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Sample records for continuous beta exposure

  1. Beta/alpha continuous air monitor

    DOEpatents

    Becker, Gregory K.; Martz, Dowell E.

    1989-01-01

    A single deep layer silicon detector in combination with a microcomputer, recording both alpha and beta activity and the energy of each pulse, distinguishing energy peaks using a novel curve fitting technique to reduce the natural alpha counts in the energy region where plutonium and other transuranic alpha emitters are present, and using a novel algorithm to strip out radon daughter contribution to actual beta counts.

  2. Beta/alpha continuous air monitor

    DOEpatents

    Becker, G.K.; Martz, D.E.

    1988-06-27

    A single deep layer silicon detector in combination with a microcomputer, recording both alpha and beta activity and the energy of each pulse, distinquishing energy peaks using a novel curve fitting technique to reduce the natural alpha counts in the energy region where plutonium and other transuranic alpha emitters are present, and using a novel algorithm to strip out radon daughter contribution to actual beta counts. 7 figs.

  3. Early and continuing effects of combined alpha and beta irradiation of the lung:

    SciTech Connect

    Scott, B.R.; Hahn, F.F.; Snipes, M.B.; Newton, G.J.; Eidson, A.F.; Mauderly, J.L.; Boecker, B.B.

    1988-03-01

    This report summarizes an inhalation exposure experiment that concerns early and continuing effects of combined alpha and beta irradiation of the lung of rats. Both morbidity at 18 months and mortality within 18 months after exposure were examined for rats exposed to the beta-emitter /sup 147/Pm, the alpha-emitter /sup 238/Pu, or both combined. The results were used to validate hazard-function models that were developed (1)for pulmonary functional morbidity at 18 months and (2) for lethality from radiation pneumonitis and pulmonary fibrosis within 18 months. Both models were found to adequately predict the experimental observations after combined chronic alpha and beta irradiation of the lung. A relative biological effectiveness of approximately 7 was obtained for /sup 238/Pu alpha radiation compared to /sup 147/Pm beta radiation for both pulmonary functional morbidity and lethality from radiation pneumonitis and pulmonary fibrosis. 12 refs., 16 figs., 11 tabs.

  4. Continuous exposure of animals to methylisobutylketone

    NASA Technical Reports Server (NTRS)

    Vernot, E. H.; Macewen, J. D.; Harris, E. S.

    1971-01-01

    Continuous exposure of dogs, monkeys, mice, and rats to MIBK for two weeks and all animals except mice for 90 days resulted in measurable adverse effects only in the case of rats. Rat kidney weights and kidney to body weight ratios were significantly elevated after exposure to 410 mg/cu m for two weeks, and kidney and liver organ weights and organ to body weight ratios were elevated after exposure to 820 mg/cu m for two weeks and to 410 mg/cu m for 90 days.

  5. Early continuous white noise exposure alters l-alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor subunit glutamate receptor 2 and gamma-aminobutyric acid type a receptor subunit beta3 protein expression in rat auditory cortex.

    PubMed

    Xu, Jinghong; Yu, Liping; Zhang, Jiping; Cai, Rui; Sun, Xinde

    2010-02-15

    Auditory experience during the postnatal critical period is essential for the normal maturation of auditory function. Previous studies have shown that rearing infant rat pups under conditions of continuous moderate-level noise delayed the emergence of adult-like topographic representational order and the refinement of response selectivity in the primary auditory cortex (A1) beyond normal developmental benchmarks and indefinitely blocked the closure of a brief, critical-period window. To gain insight into the molecular mechanisms of these physiological changes after noise rearing, we studied expression of the AMPA receptor subunit GluR2 and GABA(A) receptor subunit beta3 in the auditory cortex after noise rearing. Our results show that continuous moderate-level noise rearing during the early stages of development decreases the expression levels of GluR2 and GABA(A)beta3. Furthermore, noise rearing also induced a significant decrease in the level of GABA(A) receptors relative to AMPA receptors. However, in adult rats, noise rearing did not have significant effects on GluR2 and GABA(A)beta3 expression or the ratio between the two units. These changes could have a role in the cellular mechanisms involved in the delayed maturation of auditory receptive field structure and topographic organization of A1 after noise rearing.

  6. Human melatonin during continuous magnetic field exposure

    SciTech Connect

    Graham, C.; Cook, M.R.; Riffle, D.W.

    1997-05-01

    This report describes the third in a series of double-blind, laboratory-based studies that were aimed at determining the effects of nocturnal exposure to power frequency magnetic fields on blood levels of melatonin in human volunteers. The two earlier studies evaluated effects on melatonin of intermittent exposure to 60 Hz circularly polarized magnetic fields at 10 and 200 mG. No overall effects on melatonin levels were found. In the present study, men were exposed continuously rather than intermittently through the night to the same 200 mG magnetic field condition that was used previously; again, no overall effects on melatonin levels were found. The authors conclude that the intermittent and continuous exposure conditions used in the laboratory to date are not effective in altering nocturnal blood levels of melatonin in human volunteers.

  7. Re-exposure to beta cell autoantigens in pancreatic allograft recipients with preexisting beta cell autoantibodies.

    PubMed

    Mujtaba, Muhammad Ahmad; Fridell, Jonathan; Book, Benita; Faiz, Sara; Sharfuddin, Asif; Wiebke, Eric; Rigby, Mark; Taber, Tim

    2015-11-01

    Re-exposure to beta cell autoantigens and its relevance in the presence of donor-specific antibodies (DSA) in pancreatic allograft recipients is not well known. Thirty-three patients requiring a pancreas transplant were enrolled in an IRB approved study. They underwent prospective monitoring for DSA and beta cell autoantibody (BCAA) levels to GAD65, insulinoma-associated antigen 2 (IA-2), insulin (micro-IAA [mIAA]), and islet-specific zinc transporter isoform-8 (ZnT8). Twenty-five (75.7%) had pre-transplant BCAA. Twenty had a single antibody (mIAA n = 15, GAD65 n = 5); five had two or more BCAA (GAD65 + mIAA n = 2, GAD65 + mIAA+IA-2 n = 2, GA65 + mIAA+IA-2 + ZnT8 = 1). No changes in GAD65 (p > 0.29), IA-2 (>0.16), and ZnT8 (p > 0.07) were observed between pre-transplant and post-transplant at 6 or 12 months. A decrease in mIAA from pre- to post-6 months (p < 0.0001), 12 months (p < 0.0001), and from post-6 to post-12 months (p = 0.0002) was seen. No new BCAA was observed at one yr. Seven (21.0%) developed de novo DSA. The incidence of DSA was 24% in patients with BCAA vs. 25% in patients without BCAA (p = 0.69). Pancreatic allograft function of patients with vs. without BCAA, and with and without BCAA + DSA was comparable until last follow-up (three yr). Re-exposure to beta cell autoantigens by pancreas transplant may not lead to increased levels or development of new BCAA or pancreatic allograft dysfunction.

  8. Antioxidant activity of cysteine, tryptophan, and methionine residues in continuous phase beta-lactoglobulin in oil-in-water emulsions.

    PubMed

    Elias, Ryan J; McClements, D Julian; Decker, Eric A

    2005-12-28

    Proteins dispersed in the continuous phase of oil-in-water emulsions are capable of inhibiting lipid oxidation reactions. The antioxidant activity of these proteins is thought to encompass both free radical scavenging by amino acid residues and chelation of prooxidative transition metals; however, the precise mechanism by which this occurs remains unclear. In this study, the oxidative stability of cysteine, tryptophan, and methionine residues in continuous phase beta-lactoglobulin (beta-Lg) in a Brij-stabilized menhaden oil-in-water emulsion was determined. The presence of low concentrations of continuous phase beta-Lg (250 and 750 microg/mL) significantly inhibited lipid oxidation as determined by lipid hydroperoxides and thiobarbituric acid reactive substances analysis. It was observed that cysteine oxidized before tryptophan in beta-Lg, and both residues oxidized before lipid oxidation could be detected. No oxidation of the methionine residues of beta-Lg was observed despite its reported high oxidative susceptibility. It is conceivable that surface exposure of amino acid residues greatly affects their oxidation kinetics, which may explain why some residues are preferentially oxidized relative to others. Further elucidation of the mechanisms governing free radical scavenging of amino acids could lead to more effective applications of proteins as antioxidants within oil-in-water food emulsions.

  9. Beta-lactam dosing in critically ill patients with septic shock and continuous renal replacement therapy

    PubMed Central

    2014-01-01

    Although early and appropriate antibiotic therapy remains the most important intervention for successful treatment of septic shock, data guiding optimization of beta-lactam prescription in critically ill patients prescribed with continuous renal replacement therapy (CRRT) are still limited. Being small hydrophilic molecules, beta-lactams are likely to be cleared by CRRT to a significant extent. As a result, additional variability may be introduced to the per se variable antibiotic concentrations in critically ill patients. This article aims to describe the current clinical scenario for beta-lactam dosing in critically ill patients with septic shock and CRRT, to highlight the sources of variability among the different studies that reduce extrapolation to clinical practice, and to identify the opportunities for future research and improvement in this field. Three frequently prescribed beta-lactams (meropenem, piperacillin and ceftriaxone) were chosen for review. Our findings showed that present dosing recommendations are based on studies with drawbacks limiting their applicability in the clinical setting. In general, current antibiotic dosing regimens for CRRT follow a one-size-fits-all fashion despite emerging clinical data suggesting that drug clearance is partially dependent on CRRT modality and intensity. Moreover, some studies pool data from heterogeneous populations with CRRT that may exhibit different pharmacokinetics (for example, admission diagnoses different to septic shock, such as trauma), which also limit their extrapolation to critically ill patients with septic shock. Finally, there is still no consensus regarding the %T>MIC (percentage of dosing interval when concentration of the antibiotic is above the minimum inhibitory concentration of the pathogen) value that should be chosen as the pharmacodynamic target for antibiotic therapy in patients with septic shock and CRRT. For empirically optimized dosing, during the first day a loading dose is required

  10. Beta-lactam dosing in critically ill patients with septic shock and continuous renal replacement therapy.

    PubMed

    Ulldemolins, Marta; Vaquer, Sergi; Llauradó-Serra, Mireia; Pontes, Caridad; Calvo, Gonzalo; Soy, Dolors; Martín-Loeches, Ignacio

    2014-06-23

    Although early and appropriate antibiotic therapy remains the most important intervention for successful treatment of septic shock, data guiding optimization of beta-lactam prescription in critically ill patients prescribed with continuous renal replacement therapy (CRRT) are still limited. Being small hydrophilic molecules, beta-lactams are likely to be cleared by CRRT to a significant extent. As a result, additional variability may be introduced to the per se variable antibiotic concentrations in critically ill patients. This article aims to describe the current clinical scenario for beta-lactam dosing in critically ill patients with septic shock and CRRT, to highlight the sources of variability among the different studies that reduce extrapolation to clinical practice, and to identify the opportunities for future research and improvement in this field. Three frequently prescribed beta-lactams (meropenem, piperacillin and ceftriaxone) were chosen for review. Our findings showed that present dosing recommendations are based on studies with drawbacks limiting their applicability in the clinical setting. In general, current antibiotic dosing regimens for CRRT follow a one-size-fits-all fashion despite emerging clinical data suggesting that drug clearance is partially dependent on CRRT modality and intensity. Moreover, some studies pool data from heterogeneous populations with CRRT that may exhibit different pharmacokinetics (for example, admission diagnoses different to septic shock, such as trauma), which also limit their extrapolation to critically ill patients with septic shock. Finally, there is still no consensus regarding the %T>MIC (percentage of dosing interval when concentration of the antibiotic is above the minimum inhibitory concentration of the pathogen) value that should be chosen as the pharmacodynamic target for antibiotic therapy in patients with septic shock and CRRT. For empirically optimized dosing, during the first day a loading dose is required

  11. Elevated urinary excretion of beta-aminoisobutyric acid and exposure to inorganic lead.

    PubMed

    Farkas, W R; Fischbein, A; Solomon, S; Buschman, F; Borek, E; Sharma, O K

    1987-01-01

    beta-Aminoisobutyric acid (beta-AIB), a normal degradation product of thymine, a constituent of DNA and, to a lesser extent, of transfer RNA, is excreted in low levels in human urine. We found that a group of iron workers occupationally exposed to inorganic lead excreted high levels of urinary beta-AIB. Elevated urinary excretion of beta-AIB was also observed in marmosets, Callithrix jacchus, that received lead acetate in drinking water. Our results suggest that increased urinary excretion of beta-AIB could stem from damage to DNA on exposure to lead.

  12. Continuous infusion of beta-lactam antibiotics in severe infections: a review of its role.

    PubMed

    Roberts, Jason A; Paratz, Jennifer; Paratz, Elizabeth; Krueger, Wolfgang A; Lipman, Jeffrey

    2007-07-01

    Continuous infusion of beta-lactam antibiotics has been widely promoted to optimise their time-dependent activity. Increasing evidence is emerging suggesting potential benefits in patient populations with altered pathophysiology, such as seriously ill patients. From a pharmacokinetic viewpoint, much information supports higher trough concentrations of beta-lactam antibiotics when administered by continuous infusion. This advantage of continuous infusion translates into a superior ability to achieve pharmacodynamic targets, particularly when the minimum inhibitory concentration (MIC) of the pathogen is >or=4 mg/L. One drawback of continuous infusion may be limited physicochemical stability. This issue exists particularly for carbapenem antibiotics whereby prolonged infusions (i.e. >3h) can be used to improve the time above the MIC compared with conventional bolus dosing. Few studies have examined clinical outcomes of bolus and continuous dosing of beta-lactam antibiotics in seriously ill patients. No statistically significant differences have been shown for: mortality; time to normalisation of leukocytosis or pyrexia; or duration of mechanical ventilation, intensive care unit stay or hospital stay. Some evidence suggests improved clinical cure and resolution of illness with continuous infusion in seriously ill patients. Pharmacoeconomic advantages of continuous infusion of beta-lactam antibiotics are well characterised. Available data suggest that seriously ill patients with severe infections requiring significant antibiotic courses (>or=4 days) may be the subgroup that will achieve better outcomes with continuous infusion.

  13. Continuous infusion vs. bolus dosing: implications for beta-lactam antibiotics.

    PubMed

    Mohd Hafiz, Abdul-Aziz; Staatz, C E; Kirkpatrick, C M J; Lipman, J; Roberts, J A

    2012-01-01

    Beta-lactam antibiotics display time-dependant pharmacodynamics whereby constant antibiotic concentrations rather than high peak concentrations are most likely to result in effective treatment of infections caused by susceptible bacteria. Continuous administration has been suggested as an alternative strategy, to conventional intermittent dosing, to optimise beta-lactam pharmacokinetic/pharmacodynamic (PK/PD) properties. With the availability of emerging data, we elected to systematically investigate the published literature describing the comparative PK/PD and clinical outcomes of beta-lactam antibiotics administered by continuous or intermittent infusion. We found that the studies have been performed in various patient populations including critically ill, cancer and cystic fibrosis patients. Available in vitro PK/PD data conclusively support the administration of beta-lactams via continuous infusion for maximizing bacterial killing from consistent attainment of pharmacodynamic end-points. In addition, clinical outcome data supports equivalence, even with the use of a lower dose by continuous infusion. However, the present clinical data is limited with small sample sizes common with insufficient power to detect advantages in favour of either dosing strategy. With abundant positive pre-clinical data as well as document in vivo PK/PD advantages, large multi-centre trials are needed to describe whether continuous administration of beta-lactams is truly more effective than intermittent dosing.

  14. Effects of transforming growth factor-beta on growth and differentiation of the continuous rat thyroid follicular cell line, FRTL-5

    SciTech Connect

    Morris, J.C. III; Ranganathan, G.; Hay, I.D.; Nelson, R.E.; Jiang, N.S.

    1988-09-01

    Transforming growth factor-beta (TGF beta) has been shown to influence the growth and differentiation of many widely varied cell types in vitro, including some that are endocrinologically active. We have investigated the previously unknown effects of this unique growth factor in the differentiated rat thyroid follicular cell line FRTL-5. The cells demonstrated specific, high affinity binding of TGF beta, and as with other epithelial cells, the growth of these thyroid follicular cells was potently inhibited by addition of TGF beta to the culture medium. TGF beta caused a significant reduction in TSH-sensitive adenylate cyclase activity in the cells. The addition of (Bu)2cAMP along with the growth factor to cultures partially reversed the characteristic morphological changes seen with TGF beta, but did not reverse the growth inhibition. To further investigate the possible mechanisms of the effects of TGF beta on the cells, we measured the influence of the growth factor on (125I)TSH binding. TGF beta did not compete for specific TSH-binding sites; however, exposure of the cells to TGF beta for 12 or more h resulted in a dose-dependent down-regulation of TSH receptors that was fully reversible. While cellular proliferation was potently inhibited by TGF beta, differentiated function, as manifest by iodine-trapping ability, was stimulated by the growth factor. This stimulation of iodine uptake was independent of, and additive to, the stimulatory effects of TSH. Finally, FRTL-5 cells in serum-free medium and in response to TSH were shown to secrete TGF beta-like activity that competed for (125I)TGF beta in a RRA. These studies suggest that TGF beta may represent an autocrine mechanism of controlling the growth response to TSH in thyroid follicular cells, while allowing the continuance of differentiated function.

  15. Exposure to inhaled THM: comparison of continuous and event-specific exposure assessment for epidemiologic purposes.

    PubMed

    Thiriat, N; Paulus, H; Le Bot, B; Glorennec, P

    2009-10-01

    Trihalomethanes (THMs) (chloroform, bromoform, dibromochloromethane, and bromodichloromethane) are the most abundant by-products of chlorination. People are exposed to THMs through ingestion, dermal contact and inhalation. The objective of this study was to compare two methods for assessing THM inhalation: a direct method with personal monitors assessing continuous exposure and an indirect one with microenvironmental sampling and collection of time-activity data during the main event exposures: bathing, showering and swimming. This comparison was conducted to help plan a future epidemiologic study of the effects of THMs on the upper airways of children. 30 children aged from 4 to 10 years were included. They wore a 3M 3520 organic vapor monitor for 7 days. We sampled air in their bathrooms (during baths or showers) and in the indoor swimming pools they visited and recorded their time-activity patterns. We used stainless steel tubes full of Tenax to collect air samples. All analyses were performed with Gas Chromatography and Mass Spectrometry (GC-MS). Chloroform was the THM with the highest concentrations in the air of both bathrooms and indoor swimming pools. Its continuous and event exposure measurements were significantly correlated (r(s)=0.69 p<0.001). Continuous exposures were higher than event exposures, suggesting that the event exposure method does not take into account some influential microenvironments. In an epidemiologic study, this might lead to random exposure misclassification, thus underestimation of the risk, and reduced statistical power. The continuous exposure method was difficult to implement because of its poor acceptability and the fragility of the personal monitors. These two points may also reduce the statistical power of an epidemiologic study. It would be useful to test the advantages and disadvantages of a second sample in the home or of modeling the baseline concentration of THM in the home to improve the event exposure method.

  16. Exposure to wireless phone emissions and serum beta-trace protein.

    PubMed

    Hardell, Lennart; Söderqvist, Fredrik; Carlberg, Michael; Zetterberg, Henrik; Mild, Kjell Hansson

    2010-08-01

    The lipocalin type of prostaglandin D synthase or beta-trace protein is synthesized in the choroid plexus, lepto-meninges and oligodendrocytes of the central nervous system and is secreted into the cerebrospinal fluid. beta-trace protein is the key enzyme in the synthesis of prostaglandin D2, an endogenous sleep-promoting neurohormone in the brain. Electromagnetic fields (EMF) in the radio frequency (RF) range have in some studies been associated with disturbed sleep. We studied the concentration of beta-trace protein in blood in relation to emissions from wireless phones. This study included 62 persons aged 18-30 years. The concentration of beta-trace protein decreased with increasing number of years of use of a wireless phone yielding a negative beta coefficient = -0.32, 95% confidence interval -0.60 to -0.04. Also cumulative use in hours gave a negative beta coefficient, although not statistically significant. Of the 62 persons, 40 participated in an experimental study with 30 min exposure to an 890-MHz GSM signal. No statistically significant change of beta-trace protein was found. In a similar study of the remaining 22 participitants with no exposure, beta-trace protein increased significantly over time, probably due to a relaxed situation. EMF emissions may down-regulate the synthesis of beta-trace protein. This mechanism might be involved in sleep disturbances reported in persons exposed to RF fields. The results must be interpreted with caution since use of mobile and cordless phones were self-reported. Awareness of exposure condition in the experimental study may have influenced beta-trace protein concentrations.

  17. Beta2-microglobulin causes abnormal phosphatidylserine exposure in human red blood cells.

    PubMed

    Pavone, Barbara; Bucci, Sonia; Sirolli, Vittorio; Merlini, Giampaolo; Del Boccio, Piero; Di Rienzo, Marianna; Felaco, Paolo; Amoroso, Luigi; Sacchetta, Paolo; Di Ilio, Carmine; Federici, Giorgio; Urbani, Andrea; Bonomini, Mario

    2011-03-01

    The exposure of the aminophospholipid phosphatidylserine on the external leaflet of red blood cell plasma membrane can have several pathophysiological consequences with particular regard to the processes of cell phagocytosis, haemostasis and cell-cell interaction. A significant increase in phosphatidylserine-exposing erythrocytes has been reported in chronic haemodialysis patients and found to be strongly influenced by the uraemic milieu. To identify uraemic compound(s) enhancing phosphatidylserine externalization in erythrocytes, we fractionated by chromatographic methods the ultrafiltrate obtained during dialysis, and examined by flow cytometry the effect of the resulting fractions on phosphatidylserine exposure in human red cells. Chromatographic procedures disclosed a homogeneous fraction able to increase erythrocyte phosphatidylserine exposure. The inducer of such externalization was identified by monodimensional gel electrophoresis and mass spectrometry investigations as beta2-microglobulin. To confirm the beta2-microglobulin effect and to examine the influence of protein glycation (as it occurs in uraemia) on phosphatidylserine erythrocyte exposure, erythrocytes from normal subjects were incubated with recombinant beta2-microglobulin (showing no glycation sites at mass analysis), commercial beta2-microglobulin (8 glycation sites), or with in vitro glycated recombinant beta2-microglobulin (showing multiple glycation sites). Elevated concentrations of beta2-microglobulin (corresponding to plasma levels reached in dialysis patients) increased slightly but significantly the protein's ability to externalize phosphatidylserine on human erythrocytes. Such an effect was markedly enhanced by glycated forms of the protein. Beta2-microglobulin is recognized as a surrogate marker of middle-molecule uraemic toxins and represents a key component of dialysis-associated amyloidosis. Our study adds further evidence to the potential pathophysiologic consequences of beta2

  18. Effects of controlled exposure of sunlight on plasma and skin levels of beta-carotene.

    PubMed

    Biesalski, H K; Hemmes, C; Hopfenmuller, W; Schmid, C; Gollnick, H P

    1996-03-01

    We conducted a randomized placebo-controlled double-blind study in 20 healthy young female students (skin type II + III, body mass index 18-22) in order to evaluate the efficacy of 10 weeks of moderate dose (30 mg/d) beta-carotene (BC) on plasma and skin beta-carotene levels during 12 days of time and intensity controlled sunlight exposure at sea level (30 degrees latitude, Red Sea, Eilath, Israel). After 12 days of controlled sun exposure (total UV dose of about 10.000J/cm2), plasma beta-carotene decreased in the placebo (p < 0.01) and beta-carotene group (not significant). In addition cutaneous beta-carotene decreased significantly in both groups. Plasma alpha-tocopherol decreased significantly (p < 0.01) during exposure time in both groups. In the supplemented group, however, the decrease of a-tocopherol was significantly greater (p < 0.01) than in the placebo group. We conclude that sunlight influences the beta-carotene and alpha-tocopherol content of blood and tissues.

  19. Propensity score weighting for a continuous exposure with multilevel data.

    PubMed

    Schuler, Megan S; Chu, Wanghuan; Coffman, Donna

    2016-12-01

    Propensity score methods (e.g., matching, weighting, subclassification) provide a statistical approach for balancing dissimilar exposure groups on baseline covariates. These methods were developed in the context of data with no hierarchical structure or clustering. Yet in many applications the data have a clustered structure that is of substantive importance, such as when individuals are nested within healthcare providers or within schools. Recent work has extended propensity score methods to a multilevel setting, primarily focusing on binary exposures. In this paper, we focus on propensity score weighting for a continuous, rather than binary, exposure in a multilevel setting. Using simulations, we compare several specifications of the propensity score: a random effects model, a fixed effects model, and a single-level model. Additionally, our simulations compare the performance of marginal versus cluster-mean stabilized propensity score weights. In our results, regression specifications that accounted for the multilevel structure reduced bias, particularly when cluster-level confounders were omitted. Furthermore, cluster mean weights outperformed marginal weights.

  20. Marine Bivalve Cellular Responses to Beta Blocker Exposures ...

    EPA Pesticide Factsheets

    β blockers are prescription drugs used for medical treatment of hypertension and arrhythmias. They prevent binding of agonists such as catecholamines to β adrenoceptors. In the absence of agonist induced activation of the receptor, adenylate cyclase is not activated which in turn limits cAMP production and protein kinase A activation, preventing increases in blood pressure and arrhythmias. After being taken therapeutically, commonly prescribed β blockers may make their way to coastal habitats via discharge from waste water treatment plants (WWTP) posing a potential risk to aquatic organisms. The aim of our research is to evaluate cellular responses of three commercially important marine bivalves - Eastern oysters, blue mussels and hard clams - upon exposure to two β blocker drugs, propranolol and metoprolol, and to find molecular initiating events (MIEs) indicative of the exposure. Bivalves were obtained from Narragansett Bay (Rhode Island, USA) and acclimated in the laboratory. Following acclimation, gills and hepatopancreas (HP) tissues were harvested and separately exposed to 0, 1, 10, 100 and 1000 ng/l of each drug. Tissues were bathed in 30 parts per thousand (ppt) filtered seawater, antibiotic mix, Leibovitz nutrient media, and the test drug. Exposures were conducted for 24 hours and samples were saved for cellular biomarker assays. A lysosomal destabilization assay, which is a marker of membrane damage, was also performed at the end of each exposure.

  1. Ammonia toxicity to the freshwater planarian Polycelis felina: contrasting effects of continuous versus discontinuous exposures.

    PubMed

    Alonso, Álvaro; Camargo, Julio A

    2015-05-01

    Aquatic animals can be exposed to fluctuating concentrations of toxicants. In fact, for some toxicants (i.e., pesticides, ammonia), discontinuous exposure is more environmentally relevant than constant exposure. Responses of aquatic animals to each type of exposure may be different. However, despite the high ecological relevance of behaviour, there is still scarce information on the effects of discontinuous exposure on behaviour. Our study focused on the assessment of unionized ammonia toxicity on the behaviour of a freshwater planarian under continuous exposure (3 days of exposure and 18 days of recovery) versus discontinuous exposure (3 pulses of 1 day with 6 days of recovery between pulses = total 3 days of exposure and 18 days of recovery). Behaviour was assessed as locomotion activity. Bioassays with continuous and discontinuous exposure were performed with one control and five unionized ammonia concentrations (0.14-0.35 mg N-NH3/L). Unionized ammonia in continuous exposure caused less impact on behaviour than equivalent concentrations provided in a discontinuous exposure. By contrast, continuous exposures caused more impact on survival. The discontinuous exposure may allow detoxification during recovery periods, thus increasing the probability of survival in the next pulse. Under continuous exposure, the mortality threshold could be exceeded, and animals could die in greater proportion during exposure as well as the recovery period. We conclude that behavioural activity was a sensitive endpoint to assess the contrasting effects of continuous versus discontinuous exposure and that the response of planarians to discontinuous exposure is different to its response to continuous exposure.

  2. 76 FR 2617 - Lowering Miners' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-14

    ...' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors AGENCY: Mine Safety and... rule addressing Lowering Miners' Exposure to Respirable Coal Mine Dust, Including Continuous Personal..., Lowering Miners' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors....

  3. Exposure assessment to alpha- and beta-pinene, delta(3)-carene and wood dust in industrial production of wood pellets.

    PubMed

    Edman, K; Lofstedt, H; Berg, P; Eriksson, K; Axelsson, S; Bryngelsson, I; Fedeli, C

    2003-04-01

    The main aim of the study was to measure the exposure to monoterpenes (alpha- and beta-pinene and Delta(3)-carene) and wood dust during industrial production of wood pellets and briquettes. Additional aims were to compare the results from wood dust sampled on a filter with real time measurements using a direct reading instrument and to identify peak exposures to dust. Twenty-four men working at six companies involved in industrial production of wood pellets and briquettes participated in the study. Monoterpenes were measured by diffusive sampling and wood dust was measured as total dust. A data logger (DataRAM) was used for continuous monitoring of dust concentration for 18 of the participants. The sampling time was approximately 8 h. The personal exposure to monoterpenes ranged from 0.64 to 28 mg/m(3) and a statistically significant (Kruskal-Wallis test, P = 0.0002) difference in levels of monoterpenes for workers at different companies was seen. In the companies the personal exposure to wood dust varied between 0.16 and 19 mg/m(3) and for 10 participants the levels exceeded the present Swedish occupational exposure limit (OEL) of 2 mg/m(3). The levels of wood dust during the morning shift were significantly (Mann-Whitney test, P = 0.04) higher compared with the afternoon shift. Continuous registration of dust concentration showed peak values for several working operations, especially cleaning of truck engines with compressed air. For 24 workers in six companies involved in industrial production of wood pellets the personal exposure to monoterpenes was low and to wood dust high compared with the present Swedish OEL and previous studies in Swedish wood industries. Since the DataRAM can identify critical working tasks with high wood dust exposure a reduction in exposure levels could probably be achieved by changes in working routines and by the use of protective equipment.

  4. Sustained nicotine exposure differentially affects alpha 3 beta 2 and alpha 4 beta 2 neuronal nicotinic receptors expressed in Xenopus oocytes.

    PubMed

    Hsu, Y N; Amin, J; Weiss, D S; Wecker, L

    1996-02-01

    To determine whether prolonged exposure to nicotine differentially affects alpha 3 beta 2 versus alpha 4 beta 2 nicotinic receptors expressed in Xenopus oocytes, oocytes were coinjected with subunit cRNAs, and peak responses to agonist, evoked by 0.7 or 7 microM nicotine for alpha 4 beta 2 and alpha 3 beta 2 receptors, respectively, were determined before and following incubation for up to 48 h with nanomolar concentrations of nicotine. Agonist responses of alpha 4 beta 2 receptors decreased in a concentration-dependent manner with IC50 values in the 10 nM range following incubation for 24 h and in the 1 nM range following incubation for 48 h. In contrast, responses of alpha 3 beta 2 receptors following incubation for 24-48 h with 1,000 nM nicotine decreased by only 50-60%, and total ablation of responses could not be achieved. Attenuation of responses occurred within the first 5 min of nicotine exposure and was a first-order process for both subtypes; half-lives for inactivation were 4.09 and 2.36 min for alpha 4 beta 2 and alpha 3 beta 2 receptors, respectively. Recovery was also first-order for both subtypes; half-lives for recovery were 21 and 7.5 h for alpha 4 beta 2 and alpha 3 beta 2 receptors, respectively. Thus, the responsiveness of both receptors decreased following sustained exposure to nicotine, but alpha 4 beta 2 receptors recovered much slower. Results may explain the differential effect of sustained nicotine exposure on nicotinic receptor-mediated neurotransmitter release.

  5. Cellular Responses to Beta Blocker Exposures in Marine ...

    EPA Pesticide Factsheets

    β blockers are prescription drugs used for medical treatment of hypertension and arrhythmias. They prevent activation of adenylate cyclase and increases in blood pressure by limiting cAMP production and protein kinase A activation. After being taken therapeutically, β blockers may make their way to coastal habitats via discharge from waste water treatment plants, posing a potential risk to aquatic organisms. The aim of our research is to evaluate cellular biomarkers of β blocker exposure using two drugs, propranolol and metoprolol, in three commercially important marine bivalves -Crassostrea virginica, Mytilus edulis and Mercenaria mercenaria. Bivalves were obtained from Narragansett Bay (Rhode Island, USA) and acclimated in the laboratory. Following acclimation, gills and hepatopancreas tissues were harvested and separately exposed to 0, 1, 10, 100 and 1000 ng/l of each drug for 24 hours. Samples were preserved for cellular biomarker assays. Elevated cellular damage and changes in enzymatic activities were noted at environmentally relevant concentrations, and M. mercenaria was found to be the most sensitive bivalve out of the three species tested. These studies enhance our understanding of the potential impacts of commonly used prescription medication on organisms in coastal ecosystems, and demonstrate that filter feeders such as marine bivalves may serve as good model organisms to examine the effects of water soluble drugs. Evaluating a suite of biomarkers

  6. Evaluation of blue light exposure to beta brainwaves on simulated night driving

    NASA Astrophysics Data System (ADS)

    Purawijaya, Dandri Aly; Fitri, Lulu Lusianti; Suprijanto

    2015-09-01

    Numbers of night driving accident in Indonesia since 2010 are exponentially rising each year with total of loss more than 50 billion rupiah. One of the causes that contribute to night driving accident is drowsiness. Drowsiness is affected by circadian rhythm resulted from the difference of blue light quality and quantity between night and day. Blue light may effect on human physiology through non-visual pathway by suppressing melatonin hormone suppression that influence drowsiness. Meanwhile, the production of hormones and other activities in brain generate bioelectrical activity such as brainwaves and can be recorded using Electroencephalograph (EEG). Therefore, this research objective is to evaluate the effect of blue light exposure to beta brainwave emergence during night driving simulation to a driver. This research was conducted to 4 male subjects who are able to drive and have a legitimate car driving license. The driving simulator was done using SCANIA Truck Driving Simulator on freeform driving mode in dark environment. Subjects drove for total 32 minutes. The data collections were taken in 2 days with 16 minutes for each day. The 16 minutes were divided again into 8 minutes adaptation in dark and 8 minutes for driving either in blue light exposure or in total darkness. While driving the simulation, subjects' brainwaves were recorded using EEG EMOTIV 14 Channels, exposed by LED monochromatic blue light with 160 Lux from source and angle 45o and sat 1 m in front of the screen. Channels used on this research were for visual (O1; O2), cognition (F3; F4; P7; P8), and motor (FC5; FC6). EEG brainwave result was filtered with EEGLab to obtain beta waves at 13 - 30 Hz frequencies. Results showed that beta waves response to blue light varied for each subject. Blue light exposure either increased or decreased beta waves in 2 minutes pattern and maintaining beta waves on cognition and motor area in 3 out of 4 subjects. Meanwhile, blue light exposure did not maintain

  7. Evaluation of the Eberline AMS-3A and AMS-4 Beta continuous air monitors

    SciTech Connect

    Johnson, M.L.; Sisk, D.R.

    1996-03-01

    Eberline AMS-3A-1 and AMS-4 beta continuous air monitors were tested against the criteria set forth in the ANSI Standards N42.18, Specification and Performance of On-site Instrumentation for Continuously Monitoring Radioactivity in Effluents, and ANSI N42.17B, Performance Specification for Health Physics Instrumentation - Occupational Airborne Radioactivity Monitoring Instrumentation. ANSI N42.18 does not, in general, specify testing procedures for demonstrating compliance with the criteria set forth in the standard; therefore, wherever possible, the testing procedures given in ANSI N42.17B were adopted. In all cases, the more restrictive acceptance criteria and/or the more demanding test conditions of the two standards were used.

  8. Constructing inverse probability weights for continuous exposures: a comparison of methods.

    PubMed

    Naimi, Ashley I; Moodie, Erica E M; Auger, Nathalie; Kaufman, Jay S

    2014-03-01

    Inverse probability-weighted marginal structural models with binary exposures are common in epidemiology. Constructing inverse probability weights for a continuous exposure can be complicated by the presence of outliers, and the need to identify a parametric form for the exposure and account for nonconstant exposure variance. We explored the performance of various methods to construct inverse probability weights for continuous exposures using Monte Carlo simulation. We generated two continuous exposures and binary outcomes using data sampled from a large empirical cohort. The first exposure followed a normal distribution with homoscedastic variance. The second exposure followed a contaminated Poisson distribution, with heteroscedastic variance equal to the conditional mean. We assessed six methods to construct inverse probability weights using: a normal distribution, a normal distribution with heteroscedastic variance, a truncated normal distribution with heteroscedastic variance, a gamma distribution, a t distribution (1, 3, and 5 degrees of freedom), and a quantile binning approach (based on 10, 15, and 20 exposure categories). We estimated the marginal odds ratio for a single-unit increase in each simulated exposure in a regression model weighted by the inverse probability weights constructed using each approach, and then computed the bias and mean squared error for each method. For the homoscedastic exposure, the standard normal, gamma, and quantile binning approaches performed best. For the heteroscedastic exposure, the quantile binning, gamma, and heteroscedastic normal approaches performed best. Our results suggest that the quantile binning approach is a simple and versatile way to construct inverse probability weights for continuous exposures.

  9. Fast Sausage Modes in Magnetic Tubes with Continuous Transverse Profiles: Effects of a Finite Plasma Beta

    NASA Astrophysics Data System (ADS)

    Chen, Shao-Xia; Li, Bo; Xiong, Ming; Yu, Hui; Guo, Ming-Zhe

    2016-12-01

    While standing fast sausage modes in flare loops are often invoked to interpret quasi-periodic pulsations (QPPs) in solar flares, it is unclear as to how they are influenced by the combined effects of a continuous transverse structuring and a finite internal plasma beta ({β }{{i}}). We derive a generic dispersion relation governing linear sausage waves in straight magnetic tubes for which plasma pressure is not negligible, and the density and temperature inhomogeneities of essentially arbitrary form take place in a layer of arbitrary width. Focusing on fast modes, we find that {β }{{i}} only weakly influences {k}{{c}}, the critical longitudinal wavenumber separating the leaky from trapped modes. Likewise, for both trapped and leaky modes, the periods P in units of the transverse fast time depend only weakly on {β }{{i}}, which is compatible with the fact that the effective wave vectors of fast sausage modes are largely perpendicular to the background magnetic field. However, a weak {β }{{i}} dependence of the damping times τ is seen only when the length-to-radius ratio L/R is ∼50% larger than some critical value π /({k}{{c}}R), which itself rather sensitively depends on the density contrast, profile steepness, as well as on how the transverse structuring is described. In the context of QPPs, we conclude that the much simpler zero-beta theory can be employed for trapped modes, as long as one sees the deduced internal Alfvén speed as actually being the fast speed. In contrast, effects due to a finite beta in flare loops should be considered when leaky modes are exploited.

  10. 76 FR 25277 - Lowering Miners' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-04

    ...' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors AGENCY: Mine Safety and... period on the proposed rule addressing Lowering Miners' Exposure to Respirable Coal Mine Dust, Including... FR 64412), MSHA published a proposed rule, Lowering Miners' Exposure to Respirable Coal Mine...

  11. Continuous 3-day exposure assessment of workplace manufacturing silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Lee, Ji Hyun; Ahn, Kangho; Kim, Sun Man; Jeon, Ki Soo; Lee, Jong Seong; Yu, Il Je

    2012-09-01

    With the increased production and widespread use of nanomaterials, human and environmental exposure to nanomaterials is inevitably increasing. Therefore, this study monitored the possible nanoparticle exposure at a workplace that manufactures silver nanoparticles. To estimate the potential exposure of workers, personal sampling, area monitoring, and real-time monitoring were conducted over 3 days using a scanning mobility particle sizer and dust monitor at a workplace where the workers handle nanomaterials. The area sampling concentrations obtained from the injection room showed the highest concentration, ranging from 0.00501 to 0.28873 mg/m3. However, apart from the injection room, none of the area samplings obtained from other locations showed a concentration higher than 0.0013 mg/m3. Meanwhile, the personal sampling concentrations ranged from 0.00004 to 0.00243 mg/m3 over the 3 days of sampling, which was much lower than the silver TLV. The particle number concentrations at the silver nanoparticle manufacturing workplace were 911,170 (1st day), 1,631,230 (2nd day), and 1,265,024 (3rd day) particles/cm3 with a size range of 15-710.5 nm during the operation of the reactor, while the concentration decreased to 877,364.9 (1st day), 492,732 (2nd day), and 344,343 (3rd day) particles/cm3 when the reactor was stopped.

  12. Examination of Urinary Beta-Naphthol as a Biomarker Indicative of Jet Fuel Exposures

    DTIC Science & Technology

    2015-04-01

    biomarker of exposure to jet fuels. Beta-naphthol is a metabolic product of naphthalene, a poly aromatic hydrocarbon found in jet fuel. Published...Statistical analyses of the meta data and uβ−Nph included standard analysis of variance, Mann-Whitney Rank Sum test, factor analysis ...Concentration in Smokers and Nonsmokers………………… 17 3.3.2 β-Nph Concentration in Smokers and Nonsmokers…………………………………….. 19 3.3.3 Statistical Analysis of uβ

  13. Characterization of commercial proton exchange membrane materials after exposure to beta and gamma radiation

    SciTech Connect

    Thomson, S.N.; Carson, R.; Muirhead, C.; Li, H.; Castillo, I.; Boniface, H.; Suppiah, S.; Ratnayake, A.; Robinson, J.

    2015-03-15

    Proton Exchange Membrane (PEM) type electrolysis cells have a potential use for tritium removal and heavy water upgrading. AECL is currently exposing various commercial PEM materials to both gamma (Cobalt-60 source) and beta (tritiated water) radiation to study the effects of radiation on these materials. This paper summarizes the testing methods and results that have been collected to date. The PEM materials that are or have been exposed to radiation are: Nafion 112, 212, 117 and 1110. Membrane characterization pre- and post- exposure consists of non-destructive inspection (FTIR, SEM/XPS), mechanical (tensile strength, percentage elongation, and modulus), electrical (resistance), or chemical (ion-exchange capacity - IEC). It has appeared that the best characterization techniques to compare exposed versus unexposed membranes were IEC, ultimate tensile strength and percent elongation. These testing techniques are easy and cheap to perform. The non-destructive tests, such as SEM and FTIR did not provide particularly useful information on radiation-induced degradation. Where changes in material properties were measured after radiation exposure, they would be expected to result in poorer cell performance. However, for modest γ-radiation exposure, all membranes showed a slight decrease in cell voltage (better performance). In contrast, the one β-radiation exposed membrane did show the expected increase in cell voltage. The counterintuitive trend for γ-radiation exposed membranes is not yet understood. Based on these preliminary results, it appears that γ- and β-radiation exposures have different effects.

  14. Mixed-effects beta regression for modeling continuous bounded outcome scores using NONMEM when data are not on the boundaries.

    PubMed

    Xu, Xu Steven; Samtani, Mahesh N; Dunne, Adrian; Nandy, Partha; Vermeulen, An; De Ridder, Filip

    2013-08-01

    Beta regression models have been recommended for continuous bounded outcome scores that are often collected in clinical studies. Implementing beta regression in NONMEM presents difficulties since it does not provide gamma functions required by the beta distribution density function. The objective of the study was to implement mixed-effects beta regression models in NONMEM using Nemes' approximation to the gamma function and to evaluate the performance of the NONMEM implementation of mixed-effects beta regression in comparison to the commonly used SAS approach. Monte Carlo simulations were conducted to simulate continuous outcomes within an interval of (0, 70) based on a beta regression model in the context of Alzheimer's disease. Six samples per subject over a 3 years period were simulated at 0, 0.5, 1, 1.5, 2, and 3 years. One thousand trials were simulated and each trial had 250 subjects. The simulation-reestimation exercise indicated that the NONMEM implementation using Laplace and Nemes' approximations provided only slightly higher bias and relative RMSE (RRMSE) compared to the commonly used SAS approach with adaptive Gaussian quadrature and built-in gamma functions, i.e., the difference in bias and RRMSE for fixed-effect parameters, random effects on intercept, and the precision parameter were <1-3 %, while the difference in the random effects on the slope was <3-7 % under the studied simulation conditions. The mixed-effect beta regression model described the disease progression for the cognitive component of the Alzheimer's disease assessment scale from the Alzheimer's Disease Neuroimaging Initiative study. In conclusion, with Nemes' approximation of the gamma function, NONMEM provided comparable estimates to those from SAS for both fixed and random-effect parameters. In addition, the NONMEM run time for the mixed beta regression models appeared to be much shorter compared to SAS, i.e., 1-2 versus 20-40 s for the model and data used in the manuscript.

  15. Effects of continuous and pulsed chronic microwave exposure on rabbits

    NASA Astrophysics Data System (ADS)

    Chou, Chung-Kwang; Guy, Arthur W.; McDougall, John A.; Han, Lock-Fong

    1982-01-01

    Eighteen young adult New Zealand rabbits (nine males, nine females) were equally divided into three groups. One group was exposed to CW 2450-MHz fields at an incident power density of 1.5 mW/cm2 for 2 hours daily for 3 months. Another group was exposed to pulsed fields with pulses of 10 μ s duration occurring 100 times per second. The third group was sham exposed. Each rabbit was placed in a Plexiglas cage and exposed in a miniature plane wave exposure chamber. An S band horn was mounted 1 m above the animal. Thermographic data showed a peak specific absorption rate of 1.64 W/kg in the head and 2.1 W/kg in the back. Body weights were measured every other day. Electroencephalogram and evoked potentials were recorded weekly via implanted carbon-loaded Teflon electrodes. Blood samples were taken monthly for hematological, chemical, and morphological studies. Eyes were examined for cataract formation. Before the animals were sacrificed, apomorphine-induced behavioral excitation and hyperthermia were studied. Finally, pathological examinations on many tissues and organs were performed. Statistically, there were no significant differences in measured parameters observed between the exposed and sham animals.

  16. Is plasma {beta}-glucuronidase a novel human biomarker for monitoring anticholinesterase pesticides exposure? A Malaysian experience

    SciTech Connect

    Inayat-Hussain, Salmaan H. |. E-mail: salmaan@mib.gov.my; Lubis, Syarif Husin; Sakian, Noor Ibrahim Mohamed; Ghazali, Ahmad Rohi; Ali, Noor Suhailah; El Sersi, Magdi; Toong, Lee Mun; Zainal, Awang Mat; Hashim, Suhaimi; Ghazali, Mohd Shariman; Saidin, Mohd Nazri; Rahman, Ab Razak Ab; Rafaai, Mohd Jamil Mohd; Omar, Sollahudin; Rapiai, Rafiah; Othman, Radziah; Chan, Lee Tiong; Johari, Amran; Soon, Wong Hing; Salleh, Abdul Rahim; Satoh, Tetsuo

    2007-03-15

    A cross-sectional study was conducted to investigate the effects of acute and chronic pesticide exposure on the plasma {beta}-glucuronidase enzyme activity among five patients of acute pesticide poisoning in Tengku Ampuan Rahimah Hospital, Klang, 230 farmers in the MADA area, Kedah and 49 fishermen in Setiu, Terengganu. The duration of pesticide exposure among the patients was unknown, but the plasma samples from patients were collected on day one in the hospital. The duration of pesticide exposure among the farmers was between 1 and 45 years. The {beta}-glucuronidase activity was compared with plasma cholinesterase activity in the same individual. The plasma cholinesterase activity was measured using Cholinesterase (PTC) Reagent set kit (Teco Diagnostics, UK) based on colorimetric method, while the plasma {beta}-glucuronidase activity was measured fluorometrically based on {beta}-glucuronidase assay. The plasma cholinesterase activity was significantly reduced (p < 0.05) among the patients (1386.786 {+-} 791.291 U/L/min) but the inhibition in plasma cholinesterase activity among the farmers (7346.5 {+-} 1860.786 U/L/min) was not significant (p > 0.05). The plasma {beta}-glucuronidase activity among the farmers was significantly elevated (p < 0.05) (0.737 {+-} 0.425 {mu}M/h) but not significant among the patients (p > 0.05). The plasma cholinesterase activity was positively correlated with the plasma {beta}-glucuronidase activity among the farmers (r = 0.205, p < 0.01) but not among the patients (r = 0.79, p > 0.05). Thus, plasma {beta}-glucuronidase enzyme activity can be measured as a biomarker for the chronic exposure of pesticide. However, further studies need to be performed to confirm whether plasma {beta}-glucuronidase can be a sensitive biomarker for anticholinesterase pesticide poisoning.

  17. Continuous exposure to dibromoacetic acid delays pubertal development and compromises sperm quality in the rat

    EPA Science Inventory

    Previously our work on the haloacid by-products of drinking water disinfection focused on adult exposures. Herein we evaluate the consequence of continuous exposure to dibromoacetic acid (DBA) via drinking water through reproductive development into adulthood. An initial study in...

  18. A Preliminary Investigation of Continuous and Intermittent Exposures in the Treatment of Public Speaking Anxiety

    ERIC Educational Resources Information Center

    Seim, Richard W.; Waller, Stacey A.; Spates, C. Richard

    2010-01-01

    It is often argued that exposure-based treatments for anxiety disorders are only effective if the exposures are presented continuously until a marked decrement in anxiety is achieved (e.g. Foa & Kozak, 1986). However, the data supporting this conclusion is limited. This study compared two treatments for public speaking anxiety: one requiring…

  19. 75 FR 69617 - Lowering Miners' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-15

    ... 30 CFR Parts 70, 71, 72, 75, and 90 RIN 1219-AB64 Lowering Miners' Exposure to Respirable Coal Mine... Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors. The proposed rule was published on... rule. The proposed rule would lower miners' exposure to respirable coal mine dust by revising...

  20. Multigenerational effects of gold nanoparticles in Caenorhabditis elegans: Continuous versus intermittent exposures.

    PubMed

    Moon, Jongmin; Kwak, Jin Il; Kim, Shin Woong; An, Youn-Joo

    2017-01-01

    Nanomaterials can become disseminated directly or indirectly into the soil ecosystem through various exposure routes. Thus, it is important to study various deposition routes of nanomaterials into the soil, as well as their toxicities. Here, we investigated the multigenerational effects of gold nanoparticles (AuNPs) on C. elegans after continuous or intermittent food intake. Following continuous exposure, significant differences were observed in the reproduction rate of C. elegans in the F2-F4 generations, which were associated with reproductive system abnormalities. However, following intermittent AuNP exposure in P0 and F3, reproductive system abnormalities and inhibited reproduction rates were observed in F2 and F3. While continuous AuNP exposure impaired reproduction from F2 to F4, intermittent exposure caused more pronounced effects on F3 worms, which may have resulted from damage during the convalescence period up through F2. These data showed the occurrence of multigenerational effects following different exposure patterns, exposure levels, and recovery periods. To our knowledge, this is the first study to demonstrate that multigenerational nano-toxicity is caused by different exposure patterns and provides insights into the unpredictable exposure scenarios of AuNPs and their adverse effects.

  1. Subcellular glucose exposure biases the spatial distribution of insulin granules in single pancreatic beta cells

    NASA Astrophysics Data System (ADS)

    Terao, Kyohei; Gel, Murat; Okonogi, Atsuhito; Fuke, Ariko; Okitsu, Teru; Tada, Takashi; Suzuki, Takaaki; Nagamatsu, Shinya; Washizu, Masao; Kotera, Hidetoshi

    2014-02-01

    In living tissues, a cell is exposed to chemical substances delivered partially to its surface. Such a heterogeneous chemical environment potentially induces cell polarity. To evaluate this effect, we developed a microfluidic device that realizes spatially confined delivery of chemical substances at subcellular resolution. Our microfluidic device allows simple setup and stable operation for over 4 h to deliver chemicals partially to a single cell. Using the device, we showed that subcellular glucose exposure triggers an intracellular [Ca2+] change in the β-cells. In addition, the imaging of a cell expressing GFP-tagged insulin showed that continuous subcellular exposure to glucose biased the spatial distribution of insulin granules toward the site where the glucose was delivered. Our approach illustrates an experimental technique that will be applicable to many biological experiments for imaging the response to subcellular chemical exposure and will also provide new insights about the development of polarity of β-cells.

  2. Aerosolized Red Tide Toxins (Brevetoxins) and Asthma: Continued health effects after 1 hour beach exposure.

    PubMed

    Kirkpatrick, Barbara; Fleming, Lora E; Bean, Judy A; Nierenberg, Kate; Backer, Lorraine C; Cheng, Yung Sung; Pierce, Richard; Reich, Andrew; Naar, Jerome; Wanner, Adam; Abraham, William M; Zhou, Yue; Hollenbeck, Julie; Baden, Daniel G

    2011-01-01

    Blooms of the toxic dinoflagellate, Karenia brevis, produce potent neurotoxins in marine aerosols. Recent studies have demonstrated acute changes in both symptoms and pulmonary function in asthmatics after only 1 hour of beach exposure to these aerosols. This study investigated if there were latent and/or sustained effects in asthmatics in the days following the initial beach exposure during periods with and without an active Florida red tide.Symptom data and spirometry data were collected before and after 1 hour of beach exposure. Subjects kept daily symptom diaries and measured their peak flow each morning for 5 days following beach exposure. During non-exposure periods, there were no significant changes in symptoms or pulmonary function either acutely or over 5 days of follow-up. After the beach exposure during an active Florida red tide, subjects had elevated mean symptoms which did not return to the pre-exposure baseline for at least 4 days. The peak flow measurements decreased after the initial beach exposure, decreased further within 24 hours, and continued to be suppressed even after 5 days. Asthmatics may continue to have increased symptoms and delayed respiratory function suppression for several days after 1 hour of exposure to the Florida red tide toxin aerosols.

  3. Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells.

    PubMed

    Pavlikova, Nela; Smetana, Pavel; Halada, Petr; Kovar, Jan

    2015-10-01

    Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE.

  4. A Continuous Correlated Beta Process Model for Genetic Ancestry in Admixed Populations

    PubMed Central

    Gompert, Zachariah

    2016-01-01

    Admixture and recombination create populations and genomes with genetic ancestry from multiple source populations. Analyses of genetic ancestry in admixed populations are relevant for trait and disease mapping, studies of speciation, and conservation efforts. Consequently, many methods have been developed to infer genome-average ancestry and to deconvolute ancestry into continuous local ancestry blocks or tracts within individuals. Current methods for local ancestry inference perform well when admixture occurred recently or hybridization is ongoing, or when admixture occurred in the distant past such that local ancestry blocks have fixed in the admixed population. However, methods to infer local ancestry frequencies in isolated admixed populations still segregating for ancestry do not exist. In the current paper, I develop and test a continuous correlated beta process model to fill this analytical gap. The method explicitly models autocorrelations in ancestry frequencies at the population-level and uses discriminant analysis of SNP windows to take advantage of ancestry blocks within individuals. Analyses of simulated data sets show that the method is generally accurate such that ancestry frequency estimates exhibited low root-mean-square error and were highly correlated with the true values, particularly when large (±10 or ±20) SNP windows were used. Along these lines, the proposed method outperformed post hoc inference of ancestry frequencies from a traditional hidden Markov model (i.e., the linkage model in structure), particularly when admixture occurred more distantly in the past with little on-going gene flow or was followed by natural selection. The reliability and utility of the method was further assessed by analyzing genetic ancestry in an admixed human population (Uyghur) and three populations from a hybrid zone between Mus domesticus and M. musculus. Considerable variation in ancestry frequencies was detected within and among chromosomes in the Uyghur

  5. A Continuous Correlated Beta Process Model for Genetic Ancestry in Admixed Populations.

    PubMed

    Gompert, Zachariah

    2016-01-01

    Admixture and recombination create populations and genomes with genetic ancestry from multiple source populations. Analyses of genetic ancestry in admixed populations are relevant for trait and disease mapping, studies of speciation, and conservation efforts. Consequently, many methods have been developed to infer genome-average ancestry and to deconvolute ancestry into continuous local ancestry blocks or tracts within individuals. Current methods for local ancestry inference perform well when admixture occurred recently or hybridization is ongoing, or when admixture occurred in the distant past such that local ancestry blocks have fixed in the admixed population. However, methods to infer local ancestry frequencies in isolated admixed populations still segregating for ancestry do not exist. In the current paper, I develop and test a continuous correlated beta process model to fill this analytical gap. The method explicitly models autocorrelations in ancestry frequencies at the population-level and uses discriminant analysis of SNP windows to take advantage of ancestry blocks within individuals. Analyses of simulated data sets show that the method is generally accurate such that ancestry frequency estimates exhibited low root-mean-square error and were highly correlated with the true values, particularly when large (±10 or ±20) SNP windows were used. Along these lines, the proposed method outperformed post hoc inference of ancestry frequencies from a traditional hidden Markov model (i.e., the linkage model in structure), particularly when admixture occurred more distantly in the past with little on-going gene flow or was followed by natural selection. The reliability and utility of the method was further assessed by analyzing genetic ancestry in an admixed human population (Uyghur) and three populations from a hybrid zone between Mus domesticus and M. musculus. Considerable variation in ancestry frequencies was detected within and among chromosomes in the Uyghur

  6. Enantiomerically pure trans-beta-lactams from alpha-amino acids via compact fluorescent light (CFL) continuous-flow photolysis.

    PubMed

    Vaske, Yvette S Mimieux; Mahoney, Maximillian E; Konopelski, Joseph P; Rogow, David L; McDonald, William J

    2010-08-18

    Photolysis of alpha-diazo-N-methoxy-N-methyl (Weinreb) beta-ketoamides derived from enantiomerically pure (EP) alpha-amino acids affords the corresponding EP beta-lactams via an intramolecular Wolff rearrangement. The photochemistry is promoted with either standard UV irradiation or through the use of a 100 W compact fluorescent light; the latter affords a safe and environmentally friendly alternative to standard photolysis conditions. A continuous-flow photochemical reactor made from inexpensive laboratory equipment reduced reaction times and was amenable to scale-up. The diastereoselectivity (cis or trans) of the product beta-lactams has been shown to vary from modest to nearly complete. An extremely facile, atom-economical method for the epimerization of the product mixture to the trans isomer, which is generally highly crystalline, has been developed. Evidence for C3 epimerization of Weinreb amide structures via a nonbasic, purely thermal route is presented. Subsequent transformations of both the Weinreb amide at C3 (beta-lactam numbering) and the amino acid side chain at C4 are well-tolerated, allowing for a versatile approach to diverse beta-lactam structures. The technology is showcased in the synthesis of a common intermediate used toward several carbapenem-derived structures starting from unfunctionalized aspartic acid.

  7. Differing response of asthmatics to sulfur dioxide exposure with continuous and intermittent exercise

    SciTech Connect

    Kehrl, H.R.; Roger, L.J.; Hazucha, M.J.; Horstman, D.H.

    1986-08-29

    Ten mild asthmatics were initially exposed in an environmental chamber (26 C, 70% RH) to clean air and 1.0 ppm sulfur dioxide while performing three sets of 10 minutes treadmill exercise (ventilation = 41 1/min) and 15 minutes rest. To evaluate the effects of the pattern and duration of exercise on the response to sulfur dioxide exposure, the subjects were then exposed to the same environmental conditions, while exercising continuously for 30 minutes. Specific airways resistance (SRaw) was measured by body plethysmography prior to exposures and after each exercise. All SRaw responses with sulfur dioxide exposure were significantly different than the clean air responses. It appears that asthmatics show an attenuated response to repetitive exercise in a 1.00 ppm sulfur dioxide atmosphere and that the response to sulfur dioxide exposure develops rapidly and is maintained during 30 minutes continuous exercise.

  8. Prenatal cadmium exposure dysregulates sonic hedgehog and Wnt/beta-catenin signaling in the thymus resulting in altered thymocyte development

    SciTech Connect

    Hanson, Miranda L.; Brundage, Kathleen M.; Schafer, Rosana; Tou, Janet C.; Barnett, John B.

    2010-01-15

    Cadmium (Cd) is both an environmental pollutant and a component of cigarette smoke. Although evidence demonstrates that adult exposure to Cd causes changes in the immune system, there are limited reports in the literature of immunomodulatory effects of prenatal exposure to Cd. The sonic hedgehog (Shh) and Wnt/beta-catenin pathways are required for thymocyte maturation. Several studies have demonstrated that Cd exposure affects these pathways in different organ systems. This study was designed to investigate the effect of prenatal Cd exposure on thymocyte development, and to determine if these effects were linked to dysregulation of Shh and Wnt/beta-catenin pathways. Pregnant C57Bl/6 mice were exposed to an environmentally relevant dose (10 ppm) of Cd throughout pregnancy and effects on the thymus were assessed on the day of birth. Thymocyte phenotype was determined by flow cytometry. A Gli:luciferase reporter cell line was used to measure Shh signaling. Transcription of target genes and translation of key components of both signaling pathways were assessed using real-time RT-PCR and western blot, respectively. Prenatal Cd exposure increased the number of CD4{sup +} cells and a subpopulation of double-negative cells (DN; CD4{sup -}CD8{sup -}), DN4 (CD44{sup -}CD25{sup -}). Shh and Wnt/beta-catenin signaling were both decreased in the thymus. Target genes of Shh (Patched1 and Gli1) and Wnt/beta-catenin (c-fos, and c-myc) were affected differentially among thymocyte subpopulations. These findings suggest that prenatal exposure to Cd dysregulates two signaling pathways in the thymus, resulting in altered thymocyte development.

  9. Developmental and hematological responses to low level continuous exposure of nitrogen dioxide in mice

    NASA Technical Reports Server (NTRS)

    Singh, J.

    1977-01-01

    Young healthy mice were continuously exposed to 0ppm, 0.5ppm, 1.0ppm and 5ppm nitrogen dioxide gas for eight weeks. Nitrogen dioxide exposure for eight weeks decreased the average weight of mice, increased the average weight of lungs, heart, and brain and decreased the average weight of liver. Nitrogen dioxide exposure did not have any effects on the WBC and RBC in mice blood but it increased the HCT and HGB in mice blood. Nitrogen dioxide exposure increased the MCV and decreased the MCH and MCHC in mice blood.

  10. Effects of 17 beta-estradiol exposure on Xenopus laevis gonadal histopathology.

    PubMed

    Wolf, Jeffrey C; Lutz, Ilka; Kloas, Werner; Springer, Timothy A; Holden, Larry R; Krueger, Henry O; Hosmer, Alan J

    2010-05-01

    The natural estrogen 17 beta-estradiol (E2) is a potential environmental contaminant commonly employed as a positive control substance in bioassays involving estrogenic effects. The aquatic anuran Xenopus laevis is a frequent subject of reproductive endocrine disruptor research; however, histopathological investigations have tended to be less than comprehensive. Consequently, a study was designed to characterize gross and microscopic changes in the gonads of X. laevis as a result of E2 exposure. Additional goals of this study, which consisted of three separate experiments, included the standardization of diagnostic terminology and criteria, the validation of statistical methodology, and the establishment of a half maximal effective concentration (EC50) for E2 as defined by an approximately 50% conversion of presumptive genotypic males to phenotypic females. In the first experiment, frogs were exposed to nominal concentrations of 0, 0.2, 1.5, or 6.0 microg/L E2. From these experimental results and those of a subsequent range finding trial, the EC50 for E2 was determined to be approximately 0.2 microg/L. This E2 concentration was utilized in the other two experiments, which were performed at different facilities to confirm the reproducibility of results. Experiments were conducted according to Good Laboratory Practice guidelines, and the histopathologic evaluations were peer reviewed by an independent pathologist. Among the three trials, the histopathological findings that were strongly associated with E2-exposure (p<0.001 to 0.0001) included an increase in the proportion of phenotypic females, mixed sex, dilated testis tubules, dividing gonocytes in the testis, and dilated ovarian cavities in phenotypic ovaries. A comparison of the gross and microscopic evaluations suggested that some morphologic changes in the gonads may potentially be missed if studies rely entirely on macroscopic assessment.

  11. Overexpression of G6PD and HSP90 Beta in Mice with Benzene Exposure Revealed by Serum Peptidome Analysis.

    PubMed

    Zhang, Juan; Tan, Kehong; Meng, Xing; Yang, Wenwen; Wei, Haiyan; Sun, Rongli; Yin, Lihong; Pu, Yuepu

    2015-09-10

    The small peptides representation of the original proteins are a valuable source of information that can be used as biomarkers involved in toxicity mechanism for chemical exposure. The aim of this study is to investigate serum peptide biomarkers of benzene exposure. C57BL/6 mice were enrolled into control group and benzene groups of 150 and 300 mg/kg/d Serum peptides were identified by mass spectrometry using an assisted laser desorption ionization/time of flight mass spectrometry (MS). Differential peptide spectra were obtained by tandem mass spectrometry and analyzed by searching the International Protein Index using the Sequest program. Forty-one peptide peaks were found in the range of 1000-10,000 Da molecular weight. Among them, seven peaks showed significantly different expression between exposure groups and control group. Two peptide peaks (1231.2 and 1241.8), which showed a two-fold increase in expression, were sequenced and confirmed as glucose 6-phosphate dehydrogenase (G6PD) and heat shock protein 90 Beta (HSP90 Beta), respectively. Furthermore, the expression of the two proteins in liver cells showed the same trend as in serum. In conclusion, G6PD and HSP90 beta might be the candidate serum biomarkers of benzene exposure. It also provided possible clues for the molecular mechanism of benzene-induced oxidative stress.

  12. Overexpression of G6PD and HSP90 Beta in Mice with Benzene Exposure Revealed by Serum Peptidome Analysis

    PubMed Central

    Zhang, Juan; Tan, Kehong; Meng, Xing; Yang, Wenwen; Wei, Haiyan; Sun, Rongli; Yin, Lihong; Pu, Yuepu

    2015-01-01

    The small peptides representation of the original proteins are a valuable source of information that can be used as biomarkers involved in toxicity mechanism for chemical exposure. The aim of this study is to investigate serum peptide biomarkers of benzene exposure. C57BL/6 mice were enrolled into control group and benzene groups of 150 and 300 mg/kg/d Serum peptides were identified by mass spectrometry using an assisted laser desorption ionization/time of flight mass spectrometry (MS). Differential peptide spectra were obtained by tandem mass spectrometry and analyzed by searching the International Protein Index using the Sequest program. Forty-one peptide peaks were found in the range of 1000–10,000 Da molecular weight. Among them, seven peaks showed significantly different expression between exposure groups and control group. Two peptide peaks (1231.2 and 1241.8), which showed a two-fold increase in expression, were sequenced and confirmed as glucose 6-phosphate dehydrogenase (G6PD) and heat shock protein 90 Beta (HSP90 Beta), respectively. Furthermore, the expression of the two proteins in liver cells showed the same trend as in serum. In conclusion, G6PD and HSP90 beta might be the candidate serum biomarkers of benzene exposure. It also provided possible clues for the molecular mechanism of benzene-induced oxidative stress. PMID:26378550

  13. Infrared skin damage thresholds from 1940-nm continuous-wave laser exposures

    NASA Astrophysics Data System (ADS)

    Oliver, Jeffrey W.; Stolarski, David J.; Noojin, Gary D.; Hodnett, Harvey M.; Harbert, Corey A.; Schuster, Kurt J.; Foltz, Michael F.; Kumru, Semih S.; Cain, Clarence P.; Finkeldei, C. J.; Buffington, Gavin D.; Noojin, Isaac D.; Thomas, Robert J.

    2010-11-01

    A series of experiments are conducted in vivo using Yucatan mini-pigs (Sus scrofa domestica) to determine thermal damage thresholds to the skin from 1940-nm continuous-wave thulium fiber laser irradiation. Experiments employ exposure durations from 10 ms to 10 s and beam diameters of approximately 4.8 to 18 mm. Thermal imagery data provide a time-dependent surface temperature response from the laser. A damage endpoint of minimally visible effect is employed to determine threshold for damage at 1 and 24 h postexposure. Predicted thermal response and damage thresholds are compared with a numerical model of optical-thermal interaction. Results are compared with current exposure limits for laser safety. It is concluded that exposure limits should be based on data representative of large-beam exposures, where effects of radial diffusion are minimized for longer-duration damage thresholds.

  14. Graded exposure therapy for addressing claustrophobic reactions to continuous positive airway pressure: a case series report.

    PubMed

    Means, Melanie K; Edinger, Jack D

    2007-01-01

    Continuous positive airway pressure (CPAP) is a safe, effective treatment for obstructive sleep apnea, and yet many patients develop claustrophobic reactions to the CPAP nasal mask and cannot tolerate this treatment. We examined the efficacy of a graded in-vivo exposure therapy for enhancing CPAP adherence using a retrospective, case series design. Objective CPAP adherence data were obtained on clinical patients who attended 1 or more sessions of exposure therapy with a behavioral sleep psychologist. Compared to pre-treatment, patients used CPAP significantly longer after exposure therapy. No predictors of treatment response were identified. CPAP exposure therapy may be beneficial in some cases; however, further research is needed to determine types of patients most likely to benefit from this therapy.

  15. Translocation of PKC-betaII is mediated via RACK-1 in the neuronal cells following dioxin exposure.

    PubMed

    Lee, Hyun-Gyo; Kim, Sun-Young; Choi, Eun-Jung; Park, Ki-Yeon; Yang, Jae-Ho

    2007-03-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is known to induce neurotoxic effects. However, the mechanism of TCDD-mediated signaling pathways and its possible molecular targets in neurons remains unknown. In this study, we analyzed effects of TCDD on neurofilament subunits, receptor for activated C kinase-1 (RACK-1), and PKC-betaII activity in developing neuronal cells. TCDD induced a significant increase of RACK-1, an adaptor protein for protein kinase C (PKC), in cerebellar granule cells in both dose- and time-dependent manner, indicating that RACK-1 is a sensitive molecular target in neuronal cells for TCDD exposure. TCDD induced a dose-dependent translocation of PKC-betaII from cytosol to membrane fractions. However, when RACK-1 induction was blocked by antisense oligonucleotide or alpha-naphthoflavone, Ah receptor (AhR) inhibitor, the translocation of PKC-betaII was inhibited. Our data suggests that TCDD activates PKC-betaII via RACK-1 in an AhR-dependent manner. This is the first report identifying RACK-1 as a target molecule involved in TCDD-mediated signaling pathways. TCDD exposure also increased the level of neurofilament-H mRNA. These results suggest that identification of target molecules may contribute to improve our understanding of TCDD-mediated signaling pathway and the risk assessment of TCDD-induced neurotoxicities.

  16. Increased pancreatic beta-cell apoptosis following fetal and neonatal exposure to nicotine is mediated via the mitochondria.

    PubMed

    Bruin, Jennifer E; Gerstein, Hertzel C; Morrison, Katherine M; Holloway, Alison C

    2008-06-01

    In Canada, nicotine replacement therapy is recommended as a safe smoking cessation aid for pregnant women. However, we have shown in an animal model that fetal and neonatal nicotine exposure causes increased beta-cell apoptosis and loss of beta-cell mass, which leads to the development of postnatal dysglycemia and obesity. The goal of this study was to determine whether the observed beta-cell apoptosis is mediated via the mitochondrial and/or death receptor pathway. Female Wistar rats were given saline (control) or nicotine bitartrate (1 mg/kg/day) via sc injection for 2 weeks prior to mating until weaning (postnatal day 21). At weaning, pancreas tissue was collected for Western blotting, electron microscopy (EM), and immunohistochemistry. Key markers of each apoptotic pathway were examined in whole pancreas homogenates and mitochondrial/cytosolic pancreas fractions. In the death receptor pathway, Fas and soluble Fas ligand (FasL) protein were significantly increased in the nicotine-exposed offspring compared to control animals; there was no difference in the ratio of inactive/active caspase-8 or membrane-bound FasL expression. In the mitochondrial pathway, there was a significant increase in the ratio of Bcl2/Bax, Bax translocation to the mitochondria, cytochrome c release to the cytosol, and the ratio of active/inactive caspase-3 in nicotine-exposed offspring relative to control animals. Furthermore, increased mitochondrial swelling was observed by EM in the pancreatic beta cells of nicotine-exposed offspring. Taken together, these data suggest that beta-cell apoptosis following developmental nicotine exposure is mediated via the mitochondria.

  17. Effects of cigarette smoke exposure on nicotinic acetylcholine receptor subunits {alpha}7 and {beta}2 in the sudden infant death syndrome (SIDS) brainstem

    SciTech Connect

    Machaalani, Rita; Say, Meichien; Waters, Karen A.

