Science.gov

Sample records for continuous beta exposure

  1. 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.

  2. 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.

  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. 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.

  6. 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

  7. beta-(1,3)-Glucan exposure assessment by passive airborne dust sampling and new sensitive immunoassays.

    PubMed

    Noss, Ilka; Wouters, Inge M; Bezemer, Gillina; Metwali, Nervana; Sander, Ingrid; Raulf-Heimsoth, Monika; Heederik, Dick J J; Thorne, Peter S; Doekes, Gert

    2010-02-01

    Associations between house dust-associated beta-(1,3)-glucan exposure and airway inflammatory reactions have been reported, while such exposures in early childhood have been suggested to protect against asthma and wheezing. Most epidemiological studies have used reservoir dust samples and an inhibition enzyme immunoassay (EIA) for beta-(1,3)-glucan exposure assessment. The objective of this study was to develop inexpensive but highly sensitive enzyme immunoassays to measure airborne beta-(1,3)-glucans in low-exposure environments, like homes. Specificities of available anti-beta-(1,3)-glucan antibodies were defined by direct and inhibition experiments. Three suitable antibody combinations were selected for sandwich EIAs. beta-(1,3)-Glucans in passive airborne dust collected with an electrostatic dust fall collector (EDC) and floor dust from seven homes were measured with the three EIAs. Floor dust samples were additionally analyzed in the inhibition EIA. The sandwich EIAs were sensitive enough for airborne glucan measurement and showed different specificities for commercial glucans, while the beta-(1,3)-glucan levels in house dust samples correlated strongly. The feasibility of measuring glucans in airborne dust with the recently introduced EDC method was further investigated by selecting the most suitable of the three EIAs to measure and compare beta-(1,3)-glucan levels in the EDC and in floor and actively collected airborne dust samples of the previously performed EDC validation study. The EDC beta-(1,3)-glucan levels correlated moderately with beta-(1,3)-glucans in actively collected airborne dust and floor dust samples, while the glucan levels in the airborne dust and floor dust samples did not correlate. The combination of the newly developed beta-(1,3)-glucan sandwich EIA with EDC sampling now allows assessment in large-scale population studies of exposure to airborne beta-(1,3)-glucans in homes or other low-exposure environments.

  8. Building a continuous cooling transformation diagram of {beta}-CEZ alloy by metallography and electrical resistivity measurements

    SciTech Connect

    Angelier, C.; Bein, S.; Bechet, J.

    1997-12-01

    The phase transformations of Ti-5Al-2SN-4Zr-4Mo-2Cr-1Fe ({beta}-CEZ) have been studied during continuous cooling after {beta}-solution treatment. For this purpose, electrical resistivity measurements and metallographical examinations have been carried out, and the continuous cooling transformation (CCT) diagram of {beta}-CEZ alloy has been plotted. The different kinds of {beta}-phase decomposition schemes in {beta}-CEZ alloy during continuous cooling have been investigated in detail. Two main morphological features of the {alpha}/{beta} structure are involved, depending on the cooling rate: the basket-weave and the colony structures are observed for high and low cooling rates, respectively. For the intermediate cooling rates, the two morphologies coexist. Finally, a generalized scheme of the {beta} {yields} {beta} + {alpha} transformation sequences during continuous cooling is presented.

  9. Continuous beta-galactosidase production with a recombinant baculovirus insect-cell system in bioreactors.

    PubMed

    van Lier, F L; van der Meijs, W C; Grobben, N G; Olie, R A; Vlak, J M; Tramper, J

    1992-02-01

    Insect cells were exploited to produce bacterial beta-galactosidase by infecting them with a recombinant nuclear polyhedrosis virus (baculovirus) of Autographa californica. The insect cells were cultured in a continuous stirred tank reactor (CSTR) and led to a second CSTR where they were infected with a recombinant virus in which the lacZ gene from Escherichia coli was inserted. In the effluent of the production reactor, maximum activities of 15 units beta-galactosidase per 10(6) cells were measured. For about 25 d beta-galactosidase production remained constant, but then rapidly declined. This drop was due to a decrease in production of active beta-galactosidase rather than to inactivation of this enzyme. It was concluded that the reduced production was due to reduced polyhedrin promoter-driven synthesis.

  10. Behaviour of beta 2-adrenoceptors on lymphocytes under continuous and pulsatile tocolysis with Fenoterol.

    PubMed

    Schmidt-Rhode, Peter; Brunke, Björn; Schröer, Heinrich; Obert, Kirstin; Schlegel, Kerstin; Sturm, Gerhard; Schulz, Klaus-Dieter; von Wichert, Peter

    2003-01-01

    The present study investigates the population of beta 2-receptors on lymphocytes in pregnant women with premature labor between the 29th and 34th week of pregnancy. The population of receptors on lymphocytes correlates with that on the myometrium, which is not accessible for study during pregnancy. Fourteen patients received a pulsatile tocolysis, while ten women received a continuous tocolysis with Fenoterol. Assuming an equal population of receptors in both groups before commencement of therapy, the numbers of receptors in the patients with continuous tocolysis fell to about 35% of the initial value after 72 hours. Under pulsatile tocolysis, the numbers of receptors remained unchanged for a period of three days and was still only just below 70% of the initial value by the seventh day. Our data demonstrate that continuous administration of the short-acting beta 2-agonist Fenoterol resulted in a substantial loss of beta 2-adrenoceptors on lymphocytes. In contrast, intermittent administration of the same beta 2-adrenergic agonist prevented the onset of receptor down-regulation in pregnant women with preterm labor. Further studies are required to investigate the impact of the decreased loss of beta 2-adrenoceptor density on the good clinical experience with intermittent tocolysis.

  11. 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. PMID:20596612

  12. Management of drug interactions with beta-blockers: continuing education has a short-term impact

    PubMed Central

    Driesen, Annelies; Simoens, Steven; Laekeman, Gert

    There is a lack of clear guidelines regarding the management of drug-drug interactions. Objective To assess the impact of an educational intervention on the management of drug interactions with beta-blockers. Methods The study had a controlled before-and-after design. The intervention group (n=10 pharmacies) received a continuing education course and guidelines on the management of drug interactions with beta-blockers. The control group (n=10 pharmacies) received no intervention. Pharmacy students and staff of internship pharmacies participated in this study. Before and after the intervention, students registered interactions with beta-blockers during two weeks. Information was obtained on drug information of the beta-blocker and the interacting drug, patient’s demographics, and the mode of transaction. Results A total number of 288 interactions were detected during both study periods. Most beta-blockers causing an interaction were prescribed for hypertension, and interacted with hypoglycemic agents, NSAIDs, or beta2-agonists. Pharmacists’ intervention rate was low (14% in the pre-test compared to 39% in the post-test), but increased significantly in the post-test in the intervention group. Reasons for overriding the interaction included limited clinical relevance, refill prescriptions, not being aware of the interaction, and communication problems with the prescriber. Conclusion An interactive continuing education course, during which practice-oriented guidelines were offered, affected pharmacists’ short-term behavior at the counter in dealing with interactions of beta-blockers. Continuing education plays a role in raising pharmacists’ awareness and responsibility towards the detection and management of drug interactions in the pharmacy. PMID:25214902

  13. 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.

  14. 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.

  15. Three-Day Continuous Exposure Monitoring of CNT Manufacturing Workplaces.

    PubMed

    Lee, Ji Hyun; Ahn, Kang Ho; Kim, Sun Man; Kim, Ellen; Lee, Gun Ho; Han, Jeong Hee; Yu, Il Je

    2015-01-01

    Continuous monitoring for possible exposure to carbon nanotubes was conducted over a period of 2 to 3 days at workplaces that manufacture multiwall carbon nanotubes (MWCNTs) and single wall carbon nanotubes (SWCNTs). To estimate the potential emission of carbon nanotubes (CNTs) and potential exposure of workers, personal sampling, area monitoring, and real-time monitoring using an scanning mobility particle sizer (SMPS) and dust monitor were conducted at workplaces where the workers manufactured CNTs. The personal and area sampling of the total suspended particulate (TSP) at the MWCNT manufacturing facilities ranged from 0.031 to 0.254 and from N.D (not detected) to 0.253 mg/m(3), respectively. This 2- to 3-day monitoring study found that nanoparticles were released when opening the chemical vapor deposit (CVD) reactor door after the synthesis of MWCNTs, when transferring the MWCNTs to containers and during blending and grinding. However, distinguishing the background concentration from the work process particle emission was complicated due to sustained and even increased particle concentrations after the work processes were terminated. The MWCNTs sampled for transmission electron microscopy (TEM) observation exhibited a tangled shape with no individual dispersed CNT structures. PMID:26125022

  16. 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

  17. 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.

  18. Requirements regarding dose rate and exposure time for killing of tumour cells in beta particle radionuclide therapy

    PubMed Central

    Eriksson, Veronika; Stenerlöw, Bo; Lundqvist, Hans

    2006-01-01

    Purpose The purpose of this study was to identify combinations of dose rate and exposure time that have the potential to provide curative treatment with targeted radionuclide therapy applying low dose rate beta irradiation. Methods Five tumour cell lines, U-373MG and U-118MG gliomas, HT-29 colon carcinoma, A-431 cervical squamous carcinoma and SKBR-3 breast cancer, were used. An experimental model with 105 tumour cells in each sample was irradiated with low dose rate beta particles. The criterion for successful treatment was absence of recovery of cells during a follow-up period of 3 months. The initial dose rates were in the range 0.1–0.8 Gy/h, and the cells were continuously exposed for 1, 3 or 7 days. These combinations covered dose rates and doses achievable in targeted radionuclide therapy. Results Continuous irradiation with dose rates of 0.2–0.3 and 0.4–0.6 Gy/h for 7 and 3 days, respectively, could kill all cells in each tumour cell sample. These treatments gave total radiation doses of 30–40 Gy. However, when exposed for just 24 h with about 0.8 Gy/h, only the SKBR-3 cells were successfully treated; all the other cell types recovered. There were large cell type-dependent variations in the growth delay patterns for the cultures that recovered. The U-118MG cells were most resistant and the U-373MG and SKBR-3 cells most sensitive to the treatments. The HT-29 and A-431 cells were intermediate. Conclusion The results serve as a guideline for the combinations of dose rate and exposure time necessary to kill tumour cells when applying low dose rate beta irradiation. The shift from recovery to “cure” fell within a narrow range of dose rate and exposure time combinations. PMID:16718515

  19. Increased beta-adrenergic responsiveness induced by 14 days exposure to simulated microgravity

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.; Polet, J. L.; Engelke, K. A.; Hoffler, G. W.; Lane, L. D.; Blomqvist, C. G.

    1995-01-01

    Increased sensitivity of end-organ responses to neuroendocrine stimuli as a result of prolonged exposure to the relative inactivity of microgravity has recently been hypothesized. This notion is based on the inverse relationship between circulating norepinephrine and beta-adrenoreceptor sensitivity. The beta-adrenoreceptor activity is reduced in individuals who have elevated plasma norepinephrine as a result of regular exposure to upright posture and physical exercise. In contrast, adrenoreceptor hypersensitivity has been reported in patients with dysautonomias in which circulating catecholamines are absent or reduced. Taken together, these studies and the observation that circulating plasma norepinephrine has been reduced during spaceflight and in groundbased simulations of microgravity prompt the suggestion that adrenoreceptor hypersensitivity may be a consequence of the adaptation to spaceflight. We conducted an experiment designed to measure cardiovascular responses to adrenoreceptor agonists in human subjects before and after prolonged exposure to 6 deg head-down tilt (HDT) to test the hypothesis that adaptation to microgravity increases adrenoreceptor responsiveness, and that this adaptation is associated with reduced levels of circulating norepinephrine.

  20. 76 FR 12648 - Lowering Miners' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-08

    ...' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors AGENCY: Mine Safety and... Continuous Personal Dust Monitors. The proposed rule would improve health protections for coal miners by... Occupational Exposure to Respirable Coal Mine Dust, the National Institute for Occupational Safety and...

  1. 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

    ... addressing Lowering Miners' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors. The proposed rule was published on October 19, 2010 (75 FR 64412) and is available on MSHA's Web...' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors AGENCY: Mine Safety...

  2. 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.

  3. 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.

  4. 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.

  5. 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…

  6. 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

    ... FR 64412), MSHA published a proposed rule, Lowering Miners' Exposure to Respirable Coal Mine Dust... the proposed rule. The proposal was published on October 19, 2010 (75 FR 64412). DATES: All comments...' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors AGENCY: Mine Safety...

  7. 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...

  8. Modeling impacts on populations: fathead minnow (Pimephales promelas) exposure to the endocrine disruptor 17beta-trenbolone as a case study.

    PubMed

    Miller, David H; Ankley, Gerald T

    2004-09-01

    Evaluation of population-level impacts is critical to credible ecological risk assessments. In this study, a predictive model was developed to translate changes in fecundity of the fathead minnow (Pimephales promelas) in a short-term laboratory toxicity test to alterations in population growth rate. The model uniquely combines a Leslie population projection matrix and the logistic equation. Application of the model requires only a life table for the organism of interest, a measure of carrying capacity for the given population, and an estimation of the effect of a stressor on vital rates. The model was applied to investigate population dynamics for fathead minnow exposed to the androgen receptor agonist 17beta-trenbolone. Organismal-level responses for fathead minnows exposed to varying levels of 17beta-trenbolone were used to determine projected alterations in a population existing in a small body of water containing varying concentrations of the androgen. Fathead minnow populations occurring at carrying capacity and subsequently exposed to 0.027 microg/L of 17beta-trenbolone exhibited a 51% projected decrease in average population size after 2 years of exposure. Populations at carrying capacity exposed to concentrations of 17beta-trenbolone > or = 0.266 microg/L exhibited a 93% projected decrease in average population size after 2 years of exposure. Overall, fathead minnow populations exposed to continued concentrations of 17beta-trenbolone equal to or greater than 0.027 microg/L were projected to have average equilibrium population sizes that approached zero.

  9. 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.

  10. 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

  11. Carcinogen exposure differentially modulates RAR-beta promoter hypermethylation, an early and frequent event in mouse lung carcinogenesis.

    PubMed

    Vuillemenot, Brian R; Pulling, Leah C; Palmisano, William A; Hutt, Julie A; Belinsky, Steven A

    2004-04-01

    The retinoic acid receptor beta (RAR-beta) gene encodes one of the primary receptors for retinoic acid, an important signaling molecule in lung growth, differentiation and carcinogenesis. RAR-beta has been shown to be down-regulated by methylation in human lung cancer. We have used previously lung tumors induced in mice to evaluate the timing and effect of specific carcinogen exposures on targeting genes altered in human lung cancer. These studies were extended to characterize the role of methylation of the RAR-beta gene in murine lung cancers. After treatment with the demethylating agent 5-aza-2'-deoxycytidine (DAC), RAR-beta was re-expressed in silenced cell lines or expressed at a higher rate than without DAC, supporting methylation as the inactivating mechanism. Bisulfite sequencing detected dense methylation in the area of the CpG island that contained the 5' untranslated region and the first translated exon in non-expressing cell lines, compared with minimal and heterogeneous methylation in normal mouse lung. Methylation-specific PCR revealed that this gene is targeted differentially by carcinogen exposures with the detection of methylated alleles in virtually all primary tumors associated with cigarette smoke or 4-methylnitrosamino-1-(3-pyridyl)-butanone (NNK) in contrast to half of tumors induced by methylene chloride or vinyl carbamate. RAR-beta methylation was also detected in 54% of preneoplastic hyperplasias induced by treatment with NNK. Bisulfite sequencing of both premalignant and malignant lesions detected dense methylation in the same area observed in cell lines, substantiating that this gene is functionally inactivated at the earliest histologic stage of adenocarcinoma development. These studies demonstrate that aberrant methylation of RAR-beta is an early and common alteration in murine lung tumors induced by several environmentally relevant exposures. PMID:14656941

  12. Comparison of pulsatile and continuous ritodrine administration: effects on uterine contractility and beta-adrenergic receptor cascade.

    PubMed

    Caritis, S N; Chiao, J P; Kridgen, P

    1991-04-01

    In this study we compare the uterine contractility and beta-adrenergic receptor effects of identical doses of ritodrine administered intermittently or continuously for 24 hours in pregnant sheep. Ritodrine was administered intravenously to five animals as a pulse, 16 micrograms/kg every 1.5 hours, whereas five other animals received ritodrine as a continuous infusion of 0.18 microgram/kg/min. Ritodrine plasma concentrations at steady state were comparable in both groups and averaged 18 ng/ml. Animals receiving ritodrine pulses demonstrated no alteration of myometrial beta-adrenergic receptors or adenylyl cyclase activity, and ritodrine inhibited oxytocin-induced contractility comparably at 4 and 24 hours. Animals receiving ritodrine continuously had a significant decrease in myometrial beta-adrenergic receptors and adenylyl cyclase activity, yet ritodrine inhibition of oxytocin-induced uterine contractility was sustained for 24 hours. Oxytocin receptors were not affected by ritodrine administration and were similar in both groups. At the dose studied, oxytocin-induced contractions are comparably inhibited by ritodrine for 24 hours whether the drug is given continuously or in a pulsatile fashion.

  13. 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.

  14. 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. PMID:21499552

  15. 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.

  16. Exposure of Chironomus riparius larvae (diptera) to lead, mercury and beta-sitosterol: effects on mouthpart deformation and moulting.

    PubMed

    Vermeulen, A C; Liberloo, G; Dumont, P; Ollevier, F; Goddeeris, B

    2000-11-01

    Mouthpart deformation in chironomid larvae is induced by exposure to chemical contaminants and is becoming an established bio-indicator in sediment assessment programmes. However, concentration-response relationships with causal agents have only been established occasionally and with varying success. In this laboratory study, instar II and III larvae were exposed to sub-lethal concentrations of lead, mercury and beta-sitosterol. A significant deformation response was induced in the pecten with lead and mercury. Deformation frequencies of the mentum after metal exposures were not significantly different from the control. Moulting was retarded by both metals and was well correlated with mouthpart deformation. The beta-sitosterol is an endocrine disruptor, which was used to test the hypothetical cause-effect relation between disruption of ecdyson functioning and chironomid deformation. In the present study, exposure to sublethal concentrations of beta-sitosterol did not result in any effect on deformation or moulting. As such, the proposed hypothesis of endocrine disruptors as primary causal agents of chironomid deformation could not be substantiated. Acetone, which was used as a solvent to apply beta-sitosterol caused a significant increase of mentum deformation. The ground filtration paper used as substrate seemed to induce deformities as well. Substrate contamination, acetone and (especially) inbreeding were most probably responsible for the high deformation frequencies in the control conditions. PMID:11057685

  17. Exposure to particulate 1-->3-beta-glucans induces greater pulmonary toxicity than soluble 1-->3-beta-glucans in rats.

    PubMed

    Young, Shih-Houng; Robinson, Victor A; Barger, Mark; Whitmer, Michael; Porter, Dale W; Frazer, David G; Castranova, Vincent

    2003-01-10

    1-->3-beta-Glucans, derived from the inner cell wall of yeasts and fungi, are commonly found in indoor air dust samples and have been implicated in organic dust toxic syndrome. In a previous study, it was reported that 1-->3-beta-glucan (zymosan A) induced acute pulmonary inflammation in rats. This study investigates which form of 1-->3-beta-glucans, particulate or soluble, is more potent in inducing pulmonary inflammation. Zymosan A was suspended in 0.25 N NaOH for 30 min, neutralized, dialyzed for 2 d using deionized water, and particulate and soluble fractions were collected. Male Sprague-Dawley rats were exposed via intratracheal instillation to NaOH-soluble or NaOH-insoluble zymosan A. At 18 h postexposure, various indicators of pulmonary response were monitored, including indicators of lung damage, such as serum albumin concentration and lactate dehydrogenase (LDH) activity in acellular bronchoalveolar lavage fluid. Inflammation was characterized by an increase in lavageable polymorphonuclear leukocytes (PMN). Pulmonary irritation (breathing frequency increase) and oxidant production (nitric oxide and chemiluminescence, CL) were also monitored. Exposure to the particulate form of NaOH-treated zymosan produced a significant increase in all these indicators. In contrast, rats exposed to the NaOH-soluble fraction were not markedly affected except for LDH, PMN, and CL. However, these increases were significantly less than with exposure to NaOH-insoluble zymosan. Therefore, results demonstrate that particulate zymosan A is more potent in inducing pulmonary inflammation and damage in rats than the soluble form of this beta-glucan. PMID:12587289

  18. 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.

  19. Exposure assessment of extended-spectrum beta-lactamases/AmpC beta-lactamases-producing Escherichia coli in meat in Denmark

    PubMed Central

    Carmo, Luís P.; Nielsen, Liza R.; da Costa, Paulo M.; Alban, Lis

    2014-01-01

    Introduction Extended-spectrum beta-lactamases (ESBL) and AmpC beta-lactamases (AmpC) are of concern for veterinary and public health because of their ability to cause treatment failure due to antimicrobial resistance in Enterobacteriaceae. The main objective was to assess the relative contribution (RC) of different types of meat to the exposure of consumers to ESBL/AmpC and their potential importance for human infections in Denmark. Material and methods The prevalence of each genotype of ESBL/AmpC-producing E. coli in imported and nationally produced broiler meat, pork and beef was weighted by the meat consumption patterns. Data originated from the Danish surveillance program for antibiotic use and antibiotic resistance (DANMAP) from 2009 to 2011. DANMAP also provided data about human ESBL/AmpC cases in 2011, which were used to assess a possible genotype overlap. Uncertainty about the occurrence of ESBL/AmpC-producing E. coli in meat was assessed by inspecting beta distributions given the available data of the genotypes in each type of meat. Results and discussion Broiler meat represented the largest part (83.8%) of the estimated ESBL/AmpC-contaminated pool of meat compared to pork (12.5%) and beef (3.7%). CMY-2 was the genotype with the highest RC to human exposure (58.3%). However, this genotype is rarely found in human infections in Denmark. Conclusion The overlap between ESBL/AmpC genotypes in meat and human E. coli infections was limited. This suggests that meat might constitute a less important source of ESBL/AmpC exposure to humans in Denmark than previously thought – maybe because the use of cephalosporins is restricted in cattle and banned in poultry and pigs. Nonetheless, more detailed surveillance data are required to determine the contribution of meat compared to other sources, such as travelling, pets, water resources, community and hospitals in the pursuit of a full source attribution model. PMID:24511370

  20. 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.

  1. Serum clara-cell protein and beta2-microglobulin as early markers of occupational exposure to nitric oxides.

    PubMed

    Hałatek, T; Gromadzińska, J; Wasowicz, W; Rydzyński, K

    2005-02-01

    Biochemical effects of NOx on 60 workers (both genders) of nitric acid production were studied. The control group consisted of 61 nonexposed people employed elsewhere in the plant. Although the actual threshold limit valuetime weighted averages (TLV-TWA) were not exceeded in the specific conditions of our study, the subjects were exposed to NO2 and NO during several exposure episodes with peak maximal concentrations of 140 ppm and 515 ppm, respectively. Additional cross-week evaluation of several biochemical biomarkers in 15 NOx-exposed workers from one shift was performed. The objective of the study was to evaluate the value of serum Clara-cell protein (CC16) as a marker of bronchoalveolar epithelium activity. Antioxidant status was assessed by measuring activity of enzymes: glutathione peroxidase (GSH-Px), ceruloplasmin (Cp) in plasma, or superoxide dismutase (SOD), gluthatione S-transferase (GST), and nonenzymatic alpha-tocopherol in erythrocytes and thiobarbituric acid-reactive substances (TBARS) in plasma. Serum hyaluronic acid (HA) determining the connective tissue matrix status of airways, and beta2-microglobulin in serum (beta2M-S) and urine (beta2M-U) as a marker of renal function in occupational exposure to NOx were also employed. Exposure to NOx initiates peroxidative chain depleting of lipoprotein pool (alpha-tocopherol) in blood. Serum CC16 levels in NOx-exposed workers were found to be closely connected with alpha-tocopherol content. In NOx-exposed workers, the beta2M-S level was significantly higher than in the nonexposed ones, with the exception of smokers. Results of the cross-week study confirm cumulative systemic effects of NOx on several examined biomarkers. SOD and GST were found to be depleted. A transient higher level of HA after a 5-d shift significantly inversely correlated with CC16 level. The data imply that NOx-depleted levels of CC16 are detectable already after an 8-h shift. Our results demonstrate that even low NOx human exposure can

  2. 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

  3. 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.

  4. 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.

  5. 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

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Mine...' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors AGENCY: Mine Safety and.... SUMMARY: The Mine Safety and Health Administration (MSHA) is extending the comment period on the...

  6. 75 FR 73995 - Lowering Miners' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-30

    ..., 2010, MSHA announced that it would hold six public hearings on the proposed rule (75 FR 69617). Due to... the proposed rule on October 19, 2010 (75 FR 64412); it is available on MSHA's Web site at http://www...' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors AGENCY: Mine Safety...

  7. Continuous infusion of antibiotics in the critically ill: The new holy grail for beta-lactams and vancomycin?

    PubMed Central

    2012-01-01

    The alarming global rise of antimicrobial resistance combined with the lack of new antimicrobial agents has led to a renewed interest in optimization of our current antibiotics. Continuous infusion (CI) of time-dependent antibiotics has certain theoretical advantages toward efficacy based on pharmacokinetic/pharmacodynamic principles. We reviewed the available clinical studies concerning continuous infusion of beta-lactam antibiotics and vancomycin in critically ill patients. We conclude that CI of beta-lactam antibiotics is not necessarily more advantageous for all patients. Continuous infusion is only likely to have clinical benefits in subpopulations of patients where intermittent infusion is unable to achieve an adequate time above the minimal inhibitory concentration (T > MIC). For example, in patients with infections caused by organisms with elevated MICs, patients with altered pharmacokinetics (such as the critically ill) and possibly also immunocompromised patients. For vancomycin CI can be chosen, not always for better clinical efficacy, but because it is practical, cheaper, associated with less AUC24h (area under the curve >24 h)-variability, and easier to monitor. PMID:22747633

  8. Immunity to HIV-1 Is Influenced by Continued Natural Exposure to Exogenous Virus

    PubMed Central

    Willberg, Christian B.; McConnell, J. Jeff; Eriksson, Emily M.; Bragg, Larry A.; York, Vanessa A.; Liegler, Teri J.; Hecht, Fredrick M.; Grant, Robert M.; Nixon, Douglas F.

