radiosensitive and radio resistive organs molecular mechanisms of stimulating effect of low doses are similar. (author). 10 refs.; 1 fig.; 2 tabs

  14. ACTH antagonists

    Directory of Open Access Journals (Sweden)

    Adrian John Clark

    2016-08-01

    Full Text Available ACTH acts via a highly selective receptor that is a member of the melanocortin receptor subfamily of type 1 G protein-coupled receptors. The ACTH receptor, also known as the melanocortin 2 receptor (MC2R is unusual in that it is absolutely dependent on a small accessory protein, melanocortin receptor accessory protein (MRAP for cell surface expression and function. ACTH is the only known naturally occurring agonist for this receptor. This lack of redundancy and high degree of ligand specificity suggests that antagonism of this receptor could provide a useful therapeutic aid and a potential investigational tool. Clinical situations in which this could be useful include (1 Cushing’s disease and ectopic ACTH syndrome – especially whilst preparing for definitive treatment of a causative tumour, or in refractory cases, or (2 congenital adrenal hyperplasia – as an adjunct to glucocorticoid replacement. A case for antagonism in other clinical situations in which there is ACTH excess can also be made. In this article we will explore the scientific and clinical case for an ACTH antagonist, and will review the evidence for existing and recently described peptides and modified peptides in this role.

  15. Effect of irradiation on human T-cell proliferation: low dose irradiation stimulates mitogen-induced proliferation and function of the suppressor/cytotoxic T-cell subset

    International Nuclear Information System (INIS)

    Gualde, N.; Goodwin, J.S.

    1984-01-01

    Unfractionated human T cells exposed to 10-50 rad of X irradiation incorporated less [ 3 H]thymidine than nonirradiated T cells when subsequently cultured with PHA or Con A. The cytotoxic/suppressor T-cell subset, isolated as either OKT8(+) or OKT4(-) cells, demonstrated significantly enhanced [ 3 H]thymidine incorporation in PHA- or Con A-stimulated cultures after exposure to 10-50 rad, compared to unirradiated cells, while the proliferation of the OKT4(+) helper/inducer subset was inhibited by low dose irradiation. It has been previously reported that approximately 30% of the cytotoxic/suppressor subset also stains with OKM1. When the cytotoxic/suppressor subset was further subdivided into OKT4(-), OKM1(+), and OKT4(-), OKM1(-) cells, proliferation of the OKT4(-), OKM1(+) population was inhibited by exposure to 25 rad while proliferation of the OKT4(-), OKM1(-) population was stimulated. The increase in proliferation of the cytotoxic/suppressor T-cell subset after low dose irradiation is paralleled by an increase in suppressor activity of these cells. T cells exposed to 25 rad and then cultured with Con A for 48 hr caused greater inhibition of IgG production when added to fresh autologous lymphocytes stimulated by pokeweed mitogen than did unirradiated cells. Thus, low dose irradiation enhances both the proliferation and function of the human suppressor T-cell subset

  16. The intramuscular glucagon stimulation test does not provide good discrimination between normal and inadequate ACTH reserve when used in the investigation of short healthy children.

    Science.gov (United States)

    Tenenbaum, Ariel; Phillip, Moshe; de Vries, Liat

    2014-01-01

    Few studies have addressed the role of the glucagon stimulation test (GST) in evaluating the hypothalamic-pituitary-adrenal axis in children. We investigated the diagnostic value of the GST in evaluating the adrenocortical response in short healthy children. The GST was performed in 190 children investigated for short stature. A peak cortisol >500 nmol/l was considered a normal response. In the 45 (23.7%) with subnormal response, a 250-μg ACTH test was done. The rate of subnormal adrenal response to GST was higher among boys (33.9 vs. 8.9%, p 500 nmol/l in all the patients undergoing an ACTH stimulation test. Since adrenal response to GST is age- and gender-related and the false-positive rate is high, its routine performance in healthy children warrants reconsideration. © 2014 S. Karger AG, Basel.

  17. Effect of granulocyte colony-stimulating factor treatment at a low dose but for a long duration in patients with coronary heart disease. A pilot study

    International Nuclear Information System (INIS)

    Suzuki, Koji; Nagashima, Kenshi; Arai, Masazumi

    2006-01-01

    In animal models, granulocyte colony-stimulating factor (G-CSF) improves post-infarct cardiac function. However, in pilot studies involving patients with angina and acute myocardial infarction (AMI), G-CSF at a high dose frequently induced coronary occlusion or restenosis, but those at a low dose showed no significant beneficial effect. We hypothesized that a low dose but long duration of G-CSF will have a beneficial effect without serious complications to patients with coronary heart disease. Forty-six patients with angina or AMI were randomly assigned into G-CSF and non-G-CSF control groups, respectively. Recombinant G-CSF was subcutaneously injected once a day for 10 days. The leukocyte counts in the peripheral blood were controlled at approximately 30,000/μl. One month later, a Thallium-201 single photon emission computed tomography revealed the increased percentage uptake and the reduced extent and severity scores in the G-CSF angina group. In the G-CSF AMI group, the curve between the ejection fraction and peak creatine kinase shifted significantly upward, compared with that of the non-G-CSF AMI group. Serious complications were not observed during the 6 months of observation. A low dose but long duration of G-CSF treatment may have a beneficial effect without any serious complications in patients with coronary heart disease. (author)

  18. Stimulation effects of low dose-rate irradiation on pancreatic antioxidant activity in type II diabetes model mice

    International Nuclear Information System (INIS)

    Nomura, Takaharu; Sakai, Kazuo

    2005-01-01

    The effects of low dose-rate gamma irradiation on the type II diabetes mellitus were investigated in BKS.Cg-+Lepr db /+Lepr db /Jcl (DB mice). Ten-week-old female DB mice (5 mice in each group) were irradiated with gamma ray at 0.35, 0.70, or 1.2 mGy/hr. During the course of the 12 weeks the glucose level slightly increased with little difference between the irradiated and the non-irradiated groups. The plasma insulin concentration decreased within the first 4 weeks in all groups. The level was kept low in the non-irradiated mice; while the insulin level in the irradiated groups showed a tendency to increase. In the 0.70 mGy/hr group the increase was statistically significant after 12 weeks of irradiation. Total activity of SOD, one of antioxidative enzymes, decreased both in non-irradiated and irradiated groups; however the decrease was less in the irradiated groups, especially 0.70 mGy/hr group. In the 0.70 mGy/hr group Mn-SOD activity, one of the components of total SOD activity, increased after 12-week irradiation. A pathological examination of the pancreas revealed that damage to β cells responsible for the secretion of insulin was much less in the 0.70 mGy/hr group compared to that in the non-irradiated group. These results indicated that the low dose-rate irradiation increase the antioxidative capacity in the pancreas to protect β cells from oxidative damage, and the to increase the insulin level. This mechanism would lead the mice to the recovery from the disease and the prolongation of the life span as is demonstrated in our previous report. (author)

  19. Stimulating action of continuous γ-irradiation with low dose-rates on the growth and development of Aspergillus niger

    International Nuclear Information System (INIS)

    Kuzin, A.M.; Nikitina, A.N.; Yurov, S.S.; Primak, V.N.

    1976-01-01

    Continuous γ-irradiation (1.6 - 4.1 rad/hr) of Aspergillus niger cultured in a mineral medium has been shown to stimulate markedly the growth of the culture and the production of organic acids. Optimum conditions for the stimulating effect have been found

  20. Immune modulating effects of NKT cells in a physiologically low dose Leishmania major infection model after αGalCer analog PBS57 stimulation.

    Science.gov (United States)

    Griewank, Klaus G; Lorenz, Beate; Fischer, Michael R; Boon, Louis; Lopez Kostka, Susanna; von Stebut, Esther

    2014-06-01

    Leishmaniasis is a parasitic infection affecting ∼12 million people worldwide, mostly in developing countries. Treatment options are limited and no effective vaccines exist to date. Natural Killer T (NKT) cells are a conserved innate-like lymphocyte population with immunomodulating effects in various settings. A number of reports state a role of NKT cells in different models of Leishmania infection. Here, we investigated the effect of NKT cells in a physiologically relevant, intradermal low dose infection model. After inoculation of 103 infectious-stage L. major, comparable numbers of skin-immigrating NKT cells in both susceptible BALB/c mice and resistant C57BL/6 mice were noted. Compared to their wild type counterparts, NKT cell-deficient mice on a C57BL/6 background were better able to contain infection with L. major and showed decreased IL-4 production in cytokine analysis performed 5 and 8 weeks after infection. Low doses of the NKT cell stimulating αGalCer analog PBS57 applied at the time of infection led to disease exacerbation in C57BL/6 wild-type, but not NKT-deficient mice. The effect was dependent both on the timing and amount of PBS57 administered. The effect of NKT cell stimulation by PBS57 proved to be IL-4 dependent, as it was neutralized in IL-4-deficient C57BL/6 or anti-IL-4 antibody-treated wild-type mice. In contrast to C57BL/6 mice, administration of PBS57 in susceptible BALB/c mice resulted in an improved course of disease. Our results reveal a strain- and cytokine-dependent regulatory role of NKT cells in the development of immunity to low dose L. major infections. These effects, probably masked in previous studies using higher parasite inocula, should be considered in future therapy and immunization approaches.

  1. Functional response of white rats isolated heart to the stimulation of adrenergic receptors after gamma-irradiation in low doses

    International Nuclear Information System (INIS)

    Antonenko, A.N.; Lobanok, L.M.

    1999-01-01

    It was investigated the effects of acute gamma-irradiation on bio mechanical activity of rats heart isolated by Langendorf's method in early and delayed terms after exposure to gamma-rays. Intra ventricle pressure and the rate of its growth, volumetric rate of coronal flow, frequency of heart contraction were registered. Stimulation of alpha-adrenergic receptors was conducted by means of specific agonist mesatone and stimulation of beta-adrenergic receptors was made by means of isoprenaline. The study has shown that acute irradiation of rats caused the decrease of both contractile ability and relaxation of myocardium in a 10 days after exposure. In delayed period bio mechanical activity of isolated heart was restored. Functional response of heart to the stimulation of alpha- and beta-adrenergic receptors was decreased in all terms of investigation

  2. Low dose irradiation does not stimulate in vivo primary antibody response in specific-pathogen-free mice

    International Nuclear Information System (INIS)

    Kamisaku, H.; Sado, T.; Muto, M.; Pongpiachan, P.; Magnemi, U.

    1991-01-01

    Recent studies from other laboratories indicated that exposure of mice to low dose radiation resulted in the enhancement of primary anti-SRBC PFC response in mice. We have repeated these experiments using four strains of mice that are known to differ in radiosensitivity of immune response potential in vivo. In one study mice were exposed to 2.5-25 cGy of X-rays. Nine hours later they were injected with SRBC and the number of PFCs per spleen was assessed individually at 4.5 days. The results indicated no evidence for the enhancement of PFC response at all exposure levels examined. In another study, groups of C57BL/6J mice were immunized with SRBC and exposed to 0, 150, or 300 cGy of X-rays 2 days later. Numbers of direct as well as indirect PFCs per spleen were then assessed individually at frequent intervals thereafter. The results indicated that exposure of mice to 150 cGy resulted in a significant increase in the number of indirect PFCs assessed at day 11 after SRBC injection, or 9 days after radiation exposure. Dose-response analysis of radiation-induced enhancement of indirect PFC response by this protocol indicated that only after exposure to 150 and 300 cGy for C57BL/6 and C3H/He strain, respectively, a significant enhancement of indirect PFC response was demonstrated. Flow cytometric analysis of spleen cells from these animals indicated that CD4+/CD+ cell ratios increased rapidly during the first three days after radiation exposure, followed by a rapid decline, suggesting that relative proportion of helper/inducer as compared to cytotoxic/suppressor T cell subset changed rapidly in favor of the former shortly after radiation exposure and possibly contributed to the observed enhancement of indirect PFC response. (author)

  3. Low dose decitabine treatment induces CD80 expression in cancer cells and stimulates tumor specific cytotoxic T lymphocyte responses.

    Directory of Open Access Journals (Sweden)

    Li-Xin Wang

    Full Text Available Lack of immunogenicity of cancer cells has been considered a major reason for their failure in induction of a tumor specific T cell response. In this paper, we present evidence that decitabine (DAC, a DNA methylation inhibitor that is currently used for the treatment of myelodysplastic syndrome (MDS, acute myeloid leukemia (AML and other malignant neoplasms, is capable of eliciting an anti-tumor cytotoxic T lymphocyte (CTL response in mouse EL4 tumor model. C57BL/6 mice with established EL4 tumors were treated with DAC (1.0 mg/kg body weight once daily for 5 days. We found that DAC treatment resulted in infiltration of IFN-γ producing T lymphocytes into tumors and caused tumor rejection. Depletion of CD8(+, but not CD4(+ T cells resumed tumor growth. DAC-induced CTL response appeared to be elicited by the induction of CD80 expression on tumor cells. Epigenetic evidence suggests that DAC induces CD80 expression in EL4 cells via demethylation of CpG dinucleotide sites in the promoter of CD80 gene. In addition, we also showed that a transient, low-dose DAC treatment can induce CD80 gene expression in a variety of human cancer cells. This study provides the first evidence that epigenetic modulation can induce the expression of a major T cell co-stimulatory molecule on cancer cells, which can overcome immune tolerance, and induce an efficient anti-tumor CTL response. The results have important implications in designing DAC-based cancer immunotherapy.

  4. Low Dose Decitabine Treatment Induces CD80 Expression in Cancer Cells and Stimulates Tumor Specific Cytotoxic T Lymphocyte Responses

    Science.gov (United States)

    Zhou, Ji-Hao; Yao, Yu-Shi; Li, Yong-Hui; Xu, Yi-Han; Li, Jing-Xin; Gao, Xiao-Ning; Zhou, Min-Hang; Jiang, Meng-Meng; Gao, Li; Ding, Yi; Lu, Xue-Chun; Shi, Jin-Long; Luo, Xu-Feng; Wang, Jia; Wang, Li-Li; Qu, Chunfeng; Bai, Xue-Feng; Yu, Li

    2013-01-01

    Lack of immunogenicity of cancer cells has been considered a major reason for their failure in induction of a tumor specific T cell response. In this paper, we present evidence that decitabine (DAC), a DNA methylation inhibitor that is currently used for the treatment of myelodysplastic syndrome (MDS), acute myeloid leukemia (AML) and other malignant neoplasms, is capable of eliciting an anti-tumor cytotoxic T lymphocyte (CTL) response in mouse EL4 tumor model. C57BL/6 mice with established EL4 tumors were treated with DAC (1.0 mg/kg body weight) once daily for 5 days. We found that DAC treatment resulted in infiltration of IFN-γ producing T lymphocytes into tumors and caused tumor rejection. Depletion of CD8+, but not CD4+ T cells resumed tumor growth. DAC-induced CTL response appeared to be elicited by the induction of CD80 expression on tumor cells. Epigenetic evidence suggests that DAC induces CD80 expression in EL4 cells via demethylation of CpG dinucleotide sites in the promoter of CD80 gene. In addition, we also showed that a transient, low-dose DAC treatment can induce CD80 gene expression in a variety of human cancer cells. This study provides the first evidence that epigenetic modulation can induce the expression of a major T cell co-stimulatory molecule on cancer cells, which can overcome immune tolerance, and induce an efficient anti-tumor CTL response. The results have important implications in designing DAC-based cancer immunotherapy. PMID:23671644

  5. Low dose decitabine treatment induces CD80 expression in cancer cells and stimulates tumor specific cytotoxic T lymphocyte responses.

    Science.gov (United States)

    Wang, Li-Xin; Mei, Zhen-Yang; Zhou, Ji-Hao; Yao, Yu-Shi; Li, Yong-Hui; Xu, Yi-Han; Li, Jing-Xin; Gao, Xiao-Ning; Zhou, Min-Hang; Jiang, Meng-Meng; Gao, Li; Ding, Yi; Lu, Xue-Chun; Shi, Jin-Long; Luo, Xu-Feng; Wang, Jia; Wang, Li-Li; Qu, Chunfeng; Bai, Xue-Feng; Yu, Li

    2013-01-01

    Lack of immunogenicity of cancer cells has been considered a major reason for their failure in induction of a tumor specific T cell response. In this paper, we present evidence that decitabine (DAC), a DNA methylation inhibitor that is currently used for the treatment of myelodysplastic syndrome (MDS), acute myeloid leukemia (AML) and other malignant neoplasms, is capable of eliciting an anti-tumor cytotoxic T lymphocyte (CTL) response in mouse EL4 tumor model. C57BL/6 mice with established EL4 tumors were treated with DAC (1.0 mg/kg body weight) once daily for 5 days. We found that DAC treatment resulted in infiltration of IFN-γ producing T lymphocytes into tumors and caused tumor rejection. Depletion of CD8(+), but not CD4(+) T cells resumed tumor growth. DAC-induced CTL response appeared to be elicited by the induction of CD80 expression on tumor cells. Epigenetic evidence suggests that DAC induces CD80 expression in EL4 cells via demethylation of CpG dinucleotide sites in the promoter of CD80 gene. In addition, we also showed that a transient, low-dose DAC treatment can induce CD80 gene expression in a variety of human cancer cells. This study provides the first evidence that epigenetic modulation can induce the expression of a major T cell co-stimulatory molecule on cancer cells, which can overcome immune tolerance, and induce an efficient anti-tumor CTL response. The results have important implications in designing DAC-based cancer immunotherapy.

  6. ACTH (cosyntropin) stimulation test

    Science.gov (United States)

    ... occurs when there is not enough cortisol) Addison disease (adrenal glands do not produce enough cortisol) Hypopituitarism (pituitary gland ... A.M. Editorial team. Addison Disease Read more Adrenal Gland Disorders Read more Pituitary Disorders Read more A.D. ...

  7. Gamma Low-Dose-Rate Ionizing Radiation Stimulates Adaptive Functional and Molecular Response in Human Aortic Endothelial Cells in a Threshold-, Dose-, and Dose Rate-Dependent Manner.

    Science.gov (United States)

    Vieira Dias, Juliana; Gloaguen, Celine; Kereselidze, Dimitri; Manens, Line; Tack, Karine; Ebrahimian, Teni G

    2018-01-01

    A central question in radiation protection research is whether low-dose and low-dose-rate (LDR) exposures to ionizing radiation play a role in progression of cardiovascular disease. The response of endothelial cells to different LDR exposures may help estimate risk of cardiovascular disease by providing the biological mechanism involved. We investigated the effect of chronic LDR radiation on functional and molecular responses of human aorta endothelial cells (HAoECs). Human aorta endothelial cells were continuously irradiated at LDR (6 mGy/h) for 15 days and analyzed at time points when the cumulative dose reached 0.05, 0.5, 1.0, and 2.0 Gy. The same doses were administered acutely at high-dose rate (HDR; 1 Gy/min). The threshold for the loss of angiogenic capacity for both LDR and HDR radiations was between 0.5 and 1.0 Gy. At 2.0 Gy, angiogenic capacity returned to normal only for HAoEC exposed to LDR radiation, associated with increased expression of antioxidant and anti-inflammatory genes. Pre-LDR, but not pre-HDR, radiation, followed by a single acute 2.0 Gy challenge dose sustained the expression of antioxidant and anti-inflammatory genes and stimulated angiogenesis. Our results suggest that dose rate is important in cellular response and that a radioadaptive response is involved for a 2.0 Gy dose at LDR.

  8. Gamma Low-Dose-Rate Ionizing Radiation Stimulates Adaptive Functional and Molecular Response in Human Aortic Endothelial Cells in a Threshold-, Dose-, and Dose Rate–Dependent Manner

    Science.gov (United States)

    Vieira Dias, Juliana; Gloaguen, Celine; Kereselidze, Dimitri; Manens, Line; Tack, Karine; Ebrahimian, Teni G

    2018-01-01

    A central question in radiation protection research is whether low-dose and low-dose-rate (LDR) exposures to ionizing radiation play a role in progression of cardiovascular disease. The response of endothelial cells to different LDR exposures may help estimate risk of cardiovascular disease by providing the biological mechanism involved. We investigated the effect of chronic LDR radiation on functional and molecular responses of human aorta endothelial cells (HAoECs). Human aorta endothelial cells were continuously irradiated at LDR (6 mGy/h) for 15 days and analyzed at time points when the cumulative dose reached 0.05, 0.5, 1.0, and 2.0 Gy. The same doses were administered acutely at high-dose rate (HDR; 1 Gy/min). The threshold for the loss of angiogenic capacity for both LDR and HDR radiations was between 0.5 and 1.0 Gy. At 2.0 Gy, angiogenic capacity returned to normal only for HAoEC exposed to LDR radiation, associated with increased expression of antioxidant and anti-inflammatory genes. Pre-LDR, but not pre-HDR, radiation, followed by a single acute 2.0 Gy challenge dose sustained the expression of antioxidant and anti-inflammatory genes and stimulated angiogenesis. Our results suggest that dose rate is important in cellular response and that a radioadaptive response is involved for a 2.0 Gy dose at LDR. PMID:29531508

  9. Long-time treatment by low-dose N-acetyl-L-cysteine enhances proinflammatory cytokine expressions in LPS-stimulated macrophages.

    Directory of Open Access Journals (Sweden)

    Tomokazu Ohnishi

    Full Text Available N-acetyl-L-cysteine is known to act as a reactive oxygen species scavenger and used in clinical applications. Previous reports have shown that high-dose N-acetyl-L-cysteine treatment inhibits the expression of proinflammatory cytokines in activated macrophages. Here, we have found that long-time N-acetyl-L-cysteine treatment at low-concentration increases phosphorylation of extracellular signal-regulated kinase 1/2 and AKT, which are essential for the induction of proinflammatory cytokines including interleukin 1β and interleukin 6 in lipopolysaccharide-stimulated RAW264.7 cells. Furthermore, long-time N-acetyl-L-cysteine treatment decreases expressions of protein phosphatases, catalytic subunit of protein phosphatase-2A and dual specificity phosphatase 1. On the other hand, we have found that short-time N-acetyl-L-cysteine treatment at low dose increases p53 expression, which inhibits expressions of proinflammatory cytokines. These observations suggest that long-time low-dose N-acetyl-L-cysteine treatment increases expressions of proinflammatory cytokines through enhancement of kinase phosphorylation.

  10. Steroidogenic activity of high molecular weight forms of ACTH

    International Nuclear Information System (INIS)

    Gasson, J.C.

    1979-01-01

    The relative steroidogenic potencies of high molecular weight forms of adrenocorticotropic hormone (ACTH) were investigated using in vitro bioassays. In order to prepare pools of separated pro-ACTH/endorphin, ACTH biosynthetic intermediate and glycosylated ACTH (1-39), the protein present in serum-free tissue culture medium obtained from cultured AtT-20/D-16v mouse pituitary tumor cells was concentrated and fractionated by gel filtration. Based on sodium dodecyl sulfate polyacrylamide gel electrophoresis, over 97% of the immunoactive ACTH in each pool had the appropriate molecular weight. Suspensions of isolated rat and guinea pig adrenal cortical cells were prepared by enzymatic dissociation and mechanical dispersion. Cells were incubated in complete tissue culture medium overnight then used in a 2 hour steroid production assay. Synthetic hACTH(1-39) was used as a bioassay and immunoassay standard. The amounts of pro-ACTH/endorphin, ACTH biosynthetic intermediate and glycosylated ACTH(1-39) bioassayed were estimated by ACTH(17-24) radioimmunoassay. All three high molecular weight forms of ACTH were capable of stimulating the same maximal level of steroidogenesis, by both isolated rat and guinea pig adrenal cells, as hACTH(1-39). Glycosylated ACTH(1-39) was equipotent with hACTH(1-39); pro-ACTH/endorphin and ACTH biosynthetic intermediate were two orders of magnitude less potent than hACTH(1-39) in both bioassay systems

  11. Basal and meal-stimulated ghrelin, PYY, CCK levels and satiety in lean women with polycystic ovary syndrome: effect of low-dose oral contraceptive.

    Science.gov (United States)

    Arusoglu, Gulcan; Koksal, Gulden; Cinar, Nese; Tapan, Serkan; Aksoy, Duygu Yazgan; Yildiz, Bulent O

    2013-11-01

    Ghrelin is an orexigenic peptide that stimulates food intake, whereas peptide YY (PYY) and cholecystokinin (CCK) are anorexigenic gut hormones. Patients with polycystic ovary syndrome (PCOS) appear to have alterations in appetite regulation. We aimed to determine whether fasting or meal-stimulated ghrelin, PYY, CCK, and satiety responses are different between lean PCOS patients and healthy women. We also aimed to assess the potential effect of oral contraceptive use on these hormones and satiety response. We conducted a prospective observational study in a university practice. Eighteen lean PCOS patients and 18 healthy control women matched for age and body mass index underwent measurements of circulating ghrelin, PYY, CCK, and satiety index (SI) before and after a standardized mixed meal at 0, 15, 30, 45, 60, 90, 120, and 180 minutes. For PCOS patients who were treated with ethinyl estradiol 30 μg/drospirenone 3 mg for 3 months, measurements were repeated. We measured ghrelin, PYY, and CCK levels and SI. At baseline, fasting ghrelin, PYY, CCK, and SI values in PCOS patients were not different from controls. Meal-stimulated PYY, CCK, and SI were also not different between the groups, whereas PCOS patients had significantly lower meal-stimulated ghrelin levels compared to controls (P = .04). Ghrelin, PYY, CCK, and SI did not show a significant change after treatment with ethinyl estradiol/drospirenone for 3 months. Basal and stimulated hunger and satiety hormones in lean PCOS patients are not different from lean healthy women, except for a lower meal-stimulated ghrelin response. Short-term use of a low-dose oral contraceptive does not have an effect on appetite regulation of PCOS.

  12. The expression of the ACTH receptor

    Directory of Open Access Journals (Sweden)

    L.L.K. Elias

    2000-10-01

    Full Text Available Adrenal glucocorticoid secretion is regulated by adrenocorticotropic hormone (ACTH acting through a specific cell membrane receptor (ACTH-R. The ACTH-R is a member of the G protein superfamily-coupled receptors and belongs to the subfamily of melanocortin receptors. The ACTH-R is mainly expressed in the adrenocortical cells showing a restricted tissue specificity, although ACTH is recognized by the other four melanocortin receptors. The cloning of the ACTH-R was followed by the study of this gene in human diseases such as familial glucocorticoid deficiency (FGD and adrenocortical tumors. FGD is a rare autosomal recessive disease characterized by glucocorticoid deficiency, elevated plasma ACTH levels and preserved renin/aldosterone secretion. This disorder has been ascribed to an impaired adrenal responsiveness to ACTH due to a defective ACTH-R, a defect in intracellular signal transduction or an abnormality in adrenal cortical development. Mutations of the ACTH-R have been described in patients with FGD in segregation with the disease. The functional characterization of these mutations has been prevented by difficulties in expressing human ACTH-R in cells that lack endogenous melanocortin receptor activity. To overcome these difficulties we used Y6 cells, a mutant variant of the Y1 cell line, which possesses a non-expressed ACTH-R gene allowing the functional study without any background activity. Our results demonstrated that the several mutations of the ACTH-R found in FGD result in an impaired cAMP response or loss of sensitivity to ACTH stimulation. An ACTH-binding study showed an impairment of ligand binding with loss of the high affinity site in most of the mutations studied.

  13. Emission of thermally stimulated luminescence in mixed monocrystals KCl-KBr: Pb2+, KCl: Pb2+ and KBr: Pb2+ exposed at low doses

    International Nuclear Information System (INIS)

    Cruz Z, E.; Ramos B, S.; Melendrez A, R.; Chernov, V.; Piters, T.M.; Barboza F, M.; Hernandez A, J.; Murrieta S, H.

    2002-01-01

    It is reported the behavior of solid solutions of mixed crystals KCl 1-x KBr x doped with divalent lead which were exposed to gamma radiation. The mixtures of KCl-KBr were varied, with x equivalents at 2, 50, 65, and 85 % including the extremes KCl: Pb 2+ and KBr: Pb 2+ . It was maintained a concentration of divalent lead between 20 and 40 ppm in the crystalline lattice. The production of the generated defects by radiation have been correlated with the increase in the brilliance curves depending on the received dose by the mixed doped crystal. It has been used the thermal stimulation (Tl) for obtaining the crystal luminescence depending on the dose until 130 Gy with gammas of cobalt 60. The results shows that this mixed crystalline material of varied composition responds adequately to low doses which indicates that this would be a good detector of ionizing radiation. The results have been correlated with the optical properties of this mixed doped crystal, however it has been found that exists an important loss of luminescence depending on the halogen quantity presents in the mixed crystal. (Author)

  14. Very low dose gamma irradiation stimulates gaseous exchange and carboxylation efficiency, but inhibits vascular sap flow in groundnut (Arachis hypogaea L.).

    Science.gov (United States)

    Ahuja, Sumedha; Singh, Bhupinder; Gupta, Vijay Kumar; Singhal, R K; Venu Babu, P

    2014-02-01

    An experiment was carried out to determine the effect of low dose gamma radiation on germination, plant growth, nitrogen and carbon fixation and carbon flow and release characteristics of groundnut. Dry seeds of groundnut variety Trombay groundnut 37A (TG 37A), a radio mutant type developed by Bhabha Atomic Research Centre (BARC), Mumbai, India, were subjected to the pre-sowing treatment of gamma radiation within low to high dose physiological range, i.e., 0.0, 0.0082, 0.0164. 0.0328, 0.0656, 0.1312, 5, 25, 100, 500 Gray (Gy) from a cobalt source ((60)Co). Observations were recorded for the radiation effect on percentage germination, vigour, gas exchange attributes such as photosynthetic rate, stomatal conductance and transpiration rate, chlorophyll content, root exudation in terms of (14)C release, vascular sap flow rate and activities of rate defining carbon and nitrogen assimilating enzymes such as ribulose-1,5-bisphosphate carboxylase (rubisco) and nitrate reductase (NR). Seed germination was increased by 10-25% at the lower doses up to 5 Gy while the improvement in plant vigour in the same dose range was much higher (22-84%) than the unirradiated control. For radiation exposure above 5 Gy, a dose-dependent decline in germination and plant vigour was measured. No significant effect was observed on the photosynthesis at radiation exposure below 5 Gy but above 5 Gy dose there was a decline in the photosynthetic rate. Stomatal conductance and transpiration rate, however, were only inhibited at a high dose of 500 Gy. Leaf rubisco activity and NR activities remained unaffected at all the investigated doses of gamma irradiation. Mean root exudation and sap flow rate of the irradiated plants, irrespective of the dose, was reduced over the unirradiated control more so in a dose-dependent manner. Results indicated that a very low dose of gamma radiation, in centigray to gray range, did not pose any threat and in fact stimulated metabolic functions in such a way to aid

  15. Low doses effects

    International Nuclear Information System (INIS)

    Tubiana, M.

    1997-01-01

    In this article is asked the question about a possible carcinogens effect of low dose irradiation. With epidemiological data, knowledge about the carcinogenesis, the professor Tubiana explains that in spite of experiments made on thousand or hundred of thousands animals it has not been possible to bring to the fore a carcinogens effect for low doses and then it is not reasonable to believe and let the population believe that low dose irradiation could lead to an increase of neoplasms and from this point of view any hardening of radiation protection standards could in fact, increase anguish about ionizing radiations. (N.C.)

  16. ACTH blood test

    Science.gov (United States)

    ... thyroid, or pancreas) making too much ACTH ( ectopic Cushing syndrome ) A lower-than-normal level of ACTH may ... Disease Read more Adrenal Gland Disorders Read more Cushing's Syndrome Read more A.D.A.M., Inc. is ...

  17. Resposta do ACTH plasmático ao estímulo com CRH ou CRH + desmopressina em pacientes com síndrome de Cushing ACTH- dependente submetidos a cateterismo bilateral simultâneo dos seios petrosos inferiores Response of plasmatic ACTH to CRH or combined CRH/desmopressin stimulation in patients with ACTHdependent Cushing's syndrome submitted to simultaneous bilateral petrosal sinuses sampling

    Directory of Open Access Journals (Sweden)

    Daniella Maria Carneiro do Rêgo

    2007-12-01

    Full Text Available OBJETIVO: Comparar a resposta do ACTH plasmático após estímulo com CRH ou CRH + desmopressina em pacientes com síndrome de Cushing ACTH-dependente que realizaram cateterismo bilateral simultâneo dos seios petrosos inferiores. MATERIAIS E MÉTODOS: O procedimento foi realizado em 21 pacientes - 14 mulheres e 7 homens - com síndrome de Cushing ACTH-dependente no período de janeiro de 1998 a dezembro de 2003. Após a cateterização de ambos os seios petrosos, amostras de sangue para ACTH foram colhidas, simultaneamente, nos seios petrosos e veia periférica, tanto no estado basal como após três e cinco minutos da administração de CRH humano (100 mg (6 pacientes ou CRH + desmopressina (100 mg + 10 mg (15 pacientes. RESULTADOS: Aos três minutos, houve aumento percentual do ACTH tanto no grupo CRH (257,77 ± 240,36 no seio petroso direito e 718,78 ± 1.358,82 no seio petroso esquerdo [média ± desvio-padrão] como no grupo CRH + desmopressina (1.263,35 ± 1.842,91 no seio petroso direito [p = 0,06] e 583,93 ± 1.020,03 no seio petroso esquerdo [p = 0,83]. Aos cinco minutos houve declínio percentual do ACTH no grupo do CRH (181,07 ± 217,39 no seio petroso direito e 188,25 ± 270,15 no seio petroso esquerdo e aumento progressivo no grupo do CRH + desmopressina (1.365,29 ± 1.832,31 no seio petroso direito [p = 0,03] e 866,43 ± 1.431,72 no seio petroso esquerdo [p = 0,11]. Nos três pacientes com secreção ectópica não houve gradiente. CONCLUSÃO: A estimulação combinada CRH + desmopressina induziu maior produção de ACTH em adenomas corticotróficos em comparação ao CRH, o que pode melhorar a sensibilidade diagnóstica deste procedimento.OBJECTIVE: To compare the responses of plasmatic ACTH to CRH or combined CRH/desmopressin stimulation in patients with ACTH-dependent Cushing's syndrome submitted to simultaneous, bilateral inferior petrosal sinuses sampling. MATERIALS AND METHODS: The procedure was performed in 21 patients - 14

  18. Differential sensitivity to the antifouling chemical medetomidine between wood frog and American toad tadpoles with evidence for low-dose stimulation and high-dose inhibition of metamorphosis.

    Science.gov (United States)

    Fong, Peter P; Lambert, Olivia J; Hoagland, Margot L; Kurtz, Emily R

    2018-05-05

    significantly reduced both percent activity and startle response. In wood frogs, medetomidine significantly reduced percent activity, but increased startle response. We discuss our finding of low-dose stimulation and high-dose inhibition of different life history endpoints in terms of hormetic mechanisms. The differential sensitivity between species in terms of mortality, frequency of metamorphosis, and behavior highlights the potential negative environmental effects of medetomidine to amphibians.

  19. Low dose epidemiologic studies

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    In this chapter the BEIR committee has reviewed low-dose irradiation studies since the BEIR III report. They have considered the carcinogenic effectiveness of low-LET in populations exposed to radiation from a number of different sources: diagnostic radiography; fallout from nuclear weapons testing; nuclear installations; radiation in the workplace and high levels of natural background radiation

  20. Radioimmunoassay for human ACTH

    Energy Technology Data Exchange (ETDEWEB)

    Matsumura, S; Oyama, H; Tenku, A; Horino, M [Kawasaki Medicial School, Kurashiki, Okayama (Japan); Kobayashi, K

    1977-03-01

    A radioimmunoassay method for human adrenocorticotropic hormone (ACTH) is described. The antiserum was produced in a guinea pig by multiple injections of a total of 1 mg of porcine ACTH adsorbed with CM-cellulose and mixed with complete Freund's adjuvant. The antiserum used for this study at a final dilution of 1:500,000 was obtained from a guinea pig after 10 immunizations. A highly purified native ACTH (Li, ..cap alpha.. sub(h)sup(1-39) ACTH) was used as an assay standard and a tracer hormone. Separation of free and bound hormone was achieved by dextran coated charcoal. Extraction of ACTH from plasma samples was performed by Donald's method modified with silicic acid. The antibody appeared to be directed against the C-terminal portion of the hormone molecule and showed no significant reaction with other pituitary hormones (GH, TSH, LH, FSH, Hpr, Oxytocin, Arginine-and Lysine-Vasopressin). Plasma ACTH levels of 5 healthy subjects at nine o'clock averaged 32 +- 8.5 pg/ml (M +- SD). Plasma ACTH concentrations in a case of Sheehan's syndrome and of an untreated adrenogenital syndrome at nine o'clock were less than 20 and 194 pg/ml, respectively. A case of Cushing's syndrome accompanied with bilateral nodular hyperplasia of the adrenal cortex showed diminished diurnal variation and normal levels of plasma ACTH. In contrast, elevated plasma ACTH levels and lack of diurnal rhythm of ACTH secretion were observed in a suspected case of Cushing's disease.

  1. Effects of low doses

    International Nuclear Information System (INIS)

    Le Guen, B.

    2001-01-01

    Actually, even though it is comfortable for the risk management, the hypothesis of the dose-effect relationship linearity is not confirmed for any model. In particular, in the area of low dose rate delivered by low let emitters. this hypothesis is debated at the light of recent observations, notably these ones relative to the mechanisms leading to genetic instability and induction eventuality of DNA repair. The problem of strong let emitters is still to solve. (N.C.)

  2. Low dose irradiation and biological defense mechanisms

    International Nuclear Information System (INIS)

    Sugahara, Tsutomu; Sagan, L.A.; Aoyama, Takashi

    1992-01-01

    It has been generally accepted in the context of radiation protection that ionizing radiation has some adverse effect even at low doses. However, epidemiological studies of human populations cannot definitively show its existence or absence. Furthermore, recent studies of populations living in areas of different background radiation levels reported some decrease in adverse health effects at high background levels. Genetic studies of atomic bomb survivors failed to produce statistically significant findings on the mutagenic effects of ionizing radiation. A British study however, suggests that a father's exposure to low dose radiation on the job may increase his children's risk of leukemia. On the other hand, many experimental studies have raised the possibility that low doses of ionizing radiation may not be harmful or may even produce stimulating or adaptive responses. The term 'hormesis' has come to be used to describe these phenomena produced by low doses of ionizing radiation when they were beneficial for the organisms studied. At the end of the International Conference on Low Dose Irradiation one conclusion appeared to be justified: radiation produces an adaptive response, though it is not universally detected yet. The conference failed to obtain any consensus on risk assessment at low doses, but raised many problems to be dealt with by future studies. The editors therefore believe that the Proceedings will be useful for all scientists and people concerned with radiation protection and the biological effects of low-dose irradiation

  3. Stimulation of anti-tumor effect by low-dose irradiation. Pt. 2. The prolongation of life span in AKR mice

    International Nuclear Information System (INIS)

    Ishii, Keiichiro; Misonoh, Jun; Hosoi, Yoshio; Ono, Tetsuya; Sakamoto, Kiyohiko.

    1994-01-01

    To elucidate the antileukemic effect of low-dose X-irradiation, we studied the influence of periodical low-dose X-irradiation on survival and tumor incidence of thymus using AKR mice. The findings of the experiments were as follows; (1) The median survival time of control AKR mice was 283±3 days. It of irradiation group of 15 cGy/week and 30cGy was 309±14 days and 316±10 days respectively. The life span was significantly prolonged (p < 0.05 and p < 0.01 respectively by Wilcoxon test) by periodical low-dose X-irradiation in term of breeding. (2) The incidence of thymus tumor which is observed remarkably in control AKR mice was 48.8%. It of irradiation group of 15 cGy/week and 30 cGy/week was 40% and 20% respectively. Inversely, the non-tumor incidence of tymus in control AKR mice was 19.5%. It of irradiation group of 15 cGy/week and 30 cGy/week was 32.5% and 51.4% respectively. The thymic tumor incidence was significantly decreased (p < 0.01 by chi-square test) in irradiation group of 30 cGy/week. (3) The incidence of thymic lymphoma as a death cause in control AKR mice was 80.4%. It of irradiation group of 15 cGy/week and 30cGy/week was 67.5% and 48.6% respectively. The incidence of thymic lymphoma was significantly decreased (p < 0.05 by chi-square test) in irradiation group of 30 cGy/week. (author)

  4. Biological influence from low dose and low-dose rate radiation

    International Nuclear Information System (INIS)

    Magae, Junji

    2007-01-01

    Although living organisms have defense mechanisms for radioadaptive response, the influence is considered to vary qualitatively and quantitatively for low dose and high dose, as well as for low-dose rate and high-dose rate. This article describes the bioresponse to low dose and low-dose rate. Among various biomolecules, DNA is the most sensitive to radiation, and accurate replication of DNA is an essential requirement for the survival of living organisms. Also, the influence of active enzymes resulted from the effect of radiation on enzymes in the body is larger than the direct influence of radiation on the body. After this, the article describes the carcinogenic risk by low-dose radiation, and then so-called Hormesis effect to create cancer inhibition effect by stimulating active physiology. (S.K.)

  5. Use of low doses of cobalt 60 gamma radiation on beet (Beta vulgaris L.), carrot (Daucus carota L.) and radish (Raphanus sativus L.) seed to stimulate increase yield

    International Nuclear Information System (INIS)

    Bovi, Jose Eduardo

    2000-01-01

    The research had the aim of evaluating the effects of low doses of Cobalt-60 gamma radiation on seeds of radish (Raphanus sativus L.) cultiva Champion, cultivars Nantes Forto (european origin) and Brasilia (Rio Grande do Sul origin) carrot (Daucus carota L. var. sativus (Hoffm.) Thell), and red beet (Beta vulgaris L.) cultivar Tall Top Early Wonder before sowing, its effects on plant growth, on the yield and roots storage of two tillages: with sowing in the same day of radiation and six days after radiation seeds. The data showed that the seeds radiation did not interfered negatively on plants growth, and the species presented differences as roots production and doses on both plantation: radish with 5,0 Gy and 2,5 Gy doses respectively to the first and the second sowings, Brasilia carrot with 2,5 Gy dose to both sowings. Nantes carrot with 2,5 Gy and 5,0 Gy respectively to the first and the second sowings, and beet with 7,5 Gy and 5,0 Gy respectively to the first and the second plantations. There is not statistics difference by Tukey test (5% and 1%) and none relation between seeds radiation and loss weight on roots storage. (author)

  6. Daily low-dose hCG stimulation during the luteal phase combined with GnRHa triggered IVF cycles without exogenous progesterone

    DEFF Research Database (Denmark)

    Andersen, Claus Yding; Elbaek, Helle Olesen; Alsbjerg, Birgit

    2015-01-01

    antagonist protocol. Two study arms were included both having 125 IU hCG daily for luteal phase support without exogenous progesterone after using a GnRHa trigger for ovulation induction. In both study arms exogenous FSH was stopped on stimulation day 6 and replaced by exogenous hCG that was initiated...... on either stimulation day 2 or day 6. Blood samples were obtained on the day of ovulation induction, on the day of oocyte pickup (OPU) and day OPU + 7. MAIN RESULTS AND THE ROLE OF CHANCE: The mean serum levels of hCG did not exceeded the normal physiological range of LH activity in any samples. Mid...... were seen between groups. LIMITATIONS, REASONS FOR CAUTION: The number of patients included is limited and conclusions need to be verified in a larger RCT. WIDER IMPLICATIONS OF THE FINDINGS: Endogenous production of progesterone may become more attractive as the luteal phase support with levels of LH...

  7. Low doses effects and gamma radiations low dose rates

    International Nuclear Information System (INIS)

    Averbeck, D.

    1999-01-01

    This expose wishes for bringing some definitions and base facts relative to the problematics of low doses effects and low dose rates effects. It shows some already used methods and some actual experimental approaches by focusing on the effects of ionizing radiations with a low linear energy transfer. (N.C.)

  8. Proliferative signaling initiated in ACTH receptors

    Directory of Open Access Journals (Sweden)

    C.F.P. Lotfi

    2000-10-01

    Full Text Available This article reviews recent results of studies aiming to elucidate modes of integrating signals initiated in ACTH receptors and FGF2 receptors, within the network system of signal transduction found in Y1 adrenocortical cells. These modes of signal integration should be central to the mechanisms underlying the regulation of the G0->G1->S transition in the adrenal cell cycle. FGF2 elicits a strong mitogenic response in G0/G1-arrested Y1 adrenocortical cells, that includes a rapid and transient activation of extracellular signal-regulated kinases-mitogen-activated protein kinases (ERK-MAPK (2 to 10 min, b transcription activation of c-fos, c-jun and c-myc genes (10 to 30 min, c induction of c-Fos and c-Myc proteins by 1 h and cyclin D1 protein by 5 h, and d onset of DNA synthesis stimulation within 8 h. ACTH, itself a weak mitogen, interacts with FGF2 in a complex manner, blocking the FGF2 mitogenic response during the early and middle G1 phase, keeping ERK-MAPK activation and c-Fos and cyclin D1 induction at maximal levels, but post-transcriptionally inhibiting c-Myc expression. c-Fos and c-Jun proteins are mediators in both the strong and the weak mitogenic responses respectively triggered by FGF2 and ACTH. Induction of c-Fos and stimulation of DNA synthesis by ACTH are independent of PKA and are inhibited by the PKC inhibitor GF109203X. In addition, ACTH is a poor activator of ERK-MAPK, but c-Fos induction and DNA synthesis stimulation by ACTH are strongly inhibited by the inhibitor of MEK1 PD98059.

  9. Low doses of gamma radiation in soybean

    International Nuclear Information System (INIS)

    Franco, José G.; Franco, Suely S.H.; Villavicencio, Anna L.C.; Arthur, Valter; Arthur, Paula B.; Franco, Caio H.

    2017-01-01

    The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Dry soya seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.210 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. A treatment with four radiation doses was applied as follows: 0 (control); 12.5; 25.0 and 50.0 Gy. Seed germination and harvested of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds number and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were the doses of 12.5 and 50.0 Gy. The results show that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

  10. Low doses of gamma radiation in soybean

    Energy Technology Data Exchange (ETDEWEB)

    Franco, José G.; Franco, Suely S.H.; Villavicencio, Anna L.C., E-mail: zegilmar60@gmail.com, E-mail: gilmita@uol.com.br, E-mail: villavic@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Arthur, Valter; Arthur, Paula B., E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Franco, Caio H. [Universidade Federal de São Paulo (UNIFESP), SP (Brazil). Departamento de Microbiologia, Imunologia e Parasitologia

    2017-07-01

    The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Dry soya seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.210 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. A treatment with four radiation doses was applied as follows: 0 (control); 12.5; 25.0 and 50.0 Gy. Seed germination and harvested of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds number and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were the doses of 12.5 and 50.0 Gy. The results show that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

  11. Low dose irradiation reduces cancer mortality rates

    International Nuclear Information System (INIS)

    Luckey, T.D.

    2000-01-01

    Low doses of ionizing radiation stimulate development, growth, memory, sensual acuity, fecundity, and immunity (Luckey, T.D., ''Radiation Hormesis'', CRC Press, 1991). Increased immune competence reduces cancer mortality rates and provides increased average lifespan in animals. Decreased cancer mortality rates in atom bomb victims who received low dose irradiation makes it desirable to examine populations exposed to low dose irradiation. Studies with over 300,000 workers and 7 million person-years provide a valid comparison of radiation exposed and control unclear workers (Luckey, T.D., Nurture with Ionizing Radiation, Nutrition and Cancer, 34:1-11, 1999). Careful selection of controls eliminated any ''healthy worker effect''. The person-year corrected average indicated the cancer mortality rate of exposed workers was only 51% that of control workers. Lung cancer mortality rates showed a highly significant negative correlation with radon concentrations in 272,000 U.S. homes (Cohen, B.L., Health Physics 68:157-174, 1995). In contrast, radon concentrations showed no effect on lung cancer rates in miners from different countries (Lubin, J.H. Am. J. Epidemiology 140:323-332, 1994). This provides evidence that excessive lung cancer in miners is caused by particulates (the major factor) or toxic gases. The relative risk for cancer mortality was 3.7% in 10,000 Taiwanese exposed to low level of radiation from 60 Co in their steel supported homes (Luan, Y.C. et al., Am. Nuclear Soc. Trans. Boston, 1999). This remarkable finding needs further study. A major mechanism for reduced cancer mortality rates is increased immune competence; this includes both cell and humoral components. Low dose irradiation increases circulating lymphocytes. Macrophage and ''natural killer'' cells can destroy altered (cancer) cells before the mass becomes too large. Low dose irradiation also kills suppressor T-cells; this allows helper T-cells to activate killer cells and antibody producing cells

  12. Topics on study of low dose-effect relationship

    International Nuclear Information System (INIS)

    Yamada, Takeshi; Ohyama, Harumi

    1999-01-01

    It is not exceptional but usually observed that a dose-effect relationship in biosystem is not linear. Sometimes, the low dose-effect relationship appears entirely contrary to the expectation from high dose-effect. This is called a 'hormesis' phenomena. A high dose irradiation inflicts certainly an injury on biosystem. No matter how low the dose may be, an irradiation might inflict some injury on biosystem according to Linear Non-Threshold hypothesis(LNT). On the contrary to the expectation, a low dose irradiation stimulates immune system, and promotes cell proliferation. This is called 'radiation hormesis'. The studies of the radiation hormesis are made on from four points of view as follows: (1) radiation adaptive response, (2) revitalization caused by a low dose stimulation, (3) a low dose response unexpected from the LNT hypothesis, (4) negation of the LNT hypothesis. The various empirical proofs of radiation hormesis are introduced in the report. (M . Suetake)

  13. Health effect of low dose/low dose rate radiation

    International Nuclear Information System (INIS)

    Kodama, Seiji

    2012-01-01

    The clarified and non-clarified scientific knowledge is discussed to consider the cause of confusion of explanation of the title subject. The low dose is defined roughly lower than 200 mGy and low dose rate, 0.05 mGy/min. The health effect is evaluated from 2 aspects of clinical symptom/radiation hazard protection. In the clinical aspect, the effect is classified in physical (early and late) and genetic ones, and is classified in stochastic (no threshold value, TV) and deterministic (with TV) ones from the radioprotection aspect. Although the absence of TV in the carcinogenic and genetic effects has not been proved, ICRP employs the stochastic standpoint from the safety aspect for radioprotection. The lowest human TV known now is 100 mGy, meaning that human deterministic effect would not be generated below this dose. Genetic deterministic effect can be observable only in animal experiments. These facts suggest that the practical risk of exposure to <100 mGy in human is the carcinogenesis. The relationship between carcinogenic risk in A-bomb survivors and their exposed dose are found fitted to the linear no TV model, but the epidemiologic data, because of restriction of subject number analyzed, do not always mean that the model is applicable even below the dose <100 mGy. This would be one of confusing causes in explanation: no carcinogenic risk at <100 mGy or risk linear to dose even at <100 mGy, neither of which is scientifically conclusive at present. Also mentioned is the scarce risk of cancer in residents living in the high background radiation regions in the world in comparison with that in the A-bomb survivors exposed to the chronic or acute low dose/dose rate. Molecular events are explained for the low-dose radiation-induced DNA damage and its repair, gene mutation and chromosome aberration, hypothesis of carcinogenesis by mutation, and non-targeting effect of radiation (bystander effect and gene instability). Further researches to elucidate the low dose

  14. Severe Hypoglycemia due to Isolated ACTH Deficiency in Children: A New Case Report and Review of the Literature

    OpenAIRE

    Torchinsky, Michael Y.; Wineman, Robert; Moll, George W.

    2011-01-01

    Isolated ACTH deficiency causes life-threatening severe hypoglycemia. A 7-year-old girl with hypoglycemia due to this rare disorder is described. Our patient had undetectable plasma ACTH repeatedly and cortisol 0 mcg/dl before and after ACTH 1-24 stimulation. There was no evidence of other pituitary hormone deficiency. Glucocorticoid replacement therapy resulted in resolution of all symptoms and normalization of blood glucose. Previously published data on isolated ACTH deficiency in children ...

  15. Development of Plant Application Technique of Low Dose Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Byung Yeoup; Kim, Jae Sung; Lim, Yong Taek (and others)

    2007-07-15

    The project was carried out to achieve three aims. First, development of application techniques of cell-stimulating effects by low-dose radiation. Following irradiation with gamma-rays of low doses, beneficial effects in crop germination, early growth, and yield were investigated using various plant species and experimental approaches. For the actual field application, corroborative studies were also carried out with a few concerned experimental stations and farmers. Moreover, we attempted to establish a new technique of cell cultivation for industrial mass-production of shikonin, a medicinal compound from Lithospermum erythrorhizon and thereby suggested new application fields for application techniques of low-dose radiation. Second, elucidation of action mechanisms of ionizing radiation in plants. By investigating changes in plant photosynthesis and physiological metabolism, we attempted to elucidate physiological activity-stimulating effects of low-dose radiation and to search for radiation-adaptive cellular components. Besides, analyses of biochemical and molecular biological mechanisms for stimulus-stimulating effects of low-dose radiation were accomplished by examining genes and proteins inducible by low-dose radiation. Third, development of functional crop plants using radiation-resistant factors. Changes in stress-tolerance of plants against environmental stress factors such as light, temperature, salinity and UV-B stress after exposed to low-dose gamma-rays were investigated. Concerned reactive oxygen species, antioxidative enzymes, and antioxidants were also analyzed to develop high value-added and environment-friendly functional plants using radiation-resistant factors. These researches are important to elucidate biological activities increased by low-dose radiation and help to provide leading technologies for improvement of domestic productivity in agriculture and development of high value-added genetic resources.

  16. Development of Plant Application Technique of Low Dose Radiation

    International Nuclear Information System (INIS)

    Chung, Byung Yeoup; Kim, Jae Sung; Lim, Yong Taek

    2007-07-01

    The project was carried out to achieve three aims. First, development of application techniques of cell-stimulating effects by low-dose radiation. Following irradiation with gamma-rays of low doses, beneficial effects in crop germination, early growth, and yield were investigated using various plant species and experimental approaches. For the actual field application, corroborative studies were also carried out with a few concerned experimental stations and farmers. Moreover, we attempted to establish a new technique of cell cultivation for industrial mass-production of shikonin, a medicinal compound from Lithospermum erythrorhizon and thereby suggested new application fields for application techniques of low-dose radiation. Second, elucidation of action mechanisms of ionizing radiation in plants. By investigating changes in plant photosynthesis and physiological metabolism, we attempted to elucidate physiological activity-stimulating effects of low-dose radiation and to search for radiation-adaptive cellular components. Besides, analyses of biochemical and molecular biological mechanisms for stimulus-stimulating effects of low-dose radiation were accomplished by examining genes and proteins inducible by low-dose radiation. Third, development of functional crop plants using radiation-resistant factors. Changes in stress-tolerance of plants against environmental stress factors such as light, temperature, salinity and UV-B stress after exposed to low-dose gamma-rays were investigated. Concerned reactive oxygen species, antioxidative enzymes, and antioxidants were also analyzed to develop high value-added and environment-friendly functional plants using radiation-resistant factors. These researches are important to elucidate biological activities increased by low-dose radiation and help to provide leading technologies for improvement of domestic productivity in agriculture and development of high value-added genetic resources

  17. Statistical and low dose response

    International Nuclear Information System (INIS)

    Thorson, M.R.; Endres, G.W.R.

    1981-01-01

    The low dose response and the lower limit of detection of the Hanford dosimeter depend upon may factors, including the energy of the radiation, whether the exposure is to be a single radiation or mixed fields, annealing cycles, environmental factors, and how well various batches of TLD materials are matched in the system. A careful statistical study and sensitivity analysis were performed to determine how these factors influence the response of the dosimeter system. Estimates have been included in this study of the standard deviation of calculated dose for various mixed field exposures from 0 to 1000 mrem

  18. The diagnosis of nonclassic congenital adrenal hyperplasia due to 21-hydroxylase deficiency, based on serum basal or post-ACTH stimulation 17-hydroxyprogesterone, can lead to false-positive diagnosis.

    Science.gov (United States)

    Ambroziak, Urszula; Kępczyńska-Nyk, Anna; Kuryłowicz, Alina; Małunowicz, Ewa Maria; Wójcicka, Anna; Miśkiewicz, Piotr; Macech, Magdalena

    2016-01-01

    As nonclassic congenital adrenal hyperplasia (NCCAH) needs to be taken into account in women with hyperandrogenism, we aimed to assess whether the recommended level of poststimulated 17OHP ≥30 nmol/l confirms NCCAH. Forty, consecutive women with biochemical and/or clinical hyperandrogenism (aged 25·4, 18-38) suspected of having NCCAH were recruited to the study. In patients with 17OHP level between 5·1 and 29·9 nmol/l an ACTH stimulation test was performed. In patients with basal or poststimulated 17OHP ≥30 nmol/l, twenty-four-hour urinary steroid profile (USP) analysis was performed and CYP21A2 mutation was assessed. In selected patients with poststimulated 17OHP basal or poststimulated 17OHP ≥30 nmol/l (group A) and with poststimulated 17OHP basal or poststimulated 17OHP ≥30 nmol/l was found in 21, but NCCAH was confirmed by USP followed by genetic testing only in 5 (24%). Four patients were diagnosed as heterozygotes, and in twelve, no CYP21A2 mutation was detected. The diagnosis of NCCAH based only on serum 17OHP measurements (basal or poststimulated) may lead to false-positive diagnosis when performed by immunoassay with a cut-off value of ≥30 nmol/l. The definitive diagnosis can be established based on USP and/or genetic testing. © 2015 John Wiley & Sons Ltd.

  19. 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

    applications of NEOTRANS2, indicate that nonlinear threshold-type, dose-response relationships for excess stochastic effects (problematic nonlethal mutations, neoplastic transformation) should be expected after exposure to low linear energy transfer (LET) gamma rays or gamma rays in combination with high-LET alpha radiation. Similar thresholds are expected for low-dose-rate low-LET beta irradiation. We attribute the thresholds to low-dose, low-LET radiation induced protection against spontaneous mutations and neoplastic transformations. The protection is presumed mainly to involve selective elimination of problematic cells via apoptosis. Low-dose, low-LET radiation is presumed to trigger wide-area cell signaling, which in turn leads to problematic bystander cells (e.g., mutants, neoplastically transformed cells) selectively undergoing apoptosis. Thus, this protective bystander effect leads to selective elimination of problematic cells (a tissue cleansing process in vivo). However, this protective bystander effects is a different process from low-dose stimulation of the immune system. Low-dose, low-LET radiation stimulation of the immune system may explain why thresholds for inducing excess cancer appear much larger (possibly more than 100-fold larger) than thresholds for inducing excess mutations and neoplastic transformations, when the dose rate is low. For ionizing radiation, the current risk assessment paradigm is such that the relative risk (RR) is always ¡Ý 1, no matter how small the dose. Our research results indicate that for low-dose or low-dose-rate, low-LET irradiation, RR < 1 may be more the rule than the exception. Directly tied to the current RR paradigm are the billion-dollar cleanup costs for radionuclide-contaminated DOE sites. Our research results suggest that continued use of the current RR paradigm for which RR ¡Ý 1 could cause more harm than benefit to society (e.g., by spreading unwarranted fear about phantom excess risks associated with low-dose low

  20. Ameliorative effects of low dose/low dose-rate irradiation on reactive oxygen species-related diseases model mice

    International Nuclear Information System (INIS)

    Nomura, Takaharu

    2008-01-01

    Living organisms have developed complex biological system which protects themselves against environmental radiation, and irradiation with proper dose, dose-rate and irradiation time can stimulate their biological responses against oxidative stress evoked by the irradiation. Because reactive oxygen species are involved in various human diseases, non-toxic low dose/low dose-rate radiation can be utilized for the amelioration of such diseases. In this study, we used mouse experimental models for fatty liver, nephritis, diabetes, and ageing to elucidate the ameliorative effect of low dose/low dose-rate radiation in relation to endogenous antioxidant activity. Single irradiation at 0.5 Gy ameliorates carbon tetrachloride-induced fatty liver. The irradiation increases hepatic anti-oxidative system involving glutathione and glutathione peroxidase, suggesting that endogenous radical scavenger is essential for the ameliorative effect of low dose radiation on carbon tetrachloride-induced fatty liver. Single irradiation at 0.5 Gy ameliorates ferric nitrilotriacetate-induced nephritis. The irradiation increases catalase and decreases superoxide dismutase in kidney. The result suggests that low dose radiation reduced generation of hydroxide radical generation by reducing cellular hydroperoxide level. Single irradiation at 0.5 Gy at 12 week of age ameliorates incidence of type I diabetes in non-obese diabetic (NOD) mice through the suppression of inflammatory activity of splenocytes, and resultant apoptosis of β-cells in pancreas. The irradiation activities of superoxide dismutase and catalase, which coordinately diminish intracellular reactive oxygen species. Continuous irradiation at 0.70 mGy/hr from 10 week of age elongates life span, and suppresses alopecia in type II diabetesmice. The irradiation improved glucose clearance without affecting insulin-resistance, and increased pancreatic catalase activity. The results suggest that continuous low dose-rate irradiation protect

  1. ACTH Regulation of Adrenal SR-B1

    Directory of Open Access Journals (Sweden)

    Wen-Jun eShen

    2016-05-01

    Full Text Available The adrenal gland is one of the prominent sites for steroid hormone synthesis. Lipoprotein-derived cholesterol esters delivered via scavenger receptor, class B type 1 (SR-B1 constitute the dominant source of cholesterol for steroidogenesis, particularly in rodents. ACTH stimulates steroidogenesis through downstream actions on multiple components involved in steroidogenesis. Both acute and chronic ACTH treatment can modulate SR-B1 function including its transcription, its post transcriptional stability, its phosphorylation and dimerization status, as well as its interaction with other protein partners; all of which result in changes in the ability of SR-B1 to mediate HDL-cholesterol ester uptake and the supply of cholesterol for conversion to steroids. Here we provide a review of the recent findings on the regulation of adrenal SR-B1 function by ACTH.

  2. Fournier's gangrene during ACTH therapy.

    Science.gov (United States)

    Numoto, Shingo; Kurahashi, Hirokazu; Azuma, Yoshiteru; Numaguchi, Atsushi; Nakahara, Kozaburo; Tainaka, Takahisa; Takasu, Michihiko; Yamakawa, Kiyoshi; Nago, Nozomi; Muto, Taichiro; Kitagawa, Yoshiro; Okumura, Akihisa

    2017-05-01

    Fournier's gangrene is an infectious necrotizing fasciitis of the perineal, genital, or perianal regions and is uncommon in children. Adrenocorticotropic hormone (ACTH) is effective for the treatment of infantile spasms; however, suppression of immune function is one of the major adverse effects of this approach. We encountered a 2-month-old boy with infantile spasms that had been treated with ACTH and had developed complicating Fournier's gangrene. Strangulation of a right inguinal hernia was observed after ACTH treatment. Although surgical repair was successful and no intestinal injuries were detected, swelling and discoloration of the right scrotum developed in association with pyrexia and a severe inflammatory response. A scrotal incision revealed pus with a putrid smell. The patient was subsequently diagnosed with Fournier's gangrene complicated by septic shock and disseminated intravascular coagulation. Extensive debridement and intensive care was performed. Enterobactor aerogenes, methicillin-resistant Staphylococcus aureus, and Enterococcus faecalis were isolated from the pus. Meropenem, teicoplanin, and clindamycin were administered to control the bacterial infection. The patient was discharged from the intensive care unit without any obvious neurological sequelae. Suppression of immune function associated with ACTH therapy may have been related to the development of Fournier's gangrene in this case. Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  3. Topics on study of low dose-effect relationship

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Takeshi [Toho Univ., School of Medicine, Tokyo (Japan); Ohyama, Harumi

    1999-09-01

    It is not exceptional but usually observed that a dose-effect relationship in biosystem is not linear. Sometimes, the low dose-effect relationship appears entirely contrary to the expectation from high dose-effect. This is called a 'hormesis' phenomena. A high dose irradiation inflicts certainly an injury on biosystem. No matter how low the dose may be, an irradiation might inflict some injury on biosystem according to Linear Non-Threshold hypothesis(LNT). On the contrary to the expectation, a low dose irradiation stimulates immune system, and promotes cell proliferation. This is called 'radiation hormesis'. The studies of the radiation hormesis are made on from four points of view as follows: (1) radiation adaptive response, (2) revitalization caused by a low dose stimulation, (3) a low dose response unexpected from the LNT hypothesis, (4) negation of the LNT hypothesis. The various empirical proofs of radiation hormesis are introduced in the report. (M . Suetake)

  4. Low Dose Risk, Decisions, and Risk Communication

    International Nuclear Information System (INIS)

    Flynn, James

    2002-01-01

    The overall research objective was to establish new levels of information about how people, groups, and communities respond to low dose radiation exposure. This is basic research into the social psychology of individual, group, and community responses to radiation exposures. The results of this research are directed to improving risk communication and public participation in management of environmental problems resulting from low dose radiation

  5. alpha-Melanocyte-stimulating-hormone precursors in the pig pituitary

    DEFF Research Database (Denmark)

    Fenger, M

    1986-01-01

    The occurrence of intermediates from the processing of ACTH-(1-39) [adrenocorticotropic hormone-(1-39)] to alpha-melanocyte-stimulating hormone was investigated in normal pig pituitaries by the use of sensitive and specific radioimmunoassays for ACTH-(1-13), ACTH-(1-14), ACTH-(1-13)-NH2 and ACTH-(1......) were detected in lower amounts in both the intermediate lobe and the anterior lobe. ACTH-(1-17), ACTH-(1-13) and their acetylated analogues could not be detected in the anterior lobe or the intermediate lobe. The results suggest that an endopeptidase initially cleaves ACTH-(1-39) at the Lys-16-Arg-17...... bond. ACTH-(1-16) is then processed by a pituitary carboxypeptidase to ACTH-(1-14) and ACTH-(17-39) by the aminopeptidase to ACTH-(18-39)....

  6. Femtogram determination of ACTH by bioradioimmunoassay

    International Nuclear Information System (INIS)

    Bruni, G.; Dal Pra, P.; Segre, G.

    1979-01-01

    A bioradioimmunoassay is described for determining adrenocorticotropic hormone (ACTH) levels in biological fluids. Slices of guinea pig's adrenal gland surviving in vitro and depleted of their cortisol content were used. When challenged with ACTH, the slices release newly synthesised cortisol into the medium which is then determined by radioimmunoasssay. A log-linear relationship was evident between added ACTH and the cortisol measured in the medium. Unlike previous methods, the sensitivity of this assay allows the determination of 0.5 femtogram (10 -15 g) of ACTH. A good correlation was observed when rat plasma ACTH levels were determined by the present bioassay method and by an ACTH radioimmunoassay. Mean values of plasma ACTH determined by the present method are shown for man, child, guinea pig, rabbit, rat, and hamster. (UK)

  7. Femtogram determination of ACTH by bioradioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Bruni, G; Dal Pra, P; Segre, G [Siena Univ. (Italy). Inst. Pharmacology

    1979-11-01

    A bioradioimmunoassay is described for determining adrenocorticotropic hormone (ACTH) levels in biological fluids. Slices of guinea pig's adrenal gland surviving in vitro and depleted of their cortisol content were used. When challenged with ACTH, the slices release newly synthesised cortisol into the medium which is then determined by radioimmunoasssay. A log-linear relationship was evident between added ACTH and the cortisol measured in the medium. Unlike previous methods, the sensitivity of this assay allows the determination of 0.5 femtogram (10/sup -15/g) of ACTH. A good correlation was observed when rat plasma ACTH levels were determined by the present bioassay method and by an ACTH radioimmunoassay. Mean values of plasma ACTH determined by the present method are shown for man, child, guinea pig, rabbit, rat, and hamster.