    2011-12-15

    It is postulated that nicotine, as the main neurotoxic constituent of cigarette smoke, influences SIDS risk through effects on nicotinic acetylcholine receptors (nAChRs) in brainstem nuclei that control respiration and arousal. This study compared {alpha}7 and {beta}2 nAChR subunit expression in eight nuclei of the caudal and rostral medulla and seven nuclei of the pons between SIDS (n = 46) and non-SIDS infants (n = 14). Evaluation for associations with known SIDS risk factors included comparison according to whether infants had a history of exposure to cigarette smoke in the home, and stratification for sleep position and gender. Compared to non-SIDS infants, SIDS infants had significantly decreased {alpha}7 in the caudal nucleus of the solitary tract (cNTS), gracile and cuneate nuclei, with decreased {beta}2 in the cNTS and increased {beta}2 in the facial. When considering only the SIDS cohort: 1-cigarette smoke exposure was associated with increased {alpha}7 in the vestibular nucleus and increased {beta}2 in the rostral dorsal motor nucleus of the vagus, rNTS and Cuneate, 2-there was a gender interaction for {alpha}7 in the gracile and cuneate, and {beta}2 in the cNTS and rostral arcuate nucleus, and 3-there was no effect of sleep position on {alpha}7, but prone sleep was associated with decreased {beta}2 in three nuclei of the pons. In conclusion, SIDS infants demonstrate differences in expression of {alpha}7 and {beta}2 nAChRs within brainstem nuclei that control respiration and arousal, which is independent on prior history of cigarette smoke exposure, especially for the NTS, with additional differences for smoke exposure ({beta}2), gender ({alpha}7 and {beta}2) and sleep position ({beta}2) evident. -- Highlights: Black-Right-Pointing-Pointer The 'normal' response to smoke exposure is decreased {alpha}7 and {beta}2 in certain nuclei. Black-Right-Pointing-Pointer SIDS infants have decreased {alpha}7 in cNTS, Grac and Cun. Black-Right-Pointing-Pointer SIDS

  18. Infrared skin damage thresholds from 1319-nm continuous-wave laser exposures

    NASA Astrophysics Data System (ADS)

    Oliver, Jeffrey W.; Vincelette, Rebecca; Noojin, Gary D.; Clark, Clifton D.; Harbert, Corey A.; Schuster, Kurt J.; Shingledecker, Aurora D.; Kumru, Semih S.; Maughan, Justin; Kitzis, Naomi; Buffington, Gavin D.; Stolarski, David J.; Thomas, Robert J.

    2013-12-01

    A series of experiments were conducted in vivo using Yucatan miniature pigs (Sus scrofa domestica) to determine thermal damage thresholds to the skin from 1319-nm continuous-wave Nd:YAG laser irradiation. Experiments employed exposure durations of 0.25, 1.0, 2.5, and 10 s and beam diameters of ˜0.6 and 1 cm. Thermal imagery data provided a time-dependent surface temperature response from the laser. A damage endpoint of fifty percent probability of a minimally visible effect was used to determine threshold for damage at 1 and 24 h postexposure. Predicted thermal response and damage thresholds are compared with a numerical model of optical-thermal interaction. Resultant trends with respect to exposure duration and beam diameter are compared with current standardized exposure limits for laser safety. Mathematical modeling agreed well with experimental data, predicting that though laser safety standards are sufficient for exposures <10 s, they may become less safe for very long exposures.

  19. ACCOUNTING FOR THE ENDOGENEITY OF HEALTH AND ENVIRONMENTAL TOBACCO SMOKE EXPOSURE IN CHILDREN: AN APPLICATION TO CONTINUOUS LUNG FUNCTION

    EPA Science Inventory

    The goal of this study is to estimate an unbiased exposure effect of environmental tobacco smoke (ETS) exposure on children's continuous lung function. A majority of the evidence from health studies suggests that ETS exposure in early life contributes significantly to childhood ...

  20. Longitudinal distribution of ozone absorption in the lung: Effect of continuous inhalation exposure

    SciTech Connect

    Asplund, P.T.; Rigas, M.L.; Ultman, J.S.; Ben-Jebria, A. |

    1996-11-01

    The effect of continuous exposure to ozone on the absorption of ozone in the conducting airways of human lungs was investigated with a bolus-response method. Eleven healthy nonsmoking college students (8 males, 3 females) were exposed at rest for 2 h on 3 separate days to air containing 0 ppm, 0.12 ppm, and 0.36 ppm ozone. A personal inhalation chamber equipped with a head-only clear plastic dome was used for exposure. Every 30 min a subject removed the dome and orally inhaled a series of five ozone-air boluses, each in a separate breath. Penetration of the boluses distal to the lips was targeted in the range of 70-120 ml (corresponding to the central conducting airways). By integrating the inhaled and exhaled-ozone concentration curves, we obtained the absorbed fraction {Lambda} and the dispersion ({sigma}{sup 2}) of the ozone bolus for each test breath. In addition, the subtraction of baseline measurements made just before exposure enabled us to determine the changes in absorbed fraction ({Delta}{Lambda}) and in dispersion ({Delta}{sigma}{sup 2}) that resulted from exposure alone. Absorbed fraction decreased, but {sigma}{sup 2} increased during O{sub 3} exposure, and the differences in {Delta}{Lambda} and in {Delta}{sigma}{sup 2} between breathing air and exposure to either 0.12 ppm or 0.36 ppm O{sub 3} were significant. We concluded that exposure of the conducting airways to O{sub 3} reduced their capacity to absorb O{sub 3}, possibly by the depletion of biochemical substrates that are normally oxidized by O{sub 3}. 20 refs., 9 figs.

  1. Long-Term Evolution Electromagnetic Fields Exposure Modulates the Resting State EEG on Alpha and Beta Bands.

    PubMed

    Yang, Lei; Chen, Qinghua; Lv, Bin; Wu, Tongning

    2016-04-25

    Long-term evolution (LTE) wireless telecommunication systems are widely used globally, which has raised a concern that exposure to electromagnetic fields (EMF) emitted from LTE devices can change human neural function. To date, few studies have been conducted on the effect of exposure to LTE EMF. Here, we evaluated the changes in electroencephalogram (EEG) due to LTE EMF exposure. An LTE EMF exposure system with a stable power emission, which was equivalent to the maximum emission from an LTE mobile phone, was used to radiate the subjects. Numerical simulations were conducted to ensure that the specific absorption rate in the subject's head was below the safety limits. Exposure to LTE EMF reduced the spectral power and the interhemispheric coherence in the alpha and beta bands of the frontal and temporal brain regions. No significant change was observed in the spectral power and the inter-hemispheric coherence in different timeslots during and after the exposure. These findings also corroborated those of our previous study using functional magnetic resonant imaging.

  2. Mixed and Mixture Regression Models for Continuous Bounded Responses Using the Beta Distribution

    ERIC Educational Resources Information Center

    Verkuilen, Jay; Smithson, Michael

    2012-01-01

    Doubly bounded continuous data are common in the social and behavioral sciences. Examples include judged probabilities, confidence ratings, derived proportions such as percent time on task, and bounded scale scores. Dependent variables of this kind are often difficult to analyze using normal theory models because their distributions may be quite…

  3. Why Does Exposure to Arsenic from Drinking Groundwater in Asian Megadeltas Continue to be High?

    NASA Astrophysics Data System (ADS)

    van Geen, A.; Ahmed, K. M.; Ahmed, E. B.; Choudhury, I.; Mozumder, M. R. H.; Bostick, B. C.; Mailloux, B. J.; Knappett, P. S.; Schlosser, P.

    2014-12-01

    Concentrations of arsenic in groundwater pumped from a significant fraction of the millions of shallow tubewells installed, mostly privately, across S/SE Asia exceed the WHO guideline value of 10 ug/L by a factor of 10 to 100. The resulting exposure has been linked to cancers and cardio-vascular disease in adults and inhibited intellectual function in children. In Bangladesh, the most affected country, the impact of early mitigation efforts relying on water treatment has been limited by the cost and logistics of maintenance. A simpler approach based on switching human consumption to low-arsenic wells has proved to be more resilient although it remains far from sufficiently adopted. A decade ago, there was concern that low-arsenic wells might become contaminated upon use. Observations and modeling have since shown that groundwater arsenic concentrations are likely to rise only in certain hydrogeologically vulnerable areas and then only gradually. Our recently completed blanket-testing campaign of 50,000 wells in 300 villages of Bangladesh has shown that, instead, a leading cause of current exposure is that households have continued to install wells and typically have nowhere to turn for a reliable arsenic test. The same campaign has shown that another reason for continued exposure is that deeper wells that are low in arsenic and whose installation has been subsidized by the Bangladesh government are not located to maximize public access. The geographic clustering of these deep wells suggests that, all too often, their location is decided on the basis of political allegiance rather than need. Such obstacles to lowering arsenic exposure might be overcome with more widespread testing and the public posting of maps of test results also showing where deep wells have been installed. We will show that obtaining and sharing such information has been greatly facilitated by a reliable field-kit for arsenic and the increasing use of smartphones in Bangladesh.

  4. Manifestation of Hyperandrogenism in the Continuous Light Exposure-Induced PCOS Rat Model

    PubMed Central

    Kang, Xuezhi; Jia, Lina; Shen, Xueyong

    2015-01-01

    Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder, and its pathogenesis has yet to be completely clarified. A fully convincing animal model has not been established for PCOS. In earlier studies, researchers have shown that the exposure of rats to continuous light can induce PCOS; nevertheless, hyperandrogenism, a key characteristic observed in human PCOS, has not been reported previously. In the present study, we found that (1) body weights decreased in female rats in a continuous light environment with both ovarian and uterine augmentation; (2) the estrous cycle in rats under continuous light environment was disordered, and polycystic ovary-like changes occurred, accompanied with fur loss and lethargy; and (3) serum testosterone levels in rats in a continuous light environment significantly increased. Our data suggest that continuous light can lead to the occurrence of PCOS in female rats without the need for drugs; this is a reasonable PCOS animal model that is more consistent with the natural disease state in humans; and poor sleep habits or negligence of sleep hygiene may be an important lifestyle factor in pathogenesis of PCOS. PMID:26064969

  5. Batch and continuous culture kinetics for production of carotenoids by beta-ionone-resistant mutant of Xanthophyllomyces dendrorhous.

    PubMed

    Park, Ki-Moon; Song, Min-Woo; Kang, Seog-Jin; Lee, Jae-Heung

    2007-07-01

    A beta-ionone-resistant mutant strain isolated from the red yeast Xanthophyllomyces dendrorhous KCTC 7704 was used for batch and continuous fermentation kinetic studies with glucose media in a 2.5-1 jar fermentor at 22 degrees C and pH 4.5. The kinetic pattern of growth and carotenoid concentration in the batch fermentations exhibited a so-called mixed-growth-associated product formation, possibly due to the fact that the content of intracellular carotenoids depends on the degree of physical maturation toward adulthood. To determine the maximum specific growth rate constant (microm) and Monod constant (k(s)) for the mutant, glucose-limited continuous culture studies were performed at different dilution rates within a range of 0.02-0.10 h(-1). A reciprocal plot of the steady-state data (viz., reciprocal of glucose concentration versus residence time) obtained from continuous culture experiments was used to estimate a microm of 0.15 h(-1) and k(s) of 1.19 g/l. The carotenoid content related to the residence time appeared to assume a typical form of saturation kinetics. The maximum carotenoid content (Xm) for the mutant was estimated to be 1.04 microg/mg dry cell weight, and the Lee constant (k(m)), which was tentatively defined in this work, was found to be 3.0 h.

  6. Beta-lactam antibiotic dosing during continuous renal replacement therapy: how can we optimize therapy?

    PubMed

    De Waele, Jan J; Carlier, Mieke

    2014-06-26

    Correct antibiotic treatment is of utmost importance to treat infections in critically ill patients, not only in terms of spectrum and timing but also in terms of dosing. However, this is a real challenge for the clinician because the pathophysiology (such as shock, augmented renal clearance, and multiple organ dysfunction) has a major impact on the pharmacokinetics of hydrophilic antibiotics. The presence of extra-corporal circuits, such as continuous renal replacement therapy, may further complicate this difficult exercise. Standard dosing may result in inadequate concentrations, but unadjusted dosing regimens may lead to toxicity. Recent studies confirm the variability in concentrations, and the wide variation in dialysis techniques used certainly contributes to these findings. Well-designed clinical studies are needed to provide the data from which robust dosing guidance can be developed. In the meantime, non-adjusted dosing in the first 1 to 2 days of antibiotic therapy during continuous renal replacement therapy followed by dose reduction later on seems to be a prudent approach.

  7. A technical study of TLD beta calibration factor for exposures to depleted uranium

    SciTech Connect

    Ashley, J.C.; Turner, J.E.; McMahan, K.L.; Souleyrette, M.L.; Bogard, R.S.

    1995-06-01

    The beta calibration factor for converting light output (on reading a thermoluminescent dosimeter) to shallow dose equivalent has been reexamined through theoretical calculations and experimental measurements. The results support the previously determined value for contact with a depleted uranium slab but indicate that for many actual workplace situations, the contact value may be overly conservative.

  8. Chronic intracerebroventricular exposure to beta-amyloid(1-40) impairs object recognition but does not affect spontaneous locomotor activity or sensorimotor gating in the rat.

    PubMed

    Nag, S; Tang, F; Yee, B K

    2001-01-01

    This study examined the cognitive effects of chronic in vivo exposure to beta-amyloid(1-40) via the intracerebroventricular route on two distinct paradigms. The first test evaluated a form of early attentional control referred to as sensorimotor gating in which an antecedent weak prepulse stimulus modulates the reactivity to a subsequent startle-eliciting stimulus. The second test utilized the spontaneous preference for a novel object over that of a familiar one in rats as a measure of object recognition memory. We found that beta-amyloid exposure leads to a severe deficit in the object memory test but spares sensorimotor gating. Moreover, unlike the water maze deficit induced by beta-amyloid (Nag et al., in preparation), the deficit on object recognition was resistant to amelioration by systemic physostigmine treatment at a dose of 0.06 mg/kg per day intraperitoneally. The present results add to previous reports that beta-amyloid exposure can lead to deficits on hippocampal lesion sensitive tasks, suggesting that dysfunction of the rhinal cortices in addition to that of the septohippocampal system is implicated in beta-amyloid-induced behavioral impairments. It therefore lends support to the hypothesis that beta-amyloid exposure can lead to severe impairment across multiple memory systems.

  9. Reduction of the elevator illusion from continued hypergravity exposure and visual error-corrective feedback

    NASA Technical Reports Server (NTRS)

    Welch, R. B.; Cohen, M. M.; DeRoshia, C. W.

    1996-01-01

    Ten subjects served as their own controls in two conditions of continuous, centrifugally produced hypergravity (+2 Gz) and a 1-G control condition. Before and after exposure, open-loop measures were obtained of (1) motor control, (2) visual localization, and (3) hand-eye coordination. During exposure in the visual feedback/hypergravity condition, subjects received terminal visual error-corrective feedback from their target pointing, and in the no-visual feedback/hypergravity condition they pointed open loop. As expected, the motor control measures for both experimental conditions revealed very short lived underreaching (the muscle-loading effect) at the outset of hypergravity and an equally transient negative aftereffect on returning to 1 G. The substantial (approximately 17 degrees) initial elevator illusion experienced in both hypergravity conditions declined over the course of the exposure period, whether or not visual feedback was provided. This effect was tentatively attributed to habituation of the otoliths. Visual feedback produced a smaller additional decrement and a postexposure negative after-effect, possible evidence for visual recalibration. Surprisingly, the target-pointing error made during hypergravity in the no-visual-feedback condition was substantially less than that predicted by subjects' elevator illusion. This finding calls into question the neural outflow model as a complete explanation of this illusion.

  10. Assessing natural direct and indirect effects for a continuous exposure and a dichotomous outcome.

    PubMed

    Wang, Wei; Zhang, Bo

    2016-01-01

    Recent advances in the literature on mediation have extended from traditional linear structural equation modeling approach to causal mediation analysis using potential outcomes framework. Pearl proposed a mediation formula to calculate expected potential outcomes used in the natural direct and indirect effects definition under the key sequential ignorability assumptions. Current methods mainly focused on binary exposure variables, and in this article, this approach is further extended to settings in which continuous exposures may be of interest. Focusing on a dichotomous outcome, we give precise definitions of the natural direct and indirect effects on both the risk difference and odds ratio scales utilizing the empirical joint distribution of the exposure and baseline covariates from the whole sample analysis population. A mediation-formula based approach is proposed to estimate the corresponding causal quantities. Simulation study is conducted to assess the statistical properties of the proposed method and we illustrate our approach by applying it to the Jackson Heart Study to estimate the mediation effects of diabetes on the relation between obesity and chronic kidney disease. Sensitivity analysis is performed to assess the impact of violation of no unmeasured mediator-outcome confounder assumption.

  11. Continuous recording instrument for RF-exposure measurements in FM/TV broadcasting towers.

    PubMed

    Jokela, K; Ylönen, M

    1984-09-01

    A continuously recording exposure meter has been developed for radio-frequency (RF) hazard measurements in FM/TV broadcasting towers for the frequency range 47-790 MHz. The instrument consists of an electrically-small dipole, loop probes and recording electronics. The dipole and loop are attached to the safety helmet; their distance from the head is approximately 7 cm. The dipole and loop respond to the tangential E field and radial H field, respectively. The error due to body proximity and one-dimensionality is 1 to 2 dB at 100 MHz and 2 to 3 dB at 200 MHz (for average power density measurements) if the probes move continuously and the measurement period is sufficiently long. Measurements in Finnish FM/TV towers showed that the average power density inside the tower increases with increasing power and decreasing antenna surface area. The highest levels have been found near UHF and FM antennas. For the FM band (100 MHz) the average H field exposures exceed the new ANSI standard value 10 W/m2, but remain in most cases below 100 W/m2. Local maxima may exceed 300 W/m2.

  12. Connexin-43 expression in oral-derived human osteoblasts after transforming growth factor-beta and prostaglandin E2 exposure.

    PubMed

    Adamo, C T; Mailhot, J M; Smith, A K; Borke, J L

    2001-01-01

    Dental implant placement stimulates a response in the supporting tissue; the response involves bone remodeling and release of wound-healing factors, including cytokines. Important factors such as transforming growth factor-beta (TGF-beta), which promotes matrix synthesis, and prostaglandin E2 (PGE2), a mediator of inflammation, have the potential to alter the communication between bone cells and interfere with implant site healing. Cells responsible for the formation of bone are interconnected to form a multicellular network. Cell-to-cell communication in this network occurs in part via gap junctions. In bone cells, the predominant gap junction protein is connexin-43. TGF-beta is a growth modulator produced by osteoblasts and released from the matrix in response to resorption and may influence the progression of periodontal disease. TGF-beta also promotes the synthesis of extracellular matrix proteins such as collagen, fibronectin, and adhesion molecules. PGE2 is a mediator of inflammation produced in response to periodontal pathogens. PGE2 levels in the gingival sulcular fluid have been correlated with attachment loss and bone resorption. The relationship between these factors and connexin-43 is unclear. Oral-derived (alveolar) bone was used because the phenotype of bone can differ between species and between different sites in the body. For our studies, explants of human osteoblasts were cultured on eight well plates and characterized by their expression of osteocalcin, osteonectin, alkaline phosphatase, type 1 collagen, and connexin-43. Cells were grown to near confluence on 12 well plates in 20% fetal bovine serum (FBS) Dulbecco modified Eagle medium (DMEM) and then cultured for 24 hours in 0.5% FBS DMEM before exposure to either 1, 5, or 10 ng/mL of TGF-beta in serum-free DMEM for 12 or 24 hours or to 20, 80, or 300 ng/mL of PGE2 in serum-free DMEM for 12 or 24 hours. After incubation, cells were removed from plates by scraping and assayed for connexin-43

  13. Upregulation of surface alpha4beta2 nicotinic receptors is initiated by receptor desensitization after chronic exposure to nicotine.

    PubMed

    Fenster, C P; Whitworth, T L; Sheffield, E B; Quick, M W; Lester, R A

    1999-06-15

    It is hypothesized that desensitization of neuronal nicotinic acetylcholine receptors (nAChRs) induced by chronic exposure to nicotine initiates upregulation of nAChR number. To test this hypothesis directly, oocytes expressing alpha4beta2 receptors were chronically incubated (24-48 hr) in nicotine, and the resulting changes in specific [3H]nicotine binding to surface receptors on intact oocytes were compared with functional receptor desensitization. Four lines of evidence strongly support the hypothesis. (1) The half-maximal nicotine concentration necessary to produce desensitization (9.7 nM) was the same as that needed to induce upregulation (9.9 nM). (2) The concentration of [3H]nicotine for half-maximal binding to surface nAChRs on intact oocytes was also similar (11.1 nM), as predicted from cyclical desensitization models. (3) Functional desensitization of alpha3beta4 receptors required 10-fold higher nicotine concentrations, and this was mirrored by a 10-fold shift in concentrations necessary for upregulation. (4) Mutant alpha4beta2 receptors that do not recover fully from desensitization, but not wild-type channels, were upregulated after acute (1 hr) applications of nicotine. Interestingly, the nicotine concentration required for half-maximal binding of alpha4beta2 receptors in total cell membrane homogenates was 20-fold lower than that measured for surface nAChRs in intact oocytes. These data suggest that cell homogenate binding assays may not accurately reflect the in vivo desensitization affinity of surface nAChRs and may account for some of the previously reported differences in the efficacy of nicotine for inducing nAChR desensitization and upregulation.

  14. PLASMA CLEARANCE OF VITELLOGENIN IN SHEEPSHEAD MINNOWS AFTER CESSATION OF EXPOSURE TO 17BETA-ESTRADIOL AND PARA-NONYLPHENOL

    EPA Science Inventory

    Two experiments were performed to determine the rate of vitellogenin plasma accumulation and clearance in male sheepshead minnows (Cyprinodon variegatus) during and after exposure to either 17b-estradiol (E2) or para-nonylphenol (p-NP). Adult fish were continuously exposed to aqu...

  15. Particle-in-cell Simulations of Continuously Driven Mirror and Ion Cyclotron Instabilities in High Beta Astrophysical and Heliospheric Plasmas

    NASA Astrophysics Data System (ADS)

    Riquelme, Mario A.; Quataert, Eliot; Verscharen, Daniel

    2015-02-01

    We use particle-in-cell simulations to study the nonlinear evolution of ion velocity space instabilities in an idealized problem in which a background velocity shear continuously amplifies the magnetic field. We simulate the astrophysically relevant regime where the shear timescale is long compared to the ion cyclotron period, and the plasma beta is β ~ 1-100. The background field amplification in our calculation is meant to mimic processes such as turbulent fluctuations or MHD-scale instabilities. The field amplification continuously drives a pressure anisotropy with p > p ∥ and the plasma becomes unstable to the mirror and ion cyclotron instabilities. In all cases, the nonlinear state is dominated by the mirror instability, not the ion cyclotron instability, and the plasma pressure anisotropy saturates near the threshold for the linear mirror instability. The magnetic field fluctuations initially undergo exponential growth but saturate in a secular phase in which the fluctuations grow on the same timescale as the background magnetic field (with δB ~ 0.3 langBrang in the secular phase). At early times, the ion magnetic moment is well-conserved but once the fluctuation amplitudes exceed δB ~ 0.1 langBrang, the magnetic moment is no longer conserved but instead changes on a timescale comparable to that of the mean magnetic field. We discuss the implications of our results for low-collisionality astrophysical plasmas, including the near-Earth solar wind and low-luminosity accretion disks around black holes.

  16. PARTICLE-IN-CELL SIMULATIONS OF CONTINUOUSLY DRIVEN MIRROR AND ION CYCLOTRON INSTABILITIES IN HIGH BETA ASTROPHYSICAL AND HELIOSPHERIC PLASMAS

    SciTech Connect

    Riquelme, Mario A.; Quataert, Eliot; Verscharen, Daniel E-mail: eliot@berkeley.edu

    2015-02-10

    We use particle-in-cell simulations to study the nonlinear evolution of ion velocity space instabilities in an idealized problem in which a background velocity shear continuously amplifies the magnetic field. We simulate the astrophysically relevant regime where the shear timescale is long compared to the ion cyclotron period, and the plasma beta is β ∼ 1-100. The background field amplification in our calculation is meant to mimic processes such as turbulent fluctuations or MHD-scale instabilities. The field amplification continuously drives a pressure anisotropy with p > p {sub ∥} and the plasma becomes unstable to the mirror and ion cyclotron instabilities. In all cases, the nonlinear state is dominated by the mirror instability, not the ion cyclotron instability, and the plasma pressure anisotropy saturates near the threshold for the linear mirror instability. The magnetic field fluctuations initially undergo exponential growth but saturate in a secular phase in which the fluctuations grow on the same timescale as the background magnetic field (with δB ∼ 0.3 (B) in the secular phase). At early times, the ion magnetic moment is well-conserved but once the fluctuation amplitudes exceed δB ∼ 0.1 (B), the magnetic moment is no longer conserved but instead changes on a timescale comparable to that of the mean magnetic field. We discuss the implications of our results for low-collisionality astrophysical plasmas, including the near-Earth solar wind and low-luminosity accretion disks around black holes.

  17. Continuous Microfluidic Assembly of Biodegradable Poly(beta-amino ester)/DNA Nanoparticles for Enhanced Gene Delivery.

    PubMed

    Wilson, David R; Mosenia, Arman; Suprenant, Mark P; Upadhya, Rahul; Routkevitch, Denis; Meyer, Randall A; Quinones-Hinojosa, Alfredo; Green, Jordan J

    2017-02-08

    Translation of biomaterial-based nanoparticle formulations to the clinic faces significant challenges including efficacy, safety, consistency and scale-up of manufacturing, and stability during long-term storage. Continuous microfluidic fabrication of polymeric nanoparticles has the potential to alleviate the challenges associated with manufacture, while offering a scalable solution for clinical level production. Poly(beta-amino esters) (PBAE)s are a class of biodegradable cationic polymers that self-assemble with anionic plasmid DNA to form polyplex nanoparticles that have been shown to be effective for transfecting cancer cells specifically in vitro and in vivo. Here we demonstrate the use of a microfluidic device for the continuous and scalable production of PBAE/DNA nanoparticles followed by lyophilization and long term storage that results in improved in vitro efficacy in multiple cancer cell lines compared to nanoparticles produced by bulk mixing as well as in comparison to widely used commercially available transfection reagents polyethylenimine and Lipofectamine® 2000. We further characterized the nanoparticles using nanoparticle tracking analysis (NTA) to show that microfluidic mixing resulted in fewer DNA-free polymeric nanoparticles compared to those produced by bulk mixing. This article is protected by copyright. All rights reserved.

  18. Assessing the effects of exposure timing on biomarker expression using 17beta-estradiol

    EPA Science Inventory

    Temporal and spatial variability in estrogenicity has been documented for many treated wastewater effluents with the consequences of this variability on the expression of biomarkers of endocrine disruption being largely unknown. Laboratory exposure studies usually utilize constan...

  19. Arsenic Exposure and Calpain-10 Polymorphisms Impair the Function of Pancreatic Beta-Cells in Humans: A Pilot Study of Risk Factors for T2DM

    PubMed Central

    Díaz-Villaseñor, Andrea; Cruz, Laura; Cebrián, Arturo; Hernández-Ramírez, Raúl U.; Hiriart, Marcia; García-Vargas, Gonzálo; Bassol, Susana; Sordo, Monserrat; Gandolfi, A. Jay; Klimecki, Walter T.; López-Carillo, Lizbeth; Cebrián, Mariano E.; Ostrosky-Wegman, Patricia

    2013-01-01

    The incidence of type 2 diabetes mellitus (T2DM) is increasing worldwide and diverse environmental and genetic risk factors are well recognized. Single nucleotide polymorphisms (SNPs) in the calpain-10 gene (CAPN-10), which encodes a protein involved in the secretion and action of insulin, and chronic exposure to inorganic arsenic (iAs) through drinking water have been independently associated with an increase in the risk for T2DM. In the present work we evaluated if CAPN-10 SNPs and iAs exposure jointly contribute to the outcome of T2DM. Insulin secretion (beta-cell function) and insulin sensitivity were evaluated indirectly through validated indexes (HOMA2) in subjects with and without T2DM who have been exposed to a gradient of iAs in their drinking water in northern Mexico. The results were analyzed taking into account the presence of the risk factor SNPs SNP-43 and -44 in CAPN-10. Subjects with T2DM had significantly lower beta-cell function and insulin sensitivity. An inverse association was found between beta-cell function and iAs exposure, the association being more pronounced in subjects with T2DM. Subjects without T2DM who were carriers of the at-risk genotype SNP-43 or -44, also had significantly lower beta-cell function. The association of SNP-43 with beta-cell function was dependent on iAs exposure, age, gender and BMI, whereas the association with SNP-44 was independent of all of these factors. Chronic exposure to iAs seems to be a risk factor for T2DM in humans through the reduction of beta-cell function, with an enhanced effect seen in the presence of the at-risk genotype of SNP-43 in CAPN-10. Carriers of CAPN-10 SNP-44 have also shown reduced beta-cell function. PMID:23349674

  20. Cell death (apoptosis) in mouse intestine after continuous irradiation with gamma rays and with beta rays from tritiated water

    SciTech Connect

    Ijiri, K.

    1989-04-01

    Apoptosis is a pattern of cell death involving nuclear pycnosis, cytoplasmic condensation, and karyorrhexis. Apoptosis induced by continuous irradiation with gamma rays (externally given by a 137Cs source) or with beta rays (from tritiated water injected ip) was quantified in the crypts of two portions of mouse bowel, the small intestine and descending colon. The time-course change in the incidence of apoptosis after each type of radiation could be explained on the basis of the innate circadian rhythm of the cells susceptible to apoptotic death and of the excretion of tritiated water (HTO) from the body. For 6-h continuous gamma irradiation at various dose rates (0.6-480 mGy/h) and for 6 h after injection of HTO of various radioactivities (0.15-150 GBq per kg body wt), the relationships between dose and incidence of apoptosis were obtained. Survival curves were then constructed from the curves for dose vs incidence of apoptosis. For the calculation of the absorbed dose from HTO, the water content both of the mouse body and of the cells was assumed to be 70%. One megabecquerel of HTO per mouse (i.e., 40 MBq/kg body wt) gave a dose rate of 0.131 mGy/h. The mean lethal doses (D0) were calculated for gamma rays and HTO, and relative biological effectiveness values of HTO relative to gamma rays were obtained. The D0 values for continuous irradiation with gamma rays were 210 mGy for small intestine and 380 mGy for descending colon, and the respective values for HTO were 130 and 280 mGy, indicating the high radiosensitivity of target cells for apoptotic death. The relative biological effectiveness of HTO relative to 137Cs gamma rays for cell killing in both the small intestine and the descending colon in the mouse was 1.4-2.1.

  1. The effects of continuous and pulsed exposures of suspended clay on the survival, growth, and reproduction of Daphnia magna.

    PubMed

    Robinson, Sarah E; Capper, Neil A; Klaine, Stephen J

    2010-01-01

    Suspended sediments are a natural component of aquatic ecosystems, but anthropogenic activity such as land development can result in significant increases, especially after rain events. Continuous exposures of suspended clay and silt have been shown to affect growth and reproduction of Cladocera, leading to a decrease in population growth rate. The mechanism of clay toxicity in these filter-feeding organisms is clogging of the gut tract, resulting in decreased food uptake and assimilation. When placed in clean water, daphnids can purge clay from their gut and recover. In many surface waters, aquatic organisms experience episodic exposures of high concentrations of suspended solids driven by rain events. However, little is known about the consequences of pulsed exposures on individuals and populations. The objective of the present study was to characterize the effects of continuous and pulsed exposures of natural and defined clays on survival, growth, and reproduction of Daphnia magna. Two defined clays, montmorillonite and kaolinite, as well as clay isolated from the Piedmont region of South Carolina, USA, were used. Continuous exposures of clays elicited a dose dependent decrease in survival. Toxicity varied depending on clay source with montmorillonite > natural clay > kaolinite. Pulsed exposures caused a decrease in survival in a 24 h exposure of 734 mg/L kaolinite. Exposure to 73.9 mg/L also caused an increase in the time to gravidity, although there was not a corresponding decrease in neonate production over 21 d. No significant effects resulted from 12 h exposures even at 730 mg/L, almost 10 times the 24-h reproductive effects concentration. This suggests that exposure duration impacted toxicity more than exposure concentration in these pulsed exposures.

  2. Hepatic pathology in mice after continuous inhalation exposure to 1, 1, 1-trichloroethane

    NASA Technical Reports Server (NTRS)

    Mcnutt, N. S.; Master, R. L.; Mcconnell, E. E.; Morris, F.

    1974-01-01

    Mice exposed to either 250ppm or 1,000ppm 1,1,1-trichloroethane in air continuously for 14 weeks demonstrated significant changes in the centrilobular hepatocytes for the 1,000ppm group. Moderate liver triglyceride accumulation was evident in the 1,000ppm group and peaked at 40mg/gm of tissue after 7 weeks of exposure. Focal hepatocyte necrosis occurred in 40% of the mice exposed to 1,000ppm for 12 weeks. This necrosis was associated with an acute inflammatory infiltrate and hypertrophy of Kupffer cells. These findings indicate that the pathological alternations observed with 1,1,1-trichloroethane are similar to those observed with dichloromethane except for different time courses of the effects and different degrees of recovery. The toxic effects of 1,1,1-trichloroethane are of a similar type to those produced by carbon tetrachloride but appear much less severe.

  3. Mendelian Randomization Studies for a Continuous Exposure Under Case-Control Sampling

    PubMed Central

    Dai, James Y.; Zhang, Xinyi Cindy

    2015-01-01

    In this article, we assess the impact of case-control sampling on mendelian randomization analyses with a dichotomous disease outcome and a continuous exposure. The 2-stage instrumental variables (2SIV) method uses the prediction of the exposure given genotypes in the logistic regression for the outcome and provides a valid test and an approximation of the causal effect. Under case-control sampling, however, the first stage of the 2SIV procedure becomes a secondary trait association, which requires proper adjustment for the biased sampling. Through theoretical development and simulations, we compare the naïve estimator, the inverse probability weighted estimator, and the maximum likelihood estimator for the first-stage association and, more importantly, the resulting 2SIV estimates of the causal effect. We also include in our comparison the causal odds ratio estimate derived from structural mean models by double-logistic regression. Our results suggest that the naïve estimator is substantially biased under the alternative, yet it remains unbiased under the null hypothesis of no causal effect; the maximum likelihood estimator yields smaller variance and mean squared error than other estimators; and the structural mean models estimator delivers the smallest bias, though generally incurring a larger variance and sometimes having issues in algorithm stability and convergence. PMID:25713335

  4. The effects of acute and chronic ammonia exposure during early life stages of the gulf toadfish, Opsanus beta.

    PubMed

    Barimo, John F; Walsh, Patrick J

    2005-11-10

    The gulf toadfish (Opsanus beta) is unusual among teleosts in that it is facultatively ureotelic and adults and juveniles have a particularly high tolerance to environmental ammonia. Male toadfish brood their offspring in confined nests. It has been hypothesized that the potential accumulation of ammonia in nests from the male and the offspring, coupled with suspected low ammonia tolerance in offspring would provide the selective pressure necessary for excretion of the less toxic urea by adult toadfish. This study examines this so-called 'nest-fouling' hypothesis through acute and chronic ammonia toxicity testing on early life stages of O. beta. In addition, nitrogen elimination was examined among embryos, yolk-sac larvae and juveniles where we found an ontogenic shift from ammonotely to ureotely with advancing life history stages. The acute ammonia 96 h LC50 values for embryos and larvae were 63.6 and 5.45 mmol-Nl(-1) total ammonia (TAmm), respectively. Thus, these early life stages are more tolerant to ammonia than either juveniles or adults and LC50 values are at least 2 orders of magnitude greater than concentrations naturally occurring at nest sites. Furthermore, 40 days exposures at mean and maximum NH3 concentrations normally found within nests revealed no observable detrimental effects. In fact, growth in terms of wet or dry weight was greatest at the maximum NH3 concentration. We therefore conclude that the nest-fouling hypothesis is not a viable explanation for ureotely in the gulf toadfish.

  5. Estimation of beta-ray skin dose from exposure to fission fallout from the Hiroshima atomic bomb.

    PubMed

    Endo, Satoru; Tanaka, Kenichi; Shizuma, Kiyoshi; Hoshi, Masaharu; Imanaka, Tetsuji

    2012-03-01

    Beta-ray skin dose due to the fission fallout from the Hiroshima atomic bomb is potentially related to the epilation in the black rain area. The absorbed dose to the skin from beta-rays emitted by fission fallout has been estimated for an initial ¹³⁷Cs deposition of 1 kBq m⁻² on the ground at 0.5 h after the explosion. The estimated skin dose takes into account both external exposure from fission fallout radionuclides uniformly distributed in 1 mm of soil on the surface of the ground and from a 26 μm thickness of contaminated soil on the skin, using the Monte Carlo radiation transport code MCNP-4C. The cumulative skin dose for 1 month after the explosion is taken as the representative value. The estimated skin dose for an initial ¹³⁷Cs deposition of 1 kBq m⁻² was determined to be about 500 mSv.

  6. Chronic Drinking During Adolescence Predisposes the Adult Rat for Continued Heavy Drinking: Neurotrophin and Behavioral Adaptation after Long-Term, Continuous Ethanol Exposure

    PubMed Central

    Fernandez, Gina M.; Stewart, William N.; Savage, Lisa M.

    2016-01-01

    Previous research has found that adolescent ethanol (EtOH) exposure alters drug seeking behaviors, cognition and neuroplasticity. Using male Sprague Dawley rats, differences in spatial working memory, non-spatial discrimination learning and behavioral flexibility were explored as a function of age at the onset (mid-adolescent vs. adult) of chronic EtOH exposure (CET). Concentrations of mature brain-derived neurotrophic factor (mBDNF) and beta-nerve growth factor (β-NGF) in the prefrontal cortex and hippocampus were also assessed at different time-points: during CET, following acute abstinence (48-hrs), and after protracted abstinence (6–8 wks). Our results revealed that an adolescent onset of CET leads to increased EtOH consumption that persisted into adulthood. In both adult and adolescent onset CET groups, there were significant long-term reductions in prefrontal cortical mBDNF and β-NGF levels. However, only adult onset CET rats displayed decreased hippocampal BDNF levels. Spatial memory, assessed by spontaneous alternation and delayed alternation, was not significantly affected by CET as a function of age of drinking onset, but higher blood–EtOH levels were correlated with lower spontaneous alternation scores. Regardless of the age of onset, EtOH exposed rats were impaired on non-spatial discrimination learning and displayed inflexible behavioral patterns upon reversal learning. Our results indicate that adolescent EtOH exposure changes long-term consumption patterns producing behavioral and neural dysfunctions that persist across the lifespan. PMID:26930631

  7. Bioaccumulation and biotransformation of the beta-blocker propranolol in multigenerational exposure to Daphnia magna.

    PubMed

    Jeong, Tae-Yong; Kim, Tae-Hun; Kim, Sang Don

    2016-09-01

    Multigenerational bioaccumulation and biotransformation activity and short-term kinetics (e.g., uptake and depuration) of propranolol in Daphnia magna were investigated at environmental concentration. The body burden and the major metabolite, desisopropyl propranolol (DIP), of propranolol were quantified using LC-MS/MS at the end of each generation after exposure for 11 generations. The accumulation of propranolol in D. magna at an environmental concentration of 0.2 μg/L was not much different between the parent (F0) and the eleventh filial (F10) generation. However, at 28 μg/L, its accumulation was 1.6 times higher-up to 18.9 μg/g-in the F10 generation relative to the F0. In contrast to propranolol, DIP intensity gradually increased from F0 to F10 at 0.2 μg/L, reflecting an increase in detoxification load and biotransformation performance; no increasing trend was observed at 28 μg/L. The bioaccumulation factor (BAF) showed higher values with a lower concentration and longer period of exposure. The average values of the BAF for 21 days of long-term exposure in successive 11 generations were 440.4 ± 119.7 and 1026.5 ± 208.6 L/kg for 28 μg/L and 0.2 μg/L, respectively. These are comparable to the BAF of 192 for the short-term 72-h exposure at 28 μg/L in the parent generation. It is also recommended that future studies for pharmaceutical ingredients be conducted on drug-drug interaction and structural characteristics on the prediction of biotransformation activity and bioaccumulation rate.

  8. A Simulation Study of Categorizing Continuous Exposure Variables Measured with Error in Autism Research: Small Changes with Large Effects.

    PubMed

    Heavner, Karyn; Burstyn, Igor

    2015-08-24

    Variation in the odds ratio (OR) resulting from selection of cutoffs for categorizing continuous variables is rarely discussed. We present results for the effect of varying cutoffs used to categorize a mismeasured exposure in a simulated population in the context of autism spectrum disorders research. Simulated cohorts were created with three distinct exposure-outcome curves and three measurement error variances for the exposure. ORs were calculated using logistic regression for 61 cutoffs (mean ± 3 standard deviations) used to dichotomize the observed exposure. ORs were calculated for five categories with a wide range for the cutoffs. For each scenario and cutoff, the OR, sensitivity, and specificity were calculated. The three exposure-outcome relationships had distinctly shaped OR (versus cutoff) curves, but increasing measurement error obscured the shape. At extreme cutoffs, there was non-monotonic oscillation in the ORs that cannot be attributed to "small numbers." Exposure misclassification following categorization of the mismeasured exposure was differential, as predicted by theory. Sensitivity was higher among cases and specificity among controls. Cutoffs chosen for categorizing continuous variables can have profound effects on study results. When measurement error is not too great, the shape of the OR curve may provide insight into the true shape of the exposure-disease relationship.

  9. Thermal effects of continuous wave CO sub 2 laser exposure on human teeth: An in vitro study

    SciTech Connect

    Miserendino, L.J.; Neiburger, E.J.; Walia, H.; Luebke, N.; Brantley, W.

    1989-07-01

    The thermal effects of continuous wave carbon dioxide laser irradiation on human teeth were investigated. Internal temperature changes were monitored by means of electrical thermistors implanted within the pulp chambers of 20 extracted, unerupted human molar teeth. One-hundred test exposures at various powers and durations were obtained. Linear regression/correlation analysis of the data suggests a direct relationship between the independent variable, exposure energy (joules), and the dependent variable, internal temperature, under the conditions of this study.

  10. Abbreviated environmental enrichment enhances neurobehavioral recovery comparably to continuous exposure after traumatic brain injury

    PubMed Central

    de Witt, Benjamin Wells; Ehrenberg, Kathryn M.; McAloon, Rose L.; Panos, Amanda H.; Shaw, Kaitlyn E.; Raghavan, Priya V.; Skidmore, Elizabeth R.; Kline, Anthony E.

    2011-01-01

    Background Environmental enrichment (EE) is a complex living milieu that has been shown to enhance functional recovery vs. standard (STD) housing after experimental traumatic brain injury (TBI) and therefore may be considered a rodent correlate of rehabilitation. However, the typical EE paradigm consists of continuous exposure to enrichment after TBI, which is inconsistent with the limited time frame in clinical rehabilitation. Objective To determine whether abbreviated EE (i.e., rehabilitation-relevant dose response) confers benefits similar to typical EE after TBI. Methods Adult male rats received either a controlled cortical impact (2.8 mm depth at 4 m/sec) or sham injury and were then randomly assigned to TBI + EE, TBI + EE (2hr), TBI + EE (4hr), TBI + EE (6hr), TBI + STD, and respective sham controls. Motor (beam-balance/beam-walk; BB/BW) and cognitive (Morris water maze; MWM) performance was assessed on post-operative days 1-5 and 14-19, respectively. Results The TBI + EE (2hr) and TBI + EE (4hr) groups were not statistically different from the TBI + STD group in any behavioral assessment. In contrast, the TBI + EE (6hr) group exhibited significant enhancement of motor and cognitive performance vs. the TBI + STD group, as well as the TBI + EE (2hr) and TBI + EE (4hr) groups (p < 0.003), and did not differ from the TBI + EE (typical) group. Conclusions These data demonstrate that abbreviated EE (6hr) produces motor and cognitive benefits similar to continuous EE after TBI and thus may be considered a dose-relevant rehabilitation paradigm. PMID:21186330

  11. 75 FR 64411 - Lowering Miners' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-19

    ...The Mine Safety and Health Administration (MSHA) proposes to lower miners' exposure to respirable coal mine dust by revising the Agency's existing standards on miners' occupational exposure to respirable coal mine dust. The major provisions of the proposal would lower the existing exposure limit; provide for full-shift sampling; redefine the term ``normal production shift; '' and add......

  12. Continuous exposure to non-lethal doses of sodium iodate induces retinal pigment epithelial cell dysfunction

    PubMed Central

    Zhang, Xiao-Yu; Ng, Tsz Kin; Brelén, Mårten Erik; Wu, Di; Wang, Jian Xiong; Chan, Kwok Ping; Yung, Jasmine Sum Yee; Cao, Di; Wang, Yumeng; Zhang, Shaodan; Chan, Sun On; Pang, Chi Pui

    2016-01-01

    Age-related macular degeneration (AMD), characterized by progressive degeneration of retinal pigment epithelium (RPE), is the major cause of irreversible blindness and visual impairment in elderly population. We previously established a RPE degeneration model using an acute high dose sodium iodate to induce oxidative stress. Here we report findings on a prolonged treatment of low doses of sodium iodate on human RPE cells (ARPE-19). RPE cells were treated continuously with low doses (2–10 mM) of sodium iodate for 5 days. Low doses (2–5 mM) of sodium iodate did not reduce RPE cell viability, which is contrasting to cell apoptosis in 10 mM treatment. These low doses are sufficient to retard RPE cell migration and reduced expression of cell junction protein ZO-1. Phagocytotic activity of RPE cells was attenuated by sodium iodate dose-dependently. Sodium iodate also increased expression of FGF-2, but suppressed expression of IL-8, PDGF, TIMP-2 and VEGF. Furthermore, HTRA1 and epithelial-to-mesenchymal transition marker proteins were downregulated, whereas PERK and LC3B-II proteins were upregulated after sodium iodate treatment. These results suggested that prolonged exposure to non-lethal doses of oxidative stress induces RPE cell dysfunctions that resemble conditions in AMD. This model can be used for future drug/treatment investigation on AMD. PMID:27849035

  13. Neobenedenia melleni-Specific Antibodies Are Associated with Protection after Continuous Exposure in Mozambique Tilapia

    PubMed Central

    Kishimori, Jennifer M.; Takemura, Akihiro; Leong, Jo-Ann C.

    2015-01-01

    Neobenedenia melleni is a significant monogenean pathogen of fish in aquaculture facilities and public aquaria. Immunity after exposure to live N. melleni is well established, but the mechanisms of immunity remain unclear. In this study, tilapia (Oreochromis mossambicus) were continuously exposed to N. melleni over a four-month period and assessed for immunity as determined by a reduction in the number of parasites dislodged from the experimental animals during freshwater immersion. Specific mucosal and systemic antibody levels were by determined via enzyme-linked immunosorbent assay. At 45 days postexposure (DPE), fish displayed high parasite loads and baseline levels of mucosal antibodies. At 102 and 120 DPE parasite loads were significantly decreased, and antibody levels were significantly increased for mucus and plasma samples. The correlation between immunity (reduction in parasite load) and an increased humoral antibody response suggests a key role of antibody in the immune response. This is the first report of immunity against N. melleni that is associated with specific mucosal or systemic antibodies. PMID:25756055

  14. Increased {beta}-amyloid levels in the choroid plexus following lead exposure and the involvement of low-density lipoprotein receptor protein-1

    SciTech Connect

    Behl, Mamta; Zhang Yanshu; Monnot, Andrew D.; Jiang, Wendy; Zheng Wei

    2009-10-15

    The choroid plexus, a barrier between the blood and cerebrospinal fluid (CSF), is known to accumulate lead (Pb) and also possibly function to maintain brain's homeostasis of A{beta}, an important peptide in the etiology of Alzheimer's disease. This study was designed to investigate if Pb exposure altered A{beta} levels at the blood-CSF barrier in the choroid plexus. Rats received ip injection of 27 mg Pb/kg. Twenty-four hours later, a FAM-labeled A{beta} (200 pmol) was infused into the lateral ventricle and the plexus tissues were removed to quantify A{beta} accumulation. Results revealed a significant increase in intracellular A{beta} accumulation in the Pb-exposed animals compared to controls (p < 0.001). When choroidal epithelial Z310 cells were treated with 10 {mu}M Pb for 24 h and 48 h, A{beta} (2 {mu}M in culture medium) accumulation was significantly increased by 1.5 fold (p < 0.05) and 1.8 fold (p < 0.05), respectively. To explore the mechanism, we examined the effect of Pb on low-density lipoprotein receptor protein-1 (LRP1), an intracellular A{beta} transport protein. Following acute Pb exposure with the aforementioned dose regimen, levels of LRP1 mRNA and proteins in the choroid plexus were decreased by 35% (p < 0.05) and 31.8% (p < 0.05), respectively, in comparison to those of controls. In Z310 cells exposed to 10 {mu}M Pb for 24 h and 48 h, a 33.1% and 33.4% decrease in the protein expression of LRP1 was observed (p < 0.05), respectively. Knocking down LRP1 resulted in even more substantial increases of cellular accumulation of A{beta}, from 31% in cells without knockdown to 72% in cells with LRP1 knockdown (p < 0.05). Taken together, these results suggest that the acute exposure to Pb results in an increased accumulation of intracellular A{beta} in the choroid plexus; the effect appears to be mediated, at least in part, via suppression of LRP1 production following Pb exposure.

  15. Continuous exposure to sexually active rams extends estrous activity in ewes in spring.

    PubMed

    Abecia, J A; Chemineau, P; Flores, J A; Keller, M; Duarte, G; Forcada, F; Delgadillo, J A

    2015-12-01

    Sexual activity in sheep is under photoperiodic control, which is the main environmental factor responsible for the seasonality of reproduction. However, other natural environmental factors such as presence of conspecifics can slightly influence the timing of onset and offset of the breeding season. In goats, we have found that the continuous presence of bucks that were rendered sexually active out of season by previous exposure to long days, prevented goats from displaying seasonal anestrus, which suggests that the relative contribution of photoperiod in controlling seasonal anestrus should be reevaluated in small ruminant species. The aim of this study was to assess whether the presence of sexually active rams that had been stimulated by artificial photoperiod and melatonin implants, reduces seasonal anestrus in sheep, by prolonging ovulatory activity in spring. Ewes were assigned to one of two groups (n = 16 and 15), which were housed in two separate barns, and kept in contact, either with the treated or the control rams between March and July. Vasectomized rams were either exposed to 2 months of long days followed by the insertion of three subcutaneous melatonin implants (treated rams, n = 8), or exposed to natural light conditions (control rams, n = 2). Estrus was monitored daily, and weekly plasma progesterone analyses indicated ovulatory activity. Ewes that were exposed to treated rams exhibited a higher proportion of monthly estrus than ewes exposed to the control rams (P < 0.05). Thirteen of 15 ewes (one ewe was not considered because of the presence of persistent CL) exposed to stimulated rams exhibited estrous behavior in a cyclic manner. In contrast, all ewes exposed to control rams stopped estrous activity for a period of time during the study, such that this group exhibited a significantly longer anestrous season (mean ± standard error of the mean 89 ± 9 days) than did the ewes housed with treated rams (26 ± 10 days; P < 0

  16. Neutrophil beta-adrenergic receptor responses are potentiated by acute exposure to phorbol ester without changes in receptor distribution or coupling

    SciTech Connect

    Kilfeather, S.A.; Stein, M.; O'Malley, K. )

    1991-01-01

    Exposure to the phorbol ester, phorbol 12-myristate, 13-acetate for 10 minutes enhanced cyclic AMP accumulation in human neutrophils under basal conditions and in response to the beta-adrenergic receptor agonist isoproterenol (ISO, 1{mu}M) and the adenylate cyclase activator forskolin (FSK, 10mM). Potentiation of responses to ISO by PMA was dose-dependent between 0.1 and 100nM PMA. The diacylglycerol analogue, 1-oleoyl-2-actylgylcerol (OAG) (50 {mu}M) also elevated beta-receptor responses, but 4beta-phorbol (100nM), lacking the capacity to activate PMA, was ineffective. Short-term exposure to the peptide n-formylmethionine leucyl-phenylalanine (FMLP, 1 {mu}M) also elevated neutrophil cyclic AMP accumulation. All potentiating effects of PMA on cyclic AMP production were inhibited by the protein kinase inhibitor 1-(5-isoquinolinylsulphonyl)-2-methylpiperazine (H{sub 7}). PMA had no apparent effect on beta-receptor agonist-affinity, distribution between cell-surface and internalized compartments, or the capacity of ISO to induce beta-receptor internalization. Responses to FSK or ISO in terms of fold-stimulation of basal cyclic AMP accumulation int he presence of PMA were not elevated by PMA.

  17. Unprotected daily sun exposure is differently associated with central adiposity and beta-cell dysfunction by gender: The Korean national health and nutrition examination survey (KNHANES) V

    SciTech Connect

    Ohn, Jung Hun; Kwon, In Ho; Park, Juri; Ryu, Ohk Hyun; Lee, Seong Jin; Kim, Doo-Man; Ihm, Sung-Hee; Choi, Moon-Gi; Yoo, Hyung Joon; Hong, Eun-Gyoung

    2014-08-15

    Background: Ultraviolet irradiation by sun exposure has been associated with both harms and benefits to metabolic health. Objective: The objective of this study was to determine whether unprotected daily sun exposure is associated with the prevalence of diabetes and explore the underlying mechanism. Methods: We analyzed the Korean National Health and Nutrition Survey V from 2010 to 2011. Participants 19–60 years of age were asked about the average amount of time they had been exposed to direct sunlight per day since the age of 19. We categorized participants into three groups with different levels of lifetime daily sun exposure and explored the association of sun exposure with the prevalence of diabetes. Results: The risk of diabetes was higher in subjects with more than 5 h of unprotected sun exposure per day, with an odds ratio of 2.39 (95% CI 1.75–3.25), compared to those with less than 2 h of sun exposure, and the association remained significant after adjusting for diabetes risk factors. Long-term sun exposure was associated with increased central obesity and the possibility of an increase in visceral adiposity, especially among women, and with decrease in beta cell function and peripheral adiposity or percent body fat in men. Conclusions: Our study provides a cutoff for upper limit of sun exposure and suggests unprotected daily sun exposure for more than 5 h should be avoided to prevent diabetes. Increased central adiposity and decreased beta cell function were observed in women and men, respectively, who had long-term unprotected daily sun exposure. - Highlights: • Sun exposure for more than 5 h per day is associated with diabetes risk. • Insulin resistance associated with visceral adiposity may play a role in women. • Insulin secretory defect may explain diabetes risk in men.

  18. Continuous exposure to infectious pancreatic necrosis virus during early life stages of rainbow trout, Oncorhynchus mykiss(Walbaum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rainbow trout (Oncorhynchus mykiss, Walbaum) were exposed continuously to infectious pancreatic necrosis virus (IPNV) at 0, 10, 1,000, or 100,000 pfu/L of water to estimate the effects of chronic IPNV exposure on early life stages. Fish density averaged 35 fish/L or 140 fish/L, with a tank flow rat...

  19. Continuous Exposure to Infectious Pancreatic Necrosis Virus (IPNV) During Early Life Stages of Rainbow Trout, Oncorhynchus mykiss, Walbaum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rainbow trout (Oncorhynchus mykiss, Walbaum) were exposed continuously to infectious pancreatic necrosis virus (IPNV) at 0, 10, 1,000, or 10,000 pfu/L of water to estimate the effects of chronic IPNV exposure on early life stages. Fish density averaged 35 fish/L (low) or 140 fish/L (high), and wate...

  20. alpha4beta2 nicotinic receptors with high and low acetylcholine sensitivity: pharmacology, stoichiometry, and sensitivity to long-term exposure to nicotine.

    PubMed

    Moroni, Mirko; Zwart, Ruud; Sher, Emanuele; Cassels, Bruce K; Bermudez, Isabel

    2006-08-01

    alpha4 and beta2 nicotinic acetylcholine receptor (nAChR) subunits expressed heterologously assemble into receptors with high (HS) and low (LS) sensitivity to acetylcholine (ACh); their relative proportions depend on the alpha4to beta2 ratio. In this study, injection of oocytes with 1:10 alpha4/beta2 subunit cDNA ratios favored expression of HS alpha4beta2 nAChRs, as evidenced by monophasic ACh concentration-response curves, whereas injections with 10:1 cDNA ratios favored expression of LS alpha4beta2 receptors. The stoichiometry was inferred from the shifts in the ACh EC(50) values caused by Leu to Thr mutations at position 9' of the second transmembrane domain of alpha4 and beta2. The 1:10 injection ratio produced the (alpha4)(2)(beta2)(3) stoichiometry, whereas 10:1 injections produced the (alpha4)(3)(beta2)(2) stoichiometry. The agonists epibatidine, 3-[2(S)-azetidinylmethoxy]pyridine (A-85380), 5-ethoxy-metanicotine (TC-2559), cytisine, and 3-Br-cytisine and the antagonists dihydro-beta-erythroidine and d-tubocurarine were more potent at HS receptors. TC-2559 was more efficacious than ACh at HS receptors but was a partial agonist at LS receptors. Epibatidine was more efficacious than ACh at LS receptors and a partial agonist at HS receptors. Cytisine and 5-halogenated cytisines had moderate efficacy at LS receptors but had almost no efficacy at HS receptors. By exploiting the differential effects of ACh, TC-2559 and 5-I-cytisine we evaluated the effects of long-term exposure to nicotine on HS and LS receptors expressed in Xenopus laevis oocytes after cDNA injections or microtransplantation of alpha4beta2 receptors assembled in human embryonic kidney 293 cells. We conclude that nicotine up-regulates HS alpha4beta2 receptors, probably by influencing the assembly of receptors rather than by altering the functional state of LS alpha4beta2 nAChRs.

  1. Effects of Exposure to Intermittent versus Continuous Red Light on Human Circadian Rhythms, Melatonin Suppression, and Pupillary Constriction

    PubMed Central

    Ho Mien, Ivan; Chua, Eric Chern-Pin; Lau, Pauline; Tan, Luuan-Chin; Lee, Ivan Tian-Guang; Yeo, Sing-Chen; Tan, Sara Shuhui; Gooley, Joshua J.

    2014-01-01

    Exposure to light is a major determinant of sleep timing and hormonal rhythms. The role of retinal cones in regulating circadian physiology remains unclear, however, as most studies have used light exposures that also activate the photopigment melanopsin. Here, we tested the hypothesis that exposure to alternating red light and darkness can enhance circadian resetting responses in humans by repeatedly activating cone photoreceptors. In a between-subjects study, healthy volunteers (n = 24, 21–28 yr) lived individually in a laboratory for 6 consecutive days. Circadian rhythms of melatonin, cortisol, body temperature, and heart rate were assessed before and after exposure to 6 h of continuous red light (631 nm, 13 log photons cm−2 s−1), intermittent red light (1 min on/off), or bright white light (2,500 lux) near the onset of nocturnal melatonin secretion (n = 8 in each group). Melatonin suppression and pupillary constriction were also assessed during light exposure. We found that circadian resetting responses were similar for exposure to continuous versus intermittent red light (P = 0.69), with an average phase delay shift of almost an hour. Surprisingly, 2 subjects who were exposed to red light exhibited circadian responses similar in magnitude to those who were exposed to bright white light. Red light also elicited prolonged pupillary constriction, but did not suppress melatonin levels. These findings suggest that, for red light stimuli outside the range of sensitivity for melanopsin, cone photoreceptors can mediate circadian phase resetting of physiologic rhythms in some individuals. Our results also show that sensitivity thresholds differ across non-visual light responses, suggesting that cones may contribute differentially to circadian resetting, melatonin suppression, and the pupillary light reflex during exposure to continuous light. PMID:24797245

  2. Effects of Item Exposure for Conventional Examinations in a Continuous Testing Environment.

    ERIC Educational Resources Information Center

    Hertz, Norman R.; Chinn, Roberta N.

    This study explored the effect of item exposure on two conventional examinations administered as computer-based tests. A principal hypothesis was that item exposure would have little or no effect on average difficulty of the items over the course of an administrative cycle. This hypothesis was tested by exploring conventional item statistics and…

  3. Suppression and recovery of the alveolar macrophage phagocytic system during continuous exposure to 0. 5 ppm ozone

    SciTech Connect

    Gilmour, M.I.; Hmieleski, R.R.; Stafford, E.A.; Jakab, G.J. )

    1991-05-01

    Short-term exposures to ozone (O3) are known to impair pulmonary antibacterial defenses and alveolar macrophage (AM) phagocytosis in a dose-related manner. To determine the effect of prolonged O3 exposure, Swiss mice were exposed continuously to 0.5 ppm O3. At 1, 3, 7, and 14 days, intrapulmonary killing was assessed by inhalation challenge with Staphylococcus aureus or Proteus mirabilis and by comparing the number of viable bacteria remaining in the lungs at 4 h between O3-exposed and control animals. To evaluate the effects of O3 on the functional capacity of the AMs, Fc-receptor mediated phagocytosis was assessed. Ozone exposure impaired the intrapulmonary killing of S. aureus at 1 and 3 days; however, with prolonged exposure, the bactericidal capacity of the lungs returned to normal. This trend of an initial suppression followed by recovery was reflected in the phagocytic capacity of the AMs. In contrast to S. aureus, when P. mirabilis was used as the challenge organism, O3 exposure had no suppressive effect on pulmonary bactericidal activity, which correlated with an increase in the phagocytic cell population in the lungs. Morphologic examination of the lavaged macrophages showed that after 1 day of O3 exposure, the AMs were more foamy, and contained significantly more vacuoles. There was also a significant increase in binucleated cells at 3 days. These studies demonstrate that continuous exposure to O3 modulates AM-dependent lung defenses and points to the importance of the challenge organism and exposure protocol in establishing the adverse effect of O3.

  4. Continuous exposure to the deterrents cis-jasmone and methyl jasmonate does not alter the behavioural responses of Frankliniella occidentalis

    PubMed Central

    Egger, Barbara; Spangl, Bernhard; Koschier, Elisabeth Helene

    2016-01-01

    Behavioural responses of Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), a generalist, cell sap-feeding insect species with piercing-sucking mouthparts, after continuous exposure to two deterrent secondary plant compounds are investigated. We compared in choice assays on bean leaf discs, the settling, feeding, and oviposition preferences of F. occidentalis females that had no experience with the two fatty acid derivatives methyl jasmonate and cis-jasmone before testing (naïve thrips) vs. females that had been exposed to the deterrent compounds before testing (experienced thrips). The thrips were exposed to the deterrents at low or high concentrations for varied time periods and subsequently tested on bean leaf discs treated with the respective deterrent at either a low or a high concentration. Frankliniella occidentalis females avoided settling on the deterrent-treated bean leaf discs for an observation period of 6 h, independent of their previous experience. Our results demonstrate that feeding and oviposition deterrence of the jasmonates to the thrips were not altered by continuous exposure of the thrips to the jasmonates. Habituation was not induced, neither by exposure to the low concentration of the deterrents nor by exposure to the high concentration. These results indicate that the risk of habituation to two volatile deterrent compounds after repeated exposure is not evident in F. occidentalis. This makes the two compounds potential candidates to be integrated in pest management strategies. PMID:26726263

  5. Skin damage thresholds with continuous-wave laser exposures at the infrared wavelength of 1319 nm

    NASA Astrophysics Data System (ADS)

    Oliver, Jeffrey W.; Harbert, Corey A.; Noojin, Gary D.; Noojin, Isaac D.; Schuster, Kurt J.; Shingledecker, Aurora D.; Stolarski, David J.; Kumru, Semih S.

    2011-03-01

    ABSTRACT Damage thresholds (ED50) for skin using Yucatan mini-pig (Sus scrofa domestica) have been determined at the operational wavelength of 1319 nm with beam diameters of 0.61 cm and 0.96 cm. Exposure durations of 0.25, 1.0, 2.5 and 10 seconds were used to determine trends in damage threshold with respect to exposure time and beam diameter at this moderately-high penetrating wavelength. A relatively narrow range of total radiant exposure from 37.4 J/cm2 to 62.3 J/cm2 average was observed for threshold damage with laser parameters encompassing a factor of two in beam area and a factor of forty in exposure duration.

  6. Short Term Exposure of Beta Cells to Low Concentrations of Interleukin-1β Improves Insulin Secretion through Focal Adhesion and Actin Remodeling and Regulation of Gene Expression*

    PubMed Central

    Arous, Caroline; Ferreira, Pedro G.; Dermitzakis, Emmanouil T.; Halban, Philippe A.

    2015-01-01

    Type 2 diabetes involves defective insulin secretion with islet inflammation governed in part by IL-1β. Prolonged exposure of islets to high concentrations of IL-1β (>24 h, 20 ng/ml) impairs beta cell function and survival. Conversely, exposure to lower concentrations of IL-1β for >24 h improves these same parameters. The impact on insulin secretion of shorter exposure times to IL-1β and the underlying molecular mechanisms are poorly understood and were the focus of this study. Treatment of rat primary beta cells, as well as rat or human whole islets, with 0.1 ng/ml IL-1β for 2 h increased glucose-stimulated (but not basal) insulin secretion, whereas 20 ng/ml was without effect. Similar differential effects of IL-1β depending on concentration were observed after 15 min of KCl stimulation but were prevented by diazoxide. Studies on sorted rat beta cells indicated that the enhancement of stimulated secretion by 0.1 ng/ml IL-1β was mediated by the NF-κB pathway and c-JUN/JNK pathway acting in parallel to elicit focal adhesion remodeling and the phosphorylation of paxillin independently of upstream regulation by focal adhesion kinase. Because the beneficial effect of IL-1β was dependent in part upon transcription, gene expression was analyzed by RNAseq. There were 18 genes regulated uniquely by 0.1 but not 20 ng/ml IL-1β, which are mostly involved in transcription and apoptosis. These results indicate that 2 h of exposure of beta cells to a low but not a high concentration of IL-1β enhances glucose-stimulated insulin secretion through focal adhesion and actin remodeling, as well as modulation of gene expression. PMID:25586177

  7. Meta-analysis for deriving age- and gender-specific dose-response relationships between urinary cadmium concentration and {beta} {sub 2}-microglobulinuria under environmental exposure

    SciTech Connect

    Gamo, Masashi . E-mail: masashi-gamo@aist.go.jp; Ono, Kyoko; Nakanishi, Junko

    2006-05-15

    A meta-analysis was conducted to derive age- and gender-specific dose-response relationships between urinary cadmium (Cd) concentration and {beta} {sub 2}-microglobulinuria ({beta}2MG-uria) under environmental exposure. {beta}2MG-uria was defined by a cutoff point of 1000 {mu}g {beta} {sub 2}-microglobulin/g creatinine. We proposed a model for describing the relationships among the interindividual variabilities in urinary Cd concentration, the ratio of Cd concentrations in the target organ and in urine, and the threshold Cd concentration in the target organ. The parameters in the model were determined so that good agreement might be achieved between the prevalence rates of {beta}2MG-uria reported in the literature and those estimated by the model. In this analysis, only the data from the literature on populations environmentally exposed to Cd were used. Using the model and estimated parameters, the prevalence rate of {beta}2MG-uria can be estimated for an age- and gender-specific subpopulation for which the distribution of urinary Cd concentrations is known. The maximum permissible level of urinary Cd concentration was defined as the maximum geometric mean of the urinary Cd concentration in an age- and gender-specific subpopulation that would not result in a statistically significant increase in the prevalence rate of {beta}2MG-uria. This was estimated to be approximately 3 {mu}g/g creatinine for a population in a small geographical area and approximately 2 {mu}g/g creatinine for a nationwide population.

  8. Continuous extraction of alpha- and beta-amylases from Zea mays malt in a PEG4000/CaCl2 ATPS.

    PubMed

    Biazus, J P M; Santana, J C C; Souza, R R; Jordão, E; Tambourgi, E B

    2007-10-15

    In the present work, alpha- and beta-amylase enzymes from Zea mays malt were recovered by continuous extraction in a PEG/CaCl2 aqueous two-phase system (ATPS). The influences of the flux rate (RQ), free area of vane (A(free)) and vane rotation (RV) on enzyme recovery were studied by optimization using response surface methodology (RSM). The protein content and enzyme activity were measured from time to time in the extract and refined fluxes. RSM curves showed a squared dependence of recovery index with the RQ, A(free) and RV. The best system for recovering the maize malt enzymes was with low vane rotation and flux rate and high free area of vane. Alpha- and beta-amylases were purified 130-fold in the salt-rich phase.

  9. Chronic stress exposure following photothrombotic stroke is associated with increased levels of Amyloid beta accumulation and altered oligomerisation at sites of thalamic secondary neurodegeneration in mice.

    PubMed

    Ong, Lin Kooi; Zhao, Zidan; Kluge, Murielle; Walker, Frederick R; Nilsson, Michael

    2017-04-01

    Exposure to severe stress following stroke is recognised to complicate the recovery process. We have identified that stress can exacerbate the severity of post-stroke secondary neurodegeneration in the thalamus. In this study, we investigated whether exposure to stress could influence the accumulation of the neurotoxic protein Amyloid-β. Using an experimental model of focal cortical ischemia in adult mice combined with exposure to chronic restraint stress, we examined changes within the contra- and ipsilateral thalamus at six weeks post-stroke using Western blotting and immunohistochemical approaches. Western blotting analysis indicated that stroke was associated with a significant enhancement of the 25 and 50 kDa oligomers within the ipsilateral hemisphere and the 20 kDa oligomer within the contralateral hemisphere. Stroked animals exposed to stress exhibited an additional increase in multiple forms of Amyloid-beta oligomers. Immunohistochemistry analysis confirmed that stroke was associated with a significant accumulation of Amyloid-beta within the thalami of both hemispheres, an effect that was exacerbated in stroke animals exposed to stress. Given that Amyloid-beta oligomers, most notably the 30-40 and 50 kDa oligomers, are recognised to correlate with accelerated cognitive decline, our results suggest that monitoring stress levels in patients recovering from stroke may merit consideration in the future.

  10. An animal model to study health effects during continuous low-dose exposure to the nerve agent VX.

    PubMed

    Rocksén, David; Elfsmark, Daniel; Heldestad, Victoria; Wallgren, Karin; Cassel, Gudrun; Göransson Nyberg, Ann

    2008-08-19

    In the present study, we have developed an animal model to study long-term health effects of continuous exposure of toxic chemical agents, in awake, freely moving rats. The aim was to evaluate the effect of low-dose exposure of the nerve agent VX, and to find specific biomarkers for intoxication. To exclude the influence of stress, we used an implanted radio-telemetric device for online registration of physiological parameters, and an osmotic pump, implanted subcutaneously, for continuous exposure of the toxic agent. Our results showed that the lowest observable effect dose of VX in Wistar rats was 5 microg/kg/24 h, after continuous exposure by the osmotic pump. Although we observed significant inhibition of acetylcholinesterase (AChE) in blood and a significant decrease in body weight gain at this dose, no change in blood pressure, heart rate or respiratory rate was registered. However, a significant decrease in the thyroid hormone, free T4, was measured in blood after 8 weeks, indicating that low doses of VX might affect the thyroid function. Rats given repeated daily injections were more sensitive to VX and needed only 1/10 of the concentration to reach a similar level of AChE inhibition, compared to animals exposed by the osmotic pump. Moreover, the results showed that exposure of VX in our experimental design, does not induce an increase in corticosterone blood levels. Thus, the model used in this investigation renders minimal stress and will not cause unnecessary pain to the animals, indicating that this model could be a useful tool to study long-term effects of various toxic substances in freely moving rats.

  11. Killing rates for caspofungin against Candida albicans after brief and continuous caspofungin exposure in the presence and absence of serum.