    2008-01-01

    Unprotected sexual intercourse between individuals who are both infected with HIV-1 can lead to exposure to their partner's virus, and potentially to super-infection. However, the immunological consequences of continued exposure to HIV-1 by individuals already infected, has to our knowledge never been reported. We measured T cell responses in 49 HIV-1 infected individuals who were on antiretroviral therapy with suppressed viral loads. All the individuals were in a long-term sexual partnership with another HIV-1 infected individual, who was either also on HAART and suppressing their viral loads, or viremic (>9000 copies/ml). T cell responses to HIV-1 epitopes were measured directly ex-vivo by the IFN-γ enzyme linked immuno-spot assay and by cytokine flow cytometry. Sexual exposure data was generated from questionnaires given to both individuals within each partnership. Individuals who continued to have regular sexual contact with a HIV-1 infected viremic partner had significantly higher frequencies of HIV-1-specific T cell responses, compared to individuals with aviremic partners. Strikingly, the magnitude of the HIV-1-specific T cell response correlated strongly with the level and route of exposure. Responses consisted of both CD4+ and CD8+ T cell subsets. Longitudinally, decreases in exposure were mirrored by a lower T cell response. However, no evidence for systemic super-infection was found in any of the individuals. Continued sexual exposure to exogenous HIV-1 was associated with increased HIV-1-specific T cell responses, in the absence of systemic super-infection, and correlated with the level and type of exposure. PMID:18949024

  9. Gestational Alcohol Exposure and Other Factors Associated With Continued Teenage Drinking

    PubMed Central

    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. Method A stepwise discriminant analysis identified differences between the two groups. Considered risk/protective factors were parenting practices, peer drinking, child and maternal depression, child behavior, prenatal alcohol exposure, home environment, and demographic factors. Results Desistence was significantly related to African American race and more parental strictness. Exposure to ≥1 drink/day during pregnancy and high levels of autonomy from parents were significant predictors of persistent drinking. Conclusions Early initiation places adolescents at risk for continued and heavier drinking. Identifying characteristics of those who start early but do or do not continue drinking can inform education programs to better target the most appropriate adolescents. PMID:27405800

  10. Long-term exposure of proximal tubular epithelial cells to glucose induces transforming growth factor-beta 1 synthesis via an autocrine PDGF loop.

    PubMed

    Fraser, Donald; Brunskill, Nigel; Ito, Takafumi; Phillips, Aled

    2003-12-01

    We have recently reported increased transforming growth factor (TGF)-beta1 gene transcription in proximal tubular cells within 12 hours of exposure to 25 mmol/L D-glucose, with a requirement for a second stimulus such as platelet-derived growth factor (PDGF) to increase its translation in short-term experiments. In the current study we investigated the effect on TGF-beta 1 production of prolonged exposure of proximal tubular cells to high glucose concentrations. Enzyme-linked immunosorbent assay of cell culture supernatant showed significant increase in latent TGF-beta 1 only after 7 days exposure to high glucose. Radiolabeling of glucose-stimulated cells with (3)H amino acids and subsequent immunoprecipitation of TGF-beta 1 demonstrated de novo synthesis from day 5 of high glucose exposure onwards. Similarly, polysome analysis showed enhanced translation of TGF-beta mRNA after 4 or more days of high glucose exposure. TGF-beta 1 synthesis, following addition of glucose, was inhibited by blockade of the PDGF-alpha receptor subunit. Glucose did not alter PDGF expression, nor expression of PDGF alpha-receptors. Activation of the receptor following addition of 25 mm D-glucose could be demonstrated suggesting increased sensitivity to endogenous PDGF. Exposure to glucose activated p38MAP kinase, and inhibition of this activation abrogated both glucose induced TGF-beta 1 transcriptional activation and TGF-beta 1 synthesis. Inhibition of p38MAP kinase did not influence the effect of exogenous PDGF when cells were stimulated sequentially by glucose and PDGF. We postulate that glucose induces an early increase in TGF-beta 1 transcription via activation of p38MAP kinase. In addition, glucose causes a late increase in PDGF-dependent TGF-beta 1 translation by enhancing cellular sensitivity to PDGF. This provides a potential explanation for the clinical observation that prolonged poor glycemic control may contribute to progression of diabetic nephropathy. PMID:14633628

  11. Calculating dosimetry parameters in brachytherapy using the continuous beta spectrum of Sm-153 in the Monte Carlo simulation approach

    NASA Astrophysics Data System (ADS)

    Shahrabi, Mohammad; Tavakoli-Anbaran, Hossien

    2015-02-01

    Calculation of dosimetry parameters by TG-60 approach for beta sources and TG-43 approach for gamma sources can help to design brachytherapy sources. In this work, TG-60 dosimetry parameters are calculated for the Sm-153 brachytherapy seed using the Monte Carlo simulation approach. The continuous beta spectrum of Sm-153 and probability density are applied to simulate the Sm-153 source. Sm-153 is produced by neutron capture during the 152Sm( n,)153Sm reaction in reactors. The Sm-153 radionuclide decays by beta rays followed by gamma-ray emissions with half-life of 1.928 days. Sm-153 source is simulated in a spherical water phantom to calculate the deposited energy and geometry function in the intended points. The Sm-153 seed consists of 20% samarium, 30% calcium and 50% silicon, in cylindrical shape with density 1.76gr/cm^3. The anisotropy function and radial dose function were calculated at 0-4mm radial distances relative to the seed center and polar angles of 0-90 degrees. The results of this research are compared with the results of Taghdiri et al. (Iran. J. Radiat. Res. 9, 103 (2011)). The final beta spectrum of Sm-153 is not considered in their work. Results show significant relative differences even up to 5 times for anisotropy functions at 0.6, 1 and 2mm distances and some angles. MCNP4C Monte Carlo code is applied in both in the present paper and in the above-mentioned one.

  12. Initiate and Maintain Cavitation by Combining High Amplitude Bursts and Continuous Ultrasound Exposure in Culture Medium

    NASA Astrophysics Data System (ADS)

    Mestas, J.-L.; Alberti, L.; Chesnais, S.; Lafon, C.; Blay, J.-Y.; Cathignol, D.

    2006-05-01

    Ultrasound can produce a variety of nonthermal bioeffects via acoustic cavitation. Most studies on cavitation effects pointed on the difficulty of initiating and controlling the cavitation phenomenon. Our objective is to obtain reproducible viability and transfection rate in the case of the application of a continuous low intensity ultrasound exposure. We propose to initiate and maintain cavitation in the medium by combining a continuous ultrasound exposure with periodical high amplitude bursts. Cells were exposed to ultrasound (444.5 kHz) transmitted through the bottom of twelve-well culture plates containing prostatic cells (AT2, 2.5 106 cells/mL), the plasmid DsRed in transfection case (200 μg/mL) and culture media. The cavitation effects were evaluated on the cell viability and transfection, determined 0 to 3 days after exposure by a flow cytometer (FACScan; total counted events: 10 000). Bursts of 1.73 W/cm2 intensity level had no effect on cells when their duration was lower than 100 ms and their frequency lower than 4 bursts/min. When combined with continuous exposure, only one burst of 1.73 W/cm2 intensity level and 50 ms duration was sufficient to activate the cavitation phenomenon in the medium.

  13. 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

  14. The effects of errors in the measurement of continuous exposure variables on the assessment of risks

    SciTech Connect

    Gilbert, E.S.

    1988-06-01

    Exposure variables in epidemiological studies are seldom measured without error. However, it is unusual for such errors to be taken into account in analyzing data, and thus distortion of results may occur. These distorting effects are evaluated for the fitting of linear and log-linear proportional hazard models based on single continuous exposure variable, and are quantified under several sets of assumptions regarding the conditional distributions of the measured exposures given the true exposures, as well as assumptions regarding the true exposure distributions. For a wide range of assumptions, it is found that the most serious consequence of ignoring error is downward bias in the estimation of regression coefficients. In addition, the shape of the dose-response function may be distorted, and variances of estimated parameters may be underestimated. Except for the case of very large errors combined with skewed exposure distributions, tests of the null hypothesis of no effect that ignore error are found to be nearly as powerful as an optimal test, available if the error structure is known. 19 refs., 3 figs., 12 tabs.

  15. Repeated stressor exposure enhances contextual fear memory in a beta-adrenergic receptor-dependent process and increases impulsivity in a non-beta receptor-dependent fashion.

    PubMed

    Camp, Robert M; Johnson, John D

    2015-10-15

    Memory formation is promoted by stress via the release of norepinephrine and stimulation of beta-adrenergic receptors (β-ARs). Previous data demonstrate that repeated stressor exposure increases norepinephrine turnover and β-AR signaling within the amygdala, which led to the hypothesis that some stress-induced behavioral changes are likely due to facilitated associative learning. To test this, Fischer rats were exposed to chronic mild stress for four days. On day 5, subjects (including non-stressed controls) were injected with the beta-blocker propranolol or vehicle prior to conditioning in an operant box (animals receive two mild foot shocks) or passive avoidance apparatus (animals received a foot shock upon entry into the dark chamber). Twenty-four hours later, subjects were returned to the operant box for measurement of freezing or returned to the passive avoidance apparatus for measurement of latency to enter the dark chamber. Subjects were also tested in an open field to assess context-independent anxiety-like behavior. Animals exposed to chronic stress showed significantly more freezing behavior in the operant box than did controls, and this exaggerated freezing was blocked by propranolol during the conditioning trial. There was no effect of stress on behavior in the open field. Unexpectedly, retention latency was significantly reduced in subjects exposed to chronic stress. These results indicate that chronic exposure to stress results in complex behavioral changes. While repeated stress appears to enhance the formation of fearful memories, it also results in behavioral responses that resemble impulsive behaviors that result in poor decision-making.

  16. The SEMONT continuous monitoring of daily EMF exposure in an open area environment.

    PubMed

    Djuric, Nikola; Kljajic, Dragan; Kasas-Lazetic, Karolina; Bajovic, Vera

    2015-04-01

    Wireless networks traffic has experienced a considerable growth in recent years. Likewise, it is to be expected that billions of objects will be connected to the Internet in years to come, many of them wirelessly. Such increase in a number of wireless connections and the inevitability of wireless communications in proximity of users highlight the healthcare concern on electromagnetic field (EMF) exposure. Thus, the intelligent monitoring systems, such as the Serbian Electromagnetic Field Monitoring Network-SEMONT-have been required to be developed and utilized for continuous and real-time EMF monitoring, as well as for the assessment of the potential in situ daily exposure of population. This paper presents the results of the SEMONT initial campaign of continuous monitoring of the high-frequency electric field strength over the campus of the University of Novi Sad, as an open area environment. Several locations, most frequently visited by the student population in their everyday activities, have been monitored during the rush hour in order to determine the fluctuation of daily exposure on this, usually considered, highly sensitive area. The results of monitoring suggest that potential exposure is far below the allowable limit, regarding reference levels prescribed by the Serbian legislation for the general population. PMID:25787169

  17. The SEMONT continuous monitoring of daily EMF exposure in an open area environment.

    PubMed

    Djuric, Nikola; Kljajic, Dragan; Kasas-Lazetic, Karolina; Bajovic, Vera

    2015-04-01

    Wireless networks traffic has experienced a considerable growth in recent years. Likewise, it is to be expected that billions of objects will be connected to the Internet in years to come, many of them wirelessly. Such increase in a number of wireless connections and the inevitability of wireless communications in proximity of users highlight the healthcare concern on electromagnetic field (EMF) exposure. Thus, the intelligent monitoring systems, such as the Serbian Electromagnetic Field Monitoring Network-SEMONT-have been required to be developed and utilized for continuous and real-time EMF monitoring, as well as for the assessment of the potential in situ daily exposure of population. This paper presents the results of the SEMONT initial campaign of continuous monitoring of the high-frequency electric field strength over the campus of the University of Novi Sad, as an open area environment. Several locations, most frequently visited by the student population in their everyday activities, have been monitored during the rush hour in order to determine the fluctuation of daily exposure on this, usually considered, highly sensitive area. The results of monitoring suggest that potential exposure is far below the allowable limit, regarding reference levels prescribed by the Serbian legislation for the general population.

  18. 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…

  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. Rat lung metabolism after 3 days of continuous exposure to 0. 6 ppm ozone

    SciTech Connect

    Bassett, D.J.; Bowen-Kelly, E.

    1986-02-01

    Continuous exposure of rats to low concentrations of ozone has previously been associated with enhanced metabolic enzyme activities, when measured in lung homogenates. In this study, metabolic rates were measured in intact perfused lungs with altered pathology brought about by 3 days continuous exposure to 0.6 ppm ozone. Increased metabolism of ozone-exposed lungs was indicated by a twofold enhancement in glucose utilization, associated with a 62% increase in lactate formation and a 166% increase in the rate of 14CO2 production from D-(U-14C)glucose from control values of 5.2 +/- 0.5 mumol lactate and 4.4 +/- 0.6 mumol 14CO2/h per lung (+/- SE, n = 4), respectively. Mitochondrial metabolism was separately assessed by measurements of 14CO2 production from (U-14C)-pyruvate, which was found not to be significantly altered by ozone exposure, although homogenate oxygen uptake in the presence of succinate was significantly enhanced by 57%. These changes in intermediary metabolism could be correlated with increased glucose carbon incorporation into lipid and elevated activity of glucose-6-phosphate dehydrogenase. The observed elevated metabolic rates were consistent with the energy and synthetic needs of a lung during repair of ozone-induced damage.

  1. Impaired beta-cell functions induced by chronic exposure of cultured human pancreatic islets to high glucose.

    PubMed

    Marshak, S; Leibowitz, G; Bertuzzi, F; Socci, C; Kaiser, N; Gross, D J; Cerasi, E; Melloul, D

    1999-06-01

    In type 2 diabetes, chronic hyperglycemia has been suggested to be detrimental to beta-cell function, causing reduced glucose-stimulated insulin secretion and disproportionately elevated proinsulin. In the present study, we investigated the effect on several beta-cell functions of prolonged in vitro exposure of human pancreatic islet cultures to high glucose concentrations. Islets exposed to high glucose levels (33 mmol/l) for 4 and 9 days showed dramatic decreases in glucose-induced insulin release and in islet insulin content, with increased proportion of proinsulin-like peptides relative to insulin. The depletion in insulin stores correlated with the reduction in insulin mRNA levels and human insulin promoter transcriptional activity. We also demonstrated that high glucose dramatically lowered the binding activity of pancreatic duodenal homeobox 1 (the glucose-sensitive transcription factor), whereas the transcription factor rat insulin promoter element 3b1 activator was less influenced and insulin enhancer factor 1 remained unaffected. Most of these beta-cell impairments were partially reversible when islets first incubated for 6 days in high glucose were transferred to normal glucose (5.5 mmol/l) concentrations for 3 days. We conclude that cultured human islets are sensitive to the deleterious effect of high glucose concentrations at multiple functional levels, and that such mechanisms may play an important role in the decreased insulin production and secretion of type 2 diabetic patients. PMID:10342809

  2. Comparative studies of pulse and continuous exposure in human tumor clonogenic assay.

    PubMed

    Kanzawa, F; Matsushima, Y; Chiang, C D; Nakano, H; Nakagawa, K; Takahashi, H; Sasaki, Y; Saijo, N

    1987-09-01

    To assess the influence of different schedules of drug exposure in human tumor clonogenic assay on in vitro cytotoxicity of antitumor drugs, the in vitro sensitivities of a human carcinoma cell line, PC-9, to various antitumor drugs were measured by using two different procedures: exposure was either by pulse for 1 h prior to plating or continuous throughout the period of growth in agar. Marked differences between the two procedures in testing actinomycin D, etoposide, 5-fluorouracil, vinblastine and vindesine but not in adriamycin, daunomycin, melphalan, nimustine and ranomustine were observed. The former and the latter were classified as schedule dependent drugs and a schedule independent drugs, respectively. In this study, the schedule dependency of in vitro drug response appears to be related mainly to time-dependency and partially to other factors, such as stability during culture in medium. PMID:3437386

  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. Rat lung recovery from 3 days of continuous exposure to 0. 75 ppm ozone

    SciTech Connect

    Bassett, D.J.; Bowen-Kelly, E.; Elbon, C.L.; Reichenbaugh, S.S.

    1988-01-01

    The present study investigated the inflammatory responses and enzyme levels in lungs isolated from male Wistar rats after 3 d of continuous exposure to 0.75 ppm ozone and following 4 d of recovery in air. These times are associated with maximal proliferation of the alveolar type II epithelium and their subsequent transformation to new type I cells. Immediately following ozone exposure, bronchoalveolar lavage demonstrated neutrophil accumulation that was no longer present 4 d later. The number of lavaged macrophages was also found to be increased immediately following ozone exposure, and remained elevated at 4 d postexposure. Whole-lung determinations of key enzymes involved in energy generation (succinate oxidase) and maintenance of lung NADPH and reduced glutathione were corrected for changes in cell number, by use of lung DNA measurements. Immediately following ozone exposure succinate oxidase (SOX), glucose-6-phosphate (G6PD), and 6-phosphogluconate (6PGD) dehydrogenase activities per milligram DNA were significantly enhanced by 76%, 48%, and 21%, respectively. These data suggested that ozone-exposed lungs had cells with increased mitochondria and NADPH-generating capability consistent with the increased metabolic needs of a proliferating epithelium. At 4 d postexposure, only G6PD activity per milligram DNA remained higher by 22% than air-exposed controls. Although both glutathione reductase (GSSG-R) and peroxidase (GSH-Px) activities per lung were elevated in lungs immediately following exposure and 4 d later, when corrected for DNA only GSH-Px activity was significantly increased by 29% in lungs after the postexposure period. Lungs 4 d postexposure therefore had cells relatively enriched in G6PD and GSH-Px that might account for the increased ozone tolerance that has previously been associated with the formation of new type I epithelium.

  5. 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...

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. The Influence of Exposure to Maternal Diabetes In Utero on the Rate Of Decline in Beta-Cell Function Among Youth with Diabetes

    PubMed Central

    Crume, T.L.; Andrews, J.S.; D’Agostino, R.; Pettitt, D.J.; Mayer-Davis, E.J.; Law, J.R.; Dolan, L.; Lawrence, J.M.; Saydah, S.; Greenbaum, C.; Rodriguez, B.L.; Dabelea, D.

    2014-01-01

    A relationship between exposure to maternal diabetes in utero and a younger age at diagnosis of type 2 diabetes was detected in SEARCH for Diabetes in Youth Study, while no significant association was detected with paternal diabetes status, suggesting an independent effect of the intrauterine exposure to hyperglycemia. We assessed the influence of exposure to maternal diabetes in utero on beta cell decline measured using fasting C-peptide (FCP) among 1079 youth with diabetes, including 941 with type 1 and 138 with type 2, who were followed post-diagnosis for an average of 58 months. No significant relationship was detected between exposure to maternal diabetes in utero and change in FCP levels in youth with type 1 or type 2 diabetes. These findings suggest that exposure to maternal diabetes in utero may not be an important determinant of short-term beta-cell function decline in youth with type 1 or type 2 diabetes. PMID:23645121

  11. 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...

  12. 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.

  13. 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. PMID:22042969

  14. 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.

  15. Voyager flight crew hearing threshold levels resulting from 5- and 9-day continuous in-flight noise exposure.

    PubMed

    Stephenson, M R; Billings, B L; Jutila, G A

    1990-02-01

    The flight crew of the Voyager aircraft were continuously exposed to a broadband noise for nearly 5 days during a trial flight, and for over 9 days during their nonstop flight around the world. Evaluation of the threshold shifts resulting from these exposures represents a unique opportunity to study the effect of human exposure to intense continuous noise for long durations. Postflight audiometry demonstrated that the 9-day flight did not result in larger hearing threshold shifts than those following the 5-day flight. Neither crewmember incurred a permanent threshold shift from these exposures.

  16. Bladder cancer screening program for a petrochemical cohort with potential exposure to beta-napthylamine.

    PubMed

    Felknor, Sarah A; Delclos, George L; Lerner, Seth P; Burau, Keith D; Wood, Susan M; Lusk, Christine M; Jalayer, Annette D

    2003-03-01

    Approximately 1800 workers in pipe manufacturing plants in the United States may have been exposed to beta-napthlyamnine between 1970 and 1996. Once the chemical was detected, the contaminated additive in the resin was identified and discontinued. A bladder cancer-screening program was initiated in 1999. An annual two-stage screening program was developed to test for microscopic hematuria (stage one) and cytology (stage two), with a urology referral of positive or suspicious cytology. This paper presents the program methodology, cohort enumeration, recruitment, and enrollment strategies, and screening protocol. Enrollment data from the first 3 years are presented. Annual screening of a cohort of current and former employees is feasible. Original personnel records are often incomplete, making cohort identification important. Personal contact and follow-up are key elements of successful recruitment and retention.

  17. 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.

  18. Effect of exposure to continuous light on estrogen-induced precocious sexual maturation in female rats.

    PubMed

    Piacsek, B E; Streur, W J

    1975-01-01

    Immature female rats, raised in either cyclic light (LD; 14 H LIGHT/10 H DARK) Or constant light (LL) were divided into 4 groups and given daily injections of estradiol benzoate (5, 10, or 25 ng) in 0.1 ml sesame oil starting at 24 days of age. Control animals received oil only. Injections were continued until vaginal opening (V.O.). Half of each group of animals was killed and dissected 1 day after V.O. Results indicate that both LL exposure and EB treatment accelerated sexual maturation (as indicated by the day of V.O.) with a significant interaction between the 2 treatments. Thre greatest difference in age at V.O. between LD and LL rats was observed at a dose of 10 ngEB/day. Body weights and uterine weights decreased with higher doses of EB, apparently reflecting the younger age at the time of V.O. No significant differences in ovarian weights were observed. Results are interpreted to indicate that increased exposure to light may change the sensitivity of the hypothalamic-pituitary axis to the positive feedback of estrogen.

  19. Electrocardiographic changes in healthy men during continuous low-level carbon monoxide exposure

    SciTech Connect

    Davies, D.M.; Smith, D.J.

    1980-02-01

    In separate experiments, six groups of young, healthy, nonsmoking human subjects lived in a closed-environment exposure chamber for 18 days during the middle 8 of which they were exposed continuously to 50, 15, or 0 (control) parts per million by volume (ppM) of carbon monoxide (CO) in air. Standard 12-lead electrocardiograms (ECG) were recorded from each subject during the control, exposure, and recovery periods. P-Wave changes were clearly seen in 6 of 15 subjects at 50 ppM, and in 3 of 15 at 15 ppM, but in none of 14 at 0 ppM; in addition one subject showed marked S-T changes at 15 ppM. Review of a pilot study at 75 ppM CO revealed significant ECG changes in seven of the ten subjects. It is postulated that the changes were caused by a specific toxic effect of CO on atrial pacemaking or conducting tissue in a dose-response relationship.

  20. Mendelian randomization studies for a continuous exposure under case-control sampling.

    PubMed

    Dai, James Y; Zhang, Xinyi Cindy

    2015-03-15

    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.

  1. 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. PMID:27373739

  2. Meta-analysis for deriving age- and gender-specific dose-response relationships between urinary cadmium concentration and beta2-microglobulinuria under environmental exposure.

    PubMed

    Gamo, Masashi; Ono, Kyoko; Nakanishi, Junko

    2006-05-01

    A meta-analysis was conducted to derive age- and gender-specific dose-response relationships between urinary cadmium (Cd) concentration and beta2-microglobulinuria (beta2MG-uria) under environmental exposure. beta2MG-uria was defined by a cutoff point of 1000 microg beta2-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 beta2MG-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 beta2MG-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 beta2MG-uria. This was estimated to be approximately 3 microg/g creatinine for a population in a small geographical area and approximately 2 microg/g creatinine for a nationwide population.

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

    PubMed

    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

  4. 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

  5. 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.

  6. Cumulative Effects of Exposure to Continuous and Intermittent Sounds on Temporary Hearing Threshold Shifts Induced in a Harbor Porpoise (Phocoena phocoena).

    PubMed

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

    2016-01-01

    The effects of exposure to continuous and intermittent anthropogenic sounds on temporary hearing threshold shifts (TTSs) in a harbor porpoise were investigated by testing hearing before and after exposure to 1- to 2-kHz downsweeps of 1 s, without harmonics, presented as paired-intermittent and continuous-exposure combinations with identical cumulative sound exposure levels (SEL(cum)). Exposure to intermittent sounds resulted in lower TTSs than exposure to continuous sounds with the same SEL(cum). Therefore, the hearing of marine mammals is at less risk from intermittent anthropogenic noises than from continuous ones at the same received sound pressure level and duration. PMID:26611000

  7. Cumulative Effects of Exposure to Continuous and Intermittent Sounds on Temporary Hearing Threshold Shifts Induced in a Harbor Porpoise (Phocoena phocoena).

    PubMed

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

    2016-01-01

    The effects of exposure to continuous and intermittent anthropogenic sounds on temporary hearing threshold shifts (TTSs) in a harbor porpoise were investigated by testing hearing before and after exposure to 1- to 2-kHz downsweeps of 1 s, without harmonics, presented as paired-intermittent and continuous-exposure combinations with identical cumulative sound exposure levels (SEL(cum)). Exposure to intermittent sounds resulted in lower TTSs than exposure to continuous sounds with the same SEL(cum). Therefore, the hearing of marine mammals is at less risk from intermittent anthropogenic noises than from continuous ones at the same received sound pressure level and duration.

  8. Reproductive Performance of Mouse Oocyte after In Vivo Exposure of The Ovary to Continuous Wave Ultrasound

    PubMed Central

    Nasiri, Nahid; VosoughTaqi Dizaj, Ahmad; Eftekhari-Yazdi, Poopak; Akhond, Mohammad Reza

    2012-01-01

    Background: There is a lack of studies regarding the effects of ultrasound (US) and replication of its exposure on pre-implantation events in mammals. Thus, this study assesses the reproductive performance of mouse oocytes that have been obtained from ovaries irradiated with US waves versus non-irradiated ovaries. Also comparision of their parthenogenesis, ovulation, fertilization, and pre-implantation development rates. Materials and Methods: In this experimental study, we divided extracted ovaries into three experimental groups that received the same dosage, but different replicates of radiation for each group. Results were compared with the control and sham groups. Continuous wave (CW) US, at a spatial average intensity of 355 mW/cm2 and a frequency of 3.28 MHz, was administered for 5 minutes to the ovaries at an interval between pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) injections. Statistical analysis was performed using the ANOVA test and the level of significance was determined to be 0.05. Results: Data collection was based on microscopic visualization. According to the obtained results, metaphase II (MII) oocyte numbers and the percentage of blastocysts significantly reduced in the USexposed groups versus the unexposed groups. Fertilization rate was comparable between groups while parthenogenesis was significantly higher in the US-exposed groups compared to the unexposed groups. Conclusion: Structural damage to cells, intracellular organelles and proteins, as well as changes in signaling pathways induced by US may be reasons for some of the observed adverse effects in groups that have received more US exposure. PMID:24520439

  9. 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.