  8. The role of ACTH and glucocorticoids in nonenzymatic fibrinolysis during immobilization stress in animals

    Science.gov (United States)

    Kudryashov, B. A.; Shapiro, F. B.; Lomovskaya, E. G.; Lyapina, L. A.

    1980-01-01

    The role of the altered hormonal status of an organism in the activation of the anticoagulative system during stress is investigated. The 30 minute immobilization stress was shown to raise significantly the nonenzymatic fibrinolytic activity of blood in rats. Combined with adrenocorticotropin (ACTH) the effect is still greater. Intravenous administration of 0.2 m1 0.01 percent solution of protamine sulphate prevented the nonenzymatic fibrinolysis induced by the stress. Administration of ACTH after protomine sulphate again raised the fibrinolysis. This suggests that ACTH stimulates the release of heparin.

  9. In vitro assay for ACTH-releasing activity using ACTH radioimmunoassay. ACTH releasing activities by various drugs

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, K; Takahara, J; Hosogi, H; Ofuji, N; Yasuhara, T [Okayama Univ. (Japan). School of Medicine

    1976-02-01

    This report deals with an in vitro assay of ACTH releasing activity utilizing pituitary incubation combined with ACTH radioimmunoassay. Half of a rat pituitary was preincubated in 2ml Krebs Ringer bicarbonate buffer containing 0.2% glucose and 0.25% BSA (KRBG-BSA) for 1.5 hr (45 min x 2). The medium was replaced by 1 ml KRBG-BSA and incubated for 30 min. Then the medium was again replaced by 1 ml KRBG-BSA or KRBG-BSA containing test materials and incubated for another 30 min. The amount of ACTH assayed by radioimmunoassay in the 2nd 30 min incubation was compared with that in the 1st 30 min incubation, and the result was expressed as a percentage. In the ACTH radioimmunoassay, anti-ACTH serum was diluted to 1:1,500-3,000. The /sup 125/I-..cap alpha../sup 1 -24/ACTH-antibody system was not affected by lysine-vasopressin (LVP), arginine-vasopressin (AVP), rat's pituitary LH, GH or prolactin. Human /sup 1 -39/ACTH was used as the ACTH standard. The dilution curve of the incubation medium was parallel to the standard curve. Reproducibility of immunoassayable ACTH within-assay was 174 +- 5.0 pg/tube (CV=2.9%). A log dose-relationship was observed between the amounts of stalk median eminence extracts (SME; NIAMDD) added to the incubation medium and its ACTH releasing activities. The sensitivity of this assay method was at least 0.1 SME or 10 mU of LVP and AVP. Using this method, it was found that LVP, AVP, norepinephrine (100 ng/ml--200 ng/ml) and 5-hydroxytryptophane (1 ..mu..g/ml) had ACTH releasing activities, but LH-RH, TRH, glucagon, dopamine, phentolamine, propranolol, haloperidol, prostaglandin E/sub 1/ and indomethacin did not affect the release of ACTH.

  10. An unusual case of ectopic ACTH syndrome.

    Science.gov (United States)

    Willhauck, M J; Pöpperl, G; Rachinger, W; Giese, A; Auernhammer, C J; Spitzweg, C

    2012-02-01

    Ectopic ACTH-syndrome is a rare cause of Cushing's disease. Despite extensive diagnostic procedures the source of ACTH secretion often remains occult. This case describes a 45-year old woman with an ectopic Cushing's syndrome. Extensive imaging procedures including CT scan of chest and abdomen, octreotide scan and MRI of the chest and pituitary did not reveal the source of ACTH secretion. In consideration of an occult source of ACTH secretion we started a therapeutic trial with cabergoline (0.5 mg/d), a dopamine receptor agonist, which has been shown to be effective in ectopic Cushing's syndrome. 2 months after cabergoline treatment had been initiated, ACTH and cortisol levels normalized in association with significant improvement of the clinical symptoms. During follow-up a [(68)Ga-DOTA-dPhe(1), Tyr(3)]-octreotate ([(68)Ga-DOTA]-TATE) PET-CT was performed revealing a somatostatin receptor positive lesion in the right sphenoidal sinus suggesting the source of ACTH secretion. The patient was cured by transnasal resection of the polypoid lesion, which was immunohistochemically characterized as an ACTH-positive neuroendocrine tumor. This case report demonstrates the management of ectopic ACTH-syndrome by molecularly -targeted therapy with dopamine receptor -agonists as well as improved detection of the ectopic ACTH source by novel imaging modalities, such as [(68)Ga-DOTA]-TATE PET specifically targeting somatostatin receptor subtype-2 with high affinity. © J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York.

  11. Reduced oxygen enhancement ratio at low doses

    International Nuclear Information System (INIS)

    Palcic, B.; Skarsgard, L.D.

    1984-01-01

    The oxygen depletion rate in cell suspensions was measured using a Clark electrode. It was found that under experimental conditions used in this laboratory for hypoxic irradiations, the oxygen levels before the start of irradiation are always below 0.1μm, the levels which could give any significant enhancement to radiation inactivation by x-rays. The measured O/sub 2/ depletion rates were comparable to those reported in the literature. Chinese hamster cells (CHO) were made hypoxic by gas exchange, combined with metabolic consumption of oxygen by cells at 37 0 C. Full survival curves were determined in the dose range 0 to 3Gy using the low dose survival assay. The results confirmed the authors' earlier finding that the OER decreases at low doses. The authors therefore believe that the dose-dependent OER is a true radiobiological phenomenon and not an artifact of the experimental method used in the low dose survival assay

  12. LOW DOSE RISK, DECISIONS, and RISK COMMUNICATION

    International Nuclear Information System (INIS)

    Flynn, James

    2002-01-01

    The objective of this project is to conduct basic research on how people receive, evaluate, and form positions on scientific information and its relationship to low-dose radiation exposure. There are three major areas of study in our research program. First is the development of theories, frameworks and concepts essential to guiding data collection and analysis. The second area is a program of experimental studies on risk perception, evaluation of science information, and the structure of individual positions regarding low-dose exposures. Third is the community-level studies to examine and record how the social conditions, under which science communications take place, influence the development of attitudes and opinions about: low-dose exposures, the available management options, control of radiation risks, and preferences for program and policy goals

  13. Exposure to low doses of ionizing radiations

    International Nuclear Information System (INIS)

    Le Guen, B.

    2008-01-01

    The author discusses the knowledge about the effects of ionizing radiations on mankind. Some of them have been well documented (skin cancer and leukaemia for the pioneer scientists who worked on radiations, some other types of cancer for workers who handled luminescent paints, rock miners, nuclear explosion survivors, patients submitted to radiological treatments). He also evokes the issue of hereditary cancers, and discusses the issue of low dose irradiation where some surveys can now be performed on workers. He discusses the biological effects of these low doses. He outlines that many questions remain about these effects, notably the influence of dose level and of dose rate level on the biological reaction

  14. Evaluation of aldosterone-and cortisol levels in blood plasma in normal conditions of ingestion of sodium and potassium, after saline-increase and depletion, in regard to position, and after stimulation with ACTH and angiotensin II

    International Nuclear Information System (INIS)

    Okada, H.

    1979-01-01

    Methods for the determination of plasma aldosterone and cortisol, by radioimmunoassay, were performed utilizing highly specific antisera. With this methodology it was possible to evaluate cortisol and aldosterone secretion, in six normal subjects, submitted to a basal rice diet on standing and recumbent positions, the effects of exogenous cortrosyn (β1-24 ACTH) and angiotensin II and the same manoevres with progressively increased Na + content of the diet. Aldosterone basal levels decreased with the increase of Na + content in the diet. However, there were no significant differences between the relative increments observed on the recumbent position, at the three levels of sodium intake. The relative increase of plasma aldosterone after ACTH was similar for each basal level of aldosterone induced by different sodium intakes. The responsiveness of aldosterone secretion to cortrosyn and standing position was similar, with no relation to the sodium intake. The infusion of angiotensin II induced an increase in plasma aldosterone, and the relative increment in the levels of the hormone were higher with high sodium than on the rice diet. The average basal cortisol value at the different levels of sodium intake was significantly different being greater on the basal, rice diet, and there was a decrease in cortisol level after recumbency, with the theree diets. The injection of ACTH induced similar cortisol secretion with no relation to the sodium intake. The infusion of non-hypertensive doses of angiotensin II resulted in an anomalous fall in cortisol level, probably because of 'shunt' of substrates to biosynthesis with the added effect of cortisol diurnal rhythmycity. (Author) [pt

  15. Carcinogenesis induced by low-dose radiation

    Directory of Open Access Journals (Sweden)

    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.

  16. Effect of low dose ionizing radiation upon concentration of

    International Nuclear Information System (INIS)

    Viliae, M.; Kraljeviae, P.; Simpraga, M.; Miljaniae, S.

    2004-01-01

    It is known that low dose ionizing radiation might have stimulating effects (Luckey, 1982, Kraljeviae, 1988). This fact has also been confirmed in the previous papers of Kraljeviae et al. (2000-2000a; 2001). Namely, those authors showed that irradiation of chicken eggs before incubation by a low dose of 0.15 Gy gamma radiation increases the activity aspartateaminotrasferases (AST) and alanine-aminotransferases (ALT) in blood plasma of chickens hatched from irradiated eggs, as well as growth of chickens during the fattening period. Low doses might also cause changes in the concentration of some biochemical parameters in blood plasma of the same chickens such as changes in the concentration of total proteins, glucose and cholesterol. In this paper, an attempt was made to investigate the effects of low dose gamma radiation upon the concentration of sodium and potassium in the blood plasma of chickens which were hatched from eggs irradiated on the 19th day of incubation by dose of 0.15 Gy. Obtained results were compared with the results from the control group (chickens hatched from nonirradiated eggs). After hatching, all other conditions were the same for both groups. Blood samples were drawn from heart, and later from the wing vein on days 1, 3, 5, 7, 10, 20, 30 and 42. The concentration of sodium and potassium was determined spectrophotometrically by atomic absorbing spectrophotometer Perkin-Elmer 1100B. The concentration of sodium and potassium in blood plasma of chickens hatched from eggs irradiated on the 19th day of incubation by dose of 0.15 Gy indicated a statistically significant increase (P>0.01) only on the first day of the experiment. Obtained results showed that irradiation of eggs on the 19th day of incubation by dose of 0.15 Gy gamma radiation could have effects upon the metabolism of electrolytes in chickens. (Author)

  17. Low-dose strontium stimulates osteogenesis but high-dose doses cause apoptosis in human adipose-derived stem cells via regulation of the ERK1/2 signaling pathway.

    Science.gov (United States)

    Aimaiti, Abudousaimi; Maimaitiyiming, Asihaerjiang; Boyong, Xu; Aji, Kaisaier; Li, Cao; Cui, Lei

    2017-12-19

    Strontium is a widely used anti-osteoporotic agent due to its dual effects on inhibiting bone resorption and stimulating bone formation. Thus, we studied the dose response of strontium on osteo-inductive efficiency in human adipose-derived stem cells (hASCs). Qualitative alkaline phosphatase (ALP) staining, quantitative ALP activity, Alizarin Red staining, real-time polymerase chain reaction and Western blot were used to investigate the in vitro effects of a range of strontium concentrations on hASC osteogenesis and associated signaling pathways. In vitro work revealed that strontium (25-500 μM) promoted osteogenic differentiation of hASCs according to ALP activity, extracellular calcium deposition, and expression of osteogenic genes such as runt-related transcription factor 2, ALP, collagen-1, and osteocalcin. However, osteogenic differentiation of hASCs was significantly inhibited with higher doses of strontium (1000-3000 μM). These latter doses of strontium promoted apoptosis, and phosphorylation of ERK1/2 signaling was increased and accompanied by the downregulation of Bcl-2 and increased phosphorylation of BAX. The inhibition of ERK1/2 decreased apoptosis in hASCs. Lower concentrations of strontium facilitate osteogenic differentiation of hASCs up to a point; higher doses cause apoptosis of hASCs, with activation of the ERK1/2 signaling pathway contributing to this process.

  18. Mammography-oncogenecity at low doses

    International Nuclear Information System (INIS)

    Heyes, G J; Mill, A J; Charles, M W

    2009-01-01

    Controversy exists regarding the biological effectiveness of low energy x-rays used for mammography breast screening. Recent radiobiology studies have provided compelling evidence that these low energy x-rays may be 4.42 ± 2.02 times more effective in causing mutational damage than higher energy x-rays. These data include a study involving in vitro irradiation of a human cell line using a mammography x-ray source and a high energy source which matches the spectrum of radiation observed in survivors from the Hiroshima atomic bomb. Current radiation risk estimates rely heavily on data from the atomic bomb survivors, and a direct comparison between the diagnostic energies used in the UK breast screening programme and those used for risk estimates can now be made. Evidence highlighting the increase in relative biological effectiveness (RBE) of mammography x-rays to a range of x-ray energies implies that the risks of radiation-induced breast cancers for mammography x-rays are potentially underestimated by a factor of four. A pooled analysis of three measurements gives a maximal RBE (for malignant transformation of human cells in vitro) of 4.02 ± 0.72 for 29 kVp (peak accelerating voltage) x-rays compared to high energy electrons and higher energy x-rays. For the majority of women in the UK NHS breast screening programme, it is shown that the benefit safely exceeds the risk of possible cancer induction even when this higher biological effectiveness factor is applied. The risk/benefit analysis, however, implies the need for caution for women screened under the age of 50, and particularly for those with a family history (and therefore a likely genetic susceptibility) of breast cancer. In vitro radiobiological data are generally acquired at high doses, and there are different extrapolation mechanisms to the low doses seen clinically. Recent low dose in vitro data have indicated a potential suppressive effect at very low dose rates and doses. Whilst mammography is a low

  19. Severe Hypoglycemia due to Isolated ACTH Deficiency in Children: A New Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Michael Y. Torchinsky

    2011-01-01

    Full Text Available Isolated ACTH deficiency causes life-threatening severe hypoglycemia. A 7-year-old girl with hypoglycemia due to this rare disorder is described. Our patient had undetectable plasma ACTH repeatedly and cortisol 0 mcg/dl before and after ACTH 1-24 stimulation. There was no evidence of other pituitary hormone deficiency. Glucocorticoid replacement therapy resulted in resolution of all symptoms and normalization of blood glucose. Previously published data on isolated ACTH deficiency in children is summarized. Review of the literature showed that the prevalence of this condition could be underestimated in the neonatal period and in Prader-Willi syndrome. Isolated ACTH deficiency occurs in older children as well as in neonates.

  20. New risk estimates at low doses

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1992-01-01

    The age of molecular radiation epidemiology may be at hand. The techniques are available to establish with the degree of precision required to determine whether agent-specific mutations can be identified consistently. A concerted effort to examine radiation-induced changes in as many relevant genes as possible appears to be justified. Cancers in those exposed to low doses of ionizing radiation should be chosen for the investigation. Parallel studies of radiation-induced cancers in experimental animals would not only complement the human studies, but perhaps reveal approaches to extrapolation of risk estimates across species. A caveat should be added to this optimistic view of what molecular studies might contribute to the knotty problem of risk estimates at low doses. The suggestions are made by one with no expertise in the field of molecular biology

  1. Cytogenetic effects of low-dose radiation

    International Nuclear Information System (INIS)

    Metalli, P.

    1983-01-01

    The effects of ionizing radiation on chromosomes have been known for several decades and dose-effect relationships are also fairly well established in the mid- and high-dose and dose-rate range for chromosomes of mammalian cells. In the range of low doses and dose rates of different types of radiation few data are available for direct analysis of the dose-effect relationships, and extrapolation from high to low doses is still the unavoidable approach in many cases of interest for risk assessment. A review is presented of the data actually available and of the attempts that have been made to obtain possible generalizations. Attention is focused on some specific chromosomal anomalies experimentally induced by radiation (such as reciprocal translocations and aneuploidies in germinal cells) and on their relevance for the human situation. (author)

  2. Epigenomic Adaptation to Low Dose Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gould, Michael N. [Univ. of Wisconsin, Madison, WI (United States)

    2015-06-30

    The overall hypothesis of this grant application is that the adaptive responses elicited by low dose ionizing radiation (LDIR) result in part from heritable DNA methylation changes in the epigenome. In the final budget period at the University of Wisconsin-Madison, we will specifically address this hypothesis by determining if the epigenetically labile, differentially methylated regions (DMRs) that regulate parental-specific expression of imprinted genes are deregulated in agouti mice by low dose radiation exposure during gestation. This information is particularly important to ascertain given the 1) increased human exposure to medical sources of radiation; 2) increased number of people predicted to live and work in space; and 3) enhanced citizen concern about radiation exposure from nuclear power plant accidents and terrorist ‘dirty bombs.’

  3. Role of changes in functional status of hypothalamic-pituitary-adrenocortical axis in immunoenhancement after low dose radiation

    International Nuclear Information System (INIS)

    Liu Shuzheng; Zhao Yong; Han Zhenbo

    1994-01-01

    Whole-body irradiation (WBI) of mice with 75 mGy X-rays caused increase in 5-hydroxytryptamine (5HT) content of hypothalamus and decrease in serum adrenocorticotropic hormone (ACTH) and corticosterone (CS) level, accompanied with potentiation of immune functions, expressed as increased spontaneous incorporation of 3 H-TdR into thymocytes, augmented proliferative reaction of the splenocytes to Con A and increased production of interleukin-2 by the splenocytes. After intra hypothalamic injection of 5HT there occurred a lowering of serum ACTH level and enhancement of immune reactivity of the splenic and thymic lymphocytes. It is assumed that low dose radiation could influence the central 5-hydroxytryptaminergic neurons causing increase in hypothalamic 5HT content and this, in turn, decreases pituitary secretion of ACTH with a down-regulation of the adrenocortical function. This would partially release the tonic suppression normally exerted on the immune organs by the hypothalamic-pituitary-adrenocortical axis, thus leading to potentiation of immune functions. These neuroendocrine changes should be considered as an important factor in the analysis of the mechanism of immunoenhancement after WBI with low doses

  4. Radiation effects of high and low doses

    International Nuclear Information System (INIS)

    El-Naggar, A.M.

    1998-01-01

    The extensive proliferation of the uses and applications of atomic and nuclear energy resulted in possible repercussions on human health. The prominent features of the health hazards that may be incurred after exposure to high and low radiation doses are discussed. The physical and biological factors involved in the sequential development of radiation health effects and the different cellular responses to radiation injury are considered. The main criteria and features of radiation effects of high and low doses are comprehensively outlined

  5. Aged PROP1 deficient dwarf mice maintain ACTH production.

    Directory of Open Access Journals (Sweden)

    Igor O Nasonkin

    Full Text Available Humans with PROP1 mutations have multiple pituitary hormone deficiencies (MPHD that typically advance from growth insufficiency diagnosed in infancy to include more severe growth hormone (GH deficiency and progressive reduction in other anterior pituitary hormones, eventually including adrenocorticotropic hormone (ACTH deficiency and hypocortisolism. Congenital deficiencies of GH, prolactin, and thyroid stimulating hormone have been reported in the Prop1(null (Prop1(-/- and the Ames dwarf (Prop1(df/df mouse models, but corticotroph and pituitary adrenal axis function have not been thoroughly investigated. Here we report that the C57BL6 background sensitizes mutants to a wasting phenotype that causes approximately one third to die precipitously between weaning and adulthood, while remaining homozygotes live with no signs of illness. The wasting phenotype is associated with severe hypoglycemia. Circulating ACTH and corticosterone levels are elevated in juvenile and aged Prop1 mutants, indicating activation of the pituitary-adrenal axis. Despite this, young adult Prop1 deficient mice are capable of responding to restraint stress with further elevation of ACTH and corticosterone. Low blood glucose, an expected side effect of GH deficiency, is likely responsible for the elevated corticosterone level. These studies suggest that the mouse model differs from the human patients who display progressive hormone loss and hypocortisolism.

  6. Estimation of radiation risks at low dose

    International Nuclear Information System (INIS)

    1990-04-01

    The report presents a review of the effects caused by radiation in low doses, or at low dose rates. For the inheritable (or ''genetic''), as well as for the cancer producing effects of radiation, present evidence is consistent with: (a) a non-linear relationship between the frequency of at least some forms of these effects, with comparing frequencies caused by doses many times those received annually from natural sources, with those caused by lower doses; (b) a probably linear relationship, however, between dose and frequency of effects for dose rates in the region of that received from natural sources, or at several times this rate; (c) no evidence to indicate the existence of a threshold dose below which such effects are not produced, and a strong inference from the mode of action of radiation on cells at low dose rates that no such thresholds are likely to apply to the detrimental, cancer-producing or inheritable, effects resulting from unrepaired damage to single cells. 19 refs

  7. Deep learning for low-dose CT

    Science.gov (United States)

    Chen, Hu; Zhang, Yi; Zhou, Jiliu; Wang, Ge

    2017-09-01

    Given the potential risk of X-ray radiation to the patient, low-dose CT has attracted a considerable interest in the medical imaging field. Currently, the main stream low-dose CT methods include vendor-specific sinogram domain filtration and iterative reconstruction algorithms, but they need to access raw data whose formats are not transparent to most users. Due to the difficulty of modeling the statistical characteristics in the image domain, the existing methods for directly processing reconstructed images cannot eliminate image noise very well while keeping structural details. Inspired by the idea of deep learning, here we combine the autoencoder, deconvolution network, and shortcut connections into the residual encoder-decoder convolutional neural network (RED-CNN) for low-dose CT imaging. After patch-based training, the proposed RED-CNN achieves a competitive performance relative to the-state-of-art methods. Especially, our method has been favorably evaluated in terms of noise suppression and structural preservation.

  8. Modification of damage following low doses

    International Nuclear Information System (INIS)

    Braby, L.A.; Nelson, J.M.; Metting, N.F.

    1988-01-01

    At very low doses the damage-interaction mechanism is responsible for very little lethal or potentially lethal damage, and repair of the latter should essentially disappear. An alternative model suggests that potentially lethal damage is either repaired with a constant half time or misrepaired at a rate which is proportional to the square of the damage concentration. In this case, as the dose decreases, the probability of misrepair decreases faster than the probability of repair, and repair becomes a more pronounced feature of the cell response. Since the consequence of unrepaired damage is an important question in determining the effects of low doses of radiation delivered at low dose rates, we have attempted to determine which of these two types of models is consistent with the response of plateau-phase CHO cells. In the earlier experiments, there was no indication of repair after a 50-rad exposure with a 24-hour split dose or plating delay; in fact, immediate plating resulted in survival slightly above control and delayed plating in survival slightly below the control value

  9. Biological effects of low doses of radiation at low dose rate

    International Nuclear Information System (INIS)

    1996-05-01

    The purpose of this report was to examine available scientific data and models relevant to the hypothesis that induction of genetic changes and cancers by low doses of ionizing radiation at low dose rate is a stochastic process with no threshold or apparent threshold. Assessment of the effects of higher doses of radiation is based on a wealth of data from both humans and other organisms. 234 refs., 26 figs., 14 tabs

  10. Multiple sclerosis, relapses, and the mechanism of action of adrenocorticotropic hormone (ACTH

    Directory of Open Access Journals (Sweden)

    Amy ePerrin Ross

    2013-03-01

    Full Text Available Relapses in multiple sclerosis (MS are disruptive and frequently disabling for patients, and their treatment is often a challenge to clinicians. Despite progress in the understanding of the pathophysiology of MS and development of new treatments for long-term management of MS, options for treating relapses have not changed substantially over the past few decades. Corticosteroids, a component of the HPA axis that modulate immune responses and reduce inflammation, are currently the mainstay of relapse treatment. Adrenocorticotropic hormone (ACTH gel is another treatment option. Although it has long been assumed that the efficacy of ACTH in treating relapses depends on the peptide’s ability to increase endogenous corticosteroid production, evidence from research on the melanocortin system suggests that steroidogenesis may only partly account for ACTH influences. Indeed, the melanocortin peptides (ACTH and α-, β-, γ-melanocyte-stimulating hormones [MSH] and their receptors (MCRs exert multiple actions, including modulation of inflammatory and immune mediator production. Melanocortin receptors are widely distributed within the central nervous system and in peripheral tissues including immune cells (eg, macrophages. This suggests that the mechanism of action of ACTH includes not only steroid-mediated indirect effects, but also direct anti-inflammatory and immune-modulating actions via the melanocortin system. An increased understanding of the role of the melanocortin system, particularly ACTH, in the immune and inflammatory processes underlying relapses may help to improve relapse management.

  11. Syndrome of achalasia, ACTH insensitivity and alacrima

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosino, M.M.; Genieser, N.B.; Becker, M.H.; Bangaru, B.S.; Sklar, C.

    1986-05-01

    An unusual multisystem disorder characterized by the triad of selective ACTH insensitivity, achalasia and alacrima has recently been described. The following case fulfills the criteria for this syndrome which has not been previously reported in the radiographic literature.

  12. Permanent metabolic stimulation of leaves by low-dose irradiation

    International Nuclear Information System (INIS)

    Barabas, Z.

    1979-01-01

    By X-ray and colchicin treatment male-sterile mutants were produced from the Ra K9 Sorghum species. The characteristics of the mutants are compared with those of the original species. By this means the bisexual plant became unisexual, in later generations even asexual forms of reproduction were observed. This mutation chain is regarded as an artificially induced recapitulation of the natural evolution. Irradiation experiments were carried out in order to obtain wheat types resistant to brownrot, however, no success could be achieved with the present methods. (L.E.)

  13. Bioavailability of diclofenac potassium at low doses

    Science.gov (United States)

    Hinz, Burkhard; Chevts, Julia; Renner, Bertold; Wuttke, Henrike; Rau, Thomas; Schmidt, Andreas; Szelenyi, Istvan; Brune, Kay; Werner, Ulrike

    2005-01-01

    Aim Diclofenac-K has been recently launched at low oral doses in different countries for over-the-counter use. However, given the considerable first-pass metabolism of diclofenac, the degree of absorption of diclofenac-K at low doses remained to be determined. The aim of this study was to determine the bioavailability of low-dose diclofenac-K. Methods A randomized, three-way, cross-over study was performed in 10 subjects. Each received diclofenac-K, 22.5 mg via short-term i.v. infusion and orally at single doses of 12.5 mg and 25 mg. Results Mean (± SD) times to maximal plasma concentration (tmax) of diclofenac were 0.48 ± 0.28 h (12.5 mg) and 0.93 ± 0.96 h (25 mg). The absolute bioavailability of diclofenac-K after oral administration did not differ significantly in the 12.5-mg and 25-mg dose group (63.1 ± 12.6% vs. 65.1 ± 19.4%, respectively). The 90% confidence intervals for the AUC∞ and AUCt ratios for the two oral regimes were 82.6, 103.4% (point estimate 92.4%) and 86.2, 112.9% (point estimate 98.6%), respectively. These values were within the acceptance criteria for bioequivalence (80–125%). Conclusions Our data indicate that diclofenac-K is rapidly and well absorbed at low dose, and are consistent with a rapid onset of action of the drug. Abbreviations AUC, area under plasma concentraton-time curve; Cmax, peak plasma concentration; CI, confidence interval; COX, cyclooxygenase; D, dose; F, absolute bioavailability; tmax, time to reach Cmax. PMID:15606444

  14. Effects of low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Anon.

    2008-01-01

    Ionizing radiation of cosmic or terrestrial origin is part of the environment in which all living things have evolved since the creation of the universe. The artificial radioactivity generated by medical diagnostic and treatment techniques, some industrial activities, radioactive fallout, etc. has now been added to this natural radioactivity. This article reviews the biological effects of the low doses of ionizing radiation to which the population is thus exposed. Their carcinogenic risk cannot simply be extrapolated from what we know about high-dose exposure. (author)

  15. Low dose radiation and diabetes mellitus

    International Nuclear Information System (INIS)

    Zhao Hongguang; Gong Shouliang; Cai Lu

    2006-01-01

    Induction of hormesis and adaptive response by low-dose radiatio (LDR) has been extensively indicated. It's mechanism may be related with the protective protein and antioxidants that LDR induced, which take effects on the diabetes mellitus (DM) and other diseases. This review will summarize available dat with emphasis on three points: the preventive effect of LDR on the development of diabetes, the therapeutic effect of LDR on diabetic complications and possible mechanisms by which LDR prevents the development of diabetes and diabetic complications. Finally, the perspectives of LDR clinical, diabetes-related implication are discussed. (authors)

  16. Low-dose effect on blood chromosomes

    International Nuclear Information System (INIS)

    Pohl-Rueling, J.

    1992-01-01

    Linear dose response relationships of biological effects at low doses are experimentally and theoretically disputed. Structural chromosome aberration rates at doses ranging from normal background exposures up to about 30 mGy/yr in vivo and up to 50 mGy in vitro were investigated by the author and other scientists. Results are comparable and dose effect curves reveal following shapes; within the normal burden and up to 2-10 mGy/yr in vivo rates they increase sharply to about 3-6 times the lowest values; subsequent doses either from natural, occupational or accidental exposures up to about 30 mGy/yr yield either constant aberration rates, assuming a plateau, or perhaps even a decrease. In vitro experiments show comparable results up to 50 mGy. Other biological effects seem to have similar dose dependencies. The non-linearity of low-dose effects can be explained by induction of repair enzymes at certain damage to the DNA. This hypothesis is sustained experimentally and theoretically by several papers in literature. (author). 14 refs., 5 figs

  17. Low and very low doses, new recommendations?

    International Nuclear Information System (INIS)

    Foucher, N.

    1999-01-01

    The topic of the seminar organized by the world council of nuclear workers (WONUC) was the effects of low or very low doses on human health. Discussions centred round the linearity of the relation between dose and effect in the evaluation and management of the health hazard. The recommendations proposed by ICPR (international commission for radiological protection) are based on this linearity as a precaution. On the one hand it is remembered that low dose irradiation might be beneficial. It has been proved that the irradiation of the whole body is efficient in case of Hodgkin lymphoma. On the other hand it is remembered that doses as low as 10 mSv in utero have led to an excess of cancer in children. Studies based on experimentally radio-induced cancers have been carried out in Japan, China, Canada and France.Their results seem to be not consistent with the hypothesis of linearity. During the last decade a lot of work has been made but a conclusion is far to be reached, it is said that the American department of energy (DOE) has invited bids in 1999 to launch research programs in order to clarify the situation. (A.C.)

  18. The function of the adrenal cortex in patients with paracoccidioidomycosis: a study by radioimmunoassay of plasma ACTH

    International Nuclear Information System (INIS)

    Tendrich, M.; Vaisman, M.; Pedrosa, P.N.; Guimaraes, M.M.; Cordeiro, J.G.H.

    1987-01-01

    Fifteen patients with paracoccidioidomycosis were studied: ten with the chronic disseminated form (adult types), 4 with the acute or subacute disseminated form (juvenile type) and 1 with the progressive pulmonary form. Ten patients reported no previous treatment and 5 had relapse of the disease. In all cases P. brasiliensis was demonstrated in specimens obtained from the lesions by direct microscopy (KOH), histopathology and/or culture. The adrenocortical function was evaluated by means of basal plasma determination of ACTH and cortisol, and 24 hour urine determination of 17 hydroxisteroids (17 OHCS); after stimulation by ACTH determinations were repeated. Patients were classified in 3 groups: 1) plasma ACTH 58 pg/ml. According to the correlation between ACTH and cortisol level after simulation test 8 patients were classified in group 1, 2 of them with cortisol response lower than twice the basal levels; four patients were classified in group 3. All them had ACTH levels definitely above the normal, 2 of them had no cortisol response after stimulation in addition to signs and symptoms of Addison's disease, thus fulfilling the criteria of primary adrenal insufficiency. The correlation between ACTH and 17 OHCS after stimulation test demonstrated that in 7 out of 8 patientes from group 1 response was lower than twice the basal and that in 3 out of 4 patientes from group 3 proven primary adrenal insufficiency was present. (The other patient showed a 17 OHCS response three times higher than the basal levels). (author) [pt

  19. Biological Effects of Low-Dose Exposure

    CERN Document Server

    Komochkov, M M

    2000-01-01

    On the basis of the two-protection reaction model an analysis of stochastic radiobiological effects of low-dose exposure of different biological objects has been carried out. The stochastic effects are the results published in the last decade: epidemiological studies of human cancer mortality, the yield of thymocyte apoptosis of mice and different types of chromosomal aberrations. The results of the analysis show that as dependent upon the nature of biological object, spontanous effect, exposure conditions and radiation type one or another form dose - effect relationship is realized: downwards concave, near to linear and upwards concave with the effect of hormesis included. This result testifies to the incomplete conformity of studied effects of 1990 ICRP recomendations based on the linear no-threshold hypothesis about dose - effect relationship. Because of this the methodology of radiation risk estimation recomended by ICRP needs more precisian and such quantity as collective dose ought to be classified into...

  20. Low-dose irradiation for controlling prostate cancer

    International Nuclear Information System (INIS)

    Cuttler, J.M.

    2003-01-01

    Prostate cancer is the second most commonly diagnosed cancer among North American men and the second leading cause of death in those aged 65 and over. The American Cancer Society recommends testing those over age 50 who are expected to live at least 10 years, even though the ability of early detection to decrease prostate cancer mortality has not been demonstrated. So controversy exists about the appropriateness of screening because of the considerable economic and social burden of diagnosing and treating prostate cancer, coupled with the projected large increase in the number of new cases as the population ages. This very important public health issue could be addressed at low cost by total-body low-dose irradiation therapy to stimulate the patient's own defences to prevent and control most cancers, including prostate cancer, with no symptomatic side effects. (author)

  1. Low Dose Ionizing Radiation Modulates Immune Function

    International Nuclear Information System (INIS)

    Nelson, Gregory A.

    2016-01-01

    In order to examine the effects of low dose ionizing radiation on the immune system we chose to examine an amplified adaptive cellular immunity response. This response is Type IV delayed-type hypersensitivity also called contact hypersensitivity. The agent fluorescein isothiocyanate (FITC) is a low molecular weight, lipophilic, reactive, fluorescent molecule that can be applied to the skin where it (hapten) reacts with proteins (carriers) to become a complete antigen. Exposure to FITC leads to sensitization which is easily measured as a hypersensitivity inflammatory reaction following a subsequent exposure to the ear. Ear swelling, eosinophil infiltration, immunoglobulin E production and cytokine secretion patterns characteristic of a 'Th2 polarized' immune response are the components of the reaction. The reaction requires successful implementation of antigen processing and presentation by antigen presenting Langerhans cells, communication with naïve T lymphocytes in draining lymph nodes, expansion of activated T cell clones, migration of activated T cells to the circulation, and recruitment of memory T cells, macrophages and eosinophils to the site of the secondary challenge. Using this model our approach was to quantify system function rather than relying only on indirect biomarkers of cell. We measured the FITC-induced hypersensitivity reaction over a range of doses from 2 cGy to 2 Gy. Irradiations were performed during key events or prior to key events to deplete critical cell populations. In addition to quantifying the final inflammatory response, we assessed cell populations in peripheral blood and spleen, cytokine signatures, IgE levels and expression of genes associated with key processes in sensitization and elicitation/recall. We hypothesized that ionizing radiation would produce a biphasic effect on immune system function resulting in an enhancement at low doses and a depression at higher doses and suggested that this transition would occur in

  2. Low Dose Ionizing Radiation Modulates Immune Function

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Gregory A. [Loma Linda Univ., CA (United States)

    2016-01-12

    In order to examine the effects of low dose ionizing radiation on the immune system we chose to examine an amplified adaptive cellular immunity response. This response is Type IV delayed-type hypersensitivity also called contact hypersensitivity. The agent fluorescein isothiocyanate (FITC) is a low molecular weight, lipophilic, reactive, fluorescent molecule that can be applied to the skin where it (hapten) reacts with proteins (carriers) to become a complete antigen. Exposure to FITC leads to sensitization which is easily measured as a hypersensitivity inflammatory reaction following a subsequent exposure to the ear. Ear swelling, eosinophil infiltration, immunoglobulin E production and cytokine secretion patterns characteristic of a “Th2 polarized” immune response are the components of the reaction. The reaction requires successful implementation of antigen processing and presentation by antigen presenting Langerhans cells, communication with naïve T lymphocytes in draining lymph nodes, expansion of activated T cell clones, migration of activated T cells to the circulation, and recruitment of memory T cells, macrophages and eosinophils to the site of the secondary challenge. Using this model our approach was to quantify system function rather than relying only on indirect biomarkers of cell. We measured the FITC-induced hypersensitivity reaction over a range of doses from 2 cGy to 2 Gy. Irradiations were performed during key events or prior to key events to deplete critical cell populations. In addition to quantifying the final inflammatory response, we assessed cell populations in peripheral blood and spleen, cytokine signatures, IgE levels and expression of genes associated with key processes in sensitization and elicitation/recall. We hypothesized that ionizing radiation would produce a biphasic effect on immune system function resulting in an enhancement at low doses and a depression at higher doses and suggested that this transition would occur in the

  3. Whole body exposure to low-dose γ-radiation enhances the antioxidant defense system

    International Nuclear Information System (INIS)

    Pathak, C.M.; Avti, P.K.; Khanduja, K.L.; Sharma, S.C.

    2008-01-01

    It is believed that the extent of cellular damage by low- radiation dose is proportional to the effects observed at high radiation dose as per the Linear-No-Threshold (LNT) hypothesis. However, this notion may not be true at low-dose radiation exposure in the living system. Recent evidence suggest that the living organisms do not respond to ionizing radiations in a linear manner in the low dose range 0.01-0.5Gy and rather restore the homeostasis both in vivo and in vitro by normal physiological mechanisms such as cellular and DNA repair processes, immune reactions, antioxidant defense, adaptive responses, activation of immune functions, stimulation of growth etc. In this study, we have attempted to find the critical radiation dose range and the post irradiation period during which the antioxidant defense systems in the lungs, liver and kidneys remain stimulated in these organs after whole body exposure of the animals to low-dose radiation

  4. Cortisol secretion after adrenocorticotrophin (ACTH and Dexamethasone tests in healthy female and male dogs

    Directory of Open Access Journals (Sweden)

    Castillo Victor

    2009-08-01

    Full Text Available Abstract Background For the conclusive diagnosis of Cushing's Syndrome, a stimulating ACTH test or a low suppressive Dexamethasone test is used. Reports in other species than the dog indicate that plasma cortisol concentration after ACTH administration is affected by gender. We investigated the effect of gender on the cortisol response to ACTH and Dexamethasone tests in dogs. Methods Seven healthy adult Cocker Spaniels (4 females and 3 males were assigned to a two by two factorial design: 4 dogs (2 females and 2 males received IV Dexamethasone 0.01 mg/kg, while the other 3 dogs received an IV saline solution (control group. Two weeks later the treatments were reversed. After one month, ACTH was given IV (250 μg/animal to 4 dogs (2 female and 2 males while the rest was treated with saline solution (control group. Cortisol concentrations were determined by a direct solid-phase radioimmunoassay and cholesterol and triglycerides by commercial kits. Results and Discussion No effect of treatment was observed in metabolite concentrations, but females presented higher cholesterol concentrations. ACTH-treated dogs showed an increase in cortisol levels in the first hour after sampling until 3 hours post injection. Cortisol concentrations in Dexamethasone-treated dogs decreased one hour post injection and remained low for 3 hours, thereafter cortisol concentrations increased. The increase in cortisol levels from one to two hours post ACTH injection was significantly higher in females than males. In Dexamethasone-treated males cortisol levels decreased one hour post injection up to 3 hours; in females the decrease was more pronounced and prolonged, up to 5 hours post injection. Conclusion We have demonstrated that cortisol response to ACTH and Dexamethasone treatment in dogs differs according to sex.

  5. Multidisciplinary European Low Dose Initiative (MELODI). Strategic research agenda for low dose radiation risk research

    Energy Technology Data Exchange (ETDEWEB)

    Kreuzer, M. [Federal Office for Radiation Protection, BfS, Department of Radiation Protection and Health, Neuherberg (Germany); Auvinen, A. [University of Tampere, Tampere (Finland); STUK, Helsinki (Finland); Cardis, E. [ISGlobal, Barcelona Institute for Global Health, Barcelona (Spain); Durante, M. [Institute for Fundamental Physics and Applications, TIFPA, Trento (Italy); Harms-Ringdahl, M. [Stockholm University, Centre for Radiation Protection Research, Stockholm (Sweden); Jourdain, J.R. [Institute for Radiological Protection and Nuclear Safety, IRSN, Fontenay-aux-roses (France); Madas, B.G. [MTA Centre for Energy Research, Environmental Physics Department, Budapest (Hungary); Ottolenghi, A. [University of Pavia, Physics Department, Pavia (Italy); Pazzaglia, S. [Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Rome (Italy); Prise, K.M. [Queens University Belfast, Belfast (United Kingdom); Quintens, R. [Belgian Nuclear Research Centre, SCK-CEN, Mol (Belgium); Sabatier, L. [French Atomic Energy Commission, CEA, Paris (France); Bouffler, S. [Public Health England, PHE, Chilton (United Kingdom)

    2018-03-15

    MELODI (Multidisciplinary European Low Dose Initiative) is a European radiation protection research platform with focus on research on health risks after exposure to low-dose ionising radiation. It was founded in 2010 and currently includes 44 members from 18 countries. A major activity of MELODI is the continuous development of a long-term European Strategic Research Agenda (SRA) on low-dose risk for radiation protection. The SRA is intended to identify priorities for national and European radiation protection research programs as a basis for the preparation of competitive calls at the European level. Among those key priorities is the improvement of health risk estimates for exposures close to the dose limits for workers and to reference levels for the population in emergency situations. Another activity of MELODI is to ensure the availability of European key infrastructures for research activities, and the long-term maintenance of competences in radiation research via an integrated European approach for training and education. The MELODI SRA identifies three key research topics in low dose or low dose-rate radiation risk research: (1) dose and dose rate dependence of cancer risk, (2) radiation-induced non-cancer effects and (3) individual radiation sensitivity. The research required to improve the evidence base for each of the three key topics relates to three research lines: (1) research to improve understanding of the mechanisms contributing to radiogenic diseases, (2) epidemiological research to improve health risk evaluation of radiation exposure and (3) research to address the effects and risks associated with internal exposures, differing radiation qualities and inhomogeneous exposures. The full SRA and associated documents can be downloaded from the MELODI website (http://www.melodi-online.eu/sra.html). (orig.)

  6. Low dose irradiation facilitates hepatocellular carcinoma genesis involving HULC.

    Science.gov (United States)

    Li, Yuan; Ge, Chang; Feng, Guoxing; Xiao, Huiwen; Dong, Jiali; Zhu, Changchun; Jiang, Mian; Cui, Ming; Fan, Saijun

    2018-03-24

    Irradiation exposure positive correlates with tumor formation, such as breast cancer and lung cancer. However, whether low dose irradiation induces hepatocarcinogenesis and the underlying mechanism remain poorly defined. In the present study, we reported that low dose irradiation facilitated the proliferation of hepatocyte through up-regulating HULC in vitro and in vivo. Low dose irradiation exposure elevated HULC expression level in hepatocyte. Deletion of heightened HULC erased the cells growth accelerated following low dose irradiation exposure. CDKN1, the neighbor gene of HULC, was down-regulated by overexpression of HULC following low dose irradiation exposure via complementary base pairing, resulting in promoting cell cycle process. Thus, our findings provide new insights into the mechanism of low dose irradiation-induced hepatocarcinogenesis through HULC/CDKN1 signaling, and shed light on the potential risk of low dose irradiation for the development of hepatocellular carcinoma in pre-clinical settings. © 2018 Wiley Periodicals, Inc.

  7. 21 CFR 862.1025 - Adrenocorticotropic hormone (ACTH) test system.

    Science.gov (United States)

    2010-04-01

    ... and serum. ACTH measurements are used in the differential diagnosis and treatment of certain disorders of the adrenal glands such as Cushing's syndrome, adrenocortical insufficiency, and the ectopic ACTH...

  8. low dose irradiation growth in zirconium

    International Nuclear Information System (INIS)

    Fortis, A.M.

    1987-01-01

    Low dose neutron irradiation growth in textured and recrystallized zirconium, is studied, at the Candu Reactors Calandria temperature (340 K) and at 77 K. It was necessary to design and build 1: A facility to irradiate at high temperatures, which was installed in the Argentine Atomic Energy Commission's RA1 Reactor; 2: Devices to carry out thermal recoveries, and 3: Devices for 'in situ' measurements of dimensional changes. The first growth kinetics curves were obtained at 365 K and at 77 K in a cryostat under neutron fluxes of similar spectra. Irradiation growth experiments were made in zirconium doped with fissionable material (0,1 at % 235 U). In this way an equivalent dose two orders of magnitude greater than the reactor's fast neutrons dose was obtained, significantly reducing the irradiation time. The specimens used were bimetallic couples, thus obtaining a great accuracy in the measurements. The results allow to determine that the dislocation loops are the main cause of irradiation growth in recrystallized zirconium. Furthermore, it is shown the importance of 'in situ' measurements as a way to avoid the effect that temperature changes have in the final growth measurement; since they can modify the residual stresses and the overconcentrations of defects. (M.E.L.) [es

  9. Lymphocytic subsets and low-dose exposure

    International Nuclear Information System (INIS)

    Tuschl, H.; Kovac, R.; Eybl, E.

    1993-03-01

    The present investigations proved the differential radiosensitivity of lymphocytic subpopulations: From in vivo and in vitro irradiations it may be followed that the most sensitive subset are CD8 positive suppressor T cells. CD4/CD8 ratios are increased both in peripheral blood and after mitogen stimulation of lymphocytes of exposed persons. The decrease in B cells is pronounced only at higher radiation doses. Though the rate of DNA synthesis after mitogen stimulation was reduced in some exposed persons, that was no general phenomenon. Especially after tritium exposure, the observed lymphopenia correlated with an increased stimulation by PHA and an increased rate of DNA synthesis in some probands. Thus the present investigations indicate that - despite an inhibition of some immune parameters by radioexposure - the body is able to maintain its immunological homoeostasis. (authors)

  10. Modifying effect of low dose irradiation

    International Nuclear Information System (INIS)

    Kalendo, G.S.

    1989-01-01

    It is shown that irradiation of Hela cells with stimulating doses of 0,1 Gy changes the cells' response to the subsequent radiation effect of greater value: instead of DNA synthesis inhibition stimulation takes place. Modifying effect of preliminary irradiation with 0,1 Gy manifests it self only in case if there is a certain time interval not less than 3 minutes and not more than 10 minutes (3-5 minutes is optimal interval). Data on modifying effect with 0,1 Gy at subcellular and cellular-population levels are presented. 21 refs.; 6 figs

  11. Effects of low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Masse, R.

    2006-01-01

    Several groups of human have been irradiated by accidental or medical exposure, if no gene defect has been associated to these exposures, some radioinduced cancers interesting several organs are observed among persons exposed over 100 to 200 mSv delivered at high dose rate. Numerous steps are now identified between the initial energy deposit in tissue and the aberrations of cell that lead to tumors but the sequence of events and the specific character of some of them are the subject of controversy. The stake of this controversy is the risk assessment. From the hypothesis called linear relationship without threshold is developed an approach that leads to predict cancers at any tiny dose without real scientific foundation. The nature and the intensity of biological effects depend on the quantity of energy absorbed in tissue and the modality of its distribution in space and time. The probability to reach a target (a gene) associated to the cancerating of tissue is directly proportional to the dose without any other threshold than the quantity of energy necessary to the effect, its probability of effect can be a more complex function and depends on the quality of the damage produced as well as the ability of the cell to repair the damage. These two parameters are influenced by the concentration of initial injuries in the target so by the quality of radiation and by the dose rate. The mechanisms of defence explain the low efficiency of radiation as carcinogen and then the linearity of effects in the area of low doses is certainly the least defensible scientific hypothesis for the prediction of the risks. (N.C.)

  12. Characteristics of repair following very low doses

    International Nuclear Information System (INIS)

    Braby, L.A.; Metting, N.F.; Nelson, J.M.

    1987-01-01

    The effects of ionizing radiation on living systems being with the physical processes of energy deposition and develop through many stages of chemical reaction and biological response. The modeling effort attempts to organize the available data and theories of all of these stages into self-consistent models that can be compared and tested. In some cases, important differences among models result in only small differences in cell survival within the ranges of dose and dose rate that are normally investigated. To overcome this limitation, new ways of irradiating cells at extremes of dose rate, or ways of evaluating the effects of very small doses, are developed. Mathematical modeling and cellular studies complement each other. It has recently been found that some mechanisms are not adequate to account for the interaction of dose and repair time as they affect the reproductive survival of plateau-phase Chinese hamster ovary (CHO) cells. Repair of radiation-induced cellular damage plays a central role in the survival of cells exposed to doses of 1 Gy or more. This repair is responsible for the dose rate, split-dose and delayed plating effect and can be evaluated. Because split-dose and dose-rate experiments involve repair during irradiation and delayed plating experiments involve repair after irradiation is completed, it was originally thought that different repair processes were involved. It is now clear that this is not necessarily the case. Appropriately designed models can account for observed effects at conventional doses (1 Gy or more) whether they assume all damage is lethal unless repaired or some damage is innocuous unless it interacts with additional damage. The fact that the survival following a plating delay is always less than the survival following immediate plating at low doses indicates that the damage produced is probably not potentially lethal

  13. On the common mechanism for initiation of different effects of low doses of ionizing radiations

    International Nuclear Information System (INIS)

    Ehjdus, L.Kh.

    1996-01-01

    Main regularities of different endpoints of ionizing radiation low dose effects (adaptive response, stimulation of proliferation, special radiosensitivity of lymphoid cells, and others) have been examined. It has been shown that these endpoints have a commonness for the dose interval, the shape of the dose-response curve, the reverse effect of dose rate, non-specificity toward initiating agents, and others. An explanation is suggested for the common mechanism of the initiation of all the studied low dose effects, basing on the theory of the non-specific reaction of cell to external influences. It is concluded that initiation of the low dose effects is conditioned by radiation induced damage of functions of plasmic and internal membranes

  14. Effects of low dose mitomycin C on experimental tumor radiotherapy

    International Nuclear Information System (INIS)

    Yang Jianzheng; Liang Shuo; Qu Yaqin; Pu Chunji; Zhang Haiying; Wu Zhenfeng; Wang Xianli

    2001-01-01

    Objective: To evaluate the possibility of low dose mitomycin C(MMC) as an adjunct therapy for radiotherapy. Methods: Change in tumor size tumor-bearing mice was measured. Radioimmunoassay was used to determine immune function of mice. Results: Low dose Mac's pretreatment reduced tumor size more markedly than did radiotherapy only. The immune function in mice given with low dose MMC 12h before radiotherapy was obviously higher than that in mice subjected to radiotherapy only (P<0.05), and was close to that in the tumor-bearing mice before radiotherapy. Conclusion: Low dose MMC could improve the radiotherapy effect. Pretreatment with low dose MMC could obviously improve the immune suppression state in mice caused by radiotherapy. The mechanism of its improvement of radiotherapeutic effect by low dose of MMC might be due to its enhancement of immune function and induction of adaptive response in tumor-bearing mice

  15. Low-dose effects of hormones and endocrine disruptors.

    Science.gov (United States)

    Vandenberg, Laura N

    2014-01-01

    Endogenous hormones have effects on tissue morphology, cell physiology, and behaviors at low doses. In fact, hormones are known to circulate in the part-per-trillion and part-per-billion concentrations, making them highly effective and potent signaling molecules. Many endocrine-disrupting chemicals (EDCs) mimic hormones, yet there is strong debate over whether these chemicals can also have effects at low doses. In the 1990s, scientists proposed the "low-dose hypothesis," which postulated that EDCs affect humans and animals at environmentally relevant doses. This chapter focuses on data that support and refute the low-dose hypothesis. A case study examining the highly controversial example of bisphenol A and its low-dose effects on the prostate is examined through the lens of endocrinology. Finally, the chapter concludes with a discussion of factors that can influence the ability of a study to detect and interpret low-dose effects appropriately. © 2014 Elsevier Inc. All rights reserved.

  16. Stimulatory effect of low dose radionuclide on DNA synthesis and UDS in splenic lymphocytes

    International Nuclear Information System (INIS)

    Zhu Shoupeng; Yang Zhanshan

    1999-12-01

    To study the stimulatory effect on DNA synthesis and unscheduled DNA synthesis (UDS) in splenic lymphocytes induced by low dose enriched uranium 235 U. By using 3 H-TdR incorporation assay technique, the DNA replicative synthesis in PHA and LPS stimulated splenic lymphocytes was observed. By using DNA synthesis inhibitor such as hydroxyurea, the UV-induced unscheduled DNA synthesis in splenic lymphocytes occurred. When the injected low dose of enriched uranium 235 u was 0.1 μg/kg body weight, the transformation capacity was elevated for splenic T lymphocytes, simultaneously the stimulative index increased. The UDS of splenic lymphocytes induced by ultra-violate revealed a statistically significant increase by low dose of enriched uranium 235 U at the range of 0.1-20 μg/kg body weight. A stimulatory action of low dose enriched uranium 235 U on DNA replicative synthesis as well as on UV-induced UDS in splenic lymphocytes was detected

  17. Endometrial safety of ultra-low-dose estradiol vaginal tablets

    DEFF Research Database (Denmark)

    Simon, James; Nachtigall, Lila; Ulrich, Lian G

    2010-01-01

    To evaluate the endometrial hyperplasia and carcinoma rate after 52-week treatment with ultra-low-dose 10-microgram 17ß-estradiol vaginal tablets in postmenopausal women with vaginal atrophy.......To evaluate the endometrial hyperplasia and carcinoma rate after 52-week treatment with ultra-low-dose 10-microgram 17ß-estradiol vaginal tablets in postmenopausal women with vaginal atrophy....

  18. Endometrial safety of ultra-low-dose estradiol vaginal tablets

    DEFF Research Database (Denmark)

    Simon, James; Nachtigall, Lila; Ulrich, Lian G

    2010-01-01

    To evaluate the endometrial hyperplasia and carcinoma rate after 52-week treatment with ultra-low-dose 10-microgram 17β-estradiol vaginal tablets in postmenopausal women with vaginal atrophy.......To evaluate the endometrial hyperplasia and carcinoma rate after 52-week treatment with ultra-low-dose 10-microgram 17β-estradiol vaginal tablets in postmenopausal women with vaginal atrophy....

  19. Study of genomic instability induced by low dose ionizing radiation

    International Nuclear Information System (INIS)

    Seoane, A.; Crudeli, C.; Dulout, F.

    2006-01-01

    The crews of commercial flights and services staff of radiology and radiotherapy from hospitals are exposed to low doses of ionizing radiation. Genomic instability includes those adverse effects observed in cells, several generations after the exposure occurred. The purpose of this study was to analyze the occurrence of genomic instability by very low doses of ionizing radiation [es

  20. Extended low-dose dexamethasone suppression test for diagnosis of atypical Cushing's syndrome in dogs.

    Science.gov (United States)

    Fowler, K M; Frank, L A; Morandi, F; Whittemore, J C

    2017-07-01

    The purpose of this study was to evaluate extension of the low-dose dexamethasone suppression (LDDS) test from 8 h to 12 h to detect possible hypercortisolemia associated with atypical hyperadrenocorticism (AHAC). Twelve client-owned dogs were enrolled in the study: 6 healthy dogs (group 1) and 6 dogs with suspected AHAC (group 2). Baseline EDTA plasma samples were collected for endogenous ACTH determination using an immunoradiometric assay. Serum samples were collected before and at 4, 8, 10, and 12 h post-administration of 0.01 mg/kg dexamethasone IV for cortisol concentration determination via chemiluminescent assay. Mean endogenous ACTH concentration did not differ between groups (group 1: 22.4 pg/mL, group 2: 20.0 pg/mL; P > 0.2). Mean baseline cortisol concentration also did not differ significantly between groups (group 1: 3.03 μg/dL, group 2: 4.95 μg/dL; P > 0.2) nor was there any difference in mean cortisol concentration between the groups at any other time point (P > 0.2). The cortisol concentration from 1 dog in group 2 suppressed to 0.7 μg/dL at 8 h but increased to 1.5 μg/dL at 10 h and 3.7 μg/dL at 12 h post-dexamethasone. Based on results of this study, use of an extended LDDS test could not differentiate between healthy dogs and dogs with AHAC. Diagnosis of AHAC should continue to be based on prior established criteria until new testing has been identified. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Acth e enzimas na supra-renal ACTH and enzymes in adrenal gland

    Directory of Open Access Journals (Sweden)

    H. Povoa Junior

    1974-01-01

    Full Text Available Estudou-se a atividade da ceruloplasmina, adenosina desaminase (AD e transaminases glutâmico oxalacética (TGO e glutâmico pirúvica (TGP na supra-renal de ratos normais e injetados previamente (24 horas antes com uma injeção única, por via intraperitoneal, de ACTH em doses de 0,5 e 1,2 un. internacionais. observou-se uma elevação estatisticamente significativa das TGO e ceruloplasmina enquanto a AD sofria diminuição sensível em sua atividade.Activities of several enzymes have been studied in rat adrenal glands after ACTH injection. Activity of glutamic oxalacetic transaminase increases significantly after ACTH. The same was observed with ceruloplasmin. Adrenosine desaminase inthe same gland was decreased after administration of this hormone.

  2. ACTH-induced caveolin-1 tyrosine phosphorylation is related to podosome assembly in Y1 adrenal cells

    International Nuclear Information System (INIS)

    Colonna, Cecilia; Podesta, Ernesto J.

    2005-01-01

    Y1 adrenocortical cells respond to ACTH with a characteristic rounding-up that facilitates cAMP signaling, critical for transport of cholesterol to the mitochondria and increase in steroid secretion. We here demonstrate that caveolin-1 participates in coupling activation of protein kinase A (PKA) to the control of cell shape. ACTH/8-Br-cAMP induced reorganization of caveolin-1-positive structures in correlation with the cellular rounding-up. Concomitant with this change, there was an increase in the phosphorylation of caveolin-1 (Tyr-14) localized at focal adhesions (FA) with reorganization of FA to rounded, ringlike structures. Colocalization with phalloidin showed that phosphocaveolin is present at the edge of actin filaments and that after ACTH stimulation F-actin dots at the cell periphery become surrounded by phosphocaveolin-1. These observations along with electron microscopy studies revealed these structures as podosomes. Podosome assembly was dependent on both PKA and tyrosine kinase activities because their formation was impaired after treatment with specific inhibitors [myristoylated PKI (mPKI) or PP2, respectively] previous to ACTH/8-Br-cAMP stimulation. These results show for the first time that ACTH induces caveolin-1 phosphorylation and podosome assembly in Y1 cells and support the view that the morphological and functional responses to PKA activation in steroidogenic cells are related to cytoskeleton dynamics

  3. Alteration of cytokine profiles in mice exposed to chronic low-dose ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Suk Chul [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Lee, Kyung-Mi [Global Research Lab, BAERI Institute, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 136-705 (Korea, Republic of); Kang, Yu Mi [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Kim, Kwanghee [Global Research Lab, BAERI Institute, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 136-705 (Korea, Republic of); Kim, Cha Soon; Yang, Kwang Hee; Jin, Young-Woo [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Kim, Chong Soon [Department of Nuclear Medicine, Haeundae Paik Hospital, Inje University, Busan 612-030 (Korea, Republic of); Kim, Hee Sun, E-mail: hskimdvm@khnp.co.kr [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of)

    2010-07-09

    While a high-dose of ionizing radiation is generally harmful and causes damage to living organisms, a low-dose of radiation has been shown to be beneficial in a variety of animal models. To understand the basis for the effect of low-dose radiation in vivo, we examined the cellular and immunological changes evoked in mice exposed to low-dose radiation at very low (0.7 mGy/h) and low (3.95 mGy/h) dose rate for the total dose of 0.2 and 2 Gy, respectively. Mice exposed to low-dose radiation, either at very low- or low-dose rate, demonstrated normal range of body weight and complete blood counts. Likewise, the number and percentage of peripheral lymphocyte populations, CD4{sup +} T, CD8{sup +} T, B, or NK cells, stayed unchanged following irradiation. Nonetheless, the sera from these mice exhibited elevated levels of IL-3, IL-4, leptin, MCP-1, MCP-5, MIP-1{alpha}, thrombopoietin, and VEGF along with slight reduction of IL-12p70, IL-13, IL-17, and IFN-{gamma}. This pattern of cytokine release suggests the stimulation of innate immunity facilitating myeloid differentiation and activation while suppressing pro-inflammatory responses and promoting differentiation of naive T cells into T-helper 2, not T-helper 1, types. Collectively, our data highlight the subtle changes of cytokine milieu by chronic low-dose {gamma}-radiation, which may be associated with the functional benefits observed in various experimental models.

  4. Effects of Low Dose DD Radiation on Callus Growth of Lithospermum erythrorhizon S

    International Nuclear Information System (INIS)

    Hwang, H.Y.; Kim, J.S.

    2001-01-01

    The effect of low dose DD-radiation on the callus growth of Lithospermum erythrorhizon S. cultured on different medium and lighting condition was investigated. The 8 Gy irradiation stimulated callus growth on LS medium supplemented with BA 2 mg/L and NAA 2mg/L, however, the growth of callus was more effective on LS medium supplemented with BA 1 mg/L and NAA 1 mg/L under 16 hrs day light

  5. The biological effects of low doses of ionizing radiation on adaptive possibilities of the organism

    International Nuclear Information System (INIS)

    Bulbuc, G.

    1997-01-01

    The study of adaptive possibilities and cancer risk in animals exposed at low doses of ionizing radiation was the object of the present work. The action of immunostimulating treatment on these processes was studied as well. In previously irradiated animals the diminution of adaptive possibilities and of the antitumoral resistance of the organism was observed. The stimulating action of Bufostimulin on these processes in irradiated animals was less pronounced than in unirradiated ones. (author)

  6. Low Doses of Ethanol Enhance LTD-like Plasticity in Human Motor Cortex.

    Science.gov (United States)

    Fuhl, Anna; Müller-Dahlhaus, Florian; Lücke, Caroline; Toennes, Stefan W; Ziemann, Ulf

    2015-12-01

    Humans liberally use ethanol for its facilitating effects on social interactions but its effects on central nervous system function remain underexplored. We have recently described that very low doses of ethanol abolish long-term potentiation (LTP)-like plasticity in human cortex, most likely through enhancement of tonic inhibition [Lücke et al, 2014, Neuropsychopharmacology 39:1508-18]. Here, we studied the effects of low-dose ethanol on long-term depression (LTD)-like plasticity. LTD-like plasticity was induced in human motor cortex by paired associative transcranial magnetic stimulation (PASLTD), and measured as decreases of motor evoked potential input-output curve (IO-curve). In addition, sedation was measured by decreases in saccade peak velocity (SPV). Ethanol in two low doses (EtOH<10mM, EtOH<20mM) was compared to single oral doses of alprazolam (APZ, 1mg) a classical benzodiazepine, and zolpidem (ZLP, 10 mg), a non-benzodiazepine hypnotic, in a double-blinded randomized placebo-controlled crossover design in ten healthy human subjects. EtOH<10mM and EtOH<20mM but not APZ or ZLP enhanced the PASLTD-induced LTD-like plasticity, while APZ and ZLP but not EtOH<10mM or EtOH<20mM decreased SPV. Non-sedating low doses of ethanol, easily reached during social drinking, enhance LTD-like plasticity in human cortex. This effect is most likely explained by the activation of extrasynaptic α4-subunit containing gamma-aminobutyric type A receptors by low-dose EtOH, resulting in increased tonic inhibition. Findings may stimulate cellular research on the role of tonic inhibition in regulating excitability and plasticity of cortical neuronal networks.

  7. Biological responses to low dose rate gamma radiation

    International Nuclear Information System (INIS)

    Magae, Junji; Ogata, Hiromitsu

    2003-01-01

    Linear non-threshold (LNT) theory is a basic theory for radioprotection. While LNT dose not consider irradiation time or dose-rate, biological responses to radiation are complex processes dependent on irradiation time as well as total dose. Moreover, experimental and epidemiological studies that can evaluate LNT at low dose/low dose-rate are not sufficiently accumulated. Here we analyzed quantitative relationship among dose, dose-rate and irradiation time using chromosomal breakage and proliferation inhibition of human cells as indicators of biological responses. We also acquired quantitative data at low doses that can evaluate adaptability of LNT with statistically sufficient accuracy. Our results demonstrate that biological responses at low dose-rate are remarkably affected by exposure time, and they are dependent on dose-rate rather than total dose in long-term irradiation. We also found that change of biological responses at low dose was not linearly correlated to dose. These results suggest that it is necessary for us to create a new model which sufficiently includes dose-rate effect and correctly fits of actual experimental and epidemiological results to evaluate risk of radiation at low dose/low dose-rate. (author)

  8. CT findings in patients with infantile epilepsy on ACTH therapy

    International Nuclear Information System (INIS)

    Watanabe, Kazunari; Hara, Kimiko; Hakamada, Akira; Miyazaki, Shuji.

    1981-01-01

    A case of infantile spasms in which subdural hematoma developed after ACTH-Z therapy was reported. The results of CT evaluated before and after the therapy in 17 cases of infantile epilepsy including infantile spasms. Cerebral atrophy due to ACTH-Z therapy was remarkable, especially in the infants under one year old. We should vary careful in employing ACTH-Z therapy for infants of this age. (Ueda, J.)

  9. Cancer risk of low dose/low dose rate radiation: a meta-analysis of cancer data of mammals exposed to low doses of radiation

    International Nuclear Information System (INIS)

    Ogata, Hiromitsu; Magae, Junji

    2008-01-01

    Full text: Linear No Threshold (LNT) model is a basic theory for radioprotection, but the adaptability of this hypothesis to biological responses at low doses or at low dose rates is not sufficiently investigated. Simultaneous consideration of the cumulative dose and the dose rate is necessary for evaluating the risk of long-term exposure to ionizing radiation at low dose. This study intends to examine several numerical relationships between doses and dose rates in biological responses to gamma radiation. Collected datasets on the relationship between dose and the incidence of cancer in mammals exposed to low doses of radiation were analysed using meta-regression models and modified exponential (MOE) model, which we previously published, that predicts irradiation time-dependent biological response at low dose rate ionizing radiation. Minimum doses of observable risk and effective doses with a variety of dose rates were calculated using parameters estimated by fitting meta-regression models to the data and compared them with other statistical models that find values corresponding to 'threshold limits'. By fitting a weighted regression model (fixed-effects meta-regression model) to the data on risk of all cancers, it was found that the log relative risk [log(RR)] increased as the total exposure dose increased. The intersection of this regression line with the x-axis denotes the minimum dose of observable risk. These estimated minimum doses and effective doses increased with decrease of dose rate. The goodness of fits of MOE-model depended on cancer types, but the total cancer risk is reduced when dose rates are very low. The results suggest that dose response curve for cancer risk is remarkably affected by dose rate and that dose rate effect changes as a function of dose rate. For scientific discussion on the low dose exposure risk and its uncertainty, the term 'threshold' should be statistically defined, and dose rate effects should be included in the risk

  10. Increased adrenocortical response to adrenocorticotropic hormone (ACTH) in sport horses with equine glandular gastric disease (EGGD).