    PubMed

    Kovács, Renátó; Gesztelyi, Rudolf; Perlin, David S; Kardos, Gábor; Domán, Marianna; Berényi, Réka; Majoros, László

    2014-10-01

    It was previously demonstrated that brief (≤1 h) exposures to echinocandins are as effective to kill Candida albicans cells as continuous 24-h exposure. However, killing rates after continuous and short (1 h) echinocandin exposures to C. albicans have not yet been evaluated in RPMI-1640 with and without 50 % serum. We evaluated four echinocandin susceptible C. albicans bloodstream isolates, ATCC 10231 type strain and an echinocandin-resistant isolate (DPL20, FKS F645P). Caspofungin MICs, time-kill and postantifungal effect (PAFE) tests were performed in RPMI-1640 with and without 50 % serum. Killing rates (k values) in time-kill and PAFE experiments were determined for each strain and concentration. In time-kill experiments, colony count decreases were isolate- and concentration-dependent at 0.25, 1, 4, 8, 16 and 32 mg/L in RPMI-1640, but concentration-independent at 1, 4, 8, 16 and 32 mg/L in 50 % serum. One-hour caspofungin exposure at 4, 16 and 32 mg/L resulted in CFU decreases comparable with the results obtained in time-kill experiments in RPMI-1640, but 50 % serum at 4, 16 and 32 mg/L allowed growth of all isolates (k values were negative) (P < 0.05-0.001). PAFE in 50 % serum decreased markedly at 4, 16 and 32 mg/L. Killing rates remained high and concentration-independent in 50 % serum in case of continuous but not in case of brief caspofungin exposure. As only a short growth inhibition without killing was observed in 50 % serum, clinical relevance of caspofungin PAFE in vivo is questionable.

  12. Effect of continuous gamma-ray exposure on performance of learned tasks and effect of subsequent fractionated exposures on blood-forming tissue

    NASA Technical Reports Server (NTRS)

    Spalding, J. F.; Holland, L. M.; Prine, J. R.; Farrer, D. N.; Braun, R. G.

    1972-01-01

    Sixteen monkeys trained to perform continuous and discrete-avoidance and fixed-ratio tasks with visual and auditory cues were performance-tested before, during, and after 10-day gamma-ray exposures totaling 0, 500, 750, and 1000 rads. Approximately 14 months after the performance-test exposures, surviving animals were exposed to 100-rad gamma-ray fractions at 56-day intervals to observe injury and recovery patterns of blood-forming tissues. The fixed-ratio, food-reward task performance showed a transient decline in all dose groups within 24 hours of the start of gamma-ray exposure, followed by recovery to normal food-consumption levels within 48 to 72 hours. Avoidance tasks were performed successfully by all groups during the 10-day exposure, but reaction times of the two higher dose-rate groups in which animals received 3 and 4 rads per hour or total doses of 750 and 1000 rads, respectively, were somewhat slower.

  13. CalTOX (registered trademark), A multimedia total exposure model spreadsheet user's guide. Version 4.0(Beta)

    SciTech Connect

    McKone, T.E.; Enoch, K.G.

    2002-08-01

    CalTOX has been developed as a set of spreadsheet models and spreadsheet data sets to assist in assessing human exposures from continuous releases to multiple environmental media, i.e. air, soil, and water. It has also been used for waste classification and for setting soil clean-up levels at uncontrolled hazardous wastes sites. The modeling components of CalTOX include a multimedia transport and transformation model, multi-pathway exposure scenario models, and add-ins to quantify and evaluate uncertainty and variability. All parameter values used as inputs to CalTOX are distributions, described in terms of mean values and a coefficient of variation, rather than as point estimates or plausible upper values such as most other models employ. This probabilistic approach allows both sensitivity and uncertainty analyses to be directly incorporated into the model operation. This manual provides CalTOX users with a brief overview of the CalTOX spreadsheet model and provides instructions for using the spreadsheet to make deterministic and probabilistic calculations of source-dose-risk relationships.

  14. Regulatory CD8{sup +} T cells induced by exposure to all-trans retinoic acid and TGF-{beta} suppress autoimmune diabetes

    SciTech Connect

    Kishi, Minoru; Yasuda, Hisafumi; Abe, Yasuhisa; Sasaki, Hirotomo; Shimizu, Mami; Arai, Takashi; Okumachi, Yasuyo; Moriyama, Hiroaki; Hara, Kenta; Yokono, Koichi; Nagata, Masao

    2010-03-26

    Antigen-specific regulatory CD4{sup +} T cells have been described but there are few reports on regulatory CD8{sup +} T cells. We generated islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)-specific regulatory CD8{sup +} T cells from 8.3-NOD transgenic mice. CD8{sup +} T cells from 8.3-NOD splenocytes were cultured with IGRP, splenic dendritic cells (SpDCs), TGF-{beta}, and all-trans retinoic acid (ATRA) for 5 days. CD8{sup +} T cells cultured with either IGRP alone or IGRP and SpDCs in the absence of TGF-{beta} and ATRA had low Foxp3{sup +} expression (1.7 {+-} 0.9% and 3.2 {+-} 4.5%, respectively). In contrast, CD8{sup +} T cells induced by exposure to IGRP, SpDCs, TGF-{beta}, and ATRA showed the highest expression of Foxp3{sup +} in IGRP-reactive CD8{sup +} T cells (36.1 {+-} 10.6%), which was approximately 40-fold increase compared with that before induction culture. CD25 expression on CD8{sup +} T cells cultured with IGRP, SpDCs, TGF-{beta}, and ATRA was only 7.42%, whereas CD103 expression was greater than 90%. These CD8{sup +} T cells suppressed the proliferation of diabetogenic CD8{sup +} T cells from 8.3-NOD splenocytes in vitro and completely prevented diabetes onset in NOD-scid mice in cotransfer experiments with diabetogenic splenocytes from NOD mice in vivo. Here we show that exposure to ATRA and TGF-{beta} induces CD8{sup +}Foxp3{sup +} T cells ex vivo, which suppress diabetogenic T cells in vitro and in vivo.

  15. USE OF A CONTINUOUS NEPHELOMETER TO MEASURE PERSONAL EXPOSURE TO PARTICLES DURING THE U.S. EPA BALTIMORE AND FRESNO PANEL STUDIES

    EPA Science Inventory

    In population exposure studies, personal exposure to particulate matter (PM) is typically measured as a 12- to 24-hour integrated mass concentration. To better understand short-term variation in personal PM exposure, continuous (one-minute averaging time) nephelometers were wo...

  16. Up- and down-regulation of beta-adrenoreceptors in rat cerebral cortex following exposure to isomers of hexachlorocyclohexane

    SciTech Connect

    Stark, L.; Hollinger, M.; Joy, R.

    1986-03-01

    The authors have shown that the gamma (lindane) and beta isomers of hexachlorocyclohexane (HCH) have opposite effects on the kindling model of epilepsy (gamma facilitates, beta retards kindling acquisition). In the present study the authors determined the effects of these two isomers on ..beta..-adrenoreceptors in rat brain using /sup 3/H-dihydroalprenolol as the ligand following 10 days treatment with 10 mg/kg p.o. of isomers or corn oil. Results showed a statistically significant decrease in the number of ..beta..-adrenoreceptors in cortical tissue taken from lindane treated rats. In contrast, there was a significant increase in the number of ..beta..-adreno receptors in cortical tissue taken from beta-HCH treated rats. Neither treatment caused a significant change in Kd. It is concluded that the ..beta..-adrenoreceptor system in rat brain is differentially affected by the isomers of HCH. Since the kindling model of epilepsy is sensitive to modulation in adrenergic function, this system may be involved in the pro- and anticonvulsant effects of these HCH isomers on kindling acquisition.

  17. Comparison of intermittent and continuous exposures to inorganic mercury in the mussel, Mytilus edulis: accumulation and sub-lethal physiological effects.

    PubMed

    Amachree, Dokuboba; Moody, A John; Handy, Richard D

    2014-11-01

    Aquatic organisms are often subject to intermittent exposure to pollutants in real ecosystems. This study aimed to compare mercury accumulation and the physiological responses of mussels, Mytilus edulis during continuous and intermittent exposure to the metal. Mussels were treated in a semi-static, triplicated design to either a control (no added Hg) or 50 µg l(-1) Hg as HgCl2 in continuous (daily) or intermittent (2 day exposure, 2 days in clean seawater alternately) exposure for 14 days. A time-dependent increase in Hg accumulation was observed in the continuous exposure, while the intermittent treatment showed step-wise changes in Hg concentrations with the exposure profile, especially in the gills. At the end of the experiment, tissue Hg concentrations were significantly increased in the continuous compared to the intermittent exposure for digestive gland (4 fold), gonad and remaining soft tissue (>2 fold), but not for the gill and adductor muscle. There was no observed oxidative damage at the end of the experiment as measured by the thiobarbituric acid reactive substances (TBARS) concentrations in tissues from all treatments. However, total glutathione was significantly decreased in the gill and digestive gland of both the continuous and intermittent exposure by the end of the experiment. The neutral red retention ability of the haemocytes was not affected, but total haemocyte counts were significantly decreased (<2 fold) in the intermittent compared to the continuous exposure. Histopathological examinations showed less pathology in the gill, but more inflammation in the digestive gland of mussels for the intermittent compared to the continuous exposure. Overall, the results showed that Hg accumulation from intermittent exposure was less than that of the continuous exposure regime, but the sub-lethal responses are sometimes more severe than expected in the former.

  18. Human exposure to rabid free-ranging cats: a continuing public health concern in Pennsylvania.

    PubMed

    Campagnolo, E R; Lind, L R; Long, J M; Moll, M E; Rankin, J T; Martin, K F; Deasy, M P; Dato, V M; Ostroff, S M

    2014-08-01

    Rabid free-ranging cats have been a public health concern in Pennsylvania since raccoon variant rabies first was recognized in the state in the early 1980s. Over the last decade, between 1.5 and 2.5% of cats submitted to Pennsylvania's state laboratories for rabies testing have been positive. In this report, we describe the extent of rabies in free-ranging cats in Pennsylvania. We also present two examples of human exposure to rabid free-ranging cats that occurred in Pennsylvania during 2010-2011 and the public health actions taken to address rabies exposure in the humans and animals. We then describe the concerns surrounding the unvaccinated and free-ranging cat population in Pennsylvania and possible options in managing this public and animal health problem.

  19. Repellence produced by monoterpenes on Rhodnius prolixus (Hemiptera: Reduviidae) decreases after continuous exposure to these compounds.

    PubMed

    Lutz, Alejandra; Sfara, Valeria; Alzogaray, Raúl Adolfo

    2014-01-01

    Botanical monoterpenes are secondary metabolites present in essential oils produced by plants. Some of them are insect repellents. The bloodsucking bug Rhodnius prolixus Ståhl (Hemiptera: Reduviidae) is one of the main vectors of Chagas disease in the north of South America and some countries in Central America. In this study, we studied the repellence produced by two monoterpenes, menthyl acetate and geraniol, on fifth instar nymphs of R. prolixus. In the absence of other stimuli, both menthyl acetate and geraniol produced a repellent effect from 740 μg/cm(2) and 74 μg/cm(2), respectively. Pre-exposure to each monoterpene reduced the repellent activity produced by the same substance. Additionally, pre-exposure to one monoterpene decreased the behavioral response of the nymphs to the other one. The repellent effect of both monoterpenes also decreased when nymphs' antennae were previously treated with the nitric oxide donor S-nitroso-N-acetyl-cysteine.

  20. Pulsed and continuous wave mobile phone exposure over left versus right hemisphere: effects on human cognitive function.

    PubMed

    Haarala, Christian; Takio, Fiia; Rintee, Taija; Laine, Matti; Koivisto, Mika; Revonsuo, Antti; Hämäläinen, Heikki

    2007-05-01

    The possible effects of continuous wave (CW) and pulse modulated (PM) electromagnetic field (EMF) on human cognition was studied in 36 healthy male subjects. They performed cognitive tasks while exposed to CW, PM, and sham EMF. The subjects performed the same tasks twice during each session; once with left-sided and once with right-sided exposure. The EMF conditions were spread across three testing sessions, each session separated by 1 week. The exposed hemisphere, EMF condition, and test order were counterbalanced over all subjects. We employed a double-blind design: both the subject and the experimenter were unaware of the EMF condition. The EMF was created with a signal generator connected via amplifier to a dummy phone antenna, creating a power output distribution similar to the original commercial mobile phone. The EMF had either a continuous power output of 0.25 W (CW) or pulsed power output with a mean of 0.25 W. An additional control group of 16 healthy male volunteers performed the same tasks without any exposure equipment to see if mere presence of the equipment could have affected the subjects' performance. No effects were found between the different EMF conditions, separate hemisphere exposures, or between the control and experimental group. In conclusion, the current results indicate that normal mobile phones have no discernible effect on human cognitive function as measured by behavioral tests.

  1. Continuous Exposure to Chrysotile Asbestos Can Cause Transformation of Human Mesothelial Cells via HMGB1 and TNF-α Signaling

    PubMed Central

    Qi, Fang; Okimoto, Gordon; Jube, Sandro; Napolitano, Andrea; Pass, Harvey I.; Laczko, Rozalia; DeMay, Richard M.; Khan, Ghazal; Tiirikainen, Maarit; Rinaudo, Caterina; Croce, Alessandro; Yang, Haining; Gaudino, Giovanni; Carbone, Michele

    2014-01-01

    Malignant mesothelioma is strongly associated with asbestos exposure. Among asbestos fibers, crocidolite is considered the most and chrysotile the least oncogenic. Chrysotile accounts for more than 90% of the asbestos used worldwide, but its capacity to induce malignant mesothelioma is still debated. We found that chrysotile and crocidolite exposures have similar effects on human mesothelial cells. Morphological and molecular alterations suggestive of epithelial–mesenchymal transition, such as E-cadherin down-regulation and β-catenin phosphorylation followed by nuclear translocation, were induced by both chrysotile and crocidolite. Gene expression profiling revealed high-mobility group box-1 protein (HMGB1) as a key regulator of the transcriptional alterations induced by both types of asbestos. Crocidolite and chrysotile induced differential expression of 438 out of 28,869 genes interrogated by oligonucleotide microarrays. Out of these 438 genes, 57 were associated with inflammatory and immune response and cancer, and 14 were HMGB1 targeted genes. Crocidolite-induced gene alterations were sustained, whereas chrysotile-induced gene alterations returned to background levels within 5 weeks. Similarly, HMGB1 release in vivo progressively increased for 10 or more weeks after crocidolite exposure, but returned to background levels within 8 weeks after chrysotile exposure. Continuous administration of chrysotile was required for sustained high serum levels of HMGB1. These data support the hypothesis that differences in biopersistence influence the biological activities of these two asbestos fibers. PMID:24160326

  2. Design and construction of a simple, continuous flow sulfur dioxide exposure chamber

    SciTech Connect

    Leetham, J.W.; Ferguson, W.; Dodd, J.L.; Lauenroth, W.K.

    1982-02-01

    For experimental purposes, a reasonably large capacity, low cost, low maintenance chamber was needed to study the long-term (2-4 months) effects of sulfur dioxide on developmental rates of grasshoppers and decomposition rates of plant litter. Internal temperature, humidity, and light controls were not required since the chamber would be used in externally controlled environments. The controlled exposure chamber herein described has proved to be adequate for such studies and satisfied most of the conditions discussed by Heagle and Philbeck. Its utility could be increased by use within an environmentally controlled greenhouse. It is comparatively simple and inexpensive to contruct and maintain.

  3. Sensitivity of a Tier I screening battery compared to an in utero exposure for detecting the estrogen receptor agonist 17 beta-estradiol.

    PubMed

    O'Connor, J C; Frame, S R; Biegel, L B; Cook, J C; Davis, L G

    1998-08-01

    A Tier I screening battery for detecting endocrine active compounds (EACs) has been evaluated for its ability to identify 17 beta-estradiol, a pure estrogen receptor agonist. In addition, the responses obtained with the Tier I battery were compared to the responses obtained from F1 generation rats from a 90-day/one-generation reproduction study with 17 beta-estradiol in order to characterize the sensitivity of the Tier I battery against the sensitivity of an in utero exposure for detecting EACs. The Tier I battery incorporates two short-term in vivo tests (5-day ovariectomized female battery; 15-day intact male battery) and an in vitro yeast transactivation system (YTS) for identifying compounds that alter endocrine homeostasis. The Tier I female battery consists of traditional uterotrophic endpoints coupled with biochemical and hormonal endpoints. It is designed to identify compounds that are estrogenic/antiestrogenic or modulate dopamine levels. The Tier I male battery consists of organ weights coupled with microscopic evaluations and a comprehensive hormonal assessment. It is designed to identify compounds that have the potential to act as agonists or antagonists to the estrogen, androgen, progesterone, or dopamine receptor; steroid biosynthesis inhibitors (aromatase, 5 alpha-reductase, and testosterone biosynthesis); or compounds that alter thyroid function. The YTS is designed to identify compounds that bind to steroid hormone receptors (estrogen, androgen, and progesterone) and activate gene transcription. The profile generated for 17 beta-estradiol was characteristic of the responses expected with a pure estrogen receptor agonist. In the female battery, responses to 17 beta-estradiol included increases in uterine fluid imbibition, uterine weight, estrus conversion, uterine stromal cell proliferation, uterine epithelial cell height, uterine progesterone receptor content, serum prolactin and estradiol levels, and decreases in uterine estrogen receptor content

  4. Gestational Alcohol Exposure and Other Factors Associated with Continued Teenage Drinking

    ERIC Educational Resources Information Center

    Cornelius, Marie D.; Goldschmidt, Lidush; Day, Nancy L.

    2016-01-01

    Purpose: A longitudinal cohort of adolescents who initiated drinking before age 15 were studied to determine which factors distinguished between early initiators who continued to drink (persisters) from those who stopped drinking (desisters). There were 308 early initiators in the total sample (n = 917); 247 were persisters, and 61 were desisters.…

  5. Continuous measurement of peak hydrogen fluoride exposures in aluminum smelter potrooms: instrument development and in-plant evaluation.

    PubMed

    Dando, Neal; Xu, Weizong; Peace, Jon Nathaniel

    2008-02-01

    The aluminum smelting process continuously evolves both sulfur dioxide (SO2) and hydrogen fluoride (HF) gases. The vast majority of these evolved gases are captured by local exhaust ventilation systems and transported to fume treatment centers. Any gas escaping the ventilation systems could create the potential for workplace exposures. Currently, there are no commercially available sensors that are capable of selectively measuring peak concentrations (< 10 sec) of HF in the presence of SO2. This measurement capability is critical for facilitating a better understanding of the etiology of respiratory health effects. This article presents the development and in-plant testing of a portable, tunable diode-based HF sensor that shows equivalent or improved performance relative to NIOSH Method 7902 and is capable of measuring short-term personal peak HF exposure potentials in operating aluminum smelters.

  6. Effect of continuous exposure to apomorphine and acute exposure to fluphenazine-N-mustard on dopaminergic behavior and radioligand binding in supersensitive mice

    SciTech Connect

    Winkler, J.D.

    1987-01-01

    Mice with unilateral, 6-hydroxydopamine-induced lesions of the corpus striatum were exposed to continuous infusion of apomorphine via a subcutaneously implanted osmotic pump. The turning response of these mice when challenged with an acute injection of apomorphine was significantly reduced at one day after chronic implantation and was totally absent at two and four days after implantation. This effect of continuous exposure to apomorphine was found to be concentration- and time-dependent as well as reversible when the implant was removed. Mice tolerant to apomorphine were cross-tolerant to the rotational effects of the D{sub 1} dopaminergic agonist SKF 38393 and the D{sub 2} dopaminergic agonist Ly 171555, but not to amphetamine. Continuous exposure to apomorphine resulted in a decrease in the binding of ({sup 3}H)spiroperidol (D{sub 2} sites) by 44%, whereas the binding of ({sup 3}H)SCH 23390 (D{sub 1} sites) was not affected. Fluphenazine-N-mustard (FNM) has been shown to bind irreversibly to dopaminergic sites. Experiments using varying doses of FNM demonstrated that FNM inhibited Ly 171555-induced rotational behavior at doses ten fold lower than those required to block rotations induced by SKF 38393. In vitro, FNM inhibited the specific binding of ({sup 3}H) spiroperidol at concentrations ten fold lower than those required to inhibit the binding of ({sup 3}H)Sch23390. In vivo, FNM inhibited the binding of ({sup 3}H) spiroperidol measured ex vivo, but did not inhibit the binding of ({sup 3}H) Sch 23390, even when given in doses as high as 100 mg/kg. These studies indicate that FNM was approximately ten times more potent at inhibiting D{sub 2} than D{sub 1} mediated behavior and at displacing D{sub 2} versus D{sub 1} ligands, suggesting that FNM may be useful for studying and differentiating D{sub 2} and D{sub 1} mediated events.

  7. [Morphological changes in penicillin-resistant Streptococcus pneumoniae and beta-lactamase-nonproducing, ampicillin-resistant Haemophilus influenzae after exposure to oral antibacterial agents].

    PubMed

    Chiba, Naoko; Morozumi, Miyuki; Ubukata, Kimiko

    2012-10-01

    Morphological changes in penicillin-resistant Streptococcus pneumoniae (PRSP) and beta-lactamase-nonproducing, ampicillin-resistant Haemophilus influenzae (BLNAR) after exposure to oral antibacterial agents could be observed over time under a phase-contrast microscope. Morphological changes in BLNAR were also observed using a scanning electron microscope. The organisms used in this study were ME19F strain identified as genotypic(g) gPRSP (serotype: 19F) and JPH002 strain identified as gBLNAR (serotype: b). The antibacterial agents used were amoxicillin (AMPC), cefditoren (CDTR), tebipenem (TBPM), and tosufloxacin (TFLX). The concentration of each antibacterial agent to which the bacteria were exposed was set at the blood level one hour after Cmax when administered to children at the usual dose. Bacteriolysis of gPRSP cells started after exposure of only 20minutes to TBPM, and 90% of the cells were lysed within 2 hours. A high bactericidal action of TBPM on gPRSP was supported by these findings. When gBLNAR was exposed to AMPC and TBPM, lysis from spheroplasts and cells with vacuoles were sometimes observed. In contrast, after gBLNAR was exposed to CDTR, lysis occurred after marked filamentation in the cells, but after exposure to TFLX, cells deduced to be killed after mild filamentation without lysis. Time-dependent morphological changes that reflect the differences in bactericidal activity and PBP affinity among beta-lactams provide beneficial information to select antibacterial agents.

  8. Continuous measurements of bronchial exposure induced by radon decay products during inhalation

    SciTech Connect

    Iwaoka, Kazuki; Tokonami, Shinji; Yonehara, Hidenori; Ishikawa, Tetsuo; Doi, Masahiro; Kobayashi, Yosuke; Yatabe, Yoshinori; Takahashi, Hiroyuki; Yamada, Yuji

    2007-09-15

    The deposition of radon decay products is not equal in each of the respiratory regions and as the presence of radon has been linked with an increase in lung cancer risk, it is important to calculate the deposition of radon decay products in each of the respiratory regions. Recently, many studies on the deposition of radon in respiratory regions have been simulated using wire screens. The systems and equipment used in those studies are not suitable for field measurements as their dimensions are relatively massive, nor can they measure continuously. We developed a continuous bronchial dosimeter (CBD) which is suitable for field measurements. It was designed with specifications that allow it to be remain compact. The CBD simulates the deposition of radon decay products in the different respiratory regions by the use of a combination of wire screens. Deposition in the simulated regions of the lung can be continuously estimated in various environments. The ratio of activities deposited in a simulated nasal cavity (N) and tracheobronchial (TB) regions was calculated from the results of simultaneous measurements using CBD-R (reference), CBD-N (nasal), and CBD-TB (tracheobronchial) measurement units. After aerosols were injected into the radon chamber, the ratio of N and TB depositions decreased. This results indicate that the CBD gave a good response to changes in the environment. It was found that the ratio of N and TB deposition also varied with time in each actual environment.

  9. Erythrocyte deformability and aggregation responses to intermittent and continuous artificial gravity exposure

    NASA Astrophysics Data System (ADS)

    Marijke, Grau; Vera, Abeln; Tobias, Vogt; Wilhelm, Bloch; Stefan, Schneider

    2017-02-01

    Artificial gravity protocols are used to improve g-tolerance of aviators and discussed as countermeasure during prolonged space flight. Little is known about the impact of artificial gravity on the red blood cells (RBC). The purpose of the study was to test how artificial gravity affects RBC deformability and aggregation, which are important determinants of microcirculation. Nine male subjects were exposed to two hypergravity protocols using a short arm human centrifuge: a continuous (CONT) protocol with constant +2 Gz for 30 min and an intermittent (INTER) protocol with repeated intervals of +2 Gz and rest. Blood was sampled pre and post interventions to measure basal blood parameters, RBC nitrite, RBC deformability, aggregation, and to determine the shear rate balancing aggregation and disaggregation (γ at dIsc min). To test for orthostasis effects, five male subjects were asked to stay for 46 min, corresponding to the length of the centrifuge protocols, with blood sampling pre and post intervention. Artificial gravity programs did not affect basal blood parameters or RBC nitrite levels; a marker for RBC deformability influencing nitric oxide. The INTER program did not affect any of the tested parameters. The CONT program did not remarkably affect RBC deformability or γ at dIsc min but significantly aggravated aggregation. Orthostasis effects were thus excluded. The results indicate that continuous artificial gravity, especially with higher g-forces applied, may negatively affect the RBC system and that for a prolonged space flight intermittent but not continuous artificial gravity might represent an appropriate countermeasure.

  10. Erythrocyte deformability and aggregation responses to intermittent and continuous artificial gravity exposure.

    PubMed

    Marijke, Grau; Vera, Abeln; Tobias, Vogt; Wilhelm, Bloch; Stefan, Schneider

    2017-02-01

    Artificial gravity protocols are used to improve g-tolerance of aviators and discussed as countermeasure during prolonged space flight. Little is known about the impact of artificial gravity on the red blood cells (RBC). The purpose of the study was to test how artificial gravity affects RBC deformability and aggregation, which are important determinants of microcirculation. Nine male subjects were exposed to two hypergravity protocols using a short arm human centrifuge: a continuous (CONT) protocol with constant +2Gz for 30min and an intermittent (INTER) protocol with repeated intervals of +2Gz and rest. Blood was sampled pre and post interventions to measure basal blood parameters, RBC nitrite, RBC deformability, aggregation, and to determine the shear rate balancing aggregation and disaggregation (γ at dIsc min). To test for orthostasis effects, five male subjects were asked to stay for 46min, corresponding to the length of the centrifuge protocols, with blood sampling pre and post intervention. Artificial gravity programs did not affect basal blood parameters or RBC nitrite levels; a marker for RBC deformability influencing nitric oxide. The INTER program did not affect any of the tested parameters. The CONT program did not remarkably affect RBC deformability or γ at dIsc min but significantly aggravated aggregation. Orthostasis effects were thus excluded. The results indicate that continuous artificial gravity, especially with higher g-forces applied, may negatively affect the RBC system and that for a prolonged space flight intermittent but not continuous artificial gravity might represent an appropriate countermeasure.

  11. Continuous measurements of bronchial exposure induced by radon decay products during inhalation

    NASA Astrophysics Data System (ADS)

    Iwaoka, Kazuki; Tokonami, Shinji; Yonehara, Hidenori; Ishikawa, Tetsuo; Doi, Masahiro; Kobayashi, Yosuke; Yatabe, Yoshinori; Takahashi, Hiroyuki; Yamada, Yuji

    2007-09-01

    The deposition of radon decay products is not equal in each of the respiratory regions and as the presence of radon has been linked with an increase in lung cancer risk, it is important to calculate the deposition of radon decay products in each of the respiratory regions. Recently, many studies on the deposition of radon in respiratory regions have been simulated using wire screens. The systems and equipment used in those studies are not suitable for field measurements as their dimensions are relatively massive, nor can they measure continuously. We developed a continuous bronchial dosimeter (CBD) which is suitable for field measurements. It was designed with specifications that allow it to be remain compact. The CBD simulates the deposition of radon decay products in the different respiratory regions by the use of a combination of wire screens. Deposition in the simulated regions of the lung can be continuously estimated in various environments. The ratio of activities deposited in a simulated nasal cavity (N) and tracheobronchial (TB) regions was calculated from the results of simultaneous measurements using CBD-R (reference), CBD-N (nasal), and CBD-TB (tracheobronchial) measurement units. After aerosols were injected into the radon chamber, the ratio of N and TB depositions decreased. This results indicate that the CBD gave a good response to changes in the environment. It was found that the ratio of N and TB deposition also varied with time in each actual environment.

  12. Beta-lactam antibiotic-induced platelet dysfunction: Evidence for irreversible inhibition of platelet activation in vitro and in vivo after prolonged exposure to penicillin

    SciTech Connect

    Burroughs, S.F.; Johnson, G.J. )

    1990-04-01

    beta-Lactam antibiotics cause platelet dysfunction with bleeding complications. Previous in vitro studies documented reversible inhibition of agonist-receptor interaction. This mechanism is inadequate to explain the effect of beta-lactam antibiotics in vivo. Platelet function does not return to normal immediately after drug treatment, implying irreversible inhibition of platelet function. We report here evidence of irreversible platelet functional and biochemical abnormalities after in vitro and in vivo exposure to beta-lactam antibiotics. Irreversible binding of (14C)-penicillin (Pen) occurred in vitro. After 24 hours' in vitro incubation with 10 to 20 mmol/L Pen, or ex vivo after antibiotic treatment, irreversible functional impairment occurred; but no irreversible inhibition of alpha 2 adrenergic receptors, measured with (3H)-yohimbine, or high-affinity thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptors, measured with agonist (3H)-U46619 and antagonist (3H)-SQ29548, occurred. However, low-affinity platelet TXA2/PGH2 receptors were decreased 40% after Pen exposure in vitro or in vivo, indicating irreversible membrane alteration. Two postreceptor biochemical events were irreversibly inhibited in platelets incubated with Pen for 24 hours in vitro or ex vivo after antibiotic treatment. Thromboxane synthesis was inhibited 28.3% to 81.7%. Agonist-induced rises in cytosolic calcium ((Ca2+)i) were inhibited 40.1% to 67.5% in vitro and 26.6% to 52.2% ex vivo. Therefore, Pen binds to platelets after prolonged exposure, resulting in irreversible dysfunction attributable to inhibition of TXA2 synthesis and impairment of the rise in (Ca2+)i. The loss of low-affinity TXA2/PGH2 receptors suggests that the primary site of action of these drugs is on the platelet membrane.

  13. Continuous exposure to bisphenol A during in vitro follicular development induces meiotic abnormalities.

    PubMed

    Lenie, Sandy; Cortvrindt, Rita; Eichenlaub-Ritter, Ursula; Smitz, Johan

    2008-03-12

    Bisphenol A (BPA), a widely used environmental contaminant, may exert weak estrogenic, anti-androgenic and anti-thyroidic activities. BPA is suspected to possess aneugenic properties that may affect somatic cells and mammalian oocytes. Oocyte growth and maturation depend upon a complex bi-directional signaling between the oocyte and its companion somatic cells. Consequently, disturbances in oocyte maturation may originate either from direct effects of BPA at the level of the oocyte or from indirect influences at the follicular level, such as alterations in hormonal homeostasis. This study aimed to analyze the effects of chronic BPA exposure (3 nM to 30 microM) on follicle-enclosed growth and maturation of mouse oocytes in vitro. Oocytes were cultured and their spindle and chromosomes were stained by alpha-tubulin immunofluorescence and ethidium homodimer-2, respectively. Confocal microscopy was utilized for subsequent analysis. Only follicles that were exposed to 30 microM BPA during follicular development showed a slightly reduced granulosa cell proliferation and a lower total estrogen production, but they still developed and formed antral-like cavities. However, 18% of oocytes were unable to resume meiosis after stimulation of oocyte maturation, and 37% arrested after germinal vesicle breakdown, significantly different from controls (p<0.05). Only 45% of the oocytes extruded a first polar body (p < 0.05). 30 microM BPA led also to a significant increase in meiosis I-arrested oocytes with unaligned chromosomes and spindle aberrations. Oocytes that were able to progress beyond meiosis I, frequently arrested at an abnormal telophase I. Additionally, in many oocytes exposed to low chronic BPA that matured to meiosis II chromosomes failed to congress at the spindle equator. In conclusion, mouse follicle culture reveals non-linear dose-dependent effects of BPA on the meiotic spindle in mouse oocytes when exposure was chronic throughout oocyte growth and maturation.

  14. Dectin-1 and IL-17A suppress murine asthma induced by Aspergillus versicolor but not Cladosporium cladosporioides due to differences in beta-glucan surface exposure1

    PubMed Central

    Mintz-Cole, Rachael A.; Gibson, Aaron M.; Bass, Stacey A.; Budelsky, Alison L.; Reponen, Tiina; Hershey, Gurjit K. Khurana

    2012-01-01

    There is considerable evidence supporting a role for mold exposure in the pathogenesis and expression of childhood asthma. Aspergillus versicolor and Cladosporium cladosporioides are common molds that have been implicated in asthma. In a model of mold-induced asthma, mice were repeatedly exposed to either A. versicolor or C. cladosporioides spores. The two molds induced distinct phenotypes and this effect was observed in both Balb/c and C57BL/6 strains. C. cladosporioides induced robust airway hyperresponsiveness (AHR), eosinophilia, and a predominately Th2 response, while A. versicolor induced a strong Th17 response and neutrophilic inflammation, but very mild AHR. Neutralization of IL-17A resulted in strong AHR and eosinophilic inflammation following A. versicolor exposure. In Dectin-1 deficient mice, A. versicolor exposure resulted in markedly attenuated IL-17A and robust AHR compared to wild type mice. In contrast, C. cladosporioides induced AHR and eosinophilic inflammation independent of IL-17A and Dectin-1. A. versicolor, but not C. cladosporioides, spores had increased exposure of beta-glucans on their surface and were able to bind Dectin-1. Thus, the host response to C. cladosporioides was IL-17A- and Dectin1-independent, while Dectin-1 and IL-17A-dependent pathways were protective against the development of asthma after exposure to A. versicolor. PMID:22962686

  15. Mechanical properties of coated titanium Beta-21S after exposure to air at 700 and 800 C

    SciTech Connect

    Wiedemann, K.E.; Bird, R.K.; Wallace, T.A.; Clark, R.K.

    1992-06-01

    Mechanical properties of Beta-21S (Ti-15Mo-3Al-2.7Nb-0.2Si, wt percent) with glass, aluminide, and glass-on-aluminide coatings less than 3-micron thick were studied. Coatings were deposited by sol-gel processing or electron-beam evaporation onto 4.5-mil (113-micron) thick Beta-21S sheet from which, after oxidizing in air at 700 or 800 C, tensile test specimens were machined. Plastic elongation was the most severely degraded of the tensile properties; the glass-on-aluminide coatings were the most effective in preventing degradation. It was found that oxygen trapping by forming oxides in the coating, and reactions between the coatings and the Beta-21S alloy played significant roles.

  16. Mechanical properties of coated titanium Beta-21S after exposure to air at 700 and 800 C

    NASA Technical Reports Server (NTRS)

    Wiedemann, Karl E.; Bird, R. Keith; Wallace, Terryl A.; Clark, Ronald K.

    1992-01-01

    Mechanical properties of Beta-21S (Ti-15Mo-3Al-2.7Nb-0.2Si, wt percent) with glass, aluminide, and glass-on-aluminide coatings less than 3-micron thick were studied. Coatings were deposited by sol-gel processing or electron-beam evaporation onto 4.5-mil (113-micron) thick Beta-21S sheet from which, after oxidizing in air at 700 or 800 C, tensile test specimens were machined. Plastic elongation was the most severely degraded of the tensile properties; the glass-on-aluminide coatings were the most effective in preventing degradation. It was found that oxygen trapping by forming oxides in the coating, and reactions between the coatings and the Beta-21S alloy played significant roles.

  17. Immunoreactive somatostatin and. beta. -endorphin content in the brain of mature rats after neonatal exposure to propylthiouracil

    SciTech Connect

    Kato, N.; Sundmark, V.C.; Van Middlesworth, L.; Havlicek, V.; Friesen, H.G.

    1982-06-01

    The contents of immunoreactive somatostatin (IR-SRIF) and ..beta..-endorphin (IR-..beta..-EP) in 12 brain regions were examined in rats exposed neonatally to propylthiouracil (PTU) through the mother's milk. Since the dose of PTU used in the study is lower than the usual dose employed to induce hypothyroidism, a milder form of neonatal hypothyroidism resulted. This conclusion is supported by the only mild subnormal growth of rats to adulthood and serum T/sub 4/ and T/sub 3/ concentrations in the normal range. Adult rats treated with PTU neonatally had significantly higher IR-SRIF contents in several brain regions compared to controls, whereas IR-..beta..-EP levels were not significantly different (significant increase only in the thalamus) in most regions. The results indicate that even mild hypothyroidism during early postnatal development causes permanent impairment of brain function, which manifests itself in part by an altered brain content of IR-SRIF.

  18. Immunoreactive somatostatin and. beta. -endorphin content in the brain of mature rats after neonatal exposure to propylthiouacil. [Propylthiouracil

    SciTech Connect

    Kato, N.; Sundmark, V.C.; Van Middlesworth, L.; Havlicek, V.; Friesen, H.G.

    1982-01-01

    The contents of immunoreactive somatostatin (IR-SRIF) and ..beta..-endorphin (IR-..beta..-EP) in 12 brain regions were examined in rats exposed neonatally to propylthiouracil (PTU) through the mother's milk. Since the dose of PTU used in this study is lower than the usual dose employed to induce hypothyroidism, a milder form of neonatal hypothyroidism resulted. This conclusion is supported by the only mild subnormal growth of rats to adulthood and serum T/sub 4/ and T/sub 3/ concentrations in the normal range. Adult rats treated with PTU neonatally had significantly higher IR-SRIF contents in several brain regions compared to controls, whereas IR-..beta..-EP levels were not significantly different in most regions. The results indicate that even mild hypothyroidism during early postnatal development causes permanent impairment of brain function, which manifests itself in part by an altered brain content of IR-SRIF.

  19. Impairment of Rat Fetal Beta-Cell Development by Maternal Exposure to Dexamethasone during Different Time-Windows

    PubMed Central

    Dumortier, Olivier; Theys, Nicolas; Ahn, Marie-Thérèse; Remacle, Claude; Reusens, Brigitte

    2011-01-01

    Aim Glucocorticoids (GCs) take part in the direct control of cell lineage during the late phase of pancreas development when endocrine and exocrine cell differentiation occurs. However, other tissues such as the vasculature exert a critical role before that phase. This study aims to investigate the consequences of overexposure to exogenous glucocorticoids during different time-windows of gestation for the development of the fetal endocrine pancreas. Methods Pregnant Wistar rats received dexamethasone acetate in their drinking water (1 µg/ml) during the last week or throughout gestation. Fetuses and their pancreases were analyzed at day 15 and 21 of gestation. Morphometrical analysis was performed on pancreatic sections after immunohistochemistry techniques and insulin secretion was evaluated on fetal islets collected in vitro. Results Dexamethasone given the last week or throughout gestation reduced the beta-cell mass in 21-day-old fetuses by respectively 18% or 62%. This was accompanied by a defect in insulin secretion. The alpha-cell mass was reduced similarly. Neither islet vascularization nor beta-cell proliferation was affected when dexamethasone was administered during the last week, which was however the case when given throughout gestation. When given from the beginning of gestation, dexamethasone reduced the number of cells expressing the early marker of endocrine lineage neurogenin-3 when analyzed at 15 days of fetal age. Conclusions GCs reduce the beta- and alpha-cell mass by different mechanisms according to the stage of development during which the treatment was applied. In fetuses exposed to glucocorticoids the last week of gestation only, beta-cell mass is reduced due to impairment of beta-cell commitment, whereas in fetuses exposed throughout gestation, islet vascularization and lower beta-cell proliferation are involved as well, amplifying the reduction of the endocrine mass. PMID:21991320

  20. Bisphenol A (BPA) pharmacokinetics with daily oral bolus or continuous exposure via silastic capsules in pregnant rhesus monkeys: Relevance for human exposures.

    PubMed

    Vom Saal, Frederick S; VandeVoort, Catherine A; Taylor, Julia A; Welshons, Wade V; Toutain, Pierre-Louis; Hunt, Patricia A

    2014-06-01

    We measured serum dBPA in non-pregnant and pregnant female rhesus monkeys, fetuses and amniotic fluid. dBPA was administered by a daily oral bolus or sc implantation of Silastic capsules; both resulted in daily average serum unconjugated dBPA concentrations of <1ng/ml. We observed lower serum concentrations of unconjugated dBPA in pregnant females relative to pre-pregnancy values, and generally lower concentrations in fetal serum than in maternal serum. Differences in pharmacokinetics of dBPA were evident between pre-pregnancy, early and late pregnancy, likely reflecting changes in maternal, fetal and placental physiology. The serum ratio of conjugated to unconjugated dBPA after continuous sc release of dBPA was similar to values reported in human biomonitoring studies and markedly lower than with oral administration, suggesting oral bolus exposure is not an appropriate human exposure model. We report elsewhere that there were numerous adverse effects on fetuses exposed to very low serum dBPA in these studies.

  1. The Relationship between Amygdala Activation and Passive Exposure Time to an Aversive Cue during a Continuous Performance Task

    PubMed Central

    Strigo, Irina A.; Simmons, Alan N.; Matthews, Scott C.; Craig, Arthur D. (Bud)

    2010-01-01

    The allocation of attention modulates negative emotional processing in the amygdala. However, the role of passive exposure time to emotional signals in the modulation of amygdala activity during active task performance has not been examined. In two functional Magnetic Resonance Imaging (fMRI) experiments conducted in two different groups of healthy human subjects, we examined activation in the amygdala due to cued anticipation of painful stimuli while subjects performed a simple continuous performance task (CPT) with either a fixed or a parametrically varied trial duration. In the first experiment (N = 16), engagement in the CPT during a task with fixed trial duration produced the expected attenuation of amygdala activation, but close analysis suggested that the attenuation occurred during the period of active engagement in CPT, and that amygdala activity increased proportionately during the remainder of each trial, when subjects were passively exposed to the pain cue. In the second experiment (N = 12), the duration of each trial was parametrically varied, and we found that amygdala activation was linearly related to the time of passive exposure to the anticipatory cue. We suggest that amygdala activation during negative anticipatory processing depends directly on the passive exposure time to the negative cue. PMID:21124739

  2. Comparison of biological effects between continuous and intermittent exposure to GSM-900-MHz mobile phone radiation: Detection of apoptotic cell-death features.

    PubMed

    Chavdoula, Evangelia D; Panagopoulos, Dimitris J; Margaritis, Lukas H

    2010-07-19

    In the present study we used a 6-min daily exposure of dipteran flies, Drosophila melanogaster, to GSM-900MHz (Global System for Mobile Telecommunications) mobile phone electromagnetic radiation (EMR), to compare the effects between the continuous and four different intermittent exposures of 6min total duration, and also to test whether intermittent exposure provides any cumulative effects on the insect's reproductive capacity as well as on the induction of apoptotic cell death. According to our previous experiments, a 6-min continuous exposure per day for 5 days to GSM-900MHz and DCS-1800MHz (Digital Cellular System) mobile phone radiation, brought about a large decrease in the insect's reproductive capacity, as defined by the number of F(1) pupae. This decrease was found to be non-thermal and correlated with an increased percentage of induced fragmented DNA in the egg chambers' cells at early- and mid-oogenesis. In the present experiments we show that intermittent exposure also decreases the reproductive capacity and alters the actin-cytoskeleton network of the egg chambers, another known aspect of cell death that was not investigated in previous experiments, and that the effect is also due to DNA fragmentation. Intermittent exposures with 10-min intervals between exposure sessions proved to be almost equally effective as continuous exposure of the same total duration, whereas longer intervals between the exposures seemed to allow the organism the time required to recover and partly overcome the above-mentioned effects of the GSM exposure.

  3. Chronic exposure of a honey bee colony to 2.45 GHz continuous wave microwaves

    NASA Technical Reports Server (NTRS)

    Westerdahl, B. B.; Gary, N. E.

    1981-01-01

    A honey bee colony (Apis mellifera L.) was exposed 28 days to 2.45 GHz continuous wave microwaves at a power density (1 mW/sq cm) expected to be associated with rectennae in the solar power satellite power transmission system. Differences found between the control and microwave-treated colonies were not large, and were in the range of normal variation among similar colonies. Thus, there is an indication that microwave treatment had little, if any, effect on (1) flight and pollen foraging activity, (2) maintenance of internal colony temperature, (3) brood rearing activity, (4) food collection and storage, (5) colony weight, and (6) adult populations. Additional experiments are necessary before firm conclusions can be made.

  4. Chronic exposure of a honey bee colony to 2. 45 GHz continuous wave microwaves

    SciTech Connect

    Westerdahl, B.B.; Gary, N.E.

    1981-01-01

    A honey bee colony (Apis mellifera L.) was exposed 28 days to 2.45 GHz continuous wave microwaves at a power density (1 mW/sq cm) expected to be associated with rectennae in the solar power satellite power transmission system. Differences found between the control and microwave-treated colonies were not large, and were in the range of normal variation among similar colonies. Thus, there is an indication that microwave treatment had little, if any, effect on (1) flight and pollen foraging activity, (2) maintenance of internal colony temperature, (3) brood rearing activity, (4) food collection and storage, (5) colony weight, and (6) adult populations. Additional experiments are necessary before firm conclusions can be made.

  5. The endoplasmic reticulum stress response is stimulated through the continuous activation of transcription factors ATF6 and XBP1 in Ins2+/Akita pancreatic beta cells.

    PubMed

    Nozaki, Jun ichi; Kubota, Hiroshi; Yoshida, Hiderou; Naitoh, Motoko; Goji, Junko; Yoshinaga, Takeo; Mori, Kazutoshi; Koizumi, Akio; Nagata, Kazuhiro

    2004-03-01

    The dominant C96Y mutation of one of the two murine insulin genes, Ins2, causes diabetes mellitus in 'Akita' mice. Here we established pancreatic islet beta cell lines from heterozygous mice (Ins2+/Akita). Western blot analysis of endoplasmic reticulum (ER) molecular chaperones indicated that Grp78, Grp94 and Orp150 are significantly increased in Ins2+/Akita cells compared with wild-type (Ins2+/+) cells. Reporter gene assays using the human GRP78 promoter with or without the ER stress response element (ERSE) showed that Ins2+/Akita cells exhibit significantly stronger ERSE-dependent transcriptional activity than Ins2+/+ cells. Transient over-expression of the Ins2 C96Y mutant in wild-type beta cells induces a stronger ERSE-dependent stress response than does wild-type Ins2 over-expression. The ERSE-binding transcription factor ATF6 is strongly activated in Ins2+/Akita cells. The activity of a reporter containing the specific binding sequence of another ERSE-binding transcription factor, XBP1, is also enhanced in Ins2+/Akita cells. Levels of active forms of XBP1 mRNA and protein are both markedly elevated in Ins2+/Akita cells. These results indicate that this cell line is subject to continuous ER stress and that the Ins2 C96Y mutation induces the expression of ER chaperones through the activation of ATF6 and XBP1.

  6. Trichloroethylene alters central and peripheral immune function in autoimmune-prone MRL(+/+) mice following continuous developmental and early life exposure.

    PubMed

    Blossom, Sarah J; Doss, Jason C

    2007-04-01

    Trichloroethylene (TCE) is a widespread environmental toxicant known to promote CD4(+) T-lymphocyte activation, IFNgamma production, and autoimmunity in adult MRL(+/+) mice. Because developing tissues may be more sensitive to toxicant exposure, it was hypothesized that continuous TCE exposure beginning at conception might induce even more pronounced CD4(+) T-lymphocyte effects and exacerbate the development of autoimmunity in MRL(+/+) mice. In the current study, MRL(+/+) mice were exposed to occupationally-relevant doses of TCE from conception until adulthood (i.e., 7-8 wk-of-age). The CD4(+) T-lymphocyte effects in the thymus and periphery were evaluated, as well as serum antibody levels. TCE exposure altered the number of thymocyte subsets, and reduced the capacity of the most immature CD4-/CD8- thymocytes to undergo apoptosis in vitro. In the periphery, T-lymphocyte IFN(gamma) production was monitored in the blood prior to sacrifice by intracellular cytokine staining and flow cytometry. TCE induced a dose-dependent increase in T-lymphocyte IFN(gamma) as early as 4-5-week-of-age. However, these effects were transient, and not observed in splenic T-lymphocytes in 7-8-week-old mice. In contrast, the serum levels of anti-histone autoantibodies and total IgG(2a) were significantly elevated in the TCE-exposed offspring. The data illustrated that occupationally-relevant doses of TCE administered throughout development until adulthood affected central and peripheral immune function in association with early signs of autoimmunity. Future studies will address the possibility that early-life exposure to TCE may alter some aspect of self tolerance in the thymus, leading to autoimmune disease later in life.

  7. Modulation of DNA polymerase beta-dependent base excision repair in cultured human cells after low dose exposure to arsenite

    SciTech Connect

    Sykora, Peter; Snow, Elizabeth T.

    2008-05-01

    Base excision repair (BER) is crucial for development and for the repair of endogenous DNA damage. However, unlike nucleotide excision repair, the regulation of BER is not well understood. Arsenic, a well-established human carcinogen, is known to produce oxidative DNA damage, which is repaired primarily by BER, whilst high doses of arsenic can also inhibit DNA repair. However, the mechanism of repair inhibition by arsenic and the steps inhibited are not well defined. To address this question we have investigated the regulation of DNA polymerase {beta} (Pol {beta}) and AP endonuclease (APE1), in response to low, physiologically relevant doses of arsenic. GM847 lung fibroblasts and HaCaT keratinocytes were exposed to sodium arsenite, As(III), and mRNA, protein levels and BER activity were assessed. Both Pol {beta} and APE1 mRNA exhibited significant dose-dependant down regulation at doses of As(III) above 1 {mu}M. However, at lower doses Pol {beta} mRNA and protein levels, and consequently, BER activity were significantly increased. In contrast, APE1 protein levels were only marginally increased by low doses of As(III) and there was no correlation between APE1 and overall BER activity. Enzyme supplementation of nuclear extracts confirmed that Pol {beta} was rate limiting. These changes in BER correlated with overall protection against sunlight UV-induced toxicity at low doses of As(III) and produced synergistic toxicity at high doses. The results provide evidence that changes in BER due to low doses of arsenic could contribute to a non-linear, threshold dose response for arsenic carcinogenesis.

  8. Interleukin-1beta levels, pain intensity, and tooth movement using two different magnitudes of continuous orthodontic force.

    PubMed

    Luppanapornlarp, Suwannee; Kajii, Takashi S; Surarit, Rudee; Iida, Junichiro

    2010-10-01

    This study aimed to determine the optimum orthodontic force from a broader perspective. Interleukin (IL)-1β levels in human gingival crevicular fluid (GCF), pain intensity, and the amount of tooth movement were measured during canine retraction using different magnitudes of continuous orthodontic force. Sixteen subjects (two males and 14 females), aged 18-24 years, diagnosed with Class I bimaxillary protrusion and treated with first premolar extractions participated in this study. The upper canines were retracted with continuous forces of 50 or 150 g using nickel-titanium coil springs on segmented archwires. One of the lower canines was used as a control. GCF was collected from the distal site of each tooth at specific time points. IL-1β concentrations, pain intensity, using the visual analogue scale (VAS), and the amount of tooth movement were evaluated. One-way analysis of variance, Friedman, and paired t-tests were used for comparisons of IL-1β in GCF, the plaque and gingival indices, and the efficiency of tooth movement on pain perception, respectively. IL-1β concentration in the 150 g group showed the highest level at 24 hours and 2 months with significant differences compared with the control group (P < 0.05). The mean VAS score of pain intensity from the 150 g force was significantly greater than from the 50 g force at 24 hours (P < 0.01). However, no significant difference in the amount of tooth movement was found between these two different magnitudes of continuous force at 2 months. A 50 g force could effectively induce tooth movement similar to 150 g with less pain and less inflammation.

  9. Core binding factor beta functions in the maintenance of stem cells and orchestrates continuous proliferation and differentiation in mouse incisors.

    PubMed

    Kurosaka, Hiroshi; Islam, Md Nurul; Kuremoto, Koh-Ichi; Hayano, Satoru; Nakamura, Masahiro; Kawanabe, Noriaki; Yanagita, Takeshi; Rice, David P C; Harada, Hidemitsu; Taniuchi, Ichiro; Yamashiro, Takashi

    2011-11-01

    Rodent incisors grow continuously throughout life, and epithelial progenitor cells are supplied from stem cells in the cervical loop. We report that epithelial Runx genes are involved in the maintenance of epithelial stem cells and their subsequent continuous differentiation and therefore growth of the incisors. Core binding factor β (Cbfb) acts as a binding partner for all Runx proteins, and targeted inactivation of this molecule abrogates the activity of all Runx complexes. Mice deficient in epithelial Cbfb produce short incisors and display marked underdevelopment of the cervical loop and suppressed epithelial Fgf9 expression and mesenchymal Fgf3 and Fgf10 expression in the cervical loop. In culture, FGF9 protein rescues these phenotypes. These findings indicate that epithelial Runx functions to maintain epithelial stem cells and that Fgf9 may be a target gene of Runx signaling. Cbfb mutants also lack enamel formation and display downregulated Shh mRNA expression in cells differentiating into ameloblasts. Furthermore, Fgf9 deficiency results in a proximal shift of the Shh expressing cell population and ectopic FGF9 protein suppresses Shh expression. These findings indicate that Shh as well as Fgf9 expression is maintained by Runx/Cbfb but that Fgf9 antagonizes Shh expression. The present results provide the first genetic evidence that Runx/Cbfb genes function in the maintenance of stem cells in developing incisors by activating Fgf signaling loops between the epithelium and mesenchyme. In addition, Runx genes also orchestrate continuous proliferation and differentiation by maintaining the expression of Fgf9 and Shh mRNA.

  10. Developmental Timing and Continuity of Exposure to Interparental Violence and Externalizing Behavior as Prospective Predictors of Dating Violence

    PubMed Central

    Narayan, Angela J.; Englund, Michelle M.; Egeland, Byron

    2014-01-01

    This study investigated the prospective pathways of children's exposure to interparental violence (EIPV) in early and middle childhood and externalizing behavior in middle childhood and adolescence as developmental predictors of dating violence perpetration and victimization at ages 23 and 26 years. Participants (N = 168) were drawn from a longitudinal study of low-income families. Path analyses examined whether timing or continuity of EIPV predicted dating violence and whether timing or continuity of externalizing behavior mediated these pathways. Results indicated that EIPV in early childhood directly predicted perpetration and victimization at age 23. There were significant indirect effects from EIPV to dating violence through externalizing behavior in adolescence and life stress at age 23. Independent of EIPV, externalizing behavior in middle childhood also predicted dating violence through externalizing behavior in adolescence and life stress at age 23, but this pathway stemmed from maltreatment. These results highlight that the timing of EIPV and both the timing and continuity of externalizing behavior are critical risks for the intergenerational transmission of dating violence. Findings support a developmental perspective that negative early experiences and children's externalizing behavior are powerful influences for dating violence in early adulthood. PMID:24229543

  11. Developmental timing and continuity of exposure to interparental violence and externalizing behavior as prospective predictors of dating violence.

    PubMed

    Narayan, Angela J; Englund, Michelle M; Egeland, Byron

    2013-11-01

    This study investigated the prospective pathways of children's exposure to interparental violence (EIPV) in early and middle childhood and externalizing behavior in middle childhood and adolescence as developmental predictors of dating violence perpetration and victimization at ages 23 and 26 years. Participants (N = 168) were drawn from a longitudinal study of low-income families. Path analyses examined whether timing or continuity of EIPV predicted dating violence and whether timing or continuity of externalizing behavior mediated these pathways. Results indicated that EIPV in early childhood directly predicted perpetration and victimization at age 23. There were significant indirect effects from EIPV to dating violence through externalizing behavior in adolescence and life stress at age 23. Independent of EIPV, externalizing behavior in middle childhood also predicted dating violence through externalizing behavior in adolescence and life stress at age 23, but this pathway stemmed from maltreatment. These results highlight that the timing of EIPV and both the timing and the continuity of externalizing behavior are critical risks for the intergenerational transmission of dating violence. The findings support a developmental perspective that negative early experiences and children's externalizing behavior are powerful influences for dating violence in early adulthood.

  12. Modeling the beta diversity of coral reefs.

    PubMed

    Harborne, Alastair R; Mumby, Peter J; Zychaluk, Kamila; Hedley, John D; Blackwell, Paul G

    2006-11-01

    Quantifying the beta diversity (species replacement along spatiotemporal gradients) of ecosystems is important for understanding and conserving patterns of biodiversity. However, virtually all studies of beta diversity focus on one-dimensional transects orientated along a specific environmental gradient that is defined a priori. By ignoring a second spatial dimension and the associated changes in species composition and environmental gradients, this approach may provide limited insight into the full pattern of beta diversity. Here, we use remotely sensed imagery to quantify beta diversity continuously, in two dimensions, and at multiple scales across an entire tropical marine seascape. We then show that beta diversity can be modeled (0.852 > or = r2 > or = 0.590) at spatial scales between 0.5 and 5.0 km2, using the environmental variables of mean and variance of depth and wave exposure. Beta diversity, quantified within a "window" of a given size, is positively correlated to the range of environmental conditions within that window. For example, beta diversity increases with increasing variance of depth. By analyzing such relationships across seascapes, this study provides a framework for a range of disparate coral reef literature including studies of zonation, diversity, and disturbance. Using supporting evidence from soft-bottom communities, we hypothesize that depth will be an important variable for modeling beta diversity in a range of marine systems. We discuss the implications of our results for the design of marine reserves.

  13. Chronic aerial exposure to glucorticoids or beta-agonists affects avoidance learning and exploratory motivation in rats.

    PubMed

    Elías, Pedro C; Sagua, Delia; Alvarez, Edgardo O

    2004-02-04

    The purpose of the present work was to examine if the conventional asthma treatments in humans (inhalation of glucocorticoids or beta-agonists, administered in a chronic regimen) might affect behavioral processes (learning and exploratory motivation) in rats. Adult male rats were exposed to an atmosphere saturated with either saline, budesonide (a glucocorticoid), or salbutamol (a beta-adrenergic receptor agonist) in a forced ventilation cage, connected to a nebulizer for 5 min twice a day for 15 days at the same hours of the day. Doses of budesonide in the nebulizing solution were 0.116, 1.16, and 11.6mM. Doses of salbutamol in the nebulizing solution were 1.3, 13, and 130 mM. Forty-eight hours after treatment, the different groups were subjected to exploration of an elevated asymmetric plus-maze (APM, model of exploratory motivation), and 24h later to learning of an avoidance response to an ultrasonic tone in a two-compartment cage (model of memory and learning). Results showed that budesonide induces moderate effects on exploratory motivation. In one of the fear-inducing arms (single wall arm), exploration decreased and this effect was not dose dependent. In the cognitive model, glucocorticoids affected slightly the latency to escape but with no interference in memory efficiency. On the other hand, at the lower dose in the APM, salbutamol increased significantly the exploration of both fear-inducing arms (no walls and single wall arms). In the learning model, the beta-agonist induced two opposing effects. The lower dose (1.3mM) facilitated learning and the higher dose (13 mM) inhibited learning instead. In conclusion, results are compatible with the notion that inhaled glucocorticoids or beta-agonists might cross the lung aerial barrier into the blood compartment, exerting effects on learning and motivation functions.

  14. Early developmental 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure decreases chick embryo heart chronotropic response to isoproterenol but not to agents affecting signals downstream of the beta-adrenergic receptor.

    PubMed

    Sommer, Rebecca J; Hume, Adam J; Ciak, Jessica M; Vannostrand, John J; Friggens, Megan; Walker, Mary K

    2005-02-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) causes cardiovascular toxicity in laboratory animals, including alteration in several processes in which beta-adrenergic receptor (beta-AR) signaling plays important roles. Thus, our laboratory investigated the effects of TCDD on beta-AR expression and signal transduction. Fertile chicken eggs were injected with vehicle (corn oil), 0.24 or 0.3 pmol TCDD/g egg on incubation day 0 (D0) or D5. On D10, heart function was assessed by ECG in ovo. Exposure to TCDD increased the incidence of arrhythmias and decreased the positive chronotropic responsiveness of the heart to isoproterenol. The reduced beta-AR responsiveness was, in part, independent of any overt morphological changes in the heart as chick embryos exposed to TCDD on D5 displayed an intermediate responsiveness to beta-AR agonist in the absence of the dilated cardiomyopathy observed in chick embryos exposed to TCDD on D0. TCDD did not decrease the chronotropic response of the heart to agents that stimulate signals downstream of the beta-AR. In fact, TCDD-exposed embryos were more sensitive than controls to forskolin, increasing heart rates (HR) 21.8 +/- 3.5 beats per min (bpm) above baseline versus control values at 6.3 +/- 2.7 bpm above baseline. TCDD exposure also augmented the negative chronotropic response of the heart to verapamil, decreasing HR -23.2 +/- 7.4 bpm relative to baseline versus control embryos at -12.7 +/- 5.9 bpm below baseline. Finally, the mean cardiac beta1-AR mRNA expression in D10 embryos was not significantly altered by exposure to TCDD on D0. These findings establish that a functional end point of the developing chick heart is sensitive to TCDD exposure and that the TCDD-induced reduction in beta-AR responsiveness may result from alterations in signal transduction upstream of adenylyl cyclase.

  15. Chronic toxicity of diphenhydramine hydrochloride and erythromycin thiocyanate to Daphnia, Daphnia magna, in a continuous exposure test system

    USGS Publications Warehouse

    Meinertz, J.R.; Schreier, T.M.; Bernardy, J.A.; Franz, J.L.

    2010-01-01

    Diphenhydramine hydrochloride (DH; Benadryl TM, an over-the-counter antihistamine) and erythromycin thiocyanate (ET; a commonly used macrolide antibiotic) are pharmaceutical compounds whose chronic toxicity to Daphnia magna had not been characterized. Continuous exposure to DH concentrations about 5 times greater than the maximum reported environmental concentration of 0.023 lg/L for 21 days or to ET concentrations about 40 times the maximum reported environmental concentration of 6 (mu or u)g/L for 21 days did not significantly impact D. magna survival and production. In this study the no observable effect concentration for DH was 0.12 (mu or u)g/L and for ET was 248 (mu or u)g/L.

  16. A study of the biological effect of continuous inhalation exposure of 1, 1, 1-trichloroethene (methyl chloroform) on animals

    NASA Technical Reports Server (NTRS)

    Macewen, J. D.; Kinkead, E. R.; Haun, C. C.

    1974-01-01

    The effects of continuous exposure to 1,1,1-trichloroethane on hepatic morphology and function are evaluated and compared with those produced by methylene chloride (dichloromethane) to determine environmental concentrations of each compound that would produce a similar biological response, i.e., a comparable increase in liver triglycerides over control levels. Experimental findings on mice, rats, dogs, and monkeys indicate that the pathological alternations observed with 1,1,1-trichloroethane are similar to those observed with dichloromethane except for different time courses of the effects and different degrees of recovery. A ten fold greater atmospheric concentration of 1,1,1-trichloroethane is required to produce the minimal liver changes found at 100 ppm dichloromethane.

  17. Chronic toxicity of diphenhydramine hydrochloride and erythromycin thiocyanate to daphnia, Daphnia magna, in a continuous exposure test system.

    PubMed

    Meinertz, Jeffery R; Schreier, Theresa M; Bernardy, Jeffry A; Franz, Jeanne L

    2010-11-01

    Diphenhydramine hydrochloride (DH; Benadryl™, an over-the-counter antihistamine) and erythromycin thiocyanate (ET; a commonly used macrolide antibiotic) are pharmaceutical compounds whose chronic toxicity to Daphnia magna had not been characterized. Continuous exposure to DH concentrations about 5 times greater than the maximum reported environmental concentration of 0.023 μg/L for 21 days or to ET concentrations about 40 times the maximum reported environmental concentration of 6 μg/L for 21 days did not significantly impact D. magna survival and production. In this study the no observable effect concentration for DH was 0.12 μg/L and for ET was 248 μg/L.

  18. [Hearing loss by continuous exposure to high sound pressure among maintenance workers at a Brazilian Air Force helicopters unity].

    PubMed

    Ribeiro, Ana Maria Dutra; Câmara, Volney de M

    2006-06-01

    Continuous exposure to high sound pressure in aeronautical workers can be associated with inner ear hearing loss. This study aims to evaluate the prevalence of deafness among all maintenance workers from a Brazilian Air Force helicopter unit. The methods included the application of individual questionnaires and audiometric tests. The results showed a high prevalence (32.4%) of hearing loss related to time on the job (p < 0.05; RP = 2.11; 95%CI: 1.03-4.32) and the 41-50-year age bracket (p = 0.00; RP < 3.94; 95%CI: 2.04-7.62). No influence was found from selected variables that might result in bias. Finally, a program to prevent hearing loss was recommended.

  19. Dissemination of well water arsenic results to homeowners in Central Maine: influences on mitigation behavior and continued risks for exposure.

    PubMed

    Flanagan, Sara V; Marvinney, Robert G; Johnston, Robert A; Yang, Qiang; Zheng, Yan

    2015-02-01

    Private wells in the United States are unregulated for drinking water standards and are the homeowner's responsibility to test and treat. Testing for water quality parameters such as arsenic (As) is a crucial first step for homeowners to take protective actions. This study seeks to identify key behavioral factors influencing homeowners' decisions to take action after receiving well As test results. A January 2013 survey of central Maine households (n=386, 73% response) who were notified 3-7 years earlier that their well water contained As above 10 μg/L found that 43% of households report installing As treatment systems. Another 30% report taking other mitigation actions such as drinking bottled water because of the As, but the remaining 27% of households did not act. Well water As level appears to be a motivation for mitigation: 31% of households with well water level between 10 and 50 μg/L did not act, compared to 11% of households with well water >50 μg/L. The belief that the untreated water is not safe to drink (risk) and that reducing drinking water As would increase home value (instrumental attitude) were identified as significant predictors of mitigating As. Mitigating As exposure is associated with less worry about the As level (affective attitude), possibly because those acting to reduce exposure feel less worried about As. Use of a treatment system specifically was significantly predicted by confidence that one can maintain a treatment system, even if there are additional costs (self-efficacy). An assessment of As treatment systems used by 68 of these households with well water As >10 μg/L followed up within August-November 2013 found that 15% of treatment units failed to produce water below As 10 μg/L, suggesting that there are continued risks for exposure even after the decision is made to treat.

  20. Dissemination of well water arsenic results to homeowners in Central Maine: Influences on mitigation behavior and continued risks for exposure

    PubMed Central

    Flanagan, Sara V.; Marvinney, Robert G.; Johnston, Robert A.; Yang, Qiang; Zheng, Yan

    2014-01-01

    Private wells in the United States are unregulated for drinking water standards and are the homeowner’s responsibility to test and treat. Testing for water quality parameters such as arsenic (As) is a crucial first step for homeowners to take protective actions. This study seeks to identify key behavioral factors influencing homeowners’ decisions to take action after receiving well As test results. A January 2013 survey of central Maine households (n=386, 73% response) who were notified 3–7 years earlier that their well water contained As above 10 μg/L found that 43% of households report installing As treatment systems. Another 30% report taking other mitigation actions such as drinking bottled water because of the As, but the remaining 27% of households did not act. Well water As level appears to be a motivation for mitigation: 31% of households with well water level between 10 and 50 μg/L did not act, compared to 13% of households with well water > 50 μg/L. Belief that the untreated water is not safe to drink (risk) and that reducing drinking water As would increase home value (instrumental attitude) were identified as significant predictors of mitigating As. Mitigating As exposure is associated with less worry about the As level (affective attitude), possibly because those acting to reduce exposure feel less worried about As. Use of a treatment system specifically was significantly predicted by confidence that one can maintain a treatment system, even if there are additional costs (self-efficacy). An assessment of As treatment systems used by 68 of these households with well water As >10 μg/L followed up with in August-November 2013 found that 15% of treatment units failed to produce water below As 10 μg/L, suggesting there are continued risks for exposure even after the decision is made to treat. PMID:24726512

  1. TIM Version 3.0 beta Technical Description and User Guide - Appendix F - Approach for Calculating Juvenile Dietary Exposure

    EPA Pesticide Factsheets

    Use the available information on the relationship between juvenile body weights and energetic requirements to develop a general approach for calculating juvenile dietary exposure doses appropriate for a range of avian species.

  2. Exercise during Short-Term and Long-Term Continuous Exposure to Hypoxia Exacerbates Sleep-Related Periodic Breathing

    PubMed Central

    Tellez, Helio Fernandez; Morrison, Shawnda A.; Neyt, Xavier; Mairesse, Olivier; Piacentini, Maria Francesca; Macdonald-Nethercott, Eoin; Pangerc, Andrej; Dolenc-Groselj, Leja; Eiken, Ola; Pattyn, Nathalie; Mekjavic, Igor B.; Meeusen, Romain

    2016-01-01

    Study Objectives: Exposure to hypoxia elevates chemosensitivity, which can lead to periodic breathing. Exercise impacts gas exchange, altering chemosensitivity; however, interactions between sleep, exercise and chronic hypoxic exposure have not been examined. This study investigated whether exercise exacerbates sleep-related periodic breathing in hypoxia. Methods: Two experimental phases. Short-Term Phase: a laboratory controlled, group-design study in which 16 active, healthy men (age: 25 ± 3 y, height: 1.79 ± 0.06 m, mass: 74 ± 8 kg) were confined to a normobaric hypoxic environment (FIO2 = 0.139 ± 0.003, 4,000 m) for 10 days, after random assignment to a sedentary (control, CON) or cycle-exercise group (EX). Long-Term Phase: conducted at the Concordia Antarctic Research Station (3,800 m equivalent at the Equator) where 14 men (age: 36 ± 9 y, height: 1.77 ± 0.09 m, mass: 75 ± 10 kg) lived for 12–14 months, continuously confined. Participants were stratified post hoc based on self-reported physical activity levels. We quantified apnea-hypopnea index (AHI) and physical activity variables. Results: Short-Term Phase: mean AHI scores were significantly elevated in the EX group compared to CON (Night1 = CON: 39 ± 51, EX: 91 ± 59; Night10 = CON: 32 ± 32, EX: 92 ± 48; P = 0.046). Long-Term Phase: AHI was correlated to mean exercise time (R2 = 0.4857; P = 0.008) and the coefficient of variation in night oxyhemoglobin saturation (SpO2; R2 = 0.3062; P = 0.049). Conclusions: Data indicate that exercise (physical activity) per se affects night SpO2 concentrations and AHI after a minimum of two bouts of moderate-intensity hypoxic exercise, while habitual physical activity in hypobaric hypoxic confinement affects breathing during sleep, up to 13+ months' duration Citation: Tellez HF, Morrison SA, Neyt X, Mairesse O, Piacentini MF, Macdonald-Nethercott E, Pangerc A, Dolenc-Groselj L, Eiken O, Pattyn N, Mekjavic IB, Meeusen R. Exercise during short-term and long

  3. The effect of transient and continuous drought on yield, photosynthesis and carbon isotope discrimination in sugar beet (Beta vulgaris L.).