  10. Plasma corticosterone response in continuous versus discontinuous chronic heat exposure in rat.

    PubMed

    Cure, M

    1989-06-01

    Effects of chronic exposure (25 days) to continuous (CHE) or discontinuous (DHE) hot environment (34 degrees C) on growth rate, food intake and cortico-adrenal function were studied in adult male rats. Growth rate and food intake were 40 and 31% less respectively in CHE and 7 and 9% less respectively in DHE than in control (CE) animals. The adrenal response to heat (40 degrees C) was reduced by 54 and 82% in CHE and DHE rats respectively but the plasma corticosterone (B) response to exogenous ACTH and ether stress was not altered by chronic heat. The plasma B rhythm was altered only in CHE rats which exhibited a 40% decrease in amplitude and a delayed nocturnal recession of plasma B values. These results indicate that 1) CHE induced major alterations of behavior specially during the nocturnal period of the L-D cycle, 2) that the altered circadian B rhythm of CHE rats could be linked to changes in feeding behavior and to reduced metabolic activity, 3) and that CHE induced a poorer adaptation than DHE.

  11. Maternal antioxidants prevent beta cell apoptosis and promote formation of dual hormone-expressing endocrine cells in male offspring following fetal and neonatal nicotine exposure

    PubMed Central

    BRUIN, Jennifer E; WOYNILLOWICZ, Amanda K; HETTINGA, Bart P; TARNOPOLSKY, Mark A; MORRISON, Katherine M; GERSTEIN, Hertzel C; HOLLOWAY, Alison C

    2013-01-01

    Aim Fetal and neonatal nicotine exposure causes beta cell oxidative stress and apoptosis in neonates, leading to adult-onset dysglycemia. The goal of this study was to determine whether an antioxidant intervention could prevent nicotine-induced beta cell loss. Methods Nulliparous female Wistar rats received daily subcutaneous injections of either saline or nicotine bitartrate (1.0 mg/kg/d) for 2 weeks prior to mating until weaning. Nicotine-exposed dams received either normal chow or diet containing antioxidants (1000 IU/kg vitamin E, 0.25% w/w coenzyme Q10 and 0.1% w/w alpha-lipoic acid) during mating, pregnancy and lactation; saline-exposed dams received normal chow. Pancreas tissue was collected from male offspring at 3 weeks of age to measure beta cell fraction, apoptosis, proliferation and the presence of cells co-expressing insulin and glucagon. Results The birth weight of the offspring born to nicotine-exposed dams receiving dietary antioxidants was significantly reduced. Most interestingly, the antioxidant intervention to nicotine-exposed dams prevented the beta cell loss and apoptosis observed in nicotine exposed male offspring whose mothers did not receive antioxidants. Male pups born to nicotine-treated mothers receiving antioxidants also had a trend towards increased beta cell proliferation and a significant increase in islets containing insulin/glucagon bi-hormonal cells relative to the other two treatment groups. Conclusion This study demonstrates that exposure to maternal antioxidants protects beta cells from the damaging effects of nicotine thus preserving beta cell mass. PMID:22385833

  12. 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.

  13. Exposure to nitrous oxide stimulates a nitric oxide-dependent neuronal release of beta-endorphin in ventricular-cisternally-perfused rats.

    PubMed

    Zelinski, Lisa M; Ohgami, Yusuke; Quock, Raymond M

    2009-12-01

    We have previously shown that the antinociceptive effect of nitrous oxide (N(2)O) in the rat hot plate test is sensitive to antagonism by antisera against the endogenous opioid peptide beta-endorphin. Moreover, N(2)O-induced antinociception is reduced by inhibition of nitric oxide (NO) production in the brain. To test the hypothesis that N(2)O might stimulate an NO-dependent neuronal release of beta-endorphin, we conducted a ventricular-cisternal perfusion with artificial cerebrospinal fluid (aCSF) in urethane-anesthetized Sprague-Dawley rats. Ten-minute fractions of aCSF perfusate were collected from separate groups of room air-exposed rats, N(2)O-exposed rats, and L-NAME-pretreated, N(2)O-exposed rats; they were then analyzed for their content of NO metabolites and beta-endorphin. Compared to room air control, exposure to 70% N(2)O increased perfusate levels of the NO metabolites nitrite and nitrate as well as beta-endorphin. Pretreatment of rats with L-N(G)-nitro arginine methyl ester, an inhibitor of NO synthase, prevented the N(2)O-induced increases in nitrite, nitrate and beta-endorphin. These findings demonstrate in an in vivo rat model that N(2)O may stimulate an NO-dependent neuronal release of beta-endorphin. PMID:19747467

  14. 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

  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. Expression of transforming growth factor-beta in developing rat cerebral cortex: effects of prenatal exposure to ethanol.

    PubMed

    Miller, Michael W

    2003-06-01

    The effects of prenatal ethanol exposure on the spatiotemporal expression of transforming growth factor-beta (TGFbeta) and its receptors in developing rat cerebral cortex in vivo were examined. Pregnant Long-Evans rats were fed ad libitum with a diet containing ethanol from gestational day (G) 6 through G21 or were pair fed an isocaloric nonalcoholic liquid diet. A quantitative immunoblotting study showed that expression of TGFbeta ligands was differentially affected by ethanol; ethanol decreased TGFbeta1 expression fetally and in the mature cortex and increased TGFbeta2 at most ages. A complementary immunohistochemical experiment generated similar results so far as the timing of ligand expression was concerned. In both control and ethanol-treated rats, TGFbeta1 was expressed by cells in the two neocortical proliferative zones and neurons in the cortical plate. TGFbeta2 was expressed principally by radial glia and astrocytes in developing rats. In the adult, both ligands were expressed by glia and neurons. Ethanol virtually eliminated the TGFbeta1 expression in the perinatal subventricular zone. The TGFbeta2-positive radial glial labeling was transient and was lost earlier in ethanol-treated neonates than in controls. Concomitantly, the appearance of TGFbeta2-positive glia occurred earlier in the ethanol-treated rats. The expression of only one receptor (TGFbetaIr) was affected by ethanol; it was increased during the pre- and early postnatal periods. TGFbetaIr was expressed by glia perinatally and by all cell types in weanlings. As with TGFbeta2, ethanol exposure promoted the loss of TGFbetaIr expression in radial glia and the precocious expression among astrocytes. TGFbetaIIr was expressed primarily by neurons. Thus, TGFbeta ligands and receptors are strategically placed both in time and space to regulate cell proliferation and migration. Ethanol, which affects both of these processes, has marked effects on the TGFbeta system and apparently promotes the early

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

    PubMed

    Hammond, Davyda; Croghan, Carry; Shin, Hwashin; Burnett, Richard; Bard, Robert; Brook, Robert D; Williams, Ron

    2014-07-01

    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 cardiovascular (CV) health outcomes such as increase in heart rate (HR) associated with hourly based continuous personal fine particulate matter (PM2.5) exposures in this adult, non-smoking cohort. Examination of time activity diary (TAD), follow-up questionnaire (FQ) and the continuous PM2.5 personal monitoring data provided the means to more fully examine the impact of discreet human activity patterns on personal PM2.5 exposures and changes in CV outcomes. A total of 329 343 min-based PM2.5 personal measurements involving 50 participants indicated that ∼75% of these total events resulted in exposures <35 μg/m(3). Cooking and car-related events accounted for nearly 10% of the hourly activities that were identified with observed peaks in personal PM2.5 exposures. In-residence cooking often resulted in some of the highest incidents of 1 min exposures (33.5-17.6 μg/m(3)), with average peaks for such events in excess of 209 μg/m(3). PM2.5 exposure data from hourly based personal exposure activities (for example,, cooking, cleaning and household products) were compared with daily CV data from the DEARS subject population. A total of 1300 hourly based lag risk estimates associated with changes in brachial artery diameter and flow-mediated dilatation (BAD and FMD, respectively), among others, were defined for this cohort. Findings indicate that environmental tobacco smoke (ETS) exposures resulted in significant HR changes between 3 and 7 h following the event, and exposure to smells resulted in increases in BAD on the order of 0.2-0.7 mm/μg/m(3). Results demonstrate that personal exposures may be associated with several biological responses, sometimes varying in degree and direction in

  18. 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...

  19. 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...

  20. Effects of exposure to intermittent versus continuous red light on human circadian rhythms, melatonin suppression, and pupillary constriction.

    PubMed

    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.

  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 exposure to intermittent versus continuous red light on human circadian rhythms, melatonin suppression, and pupillary constriction.

    PubMed

    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

  3. 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…

  4. Prolonged L-alanine exposure induces changes in metabolism, Ca(2+) handling and desensitization of insulin secretion in clonal pancreatic beta-cells.

    PubMed

    McClenaghan, Neville H; Scullion, Siobhan M; Mion, Brian; Hewage, Chandralal; Malthouse, J Paul G; Flatt, Peter R; Newsholme, Philip; Brennan, Lorraine

    2009-02-01

    Acute insulin-releasing actions of amino acids have been studied in detail, but comparatively little is known about the beta-cell effects of long-term exposure to amino acids. The present study examined the effects of prolonged exposure of beta-cells to the metabolizable amino acid L-alanine. Basal insulin release or cellular insulin content were not significantly altered by alanine culture, but acute alanine-induced insulin secretion was suppressed by 74% (P<0.001). Acute stimulation of insulin secretion with glucose, KCl or KIC (2-oxoisocaproic acid) following alanine culture was not affected. Acute alanine exposure evoked strong cellular depolarization after control culture, whereas AUC (area under the curve) analysis revealed significant (P<0.01) suppression of this action after culture with alanine. Compared with control cells, prior exposure to alanine also markedly decreased (P<0.01) the acute elevation of [Ca(2+)](i) (intracellular [Ca(2+)]) induced by acute alanine exposure. These diminished stimulatory responses were partially restored after 18 h of culture in the absence of alanine, indicating reversible amino-acid-induced desensitization. (13)C NMR spectra revealed that alanine culture increased glutamate labelling at position C4 (by 60%; P<0.01), as a result of an increase in the singlet peak, indicating increased flux through pyruvate dehydrogenase. Consistent with this, protein expression of the pyruvate dehydrogenase kinases PDK2 and PDK4 was significantly reduced. This was accompanied by a decrease in cellular ATP (P<0.05), consistent with diminished insulin-releasing actions of this amino acid. Collectively, these results illustrate the phenomenon of beta-cell desensitization by amino acids, indicating that prolonged exposure to alanine can induce reversible alterations to metabolic flux, Ca(2+) handling and insulin secretion. PMID:18702613

  5. 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.

  6. Chronic LPS exposure produces changes in intrinsic membrane properties and a sustained IL-beta-dependent increase in GABAergic inhibition in hippocampal CA1 pyramidal neurons.

    PubMed

    Hellstrom, Ian C; Danik, Marc; Luheshi, Giamal N; Williams, Sylvain

    2005-01-01

    Chronic inflammation has been reported to be a significant factor in the induction and progression of a number of chronic neurological disorders including Alzheimer's disease and Down syndrome. It is believed that inflammation may promote synaptic dysfunction, an effect that is mediated in part by pro-inflammatory cytokines such as interleukin-1beta (IL-1beta). However, the role of IL-1beta and other cytokines in synaptic transmission is still poorly understood. In this study, we have investigated how synaptic transmission and neuronal excitability in hippocampal pyramidal neurons are affected by chronic inflammation induced by exposing organotypic slices to the bacterial cell-wall product lipopolysaccharide (LPS). We report that CA1 pyramidal neurons recorded in whole cell from slices previously exposed to LPS for 7 days had resting membrane potential and action potential properties similar to those of the controls. However, they had significantly lower membrane resistance and a more elevated action potential threshold, and displayed a slower frequency of action potential discharge. Moreover, the amplitude of pharmacologically isolated postsynaptic gamma-aminobutyric acid (GABA)ergic potentials, but not excitatory glutamatergic postsynaptic potentials, was significantly larger following chronic LPS exposure. Interestingly, co-incubation of the IL-1 receptor antagonist (IL-1Ra) concurrently with LPS prevented the increase in GABAergic transmission, but not the reduction in intrinsic neuronal excitability. Finally, we confirmed that LPS dramatically increased IL-1beta, and IL-1beta-dependent IL-6 levels in the culture medium for 2 days before returning to baseline. We conclude that CA1 pyramidal neurons in slices chronically exposed to LPS show a persistent decrease in excitability due to a combined decrease in intrinsic membrane excitability and an enhancement in synaptic GABAergic input, the latter being dependent on IL-1beta. Therefore, chronic inflammation in

  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. 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

  10. Aqueous exposure to 4-nonylphenol and 17beta-estradiol increases stress sensitivity and disrupts ion regulatory ability of juvenile Atlantic salmon.

    PubMed

    Lerner, Darren T; Björnsson, Björn Thrandur; McCormick, Stephen D

    2007-07-01

    Population declines of wild Atlantic salmon have been attributed to an array of anthropogenic disturbances, including dams, commercial and recreational fishing, habitat loss, and pollution. Environmental contaminants in particular, can act as environmental stressors on fish, typically causing disruption of ion homeostasis due to their close association with the aquatic environment. To examine the effects of the xenoestrogen 4-nonylphenol (NP) or 17beta-estradiol (E2) on stress sensitivity and ion regulation, we exposed juvenile Atlantic salmon continuously for 21 d to either 10 or 100 microg/L NP (NP-L or NP-H), 2 microg/L E2 (positive control), or vehicle control during the parr-smolt transformation in April. After treatment, fish were sampled in freshwater (FW), transferred to 30 per thousand seawater (SW) for 24 h, or subjected to a handling stress. Estradiol and NP-H increased plasma vitellogenin in males and females, and E2 increased gonadosomatic index only in males. In FW, E2 reduced sodium potassium-activated adenosine triphosphatase activity as well as plasma levels of growth hormone, insulin-like growth factor I, and triiodothyronine. Both E2 and NP-H reduced plasma sodium in FW and increased plasma chloride in SW. Plasma cortisol levels pre- and poststressor were significantly elevated by all treatments relative to controls, but only E2 increased plasma glucose before and after the stressor. These results indicate that exposure of anadromous salmonids to environmental estrogens heightens sensitivity to external stressors, impairs ion regulation in both FW and SW, and disrupts endocrine pathways critical for smolt development. PMID:17665683

  11. 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.

  12. Smooth muscle cell expression of type I cyclic GMP-dependent protein kinase is suppressed by continuous exposure to nitrovasodilators, theophylline, cyclic GMP, and cyclic AMP.

    PubMed Central

    Soff, G A; Cornwell, T L; Cundiff, D L; Gately, S; Lincoln, T M

    1997-01-01

    A key component of the nitric oxide-cyclic guanosine monophosphate (cGMP) pathway in smooth muscle cells (SMC) is the type I GMP-dependent protein kinase (PK-G I). Activation of PK-G I mediates the reduction of cytoplasmic calcium concentrations and vasorelaxation. In this manuscript, we demonstrate that continuous exposure of SMC in culture to the nitrovasodilators S-nitroso-N-acetylpenicillamine (SNAP) or sodium nitroprusside (SNP) results in approximately 75% suppression of PK-G I mRNA by 48 h. PK-G I mRNA and protein were also suppressed by continuous exposure to cGMP analogues 8-bromo- and 8-(4-chlorophenylthio) guanosine-3,5-monophosphate or the cAMP analogue dibutyryl cAMP. These results suggest that activation of one or both of the cyclic nucleotide-dependent protein kinases mediates PK-G I mRNA suppression. Using isoform-specific cDNA probes, only the PK-G I alpha was detected in SMC, either at baseline or after suppression, while PK-G I beta was not detected, indicating that isoform switch was not contributing to the gene regulation. Using the transcription inhibitor actinomycin D, the PK-G I mRNA half-life in bovine SMC was observed to be 5 h. The half-life was not affected by the addition of SNAP to actinomycin D, indicating no effect on PK-G I mRNA stability. Nuclear runoff studies indicated a suppression of PK-G I gene transcription by SNAP. PK-G I suppression was also observed in vivo in rats given isosorbide dinitrate in the drinking water, with a dose-dependent suppression of PK-G I protein in the aorta. PK-G I antigen in whole rat lung extract was also suppressed by administration of isosorbide or theophylline in the drinking water. These data may contribute to our understanding of nitrovasodilator resistance, a phenomenon resulting from continuous exposure to nitroglycerin or other nitrovasodilators. PMID:9366573

  13. 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.

  14. 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.

  15. Is Ionizing Radiation Harmful at any Exposure? An Echo That Continues to Vibrate.

    PubMed

    Azzam, Edouard I; Colangelo, Nicholas W; Domogauer, Jason D; Sharma, Neha; de Toledo, Sonia M

    2016-03-01

    The health risks to humans and non-human biota exposed to low dose ionizing radiation remain ambiguous and are the subject of intense debate. The need to establish risk assessment standards based on the mechanisms underlying low-level radiation exposure has been recognized by regulatory agencies as critical to adequately protect people and to make the most effective use of national resources. Here, the authors briefly review evidence showing that the molecular and biochemical changes induced by low doses of radiation differ from those induced by high doses. In particular, an array of redundant and inter-related mechanisms act in both prokaryotes and eukaryotes to restore DNA integrity following exposures to relatively low doses of sparsely ionizing radiation. Furthermore, the radiation-induced protective mechanisms often overcompensate and minimize the mutagenic potential of the byproducts of normal oxidative metabolism. In contrast to adaptive protection observed at low doses of sparsely ionizing radiation, there is evidence that even a single nuclear traversal by a densely ionizing particle track can trigger harmful effects that spread beyond the traversed cell and induce damaging effects in the nearby bystander cells. In vivo studies examining whether exposure to low dose radiation at younger age modulates the latency of expression of age-related diseases such as cancer, together with studies on the role of genetic susceptibility, will further illuminate the magnitude of risk of exposure to low dose radiation. PMID:26808874

  16. Photometrically measured continuous personal PM(2.5) exposure: levels and correlation to a gravimetric method.

    PubMed

    Lanki, Timo; Alm, Sari; Ruuskanen, Juhani; Janssen, Nicole A H; Jantunen, Matti; Pekkanen, Juha

    2002-05-01

    There is evidence that hourly variations in exposure to airborne particulate matter (PM) may be associated with adverse health effects. Still there are only few published data on short-term levels of personal exposure to PM in community settings. The objectives of the study were to assess hourly and shorter-term variations in personal PM(2.5) exposure in Helsinki, Finland, and to compare results from portable photometers to simultaneously measured gravimetric concentrations. The effect of relative humidity on the photometric results was also evaluated. Personal PM(2.5) exposures of elderly persons were assessed for 24 h every second week, resulting in 308 successful measurements from 47 different subjects. Large changes in concentrations in minutes after cooking or changing microenvironment were seen. The median of daily 1-h maxima was over twice the median of 24-h averages. There was a strong significant association between the two means, which was not linear. Median (95th percentile) of the photometric 24-h concentrations was 12.1 (37.7) and of the 24-h gravimetric concentrations 9.2 (21.3) microg/m3. The correlation between the photometric and the gravimetric method was quite good (R2=0.86). Participants spent 94.1% of their time indoors or in a vehicle, where relative humidity is usually low and thus not likely to cause significant effects on photometric results. Even outdoors, the relative humidity had only modest effect on concentrations. Photometers are a promising method to explore the health effects of short-term variation in personal PM(2.5) exposure.

  17. Pattern of REM sleep occurrence in continuous darkness following the exposure to low ambient temperature in the rat.

    PubMed

    Zamboni, G; Amici, R; Perez, E; Jones, C A; Parmeggiani, P L

    2001-07-01

    The occurrence of REM sleep episodes, separated by intervals >3 min (single episodes) and < or =3 min (sequential episodes), was determined in the rat during the recovery (ambient temperature (Ta) 23 degrees C, L period of the LD [12 h:12 h]-cycle), which followed the exposure to low Ta (0 and -10 degrees C) during the D period of the previous LD-cycle, either in normal light (DL) or in continuous darkness (DD). Both exposures were characterized by an almost complete disappearance of REM sleep, whilst the recoveries showed an increase in the amount of REM sleep in the form of sequential episodes, which in DD was particularly prominent and concomitant with a decrease in the amount of REM sleep in the form of single episodes. The initial 2 h-rate of REM sleep occurrence was lower following the exposure to Ta -10 degrees C, than to Ta 0 degrees C. In DD, such an effect was due to the large reduction in the occurrence of sequential REM sleep episodes. A functional correlate of this finding is that the accumulation capacity of a second messenger (cAMP) was found to be lower at the end of the exposure to Ta -10 degrees C, with respect to both the control (Ta 23 degrees C) and the end of exposure to Ta 0 degrees C, in the preoptic-anterior hypothalamus, but not in the cerebral cortex.

  18. 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...

  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. 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.

  1. 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.

  2. Temporary auditory-threshold shifts induced by twenty-five-minute continuous exposures to intense tones in water

    NASA Astrophysics Data System (ADS)

    Smith, P. F.; Wojtowicz, J. J.

    1985-09-01

    Four bare-headed divers were exposed for twenty-five minutes to continuous tones in water at frequencies of 700, 1400, and 5600 hertz at estimated sound pressure levels between 153 and 165 decibels (dB) above 20 micropascal. Subsequent analyses revealed that the eight ears involved were actually exposed to average sound pressure levels between 143.1 and 165.1 dB. These exposure levels are comparable to those to which divers may be exposed while using some underwater hand-held tools. Temporary auditory-threshold shifts (TTS) were measured from two minutes to five minutes after the exposure terminated. TTS at two minutes post-exposure was between 23 and 55 dB and recovery times varied from twenty-four hours to more than fifty hours depending on exposure conditions. Nonauditory effects including middle-ear sensations and a reddened ear-drum were also observed. The results indicate that several hand-held tools now in use by military and civilian divers are extremely hazardous to hearing. The results also support the theory that the dynamic range of the water-immersed ear is smaller than the dynamic range of the ear in air.

  3. 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

  4. Continuous exposure to chrysotile asbestos can cause transformation of human mesothelial cells via HMGB1 and TNF-α signaling.

    PubMed

    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

    2013-11-01

    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.

  5. Larval exposure to 4-nonylphenol and 17beta-estradiol affects physiological and behavioral development of seawater adaptation in Atlantic salmon smolts.

    PubMed

    Lerner, Darren T; Björnsson, Björn Thrandur; McCormick, Stephen D

    2007-06-15

    Population declines of anadromous salmonids are attributed to anthropogenic disturbances including dams, commercial and recreational fisheries, and pollutants, such as estrogenic compounds. Nonylphenol (NP), a xenoestrogen, is widespread in the aquatic environment due to its use in agricultural, industrial, and household products. We exposed Atlantic salmon yolk-sac larvae to waterborne 10 or 100 microg L(-1) NP (NP-L or NP-H, respectively), 2 microg L(-1) 17beta-estradiol (E2), or vehicle, for 21 days to investigate their effects on smolt physiology and behavior 1 year later. NP-H caused approximately 50% mortality during exposure, 30 days after exposure, and 60 days after exposure. Mortality rates of NP-L and E2 fish were not affected until 60 days after treatment, when they were 4-fold greater than those of controls. Treatment with NP-L or E2 as yolk-sac larvae decreased gill sodium-potassium-activated adenosine triphosphatase (Na+,K(+)-ATPase) activity and seawater (SW) tolerance during smolt development, 1 year after exposure. Exposure to NP-L and E2 resulted in a latency to enter SW and reduced preference for SW approximately 2- and 5-fold, respectively. NP-L-exposed fish had 20% lower plasma insulin-like growth factor I (IGF-I) levels and 35% lower plasma triiodothyronine (T3). Plasma growth hormone and thyroxine (T4) were unaffected. Exposure to E2 did not affect plasma levels of IGF-I, GH, T3, or T4. Both treatment groups exhibited increased plasma cortisol and decreased osmoregulatory capacity in response to a handling stressor. These results suggest that early exposure to environmentally relevant concentrations of NP, and other estrogenic compounds, can cause direct and delayed mortalities and that this exposure can have long-term, "organizational" effects on life-history events in salmonids. PMID:17626455

  6. 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

    ... Verification) (65 FR 42122, July 7, 2000, and 68 FR 10784, March 6, 2003); (3) ``Determination of Concentration of Respirable Coal Mine Dust'' (Single Sample) (65 FR 42068, July 7, 2000, and 68 FR 10940 March 6, 2003); and (4) ``Respirable Coal Mine Dust: Continuous Personal Dust Monitor (CPDM)'' (74 FR...

  7. 76 FR 30878 - Lowering Miners' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-27

    ... FR 64412), extended January 14, 2011 (76 FR 2617) and May 4, 2011 (76 FR 25277), is further extended. All comments must be received or postmarked by midnight Eastern Daylight Saving Time on June 20, 2011... Continuous Personal Dust Monitors. This extension gives commenters additional time to review and comment...

  8. 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.…

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. Effects of pulsed and continuous wave 902 MHz mobile phone exposure on brain oscillatory activity during cognitive processing.

    PubMed

    Krause, Christina M; Pesonen, Mirka; Haarala Björnberg, Christian; Hämäläinen, Heikki

    2007-05-01

    The aim of the current double-blind studies was to partially replicate the studies by Krause et al. [2000ab, 2004] and to further investigate the possible effects of electromagnetic fields (EMF) emitted by mobile phones (MP) on the event-related desynchronisation/synchronisation (ERD/ERS) EEG (electroencephalogram) responses during cognitive processing. Two groups, both consisting of 36 male participants, were recruited. One group performed an auditory memory task and the other performed a visual working memory task in six exposure conditions: SHAM (no EMF), CW (continuous wave EMF) and PM (pulse modulated EMF) during both left- and right-side exposure, while the EEG was recorded. In line with our previous studies, we observed that the exposure to EMF had modest effects on brain oscillatory responses in the alpha frequency range ( approximately 8-12 Hz) and had no effects on the behavioural measures. The effects on the EEG were, however, varying, unsystematic and inconsistent with previous reports. We conclude that the effects of EMF on brain oscillatory responses may be subtle, variable and difficult to replicate for unknown reasons. PMID:17203478

  18. 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.

  19. 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.

  20. Maturation of maritime pine (Pinus pinaster Ait.) seedlings after exposure to a period of continuous light.

    PubMed

    Lascoux, D M; Notivol Paino, E; Sierra De Grado, R; Kremer, A; Dormling, I

    1993-06-01

    Nine half-sib families of maritime pine (Pinus pinaster Ait.) of known adult performance were grown in continuous light at either 25 degrees C or 25/20 degrees C for 18 weeks. They were then exposed to a dormancy induction period followed by a dormancy release period and then grown for a further 9 weeks in a 16-h photoperiod at a day/night temperature of 25/20 degrees C. Seedlings exhibited great diversity in morphology at the end of the first growth period. The number of morphogenetic cycles varied between one and three and the form of the apical meristem ranged from a typical rosette to an adult-like bud. The type of seedling obtained at the end of the first growth period strongly influenced later growth, independently of the temperature regime. Maturity was proportional to the number of morphogenetic cycles achieved during the first growth period and was characterized by short growth duration, small primary needles and a high degree of fixed growth. The state of the apical meristem that underwent the dormancy period had less influence on the rate of maturation than the number of morphogenetic cycles. The time course of maturation was endogenously controlled and varied among traits. Conspicuous morphological differences were not associated with changes in the relationship between growth components at the phenotypic level. However, there seemed to be a shift in the genetic correlations between growth components after first budset.