    Science.gov (United States)

    Scheidegger, M D; Gerber, V; Bruckmaier, R M; van der Kolk, J H; Burger, D; Ramseyer, A

    2017-10-01

    This study tested the hypothesis that adrenocortical function would be altered in horses with equine gastric ulcer syndrome (EGUS). Twenty-six sport horses competing at national or international levels in eventing (n=15) or endurance (n=11) were subjected to a gastroscopic examination and an adrenocorticotropic hormone (ACTH) stimulation test. Salivary cortisol concentrations were measured before (baseline) and after (30, 60, 90, 120 and 150min) IV ACTH injection (1μg/kg bodyweight). Within EGUS, two distinct diseases, equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD), can be distinguished. ESGD was diagnosed in 8/11 (73%; 95% confidence intervals [95%CI], 43-92%) endurance horses and 5/15 (33%; 95% CI, 14-58%) eventing horses. EGGD was observed in 9/11 (82%; 95% CI, 53-96%) endurance horses and 9/15 (60%; 95% CI, 35-81%) eventing horses. The presence or severity of ESGD was unrelated to the presence or severity of EGGD. ACTH stimulation induced a larger increase in cortisol concentration in horses with moderate EGGD than in horses with mild EGGD. Cortisol concentration during the entire sampling period (total increase in cortisol concentration during the entire sampling period [dAUC], 31.1±6.4ng/mL) and the highest measured concentration at a single time point (maximal increase in cortisol concentration [dMAX], 10.3±2.3ng/mL) were increased (P=0.005 and P=0.038, respectively), indicating that horses with glandular gastric disease exhibited increased adrenocortical responses to ACTH stimulation. These results suggest that EGGD might be associated with an enhanced adrenocortical sensitivity. Further investigations are warranted to confirm the association between adrenocortical sensitivity and EGGD and to elucidate the pathophysiological mechanisms involved. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Risk of cancer subsequent to low-dose radiation

    International Nuclear Information System (INIS)

    Warren, S.

    1980-01-01

    The author puts low dose irradiation risks in perspective using average background radiation doses for standards. He assailed irresponsible media coverage during the height of public interest in the Three-Mile Island Reactor incident

  12. Radiation effects after low dose chronic long-term exposure

    International Nuclear Information System (INIS)

    Fliedner, T.M.; Friesecke, I.

    1997-01-01

    This document approaches the radiation effects after low dose chronic long-term exposure, presenting examples occurred, the pathophysiologic mechanisms for cell system tolerance in elevated radiation fields, and the diagnostic and therapeutic possibilities

  13. Effects of ACTH on RNA synthesis and migration in the adrenal cortex cells of the young rat, as shown by radioautography

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, M.C.; Vitor, A.B.; Magalhaes, M.M.

    1986-01-01

    The effect of ACTH on the RNA synthesis in adrenal zona fasciculata cells of the young rat were studied by light and electron microscope radioautography. Two units of ACTH were administered sc to animals and immediately followed by an iv injection of (/sup 3/)uridine. ACTH-injected and control rats, which received the isotope alone, were sacrificed at various time intervals. Labelling over extranucleolar areas was higher in the ACTH-treated animals at 20 min, then becoming lower than in the controls at 60 min and 24 h. Nucleolar radioactivity, however, was consistently decreased by ACTH at all experimental times. Apart from these changes in the rate of synthesis, the over-all curves of labelling were similar to those in the control animals with a striking peak at 1 h. The short-term increase in extranucleolar RNA synthesis observed after ACTH injection was considered to be consistent with the hypothesis that an enhanced extranucleolar synthesis of mRNA takes place early in stimulated animals and is associated with the synthesis of steroidogenic proteins. On the other hand, the relatively decreased uridine uptake of the label by the nucleolus in ACTH-treated animals, suggests an inhibition of nucleolar transcription with diminished pre-rRNA formation in treated animals.

  14. Effects of ACTH on RNA synthesis and migration in the adrenal cortex cells of the young rat, as shown by radioautography

    International Nuclear Information System (INIS)

    Magalhaes, M.C.; Vitor, A.B.; Magalhaes, M.M.

    1986-01-01

    The effect of ACTH on the RNA synthesis in adrenal zona fasciculata cells of the young rat were studied by light and electron microscope radioautography. Two units of ACTH were administered sc to animals and immediately followed by an iv injection of [ 3 ]uridine. ACTH-injected and control rats, which received the isotope alone, were sacrificed at various time intervals. Labelling over extranucleolar areas was higher in the ACTH-treated animals at 20 min, then becoming lower than in the controls at 60 min and 24 h. Nucleolar radioactivity, however, was consistently decreased by ACTH at all experimental times. Apart from these changes in the rate of synthesis, the over-all curves of labelling were similar to those in the control animals with a striking peak at 1 h. The short-term increase in extranucleolar RNA synthesis observed after ACTH injection was considered to be consistent with the hypothesis that an enhanced extranucleolar synthesis of mRNA takes place early in stimulated animals and is associated with the synthesis of steroidogenic proteins. On the other hand, the relatively decreased uridine uptake of the label by the nucleolus in ACTH-treated animals, suggests an inhibition of nucleolar transcription with diminished pre-rRNA formation in treated animals. (author)

  15. Low dose rate Ir-192 interstitial brachytherapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Oki, Yosuke; Dokiya, Takushi; Yorozu, Atsunori; Suzuki, Takayuki; Saito, Shiro; Monma, Tetsuo; Ohki, Takahiro [National Tokyo Medical Center (Japan); Murai, Masaru; Kubo, Atsushi

    2000-04-01

    From December 1997 through January 1999, fifteen prostatic cancer patients were treated with low dose rate Ir-192 interstitial brachytherapy using TRUS and perineal template guidance without external radiotherapy. Up to now, as no apparent side effects were found, the safety of this treatment is suggested. In the future, in order to treat prostatic cancer patients with interstitial brachytherapy using I-125 or Pd-103, more investigation for this low dose rate Ir-192 interstitial brachytherapy is needed. (author)

  16. ACTH overexpressing pituitary hyperplasia in a patient with ectopic ACTH-syndrome due to carcinoid of the lung

    Directory of Open Access Journals (Sweden)

    Larisa Konstantinovna Dzeranova

    2015-01-01

    Full Text Available Ectopic ACTH-syndrome is the most diagnostically challenging  variant of endogenous hypercortisolism. Particularly difficult differential diagnosis of this syndrome is from Cushing's disease (CD, as currently there is no single test sufficiently accurate to differentiate accurately ectopic ACTH production from the pituitary. The main functional tests are based on the fact that the vast majority of ectopic ACTH production is autonomous and suppresses one from pituitary. But in some cases this is not observed, and then the data obtained all necessary laboratory and instrumental research evidence in favor of central genesis of CD in a patient with ACTH ectopic secretion, which can lead to inappropriate treatment. If you confirm the ectopic ACTH-syndrome, it may take quite a long time of searching for the pathological focus, as there is no sufficiently precise imaging and diagnostic method for determining the localization of ectopic source of ACTH production. Thus, the differential diagnosis of ACTH-dependent hypercortisolism and localization of the ectopic tumor is the cornerstone of early and radical treatment of patients. We present a difficult clinical case of a patient having a pituitary hyperplasia with excessive ACTH expression with primary ectopic ACTH syndrome caused by lung carcinoid.

  17. Review of European research trends of low dose radiation risk

    International Nuclear Information System (INIS)

    Iwasaki, Toshiyasu; Yoshida, Kazuo

    2010-01-01

    Large research projects on low dose radiation effects in Europe and US over the past decade have provided limited scientific knowledge which could underpin the validation of radiation protection systems. Recently in Europe, there have been repeated discussions and dialogues to improve the situation, and as the consequence, the circumstances surrounding low dose radiation risks are changing. In 2009, Multidisciplinary European Low Dose Initiative (MELODI) was established as a trans-national organization capable of ensuring appropriate governance of research in the pursuit of a long term shared vision, and Low Dose Research towards Multidisciplinary Integration (DoReMi) network was launched in 2010 to achieve fairly short term results in order to prove the validity of the MELODI approach. It is expected to be very effective and powerful activities to facilitate the reduction of uncertainties in the understanding of low dose risks, but the regulatory requests rushing the reinforcement of radiological protection regulations based on the precautional principles are more increasing. To develop reasonable radiological protection systems based on scientific evidences, we need to accelerate to collect scientific evidences which could directly underpin more appropriate radiation protection systems even in Japan. For the purpose, we Japan need to develop from an independent standpoint and share as a multidisciplinary vision a long term and holistic research strategy which enables to enhance Japanese advantages such as low dose rate facilities and animal facilities, as soon as possible. (author)

  18. Low Dose Suppression of Neoplastic Transformation in Vitro

    Energy Technology Data Exchange (ETDEWEB)

    John Leslie Redpath

    2012-05-01

    This grant was to study the low dose suppression of neoplastic transformation in vitro and the shape of the dose-response curve at low doses and dose-rates of ionizing radiation. Previous findings had indicated a suppression of transformation at dose <10cGy of low-LET radiation when delivered at high dose-rate. The present study indicates that such suppression extends out to doses in excess of 100cGy when the dose (from I-125 photons) is delivered at dose-rates as low as 0.2 mGy/min and out to in excess of {approx}25cGy the highest dose studied at the very low dose-rate of 0.5 mGy/day. We also examined dose-rate effects for high energy protons (which are a low-LET radiation) and suppression was evident below {approx}10cGy for high dose-rate delivery and at least out to 50cGy for low dose-rate (20cGy/h) delivery. Finally, we also examined the effect of low doses of 1 GeV/n iron ions (a high-LET radiation) delivered at high dose-rate on transformation at low doses and found a suppression below {approx}10cGy that could be attributable to an adaptive response in bystander cells induced by the associated low-LET delta rays. These results have implications for cancer risk assessment at low doses.

  19. 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.)

  20. Effect of Hashimoto thyroiditis on low-dose radioactive-iodine remnant ablation.

    Science.gov (United States)

    Kwon, Hyungju; Choi, June Young; Moon, Jae Hoon; Park, Hyo Jin; Lee, Won Woo; Lee, Kyu Eun

    2016-04-01

    Radioactive-iodine remnant ablation is an integral part of the papillary thyroid carcinoma (PTC) treatment. Although a minimum dose is usually recommended, there is controversy as to whether the low-dose (1100 MBq) radioactive-iodine remnant ablation is adequate for selected patients. A retrospective cohort study was conducted on 691 patients. Patients with no remnant thyroid on the follow-up whole body scan and low stimulated thyroglobulin (sTg) level (Hashimoto thyroiditis based on histopathology diagnosis (odds ratio [OR] = 3.23; p Hashimoto thyroiditis and elevated sTg are negative predictive factors for successful low-dose radioactive-iodine remnant ablation treatment. An appropriate risk-adjusted approach may improve the efficacy of radioactive-iodine remnant ablation treatment. © 2015 Wiley Periodicals, Inc. Head Neck 38: E730-E735, 2016. © 2015 Wiley Periodicals, Inc.

  1. Health effects of low-dose radiation: Molecular, cellular, and biosystem response

    International Nuclear Information System (INIS)

    Pollycove, M.; Paperiello, C.J.

    1997-01-01

    Since the fifties, the prime concern of radiation protection has been protecting DNA from damage. UNSCEAR initiated a focus on biosystem response to damage with its 1994 report, ''Adaptive Responses to Radiation of Cells and Organisms''. The DNA damage-control biosystem is physiologically operative on both metabolic and radiation induced damage, both effected predominantly by free radicals. These adaptive responses are suppressed by high-dose and stimulated by low dose radiation. Increased biosystem efficiently reduces the number of mutations that accumulate during a lifetime and decrease DNA damage-control with resultant aging and malignancy. Several statistically significant epidemiologic studies have shown risk decrements of cancer mortality and mortality from all causes in populations exposed to low-dose radiation. Further biologic and epidemiologic research is needed to establish a valid threshold below which risk decrements occur. (author)

  2. Effects of low dose radiation on tumor-bearing mice

    International Nuclear Information System (INIS)

    Feng Li; Hou Dianjun; Huang Shanying; Deng Daping; Wang Linchao; Cheng Yufeng

    2007-01-01

    Objective: To explore the effects of low-dose radiation on tumor-bearing mice and radiotherapy induced by low-dose radiation. Methods: Male Wistar mice were implanted with Walker-256 sarcoma cells in the right armpit. On day 4, the mice were given 75 mGy whole-body X-ray radiation. From the fifth day, tumor volume was measured, allowing for the creation of a graph depicting tumor growth. Lymphocytes activity in mice after whole-body X-ray radiation with LDR was determinned by FCM. Cytokines level were also determined by ELISA. Results: Compared with the radiotherapy group, tumor growth was significantly slower in the mice pre-exposed to low-dose radiation (P<0.05), after 15 days, the average tumor weight in the mice pre- exposed to low-dose radiation was also significantly lower (P<0.05). Lymphocytes activity and the expression of the CK in mice after whole-body y-ray radiation with LDR increased significantly. Conclusions: Low-dose radiation can markedly improve the immune function of the lymphocyte, inhibit the tumor growth, increase the resistant of the high-dose radiotherapy and enhance the effect of radiotherapy. (authors)

  3. Low Dose Vaporized Cannabis Significantly Improves Neuropathic Pain

    Science.gov (United States)

    Wilsey, Barth; Marcotte, Thomas D.; Deutsch, Reena; Gouaux, Ben; Sakai, Staci; Donaghe, Haylee

    2013-01-01

    We conducted a double-blind, placebo-controlled, crossover study evaluating the analgesic efficacy of vaporized cannabis in subjects, the majority of whom were experiencing neuropathic pain despite traditional treatment. Thirty-nine patients with central and peripheral neuropathic pain underwent a standardized procedure for inhaling either medium dose (3.53%), low dose (1.29%), or placebo cannabis with the primary outcome being VAS pain intensity. Psychoactive side-effects, and neuropsychological performance were also evaluated. Mixed effects regression models demonstrated an analgesic response to vaporized cannabis. There was no significant difference between the two active dose groups’ results (p>0.7). The number needed to treat (NNT) to achieve 30% pain reduction was 3.2 for placebo vs. low dose, 2.9 for placebo vs. medium dose, and 25 for medium vs. low dose. As these NNT are comparable to those of traditional neuropathic pain medications, cannabis has analgesic efficacy with the low dose being, for all intents and purposes, as effective a pain reliever as the medium dose. Psychoactive effects were minimal and well-tolerated, and neuropsychological effects were of limited duration and readily reversible within 1–2 hours. Vaporized cannabis, even at low doses, may present an effective option for patients with treatment-resistant neuropathic pain. PMID:23237736

  4. Risks to health from radiation at low dose rates

    International Nuclear Information System (INIS)

    Gentner, N.E.; Osborne, R.V.

    1997-01-01

    Our focus is on whether, using a balance-of-evidence approach, it is possible to say that at a low enough dose, or at a sufficiently low dose rate, radiation risk reduces to zero in a population. We conclude that insufficient evidence exists at present to support such a conclusion. In part this reflects statistical limitations at low doses, and in part (although mechanisms unquestionably exist to protect us against much of the damage induced by ionizing radiation) the biological heterogeneity of human populations, which means these mechanisms do not act in all members of the population at all times. If it is going to be possible to demonstrate that low doses are less dangerous than we presently assume, the evidence, paradoxically, will likely come from studies of higher dose and dose rate scenarios than are encountered occupationally. (author)

  5. Biological effects of low-dose ionizing radiation exposure

    International Nuclear Information System (INIS)

    Reinoehl-Kompa, Sabine; Baldauf, Daniela; Heller, Horst

    2009-01-01

    The report on the meeting of the Strahlenschutzkommission 2007 concerning biological effects of low-dose ionizing radiation exposure includes the following contributions: Adaptive response. The importance of DNA damage mechanisms for the biological efficiency of low-energy photons. Radiation effects in mammography: the relative biological radiation effects of low-energy photons. Radiation-induced cataracts. Carcinomas following prenatal radiation exposure. Intercellular apoptosis induction and low-dose irradiation: possible consequences for the oncogenesis control. Mechanistic models for the carcinogenesis with radiation-induced cell inactivation: application to all solid tumors in the Japanese atomic bomb survivors. Microarrays at low radiation doses. Mouse models for the analysis of biological effects of low-dose ionizing radiation. The bystander effect: observations, mechanisms and implications. Lung carcinoma risk of Majak workers - modeling of carcinogenesis and the bystander effect. Microbeam studies in radiation biology - an overview. Carcinogenesis models with radiation-induced genomic instability. Application to two epidemiological cohorts.

  6. Low doses of arsenic, via perturbing p53, promotes tumorigenesis

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, Suthakar, E-mail: s.ganapathy@neu.edu [Center for Drug Development, Northeastern University, Boston (United States); Li, Ping [The First Affiliated Hospital, Zhengzhou University, Zhengzhou (China); The Institute of Clinic Sciences, Sahlgrenska Academy, Gothenburg (Sweden); Fagman, Johan [The Institute of Clinic Sciences, Sahlgrenska Academy, Gothenburg (Sweden); Yu, Tianqi; Lafontant, Jean [Center for Drug Development, Northeastern University, Boston (United States); Zhang, Guojun [The First Affiliated Hospital, Zhengzhou University, Zhengzhou (China); Chen, Changyan [Center for Drug Development, Northeastern University, Boston (United States); The Institute of Clinic Sciences, Sahlgrenska Academy, Gothenburg (Sweden)

    2016-09-01

    In drinking water and in workplace or living environments, low doses of arsenic can exist and operate as a potent carcinogen. Due to insufficient understanding and information on the pervasiveness of environmental exposures to arsenic, there is an urgent need to elucidate the underlying molecular mechanisms of arsenic regarding its carcinogenic effect on human health. In this study, we demonstrate that low doses of arsenic exposure mitigate or mask p53 function and further perturb intracellular redox state, which triggers persistent endoplasmic reticulum (ER) stress and activates UPR (unfolded protein response), leading to transformation or tumorigenesis. Thus, the results suggest that low doses of arsenic exposure, through attenuating p53-regulated tumor suppressive function, change the state of intracellular redox and create a microenvironment for tumorigenesis. Our study also provides the information for designing more effective strategies to prevent or treat human cancers initiated by arsenic exposure.

  7. Low doses of arsenic, via perturbing p53, promotes tumorigenesis

    International Nuclear Information System (INIS)

    Ganapathy, Suthakar; Li, Ping; Fagman, Johan; Yu, Tianqi; Lafontant, Jean; Zhang, Guojun; Chen, Changyan

    2016-01-01

    In drinking water and in workplace or living environments, low doses of arsenic can exist and operate as a potent carcinogen. Due to insufficient understanding and information on the pervasiveness of environmental exposures to arsenic, there is an urgent need to elucidate the underlying molecular mechanisms of arsenic regarding its carcinogenic effect on human health. In this study, we demonstrate that low doses of arsenic exposure mitigate or mask p53 function and further perturb intracellular redox state, which triggers persistent endoplasmic reticulum (ER) stress and activates UPR (unfolded protein response), leading to transformation or tumorigenesis. Thus, the results suggest that low doses of arsenic exposure, through attenuating p53-regulated tumor suppressive function, change the state of intracellular redox and create a microenvironment for tumorigenesis. Our study also provides the information for designing more effective strategies to prevent or treat human cancers initiated by arsenic exposure.

  8. Regulatory aspects of low doses control in Albania

    International Nuclear Information System (INIS)

    Dollani, K.; Kushe, R.

    1997-01-01

    In the present paper are described the status of regulatory aspects of low doses control as well as the existing procedures for their implementation in Albania. According to new Radiological Protection Act, approved by Parliament in 1995, the establishment of the infrastructures in radiation protection area is in course, accompanied by the installation and functioning of new equipment for low dose control. Based in many years experience it is concluded that personal doses of the workers added by practices in Albania are 1/10 of dose Emits. Some particular cases of overexposured workers were investigated. Last times the elements of the optimisation procedures (QA and QC) are outlined in the frame of improving regulatory aspects of low doses control. (author)

  9. Low-Dose Risk, Decisions, and Risk Communication

    International Nuclear Information System (INIS)

    Flynn, James; Slovic, Paul

    2001-01-01

    To conduct basic research on how people receive, evaluate, and form positions on scientific information and its relationship to low-dose radiation exposure. There are three major areas of study in our research program. First is the development of theories, frameworks and concepts essential to guiding data collection and analysis. The second area is a program of experimental studies on risk perception, evaluation of science information, and the structure of individual positions regarding low dose exposures. This involves the study of existing knowledge and the evaluation of science information presented within a variety of formats, as educational information, news media stories, and alternative communication methods (personal contact, small group interaction, email and internet, etc.). Third is the community-level studies to examine and record how the social conditions, under which science communications take place, influence the development of attitudes and opinions about: low- dose exposures, the available management options, control of radiation risks, and preferences for program and policy goals

  10. Effects of low dose radiation and epigenetic regulation

    International Nuclear Information System (INIS)

    Jiao Benzheng; Ma Shumei; Yi Heqing; Kong Dejuan; Zhao Guangtong; Gao Lin; Liu Xiaodong

    2010-01-01

    Purpose: To conclude the relationship between epigenetics regulation and radiation responses, especially in low-dose area. Methods: The literature was examined for papers related to the topics of DNA methylation, histone modifications, chromatin remodeling and non-coding RNA modulation in low-dose radiation responses. Results: DNA methylation and radiation can regulate reciprocally, especially in low-dose radiation responses. The relationship between histone methylation and radiation mainly exists in the high-dose radiation area; histone deacetylase (HDAC) inhibitors show a promising application to enhance radiation sensitivity, no matter whether in low-dose or high-dose areas; the connection between γ-H2AX and LDR has been remained unknown, although γ-H2AX has been shown no radiation sensitivities with 1-15 Gy irradiation; histone ubiquitination play an important role in DNA damage repair mechanism. Moreover, chromatin remodeling has an integral role in DSB repair and the chromatin response, in general, may be precede DNA end resection. Finally, the effect of radiation on miRNA expression seems to vary according to cell type, radiation dose, and post-irradiation time point. Conclusion: Although the advance of epigenetic regulation on radiation responses, which we are managing to elucidate in this review, has been concluded, there are many questions and blind blots deserved to investigated, especially in low-dose radiation area. However, as progress on epigenetics, we believe that many new elements will be identified in the low-dose radiation responses which may put new sights into the mechanisms of radiation responses and radiotherapy. (authors)

  11. Low-dose vaporized cannabis significantly improves neuropathic pain.

    Science.gov (United States)

    Wilsey, Barth; Marcotte, Thomas; Deutsch, Reena; Gouaux, Ben; Sakai, Staci; Donaghe, Haylee

    2013-02-01

    We conducted a double-blind, placebo-controlled, crossover study evaluating the analgesic efficacy of vaporized cannabis in subjects, the majority of whom were experiencing neuropathic pain despite traditional treatment. Thirty-nine patients with central and peripheral neuropathic pain underwent a standardized procedure for inhaling medium-dose (3.53%), low-dose (1.29%), or placebo cannabis with the primary outcome being visual analog scale pain intensity. Psychoactive side effects and neuropsychological performance were also evaluated. Mixed-effects regression models demonstrated an analgesic response to vaporized cannabis. There was no significant difference between the 2 active dose groups' results (P > .7). The number needed to treat (NNT) to achieve 30% pain reduction was 3.2 for placebo versus low-dose, 2.9 for placebo versus medium-dose, and 25 for medium- versus low-dose. As these NNTs are comparable to those of traditional neuropathic pain medications, cannabis has analgesic efficacy with the low dose being as effective a pain reliever as the medium dose. Psychoactive effects were minimal and well tolerated, and neuropsychological effects were of limited duration and readily reversible within 1 to 2 hours. Vaporized cannabis, even at low doses, may present an effective option for patients with treatment-resistant neuropathic pain. The analgesia obtained from a low dose of delta-9-tetrahydrocannabinol (1.29%) in patients, most of whom were experiencing neuropathic pain despite conventional treatments, is a clinically significant outcome. In general, the effect sizes on cognitive testing were consistent with this minimal dose. As a result, one might not anticipate a significant impact on daily functioning. Published by Elsevier Inc.

  12. The researches on the effects of low doses irradiation

    International Nuclear Information System (INIS)

    2009-02-01

    All research conducted as part of 'Risc-Rad' and those conducted by actors in international programs on low doses allow progress in understanding mechanisms of carcinogenesis associated with irradiation. The data do not question the use in radiation protection, risk estimation models based on a linear increase of the risk with the dose of radiation. Nevertheless, they show that the nature of biological responses induced by low doses of radiation has differences with the responses induced by high doses of radiation. They also show the diversity of effects/dose relationships as the mechanism observed and the importance of genetic predisposition in the individual sensitivity to low doses of radiation. It is therefore essential to continue to bring new data to better understand the complex biological effects and their impact on the establishment of radiation protection standards. In addition, the results have often been at the cellular level. The diversity of responses induced by radiations is also a function of cell types observed, the aging of cells and tissue organization. It is essential to strengthen researches at the tissue and body level, involving in vitro and in vivo approaches while testing the hypothesis in epidemiology with a global approach to systems biology. Over the past four years, the collaboration between partners of 'Risc-Rad' using experimental biology approaches and those using mathematical modeling techniques aimed at developing a new model describing the carcinogenesis induced by low radiation doses. On an other hand, The High level expert group on European low dose risk research (H.L.E.G.) develop programmes in the area of low dose irradiation (Germany, Finland, France, Italy and United Kingdom). It proposed a structure of trans national government called M.E.L.O.D.I. ( multidisciplinary european low dose initiative). Its objective is to structure and integrate European research by gathering around a common programme of multidisciplinary

  13. Some remarks on the significance of low doses

    International Nuclear Information System (INIS)

    Cigna, A.A.

    1989-12-01

    The criteria of the present system of individual dose limitation are considered as well as the evolution of the limiting values. The assumption of the linearity of the dose-effect relationship without any threshold is probably the best approach to adopt for recommendations in radiation protection and for accounting the doses acquired by exposure to ionizing radiation. On the other hand the present evaluation of the natural background could imply a different dose-effect relationship in the low doses region and perhaps the existence of a threshold. Therefore the extrapolations which are usually made after exposures of different groups of people to low doses cannot be considered as scientifically sound. (author)

  14. Refractory Cushing's disease caused by multinodular ACTH-cell hyperplasia.

    Science.gov (United States)

    McKeever, P E; Koppelman, M C; Metcalf, D; Quindlen, E; Kornblith, P L; Strott, C A; Howard, R; Smith, B H

    1982-09-01

    A patient with pituitary-dependent hypercortisolism, unresponsive to resection of nodules in the anterior lobe, is described. Histochemical stains of the nodules showed multiple, focal, cellular expansions of the fibrovascular stroma. Transitions between normal and expanded adenohypophysial acini were present. Immunoperoxidase stains for ACTH and other pituitary hormones revealed that these multiple foci contained an excess of ACTH-positive cells. Less than 10% of the cells in these foci were negative for ACTH and positive for other hormones. Serial sections showed that these foci of predominantly ACTH-producing acini were not connected. Clinical, morphological, and immunohistochemical data indicated that ACTH-cell hyperplasia caused Crushing's disease in this patient. Pathologic study of individual cases should concentrate on determining whether hyperplasia or adenoma exist at the time of surgical exploration of the pituitary gland, since this determination is important to proper treatment. Tentative criteria to recognize ACTH-cell hyperplasia are: 1. Multiple foci of ACTH laden cells. 2. A minor subpopulation of cells of alternate hormone series. 3. Expansion without destruction of acini in the adenohypophysis.

  15. Influence of heparin on radioimmunological assay of ACTH

    International Nuclear Information System (INIS)

    Dupouy, J.P.; Godaut, M.; Chatelain, A.

    1986-01-01

    1 - Heparin traps plasma ACTH, promoting the formation of aggregates with apparent high molecular weight as shown by chromatography on Sephadex G 50 fine columns. The percentage of 125 I-ACTH which appeared in the void volume of the column, increased linearly with the log. dose of heparin. 2 - Heparin at concentrations of up to 100 IU/ml does not impair ACTH adsorption on either silicic acid or Quso G 32 as well as further elution by acetic acid/acetone/water (I: 40: 59; V/V) or HCl O.I N. Silicic acid traps selectively ACTH but not heparin. 3 - Heparin interferes with direct RIA-ACTH in the plasma by decreasing 125 I-ACTH binding to the antibodies and modifying the slope of the standard curve. Unsuitable artefacts induced by heparin, as overestimation or underestimation of plasma ACTH levels by RIA, can be avoid by previous hormone extraction from heparinized plasmas. Such results emphasized the importance of the sample preparation in order to obtain consistent results [fr

  16. Late effects of low-dose ionizing radiation on man

    International Nuclear Information System (INIS)

    Brilliant, M.D.; Vorob'ev, A.I.; Gogin, E.E.

    1987-01-01

    One of the most important problems, being stated before the medicine by the accident, which took place in Chernobyl in 1986- the problem of the so-called ionizing radiation low dose effect on a man's organism, is considered because a lot of people were subjected to low dose action. The concept of low doses of radiaion action and specificity of its immediate action in comparison with high dose action is considered. One of the most important poit while studying low dose action is the necessity to develop a system including all irradiated people and dosimetry, and espicially to study frequencies and periods of tumor appearance in different irradiated tissues. The results obtained when examining people who survived the atomic explosion in Japan and on the Marshall islands are analyzed. They testify to the fact that radiation affets more tissues than the clinical picture about the acute radiation sickness tells, and that tumors developing in them many years after radiation action tell about radiosensitivity in some tissues

  17. Use of combined paracetamol and low dose ketamine in pain ...

    African Journals Online (AJOL)

    Objective: To determine the effectiveness of Paracetamol and low dose Ketamine in controlling burn pain during dressings. Setting: The burns ward of Moi Teaching and Referral Hospital, a 750 bed capacity tertiary centre in Western Kenya. Subjects: Consenting patients were recruited to the study on admission. Babies and ...

  18. Low-dose aspirin and risk of intracranial bleeds

    DEFF Research Database (Denmark)

    Cea Soriano, Lucía; Gaist, David; Soriano-Gabarró, Montse

    2017-01-01

    cohort of nonusers of low-dose aspirin at baseline were followed (maximum 14 years, median 5.4 years) to identify incident cases of ICB, with validation by manual review of patient records or linkage to hospitalization data. Using 10,000 frequency-matched controls, adjusted rate ratios (RRs) with 95...

  19. Biological effects of very low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Evseev, V.S.

    1987-01-01

    The paper deals with a qualitative microdosimetric analysis of a new radiobiological phenomenon (physiological reaction of the cell as a whole to very low doses of ionizing radiations). The analysis is aimed at identifying the type of the primary interaction of radiation with the cell and finding its place in the cell

  20. Advance of study on hormesis of low dose radiation

    International Nuclear Information System (INIS)

    Su Liaoyuan

    2003-01-01

    There have been growing interests in recent years over the effects of low doses of ionizing radiation on human. The paper gives a brief review on the LDR studies, which include LDR-induced hormesis and adaptive response, LDR experiments in vivo or in vitro and epidemiologic investigation, and clinical applications of LDR as well

  1. Low dose CT simulation using experimental noise model

    Energy Technology Data Exchange (ETDEWEB)

    Nakanishi, Satori; Zamyatin, Alexander A. [Toshiba Medical Systems Corporation, Tochigi, Otawarashi (Japan); Silver, Michael D. [Toshiba Medical Research Institute, Vernon Hills, IL (United States)

    2011-07-01

    We suggest a method to obtain system noise model experimentally without relying on assumptions on statistical distribution of the noise; also, knowledge of DAS gain and electronic noise level are not required. Evaluation with ultra-low dose CT data (5 mAs) shows good match between simulated and real data noise. (orig.)

  2. CARCINOGENIC EFFECTS OF LOW DOSES OF IONIZING RADIATION

    Science.gov (United States)

    Carcinogenic Effects of Low Doses of Ionizing RadiationR Julian Preston, Environmental Carcinogenesis Division, NHEERL, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711The form of the dose-response curve for radiation-induced cancers, particu...

  3. Malignant melanoma of the tongue following low-dose radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kalemeris, G.C.; Rosenfeld, L.; Gray, G.F. Jr.; Glick, A.D.

    1985-03-01

    A 47-year-old man had a spindly malignant melanoma of the tongue many years after low-dose radiation therapy for lichen planus. To our knowledge, only 12 melanomas of the tongue have been reported previously, and in none of these was radiation documented.

  4. Malignant melanoma of the tongue following low-dose radiation

    International Nuclear Information System (INIS)

    Kalemeris, G.C.; Rosenfeld, L.; Gray, G.F. Jr.; Glick, A.D.

    1985-01-01

    A 47-year-old man had a spindly malignant melanoma of the tongue many years after low-dose radiation therapy for lichen planus. To our knowledge, only 12 melanomas of the tongue have been reported previously, and in none of these was radiation documented

  5. Health hazards of low doses of ionizing radiations. Vo. 1

    International Nuclear Information System (INIS)

    El-Naggar, M.A.

    1996-01-01

    Exposure to high doses of ionizing radiation results in clinical manifestations of several disease entities that may be fatal. The onset and severity of these acute radiation syndromes are deterministic in relation to dose magnitude. Exposure to ionizing radiations at low doses and low dose rates could initiate certain damage in critical molecules of the cell, that may develop in time into serious health effects. The incidence of such delayed effects in low, and is only detectable through sophisticated epidemiological models carried out on large populations. The radiation damage induced in critical molecules of cells may develop by stochastic biochemical mechanisms of repair, residual damage, adaptive response, cellular transformation, promotion and progression into delayed health effects, the most important of which is carcinogenesis. The dose response relationship of probabilistic stochastic delayed effects of radiation at low doses and low dose rates, is very complex indeed. The purpose of this review is to provide a comprehensive understanding of the underlying mechanisms, the factors involved, and the uncertainties encountered. Contrary to acute deterministic effects, the occurrence of probabilistic delayed effects of radiation remains to be enigmatic. 7 figs

  6. Mechanisms of Low Dose Radio-Suppression of Genomic Instability

    Energy Technology Data Exchange (ETDEWEB)

    Engelward, Bevin P. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2009-09-16

    The major goal of this project is to contribute toward the elucidation of the impact of long term low dose radiation on genomic stability. We have created and characterized novel technologies for delivering long term low dose radiation to animals, and we have studied genomic stability by applying cutting edge molecular analysis technologies. Remarkably, we have found that a dose rate that is 300X higher than background radiation does not lead to any detectable genomic damage, nor is there any significant change in gene expression for genes pertinent to the DNA damage response. These results point to the critical importance of dose rate, rather than just total dose, when evaluating public health risks and when creating regulatory guidelines. In addition to these studies, we have also further developed a mouse model for quantifying cells that have undergone a large scale DNA sequence rearrangement via homologous recombination, and we have applied these mice in studies of both low dose radiation and space radiation. In addition to more traditional approaches for assessing genomic stability, we have also explored radiation and possible beneficial effects (adaptive response), long term effects (persistent effects) and effects on communication among cells (bystander effects), both in vitro and in vivo. In terms of the adaptive response, we have not observed any significant induction of an adaptive response following long term low dose radiation in vivo, delivered at 300X background. In terms of persistent and bystander effects, we have revealed evidence of a bystander effect in vivo and with researchers at and demonstrated for the first time the molecular mechanism by which cells “remember” radiation exposure. Understanding the underlying molecular mechanisms by which radiation can induce genomic instability is fundamental to our ability to assess the biological impact of low dose radiation. Finally, in a parallel set of studies we have explored the effects of heavy

  7. Rare case of Cushing's disease due to double ACTH-producing adenomas, one located in the pituitary gland and one into the stalk.

    Science.gov (United States)

    Mendola, Marco; Dolci, Alessia; Piscopello, Lanfranco; Tomei, Giustino; Bauer, Dario; Corbetta, Sabrina; Ambrosi, Bruno

    2014-01-01

    We describe a patient affected by Cushing's disease due to the presence of double pituitary adenomas, one located within the anterior pituitary and the other in the infundibulum associated with a remnant of Rakthe's pouch. Cure was achieved only after the infundibulum lesion was surgically removed. A 38-year-old female presented with unexplained weight gain, hirsutism, amenorrhea, asthenia, recurrent cutaneous micotic infections and alopecia. Hormonal studies indicated Cushing's disease and MRI showed an enlarged pituitary gland with a marked and homogeneous enhancement after injection of gadolinium and an enlarged infundibulum with a maximum diameter of 8 mm. As a venous sampling of the inferior petrosal sinus after 10 μg iv desmopressin stimulation revealed a central to peripheral ACTH ratio consistent with a pituitary ACTH-secreting tumor, transphenoidal explorative surgery was performed and a 4-mm pituitary adenoma immunopositive for ACTH was disclosed and removed. Since postoperative hormonal evaluation showed persistent hypercortisolism, confirmed by dynamic tests, the patient again underwent surgery by transcranial access and the infundibulum mass was removed. Histology and immunochemistry were consistent with an ACTH-secreting adenoma. A few months after the second operation, cushingoid features were significantly reverted and symptoms improved. Although Cushing's patients bearing multiple adenomas have already been documented, the presence of two adenomas both immunohistochemically positive for ACTH is a very rare cause of Cushing's disease and this is the first report of a case of double ACTH-producing adenomas, one located in the pituitary gland and one attached to the stalk.

  8. Personal dosimetry statistics and specifics of low dose evaluation

    International Nuclear Information System (INIS)

    Avila, R.E.; Gómez Salinas, R.A.; Oyarzún Cortés, C.H.

    2015-01-01

    The dose statistics of a personal dosimetry service, considering 35,000+ readings, display a sharp peak at low dose (below 0.5 mSv) with skewness to higher values. A measure of the dispersion is that approximately 65% of the doses fall below the average plus 2 standard deviations, an observation which may prove helpful to radiation protection agencies. Categorizing the doses by the concomitant use of a finger ring dosimeter, that skewness is larger in the whole body, and ring dosimeters. The use of Harshaw 5500 readers at high gain leads to frequent values of the glow curve that are judged to be spurious, i.e. values not belonging to the roughly normal noise over the curve. A statistical criterion is shown for identifying those anomalous values, and replacing them with the local behavior, as fit by a cubic polynomial. As a result, the doses above 0.05 mSv which are affected by more than 2% comprise over 10% of the data base. The low dose peak of the statistics, above, has focused our attention on the evaluation of LiF(Mg,Ti) dosimeters exposed at low dose, and read with Harshaw 5500 readers. The standard linear procedure, via an overall reader calibration factor, is observed to fail at low dose, in detailed calibrations from 0.02 mSv to 1 Sv. A significant improvement is achieved by a piecewise polynomials calibration curve. A cubic, at low dose is matched, at ∼10 mSv, in value and first derivative, to a linear dependence at higher doses. This improvement is particularly noticeable below 2 mSv, where over 60% of the evaluated dosimeters are found. (author)

  9. The effect of low-dose X-irradiation on immune system

    International Nuclear Information System (INIS)

    Ishii, Keiichiro

    1996-01-01

    The hypothesis of radiation hormesis has been proposed. To elucidate the hormetic effect on the immune system, we studied the mitogen-induced proliferation of splenocytes of F344/NSlc rat and BALB/c mouse after low-dose X-irradiation. Con A, PHA or LPS-induced proliferation of rat splenocytes prepared at 4 hr after irradiation was augmented with 5 cGy. This augmentation was observed within a few hours after irradiation, being a temporary effect. In case of mice, the proliferation of splenocytes induced by Con A, PHA or LPS was augmented by irradiation with 2.5 cGy. Thus, some phenomena of hormetic effect on the immune system were observed. However, the mechanism of augmentation of immune splenocytes is uncertainty. Therefore, we examined changes in production of LTB 4 and IL-1 being inflammatory mediators. After 5 cGy irradiation the production of LTB 4 of rat splenocyte showed a significant increase. Furthermore, 2.5 cGy irradiation also enhanced, the biological activity of intracellular IL-1 of LPS-stimulated mouse splenocytes. Additionally, to elucidate the stimulative effect on the antitumor immunity by low-dose X-irradiation, we studied the changes in the incidence of thymic lymphoma using AKR mice and of spontaneous metastasis to lung using tumor bearing mice. The incidence of thymic lymphoma was significantly decreased and the life span was significantly prolonged by periodical low-dose X-irradiation in terms of breeding of AKR mice. By an irradiation with 15 cGy, numbers of lung colony in the tumor bearing mice were decreased by 57% relative to the sham-irradiated controls. Then, IL-6 and TNF-α production of tumor bearing mice splenocytes were enhanced. These findings suggest that the low-dose X-irradiation might have caused a light inflammation and might have induced an augmentation of immune splenocytes. Furthermore, these results indicate that an augmentation of the antitumor immunity was induced by low-dose X-irradiation. (author). 127 refs

  10. The effect of low-dose X-irradiation on immune system

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Keiichiro [Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan). Komae Research Lab.

    1996-06-01

    The hypothesis of radiation hormesis has been proposed. To elucidate the hormetic effect on the immune system, we studied the mitogen-induced proliferation of splenocytes of F344/NSlc rat and BALB/c mouse after low-dose X-irradiation. Con A, PHA or LPS-induced proliferation of rat splenocytes prepared at 4 hr after irradiation was augmented with 5 cGy. This augmentation was observed within a few hours after irradiation, being a temporary effect. In case of mice, the proliferation of splenocytes induced by Con A, PHA or LPS was augmented by irradiation with 2.5 cGy. Thus, some phenomena of hormetic effect on the immune system were observed. However, the mechanism of augmentation of immune splenocytes is uncertainty. Therefore, we examined changes in production of LTB{sub 4} and IL-1 being inflammatory mediators. After 5 cGy irradiation the production of LTB{sub 4} of rat splenocyte showed a significant increase. Furthermore, 2.5 cGy irradiation also enhanced, the biological activity of intracellular IL-1 of LPS-stimulated mouse splenocytes. Additionally, to elucidate the stimulative effect on the antitumor immunity by low-dose X-irradiation, we studied the changes in the incidence of thymic lymphoma using AKR mice and of spontaneous metastasis to lung using tumor bearing mice. The incidence of thymic lymphoma was significantly decreased and the life span was significantly prolonged by periodical low-dose X-irradiation in terms of breeding of AKR mice. By an irradiation with 15 cGy, numbers of lung colony in the tumor bearing mice were decreased by 57% relative to the sham-irradiated controls. Then, IL-6 and TNF-{alpha} production of tumor bearing mice splenocytes were enhanced. These findings suggest that the low-dose X-irradiation might have caused a light inflammation and might have induced an augmentation of immune splenocytes. Furthermore, these results indicate that an augmentation of the antitumor immunity was induced by low-dose X-irradiation. 127 refs.

  11. Low doses of six toxicants change plant size distribution in dense populations of Lactuca sativa.

    Science.gov (United States)

    Belz, Regina G; Patama, Marjo; Sinkkonen, Aki

    2018-08-01

    Toxicants are known to have negligible or stimulatory, i.e. hormetic, effects at low doses below those that decrease the mean response of a plant population. Our earlier observations indicated that at such low toxicant doses the growth of very fast- and slow-growing seedlings is selectively altered, even if the population mean remains constant. Currently, it is not known how common these selective low-dose effects are, whether they are similar among fast- and slow-growing seedlings, and whether they occur concurrently with hormetic effects. We tested the response of Lactuca sativa in complete dose-response experiments to six different toxicants at doses that did not decrease population mean and beyond. The tested toxicants were IAA, parthenin, HHCB, 4-tert-octylphenol, glyphosate, and pelargonic acid. Each experiment consisted of 14,400-16,800 seedlings, 12-14 concentrations, 24 replicates per concentration and 50 germinated seeds per replicate. We analyzed the commonness of selective low-dose effects and explored if toxic effects and hormetic stimulation among fast- and slow-growing individuals occurred at the same concentrations as they occur at the population level. Irrespective of the observed response pattern and toxicant, selective low-dose effects were found. Toxin effects among fast-growing individuals usually started at higher doses compared to the population mean, while the opposite was found among slow-growing individuals. Very low toxin exposures tended to homogenize plant populations due to selective effects, while higher, but still hormetic doses tended to heterogenize plant populations. Although the extent of observed size segregation varied with the specific toxin tested, we conclude that a dose-dependent alteration in size distribution of a plant population may generally apply for many toxin exposures. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. The treatment of autism with low-dose phenytoin: a case report.

    Science.gov (United States)

    Bird, Philip D

    2015-01-16

    The drug treatment of autism spectrum disorders is often poorly tolerated and has traditionally targeted associated conditions (such as inattention or irritability) that frequently coexist, with limited benefit for the core social deficits. Here, I describe the novel use of a low dose of the anti-epileptic phenytoin to enhance social functioning in a patient with an autism spectrum disorder. I present the case of a 19-year-old Caucasian man with autism spectrum disorder treated with stimulant medication since early childhood. He experienced long-standing difficulties in establishing and maintaining relationships and reading social cues, and was socially isolated. Within 10 minutes of a single sublingual low dose of phenytoin there was an immediate observable improvement in his eye contact and integration of both verbal and non-verbal communication. This enhanced social functioning associated with his adherence to the low-dose phenytoin therapy was maintained for over 18 months of follow-up. These clinical observations were supported by ratings using the Autism-Spectrum Quotient and the Depression, Anxiety and Stress Scales, recorded pre-treatment and after seven months on 5mg phenytoin. This case report provides the first potential evidence that a low dose of phenytoin, a widely used and well tolerated anti-epileptic medication, may be capable of modifying the core social cognitive deficits associated with autism spectrum disorders. While acknowledging this is a single case study, the lack of availability of safe and effective treatments to address the important core deficits associated with autism spectrum disorders makes this case noteworthy.

  13. ACTH-secreting bronchial carcinoid: a diagnostic and therapeutic challenge.

    LENUS (Irish Health Repository)

    McDermott, J H

    2008-09-01

    We describe a case of Cushing\\'s syndrome due to ectopic ACTH secretion, where the only potential source on conventional imaging was a tiny benign-appearing lung nodule, which failed to take up radiolabelled octreotide.

  14. Comparison of hyperuricemia in type 2 diabetics on low dose aspirin and not on low dose aspirin

    International Nuclear Information System (INIS)

    Malik, M.I.

    2013-01-01

    Objective: To compare the frequency of hyperuricemia in type 2 diabetes patients who are taking low dose aspirin with those patients who are not taking low dose aspirin. Study design: Quasi experimental study. Place and duration of study: This study was carried out at Military Hospital Rawalpindi for a period of two years (June 2006-May 2008). Patients and Methods: Sixty diabetic patients were selected who were taking low dose aspirin comparing group A and sixty diabetic patients who were not taking aspirin were placed in group B. These patients were selected from the OPD through non probability convenience sampling. All these patients were being followed up in medical outpatient quite regularly on fort-nightly basis. Data had been collected through a carefully designed questionnaire. Results: In group A, 90% of the patients had uric acid less than 445 micro mol/l and 10% of the patients had uric acid more than 445micro mol/l. Whereas in group B 100% of the patients had uric acid less than 445umol/l, there was a statistically significant difference between the two groups (p< 0.05). Conclusion: Aspirin in low doses cause hyperuricemia and regular monitoring of uric acid is mandatory to prevent its adverse effects. (author)

  15. Effects of low dose gamma-ray radiation on the seed germination and physiological activity of vegetable crops

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. S.; Baek, M. H.; Lee, Y. G. [KAERI, Taejon (Korea, Republic of); Jung, K. H. [Kyunghee Univ., Yongin (Korea, Republic of)

    2000-10-01

    To determine the effect of low dose gamma-ray radiation on the germination rate and physiology of germinative seeds of Chinese cabbage(Brassica campestris L. cv. Hanyoreum) and radish(Raphanus sativus L. cv. Chungsukoungzoung). The germination rate of irradiation group was higher than that of the control. Especially it was highest at the early stage of induction. The germination rate of Chinese cabbage increased at 4 Gy-, 10 Gy- and 50 Gy irradiation group and that of radish increased at 2 Gy-, 6 Gy- and 10 Gy irradiation group. The seedling height of Chinese cabbage and radish increased positively in low dose irradiation group. The seedling height of Chinese cabbage was noticeably higher at 4 Gy and 10 Gy irradiation group and that of radish at 6 Gy irradiation group. The protein contents of seeds irradiated with low dose gamma-ray radiation was increased compared to that of the control especially at the early stage of induction. The enzyme activity of seeds irradiated with low dose of gamma-ray radiation was increased at 4 Gy and 10 Gy irradiation group. These results suggest that the germination and physiological activity of old seeds could be stimulated promisingly by the low dose gamma-ray radiation.

  16. ACTH radioimmunocytochemistry (RICH) on rat anterior pituitary cells

    International Nuclear Information System (INIS)

    Rappay, G.; Karteszi, M.; Makara, G.B.

    1979-01-01

    Radioimmunocytochemistry (RICH) was applied to detect corticotrophs in adult rat pituitaries and 8-day-old anterior pituitary monolayers by incubating sections and cultures with 125 I-ACTH-anti ACTH immune complexes. After incubations autoradiography was made. In comparison, 'conventional' immunostaining was carried out on adjacent sections and parallel cultures. It has been established that RICH is suitable for detection of corticotrophs. (orig.) [de

  17. A Paradigm Shift in Low Dose Radiation Biology

    Directory of Open Access Journals (Sweden)

    Z. Alatas

    2015-08-01

    Full Text Available When ionizing radiation traverses biological material, some energy depositions occur and ionize directly deoxyribonucleic acid (DNA molecules, the critical target. A classical paradigm in radiobiology is that the deposition of energy in the cell nucleus and the resulting damage to DNA are responsible for the detrimental biological effects of radiation. It is presumed that no radiation effect would be expected in cells that receive no direct radiation exposure through nucleus. The risks of exposure to low dose ionizing radiation are estimated by extrapolating from data obtained after exposure to high dose radiation. However, the validity of using this dose-response model is controversial because evidence accumulated over the past decade has indicated that living organisms, including humans, respond differently to low dose radiation than they do to high dose radiation. Moreover, recent experimental evidences from many laboratories reveal the fact that radiation effects also occur in cells that were not exposed to radiation and in the progeny of irradiated cells at delayed times after radiation exposure where cells do not encounter direct DNA damage. Recently, the classical paradigm in radiobiology has been shifted from the nucleus, specifically the DNA, as the principal target for the biological effects of radiation to cells. The universality of target theory has been challenged by phenomena of radiation-induced genomic instability, bystander effect and adaptive response. The new radiation biology paradigm would cover both targeted and non-targeted effects of ionizing radiation. The mechanisms underlying these responses involve biochemical/molecular signals that respond to targeted and non-targeted events. These results brought in understanding that the biological response to low dose radiation at tissue or organism level is a complex process of integrated response of cellular targets as well as extra-cellular factors. Biological understanding of

  18. Genetic Factors Affecting Susceptibility to Low Dose & Low Dose-Rate Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bedford, Joel

    2014-04-18

    Our laboratory has, among other things, developed and used the gamma H2AX focus assay and other chromosomal and cell killing assays to show that differences in this DNA double strand break (dsb) related response can be clearly and distinctly demonstrated for cells which are mildly hyper-radiosensitive such as those associated with A-T heterozygosity. We have found this level of mild hypersensitivity for cells from some 20 to 30 % of apparently normal individuals and from apparently normal parents of Retinoblastoma patients. We found significant differences in gene expression in somatic cells from unaffected parents of Rb patients as compared with normal controls, suggesting that these parents may harbor some as yet unidentified genetic abnormality. In other experiments we sought to determine the extent of differences in normal human cellular reaponses to radiation depending on their irradiation in 2D monolayer vs 3D organized acinar growth conditions. We exmined cell reproductive death, chromosomal aberration induction, and the levels of γ-H2AX foci in cells after single acute gamma-ray doses and immediately after 20 hours of irradiation at a dose rate of 0.0017 Gy/min. We found no significant differences in the dose-responses of these cells under the 2D or 3D growth conditions. While this does not mean such differences cannot occur in other situations, it does mean that they do not generally or necessarily occur. In another series of studies in collaboration with Dr Chuan Li, with supprt from this current grant. We reported a role for apoptotic cell death in promoting wound healing and tissue regeneration in mice. Apoptotic cells released growth signals that stimulated the proliferation of progenitor or stem cells. In yet another collaboration with Dr, B. Chen with funds from this grant, the relative radiosensitivity to cell killing as well as chromosomal instability of 13 DNA-PKcs site-directed mutant cell lines (defective at phosphorylation sites or kinase

  19. Addition of low-dose ketamine to midazolam and low-dose bupivacaine improves hemodynamics and postoperative analgesia during spinal anesthesia for cesarean section

    Directory of Open Access Journals (Sweden)

    Ahmed Sobhy Basuni

    2016-01-01

    Conclusion: Intrathecal low-dose ketamine combined with midazolam and low-dose bupivacaine stabilizes hemodynamics and prolongs postoperative analgesia without significant side-effects in parturients undergoing CS.

  20. Repair and dose-response at low doses

    International Nuclear Information System (INIS)

    Totter, J.R.; Weinberg, A.M.

    1977-04-01

    The DNA of each individual is subject to formation of some 2-4 x 10 14 ion pairs during the first 30 years of life from background radiation. If a single hit is sufficient to cause cancer, as is implicit in the linear, no-threshold theories, it is unclear why all individuals do not succumb to cancer, unless repair mechanisms operate to remove the damage. We describe a simple model in which the exposed population displays a distribution of repair thresholds. The dose-response at low dose is shown to depend on the shape of the threshold distribution at low thresholds. If the probability of zero threshold is zero, the response at low dose is quadratic. The model is used to resolve a longstanding discrepancy between observed incidence of leukemia at Nagasaki and the predictions of the usual linear hypothesis

  1. Response of human fibroblasts to low dose rate gamma irradiation

    International Nuclear Information System (INIS)

    Dritschilo, A.; Brennan, T.; Weichselbaum, R.R.; Mossman, K.L.

    1984-01-01

    Cells from 11 human strains, including fibroblasts from patients with the genetic diseases of ataxia telangiectasia (AT), xeroderma pigmentosum (XP), and Fanconi's anemia (FA), were exposed to γ radiation at high (1.6-2.2 Gy/min) and at low (0.03-0.07 Gy/min) dose rates. Survival curves reveal an increase inthe terminal slope (D 0 ) when cells are irradiated at low dose rates compared to high dose rates. This was true for all cell lines tested, although the AT, FA, and XP cells are reported or postulated to have radiation repair deficiencies. From the response of these cells, it is apparent that radiation sensitivities differ; however, at low dose rate, all tested human cells are able to repair injury

  2. Low dose CT in early lung cancer diagnosis: prevalence data

    International Nuclear Information System (INIS)

    Cardinale, Luciano; Cortese, Giancarlo; Ferraris, Fabrizio; Perotto, Fabio; Fava, Cesare; Borasio, Piero; Dogliotti, Luigi; Novello, Silvia; Scagliotti, Giorgio

    2005-01-01

    Purpose. Lung cancer has a high mortality rate and its prognosis largely depends on early detection. We report the prevalence data of the study on early detection of lung cancer with low-dose spiral CT underway at our hospital. Materials and methods. Since the beginning of 2001, 519 asymptomatic volunteers have undergone annual blood tests, sputum tests, urinalyses and low-dose spiral CT. The inclusion criteria were age (55 years old), a history of cigarette smoking and a negative history for previous neoplastic disease. The diagnostic workup varied depending on the size and CT features of the nodules detected. Results. At baseline, the CT scan detected nodules> 5 mm in 22% of subjects; the nodules were single in 42 and multiple in 71. In 53% of cases the findings were completely negative, while in 122 (23.4%) nodules with a diameter [it

  3. Low-Dose Aspirin for the Prevention of Preeclampsia.

    Science.gov (United States)

    Fantasia, Heidi Collins

    2018-02-01

    Preeclampsia is a hypertensive disorder specific to pregnancy that remains a significant cause of maternal and neonatal morbidity and mortality. Identification of women who are most at risk for preeclampsia is imprecise. Because of the potential negative health consequences of preeclampsia for women and newborns and the lack of effective screening mechanisms preventing preeclampsia is an important component of prenatal care. Researchers have documented that low-dose aspirin, taken daily after the first trimester, can decrease the development of preeclampsia and reduce the incidence of preterm birth and birth of small-for-gestational-age infants. This column includes an overview of low-dose aspirin in pregnancy and a review of current recommendations from leading national organizations. © 2018 AWHONN, the Association of Women’s Health, Obstetric and Neonatal Nurses.

  4. The assessment of the carcinogenic effects of low dose radiation

    International Nuclear Information System (INIS)

    Tubiana, M.; Lafuma, J.; Masse, R.; Latarjet, R.

    1991-01-01

    It is concluded that the exclusion of patients for the purposes of risk estimation, the choice of a particular relative risk projection model and of a dose reduction factor equal to 2 are all decisions which result in an overestimation of the actual risk. These choices can be understood when the aim is radiation protection and when it is safer to overestimate the risk; however, they are open to criticism if the aim is a realistic assessment of the risk. For low doses, below 50 mSv/year, and when all causes of uncertainty are added, the actual risk might be markedly lower than the risk estimated with the ICRP (1991) carcinogenic risk coefficient and the DRF estimated by ICRP. Future studies should aim at providing direct and more precise assessments of risk coefficients in the low dose region. (Author)

  5. Gamma regularization based reconstruction for low dose CT

    International Nuclear Information System (INIS)

    Zhang, Junfeng; Chen, Yang; Hu, Yining; Luo, Limin; Shu, Huazhong; Li, Bicao; Liu, Jin; Coatrieux, Jean-Louis

    2015-01-01

    Reducing the radiation in computerized tomography is today a major concern in radiology. Low dose computerized tomography (LDCT) offers a sound way to deal with this problem. However, more severe noise in the reconstructed CT images is observed under low dose scan protocols (e.g. lowered tube current or voltage values). In this paper we propose a Gamma regularization based algorithm for LDCT image reconstruction. This solution is flexible and provides a good balance between the regularizations based on l 0 -norm and l 1 -norm. We evaluate the proposed approach using the projection data from simulated phantoms and scanned Catphan phantoms. Qualitative and quantitative results show that the Gamma regularization based reconstruction can perform better in both edge-preserving and noise suppression when compared with other norms. (paper)

  6. Low-dose effects hypothesis and observations on NPP personal

    Energy Technology Data Exchange (ETDEWEB)

    Georgieva, R.; Acheva, A.; Boteva, R.; Chobanova, N.; Djounova, J.; Gyuleva, I.; Ivanova, K.; Kurchatova, G.; Milchev, A.; Negoicheva, K.; Nikolov, V.; Panova, D.; Pejankov, I.; Rupova, I.; Stankova, K.; Zacharieva, E. [Radiobiology Department, National Centre of Radiobiology and Radiation Protection, Sofia (Bulgaria)

    2013-07-01

    In the modern world the use of various sources of ionizing radiation is nearly ubiquitous. They have numerous applications in industry, medicine, science, agriculture, etc. Radiation doses to workers nevertheless are commensurable to the natural background exposure. Published data on the health effects of occupational radiation exposure are often contradictory. Addressing the issue of „negative” (bystander effects, genomic instability) and „positive” (adaptive response, radiation hormesis) effects of low doses is important and has a significant social and economic impact. In this paper we summarize the results of our extensive monitoring of nuclear power plant (NPP) staff. We believe it is a cohort suitable for analysis of health effects at low doses, because of their good medical and dosimetric control. Our results rather support the idea of absence of adverse health effects in NPP workers. (author)

  7. Effect of low-dose radiation on ocular circulation

    International Nuclear Information System (INIS)

    Baba, Keiko; Hiroishi, Goro; Honda, Masae; Yoshikawa, Hiroshi; Fujisawa, Kimihiko; Ishibashi, Tatsuro

    1999-01-01

    We treated 6 eyes of unilateral age-related macular degeneration by low-dose radiation. Each eye received daily dose of 2 Gy by 4MV lineac totalling 20 Gy over 2 weeks. Color doppler flowmetry was used to determine the mean blood flow velocity (Vmean) and vascular resistive index (RI) in the short posterior ciliary artery, central retinal artery and ophthalmic artery in the treated and fellow eyes before and up to 6 months of treatment. There were no significant differences in Vmean and RI before and after treatment. The findings show the absence of apparent influence of low-dose radiation on the ocular circulation in age-related macular degeneration. (author)

  8. 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.

  9. Effect of low-dose radiation on ocular circulation

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Keiko; Hiroishi, Goro; Honda, Masae; Yoshikawa, Hiroshi; Fujisawa, Kimihiko; Ishibashi, Tatsuro [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

    1999-05-01

    We treated 6 eyes of unilateral age-related macular degeneration by low-dose radiation. Each eye received daily dose of 2 Gy by 4MV lineac totalling 20 Gy over 2 weeks. Color doppler flowmetry was used to determine the mean blood flow velocity (Vmean) and vascular resistive index (RI) in the short posterior ciliary artery, central retinal artery and ophthalmic artery in the treated and fellow eyes before and up to 6 months of treatment. There were no significant differences in Vmean and RI before and after treatment. The findings show the absence of apparent influence of low-dose radiation on the ocular circulation in age-related macular degeneration. (author)

  10. Use of low doses of cobalt 60 gamma radiation on beet (Beta vulgaris L.), carrot (Daucus carota L.) and radish (Raphanus sativus L.) seed to stimulate increase yield; Emprego da radiacao gama do cobalto 60 em sementes de beterraba (Beta vulgaris L.), cenoura (Daucus carota L.) e rabanete (Raphanus sativus L.) para estimular o aumento da producao

    Energy Technology Data Exchange (ETDEWEB)

    Bovi, Jose Eduardo

    2000-07-01

    The research had the aim of evaluating the effects of low doses of Cobalt-60 gamma radiation on seeds of radish (Raphanus sativus L.) cultiva Champion, cultivars Nantes Forto (european origin) and Brasilia (Rio Grande do Sul origin) carrot (Daucus carota L. var. sativus (Hoffm.) Thell), and red beet (Beta vulgaris L.) cultivar Tall Top Early Wonder before sowing, its effects on plant growth, on the yield and roots storage of two tillages: with sowing in the same day of radiation and six days after radiation seeds. The data showed that the seeds radiation did not interfered negatively on plants growth, and the species presented differences as roots production and doses on both plantation: radish with 5,0 Gy and 2,5 Gy doses respectively to the first and the second sowings, Brasilia carrot with 2,5 Gy dose to both sowings. Nantes carrot with 2,5 Gy and 5,0 Gy respectively to the first and the second sowings, and beet with 7,5 Gy and 5,0 Gy respectively to the first and the second plantations. There is not statistics difference by Tukey test (5% and 1%) and none relation between seeds radiation and loss weight on roots storage. (author)

  11. 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)

  12. Late effects of low doses and dose rates

    International Nuclear Information System (INIS)

    Paretzke, H.G.

    1980-01-01

    This paper outlines the spectrum of problems and approaches used in work on the derivation of quantitative prognoses of late effects in man of low doses and dose rates. The origins of principal problems encountered in radiation risks assessments, definitions and explanations of useful quantities, methods of deriving risk factors from biological and epidemiological data, and concepts of risk evaluation and problems of acceptance are individually discussed

  13. Effects of low doses; Effet des faibles doses

    Energy Technology Data Exchange (ETDEWEB)

    Le Guen, B. [Electricite de France (EDF-LAM-SCAST), 93 - Saint-Denis (France)

    2001-07-01

    Actually, even though it is comfortable for the risk management, the hypothesis of the dose-effect relationship linearity is not confirmed for any model. In particular, in the area of low dose rate delivered by low let emitters. this hypothesis is debated at the light of recent observations, notably these ones relative to the mechanisms leading to genetic instability and induction eventuality of DNA repair. The problem of strong let emitters is still to solve. (N.C.)

  14. Fruit-flies in low-dose exposure experiments

    International Nuclear Information System (INIS)

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

    2002-01-01

    In vivo exposure of fruit-flies of Drosophila melanogaster line to low doses provided new data indicating that mechanisms of induced genetic instability are involved in radiation-induced alteration of genotype. It is true for increase of genetic variance due to change in transposition number, for change in adaptation capabilities due to modification of gene expression, and for mutability-associated reparation and apoptosis. (author)

  15. Transportable, Low-Dose Active Fast-Neutron Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mihalczo, John T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wright, Michael C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McConchie, Seth M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Archer, Daniel E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Palles, Blake A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-08-01

    This document contains a description of the method of transportable, low-dose active fast-neutron imaging as developed by ORNL. The discussion begins with the technique and instrumentation and continues with the image reconstruction and analysis. The analysis discussion includes an example of how a gap smaller than the neutron production spot size and detector size can be detected and characterized depending upon the measurement time.

  16. Biological effects of low doses of ionising radiation

    International Nuclear Information System (INIS)

    Osmak, M.

    1998-01-01

    A study was performed with the aim to examine whether the progeny of cells that had been repeatedly irradiated with low doses of gamma rays will change their sensitivity to cytotoxic agents. Four mammalian cell lines were used in the experiment. It was found that the progeny of cells irradiated in this way do not change their sensitivity to gamma rays but would change their sensitivity to various cytostatics drugs. (A.K.)

  17. Low dose monitoring by double implant technique in IC fabrication

    International Nuclear Information System (INIS)

    Ahmad, I.B.; Weidemann, J.

    1995-01-01

    The utilisation of low dose implant monitoring (using Boron) in a manufacturing line has been discussed. The utilisation of phosphorus ions as the second implant dose were also studied as comparison. The technique relies on the fact that the sheet resistant of doped layer will increase significantly when damaged by relatively low implant dose. The technique is very sensitive and applicable for adjusting the channel dose so that an accurate threshold voltage in MOS device could be achieved

  18. adverse effects of low dose methotrexate in rheumatoid arthritis patients

    International Nuclear Information System (INIS)

    Gilani, S.T.; Khan, D.A.; Khan, F.A.; Ahmed, M.

    2012-01-01

    To determine the frequency of adverse effects attributed to Methotrexate (MTX) toxicity and serum minimum toxic concentration with low dose MTX in Rheumatoid Arthritis (RA) patients. Study Design: Cross-sectional observational study. Place and Duration of Study: Department of Chemical Pathology and Endocrinology, Armed Forces Institute of Pathology, Rawalpindi, from March 2010 to March 2011. Methodology: One hundred and forty adult patients of RA receiving low dose MTX (10 mg/week) for at least 3 months, ere included by consecutive sampling. Blood samples were collected 2 hours after the oral dose of MTX. Serum alanine transaminase and creatinine were analyzed on Hitachi and blood counts on Sysmex analyzer. Serum MTX concentration was measured on TDX analyzer. Results: Out of one hundred and forty patients; 68 males (49%) and 72 females (51%), 38 developed MTX toxicity (27%), comprising of hepatotoxicity in 12 (8.6%), nephrotoxicity in 3 (2.1%), anaemia in 8 (5.7%), leucopenia in 2 (1.4%), thrombocytopenia in 3 (2.1%), pancytopenia in 2 (1.4%), gastrointestinal adverse effects in 5 (3.6%) and mucocutaneous problems in 3 (2.1%). Receiver operating characteristic curve revealed serum minimum toxic concentration of MTX at cutoff value of 0.71 mu mol/l with a sensitivity of 71% and specificity of 76%. Conclusion: Adverse effects of low dose MTX were found in 27% of RA patients, mainly comprising of hepatotoxicity and haematological problems. MTX toxicity can be detected by therapeutic drug monitoring of serum concentration of 0.71 mu mol/l with sensitivity of 71% and specificity of 76% in the patients on low dose MTX maintenance therapy. (author)

  19. Global DNA methylation responses to low dose radiation exposure

    International Nuclear Information System (INIS)

    Newman, M.R.; Ormsby, R.J.; Blyth, B.J.; Sykes, P.J.; Bezak, E.