    PubMed

    Monti, A; Brugnoli, E; Scartazza, A; Amaducci, M T

    2006-01-01

    Stable carbon isotope discrimination (delta13C), photosynthetic performance (A), dry matter accumulation (DW), and sucrose yield (Y(s)) of sugar beet were evaluated in a glasshouse experiment under transient (TS) and permanent (PS) water stress. A was significantly reduced under drought, to an extent depending on stress duration. The reduced A was strictly associated with a low DW and Y(s), the later being 42% lower in PS than control plants (C). Restoring water steeply increased A and the associated leaf traits (RWC, leaf water potential etc.), but the increase of Y(s) was negligible. Therefore, the negative effects of severe water stress in the early growth period, though reversible on gas-exchange and most leaf traits, can drastically reduce Y(s) of sugar beet. Furthermore, A seems not to be effective in predicting sucrose accumulation, although it was very effective in detecting the occurrence of plant water stress. The A/C(i) model was used to assess the photosynthetic adjustments to continuous or transient drought by calculating the photosynthetic parameters Vcmax and Jmax and then compared with delta13C. Mesophyll conductance (g(m)) was estimated by comparing delta13C measured on soluble sugars and gas-exchange data. This approach confirmed the expectation that g(m) was limiting A and that there was a significant drop in [CO2] from the substomatal cavities and the chloroplast stroma both in favourable and drought conditions. Therefore, the carbon concentration at the carboxylation site was overestimated by 25-35% by conventional gas-exchange measurements, and Vcmax was consistently underestimated when g(m) was not taken into account, especially under severe drought. Root delta13C was found to be strictly related to sucrose content (brix%), Y(s) and root dry weight, and this was especially clear when delta13C was measured on bulk dry matter. By contrast, leaf delta13C measured in soluble sugars (delta(s)) and bulk dry matter (delta(dm)) were found to

  4. Chronic toxicity of hydrogen peroxide to Daphnia magna in a continuous exposure, flow-through test system

    USGS Publications Warehouse

    Meinertz, J.R.; Greseth, Shari L.; Gaikowski, M.P.; Schmidt, L.J.

    2008-01-01

    A flow-through, continuous exposure test system was developed to expose Daphnia magna to an unstable compound. 35% Perox-Aid?? is a specially formulated hydrogen peroxide (a highly oxidative chemical) product approved for use in U.S. aquaculture and therefore has the potential to be released from aquaculture facilities and pose a risk to aquatic invertebrates. The study objective was to assess the effects of 35% Perox-Aid?? on an aquatic invertebrate by evaluating the survival, growth, production, and gender ratio of progeny from a representative aquatic invertebrate continuously exposed to 35% Perox-Aid??. The study design consisted of 6 treatment groups (10 test chambers each) with target hydrogen peroxide concentrations of 0.0, 0.32, 0.63, 1.25, 2.5, and 5.0??mg L- 1. The study was initiated with < 24-h-old Daphnia (1 daphnid per chamber) that were exposed to hydrogen peroxide for 21??days. Hydrogen peroxide concentrations ??? 1.25??mg L- 1 had no significant effect on Daphnia time to death compared to controls and no significant effect on the time to first brood production and the number of broods produced. Concentrations ??? 0.63??mg L- 1 had no significant effect on the total number of young produced. Concentrations ??? 0.32??mg L- 1 had a negative effect on Daphnia growth. Hydrogen peroxide had no significant effect on the gender ratio of young produced. All second generation Daphnia were female. A continuous discharge of hydrogen peroxide into aquatic ecosystems is not likely to affect cladocerans if the concentration is maintained at ??? 0.63??mg L- 1 for less than 21??days.

  5. Beta-carotene

    MedlinePlus

    ... cigarettes per day), former smokers, people exposed to asbestos, and those who use alcohol (one or more ... beta-carotene supplements if you smoke. History of asbestos exposure: In people who have been exposed to ...

  6. Continuous Exposure to L-Arginine Induces Oxidative Stress and Physiological Tolerance in Cultured Human Endothelial Cells

    PubMed Central

    Mohan, Srinidi; Wu, Chia-Ching; Shin, Soyoung; Fung, Ho-Leung

    2011-01-01

    The therapeutic benefits of L-arginine (ARG) supplementation in humans, often clearly observed in short-term studies, are not evident after long-term use. The mechanisms for the development of ARG tolerance are not known and cannot be readily examined in humans. We have developed a sensitive in vitro model using a low glucose/low arginine culture medium to study the mechanisms of ARG action and tolerance using two different human endothelial cells, i.e., Ea.hy926 and human umbilical venous endothelial cells (HUVEC). Cultured cells were incubated with different concentrations of ARG and other agents to monitor their effects on eNOS expression and function, as well as glucose and superoxide (O2•−) accumulation. Short-term (2 h) exposure to at least 50 μM ARG moderately increased eNOS activity and intracellular glucose (p<0.05), with no change in eNOS mRNA or protein expression. In contrast, 7-day continuous ARG exposure suppressed eNOS expression and activity. This was accompanied by increase in glucose and O2•− accumulation. Co-incubation with 100 μM ascorbic acid, 300 U/ml PEG-superoxide dismutase (PEG-SOD), 100 μM L-lysine or 30 μM 5-chloro-2-(N-2,5-dichlorobenenesulfonamido))-benzoxazole (a fructose-1,6-bisphosphatase inhibitor) prevented the occurrence of cellular ARG tolerance. Short-term co-incubation of ARG with PEG-SOD improved cellular nitrite accumulation without altering cellular ARG uptake. These studies suggest that ARG-induced oxidative stress may be a primary causative factor for the development of cellular ARG tolerance. PMID:22130739

  7. Comparison between immobilized Kluyveromyces fragilis and saccharomyces cerevisiae coimmobilized with. beta. -galactosidase, with respect to continuous ethanol production from concentrated whey permeate

    SciTech Connect

    Hahn-Haegerdal, B.

    1985-06-01

    Kluyveromyces fragilis immobilized in calcium alginate gel was compared to Saccharomyces cerevisiae coimmobilized with ..beta..-galactosidase, for continuous ethanol production from whey permeate in packed-bed-type columns. Four different whey concentrations were studied, equivalent to 4.5, 10, 15 and 20% lactose, respectively. In all cases the coimmobilized preparation produced more ethanol than Kluyveromyces fragilis. The study went on for more than 5 weeks. Kluyveromyces fragilis showed a decline in activity after 20 days, while the coimmobilized preparation was stable during the entire investigation. Under experimental conditions theoretical yields of ethanol were obtained from 4.5 and 10% lactose substrates with the coimmobilized system. Using 15% lactose substrate, theoretical yields were only obtained when a galactose-adapted immobilized Saccharomyces cerevisiae column was run in series with the coimmobilized column. Then a maximum of 71 g/l ethanol was produced with a productivity of 2.5 g/l hour. The coimmobilized column alone gave a maximum ethanol concentration of 52 g/l with a productivity of 4.5 g/l hour, whereas immobilized Kluyveromyces fragilis only produced 13 g/l ethanol with a productivity of 1.1 g/l hour. It was not possible to obtain theoretical yields of ethanol from the highest substrate concentration. 13 references.

  8. Pulmonary tolerance in man to continuous oxygen exposure at 3.0, 2.5, 2.0, and 1.5 ATA in Predictive Studies V

    NASA Technical Reports Server (NTRS)

    Clark, J. M.; Gelfand, R.; Flores, N. D.; Lambertsen, C. J.; Pisarello, J. B.

    1987-01-01

    Oxygen effects on pulmonary function were measured in normal, resting men who breathed oxygen continuously at 3.0, 2.5, 2.0, and 1.5 ATA to predefined limits of CNS, cardiac, or pulmonary tolerance. Rates of pulmonary symptom intensification and decrease in vital capacity (VC) increased progressively with elevation of inspired oxygen pressure. Although VC decrements occurred concurrently with symptoms, the lung volume changes became prominent when symptoms were still mild. The observed effects were consistent with the interpretation that small airway function is impaired more selectively by oxygen exposure at 3.0 and 2.5 ATA than by exposure at 2.0 and 1.5 ATA. Despite similar VC changes after oxygen exposure at 2.0 ATA for nearly 10 hr and exposure at 1.5 ATA for almost 18 hr, the 2.0 ATA exposure caused greater impairment of pulmonary function and required a longer recovery period.

  9. No induction of antimicrobial resistance in Staphylococcus aureus and Listeria monocytogenes during continuous exposure to eugenol and citral.

    PubMed

    Apolónio, Joana; Faleiro, Maria L; Miguel, Maria G; Neto, Luís

    2014-05-01

    The aim of this study was to evaluate the adaptation response of Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), and Listeria monocytogenes to the essential oil (EO), eugenol, and citral. The minimum inhibitory concentration of eugenol and citral was determined by agar dilution and microdilution. Adaptation to eugenol and citral was done by sequential exposure of the pathogens to increasing concentrations of the essential oils. The M2-A9 standard was used to determine the antibiotic susceptibility. The effect of eugenol and citral on the adherence ability was evaluated by the crystal violet assay. The impact of adaptation to eugenol on virulence was estimated using the Galleria mellonella model. No development of resistance to the components and antibiotics was observed in the adapted cells of S. aureus, MRSA, and L. monocytogenes. Eugenol and citral at subinhibitory concentration reduced the bacterial adherence. Adaptation to subinhibitory concentration of eugenol affected the virulence potential of S. aureus, MRSA, and L. monocytogenes. Eugenol and citral do not pose a risk of resistance development in a continuous mode of use. These EO components showed a high efficacy as antistaphylococcal and antilisterial biofilm agents. Adaptation at subinhibitory concentration of eugenol protected the larvae against listerial and staphylococcal infection.

  10. Exposure to di(n-butyl)phthalate and benzo(a)pyrene alters IL-1{beta} secretion and subset expression of testicular macrophages, resulting in decreased testosterone production in rats

    SciTech Connect

    Zheng Shanjun; Tian Huaijun; Cao Jia; Gao Yuqi

    2010-10-01

    Di(n-butyl)phthalate (DBP) and benzo(a)pyrene (BaP) are environmental endocrine disruptors that are potentially hazardous to humans. These chemicals affect testicular macrophage immuno-endocrine function and testosterone production. However, the underlying mechanisms for these effects are not fully understood. It is well known that interleukin-1 beta (IL-1{beta}), which is secreted by testicular macrophages, plays a trigger role in regulating Leydig cell steroidogenesis. The purpose of this study was to reveal the effects of co-exposure to DBP and BaP on testicular macrophage subset expression, IL-1{beta} secretion and testosterone production. Adult male Sprague-Dawley rats were randomly divided into seven groups; two groups received DBP plus BaP (DBP + BaP: 50 + 1 or 250 + 5 mg/kg/day) four groups received DBP or BaP alone (DBP: 50 or 250 mg/kg/day; BaP: 1 or 5 mg/kg/day), and one group received vehicle alone (control). After co-exposure for 90 days, the relative expression of macrophage subsets and their functions changed. ED2{sup +} testicular macrophages (reactive with a differentiation-related antigen present on the resident macrophages) were activated and IL-1{beta} secretion was enhanced. DBP and BaP acted additively, as demonstrated by greater IL-1{beta} secretion relative to each compound alone. These observations suggest that exposure to DBP plus BaP exerted greater suppression on testosterone production compared with each compound alone. The altered balance in the subsets of testicular macrophages and the enhanced ability of resident testicular macrophages to secrete IL-1{beta}, resulted in enhanced production of IL-1{beta} as a potent steroidogenesis repressor. This may represent an important mechanism by which DBP and BaP repress steroidogenesis.

  11. Hepatic estrogen receptor and plasma 17{beta}-estradiol concentrations as biomarkers of 2,3,7,8-TCDD exposure in avian hatchlings

    SciTech Connect

    Janz, D.M.; Bellward, G.D.

    1995-12-31

    The authors have been investigating the sensitivity of various toxicologically relevant endpoints as environmental biomarkers in avian hatchlings exposed in ovo to 2,3,7,8-TCDD. Potential biomarkers included various endocrine endpoints such as plasma 17{beta}-estradiol (E{sub 2}), hepatic estrogen receptor (ER) affinities and concentrations, and plasma thyroid hormones, which were compared to hepatic ethoxyresorufin O-deethylase (EROD) induction. The animal models used were domestic chickens and pigeons, and great blue herons. An experiment conducted in pigeon hatchlings compared ``early`` (embryonic day 4; E4) vs. ``late`` (E14) in ovo exposure to 1 {micro}g/kg and 3 {micro}g/kg of TCDD, respectively. Birds were sacrificed on day of hatch (H) and day 7 after hatch (D7). In the late exposure experiment, plasma E{sub 2} concentrations were reduced at H and elevated at D7 in the TCDD-exposed birds (p < 0.05). Hepatic ER concentrations were elevated at H (p < 0.01). Although EROD was half-maximally induced at H and D7 in the early exposure experiment in pigeons, there was no effect of TCDD treatment on E, or ER levels. The nominal TCDD concentration in these pigeons (1 {micro}g/kg egg) was within the range observed in wild piscivorous bird eggs collected from aquatic systems contaminated with TCDD and related chemicals (approx. 0.5--2 ng TEQ/g egg). In herons exposed to 2 {micro}g/kg of TCDD at the midpoint of incubation, hepatic ER affinities (Kd) and concentrations (Bmax) were elevated in treated birds at H (p < 0.05); however there was no effect on plasma E, levels. Liver [{sup 3}H]-TCDD concentrations were 11.3 {+-} 0.8 ng/g at H, and 0.8 {+-} 0.1 ng/g at D7, representing 9.9% and 4.9% of the nominal TCDD dose, respectively.

  12. Exposure of three generations of the estuarine sheepshead minnow (Cyprinodon variegatus) to the androgen, 17beta-trenbolone: effects on survival, development, and reproduction.

    PubMed

    Cripe, Geraldine M; Hemmer, Becky L; Raimondo, Sandy; Goodman, Larry R; Kulaw, Dannielle H

    2010-09-01

    Estimating long-term effects of endocrine-disrupting chemicals on a species is important to assessing the overall risk to the populations. The present study reports the results of a 42-week exposure of estuarine sheepshead minnows (Cyprinodon variegatus) to the androgen, 17beta-trenbolone (Tb) conducted to determine if partial-(F0) or single-generation (F1) fish exposures identify multigenerational (F0-F3) effects of androgens on fish. Adult F0 fish were exposed to 0.007, 0.027, 0.13, 0.87,and 4.1 microg Tb/L, the F1 generation to < or =0.87 microg Tb/L, the F2 fish to < or =0.13 microg Tb/L, and the F3 fish to < or =0.027 microg Tb/L. The highest concentrations with reproducing populations at the end of the F0, F1, and F2 generations were 4.1, 0.87, and 0.027 microg Tb/L, respectively. Reproduction in the F0, F1, and F2 generations was significantly reduced at 0.87, 0.027, and 0.027 microg Tb/L, respectively. Fish were significantly masculinized in the F1 generation exposed to 0.13 microg Tb/L or greater. Female plasma vitellogenin was significantly reduced in F0 fish exposed to > or =0.87 microg Tb/L. Gonadosomatic indices of the F0 and F1 generations were significantly increased at 0.87 and 0.13 microg Tb/L in the F0 and F1 generation, respectively, and were accompanied by ovarian histological changes. Reproduction was the most consistently sensitive measure of androgen effects and, after a life-cycle exposure, the daily reproductive rate predicted concentrations affecting successive generations. The present study provides evidence that a multiple generation exposure of fish to some endocrine-disrupting chemicals can result in developmental and reproductive changes that have a much greater impact on the success of a species than was indicated from shorter term exposures.

  13. Exposure-dependent increases in IL-1beta, substance P, CTGF, and tendinosis in flexor digitorum tendons with upper extremity repetitive strain injury.

    PubMed

    Fedorczyk, Jane M; Barr, Ann E; Rani, Shobha; Gao, Helen G; Amin, Mamta; Amin, Shreya; Litvin, Judith; Barbe, Mary F

    2010-03-01

    Upper extremity tendinopathies are associated with performance of forceful repetitive tasks. We used our rat model of repetitive strain injury to study changes induced in forelimb flexor digitorum tendons. Rats were trained to perform a high repetition high force (HRHF) handle-pulling task (12 reaches/min at 60 +/- 5% maximum pulling force [MPF]), or a low repetition negligible force (LRNF) reaching and food retrieval task (three reaches/min at 5 +/- 5% MPF), for 2 h/day in 30 min sessions, 3 days/week for 3-12 weeks. Forelimb grip strength was tested. Flexor digitorum tendons were examined at midtendon at the level of the carpal tunnel for interleukin (IL)-1beta, neutrophil, and macrophage influx, Substance P, connective tissue growth factor (CTGF), and periostin-like factor (PLF) immunoexpression, and histopathological changes. In HRHF rats, grip strength progressively decreased, while IL-1beta levels progressively increased in the flexor digitorum peritendon (para- and epitendon combined) and endotendon with task performance. Macrophage invasion was evident in week 6 and 12 HRHF peritendon but not endotendon. Also in HRHF rats, Substance P immunoexpression increased in week 12 peritendon as did CTGF- and PLF-immunopositive fibroblasts, the increased fibroblasts contributing greatly to peritendon thickening. Endotendon collagen disorganization was evident in week 12 HRHF tendons. LRNF tendons did not differ from controls, even at 12 weeks. Thus, we observed exposure-dependent changes in flexor digitorum tendons within the carpal tunnel, including increased inflammation, nociceptor-related neuropeptide immunoexpression, and fibrotic histopathology, changes associated with grip strength decline.

  14. Alteration of cytoskeletal molecules in a human T cell line caused by continuous exposure to chrysotile asbestos.

    PubMed

    Maeda, Megumi; Chen, Ying; Kumagai-Takei, Naoko; Hayashi, Hiroaki; Matsuzaki, Hidenori; Lee, Suni; Hiratsuka, Jun-Ichi; Nishimura, Yasumitsu; Kimura, Yoshinobu; Otsuki, Takemi

    2013-09-01

    Among the various biological effects of asbestos such as fibrogenesis and carcinogenesis, we have been focusing on the immunological effects becausesilica (SiO(2)) and asbestos chemically is a mineral silicate of silica. Observations of the effects of asbestos on CD4+ T cells showed reduction of CXCR3 chemokine receptor and reduced capacity of interferon γ production. In particular, use of theHTLV-1 immortalized human T cell line, MT-2, and cDNA array analysis have helped to identify the modification of CXCR3. We investigated alteration of protein expression among MT-2 original cells that had no contact with asbestos, and six chrysotile-continuously exposed independent sublines using ProteinChip and two-dimensional gel electrophoresis (2DGE) assays. Further confirmation of the changes in protein expression due to asbestos exposure was obtained after the 2DGE method indicated protein modification of β-actin. β-actin was upregulated in mRNA, as were the levels of protein expression and phosphorylation. Moreover, a binding assay between cells and chrysotile showed that various molecules related to the cytoskeleton such as vimentin, myosin-9 and tubulin-β2, as well as β-actin, exhibited enhanced bindings in asbestos-exposed cells. The overall findings indicate that the cell surface cytoskeleton may play an important role in inducing the cellular changes caused by asbestos in immune cells, since fibers are not incorporated to the cells and how the alterations of cytoskeleton determined cell destiny to cause the reduction of tumor immunity is important to consider the biological effects of asbestos. Further studies to target several cytoskeleton-related molecules associated with the effects of asbestos will result in a better understanding of the immunological effects of asbestos and support the development of chemo-prevention to recover anti-tumor immunity in asbestos-exposed patients.

  15. Cardiovascular impacts and micro-environmental exposure factors associated with continuous personal PM2.5 monitoring

    EPA Science Inventory

    The US Environmental Protection Agency’s (US EPA) Detroit Exposure and Aerosol Research Study (DEARS) has provided extensive data on human exposures to a wide variety of air pollutants and their impact on human health. Previous analyses in the DEARS revealed select cardiovascul...

  16. Comparison of the effects of continuous and pulsed mobile phone like RF exposure on the human EEG.

    PubMed

    Perentos, N; Croft, R J; McKenzie, R J; Cvetkovic, D; Cosic, I

    2007-12-01

    It is not clear yet whether Global System for Mobiles (GSM) mobile phone radiation has the ability to interfere with normal resting brain function. There have been reports that GSM exposure increases alpha band power, and does so only when the signal is modulated at low frequencies (Huber, R., Treyer, V., Borbely, A. A., Schuderer, J., Gottselig, J. M., Landolt, H.P., Werth, E., Berthold,T., Kuster, N., Buck, A and Achermann, P. Electromagnetic fields, such as those from mobile phones, alter regional cerebral blood flow and sleep and waking EEG. J Sleep Res 11, 289-295, 2002.) However, as that research employed exposure distributions that are not typical of normal GSM handset usage (deep brain areas were overexposed), it remains to be determined whether a similar result patterning would arise from a more representative exposure. In this fully counterbalanced cross-over design, we recruited 12 participants and tried to replicate the modulation linked post exposure alpha band power increase described above, but with an exposure source (dipole antenna) more closely resembling that of a real GSM handset. Exposures lasted for 15 minutes. No changes to alpha power were found for either modulated or unmodulated radiofrequency fields, and thus we failed to replicate the above results. Possible reasons for this failure to replicate are discussed, with the main reason argued to be the lower and more representative exposure distribution employed in the present study. In addition we investigated the possible GSM exposure related effects on the non-linear features of the resting electroencephalogram using the Approximate Entropy (ApEn) method of analysis. Again, no effect was demonstrated for either modulated or unmodulated radiofrequency exposures.

  17. Chronic exposure to sub-lethal beta-amyloid (Abeta) inhibits the import of nuclear-encoded proteins to mitochondria in differentiated PC12 cells.

    PubMed

    Sirk, Daniel; Zhu, Ziping; Wadia, Jehangir S; Shulyakova, Natalya; Phan, Nam; Fong, Jamie; Mills, Linda R

    2007-12-01

    Studies on amyloid beta (Abeta|), the peptide thought to play a crucial role in the pathogenesis of Alzheimer's disease, have implicated mitochondria in Abeta-mediated neurotoxicity. We used differentiated PC12 cells stably transfected with an inducible green fluorescent protein (GFP) fusion protein containing an N'-terminal mitochondrial targeting sequence (mtGFP), to examine the effects of sub-lethal Abeta on the import of nuclear-encoded proteins to mitochondria. Exposure to sub-lethal Abeta(25-35) (10 mumol/L) for 48 h inhibited mtGFP import to mitochondria; average rates decreased by 20 +/- 4%. Concomitant with the decline in mtGFP, cytoplasmic mtGFP increased significantly while mtGFP expression and intramitochondrial mtGFP turnover were unchanged. Sub-lethal Abeta(1-42) inhibited mtGFP import and increased cytoplasmic mtGFP but only after 96 h. The import of two endogenous nuclear-encoded mitochondrial proteins, mortalin/mtHsp70 and Tom20 also declined. Prior to the decline in import, mitochondrial membrane potential (mmp), and reactive oxygen species levels were unchanged in Abeta-treated cells versus reverse phase controls. Sustained periods of decreased import were associated with decreased mmp, increased reactive oxygen species, increased vulnerability to oxygen-glucose deprivation and altered mitochondrial morphology. These findings suggest that an Abeta-mediated inhibition of mitochondrial protein import, and the consequent mitochondrial impairment, may contribute to Alzheimer's disease.

  18. Epigenetic regulation of spinal cord gene expression contributes to enhanced postoperative pain and analgesic tolerance subsequent to continuous opioid exposure

    PubMed Central

    Liang, De-Yong; Shi, Xiao-You; Sun, Yuan; Clark, J David

    2016-01-01

    involving Bdnf and Pdyn may contribute to the enhanced postoperative nociceptive sensitization and analgesic tolerance observed after continuous opioid exposure. Treatments blocking the epigenetically mediated up-regulation of these genes or administration of TrkB or κ-opioid receptor antagonists may improve the clinical utility of opioids, particularly after surgery. PMID:27094549

  19. In Vitro Development from Leaf Explants of Sugar Beet (Beta vulgaris L). Rhizogenesis and the Effect of Sequential Exposure to Auxin and Cytokinin

    PubMed Central

    Gürel, Ekrem; Wren, M. Jill

    1995-01-01

    Adventitious root development in lamina and midrib-petiole junction expiants of sugar beet cv. Primo was investigated using scanning electron microscopy and light microscopy. Primordia developed close to the vascular strands and areas of newly dividing cells (meristematic centres) were seen adjacent to the intrafascicular cambium after 2 d incubation on medium containing 30 mg 1−11-naphthalene acetic acid. Clearly defined primordia were visible at 4 d and the first roots had emerged by 6 d. A minimum of 24 h exposure to NAA was necessary for root induction. Four days on NAA caused twice as many roots to be initiated but more prolonged exposure (5 and 10 d) inhibited root development. Root initiation continued after transfer to medium containing no plant growth regulators, new primordia appearing as the older ones extended as roots. Attempts were made to modify the development of primordia by sequential culture on cytokinin after induction by auxin. Incubation on N6-benzylaminopurine within 48 h of exposure to NAA disrupted the development of primordia and roots but did not induce shoot formation. PMID:21247910

  20. Alteration of brain and interrenal StAR protein, P450scc, and Cyp11beta mRNA levels in atlantic salmon after nominal waterborne exposure to the synthetic pharmaceutical estrogen ethynylestradiol.

    PubMed

    Lyssimachou, Angeliki; Arukwe, Augustine

    2007-04-01

    Pharmaceuticals are ubiquitous pollutants in the aquatic environment, where their potential effects on nontarget species like fish has only recently become subject of systematic investigations. Recently, it was shown that the documented xenoestrogen nonylphenol produced variations in brain steroidogenic acute regulatory (StAR) protein, cytochrome P-450-mediated cholesterol side-chain cleavage (P450scc), and cytochrome P-45011beta hydroxylase (CYP11beta) gene transcripts of exposed juvenile salmon (Arukwe, 2005). In the present study, experiments were undertaken to examine the effect of the synthetic pharmaceutical endocrine disruptor ethynylestradiol (EE2), given in water at 5 or 50 ng/L and sampled at d 0 (control), 3, and 7 after exposure, on these key and rate-limiting brain and interrenal steroidogenic pathways of juvenile salmon using quantitative (real-time) polymerase chain reaction (qPCR). Our data, which are based on nominal exposure concentrations, show that brain and head kidney StAR and P450scc expression were modulated by EE2 in a time- and concentration-specific manner. While the StAR protein and P450scc showed EE2 concentration-dependent transcriptional increases in the brain and head kidney at d 3 after exposure, no significant effect was observed at d 7. The EE2 induced effects at d 7 were underscored because the carrier solvent (dimethyl sulfoxide, DMSO) produced significant induction of the StAR protein and P450scc in both the brain and head kidney at d 7 compared to d 3 postexposure. CYP11beta transcript was detected in the brain and head kidney, where the expression patterns were modulated by EE2 in a concentration-and time-specific manner. In the brain, DMSO produced significant changes in the CYP11beta gene expression at d 7 compared to d 3 after exposure. These changes in the levels of StAR, P450scc, and CYP11beta mRNA levels in important steroidogenic organs suggest that the experimental animals are experiencing a time-dependent impaired

  1. Toxicity of CuSO{sub 4} and Cutrine to fish under continuous and episodic exposure from agricultural use to control algae

    SciTech Connect

    Davies, P.H.; Brinkman, S.F.

    1995-12-31

    A series of toxicity tests were performed to investigate possible impacts of repeated application of copper sulfate and/or cutrine to control algae in irrigation canals. Rainbow trout (Oncorhynchus mykiss) were exposed to copper sulfate and Cutrine, a commercially available algicide using chelated copper ion, under continuous and episodic exposure in very soft, low alkaline, water of 10 mg/liter which is characteristic of the Big Thompson River in Colorado. The most important factor controlling short-term toxicity of copper in soft water is duration of exposure. Rainbow trout exposed to 40 mg Cu/liter as CUSO, for 30, 45 and 60 minutes resulted in 100% mortality after 110, 5.6, and 1.3 hours, respectively. Exposure of copper sulfate for 30 minutes resulted in a 96-hr LC50 of 25.8 mg Cu/liter compared to 1.93 mg Cu/liter for Cutrine following the recommended 3 hour exposure period. Repeated episodic exposure of rainbow trout to copper sulfate and Cutrine resulted in increased mortality through six, weekly episodic events. Effect/no effect concentrations for weekly exposure to copper sulfate for 30 minutes for eighteen weeks were 2.14 and 1.03 mg Cu/liter, giving a chronic value of 1.48 mg/liter. The effect/no effect concentrations for weekly exposure episodes of 3 hours to Cutrine were 0.26 and (an estimated) 0.1 mg/liter for a chronic value of 0.16 mg Cu/liter. Ninety-six hour LC50s from continuous exposure of rainbow trout to copper sulfate and Cutrine were 4.92 and 7.20 /{micro}g Cu/liter, respectively. Chronic values for rainbow trout continuously exposed to copper sulfate and Cutrine were 1.77 and 2.47 {micro}g Cu/liter, respectively. Recommended use and application of copper sulfate and Cutrine where fish reside are also discussed.

  2. Bacterial response to a continuous long-term exposure of silver nanoparticles at sub-ppm silver concentrations in a membrane bioreactor activated sludge system.

    PubMed

    Zhang, Chiqian; Liang, Zhihua; Hu, Zhiqiang

    2014-03-01

    Silver nanoparticles (nanosilver or AgNPs) have excellent antimicrobial properties. Because of their increasing use, there is a concern about the potential impact of AgNPs in wastewater treatment systems. This study investigated the long-term effects of AgNPs (continuous loading for more than 60 days) on membrane bioreactor (MBR) activated sludge performance. At the influent AgNP concentration of 0.10 mg Ag/L, there was no significant difference in effluent water quality or bacterial activities before and after AgNP exposure. Nitrifying bacterial community structure was relatively stable before and after the long-term AgNP loading. Both ammonia-oxidizing bacteria (AOB) Nitrosomonas spp. and Nitrosospira spp. were present while Nitrospira spp. was the dominant nitrite-oxidizing bacterial species throughout this study. Abundance of silver resistance gene silE in the MBR, however, increased by 50-fold 41 days after the AgNP exposure, and then decreased with continuous AgNP exposure. The long-term nanosilver exposure did not change the membrane fouling rate although extracellular polymeric substances (EPS) concentration increased significantly after nanosilver dosing. The results suggest that AgNPs at the influent concentrations of 0.10 mg/L and below have almost no impact on activated sludge wastewater treatment performance, as activated sludge can effectively reduce nanosilver toxicity by adsorbing or precipitating AgNPs and silver ions (Ag(+)) released from the dissolution of AgNPs.

  3. Evaluation of the Toxic Effects of a 90-Day Continuous Exposure of Rats to Water-In-Oil Hydraulic Fluid Emulsion.

    DTIC Science & Technology

    1991-09-01

    not request copies of this report from the Harry G. Armstrong Aerospace Medical Research Laboratory. Additional copies may be purchased from: National...evaluate ite poter , t! t-cs from a 9C-aay continuous exposure of water-in-oil hydraulic fluid aeroso; to rats in Thomas Dome innalation chambers An air... Harry G Armstrong Aerospace Medical Research Laboratory, Wright-Patterson Air Force Base, OH Kimmel, E.C. and H.F. Leahy. 1991 A High Pressure

  4. Transforming growth factor type. beta. can act as a potent competence factor for AKR-2B cells

    SciTech Connect

    Goustin, A.S.; Nuttall, G.A.; Leof, E.B.; Ranganathan, G.; Moses, H.L. )

    1987-10-01

    Transforming growth factor type {beta} (TGF{beta}) is a pleiotropic regulator of cell growth with specific high-affinity cell-surface receptors on a large number of cells; its mechanism of action, however, is poorly defined. In this report, the authors utilized the mouse fibroblast line AKR-2B to explore the question of the temporal requirements during the cell cycle in regard to both the growth inhibitory and the growth stimulatory action of TGF{beta}. The results indicate that AKR-2B cells are most sensitive to the inhibitory action of TGF{beta} during early to mid-G{sub 1}. In addition, TGF{beta} need be present only briefly in order to exert its inhibitory effect on EGF-induced DNA synthesis. Likewise, the stimulatory effect of TGF{beta} in the absence of EGF requires only an equally brief exposure to TGF{beta}. Use of homogeneous {sup 125}I-labeled TGF{beta} in a cell-binding assay demonstrates that TGF{beta} bound to cell-surface receptors can readily exchange into the culture medium, helping to rule out the possibility that persistent receptor-bound TGF{beta} is the source of a continuous stimulus. The data indicate that TGF{beta} exposure induces a stable state in the cell similar to but distinct from the state of competence induced by platelet-derived growth factor (PDGF).

  5. Sustained expression of CYPs and DNA adduct accumulation with continuous exposure to PCB126 and PCB153 through a new delivery method: Polymeric implants

    PubMed Central

    Aqil, Farrukh; Xin, Xing; Lehmler, Hans-Joachim; Ludewig, Gabriele; Robertson, Larry W.; Gupta, Ramesh C.

    2014-01-01

    A new delivery method via polymeric implants was used for continuous exposure to PCBs. Female Sprague-Dawley rats received subcutaneous polymeric implants containing PCB126 (0.15% load), PCB153 (5% load), or both, for up to 45 days and release kinetics and tissue distribution were measured. PCB153 tissue levels on day 15 were readily detected in lung, liver, mammary and serum, with highest levels in the mammary tissue. PCB126 was detected only in liver and mammary tissues. However, a completely different pharmacokinetics was observed on co-exposure of PCB153 and PCB126, with a 1.8-fold higher levels of PCB153 in the liver whereas a 1.7-fold lower levels in the mammary tissue. PCB126 and PCB153 caused an increase in expression of key PCB-inducible enzymes, CYP 1A1/2 and 2B1/2, respectively. Serum and liver activities of the antioxidant enzymes, PON1 and PON3, and AhR transcription were also significantly increased by PCB126. 32P-Postlabeling for polar and lipophilic DNA-adducts showed significant quantitative differences: PCB126 increased 8-oxodG, an oxidative DNA lesion, in liver and lung tissues. Adduct levels in the liver remained upregulated up to 45 days, while some lung DNA adducts declined. This is the first demonstration that continuous low-dose exposure to PCBs via implants can produce sustained tissue levels leading to the accumulation of DNA-adducts in target tissue and induction of indicator enzymes. Collectively, these data demonstrate that this exposure model is a promising tool for long-term exposure studies. PMID:25530946

  6. Vibrio anguillarum Is Genetically and Phenotypically Unaffected by Long-Term Continuous Exposure to the Antibacterial Compound Tropodithietic Acid

    PubMed Central

    Grotkjær, Torben; D'Alvise, Paul W.; Yin, Guangliang; Zhang, Faxing; Bunk, Boyke; Spröer, Cathrin

    2016-01-01

    ABSTRACT Minimizing the use of antibiotics in the food production chain is essential for limiting the development and spread of antibiotic-resistant bacteria. One alternative intervention strategy is the use of probiotic bacteria, and bacteria of the marine Roseobacter clade are capable of antagonizing fish-pathogenic vibrios in fish larvae and live feed cultures for fish larvae. The antibacterial compound tropodithietic acid (TDA), an antiporter that disrupts the proton motive force, is key in the antibacterial activity of several roseobacters. Introducing probiotics on a larger scale requires understanding of any potential side effects of long-term exposure of the pathogen to the probionts or any compounds they produce. Here we exposed the fish pathogen Vibrio anguillarum to TDA for several hundred generations in an adaptive evolution experiment. No tolerance or resistance arose during the 90 days of exposure, and whole-genome sequencing of TDA-exposed lineages and clones revealed few mutational changes, compared to lineages grown without TDA. Amino acid-changing mutations were found in two to six different genes per clone; however, no mutations appeared unique to the TDA-exposed lineages or clones. None of the virulence genes of V. anguillarum was affected, and infectivity assays using fish cell lines indicated that the TDA-exposed lineages and clones were less invasive than the wild-type strain. Thus, long-term TDA exposure does not appear to result in TDA resistance and the physiology of V. anguillarum appears unaffected, supporting the application of TDA-producing roseobacters as probiotics in aquaculture. IMPORTANCE It is important to limit the use of antibiotics in our food production, to reduce the risk of bacteria developing antibiotic resistance. We showed previously that marine bacteria of the Roseobacter clade can prevent or reduce bacterial diseases in fish larvae, acting as probiotics. Roseobacters produce the antimicrobial compound tropodithietic

  7. Long-term air pollution exposure is associated with neuroinflammation, an altered innate immune response, disruption of the blood-brain barrier, ultrafine particulate deposition, and accumulation of amyloid beta-42 and alpha-synuclein in children and young adults.

    PubMed

    Calderón-Garcidueñas, Lilian; Solt, Anna C; Henríquez-Roldán, Carlos; Torres-Jardón, Ricardo; Nuse, Bryan; Herritt, Lou; Villarreal-Calderón, Rafael; Osnaya, Norma; Stone, Ida; García, Raquel; Brooks, Diane M; González-Maciel, Angelica; Reynoso-Robles, Rafael; Delgado-Chávez, Ricardo; Reed, William

    2008-02-01

    Air pollution is a serious environmental problem. We investigated whether residency in cities with high air pollution is associated with neuroinflammation/neurodegeneration in healthy children and young adults who died suddenly. We measured mRNA cyclooxygenase-2, interleukin-1beta, and CD14 in target brain regions from low (n = 12) or highly exposed residents (n = 35) aged 25.1 +/- 1.5 years. Upregulation of cyclooxygenase-2, interleukin-1beta, and CD14 in olfactory bulb, frontal cortex, substantia nigrae and vagus nerves; disruption of the blood-brain barrier; endothelial activation, oxidative stress, and inflammatory cell trafficking were seen in highly exposed subjects. Amyloid beta42 (Abeta42) immunoreactivity was observed in 58.8% of apolipoprotein E (APOE) 3/3 < 25 y, and 100% of the APOE 4 subjects, whereas alpha-synuclein was seen in 23.5% of < 25 y subjects. Particulate material (PM) was seen in olfactory bulb neurons, and PM < 100 nm were observed in intraluminal erythrocytes from lung, frontal, and trigeminal ganglia capillaries. Exposure to air pollution causes neuroinflammation, an altered brain innate immune response, and accumulation of Abeta42 and alpha-synuclein starting in childhood. Exposure to air pollution should be considered a risk factor for Alzheimer's and Parkinson's diseases, and carriers of the APOE 4 allele could have a higher risk of developing Alzheimer's disease if they reside in a polluted environment.

  8. Effects of Liraglutide Combined with Short-Term Continuous Subcutaneous Insulin Infusion on Glycemic Control and Beta Cell Function in Patients with Newly Diagnosed Type 2 Diabetes Mellitus: A Pilot Study.

    PubMed

    Ke, Weijian; Liu, Liehua; Liu, Juan; Chen, Ailing; Deng, Wanping; Zhang, Pengyuan; Cao, Xiaopei; Liao, Zhihong; Xiao, Haipeng; Liu, Jianbin; Li, Yanbing

    2016-01-01

    The objective of this paper is to investigate the effects of liraglutide in combination with short-term continuous subcutaneous insulin infusion (CSII) therapy on glycemic control and beta cell function in patients with newly diagnosed type 2 diabetes mellitus (T2DM). Thirty-nine eligible newly diagnosed T2DM patients were recruited and randomized to receive either of two therapies: short-term CSII alone (CSII alone group) or CSII in combination with liraglutide (CSII + Lira group) for 12 weeks. Blood glucose control, homeostasis model assessment (HOMA) indices, and acute insulin response (AIR) were compared between the two groups. The patients in CSII + Lira group achieved euglycemia with equivalent insulin dosage in shorter time (1 (0) versus 2 (3) days, P = 0.039). HbA1c at the end of study was comparable between two groups (6.3 ± 0.7% versus 6.0 ± 0.5%, for CSII alone group and CSII + Lira group, resp., P = 0.325). The increment of AIR was higher in CSII + Lira group (177.58 (351.57) μU · min/mL versus 58.15 (51.30) μU · min/mL, P < 0.001). However, after stopping liraglutide, its effect on beta cell function disappeared completely. Liraglutide combined with short-term CSII was effective in further improving beta cell function, but the beneficial effects did not sustain after suspension of the therapy.

  9. Year-long continuous personal exposure to PM 2.5 recorded by a fast responding portable nephelometer

    NASA Astrophysics Data System (ADS)

    Braniš, Martin; Kolomazníková, Jana

    2010-08-01

    Personal exposure to particulate matter of aerodynamic diameter under 2.5 μm (PM 2.5) was monitored using a DustTrak nephelometer. The battery-operated unit, worn by an adult individual for a period of approximately one year, logged integrated average PM 2.5 concentrations over 5 min intervals. A detailed time-activity diary was used to record the experimental subject's movement and the microenvironments visited. Altogether 239 days covering all the months (except April) were available for the analysis. In total, 60 463 acceptable 5-min averages were obtained. The dataset was divided into 7 indoor and 4 outdoor microenvironments. Of the total time, 84% was spent indoors, 10.9% outdoors and 5.1% in transport. The indoor 5-min PM 2.5 average was higher (55.7 μg m -3) than the outdoor value (49.8 μg m -3). The highest 5-min PM 2.5 average concentration was detected in restaurant microenvironments (1103 μg m -3), the second highest 5-min average concentration was recorded in indoor spaces heated by stoves burning solid fuels (420 μg m -3). The lowest 5-min mean aerosol concentrations were detected outdoors in rural/natural environments (25 μg m -3) and indoors at the monitored person's home (36 μg m -3). Outdoor and indoor concentrations of PM 2.5 measured by the nephelometer at home and during movement in the vicinity of the experimental subject's home were compared with those of the nearest fixed-site monitor of the national air quality monitoring network. The high correlation coefficient (0.78) between the personal and fixed-site monitor aerosol concentrations suggested that fixed-site monitor data can be used as proxies for personal exposure in residential and some other microenvironments. Collocated measurements with a reference method (β-attenuation) showed a non-linear systematic bias of the light-scattering method, limiting the use of direct concentration readings for exact exposure analysis.

  10. Beta Blockers

    MedlinePlus

    Diseases and Conditions High blood pressure (hypertension) Beta blockers, also called beta-adrenergic blocking agents, treat a variety of conditions, such as high blood pressure and migraines. Find out more about this ...

  11. Effects of exposure to intermittent and continuous 6-7 kHz sonar sweeps on harbor porpoise (Phocoena phocoena) hearing.

    PubMed

    Kastelein, Ronald A; Gransier, Robin; Schop, Jessica; Hoek, Lean

    2015-04-01

    Safety criteria for mid-frequency naval sonar sounds are needed to protect harbor porpoise hearing. A porpoise was exposed to sequences of one-second 6-7 kHz sonar down-sweeps, with 10-200 sweeps in a sequence, at an average received sound pressure level (SPLav.re.) of 166 dB re 1 μPa, with duty cycles of 10% (intermittent sounds) and 100% (continuous). Behavioral hearing thresholds at 9.2 kHz were determined before and after exposure to the fatiguing noise, to quantify temporary hearing threshold shifts (TTS1-4 min) and recovery. Significant TTS1-4 min occurred after 10-25 sweeps when the duty cycle was 10% (cumulative sound exposure level, SELcum: ∼178 dB re 1 μPa(2)s). For the same SELcum, the TTS1-4 min was greater for exposures with 100% duty cycle. The difference in TTS between the two duty cycle exposures increased as the number of sweeps in the exposure sequences increased. Therefore, to predict TTS and permanent threshold shift, not only SELcum needs to be known, but also the duty cycle or equivalent sound pressure level (Leq). It appears that the injury criterion for non-pulses proposed by Southall, Bowles, Ellison, Finneran, Gentry, Greene, Kastak, Ketten, Miller, Nachtigall, Richardson, Thomas, and Tyack [(2007). Aquat. Mamm. 33, 411-521] for cetaceans echolocating at high frequency (SEL 215 dB re 1 μPa(2)s) is too high for the harbor porpoise.

  12. Effect of continuous female exposure on behavioral repertoire and stereotypical behaviors in restrained male dromedary camels during the onset of the breeding season.

    PubMed

    Fatnassi, Meriem; Padalino, Barbara; Monaco, David; Khorchani, Touhami; Lacalandra, Giovanni Michele; Hammadi, Mohamed

    2016-06-01

    This study aimed to test the effects of the three management systems on the behavioral repertoire and particularly on the incidence of stereotypical behavior in restrained camels. Five male camels were tested under the following management systems: (i) unexposed, housing in a single box (Unexpo); (ii) continuous exposure, exposed continuously to females (ConExpoF); and (iii) re-unexposed, housing again in a single box (Re-Unexpo). Every day, bulls were filmed for 30 min and videos were analyzed using a focal animal sampling ethogram. Under the ConExpoF system, camels spent the majority of time in standing with opened legs (490.0 ± 94.3 s), looking (925.0 ± 93.7 s), and walking toward the females (206.0 ± 73.4 s) and they ate and ruminated less compared to Unexpo and Re-Unexpo systems. Rumination and standing durations were significantly longer in Re-Unexpo than in Unexpo and ConExpoF management systems. When camels were continuously exposed to females, they showed few stereotypical behaviors compared to Unexpo (490.0 ± 146.1 s) and Re-Unexpo (624.0 ± 146.1 s) systems. The frequency of both total and oral stereotypes was significantly higher in Unexpo and Re-Unexpo systems compared to ConExpoF; however, no significant difference was observed among the three management systems in the frequency of locomotor stereotypes. Overall, it appears that the continuous female exposure system might be a suitable management practice for male camels used for intensive reproduction, as it decreases the manifestation of stereotypical behavior in comparison with housing for 24 h in a single box.

  13. Causal Analysis of the Unanticipated Extremity Exposure at HFEF

    SciTech Connect

    David E. James; Charles R. Posegate; Thomas P. Zahn; Alan G. Wagner

    2011-11-01

    This report covers the unintended extremity exposure to an operator while handling a metallurgical mount sample of irradiated fuel following an off-scale high beta radiation reading of the sample. The decision was made to continue working after the meter indicated high off-scale by the HPT Supervisor, which resulted in the operator at the next operation being exposed.

  14. Reduced tumor necrosis factor-alpha and transforming growth factor-beta1 expression in the lungs of inbred mice that fail to develop fibroproliferative lesions consequent to asbestos exposure.

    PubMed

    Brass, D M; Hoyle, G W; Poovey, H G; Liu, J Y; Brody, A R

    1999-03-01

    Tumor necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta mRNA and protein expression and the degree of fibroproliferative response to inhaled asbestos fibers are clearly reduced in the 129 inbred mouse strain as compared with typical fibrogenesis observed in the C57BL/6 inbred strain. The C57BL/6 mice showed prominent lesions at bronchiolar-alveolar duct (BAD) junctions where asbestos fibers deposit and responding macrophages accumulate. The 129 mice, however, were generally indistinguishable from controls even though the numbers of asbestos fibers deposited in the lungs of all exposed animals were the same. Quantitative morphometry of H&E-stained lung sections comparing the C57BL/6 and 129 mice showed significantly less mean cross-sectional area of the BAD junctions in the 129 animals, apparent at both 48 hours and 4 weeks after exposure. In addition, fewer macrophages had accumulated at these sites in the 129 mice. Nuclear bromodeoxyuridine immunostaining demonstrated that the number of proliferating cells at first alveolar duct bifurcations and in adjacent terminal bronchioles was significantly reduced in the 129 strain compared with C57BL/6 mice at 48 hours after exposure (P < 0.01). TNF-alpha and TGF-beta1 gene expression, as measured by in situ hybridization, was reduced in the 129 mice at 48 hours after exposure, and expression of TNF-alpha and TGF-beta1 protein, as measured by immunohistochemistry, was similarly reduced or absent in the 129 animals. We postulate that the protection afforded the 129 mice is related to reduction of growth factor expression by the bronchiolar-alveolar epithelium and lung macrophages.

  15. Assessment of biological changes of continuous whole body exposure to static magnetic field and extremely low frequency electromagnetic fields in mice.

    PubMed

    Hashish, A H; El-Missiry, M A; Abdelkader, H I; Abou-Saleh, R H

    2008-11-01

    The question whether static magnetic fields (SMFs) and extremely low frequency electromagnetic fields (ELF-EMF) cause biological effects is of special interest. We investigated the effects of continuous whole body exposure to both fields for 30 days on some liver and blood parameters in mice. Two exposure systems were designed; the first produced a gradient SMF while the second generated uniform 50 Hz ELF-EMF. The results showed a gradual body weight loss when mice were exposed to either field. This is coupled with a significant decrease (P<0.05) in the levels of glucose, total protein and the activity of alkaline phosphatase in serum. A significant increase in lactate dehydrogenase activity was demonstrated in serum and liver paralleled with a significant elevation in hepatic γ-glutamyl transferase activity. The glutathione-S-transferase activity and lipid peroxidation level in the liver were significantly increased while a significant decrease in hepatic gluthathione content was recorded. A significant decrease in the counts of monocytes, platelets, peripheral lymphocytes as well as splenic total, T and B lymphocytes levels was observed for SMF and ELF-EMF exposed groups. The granulocytes percentage was significantly increased. The results indicate that there is a relation between the exposure to SMF or ELF-EMF and the oxidative stress through distressing redox balance leading to physiological disturbances.

  16. Migratory-stage sea lamprey Petromyzon marinus stop responding to conspecific damage-released alarm cues after 4 h of continuous exposure in laboratory conditions

    USGS Publications Warehouse

    Imre, Istvan; Di Rocco, Richard T.; McClure, Haley; Johnson, Nicholas; Brown, Grant E.

    2016-01-01

    This study investigated the length of avoidance response of migratory-stage sea lamprey Petromyzon marinus exposed continuously to conspecific damage-released alarm cues for varying lengths of time in laboratory stream channels. Ten replicate groups of P. marinus, separated by sex, were exposed to either deionized water control or to P. marinus extract for 0, 2 or 4 h continuously. Petromyzon marinus maintained their avoidance response to the conspecific damage-released alarm cue after continuous exposure to the alarm cue for 0 and 2 h but not 4 h. Beyond being one of the first studies in regards to sensory–olfactory adaptation–acclimation of fishes to alarm cues of any kind, these results have important implications for use of conspecific alarm cues in P. marinus control. For example, continuous application of conspecific alarm cue during the day, when P. marinus are inactive and hiding, may result in sensory adaptation to the odour by nightfall when they migrate upstream.

  17. Long term, continuous exposure to panobinostat induces terminal differentiation and long term survival in the TH-MYCN neuroblastoma mouse model.

    PubMed

    Waldeck, Kelly; Cullinane, Carleen; Ardley, Kerry; Shortt, Jake; Martin, Ben; Tothill, Richard W; Li, Jason; Johnstone, Ricky W; McArthur, Grant A; Hicks, Rodney J; Wood, Paul J

    2016-07-01

    Neuroblastoma is the most common extra-cranial malignancy in childhood and accounts for ∼15% of childhood cancer deaths. Amplification of MYCN in neuroblastoma is associated with aggressive disease and predicts for poor prognosis. Novel therapeutic approaches are therefore essential to improving patient outcomes in this setting. The histone deacetylases are known to interact with N-Myc and regulate numerous cellular processes via epigenetic modulation, including differentiation. In this study, we used the TH-MYCN mouse model of neuroblastoma to investigate the antitumor activity of the pan-HDAC inhibitor, panobinostat. In particular we sought to explore the impact of long term, continuous panobinostat exposure on the epigenetically driven differentiation process. Continuous treatment of tumor bearing TH-MYCN transgenic mice with panobinostat for nine weeks led to a significant improvement in survival as compared with mice treated with panobinostat for a three-week period. Panobinostat induced rapid tumor regression with no regrowth observed following a nine-week treatment period. Initial tumor response was associated with apoptosis mediated via upregulation of BMF and BIM. The process of terminal differentiation of neuroblastoma into benign ganglioneuroma, with a characteristic increase in S100 expression and reduction of N-Myc expression, occurred following prolonged exposure to the drug. RNA-sequencing analysis of tumors from treated animals confirmed significant upregulation of gene pathways associated with apoptosis and differentiation. Together our data demonstrate the potential of panobinostat as a novel therapeutic strategy for high-risk neuroblastoma patients.

  18. Continuous weeklong measurements of personal exposures and indoor concentrations of fine particles for 37 health-impaired North Carolina residents for up to four seasons

    NASA Astrophysics Data System (ADS)

    Wallace, Lance; Williams, Ron; Rea, Anne; Croghan, Carry

    A study of personal exposures and indoor and outdoor concentrations of particles was carried out in 2000-2001 for 37 health-impaired residents of North Carolina. Earlier papers have dealt with the 24-h integrated gravimetric samples; this report adds the continuous data (1-min resolution) using optical scattering devices (personal data RAMs, or pDRs) for personal and indoor measurements. Subjects and their households were sampled for 7 consecutive days in each of four seasons, although not all subjects completed all four seasons. Each subject completed an activity diary with 15-min resolution on each day giving his or her presence in one of six locations and describing activities with the potential for increased exposure to particles. More than 800 person-days and 1.1×10 6 person-min of valid personal exposures and indoor air concentrations were collected. The pDRs compared well with the PM 2.5 gravimetric devices, with an R2 of 87% compared to the indoor Harvard impactor (HI), and 70% compared to the personal exposure monitor (PEM). As found in previous studies, (and as expected due to the calibration of these devices with an aerosol of higher density than normal ambient and indoor aerosols), the pDRs overestimated the gravimetric concentrations by 20-50%. Because the correction factor varied by season and by type of sample (indoor vs. personal), no overall correction factor could be applied. The estimated mean increases in exposure during three common activities (cooking, cleaning, and personal care) were 56, 28, and 20 μg m -3, respectively. Several less common activities, such as burning food and using a fireplace were found to result occasionally in very high (>1500 μg m -3) short-term peaks of exposure. Although households with smoking were ineligible for participation, two households did have significant smoking, and had the highest average personal exposures and indoor concentrations of all the study homes. The diurnal variation of personal exposures and

  19. Chronic toxicity of erythromycin thiocyanate to Daphnia magna in a flow-through, continuous exposure test system

    USGS Publications Warehouse

    Meinertz, J.R.; Schreier, T.M.; Bernardy, J.A.

    2011-01-01

    Approval of a new animal drug application for AQUAMYCIN 100?? (erythromycin thiocyanate; ET) to treat freshwater salmonid species with bacterial kidney disease is being pursued in the US. As part of the approval process, ETs impact on an aquatic environment had to be described in an environmental assessment. The environmental assessment was lacking data to characterize the effect ET would have on a chronically exposed aquatic invertebrate organism. A major step to fulfilling the environmental assessment was completed after conducting a comprehensive study continuously exposing Daphnia magna to ET for 21 days. Results indicated that the no observable effect concentration for ET was 179 ??g/L. ?? 2011 Springer Science+Business Media, LLC (outside the USA).

  20. How to minimize toxic exposure to pyridine during continuous infusion of ceftazidime in patients with cystic fibrosis?

    PubMed

    Bourget, P; Amin, A; Dupont, C; Abely, M; Desmazes-Dufeu, N; Dubus, J C; Jouani, B-L; Merlette, C; Nové-Josserand, R; Pages, J; Panzo, R; Vidal, F; Voge, F; Hubert, D

    2014-05-01

    Ceftazidime is particularly efficient against Pseudomonas aeruginosa in cystic fibrosis patients. Thus, the spontaneous production of pyridine, which is a toxic product, raises some concern. Our aim was to examine the kinetics of degradation of ceftazidime in portable infusion pumps either at 4°C, 22°C, or 33°C and to propose some recommendations in order to reduce the pyridine exposure. Two administration models were studied in vitro. In model 1, we administered 12 g of ceftazidime infused over 23 h (once-daily infusion) compared to 6 g infused over 11.5 h in model 2 (twice-daily regimen). Samples were collected at 0 h and then every 4 and 2 h after the shaping of portable infusion pumps in models 1 and 2, respectively. Both ceftazidime and pyridine were analyzed using an ultraviolet high-performance liquid chromatograph. Production of pyridine is highly depending on the temperature. The in situ production of pyridine per day of treatment decreases at a ratio close to 1/6 and 1/3 between 33°C and 4°C in models 1 and 2, respectively. Regardless of the conditions, the production of pyridine is significantly lower in model 2, whereas the total delivery amount of ceftazidime is significantly higher at 4°C and 33°C compared to that in model 1. According to a the precautionary principle, these findings lead to three major recommendations: (i) exposing a solution of ceftazidime to over 22°C should be strictly avoided, (ii) a divided dose of 6 g over 11.5 h instead of a once-daily administration is preferred, and (iii) infusion should be administered immediately after reconstitution.

  1. How To Minimize Toxic Exposure to Pyridine during Continuous Infusion of Ceftazidime in Patients with Cystic Fibrosis?

    PubMed Central

    Amin, A.; Dupont, C.; Abely, M.; Desmazes-Dufeu, N.; Dubus, J. C.; Jouani, B.-L.; Merlette, C.; Nové-Josserand, R.; Pages, J.; Panzo, R.; Vidal, F.; Voge, F.; Hubert, D.

    2014-01-01

    Ceftazidime is particularly efficient against Pseudomonas aeruginosa in cystic fibrosis patients. Thus, the spontaneous production of pyridine, which is a toxic product, raises some concern. Our aim was to examine the kinetics of degradation of ceftazidime in portable infusion pumps either at 4°C, 22°C, or 33°C and to propose some recommendations in order to reduce the pyridine exposure. Two administration models were studied in vitro. In model 1, we administered 12 g of ceftazidime infused over 23 h (once-daily infusion) compared to 6 g infused over 11.5 h in model 2 (twice-daily regimen). Samples were collected at 0 h and then every 4 and 2 h after the shaping of portable infusion pumps in models 1 and 2, respectively. Both ceftazidime and pyridine were analyzed using an ultraviolet high-performance liquid chromatograph. Production of pyridine is highly depending on the temperature. The in situ production of pyridine per day of treatment decreases at a ratio close to 1/6 and 1/3 between 33°C and 4°C in models 1 and 2, respectively. Regardless of the conditions, the production of pyridine is significantly lower in model 2, whereas the total delivery amount of ceftazidime is significantly higher at 4°C and 33°C compared to that in model 1. According to a the precautionary principle, these findings lead to three major recommendations: (i) exposing a solution of ceftazidime to over 22°C should be strictly avoided, (ii) a divided dose of 6 g over 11.5 h instead of a once-daily administration is preferred, and (iii) infusion should be administered immediately after reconstitution. PMID:24614367

  2. Balkan Endemic Nephropathy - Still continuing enigma, risk assessment and underestimated hazard of joint mycotoxin exposure of animals or humans.

    PubMed

    Stoev, Stoycho D

    2017-01-05

    The spreading of mycotoxic nephropathy in animals/humans was studied. The possible etiological causes provoking this nephropathy were carefully reviewed and analyzed. The natural content of the most frequent nephrotoxic mycotoxins in target feedstuffs/foods were investigated, in addition to their significance for development of renal damages in endemic areas. An estimation of the level of exposure of humans to the nephrotoxic mycotoxin, ochratoxin A (OTA), is made. The possible synergism or additive effects between some target mycotoxins in the development of nephropathy is also covered. The significance of joint mycotoxin interaction and masked mycotoxins, in addition to some newly isolated fungal toxic agents in the complicated etiology of mycotoxic nephropathy ranged in Balkan countries is discussed. The importance of some target fungal species which can induce kidney damages was evaluated. The morphological/ultrastructural, functional and toxicological similarities between human and animal nephropathy are studied. The possible hazard of low content of combinations of some target mycotoxins in food or feedstuff ingested by pigs, chickens or humans under natural conditions is evaluated and a risk assessment was made. Some different but more effective manners of prophylaxis and/or prevention against OTA contamination of feedstuffs/foods are suggested. A survey was made in regard to the best possible ways of veterinary hygiene control of OTA-exposed animals at slaughter time for preventing the entrance of OTA in commercial feedstuffs/food channels with a view to reduce the possible health hazard for humans. The economic efficacy and applicability of such preventive measures is additionally discussed and some practical suggestions are made.

  3. Cytopathological changes associated with continuous and intermittent exposure to glucocorticoids using raw cell line as a model.

    PubMed

    Fletcher, Audwin; Benghuzzi, Hamed; Tucci, Michelle

    2003-01-01

    In a world of pathogens, the ability to detect an incipient infection and to respond rapidly and appropriately to it, is a decisive part of our survival strategy. The innate immune system provides the first response to an infection by initiating an inflammatory response. The monocyte surface of the molecule CD14 is a key element in this response system. Over activation of the inflammatory response can lead to systemic inflammation and septic shock. Glucocorticoids are anti-inflammatory and immunosuppressive agents that act on many cells of the body, including monocytes/macrophages. The specific aim of this investigation was to compare the role of conventional versus sustained delivery of Cortisol on the viability and morphology of RAW 264.7 macrophages. RAW cells were obtained from American Type Culture Collection. Standard laboratory protocols were followed in cell plating (10(4) cells/well), phase terminating, and morphological evaluation. The experimental design consisted of two phases. Each phase had non-treated control groups and experimental groups. The results of this investigation yielded that: (i) TCP drug delivery system was capable of providing sustained and continuous release of Cortisol as evidenced by survival of cells in all experimental wells, and (ii) regardless of the Cortisol concentration, RAW cells were viable throughout the experimental periods. Overall, the results of this study provide a comparative analysis of the modes of actions of steriods; and, the results document the effects of the susceptibility of infection based on route.

  4. Evidence of biogenic corrosion of titanium after exposure to a continuous culture of thiobacillus ferrooxidans grown in thiosulfate medium

    SciTech Connect

    Horn, J M; Martin, S I; Masterson, B

    2000-12-07

    Experiments were undertaken to evaluate extreme conditions under which candidate materials intended for use in a proposed nuclear waste repository might be susceptible to corrosion by endogenous microorganisms. Thiobucillus ferrooxidans, a sulfur-oxidizing bacterium, was grown in continuous culture using thiosulfate as an energy source; thiosulfate is oxidized to sulfate as a metabolic endproduct by this organism. Culture conditions were optimized to produce a high-density, metabolically active culture throughout a period of long term incubation in the presence of Alloy 22 (a high nickel-based alloy) and Titanium grade 7 (Tigr7) material coupons. After seven months incubation under these conditions, material coupons were withdrawn and analyzed by high resolution microscopy and energy dispersive x-ray analyses. Alloy 22 coupons showed no detectable signs of corrosion. Tigr7, however, demonstrated distinct roughening of the coupon surface, and [presumably solubilized and precipitated] titanium was detected on Alloy 22 coupons incubated in the same T. ferrooxiduns culture vessel. Control coupons of these materials incubated in sterile thiosulfate medium did not demonstrate any signs of corrosion, thus showing that observed corrosive effects were due to the T. ferrooxidans metabolic activities. T. ferrooxidans intermediates of thiosulfate oxidation or sulfate may have caused the corrosive effects observed on Tigr7.

  5. Non-parametric estimation of the odds ratios for continuous exposures using generalized additive models with an unknown link function.

    PubMed

    Cadarso-Suárez, Carmen; Roca-Pardiñas, Javier; Figueiras, Adolfo; González-Manteiga, Wenceslao

    2005-04-30

    The generalized additive, model (GAM) is a powerful and widely used tool that allows researchers to fit, non-parametrically, the effect of continuous predictors on a transformation of the mean response variable. Such a transformation is given by a so-called link function, and in GAMs this link function is assumed to be known. Nevertheless, if an incorrect choice is made for the link, the resulting GAM is misspecified and the results obtained may be misleading. In this paper, we propose a modified version of the local scoring algorithm that allows for the non-parametric estimation of the link function, by using local linear kernel smoothers. To better understand the effect that each covariate produces on the outcome, results are expressed in terms of the non-parametric odds ratio (OR) curves. Bootstrap techniques were used to correct the bias in the OR estimation and to construct point-wise confidence intervals. A simulation study was carried out to assess the behaviour of the resulting estimates. The proposed methodology was illustrated using data from the AIDS Register of Galicia (NW Spain), with a view to assessing the effect of the CD4 lymphocyte count on the probability of being AIDS-diagnosed via Tuberculosis (TB). This application shows how the link's flexibility makes it possible to obtain OR curve estimates that are less sensitive to the presence of outliers and unusual values that are often present in the extremes of the covariate distributions.

  6. Exposure of beta H-crystallin to hydroxyl radicals enhances the transglutaminase-susceptibility of its existing amine-donor and amine-acceptor sites.

    PubMed Central

    Groenen, P J; Seccia, M; Smulders, R H; Gravela, E; Cheeseman, K H; Bloemendal, H; de Jong, W W

    1993-01-01

    beta H-crystallin was exposed to radiolytically generated hydroxyl radicals at defined radical concentrations, and its capacity to act as an amine-acceptor substrate and as an amine-donor substrate for transglutaminase were investigated. [14C]Methylamine was used as a probe for labelling amine-acceptor sites; a novel biotinylated hexapeptide was used to label amine-donor sites. The results demonstrate that both primary amine incorporation and hexapeptide incorporation by transglutaminase are considerably increased after oxidative attack on the crystallin. The identity of the labelled subunits was established, and it is shown that, in both cases, this increased incorporation is not due to the production of new substrates, but that the existing incorporation sites become more susceptible. Moreover, using the newly developed probe, we could identify, for the first time, the major crystallin subunits active as amine-donor substrates (both before and after treatment) to be beta B1-, beta A3- and beta A4-crystallin. These data support the proposal that oxidative stress and transglutaminase activity may be jointly involved in the changes found in lens crystallins with age and in the development of cataract. Images Figure 1 Figure 2 Figure 3 PMID:7902086

  7. Beta experiment

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A focused laser doppler velocimeter (LDV) system was developed for the measurement of atmospheric backscatter (beta) from aerosols at infrared wavelengths. A Doppler signal generator was used in mapping the coherent sensitive focal volume of a focused LDV system. System calibration data was analyzed during the flight test activity scheduled for the Beta system. These analyses were performed to determine the acceptability of the Beta measurement system's performance.

  8. Model Beta 5M: A potential instrumental counterpart to Method 5 for the continuous measurement of particulate matter emissions from combustion and other sources using isokinetic sample extraction technology followed by beta ray attenuation mass measurement techniques

    SciTech Connect

    Griguoli, F.T.

    1997-12-31

    For many years opacity and other values available from optical devices have been used in an attempt to assess and often quantify particulate matter emissions from stationary sources, particularly combustion sources using coal. These opacity values have also been used to obtain mass concentration data. Today`s reality is such that pollution abatement technologies have become better and better, dry or wet, and most processes are subject to a variety of conditions no longer suitable, in the author`s opinion, for the use of optical devices or derivatives of them. This paper describes a continuous extractive technique to measure particulate matter which has been used in Europe and around the world for more than 10 years. This technique works very well in changing particulate matter conditions, low particulate concentrations, small diameter stacks, and stacks/ducts with high water vapor content in the flue gas.

  9. THE INFLUENCE OF HUMAN ACTIVITY PATTERNS ON PERSONAL PM EXPOSURE: A COMPARATIVE ANALYSIS OF FILTER-BASED AND CONTINUOUS PARTICLE MEASUREMENTS

    EPA Science Inventory

    Particulate matter (PM) exposure data from the U.S. Environmental Protection Agency sponsored 1998 Baltimore and 1999 Fresno PM Exposure Studies were analyzed to identify important microenvironments and activities that may lead to increased particle exposure for select elderly ...

  10. Continuous exposure to a novel stressor based on water aversion induces abnormal circadian locomotor rhythms and sleep-wake cycles in mice.

    PubMed

    Miyazaki, Koyomi; Itoh, Nanako; Ohyama, Sumika; Kadota, Koji; Oishi, Katsutaka

    2013-01-01

    Psychological stressors prominently affect diurnal rhythms, including locomotor activity, sleep, blood pressure, and body temperature, in humans. Here, we found that a novel continuous stress imposed by the perpetual avoidance of water on a wheel (PAWW) affected several physiological diurnal rhythms in mice. One week of PAWW stress decayed robust circadian locomotor rhythmicity, while locomotor activity was evident even during the light period when the mice are normally asleep. Daytime activity was significantly upregulated, whereas nighttime activity was downregulated, resulting in a low amplitude of activity. Total daily activity gradually decreased with increasing exposure to PAWW stress. The mice could be exposed to PAWW stress for over 3 weeks without adaptation. Furthermore, continuous PAWW stress enhanced food intake, but decreased body weight and plasma leptin levels, indicating that sleep loss and PAWW stress altered the energy balance in these mice. The diurnal rhythm of corticosterone levels was not severely affected. The body temperature rhythm was diurnal in the stressed mice, but significantly dysregulated during the dark period. Plasma catecholamines were elevated in the stressed mice. Continuous PAWW stress reduced the duration of daytime sleep, especially during the first half of the light period, and increased nighttime sleepiness. Continuous PAWW stress also simultaneously obscured sleep/wake and locomotor activity rhythms compared with control mice. These sleep architecture phenotypes under stress are similar to those of patients with insomnia. The stressed mice could be entrained to the light/dark cycle, and when they were transferred to constant darkness, they exhibited a free-running circadian rhythm with a timing of activity onset predicted by the phase of their entrained rhythms. Circadian gene expression in the liver and muscle was unaltered, indicating that the peripheral clocks in these tissues remained intact.

  11. Water Sparing in Chronic Ethanol Exposure is Associated With Elevated Renal Estrogen Receptor Beta and Vasopressin V2 Receptor mRNA in the Female Rate

    DTIC Science & Technology

    2007-12-01

    quality as a thesis for the degree of Master of Science in Medical and Molecular Physiology. THESIS COMMITTEE Chairperson ii TABLE OF CONTENTS List of...of biology = Revista brasleira de biologia 62, 609-614 20. Bevan, D. R. (1978) Osmometry. 1. Terminology and principles of measurement. Anaesthesia 33... molecular endocrinology 24, 145-155 32. Suzuki, S., and Handa, R. J. (2004) Regulation of estrogen receptor-beta expression in the female rat

  12. Functional receptor coupling to Gi is a mechanism of agonist-promoted desensitization of the beta2-adrenergic receptor.

    PubMed

    Tepe, N M; Liggett, S B

    2000-01-01

    The beta2-adrenergic receptor (beta2AR) couples to Gs activating adenylyl cyclase (AC) and increasing cAMP. Such signaling undergoes desensitization with continued agonist exposure. Beta2AR also couple to Gi after receptor phosphorylation by the cAMP dependent protein kinase A, but the efficiency of such coupling is not known. Given the PKA dependence of beta2AR-Gi coupling, we explored whether this may be a mechanism of agonist-promoted desensitization. HEK293 cells were transfected to express beta2AR or beta2AR and Gialpha2, and then treated with vehicle or the agonist isoproterenol to evoke agonist-promoted beta2AR desensitization. Membrane AC activities showed that Gialpha2 overexpression decreased basal levels, but the fold-stimulation of the AC over basal by agonist was not altered. However, with treatment of the cells with isoproterenol prior to membrane preparation, a marked decrease in agonist-stimulated AC was observed with the cells overexpressing Gialpha2. In the absence of such overexpression, beta2AR desensitization was 23+/-7%, while with 5-fold Gialpha2 overexpression desensitization was 58+/-5% (p<0.01, n=4). The effect of Gi on desensitization was receptor-specific, in that forskolin responses were not altered by G(i)alpha2 overexpression. Thus, acquired beta2AR coupling to Gi is an important mechanism of agonist-promoted desensitization, and pathologic conditions that increase Gi levels contribute to beta2AR dysfunction.

  13. Selective development of T helper (Th)2 cells induced by continuous administration of low dose soluble proteins to normal and beta(2)- microglobulin-deficient BALB/c mice

    PubMed Central

    1996-01-01

    Continuous administration of soluble proteins, delivered over a 10-d period by a mini-osmotic pump implanted subcutaneously, induces a long- lasting inhibition of antigen-specific T cell proliferation in lymph node cells from BALB/c mice subsequently primed with antigen in adjuvant. The decreased T cell proliferative response is associated with a down-regulation of the T helper cell (Th)1 cytokines interleukin (IL)-2 and interferon (IFN)-gamma and with a strong increase in the secretion of the Th2 cytokines IL-4 and IL-5 by antigen specific CD4+ T cells. This is accompanied by predominant inhibition of antigen- specific antibody production of IgG2a and IgG2b, rather than IgG1 isotype. Interestingly, inhibition of Th1 and priming of Th2 cells is also induced in beta(2) microglobulin-deficient BALB/c mice, indicating that neither CD8+ nor CD4+ NK1.1+ T cells, respectively, are required. The polarization in Th2 cells is stably maintained by T cell lines, all composed of CD4+/CD8- cells expressing T cell receptor for antigen (TCR) alpha/beta chains, derived from BALB/c mice treated with continuous antigen administration, indicating that they originate from Th2 cells fully differentiated in vivo. This polarization is induced in BALB/c mice by continuous administration of any protein antigen tested, including soluble extracts from pathogenic microorganisms. Priming of Th2 cells is dose dependent and it is optimal for low rather than high doses of protein. Blocking endogenous IL-4 in vivo inhibits expansion of antigen-specific Th2 cells, but does not restore IFN-gamma production by T cells from mice treated with soluble antigen-specific Th2 cells, but does not restore IFN-gamma production by T cells from mice treated with soluble antigen, indicating the involvement of two independent mechanisms. Consistent with this, Th2 cell development, but not inhibition of Th1 cells, depends on non-major histocompatibility complex genetic predisposition, since the Th2 response is

  14. EFFECTS OF TRITIUM GAS EXPOSURE ON POLYMERS

    SciTech Connect

    Clark, E.; Fox, E.; Kane, M.; Staack, G.