  1. Ureidopenicillins and beta-lactam/beta-lactamase inhibitor combinations.

    PubMed

    Bush, L M; Johnson, C C

    2000-06-01

    Although research and development of new penicillins have declined, penicillins continue to be essential antibiotics for the treatment and prophylaxis of infectious diseases. The most recent additions are the ureidopenicillins and beta-lactam/beta-lactamase inhibitor combinations. This article reviews the spectrum of activity, toxicity, pharmacokinetics, and clinical uses of the ureidopenicillins, and the beta-lactam/beta-lactamase inhibitor combination agents.

  2. Prenatal and Postnatal Polycyclic Aromatic Hydrocarbon Exposure, Airway Hyperreactivity, and Beta-2 Adrenergic Receptor Function in Sensitized Mouse Offspring

    PubMed Central

    Zhang, Hanjie; Maher, Christina; McDonald, Jacob D.; Zhang, Xiang; Ho, Shuk-Mei; Yan, Beizhan; Chillrud, Steven; Perera, Frederica; Factor, Phillip; Miller, Rachel L.

    2013-01-01

    Despite data associating exposure to traffic-related polycyclic aromatic hydrocarbons (PAH) in asthma, mechanistic support has been limited. We hypothesized that both prenatal and early postnatal exposure to PAH would increase airway hyperreactivity (AHR) and that the resulting AHR may be insensitive to treatment with a β2AR agonist drug, procaterol. Further, we hypothesized that these exposures would be associated with altered β2AR gene expression and DNA methylation in mouse lungs. Mice were exposed prenatally or postnatally to a nebulized PAH mixture versus negative control aerosol 5 days a week. Double knockout β2AR mice were exposed postnatally only. Prenatal exposure to PAH was associated with reduced β2AR gene expression among nonsensitized mice offspring, but not increases in DNA methylation or AHR. Postnatal exposure to PAH was borderline associated with increased AHR among sensitized wildtype, but not knockout mice. In the first study that delivers PAH aerosols to mice in a relatively physiological manner, small effects on AHR and β2AR gene expression, but not β2AR agonist drug activity, were observed. If confirmed, the results may suggest that exposure to PAH, common ambient urban pollutants, affects β2AR function, although the impact on the efficacy of β2AR agonist drugs used in treating asthma remains uncertain. PMID:24454363

  3. 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.

  4. [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.

  5. 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.

  6. Expression of glucocorticoid receptor, mineralocorticoid receptor, and 11beta-hydroxysteroid dehydrogenase 1 and 2 in the fetal and postnatal ovine hippocampus: ontogeny and effects of prenatal glucocorticoid exposure.

    PubMed

    Sloboda, Deborah M; Moss, Timothy J M; Li, Shaofu; Matthews, Stephen G; Challis, John R G; Newnham, John P

    2008-05-01

    To determine the expression of glucocorticoid metabolizing and action genes in the hippocampus of fetal, neonatal, and adult sheep. Pregnant ewes (or their fetuses) received intramuscular injections of saline or betamethasone (BETA, 0-5 mg/kg) at 104, 111, 118, and/or 125 days of gestation (dG). Hippocampal tissue was collected prior to (75, 84, and 101 dG), during (109 and 116 dG), or after (121, 132, and 146 dG; 6 and 12 postnatal weeks; 3.5 years of age) saline or BETA injections. Hippocampal glucocorticoid receptor (GR), mineralocorticoid receptor (MR), and 11beta-hydroxysteroid dehydrogenase (11betaHSD)1 and 11betaHSD2 mRNA levels were determined using qRT-PCR. Control animals late in gestation demonstrated a decrease in mRNA encoding GR and 11betaHSD1, whereas 11betaHSD2 was undetectable, consistent with a damping of the negative feedback influence of circulating or locally produced cortisol on the hypothalamic-pituitary-adrenal (HPA) axis. BETA-administration had transient effects on fetal GR and MR, and early in postnatal life (12 weeks of age) 11betaHSD1 mRNA was increased. Hippocampal MR mRNA was elevated in adult offspring exposed to either one or four doses of maternal BETA (P<0.001). Four courses of maternal BETA increased 11betaHSD2 (P<0.05) but not 11betaHSD1 mRNA levels. Late in gestation a reduction in hippocampal GR and 11betaHSD1 mRNA suggests lessening of glucocorticoid negative feedback, facilitating increased preterm HPA activity and parturition. Adult offspring of BETA-treated mothers demonstrated increased MR and 11betaHSD2 mRNA, therefore it appears that exposure of fetus to high levels of synthetic glucocorticoids may have long-lasting effects on the hippocampal expression of HPA-related genes into adulthood.

  7. 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. PMID:24726512

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. Prenatal nicotine exposure alters the nicotinic receptor subtypes that modulate excitation of parasympathetic cardiac neurons in the nucleus ambiguus from primarily alpha3beta2 and/or alpha6betaX to alpha3beta4.

    PubMed

    Kamendi, Harriet; Stephens, Christopher; Dergacheva, Olga; Wang, Xin; Huang, Zheng-Gui; Bouairi, Evguenia; Gorini, Christopher; McIntosh, J Michael; Mendelowitz, David

    2006-07-01

    Nicotinic receptors play an essential role in central cardiorespiratory function, however, the types of nicotinic receptors responsible for activating cardiac vagal neurons in the nucleus ambiguus that control heart rate are unknown. This study tests whether alpha-conotoxin MII and alpha-conotoxin AuIB sensitive nicotinic receptors are involved in augmentation of glutamatergic neurotransmission and changes in holding current in cardiac vagal neurons, and whether exposure to nicotine in the prenatal period alters these responses. The nicotinic agonist cytisine significantly increased the holding current and amplitude of glutamatergic mEPSCs. In unexposed animals alpha-conotoxin MII (100nM) significantly reduced the increase in mEPSC amplitude and change in holding current evoked by cytisine. However, in animals prenatally exposed to nicotine, alpha-conotoxin MII blunted but did not block the increase in mEPSC amplitude but blocked the increase in holding current evoked by cytisine. In unexposed animals, alpha-conotoxin AuIB (10microM) blocked the cytisine evoked increase in mEPSC amplitude and inhibited but did not abolish the increase in holding current. In contrast, in animals exposed to nicotine, alpha-conotoxin AuIB blunted the increase in mEPSC amplitude, and completely abolished the cytisine evoked increase in holding current. These data demonstrate that the prenatal nicotine exposure alters the nicotinic receptors involved in excitation of cardiac vagal neurons.

  13. 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.

  14. 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.

  15. Increased expression of alpha- and beta-globin mRNAs at the pituitary following exposure to estrogen during the critical period of neonatal sex differentiation in the rat.

    PubMed

    Leffers, H; Navarro, V M; Nielsen, John E; Mayen, A; Pinilla, L; Dalgaard, M; Malagon, M M; Castaño, J P; Skakkebaek, N E; Aguilar, E; Tena-Sempere, M

    2006-04-01

    Deterioration of reproductive health in human and wildlife species during the past decades has drawn considerable attention to the potential adverse effects of exposure to xenosteroids during sensitive periods of sex development. The hypothalamic-pituitary (HP) unit is a key element in the neuroendocrine system controlling development and function of the reproductive axis; the HP unit being highly sensitive to the organizing effects of endogenous and exogenous sex steroids. To gain knowledge on the molecular mode of action and potential biomarkers of exposure to estrogenic compounds at the HP unit, we screened for differentially expressed genes at the pituitary and hypothalamus of rats after neonatal exposure to estradiol benzoate. Our analyses identified persistent up-regulation of alpha- and beta-globin mRNAs at the pituitary following neonatal estrogenization. This finding was confirmed by combination of RT-PCR analyses and in situ hybridization. Induction of alpha- and beta-globin mRNA expression at the pituitary by neonatal exposure to estrogen was demonstrated as dose-dependent and it was persistently detected up to puberty. In contrast, durable up-regulation of alpha- and beta-globin genes was not detected at the hypothalamus, cortex, cerebellum, liver and testis. Finally, enhanced levels of alpha- and beta-globin mRNAs at the pituitary were also demonstrated after neonatal administration of the anti-androgen flutamide. In summary, alpha- and beta-globin genes may prove as sensitive, pituitary-specific biomarkers of exposure to estrogenic (and/or anti-androgenic) compounds at critical periods of sex development, whose potential in the assessment of endocrine disrupting events at the HP unit merits further investigation. PMID:16520034

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Brain acetylcholinesterase, malondialdehyde and reduced glutathione as biomarkers of continuous exposure of tench, Tinca tinca, to carbofuran or deltamethrin.

    PubMed

    Hernández-Moreno, D; Soler, F; Míguez, M P; Pérez-López, M

    2010-10-01

    In this study, the chronic effect of the insecticides carbofuran and deltamethrin on acetylcholinesterase (AChE) activity and malondialdehyde (MDA) and reduced glutathione (GSH) levels were examined in the brain of tench. Both pesticides were evaluated in two separate experiments, and animals were exposed in a continuous flow-system to three different concentrations of carbofuran (0, 10 and 100 microg/L) and deltamethrin (0, 0.0039 and 0.039 microg/L) for 60 days. After that period, animals were kept into pesticide-free water for other 30 days. In all cases, animals were sampled every 10 days all along the experience. AChE activity was significantly inhibited in fish exposed to 100 microg/L of carbofuran, during the first 30 days of exposition, returning to basal levels after this initial period. With respect to deltamethrin exposure, AChE activity was not significantly affected. When considering MDA levels, significant changes could only be detected during the recovery period for both pesticides, with a maximum of induction at 70 and 80 days, respectively associated to the highest dose of carbofuran and deltamethrin. Similarly, GSH levels varied all along the experience, with a maximum of significant increase at day 80 of exposition to the highest dose of both pesticides. This study shows that changes in AChE brain activity in tench can be used as a biomarker of early pesticide exposition in environmental monitoring programs, whereas MDA and GSH levels could be more associated to long-term expositions. The above results confirm and broaden former observations, suggesting that more investigations are needed before these biochemical parameters can be used as biomarkers.

  1. Signaling responses after exposure to 5 alpha-dihydrotestosterone or 17 beta-estradiol in norepinephrine-induced hypertrophy of neonatal rat ventricular myocytes.

    PubMed

    Koshman, Yevgeniya E; Piano, Mariann R; Russell, Brenda; Schwertz, Dorie W

    2010-03-01

    Androgens appear to enhance, whereas estrogens mitigate, cardiac hypertrophy. However, signaling pathways in cells for short (3 min) and longer term (48 h) treatment with 17beta-estradiol (E2) or 5 alpha-dihydrotestosterone (DHT) are understudied. We compared the effect of adrenergic stimulation by norepinephrine (NE; 1 microM) alone or in combination with DHT (10 nM) or E2 (10 nM) treatment in neonatal rat ventricular myocytes (NRVMs) by cell area, protein synthesis, sarcomeric structure, gene expression, phosphorylation of extracellular signal-regulated (ERK), and focal adhesion kinases (FAK), and phospho-FAK nuclear localization. NE alone elicited the expected hypertrophy and strong sarcomeric organization, and DHT alone gave a similar but more modest response, whereas E2 did not alter cell size. Effects of NE dominated when used with either E2 or DHT with all combinations. Both sex hormones alone rapidly activated FAK but not ERK. Long-term or brief exposure to E2 attenuated NE-induced FAK phosphorylation, whereas DHT had no effect. Neither hormone altered NE-elicited ERK activation. Longer term exposure to E2 alone reduced FAK phosphorylation and reduced nuclear phospho-FAK, whereas its elevation was seen in the presence of NE with both sex hormones. The mitigating effects of E2 on the NE-elicited increase in cell size and the hypertrophic effect of DHT in NRVMs are in accordance with results observed in whole animal models. This is the first report of rapid, nongenomic sex hormone signaling via FAK activation and altered FAK trafficking to the nucleus in heart cells. PMID:20044473

  2. Low dose monoethyl phthalate (MEP) exposure triggers proliferation by activating PDX-1 at 1.1B4 human pancreatic beta cells.

    PubMed

    Güven, Celal; Dal, Fulya; Aydoğan Ahbab, Müfide; Taskin, Eylem; Ahbab, Süleyman; Adin Çinar, Suzan; Sırma Ekmekçi, Sema; Güleç, Çağrı; Abacı, Neslihan; Akçakaya, Handan

    2016-07-01

    Phthalate plasticizers used in a wide range of common plastic products are released into the environment and may pose a risk of increased incidence of type 2 diabetes. In this work, we studied the effects of monoethyl phthalate (MEP), the metabolite of diethyl phthalate, exposure on 1.1B4 human pancreatic beta cells at low doses (1-1000 nM). We showed that MEP treatment induced proliferation in 1.1B4 cells. Also PCNA protein expression levels were increased related to proliferation induction. It has been noted that phthalates can exert estrogen mediated response by interacting with ER. In our study 24 h MEP treatment decreased ERα protein expression level conversely it increased the same protein expression level after 72 h treatment. Also MEP treatment decreased ERβ expression after 72 h at 1.1B4 cells. Our results further show that insulin content of 1.1B4 cells were increased with low dose MEP treatment. Along with our insulin content results, PDX- 1 expression levels were also increased at 1.1B4 cells with MEP treatment. These findings suggest that MEP acts as an estrogenic compound and PPARγ agonist at lower concentrations. Also it should be noted that PDX-1 may be a critical regulator of 1.1B4 cells treated with MEP.

  3. 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...

  4. 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

  5. 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

  6. 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. PMID:24210505

  7. Selective expansion followed by profound deletion of mature V beta 8.3+ T cells in vivo after exposure to the superantigenic lectin Urtica dioica agglutinin.

    PubMed

    Galelli, A; Delcourt, M; Wagner, M C; Peumans, W; Truffa-Bachi, P

    1995-03-15

    Urtica dioica agglutinin (UDA) is a superantigen that, in vitro, binds to specific carbohydrate structures on class II and induces a sixfold enrichment of V beta 8.3+ BALB/c mice splenic T cells. Superantigens have pleiotropic effects in vivo, causing the activation, proliferation, and deletion of specific T cells, but are heterogenous in regard to their effects on T cell tolerization. We, therefore, compared the responses of peripheral T cells from adult BALB/c mice with the i.v. injection of 50 micrograms UDA or the bacterial superantigen staphylococcal enterotoxin B (SEB) that also recognizes the V beta 8.3 gene product. The data presented indicate that activation, clonal expansion, anergy, and death of V beta 8.3+ T cells occur sequentially after UDA administration. Two days after UDA injection, the proportion of V beta 8.3+ T cells in the periphery is elevated to approximately twice that of normal mice. This expansion occurs in both CD4+ and CD8+ subsets. V beta 8.3+ T cells from UDA-primed mice are anergic to UDA restimulation and fail to proliferate or to produce IL-2. Futhermore, the proliferation of V beta 8.3+ T cells is followed by their rapid disappearance concomitant with their specific elimination by apoptosis. In 1 wk, all CD4+ V beta 8.3+ peripheral T cells are deleted. The decline of V beta 8.3+ T cells in the CD4+ subset is more than in the CD8+ subset. This occurs in thymectomized and in thymus-intact animals. Two months after UDA priming, the percentage of V beta 8.3+ T cells is still lower than in control mice. PMID:7876535

  8. Influence of high past lead-in-air exposures on the lead-in-blood levels of lead-acid battery workers with continuing exposure.

    PubMed

    Hodgkins, D G; Hinkamp, D L; Robins, T G; Schork, M A; Krebs, W H

    1991-07-01

    We investigated the relationship between air lead levels and blood lead levels in 132 lead-acid battery workers in two plants who were followed for 30 months between 1983 and 1985 with frequent air lead and blood lead determinations. Both plants converted to more modern, expanded-metal battery manufacturing technologies around 1978 with associated reductions in mean air lead exposures from greater than 100 to less than 30 micrograms/m3. In multiple regression analyses including consideration of job category, seniority, age, ethnicity, gender, and smoking habit as covariates, there was a highly significant association of blood lead in micrograms/dL with air lead in micrograms/m3 (partial R2 = .20, P less than .0001) among the 68 workers in plant B but no association (P = .91) in plant A. Restriction of the regression analysis to those 44 workers in plant B with less than or equal to 22 years of seniority yielded the most significant air lead-blood lead association (partial R2 = .36, P less than .0001). Among the remaining 24 plant B workers, seniority, but not air lead, had a significant positive association with blood lead. Despite very stable air lead levels over the 30-month study, the 51 workers in plant A with more than 20 years' seniority had a mean decline of 0.04 microgram/dL in mean blood lead over the study period, whereas the 13 workers in plant A with less than or equal to 20 years' seniority had a mean increase of 7.6 microgram/dL.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Demonstration of long-term reliability of a 266-nm, continuous-wave, frequency-quadrupled solid-state laser using beta-BaB(2)O(4).

    PubMed

    Kondo, K; Oka, M; Wada, H; Fukui, T; Umezu, N; Tatsuki, K; Kubota, S

    1998-02-01

    We report what we believe to be the first operation of more than 1000 h of a 266-nm (cw) frequency-quadrupled solid-state laser with a 100-mW output. We used beta-BaB(2)O(4)(BBO) crystal grown by the Czochralski method to double the green-light (532-nm) wavelength, using an external resonant cavity. The green light was generated with an intracavity frequency-doubled Nd:YVO(4)laser pumped by a 4-W laser diode. When the incident 532-nm power on the external resonant doubler was 500 mW, we generated 100 mW of cw 266-nm radiation with the BBO crystal. The degradation rate seems to be proportional to the strength of the UV optical electric field. We also obtained a relative intensity noise of -130dB/Hz at frequencies of 2 to 10 MHz for 266-nm laser light.

  10. 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.

  11. Analysis of continuous oxygen saturation data for accurate representation of retinal exposure to oxygen in the preterm infant.

    PubMed

    Cirelli, Josie; McGregor, Carolyn; Graydon, Brenda; James, Andrew

    2013-01-01

    Maintaining blood oxygen saturation within the intended target range for preterm infants receiving neonatal intensive care is challenging. Supplemental oxygen is believed to lead to increased risk of retinopathy of prematurity and hence managing the level of oxygen within this population is important within their care. Current quality improvement activities use coarse hourly spot readings to measure supplemental oxygen levels as associated with targeted ranges that vary based on gestational age. In this research we use Artemis, a real-time online healthcare analytics platform to ascertain if the collection of second by second data provides a better representation of retinal exposure to oxygen than an infrequent, intermittent spot reading. We show that Artemis is capable of producing more accurate information from the higher frequency data, as it includes all the episodic events in the activity of the hour, which provides a better understanding of oxygen fluctuation ranges which affect the physiological status of the infant.

  12. Rat lung benzo(a)pyrene metabolism following three days continuous exposure to 0. 6 ppm ozone

    SciTech Connect

    Bassett, D.J.; Bowen-Kelly, E.; Seed, J.L.

    1988-06-01

    Changes in the extent and pattern of benzo(a)pyrene metabolism were investigated in lungs isolated from rats following ozone exposures that are associated with the proliferation of alveolar and bronchiolar epithelia. Radiolabel incorporation into metabolic products were determined at the end of 60 min perfusions with 50-55 nmol of (6-3H) (7, 10-14C) benzo(a)pyrene (BaP), which in unexposed lungs resulted in a total BaP utilization of 0.77 +/- 0.05 nmol (14C) BaP/h/lung, recovered bound to tissue macromolecules (12%), as tissue and perfusate ethyl acetate-soluble products (59%), and as perfusate water-soluble conjugates (29%). Total metabolism at the sixth position of the BaP molecule was indicated by a 3H2O production of 0.07 +/- 0.01 nmol BaP/h per lung, that resulted in the formation of quinones (33%), acid-hydrolysable (40%) and acid-resistant (27%) water-soluble products, indicated by 14C- minus 3H-labelling. Ozone-exposed lungs demonstrated an increased total (14C) BaP utilization to 3.05 +/- 0.05 nmol/h/lung. Although BaP metabolism to all products was increased, the proportion of metabolism involving the 6th position was enhanced from 10% to 25% of total BaP utilization, which was accounted for by relative increases in tissue retained quinones and in perfusate acid-hydrolysable conjugates. These data demonstrated that quinone formation represents a major pathway of lung polycyclic aromatic hydrocarbon metabolism that is greatly enhanced in lungs with proliferating epithelia associated with oxidant exposure.

  13. 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.

  14. 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.

  15. 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.

  16. 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).

  17. 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

  18. Alterations in intermediate filaments expression in disc cells from the rat temporomandibular joint following exposure to continuous compressive force.

    PubMed

    Magara, Jin; Nozawa-Inoue, Kayoko; Suzuki, Akiko; Kawano, Yoshiro; Ono, Kazuhiro; Nomura, Shuichi; Maeda, Takeyasu

    2012-06-01

    The articular disc in the temporomandibular joint (TMJ) that serves in load relief and stabilizing in jaw movements is a dense collagenous tissue consisting of extracellular matrices and disc cells. The various morphological configurations of the disc cells have given us diverse names, such as fibroblasts, chondrocyte-like cells and fibrochondrocytes; however, the characteristics of these cells have remained to be elucidated in detail. The disc cells have been reported to exhibit heterogeneous immunoreaction patterns for intermediate filaments including glial fibrillary acidic protein (GFAP), nestin and vimentin in the adult rat TMJ. Because these intermediate filaments accumulate in the disc cells as tooth eruption proceeds during postnatal development, it might be surmised that the expression of these intermediate filaments in the disc cells closely relates to mechanical stress. The present study was therefore undertaken to examine the effect of a continuous compressive force on the immunoexpression of these intermediate filaments and an additional intermediate filament - muscle-specific desmin - in the disc cells of the TMJ disc using a rat experimental model. The rats wore an appliance that exerts a continuous compressive load on the TMJ. The experimental period with the appliance was 5 days as determined by previous studies, after which some experimental animals were allowed to survive another 5 days after removal of the appliance. Histological observations demonstrated that the compressive force provoked a remarkable acellular region and a decrease in the thickness of the condylar cartilage of the mandible, and a sparse collagen fiber distribution in the articular disc. The articular disc showed a significant increase in the number of desmin-positive cells as compared with the controls. In contrast, immunopositive cells for GFAP, nestin and vimentin remained unchanged in number as well as intensity. At 5 days after removal of the appliance, both the disc and

  19. 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.

  20. Continuous Re-Exposure to Environmental Sound Cues During Sleep Does Not Improve Memory for Semantically Unrelated Word Pairs

    PubMed Central

    Donohue, Kelly C.; Spencer, Rebecca M. C.

    2015-01-01

    Two recent studies illustrated that cues present during encoding can enhance recall if re-presented during sleep. This suggests an academic strategy. Such effects have only been demonstrated with spatial learning and cue presentation was isolated to slow wave sleep (SWS). The goal of this study was to examine whether sounds enhance sleep-dependent consolidation of a semantic task if the sounds are re-presented continuously during sleep. Participants encoded a list of word pairs in the evening and recall was probed following an interval with overnight sleep. Participants encoded the pairs with the sound of “the ocean” from a sound machine. The first group slept with this sound; the second group slept with a different sound (“rain”); and the third group slept with no sound. Sleeping with sound had no impact on subsequent recall. Although a null result, this work provides an important test of the implications of context effects on sleep-dependent memory consolidation. PMID:26435767

  1. 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 ...

  2. 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. PMID:23383193

  3. Neoclassical transport in high [beta] tokamaks

    SciTech Connect

    Cowley, S.C.

    1992-12-01

    Neoclassical, transport in high [beta] large aspect ratio tokamaks is calculated. The variational method introduced by Rosenbluth, et al., is used to calculate the full Onsager matrix in the banana regime. These results are part of a continuing study of the high [beta] large aspect ratio equilibria introduced in Cowley, et al. All the neoclassical coefficients are reduced from their nominal low [beta] values by a factor ([var epsilon]/q[sup 2][beta])[sup [1/2

  4. Neurotoxic amyloid beta oligomeric assemblies recreated in microfluidic platform with interstitial level of slow flow

    PubMed Central

    Choi, Yoon Jung; Chae, Sukyung; Kim, Jeong Hun; Barald, Kate F.; Park, Joong Yull; Lee, Sang-Hoon

    2013-01-01

    Alzheimer's disease is accompanied by progressive, time-dependent changes of three moieties of amyloid beta. In vitro models therefore should provide same conditions for more physiologic studies. Here we observed changes in the number of fibrils over time and studied the correlation between amyloid beta moieties and neurotoxicity. Although the number of fibrils increased dramatically, the change in neurotoxicity with time was small, suggesting that fibrils make little contribution to neurotoxicity. To study the neurotoxicity of diffusible moieties by regulating microenvironments, we created a bio-mimetic microfluidic system generating spatial gradients of diffusible oligomeric assemblies and assessed their effects on cultured neurons. We found amyloid beta exposure produced an atrophy effect and observed neurite extension during the differentiation of neural progenitor cells increased when cells were cultured with continuous flow. The results demonstrate the potential neurotoxicity of oligomeric assemblies and establish a prospective microfluidic platform for studying the neurotoxicity of amyloid beta. PMID:23719665

  5. 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.

  6. 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...

  7. Epigenetic and phenotypic changes result from a continuous pre and post natal dietary exposure to phytoestrogens in an experimental population of mice

    PubMed Central

    Guerrero-Bosagna, Carlos M; Sabat, Pablo; Valdovinos, Fernanda S; Valladares, Luis E; Clark, Susan J

    2008-01-01

    Background Developmental effects of exposure to endocrine disruptors can influence adult characters in mammals, but could also have evolutionary consequences. The aim of this study was to simulate an environmental exposure of an experimental population of mice to high amounts of nutritional phytoestrogens and to evaluate parameters of relevance for evolutionary change in the offspring. The effect of a continuous pre- and post-natal exposure to high levels of dietary isoflavones was evaluated on sexual maturity, morphometric parameters and DNA methylation status in mice. Adult mice male/female couples were fed ad libitum either with control diet (standard laboratory chow) or ISF diet (control diet plus a soy isoflavone extract at 2% (w/w) that contained the phytoestrogens genistein and daidzein). In the offspring we measured: i) the onset of vaginal opening (sexual maturation) in females, ii) weight and size in all pups at 7, 14, 21 and 42 days post-natal (dpn) and iii) DNA methylation patterns in skeletal α-actin (Acta1), estrogen receptor-α and c-fos in adults (42 dpn). Results Vaginal opening was advanced in female pups in the ISF group, from 31.6 ± 0.75 dpn to 25.7 ± 0.48. No differences in size or weight at ages 7, 14 or 21 dpn were detected between experimental groups. Nevertheless, at age 42 dpn reduced size and weight were observed in ISF pups, in addition to suppression of normal gender differences in weight seen in the control group (males heavier that females). Also, natural differences seen in DNA methylation at Acta1 promoter in the offspring originated in the control group were suppressed in the ISF group. Acta1 is known to be developmentally regulated and related to morphomotric features. Conclusion This study demonstrates in mammals that individuals from a population subjected to a high consumption of isoflavones can show alterations in characters that may be of importance from an evolutionary perspective, such as epigenetic and morphometric

  8. Long-term pancreatic beta cell exposure to high levels of glucose but not palmitate induces DNA methylation within the insulin gene promoter and represses transcriptional activity.