    2011-01-01

    Full text: High radiation doses cause breaks in the DNA which are considered the critical lesions in initiation of radiation-induced cancer. However, at very low radiation doses relevant for the general public, the induction of such breaks will be rare, and other changes to the DNA such as DNA methylation which affects gene expression may playa role in radiation responses. We are studying global DNA methylation after low dose radiation exposure to determine if low dose radiation has short- and/or long-term effects on chromatin structure. We developed a sensitive high resolution melt assay to measure the levels of DNA methylation across the mouse genome by analysing a stretch of DNA sequence within Long Interspersed Nuclear Elements-I (LINE I) that comprise a very large proportion of the mouse and human genomes. Our initial results suggest no significant short-term or longterm) changes in global NA methylation after low dose whole-body X-radiation of 10 J1Gyor 10 mGy, with a significant transient increase in NA methylation observed I day after a high dose of I Gy. If the low radiation doses tested are inducing changes in bal DNA methylation, these would appear to be smaller than the variation observed between the sexes and following the general stress of the sham-irradiation procedure itself. This research was funded by the Low Dose Radiation Research Program, Biological and Environmental Research, US DOE, Grant DE-FG02-05ER64104 and MN is the recipient of the FMCF/BHP Dose Radiation Research Scholarship.

  20. Exercise and Sport Performance with Low Doses of Caffeine

    OpenAIRE

    Spriet, Lawrence L.

    2014-01-01

    Caffeine is a popular work-enhancing supplement that has been actively researched since the 1970s. The majority of research has examined the effects of moderate to high caffeine doses (5–13 mg/kg body mass) on exercise and sport. These caffeine doses have profound effects on the responses to exercise at the whole-body level and are associated with variable results and some undesirable side effects. Low doses of caffeine (

  1. MELODI: The 'Multidisciplinary European Low-Dose Initiative'

    International Nuclear Information System (INIS)

    Belli, M.; Salomaa, S.; Ottolenghi, A.

    2011-01-01

    The importance of research to reduce uncertainties in risk assessment of low and protracted exposures is now recognised globally. In Europe a new initiative, called 'Multidisciplinary European Low Dose Initiative' (MELODI), has been proposed by a 'European High Level and Expert Group on low-dose risk research' (www.hleg.de), aimed at integrating national and EC (Euratom) efforts. Five national organisations: BfS (DE), CEA (FR), IRSN (FR), ISS (IT) and STUK (FI), with the support of the EC, have initiated the creation of MELODI by signing a letter of intent. In the forthcoming years, MELODI will integrate in a step-by-step approach EU institutions with significant programmes in the field and will be open to other scientific organisations and stakeholders. A key role of MELODI is to develop and maintain over time a strategic research agenda (SRA) and a road map of scientific priorities within a multidisciplinary approach, and to transfer the results for the radiation protection system. Under the coordination of STUK a network has been proposed in the 2009 Euratom Programme, called DoReMi (Low-Dose Research towards Multidisciplinary Integration), which can help the integration process within the MELODI platform. DoReMi and the First MELODI Open Workshop, organised by BfS in September 2009, are now important inputs for the European SRA. (authors)

  2. Low dose effects detected by micronucleus assay in lymphocytes

    International Nuclear Information System (INIS)

    Koeteles, G.J.; Bojtor, I.; Kubasova, T.; Horvath, G.

    1997-01-01

    The effects of low doses of X-rays between 0.01 and 1 Gy were studied on whole blood samples of various individuals using the cytokinesis-blocked lymphocyte micronucleus assay as an endpoint. The adaptive response could be induced in G 0 cells by 0.01 Gy followed by 1 Gy challenging dose within a time period of 8 hours, in vitro. The probability distribution of micronucleus increments in those samples which had received very low doses in the range 0.01-0.05 Gy proved to be of asymmetrical type (i.e. lognormal) -very likely to the same shape which has been verified for unirradiated (control) population - while the variable turned to be normally distributed at or above 1 Gy. Profound changes have been experienced in the main characteristics of the linear dose - response relationship and in regression parameters, as well, when successively lessened dose ranges were studied toward 0.01 Gy. In the range below ∼ 0.2 Gy the response were found to be unrelated to the absorbed dose. These findings suggest that in (very) low dose range a higher attention should be needed to biological parameters like repair, protective mechanisms and antioxidant capacities, rather than to the absorbed radiation energy only. (author)

  3. Problems linked to effects of ionizing radiations low doses

    International Nuclear Information System (INIS)

    Anon.

    1995-10-01

    The question of exposure to ionizing radiations low doses and risks existing for professional and populations has been asked again, with the recommendations of the International Commission of Radiation Protection (ICRP) to lower the previous standards and agreed as guides to organize radiation protection, by concerned countries and big international organisms. The sciences academy presents an analysis which concerned on epidemiological and dosimetric aspects in risk estimation, on cellular and molecular aspects of response mechanism to irradiation. The observation of absence of carcinogen effects for doses inferior to 200 milli-sieverts and a re-evaluation of data coming from Nagasaki and Hiroshima, lead to revise the methodology of studies to pursue, to appreciate more exactly the effects of low doses, in taking in part, particularly, the dose rate. The progress of molecular and cellular biology showed that the extrapolation from high doses to low doses is not in accordance with actual data. The acknowledge of DNA repair and carcinogenesis should make clearer the debate. (N.C.). 61 refs., 9 annexes

  4. Thermoluminescent dosimeters for low dose X-ray measurements

    International Nuclear Information System (INIS)

    Del Sol Fernández, S.; García-Salcedo, R.; Sánchez-Guzmán, D.; Ramírez-Rodríguez, G.; Gaona, E.; León-Alfaro, M.A. de; Rivera-Montalvo, T.

    2016-01-01

    The response of TLD-100, CaSO_4:Dy and LiF:Mg,Cu,P for a range of X-ray low dose was measured. For calibration, the TLDs were arranged at the center of the X-ray field. The dose output of the X-ray machine was determined using an ACCU-Gold. All dosimeters were exposed at the available air kerma values of 14.69 mGy within a field 10×10 cm"2 at 80 cm of SSD. Results of LiF:Mg,Cu,P X-ray irradiated showed 4.8 times higher sensitivity than TLD-100. Meanwhile, TL response of CaSO_4:Dy exposed at the same dose was 5.6 time higher than TLD-100. Experimental results show for low dose X-ray measurements a better linearity for LiF:Mg,Cu,P compared with that of TLD-100. CaSO_4:Dy showed a linearity from 0.1 to 60 mGy - Highlights: • Low dose X-ray doses for personal dosimetry were measured. • Radiation dose (µGy ) for environmental dosimetry were determined. • Scattering radiation dose were measured by TLDs. • Linearity of pair TLD system was successful in the range of microgray. • Pair TLDs composed by CaSO_4:Dy and by LiF:Mg,Cu,P. is suggested for clinical dosimetry.

  5. Low-dose prophylactic craniospinal radiotherapy for intracranial germinoma

    International Nuclear Information System (INIS)

    Schoenfeld, Gordon O.; Amdur, Robert J.; Schmalfuss, Ilona M.; Morris, Christopher G.; Keole, Sameer R.; Mendenhall, William M.; Marcus, Robert B.

    2006-01-01

    Purpose: To report outcomes of patients with localized intracranial germinoma treated with low-dose craniospinal irradiation (CSI) followed by a boost to the ventricular system and primary site. Methods and Materials: Thirty-one patients had pathologically confirmed intracranial germinoma and no spine metastases. Low-dose CSI was administered in 29 patients: usually 21 Gy of CSI, 9.0 Gy of ventricular boost, and a 19.5-Gy tumor boost, all at 1.5 Gy per fraction. Our neuroradiologist recorded three-dimensional tumor size on magnetic resonance images before, during, and after radiotherapy. Results: With a median follow-up of 7.0 years, 29 of 31 patients (94%) are disease free. One failure had nongerminomatous histology; the initial diagnosis was a sampling error. Of 3 patients who did not receive CSI, 1 died. No patient developed myelopathy, visual deficits, dementia, or skeletal growth problems. In locally controlled patients, tumor response according to magnetic resonance scan was nearly complete within 6 months after radiotherapy. Conclusions: Radiotherapy alone with low-dose prophylactic CSI cures almost all patients with localized intracranial germinoma. Complications are rare when the daily dose of radiotherapy is limited to 1.5 Gy and the total CSI dose to 21 Gy. Patients without a near-complete response to radiotherapy should undergo resection to rule out a nongerminomatous element

  6. Ageing effects of polymers at very low dose-rates

    International Nuclear Information System (INIS)

    Chenion, J.; Armand, X.; Berthet, J.; Carlin, F.; Gaussens, G.; Le Meur, M.

    1987-10-01

    The equipment irradiation dose-rate into the containment is variable from 10 -6 to 10 -4 gray per second for the most exposed materials. During qualification, safety equipments are submitted in France to dose-rates around 0.28 gray per second. This study purpose is to now if a so large irradiation dose-rate increase is reasonable. Three elastomeric materials used in electrical cables, o'rings seals and connectors, are exposed to a very large dose-rates scale between 2.1.10 -4 and 1.4 gray per second, to 49 KGy dose. This work was carried out during 3.5 years. Oxygen consumption measurement of the air in contact with polymer materials, as mechanical properties measurement show that: - at very low dose-rate, oxygen consumption is maximum at the same time (1.4 year) for the three elastomeric samples. Also, mechanical properties simultaneously change with oxygen consumption. At very low dose-rate, for the low irradiation doses, oxygen consumption is at least 10 times more important that it is showed when irradiation is carried out with usual material qualification dose-rate. At very low dose-rate, oxygen consumption decreases when absorbed irradiation dose by samples increases. The polymer samples irradiation dose is not still sufficient (49 KGy) to certainly determine, for the three chosen polymer materials, the reasonable irradiation acceleration boundary during nuclear qualification tests [fr

  7. Biochemical and cellular mechanisms of low-dose effects

    International Nuclear Information System (INIS)

    Feinendegen, L.E.; Booz, J.; Muehlensiepen, H.

    1988-01-01

    The question of health effects from small radiation doses remains open. Individual cells, when being hit by single elemental doses - in low-dose irradiation - react acutely and temporarily by altering control of enzyme activity, as is demonstrated for the case of thymidine kinase. This response is not constant in that it provides a temporary protection of enzyme activity against a second irradiation, by a mechanism likely to be via improved detoxification of intracellular radicals. It must be considered that in the low-dose region radiation may also exert protection against other challenges involving radicals, causing a net beneficial effect by temporarily shielding the hit cell against radicals produced by metabolism. Since molecular alterations leading to late effects are considered a consequence of the initial cellular response, late effects from small radiation doses do not necessarily adhere to a linear dose-effect relationship. The reality of the linear relationship between the risk of late effects from high doses to small doses is an assumption, for setting dose limits, but it must not be taken for predicting health detriment from low doses. (author)

  8. Exercise and sport performance with low doses of caffeine.

    Science.gov (United States)

    Spriet, Lawrence L

    2014-11-01

    Caffeine is a popular work-enhancing supplement that has been actively researched since the 1970s. The majority of research has examined the effects of moderate to high caffeine doses (5-13 mg/kg body mass) on exercise and sport. These caffeine doses have profound effects on the responses to exercise at the whole-body level and are associated with variable results and some undesirable side effects. Low doses of caffeine (caffeine doses (1) do not alter the peripheral whole-body responses to exercise; (2) improve vigilance, alertness, and mood and cognitive processes during and after exercise; and (3) are associated with few, if any, side effects. Therefore, the ergogenic effect of low caffeine doses appears to result from alterations in the central nervous system. However, several aspects of consuming low doses of caffeine remain unresolved and suffer from a paucity of research, including the potential effects on high-intensity sprint and burst activities. The responses to low doses of caffeine are also variable and athletes need to determine whether the ingestion of ~200 mg of caffeine before and/or during training and competitions is ergogenic on an individual basis.

  9. Plants as warning signal for exposure to low dose radiation

    International Nuclear Information System (INIS)

    Rusli Ibrahim; Norhafiz Talib

    2012-01-01

    The stamen-hair system of Tradescantia for flower colour has proven to be one of the most suitable materials to study the frequency of mutations induced by low doses of various ionizing radiations and chemical mutagens. The system has also been used successfully for detecting mutagenic synergisms among chemical mutagens and ionizing radiations as well as for studying the variations of spontaneous mutation frequency. In this study of radiobiology, the main objective is to observe somatic mutation (occurrence of pink cells from blue cells) induced on stamen hairs of five Tradescantia sp. available in Malaysia after exposure to low doses of chronic gamma irradiation using Gamma Green House. Pink cells appeared only on Tradescantia Pallida Purpurea stamen hairs after 13 days of exposure to irradiation with different doses of gamma rays. The highest number of stamens with pink cells was recorded from flowers irradiated with the highest dose of 6.37 Gy with 0.07 Gy/ h of dose rate. The lowest number of stamens with pink cells was recorded with an average of 0.57, irradiated with the lowest dose of 0.91 Gy with 0.01 Gy/ h of dose rate. There were no pink cells observed on Tradescantia Spathaceae Discolor after exposure to different doses of gamma rays. Similar negative results were observed for the control experiments. The principal cells in this assay are the mitotic stamen hair cells developing in the young flower buds. After exposure to radiation, the heterozygous dominant blue character of the stamen hair cell is prevented, resulting in the appearance of the recessive pink color. Furthermore, no pink cell appears on all species of Tradescantia spathaceae after irradiated with different doses of gamma rays. The sensitivity of the Tradescantia has been used widely and has demonstrated the relation between radiation dose and frequency of mutation observed at low doses which can contribute to the effects of low doses and their consequences for human health. This system

  10. The effects of low dose radiation (LDR) on mice of immune function

    International Nuclear Information System (INIS)

    Feng Li; Deng Daping

    2007-01-01

    Objective: To find out the Effects of Low Dose Radiation(LDR) on mice of immune function. Methods: Through flow cytometry to observe and analyse the effects of the leukomonocyte. Through immunohistochemistry to study IL-2, TNF-α. Results: At dose of 100mGy the stimulative effect on CD 4 + cells, CD 8 + cells and NK activity was higher than that at other doses. At dose of 500mGy leukomonocyte activity was lower. At dose of 100mGy, the colorations about IL-2, TNF-α deepen. Conclusion: LDR could stimulate immune function, especially at dose of 100mGy. while at dose of 500mGy, radiation could restrain the leukomonocyte activity. (authors)

  11. Intracranial germinomas: a case for low dose radiation therapy alone

    International Nuclear Information System (INIS)

    Harrigan, Patricia M.; Loeffler, Jay S.; Shrieve, Dennis; Tarbell, Nancy J.

    1995-01-01

    Purpose: To determine the optimal dose and treatment outcome of patients treated with radiation for intracranial germinoma. Materials and Methods: Between 1975 and 1995, 39 patients with a diagnosis of intracranial germinoma were treated with radiation (RT) to the central nervous system. All but one pt received whole brain (WB) RT, (median dose: 3240 cGy range: 1500-4437 cGy) and a boost to the tumor volume (median total tumor volume dose: 5200 cGy, range: 3960-5950 cGy). Thirty-one pts received RT to the spine (median dose: 2500, range: 1875-3750). Eleven pts were treated with low dose RT and a tumor volume boost, (WB dose ≤ 2550 cGy, and spine dose ≤ 2160 cGy). Five pts were treated with cisplatin-based chemotherapy and low dose WB RT. Fifteen pts were biopsy-proven and 18 presented with multiple midline germinomas (MMG). Among all pts, 33% had serum or CSF positive for low levels of HCG and none of 19 (9 biopsy-proven) germinomas measured positive for AFP tumor marker. Six of 22 (27%) pts who had spine imaging or CSF cytology had evidence of tumor seeding. The male-to female-ratio was 1.4. Median age at diagnosis was 14 yrs for male pts and 9.5 yrs for females (p=.02, overall age range: 1-31 yrs). Median follow-up for survivors is 64 months (range: 1-226 months). Toxicity of treatment relative to dose was assessed. Results: The 5-yr. actuarial rate of disease-free survival (DFS) and overall survival for presumed germinomas was 97%. No pts died of germinoma. One pt died of a shunt infection who had received concurrent chemotherapy and low dose whole brain RT. Among the low dose RT alone group 6 pts received whole brain RT of ≤ 2550 cGy and 9 pts were treated with spinal RT of ≤ 2160 cGy without chemotherapy. Two of these pts had CSF cytology positive for tumor seeding. Additionally, 8 pts received a total dose to the tumor volume of ≤ 4800 cGy without chemotherapy. The 5-yr DFS was 100%. Five pts were treated with cisplatin-based chemotherapy followed

  12. Intracranial germinomas: a case for low dose radiation therapy alone

    Energy Technology Data Exchange (ETDEWEB)

    Harrigan, Patricia M; Loeffler, Jay S; Shrieve, Dennis; Tarbell, Nancy J

    1995-07-01

    Purpose: To determine the optimal dose and treatment outcome of patients treated with radiation for intracranial germinoma. Materials and Methods: Between 1975 and 1995, 39 patients with a diagnosis of intracranial germinoma were treated with radiation (RT) to the central nervous system. All but one pt received whole brain (WB) RT, (median dose: 3240 cGy range: 1500-4437 cGy) and a boost to the tumor volume (median total tumor volume dose: 5200 cGy, range: 3960-5950 cGy). Thirty-one pts received RT to the spine (median dose: 2500, range: 1875-3750). Eleven pts were treated with low dose RT and a tumor volume boost, (WB dose {<=} 2550 cGy, and spine dose {<=} 2160 cGy). Five pts were treated with cisplatin-based chemotherapy and low dose WB RT. Fifteen pts were biopsy-proven and 18 presented with multiple midline germinomas (MMG). Among all pts, 33% had serum or CSF positive for low levels of HCG and none of 19 (9 biopsy-proven) germinomas measured positive for AFP tumor marker. Six of 22 (27%) pts who had spine imaging or CSF cytology had evidence of tumor seeding. The male-to female-ratio was 1.4. Median age at diagnosis was 14 yrs for male pts and 9.5 yrs for females (p=.02, overall age range: 1-31 yrs). Median follow-up for survivors is 64 months (range: 1-226 months). Toxicity of treatment relative to dose was assessed. Results: The 5-yr. actuarial rate of disease-free survival (DFS) and overall survival for presumed germinomas was 97%. No pts died of germinoma. One pt died of a shunt infection who had received concurrent chemotherapy and low dose whole brain RT. Among the low dose RT alone group 6 pts received whole brain RT of {<=} 2550 cGy and 9 pts were treated with spinal RT of {<=} 2160 cGy without chemotherapy. Two of these pts had CSF cytology positive for tumor seeding. Additionally, 8 pts received a total dose to the tumor volume of {<=} 4800 cGy without chemotherapy. The 5-yr DFS was 100%. Five pts were treated with cisplatin-based chemotherapy

  13. New approach for food allergy management using low-dose oral food challenges and low-dose oral immunotherapies.

    Science.gov (United States)

    Yanagida, Noriyuki; Okada, Yu; Sato, Sakura; Ebisawa, Motohiro

    2016-04-01

    A number of studies have suggested that a large subset of children (approximately 70%) who react to unheated milk or egg can tolerate extensively heated forms of these foods. A diet that includes baked milk or egg is well tolerated and appears to accelerate the development of regular milk or egg tolerance when compared with strict avoidance. However, the indications for an oral food challenge (OFC) using baked products are limited for patients with high specific IgE values or large skin prick test diameters. Oral immunotherapies (OITs) are becoming increasingly popular for the management of food allergies. However, the reported efficacy of OIT is not satisfactory, given the high frequency of symptoms and requirement for long-term therapy. With food allergies, removing the need to eliminate a food that could be consumed in low doses could significantly improve quality of life. This review discusses the importance of an OFC and OIT that use low doses of causative foods as the target volumes. Utilizing an OFC or OIT with a low dose as the target volume could be a novel approach for accelerating the tolerance to causative foods. Copyright © 2015 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

  14. Acomparative Study Comparing Low-dose Step-up Versus Step-down in Polycystic Ovary Syndrome Resistant to Clomiphene

    Directory of Open Access Journals (Sweden)

    S Peivandi

    2010-03-01

    Full Text Available Introduction: Polycystic ovary syndrome(PCOS is one of the most common cause of infertility in women. clomiphene is the first line of treatment. however 20% of patients are resistant to clomiphene. because of follicular hypersensitivity to gonadotropins in pcod, multiple follicular growth and development occurs which is cause of OHSS and multiple pregnancy. Our aim of this random and clinical study was comparation between step-down and low dose step-up methods for induction ovulation in clomiphene resistant. Methods: 60 cases were included 30 women in low-dose step-up group and 30 women in step-down group. In low-dose step-up HMG 75u/d and in step-down HMG 225u/d was started on 3th days of cycle, monitoring with vaginal sonography was done on 8th days of cycle. When follicle with>14 mm in diameter was seen HMG dose was continued in low-dose step-up and was decreased in step-down group. When follicle reached to 18mm in diameter, amp HCG 10000 unit was injected and IUI was performed 36 hours later. Results: Number of HMG ampules, number of follicles> 14mm on the day of HCG injection and level of serum estradiol was greater in low dose step up protocol than step down protocol(p<0/0001. Ovulation rate and pregnancy rate was greater in lowdose step up group than step down group with significant difference (p<0/0001. Conclusion: Our study showed that low-dose step-up regimen with HMG is effective for stimulating ovulation and clinical pregnancy but in view of monofollicular growth, the step down method was more effective and safe. In our study multifolliular growth in step-up method was higher than step-down method. We can predict possibility of Ovarian Hyperstimulation Syndrome syndrome in highly sensitive PCOS patients.

  15. Prolactin as a Marker of Successful Catheterization during IPSS in Patients with ACTH-Dependent Cushing's Syndrome

    Science.gov (United States)

    Sharma, S. T.; Raff, H.

    2011-01-01

    Context: Anomalous venous drainage can lead to false-negative inferior petrosal sinus sampling (IPSS) results. Baseline inferior petrosal sinus to peripheral (IPS/P) prolactin ratio higher than 1.8 ipsilateral to the highest ACTH ratio has been proposed to verify successful catheterization. Prolactin-normalized ACTH IPS/P ratios may differentiate Cushing's disease (CD) from ectopic ACTH syndrome (EAS). Objective: Our objective was to examine the utility of prolactin measurement during IPSS. Design, Setting, and Participants: We conducted a retrospective analysis of prolactin levels in basal and CRH-stimulated IPSS samples in ACTH-dependent Cushing's syndrome (2007–2010). Results: Twenty-five of 29 patients had a pathologically proven diagnosis (17 CD and eight EAS). IPSS results were partitioned into true positive for CD (n = 16), true negative (n = 7), false negative (n = 1), and false positive (n = 1). Prolactin IPS/P ratio suggested successful IPSS in eight of 11 with abnormal venograms. Baseline prolactin IPS/P ratio was helpful in two patients with abnormal venograms and false-negative (catheterization unsuccessful) or true-negative (catheterization successful) IPSS results; the normalized ratio correctly diagnosed their disease. Normalized ACTH IPS/P ratio was at least 1.3 in all with CD, but prolactin IPS/P ratios were misleadingly low in two. One patient with cyclic EAS had a false-positive IPSS when eucortisolemic (baseline prolactin IPS/P = 1.7; normalized ratio = 5.6). All other EAS patients had normalized ratios no higher than 0.7. Conclusion: Prolactin measurement and evaluation of the venogram can improve diagnostic accuracy when IPSS results suggest EAS but is not necessary with positive IPSS results. Confirmation of hypercortisolemia remains a prerequisite for IPSS. A normalized ratio of 0.7–1.3 was not diagnostic. PMID:22031511

  16. Adrenal Incidentalomas with Supraphysiologic Response to ACTH Stimulus: A Case Report

    Directory of Open Access Journals (Sweden)

    Marianna Antonopoulou

    2012-01-01

    Full Text Available We present the diagnostic approach of a patient with adrenal incidentalomas. A 72-year-old African American male had a CT scan of the abdomen showing right and left adrenal masses measuring and , respectively. The patient had negative hormonal workup. The radiologist insisted that the CT findings are consistent with adrenal hyperplasia, and therefore he underwent ACTH stimulation to rule out late-onset congenital adrenal hyperplasia (CAH. The stimulation test revealed that 17-hydroxyprogesterone and 11-deoxycortisol increased to levels high enough to confirm CAH, but cortisol had exaggerated response as well, thus making the diagnosis of CAH unlikely where metabolism is shifted to precursors. Subsequently, the patient underwent screening for Cushing's syndrome (CS with a dexamethasone suppression test. Patient failed the suppresion test, raising the issue for subclinical CS (SCS, likely due to ACTH-independent macronodular adrenal hyperplasia. Our patient had been diagnosed with MGUS and so far there are only 3 case reports of extramedullary plasmacytoma arising from the adrenals. One was bilateral and one had functional abnormalities. Our differential diagnosis includes subclinical CS with aberrant receptors versus a functioning extramedullary plasmacytoma.

  17. Low-dose CT: new tool for screening lung cancer?

    International Nuclear Information System (INIS)

    Diederich, S.; Wormanns, D.; Heindel, W.

    2001-01-01

    Lung cancer is the leading cause of death from malignant tumours as it is very common and has a poor prognosis at advanced tumour stages. Prognosis could be improved by treatment at early stages. As these stages are usually asymptomatic, a diagnostic test that would allow detection of early tumour stages in a population at risk could potentially reduce mortality from lung cancer. Previous approaches using chest radiography and sputum cytology in smokers have been disappointing. Fluorescent bronchoscopy and molecular markers are not yet applicable in clinical routine. Because of its high sensitivity for small pulmonary nodules, which are the most common manifestation of early lung cancer, CT appears suitable as a screening test. Low-dose examination parameters can and should be used for this purpose. From clinical practice it is well known that chest CT often demonstrates small pulmonary nodules, which do not represent lung cancer. Therefore, non-invasive diagnostic algorithms are required to avoid unnecessary biopsies in benign lesions. In preliminary studies of low-dose CT using algorithms based on size and density of detected nodules a large proportion of asymptomatic lung cancers and a large proportion of early, resectable tumour stages were found with a small proportion of invasive procedures for benign nodules. Before this technology can be recommended for broad application, however, further information is required regarding appropriate inclusion criteria (smoking habits, age groups) and screening intervals. Most importantly, further data are required to clarify whether lung cancer screening using low-dose CT can actually reduce mortality from lung cancer. (orig.)

  18. Low-dose multislice CT in febrile neutropenic patients

    International Nuclear Information System (INIS)

    Wendel, F.; Jenett, M.; Hahn, D.; Sandstede, J.; Geib, A.

    2005-01-01

    Purpose: to define the value of low-dose multislice CT in a clinical setting for early detection of pneumonia in neutropenic patients with fever of unknown origin. Materials and methods: thirty-five neutropenic patients suffering from fever of unknown origin with normal chest X-ray underwent unenhanced low-dose CT of the chest (120 kV, 10 eff. mAs, collimation 4 x 1 mm) using a multislice CT scanner. Axial und frontal slices with a thickness of 5 mm were calculated. If no pneumonia was found, standard antibiotics were given and a repeated examination was performed if fever continued. In case of pneumonia, antimycotic therapy was added and a follow-up CT was performed within one week. Regression or progression of pneumonia at follow-up served as evidence of pneumonia; lowering of fever within 48 h or inconspicuous follow-up CT was regarded as absence of pneumonia. Results: ten of 35 patients had pneumonic infiltration, which decreased or increased on follow-up CT in 3 and 6 patients, respectively. One patient revealed leucemic infiltration by bronchoalveolar lavage. Twenty-five of 35 patients had no evidence of pneumonia. Twenty of these patients were free of fever within 48 h under antibiotics; one patient died due to his basic illness. Out of 4 patients with persisting fever, 3 patients had no pneumonia on repeated examination; one patient showed disseminated micronodular infiltration. Frontal reconstructions helped to differentiate infiltration from atelectasis in 4 patients. Sensitivity and specificity for the detection of pneumonia at the first examination were 90% and 96%, negative predictive value was 96%. Conclusion: low-dose multislice CT should be performed in neutropenic patients having a fever of unknown origin and normal chest X-ray. (orig.)

  19. Development of new chemical dosimeter for low dose range

    International Nuclear Information System (INIS)

    Mhatre, Sachin G.V.; Adhikari, S.

    2012-01-01

    Accurate measurement of low dose radiation in complex systems is of utmost importance in radiation biology and related areas. Ferrous Benzoic acid Xylenol orange (FBX) system is being widely used for measurement of low dose gamma radiation because of its reproducibility and precision. However, an additional step, i.e., dissolution of benzoic acid in water at higher temperature followed by cooling at room temperature is involved for the preparation of this dosimeter. This makes it inconvenient as a ready to use dosimeter. In the present work, the organic molecule, sorbitol has been used for measurement of low doses of radiation. The advantages of using sorbitol are its ready availability and instantaneous water solubility. Owing to its dissolution at room temperature, possible errors those are involved in calculation of dose due to thermal oxidation of ferrous ions during preparation of the FBX dosimetric solution could be made insignificant in the proposed dosimeter. In the present system, sorbitol acts as radiolytic sensitizer for the oxidation of ferrous ion, and xylenol orange forms a 1:1 complex specifically with ferric ions. Thus, the analytical detection limit of ferric ions is enhanced compared to other systems. Final composition of the dosimetric solution is; 0.5 mol/m 3 xylenol orange, 10 mol/m 3 sorbitol and 0.2 mol/m 3 ferrous ion in 50 mol/m 3 sulfuric acid. Radiolytic sensitization in combination with analytical enhancement of the ferrous based system, allows us to measure radiation dose in the range of 0.05 Gy–12 Gy with ease and high reproducibility.

  20. Uncommon toxicity of low-dose methotrexate: case report

    Directory of Open Access Journals (Sweden)

    Zohreh Yousefi

    2015-10-01

    Full Text Available Background: Standard treatment of Gestational Trophoblastic Disease (GTD is chemotherapy. Single-agent chemotherapy regime including Methotrexate (MTX or Actinomycin. Single-agent is widely used in treatment of persistent trophoblastic disease. We reported an uncommon toxicity of low-dose single-agent methotrexate in a patient. Case Presentation: A 20-year-old woman, primary gravid after two months missed period and spotting with diagnosis of incomplete abortion with uterine size equivalent of ten weeks pregnancy (8-10 cm underwent evacuation curettage. In serial follow-up, based on rise of beta-hCG titer and absence of metastatic disease, it was categorized as low-risk persistent trophoblastic disease. She was referred to gynecology oncology center of Ghaem Hospital, Mashhad University of Medical Sciences in May 2014. Because of rise of beta-hCG titer, after complete metastatic work-up and lack of disease in other sites, persistent disease was diagnosed and candidate for chemotherapy (single agent low-dose. The patient received first course of therapy with MTX (50 mg/m², intra muscular. Unfortunately, after two days of treatment she developed uncommon severe toxicity, fever, severe nausea and vomiting, tachycardia, and generalized weakness. Also, we found hematologic abnormality (WBC: -14000-15000 µI, platelet- 540 µI and sever neutropenia, and abnormal rising in liver function test (SGOT, SGPT (three to four times and renal function test (BUN and Creatinine (two times. In addition, she had disseminated erosive lesion in all of body especially in face. Due to the fatal side effects of chemotherapy, she was admitted to intensive care unit (ICU. Fortunately, after two to three weeks, she was improved by conservative management. After few weeks beta-hCG titer was in normal limit. However she had normal serial beta-hCG in one year of follow-up. Conclusion: It is important to emphasis unpredictable side effects of chemotherapy with low-dose

  1. Exposure to low dose ionising radiation: Molecular and clinical consequences.

    LENUS (Irish Health Repository)

    Martin, Lynn M

    2014-07-10

    This review article provides a comprehensive overview of the experimental data detailing the incidence, mechanism and significance of low dose hyper-radiosensitivity (HRS). Important discoveries gained from past and present studies are mapped and highlighted to illustrate the pathway to our current understanding of HRS and the impact of HRS on the cellular response to radiation in mammalian cells. Particular attention is paid to the balance of evidence suggesting a role for DNA repair processes in the response, evidence suggesting a role for the cell cycle checkpoint processes, and evidence investigating the clinical implications\\/relevance of the effect.

  2. Harderian Gland Tumorigenesis: Low-Dose and LET Response

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Polly Y. [SRI International, Menlo Park, CA (United States). Biosciences Div.; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Cucinotta, Francis A. [Univ. of Nevada, Las Vegas, NV (United States). Dept. of Health Physics and Diagnostic Sciences; Bjornstad, Kathleen A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Bakke, James [SRI International, Menlo Park, CA (United States). Biosciences Div.; Rosen, Chris J. [SRI International, Menlo Park, CA (United States). Biosciences Div.; Du, Nicholas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Fairchild, David G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Cacao, Eliedonna [Univ. of Nevada, Las Vegas, NV (United States). Dept. of Health Physics and Diagnostic Sciences; Blakely, Eleanor A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.

    2016-04-19

    Increased cancer risk remains a primary concern for travel into deep space and may preclude manned missions to Mars due to large uncertainties that currently exist in estimating cancer risk from the spectrum of radiations found in space with the very limited available human epidemiological radiation-induced cancer data. Existing data on human risk of cancer from X-ray and gamma-ray exposure must be scaled to the many types and fluences of radiations found in space using radiation quality factors and dose-rate modification factors, and assuming linearity of response since the shapes of the dose responses at low doses below 100 mSv are unknown. The goal of this work was to reduce uncertainties in the relative biological effect (RBE) and linear energy transfer (LET) relationship for space-relevant doses of charged-particle radiation-induced carcinogenesis. The historical data from the studies of Fry et al. and Alpen et al. for Harderian gland (HG) tumors in the female CB6F1 strain of mouse represent the most complete set of experimental observations, including dose dependence, available on a specific radiation-induced tumor in an experimental animal using heavy ion beams that are found in the cosmic radiation spectrum. However, these data lack complete information on low-dose responses below 0.1 Gy, and for chronic low-dose-rate exposures, and there are gaps in the LET region between 25 and 190 keV/μm. In this study, we used the historical HG tumorigenesis data as reference, and obtained HG tumor data for 260 MeV/u silicon (LET ~70 keV/μm) and 1,000 MeV/u titanium (LET ~100 keV/μm) to fill existing gaps of data in this LET range to improve our understanding of the dose-response curve at low doses, to test for deviations from linearity and to provide RBE estimates. Animals were also exposed to five daily fractions of 0.026 or 0.052 Gy of 1,000 MeV/u titanium ions to simulate chronic exposure, and HG tumorigenesis from this fractionated study were compared to the

  3. Effect of low doses of ionizing radiation on human health

    International Nuclear Information System (INIS)

    Kovalenko, A.N.

    1990-01-01

    Data are reported on the possible mechanism of biological effects of low doses of ionizing radiation on the human body. The lesioning effect of this radiation resulted in some of the persons in the development of disorders of the function of information and vegetative-regulatory systems determined as a desintegration syndrome. This syndrome is manifested in unspecific neuro-vegetative disorders of the function of most important physiological and homeostatic system of the body leading to weakening of the processes of compensation and adaptation. This condition is characterized by an unspecific radiation syndrome as distinct from acute or chronic radiation disease which is a specific radiation syndrome

  4. 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

  5. A consideration of low dose radiation effects on human health

    International Nuclear Information System (INIS)

    Shimada, Yoshiya; Nishimura, Mayumi; Imaoka, Tatsuhiko; Kakinuma, Shizuko

    2011-01-01

    On March 11, 2011, an earthquake categorized as 9 Mw occurred off the northeast coast of Japan. The subsequent destructive tsunami disabled emergency units of Fukushima Dai'ichi Nuclear Power Plant and caused partial meltdown of reactors and explosions. Resulting radiation releases forced large evacuations, bore concerns about food and water and fears against human health. In this manuscript, we described the effect of radiation, especially low dose radiation below 100 mSv, on cancer risk, focusing on fetuses and children. (author)

  6. Anti-tumor effect of low dose radiation in mice

    International Nuclear Information System (INIS)

    Fan Zhengping; Lu Jiaben; Zhu Bingchai

    1997-01-01

    The author reports the effects of the total body irradiation of low dose radiation (LDR) and/or the local irradiation of large dose on average tumor weights and tumor inhibitory rates in 170 mice inoculated S 180 sarcoma cell, and the influence of LDR on average longevity in 40 tumor-bearing animals. Results show (1) LDR in the range of 75∼250 mGy can inhibit tumor growth to some extent; (2) fractionated irradiation of 75 mGy and local irradiation of 10 Gy may produce a synergism in tumor growth inhibition; and (3)LDR may enhance average longevity in ascitic tumor-bearing mice

  7. Uterine malignant degeneration after low-dose endometrial irradiation

    International Nuclear Information System (INIS)

    Nikkanen, V.; Salmi, T.; Groenroos, M.

    1980-01-01

    The effectiveness of low-dose intrauterine irradiation for benign diseases and its possible carcinogenic effect on the uterus was studied in 190 patients who were treated during the years 1952-1974. The indications for irradiation were premenopausal functional bleeding, leukemia, hemophilia, fibroids, endometriosis or other benign reason. Radiation was also performed on patients with severe neurologic diseases that contraindicated surgery and on some mentally retarded patients whose restlessness and epileptic seizures were aggravated premenstrually and during menstruation. The mean follow-up period was 15 years. Uterine bleeding recurred in 21 percent of the patients. No cases of uterine malignant degeneration were found. (author)

  8. From Chernobyl to Fukushima: the effect of low doses

    International Nuclear Information System (INIS)

    Aurengo, A.

    2011-01-01

    This Power Point presentation describes the Fukushima's reactors, recalls some data about the earthquake and tsunami, and indicates their consequences for the operation of the power station (notably the loss of cooling means). It identifies some design errors for the Chernobyl's and Fukushima's power stations, outlines differences between these two cases. It gives assessment of doses receives by external irradiation around Fukushima, of the dose rate evolution, of the sea contamination. It gives some data about the Chernobyl accident (radioactivity evolution). After some data about health consequences of Chernobyl, health risks and more particularly biological risks associated to low doses are described. Protection measures are evoked, as well as psycho-social impacts

  9. Application of low dose radiation for preservation of sea foods

    International Nuclear Information System (INIS)

    Venugopal, V.; Nair, P.M.

    1994-01-01

    Treatment of food with low doses of gamma radiation has been recognized to have two main advantages. These consist of: (1) improvement of food safety by elimination of pathogens and (2) reduction of microbial spoilage and extension of shelf life of perishable items by reducing the number of viable spoilage organisms. Studies during the last few decades have conclusively proved the beneficial effects of radiation with respect to fishery products. The three potential areas of application to fish products include: (i) radurization for shelf life extension (ii) radicidation to eliminate food borne pathogens in the products and (iii) radiation treatment to dried products to control insects

  10. Low doses of glyphosate enhance growth, CO2 assimilation, stomatal conductance and transpiration in sugarcane and eucalyptus.

    Science.gov (United States)

    Nascentes, Renan F; Carbonari, Caio A; Simões, Plinio S; Brunelli, Marcela C; Velini, Edivaldo D; Duke, Stephen O

    2018-05-01

    Sublethal doses of herbicides can enhance plant growth and stimulate other process, an effect known as hormesis. The magnitude of hormesis is dependent on the plant species, the herbicide and its dose, plant development stage and environmental parameters. Glyphosate hormesis is well established, but relatively little is known of the mechanism of this phenomenon. The objective of this study was to determine if low doses of glyphosate that cause growth stimulation in sugarcane and eucalyptus concomitantly stimulate CO 2 assimilation. Shoot dry weight in both species increased at both 40 and 60 days after application of 6.2 to 20.2 g a.e. ha -1 glyphosate. The level of enhanced shoot dry weight was 11 to 37%, depending on the time after treatment and the species. Concomitantly, CO 2 assimilation, stomatal conductance and transpiration were increased by glyphosate doses similar to those that caused growth increases. Glyphosate applied at low doses increased the dry weight of sugarcane and eucalyptus plants in all experiments. This hormetic effect was related to low dose effects on CO 2 assimilation rate, stomatal conductance and transpiration rate, indicating that low glyphosate doses enhance photosynthesis of plants. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  11. Imaging in covert ectopic ACTH secretion: a CT pictorial review

    Energy Technology Data Exchange (ETDEWEB)

    Sookur, Paul A.; Sahdev, Anju; Rockall, Andrea G.; Reznek, Rodney H. [St Bartholomew' s Hospital, Department of Academic Radiology, Dominion House, London (United Kingdom); Isidori, Andrea M. [Sapienza University of Rome, Department of Medical Pathophysiology, Rome (Italy); Monson, John P.; Grossman, Ashley B. [St Bartholomew' s Hospital, Department of Endocrinology, London (United Kingdom)

    2009-05-15

    The syndrome of ectopic adrenocorticotrophin secretion (EAS) is rare and is due to excess adrenocorticotrophin (ACTH) production from a nonpituitary tumour. These tumours can be covert, where the tumours are not readily apparent, and very small making them challenging to image. It is clinically and biochemically difficult to distinguish between covert EAS and Cushing's disease. The first-line investigation in locating the source of ACTH production is computed tomography (CT). The aim of this pictorial review is to illustrate the likely covert sites and related imaging findings. We review the CT appearances of tumours resulting in covert EAS and the associated literature. The most common tumours were bronchial carcinoid tumours, which appear as small, well-defined, round or ovoid pulmonary lesions. Rarer causes included thymic carcinoids, gastrointestinal carcinoids and pancreatic neuroendocrine tumours. Awareness of the imaging characteristics will aid identification of the source of ACTH production and allow potentially curative surgical resection. (orig.)

  12. Biologically based modelling and simulation of carcinogenesis at low doses

    International Nuclear Information System (INIS)

    Ouchi, Noriyuki B.

    2003-01-01

    The process of the carcinogenesis is studied by computer simulation. In general, we need a large number of experimental samples to detect mutations at low doses, but in practice it is difficult to get such a large number of data. To satisfy the requirements of the situation at low doses, it is good to study the process of carcinogenesis using biologically based mathematical model. We have mainly studied it by using as known as 'multi-stage model'; the model seems to get complicated, as we adopt the recent new findings of molecular biological experiments. Moreover, the basic idea of the multi-stage model is based on the epidemiologic data of log-log variation of cancer incidence with age, it seems to be difficult to compare with experimental data of irradiated cell culture system, which has been increasing in recent years. Taking above into consideration, we concluded that we had better make new model with following features: 1) a unit of the target system is a cell, 2) the new information of the molecular biology can be easily introduced, 3) having spatial coordinates for checking a colony formation or tumorigenesis. In this presentation, we will show the detail of the model and some simulation results about the carcinogenesis. (author)

  13. Low-dose aripiprazole for refractory burning mouth syndrome

    Directory of Open Access Journals (Sweden)

    Umezaki Y

    2016-05-01

    Full Text Available Yojiro Umezaki,1 Miho Takenoshita,2 Akira Toyofuku2 1Psychosomatic Dentistry Clinic, Dental Hospital, 2Psychosomatic Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan Abstract: We report a case of refractory burning mouth syndrome (BMS ameliorated with low dose of aripiprazole. The patient was a 66-year-old female who had suffered from chronic burning pain in her tongue for 13 months. No abnormality associated with the burning sensation was detected in the laboratory tests and the oral findings. Considering the clinical feature and the history together, we diagnosed the burning sensation as BMS. The BMS pain was decreased by aripiprazole (powder 1.0 mg/d, though no other antidepressants had satisfying pain relief. It could be supposed that the efficacy of aripiprazole is caused by dopamine stabilization in this case, and BMS might have a subtype that is reactive to aripiprazole. Further studies are needed to confirm the efficacy of aripiprazole for BMS. Keywords: burning mouth syndrome, low-dose aripiprazole, chronic pain

  14. 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

  15. Low dose iodine-131 therapy in solitary toxic thyroid nodules

    International Nuclear Information System (INIS)

    Prakash, Rajeev

    1999-01-01

    Forty patients with solitary hyperfunctioning thyroid nodules were treated with relatively low dose radioiodine therapy, 131 I doses were calculated taking into account thyroid mass and radioiodine kinetics to deliver 100 μCi/g of estimated nodule weight corrected for uptake. Patients remaining persistently hyperthyroid at four months after the initial therapy were retreated with a similarly calculated dose. Cure of the hyperthyroid state was achieved in all patients, total administered dose in individual cases ranging from 3-17 mCi. 28 of the 40 patients required a single therapy dose. 36 patients were euthyroid after a 4.5 year mean follow-up period. Four cases developed post therapy hypothyroidism requiring replacement therapy. Nodules regressed completely in nine cases following 131 I treatment, with partial regression in size in 19 patients. Control of hyperthyroid state in cases of solitary toxic thyroid nodules can be satisfactorily achieved using relatively low dose radioiodine therapy with low incidence of post therapy hypothyroidism. (author)

  16. Development of microcontroller based instrumentation for low dose implantation

    International Nuclear Information System (INIS)

    Suresh, K.; Saravanan, K.; Panigrahi, B.K.; Nair, K.G.M.

    2011-01-01

    In experiments like ion implantation based ion track formations, the sample is implanted to low doses of the order of 10 10 ions/cm 2 , limiting the ion beam currents to be less than 1-5 x 10 -12 A. However the standard current integrators available are not sensitive to very low currents, causing an unacceptable high level of error in dose measurement. Hence a low dose implantation measurement system has been developed. It consists of a very sensitive low current preamplifier with full scale input 1nA/100pA, a standard current integrator, a microcontroller based interface circuit, which are connected to a personal computer(PC) through USB. Two types of the software are developed for the system: the microcontroller firmware using C and windows based virtual instrument programs using LabVIEW 7.0. Necessary precautions associated with pA level measurement like rigidly fastened good quality cables, low ripple DC power supply, shielding, close mounting of the preamplifier to the sample are adopted. After necessary calibrations with an ECIL make low current source, the system has been put into regular use. Design and development details, salient features are discussed in this paper. (author)

  17. Exposures at low doses and biological effects of ionizing radiations

    International Nuclear Information System (INIS)

    Masse, R.

    2000-01-01

    Everyone is exposed to radiation from natural, man-made and medical sources, and world-wide average annual exposure can be set at about 3.5 mSv. Exposure to natural sources is characterised by very large fluctuations, not excluding a range covering two orders of magnitude. Millions of inhabitants are continuously exposed to external doses as high as 10 mSv per year, delivered at low dose rates, very few workers are exposed above the legal limit of 50 mSv/year, and referring to accidental exposures, only 5% of the 116 000 people evacuated following the Chernobyl disaster encountered doses above 100 mSv. Epidemiological survey of accidentally, occupationally or medically exposed groups have revealed radio-induced cancers, mostly following high dose-rate exposure levels, only above 100 mSv. Risk coefficients were derived from these studies and projected into linear models of risk (linear non-threshold hypothesis: LNT), for the purpose of risk management following exposures at low doses and low dose-rates. The legitimacy of this approach has been questioned, by the Academy of sciences and the Academy of medicine in France, arguing: that LNT was not supported by Hiroshima and Nagasaki studies when neutron dose was revisited; that linear modelling failed to explain why so many site-related cancers were obviously nonlinearly related to the dose, and especially when theory predicted they ought to be; that no evidence could be found of radio-induced cancers related to natural exposures or to low exposures at the work place; and that no evidence of genetic disease could be shown from any of the exposed groups. Arguments were provided from cellular and molecular biology helping to solve this issue, all resulting in dismissing the LNT hypothesis. These arguments included: different mechanisms of DNA repair at high and low dose rate; influence of inducible stress responses modifying mutagenesis and lethality; bystander effects allowing it to be considered that individual

  18. Effect of low dose {gamma} radiation on the dormancy breaking and physiological activity of 'Dejima' seed potato

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. S.; Kim, D. H.; Baek, M. H.; Lee, Y. K. [KAERI, Taejon (Korea, Republic of); Lee, Y. B. [Chungnam National Univ., Taejon (Korea, Republic of)

    2001-05-01

    To observe the stimulating effects of low dose {gamma}-radiation on the dormancy breaking and physiological activity, potato (Solanum tuberosum L. cv. Dejima) were irradiated at the dose of 0.5 {approx} 30 Gy. Low dose {gamma}-radiation had promoting effects on the srouting rate the optimum dose of 1 Gy and 2 Gy and on the sprout length at the optimum dose of 2 Gy and 4 Gy. In case of number of sprouts, there were increased in all of the low dose irradiation groups and period storages, which showed very significant promoting effects at 4,8,16 Gy of 15 DAP. The field growth of 45 DAP were increased at all of the low dose irradiation group, which particularly were very significant promoting effect at 4 Gy irradiation group. Irradiation didn't have significant effects on the antioxidant enzyme activity of potato plantlet, but the peroxidase activity of 45 DAP plantlet increased at 4 Gy irradiation group.

  19. Influence of low dose {gamma} radiation on the dormancy, growth and physiological activity of seed potato (solanum tuberosum L.)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. S.; Lee, Y. K.; Lee, H. Y.; Baek, M. H.; Yoo, Z. C. [KAERI, Taejon (Korea, Republic of)

    2002-05-01

    To observe the stimulating effect of low dose {gamma} radiation on the dormancy breaking and growth of potato with different storage duration and conditions, potato were irradiated with the dose of 1 {approx} 16 Gy. Though varied with storage duration and conditions, sprouting rate of potato stored at 5 .deg. C in the dark was promoted at the 8 and 16 Gy irradiation group compared to 20 .deg. C in the light. The field growth of potato stored at 5 .deg. C in the dark was highly increased at the 2, 4, 8 Gy irradiation group. The CAT activity of potato was increased by about 20% at 1,8 and 16 Gy irradiation group. POD activity was also increased by 7 {approx} 16% at 1, 8 and 16 Gy irradiation group compared to the control. Fv/Fm was not changed by the low dose {gamma} radiation. However, the effective quantum yield of PSII was slightly increased by about 12% at 1 and 16 Gy irradiation group. Seedling irradiated with low dose {gamma} radiation showed the lower excitation pressure on PSII (1- {sub q}P), while NPQ was greatly increased by 45% at 4 Gy irradiation group. These results clearly showed the positive effect of low dose {gamma} radiation on the seedling growth of potato via increasing photoprotective capacities of photosynthetic apparatus.

  20. Influence of low dose γ radiation on the dormancy, growth and physiological activity of seed potato (solanum tuberosum L.)

    International Nuclear Information System (INIS)

    Kim, J. S.; Lee, Y. K.; Lee, H. Y.; Baek, M. H.; Yoo, Z. C.

    2002-01-01

    To observe the stimulating effect of low dose γ radiation on the dormancy breaking and growth of potato with different storage duration and conditions, potato were irradiated with the dose of 1 ∼ 16 Gy. Though varied with storage duration and conditions, sprouting rate of potato stored at 5 .deg. C in the dark was promoted at the 8 and 16 Gy irradiation group compared to 20 .deg. C in the light. The field growth of potato stored at 5 .deg. C in the dark was highly increased at the 2, 4, 8 Gy irradiation group. The CAT activity of potato was increased by about 20% at 1,8 and 16 Gy irradiation group. POD activity was also increased by 7 ∼ 16% at 1, 8 and 16 Gy irradiation group compared to the control. Fv/Fm was not changed by the low dose γ radiation. However, the effective quantum yield of PSII was slightly increased by about 12% at 1 and 16 Gy irradiation group. Seedling irradiated with low dose γ radiation showed the lower excitation pressure on PSII (1- q P), while NPQ was greatly increased by 45% at 4 Gy irradiation group. These results clearly showed the positive effect of low dose γ radiation on the seedling growth of potato via increasing photoprotective capacities of photosynthetic apparatus

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

    Directory of Open Access Journals (Sweden)

    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.

  2. 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

  3. Low dose radiation induced hormesis and its mechanism of free radicals

    International Nuclear Information System (INIS)

    Zhang Liyuan; Huo Hongmei; Zhang Yusong; Zhao Peifeng; Li Wei; Jiang Jiagui

    2008-01-01

    Objective: To investigate whether the supernatant (the stimulating fluid) centrifuged from myeloid cells suspension after low dose radiation in vitro can produce hormesis on the normal or radiation damage cells. The mechanism of free radical was probed. Methods: Mouse myeloid cell suspension was irradiated respectively by 0, 2 and 5 Gy, and cultured in vitro. MTT method was used to measure the reproductive activity of cells. Meanwhile, Cytochrome C reduction method was used to determine the concentration of O 2 - . Lastly, the concentration of O 2 - was decreased or increased by adding DPI or PMA, and the effect of such changes on 'the stimulating fluid' was observed. Results: Co-cultured with 'the stimulating fluid', the reproductive activity of the myeloid cells after large dose radiation or the normal myeloid cells were enhanced. Decreasing the concentration of O 2 - ; may degrade the proliferation of the cells after radiation damage; while increasing it may lead to the opposite result. Conclusions: The stimulating fluid can enhance the proliferation of the myeloid cells after radiation damage and also the normal ones. The mechanism of above-mentioned phenomena might be related with the changes of O 2 - concentration. (authors)

  4. Effect of low dose radiation on thymocyte cytosol and nuclei protein synthesis in mice

    International Nuclear Information System (INIS)

    Meng Qingyong; Chen Shali; Liu Shuzheng

    2003-01-01

    Objective: To the effect of low dose radiation on thymocyte cytosol and nuclei protein synthesis in mice. Methods: The expression of proteins was analyzed by gel filtration with Sephadex G-100 and HPLC based on separation of proteins on thymocyte cytosol and nuclei after whole-body irradiation with 75 mGy X-rays and sham-irradiation, and their biological activity was examined by mouse splenocyte proliferation and chromosome aberration of human peripheral blood lymphocytes. Results: HPLC analysis showed that there was a marked increase in expression of 61.4 kD protein in the extract of thymocyte cytosol and 30.4 kD protein in the extract of thymocyte nuclei in comparison with the corresponding fractions from the sham-irradiated control mice. These protein fractions from the thymocyte cytosol and nuclei of the irradiated mice showed both stimulating effect on normal T cell proliferation and protective effect on chromosome damage induced by high dose radiation. Conclusion: These findings might have implications in study of mechanism of immunoenhancement and cytogenetic adaptive response induced by low dose radiation

  5. Low dose perfluorooctanoate exposure promotes cell proliferation in a human non-tumor liver cell line

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hongxia; Cui, Ruina [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Guo, Xuejiang [State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 210029 (China); Hu, Jiayue [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Dai, Jiayin, E-mail: daijy@ioz.ac.cn [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China)

    2016-08-05

    Highlights: • Differential expression of proteins induced by PFOA in HL-7702 was identified. • Most of the differentially expressed proteins are related to cell proliferation. • A low dose of PFOA stimulates HL-7702 cell proliferation. • A high dose of PFOA inhibits HL-7702 cell proliferation. - Abstract: Perfluorooctanoate (PFOA) is a well-known persistent organic pollutant widely found in the environment, wildlife and humans. Medical surveillance and experimental studies have investigated the potential effects of PFOA on human livers, but the hepatotoxicity of PFOA on humans and its underlying mechanism remain to be clarified. We exposed a human liver cell line (HL-7702) to 50 μM PFOA for 48 h and 96 h, and identified 111 significantly differentially expressed proteins by iTRAQ analysis. A total of 46 proteins were related to cell proliferation and apoptosis. Through further analysis of the cell cycle, apoptosis and their related proteins, we found that low doses of PFOA (50–100 μM) promoted cell proliferation and numbers by promoting cells from the G1 to S phases, whereas high doses of PFOA (200–400 μM) led to reduced HL-7702 cell numbers compared with that of the control mainly due to cell cycle arrest in the G0/G1 phase. To our knowledge, this is the first report on the promotion of cell cycle progression in human cells following PFOA exposure.

  6. Effects of low dose irradiation on NK activity of normal individuals and patients with cancer

    International Nuclear Information System (INIS)

    Tian Hailin; Su Liaoyuan

    1994-10-01

    Effects of low dose irradiation on NK activity of lymphocytes and on K 562 cells were studied. The NK activity was determined by means of 3 H-TdR release assay. While 3 H-TdR incorporation was used to reflect functional changes of K 562 cells after low dose irradiation. 21 patients with cancer and 10 normal individuals were detected. The results indicated that the NK activity of lymphocytes in normal individuals increased significantly after 10 and 50 cGy γ-ray irradiation, while in patients with cancer the NK activity of lymphocytes increased only at the dose of 50 cGy irradiation. The increase of NK activity in normal individuals was higher than that in patients with cancer after same doses of irradiation. When K 562 cells were irradiated by 10 cGy γ-rays, the 3 H-TdR incorporation value increased. After exposed to over 50 cGy the stimulating effect disappeared

  7. Multilevel mechanisms of stimulatory effect of low dose radiation on immunity

    International Nuclear Information System (INIS)

    Shu-Zeng Liu

    1992-01-01

    Attention is paid to the effects of low level ionizing radiation on humans. The conference is devoted to low dose radiation and defense mechanisms of the body. Due to the importance of the immune system in body resistance, special attention has been given to host defense mechanisms following exposure to different doses of ionizing radiation. The immune system has long been known to be highly sensitive to moderate to high doses of ionizing radiation with immuno-depression as one of the most important causes of death in acute radiation syndrome. However, the dose-effect relationship of immune functions has been found to be quite different in the low dose range, especially with doses within 0.1 Gy. With doses above 0.5 Gy most immunologic parameters show a dose dependent depression. With doses between 0.1-0.5 Gy there may be no definite changes in immune functions. Doses within 0.1 Gy, given in single or chronic exposures, have been found to stimulate many immune responses. (author). 16 refs., 2 figs., 7 tabs

  8. Nuclear energy and health: and the benefits of low-dose radiation hormesis.

    Science.gov (United States)

    Cuttler, Jerry M; Pollycove, Myron

    2009-01-01

    Energy needs worldwide are expected to increase for the foreseeable future, but fuel supplies are limited. Nuclear reactors could supply much of the energy demand in a safe, sustainable manner were it not for fear of potential releases of radioactivity. Such releases would likely deliver a low dose or dose rate of radiation, within the range of naturally occurring radiation, to which life is already accustomed. The key areas of concern are discussed. Studies of actual health effects, especially thyroid cancers, following exposures are assessed. Radiation hormesis is explained, pointing out that beneficial effects are expected following a low dose or dose rate because protective responses against stresses are stimulated. The notions that no amount of radiation is small enough to be harmless and that a nuclear accident could kill hundreds of thousands are challenged in light of experience: more than a century with radiation and six decades with reactors. If nuclear energy is to play a significant role in meeting future needs, regulatory authorities must examine the scientific evidence and communicate the real health effects of nuclear radiation. Negative images and implications of health risks derived by unscientific extrapolations of harmful effects of high doses must be dispelled.

  9. Low dose X –ray effects on catalase activity in animal tissue

    International Nuclear Information System (INIS)

    Focea, R; Nadejde, C; Creanga, D; Luchian, T

    2012-01-01

    This study was intended to investigate the effect of low-dose X ray-irradiation upon the activity of catalase (CAT) in freshly excised chicken tissues (liver, kidney, brain, muscle). The tissue samples were irradiated with 0.5Gy and 2Gy respectively, in a 6 MV photon beam produced by a clinical linear accelerator (VARIAN CLINAC 2100SC). The dose rate was of 260.88cGy/min. at 100 cm source to sample distance. The catalase level was assayed spectrophotometrically, based on reaction kinetics, using a catalase UV assay kit (SIGMA). Catalase increased activity in various tissue samples exposed to the studied X ray doses (for example with 24 % in the liver cells, p<0.05) suggested the stimulation of the antioxidant enzyme biosynthesis within several hours after exposure at doses of 0.5 Gy and 2 Gy; the putative enzyme inactivation could also occur (due to the injuries on the hydrogen bonds that ensure the specificity of CAT active site) but the resulted balance of the two concurrent processes indicates the cell ability of decomposing the hydrogen peroxide-with benefits for the cell physiology restoration for the chosen low dose radiation.

  10. Low dose perfluorooctanoate exposure promotes cell proliferation in a human non-tumor liver cell line

    International Nuclear Information System (INIS)

    Zhang, Hongxia; Cui, Ruina; Guo, Xuejiang; Hu, Jiayue; Dai, Jiayin

    2016-01-01

    Highlights: • Differential expression of proteins induced by PFOA in HL-7702 was identified. • Most of the differentially expressed proteins are related to cell proliferation. • A low dose of PFOA stimulates HL-7702 cell proliferation. • A high dose of PFOA inhibits HL-7702 cell proliferation. - Abstract: Perfluorooctanoate (PFOA) is a well-known persistent organic pollutant widely found in the environment, wildlife and humans. Medical surveillance and experimental studies have investigated the potential effects of PFOA on human livers, but the hepatotoxicity of PFOA on humans and its underlying mechanism remain to be clarified. We exposed a human liver cell line (HL-7702) to 50 μM PFOA for 48 h and 96 h, and identified 111 significantly differentially expressed proteins by iTRAQ analysis. A total of 46 proteins were related to cell proliferation and apoptosis. Through further analysis of the cell cycle, apoptosis and their related proteins, we found that low doses of PFOA (50–100 μM) promoted cell proliferation and numbers by promoting cells from the G1 to S phases, whereas high doses of PFOA (200–400 μM) led to reduced HL-7702 cell numbers compared with that of the control mainly due to cell cycle arrest in the G0/G1 phase. To our knowledge, this is the first report on the promotion of cell cycle progression in human cells following PFOA exposure.

  11. Clinical features and management of ectopic ACTH syndrome at a single institute in Japan

    International Nuclear Information System (INIS)

    Doi, Masaru; Sugiyama, Toru; Izumiyama, Hajime; Yoshimoto, Takanobu; Hirata, Yukio

    2010-01-01

    Ectopic ACTH syndrome (EAS) is a diagnostic challenge because it is often indistinguishable from Cushing's disease. We describe our series of EAS patients referred to us during 1992-2009. Among 16 cases (9 females/7 males), with mean age of 58.4±19.0 yr, the ectopic source was identified in ten (proven EAS), whereas unidentified in six (occult/unknown EAS). Their salient clinical manifestations included Cushingoid feature (88%), skin pigmentation (88%), profound hypokalemia (88%), hypertension (75%), diabetes/impaired glucose tolerance (75%), hyperlipidemia (69%), and severe infection (44%). Dynamic endocrine tests revealed markedly elevated plasma ACTH levels (211±116 pg/mL) and cortisol levels (60.9±30.1 μg/dL) which showed resistance to overnight high-dose (8 mg) dexamethasone suppression test in 15 (94%) and unresponsiveness to corticotropin releasing hormone (CRH) stimulation in 12 (75%). No ACTH gradient during inferior petrosal sampling was noted in 13 of 15 (87%). Imaging tests by CT/MRI identified the tumors in 8 of 16 (50%), in 4 of 11 (36%) and 4 of 6 (66.7%) octreotide-responders by somatostatin receptor scintigraphy, but in only one of 9 (11.1%) by [ 18 F]-fluorodeoxyglucose-positron emission tomography (FDG-PET) scan. Six cases deceased, including small cell carcinoma (2) and adenocarcinoma (1) of lung, neuroendocrine carcinoma of pancreas (1) and stomach (1), and olfactory neuroblastoma (1), whereas 4 cases survived after removal of the tumors, including bronchial carcinoid tumor (3) and thymic hyperplasia (1). Six occult/unknown EAS patients survived for 67.5 months after medical treatment with metyrapone to control hypercortisolism. Thus, various endocrine tests combined with imaging studies are required to correctly localize the tumors. Control of hypercortisolemia by metyrapone, even if tumor is unrecognized, is critical for better prognosis, and the long-term follow-up by repeated endocrine and imaging tests is mandatory. (author)

  12. 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)

  13. The health effects of low-dose ionizing radiation

    International Nuclear Information System (INIS)

    Dixit, A.N.; Dixit, Nishant

    2012-01-01

    It has been established by various researches, that high doses of ionizing radiation are harmful to health. There is substantial controversy regarding the effects of low doses of ionizing radiation despite the large amount of work carried out (both laboratory and epidemiological). Exposure to high levels of radiation can cause radiation injury, and these injuries can be relatively severe with sufficiently high radiation doses. Prolonged exposure to low levels of radiation may lead to cancer, although the nature of our response to very low radiation levels is not well known at this time. Many of our radiation safety regulations and procedures are designed to protect the health of those exposed to radiation occupationally or as members of the public. According to the linear no-threshold (LNT) hypothesis, any amount, however small, of radiation is potentially harmful, even down to zero levels. The threshold hypothesis, on the other hand, emphasizes that below a certain threshold level of radiation exposure, any deleterious effects are absent. At the same time, there are strong arguments, both experimental and epidemiological, which support the radiation hormesis (beneficial effects of low-level ionizing radiation). These effects cannot be anticipated by extrapolating from harmful effects noted at high doses. Evidence indicates an inverse relationship between chronic low-dose radiation levels and cancer incidence and/or mortality rates. Examples are drawn from: 1) state surveys for more than 200 million people in the United States; 2) state cancer hospitals for 200 million people in India; 3) 10,000 residents of Taipei who lived in cobalt-60 contaminated homes; 4) high-radiation areas of Ramsar, Iran; 5) 12 million person-years of exposed and carefully selected control nuclear workers; 6) almost 300,000 radon measurements of homes in the United States; and 7) non-smokers in high-radon areas of early Saxony, Germany. This evidence conforms to the hypothesis that

  14. The spectrum of mutation produced by low dose radiation

    International Nuclear Information System (INIS)

    Morley, Alexander A.; Turner, David R.

    2004-01-01

    Inherited mutations are the basis of evolution and acquired mutations in humans are important in ageing, cancer and possibly various forms of tissue degeneration. Mutations are responsible for many of the long-term effects of radiation. However, sensitive direct detection of mutations in humans has been difficult. The aims of the project were to develop methods for the sensitive enumeration of mutations in DNA, to measure mutation frequencies in a wide variety of tissue types and to quantify the mutational effect of direct oxidative damage produced by radiation, at both high and low doses. The project was successful in developing a sensitive method which could detect mutations directly in the genetic material, DNA at a sensitivity of 1 mutated molecule in 1000000000 unmutated molecules. However a number of methodological problems had to be overcome and lack of ongoing funding made it impossible to fulfill all of the aims of the project

  15. Low dose response analysis through a cytogenetic end-point

    International Nuclear Information System (INIS)

    Bojtor, I.; Koeteles, G.J.