    2011-01-07

    Effects of tritium gas exposure on various polymers have been studied over the last several years. Despite the deleterious effects of beta exposure on many material properties, structural polymers continued to be used in tritium systems. Improved understanding of the tritium effects will allow more resistant materials to be selected. Currently polymers find use mainly in tritium gas sealing applications (eg. valve stem tips, O-rings). Future uses being evaluated including polymeric based cracking of tritiated water, and polymer-based sensors of tritium.

  15. Population Differences in Postural Response Strategy Associated with Exposure to a Novel Continuous Perturbation Stimuli: Would Dancers Have Better Balance on a Boat?

    PubMed Central

    Ingram, Tony G. J.; Mansfield, Avril; Byrne, Jeannette M.

    2016-01-01

    Central or postural set theory suggests that the central nervous system uses short term, trial to trial adaptation associated with repeated exposure to a perturbation in order to improve postural responses and stability. It is not known if longer-term prior experiences requiring challenging balance control carryover as long-term adaptations that influence ability to react in response to novel stimuli. The purpose of this study was to determine if individuals who had long-term exposure to balance instability, such as those who train on specific skills that demand balance control, will have improved ability to adapt to complex continuous multidirectional perturbations. Healthy adults from three groups: 1) experienced maritime workers (n = 14), 2) novice individuals with no experience working in maritime environments (n = 12) and 3) individuals with training in dance (n = 13) participated in the study. All participants performed a stationary standing task while being exposed to five 6 degree of freedom motions designed to mimic the motions of a ship at sea. The balance reactions (change-in-support (CS) event occurrences and characteristics) were compared between groups. Results indicate dancers demonstrated significantly fewer CS events than novices during the first trial, but did not perform as well as those with offshore experience. Linear trend analyses revealed that short-term adaptation across all five trials was dependent on the nature of participant experience, with dancers achieving postural stability earlier than novices, but later than those with offshore experience. These results suggest that long term previous experiences also have a significant influence on the neural control of posture and balance in the development of compensatory responses. PMID:27806129

  16. COMPARISON OF METAL-INDUCED ALVEOLAR EPITHELIAL INJURY AND CHEMOKINE PRODUCTION DURING PRE,-SIMULTANEOUS, OR CONTINUED EXPOSURE TO TNFA, IL-1B, AND IFNY

    EPA Science Inventory


    Epidemiological studies have linked air pollution exposure to adverse respiratory health effects, especially in individuals with inflammatory airways disease. Symptomatic asthmatics appear to be at greatest risk. We previously demonstrated that exposure of rats to particulate...

  17. DNA ARRAYS TO MONITOR GENE EXPRESSION IN RAT BLOOD AND UTERUS FOLLOWING 17-BETA-ESTRADIOL EXPOSURE: BIOMONITORING ENVIRONMENTAL EFFECTS USING SURROGATE TISSUES

    EPA Science Inventory

    DNA arrays to monitor gene expression in rat blood and uterus following 17-b-estradiol exposure - biomonitoring environmental effects using surrogate tissues
    John C. Rockett, Robert J. Kavlock, Christy R. Lambright, Louise G. Parks, Judith E. Schmid, Vickie S. Wilson, Carmen W...

  18. High temperature exposure of in-situ thermocouple fixed-point cells: stability with up to three months of continuous use

    NASA Astrophysics Data System (ADS)

    Elliott, C. J.; Greenen, A.; Lowe, D.; Pearce, J. V.; Machin, G.

    2015-04-01

    To categorise thermocouples in batches, manufacturers state an expected operating tolerance for when the thermocouples are as-new. In use, thermocouple behaviour can rapidly change and the tolerance becomes invalid, especially when used at high temperatures (i.e. above 1000 °C) as the processes leading to de-calibration, such as oxidation and contamination, can be very fast and lead to erroneous readings. In-situ thermocouple self-validation provides a method to track the drift and correct the thermocouple reading in real-time, but it must be shown to be reliable. Two miniature temperature fixed-point cells designed at NPL for in-situ thermocouple self-validation, the first containing a Pt-C eutectic alloy and the second containing a Ru-C eutectic alloy, have been exposed to temperatures close to their melting point for 2200 h and 1570 h, respectively, and continuously, for up to three months. Recalibration after this long-term high-temperature exposure, where a tantalum-sheathed thermocouple was always in place, is used to show that no significant change of the temperature reference point (the melting temperature) has occurred in either the Pt-C ingot or the Ru-C ingot, over timescales far longer than previously demonstrated and approaching that required by industry for practical use of the device.

  19. Boosted Beta Regression

    PubMed Central

    Schmid, Matthias; Wickler, Florian; Maloney, Kelly O.; Mitchell, Richard; Fenske, Nora; Mayr, Andreas

    2013-01-01

    Regression analysis with a bounded outcome is a common problem in applied statistics. Typical examples include regression models for percentage outcomes and the analysis of ratings that are measured on a bounded scale. In this paper, we consider beta regression, which is a generalization of logit models to situations where the response is continuous on the interval (0,1). Consequently, beta regression is a convenient tool for analyzing percentage responses. The classical approach to fit a beta regression model is to use maximum likelihood estimation with subsequent AIC-based variable selection. As an alternative to this established - yet unstable - approach, we propose a new estimation technique called boosted beta regression. With boosted beta regression estimation and variable selection can be carried out simultaneously in a highly efficient way. Additionally, both the mean and the variance of a percentage response can be modeled using flexible nonlinear covariate effects. As a consequence, the new method accounts for common problems such as overdispersion and non-binomial variance structures. PMID:23626706

  20. PHYSICAL FACTORS AND DOSIMETRY IN THE MARSHALL ISLAND RADIATION EXPOSURES

    DTIC Science & Technology

    FALLOUT, *RADIATION HAZARDS, *RADIOCHEMISTRY, DOSE RATE, PERSONNEL, RADIATION, RADIATION MONITORS, DOSAGE , EXPOSURE (PHYSIOLOGY), EXPOSURE METERS, EXPERIMENTAL DATA, ENERGY, TIME, GAMMA RAY SPECTROSCOPY, BETA DECAY, PHOTONS.

  1. Beta measurement evaluation and upgrade

    SciTech Connect

    Murphy, D.W.; Faust, L.G.; Selby, J.M.; Essig, T.H.; Vallario, E.J.

    1983-01-01

    The Department of Energy (DOE), Office of Nuclear Safety, initiated a program to evaluate dosimeters and instruments used at DOE laboratories in the determination of personnel beta dose. The program focuses on significant problems which affect field measurements and is involved in the development and evaluation of new beta dosimetry systems (both dosimeters and instruments). Currently the program is reviewing systems and practices; developing calibration systems and procedures for the calibration of instruments and dosimeters; and developing new concepts which may improve beta dosimetry. The program has been designed to provide a continuing effort for resolution of problems of assessing personnel beta dose at DOE facilities. The current personnel beta dosimetry practices at DOE facilities are being surveyed.

  2. Measuring DNA Damage and Repair in Mouse Splenocytes After Chronic In Vivo Exposure to Very Low Doses of Beta- and Gamma-Radiation.

    PubMed

    Flegal, Matthew; Blimkie, Melinda S; Wyatt, Heather; Bugden, Michelle; Surette, Joel; Klokov, Dmitry

    2015-07-03

    Low dose radiation exposure may produce a variety of biological effects that are different in quantity and quality from the effects produced by high radiation doses. Addressing questions related to environmental, occupational and public health safety in a proper and scientifically justified manner heavily relies on the ability to accurately measure the biological effects of low dose pollutants, such as ionizing radiation and chemical substances. DNA damage and repair are the most important early indicators of health risks due to their potential long term consequences, such as cancer. Here we describe a protocol to study the effect of chronic in vivo exposure to low doses of γ- and β-radiation on DNA damage and repair in mouse spleen cells. Using a commonly accepted marker of DNA double-strand breaks, phosphorylated histone H2AX called γH2AX, we demonstrate how it can be used to evaluate not only the levels of DNA damage, but also changes in the DNA repair capacity potentially produced by low dose in vivo exposures. Flow cytometry allows fast, accurate and reliable measurement of immunofluorescently labeled γH2AX in a large number of samples. DNA double-strand break repair can be evaluated by exposing extracted splenocytes to a challenging dose of 2 Gy to produce a sufficient number of DNA breaks to trigger repair and by measuring the induced (1 hr post-irradiation) and residual DNA damage (24 hrs post-irradiation). Residual DNA damage would be indicative of incomplete repair and the risk of long-term genomic instability and cancer. Combined with other assays and end-points that can easily be measured in such in vivo studies (e.g., chromosomal aberrations, micronuclei frequencies in bone marrow reticulocytes, gene expression, etc.), this approach allows an accurate and contextual evaluation of the biological effects of low level stressors.

  3. Increased beta-amyloid levels in the choroid plexus following lead exposure and the involvement of low-density lipoprotein receptor protein-1.

    PubMed

    Behl, Mamta; Zhang, Yanshu; Monnot, Andrew D; Jiang, Wendy; Zheng, Wei

    2009-10-15

    The choroid plexus, a barrier between the blood and cerebrospinal fluid (CSF), is known to accumulate lead (Pb) and also possibly function to maintain brain's homeostasis of Abeta, an important peptide in the etiology of Alzheimer's disease. This study was designed to investigate if Pb exposure altered Abeta levels at the blood-CSF barrier in the choroid plexus. Rats received ip injection of 27 mg Pb/kg. Twenty-four hours later, a FAM-labeled Abeta (200 pmol) was infused into the lateral ventricle and the plexus tissues were removed to quantify Abeta accumulation. Results revealed a significant increase in intracellular Abeta accumulation in the Pb-exposed animals compared to controls (p<0.001). When choroidal epithelial Z310 cells were treated with 10 microM Pb for 24 h and 48 h, Abeta (2 microM in culture medium) accumulation was significantly increased by 1.5 fold (p<0.05) and 1.8 fold (p<0.05), respectively. To explore the mechanism, we examined the effect of Pb on low-density lipoprotein receptor protein-1 (LRP1), an intracellular Abeta transport protein. Following acute Pb exposure with the aforementioned dose regimen, levels of LRP1 mRNA and proteins in the choroid plexus were decreased by 35% (p<0.05) and 31.8% (p<0.05), respectively, in comparison to those of controls. In Z310 cells exposed to 10 microM Pb for 24 h and 48 h, a 33.1% and 33.4% decrease in the protein expression of LRP1 was observed (p<0.05), respectively. Knocking down LRP1 resulted in even more substantial increases of cellular accumulation of Abeta, from 31% in cells without knockdown to 72% in cells with LRP1 knockdown (p<0.05). Taken together, these results suggest that the acute exposure to Pb results in an increased accumulation of intracellular Abeta in the choroid plexus; the effect appears to be mediated, at least in part, via suppression of LRP1 production following Pb exposure.

  4. Toxic Shock Syndrome Toxin-1-Mediated Toxicity Inhibited by Neutralizing Antibodies Late in the Course of Continual in Vivo and in Vitro Exposure

    PubMed Central

    Stich, Norbert; Model, Nina; Samstag, Aysen; Gruener, Corina S.; Wolf, Hermann M.; Eibl, Martha M.

    2014-01-01

    Toxic shock syndrome (TSS) results from the host’s overwhelming inflammatory response and cytokine storm mainly due to superantigens (SAgs). There is no effective specific therapy. Application of immunoglobulins has been shown to improve the outcome of the disease and to neutralize SAgs both in vivo and in vitro. However, in most experiments that have been performed, antiserum was either pre-incubated with SAg, or both were applied simultaneously. To mirror more closely the clinical situation, we applied a multiple dose (over five days) lethal challenge in a rabbit model. Treatment with toxic shock syndrome toxin 1 (TSST-1) neutralizing antibody was fully protective, even when administered late in the course of the challenge. Kinetic studies on the effect of superantigen toxins are scarce. We performed in vitro kinetic studies by neutralizing the toxin with antibodies at well-defined time points. T-cell activation was determined by assessing T-cell proliferation (3H-thymidine incorporation), determination of IL-2 release in the cell supernatant (ELISA), and IL-2 gene activation (real-time PCR (RT-PCR)). Here we show that T-cell activation occurs continuously. The application of TSST-1 neutralizing antiserum reduced IL-2 and TNFα release into the cell supernatant, even if added at later time points. Interference with the prolonged stimulation of proinflammatory cytokines is likely to be in vivo relevant, as postexposure treatment protected rabbits against the multiple dose lethal SAg challenge. Our results shed new light on the treatment of TSS by specific antibodies even at late stages of exposure. PMID:24887085

  5. Toxic shock syndrome toxin-1-mediated toxicity inhibited by neutralizing antibodies late in the course of continual in vivo and in vitro exposure.

    PubMed

    Stich, Norbert; Model, Nina; Samstag, Aysen; Gruener, Corina S; Wolf, Hermann M; Eibl, Martha M

    2014-05-30

    Toxic shock syndrome (TSS) results from the host's overwhelming inflammatory response and cytokine storm mainly due to superantigens (SAgs). There is no effective specific therapy. Application of immunoglobulins has been shown to improve the outcome of the disease and to neutralize SAgs both in vivo and in vitro. However, in most experiments that have been performed, antiserum was either pre-incubated with SAg, or both were applied simultaneously. To mirror more closely the clinical situation, we applied a multiple dose (over five days) lethal challenge in a rabbit model. Treatment with toxic shock syndrome toxin 1 (TSST-1) neutralizing antibody was fully protective, even when administered late in the course of the challenge. Kinetic studies on the effect of superantigen toxins are scarce. We performed in vitro kinetic studies by neutralizing the toxin with antibodies at well-defined time points. T-cell activation was determined by assessing T-cell proliferation (3H-thymidine incorporation), determination of IL-2 release in the cell supernatant (ELISA), and IL-2 gene activation (real-time PCR (RT-PCR)). Here we show that T-cell activation occurs continuously. The application of TSST-1 neutralizing antiserum reduced IL-2 and TNFα release into the cell supernatant, even if added at later time points. Interference with the prolonged stimulation of proinflammatory cytokines is likely to be in vivo relevant, as postexposure treatment protected rabbits against the multiple dose lethal SAg challenge. Our results shed new light on the treatment of TSS by specific antibodies even at late stages of exposure.

  6. OZONE EXPOSURE INITIATES A SEQUENTIAL SIGNALING CASCADE IN AIRWAYS INVOLVING INTERLEUKIN-1BETA RELEASE, NERVE GROWTH FACTOR SECRETION, AND SUBSTANCE P UPREGULATION

    PubMed Central

    Barker, Joshua S.; Wu, Zhongxin; Hunter, Dawn D.; Dey, Richard D.

    2015-01-01

    Previous studies demonstrated that interleukin-1β (IL-1β) and nerve growth factor (NGF) increase synthesis of substance P (SP) in airway neurons both after ozone (O3) exposure and by direct application. It was postulated that NGF mediates O3-induced IL-1β effects on SP. The current study specifically focused on the influence of O3 on IL-1β, NGF, and SP levels in mice bronchoalveolar lavage fluid (BALF) and whether these mediators may be linked in an inflammatory-neuronal cascade in vivo. The findings showed that in vivo O3 exposure induced an increase of all three proteins in mouse BALF and that O3-induced elevations in both NGF and SP are mediated by the inflammatory cytokine IL-1β. Further, inhibition of NGF reduced O3 induced increases of SP in both the lung BALF and lung tissue, demonstrating NGF serves as a mediator of IL-1β effects on SP. These data indicate that IL-1β is an early mediator of O3-induced rise in NGF and subsequent SP release in mice in vivo. PMID:25734767

  7. Beta measurements at Department of Energy facilities

    SciTech Connect

    Rathbun, L.A.; Swinth, K.L.; Haggard, D.L.

    1987-08-01

    Pacific Northwest Laboratory performed a two-step process to characterize the current beta measurement practices at DOE facilities. PNL issued a survey questionnaire on beta measurement practices to DOE facilities and reported the results. PNL measured beta doses and spectra at seven selected DOE facilities and compared selected measurement techniques in the facility environment. This report documents the results of the radiation field measurements and the comparison of measurement techniques at the seven facilities. Data collected included beta dose and spectral measurements at seven DOE facilities that had high beta-to-gamma ratios (using a silicon surface barrier spectrometer, a plastic scintillator spectrometer, and a multielement beta dosimeter). Other dosimeters and survey meters representative of those used at DOE facilities or under development were also used for comparison. Field spectra were obtained under two distinct conditions. Silicon- and scintillation-based spectrometer systems were used under laboratory conditions where high beta-to-gamma dose ratios made the beta spectra easier to observe and analyze. In the second case, beta spectrometers were taken into actual production and maintenance areas of DOE facilities. Analyses of beta and gamma spectra showed that /sup 234/Th- /sup 234m/Pa, /sup 231/Th, /sup 137/Cs, and /sup 90/Sr//sup 90/Y were the major nuclides contributing to beta doses at the facilities visited. Beta doses from other fission products and /sup 60/Co were also measured, but the potential for exposure was less significant. 21 refs., 64 figs., 18 tabs.

  8. USE OF CONTINUOUS NEPHELOMETER TO MEASURE PERSONAL EXPOSURE TO PARTICULATE MATTER DURING THE 1998 U.S. EPA BALTIMORE PANEL STUDY

    EPA Science Inventory

    Personal exposures to particulate matter (PM) have typically been measured using filter samplers worn by the participants in exposure studies. Personal filter samplers, however, are limited to providing average mass concentrations integrated over a 12- to 24-hour period due to ...

  9. Investigation of Deuterium Loaded Materials Subject to X-Ray Exposure

    NASA Technical Reports Server (NTRS)

    Benyo, Theresa L.; Steinetz, Bruce M.; Hendricks, Robert C.; Martin, Richard E.; Forsley, Lawrence P.; Daniels, Christopher C.; Chait, Arnon; Pines, Vladimir; Pines, Marianna; Penney, Nicholas; Kamm, Tracy R.; Becks, Michael D.

    2017-01-01

    Results are presented from an exploratory study involving x-ray irradiation of select deuterated materials. Titanium deuteride plus deuterated polyethylene, deuterated polyethylene alone, and for control, hydrogen-based polyethylene samples and nondeuterated titanium samples were exposed to x-ray irradiation. These samples were exposed to various energy levels from 65 to 280 kV with prescribed electron flux from 500 to 9000 µA impinging on a tungsten braking target, with total exposure times ranging from 55 to 280 min. Gamma activity was measured using a high-purity germanium (HPGe) detector, and for all samples no gamma activity above background was detected. Alpha and beta activities were measured using a gas proportional counter, and for select samples beta activity was measured with a liquid scintillator spectrometer. The majority of the deuterated materials subjected to the microfocus x-ray irradiation exhibited postexposure beta activity above background and several showed short-lived alpha activity. The HPE and nondeuterated titanium control samples exposed to the x-ray irradiation showed no postexposure alpha or beta activities above background. Several of the samples (SL10A, SL16, SL17A) showed beta activity above background with a greater than 4s confidence level, months after exposure. Portions of SL10A, SL16, and SL17A samples were also scanned using a beta scintillator and found to have beta activity in the tritium energy band, continuing without noticeable decay for over 12 months. Beta scintillation investigation of as-received materials (before x-ray exposure) showed no beta activity in the tritium energy band, indicating the beta emitters were not in the starting materials.

  10. Beta measurements

    NASA Technical Reports Server (NTRS)

    Schotland, R. M.; Warren, A. J.; Funariu, O. M.

    1991-01-01

    The second year's results of the BETA project research are presented. The program is divided into two areas, aerosol modification and climatology in the trade wind region and the climatology of BETA (CO2) on remote mountain top locations. Limited data is available on the aerosol climatology of the marine free troposphere (MFT) in the trade wind region. In order to study the effects of cumulus convection on the MFT values of BETA, a cloud model was developed to simulate the evolution of a typical Pacific trade wind cumulus cloud. The stages involved in this development are outlined. The assembly of the major optical components of the lidar was made. Tests were run of the spectral bandwidth of the Synrad laser when a portion of the beam is mixed with a component which has traveled 450 meters corresponding to a delay of 1.5 microsecs. The bandwidth of the beat signal was measured to be 3 KHz. The data processing system based on a parallel processing filter bank analyzer using true time squaring detectors at each filter was completed.

  11. Trafficking of alpha4* nicotinic receptors revealed by superecliptic phluorin: effects of a beta4 amyotrophic lateral sclerosis-associated mutation and chronic exposure to nicotine.

    PubMed

    Richards, Christopher I; Srinivasan, Rahul; Xiao, Cheng; Mackey, Elisha D W; Miwa, Julie M; Lester, Henry A

    2011-09-09

    We employed a pH-sensitive GFP analog, superecliptic phluorin, to observe aspects of nicotinic acetylcholine receptor (nAChR) trafficking to the plasma membrane (PM) in cultured mouse cortical neurons. The experiments exploit differences in the pH among endoplasmic reticulum (ER), trafficking vesicles, and the extracellular solution. The data confirm that few α4β4 nAChRs, but many α4β2 nAChRs, remain in neutral intracellular compartments, mostly the ER. We observed fusion events between nAChR-containing vesicles and PM; these could be quantified in the dendritic processes. We also studied the β4R348C polymorphism, linked to amyotrophic lateral sclerosis (ALS). This mutation depressed fusion rates of α4β4 receptor-containing vesicles with the PM by ∼2-fold, with only a small decrease in the number of nAChRs per vesicle. The mutation also decreased the number of ER exit sites, showing that the reduced receptor insertion results from a change at an early stage in trafficking. We confirm the previous report that the mutation leads to reduced agonist-induced currents; in the cortical neurons studied, the reduction amounts to 2-3-fold. Therefore, the reduced agonist-induced currents are caused by the reduced number of α4β4-containing vesicles reaching the membrane. Chronic nicotine exposure (0.2 μM) did not alter the PM insertion frequency or trafficking behavior of α4β4-laden vesicles. In contrast, chronic nicotine substantially increased the number of α4β2-containing vesicle fusions at the PM; this stage in α4β2 nAChR up-regulation is presumably downstream from increased ER exit. Superecliptic phluorin provides a tool to monitor trafficking dynamics of nAChRs in disease and addiction.

  12. Assay of urinary alpha-fluoro-beta-alanine by gas chromatography-mass spectrometry for the biological monitoring of occupational exposure to 5-fluorouracil in oncology nurses and pharmacy technicians.

    PubMed

    Rubino, Federico Maria; Verduci, Cinzia; Buratti, Marina; Fustinoni, Silvia; Campo, Laura; Omodeo-Salè, Emanuela; Giglio, Margherita; Iavicoli, Sergio; Brambilla, Gabri; Colombi, Antonio

    2006-03-01

    The validation of an analytical method for the measurement of the unnatural amino acid alpha-fluoro-beta-alanine (AFBA), the main metabolite of the antineoplastic drug 5-fluorouracil (5FU), in urine for the biological monitoring of the exposure of hospital workers to the drug when preparing the therapeutical doses and administering to cancer patients is described. The method employed a two-step extractive derivatization of the analyte from urine to the N-trifluoroacety-n-butyl ester derivative and detection by selected-ion monitoring gas chromatography-mass spectrometry of structurally specific fragments. The limit of detection was 20 ng/mL with quantification accuracy better than +/-20% and precision (CV%) better than +/-20% in the range 0.020-10 microg/mL. Norleucine was used as the internal standard and the sample-to-sample analysis time was less than 15 min. The validated method has been applied to the biological monitoring of some hospital workers potentially exposed to 5FU and to matched control subjects. On a total number of 65 analyzed urine samples from control and exposed subjects, only three, obtained from exposed subjects, were found to be positive, with values of 20, 30 and 1150 ng/mL, respectively.

  13. Heterogeneity in chemical mutagen-induced chromosome damage after G2 phase exposure to bleomycin, ara-C and gentian violet in cultured lymphocytes of beta-thalassaemia traits.

    PubMed

    Krishnaja, A P; Sharma, N K

    1995-09-01

    Chemical mutagen-induced chromosome damage was analysed in cultured peripheral blood lymphocytes from beta-thalassaemia traits and healthy individuals. This was promoted by the fact that beta-thalassaemia trait is present in 1-17% of different population groups in India. To study mutagen-induced chromosome instability, G2 lymphocytes were exposed to bleomycin, ara-C or gentian violet in 48-h cultures. Spontaneous chromosome aberration frequencies in lymphocytes from beta-thalassaemia traits were found to be in the normal range. In all three clastogen-treated lymphocytes from beta-thalassaemia traits, there is a degree of hypersensitivity, when the results are averaged over a number of individuals, but some individuals overlap within the normal range. The heterogeneity in chemical mutagen sensitivity observed in beta-thalassaemia traits is discussed in terms of the oxidative damage consequent on the genetic and biochemical features peculiar to the beta-thalassaemia trait cell.

  14. Beta-agonists and animal welfare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of beta-agonists in animal feed is a high profile topic within the U.S. as consumers and activist groups continue to question its safety. The only beta-agonist currently available for use in swine is ractopamine hydrochloride (RAC). This is available as Paylean™ (Elanco Animal Health – FDA a...

  15. 21 CFR 886.5100 - Ophthalmic beta radiation source.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ophthalmic beta radiation source. 886.5100 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5100 Ophthalmic beta radiation source. (a) Identification. An ophthalmic beta radiation source is a device intended to apply...

  16. 21 CFR 886.5100 - Ophthalmic beta radiation source.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ophthalmic beta radiation source. 886.5100 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5100 Ophthalmic beta radiation source. (a) Identification. An ophthalmic beta radiation source is a device intended to apply...

  17. 21 CFR 886.5100 - Ophthalmic beta radiation source.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic beta radiation source. 886.5100 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5100 Ophthalmic beta radiation source. (a) Identification. An ophthalmic beta radiation source is a device intended to apply...

  18. 21 CFR 886.5100 - Ophthalmic beta radiation source.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ophthalmic beta radiation source. 886.5100 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5100 Ophthalmic beta radiation source. (a) Identification. An ophthalmic beta radiation source is a device intended to apply...

  19. 21 CFR 886.5100 - Ophthalmic beta radiation source.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ophthalmic beta radiation source. 886.5100 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5100 Ophthalmic beta radiation source. (a) Identification. An ophthalmic beta radiation source is a device intended to apply...

  20. Process for reducing beta activity in uranium

    DOEpatents

    Briggs, Gifford G.; Kato, Takeo R.; Schonegg, Edward

    1986-10-07

    This invention is a method for lowering the beta radiation hazards associated with the casting of uranium. The method reduces the beta radiation emitted from the as-cast surfaces of uranium ingots. The method also reduces the amount of beta radiation emitters retained on the interiors of the crucibles that have been used to melt the uranium charges and which have undergone cleaning in a remote handling facility. The lowering of the radioactivity is done by scavenging the beta emitters from the molten uranium with a molten mixture containing the fluorides of magnesium and calcium. The method provides a means of collection and disposal of the beta emitters in a manner that reduces radiation exposure to operating personnel in the work area where the ingots are cast and processed.

  1. Process for reducing beta activity in uranium

    DOEpatents

    Briggs, Gifford G.; Kato, Takeo R.; Schonegg, Edward

    1986-01-01

    This invention is a method for lowering the beta radiation hazards associated with the casting of uranium. The method reduces the beta radiation emitted from the as-cast surfaces of uranium ingots. The method also reduces the amount of beta radiation emitters retained on the interiors of the crucibles that have been used to melt the uranium charges and which have undergone cleaning in a remote handling facility. The lowering of the radioactivity is done by scavenging the beta emitters from the molten uranium with a molten mixture containing the fluorides of magnesium and calcium. The method provides a means of collection and disposal of the beta emitters in a manner that reduces radiation exposure to operating personnel in the work area where the ingots are cast and processed.

  2. Process for reducing beta activity in uranium

    DOEpatents

    Briggs, G.G.; Kato, T.R.; Schonegg, E.

    1985-04-11

    This invention is a method for lowering the beta radiation hazards associated with the casting of uranium. The method reduces the beta radiation emitted from the as-cast surfaces of uranium ingots. The method also reduces the amount of beta radiation emitters retained on the interiors of the crucibles that have been used to melt the uranium charges and which undergone cleaning in a remote handling facility. The lowering of the radioactivity is done by scavenging the beta emitters from the molten uranium with a molten mixture containing the fluorides of magnesium and calcium. The method provides a means of collection and disposal of the beta emitters in a manner that reduces radiation exposure to operating personnel in the work area where the ingots are cast and processed. 5 tabs.

  3. beta1-integrin cytoplasmic subdomains involved in dominant negative function.

    PubMed

    Retta, S F; Balzac, F; Ferraris, P; Belkin, A M; Fässler, R; Humphries, M J; De Leo, G; Silengo, L; Tarone, G

    1998-04-01

    The beta1-integrin cytoplasmic domain consists of a membrane proximal subdomain common to the four known isoforms ("common" region) and a distal subdomain specific for each isoform ("variable" region). To investigate in detail the role of these subdomains in integrin-dependent cellular functions, we used beta1A and beta1B isoforms as well as four mutants lacking the entire cytoplasmic domain (beta1TR), the variable region (beta1COM), or the common region (beta1 deltaCOM-B and beta1 deltaCOM-A). By expressing these constructs in Chinese hamster ovary and beta1 integrin-deficient GD25 cells (Wennerberg et al., J Cell Biol 132, 227-238, 1996), we show that beta1B, beta1COM, beta1 deltaCOM-B, and beta1 deltaCOM-A molecules are unable to support efficient cell adhesion to matrix proteins. On exposure to Mn++ ions, however, beta1B, but none of the mutants, can mediate cell adhesion, indicating specific functional properties of this isoform. Analysis of adhesive functions of transfected cells shows that beta1B interferes in a dominant negative manner with beta1A and beta3/beta5 integrins in cell spreading, focal adhesion formation, focal adhesion kinase tyrosine phosphorylation, and fibronectin matrix assembly. None of the beta1 mutants tested shows this property, indicating that the dominant negative effect depends on the specific combination of common and B subdomains, rather than from the absence of the A subdomain in the beta1B isoform.

  4. Effect of chloroquine and leupeptin on intracellular accumulation of amyloid-beta (A beta) 1-42 peptide in a murine N9 microglial cell line.

    PubMed

    Chu, T; Tran, T; Yang, F; Beech, W; Cole, G M; Frautschy, S A

    1998-10-09

    Murine N9 microglia accumulated A beta from media containing 0.67 microM A beta within 6 h. In N9 and in primary rat microglia, chloroquine, which disrupts lysosomal pH, increased A beta-induced accumulation of A beta, particularly A beta1-42. Leupeptin similarly enhanced A beta accumulation. The scavenger receptor antagonist fucoidan did not affect acute chloroquine-dependent A beta1-42 accumulation, demonstrating uptake of non-aggregated A beta. After prolonged incubations, chloroquine enhanced A beta multimer (8-12 kDa) accumulation, an effect inhibited by fucoidan. Disruptions of the lysosomal system enhance A beta and its multimer formation. Despite negligible effects of fucoidan on initial A beta uptake, chronic exposure inhibits multimer accumulation, demonstrating a role for scavenger receptor in multimer accumulation.

  5. Early continuous white noise exposure alters auditory spatial sensitivity and expression of GAD65 and GABAA receptor subunits in rat auditory cortex.

    PubMed

    Xu, Jinghong; Yu, Liping; Cai, Rui; Zhang, Jiping; Sun, Xinde

    2010-04-01

    Sensory experiences have important roles in the functional development of the mammalian auditory cortex. Here, we show how early continuous noise rearing influences spatial sensitivity in the rat primary auditory cortex (A1) and its underlying mechanisms. By rearing infant rat pups under conditions of continuous, moderate level white noise, we found that noise rearing markedly attenuated the spatial sensitivity of A1 neurons. Compared with rats reared under normal conditions, spike counts of A1 neurons were more poorly modulated by changes in stimulus location, and their preferred locations were distributed over a larger area. We further show that early continuous noise rearing induced significant decreases in glutamic acid decarboxylase 65 and gamma-aminobutyric acid (GABA)(A) receptor alpha1 subunit expression, and an increase in GABA(A) receptor alpha3 expression, which indicates a returned to the juvenile form of GABA(A) receptor, with no effect on the expression of N-methyl-D-aspartate receptors. These observations indicate that noise rearing has powerful adverse effects on the maturation of cortical GABAergic inhibition, which might be responsible for the reduced spatial sensitivity.

  6. Assessment of 17{alpha}-ethinylestradiol effects and underlying mechanisms in a continuous, multigeneration exposure of the Chinese rare minnow (Gobiocypris rarus)

    SciTech Connect

    Zha Jinmiao; Sun Liwei; Zhou Yiqi; Spear, Philip A.; Ma, Mei; Wang Zijian

    2008-02-01

    17{alpha}-Ethinylestradiol (EE{sub 2}) is a synthetic estrogen used primarily in birth control pills and in hormone replacement therapy. Owing to its occurrence in surface waters at concentrations frequently greater than 1 ng/l and its projected future use, EE{sub 2} is expected to pose a significant risk to aquatic organisms. This study was conducted to obtain long-term exposure data necessary for the establishment of water quality criteria and to investigate mechanisms associated with toxic effects. In a multigeneration experiment, Chinese rare minnows (Gobiocypris rarus) were constantly exposed to environmentally relevant concentrations of the synthetic estrogen EE{sub 2}. Mortality, deformities, reproductive parameters, plasma vitellogenin and histopathology were assessed. The results showed that, in the F{sub 0} generation, all endpoints were significantly affected at concentrations higher than 0.2 ng/l EE{sub 2}. No F{sub 1} phenotypic males developed to maturity at 0.2 ng/l and, when adult females of this exposure group were crossed with unexposed males, no F{sub 2} fertile eggs were produced. Kidney histopathology and ultrastructure suggest anomalies possibly associated with increased vitellogenin accumulation. We concluded that the reproduction of the F{sub 1} minnows was completely inhibited at the lowest concentration tested, 0.2 ng/l EE{sub 2}, a concentration frequently detected in surface waters. Growth effects may be related to increased energy requirements including the energy used in VTG synthesis. Reproductive effects are presumably associated with male feminization and the occurrence of testis-ova in males; however, ovarian degeneration observed in females may also have contributed to reproductive failure.

  7. Cereal beta-glucans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cereal beta-glucans occur predominantly in oats and barley, but can be found in other cereals. Beta-glucan structure is a mixture of single beta-1,3-linkages and consecutive beta-1,4-linkages, and cellotriosyl and cellotetraosyl units typically make up 90-95% of entire molecule. Lichenase can hydr...

  8. Continuous exposure to low amplitude extremely low frequency electrical fields characterizing the vascular streaming potential alters elastin accumulation in vascular smooth muscle cells.

    PubMed

    Bergethon, Peter R; Kindler, Dean D; Hallock, Kevin; Blease, Susan; Toselli, Paul

    2013-07-01

    In normal development and pathology, the vascular system depends on complex interactions between cellular elements, biochemical molecules, and physical forces. The electrokinetic vascular streaming potential (EVSP) is an endogenous extremely low frequency (ELF) electrical field resulting from blood flowing past the vessel wall. While generally unrecognized, it is a ubiquitous electrical biophysical force to which the vascular tree is exposed. Extracellular matrix elastin plays a central role in normal blood vessel function and in the development of atherosclerosis. It was hypothesized that ELF fields of low amplitude would alter elastin accumulation, supporting a link between the EVSP and the biology of vascular smooth muscle cells. Neonatal rat aortic smooth muscle cell cultures were exposed chronically to electrical fields characteristic of the EVSP. Extracellular protein accumulation, DNA content, and electron microscopic (EM) evaluation were performed after 2 weeks of exposure. Stimulated cultures showed no significant change in cellular proliferation as measured by the DNA concentration. The per-DNA normalized protein in the extracellular matrix was unchanged while extracellular elastin accumulation decreased 38% on average. EM analysis showed that the stimulated cells had a 2.85-fold increase in mitochondrial number. These results support the formulation that ELF fields are a potential factor in both normal vessel biology and in the pathogenesis of atherosclerotic diseases including heart disease, stroke, and peripheral vascular disease.

  9. Adaption of the microbial community to continuous exposures of multiple residual antibiotics in sediments from a salt-water aquacultural farm.

    PubMed

    Xi, Xiuping; Wang, Min; Chen, Yongshan; Yu, Shen; Hong, Youwei; Ma, Jun; Wu, Qian; Lin, Qiaoyin; Xu, Xiangrong

    2015-06-15

    Residual antibiotics from aquacultural farming may alter microbial community structure in aquatic environments in ways that may adversely or positively impact microbially-mediated ecological functions. This study investigated 26 ponds (26 composited samples) used to produce fish, razor clam and shrimp (farming and drying) and 2 channels (10 samples) in a saltwater aquacultural farm in southern China to characterize microbial community structure (represented by phospholipid fatty acids) in surface sediments (0-10 cm) with long-term exposure to residual antibiotics. 11 out of 14 widely-used antibiotics were quantifiable at μg kg(-1) levels in sediments but their concentrations did not statistically differ among ponds and channels, except norfloxacin in drying shrimp ponds and thiamphenicol in razor clam ponds. Concentrations of protozoan PLFAs were significantly increased in sediments from razor clam ponds while other microbial groups were similar among ponds and channels. Both canonical-correlation and stepwise-multiple-regression analyses on microbial community and residual antibiotics suggested that roxithromycin residuals were significantly related to shifts in microbial community structure in sediments. This study provided field evidence that multiple residual antibiotics at low environmental levels from aquacultural farming do not produce fundamental shifts in microbial community structure.

  10. Morphological and antioxidant impairments in the spinal cord of male offspring rats following exposure to a continuous 900MHz electromagnetic field during early and mid-adolescence.

    PubMed

    İkinci, Ayşe; Mercantepe, Tolga; Unal, Deniz; Erol, Hüseyin Serkan; Şahin, Arzu; Aslan, Ali; Baş, Orhan; Erdem, Havva; Sönmez, Osman Fikret; Kaya, Haydar; Odacı, Ersan

    2016-09-01

    The effects of devices emitting electromagnetic field (EMF) on human health have become the subject of intense research among scientists due to the rapid increase in their use. Children and adolescents are particularly attracted to the use of devices emitting EMF, such as mobile phones. The aim of this study was therefore to investigate changes in the spinal cords of male rat pups exposed to the effect of 900MHz EMF. The study began with 24 Sprague-Dawley male rats aged 3 weeks. Three groups containing equal numbers of rats were established-control group (CG), sham group (SG) and EMF group (EMFG). EMFG rats were placed inside an EMF cage every day between postnatal days (PD) 21 and 46 and exposed to the effect of 900MHz EMF for 1h. SG rats were kept in the EMF cage for 1h without being exposed to the effect of EMF. At the end of the study, the spinal cords in the upper thoracic region of all rats were removed. Tissues were collected for biochemistry, light microscopy (LM) and transmission electron microscopic (TEM) examination. Biochemistry results revealed significantly increased malondialdehyde and glutathione levels in EMFG compared to CG and SG, while SG and EMFG catalase and superoxide dismutase levels were significantly higher than those in CG. In EMFG, LM revealed atrophy in the spinal cord, vacuolization, myelin thickening and irregularities in the perikarya. TEM revealed marked loss of myelin sheath integrity and invagination into the axon and broad vacuoles in axoplasm. The study results show that biochemical alterations and pathological changes may occur in the spinal cords of male rats following exposure to 900MHz EMF for 1h a day on PD 21-46.

  11. An innovative in vitro device providing continuous low doses of gamma-rays and altered gravity mimicking spatial exposure: dosimetry study

    NASA Astrophysics Data System (ADS)

    Collin, Laetitia; Courtade-Saidi, Monique; Pereda Loth, Veronica; Franceries, Xavier; Afonso, Anne Sophie; Ayala, Alicia; Bardies, Manuel

    Astronauts are exposed to microgravity and chronic irradiation. Experimental conditions combining these two factors are difficult to reproduce on earth. The aim of our study was to create an experimental device able to combine chronic irradiation and altered gravity that may be used for cell cultures or plant models. Irradiation was provided with Thorium nitrate powder, conditioned in several bags in order to obtain a sealed source. This source was placed in an incubator. Lead leafs covered the internal walls of the incubator in order to protect people outside from radiations. Cell plates or plants seeds could be placed on direct contact with the source or at different distances above the source. Moreover, a random positioning machine (RPM) was placed inside the incubator and positioned on the source. The dosimetry was performed for different experimental conditions. The activity of the source was established considering all the decay chain of thorium. The spectrum of the source calculated according to the natural decrease of radioactivity was compared with gamma spectrometry (InterceptorTM) and showed a very good adequacy. The fluence evaluated with a gamma detector was closed to the theoretical fluence evaluated with our model, attesting that the source was uniformly distributed. Dosimetry was performed with radiophotoluminescent dosimeters (RPL) placed for one month exposition in different locations (x and y axis) inside cell culture dishes. When the dishes were placed directly on the source, we obtained a dose rate from 660 to 983 mSv/year, while it was between 80 to 127 mSv/year at a distance of 14.5 cm above the source. Using the RPM placed on the source we reached median dose rate levels of 140 mSv/year. In conclusion, we have elaborated a new device allowing the combination of chronic radiation exposure and altered gravity. This device can be used by researchers interested in the field of space biology.

  12. Transforming growth factor-beta 1 modulates beta 1 and beta 5 integrin receptors and induces the de novo expression of the alpha v beta 6 heterodimer in normal human keratinocytes: implications for wound healing

    PubMed Central

    1995-01-01

    The molecular mechanism underlying the promotion of wound healing by TGF-beta 1 is incompletely understood. We report that TGF-beta 1 regulates the regenerative/migratory phenotype of normal human keratinocytes by modulating their integrin receptor repertoire. In growing keratinocyte colonies but not in fully stratified cultured epidermis, TGF-beta 1: (a) strongly upregulates the expression of the fibronectin receptor alpha 5 beta 1, the vitronectin receptor alpha v beta 5, and the collagen receptor alpha 2 beta 1 by differentially modulating the synthesis of their alpha and beta subunits; (b) downregulates the multifunctional alpha 3 beta 1 heterodimer; (c) induces the de novo expression and surface exposure of the alpha v beta 6 fibronectin receptor; (d) stimulates keratinocyte migration toward fibronectin and vitronectin; (e) induces a marked perturbation of the general mechanism of polarized domain sorting of both beta 1 and beta 4 dimers; and (f) causes a pericellular redistribution of alpha v beta 5. These data suggest that alpha 5 beta 1, alpha v beta 6, and alpha v beta 5, not routinely used by keratinocytes resting on an intact basement membrane, act as "emergency" receptors, and uncover at least one of the molecular mechanisms responsible for the peculiar integrin expression in healing human wounds. Indeed, TGF-beta 1 reproduces the integrin expression pattern of keratinocytes located at the injury site, particularly of cells in the migrating epithelial tongue at the leading edge of the wound. Since these keratinocytes are inhibited in their proliferative capacity, these data might account for the apparent paradox of a TGF-beta 1-dependent stimulation of epidermal wound healing associated with a growth inhibitory effect on epithelial cells. PMID:7537276

  13. beta-Hexachlorocyclohexane (beta-HCH)

    Integrated Risk Information System (IRIS)

    beta - Hexachlorocyclohexane ( beta - HCH ) ; CASRN 319 - 85 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Asses

  14. Serum beta2-microglobulin in cadmium exposed workers.

    PubMed

    Piscator, M

    1978-09-01

    In cadmium exposed workers with renal tubular dysfunction the determination of beta2m in urine is an important diagnostic test. Cadmium exposure's influence on serum beta2m levels and its relationship to urinary excretion of beta2m were studied in 24 cadmium exposed workers with normal serum creatinine levels (less than 10 mg/l)) and no obvious tubular dysfunction. With increasing blood levels of cadmium beta2m was found to increase in serum. There was no concomitant increase in the urinary excretion of beta2m. Serum beta2m was not dependent on serum creatinine within the range studied. The results suggest that for evaluating renal glomerular function in cadmium exposed workers, it might be better to use the serum creatinine level, creatinine clearance or inulin clearance since beta2m might give some false positive results.

  15. Exposure to and fear of terror as predictors of self-rated health among apparently healthy employees.

    PubMed

    Shirom, Arie; Toker, Sharon; Shapira, Itzhak; Berliner, Shlomo; Melamed, Samuel

    2008-05-01

    The effects of exposure to terror on physical health were investigated by relating objective exposure to terror and fear of terror to self-rated health (SRH), a proxy measure of health status. Our respondents were apparently healthy (N=4,877, 38% women) adults who completed self-report questionnaires. Objective exposure was assessed by the number of terrorist attacks and their casualties in a respondent's urban area prior to her/his completion of the questionnaire. Using several alternative assessments, objective exposure to terror did not predict SRH for both the genders. As hypothesized, fear of terror negatively predicted SRH for both females and males (beta=-0.04, -0.05, respectively). The effects of subjective and objective exposure were not found to be more pronounced among women relative to men, thus disconfirming our hypotheses in this regard. Our findings suggest that living under continuous fear of terror may adversely influence physical health irrespective of objective exposure.

  16. Beta 2-microglobulin levels in serum and urine of cadmium exposed rabbits.

    PubMed

    Piscator, M; Björck, L; Nordberg, M

    1981-07-01

    Male rabbits were exposed to cadmium during 16 weeks by subcutaneous injections of either 0.25 mg or 0.5 md Cd as cadmium chloride per kg body weight 3 times per week. beta 2-microglobulin (beta 2-m) and creatinine in serum, cadmium in blood, as well as total protein, creatinine, beta 2-m and cadmium in urine were determined before exposure and after 3 and 7 weeks of exposure. Measurements were also made at 19 weeks, 3 weeks after the last exposure. During exposure, there was a slight increase in the serum beta 2-m/creatinine ratio among rabbits with the highest exposure, while no effect of the cadmium burden could be observed once exposure had ceased. Urinary excretion of beta 2-m was related to urinary pH, which appeared to be the case also for excretion of total protein. In the high exposure group, a significant increase in urinary beta 2-m excretion, indicative of renal tubular dysfunction was seen after 7 weeks of exposure. This was, however, not related to serum beta 2-m levels. It was concluded that before renal damage has occurred even heavy cadmium exposure has very little influence on serum beta 2-m levels.

  17. Beta-Blockers: Current State of Knowledge and Perspectives.

    PubMed

    Ogrodowczyk, Magdalena; Dettlaff, Katarzyna; Jelinska, Anna

    2016-01-01

    It has been over half a century since propranolol, the first beta-blocker, was developed for medical treatment. Since that time a large number of compounds from this group have been synthesised and many are now in clinical use. The structure, function, pharmacokinetics, and mechanism of beta-blockers have been established. The possibilities for their use in treating different conditions continue to evolve. Since the discovery of later generation beta-blockers, such as carvedilol and nebivolol, the search for new compounds continues, and may include known substances with beta-blocking properties which could extend their therapeutic potential.

  18. TGF-.beta. antagonists as mitigators of radiation-induced tissue damage

    DOEpatents

    Barcellos-Hoff, Mary H.

    1997-01-01

    A method for treating tissue damage caused by radiation is described by use of a TGF-.beta. antagonist, such as an anti-TGF-.beta. antibody or a TGF-.beta. latency associated protein. It is administered not more than a week after exposure, and is particularly useful in mitigating the side effects of breast cancer therapy.

  19. TGF-{beta} antagonists as mitigators of radiation-induced tissue damage

    DOEpatents

    Barcellos-Hoff, M.H.

    1997-04-01

    A method for treating tissue damage caused by radiation is described by use of a TGF-{beta} antagonist, such as an anti-TGF-{beta} antibody or a TGF-{beta} latency associated protein. It is administered not more than a week after exposure, and is particularly useful in mitigating the side effects of breast cancer therapy.

  20. Beta fields and measurement practices at DOE facilities

    NASA Astrophysics Data System (ADS)

    Swinth, K. L.; Rathbun, L. A.; Brackenbush, L. W.

    1985-09-01

    As part of a larger program, the beta measurement problem at DOE facilities was assessed through the use of a questionnaire and field visits to selected facilities. At 35% the facilities beta-emitting radionuclides can contribute enough to the radiation exposures that they must be considered in establishing protection requirements. Measurements were made in several facilities using scintillators, a surface barrier detector plus various dosimeters and survey instruments. Beta dose rates of several hundred mrad/hr were not unusual and beta:gamma ratios of greater than 30:1 were frequently observed. The agreement between the various measurement techniques was frequently unacceptable.

  1. THE CONTINUING CHALLENGE OF ESBLS

    PubMed Central

    Perez, Federico; Endimiani, Andrea; Hujer, Kristine M.; Bonomo, Robert A.

    2007-01-01

    Summary of recent advances Since their first description more than twenty years ago, Escherichia coli and Klebsiella pneumoniae possessing extended-spectrum class A beta-lactamases (ESBLs) continue to thwart our best clinical efforts. In the “early years” the most common beta-lactamases were of the TEM and SHV varieties. Now, CTX-M enzymes are being discovered though out the world and are becoming the most prevalent beta-lactamases found in clinical isolates. The Klebsiella pneumoniae carbapenemases (KPC) (ESBL type enzymes that confer resistance to extended spectrum cephalosporins and carbapenems) present the most significant challenge to date. Structural studies of ESBLs indicate that active site expansion and remodeling are responsible for this extended hydrolytic activity. Continuing questions still exist regarding the optimal detection method for ESBLs. Most relevant are the increasing concerns regarding the status of carbapenems as “best therapy” for ESBL producing bacteria in light of the emergence of carbapenemases. PMID:17875405

  2. Criminal exposure.

    PubMed

    1999-09-03

    In August, an HIV-positive man plead guilty to sexually assaulting a 14-year-old boy. The sleeping boy awoke to find [name removed] sexually assaulting him, while watching a pornographic video. [Name removed] plead guilty to the assault with intent to rape a child. In addition, [name removed] received three counts of indecent assault and battery on a child, and exposure of pornographic material to a minor. [Name removed] will remain on probation for five years, although the prosecution had recommended sentencing [name removed] to four or five years in prison. The boy continues to be tested for HIV.

  3. Chronic exposure to free fatty acid reduces pancreatic beta cell insulin content by increasing basal insulin secretion that is not compensated for by a corresponding increase in proinsulin biosynthesis translation.

    PubMed Central

    Bollheimer, L C; Skelly, R H; Chester, M W; McGarry, J D; Rhodes, C J

    1998-01-01

    The pancreatic beta cell normally maintains a stable balance among insulin secretion, insulin production, and insulin degradation to keep optimal intracellular stores of the hormone. Elevated levels of FFA markedly enhance insulin secretion; however, the effects of FFA on insulin production and intracellular stores remain unclear. In this study, twofold elevation in total circulating FFA effected by infusion of lard oil and heparin into rats for 6 h under normoglycemic conditions resulted in a marked elevation of circulating insulin levels evident after 4 h, and a 30% decrease in pancreatic insulin content after a 6-h infusion in vivo. Adding 125 muM oleate to isolated rat pancreatic islets cultured with 5.6 mM glucose caused a 50% fall in their insulin content over 24 h, coupled with a marked enhancement of basal insulin secretion. Both effects of fatty acid were blocked by somatostatin. In contrast to the stimulatory effects of oleate on insulin secretion, glucose-induced proinsulin biosynthesis was inhibited by oleate up to 24 h, but was unaffected thereafter. This result was in spite of a two- to threefold oleate-induced increase in preproinsulin mRNA levels, underscoring the importance of translational regulation of proinsulin biosynthesis in maintaining beta cell insulin stores. Collectively, these results suggest that chronically elevated FFA contribute to beta cell dysfunction in the pathogenesis of NIDDM by significantly increasing the basal rate of insulin secretion. This increase in turn results in a decrease in the beta cell's intracellular stores that cannot be offset by commensurate FFA induction of proinsulin biosynthesis. PMID:9486980

  4. Alterations in serum levels of inflammatory cytokines (TNF, IL-1alpha, IL-1beta and IL-1Ra) 20 years after sulfur mustard exposure: Sardasht-Iran cohort study.

    PubMed

    Yaraee, Roya; Ghazanfari, Tooba; Ebtekar, Massoumeh; Ardestani, Sussan K; Rezaei, Abbas; Kariminia, Amina; Faghihzadeh, Soghrat; Mostafaie, Ali; Vaez-Mahdavi, Mohammad R; Mahmoudi, Mahmoud; Naghizadeh, Mohammad M; Soroush, Mohammad R; Hassan, Zuhair M

    2009-12-01

    Mustard gas, even in low doses, has the ability to inflict damage in multiple organs especially the skin, eyes, as well as the respiratory tract. This damage may cause many complications which persist during the lifespan of exposed subjects. Pro-inflammatory cytokines including TNF, IL-1alpha, IL-1beta and IL-1Ra cause systemic inflammatory reactions and numerous changes including altered cell signaling and migration, changes in cytokine production and fever. The aim of this study was to determine the serum levels of these cytokines in subjects who were exposed to mustard gas 20 years ago in comparison with an unexposed control group. In this historical cohort study 368 sulfur mustard (SM) exposed participants from Sardasht and 126 age-matched unexposed volunteers from Rabat (a nearby town) as controls were chosen by a random systematic sampling. The serum concentrations of IL-1alpha, IL-1beta, IL-1Ra and TNF were measured by a sandwich ELISA technique. Median of the serum levels of cytokines TNF, IL-1alpha, IL-1beta and IL-1Ra in the control group was 23.79, 1.89, 1.91 and 32.9 pg/ml respectively, while in the SM-exposed participants these values were 11.11, 0.81, 1.73 and 26.7 pg/ml respectively. The serum pro-inflammatory cytokine levels were significantly lower in the exposed group than in controls (p<0.01). There was also significant positive correlation between concentration of all of mentioned cytokines, the strongest being between IL-1beta and TNF (r=0.809 in the control group). The observed down-regulation of pro-inflammatory cytokines should be considered in interpretation of diagnosis and therapeutic measures taken to improve clinical complications.

  5. Continuous Problem of Function Continuity

    ERIC Educational Resources Information Center

    Jayakody, Gaya; Zazkis, Rina

    2015-01-01

    We examine different definitions presented in textbooks and other mathematical sources for "continuity of a function at a point" and "continuous function" in the context of introductory level Calculus. We then identify problematic issues related to definitions of continuity and discontinuity: inconsistency and absence of…

  6. The selectivity of beta-adrenoceptor antagonists at the human beta1, beta2 and beta3 adrenoceptors.

    PubMed

    Baker, Jillian G

    2005-02-01

    Beta-adrenoceptor antagonists ("beta-blockers") are one of the most widely used classes of drugs in cardiovascular medicine (hypertension, ischaemic heart disease and increasingly in heart failure) as well as in the management of anxiety, migraine and glaucoma. Where known, the mode of action in cardiovascular disease is from antagonism of endogenous catecholamine responses in the heart (mainly at beta1-adrenoceptors), while the worrisome side effects of bronchospasm result from airway beta2-adrenoceptor blockade. The aim of this study was to determine the selectivity of beta-antagonists for the human beta-adrenoceptor subtypes. (3)H-CGP 12177 whole cell-binding studies were undertaken in CHO cell lines stably expressing either the human beta1-, beta2- or the beta3-adrenoceptor in order to determine the affinity of ligands for each receptor subtype in the same cell background. In this study, the selectivity of well-known subtype-selective ligands was clearly demonstrated: thus, the selective beta1 antagonist CGP 20712A was 501-fold selective over beta2 and 4169-fold selective over beta3; the beta2-selective antagonist ICI 118551 was 550- and 661-fold selective over beta1 and beta3, respectively, and the selective beta3 compound CL 316243 was 10-fold selective over beta2 and more than 129-fold selective over beta1. Those beta2-adrenoceptor agonists used clinically for the treatment of asthma and COPD were beta2 selective: 29-, 61- and 2818-fold for salbutamol, terbutaline and salmeterol over beta1, respectively. There was little difference in the affinity of these ligands between beta1 and beta3 adrenoceptors. The clinically used beta-antagonists studied ranged from bisoprolol (14-fold beta1-selective) to timolol (26-fold beta2-selective). However, the majority showed little selectivity for the beta1- over the beta2-adrenoceptor, with many actually being more beta2-selective. This study shows that the beta1/beta2 selectivity of most clinically used beta-blockers is

  7. Library Book Circulation and the Beta-Binomial Distribution.

    ERIC Educational Resources Information Center

    Gelman, E.; Sichel, H. S.

    1987-01-01

    Argues that library book circulation is a binomial rather than a Poisson process, and that individual book popularities are continuous beta distributions. Three examples demonstrate the superiority of beta over negative binomial distribution, and it is suggested that a bivariate-binomial process would be helpful in predicting future book…

  8. Detection of glycemic abnormalities in adolescents with beta thalassemia using continuous glucose monitoring and oral glucose tolerance in adolescents and young adults with β-thalassemia major: Pilot study

    PubMed Central

    Soliman, Ashraf T.; Yasin, Mohamed; El-Awwa, Ahmed; De Sanctis, Vincenzo

    2013-01-01

    Background: Both insulin deficiency and resistance are reported in patients with β-thalassemia major (BTM). The use of continuous blood glucose monitoring (CGM), among the different methods for early detection of glycemic abnormalities, has not been studied thoroughly in these adolescents. Materials and Methods: To assess the oralglucose tolerance (OGT) and 72-h continuous glucose concentration by the continuous glucose monitoring system (CGMS) and calculate homeostatic model assessment (HOMA), and the quantitative insulin sensitivity check index (QUICKI) was conducted in 16 adolescents with BTM who were receiving regular blood transfusions every 2-4 weeks and iron-chelation therapy since early childhood. Results: Sixteen adolescents with BTM (age: 19.75 ± 3 years) were investigated. Using OGTT, (25%) had impaired fasting blood (plasma) glucose concentration (BG) (>5.6 mmol/L). 2-h after the glucose load, one of them had BG = 16.2 mmol/L (diabetic) and two had impaired glucose tolerance (IGT) (BG > 7.8 and <11.1 mmol/L). Monitoring the maximum (postprandial) BG using CGMS,4 adolescents were diagnosed with diabetes (25%) (BG >11.1 mmol/L) and 9 with IGT (56%). HOMA and QUICKI revealed levels <2.6 (1.6 ± 0.8) and >0.33 (0.36 ± 0.03), respectively, ruling out significant insulin resistance in these adolescents. There was a significant negative correlation between the β-cell function (B%) on one hand and the fasting and the 2-h BG (r=−0.6, and − 0.48, P < 0.01, respectively) on the other hand. Neither fasting serum insulin nor c-peptide concentrations were correlated with fasting BG or ferritin levels. The average and maximum blood glucose levels during CGM were significantly correlated with the fasting BG (r = 0.68 and 0.39, respectively, with P < 0.01) and with the BG at 2-hour after oral glucose intake (r = 0.87 and 0.86 respectively, with P < 0.001). Ferritin concentrations were correlated with the fasting BG and the 2-h blood glucose levels in the OGTT (r

  9. A potential instrumental counterpart to Method 5 for the continuous measurement of particulate matter emissions from combustion and other sources using isokinetic sample extraction technology followed by beta ray attenuation mass measurements

    SciTech Connect

    Griguoli, F.T.

    1997-12-31

    For many years opacity and other values available from optical devices have been used in an attempt to assess and often quantify particulate matter emissions from stationary sources, particularly combustion sources using coal. These opacity values have also been used to obtain mass concentration data. Today`s reality is such that pollution abatement technologies have become better and better, dry or wet, and most processes are subject to a variety of conditions no longer suitable, in the author`s opinion, for the use of optical devices or derivatives of them. This paper describes a continuous extractive technique to measure particulate matter which has been used in Europe and around the word for more than 10 years. This technique works very well in changing particulate matter conditions, low particulate concentrations, small diameter stacks, and stacks/ducts with high water vapor content in the flue gas. 2 refs., 2 figs.

  10. MOON for neutrino-less {beta}{beta} decays and {beta}{beta} nuclear matrix elements

    SciTech Connect

    Ejiri, H.

    2009-11-09

    The MOON project aims at spectroscopic 0v{beta}{beta} studies with the v-mass sensitivity of 100-30 meV by measuring two beta rays from {sup 100}Mo and/or {sup 82}Se. The detector is a compact super-module of multi-layer PL scintillator plates. R and D works made by the pro to-type MOON-1 and the small PL plate show the possible energy resolution of around {sigma}{approx}2.2%, as required for the mass sensitivity. Nuclear matrix elements M{sup 2v} for 2v{beta}{beta} are shown to be given by the sum {sigma}{sub L}M{sub k} of the 2v{beta}{beta} matrix elements M{sub k} through intermediate quasi-particle states in the Fermi-surface, where Mi is obtained experimentally by using the GT(J{sup {pi}} = 1{sup +}) matrix elements of M{sub i}(k) and M{sub f}(k) for the successive single-{beta} transitions through the k-th intermediate state.

  11. Beta-Carotene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beta-carotene is a pigment that occurs naturally in many photosynthetic plants and organisms and one of the most abundant carotenoids found in human blood. The richest dietary sources of beta-carotene are yellow, orange, and leafy green fruits and vegetables, such as carrots, spinach, sweet potatoes...

  12. Beta blockers in hypertension.

    PubMed

    Thadani, U

    1983-11-10

    Beta-adrenoceptor antagonists are effective in the management of patients with mild-to-moderate hypertension. Noncardioselective agents, cardioselective agents and beta blockers with intrinsic sympathomimetic activity (ISA) are equally effective, provided they are used in equipotent doses. Beta blockers can be used as first-line therapy in the management of hypertension and can be safely combined with diuretics, vasodilators, or both, for a better control of blood pressure. The exact mechanism by which beta blockers decrease blood pressure remains speculative, but they all reduce cardiac output during long-term therapy; drugs with ISA lower cardiac output and heart rate less than do drugs without ISA. Pharmacokinetic properties of beta blockers differ widely; drugs metabolized by the liver have shorter plasma half-lives than drugs primarily excreted by the kidneys. Although many of the side effects of various beta blockers are similar, differences in water and lipid solubility account for a higher incidence of central nervous system side effects with lipid-soluble drugs (such as propranolol and metoprolol) than with hydrophilic drugs (such as atenolol and timolol). The incidence of cold extremities has been reported to be less with drugs with ISA, and the incidence of bronchospasm less with cardioselective drugs. In the management of uncomplicated mild-to-moderate hypertension, all beta blockers are equally effective and produce less troublesome side effects than alternative antihypertensive agents. For effective therapy beta blockers can be used in 2 divided daily doses or even once daily.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Continuation Education.

    ERIC Educational Resources Information Center

    Fremont Unified School District, CA.

    The Fremont, California Unified School District organized a continuing education program through a workshop held in the summer of 1968. This paper presents the results of that workshop. Following a statement of philosophy, an outline of the characteristics of the continuation student, and an outline of the functions of the program, an overview of…

  14. IN VITRO LUNG ALVEOLAR EPITHELIAL CELL INJURY AND INFLAMMATORY RESPONSE TO PARTICULATE MATTER-ASSOCIATED METALS - MODULATION BY EXPOSURE TO TNF-ALPHA, IL-BETA, OR IFN-GAMMA

    EPA Science Inventory

    IN VITRO LUNG ALVEOLAR EPITHELIAL CELL INJURY AND INFLAMMATORY RESPONSE TO PARTICULATE MATTER-ASSOCIATED METALS - MODULATION BY EXPOSURE TO TNF , IL-1 , OR IFN .

    JA Dye, KE Peoples*, CL Hayes?. US EPA, ORD, Pulmonary Toxicology Branch, RTP, NC, *HHMI-SRI, NCSU, Raleigh, NC...

  15. Rapid synthesis of beta zeolites

    DOEpatents

    Fan, Wei; Chang, Chun -Chih; Dornath, Paul; Wang, Zhuopeng

    2015-08-18

    The invention provides methods for rapidly synthesizing heteroatom containing zeolites including Sn-Beta, Si-Beta, Ti-Beta, Zr-Beta and Fe-Beta. The methods for synthesizing heteroatom zeolites include using well-crystalline zeolite crystals as seeds and using a fluoride-free, caustic medium in a seeded dry-gel conversion method. The Beta zeolite catalysts made by the methods of the invention catalyze both isomerization and dehydration reactions.

  16. Adverse effects in lumbar spinal cord morphology and tissue biochemistry in Sprague Dawley male rats following exposure to a continuous 1-h a day 900-MHz electromagnetic field throughout adolescence.

    PubMed

    Kerimoğlu, Gökçen; Aslan, Ali; Baş, Orhan; Çolakoğlu, Serdar; Odacı, Ersan

    2016-12-01

    Cell phones, an indispensable element of daily life, are today used at almost addictive levels by adolescents. Adolescents are therefore becoming increasingly exposed to the effect of the electromagnetic field (EMF) emitted by cell phones. The purpose of this study was to investigate the effect of exposure to a 900-MHz EMF throughout adolescence on the lumbar spinal cord using histopathological, immunohistochemical and biochemical techniques. Twenty-four Sprague Dawley (28.3-43.9g) aged 21days were included in the study. These were divided equally into three groups - control (CG), sham (SG) and electromagnetic (ELMAG). No procedure was performed on the CG rats until the end of the study. SG and ELMAG rats were kept inside an EMF cage (EMFC) for 1h a day every day at the same time between postnatal days 22 and 60. During this time, ELMAG rats were exposed to the effect of a 900-MHz EMF, while the SG rats were kept in the EMFC without being exposed to EMF. At the end of the study, the lumbar regions of the spinal cords of all rats in all groups were extracted. Half of each extracted tissue was stored at -80°C for biochemical analysis, while the other half was used for histopathological and immunohistochemical analyses. In terms of histopathology, a lumbar spinal cord with normal morphology was observed in the other groups, while morphological irregularity in gray matter, increased vacuolization and infiltration of white matter into gray matter were pronounced in the ELMAG rats. The cytoplasm of some neurons in the gray matter was shrunken and stained dark, and vacuoles were observed in the cytoplasms. The apoptotic index of glia cells and neurons were significantly higher in ELMAG compared to the other groups. Biochemical analysis revealed a significantly increased MDA value in ELMAG compared to CG, while SOD and GSH levels decreased significantly. In conclusion, our study results suggest that continuous exposure to a 900-MHz EMF for 1h a day through all stages of

  17. 21 CFR 862.2320 - Beta or gamma counter for clinical use.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Beta or gamma counter for clinical use. 862.2320... (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2320 Beta or gamma counter for clinical use. (a) Identification. A beta or gamma counter...

  18. Biodegradation and aquatic toxicity of beta-alaninediacetic acid (beta-ADA).

    PubMed

    Nitschke, L; Wilk, A; Cammerer, C; Lind, G; Metzner, G

    1997-02-01

    The aquatic toxicity and biodegradability of the new chelating agent beta-alaninediacetic acid (beta-ADA) were investigated. There is no inhibition effect of beta-ADA in the daphnia magna 24 h test up to a concentration of 1000 mg/L. The algal growth inhibition test resulted in an EC 50 of 19.7 mg/L. An EC 20 of 740 mg/L was determined in the luminescent bacteria test. An EC 50 was not obtained in this test up to a concentration of 2000 mg/L beta-ADA. The degree of biodegradation of beta-ADA was determined in a static and a continuous test. The beta-ADA removal reached 98% at the end of the test after eight weeks in the continuous test which was carried out with laboratory activated sludge units simulating a waste water treatment plant. Further, biodegradation and toxicity tests were coupled, i.e. the effluents of the laboratory activated sludge units were applied in the toxicity tests. A higher toxicity of the effluents of the test units in comparison with the control unit was not observed.

  19. Beta-receptors and stress protein 70 expression in hypoxic myocardium of rainbow trout and chinook salmon.

    PubMed

    Gamperl, A K; Vijayan, M M; Pereira, C; Farrell, A P

    1998-02-01

    We examined the in vivo effect of acute hypoxemia on myocardial cell-surface (sarcolemmal) beta-adrenoreceptor density (Bmax) and binding affinity (KD) and on stress protein 70 (sp70) expression by exposing rainbow trout (Oncorhynchus mykiss; 2.1-2.7 kg) to hypoxic water (3 mg/l O2) at 15 degrees C for 6 h. This degree of hypoxia was the minimum O2 level that these trout could tolerate without losing equilibrium and struggling violently. Hypoxic exposure reduced arterial PO2 (PaO2) from 98 to 26 mmHg and arterial oxygen content (CaO2) from 10.8 to 7.4 vol/100 vol, but did not elevate epinephrine and norepinephrine levels above 10 and 30 nM, respectively. Despite the substantial reduction in blood oxygen status, the Bmax and KD of myocardial cell-surface beta-adrenoreceptors were unaffected by 6 h of hypoxic exposure. In addition, acute hypoxemia did not increase myocardial sp70 expression. The failure of short-term hypoxia to decrease trout myocardial beta-adrenoreceptor density clearly contrasts with the established hypoxia-mediated down-regulation shown for mammals. To further investigate the influence of low PO2 on salmonid myocardial beta-adrenoreceptors, binding studies were performed on the spongy (continuously exposed to deoxygenated venous blood) and compact (perfused by oxygenated blood supplied by the coronary artery) myocardia of chinook salmon. The spongy myocardium has adapted to its microenvironment of continuous low PO2 by having 14% more cell-surface beta-adrenoreceptors compared with the compact myocardium. There was no tissue-specific difference in KD and no evidence of sexual dimorphism in Bmax or KD. We conclude from our studies that the salmonid heart is well adapted for sustained performance under hypoxic conditions. We found that wild chinook salmon had 2.8 x more cell-surface beta-adrenoreceptors compared with hatchery-reared rainbow trout. This difference suggests a significant degree of plasticity exists for fish myocardial beta

  20. Strategies, Implementation and Results of BETA

    NASA Astrophysics Data System (ADS)

    Leigh, Darren; Horowitz, Paul

    The Harvard University/Planetary Society BETA project is an all-sky, narrow-band, microwave search for extraterrestrial intelligent signals. It has been operating more-or-less continuously for the last four years during which time it has automatically scanned the sky visible from Agassiz station (+60^̂ - -30^̂) over the entire waterhole (1400-1720 MHz) five times. We will discuss BETA's search strategies, our implementation and the results of how these fared in the observatory's interference environment. We will also present qualified limits on the prevalence of transmitting civilizations given our (current) negative results.

  1. Mitochondrial dynamics and morphology in beta-cells.

    PubMed

    Stiles, Linsey; Shirihai, Orian S

    2012-12-01

    Mitochondrial dynamics contribute to the regulation of mitochondrial shape as well as various mitochondrial functions and quality control. This is of particular interest in the beta-cell because of the key role mitochondria play in the regulation of beta-cell insulin secretion function. Moreover, mitochondrial dysfunction has been suggested to contribute to the development of Type 2 Diabetes. Genetic tools that shift the balance of mitochondrial fusion and fission result in alterations to beta-cell function and viability. Additionally, conditions that induce beta-cell dysfunction, such as exposure to a high nutrient environment, disrupt mitochondrial morphology and dynamics. While it has been shown that mitochondria display a fragmented morphology in islets of diabetic patients and animal models, the mechanism behind this is currently unknown. Here, we review the current literature on mitochondrial morphology and dynamics in the beta-cell as well as some of the unanswered question in this field.