    PubMed

    Ishikawa, Kota; Tsunekawa, Shin; Ikeniwa, Makoto; Izumoto, Takako; Iida, Atsushi; Ogata, Hidetada; Uenishi, Eita; Seino, Yusuke; Ozaki, Nobuaki; Sugimura, Yoshihisa; Hamada, Yoji; Kuroda, Akio; Shinjo, Keiko; Kondo, Yutaka; Oiso, Yutaka

    2015-01-01

    Recent studies have implicated epigenetics in the pathophysiology of diabetes. Furthermore, DNA methylation, which irreversibly deactivates gene transcription, of the insulin promoter, particularly the cAMP response element, is increased in diabetes patients. However, the underlying mechanism remains unclear. We aimed to investigate insulin promoter DNA methylation in an over-nutrition state. INS-1 cells, the rat pancreatic beta cell line, were cultured under normal-culture-glucose (11.2 mmol/l) or experimental-high-glucose (22.4 mmol/l) conditions for 14 days, with or without 0.4 mmol/l palmitate. DNA methylation of the rat insulin 1 gene (Ins1) promoter was investigated using bisulfite sequencing and pyrosequencing analysis. Experimental-high-glucose conditions significantly suppressed insulin mRNA and increased DNA methylation at all five CpG sites within the Ins1 promoter, including the cAMP response element, in a time-dependent and glucose concentration-dependent manner. DNA methylation under experimental-high-glucose conditions was unique to the Ins1 promoter; however, palmitate did not affect DNA methylation. Artificial methylation of Ins1 promoter significantly suppressed promoter-driven luciferase activity, and a DNA methylation inhibitor significantly improved insulin mRNA suppression by experimental-high-glucose conditions. Experimental-high-glucose conditions significantly increased DNA methyltransferase activity and decreased ten-eleven-translocation methylcytosine dioxygenase activity. Oxidative stress and endoplasmic reticulum stress did not affect DNA methylation of the Ins1 promoter. High glucose but not palmitate increased ectopic triacylglycerol accumulation parallel to DNA methylation. Metformin upregulated insulin gene expression and suppressed DNA methylation and ectopic triacylglycerol accumulation. Finally, DNA methylation of the Ins1 promoter increased in isolated islets from Zucker diabetic fatty rats. This study helps to clarify the

  9. 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...

  10. The role of formation of continues thermally grown oxide layer on the nanostructured NiCrAlY bond coat during thermal exposure in air

    NASA Astrophysics Data System (ADS)

    Daroonparvar, Mohammadreza; Hussain, Mohammad Sakhawat; Yajid, Muhammad Azizi Mat

    2012-11-01

    In recent years, the life expectancy of thermal barrier coatings is expected to be improved by applying the nanostructured NiCrAlY bond coat. The present paper reviews the main technique used in the synthesis of nano-crystalline NiCrAlY powders using a planetary ball mill and investigates the microstructural evolution of thermally grown oxide (TGO) layer on the conventional and nanostructured atmospheric plasma sprayed (APS) NiCrAlY coatings in thermal barrier coating (TBC) systems during oxidation. Microstructural characterization showed that the growth of Ni(Cr,Al)2O4 (as spinel) and NiO on the surface of Al2O3 layer (as pure TGO) in nano TBC system was much lower compared to that of normal TBC system during thermal exposure at 1150 °C. These two oxides play a detrimental role in causing crack nucleation and growth, reducing the life of the TBC in air. This microstructure optimization of TGO layer is primarily associated with the formation of a continuous, dense, uniform Al2O3 layer (at first 24 h of isothermal oxidation at 1000 °C) over the nanostructured NiCrAlY coating.

  11. DNA arrays to monitor gene expression in rat blood and uterus following 17beta-estradiol exposure: biomonitoring environmental effects using surrogate tissues.

    PubMed

    Rockett, John C; Kavlock, Robert J; Lambright, Christy R; Parks, Louise G; Schmid, Judith E; Wilson, Vickie S; Wood, Carmen; Dix, David J

    2002-09-01

    We propose that gene expression changes in accessible tissues such as blood often reflect those in inaccessible tissues, thus offering a convenient biomonitoring method to provide insight into the effects of environmental toxicants on such tissues. In this pilot study, gene expression changes in peripheral blood leukocytes (PBL) were compared to those in the uteri of adult rats to identify genes that were altered in both tissues following estradiol treatment. Ovariectomized rats were treated with either 17beta-estradiol or vehicle control (corn oil) for 3 days. PBL and uterine RNAs were hybridized to arrays containing 1185 genes. One hundred and ninety three genes were expressed in common between the PBL and uterus. Eighteen were changed significantly in both tissues, 9 of which were treatment- but not tissue-specific (e.g., jun-D, phospholipase A2, thymidine kinase). These results demonstrate that many genes are coexpressed between PBL and uterus, and that some are coregulated by estradiol. Given the limited number of genes examined in this study and the estimated size of other mammalian genomes, we conclude that many more genes will also be coregulated and suggest that accessible tissues such as PBL can serve as surrogate tissues for observing gene expression changes in inaccessible target tissues.

  12. 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

    2015-01-01

    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. PMID:26168333

  13. [Serum beta 2 microglobulin (beta 2M) following renal transplantation].

    PubMed

    Pacheco-Silva, A; Nishida, S K; Silva, M S; Ramos, O L; Azjen, H; Pereira, A B

    1994-01-01

    Although there was an important improvement in graft and patient survival the last 10 years, graft rejection continues to be a major barrier to the success of renal transplantation. Identification of a laboratory test that could help to diagnose graft rejection would facilitate the management of renal transplanted patients. PURPOSE--To evaluate the utility of monitoring serum beta 2M in recently transplanted patients. METHODS--We daily determined serum beta 2M levels in 20 receptors of renal grafts (10 from living related and 10 from cadaveric donors) and compared them to their clinical and laboratory evolution. RESULTS--Eight patients who presented immediate good renal function following grafting and did not have rejection had a mean serum beta 2M of 3.7 mg/L on the 4th day post transplant. The sensitivity of the test for the diagnosis of acute rejection was 87.5%, but the specificity was only 46%. Patients who presented acute tubular necrosis (ATN) without rejection had a progressive decrease in their serum levels of beta 2M, while their serum creatinine changed as they were dialyzed. In contrast, patients with ATN and concomitance of acute rejection or CSA nephrotoxicity presented elevated beta 2M and creatinine serum levels. CONCLUSION--Daily monitoring of serum beta 2M does not improve the ability to diagnose acute rejection in patients with good renal function. However, serum beta 2M levels seemed to be useful in diagnosing acute rejection or CSA nephrotoxicity in patients with ATN.

  14. 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 ...

  15. Beta Blockers

    PubMed Central

    Admani, Shehla; Feldstein, Stephanie; Gonzalez, Ernesto M.

    2014-01-01

    Infantile hemangiomas are benign vascular tumors seen in 4.5 percent of neonates and infants. While most infantile hemangiomas can be managed with active nonintervention, a subset of patients will require more aggressive management. Here the authors review the use of beta-blockers in the treatment of infantile hemangiomas, including oral, topical, and multimodal treatment options. They discuss the latest data on propranolol, including criteria for patient selection, dosing recommendations, and appropriate monitoring for side effects and efficacy. Lastly, they review indications for topical timolol treatment and the potential benefits of concomitant laser therapy. PMID:25053982

  16. 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...

  17. Chronic beryllium disease in a precious metal refinery. Clinical epidemiologic and immunologic evidence for continuing risk from exposure to low level beryllium fumes

    SciTech Connect

    Cullen, M.R.; Kominsky, J.R.; Rossman, M.D.; Cherniack, M.G.; Rankin, J.A.; Balmes, J.R.; Kern, J.A.; Daniele, R.P.; Palmer, L.; Naegel, G.P.

    1987-01-01

    Five workers at a precious metal refinery developed granulomatous lung disease between 1972 and 1985. The original diagnosis was sarcoidosis, but 4 of the workers were subsequently proved to have hypersensitivity to beryllium by in vitro proliferative responses of lymphocytes obtained by bronchoalveolar lavage. Review of medical records of coworkers and extensive industrial hygiene surveillance of the plant demonstrated that 4 cases occurred in the furnace area where air concentrations of beryllium fume were consistently below the permissible exposure limit of 2 micrograms/M3. A single case has been recognized from parts of the refinery where exposures to cold beryllium dust often exceeded the standard by as much as 20-fold. These data demonstrate that chronic beryllium disease still occurs and confirm the importance of specific immunologic testing in patients suspected of having sarcoidosis but with potential exposure to beryllium. The data raise concern about the adequacy of modern industrial controls, especially in the setting of exposure to highly respirable beryllium fumes.

  18. Hypersomnolence with beta-adrenergic blockers.

    PubMed

    Thachil, J; Zeller, J R; Kochar, M S

    1987-11-01

    An elderly, mildly demented, hypertensive male patient developed hypersomnolence on administration of propranolol for treatment of hypertension; no other cause for hypersomnolence was detected. Upon replacement of propranolol with atenolol, he felt better but continued to be quite somnolent. When atenolol was discontinued, he reported to have lack of sleep. On readministration of subtherapeutic doses of the same beta-adrenergic blocking agents, he once again experienced excessive sleepiness. By discontinuing beta-blocking agents and introducing captopril, he felt much better, became pleasant and talkative, and blood pressure was well controlled. Beta antagonists are important drugs in the management of many cardiovascular problems. Propranolol, a lipophilic beta-blocking agent, and atenolol, a hydrophilic beta-blocking agent, are two of the major agents currently used clinically in the United States. Numerous neuropsychiatric side-effects of the beta-adrenergic blocking drugs have been reported, but hypersomnolence is not readily recognized as one of them. PMID:3665616

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. Beta Adrenergic Receptors in Keratinocytes

    PubMed Central

    Sivamani, Raja K.; Lam, Susanne T.; Isseroff, R. Rivkah

    2007-01-01

    Synopsis Beta2 adrenergic receptors were identified in keratinocytes more than 30 years ago, but their function in the epidermis continues to be elucidated. Abnormalities in their expression, signaling pathway, or in the generation of endogenous catecholamine agonists by keratinocytes have been implicated in the pathogenesis of cutaneous diseases such as atopic dermatitis, vitiligo and psoriasis. New studies also indicate that the beta2AR also modulates keratinocyte migration, and thus can function to regulate wound re-epithelialization. This review focuses on the function of these receptors in keratinocytes and their contribution to cutaneous physiology and disease. PMID:17903623

  5. 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.

  6. 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.

  7. 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.

  8. [Serum beta 2 microglobulin (beta 2M) following renal transplantation].

    PubMed

    Pacheco-Silva, A; Nishida, S K; Silva, M S; Ramos, O L; Azjen, H; Pereira, A B

    1994-01-01

    Although there was an important improvement in graft and patient survival the last 10 years, graft rejection continues to be a major barrier to the success of renal transplantation. Identification of a laboratory test that could help to diagnose graft rejection would facilitate the management of renal transplanted patients. PURPOSE--To evaluate the utility of monitoring serum beta 2M in recently transplanted patients. METHODS--We daily determined serum beta 2M levels in 20 receptors of renal grafts (10 from living related and 10 from cadaveric donors) and compared them to their clinical and laboratory evolution. RESULTS--Eight patients who presented immediate good renal function following grafting and did not have rejection had a mean serum beta 2M of 3.7 mg/L on the 4th day post transplant. The sensitivity of the test for the diagnosis of acute rejection was 87.5%, but the specificity was only 46%. Patients who presented acute tubular necrosis (ATN) without rejection had a progressive decrease in their serum levels of beta 2M, while their serum creatinine changed as they were dialyzed. In contrast, patients with ATN and concomitance of acute rejection or CSA nephrotoxicity presented elevated beta 2M and creatinine serum levels. CONCLUSION--Daily monitoring of serum beta 2M does not improve the ability to diagnose acute rejection in patients with good renal function. However, serum beta 2M levels seemed to be useful in diagnosing acute rejection or CSA nephrotoxicity in patients with ATN. PMID:7787867

  9. 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...

  10. Beta contamination monitor energy response

    SciTech Connect

    Bjork, C.W.; Olsher, R.H.

    1998-12-31

    Beta contamination is monitored at Los Alamos National Laboratory (LANL) with portable handheld probes and their associated counters, smear counters, air-breathing continuous air monitors (CAM), personnel contamination monitors (PCM), and hand and foot monitors (HFM). The response of these monitors was measured using a set of anodized-aluminum beta sources for the five isotopes: Carbon-14, Technetium-99, Cesium-137, Chlorine-36 and Strontium/Yttrium-90. The surface emission rates of the sources are traceable to the National Institute of Standards and Technology (NIST) with a precision of one relative standard deviation equal to 1.7%. All measurements were made in reproducible geometry, mostly using aluminum source holders. All counts, significantly above background, were collected to a precision of 1% or better. The study of the hand-held probes included measurements of six air gaps from 0.76 to 26.2 mm. The energy response of the detectors is well-parameterized as a function of the average beta energy of the isotopes (C14=50 keV, Tc99=85, Cs137=188, C136=246, and Sr/Y90=934). The authors conclude that Chlorine-36 is a suitable beta emitter for routine calibration. They recommend that a pancake Geiger-Mueller (GM) or gas-proportional counter be used for primarily beta contamination surveys with an air gap not to exceed 6 mm. Energy response varies about 30% from Tc99 to Sr/Y90 for the pancake GM detector. Dual alpha/beta probes have poor to negligible efficiency for low-energy betas. The rugged anodized sources represent partially imbedded contamination found in the field and they are provided with precise, NIST-traceable, emission rates for reliable calibration.

  11. 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. PMID:19620619

  12. 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.

  13. Beta systems error analysis

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The atmospheric backscatter coefficient, beta, measured with an airborne CO Laser Doppler Velocimeter (LDV) system operating in a continuous wave, focussed model is discussed. The Single Particle Mode (SPM) algorithm, was developed from concept through analysis of an extensive amount of data obtained with the system on board a NASA aircraft. The SPM algorithm is intended to be employed in situations where one particle at a time appears in the sensitive volume of the LDV. In addition to giving the backscatter coefficient, the SPM algorithm also produces as intermediate results the aerosol density and the aerosol backscatter cross section distribution. A second method, which measures only the atmospheric backscatter coefficient, is called the Volume Mode (VM) and was simultaneously employed. The results of these two methods differed by slightly less than an order of magnitude. The measurement uncertainties or other errors in the results of the two methods are examined.

  14. 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

  15. 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. PMID:25746569

  16. 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.

  17. Colorado potato beetle (Coleoptera: Chrysomelidae) feeding, development, and survival to adulthood after continuous exposure to Bacillus thuringiensis subsp. tenebrionis-treated potato foliage from the field.

    PubMed

    Nault, B A; Costa, S D; Kennedy, G G

    2000-02-01

    Colorado potato beetle, Leptinotarsa decemlineata (Say), feeding, development, and survival to adulthood were examined after continuously exposing large larvae to Bacillus thuringiensis subsp. tenebrionis-treated potato foliage from the field. In laboratory assays, the overall consumption and the length of period to become prepupae were determined for larvae, which began as 3rd and 4th instars, that were offered potato leaf disks with naturally declining levels of B. thuringiensis residue. In small-cage field experiments, survival to adulthood and the period to adult emergence for beetles confined to potato plants treated with B. thuringiensis beginning as 3rd and 4th instars also were examined. Third instars remaining on plants after a B. thuringiensis application were unlikely to feed and 4th instars consumed only approximately 50% as much foliage as those fed untreated foliage. Many late instars subjected to B. thuringiensis-treated foliage failed to survive to adulthood; 58-83% of these beetles died during the larval stage. Reduced feeding and poor survival of late instars suggest that counts of large larvae after application do not provide a complete picture of the efficacy of the B. thuringiensis treatment. Late instar Colorado potato beetles that were exposed continually to naturally declining levels of B. thuringiensis-treated potato foliage took an average of 1.8-4.5 d longer to become prepupae and 4-8 d longer to emerge as adults compared with those provided with untreated foliage. Delayed emergence of adults that fed on B. thuringiensis-treated potatoes as late instars indicated that development was prolonged in these insects because of ingestion of a sublethal dose of B. thuringiensis.

  18. 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.

  19. Resistance to beta-lactams--the permutations.

    PubMed

    Amyes, S G B

    2003-12-01

    The beta-lactam family of antimicrobials, in particular penicillins and cephalosporins, is the mainstay of treatment for community-acquired infections. However, the emergence of resistant isolates to these agents has raised concerns regarding the continued efficacy of existing therapies. Resistance to beta-lactams is most commonly expressed by the microbial production of beta-lactamases that hydrolyze the beta-lactam ring. Three further resistance mechanisms include conformational changes in penicillin-binding proteins (PBPs); permeability changes in the outer membrane; and active efflux of the antimicrobial. In addition to the pre-requisite efficacy and tolerability profiles, new beta-lactams should address these four resistance mechanisms. Overcoming resistance may be a serendipitous event or arrived at by design. A unique synthetic beta-lactam class, which demonstrates promise in terms of its activity against the range of bacteria responsible for community-acquired infections and its inherent stability to hydrolysis by beta-lactamases, is the penems. This discrete class of hybrid molecules combines properties from the penicillin (penam) and cephalosporin (cephem) beta-lactam classes. Faropenem is an example of a penem with a broad spectrum of activity designed to address these resistance issues. PMID:14998075

  20. The effects of continuous testosterone exposure on spontaneous and cadmium-induced tumors in the male Fischer (F344/NCr) rat: loss of testicular response.

    PubMed

    Waalkes, M P; Rehm, S; Devor, D E

    1997-01-01

    In the rodent testes, cadmium induces severe necrosis followed by chronic degeneration. Cadmium is also an effective testicular tumorigen, and a single dose produces a high incidence of Leydig cell tumors. The mechanism of tumor formation is unknown, but pituitary feedback, i.e., increased luteinizing hormone (LH) production due to low circulating androgen, has been implicated in causation of proliferative lesions within degenerate, hypofunctioning testes. Thus, the effects of androgen replacement on the testicular toxicity of cadmium in Fischer (F344/NCr) rats was studied. Groups (n = 50) of 10-week-old rats either received testosterone implants that approximate normal circulating levels in castrated rats or were left untreated. After 2 weeks of stabilization, rats were given either 20 micromol CdCl2/kg, s.c., weekly for the next 5 weeks (total dose 100 micromol/kg) or saline for a total of four treatment groups (control, testosterone alone, testosterone + cadmium, or cadmium alone). Portions of each group were killed either 10 weeks after initiation of cadmium exposure (n = 10), for assessment of endocrine function, or over the next 2 years (n = 40), for assessment of testicular neoplastic lesions. At 10 weeks, cadmium reduced circulating testosterone in nonimplanted rats by nearly 80% and induced a marked weight loss of the testes (>70%) and sex accessory glands (reflected in a 50% reduction in prostate mass). Testosterone implantation restored circulating testosterone levels in cadmium-treated rats and prevented Cd-induced weight loss of the sex accessory glands but not of the testes. Over 2 years, cadmium alone induced a >84% incidence of Leydig cell neoplasia and a >97% incidence of chronic degeneration, both significant increases over control rates (60 and 0%, respectively). Testosterone implantation abolished both cadmium-induced and spontaneously occurring Leydig cell tumors but had no effect on cadmium-induced chronic testicular degeneration. Thus cadmium

  1. beta-Arrestin mediates beta1-adrenergic receptor-epidermal growth factor receptor interaction and downstream signaling.

    PubMed

    Tilley, Douglas G; Kim, Il-Man; Patel, Priyesh A; Violin, Jonathan D; Rockman, Howard A

    2009-07-24

    beta1-Adrenergic receptor (beta1AR) stimulation confers cardioprotection via beta-arrestin-de pend ent transactivation of epidermal growth factor receptors (EGFRs), however, the precise mechanism for this salutary process is unknown. We tested the hypothesis that the beta1AR and EGFR form a complex that differentially directs intracellular signaling pathways. beta1AR stimulation and EGF ligand can each induce equivalent EGFR phosphorylation, internalization, and downstream activation of ERK1/2, but only EGF ligand causes translocation of activated ERK to the nucleus, whereas beta1AR-stimulated/EGFR-transactivated ERK is restricted to the cytoplasm. beta1AR and EGFR are shown to interact as a receptor complex both in cell culture and endogenously in human heart, an interaction that is selective and undergoes dynamic regulation by ligand stimulation. Although catecholamine stimulation mediates the retention of beta1AR-EGFR interaction throughout receptor internalization, direct EGF ligand stimulation initiates the internalization of EGFR alone. Continued interaction of beta1AR with EGFR following activation is dependent upon C-terminal tail GRK phosphorylation sites of the beta1AR and recruitment of beta-arrestin. These data reveal a new signaling paradigm in which beta-arrestin is required for the maintenance of a beta1AR-EGFR interaction that can direct cytosolic targeting of ERK in response to catecholamine stimulation.

  2. TGF-beta inhibits prolactin-induced expression of beta-casein by a Smad3-dependent mechanism.

    PubMed

    Wu, Wen-Jun; Lee, Chin-Feng; Hsin, Chung-Han; Du, Jyun-Yi; Hsu, Tsai-Ching; Lin, Ting-Hui; Yao, Tsung-You; Huang, Cheng-Hsieh; Lee, Yi-Ju

    2008-08-01

    Transforming growth factor-beta (TGF-beta) is a multifunctional growth factor, affecting cell proliferation, apoptosis, and extracellular matrix homeostasis. It also plays critical roles in mammary gland development, one of which involves inhibition of the expression of milk proteins, such as beta-casein, during pregnancy. Here we further explore the underlying signaling mechanism for it. Our results show that TGF-beta suppresses prolactin-induced expression of beta-casein mRNA and protein in primary mouse mammary epithelial cells, but its effect on protein expression is more evident. We also find out that this inhibition is not due to the effect of TGF-beta on cell apoptosis. Furthermore, inhibition of TGF-beta type I receptor kinase activity by a pharmacological inhibitor SB431542 or overexpression of dominant negative Smad3 substantially restores beta-casein expression. By contrast, inhibition of p38 and Erk that are known to be activated by TGF-beta does not alleviate the inhibitory effect of TGF-beta. These results are consistent with our other observation that Smad but not MAPK pathway is activated by TGF-beta in mammary epithelial cells. Lastly, we show that prolactin-induced tyrosine phosphorylation of Jak2 and Stat5 as well as serine/threonine phosphorylation of p70S6K and S6 ribosomal protein are downregulated by TGF-beta, although the former event requires considerably long exposure to TGF-beta. We speculate that these events might be involved in repressing transcription and translation of beta-casein gene, respectively. Taken together, our results demonstrate that TGF-beta abrogates prolactin-stimulated beta-casein gene expression in mammary epithelial cells through, at least in part, a Smad3-dependent mechanism.

  3. 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.

  4. 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.

  5. 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.

  6. Tevatron B0 low beta tuning report

    SciTech Connect

    Johnson, D.E.

    1982-05-05

    A detailed study of the low beta insertion for the B0 experimental area has been carried out and is described below. This insertion is similar to the Type C low beta previously report, anti p Note 169, although some changes have been made to the quadrupole lengths and positions. This insertion is designated Type E. The purpose of the study was to see if it is possible to turn the insertion on in a smooth and continuous manner and tune the insertion to a value of ..beta..* of less than one meter while maintaining the overall tune of the j Tevatron to a constant value. This was found to be possible. An examination of chromaticity corrections for the Tevatron with the low beta insertion on in various configurations was also undertaken.

  7. Exposures to lead.

    PubMed

    Callan, Anna C; Hinwood, Andrea L

    2011-01-01

    The Pacific Basin Consortium for Environment and Health hosted a workshop on Exposures to Lead. Speakers from Australia and the United States of America addressed current research knowledge on lead exposures and health effects in children, risk assessment and communication issues in dealing with lead exposure sources, different methods for assessing exposure, and the variety of scenarios where lead still remains a pollutant of concern. Mining continues to be a source of lead for many communities, and approaches to reducing exposures in these settings present particular challenges. A Perth Declaration for the Global Reduction of Childhood Lead Exposure was signed by participants of the meeting and is aimed at increasing attention to the need to continue to assess lead in the environment and to develop strategies to reduce lead in the environment and exposure by communities. PMID:21714377

  8. Exposures to lead.

    PubMed

    Callan, Anna C; Hinwood, Andrea L

    2011-01-01

    The Pacific Basin Consortium for Environment and Health hosted a workshop on Exposures to Lead. Speakers from Australia and the United States of America addressed current research knowledge on lead exposures and health effects in children, risk assessment and communication issues in dealing with lead exposure sources, different methods for assessing exposure, and the variety of scenarios where lead still remains a pollutant of concern. Mining continues to be a source of lead for many communities, and approaches to reducing exposures in these settings present particular challenges. A Perth Declaration for the Global Reduction of Childhood Lead Exposure was signed by participants of the meeting and is aimed at increasing attention to the need to continue to assess lead in the environment and to develop strategies to reduce lead in the environment and exposure by communities.

  9. High Beta Tokamaks

    SciTech Connect

    Cowley, S.

    1998-11-14

    Perhaps the ideal tokamak would have high {beta} ({beta} {approx}> 1) and classical confinement. Such a tokamak has not been found, and we do not know if one does exist. We have searched for such a possibility, so far without success. In 1990, we obtained analytic equilibrium solutions for large aspect ratio tokamaks at {beta} {approx} {Omicron}(1) [1]. These solutions and the extension at high {beta} poloidal to finite aspect ratio [2] provided a basis for the study of high {beta} tokamaks. We have shown that these configurations can be stable to short scale MHD modes [3], and that they have reduced neoclassical transport [4]. Microinstabilities (such as the {del}T{sub i} mode) seem to be stabilized at high {beta} [5] - this is due to the large local shear [3] and the magnetic well. We have some concerns about modes associated with the compressional branch which may appear at high {beta}. Bill Dorland and Mike Kotschenreuther have studied this issue and our concerns may be unfounded. It is certainly tantalizing, especially given the lowered neoclassical transport values, that these configurations could have no microinstabilities and, one could assume, no anomalous transport. Unfortunately, while this work is encouraging, the key question for high {beta} tokamaks is the stability to large scale kink modes. The MHD {beta} limit (Troyon limit) for kink modes at large aspect ratio is problematically low. There is ample evidence from computations that the limit exists. However, it is not known if stable equilibria exist at much higher {beta}--none have been found. We have explored this question in the asymptotic high {beta} poloidal limit. Unfortunately, we are unable to find stable equilibrium and also unable to show that they don't exist. The results of these calculations will be published when a more definitive answer is found.