    1998-01-01

    The effects of low doses were studied on human lymphocytes of various individuals. The frequency of micronuclei in cytokinesis-blocked cultured lymphocytes was taken as end-point. The probability distribution of radiation-induced increment was statistically proved and identified as to be asymmetric when the blood samples had been irradiated with doses of 0.01-0.05 Gy of X-rays, similarly to that in unirradiated control population. On the contrary, at or above 1 Gy the corresponding normal curve could be accepted only reflecting an approximately symmetrical scatter of the increments about their mean value. It was found that the slope as well as the closeness of correlation of the variables considerably changed when lower and lower dose ranges had been selected. Below approximately 0.2 Gy even an unrelatedness was found betwen the absorbed dose and the increment

  16. Metabolomics: new prospects in low-dose radio-toxicology

    International Nuclear Information System (INIS)

    Souidi, Maamar; Grison, Stephane

    2014-01-01

    There is recurring public concern regarding the health impact of chronic exposure to low-dose ionizing radiation. This concern is further heightened when possible sources of exposure are identified, such as disused mines, the operation of nuclear facilities and radioactive waste disposal facilities, accidental release from fuel cycle facilities or the possible return of residents to areas contaminated following a reactor accident, such as the one that occurred at Fukushima. In keeping with the guidelines set out in the European strategic research agenda for MELODI, IRSN is conducting an extensive, largely experiment-based, research program to acquire scientific data to respond to this concern. The program has already revealed that chronic ingestion of cesium-137 or uranium induces many subtle, generally slight, metabolic changes, the overall biological effects of which remain to be studied. A recent 'broad-spectrum' analytical technique known as metabolomics was used to pinpoint these metabolic changes. (authors)

  17. Transcriptome profiling of mice testes following low dose irradiation

    DEFF Research Database (Denmark)

    Belling, Kirstine C.; Tanaka, Masami; Dalgaard, Marlene Danner

    2013-01-01

    ABSTRACT: BACKGROUND: Radiotherapy is used routinely to treat testicular cancer. Testicular cells vary in radio-sensitivity and the aim of this study was to investigate cellular and molecular changes caused by low dose irradiation of mice testis and to identify transcripts from different cell types...... in the adult testis. METHODS: Transcriptome profiling was performed on total RNA from testes sampled at various time points (n = 17) after 1 Gy of irradiation. Transcripts displaying large overall expression changes during the time series, but small expression changes between neighbouring time points were...... selected for further analysis. These transcripts were separated into clusters and their cellular origin was determined. Immunohistochemistry and in silico quantification was further used to study cellular changes post-irradiation (pi). RESULTS: We identified a subset of transcripts (n = 988) where changes...

  18. The effect of low-dose spironolactone on resistant hypertension

    DEFF Research Database (Denmark)

    Engbaek, Mette; Hjerrild, Mette; Hallas, Jesper

    2010-01-01

    with three classes of antihypertensive drugs. The effect on blood pressure was estimated by office measurements together with serum potassium and adverse effects. The data were analyzed retrospectively. A total of 544 patients were identified; 200 were excluded because of secondary hypertension, other......Our objective was to estimate the effect of addition of low-dose spironolactone to previous antihypertensive therapy in patients with resistant hypertension. Patients had 25 to 50 mg of spironolactone once daily added to the treatment of hypertension that was uncontrolled despite previous treatment...... indications for spironolactone than hypertension, previous antihypertensive therapy with less than three drugs unless demonstrated intolerance to a third drug, insufficient compliance, and lack of follow-up data. Thus, 344 cases were included in the analysis. The population was 62.1 ± 12.8 years old, 45...

  19. Low-dose aripiprazole for refractory burning mouth syndrome.

    Science.gov (United States)

    Umezaki, Yojiro; Takenoshita, Miho; Toyofuku, Akira

    2016-01-01

    We report a case of refractory burning mouth syndrome (BMS) ameliorated with low dose of aripiprazole. The patient was a 66-year-old female who had suffered from chronic burning pain in her tongue for 13 months. No abnormality associated with the burning sensation was detected in the laboratory tests and the oral findings. Considering the clinical feature and the history together, we diagnosed the burning sensation as BMS. The BMS pain was decreased by aripiprazole (powder) 1.0 mg/d, though no other antidepressants had satisfying pain relief. It could be supposed that the efficacy of aripiprazole is caused by dopamine stabilization in this case, and BMS might have a subtype that is reactive to aripiprazole. Further studies are needed to confirm the efficacy of aripiprazole for BMS.

  20. 'Reasonable' regulation of low doses in the Netherlands?

    International Nuclear Information System (INIS)

    Zuur, Ciska

    2002-01-01

    As long as it is not clear exactly what the risks of low doses are, exposures should be regulated to be 'as low as reasonably achievable' (ALARA). In radiation protection, for normal situations, this means that a projected dose reduction can only be obligatory when the efforts needed to achieve the reduction are 'reasonable' in comparison with it, economical and social aspects being taken into account. In the recent Dutch regulations, 'reasonable' values have been established for the relevant parameters used in the ALARA concept and the paper discusses the values required to calculate the doses for the critical group due to a source. In some cases, the effort expended in making the ALARA dose assessments might not be reasonable in comparison with the dose reduction to be expected. The system which has been developed in the Netherlands to avoid these 'unreasonable' dose calculations, measurements and assessments is explained. (author)

  1. State of human genome at low-doses ecological influences

    International Nuclear Information System (INIS)

    Mel'nov, S.B.; Rytik, P.G.; Kruchinskij, N.G.; Kovalev, V.A.; Palamar, L.A.; Senyuk, O.F.

    2005-01-01

    The results of analysis of the state of genome (amounts of single strand breaks in DNA) of the persons exposed to influence of complex 'Chernobyl factor' in remote terms after a failure on ChNPP are resulted. Findings allowed to expose the increase of level of single strand breaks in DNA at the chronically irradiated persons mainly carry adaptive character and probably can be related to instability of genome. Thus at organism level growth of mutational pressure and strengthening of instability of cellular genome is related to the change of spectrum of biological characteristics, in particular individual reaction of somatic cells of victims on additional mutagens influences. The indicated changes can testify to existence of potential risk of remote genetic consequences of long-term irradiation influence in low doses

  2. Optical fiber sensor for low dose gamma irradiation monitoring

    Science.gov (United States)

    de Andrés, Ana I.; Esteban, Ã.`scar; Embid, Miguel

    2016-05-01

    An optical fiber gamma ray detector is presented in this work. It is based on a Terbium doped Gadolinium Oxysulfide (Gd2O2S:Tb) scintillating powder which cover a chemically etched polymer fiber tip. This etching improves the fluorescence gathering by the optical fiber. The final diameter has been selected to fulfill the trade-off between light gathering and mechanical strength. Powder has been encapsulated inside a microtube where the fiber tip is immersed. The sensor has been irradiated with different air Kerma doses up to 2 Gy/h with a 137Cs source, and the spectral distribution of the fluorescence intensity has been recorded in a commercial grade CCD spectrometer. The obtained signal-to-noise ratio is good enough even for low doses, which has allowed to reduce the integration time in the spectrometer. The presented results show the feasibility for using low cost equipment to detect/measure ionizing radiation as gamma rays are.

  3. Effect of low dose radiation on apoptosis in mouse spleen

    International Nuclear Information System (INIS)

    Chen Dong; Liu Jiamei; Chen Aijun; Liu Shuzheng

    1999-01-01

    Objective: To study the effect of whole body irradiation (WBI) with different doses of X-ray on apoptosis in mouse spleen. Methods: Time course changes and dose-effect relationship of apoptosis in mouse spleen induced by WBI were observed with transmission electron microscopy (TEM) qualitatively and TUNEL method semi-quantitatively. Results: Many typical apoptotic lymphocytes were found by TEM in mouse spleen after WBI with 2 Gy. No marked alterations of ultrastructure were found following WBI with 0.075 Gy. It was observed by TUNEL that the apoptosis of splenocytes increased after high dose radiation and decreased following low dose radiation (LDR). The dose-effect relationship of radiation-induced apoptosis showed a J-shaped curve. Conclusion: The effect of different doses of ionizing radiation on apoptosis in mouse spleen was distinct. And the decrease of apoptosis after LDR is considered a manifestation of radiation hormesis

  4. The effects of chronic low dose irradiation on drosophila melanogaster

    International Nuclear Information System (INIS)

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

    2001-01-01

    It was investigated the influence of the chronic gamma-irradiation in the dose rate of 0.17 cGy/h on the rate of genetic variability and on the life-span in the laboratory strains of Drosophila melanogaster with genotypic distinguishes in mobile genetic elements and defects in the DNA repair processes. It is shown that the radiation-induced alteration of the traits under study depends from genotype of investigated strains. In the different strains we have observed an increase as well as a decrease of the mutation rate and life-span. Also it was established that irradiation leads to the frequencies of the GD-sterility and mutability of the snw and h(w+) in the P-M and H-E dysgenic crosses. The obtained results suggest that mobile genetic elements play an important role in the forming of genetic effects in response to low dose irradiation. (author)

  5. Genetic effects of low-dose irradiation in Drosophila Melanogaster

    International Nuclear Information System (INIS)

    Zajnulin, V.G.; Shaposhnikov, M.V.; Yuraneva, I.N.

    2000-01-01

    Influence of chronic γ-irradiation at the dose rate of 0.17 cGy/h on the rate of genetic variability in the laboratory strains of Drosophila Melanogaster with genotypic distinguishes by families of mobile genetic elements and of systems of hybrid disgenesis and also violations in reparation processes control mechanisms. It was shown that the rates of induction of recessive lethal mutations depended on genotype of investigated strains. In the different strains an increase as well as a decrease of the mutation rate were observed. Also in was established that irradiation leads to the increase in frequencies of the gonads sterility and mutability of the sn w and h(w + ) in the P-M and H-E dysgenic crosses. Obtained results suggest that mobile genetic elements play an important role in the forming of genetic effects in response to low dose irradiation [ru

  6. Low dose preoperative radiotherapy for carcinoma of the oesophagus

    International Nuclear Information System (INIS)

    Arnott, S.J.; Duncan, W.; Kerr, G.R.; Jack, W.J.L.; Mackillop, W.J.; Walbaum, P.R.; Cameron, E.

    1992-01-01

    Patients (176) with potentially operable squamous cell carcinoma or adenocarcinoma of middle or lower thirds of oesophagus were randomly assigned to preoperative radiotherapy or surgery alone. Patients assigned to the radiotherapy arm received 20 Gy in 10 treatments over 2 weeks, using parallel opposed 4 MV beams. The preoperative radiotherapy was not associated with any significant acute morbidity or any increase in operative complications. The median survival of the overall group of 176 patients was 8 moths, and the 5-year survival was 13%. There was no significant difference in the survival of the 90 patients who received preoperative radiotherapy and the 86 who were managed by surgery alone. Proportional hazards analysis identified lymph node involvement, high tumor grade and male sex as significant adverse prognostic features, but the treatment option assigned had no prognostic significance. It was concluded that low dose preoperative radiotherapy offered no advantage over surgery alone. (author). 9 refs.; 3 figs.; 6 tabs

  7. High and low dose-rate brachytherapy for cervical carcinoma

    International Nuclear Information System (INIS)

    Orton, C.G.

    1998-01-01

    For the brachytherapy component of the r[iation treatment of cervical carcinoma, high dose rate (HDR) is slowly replacing conventional low dose rate (LDR) due primarily to r[iation safety and other physical benefits attributed to the HDR modality. Many r[iation oncologists are reluctant to make this change because of perceived r[iobiological dis[vantages of HDR. However, in clinical practice HDR appears to be as effective as LDR but with a lower risk of late complications, as demonstrated by one randomized clinical trial and two comprehensive literature and practice surveys. The reason for this appears to be that the r[iobiological dis[vantages of HDR are outweighed by the physical [vantages. (orig.)

  8. Radioimmunological determination of. cap alpha. -MSH and ACTH in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Usategui Echeverria, R; Oliver, C; Vaudry, H; Lombardi, G; Rozenberg, I; Vague, J [Centre Hospitalier Universitaire de la Timone, 13 - Marseille (France)

    1975-09-01

    Specific and sensitive radioimmunoassay methods for ..cap alpha..-MSH and ACTH are reported. They make possible specific measurements of each hormone in rat plasma or pituitary extracts. Endogenous ..cap alpha..-MSH and ACTH extracted from plasma or pituitary show the same immunoreactivity than synthetic ..cap alpha..-MSH and ACTH. ..cap alpha..-MSH and ACTH levels vary independently from each other in the following conditions: circadian rythm, corticoid treatment, adrenalectomy, ether stress, haloperidol injection.

  9. Lung cancer screening with low-dose CT

    International Nuclear Information System (INIS)

    Diederich, S.; Wormanns, D.; Heindel, W.

    2003-01-01

    Screening for lung cancer is hoped to reduce mortality from this common tumour, which is characterised by a dismal overall survival, relatively well defined risk groups (mainly heavy cigarette smokers and workers exposed to asbestos) and a lack of early symptoms. In the past studies using sputum cytology and chest radiography have failed to demonstrate any reduction in lung cancer mortality through screening. One of the reasons is probably the relatively poor sensitivity of both these tests in early tumours. Low radiation dose computed tomography (CT) has been shown to have a much higher sensitivity for small pulmonary nodules, which are believed to be the most common presentation of early lung cancer. As, however, small pulmonary nodules are common and most are not malignant, non-invasive diagnostic algorithms are required to correctly classify the detected lesions and avoid invasive procedures in benign nodules. Nodule density, size and the demonstration of growth at follow-up have been shown to be useful in this respect and may in the future be supplemented by contrast-enhanced CT and positron emission tomography. Based on these diagnostic algorithms preliminary studies of low-dose CT in heavy smokers have demonstrated a high proportion of asymptomatic, early, resectable cancers with good survival. As, however, several biases could explain these findings in the absence of the ultimate goal of cancer screening, i.e. mortality reduction, most researchers believe that randomised controlled trials including several 10000 subjects are required to demonstrate a possible mortality reduction. Only then general recommendations to screen individuals at risk of lung cancer with low-dose CT should be made. It can be hoped that international cooperation will succeed in providing results as early as possible

  10. Low dose radiation enhances the Locomotor activity of D. melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Seong, Ki Moon; Lee, Buyng Sub; Nam Seon Young; Kim, Ji Young; Yang, Kwang Hee; Choi, Tae In; Kim, Cha Soon [Radiation Effect Research Team, Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., Gyeongju (Korea, Republic of)

    2013-04-15

    Mild stresses at low level including radiation can induce the beneficial effects in many vertebrate and invertebrate species. However, a large amount of studies in radiation biology have focused on the detrimental effects of high dose radiation (HDR) such as the increased incidence of cancers and developmental diseases. Low dose radiation (LDR) induces biologically favorable effects in diverse fields, for example, cancer development, genomic instability, immune response, and longevity. Our previous data indicated that LDR promotes cells proliferation of which degree is not much but significant, and microarray data explained that LDR irradiated fruit flies showing the augmented immunity significantly changed the program for gene expression of many genes in Gene Ontology (GO) categories related to metabolic process. Metabolic process in development one of major contributors in organism growth, interbreeding, motility, and aging. Therefore, it is valuable to examine whether LDR change the physiological parameters related to metabolism, and how LDR regulates the metabolism in D. melanogaster. In this study, to investigate that LDR influences change of the metabolism, a representative parameter, locomotor activity. In addition, the activation of several cellular signal molecules was determined to investigate the specific molecular mechanism of LDR effects on the metabolism. We explored whether ionizing radiation affects the motility activity. We performed the RING assays to evaluate the locomotor activity, a representative parameter presenting motility of fruit flies. HDR dramatically decreased the motor activity of irradiated flies. Surprisingly, the irradiated flies at low dose radiation in both acute and chronic showed the significantly increased locomotor activity, compared to non-irradiated flies. Irradiation would induce change of the several signal pathways for flies to respond to it. The activation of some proteins involved in the cells proliferation and stress

  11. Varicose Vein Stripping Under Low-Dose Spinal Anaesthesia

    Directory of Open Access Journals (Sweden)

    Nalan Muhammedoğlu

    2014-03-01

    Full Text Available Aim: Spinal anesthesia is frequently used for procedures involving the lower limbs. Compared with general anesthesia, low-dose spinal anesthesia is a cost-effective method and has advantages such as avoiding hypotension, longer duration of anesthesia and increased length of hospitalization. The aim of this trial was to compare two different low-dose bupivacaine drug regimens. Methods: Sixty unpremedicated patients were randomly allocated into two groups (n=30. There were no differences between the groups in age, weight, the American Society of Anesthesiologists (ASA physical status classification, gender, and duration of surgery. We performed spinal anesthesia at the L3-4 interspace with the patient in the lateral decubitus position. We administered 6.5 mg (group 1 and 8 mg (group 2 0.5% heavy bupivacaine into the subarachnoid space. We positioned the patient laterally to the operation side for 15 minutes, then, turned to supine position. Motor and sensory block was assessed by the Bromage scale and pinprick test. Results: There were significant differences between the two groups in duration of motor block, but no significant differences in hemodynamic response to spinal anesthesia. None of the patients had intraoperative pain. Five patients in group 1 and 2 patients in group 2 had urinary retention. Conclusion: Our observations suggest that 6.5 mg heavy bupivacaine is efficient and suitable for unilateral varicose veins stripping operation. (The Me­di­cal Bul­le­tin of Ha­se­ki 2014; 52: 25-8

  12. Cardiovascular risks associated with low dose ionizing particle radiation.

    Directory of Open Access Journals (Sweden)

    Xinhua Yan

    Full Text Available Previous epidemiologic data demonstrate that cardiovascular (CV morbidity and mortality may occur decades after ionizing radiation exposure. With increased use of proton and carbon ion radiotherapy and concerns about space radiation exposures to astronauts on future long-duration exploration-type missions, the long-term effects and risks of low-dose charged particle irradiation on the CV system must be better appreciated. Here we report on the long-term effects of whole-body proton ((1H; 0.5 Gy, 1 GeV and iron ion ((56Fe; 0.15 Gy, 1GeV/nucleon irradiation with and without an acute myocardial ischemia (AMI event in mice. We show that cardiac function of proton-irradiated mice initially improves at 1 month but declines by 10 months post-irradiation. In AMI-induced mice, prior proton irradiation improved cardiac function restoration and enhanced cardiac remodeling. This was associated with increased pro-survival gene expression in cardiac tissues. In contrast, cardiac function was significantly declined in (56Fe ion-irradiated mice at 1 and 3 months but recovered at 10 months. In addition, (56Fe ion-irradiation led to poorer cardiac function and more adverse remodeling in AMI-induced mice, and was associated with decreased angiogenesis and pro-survival factors in cardiac tissues at any time point examined up to 10 months. This is the first study reporting CV effects following low dose proton and iron ion irradiation during normal aging and post-AMI. Understanding the biological effects of charged particle radiation qualities on the CV system is necessary both for the mitigation of space exploration CV risks and for understanding of long-term CV effects following charged particle radiotherapy.

  13. Clinical application of low-dose spiral CT for orthodontics

    International Nuclear Information System (INIS)

    Xie Na; Gan Yungen; Shu Huang; Lin FeiFei; Li Zhiyong; Sun Jie

    2009-01-01

    Objective: To determine the effect of reducing the value of mA or kV on the image quality and the radiation dose of the patients undergoing low-dose spiral CT for orthodontics. Methods: Thirty patients were divided into three groups, each group has 10 patients. They were group 1 (80 kV and 200 mA), group 2 (120 kV and 80 mA), group 3 (120 kV and 200 mA) The volume CT dose index (CTDI) was recorded and the average dose-length produce (DLP) was calculated in three groups,respectively. Image quality of three groups were compared and scored by two radiologists, and the results were statistically analysed. Results: The CTDI and DLP of 80 kV group (group 2) were 8.7 mGy and (36.80 ± 3.60) mGy · cm, respectively, those of 80 mA group (group 3) were 19.6 mGy and (82.14 ± 7.18) mGy · cm, respectively, and those of conventional-dose group (group 1) were 19.6 mGy and (82.14 ± 7.18) mGy · cm, respectively. There was no significant difference among three groups in diagnostic image quality. Conclusions: Low-dose spiral CT for orthodontics, especially the low-kV scan, may decrease the radiation exposure and guarantee the image quality. (authors)

  14. Low-Dose Radiation Cataract and Genetic Determinants of Radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Kleiman, Norman Jay [Columbia University

    2013-11-30

    The lens of the eye is one of the most radiosensitive tissues in the body. Ocular ionizing radiation exposure results in characteristic, dose related, progressive lens changes leading to cataract formation. While initial, early stages of lens opacification may not cause visual disability, the severity of such changes progressively increases with dose until vision is impaired and cataract extraction surgery may be required. Because of the transparency of the eye, radiation induced lens changes can easily be followed non-invasively over time. Thus, the lens provides a unique model system in which to study the effects of low dose ionizing radiation exposure in a complex, highly organized tissue. Despite this observation, considerable uncertainties remain surrounding the relationship between dose and risk of developing radiation cataract. For example, a growing number of human epidemiological findings suggest significant risk among various groups of occupationally and accidentally exposed individuals and confidence intervals that include zero dose. Nevertheless, questions remain concerning the relationship between lens opacities, visual disability, clinical cataract, threshold dose and/or the role of genetics in determining radiosensitivity. Experimentally, the response of the rodent eye to radiation is quite similar to that in humans and thus animal studies are well suited to examine the relationship between radiation exposure, genetic determinants of radiosensitivity and cataractogenesis. The current work has expanded our knowledge of the low-dose effects of X-irradiation or high-LET heavy ion exposure on timing and progression of radiation cataract and has provided new information on the genetic, molecular, biochemical and cell biological features which contribute to this pathology. Furthermore, findings have indicated that single and/or multiple haploinsufficiency for various genes involved in DNA repair and cell cycle checkpoint control, such as Atm, Brca1 or Rad9

  15. Latest diagnostic approaches to determine the cause of ACTH ...

    African Journals Online (AJOL)

    A case of a 50-year-old woman who was referred for the evaluation of possible ACTH-dependent Cushing's syndrome (CS) is described. The localisation of ... and facial plethora. On bone mineral density assessment she had ..... the source of EC, PET/CT using 68 Ga-DOTA-labelled octreotide analogues had the best ...

  16. Severe Cushing's syndrome and bilateral pulmonary nodules: beyond ectopic ACTH.

    Science.gov (United States)

    Tavares Bello, Carlos; van der Poest Clement, Emma; Feelders, Richard

    2017-01-01

    Cushing's syndrome is a rare disease that results from prolonged exposure to supraphysiological levels of glucocorticoids. Severe and rapidly progressive cases are often, but not exclusively, attributable to ectopic ACTH secretion. Extreme hypercortisolism usually has florid metabolic consequences and is associated with an increased infectious and thrombotic risk. The authors report on a case of a 51-year-old male that presented with severe Cushing's syndrome secondary to an ACTH-secreting pituitary macroadenoma, whose diagnostic workup was affected by concurrent subclinical multifocal pulmonary infectious nodules. The case is noteworthy for the atypically severe presentation of Cushing's disease, and it should remind the clinician of the possible infectious and thrombotic complications associated with Cushing's syndrome. Severe Cushing's syndrome is not always caused by ectopic ACTH secretion.Hypercortisolism is a state of immunosuppression, being associated with an increased risk for opportunistic infections.Infectious pulmonary infiltrates may lead to imaging diagnostic dilemmas when investigating a suspected ectopic ACTH secretion.Cushing's syndrome carries an increased thromboembolic risk that may even persist after successful surgical management.Antibiotic and venous thromboembolism prophylaxis should be considered in every patient with severe Cushing's syndrome.

  17. Molecular transduction mechanisms in ACTH-induced grooming

    NARCIS (Netherlands)

    Gispen, W.H.; Colbern, D.; Spruijt, B.M.

    1988-01-01

    Intraventricular administration of ACTH1-24 induces excessive grooming in the rat. Ethogram analysis shows that the peptide does not alter grooming behavior seen in a novel box, but that it prolongs the duration of the grooming bout. Extensive structure-activity studies have been performed which

  18. Status of calcium regulating hormonal systems in delayed period in persons exposed to occupational exposure of low doses of ionizing radiations

    International Nuclear Information System (INIS)

    Dospolova, Zh.G.; Abylaev, Zh.A.

    1997-01-01

    Purpose of study is consideration of endocrine system participation in development of calcium exchange disorders in persons exposed to action of low dose radiation . By radio- immune method in blood serum of 150 liquidators of Chernobyl accident consequences the concentration the following hormones were determined: parathormone, T 3 , T 4 , TSH, cortisol, ACTH, testosteron, insulin. Content of these hormones have been studied in according to following radiation factors: value of absorbed doses of external irradiation, degree of radioactive contamination of zone and exposition duration. It was determined, that basically dishormone disorders development have been concerned with parathormone, cortisol, hormones of thyroid axis, and in some cases to ACTH and insulin. Liquidators' frequencies of normal and changed concentration of calcium regulating hormones are sited in tabular form. It was established, that examined persons in result hormone disorders have of decrease functions of pituitary glands (76.78 %), pancreas (55 %), thyroid gland (24.31 %) and sex glands (19.23 %) and simultaneously cases of increase functions of parathyroid gland (58.2 %), adrenal glands (52.32 %) and adeno-pituitary glands (17.39). It is concluded, that inter hormonal correlation disorders are accompanying with morphologic and functional futures of secretory activity changes

  19. Stimulating effects of ionizing radiation

    International Nuclear Information System (INIS)

    Jaworowski, Z.

    1995-01-01

    The influence of low doses on human organism is not definite known up to now. The worldwide discussion on this topic has been presented. A lot of analysed statistical data proved that the stimulating effect of low doses of ionizing radiation really exists and can have a beneficial influence on human health. 43 refs, 4 figs, 6 tabs

  20. Implications of effects ''adaptive response'', ''low-dose hypersensitivity'' und ''bystander effect'' for cancer risk at low doses and low dose rates

    International Nuclear Information System (INIS)

    Jacob, P

    2006-01-01

    A model for carcinogenesis (the TSCE model) was applied in order to examine the effects of ''Low-dose hypersensitivity (LDH)'' and the ''Bystander effect (BE)'' on the derivation of radiation related cancer mortality risks. LDH has been discovered to occur in the inactivation of cells after acute exposure to low LET radiation. A corresponding version of the TSCE model was applied to the mortality data on the Abomb survivors from Hiroshima and Nagasaki. The BE has been mainly observed in cells after exposure to high LET radiation. A Version of the TSCE model which included the BE was applied to the data on lung cancer mortality from the workers at the Mayak nuclear facilities who were exposed to Plutonium. In general an equally good description of the A-bomb survivor mortality data (for all solid, stomach and lung tumours) was found for the TSCE model and the (conventional) empirical models but fewer parameters were necessary for the TSCE model. The TSCE model which included the effects of radiation induced cell killing resulted in non-linear dose response curves with excess relative risks after exposure at young ages that were generally lower than in the models without cell killing. The main results from TSCE models which included cell killing described by either conventional survival curves or LDH were very similar. A sub multiplicative effect from the interaction of smoking and exposure to plutonium was found to result from the analysis of the Mayak lung cancer mortality data. All models examined resulted in the predominant number of Mayak lung cancer deaths being ascribed to smoking. The interaction between smoking and plutonium exposures was found to be the second largest effect. The TSCE model resulted in lower estimates for the lung cancer excess relative risk per unit plutonium dose than the empirical risk model, but this difference was not found to be statistically significant. The excess relative risk dose responses were linear in the empirical model and

  1. The Contribution of Tissue Level Organization to Genomic Stability Following Low Dose/Low Dose Rate Gamma and Proton Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Cheryl G. Burrell, Ph.D.

    2012-05-14

    The formation of functional tissue units is necessary in maintaining homeostasis within living systems, with individual cells contributing to these functional units through their three-dimensional organization with integrin and adhesion proteins to form a complex extra-cellular matrix (ECM). This is of particular importance in those tissues susceptible to radiation-induced tumor formation, such as epithelial glands. The assembly of epithelial cells of the thyroid is critical to their normal receipt of, and response to, incoming signals. Traditional tissue culture and live animals present significant challenges to radiation exposure and continuous sampling, however, the production of bioreactor-engineered tissues aims to bridge this gap by improve capabilities in continuous sampling from the same functional tissue, thereby increasing the ability to extrapolate changes induced by radiation to animals and humans in vivo. Our study proposes that the level of tissue organization will affect the induction and persistence of low dose radiation-induced genomic instability. Rat thyroid cells, grown in vitro as 3D tissue analogs in bioreactors and as 2D flask grown cultures were exposed to acute low dose (1, 5, 10 and 200 cGy) gamma rays. To assess immediate (6 hours) and delayed (up to 30 days) responses post-irradiation, various biological endpoints were studied including cytogenetic analyses, apoptosis analysis and cell viability/cytotoxicity analyses. Data assessing caspase 3/7 activity levels show that, this activity varies with time post radiation and that, overall, 3D cultures display more genomic instability (as shown by the lower levels of apoptosis over time) when compared to the 2D cultures. Variation in cell viability levels were only observed at the intermediate and late time points post radiation. Extensive analysis of chromosomal aberrations will give further insight on the whether the level of tissue organization influences genomic instability patterns after

  2. 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

  3. Study of the effects of low-dose radiation and rhEGF on growth of cultured human epithelial cells

    International Nuclear Information System (INIS)

    Yang Jicheng; Zhao Xiaoyu; Sheng Weihua; Tang Zhongyi

    1998-01-01

    In authors' study, the method of taking skin sample, mincing and trypsinizing the sample are presented. The cells were inoculated on adherent membrane or, for sublethally injured 3T3 cells, in culture dish fed with Eargles' medium supplemented with fetal calf serum and various growth-stimulating factors. The cultures were incubated at 37 degree C in an atmosphere containing 5% CO 2 . The medium was changed every three days. The cultured cells became confluent in about two weeks. At the same time, low-dose-radiation and rhEGF were used to influence the growth of the epithelial cells and to test the effects of dosage and concentration. The results showed that low-dose-radiation in the conditions like authors' study could enhance the growth of human epithelial cells just like rhEGF, and it has synergetic effects with rhEGF. The mechanism is discussed

  4. Low doses effects and gamma radiations low dose rates; Les effets des faibles doses et des faibles debits de doses de rayons gamma

    Energy Technology Data Exchange (ETDEWEB)

    Averbeck, D [Institut Curie, CNRS UMR 2027, 75 - Paris (France)

    1999-07-01

    This expose wishes for bringing some definitions and base facts relative to the problematics of low doses effects and low dose rates effects. It shows some already used methods and some actual experimental approaches by focusing on the effects of ionizing radiations with a low linear energy transfer. (N.C.)

  5. Low dosing of gonadotropins in in vitro fertilization cycles for women with poor ovarian reserve: systematic review and meta-analysis

    NARCIS (Netherlands)

    Youssef, Mohamed Abdel-Fattah; van Wely, Madelon; Mochtar, Monique; Fouda, Usama Mohamed; Eldaly, Ashraf; El Abidin, Eman Zein; Elhalwagy, Ahmed; Mageed Abdallah, Ahmed Abdel; Zaki, Sherif Sameh; Abdel Ghafar, Mohamed Sayed; Mohesen, Mohamed Nagi; van der Veen, Fulco

    2018-01-01

    Objective: To evaluate the effectiveness of low doses of gonadotropins and gonadotropins combined with oral compounds compared with high doses of gonadotropins in ovarian stimulation regimens in terms of ongoing pregnancy per fresh IVF attempt in women with poor ovarian reserve undergoing

  6. Low doses effects of ionizing radiation on Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Durand, J.; Broock, M. van; Gillette, V.H.

    2000-01-01

    The exposure of living cells to low doses of ionizing radiation induce in response the activation of cellular protection mechanisms against subsequent larger doses of radiation. This cellular adaptive response may vary depending on radiation intensity and time of exposure, and also on the testing probes used whether they were mammalian cells, yeast, bacteria and other organisms or cell types. The mechanisms involved are the genome activation, followed by DNA repair enzymes synthesis. Due to the prompt cell response, the cell cycle can be delayed, and the secondary detoxification of free radicals and/or activation of membrane bound receptors may proceed. All these phenomena are submitted to intense scientific research nowadays, and their elucidation will depend on the complexity of the organism under study. In the present work, the effects of low doses of ionizing radiation (gamma rays) over a suspension of the yeast Saccharomyces cerevisiae (Baker's yeast) was studied, mainly in respect to survival rate and radio-adaptive response. At first, the yeast surviving curve was assessed towards increasing doses, and an estimation of Lethal Dose 50 (LD50) was made. The irradiation tests were performed at LINAC (electrons Linear Accelerator) where electron energy reached approximately 2.65 MeV, and gamma-radiation was produced for bremsstrahlung process over an aluminium screen target. A series of experiments of conditioning doses was performed and an increment surviving fraction was observed when the dose was 2.3 Gy and a interval time between this and a higher dose (challenging dose) of 27 Gy was 90 minutes. A value of 58 ± 4 Gy was estimated for LD50, at a dose rate of 0.44 ± 0.03 Gy/min These quantities must be optimized. Besides data obtained over yeast survival, an unusual increasing amount of tiny yeast colonies appeared on the agar plates after incubation, and this number increased as increasing the time exposure. Preliminary results indicate these colonies as

  7. Effectiveness of low-dose midazolam plus ketamine in the ...

    African Journals Online (AJOL)

    2012-11-01

    Nov 1, 2012 ... to mild physical stimulation; and 5 = eyes closed, but unarousable to mild ... 3 and above. They were given pethidine as rescue therapy, according to protocol. ..... function of geriatric patients under spinal anesthesia. Korean J.

  8. Molecular interpretation of ACTH-β-endorphin coaggregation: relevance to secretory granule biogenesis.

    Directory of Open Access Journals (Sweden)

    Srivastav Ranganathan

    Full Text Available Peptide/protein hormones could be stored as non-toxic amyloid-like structures in pituitary secretory granules. ACTH and β-endorphin are two of the important peptide hormones that get co-stored in the pituitary secretory granules. Here, we study molecular interactions between ACTH and β-endorphin and their colocalization in the form of amyloid aggregates. Although ACTH is known to be a part of ACTH-β-endorphin aggregate, ACTH alone cannot aggregate into amyloid under various plausible conditions. Using all atom molecular dynamics simulation we investigate the early molecular interaction events in the ACTH-β-endorphin system, β-endorphin-only system and ACTH-only system. We find that β-endorphin and ACTH formed an interacting unit, whereas negligible interactions were observed between ACTH molecules in ACTH-only system. Our data suggest that ACTH is not only involved in interaction with β-endorphin but also enhances the stability of mixed oligomers of the entire system.

  9. Low-dose radiation suppresses Pokemon expression under hypoxic conditions.

    Science.gov (United States)

    Kim, Seung-Whan; Yu, Kweon; Shin, Kee-Sun; Kwon, Kisang; Hwang, Tae-Sik; Kwon, O-Yu

    2014-01-01

    Our previous data demonstrated that CoCl2-induced hypoxia controls endoplasmic reticulum (ER) stress-associated and other intracellular factors. One of them, the transcription factor Pokemon, was differentially regulated by low-dose radiation (LDR). There are limited data regarding how this transcription factor is involved in expression of the unfolded protein response (UPR) under hypoxic conditions. The purpose of this study was to obtain clues on how Pokemon is involved in the UPR. Pokemon was selected as a differentially expressed gene under hypoxic conditions; however, its regulation was clearly repressed by LDR. It was also demonstrated that both expression of ER chaperones and ER stress sensors were affected by hypoxic conditions, and the same results were obtained when cells in which Pokemon was up- or down-regulated were used. The current state of UPR and LDR research associated with the Pokemon pathway offers an important opportunity to understand the oncogenesis, senescence, and differentiation of cells, as well as to facilitate introduction of new therapeutic radiopharmaceuticals.

  10. Effect of low doses gamma irradiation of cotton seeds

    International Nuclear Information System (INIS)

    Al-Oudat, M.; Khalifa, Kh.

    1996-01-01

    Field experiments and then large scale application of irradiated cotton seeds (C.V. Aleppo-40) were carried out during three seasons (1986, 1987 and 1988) for field experiment at ACSAD Station in Dier-Ezzor and 1988, 1989 and 1990 for large scale application at Euphrate's Basin, Al-Ghab and Salamia, farmers farms. The above areas were selected as they represent major cotton production areas in Syria. The aims of the experiments were to study the effect of low doses of gamma irradiation 0, 5, 10, 20, 30, 40 and 50 Gy on cotton yield and to look for the optimum dose of gamma irradiation to obtain best results. The results show that, there were positive effect (P<0.95) for doses 5-30 Gy in increasing cotton yield. The highest increase was at dose of 10 Gy. which as 19.5% higher than control. For the large scale application using 10 Gy the increase in cotton yield varied from 10-39% compared to control. (author). 11 refs., 6 figs

  11. Sensitivity to low-dose radiation in radiosensitive ''wasted'' mice

    International Nuclear Information System (INIS)

    Paunesku, T.; Protic, M.; Woloschak, G. E.

    1999-01-01

    Mice homozygous for the autosomal recessive wasted mutation (wst/wst) have abnormalities in T-lymphocytes and in the anterior motor neuron cells of the spinal cord, leading to sensitivity to low doses of ionizing radiation, hind limb paralysis, and immunodeficiency. This defect results in a failure to gain weight by 20 days and death at 28 days of age. The wasted mutation (previously mapped to mouse chromosome 2) is shown to be a 3-bp deletion in a T-cell-specific (and perhaps motor-neuron-specific) regulatory region (promoter) of the proliferating cell nuclear antigen (PCNA) gene on mouse chromosome 2. A regulatory element is also shown to be important in PCNA expression in T-lymphocytes and motor neuron cells afflicted by the 3-bp deletion in the PCNA promoter. The model is as follows: Absence of PCNA expression in the thymuses (and motor neurons) of wasted mice causes cellular apoptosis; this absence of expression is mediated by a positive transactor that can bind to the wild-type but not the wasted mutant PCNA promoter; the bound protein induces late expression of PCNA in T-lymphocytes and prevents onset of radiation sensitivity in the cells

  12. Medical effects of low doses of ionising radiation

    International Nuclear Information System (INIS)

    Coggle, J.E.

    1990-01-01

    Ionising radiation is genotoxic and causes biological effects via a chain of events involving DNA strand breaks and 'multiply damaged sites' as critical lesions that lead to cell death. The acute health effects of radiation after doses of a few gray, are due to such cell death and consequent disturbance of cell population kinetics. Because of cellular repair and repopulation there is generally a threshold dose of about 1-2 Gy below which such severe effects are not inducible. However, more subtle, sub-lethal mutational DNA damage in somatic cells of the body and the germ cells of the ovary and testis cause the two major low dose health risks -cancer induction and genetic (heritable) effects. This paper discusses some of the epidemiological and experimental evidence regarding radiation genetic effects, carcinogenesis and CNS teratogenesis. It concludes that current risk estimates imply that about 3% of all cancers; 1% of genetic disorders and between 0% and 0.3% of severe mental subnormality in the UK is attributable to the ubiquitous background radiation. The health risks associated with the medical uses of radiation are smaller, whilst the nuclear industry causes perhaps 1% of the health detriment attributable to background doses. (author)

  13. Carcinogenesis in mice after low doses and dose rates

    International Nuclear Information System (INIS)

    Ullrich, R.L.

    1979-01-01

    The results from the experimental systems reported here indicate that the dose-response curves for tumor induction in various tissues cannot be described by a single model. Furthermore, although the understanding of the mechanisms involved in different systems is incomplete, it is clear that very different mechanisms for induction are involved. For some tumors the mechanism of carcinogenesis may be mainly a result of direct effects on the target cell, perhaps involving one or more mutations. While induction may occur, in many instances, through such direct effects, the eventual expression of the tumor can be influenced by a variety of host factors including endocrine status, competence of the immune system, and kinetics of target and interacting cell populations. In other tumors, indirect effects may play a major role in the initiation or expression of tumors. Some of the hormone-modulated tumors would fall into this class. Despite the complexities of the experimental systems and the lack of understanding of the types of mechanisms involved, in nearly every example the tumorigenic effectiveness per rad of low-LET radiation tends to decrease with decreasing dose rate. For some tumor types the differences may be small or may appear only with very low dose rates, while for others the dose-rate effects may be large

  14. Fully automated gynecomastia quantification from low-dose chest CT

    Science.gov (United States)

    Liu, Shuang; Sonnenblick, Emily B.; Azour, Lea; Yankelevitz, David F.; Henschke, Claudia I.; Reeves, Anthony P.

    2018-02-01

    Gynecomastia is characterized by the enlargement of male breasts, which is a common and sometimes distressing condition found in over half of adult men over the age of 44. Although the majority of gynecomastia is physiologic or idiopathic, its occurrence may also associate with an extensive variety of underlying systemic disease or drug toxicity. With the recent large-scale implementation of annual lung cancer screening using low-dose chest CT (LDCT), gynecomastia is believed to be a frequent incidental finding on LDCT. A fully automated system for gynecomastia quantification from LDCT is presented in this paper. The whole breast region is first segmented using an anatomyorientated approach based on the propagation of pectoral muscle fronts in the vertical direction. The subareolar region is then localized, and the fibroglandular tissue within it is measured for the assessment of gynecomastia. The presented system was validated using 454 breast regions from non-contrast LDCT scans of 227 adult men. The ground truth was established by an experienced radiologist by classifying each breast into one of the five categorical scores. The automated measurements have been demonstrated to achieve promising performance for the gynecomastia diagnosis with the AUC of 0.86 for the ROC curve and have statistically significant Spearman correlation r=0.70 (p early detection as well as the treatment of both gynecomastia and the underlying medical problems, if any, that cause gynecomastia.

  15. 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.

  16. Risk at Low Doses: Scientific knowledge, uncertainties and management

    International Nuclear Information System (INIS)

    Giusssani, A.; Ballarini, F.; Ottolenghi, A.

    2002-01-01

    Most of the applications of ionizing radiation in the medical field, for the exposed workers as well as the majority of patients undergoing diagnostic examinations, can be seen as low situations. Epidemiological information is however available for dose and dose rates higher than the values typical of most medical situation. Main source of information is the Life Span Study (LSS) of Japanese. A-bomb survivors, supplemented by studies of selected groups of exposed workers (uranium miners, radium painters) or radiotherapy patients with a detailed follow-up history. All of these group studies, however, suffer from one or more of the following limitations: - lack of adequate dosimetry - lack of a reliable control group for the necessary comparison - influence of concomitant factors (not always easy to find out) - influence of social conditions. In addition exposed study populations are different than the population of patients for which the risk estimates are needed in the medical situation. Recent studies aimed to evaluate the available data on the cohorts of the inhabitants of the Techa river settlements as well as of the workers of the Mayak nuclear facilities may provide in the future useful information on large populations chronically exposed to relatively low doses. (Author)

  17. International Conference on Low Doses of Ionising Radiation

    International Nuclear Information System (INIS)

    McEwan, A.C.

    1998-01-01

    Is there a threshold? and is a little radiation good for you? were two questions raised at the International Conference on Low Doses of Ionising Radiation : Biological Effects and Regulatory Control, jointly organised by the IAEA and WHO, and convened in Seville, Spain, over 17-21 November 1997. The answer to both these questions appears to be 'Maybe', but the answer has no present implications for radiation protection practice and regulation. The conference which had over 500 participants from 65 countries, was organised around ten fora which explored basic molecular mechanisms of radiation effects, through to radiation protection principles and implementation in practices and interventions. Each forum was introduced by an overview presentation by an invited keynote speaker. Brief presentations of a few of the proffered papers followed, and then open discussion. There was opportunity for all proffered papers to be presented as posters. The fora, which occupied 3 full days, were preceded by reports on biological effects of radiation from international orgnaisations, and on related international conferences held in the recent past. The fora were followed by round table presentations of regulatory control and scientiFic research, and a summary session drawing together conclusions on the topic areas of the conference. (author)

  18. Bayesian approach in MN low dose of radiation counting

    International Nuclear Information System (INIS)

    Serna Berna, A.; Alcaraz, M.; Acevedo, C.; Navarro, J. L.; Alcanzar, M. D.; Canteras, M.

    2006-01-01

    The Micronucleus assay in lymphocytes is a well established technique for the assessment of genetic damage induced by ionizing radiation. Due to the presence of a natural background of MN the net MN is obtained by subtracting this value to the gross value. When very low doses of radiation are given the induced MN is close even lower than the predetermined background value. Furthermore, the damage distribution induced by the radiation follows a Poisson probability distribution. These two facts pose a difficult task to obtain the net counting rate in the exposed situations. It is possible to overcome this problem using a bayesian approach, in which the selection of a priori distributions for the background and net counting rate plays an important role. In the present work we make a detailed analysed using bayesian theory to infer the net counting rate in two different situations: a) when the background is known for an individual sample, using exact value value for the background and Jeffreys prior for the net counting rate, and b) when the background is not known and we make use of a population background distribution as background prior function and constant prior for the net counting rate. (Author)

  19. Dynamic low dose I-123-iodophenylpentadecanoic acid metabolic cardiac imaging

    International Nuclear Information System (INIS)

    Murray, G.L.; Magill, H.L.; Schad, N.C.

    1993-01-01

    Recognition of stunned and hibernating myocardium is essential in this era of cardiac revascularization. Positron emission tomography (PET) accurately identifies viability but is costly and unavailable to most patients. Dynamic low dose I-123-iodophenylpentadecanoic acid (IPPA) metabolic cardiac imaging is a potentially cost-effective alternative to PET. Using transmural myocardial biopsies obtained during coronary bypass surgery as the viability gold standard, resting IPPA imaging agreed with 39/43 (91%) biopsies, with a sensitivity for viability of 33/36(92%) and a specificity of 6/7 (86%) in patients with severe ischemic cardiomyopathy. Eighty percent of IPPA viable, infarcted segments improved wall motion postoperatively. Furthermore, when compared to reinjection thallium (SPECT-Tl) scans after myocardial infarction, there was IPPA-Tl concordance in 27/35 (77%)(Kappa=0.536, p=0.0003). Similar to PET, IPPA demonstrated more viability than SPECT-Tl, 26/35 (74%) vs. 18/35 (51%)(p=0.047). Finally, when compared to transvenous endomyocardial biopsy for detecting rejection following cardiac transplantation, IPPA sensitivity for ≥Grade II rejection was 100%, and IPPA screening assessment for the necessity of biopsy could result in a 31% cost-savings. Therefore, IPPA metabolic cardiac imaging is a safe, inexpensive technique with a promising future. (author)

  20. Low-dose caffeine physical dependence in humans.

    Science.gov (United States)

    Griffiths, R R; Evans, S M; Heishman, S J; Preston, K L; Sannerud, C A; Wolf, B; Woodson, P P

    1990-12-01

    This study investigated the effects of terminating low dose levels of caffeine (100 mg/day) in 7 normal humans. Substitution of placebo capsules for caffeine capsules occurred under double-blind conditions while subjects rated various dimensions of their mood and behavior. In the first phase of the study, substitution of placebo for 12 consecutive days resulted in an orderly withdrawal syndrome in 4 subjects which peaked on days 1 or 2 and progressively decreased toward prewithdrawal levels over about 1 week. Data from the remaining three subjects provided no evidence of withdrawal. In the second phase of the study, the generality of the withdrawal effect was examined by repeatedly substituting placebo for 100 mg/day of caffeine for 1-day periods separated by an average of 9 days. Despite differences within and across subjects with respect to the presence, nature and magnitude of symptoms, each of the seven subjects demonstrated a statistically significant withdrawal effect. Although the phenomenon of caffeine withdrawal has been described previously, the present report documents that the incidence of caffeine withdrawal is higher (100% of subjects), the daily dose level at which withdrawal occurs is lower (roughly equivalent to the amount of caffeine in a single cup of strong brewed coffee or 3 cans of caffeinated soft drink) and the range of symptoms experienced is broader (including headache, fatigue and other dysphoric mood changes, muscle pain/stiffness, flu-like feelings, nausea/vomiting and craving for caffeine) than heretofore recognized.

  1. Thermal stability of low dose Ga+ ion irradiated spin valves

    International Nuclear Information System (INIS)

    Qi Xianjin; Wang Yingang; Zhou Guanghong; Li Ziquan

    2009-01-01

    The thermal stability of low dose Ga + ion irradiated spin valves has been investigated and compared with that of the as-prepared ones. The dependences of exchange field, measured using vibrating sample magnetometer at room temperature, on magnetic field sweep rate and time spent at negative saturation of the pinned ferromagnetic layer, and training effect were explored. The training effect is observed on both the irradiated spin valves and the as-prepared ones. The magnetic field sweep rate dependence of the exchange bias field of the irradiated spin valves is nearly the same as that of the as-prepared ones. For the as-prepared structure thermal activation has been observed, which showed that holding the irradiated structure at negative saturation of the pinned ferromagnetic layer for up to 28 hours results in no change in the exchange field. The results indicate that the thermal stability of the ion irradiated spin valves is the same as or even better than the as-prepared ones.

  2. Biological effects of low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Gonzalez, A.J.

    1994-01-01

    Few weeks ago, when the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) submitted to the U.N. General Assembly the UNSCEAR 1994 report, the international community had at its disposal a broad view of the biological effects of low doses of ionizing radiation. The 1994 report (272 pages) specifically addressed the epidemiological studies of radiation carcinogenesis and the adaptive responses to radiation in cells and organisms. The report was aimed to supplement the UNSCEAR 1993 report to the U.N. General Assembly- an extensive document of 928 pages-which addressed the global levels of radiation exposing the world population, as well as some issues on the effects of ionizing radiation, including: mechanisms of radiation oncogenesis due to radiation exposure, influence of the level of dose and dose rate on stochastic effects of radiation, hereditary effects of radiation effects on the developing human brain, and the late deterministic effects in children. Those two UNSCEAR reports taken together provide an impressive overview of current knowledge on the biological effects of ionizing radiation. This article summarizes the essential issues of both reports, although it cannot cover all available information. (Author)

  3. Health Effects of Exposure to Low Dose of Radiation

    International Nuclear Information System (INIS)

    Alatas, Zubaidah

    2003-01-01

    Human beings are exposed to natural radiation from external sources include radionuclides in the earth and cosmic radiation, and by internal radiation from radionuclides, mainly uranium and thorium series, incorporated into the body. Living systems have adapted to the natural levels of radiation and radioactivity. But some industrial practices involving natural resources enhance these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. Biological effects of ionizing radiation are the outcomes of physical and chemical processes that occur immediately after the exposure, then followed by biological process in the body. These processes will involve successive changes in the molecular, cellular, tissue and whole organism levels. Any dose of radiation, no matter how small, may produce health effects since even a single ionizing event can result in DNA damage. The damage to DNA in the nucleus is considered to be the main initiating event by which radiation causes damage to cells that results in the development of cancer and hereditary disease. It has also been indicated that cytogenetic damage can occur in cells that receive no direct radiation exposure, known as bystander effects. This paper reviews health risks of low dose radiation exposure to human body causing stochastic effects, i.e. cancer induction in somatic cells and hereditary disease in genetic cells. (author)

  4. Low dose CT perfusion in acute ischemic stroke

    International Nuclear Information System (INIS)

    Murphy, Amanda; Symons, Sean; Jakubovic, Raphael; Zhang, Liying; Aviv, Richard I.; So, Aaron; Lee, Ting-Yim

    2014-01-01

    The purpose of this investigation is to determine if CT perfusion (CTP) measurements at low doses (LD = 20 or 50 mAs) are similar to those obtained at regular doses (RD = 100 mAs), with and without the addition of adaptive statistical iterative reconstruction (ASIR). A single-center, prospective study was performed in patients with acute ischemic stroke (n = 37; 54 % male; age = 74 ± 15 years). Two CTP scans were performed on each subject: one at 100 mAs (RD) and one at either 50 or 20 mAs (LD). CTP parameters were compared between the RD and LD scans in regions of ischemia, infarction, and normal tissue. Differences were determined using a within-subjects ANOVA (p 0.05). CTP-derived CBF and CBV are not different at 50 mAs compared to 100 mAs, even without the addition of ASIR. Current CTP protocols can be modified to reduce the effective dose by 50 % without altering CTP measurements. (orig.)

  5. Low dose CT perfusion in acute ischemic stroke.

    Science.gov (United States)

    Murphy, Amanda; So, Aaron; Lee, Ting-Yim; Symons, Sean; Jakubovic, Raphael; Zhang, Liying; Aviv, Richard I

    2014-12-01

    The purpose of this investigation is to determine if CT perfusion (CTP) measurements at low doses (LD = 20 or 50 mAs) are similar to those obtained at regular doses (RD = 100 mAs), with and without the addition of adaptive statistical iterative reconstruction (ASIR). A single-center, prospective study was performed in patients with acute ischemic stroke (n = 37; 54% male; age = 74 ± 15 years). Two CTP scans were performed on each subject: one at 100 mAs (RD) and one at either 50 or 20 mAs (LD). CTP parameters were compared between the RD and LD scans in regions of ischemia, infarction, and normal tissue. Differences were determined using a within-subjects ANOVA (p test post hoc analysis (p 50 mAs, there was no significant difference between cerebral blood flow (CBF), cerebral blood volume (CBV), or time to maximum enhancement (Tmax) values for the RD and LD scans in the ischemic, infarcted, or normal contralateral regions (p LD scans for all parameters in the ischemic and normal tissue regions (p > 0.05). CTP-derived CBF and CBV are not different at 50 mAs compared to 100 mAs, even without the addition of ASIR. Current CTP protocols can be modified to reduce the effective dose by 50 % without altering CTP measurements.

  6. Low dose radiation damage effects in silicon strip detectors

    International Nuclear Information System (INIS)

    Wiącek, P.; Dąbrowski, W.

    2016-01-01

    The radiation damage effects in silicon segmented detectors caused by X-rays have become recently an important research topic driven mainly by development of new detectors for applications at the European X-ray Free Electron Laser (E-XFEL). However, radiation damage in silicon strip is observed not only after extreme doses up to 1 GGy expected at E-XFEL, but also at doses in the range of tens of Gy, to which the detectors in laboratory instruments like X-ray diffractometers or X-ray spectrometers can be exposed. In this paper we report on investigation of radiation damage effects in a custom developed silicon strip detector used in laboratory diffractometers equipped with X-ray tubes. Our results show that significant degradation of detector performance occurs at low doses, well below 200 Gy, which can be reached during normal operation of laboratory instruments. Degradation of the detector energy resolution can be explained by increasing leakage current and increasing interstrip capacitance of the sensor. Another observed effect caused by accumulation of charge trapped in the surface oxide layer is change of charge division between adjacent strips. In addition, we have observed unexpected anomalies in the annealing process.

  7. Low dose radiation damage effects in silicon strip detectors

    Science.gov (United States)

    Wiącek, P.; Dąbrowski, W.

    2016-11-01

    The radiation damage effects in silicon segmented detectors caused by X-rays have become recently an important research topic driven mainly by development of new detectors for applications at the European X-ray Free Electron Laser (E-XFEL). However, radiation damage in silicon strip is observed not only after extreme doses up to 1 GGy expected at E-XFEL, but also at doses in the range of tens of Gy, to which the detectors in laboratory instruments like X-ray diffractometers or X-ray spectrometers can be exposed. In this paper we report on investigation of radiation damage effects in a custom developed silicon strip detector used in laboratory diffractometers equipped with X-ray tubes. Our results show that significant degradation of detector performance occurs at low doses, well below 200 Gy, which can be reached during normal operation of laboratory instruments. Degradation of the detector energy resolution can be explained by increasing leakage current and increasing interstrip capacitance of the sensor. Another observed effect caused by accumulation of charge trapped in the surface oxide layer is change of charge division between adjacent strips. In addition, we have observed unexpected anomalies in the annealing process.

  8. Marked cortisol production by intracrine ACTH in GIP-treated cultured adrenal cells in which the GIP receptor was exogenously introduced.

    Directory of Open Access Journals (Sweden)

    Hiroko Fujii

    Full Text Available The ectopic expression of the glucose-dependent insulinotropic polypeptide receptor (GIPR in the human adrenal gland causes significant hypercortisolemia after ingestion of each meal and leads to Cushing's syndrome, implying that human GIPR activation is capable of robustly activating adrenal glucocorticoid secretion. In this study, we transiently transfected the human GIPR expression vector into cultured human adrenocortical carcinoma cells (H295R and treated them with GIP to examine the direct link between GIPR activation and steroidogenesis. Using quantitative RT-PCR assay, we examined gene expression of steroidogenic related proteins, and carried out immunofluorescence analysis to prove that forced GIPR overexpression directly promotes production of steroidogenic enzymes CYP17A1 and CYP21A2 at the single cell level. Immunofluorescence showed that the transfection efficiency of the GIPR gene in H295R cells was approximately 5%, and GIP stimulation enhanced CYP21A2 and CYP17A1 expression in GIPR-introduced H295R cells (H295R-GIPR. Interestingly, these steroidogenic enzymes were also expressed in the GIPR (- cells adjacent to the GIPR (+ cells. The mRNA levels of a cholesterol transport protein required for all steroidogenesis, StAR, and steroidogenic enzymes, HSD3β2, CYP11A1, CYP21A2, and CYP17A1 increased 1.2-2.1-fold in GIP-stimulated H295R-GIPR cells. These changes were reflected in the culture medium in which 1.5-fold increase in the cortisol concentration was confirmed. Furthermore, the levels of adenocorticotropic hormone (ACTH receptor and ACTH precursor proopiomelanocortin (POMC mRNA were upregulated 2- and 1.5-fold, respectively. Immunofluorescence showed that ACTH expression was detected in GIP-stimulated H295R-GIPR cells. An ACTH-receptor antagonist significantly inhibited steroidogenic gene expression and cortisol production. Immunostaining for both CYP17A1 and CYP21A2 was attenuated in cells treated with ACTH receptor antagonists

  9. Effect of low-dose gamma-radiation upon hatchability and weight of chickens

    International Nuclear Information System (INIS)

    Vilic, M.; Kraljevic, P.; Simpraga, M.; Miljanic, S.

    2006-01-01

    Full text of publication follows: Although any dose of ionizing radiation has generally been recognized to be detrimental to living being, low dose ionizing radiation seems to invoke primary stimulative effects. Stimulatory effects of low dose ionizing radiation include many aspects such as growth, fecundity and longevity stimulation, accelerated development, enhance biological responses for immune systems, enzymatic repair, physiological functions, and the removal of cellular damage, including prevention and removal of cancers and other diseases. Low dose ionizing radiation might also cause changes in the concentration of some biochemical parameters in blood plasma of chickens such as changes in the concentration of total proteins, glucose and cholesterol. The objective of this study was to determine the effect of low doses of gamma irradiation before incubation and on the seventh day of incubation on hatchability of eggs and body weight of chickens. This study includes three independent experiments. In the first experiment, six-hundred eggs produced by a commercial flock of Avian-line 34, were irradiated by a dose of 0.15 Gy gamma radiation (60 Co) before incubation. In the second experiments also involving six-hundred-line 34 eggs were irradiated by dose of 0.15 Gy gamma radiation on the seventh day of incubation. In the third experiment three-hundred eggs produced by a commercial flock of Ross 308 were irradiated by dose 0.30 Gy gamma irradiation before incubation. Along with the chickens which were hatched from irradiated eggs, there was a control group of chickens hatched from nonirradiated eggs. All other conditions were the same for both groups. Hatchability was calculated in terms of all eggs divided with fertile eggs which hatched. The individual weights of the chickens were determined on the first and on the forty second day. Growth data were analyzed statistically by t-test. Irradiation of chicken eggs and embryos at rates o f 0.15 Gy increases

  10. Sphenoid sinus carcinoid tumour causing ectopic ACTH syndrome.

    Science.gov (United States)

    Perera, Sanjaya; Taha, Ahmad

    2017-05-01

    A thirty-eight year old patient presented with a gradual increase in weight and Cushingoid facies of two years duration. He also had orbital congestion, with puffy eyelids and corkscrew conjunctival vessels, associated with painful eye movements. An endocrine evaluation revealed raised cortisol and ACTH. Head imaging was performed which showed an enhancing tumour arising from the sphenoid sinus, with osseous erosion of the sphenoid sinus, extending to the nasopharynx, sellar and a small amount extending intracranially. He underwent an endoscopic endonasal resection of the tumour and histology revealed a low-grade carcinoid tumour with ACTH staining. The patient also underwent radiotherapy for the intracranial extension. He is currently in his fourth year of follow-up and imaging has showed a small, stable intracranial remnant. His anterior pituitary hormonal profile remains normal. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. 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

  12. Effects of low dose radiation on regulatory function between lymphocyte subsets

    International Nuclear Information System (INIS)

    Tian Hailin; Su Liaoyuan; Du Zeji; Zou Huawei; Wang Aiqing

    1997-01-01

    Four kinds of McAbs (anti CD 4 , CD 8 , CD 19 and CD 57 ) were used to separate CD 4 , CD 8 , CD 19 (B) and CD 57 (NK) lymphocyte subsets from human peripheral blood by 'Panning-direct' method. First the natural killing activity of each subsets and the regulatory functions between CD 57 and other subsets were studied. Then the effects of low dose radiation on the function of CD 57 cells and the regulatory functions between CD 57 and other subsets were studied. The results showed that the NK activity was found in all of the four subsets, with CD 57 cell having the strongest activity. When CD 4 and CD 57 cells were co-cultured, the total NK activity was higher than that of the sum of these two single subsets, i.e. there was synergistic effect between CD 4 and CD 57 cells. When CD 8 or CD 19 cells were co-cultured separately with CD 57 cells, no synergistic effect was found. Irradiation by gamma rays at doses of 50 cGy and 80 cGy was able to stimulate the function of CD 57 cells. After Cd 4 or CD 57 cells were irradiated, the total NK activity of their co-culture increased significantly. This phenomenon was not found in other subsets. This suggested that low dose radiation can enhance the synergistic action between CD 4 and CD 57 cells. So at least four subsets (CD 4 , CD 8 , CD 19 , CD 57 ) contribute to the total NK activity of peripheral blood mononuclear cells. (15 refs., 4 tabs.)

  13. Successful pregnancy following low-dose hCG administration in addition to hMG in a patient with hypothalamic amenorrhea due to weight loss.

    Science.gov (United States)

    Tsutsumi, Ryo; Fujimoto, Akihisa; Osuga, Yutaka; Harada, Miyuki; Takemura, Yuri; Koizumi, Minako; Yano, Tetsu; Taketani, Yuji

    2012-06-01

    We describe successful ovulation induction with low-dose hCG administration in addition to hMG in a patient with refractory hypothalamic amenorrhea. A 24-year-old woman with weight loss-related amenorrhea underwent ovulation induction and intracytoplasmic sperm injection (ICSI). Administration of exogenous gonadotropins was ineffective in ovulation induction. Supplementation with low-dose hCG in order to increase luteinizing hormone (LH) activity in the late follicular phase produced late folliculogenesis and steroidogenesis, and ovulation was then successfully induced. This report reacknowledges the critical role that LH plays cooperatively with follicle-stimulating hormone in both folliculogenesis and steroidogenesis.

  14. The effects of low dose radiation (LDR) on lymphocytes

    International Nuclear Information System (INIS)

    Su Liaoyuan; Du Zeji; Tian Hailin; Zhao Yujie; Zou Huawei; Zhou Jianhua; Kong Xiangrong; Zhang Jianhua; Shen Wei

    2001-01-01

    LDR could stimulate lymphocyte transformation for adults, children and infants. The effect of LDR on lymphocytes in malnourished children was lower, but higher on lymphocytes in cord blood. The effect of LDR on CD 4 + cells in adult persons was higher than that on CD + cells. NK cells were radioresistant. The stimulative effect of LDR on NK activity in tumor patients was lower than that in normal individuals. For the mice with tumors, LDR could increase the ratio of L 3 T 4 cells in blood, spleen and the number of cytotoxic T cells in the tumors. Extracellular fluid of the lymphocytes operated by LDR could also stimulate the lymphocyte transformation. The preliminary LDR could decrease the injuries to macromolecules, membrane antigens and chromosomes in lymphocytes which were induced by high dose radiation. The LDR- induced protein might be found from mouse spleen cells, and this protein could increase immune function in human and animals

  15. ACTH-Secreting tumor of cecum. Case report

    Directory of Open Access Journals (Sweden)

    N S Kuznetsov

    2013-06-01

    Full Text Available Ectopic hormonesecreting of cecum are rare. We report the case of a 52yearold woman with a typical clin ical picture of Cushing disease. Diagnostic tests confirmed ACTH dependent Cushing’s syndrome, which is caused by neuroendocrine tumor of the cecum. Due to the rarity of the disease, we believe it appropriate to share our experience of this group of patients.

  16. Effect of continuous low-dose γ-irradiation on rat Sertoli cell function

    International Nuclear Information System (INIS)

    Kamtchouing, P.; Papadopoulos, V.; Drosdowsky, M.A.; Carreau, S.; Pinon-Lataillade, G.; Maas, J.; Guillaumin, J.M.; Bardos, P.; Perreau, C.; Hochereau de Reviers, M.T.

    1988-01-01

    Continuous low-dose γ-irradiation of mature rats induced a progressive degeneration of the germ cells. Blood FSH increased by 127, 176 and 214%, respectively, after 55, 70 and 85 days of treatment when compared to FSH levels in control rats (8.50 ± 0.60 ng/ml); conversely, serum LH and testosterone levels were unchanged. The Sertoli cell function was affected by the treatment from 70 days on, as attested by androgen binding protein (ABP) and transferrin secretions which diminished 35-40%. Serum ABP levels were not altered, whatever the duration of irradiation, even though epididymal ABP contents (as well as concentrations) diminished 34-60% when compared to those of the controls. Moreover, in purified Leydig cells, LH-stimulated intracellular cAMP levels, which were decreased by seminiferous tubule medium (STM) from control rats, were enhanced in presence of STM from treated animals. Testosterone output was stimulated 9-fold in presence of oLH and further increased (46-76%) from stages XIV-V by STM prepared from control and irradiated rats, respectively. After 85 days the STM effects on both cAMP and testosterone syntheses were zero. These results demonstrate a probable alteration of Sertoli cell function after irradiation, but also a role of the germ cells in the regulation of the synthesis of ABP, transferrin and Sertoli cell paracrine factors

  17. Effect of low-dose irradiation on pregnant mouse haemopoiesis

    International Nuclear Information System (INIS)

    Weinberg, S.R.; McCarthy, E.G.; MacVittie, T.J.; Baum, S.J.