  2. Tyrosine residues 654 and 670 in {beta}-cat enin are crucial in regulation of Met-{beta}-catenin interactions

    SciTech Connect

    Zeng, Gang; Apte, Udayan; Micsenyi, Amanda; Bell, Aaron; Monga, Satdarshan P.S. . E-mail: smonga@pitt.edu

    2006-11-01

    {beta}-catenin, a key component of the canonical Wnt pathway, is also regulated by tyrosine phosphorylation that regulates its association to E-cadherin. Previously, we reported its association with the hepatocyte growth factor (HGF) receptor Met at the membrane. HGF induced Met-{beta}-catenin dissociation and nuclear translocation of {beta}-catenin, which was tyrosine-phosphorylation-dependent. Here, we further investigate the Met-{beta}-catenin interaction by selectively mutating several tyrosine residues, alone or in combination, in {beta}-catenin. The mutants were subcloned into FLAG-CMV vector and stably transfected into rat hepatoma cells, which were treated with HGF. All single or double-mutant-transfected cells continued to show HGF-induced nuclear translocation of FLAG-{beta}-catenin except the mutations affecting 654 and 670 simultaneously (Y654/670F), which coincided with the lack of formation of {beta}-catenin-TCF complex and DNA synthesis, in response to the HGF treatment. In addition, the Y654/670F-transfected cells also showed no phosphorylation of {beta}-catenin or dissociation from Met in response to HGF. Thus, intact 654 and 670 tyrosine residues in {beta}-catenin are crucial in HGF-mediated {beta}-catenin translocation, activation and mitogenesis.

  3. Space environment durability of beta cloth in LDEF thermal blankets

    NASA Technical Reports Server (NTRS)

    Linton, Roger C.; Whitaker, Ann F.; Finckenor, Miria M.

    1993-01-01

    Beta cloth performance for use on long-term space vehicles such as Space Station Freedom (S.S. Freedom) requires resistance to the degrading effects of the space environment. The major issues are retention of thermal insulating properties through maintaining optical properties, preserving mechanical integrity, and generating minimal particulates for contamination-sensitive spacecraft surfaces and payloads. The longest in-flight test of beta cloth's durability was on the Long Duration Exposure Facility (LDEF), where it was exposed to the space environment for 68 months. The LDEF contained 57 experiments which further defined the space environment and its effects on spacecraft materials. It was deployed into low-Earth orbit (LEO) in Apr. 1984 and retrieved Jan. 1990 by the space shuttle. Among the 10,000 plus material constituents and samples onboard were thermal control blankets of multilayer insulation with a beta cloth outer cover and Velcro attachments. These blankets were exposed to hard vacuum, thermal cycling, charged particles, meteoroid/debris impacts, ultraviolet (UV) radiation, and atomic oxygen (AO). Of these space environmental exposure elements, AO appears to have had the greatest effect on the beta cloth. The beta cloth analyzed in this report came from the MSFC Experiment S1005 (Transverse Flat-Plate Heat Pipe) tray oriented approximately 22 deg from the leading edge vector of the LDEF satellite. The location of the tray on LDEF and the placement of the beta cloth thermal blankets are shown. The specific space environment exposure conditions for this material are listed.

  4. Beta experiment flight report

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A focused laser Doppler velocimeter system was developed for the measurement of atmospheric backscatter (beta) from aerosols at infrared wavelengths. The system was flight tested at several different locations and the results of these tests are summarized.

  5. Genetics Home Reference: beta-ureidopropionase deficiency

    MedlinePlus

    ... down N-carbamyl-beta-alanine to beta-alanine, ammonia, and carbon dioxide. Both beta-aminoisobutyric acid and ... beta-ureidopropionase deficiency Merck Manual Professional Version: Pyrimidine Metabolism Disorders Orphanet: Beta-ureidopropionase deficiency Patient Support and ...

  6. The beta cell immunopeptidome.

    PubMed

    Dudek, Nadine L; Purcell, Anthony W

    2014-01-01

    Type 1 diabetes results from the autoimmune-mediated destruction of insulin-secreting beta cells, leading to beta cell loss and insulin deficiency. Presentation of peptides derived from beta cell proteins to autoreactive lymphocytes is critical for the development of disease, and the list of antigens recognized is increasing. A number of these proteins are found within the beta cell secretory granules, which are transiently exposed to the immune system during normal cellular function. How the interplay of environmental and genetic determinants culminates in destructive autoimmunity remains to be clearly defined. Nonconventional presentation of peptide ligands, posttranslational modification of peptides, and the role of the gut microbiome in the development of the immune system are all considered central topics in disease pathogenesis. Each of these may provide a mechanism by which presentation of antigenic peptides in the target tissue differs from presentation in the thymus, allowing autoreactive cells to escape tolerance induction. The high metabolic demand on pancreatic islets, the high concentration of granule proteins, and the susceptibility of islets to cellular stress may all contribute to the presentation of abnormal ligands in the pancreas. Moreover, the finding that small molecules can alter the repertoire of peptides presented by major histocompatibility complex molecules provides a tantalizing hypothesis for the presentation of autoantigenic peptides in the presence of microbial or endogenous metabolites. In this chapter, we provide an overview of the immunopeptidome of beta cells and the key factors that may influence presentation of beta cell antigens to the immune system.

  7. Beta cell dynamics: beta cell replenishment, beta cell compensation and diabetes.

    PubMed

    Cerf, Marlon E

    2013-10-01

    Type 2 diabetes, characterized by persistent hyperglycemia, arises mostly from beta cell dysfunction and insulin resistance and remains a highly complex metabolic disease due to various stages in its pathogenesis. Glucose homeostasis is primarily regulated by insulin secretion from the beta cells in response to prevailing glycemia. Beta cell populations are dynamic as they respond to fluctuating insulin demand. Beta cell replenishment and death primarily regulate beta cell populations. Beta cells, pancreatic cells, and extra-pancreatic cells represent the three tiers for replenishing beta cells. In rodents, beta cell self-replenishment appears to be the dominant source for new beta cells supported by pancreatic cells (non-beta islet cells, acinar cells, and duct cells) and extra-pancreatic cells (liver, neural, and stem/progenitor cells). In humans, beta cell neogenesis from non-beta cells appears to be the dominant source of beta cell replenishment as limited beta cell self-replenishment occurs particularly in adulthood. Metabolic states of increased insulin demand trigger increased insulin synthesis and secretion from beta cells. Beta cells, therefore, adapt to support their physiology. Maintaining physiological beta cell populations is a strategy for targeting metabolic states of persistently increased insulin demand as in diabetes.

  8. Amyloid-beta aggregation: selective inhibition of aggregation in mixtures of amyloid with different chain lengths.

    PubMed Central

    Snyder, S W; Ladror, U S; Wade, W S; Wang, G T; Barrett, L W; Matayoshi, E D; Huffaker, H J; Krafft, G A; Holzman, T F

    1994-01-01

    rates of production of different-length A beta and its exposure to radical damage may be factors in the accumulation of A beta in plaques in vivo. Images FIGURE 6 PMID:7811936

  9. beta. -Adrenergic stimulation of brown adipocyte proliferation

    SciTech Connect

    Geloeen, A.; Collet, A.J.; Guay, G.; Bukowiecki, L.J. Laboratoire de Thermoregulation et Metabolisme Energetique, Lyon )

    1988-01-01

    The mechanisms of brown adipose tissue (BAT) growth were studied by quantitative photonic radioautography using tritiated thymidine to follow mitotic activity. To identify the nature of the adrenergic pathways mediating brown adipocyte proliferation and differentiation, the effects of cold exposure (4 days at 4{degree}C) on BAT growth were compared with those induced by treating rats at 25{degree}C with norepinephrine (a mixed agonist), isoproterenol (a {beta}-agonist), and phenylephrine (an {alpha}-agonist). Norepinephrine mimicked the effects of cold exposure, not only on the mitotic activity, but also on the distribution of the labeling among the various cellular types. Isoproterenol entirely reproduced the effects of norepinephrine both on the labeling index and on the cellular type labeling frequency. These results demonstrate that norepinephrine triggers a coordinated proliferation of brown adipocytes and endothelial cells in warm-exposed rats that is similar to that observed after cold exposure. They also suggest that cold exposure stimulates BAT growth by increasing the release of norepinephrine from sympathetic nerves and that the neurohormone activates mitoses in BAT precursor cells via {beta}-adrenergic pathways.

  10. Modulation of receptors and adenylate cyclase activity during sucrose feeding, food deprivation, and cold exposure

    SciTech Connect

    Scarpace, P.J.; Baresi, L.A.; Morley, J.E. Univ. of California, Los Angeles )

    1987-12-01

    Thermogenesis in brown adipose tissue (BAT) serves as a regulator of body temperature and weight maintenance. Thermogenesis can be stimulated by catecholamine activation of adenylate cyclase through the {beta}-adrenergic receptor. To investigate the effects of sucrose feeding, food deprivation, and cold exposure on the {beta}-adrenergic pathway, adenylate cyclase activity and {beta}-adrenergic receptors were assessed in rat BAT after 2 wk of sucrose feeding, 2 days of food deprivation, or 2 days of cold exposure. {beta}-Adrenergic receptors were identified in BAT using ({sup 125}I)iodocyanopindolol. Binding sites had the characteristics of mixed {beta}{sub 1}- and {beta}{sub 2}-type adrenergic receptors at a ratio of 60/40. After sucrose feeding or cold exposure, there was the expected increase in BAT mitochondrial mass as measured by total cytochrome-c oxidase activity but a decrease in {beta}-adrenergic receptor density due to a loss of the {beta}{sub 1}-adrenergic subtype. This BAT {beta}-adrenergic receptor downregulation was tissue specific, since myocardial {beta}-adrenergic receptors were unchanged with either sucrose feeding or cold exposure. Forskolin-stimulated adenylate cyclase activity increased in BAT after sucrose feeding or cold exposure but not after food deprivation. These data suggest that in BAT, sucrose feeding or cold exposure result in downregulation of {beta}-adrenergic receptors and that isoproterenol-stimulated adenylate cyclase activity was limited by receptor availability.

  11. Divalent Beta’ Aluminas: High Conductivity Solid Electrolytes for Divalent Cations.

    DTIC Science & Technology

    1982-10-13

    results indicated that divalent ions diffuse very slowly in beta alumina, they discouraged interest in its divalent derivatives. After their work...using polycrystalline Na+ beta alumina to separate two NiCl2-NaCl melts at 800-10000C. After several days’ exposure, they found that the beta alumina...samples were exchanged in a nitrogen or argon atmosphere. After exchange, crystals were soaked in a suitable solvent (usually methanol), washed in

  12. IO SUBSYSTEM 1 BETA

    SciTech Connect

    Sjaardema, Greg

    2002-08-21

    "IO Subsystem Ver. 1.0 Beta" uses standard object-oriented principles to minimize dependencies between the underlying input or output database format and the client code (i.e., Sierra) using the io subsystem. The interface and priciples are simolar to the Facade pattern described in the "Design Patterns" book by Gamma, et.al. The software uses data authentication algorithms to ensure data input/output is consistent with model being defined. "IO Subsystem Ver. 1.0 Beta" is a database independent input/output library for finite element analysis, preprocessing, post processing, and translation programs.

  13. Exposure Nomographs

    NASA Astrophysics Data System (ADS)

    Zissell, Ronald E.

    Correct exposure times may be determined from nomographs relating signal-to-noise ratio, exposure time, color, seeing, and magnitude. The equations needed to construct the nomographs are developed. Calibration techniques are discussed.

  14. Environmental Contaminants and Pancreatic Beta-Cells

    PubMed Central

    Fabricio, Gabriel; Malta, Ananda; Chango, Abalo; De Freitas Mathias, Paulo Cezar

    2016-01-01

    Despite health policies as well as clinical and research efforts, diabetes prevalence is still rising around the world. A multitude of causes have been suggested for this increase, mostly related to familial background, the occidental diet which is rich in fat/carbohydrates, and sedentary life style. Type 2 diabetes involves malfunctions of the primary pancreatic beta-cells, usually attributed to local damage; however, it can be associated with other stressful environmental agents, such as chemical contaminants from food, plastic and air, among others. Indeed, exposure to these chemical agents during perinatal and adolescent life can increase the risk of developing cardiometabolic diseases later in life. This review explores data showing which environmental chemical agents may produce injury in beta-cells and further impair the insulinotropic process of type 2 diabetes. Additionally, it points the need to also consider unusual causes of metabolic diseases, such as environmental contaminants. PMID:27087124

  15. Augmented renal clearance in critically ill patients: etiology, definition and implications for beta-lactam dose optimization.

    PubMed

    Sime, Fekade Bruck; Udy, Andrew A; Roberts, Jason A

    2015-10-01

    The renal clearance of antibiotics may be elevated in some critically ill patients. This paper reviews this recently described phenomenon, referred to as augmented renal clearance (ARC). ARC is considered to be driven by pathophysiological elevation of glomerular filtration, and is defined as a creatinine clearance >130mL/min/173m(2). This in turn promotes very low antibiotic concentrations. This effect may lead to adverse clinical outcomes, particularly with beta-lactam antibiotics, as they require prolonged exposure for optimal antibacterial activity. The use of extended or continuous infusions is an effective strategy to improve exposure. However, because the effect of ARC is potentially quite variable, regular therapeutic drug monitoring (TDM) may be necessary to ensure all patients achieve effective concentrations.

  16. 29 CFR 1915.1009 - beta-Naphthylamine.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false beta-Naphthylamine. 1915.1009 Section 1915.1009 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Toxic and Hazardous...

  17. 29 CFR 1915.1013 - beta-Propiolactone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false beta-Propiolactone. 1915.1013 Section 1915.1013 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Toxic and Hazardous...

  18. Functionality of NGF-protected PC12 cells following exposure to 6-hydroxydopamine

    SciTech Connect

    Kavanagh, Edel T.; Loughlin, John P.; Herbert, Kate Reed; Dockery, Peter; Samali, Afshin; Doyle, Karen M.; Gorman, Adrienne M. . E-mail: adrienne.gorman@nuigalway.ie

    2006-12-29

    6-Hydroxydopamine (6-OHDA) is often used in models of Parkinson's disease since it can selectively target and kill dopaminergic cells of the substantia nigra. In this study, pre-treatment of PC12 cells with nerve growth factor (NGF) inhibited apoptosis and necrosis by 6-OHDA, including caspase activity and lactate dehydrogenase release. Notably, cells exposed to 6-OHDA in the presence of NGF were subsequently capable of proliferation (when replated without NGF), or neurite outgrowth (with continued presence of NGF). Following 7 days growth in the presence of NGF, expression of {beta}III tubulin and tyrosine hydroxylase and increased intracellular catecholamines was detectable in PC12 cells, features characteristic of functional dopaminergic neurons. NGF-pre-treated PC12 cells retained expression of {beta}III-tubulin and tyrosine hydroxylase, but not catecholamine content following 6-OHDA exposure. These data indicate that NGF-protected cells maintained some aspects of functionality and were subsequently capable of proliferation or differentiation.

  19. beta-Propiolactone

    Integrated Risk Information System (IRIS)

    beta - Propiolactone ; CASRN 57 - 57 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogen

  20. beta-Chloronaphthalene

    Integrated Risk Information System (IRIS)

    beta - Chloronaphthalene ; CASRN 91 - 58 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcin

  1. Trichoderma .beta.-glucosidase

    DOEpatents

    Dunn-Coleman, Nigel; Goedegebuur, Frits; Ward, Michael; Yao, Jian

    2006-01-03

    The present invention provides a novel .beta.-glucosidase nucleic acid sequence, designated bgl3, and the corresponding BGL3 amino acid sequence. The invention also provides expression vectors and host cells comprising a nucleic acid sequence encoding BGL3, recombinant BGL3 proteins and methods for producing the same.

  2. Molecular Exploration of Beta-Lactamases in Fusarium verticillioides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mycotoxigenic fungus Fusarium verticillioides (Fv) is one of the most prevalent maize fungal pathogens. Fv mycotoxins are a significant food safety issue and have given rise to exposure concerns worldwide. The FDB1 locus, a beta-lactamase-containing Fv gene cluster, was previously shown to be in...

  3. Estrogen modulates alpha(1)/beta-adrenoceptor- induced signaling and melatonin production in female rat pinealocytes.

    PubMed

    Hernández-Díaz, F J; Sánchez, J J; Abreu, P; López-Coviella, I; Tabares, L; Prieto, L; Alonso, R

    2001-02-01

    Nocturnal rise in pineal melatonin output is due to the night-induced acceleration of noradrenergic transmission and alpha(1)- and beta-adrenoceptor activation. In addition, in female animals, cyclic oscillations in circulating levels of sex steroid hormones are accompanied by changes in the rate of pineal melatonin secretion. To investigate whether estrogen directly affects pineal adrenoceptor responsiveness, pinealocytes from 21-day-old ovariectomized rats were exposed to physiological concentrations of 17beta-estradiol (17beta-E(2)) and treated with noradrenergic agonists. Direct exposure to 17beta-E(2) reduced alpha(1)/beta-adrenoceptor-induced stimulation of melatonin synthesis and release. This effect was mediated by an estrogen-dependent inhibition of both beta-adrenoceptor-induced accumulation of cAMP and alpha(1)-adrenoceptor-induced phosphoinositide hydrolysis. Furthermore, estrogen reduced transient Ca(2+) signals elicited in single pinealocytes by alpha(1)-adrenoceptor activation or by potassium-induced depolarization. In the case of beta-adrenoceptor responsiveness, neither forskolin- nor cholera toxin-induced accumulation of cAMP were affected by previous exposure to 17beta-E(2). This indicates that estrogen effects must be exerted upstream from adenylylcyclase activation, and independent of modifications in G protein expression, therefore suggesting changes in either adrenoceptor expression or receptor-effector coupling mechanisms. Since estrogen effects upon adrenoceptor responsiveness in pineal cells was not mimicked by 17beta-E(2) coupled to bovine serum albumin and showed a latency of 48 h, this effect could be compatible with a genomic action mechanism. This is also consistent with the presence of two estrogen receptor proteins, alpha- and beta-subtypes, in female rat pinealocytes under the present experimental conditions.

  4. Expression of the beta 7 integrin by human endothelial cells.

    PubMed Central

    Brezinschek, R. I.; Brezinschek, H. P.; Lazarovits, A. I.; Lipsky, P. E.; Oppenheimer-Marks, N.

    1996-01-01

    Integrin adhesion receptors mediate fundamental intercellular interactions of many cell types as well as cellular interactions with specific extracellular matrix molecules. To date, the beta 7 integrin has been shown to be expressed by leukocyte subsets and to mediate interactions of these cells with extracellular matrix molecules as well as with endothelial and epithelial cells. The data presented here indicate that human endothelial cells also express the beta 7 integrin both in vitro and in situ. Analysis of cDNA indicated that endothelial beta 7 was identical to that expressed by leukocytes. Cell surface expression of beta 7 was increased by exposure of the endothelium to the pro-inflammatory cytokines, tumor necrosis factor-alpha and interleukin-1 beta. In leukocytes, beta 7 complexes with alpha 4 or alpha E integrin chains. Endothelial cells also expressed a number of alpha-integrin chains, including alpha 4, but not alpha E. The expression and utilization of beta 7, presumably complexed with alpha 4, by endothelial cells may be instrumental in the maintenance of the function or phenotype of endothelial cells. Images Figure 2 Figure 4 Figure 6 Figure 7 PMID:8909254

  5. Artificial gravity exposure impairs exercise-related neurophysiological benefits.

    PubMed

    Vogt, Tobias; Abeln, Vera; Strüder, Heiko K; Schneider, Stefan

    2014-01-17

    Artificial gravity (AG) exposure is suggested to counteract health deconditioning, theoretically complementing exercise during space habitations. Exercise-benefits on mental health are well documented (i.e. well-being, enhanced executive functions). Although AG is coherent for the integrity of fundamental physiological systems, the effects of its exposure on neurophysiological processes related to cognitive performance are poorly understood and therefore characterize the primary aim of this study. 16 healthy males participated in two randomly assigned sessions, AG and exercise (30minute each). Participants were exposed to AG at continuous +2Gz in a short-arm human centrifuge and performed moderate exercise (cycling ergometer). Using 64 active electrodes, resting EEG was recorded before (pre), immediately after (post), and 15min after (post15) each session. Alpha (7.5-12.5Hz) and beta frequencies (12.5-35.0Hz) were exported for analysis. Cognitive performance and mood states were assessed before and after each session. Cognitive performance improved after exercise (p<0.05), but not after AG. This was reflected by typical EEG patterns after exercise, however not after AG. Frontal alpha (post p<0.01, post15 p<0.001) and beta activity (post15 p<0.001) increased after AG compared to a decrease in frontal alpha (post15 p<0.05) and beta activity (post p<0.01) after exercise. Relaxed cortical states were indicated after exercise, but were less apparent after AG. Changes in mood states failed significance after both sessions. Summarized, the benefits to mental health, recorded after exercise, were absent after AG, indicating that AG might cause neurocognitive deconditioning.

  6. ISES Training Class - Continuous Measurements

    EPA Science Inventory

    Features of Continuous Monitoring•Provides for high definition of temporal resolution•Provides means for discerning primary exposure events•Provides means for critically examining data quality rather than just an average point•Applicable to any measure of inte...

  7. High beta and confinement studies on TFTR

    SciTech Connect

    Navratil, G.A.; Bhattacharjee, A.; Iacono, R.; Mauel, M.E.; Sabbagh, S.A. ); Kesner, J. )

    1992-01-01

    A new regime of high poloidal beta operation in TFTR was developed in the course of the first two years of this project (9/25/89 to 9/24/91). Our proposal to continue this successful collaboration between Columbia University and the Massachusetts Institute of Technology with the Princeton Plasma Physics Laboratory for a three year period (9/25/91 to 9/24/94) to continue to investigate improved confinement and tokamak performance in high poloidal beta plasmas in TFTR through the DT phase of operation was approved by the DOE and this is a report of our progress during the first 9 month budget period of the three year grant (9/25/91 to 6/24/92). During the approved three year project period we plan to (1) extend and apply the low current, high QDD discharges to the operation of TFTR using Deuterium and Tritium plasma; (2) continue the analysis and plan experiments on high poloidal beta phenomena in TFTR including: stability properties, enhanced global confinement, local transport, bootstrap current, and divertor formation; (3) plan and carry out experiments on TFTR which attempt to elevate the central q to values > 2 where entry to the second stability regime is predicted to occur; and (4) collaborate on high beta experiments using bean-shaped plasmas with a stabilizing conducting shell in PBX-M. In the seven month period covered by this report we have made progress in each of these four areas through the submission of 4 TFTR Experimental Proposals and the partial execution of 3 of these using a total of 4.5 run days during the August 1991 to February 1992 run.

  8. Beta-rolls, beta-helices, and other beta-solenoid proteins.

    PubMed

    Kajava, Andrey V; Steven, Alasdair C

    2006-01-01

    Beta-rolls and beta-helices belong to a larger group of topologically similar proteins with solenoid folds: because their regular secondary structure elements are exclusively beta-strands, they are referred to as beta-solenoids. The number of beta-solenoids whose structures are known is now large enough to support a systematic analysis. Here we survey the distinguishing structural features of beta-solenoids, also documenting their notable diversity. Appraisal of these structures suggests a classification based on handedness, twist, oligomerization state, and coil shape. In addition, beta-solenoids are distinguished by the number of chains that wind around a common axis: the majority are single-stranded but there is a recently discovered subset of triple-stranded beta-solenoids. This survey has revealed some relationships of the amino acid sequences of beta-solenoids with their structures and functions-in particular, the repetitive character of the coil sequences and conformations that recur in tracts of tandem repeats. We have proposed the term beta-arc for the distinctive turns found in beta-solenoids and beta-arch for the corresponding strand-turn-strand motifs. The evolutionary mechanisms underlying these proteins are also discussed. This analysis has direct implications for sequence-based detection, structural prediction, and de novo design of other beta-solenoid proteins. The abundance of virulence factors, toxins and allergens among beta-solenoids, as well as commonalities of beta-solenoids with amyloid fibrils, imply that this class of folds may have a broader role in human diseases than was previously recognized. Thus, identification of genes with putative beta-solenoid domains promises to be a fertile direction in the search for viable targets in the development of new antibiotics and vaccines.

  9. Pharmacogenetics of beta-blockers.

    PubMed

    Shin, Jaekyu; Johnson, Julie A

    2007-06-01

    Beta-blockers are an important cardiovascular drug class, recommended as first-line treatment of numerous diseases such as heart failure, hypertension, and angina, as well as treatment after myocardial infarction. However, responses to a beta-blocker are variable among patients. Results of numerous studies now suggest that genetic polymorphisms may contribute to variability in responses to beta-blockers. This review summarizes the pharmacogenetic data for beta-blockers in patients with various diseases and discusses the potential implications of beta-blocker pharmacogenetics in clinical practice.

  10. Attenuated Response to Methamphetamine Sensitization and Deficits in Motor Learning and Memory after Selective Deletion of [beta]-Catenin in Dopamine Neurons

    ERIC Educational Resources Information Center

    Diaz-Ruiz, Oscar; Zhang, YaJun; Shan, Lufei; Malik, Nasir; Hoffman, Alexander F.; Ladenheim, Bruce; Cadet, Jean Lud; Lupica, Carl R.; Tagliaferro, Adriana; Brusco, Alicia; Backman, Cristina M.

    2012-01-01

    In the present study, we analyzed mice with a targeted deletion of [beta]-catenin in DA neurons (DA-[beta]cat KO mice) to address the functional significance of this molecule in the shaping of synaptic responses associated with motor learning and following exposure to drugs of abuse. Relative to controls, DA-[beta]cat KO mice showed significant…

  11. Investigation of horizon Beta.

    PubMed

    Windisch, C C; Leyden, R J; Worzel, J L; Saito, T; Ewing, J

    1968-12-27

    Horizon beta is a subbottom reflector in the North Atlantic deep ocean sediments that extends over a large portion of the North America basin. Cores from an outcrop of beta contained shallow-water Aptian-Albian sediments and deep-water Cenomanian sediments. A core near an outcrop of a deeper horizon, horizon B, contained shallow-water Lower Cretaceous (Barremian-Hauterivian) sediments. These cores can be interpreted to support extensive subsidence of the eastern portion of the basin in early Cretaceous time. It is equally likely that the shallow-water deposits are a result of sediments slumping into an already deep basin. A reconciliation of these interpretations depends upon the JOIDES project.

  12. Beta-thalassemia.

    PubMed

    Galanello, Renzo; Origa, Raffaella

    2010-05-21

    Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC) transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands), dilated myocardiopathy, liver fibrosis and cirrhosis). Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes), gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely, deletions in the beta

  13. Beta-thalassemia

    PubMed Central

    2010-01-01

    Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC) transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands), dilated myocardiopathy, liver fibrosis and cirrhosis). Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes), gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely, deletions in the beta

  14. Regeneration of pancreatic beta cells.

    PubMed

    Jun, Hee-Sook

    2008-05-01

    Diabetes mellitus results from inadequate mass of insulin-producing pancreatic beta cells. Type 1 diabetes is characterized by absolute loss of beta cells due to autoimmune-mediated destruction. Type 2 diabetes is characterized by relative deficiency of beta cells due to lack of compensation for insulin resistance. Restoration of deficient beta cell mass by transplantation from exogenous sources or by endogenous regeneration of insulin-producing cells would be therapeutic options. Mature beta cells have an ability to proliferate; however, it has been shown to be difficult to expand adult beta cells in vitro. Alternatively, regeneration of beta cells from embryonic and adult stem cells and pancreatic progenitor cells is an attractive method to restore islet cell mass. With information obtained from the biology of pancreatic development, direct differentiation of stem and progenitor cells toward a pancreatic beta cell phenotype has been tried using various strategies, including forced expression of beta cell-specific transcription factors. Further research is required to understand how endogenous beta cells differentiate and to develop methods to regenerate beta cells for clinically applicable therapies for diabetes.

  15. Thermophilic Beta-Glycosidase

    NASA Technical Reports Server (NTRS)

    Grogan, Dennis W.

    1992-01-01

    Report describes identification of thermophilic Beta-glycosidase enzyme from isolate of Sulfolobus solfataricus, sulfur-metabolizing archaebacteria growing aerobically and heterotrophically to relatively high cell yields. Enzyme useful in enzymatic conversion of cellulose to D-glucose and important in recycling of biomass. Used for removal of lactose from milk products. Offers promise as model substance for elucidation of basic principles of structural stabilization of proteins.

  16. Military Exposures

    MedlinePlus

    ... Chemicals (Agent Orange, contaminated water…) Radiation (nuclear weapons, X-rays…) Air Pollutants (burn pit smoke, dust…) Occupational Hazards (asbestos, lead…) Warfare Agents (chemical and biological weapons) Exposure ...

  17. Beta-sitosterol and 17beta-estradiol alter gonadal steroidogenic acute regulatory protein (StAR) expression in goldfish, Carassius auratus.

    PubMed

    Sharpe, Rainie L; Woodhouse, Amanda; Moon, Thomas W; Trudeau, Vance L; MacLatchy, Deborah L

    2007-03-01

    Fish exposed to the phytosterol beta-sitosterol (beta-sit) have decreased circulating hormone and cholesterol concentrations, and decreased gonadal intra-mitochondrial cholesterol pools. The current study examined the potential for beta-sit to alter abundance of the key cholesterol transport protein, steroidogenic acute regulatory (StAR) protein, which delivers cholesterol to the first and rate-limiting steroidogenic enzyme P450 side chain cleavage (P450(scc)) inside the mitochondria. Plasma testosterone (T) and lipids (cholesterol, lipoproteins and triglycerides) were also measured. Goldfish were exposed to 200 microg/g beta-sit (97% pure or as a 72.6% pure phytosterol mixture) and 10 microg/g 17beta-estradiol (E(2); estrogenic control) by intra-peritoneal Silastic implants for 21-days or for five-months. Plasma T was significantly decreased in male fish exposed to the phytosterol mixture following the long-term exposure (p<0.001). There were no differences in total cholesterol concentrations among treatments in the short- or long-term exposure, but male fish in the long-term exposure had significantly lower HDL as compared to control fish (p<0.025) with a corresponding increase in LDL. StAR transcript levels were unchanged following the short-term exposure, but were reduced after five months in male beta-sit fish (p=0.05) and E(2)-treated female fish (p=0.05). This reduction in StAR transcript abundance in conjunction with decreased plasma T and altered plasma lipoprotein fractions demonstrates a non-estrogenic effect of beta-sit. This is the first study to show that beta-sit has the capacity to alter gonadal StAR transcript abundance, offering a mechanism by which beta-sit disrupts reproductive endocrine endpoints.

  18. Redox-mediated activation of latent transforming growth factor-beta 1

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

    Transforming growth factor beta 1 (TGF beta) is a multifunctional cytokine that orchestrates response to injury via ubiquitous cell surface receptors. The biological activity of TGF beta is restrained by its secretion as a latent complex (LTGF beta) such that activation determines the extent of TGF beta activity during physiological and pathological events. TGF beta action has been implicated in a variety of reactive oxygen-mediated tissue processes, particularly inflammation, and in pathologies such as reperfusion injury, rheumatoid arthritis, and atherosclerosis. It was recently shown to be rapidly activated after in vivo radiation exposure, which also generates reactive oxygen species (ROS). In the present studies, the potential for redox-mediated LTGF beta activation was investigated using a cell-free system in which ROS were generated in solution by ionizing radiation or metal ion-catalyzed ascorbate reaction. Irradiation (100 Gray) of recombinant human LTGF beta in solution induced 26% activation compared with that elicited by standard thermal activation. Metal-catalyzed ascorbate oxidation elicited extremely efficient recombinant LTGF beta activation that matched or exceeded thermal activation. The efficiency of ascorbate activation depended on ascorbate concentrations and the presence of transition metal ions. We postulate that oxidation of specific amino acids in the latency-conferring peptide leads to a conformation change in the latent complex that allows release of TGF beta. Oxidative activation offers a novel route for the involvement of TGF beta in tissue processes in which ROS are implicated and endows LTGF beta with the ability to act as a sensor of oxidative stress and, by releasing TGF beta, to function as a signal for orchestrating the response of multiple cell types. LTGF beta redox sensitivity is presumably directed toward recovery of homeostasis; however, oxidation may also be a mechanism of LTGF beta activation that can be deleterious during

  19. Molecular mechanism of teratogenic effects induced by the fungicide triadimefon: Study of the expression of TGF-{beta} mRNA and TGF-{beta} and CRABPI proteins during rat in vitro development

    SciTech Connect

    Di Renzo, F.; Corsini, E.; Broccia, M.L.; Marinovich, M.; Galli, C.L.; Giavini, E.; Menegola, E.

    2009-01-01

    Azole derivatives are teratogenic in rats and mice in vitro and in vivo. The postulated mechanism for the dysmorphogenetic effects is the inhibition of retinoic acid (RA)-degrading enzyme CYP26. Azole-related abnormalities are confined to structures controlled by RA, especially the neural crest cells, hindbrain, cranial nerves, and craniofacial structures, through a complex signal cascade. The aim of this work is to study the expression of signal molecules activated by RA (TGF-{beta}s) or involved in the modulation of cellular RA concentrations (CRABPI). E9.5 (9.5 day post coitum old embryos) rat embryos, exposed in vitro to triadimefon (FON) for 24 h, were examined or cultured in normal serum for extra 4, 16, and 24 h. RT-PCR was performed to quantify TGF-{beta}1, TGF-{beta}2, TGF-{beta}3, TGF-{beta}RI, TGF-{beta}RII, and TGF-{beta}RIII mRNA in the hindbrain after 24 h of culture. TGF-{beta}1, TGF-{beta}2, and TGF-{beta}RI were found significantly decreased by FON exposure, and consequently their protein expression was analyzed by Western blot and immunohistochemistry. In both controls and FON-exposed embryos, TGF-{beta}1 and TGF-{beta}RI were detected at 24 and 24 + 4 h; TGF-{beta}2 was present only at 24 h. Only TGF-{beta}1 was expressed at the level of hindbrain and branchial tissues. After quantization, TGF-{beta}1 was reduced in the FON group. The expression of CRABPI was observed at all developmental stages. However, in FON-exposed embryos, it was increased at 24 and 24 + 4 h. The hindbrain distribution of CRABPI-positive cells was abnormal in FON-exposed embryos. The results show that the two RA-related molecules (TGF-{beta}1 and CRABPI) are altered by FON exposure in vitro.

  20. CD69 acts downstream of interferon-alpha/beta to inhibit S1P1 and lymphocyte egress from lymphoid organs.

    PubMed

    Shiow, Lawrence R; Rosen, David B; Brdicková, Nadezda; Xu, Ying; An, Jinping; Lanier, Lewis L; Cyster, Jason G; Matloubian, Mehrdad

    2006-03-23

    Naive lymphocytes continually enter and exit lymphoid organs in a recirculation process that is essential for immune surveillance. During immune responses, the egress process can be shut down transiently. When this occurs locally it increases lymphocyte numbers in the responding lymphoid organ; when it occurs systemically it can lead to immunosuppression as a result of the depletion of recirculating lymphocytes. Several mediators of the innate immune system are known to cause shutdown, including interferon alpha/beta (IFN-alpha/beta) and tumour necrosis factor, but the mechanism has been unclear. Here we show that treatment with the IFN-alpha/beta inducer polyinosine polycytidylic acid (hereafter 'poly(I:C)') inhibited egress by a mechanism that was partly lymphocyte-intrinsic. The transmembrane C-type lectin CD69 was rapidly induced and CD69-/- cells were poorly retained in lymphoid tissues after treatment with poly(I:C) or infection with lymphocytic choriomeningitis virus. Lymphocyte egress requires sphingosine 1-phosphate receptor-1 (S1P1), and IFN-alpha/beta was found to inhibit lymphocyte responsiveness to S1P. By contrast, CD69-/- cells retained S1P1 function after exposure to IFN-alpha/beta. In coexpression experiments, CD69 inhibited S1P1 chemotactic function and led to downmodulation of S1P1. In a reporter assay, S1P1 crosslinking led to co-crosslinking and activation of a CD69-CD3zeta chimaera. CD69 co-immunoprecipitated with S1P1 but not the related receptor, S1P3. These observations indicate that CD69 forms a complex with and negatively regulates S1P1 and that it functions downstream of IFN-alpha/beta, and possibly other activating stimuli, to promote lymphocyte retention in lymphoid organs.

  1. Beta-haemolytic streptococci in acute pharyngitis.

    PubMed

    Boukadida, J; Hannechi, N; Boukadida, N; Ben Said, H; Elmherbech, H; Errai, S

    2003-01-01

    To determine the role and importance of beta-haemolytic streptococci in acute pharyngitis and its relative susceptibility to antibiotics, we cultured samples from 143 patients (age range: 3-72 years) who presented over a 5-month period in 2001 at three primary health care centres in Sousse, Tunisia. The cultures yielded 80 beta-haemolytic streptococci (59 group A streptococci and 21 non-group A streptococci). All strains were susceptible to benzylpenicillin, amoxicillin, chloramphenicol, rifampicin and pristinamycin. Susceptibility was variable in erythromycin, tetracycline, fosfomycin, telithromycin and levofloxacin. Minimum inhibitory concentrations were determined by E-test for penicillin, erythromycin and levofloxacin. Our results confirm that penicillin is still the reference treatment for acute pharyngitis. However, to minimize the potential for complications arising from its use, continued vigilance is required.

  2. EXPOSURE ANALYSIS

    EPA Science Inventory

    This proceedings chapter presents the state of the science regarding the evaluation of exposure as it relates to WQC, SQGs, and wildlife criteria (WC). . . . In summary, the exposure workgroup concluded the following: There should be greater use of mechanistic models to predict b...

  3. Heat shock protein induction in rat pancreatic islets by recombinant human interleukin 1 beta.

    PubMed

    Helqvist, S; Polla, B S; Johannesen, J; Nerup, J

    1991-03-01

    Interleukin 1 beta, potentiated by tumour necrosis factor alpha, is cytotoxic to pancreatic Beta cells in vitro. We have hypothesized that interleukin 1 beta induces oxygen free radicals in Beta cells. Since cytotoxicity induced by free radicals and by heat may activate the same cellular repair mechanism (the heat shock response), the aim of this study was to investigate the pattern of protein synthesis in isolated islets after exposure to interleukin 1 beta (150 pg/ml, 24 h), tumour necrosis factor alpha (50 ng/ml, 24 h) heat shock (43 degrees C, 30 min) and H2O2 (0.1 mmol/l, 20 min). By polyacrylamide gel electrophoresis, autoradiography, Western-blot analysis and partial peptide mapping of 35S-methionine labelled islets, interleukin 1 beta was found to induce a 73 kilodalton protein belonging to the heat shock protein family heat shock protein 70, a heat shock protein 90, and haem oxygenase. A minor induction of heat shock protein 73 and haem oxygenase was seen after H2O2. Interleukin 1 beta did not induce heat shock proteins in rat thyroid cells, rat mesangial cells or in human monocytes. Tumour necrosis factor alpha did not induce selective protein synthesis. Pre-exposure of islets to heat, tumour necrosis factor alpha, or H2O2 did not prevent the impairment of glucose-stimulated insulin release seen after 24 h of interleukin 1 beta exposure. The data are compatible with free radical induction by interleukin 1 beta. However, the heat shock response is not specific for oxidative injury, and previous studies have shown discrepant effects as to a protective effect of free radical scavengers against interleukin 1 beta-mediated beta-cytotoxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. A continuous-wave electron-nuclear double resonance (X-band) study of the Cu2+ sites of particulate methane mono-oxygenase of Methylococcus capsulatus (strain M) in membrane and pure dopamine beta-mono-oxygenase of the adrenal medulla.

    PubMed Central

    Katterle, Bettina; Gvozdev, Rudolf I; Abudu, Ntei; Ljones, Torbjørn; Andersson, K Kristoffer

    2002-01-01

    All methanotrophic bacteria express a membrane-bound (particulate) methane mono-oxygenase (pMMO). In the present study, we have investigated pMMO in membrane fragments from Methylococcus capsulatus (strain M). pMMO contains a typical type-2 Cu(2+) centre with the following EPR parameters: g(z) 2.24, g(x,y) 2.06, A(Cu)(z) 19.0 mT and A(Cu)(x,y) 1.0 mT. Simulation of the Cu(2+) spectrum yielded a best match by using four equivalent nitrogens (A(N)=1.5 mT, 42 MHz). Incubation with ferricyanide neither changed nor increased the amount of EPR-active Cu(2+), in contrast with other reports. The EPR visible copper seems not to be part of any cluster, as judged from the microwave power saturation behaviour. Continuous-wave electron-nuclear double resonance (CW ENDOR; 9.4 GHz, 5-20 K) experiments at g( perpendicular) of the Cu(II) spectrum show a weak coupling to protons with an A(H) of 2.9 MHz that corresponds to a distance of 3.8 A (1 A identical with 0.1 nm), assuming that it is a purely dipolar coupling. Incubation in (2)H(2)O leads to a significant decrease in these (1)H-ENDOR intensities, showing that these protons are exchangeable. This result strongly suggests that the EPR visible copper site of pMMO is accessible to solvent, which was confirmed by the chelation of the Cu(2+) by diethyldithiocarbamic acid. The (1)H and (14)N hyperfine coupling constants confirm a histidine ligation of the EPR visible copper site in pMMO. The hyperfine structure in the ENDOR or EPR spectra of pMMO is not influenced by the inhibitors azide, cyanide or ammonia, indicating that they do not bind to the EPR visible copper. We compared pMMO with the type-2 Cu(2+) enzyme, dopamine beta-mono-oxygenase (DbetaM). For DbetaM, it is assumed that the copper site is solvent-accessible. CW ENDOR shows similar weakly coupled and (2)H(2)O-exchangeable protons (2.9 MHz), as observed in pMMO, as well as the strongly coupled nitrogens (40 MHz) from the co-ordinating N of the histidines in DbetaM. In

  5. Impaired Pancreatic Beta Cell Function by Chronic Intermittent Hypoxia

    PubMed Central

    Wang, Ning; Khan, Shakil A.; Prabhakar, Nanduri R.; Nanduri, Jayasri

    2013-01-01

    Breathing disorders with recurrent apnea produce periodic decreases in arterial blood O2 or chronic intermittent hypoxia (CIH). Recurrent apnea patients and CIH-exposed rodents exhibit several co-morbidities including diabetes. However, the effects of CIH on pancreatic beta cell function are not known. In the present study, we investigated pancreatic beta cell function in C57BL6 mice exposed to 30 days of CIH. CIH-exposed mice exhibited elevated levels of fasting plasma insulin, but comparable glucose levels, and higher homeostasis model assessment (HOMA), indicating insulin resistance. Pancreatic beta cell morphology was unaltered in CIH- exposed mice. Insulin content was decreased in CIH-exposed beta cells, and this effect was associated with increased proinsulin levels. mRNA and protein levels of the enzyme pro-hormone convertase 1 (PC1) which converts proinsulin to insulin were down regulated in CIH-treated islets. More importantly, glucose-stimulated insulin secretion (GSIS) was impaired in CIH-exposed mice and in isolated islets. Mitochondrial reactive oxygen species (ROS) levels were elevated in CIH-exposed pancreatic islets. Treatment of mice with mito-tempol, a scavenger of mitochondrial ROS during CIH exposure, prevented the augmented insulin secretion and restored the proinsulin as well as HOMA values to control levels. These results demonstrate that CIH leads to pancreatic beta cell dysfunction manifested by augmented basal insulin secretion, insulin resistance, defective proinsulin processing, impaired GSIS and mitochondrial ROS mediates the effects of CIH on pancreatic beta cell function. PMID:23709585

  6. Recommendations for the management of beta-lactam intolerance.

    PubMed

    Macy, Eric; Ngor, Eunis

    2014-08-01

    Beta-lactam intolerance, most of which is not IgE or even immunologically mediated even though it is commonly called an "allergy," can be safely managed using the following seven steps: 1. Avoid testing, re-challenging, or desensitizing individuals with histories of beta-lactam associated toxic epidermal necrolysis, Stevens-Johnson syndrome, drug reaction with eosinophilia and systemic symptoms syndrome, severe hepatitis, interstitial nephritis, or hemolytic anemia. 2. Avoid unnecessary antibiotic use, especially in the setting of viral infections. 3. Expect new intolerances to be reported after 0.5 to 4% of all antibiotic utilizations, dependent on gender and the specific antibiotic used. 4. Expect a higher incidence of new intolerances in individuals with three or more medication intolerances already noted in their medical records. 5. For individuals with an appropriate penicillin class antibiotic intolerance based on a history of anaphylaxis, urticaria, macular papular rashes, unknown symptoms, or symptoms not excluded in step one, proceed with penicillin skin testing. Skin test with penicilloyl-poly-lysine and native penicillin. If skin test is negative, proceed with an oral amoxicillin challenge. If skin test and oral challenge are negative, penicillin class antibiotics may be used. If skin test or oral challenge is positive, avoid penicillin class antibiotics. If skin test or oral challenge is positive, non-penicillin-beta-lactams may be used, unless there is a history of intolerance to a specific non-penicillin-beta-lactam, then avoid that specific non-penicillin-beta-lactam. If there is life-threatening infection that can only be treated with a penicillin class antibiotic, proceed with oral penicillin desensitization prior to any oral or parenteral penicillin use. 6. For individuals with an appropriate non-penicillin-beta-lactam intolerance, avoid re-exposure to the beta-lactam implicated. An alternative beta-lactam may be used, ideally with different side

  7. Differential sensitivity to beta-cell secretagogues in cultured rat pancreatic islets exposed to human interleukin-1 beta.

    PubMed

    Eizirik, D L; Sandler, S; Hallberg, A; Bendtzen, K; Sener, A; Malaisse, W J

    1989-08-01

    The early stages of insulin-dependent diabetes mellitus are characterized by a selective inability to secrete insulin in response to glucose, coupled to a better response to nonnutrient secretagogues. The deficient glucose response may be a result of the autoimmune process directed toward the beta-cells. Interleukin-1 (IL-1) has been suggested to be one possible mediator of immunological damage of the beta-cells. In the present study we characterized the sensitivity of beta-cells to different secretagogues after human recombinant IL-1 beta (rIL-1 beta) exposure. Furthermore, experiments were performed to clarify the biochemical mechanisms behind the defective insulin response observed in these islets. Rat pancreatic islets were isolated and kept in tissue culture (medium RPMI-1640 plus 10% calf serum) for 5 days. The islets were subsequently exposed to 60 pM human recombinant IL-1 beta during 48 h in the same culture conditions as above and examined immediately after IL-1 exposure. The rIL-1 beta-treated islets showed a marked reduction of glucose-stimulated insulin release. Stimulation with arginine plus different glucose concentrations, and leucine plus glutamine partially counteracted the rIL-1 beta-induced reduction of insulin release. The activities of the glycolytic enzymes hexokinase, glucokinase, and glyceraldehyde 3-phosphate dehydrogenase, were similar in control and IL-1-exposed islets. Treatment with IL-1 also did not impair the activities of NADH+- and NADPH+-dependent glutamate dehydrogenase, glutamate-aspartate transaminase, glutamate-alanine transaminase, citrate synthase, and NAD+-linked isocitrate dehydrogenase. The oxidation of D-[6-14C]glucose and L-[U-14C]leucine were decreased by 50% in IL-1-treated islets. Furthermore, there was a significant decrease in the ratios of [2-14C]pyruvate oxidation/[1-14C]pyruvate decarboxylation and L-[U-14C]leucine oxidation/L-[1-14C]leucine decarboxylation, indicating that IL-1 decreases the proportion of

  8. Platelets possess functional TGF-beta receptors and Smad2 protein.

    PubMed

    Lev, P R; Salim, J P; Marta, R F; Osorio, M J Mela; Goette, N P; Molinas, F C

    2007-02-01

    TGF-beta1 plays a main role in tissue repair by regulating extracellular matrix production and tissue granulation. Platelets are one of the main sources of this cytokine in the circulation. The aim of this study was to evaluate the presence of the TGF-beta receptors on platelets, the effect of TGF-beta1 on platelet aggregation and the underlying intracellular mechanisms. TGF-beta receptors on platelets were studied by flow cytometry and their mRNA by PCR. Platelet aggregation was assessed by turbidimetric methods and intracellular pathways by Western blot. TGF-beta receptor type II and mRNA codifying for TbetaRI and TbetaRII were found in platelets. We demonstrated that TGF-beta1 did not trigger platelet aggregation by itself but had a modulating effect on ADP-induced platelet aggregation. Either inhibition or increase in platelet aggregation, depending on the exposure time to TGF-beta1 and the ADP concentration used, were shown. We found that platelets possess Smad2 protein and that its phosphorylation state is increased after exposure to TGF-beta1. Besides, TGF-beta1 modified the pattern of ADP-induced tyrosine phosphorylation. Increased phosphorylation levels of 64-, 80- and 125-kDa proteins during short time incubation with TGF-beta1 and increased phosphorylation of 64- and 125-kDa proteins after longer incubation were observed. The modulating effect of TGF-beta1 on platelet aggregation could play a role during pathological states in which circulating TGF-beta1 levels are increased and intravascular platelet activation is present, such as myeloproliferative disorders. In vascular injury, in which platelet activation followed by granule release generates high local ADP concentrations, it could function as a physiological mechanism of platelet activation control.

  9. Simultaneous beta and gamma spectroscopy

    DOEpatents

    Farsoni, Abdollah T.; Hamby, David M.

    2010-03-23

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  10. Experimental Investigation of Microbially Induced Corrosion of Test Samples and Effect of Self-Assembled Hydrophobic Monolayers. Exposure of Test Samples to Continuous Microbial Cultures, Chemical Analysis, and Biochemical Studies

    SciTech Connect

    Laurinavichius, K.S.

    1998-09-30

    The study of biocorrosion of aluminum and beryllium samples were performed under conditions of continuous fermentation of thermophilic anaerobic microorganisms of different groups. This allowed us to examine the effect of various types of metabolic reactions of reduction-oxidation proceeding at different pH and temperatures under highly reduced conditions on aluminum and beryllium corrosion and effect of self-assembled hydrophobic monolayers.

  11. Cellular Responses to Beta Blocker Exposures in Marine Bivalves

    EPA Science Inventory

    β blockers are prescription drugs used for medical treatment of hypertension and arrhythmias. They prevent activation of adenylate cyclase and increases in blood pressure by limiting cAMP production and protein kinase A activation. After being taken therapeutically, β b...

  12. Marine Bivalve Cellular Responses to Beta Blocker Exposures

    EPA Science Inventory

    β blockers are prescription drugs used for medical treatment of hypertension and arrhythmias. They prevent binding of agonists such as catecholamines to β adrenoceptors. In the absence of agonist induced activation of the receptor, adenylate cyclase is not activated whi...

  13. [Cutaneous radiation syndrome after accidental skin exposure to ionizing radiation].

    PubMed

    Peter, R U

    2013-12-01

    Accidental exposure of the human skin to single doses of ionizing radiation greater than 3 Gy results in a distinct clinical picture, which is characterized by a transient and faint erythema after a few hours, then followed by severe erythema, blistering and necrosis. Depending on severity of damage, the latter generally occurs 10-30 days after exposure, but in severe cases may appear within 48 hrs. Between three and 24 months after exposure, epidermal atrophy combined with progressive dermal and subcutaneous fibrosis is the predominant clinical feature. Even years and decades after exposure, atrophy of epidermis, sweat and sebaceous glands; telangiectases; and dermal and subcutaneous fibrosis may be found and even continue to progress. For this distinct pattern of deterministic effects following cutaneous accidental radiation exposure the term "cutaneous radiation syndrome (CRS)" was coined in 1993 and has been accepted by all international authorities including IAEA and WHO since 2000. In contrast to the classical concept that inhibition of epidermal stem cell proliferation accounts for the clinical symptomatology, research of the last three decades has demonstrated the additional crucial role of inflammatory processes in the etiology of both acute and chronic sequelae of the CRS. Therefore, therapeutic approaches should include topical and systemic anti-inflammatory measures at the earliest conceivable point, and should be maintained throughout the acute and subacute stages, as this reduces the need for surgical intervention, once necrosis has occurred. If surgical intervention is planned, it should be executed with a conservative approach; no safety margins are needed. Antifibrotic measures in the chronic stage should address the chronic inflammatory nature of this process, in which over-expression TGF beta-1 may be a target for therapeutic intervention. Life-long follow-up often is required for management of delayed effects and for early detection of secondary

  14. Low-exposure tritium radiotoxicity in mammals

    SciTech Connect

    Dobson, R.L.

    1982-02-11

    Studies of tritium radiotoxicity involving chronic /sup 3/H0H exposures in mammals demonstrate in both mice and monkeys that biological effects can be measured following remarkably low levels of exposure - levels in the range of serious practical interest to radiation protection. These studies demonstrate also that deleterious effects of /sup 3/H beta radiation do not differ significantly from those of gamma radiation at high exposures. In contrast, however, at low exposures tritium is significantly more effective than gamma rays, rad for rad, by a factor approaching 3. This is important for hazard evaluation and radiation protection because knowledge concerning biological effects of chronic low-level radiation exposure has come mainly from gamma-ray data; and predictions based on gamma-ray data will underestimate tritium effects - especially at low exposures - unless the RBE is fully taken into account.

  15. Beta 1D integrin displaces the beta 1A isoform in striated muscles: localization at junctional structures and signaling potential in nonmuscle cells.

    PubMed

    Belkin, A M; Zhidkova, N I; Balzac, F; Altruda, F; Tomatis, D; Maier, A; Tarone, G; Koteliansky, V E; Burridge, K

    1996-01-01

    The cytoplasmic domains of integrins provide attachment of these extracellular matrix receptors to the cytoskeleton and play a critical role in integrin-mediated signal transduction. In this report we describe the identification, expression, localization, and initial functional characterization of a novel form of beta 1 integrin, termed beta 1D. This isoform contains a unique alternatively spliced cytoplasmic domain of 50 amino acids, with the last 24 amino acids encoded by an additional exon. Of these 24 amino acids, 11 are conserved when compared to the beta 1A isoform, but 13 are unique (Zhidkova, N. I., A. M. Belkin, and R. Mayne. 1995. Biochem. Biophys. Res. Commun. 214:279-285; van der Flier, A., I. Kuikman, C. Baudoin, R, van der Neuf, and A. Sonnenberg. 1995. FEBS Lett. 369:340-344). Using an anti-peptide antibody against the beta 1D integrin subunit, we demonstrated that the beta 1D isoform is synthesized only in skeletal and cardiac muscles, while very low amounts of beta 1A were detected by immunoblot in striated muscles. Whereas beta 1A could not be detected in adult skeletal muscle fibers and cardiomyocytes by immunofluorescence, beta 1D was localized to the sarcolemma of both cell types. In skeletal muscle, beta 1D was concentrated in costameres, myotendinous, and neuromuscular junctions. In cardiac muscle this beta 1 isoform was found in costamers and intercalated discs. beta 1D was associated with alpha 7A and alpha 7B in adult skeletal muscle. In cardiomyocytes of adult heart, alpha 7B was the major partner for the beta 1D isoform. beta 1D could not be detected in proliferating C2C12 myoblasts, but it appeared immediately after myoblast fusion and its amount continued to rise during myotube growth and maturation. In contrast, expression of the beta 1A isoform was downregulated during myodifferentiation in culture and it was completely displaced by beta 1D in mature differentiated myotubes. We also analyzed some functional properties of the beta 1D

  16. [Beta]-Adrenergic Receptors in the Insular Cortex are Differentially Involved in Aversive vs. Incidental Context Memory Formation

    ERIC Educational Resources Information Center

    Miranda, Maria Isabel; Sabath, Elizabeth; Nunez-Jaramillo, Luis; Puron-Sierra, Liliana

    2011-01-01

    The goal of this research was to determine the effects of [beta]-adrenergic antagonism in the IC before or after inhibitory avoidance (IA) training or context pre-exposure in a latent inhibition protocol. Pretraining intra-IC infusion of the [beta]-adrenergic antagonist propranolol disrupted subsequent IA retention and impaired latent inhibition…

  17. Wind-Forced Baroclinic Beta-Plumes

    NASA Astrophysics Data System (ADS)

    Belmadani, A.; Maximenko, N. A.; Melnichenko, O.; Schneider, N.; Di Lorenzo, E.

    2011-12-01

    A planetary beta-plume is a classical example of oceanic circulation induced by a localized vorticity source or sink that allows an analytical description in simplistic cases. Its barotropic structure is a zonally-elongated, gyre-like cell governed by the Sverdrup circulation on the beta-plane. The dominant zonal currents, found west of the source/sink, are often referred to as zonal jets. This simple picture describes the depth-integrated flow. Previous studies have investigated beta-plumes in a reduced-gravity framework or using other simple models with a small number of vertical layers, thereby lacking representation of the vertical structure. In addition, most previous studies use a purely linear regime without considering the role of eddies. However, these jets are often associated with strong lateral shear that makes them unstable under increased forcing. The circulation in such a nonlinear regime may involve eddy-mean flow interactions, which modify the time-averaged circulation. Here, the baroclinic structures of linear and nonlinear wind-forced beta-plumes are studied using a continuously-stratified, primitive equation, eddy-permitting ocean model (ROMS). The model is configured in an idealized rectangular domain for the subtropical ocean with a flat bottom. The surface wind forcing is a steady anticyclonic Gaussian wind vortex, which provides a localized vorticity source in the center of the domain. The associated wind stress curl and Ekman pumping comprise downwelling in the vortex center surrounded by a ring of weaker upwelling. Under weak forcing, the simulated steady-state circulation corresponds well with a theoretical linear beta-plume. While its depth-integrated transport exhibits a set of zonal jets, consistent with Sverdrup theory, the baroclinic structure of the plume is remarkably complex. Relatively fast westward decay of the surface currents occurs simultaneously with the deepening of the lower boundary of the plume. This deepening suggests

  18. Amyloid Beta Mediates Memory Formation

    ERIC Educational Resources Information Center

    Garcia-Osta, Ana; Alberini, Cristina M.

    2009-01-01

    The amyloid precursor protein (APP) undergoes sequential cleavages to generate various polypeptides, including the amyloid [beta] (1-42) peptide (A[beta][1-42]), which is believed to play a major role in amyloid plaque formation in Alzheimer's disease (AD). Here we provide evidence that, in contrast with its pathological role when accumulated,…

  19. 21 CFR 866.3050 - Beta-glucan serological assays.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Beta-glucan serological assays. 866.3050 Section 866.3050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3050...

  20. 21 CFR 866.3050 - Beta-glucan serological assays.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Beta-glucan serological assays. 866.3050 Section 866.3050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3050...

  1. 21 CFR 866.3050 - Beta-glucan serological assays.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Beta-glucan serological assays. 866.3050 Section 866.3050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3050...

  2. 21 CFR 866.3050 - Beta-glucan serological assays.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Beta-glucan serological assays. 866.3050 Section 866.3050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3050...

  3. 21 CFR 866.3050 - Beta-glucan serological assays.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Beta-glucan serological assays. 866.3050 Section 866.3050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3050...

  4. 21 CFR 522.84 - Beta-aminopropionitrile fumarate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Beta-aminopropionitrile fumarate. 522.84 Section 522.84 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  5. 21 CFR 522.84 - Beta-aminopropionitrile fumarate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Beta-aminopropionitrile fumarate. 522.84 Section 522.84 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  6. 21 CFR 522.84 - Beta-aminopropionitrile fumarate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Beta-aminopropionitrile fumarate. 522.84 Section 522.84 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  7. 21 CFR 522.84 - Beta-aminopropionitrile.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Beta-aminopropionitrile. 522.84 Section 522.84 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.84...

  8. 21 CFR 522.84 - Beta-aminopropionitrile fumarate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Beta-aminopropionitrile fumarate. 522.84 Section 522.84 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  9. RAVEN Beta Release

    SciTech Connect

    Rabiti, Cristian; Alfonsi, Andrea; Cogliati, Joshua Joseph; Mandelli, Diego; Kinoshita, Robert Arthur; Wang, Congjian; Maljovec, Daniel Patrick; Talbot, Paul William

    2016-02-01

    This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

  10. Just a beta....

    PubMed Central

    Lytle, K. S.; Bailey, D. W.; Dorman, K. F.; Moos, M. K.

    1999-01-01

    Traditional implementation of clinical information systems follows a predictable project management process. The selection, development, implementation, and evaluation of the system and the project management aspects of those phases require considerable time and effort. The purpose of this paper is to describe the beta site implementation of a knowledge-based clinical information system in a specialty area of a southeastern hospital that followed a less than traditional approach to implementation. Highlighted are brief descriptions of the hospital's traditional process, the nontraditional process, and key findings from the experience. Preliminary analysis suggests that selection of an implementation process is contextual. Selection of elements from each of these methods may provide a more useful process. The non-traditional process approached the elements of communication, areas of responsibility, training, follow-up and leadership differently. These elements are common to both processes and provide a focal point for future research. PMID:10566425

  11. Neutrinoless Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Fiorini, Ettore

    2007-06-01

    The recent results showing the presence of neutrino oscillations clearly indicate that the difference between the squared mass of neutrinos of different flavors is different from zero, but are unable to determine the nature and the absolute value of the neutrino mass. Neutrinoless double beta decay (DBD) is at present the most powerful tool to ascertain if the neutrino is a Majorana particle and to determine under this condition the absolute value of its mass. The results already obtained in this lepton violating process will be reported and the two presently running DBD experiments briefly discussed. The future second generation experiments will be reviewed with special emphasis to those already partially approved. In conclusion the peculiar and interdisciplinary nature of these searches will be stressed in their exciting aim to discover if neutrino is Dirac or Majorana particle.

  12. Superallowed Fermi beta decay

    SciTech Connect

    Hardy, J. C.; Towner, I. S.

    1998-12-21

    Superallowed 0{sup +}{yields}0{sup +} nuclear beta decay provides a direct measure of the weak vector coupling constant, G{sub V}. We survey current world data on the nine accurately determined transitions of this type, which range from the decay of {sup 10}C to that of {sup 54}Co, and demonstrate that the results confirm conservation of the weak vector current (CVC) but differ at the 98% confidence level from the unitarity condition for the Cabibbo-Kobayashi-Maskawa (CKM) matrix. We examine the reliability of the small calculated corrections that have been applied to the data, and assess the likelihood of even higher quality nuclear data becoming available to confirm or deny the discrepancy. Some of the required experiments depend upon the availability of intense radioactive beams. Others are possible today.

  13. Double beta decay: Calorimeters

    NASA Astrophysics Data System (ADS)

    Brofferio, Chiara

    2008-11-01

    Calorimeters or, with a more specific definition, low temperature detectors, have been used by now for more than 15 years in Double Beta Decay (DBD) searches, with excellent results: they compete with Ge diodes for the rank of detectors with the highest sensitivity to the effective neutrino mass, which is defined as a linear combination of the neutrino mass eigenvalues. After a brief introduction to the argument, with some notes on DBD and on bolometers, an update on the now closed experiment CUORICINO and on its successor, CUORE, is given. The fundamental role of background is then revealed and commented, introducing in this way the importance of the specific experiment now under construction, CUORE-0, that will precede CUORE to help optimizing the struggle against surface background. The possible future of this technique is then commented, quoting important R&D studies that are going on, for active shielding bolometers and for scintillating bolometers coupled with light detecting bolometers.

  14. Beta-adrenergic or parasympathetic inhibition, heart rate and cardiac output during normoxic and acute hypoxic exercise in humans.

    PubMed

    Hopkins, Susan R; Bogaard, Harm J; Niizeki, Kyuichi; Yamaya, Yoshiki; Ziegler, Michael G; Wagner, Peter D

    2003-07-15

    Acute hypoxia increases heart rate (HR) and cardiac output (Qt) at a given oxygen consumption (VO2) during submaximal exercise. It is widely believed that the underlying mechanism involves increased sympathetic activation and circulating catecholamines acting on cardiac beta receptors. Recent evidence indicating a continued role for parasympathetic modulation of HR during moderate exercise suggests that increased parasympathetic withdrawal plays a part in the increase in HR and Qt during hypoxic exercise. To test this, we separately blocked the beta-sympathetic and parasympathetic arms of the autonomic nervous system (ANS) in six healthy subjects (five male, one female; mean +/- S.E.M. age = 31.7+/-1.6 years, normoxic maximal VO2 (VO2,max)=3.1+/-0.3 l min(-1)) during exercise in conditions of normoxia and acute hypoxia (inspired oxygen fraction=0.125) to VO2,max. Data were collected on different days under the following conditions: (1)control, (2) after 8.0 mg propranolol i.v. and (3) after 0.8 mg glycopyrrolate i.v. Qt was measured using open-circuit acetylene uptake. Hypoxia increased venous [adrenaline] and [noradrenaline] but not [dopamine] at a given VO2 (P<0.05, P<0.01 and P=0.2, respectively). HR/VO2 and Qt/VO2 increased during hypoxia in all three conditions (P<0.05). Unexpectedly, the effects of hypoxia on HR and Qt were not significantly different from control with either beta-sympathetic or parasympathetic inhibition. These data suggest that although acute exposure to hypoxia increases circulating [catecholamines], the effects of hypoxia on HR and Qt do not necessarily require intact cardiac muscarinic and beta receptors. It may be that cardiac alpha receptors play a primary role in elevating HR and Qt during hypoxic exercise, or perhaps offer an alternative mechanism when other ANS pathways are blocked.

  15. The evolution of A beta peptide burden in the APP23 transgenic mice: implications for A beta deposition in Alzheimer disease.

    PubMed Central

    Kuo, Y. M.; Beach, T. G.; Sue, L. I.; Scott, S.; Layne, K. J.; Kokjohn, T. A.; Kalback, W. M.; Luehrs, D. C.; Vishnivetskaya, T. A.; Abramowski, D.; Sturchler-Pierrat, C.; Staufenbiel, M.; Weller, R. O.; Roher, A. E.

    2001-01-01

    BACKGROUND: High levels of A beta in the cerebral cortex distinguish demented Alzheimer's disease (AD) from nondemented elderly individuals, suggesting that decreased amyloid-beta (A beta) peptide clearance from the brain is a key precipitating factor in AD. MATERIALS AND METHODS: The levels of A beta in brain and plasma as well as apolipoprotein E (ApoE) in brain were investigated by enzyme-linked immunosorbent assay (ELISA) and Western blotting at various times during the life span of the APP23 transgenic (Tg) and control mice. Histochemistry and immunocytochemistry were used to assess the morphologic characteristics of the brain parenchymal and cerebrovascular amyloid deposits and the intracellular amyloid precursor protein (APP) deposits in the APP23 Tg mice. RESULTS: No significant differences were found in the plasma levels of A beta between the APP23 Tg and control mice from 2-20 months of age. In contrast, soluble A beta levels in the brain were continually elevated, increasing 4-fold at 2 months and 33-fold in the APP23 Tg mice at 20 months of age when compared to the control mice. Soluble A beta42 was about 60% higher than A beta40. In the APP23 Tg mice, insoluble A beta40 remained at basal levels in the brain until 9 months and then rose to 680 microg/g cortex by 20 months. Insoluble A beta40 was negligible in non-Tg mice at all ages. Insoluble A beta42 in APP23 Tg mice rose to 60 microg/g cortex at 20 months, representing 24 times the control A beta42 levels. Elevated levels of ApoE in the brain were observed in the APP23 Tg mice at 2 months of age, becoming substantially higher by 20 months. ApoE colocalized with A beta in the plaques. Beta-amyloid precursor protein (betaAPP) deposits were detected within the neuronal cytoplasm from 4 months of age onward. Amyloid angiopathy in the APP23 Tg mice increased markedly with age, being by far more severe than in the Tg2576 mice. CONCLUSIONS: We suggest that the APP23 Tg mouse may develop an earlier blockage

  16. DIFFERENTIAL EXPRESSION OF CAROTENE-15, 15'-OXYGENASE AND CAROTENE-9', 10'-OXYGENASE IN SELECTED FERRET TISSUES AFTER BETA-CRYPTOXANTHIN SUPPLEMENTATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dietary intake of foods rich in carotenoids, including beta-carotene, beta-cryptoxanthin and lycopene, continue to be associated with a decreased risk of several chronic diseases. While this association continues to persist, the metabolic fate of many carotenoids continues to be elucidated. The car...

  17. Nicotine-induced up-regulation and desensitization of alpha4beta2 neuronal nicotinic receptors depend on subunit ratio.

    PubMed

    López-Hernández, Gretchen Y; Sánchez-Padilla, Javier; Ortiz-Acevedo, Alejandro; Lizardi-Ortiz, José; Salas-Vincenty, Janice; Rojas, Legier V; Lasalde-Dominicci, José A

    2004-09-03

    Desensitization induced by chronic nicotine exposure has been hypothesized to trigger the up-regulation of the alpha4beta2 neuronal nicotinic acetylcholine receptor (nAChR) in the central nervous system. We studied the effect of acute and chronic nicotine exposure on the desensitization and up-regulation of different alpha4beta2 subunit ratios (1alpha:4beta, 2alpha:3beta, and 4alpha:1beta) expressed in Xenopus oocytes. The presence of alpha4 subunit in the oocyte plasmatic membrane increased linearly with the amount of alpha4 mRNA injected. nAChR function and expression were assessed during acute and after chronic nicotine exposure using a two-electrode voltage clamp and whole-mount immunofluorescence assay along with confocal imaging for the detection of the alpha4 subunit. The 2alpha4:3beta2 subunit ratio displayed the highest ACh sensitivity. Nicotine dose-response curves for the 1alpha4:4beta2 and 2alpha4:3beta2 subunit ratios displayed a biphasic behavior at concentrations ranging from 0.1 to 300 microm. A biphasic curve for 4alpha4:1beta2 was obtained at nicotine concentrations higher than 300 microm. The 1alpha4:4beta2 subunit ratio exhibited the lowest ACh- and nicotine-induced macroscopic current, whereas 4alpha4:1beta2 presented the largest currents at all agonist concentrations tested. Desensitization by acute nicotine exposure was more evident as the ratio of beta2:alpha4 subunits increased. All three alpha4beta2 subunit ratios displayed a reduced state of activation after chronic nicotine exposure. Chronic nicotine-induced up-regulation was obvious only for the 2alpha4: 3beta2 subunit ratio. Our data suggest that the subunit ratio of alpha4beta2 determines the functional state of activation, desensitization, and up-regulation of this neuronal nAChR. We propose that independent structural sites regulate alpha4beta2 receptor activation and desensitization.

  18. Effects of embryonic and adult exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin on hepatic microsomal testosterone hydroxylase activities in great blue herons (Ardea herodias)

    SciTech Connect

    Sanderson, J.T.; Giesy, J.P.; Janz, D.M.; Bellward, G.D.

    1997-06-01

    In a continuing effort to evaluate biomarkers of exposure of great blue herons (Ardea herodias) to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related halogenated aromatic hydrocarbons, the authors examined the effect of TCDD on hepatic microsomal testosterone hydroxylase activities. Heron embryos were exposed in ovo to 2 {micro}g TCDD/kg egg (or corn oil vehicle) and sacrificed at hatch or 7 d posthatch. Adult herons were exposed intraperitoneally to 20 {micro}g TCDD/kg and sacrificed 2 weeks later. The sex of the birds was known for the adults only. Hepatic microsomes of herons of each age group were able to hydroxylate testosterone at the 2{beta}, 6{beta}, 15{alpha}, 16{alpha}, or 16{beta} positions. In 7-d-old chicks, an additional unidentified compound was formed. The age of the untreated herons had a strong influence on the activities of the five hydroxylases, with changes of up to 17-fold. The TCDD significantly induced 2{beta}-, 6{beta}, and 15{alpha}-testosterone hydroxylase activities in the adult females, 15{alpha} in the adult males, and 6{beta}-testosterone hydroxylase activity in the hatchlings. In the 7-d-old chicks, induction was no longer apparent. A significant correlation existed between hepatic microsomal ethoxyresorufin O-deethylase (EROD) and 6{beta}-testosterone hydroxylase activity in hatchlings and adult female herons. The TCDD-induced changes in testosterone hydroxylase activities occurred at doses that resulted in tissue concentrations and levels of EROD induction that were environmentally relevant, but did not result in overt toxicities.