  10. 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…

  11. 29 CFR 1910.1009 - beta-Naphthylamine.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 6 2010-07-01 2010-07-01 false beta-Naphthylamine. 1910.1009 Section 1910.1009 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... beta-Naphthylamine. See § 1910.1003, 13 carcinogens....

  12. 29 CFR 1910.1013 - beta-Propiolactone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 6 2010-07-01 2010-07-01 false beta-Propiolactone. 1910.1013 Section 1910.1013 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... beta-Propiolactone. See § 1910.1003, 13 carcinogens....

  13. 29 CFR 1910.1013 - beta-Propiolactone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 6 2011-07-01 2011-07-01 false beta-Propiolactone. 1910.1013 Section 1910.1013 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... beta-Propiolactone. See § 1910.1003, 13 carcinogens....

  14. 29 CFR 1910.1009 - beta-Naphthylamine.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 6 2011-07-01 2011-07-01 false beta-Naphthylamine. 1910.1009 Section 1910.1009 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... beta-Naphthylamine. See § 1910.1003, 13 carcinogens....

  15. 29 CFR 1915.1009 - beta-Naphthylamine.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false beta-Naphthylamine. 1915.1009 Section 1915.1009 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... § 1915.1009 beta-Naphthylamine. Note: The requirements applicable to shipyard employment under...

  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... § 1915.1009 beta-Naphthylamine. Note: The requirements applicable to shipyard employment under...

  17. 29 CFR 1915.1013 - beta-Propiolactone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false beta-Propiolactone. 1915.1013 Section 1915.1013 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... § 1915.1013 beta-Propiolactone. Note: The requirements applicable to shipyard employment under...

  18. 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... § 1915.1013 beta-Propiolactone. Note: The requirements applicable to shipyard employment under...

  19. Criminal exposure.

    PubMed

    1999-09-01

    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.

  20. Transforming growth factor-beta activation in irradiated murine mammary gland.

    PubMed Central

    Barcellos-Hoff, M H; Derynck, R; Tsang, M L; Weatherbee, J A

    1994-01-01

    The biological activity of TGF-beta, an important modulator of cell proliferation and extracellular matrix formation, is governed by dissociation of mature TGF-beta from an inactive, latent TGF-beta complex in a process that is critical to its role in vivo. So far, it has not been possible to monitor activation in vivo since conventional immunohistochemical detection does not accurately discriminate latent versus active TGF-beta, nor have events associated with activation been defined well enough to serve as in situ markers of this process. We describe here a modified immunodetection method using differential antibody staining that allows the specific detection of active versus latent TGF-beta. Under these conditions, we report that an antibody raised to latency-associated peptide detects latent TGF-beta, and we demonstrate that LC(1-30) antibodies specifically recognize active TGF-beta 1 in tumor xenografts overproducing active TGF-beta 1, without cross-reactivity in tumors expressing similar levels of latent TGF-beta 1. We previously reported that TGF-beta immunoreactivity increases in murine mammary gland after whole-body 60Co-gamma radiation exposure. Using differential antibody staining we now show that radiation exposure specifically generates active TGF-beta 1. While latent TGF-beta 1 was widely distributed in unirradiated tissue, active TGF-beta 1 distribution was restricted. Active TGF-beta 1 increased significantly within 1 h of irradiation concomitant with decreased latent TGF-beta immunoreactivity. This rapid shift in immunoreactivity provides the first evidence for activation of TGF-beta in situ. This reciprocal pattern of expression persisted for 3 d and was accompanied by decreased recovery of latent TGF-beta 1 from irradiated tissue. Radiation-induced activation of TGF-beta may have profound implications for understanding tissue effects caused by radiation therapy. Images PMID:8113421

  1. Rapid synthesis of beta zeolites

    SciTech Connect

    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.

  2. Neoclassical transport in high {beta} tokamaks

    SciTech Connect

    Cowley, S.C.

    1992-12-01

    Neoclassical, transport in high {beta} large aspect ratio tokamaks is calculated. The variational method introduced by Rosenbluth, et al., is used to calculate the full Onsager matrix in the banana regime. These results are part of a continuing study of the high {beta} large aspect ratio equilibria introduced in Cowley, et al. All the neoclassical coefficients are reduced from their nominal low {beta} values by a factor ({var_epsilon}/q{sup 2}{beta}){sup {1/2}} II. This factor is the ratio of plasma volume in the boundary layer to the volume in the core. The fraction of trapped particles on a given flux surface (f{sub t}) is also reduced by this factor so that {approximately} {sub ({var_epsilon}}/q{sup 2}{beta}){sup {1/2}}. Special attention is given to the current equation, since this is thought to be relevant at low 3 and therefore may also be relevant at high {beta}. The bootstrap current term is found to exceed the actual current by a factor of the square root of the aspect ratio.

  3. On the origin of the beta cell.

    PubMed

    Oliver-Krasinski, Jennifer M; Stoffers, Doris A

    2008-08-01

    The major forms of diabetes are characterized by pancreatic islet beta-cell dysfunction and decreased beta-cell numbers, raising hope for cell replacement therapy. Although human islet transplantation is a cell-based therapy under clinical investigation for the treatment of type 1 diabetes, the limited availability of human cadaveric islets for transplantation will preclude its widespread therapeutic application. The result has been an intense focus on the development of alternate sources of beta cells, such as through the guided differentiation of stem or precursor cell populations or the transdifferentiation of more plentiful mature cell populations. Realizing the potential for cell-based therapies, however, requires a thorough understanding of pancreas development and beta-cell formation. Pancreas development is coordinated by a complex interplay of signaling pathways and transcription factors that determine early pancreatic specification as well as the later differentiation of exocrine and endocrine lineages. This review describes the current knowledge of these factors as they relate specifically to the emergence of endocrine beta cells from pancreatic endoderm. Current therapeutic efforts to generate insulin-producing beta-like cells from embryonic stem cells have already capitalized on recent advances in our understanding of the embryonic signals and transcription factors that dictate lineage specification and will most certainly be further enhanced by a continuing emphasis on the identification of novel factors and regulatory relationships. PMID:18676806

  4. 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…

  5. Serum and urinary beta-2-microglobulin among cadmium-exposed workers

    SciTech Connect

    Iwao, S.; Tsuchiya, K.; Sakurai, H.

    1980-06-01

    The effect of ten years' cadmium (Cd) exposure was investigated among a total of 18 workers (ten with previous heavy exposure, three with recent lower exposure and five control workers) by comparing indicators of previous exposure (blood and urinary Cd and ..beta..2-M) with clinical estimates of renal tubular function. The ten workers still excreted higher concentration of Cd than did the other three workers with low exposure, even after cessation of exposure. Estimates of renal function indicated that most workers among the ten and the three workers did not always exhibit dysfunction. Elevated blood Cd was significantly correlated with elevated serum ..beta..2-M. The study demonstrated that increased ..beta..2-M in urine is not necessarily due to tubular impairment, but may be the result of the increased ..beta..2-M in plasma exceeding the renal threshold.

  6. Differential expression of transforming growth factor-beta in the interstitial tissue of testis during aging.

    PubMed

    Jung, Jae-Chang; Park, Geun-Tae; Kim, Kook-Hee; Woo, Ju Hyung; An, Jung-Min; Kim, Ki-Chul; Chung, Hae Young; Bae, Young-Seuk; Park, Jeen Woo; Kang, Shin-Sung; Lee, Young-Sup

    2004-05-01

    Transforming growth factor-betas (TGF-betas) have significant effects on testis development. The pattern of TGF-beta expression in aging testis has not been established to date. We examined age-related changes in the expression of TGF-beta and its receptors in the testis using Western blot analysis. TGF-beta1 expression increased continuously in aging rat testis, whereas no age-associated changes were observed for TGF-beta3. Strong expression of TGF-beta2, as well as type I and II receptors was observed in 12-month-old testis, but following this time, expression decreased dramatically. Interestingly, TGF-beta2 and -beta3 displayed strong and similar expression patterns in liver, regardless of age, suggesting that the down-regulation of TGF-beta2 is testis-specific. We observed significant induction of p53 and p21WAF1 in 18-month-old testis that appeared to correspond with aging. Moreover, caloric restriction (CR) prevented age-related decrease in TGF-beta2 expression. Using immunohistochemistry, we showed that all TGF-beta1, -beta2, and -beta3 proteins are expressed primarily in interstitial cells, which are located in the space between adjoining seminiferous tubules. Our data collectively indicate that aging in the testis is regulated by differential expression of TGF-beta proteins, and decreased levels of TGF-beta2 contribute to the aging process.

  7. 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...

  8. 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.

  9. Pleiotrophin stimulates tyrosine phosphorylation of beta-adducin through inactivation of the transmembrane receptor protein tyrosine phosphatase beta/zeta.

    PubMed

    Pariser, Harold; Perez-Pinera, Pablo; Ezquerra, Laura; Herradon, Gonzalo; Deuel, Thomas F

    2005-09-16

    Pleiotrophin (PTN the protein, Ptn the gene) signals through a unique mechanism; it inactivates the tyrosine phosphatase activity of its receptor, the transmembrane receptor protein tyrosine phosphatase (RPTP)beta/zeta, and increases tyrosine phosphorylation of the substrates of RPTPbeta/zeta through the continued activity of a yet to be described protein tyrosine kinase(s) in PTN-stimulated cells. We have now found that the cytoskeletal protein beta-adducin interacts with the intracellular domain of RPTPbeta/zeta in a yeast two-hybrid system, that beta-adducin is a substrate of RPTPbeta/zeta, that beta-adducin is phosphorylated in tyrosine in cells not stimulated by PTN, and that tyrosine phosphorylation of beta-adducin is sharply increased in PTN-stimulated cells, suggesting that beta-adducin is a downstream target of and regulated by the PTN/RPTPbeta/zeta signaling pathway. beta-Catenin was the first downstream target of the PTN/RPTPbeta/zeta signaling pathway to be identified; these data thus also suggest that PTN coordinately regulates steady state levels of tyrosine phosphorylation of the important cytoskeletal proteins beta-adducin and beta-catenin and, through PTN-stimulated tyrosine phosphorylation, beta-adducin may contribute to the disruption of cytoskeletal structure, increased plasticity, and loss of homophilic cell-cell adhesion that are the consequences of PTN stimulation of cells and a characteristic feature of different malignant cells with mutations that activate constitutive expression of the endogenous Ptn gene.

  10. 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.

  11. High beta multipoles

    SciTech Connect

    Prager, S C

    1982-05-01

    Multipoles are being employed as devices to study fusion issues and plasma phenomena at high values of beta (plasma pressure/magnetic pressure) in a controlled manner. Due to their large volume, low magnetic field (low synchrotron radiation) region, they are also under consideration as potential steady state advanced fuel (low neutron yield) reactors. Present experiments are investigating neoclassical (bootstrap and Pfirsch-Schlueter) currents and plasma stability at extremely high beta.

  12. 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.

  13. Beta-adrenoceptors in obstetrics and gynecology.

    PubMed

    Modzelewska, Beata

    2016-01-01

    One hundred and twenty years after the description of extracts from the adrenal medulla, the use of beta-blockers and beta-agonists evolved from antianginal drugs and tocolytics to ligand-directed signaling. Beta-blockers in the fields of obstetrics and gynecology have so far been limited to the consideration of continuing treatment of disorders of the cardiovascular system and other dysfunctions that started before pregnancy. Studies in recent years have shown that beta-adrenoceptor signaling might be crucial in carcinogenesis and metastasis, apoptosis and anoikis. On the other hand, the use of beta-adrenoceptor agonists in tocolysis is, as yet, the primary method for inhibiting premature uterine contractions. Unfortunately, the efficacy of current pharmacological treatment for the management of preterm labor is regularly questioned. Moreover, studies related to non-pregnant myometrium performed to date indicate that the rhythmic contractions of the uterus are required for menstruation and have an important role in human reproduction. In turn, abnormal uterine contractility has been linked to dysmenorrhea, a condition associated with painful uterine cramping. The benefits of the use of beta2-adrenoceptor agonists in dysmenorrhea are still unclear and should be balanced against a wide range of adverse effects recognized with this class of medication. The ideal tocolytic agent is one which is effective for the pregnant or non-pregnant woman but has no side effects on either the woman or the baby. Looking to the future with both caution and hope, the potential metamorphosis of beta3-adrenoceptor agonists from experimental tools into therapeutic drugs for tocolysis warrants attention. PMID:27442692

  14. Beta-adrenoceptors in obstetrics and gynecology.

    PubMed

    Modzelewska, Beata

    2016-01-01

    One hundred and twenty years after the description of extracts from the adrenal medulla, the use of beta-blockers and beta-agonists evolved from antianginal drugs and tocolytics to ligand-directed signaling. Beta-blockers in the fields of obstetrics and gynecology have so far been limited to the consideration of continuing treatment of disorders of the cardiovascular system and other dysfunctions that started before pregnancy. Studies in recent years have shown that beta-adrenoceptor signaling might be crucial in carcinogenesis and metastasis, apoptosis and anoikis. On the other hand, the use of beta-adrenoceptor agonists in tocolysis is, as yet, the primary method for inhibiting premature uterine contractions. Unfortunately, the efficacy of current pharmacological treatment for the management of preterm labor is regularly questioned. Moreover, studies related to non-pregnant myometrium performed to date indicate that the rhythmic contractions of the uterus are required for menstruation and have an important role in human reproduction. In turn, abnormal uterine contractility has been linked to dysmenorrhea, a condition associated with painful uterine cramping. The benefits of the use of beta2-adrenoceptor agonists in dysmenorrhea are still unclear and should be balanced against a wide range of adverse effects recognized with this class of medication. The ideal tocolytic agent is one which is effective for the pregnant or non-pregnant woman but has no side effects on either the woman or the baby. Looking to the future with both caution and hope, the potential metamorphosis of beta3-adrenoceptor agonists from experimental tools into therapeutic drugs for tocolysis warrants attention.

  15. The beta-beta-alpha fold: explorations in sequence space.

    PubMed

    Sarisky, C A; Mayo, S L

    2001-04-13

    The computational redesign of the second zinc finger of Zif268 to produce a 28 residue peptide (FSD-1) that assumes a betabetaalpha fold without metal binding was recently reported. In order to explore the tolerance of this metal-free fold towards sequence variability, six additional peptides resulting from the ORBIT computational protein design process were synthesized and characterized. The experimental stabilities of five of these peptides are strongly correlated with the energies calculated by ORBIT. However, when a peptide with a mutation in the beta-turn is examined, the calculated stability does not accurately predict the experimentally determined stability. The NMR solution structure of a peptide incorporating this mutation (FSD-EY) reveals that the register between the beta-strands is different from the model structure used to select and score the sequences. FSD-EY has a type I' turn instead of the target EbaaagbE turn (rubredoxin knuckle). Two additional peptides that have improved side-chain to backbone hydrogen bonding and turn propensity for the target turn were characterized. Both are of stability comparable to that of FSD-1. These results demonstrate the robustness of the ORBIT protein design methods and underscore the need for continued improvements in negative design.

  16. Mass spectrometric analysis of lens [beta]-crystallins

    NASA Astrophysics Data System (ADS)

    Smith, Jean B.; Miesbauer, Laura R.; Leeds, Jonathan; Smith, David L.; Loo, Joseph A.; Smith, Richard D.; Edmonds, Charles G.

    1991-12-01

    A combination of electrospray ionization mass spectrometry (ESIMS), fast atom bombardment mass spectrometry (FABMS), and sodium dodecylsulfate-polyacrylamide get electrophoresis (SDS-PAGE) was used to determine the homegeneity of chromatographic fractions of [beta]-crystallins, separated by reversed-phase HPLC. The molecular weight of the major component of [beta]-crystallins, [beta]B2, was found by ESIMS to be 23 215, in agreement with the accepted value of 23 209. The practical utility of improved resolution and accuracy of ESIMS relative to SDS-PAGE of identifying proteins is discussed. The component [beta]B2 was found in more than one HPLC fraction, suggesting that it migrates through the HPLC column aggregated with itself or other [beta]-crystallins. Several proteins with different molecular weights were found to be unique to each of the two classes of [beta]-crystallins. Tryptic digest of the major HPLC fractions were analyzed by FABMS, on-line HPLC continuous-flow FABMS--MS to give detailed information about the primary structure of [beta]B2. Peptides related to all but one portion of the proposed amino acid sequence of [beta]B2 were found in the tryptic digest, suggesting that the proposed sequence is correct. On-line HPLC continuous-flow FABMS analysis of the proteolytic digest was particularly attractive because it gave a nearly complete peptide molecular weight map in 20 min.

  17. 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.

  18. Cocaine downregulates beta-adrenergic receptors in pregnant sheep myometrium.

    PubMed

    Wang, F L; Gauvin, J M; Dombrowski, M P; Smith, Y R; Christopher, K A; Hurd, W W

    1996-01-01

    Cocaine abuse is associated with premature labor. Although cocaine is known to competitively inhibit beta-adrenergic receptor binding, cocaine's effect on receptor downregulation is uncertain. This study was designed to determine the in vitro effect of cocaine on downregulation of beta-adrenergic receptors in pregnant myometrium. Pregnant sheep myometrium was incubated with either cocaine, isoproterenol, or a cocaine metabolite, benzoylecgonine. Membrane fractions were assayed for beta-adrenergic receptors using (125I)-cyanopindolol and the beta 2-adrenergic antagonist ICI 118,551. We found that cocaine (10(-6) to 10(-4) mol/L), but not benzoylecgonine, downregulated both beta 1- and beta 2-adrenergic receptors, but did not further augment receptor downregulation by isoproterenol. The 46% decrease in beta-adrenergic receptors seen after exposure to cocaine was similar to the 53% decrease seen after isoproterenol. We hypothesize downregulation of beta-adrenergic receptors by cocaine may play a role in the association of cocaine abuse with premature labor.

  19. Glucolipotoxicity age-dependently impairs beta cell function in rats despite a marked increase in beta cell mass

    PubMed Central

    Fontés, G.; Zarrouki, B.; Hagman, D. K.; Latour, M. G.; Semache, M.; Roskens, V.; Moore, P. C.; Prentki, M.; Rhodes, C. J.; Jetton, T. L.

    2010-01-01

    Aims/hypothesis Prolonged exposure of pancreatic beta cells to excessive levels of glucose and fatty acids, referred to as glucolipotoxicity, is postulated to contribute to impaired glucose homeostasis in patients with type 2 diabetes. However, the relative contribution of defective beta cell function vs diminished beta cell mass under glucolipotoxic conditions in vivo remains a subject of debate. We therefore sought to determine whether glucolipotoxicity in rats is due to impaired beta cell function and/or reduced beta cell mass, and whether older animals are more susceptible to glucolipotoxic condition. Methods Wistar rats (2 and 6 months old) received a 72 h infusion of glucose + intravenous fat emulsion or saline control. In vivo insulin secretion and sensitivity were assessed by hyperglycaemic clamps. Ex vivo insulin secretion, insulin biosynthesis and gene expression were measured in isolated islets. Beta cell mass and proliferation were examined by immunohistochemistry. Results A 72 h infusion of glucose + intravenous fat emulsion in 2-month-old Wistar rats did not affect insulin sensitivity, insulin secretion or beta cell mass. In 6-month-old rats by contrast it led to insulin resistance and reduced insulin secretion in vivo, despite an increase in beta cell mass and proliferation. This was associated with: (1) diminished glucose-stimulated second-phase insulin secretion and proinsulin biosynthesis; (2) lower insulin content; and (3) reduced expression of beta cell genes in isolated islets. Conclusions/interpretation In this in vivo model, glucolipotoxicity is characterised by an age-dependent impairment of glucose-regulated beta cell function despite a marked increase in beta cell mass. PMID:20628728

  20. Foodborne Cereulide Causes Beta-Cell Dysfunction and Apoptosis

    PubMed Central

    Vangoitsenhoven, Roman; Rondas, Dieter; Crèvecoeur, Inne; D'Hertog, Wannes; Baatsen, Pieter; Masini, Matilde; Andjelkovic, Mirjana; Van Loco, Joris; Matthys, Christophe; Mathieu, Chantal; Overbergh, Lut; Van der Schueren, Bart

    2014-01-01

    Aims/Hypothesis To study the effects of cereulide, a food toxin often found at low concentrations in take-away meals, on beta-cell survival and function. Methods Cell death was quantified by Hoechst/Propidium Iodide in mouse (MIN6) and rat (INS-1E) beta-cell lines, whole mouse islets and control cell lines (HepG2 and COS-1). Beta-cell function was studied by glucose-stimulated insulin secretion (GSIS). Mechanisms of toxicity were evaluated in MIN6 cells by mRNA profiling, electron microscopy and mitochondrial function tests. Results 24 h exposure to 5 ng/ml cereulide rendered almost all MIN6, INS-1E and pancreatic islets apoptotic, whereas cell death did not increase in the control cell lines. In MIN6 cells and murine islets, GSIS capacity was lost following 24 h exposure to 0.5 ng/ml cereulide (P<0.05). Cereulide exposure induced markers of mitochondrial stress including Puma (p53 up-regulated modulator of apoptosis, P<0.05) and general pro-apoptotic signals as Chop (CCAAT/-enhancer-binding protein homologous protein). Mitochondria appeared swollen upon transmission electron microscopy, basal respiration rate was reduced by 52% (P<0.05) and reactive oxygen species increased by more than twofold (P<0.05) following 24 h exposure to 0.25 and 0.50 ng/ml cereulide, respectively. Conclusions/Interpretation Cereulide causes apoptotic beta-cell death at low concentrations and impairs beta-cell function at even lower concentrations, with mitochondrial dysfunction underlying these defects. Thus, exposure to cereulide even at concentrations too low to cause systemic effects appears deleterious to the beta-cell. PMID:25119564

  1. IO SUBSYSTEM 1 BETA

    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/outputmore » library for finite element analysis, preprocessing, post processing, and translation programs.« less

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 29 CFR 1926.1113 - beta-Propiolactone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false beta-Propiolactone. 1926.1113 Section 1926.1113 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Toxic and Hazardous Substances § 1926.1113...

  8. 29 CFR 1926.1109 - beta-Naphthylamine.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false beta-Naphthylamine. 1926.1109 Section 1926.1109 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Toxic and Hazardous Substances § 1926.1109...

  9. 29 CFR 1926.1113 - beta-Propiolactone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false beta-Propiolactone. 1926.1113 Section 1926.1113 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Toxic and Hazardous Substances § 1926.1113...

  10. 29 CFR 1926.1109 - beta-Naphthylamine.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false beta-Naphthylamine. 1926.1109 Section 1926.1109 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Toxic and Hazardous Substances § 1926.1109...

  11. Beta galactosidases and their potential applications: a review.

    PubMed

    Husain, Qayyum

    2010-03-01

    Beta galactosidases have been obtained from microorganisms such as fungi, bacteria and yeasts; plants, animals cells, and from recombinant sources. The enzyme has two main applications; the removal of lactose from milk products for lactose intolerant people and the production of galactosylated products. In order to increase their stability, reusability, and use in continuous reactors, these enzymes have been immobilized on both organic and inorganic support via adsorption, covalent attachment, chemical aggregation, microencapsulation, and entrapment. Free and immobilized preparations of beta galactosidases have been exploited in various applications such as industrial, biotechnological, medical, analytical, and in different other applications. beta galactosidase is widely used in food industry to improve sweetness, solubility, flavor, and digestibility of dairy products. Immobilized beta galactosidases are employed for the continuous hydrolysis of lactose from whey and milk in a number of reactors such as hollow fiber reactors, tapered column reactors, packed bed reactors, fluidized bed reactors etc. PMID:20143935

  12. Beta-2 Microglobulin Tumor Marker

    MedlinePlus

    ... limited. Home Visit Global Sites Search Help? Beta-2 Microglobulin Tumor Marker Share this page: Was this page helpful? Also known as: B2M; B 2 M; β2-Microglobulin; Thymotaxin Formal name: Beta 2 ...

  13. Reduction of beta activity from depleted derbies, ingots and crucibles

    SciTech Connect

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

    1984-09-01

    The reduction of beta radiation on uranium ingot and crucible surfaces was demonstrated in the production casting operation by adding a mixture of slag liner material (MgF/sub 2/) and calcium fluoride to the remelt charge. The beta emitters (/sup 234/Th and /sup 234/Pa) are largely discharged with the fluorides into drums during a remote crucible burnout operation; thereby, reducing operator exposure to beta radiation. A production test showed that very low beta radiation from uranium flat castings can be achieved by using derbies recently prepared by reduction. Plant tests with fluoride addition indicate that pickling of derbies may not be necessary for casting uranium flats from a plasma sprayed (ZrO/sub 2/) crucible. Also, ingots produced with fluoride additions had less pipe as compared to standard production technique. 2 references, 5 tables.

  14. Misleading Betas: An Educational Example

    ERIC Educational Resources Information Center

    Chong, James; Halcoussis, Dennis; Phillips, G. Michael

    2012-01-01

    The dual-beta model is a generalization of the CAPM model. In the dual-beta model, separate beta estimates are provided for up-market and down-market days. This paper uses the historical "Anscombe quartet" results which illustrated how very different datasets can produce the same regression coefficients to motivate a discussion of the…

  15. Occupational exposure and urological cancer.

    PubMed

    Golka, Klaus; Wiese, Andreas; Assennato, Giorgio; Bolt, Hermann M

    2004-02-01

    Occupational exposure is definitely a major cause of cancer. In the field of urology, the urinary bladder is the most important target. A classical cause of bladder cancer is exposure to carcinogenic aromatic amines, especially benzidine and beta-naphthylamine. Such exposures were related to work places in the chemical industry, implying production and processing of classical aromatic amines, and in the rubber industry. Occupational bladder cancer has also been observed in dyers, painters and hairdressers. Even some occupations with much lower exposures to carcinogenic aromatic amines, like coke oven workers or workers in the rubber industry after the ban on beta-naphthylamine, are at risk. In these occupations, exposure to complex mixtures of substances containing combustion products (e.g. polycyclic aromatic hydrocarbons) or nitrosamines is common. Renal cell cancer has been observed as an occupational disease in cases of very high exposure to trichloroethylene having led to narcotic or prenarcotic symptoms. Occupationally related cancers of the prostate or the testes appear currently not relevant.

  16. 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.

  17. Military Exposures

    MedlinePlus

    ... Index Agent Orange Agent Orange Home Facts about Herbicides Veterans' Diseases Birth Defects Benefits Exposure Locations Provider ... for Providers Diagnosis and Treatment of Exposure Health Effects More Provider Resources » return to top Get Email ...

  18. 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

  19. Measurement of $\\beta_s$ at CDF

    SciTech Connect

    Oakes, Louise; /Oxford U.