    1981-01-01

    The effects of low-dose gamma radiation to haemopoietic progenitor cell compartments of the marrow and spleen of virgin female mice and pregnant mice were studied. Microplasma clot cultures were used to assess burst-forming uniterythroid (BFU-E) and colony-forming unit-erythroid (CFU-E) activity, and double-layer agar cultures were established to evaluate granulocyte-macrophage colony-forming cell (GM-CFC) and macrophage colony-forming cell (M-CFC). The apparent shift in maternal erythropoiesis from the bone marrow to the enlarged spleen was reflected by an increase in CFU-E and BFU-E per spleen and a concomitant decrease in CFU-E and BFU-E per femur. Whereas maternal GM-CFC values per femur increased 36%, maternal GM-CFC per spleen increased by 172% compared to virgin values. Total-body irradiation to the day-10.5 pregnant mouse caused a further suppression of day-14.5 medullary erythropoiesis (i.e. decreased CFU-E values) compared to the virgin female mouse. An ability of the maternal spleen to support further compensatory erythropoiesis following increasing doses of radiation was demonstrated. Four days after 1.0 Gy exposure, maternal values for GM-CFC per femur or spleen decreased to nonirradiated virgin mice values. M-CFC per maternal femur decreased to nonirradiated virgin mice values. M-CFC per maternal femur decreased following 1.5 Gy, but M-CFC per spleen appeared to be unaffected with doses from 0.5 to 2.0 Gy. (author)

  18. Low dose TBT exposure decreases amphipod immunocompetence and reproductive fitness.

    Science.gov (United States)

    Jacobson, Therese; Sundelin, Brita; Yang, Gongda; Ford, Alex T

    2011-01-17

    The antifouling agent tributyltin (TBT) is a highly toxic pollutant present in many aquatic ecosystems. Despite of regulations on the usage of TBT, it remains in high concentrations in sediments both in harbors and in off-shore sites. The toxicity of TBT in mollusks is well documented. However, adverse effects in other aquatic organisms, such as crustaceans, are less well known. This study is an effort to assess the effects of environmentally realistic concentrations of TBT on an ecologically important species in Swedish fresh and brackish water ecosystems, the benthic amphipod Monoporeia affinis. Field collected animals were exposed during gonad maturation to TBT (70 and 170 ng/g sediment d wt) for five weeks in static microcosms with natural sediment. Exposure concentrations were chosen to reflect effects at concentrations found in Swedish coastal sediment, but below expected effects on survival. TBT exposure resulted in a statistically significant adverse effect on oocyte viability and a doubling of the prevalence of microsporidian parasites in females, from 17% in the control to 34% in the 170 ng TBT/g sediment d wt exposure. No effects on survival were observed. Borderline significant effects were observed on male sexual maturation in the 70 ng TBT/g d wt exposure and on ecdysteroid levels in the 170 ng/g sediment d wt exposure. Both reproduction and parasite infection effects are of ecological importance since they have the potential to affect population viability in the field. This study gives further evidence to the connection between low dose contaminant exposure and increases in microsporidian parasite infection. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. High versus low-dose rate brachytherapy for cervical cancer.

    Science.gov (United States)

    Patankar, Sonali S; Tergas, Ana I; Deutsch, Israel; Burke, William M; Hou, June Y; Ananth, Cande V; Huang, Yongmei; Neugut, Alfred I; Hershman, Dawn L; Wright, Jason D

    2015-03-01

    Brachytherapy plays an important role in the treatment of cervical cancer. While small trials have shown comparable survival outcomes between high (HDR) and low-dose rate (LDR) brachytherapy, little data is available in the US. We examined the utilization of HDR brachytherapy and analyzed the impact of type of brachytherapy on survival for cervical cancer. Women with stages IB2-IVA cervical cancer treated with primary (external beam and brachytherapy) radiotherapy between 2003-2011 and recorded in the National Cancer Database (NCDB) were analyzed. Generalized linear mixed models and Cox proportional hazards regression were used to examine predictors of HDR brachytherapy use and the association between HDR use and survival. A total of 10,564 women including 2681 (25.4%) who received LDR and 7883 (74.6%) that received HDR were identified. Use of HDR increased from 50.2% in 2003 to 83.9% in 2011 (Puse of HDR. While patients in the Northeast were more likely to receive HDR therapy, there were no other clinical or socioeconomic characteristics associated with receipt of HDR. In a multivariable Cox model, survival was similar between the HDR and LDR groups (HR=0.93; 95% CI 0.83-1.03). Similar findings were noted in analyses stratified by stage and histology. Kaplan-Meier analyses demonstrated no difference in survival based on type of brachytherapy for stage IIB (P=0.68), IIIB (P=0.17), or IVA (P=0.16) tumors. The use of HDR therapy has increased rapidly. Overall survival is similar for LDR and HDR brachytherapy. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Relationship to carcinogenesis of repetitive low-dose radiation exposure

    International Nuclear Information System (INIS)

    Ootsuyama, Akira

    2016-01-01

    We studied the carcinogenic effects caused by repetitive irradiation at a low dose, which has received attention in recent years, and examined the experimental methods used to evaluate radiation-induced carcinogenesis. For this experiment, we selected a mouse with as few autochthonous cancers as possible. Skin cancer was selected as the target for analysis, because it is a rare cancer in mice. Beta-rays were selected as the radiation source. The advantage of using beta-rays is weaker penetration power into tissues, thus protecting organs, such as the digestive and hematogenous organs. The benefit of our experimental method is that only skin cancer requires monitoring, and it is possible to perform long-term experiments. The back skin of mice was exposed repetitively to beta-rays three times a week until the occurrence of cancer or death, and the dose per exposure ranged from 0.5 to 11.8 Gy. With the high-dose range (2.5-11.8 Gy), the latency period and carcinogenic rate were almost the same in each experimental group. When the dose was reduced to 1-1.5 Gy, the latency period increased, but the carcinogenic rate remained. When the dose was further reduced to 0.5 Gy, skin cancer never happened, even though we continued irradiation until death of the last mouse in this group. The lifespan of 0.5 Gy group mice was the same as that of the controls. We showed that the 0.5 Gy dose did not cause cancer, even in mice exposed repetitively throughout their life span, and thus refer to 0.5 Gy as the threshold-like dose. (author)

  1. Pb low doses induced genotoxicity in Lactuca sativa plants.

    Science.gov (United States)

    Silva, S; Silva, P; Oliveira, H; Gaivão, I; Matos, M; Pinto-Carnide, O; Santos, C

    2017-03-01

    Soil and water contamination by lead (Pb) remains a topic of great concern, particularly regarding crop production. The admissible Pb values in irrigation water in several countries range from ≈0.1 to ≈5 mg L -1 . In order to evaluate putative effects of Pb within legal doses on crops growth, we exposed Lactuca sativa seeds and seedlings to increasing doses of Pb(NO 3 ) 2 up to 20 mg L -1 . The OECD parameter seed germination and seedling/plant growth were not affected by any of the Pb-concentrations used. However, for doses higher than 5 mg L -1 significant DNA damage was detected: Comet assay detected DNA fragmentation at ≥ 5 mg L -1 and presence of micronuclei (MN) were detected for 20 mg L -1 . Also, cell cycle impairment was observed for doses as low as 0.05 mg L -1 and 0.5 mg L -1 (mostly G 2 arrest). Our data show that for the low doses of Pb used, the OECD endpoints were not able to detect toxicity, while more sensitive endpoints (related with DNA damage and mitotic/interphase disorders) identified genotoxic and cytostatic effects. Furthermore, the nature of the genotoxic effect was dependent on the concentration. Finally, we recommend that MN test and the comet assay should be included as sensitive endpoints in (eco)toxicological assays. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  2. Evaluation of a low-dose neonatal chest radiographic system

    International Nuclear Information System (INIS)

    Burton, E.M.; Kirks, D.R.; Strife, J.L.; Henry, G.C.; Kereiakes, J.G.

    1988-01-01

    A new low-dose chest radiographic system for use in the neonatal nursery was evaluated. This test system, composed of a Du Pont Kevlar fiber-front cassette, Quanta fast-detail screen, Cronex 4L film (wide latitude), and additional yttrium filtration (0.1 mm), reduced the radiation dose in neonatal chest radiography by 69% (0.9 vs 2.9 mrad [0.009 vs 0.029 mGy]) as compared with a conventional system without added yttrium filtration; the thyroid dose was reduced by 76% (0.9 vs 3.7 mrad [0.009 vs 0.037 mGy]). The cumulative dose reduction was achieved through a combination of factors, including (1) beam hardening by the added yttrium filter, (2) increased X-ray transmission through the Kevlar cassette, and (3) a fast film-screen combination. Scatter radiation at distances of 1 and 6 ft. (0.3 and 1.8 m) was negligible for both systems. Image sharpness was compared for the conventional system with and without added yttrium filtration and for the Kevlar system with yttrium. Although sharpness of bony detail was unchanged by adding yttrium filtration to the conventional system, a decrease in sharpness was noted with the Kevlar system. Because image sharpness was affected in the test system, we are not using the Kevlar-Cronex 4L system for mobile chest radiography in the neonatal intensive care unit, despite dose reductions. However, further study is recommended to determine if there is a slower film-screen combination with yttrium filtration that will not degrade image sharpness

  3. A new study on the effects of low doses

    International Nuclear Information System (INIS)

    Dousset, M.; Jammet, H.

    1986-01-01

    A study conducted by prof. Rose has investigated mortality among 39540 employees of the UKAEA, from 1946 to 1978. The three main points are: 1. General mortality and mortality from malignant diseases are lower than in the population of England and Wales (74 and 79 per cent respectively), thus showing no major difference between workers monitored for exposure to radiation and other workers. 2. For monitored workers, the only death cause for which there is a statistically significant correlation with radiation exposure is prostate cancer; there are many cases especially in workers with doses exceeding 0.05 Sv (5 rem) and monitored for tritium. Such a correlation has never been found in any other epidemiologic survey of workers exposed to low-level doses, Hanford (USA) workers especially; conversely, mortality from either multiple myeloma or pancreas cancer is not found here. These facts plead for a cautious interpretation of the results as a whole. 3. A linear representation of the variations of leukemia and cancer mortality vs exposure results in lines, the slopes of which are 3 times higher than those of the lines adopted by ICRP; however, the 95% confidence intervals (-2.7 + 12.4 and -22 + 52.5) are such that the results are compatible with a null effect (slope 0) and even with a benefic effect (negative slope). They are therefore compatible with ICRP estimations. A recent attempt to evaluate the two main investigations on low-dose occupational exposures (UKAEA and Hanford) suggests a dose-response relationship very near that of ICRP [fr

  4. Lung cancer risk at low doses of alpha particles

    International Nuclear Information System (INIS)

    Hofmann, W.; Katz, R.; Zhang, C.X.

    1986-01-01

    A survey of inhabitant exposures arising from the inhalation of 222 Rn and 220 Rn progeny, and lung cancer mortality has been carried out in two adjacent areas in Guangdong Province, People's Republic of China, designated as the high background and the control area. Annual exposure rates are 0.38 working level months (WLM) per year in the high background, and 0.16 WLM/yr in the control area. In 14 yr of continuous study, from 1970 to 1983, age-adjusted mortality rates were found to be 2.7 per 10(5) living persons of all ages in the high background area, and 2.9 per 10(5) living persons in the control area. From this data, we conclude that we are unable to determine excess lung cancers over the normal fluctuations below a cumulative exposure of 15 WLM. This conclusion is supported by lung cancer mortality data from Austrian and Finnish high-background areas. A theoretical analysis of epidemiological data on human lung cancer incidence from inhaled 2 ]2'' 2 Rn and 220 Rn progeny, which takes into account cell killing as competitive with malignant transformation, leads to the evaluation of a risk factor which is either a linear-exponential or a quadratic-exponential function of the alpha-particle dose. Animal lung cancer data and theoretical considerations can be supplied to support either hypothesis. Thus we conclude that at our current stage of knowledge both the linear-exponential and the quadratic-exponential extrapolation to low doses seem to be equally acceptable for Rn-induced lung cancer risk, possibly suggesting a linear-quadratic transformation function with an exponential cell-killing term, or the influence of risk-modifying factors such as repair or proliferation stimuli

  5. Low dose CT perfusion in acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Amanda; Symons, Sean; Jakubovic, Raphael; Zhang, Liying; Aviv, Richard I. [Sunnybrook Health Sciences Centre, Toronto, ON (Canada); So, Aaron; Lee, Ting-Yim [Robarts Research Institute, London, Ontario (Canada)

    2014-12-15

    The purpose of this investigation is to determine if CT perfusion (CTP) measurements at low doses (LD = 20 or 50 mAs) are similar to those obtained at regular doses (RD = 100 mAs), with and without the addition of adaptive statistical iterative reconstruction (ASIR). A single-center, prospective study was performed in patients with acute ischemic stroke (n = 37; 54 % male; age = 74 ± 15 years). Two CTP scans were performed on each subject: one at 100 mAs (RD) and one at either 50 or 20 mAs (LD). CTP parameters were compared between the RD and LD scans in regions of ischemia, infarction, and normal tissue. Differences were determined using a within-subjects ANOVA (p < 0.05) followed by a paired t test post hoc analysis (p < 0.01). At 50 mAs, there was no significant difference between cerebral blood flow (CBF), cerebral blood volume (CBV), or time to maximum enhancement (Tmax) values for the RD and LD scans in the ischemic, infarcted, or normal contralateral regions (p < 0.05). At 20 mAs, there were significant differences between the RD and LD scans for all parameters in the ischemic and normal tissue regions (p > 0.05). CTP-derived CBF and CBV are not different at 50 mAs compared to 100 mAs, even without the addition of ASIR. Current CTP protocols can be modified to reduce the effective dose by 50 % without altering CTP measurements. (orig.)

  6. Reactive thymic hyperplasia following treatment of ACTH-producing tumors

    International Nuclear Information System (INIS)

    Schmidt, S.; Klose, K.J.; Iwinska-Zelder, J.; Frank, M.; Ehlenz, K.; Kisker, O.

    1997-01-01

    Surgical or conservative treatment of ACTH-producing tumors results in acute drop of the previously excessively high cortisol levels. The following associated pathophysiological changes also occur in the organism's recovery from stress, such as trauma, operation or chemotherapy of tumors. Both cases result in a regeneration of the immune system, which might even be exalted. The corresponding radiographic feature is the 'rebound' enlargement of the thymus occuring about six months after remission of hypercortisolism. Histological examination reveals benign thymus hyperplasia. Especially in cases of still unkown primary tumor the apperance of this anterior mediastinal mass can lead to misdiagnosis. We present the cases of two patients with diffuse thymic hyperplasia following surgical and medical correction of hypercortisolism. One patient suffered from classic Cushing's disease responding to transsphenoidal resection of an ACTH-secreting pituitary microadenoma. Six monsths later CT of the chest incidentally demonstrated an anterior mediastinal mass known as thymic hyperplasia. The second patient presented with an ectopic, still unknown source of ACTH-production. (orig./AJ) [de

  7. Pretreatment with low-dose gamma irradiation enhances tolerance to the stress of cadmium and lead in Arabidopsis thaliana seedlings.

    Science.gov (United States)

    Qi, Wencai; Zhang, Liang; Wang, Lin; Xu, Hangbo; Jin, Qingsheng; Jiao, Zhen

    2015-05-01

    Heavy metals are important environmental pollutants with negative impact on plant growth and development. To investigate the physiological and molecular mechanisms of heavy metal stress mitigated by low-dose gamma irradiation, the dry seeds of Arabidopsis thaliana were exposed to a Cobalt-60 gamma source at doses ranging from 25 to 150Gy before being subjected to 75µM CdCl2 or 500µM Pb(NO3)2. Then, the growth parameters, and physiological and molecular changes were determined in response to gamma irradiation. Our results showed that 50-Gy gamma irradiation gave maximal beneficial effects on the germination index and root length in response to cadmium/lead stress in Arabidopsis seedlings. The hydrogen peroxide and malondialdehyde contents in seedlings irradiated with 50-Gy gamma rays under stress were significantly lower than those of controls. The antioxidant enzyme activities and proline levels in the irradiated seedlings were significantly increased compared with the controls. Furthermore, a transcriptional expression analysis of selected genes revealed that some components of heavy metal detoxification were stimulated by low-dose gamma irradiation under cadmium/lead stress. Our results suggest that low-dose gamma irradiation alleviates heavy metal stress, probably by modulating the physiological responses and gene expression levels related to heavy metal resistance in Arabidopsis seedlings. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Influence of low dose irradiation on differentiation, maturation and T-cell activation of human dendritic cells

    Energy Technology Data Exchange (ETDEWEB)

    Jahns, Jutta [Department of Radiotherapy and Radiation Oncology, University of Leipzig, Stephanstrasse 21, 04103 Leipzig (Germany); Anderegg, Ulf; Saalbach, Anja [Department for Dermatology, Venerology and Allergology, University of Leipzig, Johannisallee 30, 04103 Leipzig (Germany); Rosin, Britt; Patties, Ina; Glasow, Annegret [Department of Radiotherapy and Radiation Oncology, University of Leipzig, Stephanstrasse 21, 04103 Leipzig (Germany); Kamprad, Manja [Institute for Clinical Immunology and Transfusion Medicine, University of Leipzig, Johannisallee 30, 04103 Leipzig (Germany); Scholz, Markus [Institute for Medical Informatics, Statistics and Epidemiology, University of Leipzig, Haertelstr. 16-18, 04103 Leipzig (Germany); Hildebrandt, Guido, E-mail: Guido.Hildebrandt@uni-rostock.de [Department of Radiotherapy and Radiation Oncology, University of Rostock, Suedring 75, 18059 Rostock (Germany); Department of Radiotherapy and Radiation Oncology, University of Leipzig, Stephanstrasse 21, 04103 Leipzig (Germany)

    2011-05-10

    Ionizing irradiation could act directly on immune cells and may induce bystander effects mediated by soluble factors that are released by the irradiated cells. This is the first study analyzing both the direct effect of low dose ionizing radiation (LDIR) on the maturation and cytokine release of human dendritic cells (DCs) and the functional consequences for co-cultured T-cells. We showed that irradiation of DC-precursors in vitro does not influence surface marker expression or cytokine profile of immature DCs nor of mature DCs after LPS treatment. There was no difference of single dose irradiation versus fractionated irradiation protocols on the behavior of the mature DCs. Further, the low dose irradiation did not change the capacity of the DCs to stimulate T-cell proliferation. But the irradiation of the co-culture of DCs and T-cells revealed significantly lower proliferation of T-cells with higher doses. Summarizing the data from approx. 50 DC preparations there is no significant effect of low dose ionizing irradiation on the cytokine profile, surface marker expression and maturation of DCs in vitro although functional consequences cannot be excluded.

  9. Effects of low dose gamma irradiation on the germination and physiological activity of old red pepper (Capsicum annuum L.) seed

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Sung; Back, Myung Hwa; Lee, Hae Youn; Lee, Young Keun [KAERI, Daejeon (Korea, Republic of)

    2001-12-15

    To observe the stimulating effects of low dose gamma radiation on the germination and physiological activity of germinating seeds of old red pepper (Capsicum annuum L. cv, Jokwang and cv. Hongkwang), seeds were irradiated at the dose of 2{approx}50 Gy. The germination rate of irradiation group was higher than that of the control. Especially it was highest at the early stage of induction. The germination rate at 7 days after sowing in Jokwang and Hongkwang cultivar was high as 74% and 11% at 4 Gy and 8 Gy irradiation group, respectively. The seedling height of Jokwang cultivar was noticeably high at 4 Gy irradiation group and that of Hongkwang cultivar at 8 Gy Irradiation group. The protein contents of seedlings from seeds irradiated with low dose gamma radiation of Jokwang cultivar increased at the late stage of induction and that of Hongkwang cultivar at the early stage of induction. Catalase and peroxidase activities of seedlings from seeds irradiated with low dose gamma radiation of Jokwang cultivar increased at 4 Gy irradiation group and that of Hongkwang cultivar at 8 Gy irradiation group.

  10. Sperm parameters in rats after low-dose irradiation of sex cells in male parents during two cycles of gametogenesis

    International Nuclear Information System (INIS)

    Karpenko, N.O.; Chub, N.N.; Brizgalova, G.A.

    2001-01-01

    Chronic combined (internal and external) irradiation in low doses (absorbed doses 0.4 - 3.6 cGy) during two cycles of gametogenesis results in defective stimulation of spermatogenesis in male rats and provokes genotoxic action. The offspring from fathers with 0.7 and 3.6 cGy irradiation have decreased viability and oligozoospermia in mature age. The offsprings from the father with 3.6 cGy have increased sensitivity to weak irradiation and react by increases oligozoospermia. The data are accord with the idea about more pronounced genetic radioresistance of premeiosis cells during gametogenesis

  11. Transferases activity in blood plasma of chickens hatched from eggs irradiated during incubation by low dose gamma rays

    International Nuclear Information System (INIS)

    Kraljevic, P.; Vilic, M.; Miljanic, S.; Simpraga, M.

    2005-01-01

    In our earlier studies chickens hatched from eggs irradiated with 0.15 Gy gamma rays before incubation showed a significantly higher growth than controls during the fattening period (1-42 days). The activity of aspartate-aminotransferase (AST), alanine-aminotransferase (ALT) and plasma glucose in the same chickens were also significantly higher. These results suggested that low-dose gamma-radiation stimulated certain metabolic processes in chickens hatched from eggs irradiated before incubation. The goal of this study was to determine the effects of low-dose ionising radiation on AST and ALT activity in the blood plasma of chickens hatched from eggs irradiated during incubation. The eggs of heavy breeding chickens (Avian, line 34) were exposed to 0.15 Gy of gamma-radiation (6 0C o) on the seventh day of incubation, i.e. at the time when the organogenesis in chickens is completed. The control group of chickens hatched from non-irradiated eggs. All other conditions were the same for both groups. After hatching, blood samples were taken from the wing vein on days 1, 3, 5, 7, 10, 20, 32 and 42. The activity of both enzymes was determined spectrophotometrically using Boehringer Mannheim GmbH optimised kits. On day 10, AST and ALT activity were significantly higher in the blood plasma of chickens hatched from irradiated eggs, but it significantly dropped for both enzymes on day 20. Our results indicate that exposure of eggs to low-dose gamma-radiation on the seventh day of incubation affects AST and ALT activity in the blood plasma of chickens hatched from irradiated eggs. However, this effect is somewhat different from the effects of egg exposure to low-dose gamma radiation before incubation.(author)

  12. Aberrant expression of glucagon receptors in adrenal glands of a patient with Cushing's syndrome and ACTH-independent macronodular adrenal hyperplasia

    Directory of Open Access Journals (Sweden)

    Valeria de Miguel

    2010-06-01

    Full Text Available Adrenocorticotropin (ACTH independent bilateral macronodular adrenal hyperplasia (AIMAH is a rare cause of Cushing´s syndrome, characterized by bilateral adrenal lesions and excess cortisol production despite ACTH suppression. Cortisol synthesis is produced in response to abnormal activation of G-protein- coupled receptors, such as gastric inhibitory peptide, vasopressin, beta adrenergic agonists, LH/hCG and serotonin receptors. The aim of this study was to analyze the expression of glucagon receptors in adrenal glands from an AIMAH patient. A patient with ACTH-independent Cushing´s syndrome and bilateral macronodular adrenal hyperplasia was screened for altered activation of adrenal receptors by physiological (mixed meal and pharmacological (gonadotrophin releasing hormone, ACTH and glucagon tests. The results showed abnormally high levels of serum cortisol after stimulation with glucagon. Hypercortisolism was successfully managed with ketoconazole treatment. Interestingly, a 4-month treatment with a somatostatin analogue (octreotide was also able to reduce cortisol secretion. Finally, Cushing's syndrome was cured after bilateral adrenalectomy. Abnormal mRNA expression for glucagon receptor in the patient´s adrenal glands was observed by Real-Time PCR procedure. These results strongly suggest that the mechanism of AIMAH causing Cushing´s syndrome in this case involves the illicit activation of adrenal glucagon receptors. This is the first case reported of AIMAH associated with ectopic glucagon receptors.

  13. 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

    Background. Low dose pharmacological stress echocardiography with either dobutamine or dipyridamole infusion has been proposed for recognition of myocardial viability. However, dependence on adequate acoustic window, observer experience, and the mild degree of wall motion changes make the viability assessment by stress echocardiography especially bothersome. The objective of the study was to evaluate the ability of low dose dobutamine and low dose dipyridamole radionuclide ventriculography to detect contractile reserve in patients after myocardial infarction and functional recovery after coronary angioplasty. Methods. The study group consisted of 20 consecutive patients (52±10 years, 17 male) with previous myocardial infarction and resting regional dyssynergy, in whom diagnostic cardiac catheterization revealed significant one-vessel coronary artery stenosis suitable for angioplasty. Each patient underwent equilibrium 99m-Tc radionuclide ventriculography which was performed at rest and during low dose dipyridamole (0.28 mg/kg over 2 minutes) and low dose dobutamine infusion (up to 10 mcg/kg/min). Left ventricular global and regional ejection fractions were determined. Increase of regional ejection fraction for >5% (inferoapical and posterolateral regions) or >10% (anteroseptal regions) during low dose dobutamine and dipyridamole in infarcted regions, as well as in the follow up period, was considered as index of contractile reserve. After 8 weeks of successful angioplasty, resting radionuclide ventriculography was repeated in all patients in order to identify functional recovery of the infarct zone. Results. Out of the 180 analyzed segments (20x9), 90 regional ejection fractions have shown depressed contractility. The mean of the regional ejection fractions showing depressed contractility increased from the resting value of 34±12% to 42±14% in the follow-up period (p=0.06). Of the 90 with baseline dyssynergy, 46 were responders during low-dose dobutamine (51

  14. Dosimetry Modeling for Focal Low-Dose-Rate Prostate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Al-Qaisieh, Bashar [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Mason, Josh, E-mail: joshua.mason@nhs.net [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Bownes, Peter; Henry, Ann [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Dickinson, Louise [Division of Surgery and Interventional Science, University College London, London (United Kingdom); Department of Radiology, Northwick Park Hospital, London North West NHS Trust, London (United Kingdom); Ahmed, Hashim U. [Division of Surgery and Interventional Science, University College London, London (United Kingdom); University College London Hospital, London (United Kingdom); Emberton, Mark [University College London Hospital, London (United Kingdom); Langley, Stephen [St Luke' s Cancer Centre, Guildford (United Kingdom)

    2015-07-15

    Purpose: Focal brachytherapy targeted to an individual lesion(s) within the prostate may reduce side effects experienced with whole-gland brachytherapy. The outcomes of a consensus meeting on focal prostate brachytherapy were used to investigate optimal dosimetry of focal low-dose-rate (LDR) prostate brachytherapy targeted using multiparametric magnetic resonance imaging (mp-MRI) and transperineal template prostate mapping (TPM) biopsy, including the effects of random and systematic seed displacements and interseed attenuation (ISA). Methods and Materials: Nine patients were selected according to clinical characteristics and concordance of TPM and mp-MRI. Retrospectively, 3 treatment plans were analyzed for each case: whole-gland (WG), hemi-gland (hemi), and ultra-focal (UF) plans, with 145-Gy prescription dose and identical dose constraints for each plan. Plan robustness to seed displacement and ISA were assessed using Monte Carlo simulations. Results: WG plans used a mean 28 needles and 81 seeds, hemi plans used 17 needles and 56 seeds, and UF plans used 12 needles and 25 seeds. Mean D90 (minimum dose received by 90% of the target) and V100 (percentage of the target that receives 100% dose) values were 181.3 Gy and 99.8% for the prostate in WG plans, 195.7 Gy and 97.8% for the hemi-prostate in hemi plans, and 218.3 Gy and 99.8% for the focal target in UF plans. Mean urethra D10 was 205.9 Gy, 191.4 Gy, and 92.4 Gy in WG, hemi, and UF plans, respectively. Mean rectum D2 cm{sup 3} was 107.5 Gy, 77.0 Gy, and 42.7 Gy in WG, hemi, and UF plans, respectively. Focal plans were more sensitive to seed displacement errors: random shifts with a standard deviation of 4 mm reduced mean target D90 by 14.0%, 20.5%, and 32.0% for WG, hemi, and UF plans, respectively. ISA has a similar impact on dose-volume histogram parameters for all plan types. Conclusions: Treatment planning for focal LDR brachytherapy is feasible. Dose constraints are easily met with a notable

  15. Experience with the low-dose in Bangladesh.

    Science.gov (United States)

    1982-03-01

    Condom sales (brand name Raja) have grown dramatically in Bangladesh and presently, sales account for over 50% of condoms distributed and represent more than 500,000 couple-years of protection (CYP). By contrast, sales of Maya, Noriday's brand name, accounts for only 8.5% of the total oral contraceptive (OC) distribution in Bangladesh and accounts for less than 50,000 CYP. According to the Director of the Bangladesh Social Marketing Program, poor performance of Maya is attributable to marketing factors. The mass media program was ineffectual in motivating new acceptors but it did make Maya a "household word" and it is now almost synonymous with the pill. Despite the nonuse, the number of potential OC users is high and therefore the CSM Project management decided that a new product with a distinct name, a new price, and a new marketing strategy was necessary. Norminest, a low-dose 0.35 mg ethinyl estradiol became available through AID and it was seen as a real alternative to those hormonal contraceptive products already available. The name selected was Ovacon and its packaging (which included goldleaf to signify high quality) was quite different than what came before. The price was set at 4.00 taka/cycle ($.21 in U.S.) which was higher than the Maya but lower than other commercially available OCs. Distribution of this new product was to center around physicians and other medical professionals in urban areas and promotion was to be limited to professional publications. This strategy had 2 objectives: establish personal contact with users and overcome the common practice of blaming the health of clients for the complaints heard. Ovacon was launched in June 1980 and now it is being detailed to rural practitioners. It is still not available in high traffic shops or through panwallahs. While sales have grown to 20-25,000 cycles/month, they are still about 1/2 of Maya sales. Together, these 2 methods represent 50,000 CYP. What was not anticipated was the magnitude of

  16. Spectroscopic characterization of low dose rate brachytherapy sources

    Science.gov (United States)

    Beach, Stephen M.

    The low dose rate (LDR) brachytherapy seeds employed in permanent radioactive-source implant treatments usually use one of two radionuclides, 125I or 103Pd. The theoretically expected source spectroscopic output from these sources can be obtained via Monte Carlo calculation based upon seed dimensions and materials as well as the bare-source photon emissions for that specific radionuclide. However the discrepancies resulting from inconsistent manufacturing of sources in comparison to each other within model groups and simplified Monte Carlo calculational geometries ultimately result in undesirably large uncertainties in the Monte Carlo calculated values. This dissertation describes experimentally attained spectroscopic outputs of the clinically used brachytherapy sources in air and in liquid water. Such knowledge can then be applied to characterize these sources by a more fundamental and metro logically-pure classification, that of energy-based dosimetry. The spectroscopic results contained within this dissertation can be utilized in the verification and benchmarking of Monte Carlo calculational models of these brachytherapy sources. This body of work was undertaken to establish a usable spectroscopy system and analysis methods for the meaningful study of LDR brachytherapy seeds. The development of a correction algorithm and the analysis of the resultant spectroscopic measurements are presented. The characterization of the spectrometer and the subsequent deconvolution of the measured spectrum to obtain the true spectrum free of any perturbations caused by the spectrometer itself is an important contribution of this work. The approach of spectroscopic deconvolution that was applied in this work is derived in detail and it is applied to the physical measurements. In addition, the spectroscopically based analogs to the LDR dosimetry parameters that are currently employed are detailed, as well as the development of the theory and measurement methods to arrive at these

  17. Lyssavirus infection: 'low dose, multiple exposure' in the mouse model.

    Science.gov (United States)

    Banyard, Ashley C; Healy, Derek M; Brookes, Sharon M; Voller, Katja; Hicks, Daniel J; Núñez, Alejandro; Fooks, Anthony R

    2014-03-06

    The European bat lyssaviruses (EBLV-1 and EBLV-2) are zoonotic pathogens present within bat populations across Europe. The maintenance and transmission of lyssaviruses within bat colonies is poorly understood. Cases of repeated isolation of lyssaviruses from bat roosts have raised questions regarding the maintenance and intraspecies transmissibility of these viruses within colonies. Furthermore, the significance of seropositive bats in colonies remains unclear. Due to the protected nature of European bat species, and hence restrictions to working with the natural host for lyssaviruses, this study analysed the outcome following repeat inoculation of low doses of lyssaviruses in a murine model. A standardized dose of virus, EBLV-1, EBLV-2 or a 'street strain' of rabies (RABV), was administered via a peripheral route to attempt to mimic what is hypothesized as natural infection. Each mouse (n=10/virus/group/dilution) received four inoculations, two doses in each footpad over a period of four months, alternating footpad with each inoculation. Mice were tail bled between inoculations to evaluate antibody responses to infection. Mice succumbed to infection after each inoculation with 26.6% of mice developing clinical disease following the initial exposure across all dilutions (RABV, 32.5% (n=13/40); EBLV-1, 35% (n=13/40); EBLV-2, 12.5% (n=5/40)). Interestingly, the lowest dose caused clinical disease in some mice upon first exposure ((RABV, 20% (n=2/10) after first inoculation; RABV, 12.5% (n=1/8) after second inoculation; EBLV-2, 10% (n=1/10) after primary inoculation). Furthermore, five mice developed clinical disease following the second exposure to live virus (RABV, n=1; EBLV-1, n=1; EBLV-2, n=3) although histopathological examination indicated that the primary inoculation was the most probably cause of death due to levels of inflammation and virus antigen distribution observed. All the remaining mice (RABV, n=26; EBLV-1, n=26; EBLV-2, n=29) survived the tertiary and

  18. Second International MELODI Workshop on Low Dose Risk Research - Slides of the presentations

    International Nuclear Information System (INIS)

    Repussard, J.; Weiss, W.; Quintana Trias, O.; Rosario Perez, M. del; Andersen, M.; Rudiger Trott, K.; Ottolenghi, A.; Smyth, V.; Graw, J.; Little, M.P.; Yonai, S.; Barcellos-Hoff, M.H.; Bouffler, S.; Chevillard, S.; Jeggo, P.; Sabatier, L.; Baatout, S.; Niwa, O.; Oesch, F.; Atkinson, M.; Averbeck, D.; Lloyd, D.; O'Neill, P.

    2011-01-01

    The MELODI (Multidisciplinary European Low Dose Initiative) mission is to impulse low dose risk research in Europe through a strategic research agenda (SRA) and road-map of priorities. The last presentation is dedicated to the SRA and its preference research programs. The other presentations deal principally with the low-dose exposure in medical uses of ionizing radiations, radiosensitivity, radiation-induced cataracts, or epidemiology and radiobiology of cardiovascular disease. This document is composed of the slides of the presentations

  19. The Potential Neurotoxic Effects of Low-Dose Sarin Exposure in a Guinea Pig Model

    Science.gov (United States)

    2002-01-01

    1 THE POTENTIAL NEUROTOXIC EFFECTS OF LOW-DOSE SARIN EXPOSURE IN A GUINEA PIG MODEL Melinda R. Roberson, PhD, Michelle B. Schmidt...Proving Ground, MD 21010 USA ABSTRACT This study is assessing the effects in guinea pigs of repeated low-dose exposure to the nerve...COVERED - 4. TITLE AND SUBTITLE The Potential Neurotoxic Effects Of Low-Dose Sarin Exposure In A Guinea Pig Model 5a. CONTRACT NUMBER 5b

  20. Systemic effects of low-dose dopamine during administration of cytarabine.

    Science.gov (United States)

    Connelly, James; Benani, Dina J; Newman, Matthew; Burton, Bradley; Crow, Jessica; Levis, Mark

    2017-09-01

    Purpose Low-dose dopamine has been utilized to improve renal blood flow, urine output, and reduce drug-induced nephrotoxicity. The purpose of this study was to assess changes in renal function, cardiovascular adverse events, and neurologic toxicity in patients receiving cytarabine with or without low-dose dopamine. Methods A retrospective, single-center, cohort study of patients receiving cytarabine at 667 mg/m 2 /dose or greater, with or without dopamine at ≤5 mcg/kg/min. Cohorts were based upon initiation or absence of low-dose dopamine; cytarabine only, cytarabine + pre- and day of low-dose dopamine, and cytarabine + post-low-dose dopamine. Renal outcomes (urine output, serum creatinine, and creatinine clearance) were compared with baseline and between cohorts. Safety endpoints (arrhythmias, tachycardia, and neurotoxicity) were compared between cohorts based on low-dose dopamine exposure. Results There was no difference in urine output from baseline in all cohorts. Comparing cytarabine only and pre- and day of low-dose dopamine cohorts, there was no difference in urine output. In those receiving low-dose dopamine, there was no difference in serum creatinine and creatinine clearance from baseline. No arrhythmias were documented during the study period, and there was no difference in the incidence of tachycardia between groups (P = 0.66). Neurotoxicity was reported in three patients who were on low-dose dopamine. Conclusion Though variation existed in individual patients administered low-dose dopamine, the use of low-dose dopamine did not significantly impact renal function in this small sample at a single institution. In addition, low-dose dopamine did not negatively impact cardiovascular function.

  1. Chronic dietary exposure to a low-dose mixture of genistein and vinclozolin modifies the reproductive axis, testis transcriptome, and fertility.

    Science.gov (United States)

    Eustache, Florence; Mondon, Françoise; Canivenc-Lavier, Marie Chantal; Lesaffre, Corinne; Fulla, Yvonne; Berges, Raymond; Cravedi, Jean Pierre; Vaiman, Daniel; Auger, Jacques

    2009-08-01

    The reproductive consequences and mechanisms of action of chronic exposure to low-dose endocrine disruptors are poorly understood. We assessed the effects of a continuous, low-dose exposure to a phytoestrogen (genistein) and/or an antiandrogenic food contaminant (vinclozolin) on the male reproductive tract and fertility. Male rats were exposed by gavage to genistein and vinclozolin from conception to adulthood, alone or in combination, at low doses (1 mg/kg/day) or higher doses (10 and 30 mg/kg/day). We studied a number of standard reproductive toxicology end points and also assessed testicular mRNA expression profiles using long-oligonucleotide microarrays. The low-dose mixture and high-dose vinclozolin produced the most significant alterations in adults: decreased sperm counts, reduced sperm motion parameters, decreased litter sizes, and increased post implantation loss. Testicular mRNA expression profiles for these exposure conditions were strongly correlated. Functional clustering indicated that many of the genes induced belong to the "neuroactive ligand-receptor interactions" family encompassing several hormonally related actors (e.g., follicle-stimulating hormone and its receptor). All exposure conditions decreased the levels of mRNAs involved in ribosome function, indicating probable decreased protein production. Our study shows that chronic exposure to a mixture of a dose of a phytoestrogen equivalent to that in the human diet and a low dose-albeit not environmental-of a common anti-androgenic food contaminant may seriously affect the male reproductive tract and fertility.

  2. Effects of low dose {gamma} radiation on early growth and physiological activities of radish (raphanus sativus L.) and the reduction of ultraviolet-B stress

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. S.; Lee, Y. K.; Lee, H. Y.; Baek, M. H.; Yoo, J. C. [KAERI, Taejon (Korea, Republic of)

    2002-10-01

    The effect of low dose {gamma} radiation on early growth and photosynthesis in radish plant was studied. The seedling height of radish was stimulated in plants grown from seeds irradiated with the low dose of 10 Gy. The O{sub 2} evolution in the 10 Gy irradiation group was 1.2 times greater than in the control. The catalase and peroxidase activity of radish leaves grown from seeds irradiated with {gamma} radiation were increased at 10 Gy irradiation group as the superoxide dismutase activity of leaves was. To investigate the effect of low dose {gamma} radiation on response to UV-B stress, UV-B was given at the intensity of 1 W{center_dot} m{sup -2} to the detached leaves. Pmax was decreased with increasing illumination time by 76% in the control, while decreased by 75% in the 10 Gy irradiation group. The photochemical yield of PSII, estimated as Fv/Fm, was decreased with increasing illumination time by 75% after 4 hours while Fv/Fm in the 10 Gy irradiation group was decreased by 69% of inhibition, indicating that the low dose {gamma} radiation retarded the deteriorative effect of UV-B on PSII. The initial fluorescence (Fo) was slightly increased with increasing illumination time, while the maximal fluorescence (Fm) was decreased. These results showed the positive effect of low dose {gamma} radiation on the seedling growth and the reduction of the deteriorative effect of UV-B stress on photosynthesis in radish plant.

  3. Effects of Low-Dose Amoxicillin on Staphylococcus aureus USA300 Biofilms.

    Science.gov (United States)

    Mlynek, Kevin D; Callahan, Mary T; Shimkevitch, Anton V; Farmer, Jackson T; Endres, Jennifer L; Marchand, Mélodie; Bayles, Kenneth W; Horswill, Alexander R; Kaplan, Jeffrey B

    2016-05-01

    Previous studies showed that sub-MIC levels of β-lactam antibiotics stimulate biofilm formation in most methicillin-resistant Staphylococcus aureus (MRSA) strains. Here, we investigated this process by measuring the effects of sub-MIC amoxicillin on biofilm formation by the epidemic community-associated MRSA strain USA300. We found that sub-MIC amoxicillin increased the ability of USA300 cells to attach to surfaces and form biofilms under both static and flow conditions. We also found that USA300 biofilms cultured in sub-MIC amoxicillin were thicker, contained more pillar and channel structures, and were less porous than biofilms cultured without antibiotic. Biofilm formation in sub-MIC amoxicillin correlated with the production of extracellular DNA (eDNA). However, eDNA released by amoxicillin-induced cell lysis alone was evidently not sufficient to stimulate biofilm. Sub-MIC levels of two other cell wall-active agents with different mechanisms of action-d-cycloserine and fosfomycin-also stimulated eDNA-dependent biofilm, suggesting that biofilm formation may be a mechanistic adaptation to cell wall stress. Screening a USA300 mariner transposon library for mutants deficient in biofilm formation in sub-MIC amoxicillin identified numerous known mediators of S. aureus β-lactam resistance and biofilm formation, as well as novel genes not previously associated with these phenotypes. Our results link cell wall stress and biofilm formation in MRSA and suggest that eDNA-dependent biofilm formation by strain USA300 in low-dose amoxicillin is an inducible phenotype that can be used to identify novel genes impacting MRSA β-lactam resistance and biofilm formation. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  4. Influence of low dose ionizing radiation on amplification and antitumor activity of LAK/TIL cells

    International Nuclear Information System (INIS)

    Liu Wei; Hou Dianjun; Qiao Jianwei; Shang Ximei; Li Jieqing

    2000-01-01

    Objective: To study the influence of low dose ionization on amplification and antitumor activity of LAK/TIL cells. Methods: TIL cells isolated from Lewis lung cancer tissues and LAK cells from spleen of tumor-bearing mouse were irradiated with different low doses of X-rays and were cultured after irradiation. Results: Low dose ionizing radiation improved the amplification volume of LAK/TIL cells, decreased the cell death ratio in amplification process, and increased the toxicity of LAK/TIL cells, Conclusions: Low dose ionizing radiation can result in amplification of biologically activated lymphocytes, and decreases the death ratio of the cells in amplification process

  5. Total Risk Management for Low Dose Radiation Exposures

    International Nuclear Information System (INIS)

    Simic, Z.; Mikulicic, V.; Sterc, D.

    2012-01-01

    Our civilization is witnessing about century of nuclear age mixed with enormous promises and cataclysmic threats. Nuclear energy seems to encapsulate both potential for pure good and evil or at least we humans are able to perceive that. These images are continuously with us and they are both helping and distracting from making best of nuclear potentials for civilization. Today with nuclear use significantly present and with huge potential to further improve our life with energy and medical use it is of enormous importance to try to have calmed, rational, and objective view on potential risks and certain benefits. Because all use of nuclear energy proved that their immediate risks are negligible (i.e., Three Mile Island and Fukushima) or much smaller than from the other alternatives (i.e., Chernobyl) it seems that the most important issue is the amount of risk from the long term effects to people from exposure to small doses of radiation. A similar issue is present in the increased use of modern computational tomography and other radiation sources use in medicine for examination and therapy. Finally, extreme natural exposures are third such potential risk sources. Definition of low doses varies depending on the way of delivery (i.e., single, multiple or continuous exposures), and for this paper usual dose of 100 mSv is selected as yearly upper amount. There are three very different scientifically supported views on the potential risks from the low doses exposure. The most conservative theory is that all radiation is harmful, and even small increments from background levels (i.e., 2-3 mSv) present additional risk. This view is called linear no threshold theory (LNT) and it is accepted as a regulatory conservative simple approach which guarantees safety. Risk is derived from the extrapolation of the measured effects of high levels of radiation. Opposite theory to LNT is hormesis which assumes that in fact small doses of radiation are helpful and they are improving our

  6. Low-dose hydrocortisone (HC) replacement therapy is associated with improved bone remodeling balance in hypopituitary subjects

    LENUS (Irish Health Repository)

    Behan, L A

    2011-06-01

    The effect of commonly used glucocorticoid replacement regimens on bone health in hypopituitary subjects is not well known. We aimed to assess the effect of 3 hydrocortisone (HC) replacement dose regimens on bone turnover in this group.10 hypopituitary men with severe ACTH deficiency were randomised in a crossover design to 3 HC dose regimens, Dose A (20mg mane, 10mg tarde), Dose B (10mg twice daily) and Dose C (10mg mane, 5mg tarde). Following 6 weeks of each regimen participants underwent fasting sampling of bone turnover markers.Data from matched controls were used to produce a Z score for subject bone formation and resorption markers and to calculate the bone remodeling balance (formation Z score-resorption Z score) and turnover index ((formation Z + resorption Z)\\/2). A positive bone remodeling balance with increased turnover is consistent with a favourable bone cycle. Data are expressed as median (range).The Pro Collagen Type 1 Peptide (PINP) bone formation Z-score was significantly increased in Dose C, (1.805 (-0.6-10.24)) compared to Dose A (0.035 (-1.0-8.1)) p<0.05 while there was no difference in the C-terminal crosslinking telopeptide (CTx) resorption Z score. The bone remodeling balance was significantly lower for dose A -0.02 (-1.05-4.12) compared to dose C 1.13 (0.13-6.4) (p<0.05). Although there was a trend to an increased bone turnover index with the lower dose regimen, this was not statistically significant.Low dose HC replacement (10mg mane\\/5 mg tarde) was associated with increased bone formation and improved bone remodeling balance which is associated with a more favourable bone cycle. This may have a long term beneficial effect on bone health.

  7. Adrenocortical steroid response to ACTH in different phenotypes of non-obese polycystic ovary syndrome

    Directory of Open Access Journals (Sweden)

    Cinar Nese

    2012-12-01

    Full Text Available Abstract Background Adrenal androgen excess is frequently observed in PCOS. The aim of the study was to determine whether adrenal gland function varies among PCOS phenotypes, women with hyperandrogenism (H only and healthy women. Methods The study included 119 non-obese patients with PCOS (age: 22.2 ± 4.1y, BMI:22.5 ± 3.1 kg/m2, 24 women with H only and 39 age and BMI- matched controls. Among women with PCOS, 50 had H, oligo-anovulation (O, and polycystic ovaries (P (PHO, 32 had O and H (OH, 23 had P and H (PH, and 14 had P and O (PO. Total testosterone (T, SHBG and DHEAS levels at basal and serum 17-hydroxprogesterone (17-OHP, androstenedione (A4, DHEA and cortisol levels after ACTH stimulation were measured. Results T, FAI and DHEAS, and basal and AUC values for 17-OHP and A4 were significantly and similarly higher in PCOS and H groups than controls (p  Conclusion PCOS patients and women with H only have similar and higher basal and stimulated adrenal androgen levels than controls. All three hyperandrogenic subphenotypes of PCOS exhibit similar and higher basal and stimulated adrenal androgen secretion patterns compared to non-hyperandrogenic subphenotype.

  8. Low dosing of gonadotropins in in vitro fertilization cycles for women with poor ovarian reserve: systematic review and meta-analysis.

    Science.gov (United States)

    Youssef, Mohamed Abdel-Fattah; van Wely, Madelon; Mochtar, Monique; Fouda, Usama Mohamed; Eldaly, Ashraf; El Abidin, Eman Zein; Elhalwagy, Ahmed; Mageed Abdallah, Ahmed Abdel; Zaki, Sherif Sameh; Abdel Ghafar, Mohamed Sayed; Mohesen, Mohamed Nagi; van der Veen, Fulco

    2018-02-01

    To evaluate the effectiveness of low doses of gonadotropins and gonadotropins combined with oral compounds compared with high doses of gonadotropins in ovarian stimulation regimens in terms of ongoing pregnancy per fresh IVF attempt in women with poor ovarian reserve undergoing IVF/intracytoplasmic sperm injection (ICSI) treatment. A systematic review and meta-analysis of randomized controlled studies that evaluate the effectiveness of low dosing of gonadotropins alone or combined with oral compounds compared with high doses of gonadotropins in women with poor ovarian reserve undergoing IVF/ICSI treatment. Not applicable. Subfertile women with poor ovarian reserve undergoing IVF/ICSI treatment. We searched the PubMed, EMBASE, Web of Science, the Cochrane Library, and the Clinical Trials Registry using medical subject headings and free text terms up to June 2016, without language or year restrictions. We included randomized controlled studies (RCTs) enrolling subfertile women with poor ovarian reserve undergoing IVF/ICSI treatment and comparing low doses of gonadotropins and gonadotropins combined with oral compounds versus high doses of gonadotropins. We assessed the risk of bias using the criteria recommended by the Cochrane Collaboration. We pooled the results by meta-analysis using the fixed and random effects model. The primary outcome was ongoing pregnancy rate (PR) per woman randomized. We retrieved 787 records. Fourteen RCTs (N = 2,104 women) were included in the analysis. Five studies (N = 717 women) compared low doses of gonadotropins versus high doses of gonadotropins. There was no evidence of a difference in ongoing PR (2 RCTs: risk rate 0.98, 95% confidence interval 0.62-1.57, I 2 = 0). Nine studies (N = 1,387 women) compared ovarian stimulation using gonadotropins combined with the oral compounds letrozole (n = 6) or clomiphene citrate (CC) (n = 3) versus high doses of gonadotropins. There was no evidence of a difference in ongoing PR (3 RCTs: risk

  9. Low dose coronary CT angiography with 256-slice helical CT

    International Nuclear Information System (INIS)

    Zhang Xiaodong; Tang Binghang; Li Fangyun

    2011-01-01

    of 573) in B, 96.1% (548 of 570) in C, and 85.7% (505/589) in D, with no significant difference for A vs C (Z= -1.351, P>0.05) and with significant differences for B vs D (Z=-2.236, P<0.05). Linear correlation analysis indicated a significant degradation of image quality with the increase of heart rate using SAS mode (Spearman correlation, r=0.577, P<0.01). ROC analysis established an upper HR threshold of 78 bpm for obtaining diagnostic image quality using SAS mode (AUC = 0.827, P<0.05). The average radiation dose in group A [(2.6±0.5) mSv] reduced 75% comparing with that in group C [(10.6±2.3) mSv], and the average radiation dose in group B [(4.0±0.7) mSv] reduced 69% comparing with that in group D [(13.0±1.4) mSv]. Conclusion: Using SAS mode to perform low-dose CCTA with 256-slice helical CT could keep the image quality and reduce radiation dose significantly. Our preliminary experience suggests a good promise of this technique which could be applied to a wider group of patients such as with higher heart rates. (authors)

  10. The effects of repeated low-dose sarin exposure

    International Nuclear Information System (INIS)

    Shih, T.-M.; Hulet, S.W.; McDonough, J.H.

    2006-01-01

    This project assessed the effects of repeated low-dose exposure of guinea pigs to the organophosphorus nerve agent sarin. Animals were injected once a day, 5 days per week (Monday-Friday), for 2 weeks with fractions (0.3x, 0.4x, 0.5x, or 0.6x) of the established LD 5 dose of sarin (42 μg/kg, s.c.). The animals were assessed for changes in body weight, red blood cell (RBC) acetylcholinesterase (AChE) levels, neurobehavioral reactions to a functional observational battery (FOB), cortical electroencephalographic (EEG) power spectrum, and intrinsic acetylcholine (ACh) neurotransmitter (NT) regulation over the 2 weeks of sarin exposure and for up to 12 days postinjection. No guinea pig receiving 0.3, 0.4 or 0.5 x LD 5 of sarin showed signs of cortical EEG seizures despite decreases in RBC AChE levels to as low as 10% of baseline, while seizures were evident in animals receiving 0.6 x LD 5 of sarin as early as the second day; subsequent injections led to incapacitation and death. Animals receiving 0.5 x LD 5 sarin showed obvious signs of cholinergic toxicity; overall, 2 of 13 animals receiving 0.5 x LD 5 sarin died before all 10 injections were given, and there was a significant increase in the angle of gait in the animals that lived. By the 10th day of injection, the animals receiving saline were significantly easier to remove from their cages and handle and significantly less responsive to an approaching pencil and touch on the rump in comparison with the first day of testing. In contrast, the animals receiving 0.4 x LD 5 sarin failed to show any significant reductions in their responses to an approaching pencil and a touch on the rump as compared with the first day. The 0.5 x LD 5 sarin animals also failed to show any significant changes to the approach and touch responses and did not adjust to handling or removal from the cage from the first day of injections to the last day of handling. Thus, the guinea pigs receiving the 0.4 and 0.5 x LD 5 doses of sarin failed to

  11. Optimising glucocorticoid replacement therapy in severely adrenocorticotropin (ACTH) deficient hypopituitary male patients.

    LENUS (Irish Health Repository)

    Behan, Lucy-Ann

    2011-04-18

    Context:  The optimal replacement regimen of hydrocortisone in adults with severe ACTH deficiency remains unknown. Management strategies vary from treatment with 15mg to 30mg or higher in daily divided doses, reflecting the paucity of prospective data on the adequacy of different glucocorticoid regimens. Objective:  Primarily to define the hydrocortisone regimen which results in a 24hour cortisol profile that most closely resembles that of healthy controls and secondarily to assess the impact on quality of life (QoL). Design:  10 male hypopituitary patients with severe ACTH deficiency (basal cortisol <100nM and peak response to stimulation <400nM) were enrolled in a prospective, randomised, crossover study of 3 hydrocortisone dose regimens. Following 6 weeks of each regimen patients underwent 24hour serum cortisol sampling and QoL assessment with the Short Form 36 and the Nottingham Health Profile questionnaires. Free cortisol was calculated using Coolen\\'s equation. All results were compared to those of healthy, matched controls. Results:  CBG was significantly lower across all dose regimens compared to controls (p<0.05). The lower dose regimen C(10mg mane\\/5mg tarde) produced a 24hour free cortisol profile which most closely resembled that of controls. Both regimen A(20mg mane\\/10mg tarde) and B(10mg mane\\/10mg tarde) produced supraphysiological post-absorption peaks. There was no significant difference in QoL in patients between the three regimens, however energy level was significantly lower across all dose regimens compared to controls (p<0.001). Conclusions:  The lower dose of HC(10mg\\/5mg) produces a more physiological cortisol profile, without compromising quality of life, compared to higher doses still used in clinical practice. This may have important implications in these patients, known to have excess cardiovascular mortality.

  12. Biochemical and molecular study of genetic stability in tomatoes plants rom seeds treated with low doses of X-ray

    International Nuclear Information System (INIS)

    Ramirez, R; Gonzalez, LM; Chavez, Licet; Camejo, Yanelis; Gonzalez, Maria C; Fernandez, Arais

    2008-01-01

    For the extensive agricultural exploitation of vegetable radio stimulation, it is indispensable to study the genetic stability of treated varieties, having in mind X ray potentialities of inducing not only physiological but genetic changes as well. Therefore, biochemical and molecular markers were employed in tomato plants derived from irradiated seeds at low doses of X rays. For the biochemical analysis, peroxidases, polyphenoloxidases and dismutase superoxide isoenzymes were determined whereas the Random Amplification of Polymorphic DNA (RAPD) method based on Polymerase Chain Reaction (PCR) was used for the molecular analysis. When comparing the electrophoretic patterns from the control and irradiated treatments applied to the three enzymatic systems, there were not appreciable variations on the number of bands and their intensities, indicating the little variability induced in these systems by the low X ray doses. Also, from the molecular viewpoint, electrophoretic patterns showed a clear amplification of DNA by generating a total of 155 bands in all varieties studied. This molecular marker showed a high monomorphism independently of the treatments applied, with values ranging between 86 and 97 %, indicating that irradiation at low doses did not induce an important genetic variability and confirming its possible practical usefulness for stimulating some physiological processes without causing. (Author)

  13. Addison's disease and ACTH-producing pituitary microadenoma

    Directory of Open Access Journals (Sweden)

    S.S. Ortega

    2015-10-01

    Full Text Available A 28-year-old man diagnosed with primary adrenal insufficiency (Addison's disease in 2002. Following diagnosis, replacement therapy with hydrocortisone and fludrocortisone was indicated. Hydrocortisone replacement therapy was unsuccessful, and increased ACTH levels as high as 996 pg/dl were observed on outpatient follow-up. A pituitary MRI revealed a pituitary microadenoma. These findings raised three possibilities: (1 treatment is insufficient; (2 there is no relationship between Addison's disease and pituitary microadenoma; and (3 the microadenoma is similar to Nelson's syndrome. This latter is the most satisfactory explanation of this patient's clinical picture.

  14. Reduced Pro-Inflammatory Cytokines after Eight Weeks of Low-Dose Naltrexone for Fibromyalgia

    Directory of Open Access Journals (Sweden)

    Luke Parkitny

    2017-04-01

    Full Text Available Fibromyalgia (FM is a complex, multi-symptom condition that predominantly affects women. The majority of those affected are unlikely to gain significant symptomatic control from the few treatments that are approved for FM. In this 10-week, single-blind, crossover trial we tested the immune effects of eight weeks of oral administration of low-dose naltrexone (LDN. We enrolled eight women with an average age of 46 years, symptom severity of 62 out of 100, and symptom duration of 14 years. We found that LDN was associated with reduced plasma concentrations of interleukin (IL-1β, IL-1Ra, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12p40, IL-12p70, IL-15, IL-17A, IL-27, interferon (IFN-α, transforming growth factor (TGF-α, TGF-β, tumor necrosis factor (TNF-α, and granulocyte-colony stimulating factor (G-CSF. We also found a 15% reduction of FM-associated pain and an 18% reduction in overall symptoms. The findings of this pilot trial suggest that LDN treatment in fibromyalgia is associated with a reduction of several key pro-inflammatory cytokines and symptoms. The potential role of LDN as an atypical anti-inflammatory medication should be explored further.

  15. Effect of low dose gamma-radiation upon Newcastle disease virus antibody level in chicken

    International Nuclear Information System (INIS)

    Vilic, M.; Gottstein, Z.; Ciglar Grozdanic, I.; Matanovic, K.; Miljanic, S.; Mazija, H.; Kraljevic, P.

    2009-01-01

    The specific antibody response against Newcastle disease virus in the blood serum of chickens hatched from eggs exposed to low dose gamma-radiation was studied. Materials and methods: Two groups of eggs of commercial meat chicken lines were irradiated with the dose of 0.30 Gy 60 Co gamma-rays before incubation and on the 19 th day of incubation, respectively. The same number of eggs unexposed to gamma-radiation served as controls. After hatching the group of chicken hatched from eggs irradiated on the 19 th day of incubation was not vaccinated while the group of chicken hatched from eggs irradiated before incubation was vaccinated on the 14 day. Specific serum anti-Newcastle disease virus antibodies were quantified by the hemagglutination inhibition assay with 4 HA units of Newcastle disease virus La Sota strain. Result: Specific antibody titres against Newcastle disease virus in the blood serum of chickens hatched from eggs irradiated before incubation and vaccinated on the 14 th day significantly increased on the 28 th day. Specific antibody titre against Newcastle disease virus in the blood serum of chickens hatched from eggs irradiated on the 19 th day of incubation and non-vaccinated was significantly higher on the 1 st and 14 th day. Conclusion: Acute irradiation of heavy breeding chicken eggs with the dose of 0.30 Gy 60 Co gamma-rays before incubation and on the 19 th day of incubation could have a stimulative effect on humoral immunity in chickens.

  16. Enhanced aflatoxin production by aspergillus parasiticus and aspergillus flavus after low dose gamma irradiation

    International Nuclear Information System (INIS)

    Ito, Hitoshi

    1992-01-01

    Spores of Aspergillus parasiticus IFO 30179 and A. flavus var. columnaris S46 were irradiated at 0.05, 0.2 and 0.4 kGy in the synthetic low salts (SL) broth, and the effect on aflatoxin production was examined after 10 days incubation at 30 or 25degC. In these two strains, irradiation of spores at 0.05 kGy resulted in higher B1 or G1 production than the non-irradiated controles. However, spores of the both strains irradiated at 0.2 or 0.4 kGy produced less aflatoxins than non-irradiated controles. In the SL broth, apparent stimulation by low dose irradiation was slight, and these enhanced effects were not observed after reinfection to fresh SL broth. In the case of food samples, the levels of aflatoxin B 1 and G 1 with A. parasiticus were increased from 15 to 90% by incubation of irradiated spores at 1 kGy in autoclaved polished rice, black pepper, white pepper and red pepper. These enhancement would be induced by change of composition in each substrates. Mutations of fungi induced by irradiation is not effective for enhancement of aflatoxin production. (author)

  17. 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.

  18. Low-dose add-back therapy during postoperative GnRH agonist treatment

    Directory of Open Access Journals (Sweden)

    Hsiao-Wen Tsai

    2016-02-01

    Conclusion: Low dose add-back therapy could effectively ameliorate hypoestrogenic side effects and simultaneously maintain the therapeutic response of GnRH agonist treatment. The treatment dropout was lower compared with a regular dose. Therefore, low dose add-back therapy can be considered a treatment choice during postoperative GnRH agonist treatment.

  19. The biological effects of low doses of radiation: medical, biological and ecological aspects

    International Nuclear Information System (INIS)

    Gun-Aajav, T.; Ajnai, L.; Manlaijav, G.

    2007-01-01

    Full text: The results of recent studies show that low doses of radiation make many different structural and functional changes in a cell and these changes are preserved for a long time. This phenomenon is called as effects of low doses of radiation in biophysics, radiation biology and radiation medicine. The structural and functional changes depend on doses and this dependence has non-linear and bimodal behaviour. More detail, the radiation effect goes up and reaches its maximum (Low doses maximum) in low doses region, then it goes down and takes its stationary means (there is a negative effect in a few cases). With increases in doses and with further increases it goes up. It is established that low dose's maximum depends on physiological state of a biological object, radiation quality and dose rate. During the experiments another special date was established. This specialty is that many different physical and chemical factors are mutually connected and have synergetic behaviour. At present, researches are concentrating their attention on the following three directions: 1. Direct and indirect interaction of radiation's low doses: 2. Interpretation of its molecular mechanism, regulation of the positive effects and elaboration of ways o removing negative effects: 3. Application of the objective research results into practice. In conclusion the authors mention the current concepts on interpretation of low doses effect mechanism, forward their own views and emphasize the importance of considering low doses effects in researches of environmental radiation pollution, radiation medicine and radiation protection. (author)

  20. Modeling low-dose-rate effects in irradiated bipolar-base oxides

    International Nuclear Information System (INIS)

    Graves, R.J.; Cirba, C.R.; Schrimpf, R.D.; Milanowski, R.J.; Saigne, F.; Michez, A.; Fleetwood, D.M.; Witczak, S.C.

    1997-02-01

    A physical model is developed to quantify the contribution of oxide-trapped charge to enhanced low-dose-rate gain degradation in BJTs. Simulations show that space charge limited transport is partially responsible for the low-dose-rate enhancement

  1. Effects of low doses of radiation on crop plants

    International Nuclear Information System (INIS)

    1966-01-01

    Claims for radiation-induced growth stimulations in plants have been made, starting almost from the time of the discovery of X-rays. However, there is general disagreement on this question, since the numerous studies designed to prove or disprove the existence of the phenomenon have produced inconclusively and erratic results. It is obvious that small, but significant, growth increases may be produced at times by ionizing radiations in certain crop plants, but such increases have not always been reproducible from one experiment to another, and marked inconsistencies often occur with regard to the optimal exposures to produce such effects. The purpose of the FAO/IAEA Panel meeting held in Rome on 1 June, 1964, was to review and evaluate the experimental results in this area and applications for increasing crop yields. Refs, figs and tabs

  2. 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)

  3. Injury of the blood-testies barrier after low-dose-rate chronic radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Young Hoon; Bae Min Ji; Lee, Chang Geun; Yang, Kwang Mo; Jur, Kyu; Kim, Jong Sun [Dongnam Institute of Radiological and Medical Science, Busan (Korea, Republic of)

    2014-04-15

    The systemic effect of radiation increases in proportionally with the dose and dose rate. Little is known concerning the relationships between harmful effects and accumulated dose, which is derived from continuous low-dose rate radiation exposure. Recent our studies show that low-dose-rate chronic radiation exposure (3.49 mGy/h) causes adverse effects in the testis at a dose of 2 Gy (6 mGy/h). However, the mechanism of the low-dose-rate 2 Gy irradiation induced testicular injury remains unclear. The present results indicate that low-dose rate chronic radiation might affect the BTB permeability, possibly by decreasing levels of ZO-1, Occludin-1, and NPC-2. Furthermore, our results suggest that there is a risk of male infertility through BTB impairment even with low-dose-rate radiation if exposure is continuous.

  4. Effect of low doses gamma irradiation on seed, bulblets and bulbs of onion

    International Nuclear Information System (INIS)

    Al-Oudat, Mohammad

    1991-10-01

    Presowing seed irradiation has been reported as a useful application of radiation in agriculture to stimulate growth and increase the yield of certain crops. To the best of our knowledge the feasibility of this treatment has not yet been tested on onion in Syria. The effect of low doses gamma irradiation on onion seeds, bulblets and bulbs of two local varieties, red and white, was studied during three consecutive seasons (1986 - 1988). Air dried seeds were irradiated by gamma rays from 137 Cs source. Five, 10, 15, 20 and 30 GY, were applied at dose rate of 9.8 Gy/min. The irradiation of onion bulblets and bulbs were carried out with gamma-rays from 60 Co source at a dose rate of 0.5 Gy/min. using 1, 2, 3, 4 and 5 Gy. Within 7 - 10 days after irradiation, both controlled and irradiated seeds, bulblets and bulbs were sown in the field in complete randomized block design with 4 replicates. Irradiation of seeds with doses of 5, 10 and 15 Gy led to highly significant increases in bulblets yield in the three seasons. The increases ranged from 14.5 to 22.1 for red variety and from 16.2 to 22.3 for white variety. The irradiation of bulblets with 1 and 2 Gy increase significantly the yield of bulbs by 21.6 - 26.0% for red variety and 21.6 - 24.4% for white variety. A considerable increase in seed yield was obtained after irradiation of bulbs with 1 and 2 Gy doses. The average increment was about 21.0% for both varieties. Large scale application were performed in 1989 and 1990 using doses of 10 Gy for seeds and 1 Gy for bulblets and bulbs. A considerable increase in the yield was obtained. The average percentage increment was 16.9% and 23.3% for seeds, 18.6 and 20.9% for bulblets, 24.8 and 27.3% for bulbs, for red and white varieties respectively. Therefore, presowing irradiation of seeds, bulblets and bulbs of onion with low doses of gamma-rays (5 - 15 Gy for seeds and 1 - 2 Gy for bulblets and bulbs) can be of practical application resulting in improvement of yield of

  5. Biological effects of low doses of ionizing radiations. Evidence of effect of pre-irradiation of culture medium on subsequent growth in Cyanobacterium Synechococcus lividus in culture

    International Nuclear Information System (INIS)

    Conter, A.; Planel, H.