  19. Autoimmunity and beta cell regeneration in mouse and human type 1 diabetes: the peace is not enough.

    PubMed

    Ablamunits, Vitaly; Sherry, Nicole A; Kushner, Jake A; Herold, Kevan C

    2007-04-01

    Accumulating data from animal models of type 1 diabetes and some findings from clinical studies suggest that autoimmune destruction of islet beta cells is associated with enhanced beta cell regeneration. Successful immune therapies, aimed at preservation of islet cell mass, result in a remarkable reduction of beta cell regeneration. Treated or not, as long as the task of treatment is limited by "making peace" with autoimmunity, the process of beta cell loss continues. Additional therapeutic modalities capable of stimulating beta cell regeneration in the absence of active autoimmune destruction are urgently needed.

  20. High Temperature Stability of Potassium Beta Alumina

    NASA Technical Reports Server (NTRS)

    Williams, R. M.; Kisor, A.; Ryan, M. A.

    1996-01-01

    None. From Objectives section: Evaluate the stability of potassium beta alumina under potassium AMTEC operating conditions. Evaluate the stability regime in which potassium beta alumina can be fabricated.

  1. Human Beta-papillomavirus infection and keratinocyte carcinomas.

    PubMed

    Quint, Koen D; Genders, Roel E; de Koning, Maurits N C; Borgogna, Cinzia; Gariglio, Marisa; Bouwes Bavinck, Jan Nico; Doorbar, John; Feltkamp, Mariet C

    2015-01-01

    Although the role of oncogenic human Alpha-papillomaviruses (HPVs) in the development of mucosal carcinomas at different body sites (eg cervix, anus, oropharynx) is fully recognized, a role for HPV in keratinocyte carcinomas (KCs; basal and squamous cell carcinomas) of the skin is not yet clear. KCs are the most common cancers in Caucasians, with the major risk factor being ultraviolet (UV) light exposure. A possible role for Beta-HPV types (BetaPV) in the development of KC was suggested several decades ago, supported by a number of epidemiological studies. Our current review summarizes the recent molecular and histopathological evidence in support of a causal association between BetaPV and the development of KC, and outlines the suspected synergistic effect of viral gene expression with UV radiation and immune suppression. Further insights into the molecular pathways and protein interactions used by BetaPV and the host cell is likely to extend our understanding of the role of BetaPV in KC.

  2. beta- and gamma-Comparative dose estimates on Enewetak Atoll.

    PubMed

    Crase, K W; Gudiksen, P H; Robison, W L

    1982-05-01

    Enewetak Atoll is one of the Pacific atolls used for atmospheric testing of U.S. nuclear weapons. Beta dose and gamma-ray exposure measurements were made on two islands of the Enewetak Atoll during July-August 1976 to determine the beta and low energy gamma-contribution to the total external radiation doses to the returning Marshallese. Measurements were made at numerous locations with thermoluminescent dosimeters (TLD), pressurized ionization chambers, portable NaI detectors, and thin-window pancake GM probes. Results of the TLD measurements with and without a beta-attenuator indicate that approx. 29% of the total dose rate at 1 m in air is due to beta- or low energy gamma-contribution. The contribution at any particular site, however, is somewhat dependent on ground cover, since a minimal amount of vegetation will reduce it significantly from that over bare soil, but thick stands of vegetation have little effect on any further reductions. Integral 30-yr external shallow dose estimates for future inhabitants were made and compared with external dose estimates of a previous large scale radiological survey (En73). Integral 30-yr shallow external dose estimates are 25-50% higher than whole body estimates. Due to the low penetrating ability of the beta's or low energy gamma's, however, several remedial actions can be taken to reduce the shallow dose contribution to the total external dose.

  3. Beta Blockade and Clinical Outcomes in Aneurysmal Subarachnoid Hemorrhage

    PubMed Central

    Chang, Melody M.; Raval, Ronak N.; Southerland, Jessie J.; Adewumi, Dare A.; Bahjri, Khaled A.; Samuel, Rajeev K.; Woods, Rafeek O.; Ajayi, Olaide O.; Lee, Bryan S.; Hsu, Frank P. K.; Applegate II, Richard L.; Dorotta, Ihab R.

    2016-01-01

    Background: Aneurysmal subarachnoid hemorrhages are frequently complicated by hypertension and neurogenic myocardial stunning. Beta blockers may be used for management of these complications. We sought to investigate sympathetic nervous system modulation by beta blockers and their effect on radiographic vasospasm, delayed cerebral infarction, discharge destination and death. Methods: Retrospective chart review of 218 adults admitted to the ICU between 8/2004 and 9/2010 was performed. Groups were identified relevant to beta blockade: 77 were never beta blocked (No/No), 123 received post-admission beta blockers (No/Yes), and 18 were continued on their home beta blockers (Yes/Yes). Records were analyzed for baseline characteristics and the development of vasospasm, delayed cerebral infarction, discharge destination and death, expressed as adjusted odds ratio. Results: Of the 218 patients 145 patients developed vasospasm, 47 consequently infarcted, and 53 died or required care in a long-term facility. When compared to No/No patients, No/Yes patients had significantly increased vasospasm (OR 2.11 (1.06-4.16)). However, these patients also had significantly fewer deaths or need for long term care (OR 0.17 (0.05-0.64)), with decreased tendency for infarcts (OR 0.70 (0.32-1.55)). When compared to No/No patients, Yes/Yes patients demonstrated a trend toward increased vasospasm (OR 1.61 (0.50-5.29)) that led to infarction (OR 1.51 (0.44-5.13)), but with decreased mortality or need for long term care in a facility (OR 0.13 (0.01-1.30)). Conclusion: Post-admission beta blockade in aneurysmal subarachnoid hemorrhage patients was associated with increased incidence of vasospasm. However, despite the increased occurrence of vasospasm, beta blockers were associated with improved discharge characteristics and fewer deaths. PMID:28217182

  4. Amyloid-beta Alzheimer targets — protein processing, lipid rafts, and amyloid-beta pores

    PubMed Central

    Arbor, Sage C.; LaFontaine, Mike; Cumbay, Medhane

    2016-01-01

    Amyloid beta (Aβ), the hallmark of Alzheimer’s Disease (AD), now appears to be deleterious in its low number aggregate form as opposed to the macroscopic Aβ fibers historically seen postmortem. While Alzheimer targets, such as the tau protein, amyloid precursor protein (APP) processing, and immune system activation continue to be investigated, the recent discovery that amyloid beta aggregates at lipid rafts and likely forms neurotoxic pores has led to a new paradigm regarding why past therapeutics may have failed and how to design the next round of compounds for clinical trials. An atomic resolution understanding of Aβ aggregates, which appear to exist in multiple conformations, is most desirable for future therapeutic development. The investigative difficulties, structures of these small Aβ aggregates, and current therapeutics are summarized in this review. PMID:27505013

  5. Allosteric modulation of alpha4beta2 nicotinic acetylcholine receptors by HEPES.

    PubMed

    Weltzin, Maegan M; Huang, Yanzhou; Schulte, Marvin K

    2014-06-05

    A number of new positive allosteric modulators (PAMs) have been reported that enhance responses of neuronal alpha7 and alpha4beta2 nicotinic acetylcholine receptor subtypes to orthosteric ligands. PAMs represent promising new leads for the development of therapeutic agents for disorders involving alterations in nicotinic neurotransmission including Autism, Alzheimer's and Parkinson's disease. During our recent studies of alpha4beta2 PAMs, we identified a novel effect of 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES). The effects of HEPES were evaluated in a phosphate buffered recording solution using two-electrode voltage clamp techniques and alpha4beta2 and alpha7 nicotinic acetylcholine receptor subtypes expressed in Xenopus laevis oocytes. Acetylcholine induced responses of high-sensitivity alpha4beta2 receptors were potentiated 190% by co-exposure to HEPES. Responses were inhibited at higher concentrations (bell-shaped concentration/response curve). Coincidentally, at concentrations of HEPES typically used in oocyte recording (5-10mM), the potentiating effects of HEPES are matched by its inhibitory effects, thus producing no net effect. Mutagenesis results suggest HEPES potentiates the high-sensitivity stoichiometry of the alpha4beta2 receptors through action at the beta2+/beta2- interface and is dependent on residue beta2D218. HEPES did not potentiate low-sensitivity alpha4beta2 receptors and did not produce any observable effect on acetylcholine induced responses on alpha7 nicotinic acetylcholine receptors.

  6. EXPOSURE ANALYSIS

    EPA Science Inventory

    This proceedings chapter will discuss the state-of-the-science regarding the evaluation of exposure as it relates to water quality criteria (WQC), sediment quality guidelines (SQG), and wildlife criteria (WC). Throughout this discussion, attempts are made to identify the methods ...

  7. [Enterobacteria producing extended spectrum beta-lactamases].

    PubMed

    Lucet, J C; Régnier, B

    1998-04-01

    Extended-spectrum beta-lactamases (ESBL) were first observed in 1983. Since then, the number and variety of ESBLs have increased rapidly, particularly in France, and their distribution is now worldwide. The number of ESBLs has now reached more than 30, some of them spreading largely in several countries, such as SHV-4 in France. Intensive care units were first involved. Patients from nursing homes may recirculate ESBLs into acute care units. ESBL clinical epidemiology does not differ from other enterobacteriaceae. Digestive tract is the main reservoir, hands are the route of transmission. Infection develops in about 50% of colonized patients, more than one-half being urinary tract infections. Risk factors for colonization or infection are length of exposure to an epidemic strain and frequency of health-care-worker contact. Strategies for containing spreading of ESBL-producing strains include use of barrier precautions for carriers. Judicious use of antimicrobial agents is also important, by decreasing antibiotic selective pressure.

  8. Variants of beta-glucosidases

    SciTech Connect

    Fidantsef, Ana; Lamsa, Michael; Gorre-Clancy, Brian

    2014-10-07

    The present invention relates to variants of a parent beta-glucosidase, comprising a substitution at one or more positions corresponding to positions 142, 183, 266, and 703 of amino acids 1 to 842 of SEQ ID NO: 2 or corresponding to positions 142, 183, 266, and 705 of amino acids 1 to 844 of SEQ ID NO: 70, wherein the variant has beta-glucosidase activity. The present invention also relates to nucleotide sequences encoding the variant beta-glucosidases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  9. Variants of beta-glucosidase

    SciTech Connect

    Fidantsef, Ana; Lamsa, Michael; Gorre-Clancy, Brian

    2015-07-14

    The present invention relates to variants of a parent beta-glucosidase, comprising a substitution at one or more positions corresponding to positions 142, 183, 266, and 703 of amino acids 1 to 842 of SEQ ID NO: 2 or corresponding to positions 142, 183, 266, and 705 of amino acids 1 to 844 of SEQ ID NO: 70, wherein the variant has beta-glucosidase activity. The present invention also relates to nucleotide sequences encoding the variant beta-glucosidases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  10. Variants of beta-glucosidase

    DOEpatents

    Fidantsef, Ana; Lamsa, Michael; Gorre-Clancy, Brian

    2009-12-29

    The present invention relates to variants of a parent beta-glucosidase, comprising a substitution at one or more positions corresponding to positions 142, 183, 266, and 703 of amino acids 1 to 842 of SEQ ID NO: 2 or corresponding to positions 142, 183, 266, and 705 of amino acids 1 to 844 of SEQ ID NO: 70, wherein the variant has beta-glucosidase activity. The present invention also relates to nucleotide sequences encoding the variant beta-glucosidases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  11. Variants of beta-glucosidases

    DOEpatents

    Fidantsef, Ana; Lamsa, Michael; Clancy, Brian Gorre

    2008-08-19

    The present invention relates to variants of a parent beta-glucosidase, comprising a substitution at one or more positions corresponding to positions 142, 183, 266, and 703 of amino acids 1 to 842 of SEQ ID NO: 2 or corresponding to positions 142, 183, 266, and 705 of amino acids 1 to 844 of SEQ ID NO: 70, wherein the variant has beta-glucosidase activity. The present invention also relates to nucleotide sequences encoding the variant beta-glucosidases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  12. Beta-Blockers and Calcium Channel Blockers: First Line Agents.

    PubMed

    Pascual, Isaac; Moris, Cesar; Avanzas, Pablo

    2016-08-01

    Beta-blockers and calcium channel blockers (CCB) are milestones in the treatment of stable coronary ischaemic disease. Their main effects are particularly suited for the management of effort-induced angina because of the reduction of oxygen demand they achieve. The clinical benefits of these drugs are highly reproducible and have been shown to improve overall clinical outcomes. Despite the availability of other, and newer antianginal drugs, treatment guidelines continue to recommend the use of beta-blockers and calcium channel blockers as first line therapies.

  13. Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Fiorini, Ettore

    2010-12-01

    Almost exactly seventy years ago and only one year before his tragic disappearance the ingenious idea of Ettore Majorana is becoming one of the most important step in the development of fundamental physics. The problem of the nature of the neutrino, namely if it is a massless Dirac particle different from its antineutrino or a Majorana particle with finite mass, is discussed. In fact the recent results showing the presence of neutrino oscillations clearly indicates that the difference between the squared mass of neutrinos of different flavours is finite. Neutrinoless double beta decay (DBD) is at present the most powerful tool to determine the effective value of the mass of a Majorana neutrino. The results already obtained in this lepton violating process will be reported and the two presently running DBD experiments briefly discussed. The future second generation experiments will be reviewed with special emphasis to those already at least partially approved. In conclusion the peculiar and interdisciplinary nature of these searches will be stressed in their exciting aim to discover if neutrino is indeed a Majorana particle.

  14. Noise exposure of music teachers.

    PubMed

    Behar, Alberto; MacDonald, Ewen; Lee, Jason; Cui, Jie; Kunov, Hans; Wong, Willy

    2004-04-01

    A noise exposure survey was performed to assess the risk of hearing loss to school music teachers during the course of their activities. Noise exposure of 18 teachers from 15 schools was measured using noise dosimeters. The equivalent continuous noise level (L(eq)) of each teacher was recorded during single activities (classes) as well as for the entire day, and a normalized 8-hour exposure, termed the noise exposure level (L(ex)) was also computed. The measured L(eq) exceeded the 85-dBA limit for 78% of the teachers. L(ex) exceeded 85 dBA for 39% of the teachers. Limited recommendations on how to reduce the noise exposures are provided. The need for a hearing conservation program has also been emphasized.

  15. Evolution of outer membrane beta-barrels from an ancestral beta beta hairpin.

    PubMed

    Remmert, M; Biegert, A; Linke, D; Lupas, A N; Söding, J

    2010-06-01

    Outer membrane beta-barrels (OMBBs) are the major class of outer membrane proteins from Gram-negative bacteria, mitochondria, and plastids. Their transmembrane domains consist of 8-24 beta-strands forming a closed, barrel-shaped beta-sheet around a central pore. Despite their obvious structural regularity, evidence for an origin by duplication or for a common ancestry has not been found. We use three complementary approaches to show that all OMBBs from Gram-negative bacteria evolved from a single, ancestral beta beta hairpin. First, we link almost all families of known single-chain bacterial OMBBs with each other through transitive profile searches. Second, we identify a clear repeat signature in the sequences of many OMBBs in which the repeating sequence unit coincides with the structural beta beta hairpin repeat. Third, we show that the observed sequence similarity between OMBB hairpins cannot be explained by structural or membrane constraints on their sequences. The third approach addresses a longstanding problem in protein evolution: how to distinguish between a very remotely homologous relationship and the opposing scenario of "sequence convergence." The origin of a diverse group of proteins from a single hairpin module supports the hypothesis that, around the time of transition from the RNA to the protein world, proteins arose by amplification and recombination of short peptide modules that had previously evolved as cofactors of RNAs.

  16. Beta particle monitor for surfaces

    DOEpatents

    MacArthur, Duncan W.

    1997-01-01

    A beta radiation detector which is capable of reliably detecting beta radiation emitted from a surface. An electrically conductive signal collector is adjustably mounted inside an electrically conductive enclosure which may define a single large opening for placing against a surface. The adjustable mounting of the electrically conductive signal collector can be based on the distance from the surface or on the expected beta energy range. A voltage source is connected to the signal collector through an electrometer or other display means for creating an electric field between the signal collector and the enclosure. Air ions created by the beta radiation are collected and the current produced is indicated on the electrometer or other display means.

  17. Interferon Beta-1b Injection

    MedlinePlus

    ... course of disease where symptoms flare up from time to time) of multiple sclerosis (MS, a disease in which ... interferon beta-1b injection at around the same time of day each time you inject it. Follow ...

  18. Peginterferon Beta-1a Injection

    MedlinePlus

    ... course of disease where symptoms flare up from time to time) of multiple sclerosis (MS, a disease in which ... peginterferon beta-1a injection at around the same time of day each time you inject it. Follow ...

  19. Genetics Home Reference: beta thalassemia

    MedlinePlus

    ... a blood disorder that reduces the production of hemoglobin . Hemoglobin is the iron-containing protein in red blood ... In people with beta thalassemia , low levels of hemoglobin lead to a lack of oxygen in many ...

  20. Beta particle monitor for surfaces

    DOEpatents

    MacArthur, D.W.

    1997-10-21

    A beta radiation detector which is capable of reliably detecting beta radiation emitted from a surface. An electrically conductive signal collector is adjustably mounted inside an electrically conductive enclosure which may define a single large opening for placing against a surface. The adjustable mounting of the electrically conductive signal collector can be based on the distance from the surface or on the expected beta energy range. A voltage source is connected to the signal collector through an electrometer or other display means for creating an electric field between the signal collector and the enclosure. Air ions created by the beta radiation are collected and the current produced is indicated on the electrometer or other display means. 2 figs.

  1. Questions Students Ask: Beta Decay.

    ERIC Educational Resources Information Center

    Koss, Jordan; Hartt, Kenneth

    1988-01-01

    Answers a student's question about the emission of a positron from a nucleus. Discusses the problem from the aspects of the uncertainty principle, beta decay, the Fermi Theory, and modern physics. (YP)

  2. Organic dust induced pulmonary disease - the role of mould derived beta-glucan.

    PubMed

    Rylander, Ragnar

    2010-01-01

    The objective of the study was to evaluate the role of the mould cell wall agent beta-glucan in environmentally related pulmonary disease. All published articles where beta-glucan was administered by the airways, either as intratracheal injection or as inhalation were utilised as data sources. Data reporting consisted of analysis of data reports concerning the effects of beta-glucan on the immune system on the cellular level, particularly on the aggregation of inflammatory cells or production of inflammatory cytokines. High doses of soluble and particulate beta-glucan cause an inflammatory response characterized by cytokine activation and neutrophil invasion in the lung tissue. At lower doses, closer to environmental exposure levels, the predominant effect is an influence on the response to antigens, the reactivity of eosinophils and other Th2 driven immune responses. It is concluded that, beta-glucan can induce Th1 as well asTh2 driven immune responses. The pathology of atopy/allergy, hypersensitivity pneumonitis, and toxic penumonitis might be induced by exposure to beta-glucan. Measurements of beta-glucan in different environments are useful for risk control and prevention.

  3. Co-culture of clonal beta cells with GLP-1 and glucagon-secreting cell line impacts on beta cell insulin secretion, proliferation and susceptibility to cytotoxins.

    PubMed

    Green, Alastair D; Vasu, Srividya; Moffett, R Charlotte; Flatt, Peter R

    2016-06-01

    We investigated the direct effects on insulin releasing MIN6 cells of chronic exposure to GLP-1, glucagon or a combination of both peptides secreted from GLUTag L-cell and αTC1.9 alpha-cell lines in co-culture. MIN6, GLUTag and αTC1.9 cell lines exhibited high cellular hormone content and release of insulin, GLP-1 and glucagon, respectively. Co-culture of MIN6 cells with GLUTag cells significantly increased cellular insulin content, beta-cell proliferation, insulin secretory responses to a range of established secretogogues and afforded protection against exposure cytotoxic concentrations of glucose, lipid, streptozotocin or cytokines. Benefits of co-culture of MIN6 cells with αTC1.9 alphacells were limited to enhanced beta-cell proliferation with marginal positive actions on both insulin secretion and cellular protection. In contrast, co-culture of MIN6 with GLUTag cells plus αTC1.9 cells, markedly enhanced both insulin secretory responses and protection against beta-cell toxins compared with co-culture with GLUTag cells alone. These data indicate important long-term effects of conjoint GLP-1 and glucagon exposure on beta-cell function. This illustrates the possible functional significance of alpha-cell GLP-1 production as well as direct beneficial effects of dual agonism at beta-cell GLP-1 and glucagon receptors.

  4. Exposure chamber

    DOEpatents

    Moss, Owen R.; Briant, James K.

    1983-01-01

    An exposure chamber includes an imperforate casing having a fluid inlet at the top and an outlet at the bottom. A single vertical series of imperforate trays is provided. Each tray is spaced on all sides from the chamber walls. Baffles adjacent some of the trays restrict and direct the flow to give partial flow back and forth across the chambers and downward flow past the lowermost pan adjacent a central plane of the chamber.

  5. Apollo applications of beta fiber glass

    NASA Technical Reports Server (NTRS)

    Naimer, J.

    1971-01-01

    The physical characteristics of Beta fiber glass are discussed. The application of Beta fiber glass for fireproofing the interior of spacecraft compartments is described. Tests to determine the flammability of Beta fiber glass are presented. The application of Beta fiber glass for commercial purposes is examined.

  6. Polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and polynucleotides encoding same

    DOEpatents

    Morant, Marc

    2017-02-07

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  7. Modulation of the TGF{beta}/Smad signaling pathway in mesangial cells by CTGF/CCN2

    SciTech Connect

    Abdel Wahab, Nadia . E-mail: nadia.wahab@imperial.ac.uk; Weston, Benjamin S.; Mason, Roger M.

    2005-07-15

    Transforming growth factor-beta (TGF{beta}) drives fibrosis in diseases such as diabetic nephropathy (DN). Connective tissue growth factor (CTGF; CCN2) has also been implicated in this, but the molecular mechanism is unknown. We show that CTGF enhances the TGF{beta}/Smad signaling pathway by transcriptional suppression of Smad 7 following rapid and sustained induction of the transcription factor TIEG-1. Smad 7 is a known antagonist of TGF{beta} signaling and TIEG-1 is a known repressor of Smad 7 transcription. CTGF enhanced TGF{beta}-induced phosphorylation and nuclear translocation of Smad 2 and Smad 3 in mesangial cells. Antisense oligonucleotides directed against TIEG-1 prevented CTGF-induced downregulation of Smad 7. CTGF enhanced TGF{beta}-stimulated transcription of the SBE4-Luc reporter gene and this was markedly reduced by TIEG-1 antisense oligonucleotides. Expression of the TGF{beta}-responsive genes PAI-1 and Col III over 48 h was maximally stimulated by TGF{beta} + CTGF compared to TGF{beta} alone, while CTGF alone had no significant effect. TGF{beta}-stimulated expression of these genes was markedly reduced by both CTGF and TIEG-1 antisense oligonucleotides, consistent with the endogenous induction of CTGF by TGF{beta}. We propose that under pathological conditions, where CTGF expression is elevated, CTGF blocks the negative feedback loop provided by Smad 7, allowing continued activation of the TGF{beta} signaling pathway.

  8. Residues of endosulfan in carp as an indicator of exposure conditions.

    PubMed

    Nowak, B; Goodsell, A; Julli, M

    1995-12-01

    : Endosulfan is an organochlorine insecticide, consisting of a mixture of two isomers: alpha and beta endosulfan. Endosulfan residues were determined in livers and gills of carp exposed to lethal and sublethal concentrations of endosulfan. The fish which were exposed to a lethal concentration contained the highest residue level in both liver and gills. In carp liver, the percentage of beta endosulfan in the residue decreased with time between exposure and collection of samples whereas the percentage of endosulfan sulphate increased. Carp killed by exposure to endosulfan had a significantly greater ratio of beta to alpha endosulfan and a significantly greater percentage of beta endosulfan in their livers. There was no such clear relationship for the residue composition in fish gills. The determination of residue composition, in particular the percentage of beta endosulfan or the ratio of beta to alpha isomers is recommended in investigations of fish kills when endosulfan is a suspected cause.

  9. Oxidative stress-induced alternative splicing of transformer 2beta (SFRS10) and CD44 pre-mRNAs in gastric epithelial cells.

    PubMed

    Takeo, Keiko; Kawai, Tomoko; Nishida, Kensei; Masuda, Kiyoshi; Teshima-Kondo, Shigetada; Tanahashi, Toshihito; Rokutan, Kazuhito

    2009-08-01

    The tra2beta gene encoding an alternative splicing regulator, transformer 2-beta (Tra2beta), generates five alternative splice variant transcripts (tra2beta1-5). Functionally active, full-length Tra2beta is encoded by tra2beta1 isoform. Expression and physiological significance of the other isoforms, particularly tra2beta4, are not fully understood. Rat gastric mucosa constitutively expressed tra2beta1 isoform and specifically generated tra2beta4 isoform that includes premature termination codon-containing exon 2, when exposed to restraint and water immersion stress. Treatment of a gastric cancer cell line (AGS) with arsenite (100 microM) preferentially generated tra2beta4 isoform and caused translocation of Tra2beta from the nucleus to the cytoplasm in association with enhanced phosphorylation during the initial 4-6 h (acute phase). Following the acute phase, AGS cells continued upregulated tra2beta1 mRNA expression, and higher amounts of Tra2beta were reaccumulated in their nuclei. Treatment with small interference RNAs targeting up-frameshift-1 or transfection of a plasmid containing tra2beta1 cDNA did not induce tra2beta4 isoform expression and did not modify the arsenite-induced expression of this isoform, suggesting that neither the nonsense-mediated mRNA decay nor the autoregulatory control by excess amounts of Tra2beta participated in the tra2beta4 isoform generation. Knockdown of Tra2beta facilitated skipping of the central variable region of the CD44 gene and suppressed cell growth. In contrast, overexpression of Tra2beta stimulated combinatorial inclusion of multiple variable exons in the region and cell growth. The similar skipping and inclusion of the variable region were observed in arsenite-treated cells. Our results suggest that Tra2beta may regulate cellular oxidative response by changing alternative splicing of distinct genes including CD44.

  10. Asymptotic expansions of the kernel functions for line formation with continuous absorption

    NASA Technical Reports Server (NTRS)

    Hummer, D. G.

    1991-01-01

    Asymptotic expressions are obtained for the kernel functions M2(tau, alpha, beta) and K2(tau, alpha, beta) appearing in the theory of line formation with complete redistribution over a Voigt profile with damping parameter a, in the presence of a source of continuous opacity parameterized by beta. For a greater than 0, each coefficient in the asymptotic series is expressed as the product of analytic functions of a and eta. For Doppler broadening, only the leading term can be evaluated analytically.

  11. Response-surface models for deterministic effects of localized irradiation of the skin by discrete {beta}/{gamma} -emitting sources

    SciTech Connect

    Scott, B.R.

    1995-12-01

    Individuals who work at nuclear reactor facilities can be at risk for deterministic effects in the skin from exposure to discrete {Beta}- and {gamma}-emitting ({Beta}{gamma}E) sources (e.g., {Beta}{gamma}E hot particles) on the skin or clothing. Deterministic effects are non-cancer effects that have a threshold and increase in severity as dose increases (e.g., ulcer in skin). Hot {Beta}{gamma}E particles are {sup 60}Co- or nuclear fuel-derived particles with diameters > 10 {mu}m and < 3 mm and contain at least 3.7 kBq (0.1 {mu}Ci) of radioactivity. For such {Beta}{gamma}E sources on the skin, it is the beta component of the dose that is most important. To develop exposure limitation systems that adequately control exposure of workers to discrete {Beta}{gamma}E sources, models are needed for systems that adequately control exposure of workers to discrete {Beta}{gamma}E sources, models are needed for evaluating the risk of deterministic effects of localized {Beta} irradiation of the skin. The purpose of this study was to develop dose-rate and irradiated-area dependent, response-surface models for evaluating risks of significant deterministic effects of localized irradiation of the skin by discrete {Beta}{gamma}E sources and to use modeling results to recommend approaches to limiting occupational exposure to such sources. The significance of the research results as follows: (1) response-surface models are now available for evaluating the risk of specific deterministic effects of localized irradiation of the skin; (2) modeling results have been used to recommend approaches to limiting occupational exposure of workers to {Beta} radiation from {Beta}{gamma}E sources on the skin or on clothing; and (3) the generic irradiated-volume, weighting-factor approach to limiting exposure can be applied to other organs including the eye, the ear, and organs of the respiratory or gastrointestinal tract and can be used for both deterministic and stochastic effects.

  12. RhlA converts beta-hydroxyacyl-acyl carrier protein intermediates in fatty acid synthesis to the beta-hydroxydecanoyl-beta-hydroxydecanoate component of rhamnolipids in Pseudomonas aeruginosa.

    PubMed

    Zhu, Kun; Rock, Charles O

    2008-05-01

    Pseudomonas aeruginosa secretes a rhamnolipid (RL) surfactant that functions in hydrophobic nutrient uptake, swarming motility, and pathogenesis. We show that RhlA supplies the acyl moieties for RL biosynthesis by competing with the enzymes of the type II fatty acid synthase (FASII) cycle for the beta-hydroxyacyl-acyl carrier protein (ACP) pathway intermediates. Purified RhlA forms one molecule of beta-hydroxydecanoyl-beta-hydroxydecanoate from two molecules of beta-hydroxydecanoyl-ACP and is the only enzyme required to generate the lipid component of RL. The acyl groups in RL are primarily beta-hydroxydecanoyl, and in vitro, RhlA has a greater affinity for 10-carbon substrates, illustrating that RhlA functions as a molecular ruler that selectively extracts 10-carbon intermediates from FASII. Eliminating either FabA or FabI activity in P. aeruginosa increases RL production, illustrating that slowing down FASII allows RhlA to more-effectively compete for beta-hydroxydecanoyl-ACP. In Escherichia coli, the rate of fatty acid synthesis increases 1.3-fold when RhlA is expressed, to ensure the continued formation of fatty acids destined for membrane phospholipid even though 24% of the carbon entering FASII is diverted to RL synthesis. Previous studies have placed a ketoreductase, called RhlG, before RhlA in the RL biosynthetic pathway; however, our experiments show that RhlG has no role in RL biosynthesis. We conclude that RhlA is necessary and sufficient to form the acyl moiety of RL and that the flux of carbon through FASII accelerates to support RL production and maintain a supply of acyl chains for phospholipid synthesis.

  13. Characteristics of beta detection and dose measurement at Department of Energy facilities

    SciTech Connect

    Mulvehill, J.M.; Brackenbush, L.W.

    1987-02-01

    This report considers the current state of the art of beta dosimetry practices and beta detection methods used by health physicists at US Department of Energy facilities. This information is based on a survey of DOE facilities. Beta measurements are technically difficult and innovative efforts must be expended to improve their accuracy. Perhaps the most pronounced problem is that beta dosimetry and instrumentation in use are highly energy and angular dependent. Many believe that beta exposures are adequately controlled because beta to photon ratios are assumed to be low. This assumption is not always valid as demonstrated by the accident at Three Mile Island (TMI). Significant beta doses exist where personnel are exposed to mixed fission products; for example, chemical reprocessing plants, reactor accidents, or where uranium metals are processed. This report is part of an effort to increase the DOE response to this technically difficult area of health protection. Problem areas are addressed and methods recommended to improve beta dosimetry through a cooperative effort among the various DOE contractors. 34 refs., 2 figs., 16 tabs.

  14. Nicotine trapping causes the persistent desensitization of alpha4beta2 nicotinic receptors expressed in oocytes.

    PubMed

    Jia, Li; Flotildes, Karen; Li, Maureen; Cohen, Bruce N

    2003-02-01

    To determine whether prolonged nicotine exposure persistently inactivates rat alpha4beta2 nicotinic receptors expressed in Xenopus oocytes, we measured the voltage-clamped alpha4beta2 response to acetylcholine (ACh) before and 24 h after, 1-h or 12-h incubations in 10 microm nicotine. A 12-h incubation in 10 microm nicotine depressed the alpha4beta2 ACh response for 24 h without affecting total or surface alpha4beta2 expression. To determine whether oocyte-mediated nicotine release caused this depression, we co-incubated an alpha4beta2-expressing oocyte with an un-injected one (pre-incubated in 10 microm nicotine for 12 h) for 24 h and measured the change in the alpha4beta2 ACh response. The response decreased by the same factor after the co-incubation as it did after a 12-h incubation in 10 microm nicotine and a 24-h incubation in nicotine-free media. Thus, oocyte-mediated nicotine release caused the persistent desensitization we observed after a 12-h incubation in 10 microm nicotine. Consistent with this result, measurements of [3H]nicotine release show that oocytes release enough nicotine into the wash media to desensitize alpha4beta2 receptors and that prolonged incubation in 300 microm ACh (which cannot readily cross the membrane or accumulate in acidic vesicles) did not persistently depress the alpha4beta2 response.

  15. Very slow turnover of beta-cells in aged adult mice.

    PubMed

    Teta, Monica; Long, Simon Y; Wartschow, Lynn M; Rankin, Matthew M; Kushner, Jake A

    2005-09-01

    Although many signaling pathways have been shown to promote beta-cell growth, surprisingly little is known about the normal life cycle of preexisting beta-cells or the signaling pathways required for beta-cell survival. Adult beta-cells have been speculated to have a finite life span, with ongoing adult beta-cell replication throughout life to replace lost cells. However, little solid evidence supports this idea. To more accurately measure adult beta-cell turnover, we performed continuous long-term labeling of proliferating cells with the DNA precursor analog 5-bromo-2-deoxyuridine (BrdU) in 1-year-old mice. We show that beta-cells of aged adult mice have extremely low rates of replication, with minimal evidence of turnover. Although some pancreatic components acquired BrdU label in a linear fashion, only 1 in approximately 1,400 adult beta-cells were found to undergo replication per day. We conclude that adult beta-cells are very long lived.

  16. Analysis of betaS and betaA genes in a Mexican population with African roots.

    PubMed

    Magaña, María Teresa; Ongay, Zoyla; Tagle, Juan; Bentura, Gilberto; Cobián, José G; Perea, F Javier; Casas-Castañeda, Maricela; Sánchez-López, Yoaly J; Ibarra, Bertha

    2002-01-01

    To investigate the origin of the beta(A) and beta(S) genes in a Mexican population with African roots and a high frequency of hemoglobin S, we analyzed 467 individuals (288 unrelated) from different towns in the states of Guerrero and Oaxaca in the Costa Chica region. The frequency of the sickle-cell trait was 12.8%, which may represent a public health problem. The frequencies of the beta-haplotypes were determined from 350 nonrelated chromosomes (313 beta(A) and 37 beta(S)). We observed 15 different beta(A) haplotypes, the most common of which were haplotypes 1 (48.9%), 2 (13.4%), and 3 (13.4%). The calculation of pairwise distributions and Nei's genetic distance analysis using 32 worldwide populations showed that the beta(A) genes are more closely related to those of Mexican Mestizos and North Africans. Bantu and Benin haplotypes and haplotype 9 were related to the beta(S) genes, with frequencies of 78.8, 18.2, and 3.0%, respectively. Comparison of these haplotypes with 17 other populations revealed a high similitude with the population of the Central African Republic. These data suggest distinct origins for the beta(A) and beta(S) genes in Mexican individuals from the Costa Chica region.

  17. Microbial flora analysis for the degradation of beta-cypermethrin.

    PubMed

    Qi, Zhang; Wei, Zhang

    2017-01-10

    In the Xinjiang region of Eurasia, sustained long-term and continuous cropping of cotton over a wide expanse of land is practiced, which requires application of high levels of pyrethroid and other classes of pesticides-resulting in high levels of pesticide residues in the soil. In this study, soil samples were collected from areas of long-term continuous cotton crops with the aim of obtaining microbial resources applicable for remediation of pyrethroid pesticide contamination suitable for the soil type and climate of that area. Soil samples were first used to culture microbial flora capable of degrading beta-cypermethrin using an enrichment culture method. Structural changes and ultimate microbial floral composition during enrichment were analyzed by high-throughput sequencing. Four strains capable of degrading beta-cypermethrin were isolated and preliminarily classified. Finally, comparative rates and speeds of degradation of beta-cypermethrin between relevant microbial flora and single strains were determined. After continuous subculture for 3 weeks, soil sample microbial flora formed a new type of microbial flora by rapid succession, which showed stable growth by utilizing beta-cypermethrin as the sole carbon source (GXzq). This microbial flora mainly consisted of Pseudomonas, Hyphomicrobium, Dokdonella, and Methyloversatilis. Analysis of the microbial flora also permitted separation of four additional strains; i.e., GXZQ4, GXZQ6, GXZQ7, and GXZQ13 that, respectively, belonged to Streptomyces, Enterobacter, Streptomyces, and Pseudomonas. Under culture conditions of 37 °C and 180 rpm, the degradation rate of beta-cypermethrin by GXzq was as high as 89.84% within 96 h, which exceeded that achieved by the single strains GXZQ4, GXZQ6, GXZQ7, and GXZQ13 and their derived microbial flora GXh.

  18. Adult and Continuing Education: Continuities and Discontinuities

    ERIC Educational Resources Information Center

    Tennant, Mark

    2005-01-01

    This paper presents a comprehensive review of the five-volume set, "Adult and Continuing Education." This publication is a monumental and diverse collection of material related directly or indirectly to the broad theme of adult and continuing education. The collection captures a great deal of the thought which has informed the…

  19. Fundamental processes in the interacting boson model: 0{nu}{beta}{beta} decay

    SciTech Connect

    Iachello, F.; Barea, J.

    2011-05-06

    A program to calculate nuclear matrix elements for fundamental processes in the interacting boson model has been initiated. Results for the nuclear matrix elements in neutrinoless double beta decay 0{nu}{beta}{beta} are presented.

  20. beta (+)-Thalassaemia in the Po river delta region (northern Italy): genotype and beta globin synthesis.

    PubMed Central

    Del Senno, L; Pirastu, M; Barbieri, R; Bernardi, F; Buzzoni, D; Marchetti, G; Perrotta, C; Vullo, C; Kan, Y W; Conconi, F

    1985-01-01

    Six beta(+)-thalassaemic patients from the Po river delta region have been studied. Using synthetic oligonucleotides as specific hybridisation probes, the beta(+) IVS I mutation (G----A at position 108) was demonstrated. This lesion and the enzyme polymorphism pattern in the subjects examined are the same as have been described for other Mediterranean beta(+)-thalassaemias. Antenatal diagnosis through DNA analysis of beta(+)-thalassaemia is therefore possible. The production of beta globin in a beta(+), homozygote and in a beta (+), beta(0) 39 (nonsense mutation at codon 39) double heterozygote is approximately 20% and 10% respectively of total non-alpha globin synthesis. Despite some overlapping of the results, similar beta globin synthesis levels have been obtained in 43 beta(+)-thalassaemia patients. This suggests that in the Po river delta region the most common thalassaemic genes are beta(0) 39 and beta(+) IVS I. Images PMID:2580095

  1. NEURODEVELOPMENTAL EFFECTS OF ENVIRONMENTAL EXPOSURES

    EPA Science Inventory

    Neurodevelopmental Effects of Environmental Exposures
    Sherry G. Selevan, Pauline Mendola, Deborah C. Rice (US EPA, Washington,
    DC)

    The nervous system starts development early in gestation and continues to develop through adolescence. Thus, critical windows of vuln...

  2. Ultraviolet radiation augments epidermal beta-adrenergic adenylate cyclase response

    SciTech Connect

    Iizuka, H.; Kajita, S.; Ohkawara, A.

    1985-05-01

    Pig skin was irradiated in vivo with fluorescent sunlamp tubes (peak emission at 305 nm). A significant increase in epidermal beta-adrenergic adenylate cyclase response was observed as early as 12 h following 1-2 minimum erythema doses (MEDs) UVB exposure, which lasted at least 48 h. The augmentation of adenylate cyclase response was relatively specific to the beta-adrenergic system and there was no significant difference in either adenosine- or histamine-adenylate cyclase response of epidermis. The increased beta-adrenergic adenylate cyclase response was less marked at higher doses of UVB exposure (5 MEDs); in the latter condition, a significant reduction in adenosine- or histamine-adenylate cyclase response was observed. There was no significant difference in either low- or high-Km cyclic AMP phosphodiesterase activity between control and UVB-treated skin at 1-2 MEDs. These data indicate that the epidermal adenylate cyclase responses are affected in vivo by UVB irradiation, which might be a significant regulatory mechanism of epidermal cyclic AMP systems.

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

    SciTech Connect

    Lee, Minyoung; Lee, Hae-June; Seo, Woo Duck; Park, Ki Hun; Lee, Yun-Sil

    2010-04-15

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

  4. Validation of the BETA-2 Score: An Improved Tool to Estimate Beta Cell Function After Clinical Islet Transplantation Using a Single Fasting Blood Sample.

    PubMed

    Forbes, S; Oram, R A; Smith, A; Lam, A; Olateju, T; Imes, S; Malcolm, A J; Shapiro, A M J; Senior, P A

    2016-09-01

    The beta score, a composite measure of beta cell function after islet transplantation, has limited sensitivity because of its categorical nature and requires a mixed-meal tolerance test (MMTT). We developed a novel score based on a single fasting blood sample. The BETA-2 score used stepwise forward linear regression incorporating glucose (in millimoles per liter), C-peptide (in nanomoles per liter), hemoglobin A1c (as a percentage) and insulin dose (U/kg per day) as continuous variables from the original beta score data set (n = 183 MMTTs). Primary and secondary analyses assessed the score's ability to detect glucose intolerance (90-min MMTT glucose ≥8 mmol/L) and insulin independence, respectively. A validation cohort of islet transplant recipients (n = 114 MMTTs) examined 12 mo after transplantation was used to compare the score's ability to detect these outcomes. The BETA-2 score was expressed as follows (range 0-42): [Formula: see text] A score <20 and ≥15 detected glucose intolerance and insulin independence, respectively, with >82% sensitivity and specificity. The BETA-2 score demonstrated greater discrimination than the beta score for these outcomes (p < 0.05). Using a fasting blood sample, the BETA-2 score estimates graft function as a continuous variable and shows greater discrimination of glucose intolerance and insulin independence after transplantation versus the beta score, allowing frequent assessments of graft function. Studies examining its utility to track long-term graft function are required.

  5. The microbial oxidation of (-)-beta-pinene by Botrytis cinerea.

    PubMed

    Farooq, Afgan; Choudhary, M Iqbal; Tahara, Satoshi; Rahman, Atta-ur; Başer, K Hüsnü Can; Demirci, Fatih

    2002-01-01

    (-)-beta-pinene, a flavor and fragrance monoterpene is an important constituent of essential oils of many aromatic plants. It was oxidized by a plant-pathogenic fungus, Botrytis cinerea to afford four metabolites characterized as (-)-6a-hydroxy-beta-pinene, (-)-4beta,5beta-dihydroxy-beta-pinene, (-)-2beta,3beta-dihydroxypinane, and (-)-4beta-hydroxy-beta-pinene-6-one by detailed spectroscopic studies along with other known metabolites.

  6. Individual Differences in Behavioural Despair Predict Brain GSK-3beta Expression in Mice: The Power of a Modified Swim Test

    PubMed Central

    Markova, Nataliia; Shevtsova, Elena; Bakhmet, Anastassia; Steinbusch, Harry M.

    2016-01-01

    While deficient brain plasticity is a well-established pathophysiologic feature of depression, little is known about disorder-associated enhanced cognitive processing. Here, we studied a novel mouse paradigm that potentially models augmented learning of adverse memories during development of a depressive-like state. We used a modification of the classic two-day protocol of a mouse Porsolt test with an additional session occurring on Day 5 following the initial exposure. Unexpectedly, floating behaviour and brain glycogen synthase kinase-3 beta (GSK-3beta) mRNA levels, a factor of synaptic plasticity as well as a marker of distress and depression, were increased during the additional swimming session that was prevented by imipramine. Observed increases of GSK-3beta mRNA in prefrontal cortex during delayed testing session correlated with individual parameters of behavioural despair that was not found in the classic Porsolt test. Repeated swim exposure was accompanied by a lower pGSK-3beta/GSK-3beta ratio. A replacement of the second or the final swim sessions with exposure to the context of testing resulted in increased GSK-3beta mRNA level similar to the effects of swimming, while exclusion of the second testing prevented these changes. Together, our findings implicate the activation of brain GSK-3beta expression in enhanced contextual conditioning of adverse memories, which is associated with an individual susceptibility to a depressive syndrome. PMID:27478647

  7. BETA-GAMMA PERSONNEL DOSIMETER

    DOEpatents

    Davis, D.M.; Gupton, E.D.; Hart, J.C.; Hull, A.P.

    1961-01-17

    A personnel dosimeter is offered which is sensitive to both gamma and soft beta radiations from all directions within a hemisphere. The device is in the shape of a small pill box which is worn on a worker-s wrist. The top and sides of the device are provided with 50 per cent void areas to give 50 per cent response to the beta rays and complete response to the gamma rays. The device is so constructed as to have a response which will approximate the dose received by the basal layer of the human epidermis.

  8. Interplanetary Lyman-beta emissions

    NASA Technical Reports Server (NTRS)

    Paresce, F.

    1973-01-01

    Derivation of the intensity of the diffuse hydrogen Lyman-beta glow at 1025 A which is due to resonance scattering of the solar H I 1025 A line by interstellar and interplanetary hydrogen. Two sources of neutral hydrogen are considered: the local interstellar medium interacting with the solar system, and the dust deionization of the H(+) component of the solar wind. It is shown that if the dust geometrical factor is less than or equal to five quintillionths per cm, observations of backscattered Lyman-beta radiation will provide a unique determination of the density and temperature of the local interstellar medium.

  9. Beta ray flux measuring device

    DOEpatents

    Impink, Jr., Albert J.; Goldstein, Norman P.

    1990-01-01

    A beta ray flux measuring device in an activated member in-core instrumentation system for pressurized water reactors. The device includes collector rings positioned about an axis in the reactor's pressure boundary. Activated members such as hydroballs are positioned within respective ones of the collector rings. A response characteristic such as the current from or charge on a collector ring indicates the beta ray flux from the corresponding hydroball and is therefore a measure of the relative nuclear power level in the region of the reactor core corresponding to the specific exposed hydroball within the collector ring.

  10. Tumors from rats given 1,2-dimethylhydrazine plus chlorophyllin or indole-3-carbinol contain transcriptional changes in beta-catenin that are independent of beta-catenin mutation status.

    PubMed

    Wang, Rong; Dashwood, W Mohaiza; Bailey, George S; Williams, David E; Dashwood, Roderick H

    2006-10-10

    Tumors induced in the rat by 1,2-dimethylhydrazine (DMH) contain mutations in beta-catenin, but the spectrum of such mutations can be influenced by phytochemicals such as chlorophyllin (CHL) and indole-3-carbinol (I3C). In the present study, we determined the mutation status of beta-catenin in more than 50 DMH-induced colon tumors and small intestine tumors, and compared this with the concomitant expression of beta-catenin mRNA using quantitative real-time RT-PCR analysis. In total, 19/57 (33%) of the tumors harbored mutations in beta-catenin, and 14/19 (74%) of the genetic changes substituted amino acids adjacent to Ser33, a key site for phosphorylation and beta-catenin degradation. These tumors were found to express a 10-fold range of beta-catenin mRNA levels, independent of the beta-catenin mutation status and phytochemical exposure, i.e. CHL or I3C given post-initiation. However, beta-catenin mRNA levels were strongly correlated with mRNA levels of c-myc, c-jun and cyclin D1, which are targets of beta-catenin/Tcf signaling. Tumors with the highest levels of beta-catenin mRNA often had over-expressed beta-catenin protein, and those with lower beta-catenin mRNA typically had low beta-catenin protein expression, but there were exceptions (high beta-catenin mRNA/low beta-catenin protein, or vice versa). We conclude that DMH-induced mutations stabilize beta-catenin protein in tumors, which increase c-myc, c-jun and cyclin D1, but there also can be over-expression of beta-catenin itself at the mRNA level, contributing to high beta-catenin protein levels. Similar findings have been reported in primary human colon cancers and their liver metastases, compared with matched normal-looking tissue. Thus, further studies are warranted on the mechanisms that upregulate beta-catenin at the transcriptional level in human and rodent colon cancers.

  11. Design, synthesis and 3D-QSAR of beta-carboline derivatives as potent antitumor agents.

    PubMed

    Cao, Rihui; Guan, Xiangdong; Shi, Buxi; Chen, Zhiyong; Ren, Zhenhua; Peng, Wenlie; Song, Huacan

    2010-06-01

    In a continuing effort to develop novel beta-carbolines endowed with better pharmacological profiles, a series of beta-carboline derivatives were designed and synthesized based on the previously developed SARs. Cytotoxicities in vitro of these compounds against a panel of human tumor cell lines were also investigated. The results demonstrated that the N2-benzylated beta-carbolinium bromides 56-60 represented the most potent compounds with IC50 values lower than 10 microM. The application of 3D-QSAR to these compounds explored the structural basis for their biological activities. CoMFA (q2=0.513, r2=0.862) and CoMSIA (q2=0.503, r2=0.831) models were developed for a set of 47 beta-carbolines. The results indicated that the antitumor pharmacophore of these molecules were marked at position-1, -2, -3, -7 and -9 of beta-carboline ring.

  12. Beta thalassaemia mutations in Turkish Cypriots.

    PubMed Central

    Sozuoz, A; Berkalp, A; Figus, A; Loi, A; Pirastu, M; Cao, A

    1988-01-01

    Using oligonucleotide hybridisation or restriction endonuclease analysis, we have characterised the molecular defect in 94 patients with thalassaemia major and four with thalassaemia intermedia of Turkish Cypriot descent. We found that four mutations, namely beta+ IVS-1 nt 110, beta zero IVS-1 nt, beta+ IVS-1 nt 6, and beta+ IVS-2 nt 745 were prevalent, accounting for 69.9%, 11.7%, 8.7%, and 5.6% respectively of the beta thalassaemia chromosomes. This information may help in the organisation of a large scale prevention programme based on fetal diagnosis of beta thalassaemia by DNA analysis in the Turkish population. PMID:3236356

  13. 47 CFR 95.1221 - RF exposure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false RF exposure. 95.1221 Section 95.1221 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES Medical Device Radiocommunication Service (MedRadio) § 95.1221 RF exposure. MedRadio...

  14. 47 CFR 95.1221 - RF exposure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false RF exposure. 95.1221 Section 95.1221 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES Medical Device Radiocommunication Service (MedRadio) § 95.1221 RF exposure. A MedRadio...

  15. 47 CFR 95.1221 - RF exposure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false RF exposure. 95.1221 Section 95.1221 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES Medical Device Radiocommunication Service (MedRadio) § 95.1221 RF exposure. MedRadio...

  16. 47 CFR 95.1221 - RF exposure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false RF exposure. 95.1221 Section 95.1221 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES Medical Device Radiocommunication Service (MedRadio) § 95.1221 RF exposure. A MedRadio...

  17. 47 CFR 95.1221 - RF exposure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false RF exposure. 95.1221 Section 95.1221 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES Medical Device Radiocommunication Service (MedRadio) § 95.1221 RF exposure. MedRadio...

  18. Exposure-effect relations between aircraft and road traffic noise exposure at school and reading comprehension: the RANCH project.

    PubMed

    Clark, Charlotte; Martin, Rocio; van Kempen, Elise; Alfred, Tamuno; Head, Jenny; Davies, Hugh W; Haines, Mary M; Lopez Barrio, Isabel; Matheson, Mark; Stansfeld, Stephen A

    2006-01-01

    Transport noise is an increasingly prominent feature of the urban environment, making noise pollution an important environmental public health issue. This paper reports on the 2001-2003 RANCH project, the first cross-national epidemiologic study known to examine exposure-effect relations between aircraft and road traffic noise exposure and reading comprehension. Participants were 2,010 children aged 9-10 years from 89 schools around Amsterdam Schiphol, Madrid Barajas, and London Heathrow airports. Data from The Netherlands, Spain, and the United Kingdom were pooled and analyzed using multilevel modeling. Aircraft noise exposure at school was linearly associated with impaired reading comprehension; the association was maintained after adjustment for socioeconomic variables (beta = -0.008, p = 0.012), aircraft noise annoyance, and other cognitive abilities (episodic memory, working memory, and sustained attention). Aircraft noise exposure at home was highly correlated with aircraft noise exposure at school and demonstrated a similar linear association with impaired reading comprehension. Road traffic noise exposure at school was not associated with reading comprehension in either the absence or the presence of aircraft noise (beta = 0.003, p = 0.509; beta = 0.002, p = 0.540, respectively). Findings were consistent across the three countries, which varied with respect to a range of socioeconomic and environmental variables, thus offering robust evidence of a direct exposure-effect relation between aircraft noise and reading comprehension.

  19. How Administration of the Beta-Blocker Propranolol Before Extinction can Prevent the Return of Fear.

    PubMed

    Kroes, Marijn C W; Tona, Klodiana-Daphne; den Ouden, Hanneke E M; Vogel, Susanne; van Wingen, Guido A; Fernández, Guillén

    2016-05-01

    Combining beta-blockers with exposure therapy has been advocated to reduce fear, yet experimental studies combining beta-blockers with memory reactivation have had contradictory results. We explored how beta-blockade might affect the course of safety learning and the subsequent return of fear in a double-blind placebo-controlled functional magnetic resonance imaging study in humans (N=46). A single dose of propranolol before extinction learning caused a loss of conditioned fear responses, and prevented the subsequent return of fear and decreased explicit memory for the fearful events in the absence of drug. Fear-related neural responses were persistently attenuated in the dorsal medial prefrontal cortex (dmPFC), increased in the hippocampus 24 h later, and correlated with individual behavioral indices of fear. Prediction error-related responses in the ventral striatum persisted during beta-blockade. We suggest that this pattern of results is most consistent with a model where beta-blockade can prevent the return of fear by (i) reducing retrieval of fear memory, via the dmPFC and (ii) increasing contextual safety learning, via the hippocampus. Our findings suggest that retrieval of fear memory and contextual safety learning form potential mnemonic target mechanisms to optimize exposure-based therapy with beta-blockers.

  20. Cross-Reactivity among Beta-Lactams.

    PubMed

    Romano, Antonino; Gaeta, Francesco; Arribas Poves, Maria Francisca; Valluzzi, Rocco Luigi

    2016-03-01

    Penicillins and cephalosporins are the major classes of beta-lactam (BL) antibiotics in use today and one of the most frequent causes of hypersensitivity reactions to drugs. Monobactams, carbapenems, oxacephems, and beta-lactamase inhibitors constitute the four minor classes of BLs. This review takes into account mainly the prospective studies which evaluated cross-reactivity among BLs in subjects with a well-demonstrated hypersensitivity to a certain class of BLs by performing allergy tests with alternative BLs and, in case of negative results, administering them. In subjects with either IgE-mediated or T-cell-mediated hypersensitivity, cross-reactivity among BLs, particularly among penicillins and among cephalosporins, as well as between penicillins and cephalosporins, seems to be mainly related to structural similarities among their side-chain determinants. Specifically, in penicillin-allergic subjects, cross-reactivity between penicillins and cephalosporins may exceed 30% when they are administered cephalosporins with identical side chains to those of responsible penicillins. In these subjects, a few prospective studies have demonstrated a rate of cross-reactivity between penicillins and both carbapenems and aztreonam lower than 1%. With regard to subjects with an IgE-mediated hypersensitivity to cephalosporins, in a single study, about 25% of the 98 subjects with such hypersensitivity had positive results to penicillins, 3% to aztreonam, 2% to imipenem/cilastatin, and 1% to meropenem. The cross-reactivity related to the selective recognition of the BL ring by IgE or T lymphocytes, which entails positive responses to all BLs tested, appears to be exceptional. Some studies concerning cross-reactivity among BLs have found patterns of allergy-test positivity which cannot be explained by either the common BL ring or by similar or identical side chains, thus indicating the possibility of coexisting sensitivities to different BLs because of prior exposures to them.

  1. Production of poly-(beta-hydroxybutyric-co-beta-hydroxyvaleric) acids.

    PubMed Central

    Ramsay, B A; Lomaliza, K; Chavarie, C; Dubé, B; Bataille, P; Ramsay, J A

    1990-01-01

    Alcaligenes latus, Alcaligenes eutrophus, Bacillus cereus, Pseudomonas pseudoflava, Pseudomonas cepacia, and Micrococcus halodenitrificans were found to accumulate poly-(beta-hydroxybutyric-co-beta-hydroxyvaleric) acid [P(HB-co-HV)] copolymer when supplied with glucose (or sucrose in the case of A. latus) and propionic acid under nitrogen-limited conditions. A fed-batch culture of A. eutrophus produced 24 g of poly-beta-hydroxybutyric acid (PHB) liter-1 under ammonium limitation conditions. When the glucose feed was replaced with glucose and propionic acid during the polymer accumulation phase, 17 g of P(HB-co-HV) liter-1 was produced. The P(HB-co-HV) contained 5.0 mol% beta-hydroxyvaleric acid (HV). Varying the carbon-to-nitrogen ratio at a dilution rate of 0.15 h-1 in a chemostat culture of A. eutrophus resulted in a maximum value of 33% (wt/wt) PHB in the biomass. In comparison, A. latus accumulated about 40% (wt/wt) PHB in chemostat culture under nitrogen-limited conditions at the same dilution rate. When propionic acid was added to the first stage of a two-stage chemostat, A. latus produced 43% (wt/wt) P(HB-co-HV) containing 18.5 mol% HV. In the second stage, the P(HB-co-HV) increased to 58% (wt/wt) with an HV content of 11 mol% without further addition of carbon substrate. The HV composition in P(HB-co-HV) was controlled by regulating the concentration of propionic acid in the feed. Poly-beta-hydroxyalkanoates containing a higher percentage of HV were produced when pentanoic acid replaced propionic acid. PMID:2117877

  2. 2-Hydroxy-4-glutathion-S-yl-17beta-estradiol and 2-hydroxy-1-glutathion-S-yl-17beta-estradiol produce oxidative stress and renal toxicity in an animal model of 17beta-estradiol-mediated nephrocarcinogenicity.

    PubMed

    Butterworth, M; Lau, S S; Monks, T J

    1998-01-01

    Chronic exposure of male Syrian hamsters to a variety of estrogens has been linked with a high incidence of renal carcinoma. The basis of this species and tissue specificity remains to be resolved. We have recently shown that (i) 17beta-estradiol is nephrotoxic in the hamster in a manner dependent upon the activity of gamma-glutamyl transpeptidase and (ii) 17beta-estradiol is metabolized to a variety of catechol estrogen glutathione conjugates (Butterworth et al., Carcinogenesis, 18, 561-567, 1997). We report that the catechol estrogen glutathione conjugates exhibit redox properties similar to those of the catechol estrogens, and maintain the ability to generate superoxide radicals. Administration of 2-hydroxy-4-glutathion-S-yl-17beta-estradiol or 2-hydroxy-1-glutathion-S-yl-17beta-estradiol (0.27-5.0 micromol/kg) to Syrian hamsters, produces mild nephrotoxicity. Repeated daily administration of 2-hydroxy-4-glutathion-S-yl-17beta-estradiol causes a sustained elevation in urinary markers of renal damage and in the concentration of renal protein carbonyls and lipid hydroperoxides. Catechol estrogen oxidation and conjugation of glutathione in the liver, followed by the selective uptake of the redox active conjugates in tissues rich in gamma-glutamyl transpeptidase may contribute to 17beta-estradiol-induced renal tumors in the hamster.

  3. The mammalian beta-tubulin repertoire: hematopoietic expression of a novel, heterologous beta-tubulin isotype

    PubMed Central

    1986-01-01

    We describe the structure of a novel and unusually heterologous beta- tubulin isotype (M beta 1) isolated from a mouse bone marrow cDNA library, and a second isotype (M beta 3) isolated from a mouse testis cDNA library. Comparison of M beta 1 and M beta 3 with the completed (M beta 4, M beta 5) or extended (M beta 2) sequence of three previously described beta-tubulin isotypes shows that each includes a distinctive carboxy-terminal region, in addition to multiple amino acid substitutions throughout the polypeptide chain. In every case where a mammalian interspecies comparison can be made, both the carboxy- terminal and internal amino acid substitutions that distinguish one isotype from another are absolutely conserved. We conclude that these characteristic differences are important in determining functional distinctions between different kinds of microtubule. The amino acid homologies between M beta 2, M beta 3, M beta 4, and M beta 5 are in the range of 95-97%; however the homology between M beta 1 and all the other isotypes is very much less (78%). The dramatic divergence in M beta 1 is due to multiple changes that occur throughout the polypeptide chain. The overall level of expression of M beta 1 is low, and is restricted to those tissues (bone marrow, spleen, developing liver and lung) that are active in hematopoiesis in the mouse. We predict that the M beta 1 isotype is functionally specialized for assembly into the mammalian marginal band. PMID:3782288

  4. Caliber Schools. Caliber: Beta Academy

    ERIC Educational Resources Information Center

    EDUCAUSE, 2015

    2015-01-01

    Caliber: Beta Academy is reimagining education as we know it, with the belief that the innovations in its model will allow 100% of its students to graduate ready to attend and succeed in a competitive four-year college and beyond. The academic model of the school features personalized learning plans, blended learning for English and math,…

  5. Beta-Amyloid Deposition and Alzheimer's Type Changes Induced by Borrelia Spirochetes

    SciTech Connect

    Miklossy,J.; Kis, A.; Radenovic, A.; Miller, L.; Forro, L.; Martins, R.; Reiss, K.; Darbinian, N.; Darekar, P.; et al.

    2006-01-01

    The pathological hallmarks of Alzheimer's disease (AD) consist of {beta}-amyloid plaques and neurofibrillary tangles in affected brain areas. The processes, which drive this host reaction are unknown. To determine whether an analogous host reaction to that occurring in AD could be induced by infectious agents, we exposed mammalian glial and neuronal cells in vitro to Borrelia burgdorferi spirochetes and to the inflammatory bacterial lipopolysaccharide (LPS). Morphological changes analogous to the amyloid deposits of AD brain were observed following 2-8 weeks of exposure to the spirochetes. Increased levels of {beta}-amyloid presursor protein (A{beta}PP) and hyperphosphorylated tau were also detected by Western blots of extracts of cultured cells that had been treated with spirochetes or LPS. These observations indicate that, by exposure to bacteria or to their toxic products, host responses similar in nature to those observed in AD may be induced.

  6. mTOR links incretin signaling to HIF induction in pancreatic beta cells.

    PubMed

    Van de Velde, Sam; Hogan, Meghan F; Montminy, Marc

    2011-10-11

    Under feeding conditions, the incretin hormone GLP-1 promotes pancreatic islet viability by triggering the cAMP pathway in beta cells. Increases in PKA activity stimulate the phosphorylation of CREB, which in turn enhances beta cell survival by upregulating IRS2 expression. Although sustained GLP-1 action appears important for its salutary effects on islet function, the transient nature of CREB activation has pointed to the involvement of additional nuclear factors in this process. Following the acute induction of CREB-regulated genes, cAMP triggers a second delayed phase of gene expression that proceeds via the HIF transcription factor. Increases in cAMP promote the accumulation of HIF1α in beta cells by activating the mTOR pathway. As exposure to rapamycin disrupts GLP-1 effects on beta cell viability, these results demonstrate how a pathway associated with tumor growth also mediates salutary effects of an incretin hormone on pancreatic islet function.

  7. Experimental study of double-{beta} decay modes using a CdZnTe detector array

    SciTech Connect

    Dawson, J. V.; Goessling, C.; Koettig, T.; Muenstermann, D.; Rajek, S.; Schulz, O.; Janutta, B.; Zuber, K.; Junker, M.; Reeve, C.; Wilson, J. R.

    2009-08-15

    An array of sixteen 1 cm{sup 3} CdZnTe semiconductor detectors was operated at the Gran Sasso Underground Laboratory (LNGS) to further investigate the feasibility of double-{beta} decay searches with such devices. As one of the double-{beta} decay experiments with the highest granularity the 4x4 array accumulated an overall exposure of 18 kg days. The setup and performance of the array is described. Half-life limits for various double-{beta} decay modes of Cd, Zn, and Te isotopes are obtained. No signal has been found, but several limits beyond 10{sup 20} years have been performed. They are an order of magnitude better than those obtained with this technology before and comparable to most other experimental approaches for the isotopes under investigation. An improved limit for the {beta}{sup +}/EC decay of {sup 120}Te is given.

  8. Effects of chronic delta-9-THC treatment on cardiac beta-adrenoceptors in rats

    SciTech Connect

    Evans, E.B.; Seifen, E.; Kennedy, R.H.; Kafiluddi, R.; Paule, M.G.; Scallet, A.C.; Ali, S.F.; Slikker, W. Jr.

    1987-10-01

    This study was designed to determine if chronic treatment with delta-9-tetrahydrocannabinol (THC) alters cardiac beta-adrenoceptors in the rat. Following daily oral administration of 10 or 20 mg/kg THC or an equivalent volume of control solvent for 90 days, rats were sacrificed, and sarcolemmal membranes were prepared from ventricular myocardium. Beta-adrenoceptor density and binding affinity estimated with (-)(/sup 3/H)dihydroalprenolol; a beta-adrenergic antagonist, were not significantly affected by treatment with THC when compared to vehicle controls. These results suggest that the tolerance to cardiovascular effects of THC which develops during chronic exposure in the rat is not associated with alterations in cardiac beta-adrenoceptors as monitored by radiolabeled antagonist binding.

  9. Neutron beta decay studies with Nab

    NASA Astrophysics Data System (ADS)

    Baeßler, S.; Alarcon, R.; Alonzi, L. P.; Balascuta, S.; Barrón-Palos, L.; Bowman, J. D.; Bychkov, M. A.; Byrne, J.; Calarco, J. R.; Chupp, T.; Cianciolo, T. V.; Crawford, C.; Frlež, E.; Gericke, M. T.; Glück, F.; Greene, G. L.; Grzywacz, R. K.; Gudkov, V.; Harrison, D.; Hersman, F. W.; Ito, T.; Makela, M.; Martin, J.; McGaughey, P. L.; McGovern, S.; Page, S.; Penttilä, S. I.; Počanić, D.; Rykaczewski, K. P.; Salas-Bacci, A.; Tompkins, Z.; Wagner, D.; Wilburn, W. S.; Young, A. R.

    2013-10-01

    Precision measurements in neutron beta decay serve to determine the coupling constants of beta decay and allow for several stringent tests of the standard model. This paper discusses the design and the expected performance of the Nab spectrometer.

  10. How Do Beta Blocker Drugs Affect Exercise?

    MedlinePlus

    ... Aneurysm More How do beta blocker drugs affect exercise? Updated:Aug 5,2015 Beta blockers are a ... about them: Do they affect your ability to exercise? The answer can vary a great deal, depending ...

  11. Can Beta Blockers Cause Weight Gain?

    MedlinePlus

    Diseases and Conditions High blood pressure (hypertension) Can beta blockers cause weight gain? Answers from Sheldon G. Sheps, ... can occur as a side effect of some beta blockers, especially the older ones, such as atenolol (Tenormin) ...

  12. Mitochondrial and peroxisomal beta-oxidation capacities of organs from a non-oilseed plant.

    PubMed

    Masterson, C; Wood, C

    2001-09-22

    Until recently, beta-oxidation was believed to be exclusively located in the peroxisomes of all higher plants. Whilst this is true for germinating oilseeds undergoing gluconeogenesis, evidence demonstrating mitochondrial beta-oxidation in other plant systems has refuted this central dogma of plant lipid metabolism. This report describes a comparative study of the dual mitochondrial and peroxisomal beta-oxidation capacities of plant organs. Oxidation of [1-(14)C] palmitate was measured in the cotyledons, plumules and radicles of Pisum sativum L., which is a starchy seed, over a 14 day period from the commencement of imbibition. Respiratory chain inhibitors were used for differentiating between mitochondrial and peroxisomal beta-oxidation. Peroxisomal beta-oxidation gave a steady, baseline rate and, in the early stages of seedling development, accounted for 70-100% of the beta-oxidation observed. Mitochondrial beta-oxidation gave peaks of activity at days 7 and 10-11, accounting for up to 82% of the total beta-oxidation activity at these times. These peaks coincide with key stages of seedling development and were not observed when normal development was disrupted by growth in the dark. Peroxisomal beta-oxidation was unaffected by etiolation. Since mitochondrial beta-oxidation was overt only during times of intense biosynthetic activity it might be switched on or off during seedling development. In contrast, peroxisomes maintained a continuous, low beta-oxidation activity that could be essential in removing harmful free fatty acids, e.g. those produced by protein and lipid turnover.

  13. Exposure chamber

    DOEpatents

    Moss, Owen R.

    1980-01-01

    A chamber for exposing animals, plants, or materials to air containing gases or aerosols is so constructed that catch pans for animal excrement, for example, serve to aid the uniform distribution of air throughout the chamber instead of constituting obstacles as has been the case in prior animal exposure chambers. The chamber comprises the usual imperforate top, bottom and side walls. Within the chamber, cages and their associated pans are arranged in two columns. The pans are spaced horizontally from the walls of the chamber in all directions. Corresponding pans of the two columns are also spaced horizontally from each other. Preferably the pans of one column are also spaced vertically from corresponding pans of the other column. Air is introduced into the top of the chamber and withdrawn from the bottom. The general flow of air is therefore vertical. The effect of the horizontal pans is based on the fact that a gas flowing past the edge of a flat plate that is perpendicular to the flow forms a wave on the upstream side of the plate. Air flows downwardly between the chamber walls and the outer edges of the pan. It also flows downwardly between the inner edges of the pans of the two columns. It has been found that when the air carries aerosol particles, these particles are substantially uniformly distributed throughout the chamber.

  14. Chemical and microbiologic aspects of penems, a distinct class of beta-lactams: focus on faropenem.

    PubMed

    Hamilton-Miller, Jeremy M T

    2003-11-01

    Many beta-lactam antimicrobials were developed between the 1960s and 1980s, with continuing development driven by the emergence of microbial resistance. Penems form a discrete class of beta-lactams that comprises structural hybrids of penicillins (penams) and cephalosporins (cephems). The chemistry and microbiology of the representative penems MEN 10700, ritipenem, CGP 31608, sulopenem, BRL 42715, and faropenem are reviewed. Particular emphasis is placed on faropenem, which is in late clinical development.

  15. Promotion of embryonic chick limb cartilage differentiation by transforming growth factor-beta.

    PubMed

    Kulyk, W M; Rodgers, B J; Greer, K; Kosher, R A

    1989-10-01

    This study represents a first step in investigating the possible involvement of transforming growth factor-beta (TGF-beta) in the regulation of embryonic chick limb cartilage differentiation. TGF-beta 1 and 2 (1-10 ng/ml) elicit a striking increase in the accumulation of Alcian blue, pH 1-positive cartilage matrix, and a corresponding twofold to threefold increase in the accumulation of 35S-sulfate- or 3H-glucosamine-labeled sulfated glycosaminoglycans (GAG) by high density micromass cultures prepared from the cells of whole stage 23/24 limb buds or the homogeneous population of chondrogenic precursor cells comprising the distal subridge mesenchyme of stage 25 wing buds. Moreover, TGF-beta causes a striking (threefold to sixfold) increase in the steady-state cytoplasmic levels of mRNAs for cartilage-characteristic type II collagen and the core protein of cartilage-specific proteoglycan. Only a brief (2 hr) exposure to TGF-beta at the initiation of culture is sufficient to stimulate chondrogenesis, indicating that the growth factor is acting at an early step in the process. Furthermore, TGF-beta promotes the formation of cartilage matrix and cartilage-specific gene expression in low density subconfluent spot cultures of limb mesenchymal cells, which are situations in which little, or no chondrogenic differentiation normally occurs. These results provide strong incentive for considering and further investigating the role of TGF-beta in the control of limb cartilage differentiation.