    2011-02-01

    The latest results for the measurement of the CP violating phase {beta}{sub s} in B{sub s}{sup 0} {yields} J/{Psi}{phi} decays, from 5.2 fb{sup -1} integrated luminosity of CDF data are presented. For the first time, this measurement includes the contribution of B{sub s}{sup 0} {yields} J/{Psi}K{sup +}K{sup -} or B{sub s}{sup 0} {yields} J/{Psi}f{sub 0} events to the signal sample, where the f{sub 0} and non-resonant K{sup +}K{sup -} are S-wave states. Additional improvements to the analysis include more than doubling the signal sample, improved selection and particle ID, and fully calibrated flavour tagging for the full dataset. Additionally, the world's most precise single measurements of the B{sub s}{sup 0} lifetime, {tau}{sub s}, and width difference, {Delta}{Gamma}{sub s} are given.

  20. On the biodegradation of beta-peptides.

    PubMed

    Schreiber, Jürg V; Frackenpohl, Jens; Moser, Frank; Fleischmann, Thomas; Kohler, Hans-Peter E; Seebach, Dieter

    2002-05-01

    A consortium of microorganisms was established that was able to grow with the beta-tripeptide H-beta-HVal-beta-HAla-beta-HLeu-OH, with the beta-dipeptide H-beta-HAla-beta-HLeu-OH, and with the beta-amino acids H-beta-HAla-OH, H-beta-HVal-OH, and H-beta-HLeu-OH as the sole carbon and energy sources. This growth was achieved after several incubation-transfer cycles with the beta-tripeptide as the substrate. During degradation of the beta-tripeptide H-beta-HVal-beta-HAla-beta-HLeu-OH, the temporary formation of a metabolite was observed. The metabolite was identified as the beta-dipeptide H-beta-HAla-beta-HLeu-OH by nuclear magnetic resonance spectroscopy and mass spectrometry. This result indicates that in the course of the degradation of the beta-tripeptide, the N-terminal beta-HVal residue was cleaved off by a not yet known mechanism. During the subsequent degradation of the beta-dipeptide, formation of additional metabolites could not be detected. The growth-yield coefficients Y(x/s) for growth on the beta-di- and beta-tripeptide both had a value of 0.45. When a 1:1 mixture of the beta-tripeptide and the corresponding alpha-tripeptide H-Val-Ala-Leu-OH was added to the enrichment culture, the alpha-peptide was completely utilized in six days and thereafter growth of the culture stopped. This result indicates that even in beta-peptide enrichment cultures, alpha-peptides are the preferred substrates. Our experiments clearly show for the first time that beta-peptides and beta-amino acids are amenable to biodegradation and that a microbial consortium was able to utilize these compounds as sole carbon and energy sources. Furthermore, the preparation of beta-amino acids, of derivatives thereof, and of beta-di- and beta-tripeptides is described.

  1. 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.

  2. 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…

  3. 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. PMID:24184512

  4. 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.

  5. 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

  6. Weaning management of newly received beef calves with or without continuous exposure to a persistently infected bovine viral diarrhea virus pen mate: Effects on health, performance, bovine viral diarrhea virus titers,

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exposure to animals persistently infected (PI) with bovine viral diarrhea virus (BVDV) results in immunomodulation that may have health and growth consequences; however, effects may differ in low-risk, preconditioned (PC) vs. high-risk, auction market (AM) cattle. Our objective was to compare health...

  7. Weaning management of newly received beef calves with or without continuous exposure to a persistently infected bovine viral diarrhea virus pen mate: Effects on rectal temperature, peripheral blood leukocytes and serum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exposure to animals persistently infected (PI) with bovine viral diarrhea virus (BVDV) results in immunomodulation in cohorts. It is hypothesized that the extent of modulation differs for preconditioned (PC) vs. auction market (AM) cattle. Our objective was to compare immune responses of PC or AM ca...

  8. Weaning management of newly received beef calves with or without continuous exposure to a persistently infected bovine viral diarrhea virus pen mate: Effects on rectal temperature and serum proinflammatory cytokine and haptog

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exposure to animals persistently infected (PI) with bovine viral diarrhea virus (BVDV) results in immunomodulation in cohorts. It is hypothesized that the extent of modulation differs for low-risk, preconditioned (PC) vs. high-risk, auction market (AM) beef cattle. Our objective was to compare immun...

  9. 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.

  10. 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...

  11. The cytokine interleukin-1beta reduces the docking and fusion of insulin granules in pancreatic beta-cells, preferentially decreasing the first phase of exocytosis.

    PubMed

    Ohara-Imaizumi, Mica; Cardozo, Alessandra K; Kikuta, Toshiteru; Eizirik, Decio L; Nagamatsu, Shinya

    2004-10-01

    The prediabetic period in type I diabetes mellitus is characterized by the loss of first phase insulin release. This might be due to islet infiltration mediated by mononuclear cells and local release of cytokines, but the mechanisms involved are unknown. To determine the role of cytokines in insulin exocytosis, we have presently utilized total internal reflection fluorescence microscopy (TIRFM) to image and analyze the dynamic motion of single insulin secretory granules near the plasma membrane in live beta-cells exposed for 24 h to interleukin (IL)-1beta or interferon (IFN)-gamma. Immunohistochemistry observed via TIRFM showed that the number of docked insulin granules was decreased by 60% in beta-cells treated with IL-1beta, while it was not affected by exposure to IFN-gamma. This effect of IL-1beta was paralleled by a 50% reduction in the mRNA and the number of clusters of SNAP-25 in the plasma membrane. TIRF images of single insulin granule motion during a 15-min stimulation by 22 mm glucose in IL-1beta-treated beta-cells showed a marked reduction in the fusion events from previously docked granules during the first phase insulin release. Fusion from newcomers, however, was well preserved during the second phase of insulin release of IL-1beta-treated beta-cells. The present observations indicate that IL-1beta, but not IFN-gamma, has a preferential inhibitory effect on the first phase of glucose-induced insulin release, mostly via an action on previously docked granules. This suggests that beta-cell exposure to immune mediators during the course of insulitis might be responsible for the loss of first phase insulin release.

  12. Solergy (Beta Version 1)

    2009-03-30

    SOLERGY simulates the operation and power output of a user-defined solar central receiver power plant for a time period of up to one year. SOLERGY utilizes recorded or simulated weather data and plant component performance models to calculate the power flowing through each part of the solar plant. A plant control subroutine monitors these powers and determines when to operate the various plant subsystems. The original version of the code was released in May 1987,more » within SAND86-8060 and was widely distributed. The Beta Version 1 to be released in 2009, includes some relatively small modifications to the original code.« less

  13. 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.

  14. Clearance of beta-2-microglobulin and middle molecules in haemodiafiltration.

    PubMed

    Tattersall, James

    2007-01-01

    Middle molecules, consisting mostly of peptides and small proteins with molecular weight the range of 500-60,000 Da, accumulate in renal failure and contribute to the uraemic toxic state. Beta2-microglobulin (beta2-MG) with a molecular weight of 11,000 is considered representative of these middle molecules. These solutes are not well cleared by low-flux dialysis. High-flux dialysis will clear middle molecules, partly by internal filtration. This convective component of high-flux dialysis can be enhanced in a predictable way by haemodiafiltration (HDF). The convective and diffusive clearance rates of any middle molecule across any haemodiafilter can be predicted from known or measurable factors such as its sieving coefficient, bound fraction and molecular weight. The removal of middle molecules is also influenced by factors within the patient. Beta2-MG is distributed within the extracellular fluid. During HDF, beta2-MG must transfer into the intravascular compartment across the capillary walls. This transcapillary transfer at a rate of approximately 100 ml/min slows beta2-MG removal from the body. Continuing transfer after the end of a treatment session results in a significant rebound of beta2-MG levels. This intercompartment transfer and its effect on beta2-MG clearance and concentration can be predicted by a 2-compartment model. By extrapolation, the behaviour of other middle molecules can be predicted. The 2-compartment model, which takes non-dialytic beta2-MG clearance at a rate of 3 ml/min and beta2-MG generation at a rate of 0.1 mg/min into account, can predict the effect of any HDF schedule on beta2-MG levels. Low-flux dialysis results in a beta2-MG level of around 40 mg/l. Three times weekly, 4-hour HDF can reduce beta2-MG levels to around 20 mg/l. Long (nocturnal) HDF can reduce beta2-MG levels to around 10 mg/l, compared to physiological levels of less than 5 mg/l.

  15. Fluid shear stress induces endothelial transforming growth factor beta-1 transcription and production. Modulation by potassium channel blockade.

    PubMed Central

    Ohno, M; Cooke, J P; Dzau, V J; Gibbons, G H

    1995-01-01

    The endothelium has the capacity to modulate vascular structure in response to hemodynamic stimuli. We tested the hypothesis that exposure of the endothelium to increased laminar shear stress induces the expression of TGF beta 1 via a signal transduction pathway modulated by K+ channel currents. Although TGF beta 1 is normally secreted in a latent, inactive form, exposure of cultured endothelial cells to steady laminar shear stress (20 dynes/cm2) induced increased generation of biologically active TGF beta 1. This increase in active TGF beta 1 was associated with a sustained increase in TGF beta 1 mRNA expression within 2 h of stimulation. TGF beta 1 mRNA levels increased in direct proportion to the intensity of the shear stress within the physiologic range. The effect of shear stress on TGF beta 1 mRNA expression was regulated at the transcriptional level as defined by nuclear run-off studies and transient transfection of a TGF beta 1 promoter-reporter gene construct. Blockade of endothelial K+ channels with tetraethylammonium significantly inhibited: activation of TGF beta 1 gene transcription; increase in steady state mRNA levels; and generation of active TGF beta 1 in response to shear stress. These data suggest that endothelial K+ channels and autocrine-paracrine TGF beta 1 may be involved in the mechanotransduction mechanisms mediating flow-induced vascular remodeling. Images PMID:7883983

  16. Scintillator based beta batteries

    NASA Astrophysics Data System (ADS)

    Rensing, Noa M.; Tiernan, Timothy C.; Shirwadkar, Urmila; O'Dougherty, Patrick; Freed, Sara; Hawrami, Rastgo; Squillante, Michael R.

    2013-05-01

    Some long-term, remote applications do not have access to conventional harvestable energy in the form of solar radiation (or other ambient light), wind, environmental vibration, or wave motion. Radiation Monitoring Devices, Inc. (RMD) is carrying out research to address the most challenging applications that need power for many months or years and which have undependable or no access to environmental energy. Radioisotopes are an attractive candidate for this energy source, as they can offer a very high energy density combined with a long lifetime. Both large scale nuclear power plants and radiothermal generators are based on converting nuclear energy to heat, but do not scale well to small sizes. Furthermore, thermo-mechanical power plants depend on moving parts, and RTG's suffer from low efficiency. To address the need for compact nuclear power devices, RMD is developing a novel beta battery, in which the beta emissions from a radioisotope are converted to visible light in a scintillator and then the visible light is converted to electrical power in a photodiode. By incorporating 90Sr into the scintillator SrI2 and coupling the material to a wavelength-matched solar cell, we will create a scalable, compact power source capable of supplying milliwatts to several watts of power over a period of up to 30 years. We will present the latest results of radiation damage studies and materials processing development efforts, and discuss how these factors interact to set the operating life and energy density of the device.

  17. High glucose induces suppression of insulin signalling and apoptosis via upregulation of endogenous IL-1beta and suppressor of cytokine signalling-1 in mouse pancreatic beta cells.

    PubMed

    Venieratos, Panagiotis D; Drossopoulou, Garyfalia I; Kapodistria, Katerina D; Tsilibary, Effie C; Kitsiou, Paraskevi V

    2010-05-01

    Chronic hyperglycemia and inflammatory cytokines disrupt and/or attenuate signal transduction pathways that promote normal beta-cell survival, leading to the destruction of endocrine pancreas in type 2 diabetes. There is convincing evidence that autocrine insulin signalling exerts protective anti-apoptotic effects on beta cells. Suppressors of cytokine signalling (SOCS) were induced by several cytokines and inhibit insulin-initiated signal transduction. The aim of this study was to investigate whether high glucose can influence endogenous interleukin-1beta (IL-1beta) and SOCS expression thus affecting insulin signalling and survival in insulin-producing mouse pancreatic beta cells (betaTC-6). Results showed that prolonged exposure of betaTC-6 cells to increased glucose concentrations resulted in significant inhibition of insulin-induced tyrosine phosphorylation of the insulin receptor (IR), and insulin receptor substrate-2 (IRS-2) as well as PI3-kinase activation. These changes were accompanied by impaired activation of the anti-apoptotic signalling protein Akt and annulment of Akt-mediated suppression of the Forkhead family of transcription factors (FoxO) activation. Glucose-induced attenuation of IRS-2/Akt-mediated signalling was associated with increased IL-1beta expression. Enhanced endogenous IL-1beta specifically induced mRNA and protein expression of SOCS-1 in betaTC-6 cells. Inhibition of SOCS-1 expression by SOCS-1-specific small interfering RNA restored IRS-2/PI3K-mediated Akt phosphorylation suppressed by high glucose. The upregulation of endogenous cytokine signalling and FoxO activation were accompanied by enhanced caspase-3 activation and increased susceptibility of cells to apoptosis. These results indicated that glucose-induced endogenous IL-1beta expression increased betaTC-6 cells apoptosis by inhibiting, at least in part, IRS-2/Akt-mediated signalling through SOCS-1 upregulation.

  18. Organophosphate pesticide exposure and neurodegeneration.

    PubMed

    Sánchez-Santed, Fernando; Colomina, Maria Teresa; Herrero Hernández, Elena

    2016-01-01

    Organophosphate pesticides (OPs) are used extensively throughout the world. The main sources of contamination for humans are dietary ingestion and occupational exposures. The major concerns related to OP exposure are delayed effects following high level exposures as well as the impact of low level exposures during the lifespan which are suggested to be a risk factor for nervous system chronic diseases. Both high and low level exposures may have a particularly high impact in population subgroups such as aged or genetically vulnerable populations. Apart from the principle action of OPs which involves inhibition of the acetylcholinesterase (AChE) enzyme, several molecular targets, such as hormones; neurotransmitters; neurotrophic factors; enzymes related to the metabolism of beta amyloid protein as well as inflammatory changes have been identified for OP compounds. Here we review the main neurological and/or cognitive deficits described and the experimental and epidemiological relationships found between pesticide exposure and Alzheimer's, Parkinson's, and Amyotrophic Lateral Sclerosis (ALS) diseases. This report also focuses on possible individual differences making groups resilient or vulnerable to these toxicants. A critical discussion of the evidence obtained from experimental models and possible sources of bias in epidemiological studies is included. In particular this review aims to discuss common targets and pathways identified which may underlie the functional deficits associated with both pesticide exposure and neurodegeneration. PMID:26687930

  19. Thyroid storm during beta blockade.

    PubMed

    Strube, P J

    1984-04-01

    A thyrotoxic patient who had received beta-adrenoceptor blockers pre-operatively suffered an episode of severe heart failure immediately following thyroidectomy and required artificial ventilation of the lungs for six hours. The possible causes are discussed and the likelihood of thyroid storm unmitigated by beta adrenergic blockade suggested.

  20. 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,…

  1. [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…

  2. Effect of acute ethanol on beta-endorphin secretion from rat fetal hypothalamic neurons in primary cultures

    SciTech Connect

    Sarkar, D.K.; Minami, S. )

    1990-01-01

    To characterize the effect of ethanol on the hypothalamic {beta}-endorphin-containing neurons, rat fetal hypothalamic neurons were maintained in primary culture, and the secretion of {beta}-endorphin ({beta}-EP) was determined after ethanol challenges. Constant exposure to ethanol at doses of 6-50 mM produced a dose-dependent increase in basal secretion of {beta}-EP from these cultured cells. These doses of ethanol did not produce any significant effect on cell viability, DNA or protein content. The stimulated secretion of {beta}-EP following constant ethanol exposure is short-lasting. However, intermittent ethanol exposures maintained the ethanol stimulatory action on {beta}-EP secretion for a longer time. The magnitude of the {beta}-EP response to 50 mM ethanol is similar to that of the {beta}-EP response to 56 mM of potassium. Ethanol-stimulated {beta}-EP secretion required extracellular calcium and was blocked by a calcium channel blocker; a sodium channel blocker did not affect ethanol-stimulated secretion. These results suggest that the neuron culture system is a useful model for studying the cellular mechanisms involved in the ethanol-regulated hypothalamic opioid secretion.

  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 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...

  5. 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...

  6. 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...

  7. 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...

  8. Particle exposures and infections.

    PubMed

    Ghio, A J

    2014-06-01

    Particle exposures increase the risk for human infections. Particles can deposit in the nose, pharynx, larynx, trachea, bronchi, and distal lung and, accordingly, the respiratory tract is the system most frequently infected after such exposure; however, meningitis also occurs. Cigarette smoking, burning of biomass, dust storms, mining, agricultural work, environmental tobacco smoke (ETS), wood stoves, traffic-related emissions, gas stoves, and ambient air pollution are all particle-related exposures associated with an increased risk for respiratory infections. In addition, cigarette smoking, burning of biomass, dust storms, mining, and ETS can result in an elevated risk for tuberculosis, atypical mycobacterial infections, and meningitis. One of the mechanisms for particle-related infections includes an accumulation of iron by surface functional groups of particulate matter (PM). Since elevations in metal availability are common to every particle exposure, all PM potentially contributes to these infections. Therefore, exposures to wood stove emissions, diesel exhaust, and air pollution particles are predicted to increase the incidence and prevalence of tuberculosis, atypical mycobacterial infections, and meningitis, albeit these elevations are likely to be small and detectable only in large population studies. Since iron accumulation correlates with the presence of surface functional groups and dependent metal coordination by the PM, the risk for infection continues as long as the particle is retained. Subsequently, it is expected that the cessation of exposure will diminish, but not totally reverse, the elevated risk for infection.

  9. 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.

  10. Pharmacogenetics of beta2 adrenergic receptor agonists in asthma management.

    PubMed

    Ortega, V E

    2014-07-01

    Beta2 (β2) adrenergic receptor agonists (beta agonists) are a commonly prescribed treatment for asthma despite the small increase in risk for life-threatening adverse responses associated with long-acting beta agonist (LABA). The concern for life-threatening adverse effects associated with LABA and the inter-individual variability of therapeutic responsiveness to LABA-containing combination therapies provide the rationale for pharmacogenetic studies of beta agonists. These studies primarily evaluated genes within the β2-adrenergic receptor and related pathways; however, recent genome-wide studies have identified novel loci for beta agonist response. Recent studies have identified a role for rare genetic variants in determining beta agonist response and, potentially, the risk for rare, adverse responses to LABA. Before genomics research can be applied to the development of genetic profiles for personalized medicine, it will be necessary to continue adapting to the analysis of an increasing volume of genetic data in larger cohorts with a combination of analytical methods and in vitro studies.

  11. Tolerance with beta 2-adrenoceptor agonists: time for reappraisal.

    PubMed Central

    Grove, A; Lipworth, B J

    1995-01-01

    1. In spite of the widespread use of beta 2-adrenoceptor agonists in the treatment of asthma controversy continues regarding their possible role in increasing asthma mortality and morbidity. There is however no evidence available to suggest that tolerance to the bronchodilator or anti-bronchoconstrictor effects of these drugs is responsible for the deleterious effects reported with the regular use of bronchodilators. 2. There is no conclusive evidence to suggest that tolerance develops to the bronchodilator effects of short-acting beta 2-adrenoceptor agonists. Tolerance does however appear to develop to the anti-bronchoconstrictor effects of these drugs. 3. With regard to the long-acting beta 2-adrenoceptor agonists, there is evidence to suggest that tolerance develops both to their anti-bronchoconstrictor, and bronchodilator effects. Tolerance was however demonstrated in the presence of improved symptom control, therefore the clinical relevance of this phenomenon is uncertain. 4. Systemic corticosteroids can modulate lymphocyte beta 2-adrenoceptor function both preventing, and reversing tolerance. The situation regarding the effects of systemic or inhaled corticosteroids on modulating bronchodilator responses in asthmatics is less clear. There is some evidence to suggest that inhaled corticosteroids are unable to prevent bronchodilator or systemic tolerance to long-acting beta 2-adrenoceptor agonists. 5. On the basis of the current evidence, the British Thoracic Society guidelines for the management of asthma appear appropriate with regard to their recommendations for the use of long-acting beta 2-adrenoceptor agonists. PMID:7742147

  12. [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

  13. 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.

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

    PubMed

    Scarpace, P J; Baresi, L A; Morley, J E

    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 [125I]iodocyanopindolol. Binding sites had the characteristics of mixed beta 1- and beta 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 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. In contrast, food deprivation did not alter BAT beta-adrenergic receptor density. Forskolin-stimulated adenylate cyclase activity increased in BAT after sucrose feeding or cold exposure but not after food deprivation. The ratio of isoproterenol-stimulated to forskolin-stimulated adenylate cyclase activity decreased in the sucrose-fed and cold-exposed rats but not in the food-deprived rats. 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. PMID:2827501

  15. Structural and physiological studies on the storage beta-polyglucan of haptophyte Pleurochrysis haptonemofera.

    PubMed

    Hirokawa, Yasutaka; Fujiwara, Shoko; Suzuki, Motoya; Akiyama, Tomoka; Sakamoto, Minako; Kobayashi, Saori; Tsuzuki, Mikio

    2008-02-01

    The storage beta-polyglucan and catabolic enzyme activities of the haptophyte Pleurochrysis haptonemofera were characterized. The storage beta-polyglucan was prepared by the dimethylsulfoxide-extraction method. (13)C- and (1)H-NMR spectroscopy revealed that the polyglucan consists of beta-(1-->3)- and beta-(1-->6)-linked glucose polymers, with a beta-(1-->6)- to beta-(1-->3)-linkage ratio of 1.5. Gel permeation chromatography showed that the molecular weight of the polyglucan is 1.1-8.4 x 10(4) Da, with a peak at 3.4 x 10(4) Da. The degree of polymerization, which was estimated from the amounts of total carbohydrate and reduced ends, was 203, corresponding to 3.3 x 10(4) Da. A method for measurement of the beta-polyglucan in a small amount of liquid culture involving a mixture of beta-glucanases, Westase, was established. The beta-polyglucan was localized in the soluble fraction of cells. The amount of beta-polyglucan per cell increased at the stationary phase under continuous illumination and decreased in the dark, like those of storage alpha-polyglucans, starch of green algae and glycogen of cyanobacteria. The activities of beta-1,3- and beta-1,6-glucanases involved in the degradation of the storage beta-polyglucan were assayed in vitro, both being optimal at pH 5.0. The beta-1,3-glucanase activity, which was detected on active staining after native polyacrylamide gel electrophoresis, was partially purified by ammonium sulfate precipitation and anion exchange chromatography.

  16. 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.

  17. 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. PMID:25131163

  18. Expression of adiponectin receptors in pancreatic beta cells.

    PubMed

    Kharroubi, Ilham; Rasschaert, Joanne; Eizirik, Décio L; Cnop, Miriam

    2003-12-26

    Pancreatic beta cell dysfunction is an early and crucial pathogenic factor in the development of type 2 diabetes. Free fatty acids (FFA) and adipokines released from adipose tissues lead to both the development of insulin resistance and beta cell dysfunction. Adiponectin is a novel adipokine with antidiabetic properties. Its circulating concentrations are reduced in subjects with increased visceral adiposity, insulin resistance, or type 2 diabetes. Very recently, the cloning of two adiponectin receptors AdipoR1 and AdipoR2 was reported. AdipoR1 is abundantly expressed in muscle, while AdipoR2 is predominantly expressed in liver. Here we report the marked expression of mRNAs for the adiponectin receptors AdipoR1 and AdipoR2 in human and rat pancreatic beta cells, at levels similar to liver and greater than muscle. Adiponectin receptor expression is increased by beta cell exposure to the unsaturated FFA oleate, and treatment of insulin-producing cells with globular adiponectin induces lipoprotein lipase expression. Regulated adiponectin receptor expression on pancreatic beta cells might be a novel mechanism modulating the effects of circulating adiponectin. PMID:14651988

  19. Amyloid-beta Alzheimer targets - protein processing, lipid rafts, and amyloid-beta pores.

    PubMed

    Arbor, Sage C; LaFontaine, Mike; Cumbay, Medhane

    2016-03-01

    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

  20. 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

  1. Metallothionein and occupational exposure to cadmium.

    PubMed Central

    Falck, F Y; Fine, L J; Smith, R G; Garvey, J; Schork, A; England, B; McClatchey, K D; Linton, J

    1983-01-01

    The relationship between metallothionein (MT), chronic exposure to cadmium (Cd), and renal function was investigated in 53 men who were occupationally exposed to Cd. The aim was to determine if MT is a potential biological monitor for chronic exposure to Cd which would be useful for preventing Cd nephropathy. In this study MT excretion, serum MT, and serum creatinine concentrations were significantly higher in subjects with abnormal renal function who had been exposed to Cd. MT excretion was also linearly related on an individual basis to protein excretion, beta 2-microglobulin (beta 2-M) excretion, and cumulative time weighted exposure (dose). MT excretion was also a better predictor of dose than either beta 2-M excretion or Cd excretion. The findings suggest that MT is a potential biological monitor for chronic Cd exposure that would be useful for preventing Cd-induced nephropathy. Further studies of non-specific nephropathies and MT are needed to determine if MT is a specific indicator of proximal tubule function secondary to chronic exposure to Cd. PMID:6347245

  2. Microwave induced beta-cyclodextrin modification of chitosan for lead sorption.

    PubMed

    Sharma, A K; Mishra, A K

    2010-10-01

    Microwave induced copolymerization of beta-cyclodextrin (beta-CD) and chitosan (Ch) resulted in copolymer Ch-g-beta-CD synthesized without any radical initiator or catalyst. Copolymer samples of different performances in terms of Pb(II) binding were synthesized by changing beta-CD concentration at fixed microwave power and exposure time. To understand the advantage of using microwaves in the adsorbent synthesis, the copolymer synthesized using a K(2)S(2)O(8)/ascorbic acid redox pair at identical beta-CD and Chitosan concentrations (% G 103) was also evaluated as Pb(II) sorbent, and the results obtained were compared with that of microwave synthesized copolymer. A representative sample of microwave synthesized adsorbent was characterized using FTIR spectroscopy, X-ray diffraction, TGA, SEM analysis and using this sample adsorption of lead (II) was studied as a function of pH, initial Pb(II) concentration. The adsorption data followed both Freundlich and Langmuir isotherms. On the basis of the Langmuir model, Q(max) was calculated to be 434.78mg/g for microwave synthesized copolymer (Ch-g-beta-CD) in comparison to 294.11mg/g for conventionally synthesized copolymer (Ch-g-beta-CD). In order to investigate dynamic behaviour of Ch-g-beta-CD as an adsorbent, the kinetic data were modelled using pseudo-second-order and second-order. The regeneration experiments revealed that the Ch-g-beta-CD can be successfully reused for seven cycles.