    1986-01-01

    In order to distinguish the direct effects of low dose of ionizing radiations at the cellular level from those indirect through the culture medium, we have compared proliferation of Synechococcus lividus grown in pre-irradiated medium to proliferation of cultures grown in non-irradiated medium. A stimulation of growth was observed at the 7th day in cultures inoculated with cells selected in deceleration phase, while an inhibition occured in cultures inoculated with exponential growing cells. Addition of catalase (100 U/ml) counteracted the stimulating effect but did not change the inhibiting effect induced by pre-irradiated medium. Results demonstrated the indirect effect of low dose of irradiation, implying hydrogen peroxide, but let us to think that others radioproduced products could be also involved in the mechanism [fr

  6. Combined action of low doses of Ionizing Radiation, Electromagnetic Fields, and Homeopathic Remedies of low dilution on Ionic Homeostasis of a Cell

    International Nuclear Information System (INIS)

    Nadareishvili, G.

    2006-01-01

    It is known fact that low doses of ionizing radiation, electromagnetic fields (EMF) of certain frequency, and a number of homeopathic remedies produce stimulating effect in the cellular ionic homeostasis. The objective of present study was investigation of combined, simultaneous action of these three factors. The mice fibroblasts served as cell source. With an aid of ion-selective electrodes the sum effect of the following factors was evaluated: low dose irradiation (0.05 Gy), EMF (45 Hz, 2 mT), and stimulated phosphoric acid (homeopathic preparation diluted at 10 -14 ). It was found that integral index of the ionic homeostasis during above action, was higher than after action of any of these factors separately. It is suggested that these data point at beneficial action of the homeopathic remedy and it should be considered when promoting the homeopathic means of therapy. (author)

  7. The dynamics of post-operative plasma ACTH values following transsphenoidal surgery for Cushing's disease.

    Science.gov (United States)

    Srinivasan, Lakshmi; Laws, Edward R; Dodd, Robert L; Monita, Monique M; Tannenbaum, Christyn E; Kirkeby, Kjersti M; Chu, Olivia S; Harsh, Griffith R; Katznelson, Laurence

    2011-12-01

    Rapid assessment of adrenal function is critical following transsphenoidal surgery (TSS) for Cushing's disease (CD) in order to determine surgical efficacy. We hypothesize that there may be a role for ACTH measurement as a rapid indicator of adrenal function. Following surgery for CD, glucocorticoids were withheld and paired plasma ACTH and serum cortisol levels were measured every 6 h. Post-operative hypocortisolemia was defined as serum cortisol surgeries: nine subjects attained hypocortisolemia. Plasma ACTH levels decreased more in subjects with hypocortisolemia (0.9 pg/ml/hr, P = 0.0028) versus those with persistent disease (0 0.2 pg/ml/hr, P = 0.26) within the first 48 h after surgery. In contrast to subjects with persistent disease, all subjects with hypocortisolemia achieved a plasma ACTH <20 pg/ml by 19 h (range 1-19 h). Four of the nine subjects with hypocortisolemia achieved plasma ACTH <20 pg/ml by 13 h and the remaining five subjects by 19 h. Hypocortisolemia occurred between 3-36 h following achievement of a plasma ACTH <20 pg/ml. In CD, a reduction in postoperative plasma ACTH levels differentiates subjects with surgical remission versus subjects with persistent disease. The utility of plasma ACTH measurements in the postoperative management of CD remains to be determined.

  8. The effects of ACTH- and vasopressin-analogues on CO2-induced retrograde amnesia in rats

    NARCIS (Netherlands)

    Rigter, H.; Riezen, H. van; Wied, D. de

    Amnesia for a one-trial step-through passive avoidance response was induced in rats by application of CO2 until respiratory arrest occurred. The ACTH-analogue ACTH4–10 alleviated the amnesia when administered 1 hr prior to the retrieval test but not when given 1 hr prior to the acquisition trial.

  9. Effect of MSH/ACTH peptides on fast axonal transport in intact and regenerating sciatic nerves

    International Nuclear Information System (INIS)

    Crescitelli, L.A.

    1985-01-01

    Fast axonal transport was examined in intact rats treated with ACTH 4-10 or ACTH 4-9 (ORG 2766), hypophysectomized rats, adrenalectomized rats, and in ACTH 4-10 treated rats with crushed regenerating sciatic nerves by injecting 3 H-leucine into the ventral horn region of the spinal cord. The distance traveled by the transported activity along the sciatic nerve and the rate of fast axonal transport were not significantly altered as a result of treatment with ACTH 4-10, ACTH 4-9 (ORG 2766), hypophysectomy, or adrenalectomy. Treatment with ACTH 4-9 (ORG 2766) at concentrations of 1 μg/Kg /day and 10 μg/Kg/day caused significant reductions (62% and 64% respectively) in the crest height of the fast axonal transport curve as compared to 0.9% saline treated control animals. No significant differences were found in comparing the distance, rate, slope, or crest height of ACTH 4-10 treated animals with crushed regenerating (7 or 14d) sciatic nerves to control animals. In the group of animals in days, the amount of radiolabeled activity was significantly increased in the ACTH 4-10 treated animals as compared to control animals. The results indicate that during regeneration the peptide acts to prolong the initially high levels of synthetic activity which occur in regenerating axons

  10. ACTH-producing pheochromocytoma: clinical considerations and concise review of the literature

    NARCIS (Netherlands)

    Nijhoff, M. F.; Dekkers, O. M.; Vleming, L. J.; Smit, J. W. A.; Romijn, J. A.; Pereira, A. M.

    2009-01-01

    We present a patient with a rare cause of ectopic ACTH-dependent Cushing's syndrome, caused by a pheochromocytoma. The case provides clues for a detailed discussion on the pitfalls and diagnostic difficulties in establishing the correct underlying cause of ACTH-dependent Cushing's syndrome. It

  11. The effect of ACTH analogues on motor behavior and visual evoked responses in rats

    NARCIS (Netherlands)

    Wolthuis, O.L.; Wied, D. de

    1976-01-01

    Averaged visual evoked responses (VER) in cortical area 17 were recorded one hour after the administration of 7-l-phe ACTH(4-10) or 7-d-phe ACTH(4-10) to artificially ventilated rats, paralysed with gallamine. In addition, the effects of these peptides on spontaneous motor behavior were analyzed.

  12. Monte Carlo investigation of the low-dose envelope from scanned proton pencil beams

    International Nuclear Information System (INIS)

    Sawakuchi, Gabriel O; Titt, Uwe; Mirkovic, Dragan; Ciangaru, George; Zhu, X Ronald; Sahoo, Narayan; Gillin, Michael T; Mohan, Radhe

    2010-01-01

    Scanned proton pencil beams carry a low-dose envelope that extends several centimeters from the individual beam's central axis. Thus, the total delivered dose depends on the size of the target volume and the corresponding number and intensity of beams necessary to cover the target volume uniformly. This dependence must be considered in dose calculation algorithms used by treatment planning systems. In this work, we investigated the sources of particles contributing to the low-dose envelope using the Monte Carlo technique. We used a validated model of our institution's scanning beam line to determine the contributions to the low-dose envelope from secondary particles created in a water phantom and particles scattered in beam line components. Our results suggested that, for high-energy beams, secondary particles produced by nuclear interactions in the water phantom are the major contributors to the low-dose envelope. For low-energy beams, the low-dose envelope is dominated by particles undergoing multiple Coulomb scattering in the beam line components and water phantom. Clearly, in the latter situation, the low-dose envelope depends directly on beam line design features. Finally, we investigated the dosimetric consequences of the low-dose envelope. Our results showed that if not modeled properly the low-dose envelope may cause clinically relevant dose disturbance in the target volume. This work suggested that this low-dose envelope is beam line specific for low-energy beams, should be thoroughly experimentally characterized and validated during commissioning of the treatment planning system, and therefore is of great concern for accurate delivery of proton scanning beam doses.

  13. Concentration of total proteins in blood plasma of chickens hatched from irradiated eggs with low dose gamma radiation

    International Nuclear Information System (INIS)

    Vilic, M.; Kraljevic, P.; Miljanic, S.; Simpraga, M.

    2005-01-01

    It is known that low-dose ionising radiation may have stimulating effects on chickens. Low doses may also cause changes in the concentration of blood plasma total proteins, glucose and cholesterol in chickens. This study investigates the effects of low dose gamma-radiation on the concentration of total proteins in the blood plasma of chickens hatched from eggs irradiated with a dose of 0.15 Gy on incubation days 7 and 19. Results were compared with the control group (chickens hatched from non-irradiated eggs). After hatching, all other conditions were the same for both groups. Blood samples were drawn from the heart, and later from the wing vein on days 1, 3, 5, 7,10, 20, 30 and 42. The concentration of total proteins was determined spectrophotometrically using Boehringer Mannheim GmbH optimised kits. The concentration of total proteins in blood plasma in chickens hatched from eggs irradiated with 0.15 Gy on incubation day 7 showed a statistically significant decrease on the sampling day 3 (P less than 0.05) and 7 (P less than 0.01). The concentration of total proteins in blood plasma in chickens hatched from eggs irradiated with 0.15 Gy on incubation day 19 showed a statistically significant increase only on sampling day 1 (P less than 0.05). These results suggest that exposure of eggs to 0.15 Gy of gamma-radiation on the 7th and 19th day of incubation could produce different effects on the protein metabolism in chickens.(author)

  14. Enhanced low dose rate radiation effect test on typical bipolar devices

    International Nuclear Information System (INIS)

    Liu Minbo; Chen Wei; Yao Zhibin; He Baoping; Huang Shaoyan; Sheng Jiangkun; Xiao Zhigang; Wang Zujun

    2014-01-01

    Two types of bipolar transistors and nine types bipolar integrated circuit were selected in the irradiation experiment at different "6"0Co γ dose rate. The base current of bipolar transistor and input bias current of amplifier and comparator was measured, low dose enhance factor of test device was obtained. The results show that bipolar device have enhanced low dose rate sensitivity, enhancement factor of bipolar integrated circuit was bigger than that of transistor, and enhanced low dose rate sensitivity greatly varied with different structure and process of bipolar device. (authors)

  15. Low-dose radiation attenuates chemical mutagenesis in vivo. Cross adaptation

    International Nuclear Information System (INIS)

    Kakinuma, Shizuko; Yamauchi, Kazumi; Amasaki, Yoshiko; Nishimura, Mayumi; Shimada, Yoshiya

    2009-01-01

    The biological effects of low-dose radiation are not only of social concern but also of scientific interest. The radioadaptive response, which is defined as an increased radioresistance by prior exposure to low-dose radiation, has been extensively studied both in vitro and in vivo. Here we briefly review the radioadaptive response with respect to mutagenesis, survival rate, and carcinogenesis in vivo, and introduce our recent findings of cross adaptation in mouse thymic cells, that is, the suppressive effect of repeated low-dose radiation on mutation induction by the alkylating agent N-ethyl-N-nitrosourea. (author)

  16. Better management of wheat allergy using a very low-dose food challenge: A retrospective study.

    Science.gov (United States)

    Okada, Yu; Yanagida, Noriyuki; Sato, Sakura; Ebisawa, Motohiro

    2016-01-01

    Low-dose reactive wheat-allergic children are at a high risk of a positive oral food challenge (OFC). The present study aimed to evaluate whether the results of a very low-dose (VL) OFC would contribute to better wheat allergy management in this population. We retrospectively reviewed wheat-allergic subjects who underwent a VL OFC with 2 g of udon noodles (equivalent to 53 mg of wheat protein) and had a previous allergic reaction to management of some low-dose reactive wheat-allergic children from complete avoidance to partial wheat intake. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  17. Evaluation of Enhanced Low Dose Rate Sensitivity in Discrete Bipolar Junction Transistors

    Science.gov (United States)

    Chen, Dakai; Ladbury Raymond; LaBel, Kenneth; Topper, Alyson; Ladbury, Raymond; Triggs, Brian; Kazmakites, Tony

    2012-01-01

    We evaluate the low dose rate sensitivity in several families of discrete bipolar transistors across device parameter, quality assurance level, and irradiation bias configuration. The 2N2222 showed the most significant low dose rate sensitivity, with low dose rate enhancement factor of 3.91 after 100 krad(Si). The 2N2907 also showed critical degradation levels. The devices irradiated at 10 mrad(Si)/s exceeded specifications after 40 and 50 krad(Si) for the 2N2222 and 2N2907 devices, respectively.

  18. Hypocortisolemic clamp unmasks jointly feedforward- and feedback-dependent control of overnight ACTH secretion.

    Science.gov (United States)

    Iranmanesh, Ali; Veldhuis, Johannes D

    2008-11-01

    ACTH secretion is under hypothalamic stimulatory (feedforward) and adrenal inhibitory (feedback) control. Assessment of overnight ACTH secretion during a hypocortisolemic clamp will permit the estimation of changing feedforward and feedback. Seven healthy men. An oral dose of placebo (PLAC), metyrapone (METY, 3 g), or ketoconazole (KTCZ, 1.2 g) was given at midnight (MN) to block glucocorticoid synthesis. Plasma ACTH was sampled every 10 min (MN to 0800 h). Variable-waveform deconvolution analysis of ACTH secretion and approximate entropy (ApEn) analysis of pattern regularity. Compared with PLAC, administration of METY and KTCZ reduced morning cortisol concentrations by >or=77 and 54% respectively (Pfeedforward coordination. The combined data predict overnight amplification and coordination of hypothalamic feedforward drive onto ACTH release. Therefore, disruption of either mechanism might contribute to clinical pathophysiology, such as late-day elevations of cortisol output in fasting, alcoholism, depression, or aging.

  19. Muscarinic supersensibility of anterior pituitary ACTH and beta-endorphin release in major depressive illness

    International Nuclear Information System (INIS)

    Risch, S.C.; Gillin, J.C.; Janowsky, D.S.

    1986-01-01

    Since numerious physiological systems display muscarinic receptor supersensitivity in major depressive illnesses, the authors have hypothesize that anterior pituitary release of ACTH and beta-Endorphin immunoreactivity may also be muscarinically supersensitive in depression. The studies were conducted under FDA-approved IND and with local human subjects committee approval. Plasma ACTH concentrations were determined as follows: samples were assayed in duplicate using equilibrium radioimmunoassay utilizing a rabbit anti-porcine ACTH antibody. Significance ofchanges in plasma cortisol, ACTH and beta-endorphin immunoreactivity after physostigmine and saline were determined by repeated measures analysis of variance. In all subject groups, physostigmine (relative to placebo) caused significant increases in plasma concentrations of cortisol, ACTH, and beta-endorphin immonoreactivity

  20. Investigation of the hypothalamo-pituitary-adrenal axis (HPA) by 1 microg ACTH test and metyrapone test in patients with primary fibromyalgia syndrome.

    Science.gov (United States)

    Calis, M; Gökçe, C; Ates, F; Ulker, S; Izgi, H B; Demir, H; Kirnap, M; Sofuoglu, S; Durak, A C; Tutus, A; Kelestimur, F

    2004-01-01

    Primary fibromyalgia syndrome (PFS) is characterized by widespread chronic pain that affects the musculoskeletal system, fatigue, anxiety, sleep disturbance, headache and postural hypotension. The pathophysiology of PFS is unknown. The hypothalamic-pituitary-adrenal (HPA) axis seems to play an important role in PFS. Both hyperactivity and hypoactivity of the HPA axis have been reported in patients with PFS. In this study we assessed the HPA axis by 1 microg ACTH stimulation test and metyrapone test in 22 patients with PFS and in 15 age-, sex-, and body mass index (BMI)- matched controls. Metyrapone (30 mg/kg) was administered orally at 23:00 h and blood was sampled at 08:30 h the following morning for 11-deoxycortisol. ACTH stimulation test was carried out by using 1 microg (iv) ACTH as a bolus injection after an overnight fast, and blood samples were drawn at 0, 30 and 60 min. Peak cortisol level (659.4 +/- 207.2 nmol/l) was lower in the patients with PFS than peak cortisol level (838.7 +/- 129.6 nmol/l) in the control subjects (p < 0.05). Ten patients (45%) with PFS had peak cortisol responses to 1 microg ACTH test lower than the lowest peak cortisol detected in healthy controls. After metyrapone test 11-deoxycortisol level was 123.7 +/- 26 nmol/l in patients with PFS and 184.2 +/- 17.3 nmol/l in the controls (p < 0.05). Ninety five percent of the patients with PFS had lower 11-deoxycortisol level after metyrapone than the lowest 11-deoxycortisol level after metyrapone detected in healthy controls. We also compared the adrenal size of the patients with that of the healthy subjects and we found that the adrenal size between the groups was similar. This study clearly shows that HPA axis is underactivated in PFS, rather than overactivated.

  1. Mutation induction in cultured human cells after low-dose and low-dose-rate γ-ray irradiation. Detection by LOH analysis

    International Nuclear Information System (INIS)

    Umebayashi, Yukihiro; Iwaki, Masaya; Yatagai, Fumio; Honma, Masamitsu; Suzuki, Masao; Suzuki, Hiromi; Shimazu, Toru; Ishioka, Noriaki

    2007-01-01

    To study the genetic effects of low-doses and low-dose-rate ionizing radiation (IR), human lymphoblastoid TK6 cells were exposed to 30 mGy of γ-rays at a dose-rate of 1.2 mGy/hr. The frequency of early mutations (EMs) in the thymidine kinase (TK) gene locus was determined to be 1.7 x 10 -6 , or 1.9-fold higher than the level seen in unirradiated controls. These mutations were analyzed with a loss of heterozygosity (LOH) detection system, a methodology which has been shown to be sensitive to the effects of radiation. Among the 15 EMs observed after IR exposure, 8 were small interstitial-deletion events restricted to the TK gene locus. However, this specific type of event was not found in unirradiated controls. Although these results were observed under the limited conditions, they strongly suggest that the LOH detection system can be used for estimating the genetic effects of a low-dose IR exposure delivered at a low-dose-rate. (author)

  2. Proceedings of the 8. LOWRAD: International conference on the effects of low doses and very low doses of ionizing radiation on human health and biotopes

    International Nuclear Information System (INIS)

    2009-01-01

    Theoretical and experimental papers are presented in these proceedings covering the following subjects: radiation protection, dosimetry, radiation dosimetry, cells, technetium, plutonium, uranium, thorium, low dose irradiation, radiation doses, cesium, radiation chemistry, nuclear medicine, safety and occupational exposure, neoplasm, cytology and radioisotopes

  3. A systematic review of Bisphenol A "low dose" studies in the context of human exposure: a case for establishing standards for reporting "low-dose" effects of chemicals.

    Science.gov (United States)

    Teeguarden, Justin G; Hanson-Drury, Sesha

    2013-12-01

    Human exposure to the chemical Bisphenol A is almost ubiquitous in surveyed industrialized societies. Structural features similar to estrogen confer the ability of Bisphenol A (BPA) to bind estrogen receptors, giving BPA membership in the group of environmental pollutants called endocrine disruptors. References by scientists, the media, political entities, and non-governmental organizations to many toxicity studies as "low dose" has led to the belief that exposure levels in these studies are similar to humans, implying that BPA is toxic to humans at current exposures. Through systematic, objective comparison of our current, and a previous compilation of the "low-dose" literature to multiple estimates of human external and internal exposure levels, we found that the "low-dose" moniker describes exposures covering 8-12 orders of magnitude, the majority (91-99% of exposures) being greater than the upper bound of human exposure in the general infant, child and adult U.S. Population. "low dose" is therefore a descriptor without specific meaning regarding human exposure. Where human exposure data are available, for BPA and other environmental chemicals, reference to toxicity study exposures by direct comparison to human exposure would be more informative, more objective, and less susceptible to misunderstanding. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Detection of brain atrophy due to ACTH or corticosteroid therapy with computed tomography

    International Nuclear Information System (INIS)

    Tamai, Isamu; Takei, Tadao; Oota, Hideomi; Maekawa, Kihei.

    1981-01-01

    Adrenocorticotropic hormone (ACTH) or corticosteroids seemed to cause brain atrophy in intants. We studied the atrophy which was caused by these drugs with computed tomography (CT). 1) Nine cases of infantile spasms examined before, during and after ACTH therepy with CT. Brain atrophy on CT was observed immediately after the completion of ACTH therapy. The brain atrophy receded slightly after several months. It was more marked in younger patients, in cases treated by hight doses of ACTH and in cases where brain atrophy had already been obserbed before ACTH therapy. 2) Twenty cases of infantile spasms or Lennox Gastaut syndrome were examined after ACTH therapy with CT. Brain atrophy was observed in twelve cases. Main features of brain atrophy were the enlargement of sylvian fissure and the widening of subarachnoid space at the frontal or temporal region. Mental retardation was observed in eighteen cases. 3) Two cases of nephrotic syndrome were treated with pulse therapy of prednisolone. CT was carried out before and after treatment. Atrophy of cerebrum was observed in these cases. 4) A case of infantile spasms treated with anticonvulsants without ACTH was studied by electroencephalography (EEG) and CT. The abnormal pattern of EEG was markedly corrected, while brain atrophy on CT was not observed after the therapy. Because of these observations the use of ACTH has to be reconsidered. ACTH should be the drug of second choice for the therapy of infantile spasms and should be used in case other anticonvulsants have no effect. ACTH should be used at lower dosages and for shorter periods of time. (author)

  5. Detection of brain atrophy due to ACTH or corticosteroid therapy with computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Tamai, I.; Takei, T. (National Sagamihara Hospital, Kanagawa (Japan)); Oota, H.; Maekawa, K.

    1981-07-01

    Adrenocorticotropic hormone (ACTH) or corticosteroids seemed to cause brain atrophy in infants. We studied the atrophy which was caused by these drugs with computed tomography (CT). 1) Nine cases of infantile spasms examined before, during and after ACTH therapy with CT. Brain atrophy on CT was observed immediately after the completion of ACTH therapy. The brain atrophy receded slightly after several months. It was more marked in younger patients, in cases treated by high doses of ACTH and in cases where brain atrophy had already been observed before ACTH therapy. 2) Twenty cases of infantile spasms or Lennox Gastaut syndrome were examined after ACTH therapy with CT. Brain atrophy was observed in twelve cases. Main features of brain atrophy were the enlargement of sylvian fissure and the widening of subarachnoid space at the frontal or temporal region. Mental retardation was observed in eighteen cases. 3) Two cases of nephrotic syndrome were treated with pulse therapy of prednisolone. CT was carried out before and after treatment. Atrophy of cerebrum was observed in these cases. 4) A case of infantile spasms treated with anticonvulsants without ACTH was studied by electroencephalography (EEG) and CT. The abnormal pattern of EEG was markedly corrected, while brain atrophy on CT was not observed after the therapy. Because of these observations the use of ACTH has to be reconsidered. ACTH should be the drug of second choice for the therapy of infantile spasms and should be used in case other anticonvulsants have no effect. ACTH should be used at lower dosages and for shorter periods of time.

  6. Effect of Fractionated Low Doses of Gamma Radiation on Some Haematological and Immunological Parameters in Albino Rat

    International Nuclear Information System (INIS)

    Bahgat, M.M.; Abdel-Khalek, L.G.

    2003-01-01

    This study was performed on 30 mature male albino rats to evaluate the direct effect of fractionated low doses (0.5 Gy twice weekly) gamma radiation and delayed effect (one month post-irradiation) on some haematological and immunological parameters. The rats were divided into three equal groups, Control and two whole body gamma-irradiated groups the irradiated groups were subjected to total doses of 4 and 8 Grays over a period of one and two months, respectively. The blood samples and peritoneal macrophages were taken twice from each irradiated rats at the end of their irradiation period and after one month post irradiation. Activated peritoneal macrophages in all groups showed significant decrease as compared to control group denoting that irradiation may cause receptor alteration and/or decrease in the phagocytic power of macrophages lasting for a longer time. Throughout the whole experiment there was wide variation in platelet count with no significant or minimal changes in other blood elements. Moreover, in the post irradiation group after two months irradiation, all the haematological parameters tested, except the Hct, were increased as compared to the control group. These results pointed to that the bone marrow and lymphoid organs of the animals can tolerate fractionated low dose irradiation through rapid recovery and/or compensatory stimulation. The presence of many target cells in the post irradiated group increases the red blood cell fragility

  7. Involvement of p27CIP/KIP in HSP25 or HSP70 Mediated Adaptive Response by Low Dose Radiation

    International Nuclear Information System (INIS)

    Seo, Hang Rhan; Lee, Yoon Jin; Lee, Su Jae; Bae, Sang woo; Lee, Yun Sil

    2005-01-01

    Adaptive responses that reduce the harmful effects of subsequent exposure to high-dose radiation have demonstrated in chromosome aberration, cell survival, sister chromatid exchanges, micronucleus induction, mutation and neoplastic transformation. The mechanisms and conditions for the adaptive response to radiation have not been clarified, although the continuous production of free radicals from radiation and other sources has stimulated cells to evolve a repair system for chromosome breaks. An alteration of the DNA molecule triggers the repair system, and frequent activation may increase the general repair capacity, irrespective of the cause of the damage. Besides, cell cycle regulation systems, antioxidant defense systems, molecular chaperone or stress-response systems. Our previous data showed that when cells were preirradiated with 1cGy, they showed the adaptive response. A reduction of apoptosis by low-dose preirradiation is another potential mechanism for this effect. We previously demonstrated that mouse RIF cells, which did not induce HSP25 and HSP70 did not exhibit a adaptive response after 1cGy preirradiation. whereas the thermoresistant TR cells, which expressed inducible HSP25 and HSP70 showed a response. Moreover, when HSP70 and HSP25 were transfected to RIF cells, the cells acquired adaptive response. In this study, to elucidate the mechanisms in induction of adaptiveresponse, we compared cell cycle distribution by low dose radiation after HSP25 or HSP70 transfected cells and p27CIP/KIP is responsible for the different induction of adaptive response

  8. Synergistic Effects of Ad-Libitum Low-Dose Fructose Drinking and Low-Dose Streptozotocin Treatment in Wistar Rats: A Mild Model of Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Asie Sadeghi

    2017-07-01

    Full Text Available To develop a convenient animal model of T2D by pretreatment with low-dose 10% w/v fructose (FRC solution followed by the injection of low doses of streptozotocin (STZ in Wistar rats. For this 8-week experimental study; rats were first fed a standard chow ad-libitum diet and either tap water (n=40 or 10% w/v FRC solution (n=40 for 4 weeks. Next, rats in each category were randomly allocated to 4 subgroups (n=10 each of low-dose STZ (25,35, and 45 mg/kg. The final mean fasting blood sugar (FBG of FRC+STZ45 (197±55.87 mg/dl were significantly higher than that of the STZ45 (P=0.015 and FRC (P=0.019 groups. FRC+STZ45 showed the highest insulin resistance demonstrated by insulin tolerance test [area under the curve (AUC of insulin tolerance test; P<0.05]. AUC was not significantly different between the STZ45 and non-STZ groups and between FRC and non-FRC fed groups. Furthermore, FBG levels did not differ between FRC and non-FRC groups. Body weight measurement showed that the FRC+STZ45 group had the lowest body weight compared to all other groups. Our data provide the evidence that FRC and STZ45 synergistically could induce hyperglycemia and insulin resistance in Wistar rats. Here we presented a feasible model for initial forms of T2D by employing pretreatment with low-dose FRC solution and treatment with low-dose STZ.

  9. A case of radiation myelopathy responded to ACTH therapy

    International Nuclear Information System (INIS)

    Matsui, Toshiyuki; Kawanami, Sachiko; Nishimaru, Katsuya

    1981-01-01

    A patient with nasal reticulum-cell sarcoma received 60 Co irradiation in a total dose of 10,000 rad in 25 fractions and intracarotid arterial transfusion of 5-Fu 4,000 mg. The prognosis was favorable without subjective symptoms for about one year before disturbance in walking and abnormal sensation in legs occurred. Metastasis of tumor was ruled out, and diagnosis of acute radiculoneuritis was made for the reason that the region which exposed to irradiation coincided the level of neurological disturbances which rapidly advanced. This patient received ACTH therapy. Administration of dexamethasone in a dose of 4 mg per day relieved subjective pain and lowered the level of impaired sensation, and arrested progress of motor paralysis. However, the symptoms was exacerbated again after 2 weeks and the decrease of the dose caused an highered the level of impaired and resulted in motor paralysis. Total dose was 171 mg. (Ueda, J.)

  10. Design for low dose extrapolation of carcinogenicity data. Technical report No. 24

    International Nuclear Information System (INIS)

    Wong, S.C.

    1979-06-01

    Parameters for modelling dose-response relationships in carcinogenesis models were found to be very complicated, especially for distinguishing low dose effects. The author concluded that extrapolation always bears the danger of providing misleading information

  11. 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

  12. Treatment of symptomatic splenomegaly with low doses of radiotherapy: Retrospective analysis and review of the literature

    Directory of Open Access Journals (Sweden)

    Carolina de la Pinta

    2017-09-01

    Conclusion: Low doses of radiation therapy for treatment of symptomatic splenomegaly were effective, with a low rate of side effects. Splenic pain and abdominal discomfort completely improved and cytopenias rised to secure levels.

  13. Curcumin uptake enhancement using low dose light illumination during incubation in Candida albicans

    Science.gov (United States)

    Romano, Renan A.; Pratavieira, Sebastião.; da Silva, Ana P.; Kurachi, Cristina; Bagnato, Vanderlei S.; Guimarães, Francisco E. G.

    2017-07-01

    A new PDI protocol is presented in this study. C. albicans cells pre-illuminated with a low dose light demonstrated an increase of curcumin uptake when compared to dark incubation, leading to a higher PDI efficacy.

  14. Indications for suboptimal low-dose direct oral anticoagulants for non-valvular atrial fibrillation patients

    Directory of Open Access Journals (Sweden)

    Masahiko Umei, MD

    2017-10-01

    Conclusions: With good adherence, the clinical course associated with DOACs is comparatively good. In the future, suboptimal low-dose DOAC therapy may serve as an appropriate choice for some patients with a high risk of stroke and bleeding.

  15. Low-dose helical computed tomography (CT) in the perioperative workup of adolescent idiopathic scoliosis

    Energy Technology Data Exchange (ETDEWEB)

    Abul-Kasim, Kasim; Overgaard, Angelica; Maly, Pavel [Malmoe University Hospital, Department of Radiology, Section of Neuroradiology, University of Lund, Malmoe (Sweden); Ohlin, Acke [Malmoe University Hospital, Department of Orthopaedic Surgery, University of Lund, Malmoe (Sweden); Gunnarsson, Mikael [Malmoe University Hospital, Department of Radiation Physics, University of Lund, Malmoe (Sweden); Sundgren, Pia C. [University of Michigan Health Systems, Department of Radiology, Division of Neuroradiology, Ann Arbor (United States)

    2009-03-15

    The study aims were to estimate the radiation dose in patients examined with low dose spine CT and to compare it with that received by patients undergoing standard CT for trauma of the same region, as well as to evaluate the impact of dose reduction on image quality. Radiation doses in 113 consecutive low dose spine CTs were compared with those in 127 CTs for trauma. The inter- and intraobserver agreement in measurements of pedicular width, and vertebral rotation, measurements of signal-to-noise ratio and assessment of hardware status were the indicators in the evaluation of image quality. The effective dose of the low dose spine CT (0.37 mSv) was 20 times lower than that of a standard CT for trauma (13.09 mSv). This dose reduction conveyed no impact on image quality. This low dose spine CT protocol allows detailed evaluation that is necessary for preoperative planning and postoperative evaluation. (orig.)

  16. CANCER RISKS ATTRIBUTABLE TO LOW DOSES OF IONIZING RADIATION - ASSESSING WHAT WE REALLY KNOW?

    Science.gov (United States)

    Cancer Risks Attributable to Low Doses of Ionizing Radiation - What Do We Really Know?AbstractHigh doses of ionizing radiation clearly produce deleterious consequences in humans including, but not exclusively, cancer induction. At very low radiation doses the situatio...

  17. Low-Dose Radioactive Iodine Destroys Thyroid Tissue Left after Surgery

    Science.gov (United States)

    A low dose of radioactive iodine given after surgery for thyroid cancer destroyed (ablated) residual thyroid tissue as effectively as a higher dose, with fewer side effects and less exposure to radiation, according to two randomized controlled trials.

  18. The inhibitory effect of ACTH 1–10 on extinction of a conditioned avoidance response: Its independence of thyroid function

    NARCIS (Netherlands)

    Wied, D. de; Pirie, Gail

    The effect of the ACTH analogue ACTH 1–10 was studied on the rate of extinction of a pole jumping avoidance response in thyroidectomized rats with or without replacement therapy with 1-thyroxin. ACTH 1–10 appeared to delay the rate of extinction of the CAR in thyroidectomized rats in a similar way

  19. Physical mechanisms contributing to enhanced bipolar gain degradation at low dose rates

    International Nuclear Information System (INIS)

    Fleetwood, D.M.; Reber, R.A. Jr.; Winokur, P.S.; Kosier, S.L.; Schrimpf, R.D.; Wei, A.; DeLaus, M.; Combs, W.E.; Pease, R.L.

    1994-01-01

    The authors have performed capacitance-voltage (C-V) and thermally-stimulated-current (TSC) measurements on non-radiation-hard MOS capacitors simulating screen oxides of modern bipolar technologies. For 0-V irradiation of ∼25 C, the net trapped-positive-charge density (N ox ) inferred from midgap C-V shifts is ∼25--40% greater for low-dose-rate ( 2 )/s) than for high-dose-rate (> 100 rad(SiO 2 )/s) exposure. Device modeling shows that such a difference in screen-oxide N ox is enough to account for the enhanced low-rate gain degradation often observed in bipolar devices, due to the ∼ exp(N ox 2 ) dependence of the excess base current. At the higher rates, TSC measurements reveal a ∼10% decrease in trapped-hole density over low rates. Also, at high rates, up to ∼2.5-times as many trapped holes are compensated by electrons in border traps than at low rates for these devices and irradiation conditions. Both the reduction in trapped-hole density and increased charge compensation reduce the high-rate midgap shift. A physical model is developed which suggests that both effects are caused by time-dependent space charge in the bulk of these soft oxides associated with slowly transporting and/or metastably trapped holes (e.g., in Eδ' centers). On the basis of this model, bipolar transistors and screen-oxide capacitors were irradiated at 60 C at 200 rad(SiO 2 )/s in a successful effort to match low-rate damage. these surprising results provide insight into enhanced low-rate bipolar gain degradation and suggest potentially promising new approaches to bipolar and BiCMOS hardness assurance for space applications

  20. Effects of low doses of gamma irradiation on pine nuts (Araucaria angustifolia)

    Energy Technology Data Exchange (ETDEWEB)

    Modolo, Debora M.; Silva, Lucia A.C.S.; Arthur, Valter, E-mail: dmmodolo@cena.usp.br, E-mail: lcasilva@cena.usp.br, E-mail: arthur@cena.usp.br [Laboratorio de Radiobiologia e Ambiente, Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Harder, Marcia N.C.; Arthur, Paula B.; Arthur, Valter [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The Araucaria angustifolia, is known as the Pinheiro-do-Parana, Brazilian pine, Pine, Pine Tree Monkey, emerges as the main representative of the Rain Forest, also known as Araucaria Forest, part of the Atlantic Forest biome (Decree Law 750/1993). A major problem in implementing this plan is to stand the loss of germination of seeds. The storage conditions of the seeds of species, some time have been the subject of studies by various researchers. Several studies have shown that ionizing radiation can increase the germination rate, to break dormancy and plant production, thus appearing as an alternative method to increase the production of economically important crops. Despite the Hormesis Theory have been confirmed in experiments and observations made over the years, relatively few researchers who are dedicated to the study of this phenomenon. Due to losses of germination of pine nut, the aim of this work was to study the effect of low doses of gamma radiation on pine nut. The seeds were bought locally in the city of Piracicaba and irradiated with 0 (control), 0.25, 0.50, 0.75, 10, 12, 5, 15.0 and 17.5 Gy. Subsequently the seeds were planted in a plastic cup containing vermiculite as substrate. Evaluations of the germinated seeds number and measure the size of the plants every 10 days. The results indicated that the dose of 0.25 Gy there was a greater number of plants germinated and irradiation stimulated the growth of these plants. Already a lethal dose of the seeds was 15 Gy. (author)

  1. Effect of low doses of gamma radiation on alfalfa (Lucerne) yield

    Energy Technology Data Exchange (ETDEWEB)

    Al-Odat, M; Khalifa, Kh [Atomic Energy Commission, Damascus (Syrian Arab Republic). Dept. of Radiation Agriculture

    1994-11-01

    Presowing seed irradiation has been reported frequently as a useful application of radiation in agriculture to stimulate growth and increase the yield of field and horticulture crops. Lucerne seeds of previous season (local variety) were irradiated by gamma rays Cs sup 1 sup 3 sup 7 source using doses of 5, 10, 15, 20, 30, and 40 Gy at dose rate of 9.2 Gy/min. Then were planted after 7 days from irradiation with unirradiated control in complete randomized block design and 5 replicates for three seasons (1986, 1987, 1988), the field experiment was carried out at ACSAD research station in Der-Ezzor. Also pot experiments were carried out to study the effect of low doses gamma irradiation on seed germination and growth of shoot and root systems of seedlings. The following observation were made on plants grown in the field:- fresh weight and dry weight of shoot system, - seed yield at the end of the experiment. The results show that there is a positive effect of seed irradiation on percentage of germination and root systems of seedling compared with the control. the highest increase in dry weight of shoot and root systems was at doses of 10 and 15 Gy. specially when sowing was 10 days after irradiation. Gamma irradiation doses of 10 and 15 Gy led to significant increases in fresh and dry weight at shoot system in the three seasons. The increases were 17.5% and 14.6% for the doses of 10 and 15 Gy respectively. A considerable increase in seed yield obtained at doses from 10 to 40 Gy, and the seed yield varied from 13.3% to 17.9% Compared with the control. (author). 20 refs., 18 tabs.

  2. Effect of Low Dose Radiation Upon Antioxidant Parameters in Skeletal Muscle of Chick Embryo

    International Nuclear Information System (INIS)

    Vilic, M.; Pirsljin, J.; Beer Ljubic, B.; Miljanic, S.; Kraljevic, P.

    2008-01-01

    In this paper an attempt was made to determine the effect of irradiation of eggs with low dose ionizing radiation upon lipid peroxide (TBARS) level, glutathione (GSH) level, activity of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) in skeletal muscle of chick embryo and newly hatched chicks. The eggs of a heavy breeding chickens were irradiated with a dose of 0.3 Gy gamma radiation (60Co source) on the 19th day of incubation. Along with the irradiated chick embryos, there was a control group of non-irradiated chick embryos. The antioxidant parameters were measured in breast muscle (m. pectoralis superficialis) and thigh muscle (m. biceps femoris) of chick embryos on 1, 3, 6, 24 and 72 h after egg irradiation. All parameters were determined spectrophotometrically. Lipid peroxidation, GSH level and CAT activity decreased in the breast and thigh muscle of chick embryos on the first hour after irradiation, while the activity of GSH-Px increased in the thigh muscle on the 1st hour after irradiation. CAT activity decreased in the breast muscle of chick embryos on the hour 24 after irradiation. The GSH level increased in the breast and thigh muscle of chick embryos on the hour 72 after irradiation while the activity of GSH-Px increased in the breast muscle. At the same time CAT activity decreased in breast muscle while lipid peroxidation decreased in thigh muscle. The obtained results showed that acute irradiation of chicken eggs on the 19th day of incubation with the dose of 0.3 Gy gamma radiation could be an oxidative stress in both types of muscles immediately after irradiation. However, at the one-day old chicks (72 hours after irradiation) this dose could have a stimulating effect upon GSH level in both breast and thigh muscle.(author)

  3. Effects of low doses of gamma irradiation on pine nuts (Araucaria angustifolia)

    International Nuclear Information System (INIS)

    Modolo, Debora M.; Silva, Lucia A.C.S.; Arthur, Valter; Harder, Marcia N.C.; Arthur, Paula B.; Arthur, Valter

    2011-01-01

    The Araucaria angustifolia, is known as the Pinheiro-do-Parana, Brazilian pine, Pine, Pine Tree Monkey, emerges as the main representative of the Rain Forest, also known as Araucaria Forest, part of the Atlantic Forest biome (Decree Law 750/1993). A major problem in implementing this plan is to stand the loss of germination of seeds. The storage conditions of the seeds of species, some time have been the subject of studies by various researchers. Several studies have shown that ionizing radiation can increase the germination rate, to break dormancy and plant production, thus appearing as an alternative method to increase the production of economically important crops. Despite the Hormesis Theory have been confirmed in experiments and observations made over the years, relatively few researchers who are dedicated to the study of this phenomenon. Due to losses of germination of pine nut, the aim of this work was to study the effect of low doses of gamma radiation on pine nut. The seeds were bought locally in the city of Piracicaba and irradiated with 0 (control), 0.25, 0.50, 0.75, 10, 12, 5, 15.0 and 17.5 Gy. Subsequently the seeds were planted in a plastic cup containing vermiculite as substrate. Evaluations of the germinated seeds number and measure the size of the plants every 10 days. The results indicated that the dose of 0.25 Gy there was a greater number of plants germinated and irradiation stimulated the growth of these plants. Already a lethal dose of the seeds was 15 Gy. (author)

  4. The effect of low dose gamma irradiation on maize production (1985-1988)

    International Nuclear Information System (INIS)

    Al-Oudat, M.; Khalifa, K.

    1990-06-01

    Presowing seed irradiation has been reported as a useful application of radiation in agriculture to stimulate growth and increase the yield of certain field crops. To the best of our knowledge the feasibility of this treatment has not yet been tested on maize in Syria. Our experiments were carried out in controlled, in field conditions, and in a large scale application. Samples of air dried seeds of maize (Var. Gota-82 and LG-11) of previous season were irradiated by gamma-rays from a 137 Cs sourse using doses of 5, 7.5, 10, 15, 20, 30, 40 and 50 Gy. at dose rate of 9.8 - 9.2 Gy/min. Then were planted after 2 days from irradiation with unirradiated control, in complete randomized block design and replicated 4 times for four seasons (1985-1988). The date revealed that gamma irradiation, at interval doses of 5 - 10 Gy led to, first: Acceleration of seed germination, faster development, intensive development of root system, increase plant hieght (12 - 19%) and significant increase in ear size and number, and second: Increase both green mass (15 - 35%) and seed yield (10 - 31%), and percentage of seed protein (2 - 17%). Large scale applications were performed in 1987 and 1988 using a transportable irradiation unit POC-1 137 Cs and dose of 7.5 Gy. A significant yield increase was obtained from all fields. The average percentage increment varied from 13 - 30% which is approximately 382-765 Kg/h. Therefore, presowing seed irradiation with low doses gamma irradiation ranging from 5 to 10 Gy, was found to be feasible for application in qualitative and quantitative improvement of maize yield. (author). 38 refs., 12 figs., 44 tabs

  5. Effects of low dose radiation on repair processes in human lymphocytes

    International Nuclear Information System (INIS)

    Tuschl, H.; Altmann, H.; Kovac, R.; Topaloglou, A.; Egg, D.; Guenther, R.

    1978-10-01

    DNA excision repair was investigated in lymphocytes of persons occupationally exposed to low dose radiation of 222 Rn. Autoradiographic studies of unscheduled DNA synthesis and measurement of 3 H-thymidine incorporation by repair replication into double stranded and single-strand containing DNA fractions obtained by BND cellulose chromatography seem to indicate a stimulatory effect of repeated low dose radiation on repair enzymes. (author)

  6. Low dose radiation exposure and atherosclerosis in ApoE{sup -/-} mice

    Energy Technology Data Exchange (ETDEWEB)

    Mitchel, R.E.J. [Atomic Energy of Canada Limited, Chalk River, ON (Canada); Hasu, M. [Univ. of Ottawa, Department of Pathology and Lab. Medicine, and Cellular and Molecular Medicine, Ottawa, ON (Canada); Univ. of Ottawa Heart Inst., Vascular Biology Group, Ottawa, ON (Canada); Bugden, M.; Wyatt, H. [Atomic Energy of Canada Limited, Chalk River, ON (Canada); Little, M. [Imperial Coll., Faculty of Medicine, St. Marys Campus, London (United Kingdom); Hildebrandt, G. [Univ. Hospital, Dept. of Radiotherapy, Rostock (Germany); Priest, N.D. [Atomic Energy of Canada Limited, Chalk River, ON (Canada); Whitman, S.C. [Univ. of Ottawa, Department of Pathology and Lab. Medicine, and Cellular and Molecular Medicine, Ottawa, ON (Canada); Univ. of Ottawa Heart Inst., Vascular Biology Group, Ottawa, ON (Canada)

    2010-07-01

    The hypothesis that single low dose exposures (0.025-0.5 Gy) to low LET radiation, given at either high (240 mGy/min) or low (1 mGy/min) dose rate, would promote aortic atherosclerosis was tested in female C57BI/6 mice genetically predisposed to this disease (ApoE-/-). Mice were exposed either at early stage disease (2 months of age) and examined 3 or 6 months later, or at late stage disease (8 months of age) and examined 2 or 4 months later. Compared to unexposed controls, all doses given at low or high dose rate at early stage disease had significant inhibitory effects on lesion growth and, at 25 or 50 mGy, on lesion frequency. No dose given at low dose rate had any effect on total serum cholesterol, but this was elevated by every dose given at high dose rate. Exposures at low dose rate had no effect on the percentage of lesion lipids contained within macrophages, and, at either high or low dose rate, had no significant effect on lesion severity. Exposure at late stage disease, to any dose at high dose rate, had no significant effect on lesion frequency, but at low dose rate some doses produced a small transient increase in this frequency. Exposure to low doses at low, but not high dose rate, significantly, but transiently reduced average lesion size, and at either dose rate transiently reduced lesion severity. Exposure to any dose at low dose rate (but not high dose rate) resulted in large and persistent decreases in serum cholesterol. These data indicate that a single low dose exposure, depending on dose and dose rate, generally protects against various measures of atherosclerosis in genetically susceptible mice. This result contrasts with the known, generally detrimental effects of high doses on this disease in the same mice, suggesting that a linear extrapolation of risk from high doses is not appropriate. (author)

  7. Radon Exposure and the Definition of Low Doses-The Problem of Spatial Dose Distribution.

    Science.gov (United States)

    Madas, Balázs G

    2016-07-01

    Investigating the health effects of low doses of ionizing radiation is considered to be one of the most important fields in radiological protection research. Although the definition of low dose given by a dose range seems to be clear, it leaves some open questions. For example, the time frame and the target volume in which absorbed dose is measured have to be defined. While dose rate is considered in the current system of radiological protection, the same cancer risk is associated with all exposures, resulting in a given amount of energy absorbed by a single target cell or distributed among all the target cells of a given organ. However, the biological effects and so the health consequences of these extreme exposure scenarios are unlikely to be the same. Due to the heterogeneous deposition of radon progeny within the lungs, heterogeneous radiation exposure becomes a practical issue in radiological protection. While the macroscopic dose is still within the low dose range, local tissue doses on the order of Grays can be reached in the most exposed parts of the bronchial airways. It can be concluded that progress in low dose research needs not only low dose but also high dose experiments where small parts of a biological sample receive doses on the order of Grays, while the average dose over the whole sample remains low. A narrow interpretation of low dose research might exclude investigations with high relevance to radiological protection. Therefore, studies important to radiological protection should be performed in the frame of low dose research even if the applied doses do not fit in the dose range used for the definition of low doses.

  8. Responses of epithelial cells to low and very low doses of low let radiation

    International Nuclear Information System (INIS)

    Mothersill, Carmel; Seymour, Colin

    2003-01-01

    Recent advances in our knowledge of the biological effects of low doses of ionizing radiation have shown unexpected phenomena. These vary in the endpoint used to detect them and in the dose range examined but all occur as high-frequency events in cell populations. They include: 1. a 'bystander effect' which can be demonstrated at low doses as a transferable.factor(s) causing radiobiological effects in unexposed cells, 2. an assortment of delayed effects' occurring in progeny of cells exposed to low doses, 3. Low-dose Hypersensitivity (HRS) and Increased radioresistance (IRR) which can collectively be demonstrated as a change in the dose-effect relationship, occurring around 0.5-1 Gy of low LET radiation and 4. adaptive responses where cells exposed to very low doses followed by higher doses, exhibit an induced relatively resistant response to the second dose. In all cases, the effect of very low doses is greater than would be predicted by extrapolation of high dose data and is inconsistent with conventional DNA break/repair-based radiobiology. In practical risk assessment terms, the relative importance of the effects are high at low doses where they dominate the response, and small at high doses. This paper reviews these assorted phenomena and in particular seeks to explore whether related or distinct mechanisms underlie these various effects Understanding the mechanistic basis of these phenomena may suggest new approaches to controlling death or survival sectoring at low radiation doses. The key question is whether these low dose phenomena necessitate a new approach to risk assessment. (author)

  9. 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

  10. Cytogenetic Low-Dose Hyperradiosensitivity Is Observed in Human Peripheral Blood Lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Seth, Isheeta [Department of Biological Sciences, Wayne State University, Detroit, Michigan (United States); Joiner, Michael C. [Department of Radiation Oncology, Wayne State University, Detroit, Michigan (United States); Tucker, James D., E-mail: jtucker@biology.biosci.wayne.edu [Department of Biological Sciences, Wayne State University, Detroit, Michigan (United States)

    2015-01-01

    Purpose: The shape of the ionizing radiation response curve at very low doses has been the subject of considerable debate. Linear-no-threshold (LNT) models are widely used to estimate risks associated with low-dose exposures. However, the low-dose hyperradiosensitivity (HRS) phenomenon, in which cells are especially sensitive at low doses but then show increased radioresistance at higher doses, provides evidence of nonlinearity in the low-dose region. HRS is more prominent in the G2 phase of the cell cycle than in the G0/G1 or S phases. Here we provide the first cytogenetic mechanistic evidence of low-dose HRS in human peripheral blood lymphocytes using structural chromosomal aberrations. Methods and Materials: Human peripheral blood lymphocytes from 2 normal healthy female donors were acutely exposed to cobalt 60 γ rays in either G0 or G2 using closely spaced doses ranging from 0 to 1.5 Gy. Structural chromosomal aberrations were enumerated, and the slopes of the regression lines at low doses (0-0.4 Gy) were compared with doses of 0.5 Gy and above. Results: HRS was clearly evident in both donors for cells irradiated in G2. No HRS was observed in cells irradiated in G0. The radiation effect per unit dose was 2.5- to 3.5-fold higher for doses ≤0.4 Gy than for doses >0.5 Gy. Conclusions: These data provide the first cytogenetic evidence for the existence of HRS in human cells irradiated in G2 and suggest that LNT models may not always be optimal for making radiation risk assessments at low doses.

  11. Low dose radiation exposure and atherosclerosis in ApoE-/- mice

    International Nuclear Information System (INIS)

    Mitchel, R.E.J.; Hasu, M.; Bugden, M.; Wyatt, H.; Little, M.; Hildebrandt, G.; Priest, N.D.; Whitman, S.C.

    2010-01-01

    The hypothesis that single low dose exposures (0.025-0.5 Gy) to low LET radiation, given at either high (240 mGy/min) or low (1 mGy/min) dose rate, would promote aortic atherosclerosis was tested in female C57BI/6 mice genetically predisposed to this disease (ApoE-/-). Mice were exposed either at early stage disease (2 months of age) and examined 3 or 6 months later, or at late stage disease (8 months of age) and examined 2 or 4 months later. Compared to unexposed controls, all doses given at low or high dose rate at early stage disease had significant inhibitory effects on lesion growth and, at 25 or 50 mGy, on lesion frequency. No dose given at low dose rate had any effect on total serum cholesterol, but this was elevated by every dose given at high dose rate. Exposures at low dose rate had no effect on the percentage of lesion lipids contained within macrophages, and, at either high or low dose rate, had no significant effect on lesion severity. Exposure at late stage disease, to any dose at high dose rate, had no significant effect on lesion frequency, but at low dose rate some doses produced a small transient increase in this frequency. Exposure to low doses at low, but not high dose rate, significantly, but transiently reduced average lesion size, and at either dose rate transiently reduced lesion severity. Exposure to any dose at low dose rate (but not high dose rate) resulted in large and persistent decreases in serum cholesterol. These data indicate that a single low dose exposure, depending on dose and dose rate, generally protects against various measures of atherosclerosis in genetically susceptible mice. This result contrasts with the known, generally detrimental effects of high doses on this disease in the same mice, suggesting that a linear extrapolation of risk from high doses is not appropriate. (author)

  12. Effect of serial irradiation of low dose gamma rays on the growth and photosynthesis of red pepper (capsicum annuum L.) plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Hong; Wi, Seung Gon; Chung, Byung Yeoup; Baek, Myung Hwa; Yang, Dae Hwa; Kim, Jae Sung [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2004-07-01

    Ionizing radiation at several grays can induce growth stimulation in plants. This phenomenon has been called 'radiation hormesis'. Low dose radiation also modulates photosynthesis. Although an alteration in photosynthesis has been thought to involve in the growth stimulation of irradiated plants, no reports did clarify their relationship yet. In the present study, we attempted to reveal a possible relationship between them by comparing the effects of serial gamma-irradiation on the growth and photosynthesis of red pepper. Furthermore, something beyond the dose effect of ionizing radiation is discussed by this new experimental approach.

  13. The benefit of low dose prophylaxis in the treatment of hemophilia: a focus on China.

    Science.gov (United States)

    Wu, Runhui; Luke, Koon Hung

    2017-11-01

    Currently full dose prophylaxis is the standard of care in the treatment of hemophilia (World Federation of Hemophilia). However, the high costs prevent the use of standard or intermediate dose prophylaxis in China and other developing countries. Low dose prophylaxis would be a viable alternative treatment. At present global research data on the use of low dose prophylaxis is limited. Areas covered: Since 2007, China has been developing low dose prophylaxis as a high priority (90 % of moderate and severe hemophilia boys suffer joint disease by age 6 - 9). 11 studies were successfully conducted and published results showing evidence of the benefits of low dose prophylaxis to reduce joint bleeding. This new knowledge has been implemented into clinical practice in China. However the long-term outcome of arthropathy remains unclear and obstacles in execution exist. Expert commentary: In 2016, the first phenotype-based individualized prophylaxis study using four escalating low dose regimens on severe Chinese hemophilia A boys (China Individualized Prophylaxis Study (CHIP China)) launched. Using the previously published and imminent CHIP data, the goal for China is to establish an effective escalating low dose prophylaxis protocol for use in China as a standard of care.

  14. Super-low dose endotoxin pre-conditioning exacerbates sepsis mortality.

    Science.gov (United States)

    Chen, Keqiang; Geng, Shuo; Yuan, Ruoxi; Diao, Na; Upchurch, Zachary; Li, Liwu

    2015-04-01

    Sepsis mortality varies dramatically in individuals of variable immune conditions, with poorly defined mechanisms. This phenomenon complements the hypothesis that innate immunity may adopt rudimentary memory, as demonstrated in vitro with endotoxin priming and tolerance in cultured monocytes. However, previous in vivo studies only examined the protective effect of endotoxin tolerance in the context of sepsis. In sharp contrast, we report herein that pre-conditionings with super-low or low dose endotoxin lipopolysaccharide (LPS) cause strikingly opposite survival outcomes. Mice pre-conditioned with super-low dose LPS experienced severe tissue damage, inflammation, increased bacterial load in circulation, and elevated mortality when they were subjected to cecal-ligation and puncture (CLP). This is in opposite to the well-reported protective phenomenon with CLP mice pre-conditioned with low dose LPS. Mechanistically, we demonstrated that super-low and low dose LPS differentially modulate the formation of neutrophil extracellular trap (NET) in neutrophils. Instead of increased ERK activation and NET formation in neutrophils pre-conditioned with low dose LPS, we observed significantly reduced ERK activation and compromised NET generation in neutrophils pre-conditioned with super-low dose LPS. Collectively, our findings reveal a novel mechanism potentially responsible for the dynamic programming of innate immunity in vivo as it relates to sepsis risks.

  15. Super-low Dose Endotoxin Pre-conditioning Exacerbates Sepsis Mortality

    Directory of Open Access Journals (Sweden)

    Keqiang Chen

    2015-04-01

    Full Text Available Sepsis mortality varies dramatically in individuals of variable immune conditions, with poorly defined mechanisms. This phenomenon complements the hypothesis that innate immunity may adopt rudimentary memory, as demonstrated in vitro with endotoxin priming and tolerance in cultured monocytes. However, previous in vivo studies only examined the protective effect of endotoxin tolerance in the context of sepsis. In sharp contrast, we report herein that pre-conditioning with super-low or low dose endotoxin lipopolysaccharide (LPS cause strikingly opposite survival outcomes. Mice pre-conditioned with super-low dose LPS experienced severe tissue damage, inflammation, increased bacterial load in circulation, and elevated mortality when they were subjected to cecal-ligation and puncture (CLP. This is in contrast to the well-reported protective phenomenon with CLP mice pre-conditioned with low dose LPS. Mechanistically, we demonstrated that super-low and low dose LPS differentially modulate the formation of neutrophil extracellular trap (NET in neutrophils. Instead of increased ERK activation and NET formation in neutrophils pre-conditioned with low dose LPS, we observed significantly reduced ERK activation and compromised NET generation in neutrophils pre-conditioned with super-low dose LPS. Collectively, our findings reveal a mechanism potentially responsible for the dynamic programming of innate immunity in vivo as it relates to sepsis risks.

  16. The risk of low doses of ionising radiation and the linear no threshold relationship debate

    International Nuclear Information System (INIS)

    Tubiana, M.; Masse, R.; Vathaire, F. de; Averbeck, D.; Aurengo, A.

    2007-01-01

    The ICRP and the B.E.I.R. VII reports recommend a linear no threshold (L.N.T.) relationship for the estimation of cancer excess risk induced by ionising radiations (IR), but the 2005 report of Medicine and Science French Academies concludes that it leads to overestimate of risk for low and very low doses. The bases of L.N.T. are challenged by recent biological and animal experimental studies which show that the defence against IR involves the cell microenvironment and the immunologic system. The defence mechanisms against low doses are different and comparatively more effective than for high doses. Cell death is predominant against low doses. DNA repairing is activated against high doses, in order to preserve tissue functions. These mechanisms provide for multicellular organisms an effective and low cost defence system. The differences between low and high doses defence mechanisms are obvious for alpha emitters which show several greys threshold effects. These differences result in an impairment of epidemiological studies which, for statistical power purpose, amalgamate high and low doses exposure data, since it would imply that cancer IR induction and defence mechanisms are similar in both cases. Low IR dose risk estimates should rely on specific epidemiological studies restricted to low dose exposures and taking precisely into account potential confounding factors. The preliminary synthesis of cohort studies for which low dose data (< 100 mSv) were available show no significant risk excess, neither for solid cancer nor for leukemias. (authors)

  17. ATM phosphorylation in HepG2 cells following continuous low dose-rate irradiation

    International Nuclear Information System (INIS)

    Mei Quelin; Du Duanming; Chen Zaizhong; Liu Pengcheng; Yang Jianyong; Li Yanhao

    2008-01-01

    Objective: To investigate the change of ATM phosphorylation in HepG2 cells following a continuous low dose-rate irradiation. Methods: Cells were persistently exposed to low dose-rate (8.28 cGy/h) irradiation. Indirect immunofluorescence and Western blot were used to detect the expression of ATM phosphorylated proteins. Colony forming assay was used to observe the effect of a low dose-rate irradiation on HepG2 cell survival. Results: After 30 min of low dose-rate irradiation, the phosphorylation of ATM occurred. After 6 h persistent irradiation, the expression of ATM phosphorylated protein reached the peak value, then gradually decreased. After ATM phosphorylation was inhibited with Wortmannin, the surviving fraction of HepG2 cells was lower than that of the irradiation alone group at each time point (P<0.05). Conclusions: Continuous low dose-rate irradiation attenuated ATM phosphorylation, suggesting that continuous low dose-rate irradiation has a potential effect for increasing the radiosensitivity of HepG2 cells. (authors)

  18. Effect of low dose radiation on Th1 and Th2 of thymocytes and splenocytes in mice

    International Nuclear Information System (INIS)

    Bai Ou; Liu Shuzheng; Mu Ying

    1998-01-01

    Objective: To elucidate the possible mechanism of activation of helper T cells after low dose radiation (LDR) exposure, the influence of whole-body irradiation (WBI) with 75 mGy X-rays on Th1 and Th2 was studied. Methods: Mice were irradiated at a dose rate of 12.5 mGy/min, and IFN-γ and IL-6 mRNA levels of the myocytes and splenocytes were analyzed by dot blot and Northern blot hybridization. Results: It was found that IFN-γ and IL-6 mRNA significantly increased after WBI with 75 mGy X-rays. Conclusion: The gene induction of cytokine profile after LDR indicates that activation of both Th1 and Th2 subtypes may be involved in the stimulation of immune functions by LDR

  19. The Acute Effects of Low-Dose TNF-α on Glucose Metabolism and β-Cell Function in Humans

    DEFF Research Database (Denmark)

    Ibfelt, Tobias; Fischer, Christian Philip; Plomgaard, Peter

    2014-01-01

    , nondiabetic young men (n = 10) during a 4-hour basal period followed by an intravenous glucose tolerance test (IVGTT). TNF-α lowered insulin levels by 12% during the basal period (P levels increased markedly in both trials, but there was no difference between trials......Type 2 diabetes is characterized by increased insulin resistance and impaired insulin secretion. Type 2 diabetes is also associated with low-grade inflammation and increased levels of proinflammatory cytokines such as TNF-α. TNF-α has been shown to impair peripheral insulin signaling in vitro...... and in vivo. However, it is unclear whether TNF-α may also affect endogenous glucose production (EGP) during fasting and glucose-stimulated insulin secretion (GSIS) in vivo. We hypothesized that low-dose TNF- α would increase EGP and attenuate GSIS. Recombinant human TNF-α or placebo was infused in healthy...

  20. Effect of low dose irradiation on subsets of T-lymphocyte of peripheral blood, spleen and tumor tissue

    International Nuclear Information System (INIS)

    Zou Huawei; Su Liaoyuan; Tian Hailin

    1998-01-01

    Purpose: In order to understand the mechanism of the stimulation effects of low dose radiation (LDR), the author observed the immune changes of T-lymphocyte subsets. Meteria and methods: Whole body of BALB/C bring-tumor mice were exposed to the doses of 5, 10, 20 and 50 cGy γ-rays. The changes of T-lymphocyte subsets in peripheral blood, spleen and tumor-infiltrating lymphocyte (TIL) were studied with flow cytometry (FCM). Results: the ratio of L 3 T 4 + /Lyt 2 + remarkable increased in the peripheral blood and spleen (p 3 T 4 + /Lyt 2 + further decreased in the TIL group of mice exposed 10 cGy (p 2 + molecules, were concentrated in the tumor tissues and they carried out the killing function to the tumor cells

  1. Cryptochrome 2 expression level is critical for adrenocorticotropin stimulation of cortisol production in the capuchin monkey adrenal.

    Science.gov (United States)

    Torres-Farfan, C; Abarzua-Catalan, L; Valenzuela, F J; Mendez, N; Richter, H G; Valenzuela, G J; Serón-Ferré, M

    2009-06-01

    Timely production of glucocorticoid hormones in response to ACTH is essential for survival by coordinating energy intake and expenditure and acting as homeostatic regulators against stress. Adrenal cortisol response to ACTH is clock time dependent, suggesting that an intrinsic circadian oscillator in the adrenal cortex contributes to modulate the response to ACTH. Circadian clock gene expression has been reported in the adrenal cortex of several species. However, there are no reports accounting for potential involvement of adrenal clock proteins on cortisol response to ACTH. Here we explored whether the clock protein cryptochrome 2 (CRY2) knockdown modifies the adrenal response to ACTH in a primate. Adrenal gland explants from adult capuchin monkey (n = 5) were preincubated for 6 h with transfection vehicle (control) or with two different Cry2 antisense and sense probes followed by 48 h incubation in medium alone (no ACTH) or with 100 nm ACTH. Under control and sense conditions, ACTH increased cortisol production, whereas CRY2 suppression inhibited ACTH-stimulated cortisol production. Expression of the steroidogenic enzymes steroidogenic acute regulatory protein and 3beta-hydroxysteroid dehydrogenase at 48 h of incubation was increased by ACTH in control explants and suppressed by Cry2 knockdown. Additionally, we found that Cry2 knockdown decreased the expression of the clock gene brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein (Bmal1) at the mRNA and protein levels. Altogether these results strongly support that the clock protein CRY2 is involved in the mechanism by which ACTH increases the expression of steroidogenic acute regulatory protein and 3beta-hydroxysteroid dehydrogenase. Thus, adequate expression levels of components of the adrenal circadian clock are required for an appropriate cortisol response to ACTH.

  2. Edge restenosis: impact of low dose irradiation on cell proliferation and ICAM-1 expression

    Directory of Open Access Journals (Sweden)

    Hannekum Andreas

    2006-07-01

    Full Text Available Abstract Background Low dose irradiation (LDI of uninjured segments is the consequence of the suggestion of many authors to extend the irradiation area in vascular brachytherapy to minimize the edge effect. Atherosclerosis is a general disease and the uninjured segment close to the intervention area is often atherosclerotic as well, consisting of neointimal smooth muscle cells (SMC and quiescent monocytes (MC. The current study imitates this complex situation in vitro and investigates the effect of LDI on proliferation of SMC and expression of intercellular adhesion molecule-1 (ICAM-1 in MC. Methods Plaque tissue from advanced primary stenosing lesions of human coronary arteries (9 patients, age: 61 ± 7 years was extracted by local or extensive thrombendarterectomy. SMC were isolated and identified by positive reaction with smooth muscle α-actin. MC were isolated from buffy coat leukocytes using the MACS cell isolation kit. For identification of MC flow-cytometry analysis of FITC-conjugated CD68 and CD14 (FACScan was applied. SMC and MC were irradiated using megavoltage photon irradiation (CLINAC2300 C/D, VARIAN, USA of 6 mV at a focus-surface distance of 100 cm and a dose rate of 6 Gy min-1 with single doses of 1 Gy, 4 Gy, and 10 Gy. The effect on proliferation of SMC was analysed at day 10, 15, and 20. Secondly, total RNA of MC was isolated 1 h, 2 h, 3 h, and 4 h after irradiation and 5 μg of RNA was used in standard Northern blot analysis with ICAM-1 cDNA-probes. Results Both inhibitory and stimulatory effects were detected after irradiation of SMC with a dose of 1 Gy. At day 10 and 15 a significant antiproliferative effect was found; at day 20 after irradiation cell proliferation was significantly stimulated. Irradiation with 4 Gy and 10 Gy caused dose dependent inhibitory effects at day 10, 15, and 20. Expression of ICAM-1 in human MC was neihter inhibited nor stimulated by LDI. Conclusion Thus, the stimulatory effect of LDI on SMC

  3. Burden of upper gastrointestinal symptoms in patients receiving low-dose acetylsalicylic acid for cardiovascular risk management

    DEFF Research Database (Denmark)

    Bytzer, Peter; Pratt, Stephen; Elkin, Eric

    2013-01-01

    Continuous low-dose acetylsalicylic acid (aspirin; ASA) is a mainstay of cardiovascular (CV) risk management. It is well established, however, that troublesome upper gastrointestinal (GI) symptoms are commonly experienced among low-dose ASA users.......Continuous low-dose acetylsalicylic acid (aspirin; ASA) is a mainstay of cardiovascular (CV) risk management. It is well established, however, that troublesome upper gastrointestinal (GI) symptoms are commonly experienced among low-dose ASA users....