  16. Stress-induced changes of interleukin-1beta within the limbic system in the rat.

    PubMed

    Badowska-Szalewska, E; Klejbor, I; Sidor-Kaczmarek, J; Cecot, T; Lietzau, G; Spodnik, J H; Moryś, J

    2009-08-01

    The aim of this study was to investigate the influence of two periods of life, namely P28 and P360, on the changes in interleukin-1beta (IL-1beta) immunoreactivity (-ir) in the hippocampus (CA1, CA3, DG) and amygdala (central-CeA, medial-MeA) caused by acute and repeated open field (OF), or by forced swim (FS) exposition. Rats were divided into groups: non-stressed, exposed to acute (one-time for 15 min) and chronic stressors (21 days for 15 min daily). We found IL-1beta-ir in the control group to be higher in P360 than in P28. In P28, under OF and FS exposure, IL-1beta-ir in the CeA remained unaltered but increased in the MeA and in the hippocampus after acute and chronic stress. In P360 no changes were observed in the IL-1beta-ir level after acute and chronic stimulation. These data demonstrate that only the levels of IL-1beta-ir in juvenile rat brains are affected by FS and OF. Additionally, there was no significant difference between FS and OF stimulation in IL-1beta-ir.

  17. Urinary N-acetyl-beta-D-glucosaminidase and beta-aminoisobutyric acid in workers occupationally exposed to metals such as chromium, nickel, and iron.

    PubMed

    Tomokuni, K; Ichiba, M; Hirai, Y

    1993-01-01

    To examine the relationships between the urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) and beta-aminoisobutyric acid (AIBA) as a metabolite of thymine, and exposure to chromium, nickel, and iron, we determined these parameters in 58 workers engaged in the cutting and grinding of stainless steel or iron-steel plates. A significant increase in urinary NAG activity or urinary AIBA excretion was found in some of these workers. However, we could not find a significant positive correlation between the urinary excretion of NAG or AIBA and the urinary concentration of chromium, nickel, or iron as an indicator of internal dose.

  18. Programmes in Continuing Education

    ERIC Educational Resources Information Center

    Shah, L. R.

    1976-01-01

    The various types and forms of credit and non-credit university continuing education programmes are described in these extracts from a paper presented at the Hyderabad conference on university continuing education. (ABM)

  19. Forskolin delays the ethanol-induced desensitization of hypothalamic beta-endorphin neurons in primary cultures.

    PubMed

    Boyadjieva, N; Reddy, B V; Sarkar, D K

    1997-05-01

    Ethanol and its metabolite acetaldehyde have been shown to stimulate immunoreactive beta-endorphin (IR-beta-EP) secretion from hypothalamic neurons in primary cultures. Also, chronic ethanol and acetal-dehyde have been shown to cause the development of tolerance and desensitization of these neurons. In this study, we determined some of the cellular events leading to desensitization of the function of beta-endorphin (beta-EP) secretory neurons. The fetal hypothalamic cells were treated with various doses of ethanol (25 and 50 mM) or acetaldehyde (6.25, 12.5, and 25 mM) for 6 hr or treated with these drugs at 12 hr intervals for 72 hr. Determination of IR-beta-EP concentrations in the media revealed that ethanol increased IR-beta-EP secretion from these cultures for 12 hr, after this period, the cultured cells did not respond to ethanol. Acetaldehyde stimulated IR-beta-EP secretion from this culture for a period of 48 hr, but the IR-beta-EP secretory response to acetaldehyde reduced gradually with time during the first 48-hr period and reached the basal level at 72 hr. The desensitization of beta-EP neurons 12 hr after treatment with alcohol did not seem to be related to the loss of viable cells, because chronic ethanol exposures did not produce any effect on cell viability. However, reduced IR- beta-EP secretory response to acetaldehyde with time was associated with the time-dependent increase in cell death. Pretreatment of cultures with a cAMP analog, forskolin, increased the activity of functional beta-EP neurons and delayed the ethanol desensitization effects on these neurons. Pretreatment of forskolin did not delay the acetaldehyde desensitization of beta-EP neurons, but protected these cells from acetaldehyde toxicity. These results suggest that (i) chronic treatment with ethanol desensitizes beta-EP-secreting neurons due to reduced cellular functions and (ii) chronic acetaldehyde reduces beta-EP neurotransmission due to cell death. Furthermore, data suggest

  20. beta. -decay asymmetry of the free neutron

    SciTech Connect

    Bopp, P.; Dubbers, D.; Klemt, E.; Last, J.; Schuetze, H.; Weibler, W.; Freedman, S.J.; Schaerpf, O.

    1983-01-01

    The ..beta..-decay of polarized neutrons has been studied with the new superconducting spectrometer PERKEO at the ILL. The energy dependence of the ..beta..-decay asymmetry has been measured for the first time. From the measured ..beta..-asymmetry parameter we obtain a new value for the ratio of weak coupling constants g/sub A//g/sub V/. 11 references.

  1. Heterogeneity of the Pancreatic Beta Cell

    PubMed Central

    Gutierrez, Giselle Dominguez; Gromada, Jesper; Sussel, Lori

    2017-01-01

    The pancreatic beta cell functions as a key regulator of blood glucose levels by integrating a variety of signals in response to changing metabolic demands. Variations in beta cell identity that translate into functionally different subpopulations represent an interesting mechanism to allow beta cells to efficiently respond to diverse physiological and pathophysiological conditions. Recently, there is emerging evidence that morphological and functional differences between beta cells exist. Furthermore, the ability of novel single cell technologies to characterize the molecular identity of individual beta cells has created a new era in the beta cell field. These studies are providing important novel information about the origin of beta cell heterogeneity, the type and proportions of the different beta cell subpopulations, as well as their intrinsic properties. Furthermore, characterization of different beta cell subpopulations that could variably offer protection from or drive progression of diabetes has important clinical implications in diabetes prevention, beta cell regeneration and stem cell treatments. In this review, we will assess the evidence that supports the existence of heterogeneous populations of beta cells and the factors that could influence their formation. We will also address novel studies using islet single cell analysis that have provided important information toward understanding beta cell heterogeneity and discuss the caveats that may be associated with these new technologies. PMID:28321233

  2. Polypeptides having beta-glucosidase activity and beta-xylosidase activity and polynucleotides encoding same

    SciTech Connect

    Morant, Marc Dominique

    2014-05-06

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  3. Polypeptides having beta-glucosidase activity and beta-xylosidase activity and polynucleotides encoding same

    SciTech Connect

    Morant, Marc Dominique

    2014-04-29

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  4. Polypeptides having beta-glucosidase and beta-xylosidase activity and polynucleotides encoding same

    SciTech Connect

    Morant, Marc Dominique

    2014-05-06

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  5. Developing a job-exposure matrix with exposure uncertainty from expert elicitation and data modeling.

    PubMed

    Fischer, Heidi J; Vergara, Ximena P; Yost, Michael; Silva, Michael; Lombardi, David A; Kheifets, Leeka

    2017-01-01

    Job exposure matrices (JEMs) are tools used to classify exposures for job titles based on general job tasks in the absence of individual level data. However, exposure uncertainty due to variations in worker practices, job conditions, and the quality of data has never been quantified systematically in a JEM. We describe a methodology for creating a JEM which defines occupational exposures on a continuous scale and utilizes elicitation methods to quantify exposure uncertainty by assigning exposures probability distributions with parameters determined through expert involvement. Experts use their knowledge to develop mathematical models using related exposure surrogate data in the absence of available occupational level data and to adjust model output against other similar occupations. Formal expert elicitation methods provided a consistent, efficient process to incorporate expert judgment into a large, consensus-based JEM. A population-based electric shock JEM was created using these methods, allowing for transparent estimates of exposure.

  6. Effects of naphthalene on Swiss chard in a steady-state foliage exposure system

    SciTech Connect

    Love, S.D.; Hale, B.A.

    1995-12-31

    Little is known about air-to-foliage transfer of volatile organic pollutants: sink strength of leaves and toxicity to the plant via this route have not been widely documented. Using naphthalene as a model contaminant, a steady-state exposure system was developed in which a continuous stream of naphthalene vapor was generated from a chilled permeation tube. This stream was proportionately released into four separate clean airstreams to deliver four discrete concentrations of naphthalene vapor to large cuvettes in which potted plants were sealed. Each cuvette received a total flow rate of 5 LPM. Naphthalene concentration exiting the permeation tube was calculated twofold: using ideal gas laws and from the daily mass loss of the permeation tube. Daily mass loss from the permeation tube and indirect indication of naphthalene concentration by UV light attenuation indicated that the exposure system was capable of maintaining a logarithmic range of naphthalene vapor concentrations over four days. Deviation from predicted concentrations was associated with high moisture content of the air supply line used to vent the permeation tube. Swiss chard (Beta vulgaris cv. White King) plants were exposed for four days in controlled environment chambers under steady-state conditions. Gaseous naphthalene was mixed with air and applied to foliate during the day or night. Plant growth was not affected by shoot naphthalene dose. Foliar exposure increased stomatal conductance and net CO{sub 2} fixation rates.

  7. Methylmercury exposure and health effects.

    PubMed

    Hong, Young-Seoub; Kim, Yu-Mi; Lee, Kyung-Eun

    2012-11-01

    Methylmercury is a hazardous substance that is of interest with regard to environmental health, as inorganic mercury circulating in the general environment is dissolved into freshwater and seawater, condensed through the food chain, ingested by humans, and consequently affects human health. Recently, there has been much interest and discussion regarding the toxicity of methylmercury, the correlation with fish and shellfish intake, and methods of long-term management of the human health effects of methylmercury. What effects chronic exposure to a low concentration of methylmercury has on human health remains controversial. Although the possibility of methylmercury poisoning the heart and blood vessel system, the reproductive system, and the immune system is continuously raised and discussed, and the carcinogenicity of methylmercury is also under discussion, a clear conclusion regarding the human health effects according to exposure level has not yet been drawn. The Joint FAO/WHO Expert Committee on Food Additives proposed to prepare additional fish and shellfish intake recommendations for consumers based on the quantified evaluation of the hazardousness of methylmercury contained in fish and shellfish, methylmercury management in the Korea has not yet caught up with this international trend. Currently, the methylmercury exposure level of Koreans is known to be very high. The starting point of methylmercury exposure management is inorganic mercury in the general environment, but food intake through methylation is the main exposure source. Along with efforts to reduce mercury in the general environment, food intake management should be undertaken to reduce the human exposure to methylmercury in Korea.

  8. Methylmercury Exposure and Health Effects

    PubMed Central

    Hong, Young-Seoub; Kim, Yu-Mi

    2012-01-01

    Methylmercury is a hazardous substance that is of interest with regard to environmental health, as inorganic mercury circulating in the general environment is dissolved into freshwater and seawater, condensed through the food chain, ingested by humans, and consequently affects human health. Recently, there has been much interest and discussion regarding the toxicity of methylmercury, the correlation with fish and shellfish intake, and methods of long-term management of the human health effects of methylmercury. What effects chronic exposure to a low concentration of methylmercury has on human health remains controversial. Although the possibility of methylmercury poisoning the heart and blood vessel system, the reproductive system, and the immune system is continuously raised and discussed, and the carcinogenicity of methylmercury is also under discussion, a clear conclusion regarding the human health effects according to exposure level has not yet been drawn. The Joint FAO/WHO Expert Committee on Food Additives proposed to prepare additional fish and shellfish intake recommendations for consumers based on the quantified evaluation of the hazardousness of methylmercury contained in fish and shellfish, methylmercury management in the Korea has not yet caught up with this international trend. Currently, the methylmercury exposure level of Koreans is known to be very high. The starting point of methylmercury exposure management is inorganic mercury in the general environment, but food intake through methylation is the main exposure source. Along with efforts to reduce mercury in the general environment, food intake management should be undertaken to reduce the human exposure to methylmercury in Korea. PMID:23230465

  9. Beta Genus Papillomaviruses and Skin Cancer

    PubMed Central

    Howley, Peter M.; Pfister, Herbert J.

    2015-01-01

    A role for the beta genus HPVs in keratinocyte carcinoma (KC) remains to be established. In this article we examine the potential role of the beta HPVs in cancer revealed by the epidemiology associating these viruses with KC and supported by oncogenic properties of the beta HPV proteins. Unlike the cancer associated alpha genus HPVs, in which transcriptionally active viral genomes are invariably found associated with the cancers, that is not the case for the beta genus HPVs and keratinocyte carcinomas. Thus a role for the beta HPVs in KC would necessarily be in the carcinogenesis initiation and not in the maintenance of the tumor. PMID:25724416

  10. Continuous Precipitation of Ceria Nanoparticles from a Continuous Flow Micromixer

    SciTech Connect

    Tseng, Chih Heng; Paul, Brian; Chang, Chih-hung; Engelhard, Mark H.

    2013-01-01

    Cerium oxide nanoparticles were continuously precipitated from a solution of cerium(III) nitrate and ammonium hydroxide using a micro-scale T-mixer. Findings show that the method of mixing is important in the ceria precipitation process. In batch mixing and deposition, disintegration and agglomeration dominates the deposited film. In T-mixing and deposition, more uniform nanorod particles are attainable. In addition, it was found that the micromixing approach reduced the exposure of the Ce(OH)3 precipates to oxygen, yielding hydroxide precipates in place of CeO2 precipitates. Advantages of the micro-scale T-mixing approach include shorter mixing times, better control of nanoparticle shape and less agglomeration.

  11. Growth, microcystin-production and proteomic responses of Microcystis aeruginosa under long-term exposure to amoxicillin.

    PubMed

    Liu, Ying; Chen, Shi; Zhang, Jian; Gao, Baoyu

    2016-04-15

    Ecological risk of antibiotics due to the induction of antibiotic-resistant bacteria has been widely investigated, while studies on the hazard of antibiotic contaminants via the regulation of cyanobacteria were still limited. This study focused on the long-term action effect and mechanism of amoxicillin (a broadly used antibiotic) in Microcystis aeruginosa at environmentally relevant concentrations through 30 days of semi-continuous culture. Amoxicillin stimulated the photosynthesis activity and the production of microcystins, and interaction of differential proteins under amoxicillin exposure further manifested the close correlation between the two processes. D1 protein, ATP synthase subunits alpha and beta, enolase, triosephosphate isomerase and phosphoglycerate kinase were candidate target positions of amoxicillin in M. aeruginosa under long-term exposure. Amoxicillin affected the cellular biosynthesis process and the metabolism of carbohydrate and nucleoside phosphate according to the proteomic responses. Under exposure to amoxicillin, stimulated growth rate at the beginning phase and increased production and release of microcystins during the whole exposure period would lead to a higher contamination of M. aeruginosa cells and microcystins, indicating that amoxicillin was harmful to aquatic environments through the promotion of cyanobacterial bloom.

  12. Exercise-induced muscle damage is not attenuated by beta-hydroxy-beta-methylbutyrate and alpha-ketoisocaproic acid supplementation.

    PubMed

    Nunan, David; Howatson, Glyn; van Someren, Ken A

    2010-02-01

    The purpose of this study was to examine the effects of combined oral beta-hydroxy-beta-methylbutyrate (HMB) and alpha-ketoisocaproic acid (KIC) supplementation on indices of exercise-induced muscle damage (EIMD) after an acute bout of eccentric-biased exercise. Fourteen male subjects were allocated to 2 groups: a placebo group (3 g.d corn flour, N = 7) or an HMB + KIC group (3 g.d HMB and 0.3 g.d KIC, N = 7). Supplementation commenced 11 days before a 40-minute bout of downhill running and continued for 3 days post-exercise. Delayed-onset muscle soreness, mid-thigh girth, knee extensor range of motion, serum creatine kinase (CK) activity, and isometric and concentric torque were assessed pre-exercise and at 24, 48, and 72 hours post-exercise. Delayed-onset muscle soreness, CK activity, and isometric and concentric torque all changed over the 72-hour period (p < 0.05); however, HMB + KIC had no significant effect on any of the indices of muscle damage. Although 14 days HMB and KIC supplementation did not attenuate indices of EIMD after an acute bout of unaccustomed eccentric-biased exercise, there was a trend for a more rapid rate of recovery in isometric and isokinetic muscle function. beta-hydroxy-beta-methylbutyrate and KIC may therefore provide limited benefit in the recovery of muscle function after EIMD in untrained subjects or after unaccustomed exercise.

  13. Early life-stage toxicity test methods for gulf toadfish (Opsanus beta) and results using chlorpyrifos

    SciTech Connect

    Hansen, D.J.; Goodman, L.R.; Cripe, G.M.; Macauley, S.F.

    1986-02-01

    Gulf toadfish (Opsanus beta) were continuously exposed as embryos, sac fry, and juveniles to technical chlorpyrifos in two 49-day early life-stage toxicity tests. Survival was significantly (alpha = 0.05) reduced only in 150 micrograms/liter. However, toadfish exposed to chlorpyrifos concentrations from 3.7 to 150 micrograms/liter weighted significantly less than control fish: 9% lower in 3.7 micrograms/liter to 62% lower in 150 micrograms/liter. The 96-hr LC50 for juvenile fish was 520 micrograms/liter. Concentrations of chlorpyrifos in toadfish and bioconcentration factors increased with increasing exposure concentration, a condition not generally observed with other marine fishes and other test chemicals. These results demonstrated the procedures for, and the practicality of, early life-stage tests with this marine species. We recommend the use of the gulf toadfish for comparative toxicity testing and for evaluating the toxicity of substances in conjunction with ontogenetical, physiological, and histological investigations of this considerably studied genus. We do not recommend it for routine effects testing.

  14. Mono-(2-ethylhexyl) phthalate (MEHP) regulates glucocorticoid metabolism through 11{beta}-hydroxysteroid dehydrogenase 2 in murine gonadotrope cells

    SciTech Connect

    Hong, Dun; Li, Xing-Wang; Lian, Qing-Quan; Lamba, Pankaj; Bernard, Daniel J.; Hardy, Dianne O.; Chen, Hai-Xiao; Ge, Ren-Shan

    2009-11-13

    Di-(2-ethylhexyl) phthalate (DEHP) and its metabolite mono-(2-ethylhexyl) phthalate (MEHP) have been classified as toxicants to the reproductive system at the testis level and DEHP may also impair reproductive axis function at the pituitary levels. However, MEHP is 10-fold more potent than DEHP in toxicity and little is known about the toxicological effect of MEHP on pituitary. In this study, we demonstrated that 11{beta}-hydroxysteroid dehydrogenase type 2 (11{beta}-HSD2), not 11{beta}-HSD1, is strongly expressed in murine gonadotrope L{beta}T2 cells. Interestingly, MEHP inhibited Hsd11b2 mRNA level and 11{beta}-HSD2 enzyme activity in L{beta}T2 cells at as low as 10{sup -7} M. Corticosterone (CORT) at a concentration of 10{sup -6} M significantly inhibited L{beta}T2 cell proliferation after 2-day culture, and 10{sup -6} M RU486, an antagonist of glucocorticoid receptor (GR), reversed this inhibition. However, in the presence of 10{sup -5} or 10{sup -4} M MEHP, the minimal concentration of CORT to inhibit the proliferation of L{beta}T2 cells was lowered to 10{sup -7} M, and 10{sup -6} M RU486 was not able to completely reverse the CORT effect. In conclusion, along with the regulation of GR, 11{beta}-HSD2 may have a key role in glucocorticoid metabolism in L{beta}T2 cells. MEHP may participate in the glucocorticoid metabolism in L{beta}T2 cells through inhibition of 11{beta}-HSD2 enzyme activity. Such perturbation may be of pathological significance as MEHP may interfere with the reproductive system at pituitary level through regulation of glucocorticoid metabolism, especially in neonates with higher risk of phthalates exposure.

  15. Molecular basis for amyloid-[beta] polymorphism

    SciTech Connect

    Colletier, Jacques-Philippe; Laganowsky, Arthur; Landau, Meytal; Zhao, Minglei; Soriaga, Angela B.; Goldschmidt, Lukasz; Flot, David; Cascio, Duilio; Sawaya, Michael R.; Eisenberga, David

    2011-10-19

    Amyloid-beta (A{beta}) aggregates are the main constituent of senile plaques, the histological hallmark of Alzheimer's disease. A{beta} molecules form {beta}-sheet containing structures that assemble into a variety of polymorphic oligomers, protofibers, and fibers that exhibit a range of lifetimes and cellular toxicities. This polymorphic nature of A{beta} has frustrated its biophysical characterization, its structural determination, and our understanding of its pathological mechanism. To elucidate A{beta} polymorphism in atomic detail, we determined eight new microcrystal structures of fiber-forming segments of A{beta}. These structures, all of short, self-complementing pairs of {beta}-sheets termed steric zippers, reveal a variety of modes of self-association of A{beta}. Combining these atomic structures with previous NMR studies allows us to propose several fiber models, offering molecular models for some of the repertoire of polydisperse structures accessible to A{beta}. These structures and molecular models contribute fundamental information for understanding A{beta} polymorphic nature and pathogenesis.

  16. Current double beta decay experiments

    NASA Astrophysics Data System (ADS)

    Giuliani, A.

    2005-01-01

    After an introduction about double beta decay and the deep connections between the lepton-violating channel and the neutrino properties, the most sensitive experimental approaches to the search for this rare nuclear transition are described. An overview of the experiments presently running is then given, with particular emphasis on the adopted techniques and their possible extrapolation to next-generation, higher-sensitivity experiments. The present situation about the experimental determination of the Majorana neutrino mass is presented and discussed.

  17. Estimating beta-mixing coefficients

    PubMed Central

    McDonald, Daniel J.; Shalizi, Cosma Rohilla; Schervish, Mark

    2015-01-01

    The literature on statistical learning for time series assumes the asymptotic independence or “mixing” of the data-generating process. These mixing assumptions are never tested, and there are no methods for estimating mixing rates from data. We give an estimator for the beta-mixing rate based on a single stationary sample path and show it is L1-risk consistent. PMID:26279742

  18. First neutrinoless double beta decay results from CUORE-0

    SciTech Connect

    Gironi, L. Biassoni, M.; Brofferio, C.; Capelli, S.; Carniti, P.; Cassina, L.; Chiesa, D.; Clemenza, M.; Faverzani, M.; Ferri, E.; Gotti, C.; Maino, M.; Nucciotti, A.; Pavan, M.; Pozzi, S.; Sala, E.; Sisti, M.; Terranova, F.; Zanotti, L.; Alduino, C.; and others

    2015-10-28

    The CUORE-0 experiment, a 52 bolometer array searching for neutrinoless double beta decay from {sup 130}Te, has started taking data in spring 2013 underground at the Laboratori Nazionali del Gran Sasso (LNGS). The excellent results obtained in terms of energy resolution and background level allowed this experiment to reach the sensitivity of Cuoricino in approximately half the runtime. Combining CUORE-0 data (9.8 kg·yr exposure of {sup 130}Te) with the 19.75 kg·yr exposure of the Cuoricino experiment, we obtain the most stringent limit to date on the half-life of this isotope (T{sub 1/2} > 4.0 × 10{sup 24} yr). In this article, we review the results from CUORE-0 and discuss the status and the physics potential of CUORE, a 19 times larger bolometer array that plans to begin operations by end of this year.

  19. Mechanism regulating proasthmatic effects of prolonged homologous beta2-adrenergic receptor desensitization in airway smooth muscle.

    PubMed

    Nino, Gustavo; Hu, Aihua; Grunstein, Judith S; Grunstein, Michael M

    2009-10-01

    Use of long-acting beta(2)-adrenergic receptor (beta2AR) agonists to treat asthma incurs an increased risk of asthma morbidity with impaired bronchodilation and heightened bronchoconstriction, reflecting the adverse effects of prolonged homologous beta2AR desensitization on airway smooth muscle (ASM) function. Since phosphodiesterase 4 (PDE4) regulates ASM relaxation and contractility, we examined whether the changes in ASM function induced by prolonged homologous beta2AR desensitization are attributed to altered expression and action of PDE4. Cultured human ASM cells and isolated rabbit ASM tissues exposed for 24 h to the long-acting beta2AR agonist salmeterol exhibited impaired acute beta2AR-mediated cAMP accumulation and relaxation, respectively, together with ASM constrictor hyperresponsiveness. These proasthmatic-like changes in ASM function were associated with upregulated PDE4 activity due to enhanced expression of the PDE4D5 isoform and were prevented by pretreating the ASM preparations with the PDE4 inhibitor rolipram or with inhibitors of either PKA or ERK1/2 signaling. Extended studies using gene silencing and pharmacological approaches demonstrated that: 1) the mechanism underlying upregulated PDE4D5 expression following prolonged beta2AR agonist exposure involves PKA-dependent activation of G(i) protein signaling via its betagamma-subunits, which elicits downstream activation of ERK1/2 and its induction of PDE4D5 transcription; and 2) the induction of PDE4 activity and consequent changes in ASM responsiveness are prevented by pretreating the beta2AR agonist-exposed ASM preparations with inhibitors of G(i)-betagamma signaling. Collectively, these findings identify that the proasthmatic changes in ASM function resulting from prolonged homologous beta2AR desensitization are attributed to upregulated PDE4 expression induced by G(i)-betagamma-mediated cross-talk between the PKA and ERK1/2 signaling pathways.

  20. Osteocalcin protects pancreatic beta cell function and survival under high glucose conditions

    SciTech Connect

    Kover, Karen; Yan, Yun; Tong, Pei Ying; Watkins, Dara; Li, Xiaoyu; Tasch, James; Hager, Melissa; Clements, Mark; Moore, Wayne V.

    2015-06-19

    Diabetes is characterized by progressive beta cell dysfunction and loss due in part to oxidative stress that occurs from gluco/lipotoxicity. Treatments that directly protect beta cell function and survival in the diabetic milieu are of particular interest. A growing body of evidence suggests that osteocalcin, an abundant non-collagenous protein of bone, supports beta cell function and proliferation. Based on previous gene expression data by microarray, we hypothesized that osteocalcin protects beta cells from glucose-induced oxidative stress. To test our hypothesis we cultured isolated rat islets and INS-1E cells in the presence of normal, high, or high glucose ± osteocalcin for up to 72 h. Oxidative stress and viability/mitochondrial function were measured by H{sub 2}O{sub 2} assay and Alamar Blue assay, respectively. Caspase 3/7 activity was also measured as a marker of apoptosis. A functional test, glucose stimulated insulin release, was conducted and expression of genes/protein was measured by qRT-PCR/western blot/ELISA. Osteocalcin treatment significantly reduced high glucose-induced H{sub 2}O{sub 2} levels while maintaining viability/mitochondrial function. Osteocalcin also significantly improved glucose stimulated insulin secretion and insulin content in rat islets after 48 h of high glucose exposure compared to untreated islets. As expected sustained high glucose down-regulated gene/protein expression of INS1 and BCL2 while increasing TXNIP expression. Interestingly, osteocalcin treatment reversed the effects of high glucose on gene/protein expression. We conclude that osteocalcin can protect beta cells from the negative effects of glucose-induced oxidative stress, in part, by reducing TXNIP expression, thereby preserving beta cell function and survival. - Highlights: • Osteocalcin reduces glucose-induced oxidative stress in beta cells. • Osteocalcin preserves beta cell function and survival under stress conditions. • Osteocalcin reduces glucose

  1. Mammalian. beta. /sub 1/- and. beta. /sub 2/-adrenergic receptors: immunological and structural comparison

    SciTech Connect

    Moxham, C.P.; George, S.T.; Graziano, M.P.; Brandwein, H.J.; Malbon, C.C.

    1986-11-05

    ..beta../sub 1/- and ..beta../sub 2/-adrenergic receptors, pharmacologically distinct proteins, have been reported to be structurally dissimilar. In the present study three techniques were employed to compare the nature of mammalian ..beta../sub 1/- and ..beta../sub 2/-adrenergic receptors. Antibodies against each of the receptor subtypes were raised separately. Polyclonal antisera against ..beta../sub 1/-receptors of rat fat cells were raised in mice, and antisera against ..beta../sub 2/-receptors of guinea pig lung were raised in rabbits. Receptors purified from rat fat cells (..beta../sub 1/-), S49 mouse lymphoma cells (..beta../sub 2/-), and rat liver (..beta../sub 2/-) were probed with these antisera. Each anti-receptor antisera demonstrated the ability to immunoprecipitate purified receptors of both ..beta../sub 1/- and ..beta../sub 2/-subtypes. The mobility of ..beta..-receptors subjected to polyacrylamide gel electrophoresis was probed using antireceptor antibodies and nitrocellulose blots of the gels. Fat cell ..beta../sub 1/-adrenergic receptors display M/sub r/ = 67,000 under reducing conditions and M/sub r/ = 54,000 under nonreducing conditions, as previously reported. Both ..beta../sub 1/- and ..beta../sub 2/-receptors displayed this same shift in electrophoretic mobility observed in the presence as compared to the absence of disulfide bridge-reducing agents, as detected both by autoradiography of the radiolabeled receptors and by immunoblotting of native receptors. Finally, isoelectric focusing of purified radioiodinated ..beta../sub 1/- and ..beta../sub 2/-adrenergic receptors revealed identical isoelectric points. These data are the first to provide analyses of immunological, structural, and biochemical features of ..beta../sub 1/- and ..beta../sub 2/-subtypes in tandem and underscore the structural similarities that exist between these pharmacologically distinct receptors.

  2. EXPOSURE TO ENVIRONMENTALLY RELEVANT CONCENTRATIONS OF DIFFERENT NONYLPHENOL FORMULATIONS IN JAPANESE MEDAKA. (R827098)

    EPA Science Inventory

    The time course of exposure to p-nonylphenol (NP) from two different sources was compared to equalivent exposures of 17-beta.gif" border=0>-estradiol (E2) and a solvent control (ethanol; EtOH). Japanese medaka were exposed for 4 days to a nomina...

  3. Decoding {beta}-decay systematics: A global statistical model for {beta}{sup -} half-lives

    SciTech Connect

    Costiris, N. J.; Mavrommatis, E.; Gernoth, K. A.; Clark, J. W.

    2009-10-15

    Statistical modeling of nuclear data provides a novel approach to nuclear systematics complementary to established theoretical and phenomenological approaches based on quantum theory. Continuing previous studies in which global statistical modeling is pursued within the general framework of machine learning theory, we implement advances in training algorithms designed to improve generalization, in application to the problem of reproducing and predicting the half-lives of nuclear ground states that decay 100% by the {beta}{sup -} mode. More specifically, fully connected, multilayer feed-forward artificial neural network models are developed using the Levenberg-Marquardt optimization algorithm together with Bayesian regularization and cross-validation. The predictive performance of models emerging from extensive computer experiments is compared with that of traditional microscopic and phenomenological models as well as with the performance of other learning systems, including earlier neural network models as well as the support vector machines recently applied to the same problem. In discussing the results, emphasis is placed on predictions for nuclei that are far from the stability line, and especially those involved in r-process nucleosynthesis. It is found that the new statistical models can match or even surpass the predictive performance of conventional models for {beta}-decay systematics and accordingly should provide a valuable additional tool for exploring the expanding nuclear landscape.

  4. Synergistic mobilization of hemopoietic progenitor cells using concurrent beta1 and beta2 integrin blockade or beta2-deficient mice.

    PubMed

    Papayannopoulou, T; Priestley, G V; Nakamoto, B; Zafiropoulos, V; Scott, L M; Harlan, J M

    2001-03-01

    The hierarchy of cytoadhesion molecules involved in hematopoietic/stem progenitor cell mobilization has not yet been delineated. Previous studies have suggested an important role for alpha4beta1 integrin in this process. To test whether mobilization involves dynamic interactions of alpha4beta1 with other integrins on hematopoietic cells, especially the beta2 integrins, mice and primates were treated with anti-beta1 or anti-beta2 antibodies alone or in combination. A single injection of anti-alpha4beta1 antibody elicited reproducible mobilization in contrast to other antibodies, and 3 injections yielded higher mobilization efficiency than each of the other antibodies. When the anti-beta2 (anti-CD11a or anti-CD18) or anti-alpha5/beta1 integrin antibody was combined with anti-alpha4, an augmentation in mobilization was seen that was either additive or synergistic, depending on the potency of the antibody used. Synergy between anti-alpha4 and anti-CD18 (beta(2)) antibody blockade was seen in primates and confirmed in anti-alpha4-treated CD18-deficient mice. In the latter, there was a 49-fold increase in mobilization with anti-alpha4, much higher than in littermate control animals, in CD18 hypomorphic mice, or in other strains of mice tested. Data from both the antibody blockade and gene-targeted mice suggest that the cooperativity of alpha4beta1 with beta2 integrins becomes evident when they are concurrently inhibited. It is unclear whether this cooperativity is exerted at the stage of reversible adhesion versus migration, and enhancement of and whether the 2 integrins work in a sequential or parallel manner. Whatever the mechanism, the data provide a novel example of beta1 and beta2 integrin crosstalk in stem/progenitor cell mobilization.

  5. Does physiological beta cell turnover initiate autoimmune diabetes in the regional lymph nodes?

    PubMed

    Pearl-Yafe, Michal; Iskovich, Svetlana; Kaminitz, Ayelet; Stein, Jerry; Yaniv, Isaac; Askenasy, Nadir

    2006-05-01

    The initial immune process that triggers autoimmune beta cell destruction in type 1 diabetes is not fully understood. In early infancy there is an increased beta cell turnover. Recurrent exposure of tissue-specific antigens could lead to primary sensitization of immune cells in the draining lymph nodes of the pancreas. An initial immune injury to the beta cells can be inflicted by several cell types, primarily macrophages and T cells. Subsequently, infiltrating macrophages transfer antigens exposed by apoptotic beta cells to the draining lymph nodes, where antigen presenting cells process and amplify a secondary immune reaction. Antigen presenting cells evolve as dual players in the activation and suppression of the autoimmune reaction in the draining lymph nodes. We propose a scenario where destructive insulitis is caused by recurrent exposure of specific antigens due to the physiological turnover of beta cells. This sensitization initiates the evolution of reactive clones that remain silent in the regional lymph nodes, where they succeed to evade regulatory clonal deletion.

  6. Uniform Continuity of POVMs

    NASA Astrophysics Data System (ADS)

    Beneduci, Roberto

    2014-10-01

    Recently a characterization of uniformly continuous POVMs and a necessary condition for a uniformly continuous POVM F to have the norm-1 property have been provided. Moreover it was proved that in the commutative case, uniform continuity corresponds to the existence of a Feller Markov kernel. We apply such results to the analysis of some relevant physical examples; i.e., the phase space localization observables, the unsharp phase observable and the unsharp number observable of which we study the uniform continuity, the norm-1 property and the existence of a Feller Markov kernel.

  7. beta-Endorphin-induced analgesia is inhibited by synthetic analogs of beta-endorphin.

    PubMed Central

    Nicolas, P; Hammonds, R G; Li, C H

    1984-01-01

    Competitive antagonism of human beta-endorphin (beta h-EP)-induced analgesia by synthetic beta h-EP analogs with high in vitro opiate receptor binding to in vivo analgesic potency ratio has been demonstrated. A parallel shift of the dose-response curve for analgesia to the right was observed when either beta h-EP or [ Trp27 ] -beta h-EP was coinjected with various doses of [Gln8, Gly31 ]-beta h-EP-Gly-Gly-NH2, [Arg9,19,24,28,29]-beta h-EP, or [ Cys11 ,26, Phe27 , Gly31 ]-beta h-EP. It was estimated that the most potent antagonist, [Gln8, Gly31 ]-beta h-EP-Gly-NH2, is at least 200 times more potent than naloxone. PMID:6328494

  8. Association of heterocellular HPFH, beta(+)-thalassaemia, and delta beta(0)-thalassaemia: haematological and molecular aspects.

    PubMed Central

    Cianetti, L; Care, A; Sposi, N M; Giampaolo, A; Calandrini, M; Petrini, M; Massa, A; Marinucci, M; Mavilio, F; Ceccanti, M

    1984-01-01

    An Italian family in which heterocellular hereditary persistence of fetal haemoglobin (HPFH) interacts with both beta(+)- and delta beta-thalassaemia is described. The index case was an 8 year old girl who was presumed to inherit both heterocellular HPFH and beta (+)-thalassaemia from her mother and delta beta-thalassaemia from her father. She was healthy and never needed blood transfusions. The possible contribution of heterocellular HPFH to the less severe expression of the compound delta beta/beta(+)-thalassaemia heterozygosity is discussed. By DNA analysis the specific delta beta-thalassaemia defect on the gamma delta beta globin gene region has been established. In addition, a previously unreported association of a polymorphic restriction site haplotype with a beta (+)-thalassaemia mutation has been observed. PMID:6208362

  9. Skin Exposure to Isocyanates: Reasons for Concern

    PubMed Central

    Bello, Dhimiter; Herrick, Christina A.; Smith, Thomas J.; Woskie, Susan R.; Streicher, Robert P.; Cullen, Mark R.; Liu, Youcheng; Redlich, Carrie A.

    2007-01-01

    Objective Isocyanates (di- and poly-), important chemicals used worldwide to produce polyurethane products, are a leading cause of occupational asthma. Respiratory exposures have been reduced through improved hygiene controls and the use of less-volatile isocyanates. Yet isocyanate asthma continues to occur, not uncommonly in settings with minimal inhalation exposure but opportunity for skin exposure. In this review we evaluate the potential role of skin exposure in the development of isocyanate asthma. Data sources We reviewed the published animal and human literature on isocyanate skin-exposure methods, workplace skin exposure, skin absorption, and the role of skin exposure in isocyanate sensitization and asthma. Data extraction We selected relevant articles from computerized searches on Medline, U.S. Environmental Protection Agency, Occupational Safety and Health Administration, National Institute for Occupational Safety and Health, and Google databases using the keywords “isocyanate,” “asthma,” “skin,” “sensitization,” and other synonymous terms, and our own extensive collection of isocyanate publications. Data synthesis Isocyanate production and use continues to increase as the polyurethane industry expands. There is substantial opportunity for isocyanate skin exposure in many work settings, but such exposure is challenging to quantify and continues to be underappreciated. Isocyanate skin exposure can occur at work, even with the use of personal protective equipment, and may also occur with consumer use of certain isocyanate products. In animals, isocyanate skin exposure is an efficient route to induce sensitization, with subsequent inhalation challenge resulting in asthma-like responses. Several lines of evidence support a similar role for human isocyanate skin exposure, namely, that such exposure occurs and can contribute to the development of isocyanate asthma in certain settings, presumably by inducing systemic sensitization. Conclusions

  10. TGF-{beta} modulates {beta}-Catenin stability and signaling in mesenchymal proliferations

    SciTech Connect

    Amini Nik, Saeid; Ebrahim, Rasoul Pour; Dam, Kim van; Cassiman, Jean-Jacques; Tejpar, Sabine . E-mail: sabine.tejpar@med.kuleuven.be

    2007-08-01

    Here for the first time we showed, despite the oncogenic mutations in {beta}-Catenin, that TGF-{beta} is a modulator of {beta}-Catenin levels in tumoral fibroblasts as well as non-tumoral fibroblasts. The results show that the TGF-{beta} pathway is active in desmoids cells and in in situ tumors. A dose dependent increase in {beta}-Catenin protein levels was observed after TGF-{beta} treatment in combination with an increased repression of GSK-3{beta} both in normal and tumoral fibroblasts. TGF-{beta} stimulation also led to an altered - up to 5 fold - transcriptional activity of {beta}-Catenin responsive promoters, such as IGFBP6 as well as increase of TOPflash activity. TGF-{beta} stimulation increased cell proliferation and BrdU incorporation 2.5 times. Taken together, we propose that TGF-{beta} is a modulator of {beta}-Catenin levels in tumoral fibroblasts and non-tumoral fibroblasts, despite the oncogenic mutations already present in this gene in tumoral fibroblasts of desmoid tumors. This modulation of {beta}-Catenin levels by TGF-{beta} may be involved in determining the tumoral phenotype of the cells.

  11. High beta plasma operation in a toroidal plasma producing device

    DOEpatents

    Clarke, John F.

    1978-01-01

    A high beta plasma is produced in a plasma producing device of toroidal configuration by ohmic heating and auxiliary heating. The plasma pressure is continuously monitored and used in a control system to program the current in the poloidal field windings. Throughout the heating process, magnetic flux is conserved inside the plasma and the distortion of the flux surfaces drives a current in the plasma. As a consequence, the total current increases and the poloidal field windings are driven with an equal and opposing increasing current. The spatial distribution of the current in the poloidal field windings is determined by the plasma pressure. Plasma equilibrium is maintained thereby, and high temperature, high beta operation results.

  12. A method for isolating beta-casein.

    PubMed

    Ward, L S; Bastian, E D

    1996-08-01

    A new method was developed for obtaining pure beta-CN. Calcium caseinate (3%) was reconstituted, renneted to form a gel, cooled (4 degrees C) to allow beta-CN dissociation from the caseinate gel, and centrifuged. The supernatant was warmed to 30 degrees C, precipitating pure beta-CN from solution. Large quantities of beta-CN were recovered by scaling-up this procedure, but these beta-CN preparations were less pure than the beta-CN that was prepared on a smaller scale. Chromatography (FPLC) and urea-PAGE showed beta-CN to be the main component in the precipitate. Chymosin, used to form the caseinate gel, did not extensively hydrolyze beta-CN under the conditions of these experiments. Calcium concentration, cooling time, and caseinate concentration influenced the recovery of beta-CN. Maximum recovery of beta-CN, under the experimental conditions used, occurred at 10 mM calcium, 48 h of cooling, and 3% caseinate concentration.

  13. Environmental exposure to lead (Pb) and variations in its susceptibility.

    PubMed

    Kim, Jina; Lee, Youngeun; Yang, Mihi

    2014-01-01

    Based on exposure frequency and intrinsic toxicity, lead (Pb) ranks one of the highest priority toxic materials. Continuous regulation of environmental Pb exposure has contributed to dramatically diminished exposure levels of Pb, for example, blood level of Pb. However, the safety level of Pb is not established, as low-level exposure to Pb still shows severe toxicity in high susceptible population and late onset of some diseases from early exposure. In the present study, we focused on food-borne Pb exposure and found broad variations in Pb exposure levels via food among countries. In addition, there are genetic or ethnical variations in Pb-targeted and protective genes. Moreover, various epigenetic alterations were induced by Pb poisoning. Therefore, we suggest a systemic approach including governmental (public) and individual prevention from Pb exposure with continuous biological monitoring and genetic or epigenetic consideration.

  14. The Tactile Continuity Illusion

    ERIC Educational Resources Information Center

    Kitagawa, Norimichi; Igarashi, Yuka; Kashino, Makio

    2009-01-01

    We can perceive the continuity of an object or event by integrating spatially/temporally discrete sensory inputs. The mechanism underlying this perception of continuity has intrigued many researchers and has been well documented in both the visual and auditory modalities. The present study shows for the first time to our knowledge that an illusion…

  15. Reinventing Continuing Higher Education

    ERIC Educational Resources Information Center

    Walshok, Mary Lindenstein

    2012-01-01

    Re-inventing continuing higher education is about finding ways to be a more central player in a region's civic, cultural, and economic life as well as in the education of individuals for work and citizenship. Continuing higher education will require data gathering, analytical tools, convening authority, interpretive skills, new models of delivery,…

  16. Continuing Vocational Training (CVT).

    ERIC Educational Resources Information Center

    Drogosz-Zablocka, Elzbieta; Izycka, Halina; Trzeciak, Wlodzimierz

    Polish continuing education (CE) includes education, further education, and professional development in and out of school; in day, evening, or weekend courses; and distance education. The state, workplaces, grants, and foreign assistance provide financing. A variety of organizations cooperate to provide continuing education. High-risk groups…

  17. Residential Continuing Education.

    ERIC Educational Resources Information Center

    Houle, Cyril O.

    The theme of this discursive essay is residential continuing education: its definition, its development along somewhat different lines in Europe and in America, and its practice in university centers in the United States. Continuing education includes any learning or teaching program that is based on the assumptions that the learners have studied…

  18. Establishing a Continuous Repertoire.

    ERIC Educational Resources Information Center

    Meadowcroft, Pamela; Holland, James G.

    Investigators in this study looked for conditions that can rapidly establish continuous stimulus control of continuous response variations, or "response mapping." Unlike previous research in stimulus control, where a single stimulus comes to control a single response, 36 5-year-old children received errorless discrimination training at…

  19. Results from the Cuoricino (Zero-Neutrino Double Beta) Decay Experiment

    SciTech Connect

    Arnaboldi, C; Artusa, D R; Avignone, F T; Balata, M; Bandac, I; Barucci, M; Beeman, J W; Bellini, F; Brofferio, C; Bucci, C; Capelli, S; Carbone, L; Cebrian, S; Clemenza, M; Cremonesi, O; Creswick, R J; de Ward, A; Didomizio, S D; Dolinski, M J; Farach, H A; Fiorini, E; Frossati, G; Giachero, A; Giuliani, A; Gorla, P; Guardincerri, E; Gutierrez, T D; Haller, E E; Maruyama, R H; McDonald, R J; Nisi, S; Nones, C; Norman, E B; Nucciotti, A; Olivieri, E; Pallavicini, M; Palmieri, E; Pasca, E; Pavan, M; Pedretti, M; Pessina, G; Pirro, S; Previtali, E; Risegari, L; Rosenfeld, C; Sangiorgio, S; Sisti, M; Smith, A R; Torres, L; Ventura, G; Vignati, M

    2007-12-20

    Recent results from the CUORICINO {sup 130}Te zero-neutrino double-beta (0v{beta}{beta}) decay experiment are reported. CUORICINO is an array of 62 tellurium oxide (TeO{sub 2}) bolometers with an active mass of 40.7 kg. It is cooled to {approx}8 mK by a dilution refrigerator shielded from environmental radioactivity and energetic neutrons. It is running in the Laboratori Nazionali del Gran Sasso (LNGS) in Assergi, Italy. These data represent 11.83 kg y or 90.77 mole-years of {sup 130}Te. No evidence for 0v{beta}{beta}-decay was observed and a limit of T{sub 1/2}{sup 0v} ({sup 130}Te) {ge} 3.0 x 10{sup 24} y (90% C.L.) is set. This corresponds to upper limits on the effective mass, , between 0.19 and 0.68eV when analyzed with the many published nuclear structure calculations. In the context of these nuclear models, the values fall within the range corresponding to the claim of evidence of 0v{beta}{beta}-decay by H.V. Klapdor-Kleingrothaus and his co-workers. The experiment continues to acquire data.

  20. Antioxidant properties of 2-O-beta-D-glucopyranosyl-L-ascorbic acid.

    PubMed

    Takebayashi, Jun; Yagi, Yasuyuki; Ishii, Rie; Abe, Shigeki; Yamada, Kazuhiko; Tai, Akihiro

    2008-06-01

    The antioxidant activity of a provitamin C agent, 2-O-beta-D-glucopyranosyl-L-ascorbic acid (AA-2betaG), was compared to that of 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) and ascorbic acid (AA) using four in vitro methods, 1,1-diphenyl-picrylhydrazyl (DPPH) radical-scavenging assay, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS(*+))-scavenging assay, oxygen radical absorbance capacity (ORAC) assay, and 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced erythrocyte hemolysis inhibition assay. AA-2betaG slowly and continuously scavenged DPPH radicals and ABTS(*+) in roughly the same reaction profiles as AA-2G, whereas AA quenched these radicals immediately. In the ORAC assay and the hemolysis inhibition assay, AA-2betaG showed similar overall activities to AA-2G and to AA, although the reactivity of AA-2betaG against the peroxyl radical generated in both assays was lower than that of AA-2G and AA. These data indicate that AA-2betaG had roughly the same radical-scavenging properties as AA-2G, and a comprehensive in vitro antioxidant activity of AA-2betaG appeared to be comparable not only to that of AA-2G but also to that of AA.

  1. Beta

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter covers the use of wild beets in sugar beet improvement, including the basic botany of the species, its distribution; geographical locations of genetic diversity; morphology; cytology and karyotype; genome size; taxonomic position; agricultural status (model plant/weeds/invasive species/...

  2. Hypoxic induction of caspase-11/caspase-1/interleukin-1beta in brain microglia.

    PubMed

    Kim, Nam-Gon; Lee, Heasuk; Son, Eunyung; Kwon, Oh-Young; Park, Jae-Yong; Park, Jae-Hoon; Cho, Gyeong Jae; Choi, Wan Sung; Suk, Kyoungho

    2003-06-10

    Caspase-11 is an inducible protease that plays an important role in both inflammation and apoptosis. Inflammatory stimuli induce and activate caspase-11, which is required for the activation of caspase-1 or interleukin-1beta (IL-1beta) converting enzyme (ICE). Caspase-1 in turn mediates the maturation of proinflammatory cytokines such as IL-1beta, which is one of the crucial mediators of neurodegeneration in the central nervous system. Here, we report that hypoxic exposure of cultured brain microglia (BV-2 mouse microglia cells and rat primary microglial cultures) induces expression and activation of caspase-11, which is accompanied by activation of caspase-1 and secretion of mature IL-1beta and IL-18. Hypoxic induction of caspase-11 was observed in both mRNA and protein levels, and was mediated through p38 mitogen-activated protein kinase pathway. Transient global ischemia in rats also induced caspase-11 expression and IL-1beta production in hippocampus supporting our in vitro findings. Caspase-11-expressing cells in hippocampus were morphologically identified as microglia. Taken together, our results indicate that hypoxia induces a sequential event-caspase-11 induction, caspase-1 activation, and IL-1beta release-in brain microglia, and point out the importance of initial caspase-11 induction in hypoxia-induced inflammatory activation of microglia.

  3. Evidence for increased beta-adrenoreceptor responsiveness induced by 14 days of simulated microgravity in humans

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.; Polet, J. L.; Engelke, K. A.; Hoffler, G. W.; Lane, L. D.; Blomqvist, C. G.; Eckberg, D. L. (Principal Investigator)

    1997-01-01

    We studied hemodynamic responses to alpha- and beta-receptor agonists in eight healthy men before and after 14 days of 6 degrees head-down tilt (HDT) to test the hypothesis that increased adrenoreceptor responsiveness is induced by prolonged exposure to simulated microgravity. Steady-state infusions of isoproterenol (Iso) at rates of 0.005, 0.01, and 0.02 microgram.kg-1.min-1 were used to assess beta 1- and beta 2-adrenoreceptor responsiveness. Infusions of phenylephrine (PE) at rates of 0.25, 0.50, and 1.00 microgram.kg-1.min-1 were used to assess responsiveness of alpha 1-vascular adrenoreceptors. Slopes calculated from linear regressions between Iso and PE doses and changes in beat-to-beat heart rate, blood pressure, and leg vascular resistance (occlusion plethysmography) for each subject were used as an index of alpha- and beta-adrenoreceptor responsiveness. HDT increased the slopes of heart rate (1,056 +/- 107 to 1,553 +/- 83 beats micrograms-1.kg-1.min-1; P = 0.014) and vasodilation (-469 +/- 111 to -1,446 +/- 309 peripheral resistance units.microgram-1.kg-1.min-1; P = 0.0224) to Iso infusion. There was no alteration in blood pressure or vascular resistance responses to PE infusion after HDT. Our results provide evidence that simulated microgravity causes selective increases in beta 1- and beta 2-adrenoreceptor responsiveness without affecting alpha 1-vascular adrenoreceptor responses.

  4. Bmi-1 extends the life span of normal human oral keratinocytes by inhibiting the TGF-{beta} signaling

    SciTech Connect

    Kim, Reuben H.; Lieberman, Mark B.; Lee, Rachel; Shin, Ki-Hyuk; Mehrazarin, Shebli; Oh, Ju-Eun; Park, No-Hee; Kang, Mo K.

    2010-10-01

    We previously demonstrated that Bmi-1 extended the in vitro life span of normal human oral keratinocytes (NHOK). We now report that the prolonged life span of NHOK by Bmi-1 is, in part, due to inhibition of the TGF-{beta} signaling pathway. Serial subculture of NHOK resulted in replicative senescence and terminal differentiation and activation of TGF-{beta} signaling pathway. This was accompanied with enhanced intracellular and secreted TGF-{beta}1 levels, phosphorylation of Smad2/3, and increased expression of p15{sup INK4B} and p57{sup KIP2}. An ectopic expression of Bmi-1 in NHOK (HOK/Bmi-1) decreased the level of intracellular and secreted TGF-{beta}1 induced dephosphorylation of Smad2/3, and diminished the level of p15{sup INK4B} and p57{sup KIP2}. Moreover, Bmi-1 expression led to the inhibition of TGF-{beta}-responsive promoter activity in a dose-specific manner. Knockdown of Bmi-1 in rapidly proliferating HOK/Bmi-1 and cancer cells increased the level of phosphorylated Smad2/3, p15{sup INK4B}, and p57{sup KIP2}. In addition, an exposure of senescent NHOK to TGF-{beta} receptor I kinase inhibitor or anti-TGF-{beta} antibody resulted in enhanced replicative potential of cells. Taken together, these data suggest that Bmi-1 suppresses senescence of cells by inhibiting the TGF-{beta} signaling pathway in NHOK.

  5. Beta adrenergic receptor blockade of feline myocardium. Cardiac mechanics, energetics, and beta adrenoceptor regulation.

    PubMed Central

    Cooper, G; Kent, R L; McGonigle, P; Watanabe, A M

    1986-01-01

    Myocardial oxygen consumption is regulated by interrelated mechanical and inotropic conditions; there is a parallel increase in the aerobic metabolism and inotropic state during beta-adrenergic stimulation under fixed mechanical conditions. In contrast, there is some evidence that beta-blockade may reduce oxygen consumption through effects independent of its influence on mechanical conditions and contractile state, and that prolonged beta-blockade may sensitize the myocardium to beta-adrenergic stimulation. To clarify these two points, the present study examined the relationship of myocardial energetics to mechanics and inotropism during acute beta-blockade and after the withdrawal of long-term beta-blockade, whereupon the basis for any effect observed was sought by characterizing the number, affinity, and affinity states of the beta-receptors as well as the coupling of activated beta-receptors to cyclic AMP generation. Studies of right ventricular papillary muscles from control and chronically beta-blocked cats demonstrated contractile and energetic properties as well as dose-response behavior and inotropic specificity suggestive of an increase in myocardial sensitivity to beta-adrenoceptor stimulation in the latter group. Assays of cardiac beta-adrenoceptors from further groups of control and pretreated cats, both in cardiac tissue and in isolated cardiac muscle cells, failed to define a difference between the two groups either in terms of receptor number and affinity or in terms of the proportion of receptors in the high-affinity state. However, coupling of the activated beta-adrenoceptors to cyclic AMP generation was enhanced in cardiac muscle cells from chronically beta-blocked cats. These data demonstrate that beta-adrenoceptor blockade (a) produces parallel effects on inotropic state and oxygen consumption without an independent effect on either and (b) increases myocardial sensitivity to beta-adrenergic stimulation after beta-blockade withdrawal, not by "up

  6. Human globin gene analysis for a patient with beta-o/delta beta-thalassemia.

    PubMed Central

    Ottolenghi, S; Lanyon, W G; Williamson, R; Weatherall, D J; Clegg, J B; Pitcher, C S

    1975-01-01

    Complementary DNA (cDNA) was prepared with RNA-dependent DNA polymerase from human globin messenger RNA (mRNA). Annealing and translation experimenta with total mRNA from circulating cells from a patient with heterozygous beta/heterozygous beta-delta-o thalassemia (beta-o/delta beta-o-thalassemia) demonstrated no detectable mRNA for beta-globin. cDNA enriched in sequences homologous to beta-globin mRNA was prepared by hydroxylapatite fractionation of hybrids formed between beta-o/delta beta-o-thalassemic mRNA and cDNA made from mRNA from a patient with alpha-thalassemia (hemoglobin H disease). The rate of annealing of this beta-enriched cDNA to normal human nuclear DNA was that of a sequence present as only a single copy per haploid genome. The beta-enriched cDNA annealed to the beta-o-delta beta-o-thalassemia total DNA with approximately the same kinetics as to normal DNA, indicating that no total gene deletion of beta-globin genes from the diploid genome has occurred, although the accuracy of the technique could not exclude with certainty a partial deletion or a deletion of a beta-globin gene from only one of the haploid genomes. This demonstrates that at least one of the beta-o- or the delta beta-o-thalassemia haploid genomes in this case contains a substantially intact beta-globin gene. PMID:49057

  7. Neutrino Factories and Beta Beams

    SciTech Connect

    Zisman, Michael S.

    2006-06-21

    In this paper we briefly review the concepts of Neutrino Factories and Beta Beam facilities, and indicate the main challenges in terms of beam performance and technological developments. We also describe the worldwide organizations that have embarked on defining and carrying out the necessary R&D on component design, beam simulations of facility performance, and benchmarking of key subsystems via actual beam tests. Currently approved subsystem tests include the Muon Ionization Cooling Experiment (MICE), under construction at Rutherford Appleton Laboratory, and the Mercury Intense Target (MERIT) experiment, to be carried out at CERN. These experiments are briefly described, and their schedules are indicated.

  8. [Plasma beta-2-microglobulin in rheumatoid arthritis].

    PubMed

    Fioravanti, A; Giordano, N; Loi, F; D'Amato, S; Castagna, M L; Frati, E; Marcolongo, R

    1984-09-30

    The beta 2 microglobulin (beta 2m) is a low molecular weight protein, recognized on the cellular membranes of numerous nucleated cells and strictly correlated to the antigens of Major Histocompatibility Complex. Many authors have demonstrated an increase of the plasmatic beta 2m in different inflammatory diseases and, particularly in rheumatic ones, as Rheumatoid Arthritis (RA), Reiter's syndrome, Ankylosing Spondylitis, Systemic lupus erythematosus. We have also investigated the behaviour of the plasmatic beta 2m in 52 RA patients and in 17 healthy subjects. The beta 2m was measured in serum, by radioimmunoassay. We have demonstrated that the plasmatic beta 2m has moderately increased in the serum of RA patients, even if there is not a significant difference when compared to the normal subjects.

  9. Column continuous transition functions

    NASA Astrophysics Data System (ADS)

    Li, Yangrong

    2007-04-01

    A column continuous transition function is by definition a standard transition function P(t) whose every column is continuous for t[greater-or-equal, slanted]0 in the norm topology of bounded sequence space l[infinity]. We will prove that it has a stable q-matrix and that there exists a one-to-one relationship between column continuous transition functions and increasing integrated semigroups on l[infinity]. Using the theory of integrated semigroups, we give some necessary and sufficient conditions under which the minimal q-function is column continuous, in terms of its generator (of the Markov semigroup) as well as its q-matrix. Furthermore, we will construct all column continuous Q-functions for a conservative, single-exit and column bounded q-matrix Q. As applications, we find that many interesting continuous-time Markov chains (CTMCs), say Feller-Reuter-Riley processes, monotone processes, birth-death processes and branching processes, etc., have column continuity.

  10. Inhalation exposure of animals.

    PubMed Central

    Phalen, R F

    1976-01-01

    Relative advantages and disadvantages and important design criteria for various exposure methods are presented. Five types of exposures are discussed: whole-body chambers, head-only exposures, nose or mouth-only methods, lung-only exposures, and partial-lung exposures. Design considerations covered include: air cleaning and conditioning; construction materials; losses of exposure materials; evenness of exposure; sampling biases; animal observation and care; noise and vibration control, safe exhausts, chamber loading, reliability, pressure fluctuations; neck seals, masks, animal restraint methods; and animal comfort. Ethical considerations in use of animals in inhalation experiments are also discussed. PMID:1017420

  11. An observed effect of ultraviolet radiation emitted from beta-irradiated HaCaT cells upon non-beta-irradiated bystander cells.

    PubMed

    Le, Michelle; McNeill, Fiona E; Seymour, Colin; Rainbow, Andrew J; Mothersill, Carmel E

    2015-03-01

    Previous research has shown that beta radiation can induce ultraviolet (UV) photon emission in human keratinocyte cells. Spectral analysis using a filter-based method in the ultraviolet range demonstrated that the strongest externally measureable photon emission was induced by beta radiation in the UVA range. In the current study, the potential biological implications of this UV photon emission from beta-irradiated cells were investigated. HaCaT human keratinocyte cells were irradiated with tritium ((3)H) and the photon emission induced was concurrently measured at the strongest externally measurable wavelength, 340 ± 5 nm, using a combination filter-photomultiplier tube system. Unirradiated reporter HaCaT cell cultures were also placed directly above (3)H-irradiated cells so that they would receive the induced secondary photons emitted from beta-irradiated cells, and the clonogenic survival in reporter cells was then assessed. Maximum photon emission (1207.04 ± 107.65 counts per second) was observed during irradiation of 2,000 cells/cm(2) with (3)H and the maximum reporter cell death (23.2 ± 0.9% reduction in survival) was observed under the same conditions. The measured photon emission from beta-irradiated cells and reporter cell death were strongly correlated (r = 0.977, P < 0.01). Placement of a polyethylene terephthalate filter, designed to eliminate >90% of UV wavelengths below 390 nm, between the directly irradiated and reporter cell layers was effective in nearly abolishing both 340 nm photon detection and reporter cell death in treated groups. Concurrent treatment of reporter cells with lomefloxacin during exposure to the secondary photons resulted in significantly increased cell killing, indicating a potential synergistic effect, while melanin treatment resulted in decreased reporter cell killing regardless of irradiation. These results suggest that secondary photons in the UV spectral range induced by beta irradiation play a role in inducing a

  12. Medium wave exposure characterisation using exposure quotients.

    PubMed

    Paniagua, Jesús M; Rufo, Montaña; Jiménez, Antonio; Antolín, Alicia; Pinar, Iván

    2010-06-01

    One of the aspects considered in the International Commission on Non-Ionizing Radiation Protection guidelines is that, in situations of simultaneous exposure to fields of different frequencies, exposure quotients for thermal and electrical stimulation effects should be examined. The aim of the present work was to analyse the electromagnetic radiation levels and exposure quotients for exposure to multiple-frequency sources in the vicinity of medium wave radio broadcasting antennas. The measurements were made with a spectrum analyser and a monopole antenna. Kriging interpolation was used to prepare contour maps and to estimate the levels in the towns and villages of the zone. The results showed that the exposure quotient criterion based on electrical stimulation effects to be more stringent than those based on thermal effects or power density levels. Improvement of dosimetry evaluations requires the spectral components of the radiation to be quantified, followed by application of the criteria for exposure to multiple-frequency sources.

  13. Method for preparing Pb-. beta. ''-alumina ceramic

    DOEpatents

    Hellstrom, E.E.

    1984-08-30

    A process is disclosed for preparing impermeable, polycrystalline samples of Pb-..beta..''-alumina ceramic from Na-..beta..''-alumina ceramic by ion exchange. The process comprises two steps. The first step is a high-temperature vapor phase exchange of Na by K, followed by substitution of Pb for K by immersing the sample in a molten Pb salt bath. The result is a polycrystalline Pb-..beta..''-alumina ceramic that is substantially crack-free.

  14. IKK and (Beta) - Catenin in Breast Cancer

    DTIC Science & Technology

    2004-07-01

    activity is not due to a decrease in total beta-catenin protein levels, however, the dephosphorylated form of beta-catenin within the nucleus...2000. 19. Staal F J, Noort MM, Strous G J, and Clevers HC, Wnt signals are transmitted through N-terminally dephosphorylated beta-catenin. EMBO Rep. 3...catenin is phoshorylated sequentially by casein kinase 1 (CK1) and glycogen synthase kinase 3-P (GSK-313) (4,52); activation of frizzled receptors by Wnt

  15. Effects of Beta-Blocker Withdrawal in Acute Decompensated Heart Failure

    PubMed Central

    Prins, Kurt W.; Neill, John M.; Tyler, John O.; Eckman, Peter M.; Duval, Sue

    2015-01-01

    OBJECTIVES This study sought to evaluate the effects of beta-blocker withdrawal in acute decompensated heart failure (ADHF). BACKGROUND Published reports showed trends for either no harm or increased risk of in-hospital mortality, short-term mortality, and rehospitalization rates in patients admitted for ADHF that discontinued beta-blockers; however, a comprehensive analysis has not been conducted. METHODS Relevant studies from January 2000 through January 2015 were identified in the PubMed, EMBASE, and COCHRANE electronic databases. Where appropriate data were available, weighted relative risks were estimated using random-effects meta-analysis techniques. RESULTS Five observational studies and 1 randomized clinical trial (n = 2,704 patients who continued beta-blocker therapy and n = 439 patients who discontinued beta-blocker therapy) that reported the short-term effects of beta-blocker withdrawal in ADHF were included in the analyses. In 2 studies, beta-blocker withdrawal significantly increased risk of in-hospital mortality (risk ratio: 3.72; 95% confidence interval [CI]: 1.51 to 9.14). Short-term mortality (relative risk: 1.61; 95% CI: 1.04 to 2.49; 4 studies) and combined short-term rehospitalization or death (relative risk: 1.59; 95% CI: 1.03 to 2.45; 4 studies) were also significantly increased. CONCLUSIONS Discontinuation of beta-blockers in patients admitted with ADHF was associated with significantly increased in-hospital mortality, short-term mortality, and the combined endpoint of short-term rehospitalization or mortality. These data suggest beta-blockers should be continued in ADHF patients if their clinical picture allows. PMID:26251094

  16. Conformational studies on the beta subunits of human hemoglobin and their arginyl-COOH peptides.

    PubMed

    Bucci, C F; Bucci, E

    1975-10-07

    .D. Fasman ((1969), Biochemistry 8, 4108). In this way the helical content of the native and reconstituted alkylated beta subunits appeared to be near 76%, a value very near to that present in the same subunits in the hemoglobin crystal. The helical content of the apo-beta subunits in 0.04 M borate buffer at pH 9.6 decreased to a value near 45%. The helical content of the isolated peptides in electrolyte solutions was in any case near 10% indicating an almost complete loss of the structure that they have in the hemoglobin crystal. Cyanoheme reacted with the peptide beta(41-104), however, the reaction was not stoichiometric indicating a low affinity of the heme for the peptide. With the exception of the peptide beta(31-104), all of the other peptides recovered some of their helical structure when dissolved in 50% methanol. Notably also the apo-beta subunits did so suggesting that the loss of structure upon the removal of the heme could be in part due to the exposure of the heme pocket to water.

  17. Axonal regulation of Schwann cell integrin expression suggests a role for alpha 6 beta 4 in myelination

    PubMed Central

    1993-01-01

    Ensheathment and myelination of axons by Schwann cells in the peripheral nervous system requires contact with a basal lamina. The molecular mechanism(s) by which the basal lamina promotes myelination is not known but is likely to reflect the activity of integrins expressed by Schwann cells. To initiate studies on the role of integrins during myelination, we characterized the expression of two integrin subunits, beta 1 and beta 4, in an in vitro myelination system and compared their expression to that of the glial adhesion molecule, the myelin-associated glycoprotein (MAG). In the absence of neurons, Schwann cells express significant levels of beta 1 but virtually no beta 4 or MAG. When Schwann cells are cocultured with dorsal root ganglia neurons under conditions promoting myelination, expression of beta 4 and MAG increased dramatically in myelinating cells, whereas beta 1 levels remained essentially unchanged. (In general agreement with these findings, during peripheral nerve development in vivo, beta 4 levels also increase during the period of myelination in sharp contrast to beta 1 levels which show a striking decrease.) In cocultures of neurons and Schwann cells, beta 4 and MAG appear to colocalize in nascent myelin sheaths but have distinct distributions in mature sheaths, with beta 4 concentrated in the outer plasma membrane of the Schwann cell and MAG localized to the inner (periaxonal) membrane. Surprisingly, beta 4 is also present at high levels with MAG in Schmidt-Lanterman incisures. Immunoprecipitation studies demonstrated that primary Schwann cells express beta 1 in association with the alpha 1 and alpha 6 subunits, while myelinating Schwann cells express alpha 6 beta 4 and possibly alpha 1 beta 1. beta 4 is also downregulated during Wallerian degeneration in vitro, indicating that its expression requires continuous Schwann cell contact with the axon. These results indicate that axonal contact induces the expression of beta 4 during Schwann cell

  18. Beta cell device using icosahedral boride compounds

    DOEpatents

    Aselage, Terrence L.; Emin, David

    2002-01-01

    A beta cell for converting beta-particle energies into electrical energy having a semiconductor junction that incorporates an icosahedral boride compound selected from B.sub.12 As.sub.2, B.sub.12 P.sub.2, elemental boron having an .alpha.-rhombohedral structure, elemental boron having a .beta.-rhombohedral structure, and boron carbides of the chemical formula B.sub.12-x C.sub.3-x, where 0.15beta radiation source, and means for transmitting electrical energy to an outside load. The icosahedral boride compound self-heals, resisting degradation from radiation damage.

  19. Milk Intolerance, Beta-Casein and Lactose.

    PubMed

    Pal, Sebely; Woodford, Keith; Kukuljan, Sonja; Ho, Suleen

    2015-08-31

    True lactose intolerance (symptoms stemming from lactose malabsorption) is less common than is widely perceived, and should be viewed as just one potential cause of cows' milk intolerance. There is increasing evidence that A1 beta-casein, a protein produced by a major proportion of European-origin cattle but not purebred Asian or African cattle, is also associated with cows' milk intolerance. In humans, digestion of bovine A1 beta-casein, but not the alternative A2 beta-casein, releases beta-casomorphin-7, which activates μ-opioid receptors expressed throughout the gastrointestinal tract and body. Studies in rodents show that milk containing A1 beta-casein significantly increases gastrointestinal transit time, production of dipeptidyl peptidase-4 and the inflammatory marker myeloperoxidase compared with milk containing A2 beta-casein. Co-administration of the opioid receptor antagonist naloxone blocks the myeloperoxidase and gastrointestinal motility effects, indicating opioid signaling pathway involvement. In humans, a double-blind, randomized cross-over study showed that participants consuming A1 beta-casein type cows' milk experienced statistically significantly higher Bristol stool values compared with those receiving A2 beta-casein milk. Additionally, a statistically significant positive association between abdominal pain and stool consistency was observed when participants consumed the A1 but not the A2 diet. Further studies of the role of A1 beta-casein in milk intolerance are needed.

  20. Tumor necrosis factor beta and ultraviolet radiation are potent regulators of human keratinocyte ICAM-1 expression

    SciTech Connect

    Krutmann, J.; Koeck, A.S.; Schauer, E.; Parlow, F.; Moeller, A.K.; Kapp, A.; Foerster, E.S.; Schoepf, E.L.; Luger, T.A. )

    1990-08-01

    Intercellular adhesion molecule-1 (ICAM-1) functions as a ligand of leukocyte function-associated antigen-1 (LFA-1), as well as a receptor for human picorna virus, and its regulation thus affects various immunologic and inflammatory reactions. The weak, constitutive ICAM-1 expression on human keratinocytes (KC) can be up-regulated by cytokines such as interferon-gamma (IFN gamma) and tumor necrosis factor alpha (TNF alpha). In order to further examine the regulation of KC ICAM-1 expression, normal human KC or epidermoid carcinoma cells (KB) were incubated with different cytokines and/or exposed to ultraviolet (UV) radiation. Subsequently, ICAM-1 expression was monitored cytofluorometrically using a monoclonal anti-ICAM-1 antibody. Stimulation of cells with recombinant human (rh) interleukin (IL) 1 alpha, rhIL-4, rhIL-5, rhIL-6, rh granulocyte/macrophage colony-stimulating factor (GM-CSF), rh interferon alpha (rhIFN alpha), and rh transforming growth factor beta (TGF beta) did not increase ICAM-1 surface expression. In contrast, rhTNF beta significantly up-regulated ICAM-1 expression in a time- and dose-dependent manner. Moreover, the combination of rhTNF beta with rhIFN gamma increased the percentage of ICAM-1-positive KC synergistically. This stimulatory effect of rhTNF beta was further confirmed by the demonstration that rhTNF beta was capable of markedly enhancing ICAM-1 mRNA expression in KC. Finally, exposure of KC in vitro to sublethal doses of UV radiation (0-100 J/m2) prior to cytokine (rhIFN tau, rhTNF alpha, rhTNF beta) stimulation inhibited ICAM-1 up-regulation in a dose-dependent fashion. These studies identify TNF beta and UV light as potent regulators of KC ICAM-1 expression, which may influence both attachment and detachment of leukocytes and possibly viruses to KC.