  4. The potential impact of low dose ionizing γ-radiation on immune response activity up-regulated by Ikaros in IM-9 B lymphocytes

    International Nuclear Information System (INIS)

    Kim Sung Jn; Jang, Seon A; Yang, Kwang Hee; Kim, Ji Young; Kim, Cha Soon; Nam, Seon Young; Jeong, Mee Seon; Jin, Young Woo

    2011-01-01

    The biological effects of low dose ionizing radiation (LDIR) remain insufficiently understood. We examined for the scientific evidence to show the biological effects of LDIR using radiation-sensitive immune cells. We found that Ikaros protein was responded to low dose-dependent effects of gamma radiation in IM-9 B lymphocytes. Ikaros encodes zinc finger transcription factors that is important regulators of a hematopoietic stem cells (HSCs) progression to the B lymphoid lineage development, differentiation and proliferation. In this study, we observed that cell proliferation was enhanced from 10% to 20% by LDIR (0.05 Gy) in IM-9 B lymphocytes. The Ikaros protein was phosphorylated in its serine/threonine (S/T) region and decreased its DNA binding activity in the cells exposed to LDIR. We found that Ikaros phosphorylation was up-regulated by CK2/AKT pathway and the residues of ser-304 and ser-306 in Ikaros was phosphorylated by LDIR. We also observed that Ikaros protein was localized from the nucleus to the cytoplasm after LDIR and bound with Autotaxin (ENPP2, ATX) protein, stimulating proliferation, migration and survival of immune cells. In addition, we found that the lysoPLD activity of ATX was dependent on Ikaros-ATX binding activity. These results indicate that the Ikaros is an important regulator of immune activation. Therefore, we suggest that low dose ionizing radiation can be considered as a beneficial effects, stimulating the activation of immune cells.

  5. Basal and Adrenocorticotropic Hormone Stimulated Plasma Cortisol Levels Among Egyptian Autistic Children: Relation to Disease Severity

    Directory of Open Access Journals (Sweden)

    Hewedi Doaa H

    2010-10-01

    Full Text Available Abstract Background Autism is a disorder of early childhood characterized by social impairment, communication abnormalities and stereotyped behaviors. The hypothalamic-pituitary-adrenocortical (HPA axis deserves special attention, since it is the basis for emotions and social interactions that are affected in autism. Aim To assess basal and stimulated plasma cortisol, and adrenocorticotropic hormone (ACTH levels in autistic children and their relationship to disease characteristics. Methods Fifty autistic children were studied in comparison to 50 healthy age-, sex- and pubertal stage- matched children. All subjects were subjected to clinical evaluation and measurement of plasma cortisol (basal and stimulated and ACTH. In addition, electroencephalography (EEG and intelligence quotient (IQ assessment were done for all autistic children. Results Sixteen% of autistic patients had high ACTH, 10% had low basal cortisol and 10% did not show adequate cortisol response to ACTH stimulation. Autistic patients had lower basal (p = 0.032 and stimulated cortisol (p = 0.04 and higher ACTH (p = 0.01 than controls. Childhood Autism Rating Scale (CARS score correlated positively with ACTH (r = 0.71, p = 0.02 and negatively with each of basal (r = -0.64, p = 0.04 and stimulated cortisol (r = -0.88, p Conclusions The observed hormonal changes may be due to a dysfunction in the HPA axis in autistic individuals. Further studies are warranted regarding the role of HPA axis dysfunction in the pathogenesis of autism.

  6. Changes in mean plasma ACTH reflect changes in amplitude and frequency of secretory pulses

    International Nuclear Information System (INIS)

    Carnes, M.; Lent, S.J.; Erisman, S.; Feyzi, J.

    1988-01-01

    ACTH is secreted in an episodic manner from the anterior pituitary. Unanesthetized rats with indwelling jugular and femoral venous cannulae were continuously bled and simultaneously infused with isotonic fluid by peristaltic pump. Two-minute blood samples were collected for up to five hours in 8 male rats. ACTH was measured by radioimmunoassay. The resulting time series were analyzed for significant secretory pulses with the PULSAR program. Elevations or declines in mean plasma ACTH levels were associated with significant changes in amplitude and frequency of secretory pulses

  7. Ectopic ACTH syndrome complicated by multiple opportunistic infections treated with percutaneous ablation of the adrenal glands.

    Science.gov (United States)

    Chan, Chrystal; Roberts, James Mark

    2017-11-14

    Ectopic adrenocorticotropic hormone (ACTH)-related Cushing's syndrome can lead to multiple complications including severe immunosuppression. If the ACTH-secreting tumour cannot be found, definitive treatment is surgical adrenalectomy, typically followed by glucocorticoid replacement. Here, we present a case of fulminant respiratory failure secondary to coinfection with Pneumocystis jirovecii and cytomegalovirus in a patient with ectopic ACTH-dependent Cushing's syndrome with occult primary. Due to significant deconditioning, she was unable to undergo definitive adrenalectomy and instead underwent percutaneous microwave ablation of the adrenal glands. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. Risk of Low Dose/Low Dose Rate Ionizing Radiation to Humans Symposium Annual Meeting of the Environmental Mutagen Society: Agenda and Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Veigl, Martina L. [Environmental Mutagen Society (EMS), Reston, VA (United States); Case Western Reserve Univ., Cleveland, OH (United States). Case Comprehensive Cancer Center; Morgan, William F. [Univ. of Maryland, College Park, MD (United States); Schwartz, Jeffrey L. [Univ. of Washington, Seattle, WA (United States)

    2009-11-11

    The low dose symposium thoughtfully addressed controversy of risk from low dose radiation exposure, hormesis and radon therapy. The stem cell symposium cogently considered the role of DNA damage and repair in hematopoietic stem cells underlying aging and malignancy and provocatively presented evidence that stem cells may have distinct morphologies and replicative properties, as well as special roles in cancer initiation. In the epigenetics symposium, studies illustrated the long range interaction of epigenetic mechanisms, the roles of CTCF and BORIS in region/specific regulation of epigenetic processes, the impact of DNA damage on epigenetic processes as well as links between epigenetic mechanisms and early nutrition and bystander effects. This report shows the agenda and abstracts for this symposium.

  9. Low-dose total skin electron beam therapy for cutaneous lymphoma : Minimal risk of acute toxicities.

    Science.gov (United States)

    Kroeger, Kai; Elsayad, Khaled; Moustakis, Christos; Haverkamp, Uwe; Eich, Hans Theodor

    2017-12-01

    Low-dose total skin electron beam therapy (TSEBT) is attracting increased interest for the effective palliative treatment of primary cutaneous T‑cell lymphoma (pCTCL). In this study, we compared toxicity profiles following various radiation doses. We reviewed the records of 60 patients who underwent TSEBT for pCTCL between 2000 and 2016 at the University Hospital of Munster. The treatment characteristics of the radiotherapy (RT) regimens and adverse events (AEs) were then analyzed and compared. In total, 67 courses of TSEBT were administered to 60 patients. Of these patients, 34 (51%) received a standard dose with a median surface dose of 30 Gy and 33 patients (49%) received a low dose with the median surface dose of 12 Gy (7 salvage low-dose TSEBT courses were administered to 5 patients). After a median follow-up of 15 months, the overall AE rate was 100%, including 38 patients (57%) with grade 2 and 7 (10%) with grade 3 AEs. Patients treated with low-dose TSEBT had significantly fewer grade 2 AEs than those with conventional dose regimens (33 vs. 79%, P dose regimen compared to those with the conventional dose regimens (6 vs. 15%, P = 0.78). Multiple/salvage low-dose TSEBT courses were not associated with an increased risk of acute AEs. Low-dose TSEBT regimens are associated with significantly fewer grade 2 acute toxicities compared with conventional doses of TSEBT. Repeated/Salvage low-dose TSEBT, however, appears to be tolerable and can even be applied safely in patients with cutaneous relapses.

  10. Usefulness of low-dose CT in the detection of pulmonary metastasis of gestational trophoblastic tumours

    International Nuclear Information System (INIS)

    Xu, X.J.; Lou, F.L.; Zhang, M.M.; Pan, Z.M.; Zhang, L.

    2007-01-01

    Aim: To determine whether a low-dose spiral chest computed tomography (CT) examination could replace standard-dose chest CT in detecting pulmonary metastases in patients with gestational trophoblastic tumour (GTT). Materials and methods: In a prospective investigation, 67 chest CT examinations of 39 GTT patients were undertaken. All the patients underwent CT examinations using standard-dose (150 mAs, pitch 1, standard reconstruction algorithm) and low-dose (40 mAs, pitch 2, bone reconstruction algorithm) protocols. Two radiologists interpreted images independently. A metastasis was defined as a nodule within lung parenchyma that could not be attributed to a pulmonary vessel. The number of metastases detected with each protocol was recorded. The size of each lesion was measured and categorized as <5, 5-9.9, and ≥10 mm. Wilcoxon's signed rank test was used to assess the difference between the numbers of lesion detected by the two protocols. Results: The CT dose index (CTDI) for the standard-dose and low-dose CT protocols was 10.4 mGy and 1.4 mGy, respectively. One thousand, six hundred, and eighty-two metastases were detected by standard-dose CT, and 1460 lesions by the low-dose protocol. The numbers detected by low-dose CT were significantly less than those detected by standard-dose CT (Z = -3.776, p < 0.001), especially for nodules smaller than 5 mm (Z = -4.167, p < 0.001). However, the disease staging and risk score of the patients were not affected by use of the low-dose protocol. Conclusion: Low-dose chest CT can be used as a staging and follow-up procedure for patients with GTT

  11. Incidental renal tumours on low-dose CT lung cancer screening exams.

    Science.gov (United States)

    Pinsky, Paul F; Dunn, Barbara; Gierada, David; Nath, P Hrudaya; Munden, Reginald; Berland, Lincoln; Kramer, Barnett S

    2017-06-01

    Introduction Renal cancer incidence has increased markedly in the United States in recent decades, largely due to incidentally detected tumours from computed tomography imaging. Here, we analyze the potential for low-dose computed tomography lung cancer screening to detect renal cancer. Methods The National Lung Screening Trial randomized subjects to three annual screens with either low-dose computed tomography or chest X-ray. Eligibility criteria included 30 + pack-years, current smoking or quit within 15 years, and age 55-74. Subjects were followed for seven years. Low-dose computed tomography screening forms collected information on lung cancer and non-lung cancer abnormalities, including abnormalities below the diaphragm. A reader study was performed on a sample of National Lung Screening Trial low-dose computed tomography images assessing presence of abnormalities below the diaphragms and abnormalities suspicious for renal cancer. Results There were 26,722 and 26,732 subjects enrolled in the low-dose computed tomography and chest X-ray arms, respectively, and there were 104 and 85 renal cancer cases diagnosed, respectively (relative risk = 1.22, 95% CI: 0.9-1.5). From 75,126 low-dose computed tomography screens, there were 46 renal cancer diagnoses within one year. Abnormalities below the diaphragm rates were 39.1% in screens with renal cancer versus 4.1% in screens without (P cancer cases versus 13% of non-cases had abnormalities below the diaphragms; 55% of cases and 0.8% of non-cases had a finding suspicious for renal cancer (P cancers. The benefits to harms tradeoff of incidental detection of renal tumours on low-dose computed tomography is unknown.

  12. Cancer and low dose responses in vivo: implications for radiation protection

    International Nuclear Information System (INIS)

    Mitchel, R.E.J.

    2006-01-01

    Full text: Radiation protection practices assume that cancer risk is linearly proportional to total dose, without a threshold, both for people with normal cancer risk and for people who may be genetically cancer prone. Mice heterozygous for the Tp 53 gene are cancer prone, and their increased risk from high doses was not different from Tp 53 normal mice. However, in either Tp 53 normal or heterozygous mice, a single low dose of low LET radiation given at low dose rate protected against both spontaneous and radiation-induced cancer by increasing tumor latency. Increased tumor latency without a cancer frequency change implies that low doses in vivo primarily slow the process of genomic instability, consistent with the elevated capacity for correct DSB rejoining seen in low dose exposed cells. The in vivo animal data indicates that, for low doses and low dose rates in both normal and cancer prone adult mice, risk does not increase linearly with dose, and dose thresholds for increased risk exist. Below those dose thresholds (which are influenced by Tp 53 function) overall risk is reduced below that of unexposed control mice, indicating that Dose Rate Effectiveness Factors (DREF) may approach infinity, rather than the current assumption of 2. However, as dose decreases, different tissues appear to have different thresholds at which detriment turns to protection, indicating that individual tissue weighting factors (Wt) are also not constant, but vary from positive values to zero with decreasing dose. Measurements of Relative Biological Effect between high and low LET radiations are used to establish radiation weighting factors (Wr) used in radiation protection, and these are also assumed to be constant with dose. However, since the risk from an exposure to low LET radiation is not constant with dose, it would seem unlikely that radiation-weighting factors for high LET radiation are actually constant at low dose and dose rate

  13. Studies of health effects of low dose radiation and its application to medicare

    International Nuclear Information System (INIS)

    Yamaoka, Kiyonori; Ishida, Kenji; Iwasaki, Toshiyasu; Koana, Takao; Magae, Junji; Watanabe, Masami; Sakamoto, Kiyohiko

    2008-01-01

    The articles contain following 7 topics of low dose radiation effects. Studies of Health Effects of Low dose Radiation and Its Application to Medicare'', describes the indication of Rn therapy and investigations of its usefulness mechanism mainly in Misasa Spa, Okayama Pref. ''Challenges for the Paradigm Shift (CRIEPI Studies)'', introduces studies against the paradigm that radiation dose is linearly and proportionally hazardous. ''Studies of High Background Radiation Area (CRIEPI Studies)'', describes global HBRA studies on chromosome affection and effect of smoking in HBRA. ''Is the Radiation Effect on Man Proportional to Dose? (CRIEPI Studies)'', describes studies of immature sperm irradiated at low dose against Linear-Non-threshold Theory (LNT) hypothesis. ''Induction of Radiation Resistance by Low Dose Radiation and Assessment of Its Effect in Models of Human Diseases (CRIEPI Studies)'', explains the adoptive response in radiation effect, suppression of carcinogenesis and immune regulation by previous low dose radiation in the mouse, and improvement of diabetes in the db/db mouse. ''Modulation of Biological Effects of Low Dose Radiation: Adoptive Response, Bystander Effect, Genetic Instability and Radiation Hormesis'', summarizes findings of each item. ''Cancer Treatment with Low dose Radiation to the Whole Body'', describes basic studies in the mouse tumor in relation to suppression of carcinogenesis and metastasis, immune activation and treatment, and successful clinical studies in patients with ovary, colon cancers and malignant lymphoma where survival has been significantly improved: a base of recent European Organization for Research and Treatment of Cancer (EORTC) clinical trials. The mechanism is essentially based on immune activation of patients to cure the disease. (R.T.)

  14. Estimates of Health Detriments and Tissue Weighting Factors for Hong Kong Populations from Low Dose, Low Dose Rate and Low LET Ionising Radiation Exposure

    International Nuclear Information System (INIS)

    Lee, S.K.

    1998-01-01

    The total health detriments and the tissue weighting factors for the Hong Kong populations from low dose, low dose rate and low LET ionising radiation exposure are obtained according to the methodology recommended in ICRP Publication 60. The probabilities of fatal cancers for the general (ages 0-90) and working (ages 20-64) populations due to lifetime exposure at low dose and low dose rate are 4.9 x 10 -2 Sv -1 and 3.6 x 10 -2 Sv -1 respectively, comparing with the ICRP 60 estimates of 5.0 x 10 -2 Sv -1 and 4.0 x 10 -2 Sv -1 . The corresponding total health detriments for the general and working populations are 6.9 x 10 -2 Sv -1 and 4.9 x 10 -2 Sv -1 respectively comparing with the ICRP 60 estimates of 7.3 x 10 -2 Sv -1 and 5.6 x 10 -2 Sv -1 . Tissue weighting factors for the general population are 0.01 (bone surface and skin), 0.02 (liver, oesophagus and thyroid), 0.04 (bladder and breast), 0.08 (remainder), 0.10 (stomach), 0.11 (bone marrow), 0.15 (colon), 0.19 (lung) and 0.21 (gonads) and for the working population are 0.01 (bone surface and skin), 0.03 (liver, oesophagus and thyroid), 0.04 (breast), 0.06 (remainder), 0.07 (bladder), 0.08 (colon), 0.14 (bone marrow and stomach), 0.16 (lung) and 0.20 (gonads). (author)

  15. Relative implications of protective responses versus damage induction at low dose and low-dose-rate exposures, using the microdose approach

    Energy Technology Data Exchange (ETDEWEB)

    Feinendegen, L.E

    2003-07-01

    In reviewing tissue effects of low-dose radiation (1) absorbed dose to tissue is replaced by the sum of energy deposited with track events in cell-equivalent tissue micromasses, i.e. with microdose hits, in the number of exposed micromasses and (2) induced cell damage and adaptive protection are related to microdose hits in exposed micromasses for a given radiation quality. DNA damage increases with the number of microdose hits. They also can induce adaptive protection, mainly against endogenous DNA damage. This protection involves cellular defenses, DNA repair and damage removal. With increasing numbers of low linear energy transfer (LET) microdose hits in exposed micromasses, adaptive protection first tends to outweigh damage and then (above 200 mGy) fails and largely disappears. These experimental data predict that cancer risk coefficients derived by epidemiology at high-dose irradiation decline at low doses and dose rates when adaptive protection outdoes DNA damage. The dose-risk function should include both linear and non-linear terms at low doses. (author)

  16. Relative implications of protective responses versus damage induction at low dose and low-dose-rate exposures, using the microdose approach

    International Nuclear Information System (INIS)

    Feinendegen, L.E.

    2003-01-01

    In reviewing tissue effects of low-dose radiation (1) absorbed dose to tissue is replaced by the sum of energy deposited with track events in cell-equivalent tissue micromasses, i.e. with microdose hits, in the number of exposed micromasses and (2) induced cell damage and adaptive protection are related to microdose hits in exposed micromasses for a given radiation quality. DNA damage increases with the number of microdose hits. They also can induce adaptive protection, mainly against endogenous DNA damage. This protection involves cellular defenses, DNA repair and damage removal. With increasing numbers of low linear energy transfer (LET) microdose hits in exposed micromasses, adaptive protection first tends to outweigh damage and then (above 200 mGy) fails and largely disappears. These experimental data predict that cancer risk coefficients derived by epidemiology at high-dose irradiation decline at low doses and dose rates when adaptive protection outdoes DNA damage. The dose-risk function should include both linear and non-linear terms at low doses. (author)

  17. Comparison of radiosensitization by 41 deg. C hyperthermia during low dose rate irradiation and during pulsed simulated low dose rate irradiation in human glioma cells

    International Nuclear Information System (INIS)

    Raaphorst, G. Peter; Ng, Cheng E.; Shahine, Bilal

    1999-01-01

    Purpose: Long duration mild hyperthermia has been shown to be an effective radiosensitizer when given concurrently with low dose rate irradiation. Pulsed simulated low dose rate (PSLDR) is now being used clinically, and we have set out to determine whether concurrent mild hyperthermia can be an effective radiosensitizer for the PSLDR protocol. Materials and Methods: Human glioma cells (U-87MG) were grown to plateau phase and treated in plateau phase in order to minimize cell cycle redistribution during protracted treatments. Low dose rate (LDR) irradiation and 41 deg. C hyperthermia were delivered by having a radium irradiator inside a temperature-controlled incubator. PSLDR was given using a 150 kVp X-ray unit and maintaining the cells at 41 deg. C between irradiations. The duration of irradiation and concurrent heating depended on total dose and extended up to 48 h. Results: When 41 deg. C hyperthermia was given currently with LDR or PSLDR, the thermal enhancement ratios (TER) were about the same if the average dose rate for PSLDR was the same as for LDR. At higher average dose rates for PSLDR the TERs became less. Conclusions: Our data show that concurrent mild hyperthermia can be an effective sensitizer for PSLDR. This sensitization can be as effective as for LDR if the same average dose rate is used and the TER increases with decreasing dose rate. Thus mild hyperthermia combined with PSLDR may be an effective clinical protocol

  18. Expression of Cellular Isoform of Prion Protein on the Surface of Peripheral Blood Lymphocytes Among Women Exposed to Low Doses of Ionizing Radiation

    International Nuclear Information System (INIS)

    Klucinski, P.; Martirosian, G.; Mazur, B.; Kaufman, J.; Hrycek, A.; Masluch, E.; Cieslik, P.

    2007-01-01

    Ionizing radiation affect the expression of adhesive and co-stimulation molecules in lymphocytes. The objective of this study was to determinate the effect of low doses of ionizing radiation on the expression of prion protein PrPc on the surface peripheral blood lymphocytes in the women operating X-ray equipment. In female workers and persons of the control group the PrPc expression on CD3 (T-lymphocytes), Cd4 (T-helper), CD8 (T-cytotoxic) and CD19 (B- lymphocytes), were tested. We conclude that in women operating X-ray equipment the relationship between low doses of ionizing radiation and expression of PrPc on lymphocytes does exist concerning CD3, CD4 and CD lymphocytes. (author)

  19. Study of the anti-inflammatory effects of low-dose radiation. The contribution of biphasic regulation of the antioxidative system in endothelial cells

    International Nuclear Information System (INIS)

    Large, Martin; Hehlgans, Stephanie; Reichert, Sebastian; Roedel, Claus; Roedel, Franz; Gaipl, Udo S.; Fournier, Claudia; Weiss, Christian

    2015-01-01

    We examined (a) the expression of the antioxidative factor glutathione peroxidase (GPx) and the transcription factor nuclear factor E2-related factor 2 (Nrf2) following low-dose X-irradiation in endothelial cells (ECs) and (b) the impact of reactive oxygen species (ROS) and Nrf2 on functional properties of ECs to gain further knowledge about the anti-inflammatory mode of action of low doses of ionizing radiation. EA.hy926 ECs and primary human dermal microvascular ECs (HMVEC) were stimulated by tumor necrosis factor-α (TNF-α, 20 ng/ml) 4 h before irradiation with single doses ranging from 0.3 to 3 Gy. The expression and activity of GPx and Nrf2 were analyzed by flow cytometry, colorimetric assays, and real-time PCR. The impact of ROS and Nrf2 on peripheral blood mononuclear cell (PBMC) adhesion was assayed in the presence of the ROS scavenger N-acetyl-L-cysteine (NAC) and Nrf2 activator AI-1. Following a low-dose exposure, we observed in EA.hy926 EC and HMVECs a discontinuous expression and enzymatic activity of GPx concomitant with a lowered expression and DNA binding activity of Nrf2 that was most pronounced at a dose of 0.5 Gy. Scavenging of ROS by NAC and activation of Nrf2 by AI-1 significantly diminished a lowered adhesion of PBMC to EC at a dose of 0.5 Gy. Low-dose irradiation resulted in a nonlinear expression and activity of major compounds of the antioxidative system that might contribute to anti-inflammatory effects in stimulated ECs. (orig.) [de

  20. Low-dose CT image reconstruction using gain intervention-based dictionary learning

    Science.gov (United States)

    Pathak, Yadunath; Arya, K. V.; Tiwari, Shailendra

    2018-05-01

    Computed tomography (CT) approach is extensively utilized in clinical diagnoses. However, X-ray residue in human body may introduce somatic damage such as cancer. Owing to radiation risk, research has focused on the radiation exposure distributed to patients through CT investigations. Therefore, low-dose CT has become a significant research area. Many researchers have proposed different low-dose CT reconstruction techniques. But, these techniques suffer from various issues such as over smoothing, artifacts, noise, etc. Therefore, in this paper, we have proposed a novel integrated low-dose CT reconstruction technique. The proposed technique utilizes global dictionary-based statistical iterative reconstruction (GDSIR) and adaptive dictionary-based statistical iterative reconstruction (ADSIR)-based reconstruction techniques. In case the dictionary (D) is predetermined, then GDSIR can be used and if D is adaptively defined then ADSIR is appropriate choice. The gain intervention-based filter is also used as a post-processing technique for removing the artifacts from low-dose CT reconstructed images. Experiments have been done by considering the proposed and other low-dose CT reconstruction techniques on well-known benchmark CT images. Extensive experiments have shown that the proposed technique outperforms the available approaches.

  1. Research on low radiation doses - A better understanding of low doses

    International Nuclear Information System (INIS)

    2016-01-01

    Radiation doses below 100 mSv are called low doses. Epidemiological research on the health hazards of low doses are difficult to do because numerous pathologies, particularly cancer, appear lifelong for genetical or environmental causes without any link with irradiation and it is very difficult to identify the real cause of a cancer. Another concern is that the impact on human health is weak and are observed only after a long period after irradiation. These features make epidemiological studies cumbersome to implement since they require vast cohorts and a very long-term follow-up. The extrapolation of the effects of higher doses to the domain of low doses does not meet reality and it is why the European Union takes part into the financing of such research. In order to gain efficiency, scientists work together through various European networks among them: HLEG (High Level Expert Group On European Low Dose Risk Research) or MELODI (Multidisciplinary European Low Dose Initiative). Several programs are underway or have been recently launched: -) the impact of Cesium contamination on children's health (Epice program), -) the study of the impact of medical imaging on children, -) the study of the health of children living near nuclear facilities, -) the relationship between radon and lung cancer, -) the effect of occupational low radiation doses, -) the effect of uranium dissolved in water on living organisms (Envirhom program). (A.C.)

  2. Bibliometrics analysis of the PubMed literatures on low-dose CT

    International Nuclear Information System (INIS)

    Wang Qian; Xia Guanghui; Ma Xiaohong; Zhao Xinming

    2012-01-01

    Objective: The purposes of this study were to evaluate the developmental rule and feature in low-dose CT examinations and to provide useful references for study in the future. Materials and Methods: The journal articles on PubMed from 2002 to 2011 were processed by Thomson Data Analyzer and five aspects were analysed: time, authors, institutions, journals, countries, and keywords. Results: The number of journal articles in low-dose CT examinations were 6 433, 3165 were from US (49.2%), 112 from China (1.4%); 3664 authors (80.42%) published only one article, the famous authors published more than 4 articles; there were 9 core journals in this area. In the last decade, the number and quality of the journal articles in low -dose CT have been dramatically increased. Conclusion: The interest on the low -dose CT examination has been steadily increasing, and world famous research teams have been established. The research in low-dose CT is a multi-discipline involving medicine, medical physics, and mathematics. Cooperation between multiple scientific domains is needed for the future studies. (authors)

  3. What can be learned from epidemiologic studies of persons exposed to low doses of radiation?

    International Nuclear Information System (INIS)

    Gilbert, E.S.

    1993-04-01

    The main objective of radiation risk assessment is to determine the risk of various adverse health effects associated with exposure to low doses and low dose rates. Extrapolation of risks from studies of persons exposed at high doses (generally exceeding 1 Sv) and dose rates has been the primary approach used to achieve this objective. The study of Japanese atomic bomb survivors in Hiroshima and Nagasaki has played an especially important role in risk assessment efforts. A direct assessment of the dose-response function based on studies of persons exposed at low doses and dose rates is obviously desirable. This paper focuses on the potential of both current and future nuclear workers studies for investigating the dose-response functions at low doses, and also discusses analyses making use of the low dose portion of the atomic bomb survivor data. Difficulties in using these data are the statistical imprecision of estimated dose-response parameters, and potential bias resulting from confounding factors and from uncertainties in dose estimates

  4. Dose rate effect on low-dose hyper-radiosensitivity with cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Geon-Min; Kim, Eun-Hee [Seoul National University, Seoul (Korea, Republic of)

    2016-10-15

    Low-dose hyper-radiosensitivity (HRS) is the phenomenon that mammalian cells exhibit higher sensitivity to radiation at low doses (< 0.5 Gy) than expected by the linear-quadratic model. At doses above 0.5Gy, the cellular response is recovered to the level expected by the linear-quadratic model. This transition is called the increased radio-resistance (IRR). HRS was first verified using Chinese hamster V79 cells in vitro by Marples and has been confirmed in studies with other cell lines including human normal and tumor cells. HRS is known to be induced by inactivation of ataxia telangiectasia-mutated (ATM), which plays a key role in repairing DNA damages. Considering the connection between ATM and HRS, one can infer that dose rate may affect cellular response regarding HRS at low doses. In this study, we quantitated the effect of dose rate on HRS by clonogenic assay with normal and tumor cells. The HRS of cells at low dose exposures is a phenomenon already known. In this study, we observed HRS of rat normal diencephalon cells and rat gliosarcoma cells at doses below 1 Gy. In addition, we found that dose rate mattered. HRS occurred at low doses, but only when total dose was delivered at a rate below certain level.

  5. Low dose gamma irradiation enhances defined signaling components of intercellular reactive oxygen-mediated apoptosis induction

    International Nuclear Information System (INIS)

    Bauer, G

    2011-01-01

    Transformed cells are selectively removed by intercellular ROS-mediated induction of apoptosis. Signaling is based on the HOCl and the NO/peroxynitrite pathway (major pathways) and the nitryl chloride and the metal-catalyzed Haber-Weiss pathway (minor pathways). During tumor progression, resistance against intercellular induction of apoptosis is acquired through expression of membrane-associated catalase. Low dose radiation of nontransformed cells has been shown to enhance intercellular induction of apoptosis. The present study was performed to define the signaling components which are modulated by low dose gamma irradiation. Low dose radiation induced the release of peroxidase from nontransformed, transformed and tumor cells. Extracellular superoxide anion generation was strongly enhanced in the case of transformed cells and tumor cells, but not in nontransformed cells. Enhancement of peroxidase release and superoxide anion generation either increased intercellular induction of apoptosis of transformed cells, or caused a partial protection under specific signaling conditions. In tumor cells, low dose radiation enhanced the production of major signaling components, but this had no effect on apoptosis induction, due to the strong resistance mechanism of tumor cells. Our data specify the nature of low dose radiation-induced effects on specific signaling components of intercellular induction of apoptosis at defined stages of multistep carcinogenesis.

  6. The short term effects of Low-dose-rate Radiation on EL4 Lymphoma Cell

    International Nuclear Information System (INIS)

    Bong, Jin Jong; Kang, Yu Mi; Shin, Suk Chull; Choi, Moo Hyun; Choi, Seung Jin; Kim, Hee Sun; Lee, Kyung Mi

    2012-01-01

    To determine the biological effects of low-dose-rate radiation ( 137 Cs, 2.95 mGy/h) on EL4 lymphoma cells during 24 h, we investigated the expression of genes related to apoptosis, cell cycle arrest, DNA repair, iron transport, and ribonucleotide reductase. EL4 cells were continuously exposed to low-dose-rate radiation (total dose: 70.8 mGy) for 24 h. We analyzed cell proliferation and apoptosis by trypan blue exclusion and flow cytometry, gene expression by real-time PCR, and protein levels with the apoptosis ELISA kit. Apoptosis increased in the Low-dose-rate irradiated cells, but cell number did not differ between non- (Non-IR) and Low-dose-rate irradiated (LDR-IR) cells. In concordance with apoptotic rate, the transcriptional activity of ATM, p53, p21, and Parp was upregulated in the LDR-IR cells. Similarly, Phospho-p53 (Ser15), cleaved caspase 3 (Asp175), and cleaved Parp (Asp214) expression was upregulated in the LDR-IR cells. No difference was observed in the mRNA expression of DNA repair-related genes (Msh2, Msh3, Wrn, Lig4, Neil3, ERCC8, and ERCC6) between Non-IR and LDR-IR cells. Interestingly, the mRNA of Trfc was upregulated in the LDR-IR cells. Therefore, we suggest that short-term Low-dose-rate radiation activates apoptosis in EL4 lymphoma cells.

  7. The short term effects of Low-dose-rate Radiation on EL4 Lymphoma Cell

    Energy Technology Data Exchange (ETDEWEB)

    Bong, Jin Jong; Kang, Yu Mi; Shin, Suk Chull; Choi, Moo Hyun; Choi, Seung Jin; Kim, Hee Sun [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd, Seoul (Korea, Republic of); Lee, Kyung Mi [Global Research Lab, BAERI Institute, Dept. of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of)

    2012-06-15

    To determine the biological effects of low-dose-rate radiation ({sup 137}Cs, 2.95 mGy/h) on EL4 lymphoma cells during 24 h, we investigated the expression of genes related to apoptosis, cell cycle arrest, DNA repair, iron transport, and ribonucleotide reductase. EL4 cells were continuously exposed to low-dose-rate radiation (total dose: 70.8 mGy) for 24 h. We analyzed cell proliferation and apoptosis by trypan blue exclusion and flow cytometry, gene expression by real-time PCR, and protein levels with the apoptosis ELISA kit. Apoptosis increased in the Low-dose-rate irradiated cells, but cell number did not differ between non- (Non-IR) and Low-dose-rate irradiated (LDR-IR) cells. In concordance with apoptotic rate, the transcriptional activity of ATM, p53, p21, and Parp was upregulated in the LDR-IR cells. Similarly, Phospho-p53 (Ser15), cleaved caspase 3 (Asp175), and cleaved Parp (Asp214) expression was upregulated in the LDR-IR cells. No difference was observed in the mRNA expression of DNA repair-related genes (Msh2, Msh3, Wrn, Lig4, Neil3, ERCC8, and ERCC6) between Non-IR and LDR-IR cells. Interestingly, the mRNA of Trfc was upregulated in the LDR-IR cells. Therefore, we suggest that short-term Low-dose-rate radiation activates apoptosis in EL4 lymphoma cells.

  8. [Uncommon neonatal case of hypoglycemia: ACTH resistance syndrome].

    Science.gov (United States)

    Delmas, O; Marrec, C; Caietta, E; Simonin, G; Morel, Y; Girard, N; Roucher, F; Sarles, J; Chabrol, B; Reynaud, R

    2014-12-01

    Monitoring of blood glucose is usually reported to reduce the risk of hypoglycemia in term newborns with high risk factors and for prematurity in neonatal intensive care unit patients. Differential diagnosis has rarely been discussed. In the eutrophic term newborn, hypoglycemia remains rare and an etiological diagnosis must be made. Intensive management of neonatal hypoglycemia is required to prevent neurodevelopmental defects. Without evident cause or if hypoglycemia persists, a systematic review of possible causes should be made. We report isolated glucocorticoid deficiency diagnosed in an infant at 10 months of age. This boy had neonatal hypoglycemia and mild jaundice that had not been investigated. During his first 9 months of life, he presented frequent infections. At 10 months of age, febrile seizures occurred associated with shock, hypoglycemia, hyponatremia, mild hyperpigmentation, and coma. He was diagnosed with hypocortisolemia and elevated ACTH levels. Brain injury was revealed by MRI after resuscitation, with hypoxic-ischemic and hypoglycemic encephalopathy. The molecular studies demonstrated the presence of p.Asp107Asn and previously unreported frameshift p.Pro281GlnfsX9 MC2R gene mutations. A substitutive hormone therapy was provided and during a follow-up of 12 months no adrenal crisis was noted. We report an unusual case of familial glucocorticoid deficiency with severe neurological injury. This case demonstrates the importance of an appropriate etiological diagnosis in neonatal hypoglycemia. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  9. Low-dose aspirin or other nonsteroidal anti-inflammatory drug use and prostate cancer risk

    DEFF Research Database (Denmark)

    Skriver, Charlotte; Dehlendorff, Christian; Borre, Michael

    2016-01-01

    PURPOSE: Increasing evidence suggests that aspirin use may protect against prostate cancer. In a nationwide case-control study, using Danish high-quality registry data, we evaluated the association between the use of low-dose aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs......) and the risk of prostate cancer. METHODS: We identified 35,600 patients (cases) with histologically verified prostate cancer during 2000-2012. Cases were matched to 177,992 population controls on age and residence by risk-set sampling. Aspirin and nonaspirin NSAID exposure was defined by type, estimated dose......, duration, and consistency of use. We used conditional logistic regression to estimate odds ratios (ORs), with 95 % confidence intervals (CIs), for prostate cancer associated with low-dose aspirin (75-150 mg) or nonaspirin NSAID use, adjusted for potential confounders. RESULTS: Use of low-dose aspirin...

  10. Radiation protection and environment day the low doses in everyday life

    International Nuclear Information System (INIS)

    2007-01-01

    The consequences of low doses exposures are difficult to explore and the studies give often place to controversies. According to the are, differences exist in the methodological approaches. It results from it a confusion on the acceptable levels of exposure, even on the definition of low dose. This day organised by the sections 'non ionizing and research and health of the French society of radiation protection (S.F.R.P.), will be a meeting between professionals of different disciplines, to compare the approaches used for the ionizing and non ionizing radiations as well as the chemical and microbiological agents. It will allow to share the knowledge and the abilities and to progress on methodologies adapted to the evaluation and the management of risks in relation with low doses. (N.C.)

  11. Effects of low dose radiation on antioxidant enzymes after radiotherapy of tumor-bearing mice

    International Nuclear Information System (INIS)

    Li Jin; Gao Gang; Wang Qin; Tang Weisheng; Liu Xiaoqiu; Wang Zhiquan

    2005-01-01

    Objective: To search for effects of low dose radiation on the activities of antioxidant enzymes after radiotherapy of tumor-bearing mice. Methods: Superoxide dismutase (SOD), glutathione-S-transferase (GST) and catalase (CAT) were all determined by chemical colorimetry. Results: Low dose radiation increase the activities of antioxidant enzymes superoxide dismutase (SOD), glutathione-S-transferase (GST) and catalase (CAT) in serum of tumor-bearing mice more markedly than those in the unirradiated controls. The activities of antioxidant enzymes SOD, GST, CAT in serum of tumor-bearing mice (d 5 , d 3 ) irradiated with 5cGy 6h before 2.0 Gy radiation are obviously higher than those of the group (c 3 , c 5 ) given with radiotherapy only. Conclusion: The increase in the activities of antioxidant enzymes in serum of tumor-bearing mice triggered by low dose radiation could partly contribute to the protective mechanism. (authors)

  12. Chromosome aberrations induced by low doses of X-rays in human lymphocytes in vitro

    International Nuclear Information System (INIS)

    Ziemba-Zoltowska, B.; Bocian, E.; Rosiek, O.; Sablinski, J.

    1980-01-01

    Curves derived from the dose-response data for the yield of aberrations in human lymphocytes can be represented by a quadratic equation at all but low dose ranges. A calibration curve has therefore been determined at a low dose range of X-radiation (11.5 to 57.5 rad). The frequencies of dicentrics plus centric rings, and of acentrics were better fitted by linear dose-response models than quadratic. The linearity of the relationship indicated that asymmetrical chromosome exchanges at low doses of radiation are produced predominantly by a single track mechanism. A dose-response curve for dicentrics plus centric rings (5 to 60 rad) has also been derived by pooling published data with the results of this study. This calibration curve is relevant to cytogenetic dosimetry in radiological protection. (UK)

  13. Low doses of ionizing radiation to mammalian cells may rather control than cause DNA damage

    International Nuclear Information System (INIS)

    Feinendegen, L.E.; Sondhaus, C.A.; Altman, K.I.

    1998-01-01

    This report examines the origin of tissue effects that may follow from different cellular responses to low-dose irradiation, using published data. Two principal categories of cellular responses are considered. One response category relates to the probability of radiation-induced DNA damage. The other category consists of low-dose induced metabolic changes that induce mechanisms of DNA damage mitigation, which do not operate at high levels of exposure. Modeled in this way, tissue is treated as a complex adaptive system. The interaction of the various cellular responses results in a net tissue dose-effect relation that is likely to deviate from linearity in the low-dose region. This suggests that the LNT hypothesis should be reexamined. This paper aims at demonstrating tissue effects as an expression of cellular responses, both damaging and defensive, in relation to the energy deposited in cell mass, by use of microdosimetric concepts

  14. [Efficacy of low-dose tadalafil on ED assessed by Self-Esteem and Relationship Questionnaire].

    Science.gov (United States)

    Li, Jing-Ping; Li, Fei; Guo, Wen-Bin; Zhou, Qi-Zhao; Liu, Cun-Dong; Mao, Xiang-Ming; Tan, Wan-Long; Zheng, Shao-Bin

    2010-12-01

    To explore the effects of low-dose oral tadalafil on self-esteem, confidence and sexual relationship in ED patients. We treated 17 ED patients with oral tadalafil at the low dose of 5 mg once daily for 12 weeks, and used the paired t test to compare their scores on The Self-Esteem and Relationship Questionnaire (SEAR) and IIEF-5 and the results of nocturnal penile tumescence (NPT) obtained by nocturnal electrobioimpedance volumetric assessment (NEVA) before and after the medication. The scores on SEAR and IIEF-5 were significantly increased (P P Low-dose oral tadalafil once daily can significantly improve the self-esteem, confidence, sexual relationship satisfaction and NPT of ED patients.

  15. Biological effects of low-dose ionizing radiation exposure; Biologische Wirkungen niedriger Dosen ionisierender Strahlung

    Energy Technology Data Exchange (ETDEWEB)

    Reinoehl-Kompa, Sabine; Baldauf, Daniela; Heller, Horst (comps.)

    2009-07-01

    The report on the meeting of the Strahlenschutzkommission 2007 concerning biological effects of low-dose ionizing radiation exposure includes the following contributions: Adaptive response. The importance of DNA damage mechanisms for the biological efficiency of low-energy photons. Radiation effects in mammography: the relative biological radiation effects of low-energy photons. Radiation-induced cataracts. Carcinomas following prenatal radiation exposure. Intercellular apoptosis induction and low-dose irradiation: possible consequences for the oncogenesis control. Mechanistic models for the carcinogenesis with radiation-induced cell inactivation: application to all solid tumors in the Japanese atomic bomb survivors. Microarrays at low radiation doses. Mouse models for the analysis of biological effects of low-dose ionizing radiation. The bystander effect: observations, mechanisms and implications. Lung carcinoma risk of Majak workers - modeling of carcinogenesis and the bystander effect. Microbeam studies in radiation biology - an overview. Carcinogenesis models with radiation-induced genomic instability. Application to two epidemiological cohorts.

  16. Improving abdomen tumor low-dose CT images using a fast dictionary learning based processing

    International Nuclear Information System (INIS)

    Chen Yang; Shi Luyao; Shu Huazhong; Luo Limin; Coatrieux, Jean-Louis; Yin Xindao; Toumoulin, Christine

    2013-01-01

    In abdomen computed tomography (CT), repeated radiation exposures are often inevitable for cancer patients who receive surgery or radiotherapy guided by CT images. Low-dose scans should thus be considered in order to avoid the harm of accumulative x-ray radiation. This work is aimed at improving abdomen tumor CT images from low-dose scans by using a fast dictionary learning (DL) based processing. Stemming from sparse representation theory, the proposed patch-based DL approach allows effective suppression of both mottled noise and streak artifacts. The experiments carried out on clinical data show that the proposed method brings encouraging improvements in abdomen low-dose CT images with tumors. (paper)

  17. Efficacy of Low-Dose Protocol in Follow-Up of Lymphoproliferative Disorders - Preliminary Results

    International Nuclear Information System (INIS)

    Popic-Ramac, J.; Brnic, Z.; Klasic, B.; Hebrang, A.; Knezevic, Z.

    2011-01-01

    Most medically-related radiation is caused by diagnostic examinations, in particular by computed tomography (CT). The purpose of this research is to reduce radiation doses faced by the population frequently exposed to such procedures-those with lymphoproliferative disorders. The research was conducted comparing radiation-exposition doses received by the radiosensitive organs (thyroid, lens, breast and gonad) using the standard thoracic CT protocol with the radiation received using the low-dose protocol, while maintaining display quality. The standard-dose thoracic protocol implies 120 kV and 150 mAs. The low-dose protocol was conducted on the same device using 120 kV and 30 mAs. We confirmed the hypothesis that the use of the low-dose thoracic CT protocol leads to a reduction in radiation dose without compromising display quality. It is further expected that a reduction in doses will reduce the risk of radiation-related mutations. (author)

  18. Long term effects of low doses of ionising radiation: facts and fallacies

    International Nuclear Information System (INIS)

    Iyer, G.K.

    1993-01-01

    Health effects of low doses of ionising radiation have been a public concern. The public perception of these low effects is that it causes cancer and genetic effects. Enormous amount of work regarding this cancer has been done all over the world, on occupational workers exposed to low doses of ionising radiation. These studies do not show any adverse effect on them. Epidemiological studies done on members of public staying near nuclear facilities also have shown that there is no health risk involved in staying near these facilities. Genetic effects have also shown negative results. These two aspects of health effects of low dose of radiation are discussed in detail. (author). 5 refs., 1 tab

  19. Low doses of ionizing radiation to mammalian cells may rather control than cause DNA damage

    Energy Technology Data Exchange (ETDEWEB)

    Feinendegen, L.E. [Brookhaven National Lab., Upton, NY (United States). Medical Dept.; Bond, V.P. [Washington State Univ., Richland, WA (United States); Sondhaus, C.A. [Univ. of Arizona, Tucson, AZ (United States). Dept. of Radiology and Radiation Control Office; Altman, K.I. [Univ. of Rochester Medical Center, NY (United States). Dept. of Biochemistry and Biophysics

    1998-12-31

    This report examines the origin of tissue effects that may follow from different cellular responses to low-dose irradiation, using published data. Two principal categories of cellular responses are considered. One response category relates to the probability of radiation-induced DNA damage. The other category consists of low-dose induced metabolic changes that induce mechanisms of DNA damage mitigation, which do not operate at high levels of exposure. Modeled in this way, tissue is treated as a complex adaptive system. The interaction of the various cellular responses results in a net tissue dose-effect relation that is likely to deviate from linearity in the low-dose region. This suggests that the LNT hypothesis should be reexamined. This paper aims at demonstrating tissue effects as an expression of cellular responses, both damaging and defensive, in relation to the energy deposited in cell mass, by use of microdosimetric concepts.

  20. Beta-endorphin and ACTH in plasma during attacks of common and classic migraine

    DEFF Research Database (Denmark)

    Bach, F W; Jensen, K; Blegvad, N

    1985-01-01

    Plasma levels of beta-endorphin and ACTH were measured during and outside migraine attacks in 17 patients with common migraine and 11 patients with classic migraine. Specific radioimmunoassays for beta-endorphin and ACTH were used. The beta-endorphin assay did not cross-react with beta-lipotropin...... migraine. Accordingly, we could not add evidence to the theory of a dysfunction of the endogenous opioid system in migraine....

  1. ACTH Prevents Deficits in Fear Extinction Associated with Early Life Seizures

    Directory of Open Access Journals (Sweden)

    Andrew T Massey

    2016-05-01

    Full Text Available Early life seizures are often associated with cognitive and psychiatric comorbidities that are detrimental to quality of life. In a rat model of early life seizures (ELS, we explored long-term cognitive outcomes in adult rats. Using ACTH, an endogeneous HPA-axis hormone given to children with severe epilepsy, we sought to prevent cognitive deficits. Through comparisons with dexamethasone, we sought to dissociate the corticosteroid effects of ACTH from other potential mechanisms of action. We found that while rats with a history of ELS were able to acquire a conditioned fear learning paradigm as well as controls, these rats had significant deficits in their ability to extinguish fearful memories. ACTH treatment did not alter any seizure parameters but nevertheless was able to significantly improve this fear extinction, while dexamethasone treatment during the same period did not. This ACTH effect was specific for fear extinction deficits and not for spatial learning deficits in a water maze. Additionally, ACTH did not alter seizure latency or duration suggesting that cognitive and seizure outcomes may be dissociable. Expression levels of melanocortin receptors, which bind ACTH, were found to be significantly lower in animals that had experienced ELS than in control animals, potentially implicating central melanocortin receptor dysregulation in the effects of ELS and suggesting a mechanism of action for ACTH. Taken together, these data suggest that early treatment with ACTH can have significant long-term consequences for cognition in animals with a history of ELS independently of seizure cessation, and may act in part through a CNS melanocortin receptor pathway.

  2. Low-dose aspirin and risk of intracranial bleeds: An observational study in UK general practice.

    Science.gov (United States)

    Cea Soriano, Lucía; Gaist, David; Soriano-Gabarró, Montse; Bromley, Susan; García Rodríguez, Luis A

    2017-11-28

    To quantify the risk of intracranial bleeds (ICBs) associated with new use of prophylactic low-dose aspirin using a population-based primary care database in the United Kingdom. A cohort of new users of low-dose aspirin (75-300 mg; n = 199,079) aged 40-84 years and a 1:1 matched cohort of nonusers of low-dose aspirin at baseline were followed (maximum 14 years, median 5.4 years) to identify incident cases of ICB, with validation by manual review of patient records or linkage to hospitalization data. Using 10,000 frequency-matched controls, adjusted rate ratios (RRs) with 95% confidence intervals (CIs) were calculated for current low-dose aspirin use (0-7 days before the index date [ICB date for cases, random date for controls]); reference group was never used. There were 1,611 cases of ICB (n = 743 for intracerebral hemorrhage [ICH], n = 483 for subdural hematoma [SDH], and n = 385 for subarachnoid hemorrhage [SAH]). RRs (95% CI) were 0.98 (0.84-1.13) for all ICB, 0.98 (0.80-1.20) for ICH, 1.23 (0.95-1.59) for SDH, and 0.77 (0.58-1.01) for SAH. No duration of use or dose-response association was apparent. RRs (95% CI) for ≥1 year of low-dose aspirin use were 0.90 (0.72-1.13) for ICH, 1.20 (0.91-1.57) for SDH, and 0.69 (0.50-0.94) for SAH. Low-dose aspirin is not associated with an increased risk of any type of ICB and is associated with a significantly decreased risk of SAH when used for ≥1 year. © 2017 American Academy of Neurology.

  3. Data integration reveals key homeostatic mechanisms following low dose radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Tilton, Susan C.; Matzke, Melissa M. [Computational Biology and Bioinformatics, Pacific Northwest National Laboratory, Richland, WA 99338 (United States); Sowa, Marianne B.; Stenoien, David L.; Weber, Thomas J. [Health Impacts and Exposure Science, Pacific Northwest National Laboratory, Richland, WA 99338 (United States); Morgan, William F. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99338 (United States); Waters, Katrina M., E-mail: katrina.waters@pnnl.gov [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99338 (United States)

    2015-05-15

    The goal of this study was to define pathways regulated by low dose radiation to understand how biological systems respond to subtle perturbations in their environment and prioritize pathways for human health assessment. Using an in vitro 3-D human full thickness skin model, we have examined the temporal response of dermal and epidermal layers to 10 cGy X-ray using transcriptomic, proteomic, phosphoproteomic and metabolomic platforms. Bioinformatics analysis of each dataset independently revealed potential signaling mechanisms affected by low dose radiation, and integrating data shed additional insight into the mechanisms regulating low dose responses in human tissue. We examined direct interactions among datasets (top down approach) and defined several hubs as significant regulators, including transcription factors (YY1, MYC and CREB1), kinases (CDK2, PLK1) and a protease (MMP2). These data indicate a shift in response across time — with an increase in DNA repair, tissue remodeling and repression of cell proliferation acutely (24–72 h). Pathway-based integration (bottom up approach) identified common molecular and pathway responses to low dose radiation, including oxidative stress, nitric oxide signaling and transcriptional regulation through the SP1 factor that would not have been identified by the individual data sets. Significant regulation of key downstream metabolites of nitrative stress was measured within these pathways. Among the features identified in our study, the regulation of MMP2 and SP1 was experimentally validated. Our results demonstrate the advantage of data integration to broadly define the pathways and networks that represent the mechanisms by which complex biological systems respond to perturbation. - Highlights: • Low dose ionizing radiation altered homeostasis in 3D skin tissue model. • Global gene/protein/metabolite data integrated using complementary statistical approaches • Time and location-specific change in matrix regulation

  4. Low dose diagnostic radiation does not increase cancer risk in cancer prone mice

    Energy Technology Data Exchange (ETDEWEB)

    Boreham, D., E-mail: dboreham@nosm.ca [Northern Ontario School of Medicine, ON (Canada); Phan, N., E-mail: nghiphan13@yahoo.com [Univ. of Ottawa, Ottawa, ON (Canada); Lemon, J., E-mail: lemonja@mcmaster.ca [McMaster Univ., Hamilton, ON (Canada)

    2014-07-01

    The increased exposure of patients to low dose diagnostic ionizing radiation has created concern that these procedures will result in greater risk of carcinogenesis. However, there is substantial evidence that shows in many cases that low dose exposure has the opposite effect. We have investigated whether CT scans can modify mechanisms associated with carcinogenesis in cancer-prone mice. Cancer was induced in Trp53+/- mice with an acute high dose whole-body 4 Gy γ-radiation exposure. Four weeks following the cancer-inducing dose, weekly whole-body CT scans (10 mGy/scan, 75 kVp X-rays) were given for ten consecutive weeks adding an additional radiation burden of 0.1 Gy. Short-term biological responses and subsequent lifetime cancer risk were investigated. Five days following the last CT scan, there were no detectable differences in the spontaneous levels of DNA damage in blood cells (reticulocytes). In fact, CT scanned mice had significantly lower constitutive levels of oxidative DNA damage and cell death (apoptosis), compared to non-CT scanned mice. This shows that multiple low dose radiation exposures modified the radio response and indicates protective processes were induced in mice. In mice treated with the multiple CT scans following the high cancer-inducing 4 Gy dose, tumour latency was increased, significantly prolonging lifespan. We conclude that repeated CT scans can reduce the cancer risk of a prior high-dose radiation exposure, and delay the progression of specific types of radiation-induced cancers in Trp53+/-mice. This research shows for the first time that low dose exposure long after cancer initiation events alter risk and reduce cancer morbidity. Cancer induction following low doses does not follow a linear non-threshold model of risk and this model should not be used to extrapolate risk to humans following low dose exposure to ionizing radiation. (author)

  5. Cushing's syndrome in infancy due to ectopic ACTH secretion by a sacro-coccygeal teratoma.

    Science.gov (United States)

    Rydzewska, Marta; Krawczuk-Rybak, Maryna; Zajkowska, Adrianna; Jurczuk, Natalia; Polnik, Dariusz; Szalecki, Mieczysław; Moszczyńska, Elżbieta; Savage, Martin O; Bossowski, Artur

    2017-04-01

    Adenocorticotropic hormone (ACTH)-dependent Cushing's syndrome in infancy is extremely rare. We describe the case of a sacro-coccygeal ectopic ACTH-secreting immature teratoma in an infant who also presented the triad of defects characteristic of Currarino syndrome. A girl was born with a large immature teratoma in the sacro-coccygeal region associated with anal atresia. At the age of 7 days, the concentration of α-fetoprotein (AFP) was above the age-specific normal range. Two non-radical surgical excisions of the tumour were performed. At the age of 7 months, she developed polyphagia, acne, hirsutism, hypertension and hypokalemia with elevated ACTH and absence of serum cortisol circadian rhythm. Immunostaining of tumour tissue showed ACTH-immunoreactive cells. Due to unsuccessful therapy with ketoconazole and resistance to antihypertensive medications [blood pressure (BP) 210/160 mmHg], metyrapone was administered, which controlled her ACTH and cortisol levels in the normal range. Following further removal of tumour bulk after three operations during the first year of life, there was a decrease of BP to normal values. A rare case of ectopic ACTH syndrome causing Cushing's syndrome in infancy in the context of Currarino syndrome is reported. Radical surgery has resulted in excision of the tumour and current control of Cushing's syndrome.

  6. Second-line tests in the differential diagnosis of ACTH-dependent Cushing's syndrome.

    Science.gov (United States)

    Barbot, Mattia; Trementino, Laura; Zilio, Marialuisa; Ceccato, Filippo; Albiger, Nora; Daniele, Andrea; Frigo, Anna Chiara; Mardari, Rodica; Rolma, Giuseppe; Boscaro, Marco; Arnaldi, Giorgio; Scaroni, Carla

    2016-10-01

    Diagnosing Cushing's syndrome (CS) can be a challenge, especially in ACTH-dependent CS, when it comes to detecting the origin of ACTH secretion. Retrospective data were collected on 170 patients with ACTH-dependent CS (149 CD, 21 EAS) referring to two endocrinology units, focusing on three non-invasive tests: dexamethasone 8 mg overnight challenge (HDDST); corticotrophin-releasing hormone (CRH) assay and the desmopressin (DDAVP) test. Patients with EAS were slightly older and had higher ACTH, serum and urinary cortisol levels than patients with CD (p 52.7 % below the basal level suggested a pituitary origin with a SE of 88 % (95 % CI 81-93) and a SP of 90 % (95 % CI 68-99). There were no cases of EAS with positive responses to both these tests. Increases in ACTH and cortisol levels after the DDAVP test were also higher in CD than in EAS (p < 0.01), though the SE and SP were lower. Patients with CD showed a stronger response to HDDST and CRH, and the adopted cut-offs showed a good SE and SP in discriminating them from patients with EAS. Concordant tests indicated CD when positive, whereas no response to either test was highly suggestive of EAS. The DDAVP test was of limited utility in the diagnostic phase. In conclusion, the choice of tests may play an important part in the differential diagnosis of ACTH-dependent CS.

  7. Ectopic ACTH secretion due to a bronchopulmonary carcinoid localized by somatostatin receptor scintigraphy.

    Science.gov (United States)

    Iser, G; Pfohl, M; Dörr, U; Weiss, E M; Seif, F J

    1994-11-01

    We present the case of a 65-year-old woman with an adrenocorticotropic hormone (ACTH) secreting bronchopulmonary carcinoid. This patient showed the typical long history of Cushing's syndrome, including hypokaliemia, impaired glucose tolerance, high levels of ACTH and beta-endorphin, and coproduction of other peptides. At the onset of clinical symptoms in 1979 an adrenal adenoma was suspected, and left-sided adrenalectomy was performed. The symptoms soon recurred, and the diagnosis of ACTH-dependent Cushing's syndrome was made. As no ACTH-secreting tumor was found, the right adrenal was resected, and the patient was followed up regularly. Fourteen years later chest roentgenography and computed tomography revealed a para-aortic pulmonary lesion, which was suspicious for a bronchopulmonary carcinoid. ACTH and beta-endorphin were excessively, pancreatic polypeptide slightly elevated at that time. The final diagnosis was made using somatostatin receptor scintigraphy which confirmed the hormonal activity of the suspicious lesion; no additional focus was found. This method turned out to be not only a useful additional localization technique but also a promising tool for characterization and staging of a suspected ACTH-producing carcinoid. The tumor was resected curatively, and the diagnosis was confirmed histologically.

  8. Changes of serum contents of cortisol and ACTH in patients after operation

    International Nuclear Information System (INIS)

    Zhu Lianghong; Zhang Xinlu; Chen Guanghua

    2007-01-01

    Objective: To study the changes of serum contents of cortisol and ACTH after operation. Methods: Serum cortisol and ACTH levels were measured with RIA both before and ld, 3d post-operatively in 30 patients after Grade III operation and 15 patients after Grade IV operation. Results: On the first post-operative day, the serum cortisol and ACTH levels in both groups of patients were significantly higher than their respective pre-operative levels. Levels in Grade IV group were significantly higher than those in Grade III group. On the third post-operative day, the serum cortisol levels dropped markedly and were lower than their respective pre-operative levels. However, the serum ACTH levels continued to rise in both groups and were significantly higher than the respective levels pre-operatively as well as those on dl. The ACTH levels in the two groups were not significantly different on d3. Conclusion: Serum cortisol and ACTH levels increased in the early post-operative phase and the degree of increase of cortisol was correlated with the magnitude of the operation. (authors)

  9. Study on human mesenchymal stem cells from bone marrow pretreated with low dose radiation

    International Nuclear Information System (INIS)

    Yang Yan; Wang Guangjun; Wang Juan

    2008-01-01

    Objective: To study effects of human bone marrow mesenchymal stem cells (hBM-MSC) from bone marrow pretreated with low dose radiation (LDR). Methods: The cells were the hBM-MSC. They were exposed to X rays at the dose of 50 mGy, 75 mGy, 100 mGy (dose rate 12.5 mGy/min). The growth curve, cell cycle and apoptosis of hBM-MSC treated by LDR were investigated. The content changes of stem cell factor(SCF), interleukin-6 (IL-6), macrophage colony stimulating factor(M-CSF) secreted by hBM-MSC after treated by LDR were determined by enzyme linked immunosorbent assay method. Results: The growth rates of hBM-MSC treated by LDR obviously increase from 72 h. The cell cycle and apoptosis were examined with FORTRAN Atomatic Checkout Systom. The results show that the G 0 /G 1 stage cells decrease after exposure to LDR, the percent of G 0 /G 1 stage cells of 75 mGy at 72 h is the lowest(30.86%). However, the S stage cells percentage gradually increase at 48 h and 72 h. The most one is 75 mGy group at 72 h, which reaches to 68.88%. The apoptosis percentages have increased tendency at 24 h and 48h in all dose groups, especially in 100 mGy at 24 h(25.99%), while have decreased tendency at 72 h and the most decreased group is the 50 mGy(6.8%), transient enhancement of apoptosis in the early stage and soon being decreased. The contents of SCF have increased tendency at 24 h, 48 h. As for IL-6, the contents in different dose groups at 24 h and 48 h have up-regulation. These groups, 50 mGy at 24 h, 48 h, 75 mGy at 24 h, 48 h, 100 mGy at 24 h have statistical difference compared with their control groups respectively. The content of IL-6 has greatest enhancement at dose of 50 mGy. The contents of M-SCF in all the groups at 24 h, 48 h and 72 h except for the 50 mGy dose at 72 h have also been found increased. The greatest increased content occur in the 75 mGy dose group at 72 h. Conclusion: This conclusion show that LDR has hormesis effect on hBM-MSC in cell growth, cell cycle and content

  10. Response of human and rabbit lymphocytes to low doses of X-rays

    International Nuclear Information System (INIS)

    Fabry, L.

    1982-01-01

    The response of human and rabbit lymphocytes to low doses of X-rays was studied by the yields of dicentrics in first division metaphases. For both species, the dose-response curve was best fitted to the linear-quadratic model with a linear component predominating up to 67 and 42 rad respectively for man and rabbit. A calibration curve (5-400 rad) was obtained by combining the present results on man with previous data at higher doses. On the other hand, it appears that, at low doses, the radiosentivity of human lymphocytes is significantly higher than that of rabbit lymphocytes [fr

  11. Bleeding Risk with Long-Term Low-Dose Aspirin: A Systematic Review of Observational Studies

    Science.gov (United States)

    García Rodríguez, Luis A.; Martín-Pérez, Mar; Hennekens, Charles H.; Rothwell, Peter M.; Lanas, Angel

    2016-01-01

    Background Low-dose aspirin has proven effectiveness in secondary and primary prevention of cardiovascular events, but is also associated with an increased risk of major bleeding events. For primary prevention, this absolute risk must be carefully weighed against the benefits of aspirin; such assessments are currently limited by a lack of data from general populations. Methods Systematic searches of Medline and Embase were conducted to identify observational studies published between 1946 and 4 March 2015 that reported the risks of gastrointestinal (GI) bleeding or intracranial hemorrhage (ICH) with long-term, low-dose aspirin (75–325 mg/day). Pooled estimates of the relative risk (RR) for bleeding events with aspirin versus non-use were calculated using random-effects models, based on reported estimates of RR (including odds ratios, hazard ratios, incidence rate ratios and standardized incidence ratios) in 39 articles. Findings The incidence of GI bleeding with low-dose aspirin was 0.48–3.64 cases per 1000 person-years, and the overall pooled estimate of the RR with low-dose aspirin was 1.4 (95% confidence interval [CI]: 1.2–1.7). For upper and lower GI bleeding, the RRs with low-dose aspirin were 2.3 (2.0–2.6) and 1.8 (1.1–3.0), respectively. Neither aspirin dose nor duration of use had consistent effects on RRs for upper GI bleeding. The estimated RR for ICH with low-dose aspirin was 1.4 (1.2–1.7) overall. Aspirin was associated with increased bleeding risks when combined with non-steroidal anti-inflammatory drugs, clopidogrel and selective serotonin reuptake inhibitors compared with monotherapy. By contrast, concomitant use of proton pump inhibitors decreased upper GI bleeding risks relative to aspirin monotherapy. Conclusions The risks of major bleeding with low-dose aspirin in real-world settings are of a similar magnitude to those reported in randomized trials. These data will help inform clinical judgements regarding the use of low-dose aspirin

  12. Low-dose radiotherapy as treatment for benign lymphoepitelial lesion in HIV-patients

    International Nuclear Information System (INIS)

    Gonzalez Patino, E.; Lopez Vazquez, M.D.; Cascallar Caneda, L.; Antinez Lopez, J.; Victoria Fernandez, C.; Salvador Garrido, N.; Ares Banobre, M.; Porto vazquez, M.C.

    1995-01-01

    Standard treatments for benign lymphoepitelial lesion of the parotid gland in patients infected with the human immunodeficiency virus (HIV) are unsatisfactory. Recently, low-dose radiotherapy has been proposed as a noninvasive treatment option. We describe a case of bilateral benign lymphoepitelial lesion parotid gland in a HIV-positive paint, treated by radiotherapy. Low-dose radiotherapy, appears as a alternative in the treatment for benign lymphoepitelial lesion in HIV-patients, and preliminary evaluations have indicated that this treatment is effective from both the clinical and cosmetic points of view

  13. Intraocular levels of methotrexate after oral low-dose treatment in chronic uveitis.

    Science.gov (United States)

    Puchta, Joachim; Hattenbach, Lars-Olof; Baatz, Holger

    2005-01-01

    To determine the intraocular levels of methotrexate in low-dose treatment of noninfectious uveitis. One day after oral administration, the methotrexate level was measured in the aqueous humor and serum of a patient with noninfectious uveitis, who underwent cataract surgery. A fluorescence polarization immunoassay was used for determination. After oral administration, methotrexate was only measurable in aqueous humor but not in serum. In uveitis, orally administered low-dose methotrexate reaches detectable levels in aqueous humor, even in the absence of detectable levels in serum. Copyright (c) 2005 S. Karger AG, Basel.

  14. Treatment of Complex Regional Pain Syndrome (CRPS) using low dose naltrexone (LDN).

    Science.gov (United States)

    Chopra, Pradeep; Cooper, Mark S

    2013-06-01

    Complex Regional Pain Syndrome (CRPS) is a neuropathic pain syndrome, which involves glial activation and central sensitization in the central nervous system. Here, we describe positive outcomes of two CRPS patients, after they were treated with low-dose naltrexone (a glial attenuator), in combination with other CRPS therapies. Prominent CRPS symptoms remitted in these two patients, including dystonic spasms and fixed dystonia (respectively), following treatment with low-dose naltrexone (LDN). LDN, which is known to antagonize the Toll-like Receptor 4 pathway and attenuate activated microglia, was utilized in these patients after conventional CRPS pharmacotherapy failed to suppress their recalcitrant CRPS symptoms.

  15. Effects of low-dose recombinant human erythropoietin treatment on cognitive performance

    DEFF Research Database (Denmark)

    Viuff, Søren Lundgaard; Plenge, Ulla; Belhage, Bo

    2017-01-01

    , NUFI or self-reported results between the groups. CONCLUSIONS: In this small study, we found no significant effect of low-dose or micro-dose rhEpo on visual attention, cognitive performance in complex cognitive tasks or self-experienced cognitive performance compared with placebo. FU