  3. A 2D DNA lattice as an ultrasensitive detector for beta radiations.

    PubMed

    Dugasani, Sreekantha Reddy; Kim, Jang Ah; Kim, Byeonghoon; Joshirao, Pranav; Gnapareddy, Bramaramba; Vyas, Chirag; Kim, Taesung; Park, Sung Ha; Manchanda, Vijay

    2014-02-26

    There is growing demand for the development of efficient ultrasensitive radiation detectors to monitor the doses administered to individuals during therapeutic nuclear medicine which is often based on radiopharmaceuticals, especially those involving beta emitters. Recently biological materials are used in sensors in the nanobio disciplines due to their abilities to detect specific target materials or sites. Artificially designed two-dimensional (2D) DNA lattices grown on a substrate were analyzed after exposure to pure beta emitters, (90)Sr-(90)Y. We studied the Raman spectra and reflected intensities of DNA lattices at various distances from the source with different exposure times. Although beta particles have very low linear energy transfer values, the significant physical and chemical changes observed throughout the extremely thin, ∼0.6 nm, DNA lattices suggested the feasibility of using them to develop ultrasensitive detectors of beta radiations.

  4. 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.

  5. 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.

  6. Variants of beta-glucosidase

    SciTech Connect

    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.

  7. 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.

  8. Effects of transforming growth factor beta and epidermal growth factor on cell proliferation and the formation of bone nodules in isolated fetal rat calvaria cells.

    PubMed

    Antosz, M E; Bellows, C G; Aubin, J E

    1989-08-01

    When cells enzymatically isolated from fetal rat calvaria (RC cells) are cultured in vitro in the presence of ascorbic acid and Na beta-glycerophosphate, discrete three-dimensional nodules form with the histologic, immunohistochemical, and ultrastructural characteristics of bone (Bellows et al; Calcified Tissue International 38:143-154, 1986; Bhargava et al., Bone, 9:155-163, 1988). Quantitation of the number of bone nodules that forms provides a colony assay for osteoprogenitor cells present in the RC population (Bellows and Aubin, Develop. Biol., 133:8-13, 1989). Continuous culture with either epidermal growth factor (EGF) or transforming growth factor beta (TGF-beta) results in dose-dependent inhibition of bone nodule formation; however, the former causes increased proliferation and saturation density, while the latter reduces both parameters. Addition of EGF (48 h pulse, 2-200 ng/ml) to RC cells at day 1 after plating results in increased proliferation and population saturation density and an increased number of bone nodules formed. Similar pulses at confluence and in postconfluent multilayered cultures when nodules first begin forming (approx. day 11) inhibited bone nodule formation and resulted in a smaller stimulation of cell proliferation. Forty-eight hour pulses of TGF-beta (0.01-1 ng/ml) reduced bone nodule formation and proliferation at all times examined, with pulses on day 1 causing maximum inhibition. The effects of pulses with TGF-beta and EGF on inhibition of nodule formation are independent of the presence of serum in the culture medium during the pulse. The data suggest that whereas EGF can either stimulate or inhibit the formation of bone nodules depending upon the time and duration of exposure, TGF-B inhibits bone nodule formation under all conditions tested. Moreover, these effects on osteoprogenitor cell differentiation do not always correlate with the effects of the growth factors on RC cell proliferation. PMID:2787326

  9. Continuous cadmium exposure from weaning to maturity induces downregulation of ovarian follicle development-related SCF/c-kit gene expression and the corresponding changes of DNA methylation/microRNA pattern.

    PubMed

    Weng, Shaozheng; Wang, Wenxiang; Li, Yuchen; Li, Hong; Lu, Xiaoli; Xiao, Shihua; Wu, Tingting; Xie, Meimei; Zhang, Wenchang

    2014-03-21

    Cadmium (Cd) impairs ovary structure and function in mature animals. However, the influence of Cd on follicle development from weaning to maturity is obscure. In the current study, 21-day-old Wistar rats were administered Cd chloride at doses of 0, 0.5, 2.0 and 8.0 mg/kg body weight once a day for eight weeks by gavage. After administration, a significant decrease in ovarian wet weight, ovarian/body weight ratios, and primordial follicles, in addition to an increase in atresic follicles, were observed. Transmission electron microscopy and TUNEL assay confirmed the increase of follicle apoptosis as Cd concentration increased. Real-time quantitative PCR and Western blotting showed a significantly decreased expression of follicle development-related factors, stem cell factor (SCF) and c-kit. Bisulfite sequencing suggested that the total methylation percentages of SCF/c-kit promoter region were not obvious change after Cd exposure. Real-time quantitative PCR revealed a significantly increased expression of miR-193, miR-221 and miR-222, which regulate c-kit, in the 2.0 mg/kg and 8.0 mg/kg treatment groups. Overall, this study proved that Cd administration from weaning to maturity could damage follicle development, suggesting that SCF/c-kit might play an important role in this effect. In addition, microRNAs might play a role in c-kit protein downregulation.

  10. Endopeptidase-Mediated Beta Lactam Tolerance

    PubMed Central

    Dörr, Tobias; Davis, Brigid M.; Waldor, Matthew K.

    2015-01-01

    In many bacteria, inhibition of cell wall synthesis leads to cell death and lysis. The pathways and enzymes that mediate cell lysis after exposure to cell wall-acting antibiotics (e.g. beta lactams) are incompletely understood, but the activities of enzymes that degrade the cell wall (‘autolysins’) are thought to be critical. Here, we report that Vibrio cholerae, the cholera pathogen, is tolerant to antibiotics targeting cell wall synthesis. In response to a wide variety of cell wall- acting antibiotics, this pathogen loses its rod shape, indicative of cell wall degradation, and becomes spherical. Genetic analyses revealed that paradoxically, V. cholerae survival via sphere formation required the activity of D,D endopeptidases, enzymes that cleave the cell wall. Other autolysins proved dispensable for this process. Our findings suggest the enzymes that mediate cell wall degradation are critical for determining bacterial cell fate - sphere formation vs. lysis – after treatment with antibiotics that target cell wall synthesis. PMID:25884840

  11. 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.

  12. [Relationship to Carcinogenesis of Repetitive Low-Dose Radiation Exposure].

    PubMed

    Ootsuyama, Akira

    2016-06-01

    We studied the carcinogenic effects caused by repetitive irradiation at a low dose, which has received attention in recent years, and examined the experimental methods used to evaluate radiation-induced carcinogenesis. For this experiment, we selected a mouse with as few autochthonous cancers as possible. Skin cancer was selected as the target for analysis, because it is a rare cancer in mice. Beta-rays were selected as the radiation source. The advantage of using beta-rays is weaker penetration power into tissues, thus protecting organs, such as the digestive and hematogenous organs. The benefit of our experimental method is that only skin cancer requires monitoring, and it is possible to perform long-term experiments. The back skin of mice was exposed repetitively to beta-rays three times a week until the occurrence of cancer or death, and the dose per exposure ranged from 0.5 to 11.8 Gy. With the high-dose range (2.5-11.8 Gy), the latency period and carcinogenic rate were almost the same in each experimental group. When the dose was reduced to 1-1.5 Gy, the latency period increased, but the carcinogenic rate remained. When the dose was further reduced to 0.5 Gy, skin cancer never happened, even though we continued irradiation until death of the last mouse in this group. The lifespan of 0.5 Gy group mice was the same as that of the controls. We showed that the 0.5 Gy dose did not cause cancer, even in mice exposed repetitively throughout their life span, and thus refer to 0.5 Gy as the threshold-like dose. PMID:27302731

  13. [Relationship to Carcinogenesis of Repetitive Low-Dose Radiation Exposure].

    PubMed

    Ootsuyama, Akira

    2016-06-01

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

  14. 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.

  15. 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.

  16. 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 ...

  17. 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 ...

  18. 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 ...

  19. 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)

  20. Role of IL-1 beta and prostaglandins in beta 2-microglobulin-induced bone mineral dissolution.

    PubMed

    Moe, S M; Hack, B K; Cummings, S A; Sprague, S M

    1995-02-01

    beta 2-microglobulin (beta 2m) induces an osteoclast-mediated net calcium efflux from neonatal mouse calvariae which occurs only after 48 hours of incubation, suggesting that beta 2m acts via other growth factors. To further test this hypothesis, calvariae were incubated with and without beta 2m in the presence of the prostaglandin inhibitor indomethacin, anti-interleukin-1 beta antibody (anti-IL-1 beta), or interleukin-1 beta receptor antagonist (IL-1 beta RA). The addition of beta 2m to the culture medium stimulated, whereas indomethacin inhibited basal calcium efflux following 48 hours. However, the difference (delta) between the calcium efflux induced in calvariae incubated with and without beta 2m in basal medium and that in calvariae incubated with and without beta 2m in indomethacin supplemented medium was similar, suggesting a prostaglandin independent mechanism. There was a time dependent increase in PGE2 in basal medium which was unaffected by beta 2m. In contrast, pre-incubating calvariae with either anti-IL-1 beta or IL-1 beta RA did not alter basal calcium efflux but completely blocked the beta 2m induced calcium efflux. Anti-IL-1 beta had no effect on the basal release of beta-glucuronidase but partially blocked the beta 2m induced release of beta-glucuronidase. Thus, the beta 2m-induced calcium efflux observed in neonatal mouse calvariae is dependent on interleukin-1 beta but not prostaglandins.

  1. Medium Beta Superconducting Accelerating Structures

    SciTech Connect

    Jean Delayen

    2001-09-01

    While, originally, the development of superconducting structures was cleanly divided between low-beta resonators for heavy ions and beta=1 resonators for electrons, recent interest in protons accelerators (high and low current, pulsed and cw) has necessitated the development of structures that bridge the gap between the two. These activities have resulted both in new geometries and in the adaptation of well-known geometries optimized to this intermediate velocity range. Their characteristics and properties are reviewed.

  2. From Algol to Beta Lyrae

    NASA Astrophysics Data System (ADS)

    Plavec, M. J.

    Recognizing that the structure and evolutionary status of Beta Lyrae are much more complicated than for Algol, some of the problems of revealing its structure are discussed. The best model available at present considers Beta Lyrae as an Algol-type semi-detached system in a phase of fairly rapid mass transfer, i.e., younger than typical Algols. It is concluded that Beta Lyrae is not so special as it appears; some characteristics that are so puzzling in Beta Lyrae already appear in such classical Algols as U Cephei and RW Tauri. The mass-accreting components in these systems are surrounded by a hot, turbulent layer which probably expands and which is the seat of emission lines of fairly high ionization discovered in the far ultraviolet. In Beta Lyrae and the so-called W Serpenis stars, the circumstellar hot turbulent shell is much more extensive and probably also denser - a kind of 'superchromosphere'. In Beta Lyrae, a thick disk probably completely surrounds and hides the accreting star proper.

  3. Beta-decay rates

    NASA Astrophysics Data System (ADS)

    Borzov, I. N.

    2006-10-01

    Major astrophysical applications involve a huge number of exotic nuclei. Their beta-decay properties play a crucial role in stellar explosive events. An important effort has been developed in last decades to measure the masses and β-decay properties of very neutron-rich nuclei at radioactive nuclear beam facilities. However, most of them cannot be synthesized in terrestrial laboratories and only theoretical predictions can fill the gap. We will concentrate mainly on the β-decay rates needed for stellar r-process modeling and for performing the RNB experiments. An overview of the microscopic approaches to the β-decay strength function is given. The continuum QRPA approach based on the self-consistent ground state description in the framework of the density functional theory is outlined. For the first time, a systematic study of the total β-decay half-lives and delayed neutron emission probabilities takes into account the Gamow Teller and first-forbidden transitions. Due to the shell configuration effects, the first-forbidden decays have a strong impact on the β-decay characteristics of the r-process relevant nuclei at Z≈28, N>50; Z⩾50, N>82 and Z=60 70, N≈126. Suppression of the delayed neutron emission probability is found in nuclei with the neutron excess bigger than one major shell. The effect originates from the high-energy first-forbidden transitions to the states outside the (Q-B)-window in the daughter nuclei. The performance of existing global models for the nuclides near the r-process paths is critically analyzed and confronted with the recent RIB experiments in the regions of 78Ni, 132Sn and “east” of 208Pb.

  4. 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.

  5. Neutrinoless double beta decay and neutrino masses

    SciTech Connect

    Duerr, Michael

    2012-07-27

    Neutrinoless double beta decay (0{nu}{beta}{beta}) is a promising test for lepton number violating physics beyond the standard model (SM) of particle physics. There is a deep connection between this decay and the phenomenon of neutrino masses. In particular, we will discuss the relation between 0{nu}{beta}{beta} and Majorana neutrino masses provided by the so-called Schechter-Valle theorem in a quantitative way. Furthermore, we will present an experimental cross check to discriminate 0{nu}{beta}{beta} from unknown nuclear background using only one isotope, i.e., within one experiment.

  6. Effects of beta-naphthoflavone on hepatic biotransformation and glutathione biosynthesis in largemouth bass (Micropterus salmoides).

    PubMed

    Hughes, Erin M; Gallagher, Evan P

    2004-01-01

    We are investigating the effects of in vivo exposure of prototypical enzyme inducing agents on hepatic biotransformation enzyme expression in largemouth bass (Micropterus salmoides), a predatory game fish found throughout the United States and Canada. The current study targeted those genes involved in biotransformation and oxidative stress that may be regulated by Ah-receptor-dependent pathways. Exposure of bass to beta-naphthoflavone (beta-NF, 66 mg/kg, i.p.) elicited a 7-9-fold increase in hepatic microsomal cytochrome P4501A-dependent ethoxyresorufin O-deethylase (EROD) activities, but did not affect cytosolic GST catalytic activities toward 1-chloro-2,4-dinitrobenzene (CDNB) or 5-androstene-3,17-dione (ADI). Glutathione S-transferase A (GST-A) mRNA expression exhibited a transient, but non-significant increase following exposure to beta-NF, and generally tracked the minimal changes observed in GST-CDNB activities. Expression of the mRNA encoding glutamate-cysteine ligase catalytic subunit (GCLC), the rate-limiting enzyme in glutathione (GSH) biosynthesis, was increased 1.7-fold by beta-NF. Changes in GCLC mRNA expression were paralleled by increases in intracellular GSH. In summary, largemouth bass hepatic CYP1A-dependent and GSH biosynthetic pathways, and to a lesser extent GST, are responsive to exposure to beta-NF.

  7. High beta plasmas in the PBX tokamak

    SciTech Connect

    Bol, K.; Buchenauer, D.; Chance, M.; Couture, P.; Fishman, H.; Fonck, R.; Gammel, G.; Grek, B.; Ida, K.; Itami, K.

    1986-04-01

    Bean-shaped configurations favorable for high ..beta.. discharges have been investigated in the Princeton Beta Experiment (PBX) tokamak. Strongly indented bean-shaped plasmas have been successfully formed, and beta values of over 5% have been obtained with 5 MW of injected neutral beam power. These high beta discharges still lie in the first stability regime for ballooning modes, and MHD stability analysis implicates the external kink as responsible for the present ..beta.. limit.

  8. 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 ...

  9. Hypotonic exposures.

    PubMed

    Flynn, W J; Hill, R M

    1984-03-01

    Even without a contact lens, the cornea can suffer adverse physiological changes from hypotonic exposure, as well as the associated subjective phenomena (e.g., halo and rainbows). The contact lens adds a dimension to this problem that should be viewed against a background of normal (non-wearing) susceptibilities. PMID:6715776

  10. Ontogeny of the circadian system during embryogenesis in rainbow trout (Oncorhynchus mykyss) and the effect of prolonged exposure to continuous illumination on daily rhythms of per1, clock, and aanat2 expression.

    PubMed

    Davie, Andrew; Sanchez, Jose A; Vera, Luisa M; Sanchez-Vazquez, J; Migaud, H

    2011-04-01

    It is widely held that the development of the circadian system during embryogenesis is important for future survival of an organism. Work in teleosts has been, to date, limited to zebrafish, which provides little insight into the diversity of this system within such a large vertebrate class. In this study, the authors analyzed the diel expression of per1, clock, and aanat2 in unfertilized rainbow trout oocytes and embryos maintained under either a 12:12-h light:dark (LD) cycle or continuous illumination (LL) from fertilization. 24-h profiles in expression were measured at fertilization as well as 8, 21 42, and 57 days postfertilization (dpf). Both per1 and clock were expressed in unfertilized oocytes and all embryonic stages, whereas aanat2 expression was only measureable from 8 dpf. A reduction in both per1 and clock mean expression levels between unfertilized oocytes/0-1 dpf embryos and 8-9 dpf embryos was suggestive of a transition from maternal RNA to endogenous mRNA expression. Although aanat2 expression was not clearly associated with photic conditions, photoperiod treatment did alter the expression of per1 and clock expression/rhythmicity from as early as 8 dpf (per1), which could suggest the presence and functionality of an as yet unidentified "photoreceptor." As a whole, this work demonstrates that clock systems are present and functional during embryonic development in rainbow trout. Further studies of their expression and regulation will help understand how the environment interacts with embryonic development in the species.

  11. 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.

  12. The cryptic beta-fructofuranosidase of Saccharomyces rouxii.

    PubMed

    Arnold, W N

    1982-05-28

    The synthesis of beta-fructofuranosidase in synchronously dividing cells of S. rouxii was continuous (as opposed to periodic) throughout the budding cycle and followed the increase in cell mass. Similar patterns for cell mass and enzyme increases were observed even in phosphate-deprived cells which did not divide. The beta-fructofuranosidase activity remained physically cryptic throughout the cell cycle as evidenced by analyses on equilibrium density gradient fractions. The beta-fructofuranosidase activity released from mechanically disrupted cells resisted sedimentation when subjected to 131 000 g for 1 h, thus ruling out membrane association. Ethyl acetate was routinely employed to break the crypticity barrier. Enzyme in cell-free extract or in cells was equally sensitive to inactivation at pH values below 5 in the presence of ethyl acetate, which suggested that this is an inherent property of the enzyme in question and not a reflection of proteolytic inactivation. The status of beta-fructofuranosidase in selected species of Saccharomyces was compared with that for S. rouxii and a close similarity with S. bisporus var. mellis was noted. The degree of crypticity encountered in genetically defined strains of S. cerevisiae (e.g. X2180 a/alpha) was relatively high (42%) compared with that for commercially derived bakers' and brewers' strains (about 6%). Extant data on the cryptic beta-fructofuranosidase of S. rouxii are evaluated and the utility of this system for studying enzyme translocation is discussed.

  13. Atypical EEG Beta Asymmetry in Adults with ADHD1

    PubMed Central

    Hale, T. Sigi; Smalley, Susan L.; Walshaw, Patricia D.; Hanada, Grant; Macion, James; McCracken, James T.; McGough, James J.; Loo, Sandra K.

    2010-01-01

    Background Abnormal brain laterality (ABL) is well established in ADHD. However, its clinical specificity and association to cognitive and clinical symptoms is not yet understood. Previous studies indicate increased right hemisphere (RH) contribution in both ADHD and reading impaired samples. The current study investigates whether this ABL characteristic occurs in adults with ADHD absent comorbid language impairment. Methods EEG beta asymmetry was compared in 35 adult ADHD subjects and 104 controls during rest and active cognition. Group differences in beta asymmetry were then further evaluated for association to linguistic and attentional abilities, as well as association to beta asymmetry measures across different brain regions. Results Adults with ADHD showed pronounced rightward beta asymmetry (p = .00001) in inferior parietal regions (P8-P7) during a continuous performance task (CPT) that could not be attributed to linguistic ability. Among ADHD subjects only, greater rightward beta asymmetry at this measure was correlated with better CPT performance. Furthermore, this measure showed a lack of normal association (i.e., observed in controls) to left-biased processing in temporal-parietal (TP8-TP7) brain regions important for higher order language functions. Conclusion Adult ADHD involves abnormally increased right-biased contribution to CPT processing that could not be attributed to poor language ability. This appears to also involve abnormal recruitment of LH linguistic processing regions and represents an alternative, albeit less effective, CPT processing strategy. These findings suggest different pathophysiologic mechanisms likely underlie RH biased processing in ADHD and reading impaired samples. PMID:20705076

  14. 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.

  15. Interrelation of inflammation and APP in sIBM: IL-1 beta induces accumulation of beta-amyloid in skeletal muscle.

    PubMed

    Schmidt, Jens; Barthel, Konstanze; Wrede, Arne; Salajegheh, Mohammad; Bähr, Mathias; Dalakas, Marinos C

    2008-05-01

    Distinct interrelationships between inflammation and beta-amyloid-associated degeneration, the two major hallmarks of the skeletal muscle pathology in sporadic inclusion body myositis (sIBM), have remained elusive. Expression of markers relevant for these pathomechanisms were analysed in biopsies of sIBM, polymyositis (PM), dermatomyositis (DM), dystrophic and non-myopathic muscle as controls, and cultured human myotubes. By quantitative PCR, a higher upregulation was noted for the mRNA-expression of CXCL-9, CCL-3, CCL-4, IFN-gamma, TNF-alpha and IL-1 beta in sIBM muscle compared to PM, DM and controls. All inflammatory myopathies displayed overexpression of degeneration-associated markers, yet only in sIBM, expression of the mRNA of amyloid precursor protein (APP) significantly and consistently correlated with inflammation in the muscle and mRNA-levels of chemokines and IFN-gamma. Only in sIBM, immunohistochemical analysis revealed that inflammatory mediators including IL-1 beta co-localized to beta-amyloid depositions within myofibres. In human myotubes, exposure to IL-1 beta caused upregulation of APP with subsequent intracellular aggregation of beta-amyloid. Our data suggest that, in sIBM muscle, production of high amounts of pro-inflammatory mediators specifically induces beta-amyloid-associated degeneration. The observations may help to design targeted treatment strategies for chronic inflammatory disorders of the skeletal muscle.

  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. 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.

  18. The chronic intracerebroventricular infusion of interleukin-1 beta alters the activity of the hypothalamic-pituitary-gonadal axis of cycling rats. I. Effect on LHRH and gonadotropin biosynthesis and secretion.

    PubMed

    Rivest, S; Lee, S; Attardi, B; Rivier, C

    1993-12-01

    We have previously reported that the acute injection of interleukin-1 beta (IL-1 beta) into the brain ventricles of intact female rats promptly decreases LHRH release and inhibits gene expression of this peptide in the medial preoptic area (MPOA). The present studies were therefore designed to determine whether continuous exposure to the cytokine would disrupt the estrous cycle. IL-1 beta was injected intracerebroventricularly for 4-6 days at a rate of 4 ng/h. Daily vaginal smears were obtained to follow the cycle; pituitary LH and FSH secretion were measured at regular intervals. Steady state levels of LH and FSH messenger RNA (mRNA) in the pituitary, and LHRH gene expression in the MPOA, were measured at the end of the treatment. Infusion of IL-1 beta caused a total disruption of the estrous cycle, characterized by persistent smears indicative of the diestrus stage. When compared to animals treated with the vehicle, rats infused with IL-1 beta showed a significant decrease in circulating LH concentrations, which was accompanied by lowered mRNA levels in the pituitary. This statistical difference (P < 0.01) persisted even when treated rats were compared to control in a similar stage of the cycle (i.e. diestrus). Plasma FSH levels remained low at all times after IL-1 beta infusion but showed the expected cyclic changes in control animals. At the end of treatment, LHRH gene expression was also markedly suppressed in LHRH neurons distributed between the rostral preoptic area/organum vasculosum of the lamina terminalis and the MPOA of these animals. These results indicate that prolonged infusion of IL-1 beta into brain ventricles disrupts the estrous cycle, an event accompanied by decreased biosynthesis/release of LHRH and gonadotropins. We report in a related study that IL-1-treated rats also show increased plasma progesterone levels. However, it is improbable that this change was responsible for the interruption of the cycle described here; indeed we have previously

  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. Amyloid beta-peptide induces cell monolayer albumin permeability, impairs glucose transport, and induces apoptosis in vascular endothelial cells.

    PubMed

    Blanc, E M; Toborek, M; Mark, R J; Hennig, B; Mattson, M P

    1997-05-01

    Amyloid beta-peptide (A beta) is deposited as insoluble fibrils in the brain parenchyma and cerebral blood vessels in Alzheimer's disease (AD). In addition to neuronal degeneration, cerebral vascular alterations indicative of damage to vascular endothelial cells and disruption of the blood-brain barrier occur in AD. Here we report that A beta25-35 can impair regulatory functions of endothelial cells (ECs) from porcine pulmonary artery and induce their death. Subtoxic exposures to A beta25-35 induced albumin transfer across EC monolayers and impaired glucose transport into ECs. Cell death induced by A beta25-35 was of an apoptotic form, characterized by DNA condensation and fragmentation, and prevented by inhibitors of macromolecular synthesis and endonucleases. The effects of A beta25-35 were specific because A beta1-40 also induced apoptosis in ECs with the apoptotic cells localized to the microenvironment of A beta1-40 aggregates and because astrocytes did not undergo similar changes after exposure to A beta25-35. Damage and death of ECs induced by A beta25-35 were attenuated by antioxidants, a calcium channel blocker, and a chelator of intracellular calcium, indicating the involvement of free radicals and dysregulation of calcium homeostasis. The data show that A beta induces increased permeability of EC monolayers to macromolecules, impairs glucose transport, and induces apoptosis. If similar mechanisms are operative in vivo, then A beta and other amyloidogenic peptides may be directly involved in vascular EC damage documented in AD and other disorders that involve vascular amyloid accumulation. PMID:9109512

  1. 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.

  2. 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.

  3. 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.

  4. Continuous and shutterless hologram movie

    NASA Astrophysics Data System (ADS)

    Palais, Joseph C.; Miller, Mark E.

    1995-04-01

    This paper presents a unique approach to the production and display of a hologram movie. Motion was provided by rotating a 3D object in steps between exposures. Strip holograms were made on 70 mm AGFA 8E75 Holotest roll film. Each hologram was about 11 mm high and 55 mm wide. The object was rotated two degrees, while the film was advanced, between successive exposures. A complete rotation of the object was recorded on 180 holograms using the lensless Fourier-transform construction. The ends of the developed film were spliced together to produce a continuous loop. Although the film moves continuously on playback and there is no shutter, there is no flicker or image displacement because of the Fourier-transform hologram construction. The movie can be viewed for as long a time as desired because the object motion is cyclical and the film is continuous. The film is wide enough such that comfortable viewing with both eyes is possible, enhancing the 3D experience. Viewers can stand comfortably away from the film since no viewing slit or aperture is necessary. Several people can view the movie at the same time. Speckle is reduced due to the film motion.

  5. Mechanism of inactivation of alanine racemase by beta, beta, beta-trifluoroalanine

    SciTech Connect

    Faraci, W.S.; Walsh, C.T.

    1989-01-24

    The alanine racemases are a group of PLP-dependent bacterial enzymes that catalyze the racemization of alanine, providing D-alanine for cell wall synthesis. Inactivation of the alanine racemases from the Gram-negative organism Salmonella typhimurium and Gram-positive organism Bacillus stearothermophilus with beta, beta, beta-trifluoroalanine has been studied. The inactivation occurs with the same rate constant as that for formation of a broad 460-490-nm chromophore. Loss of two fluoride ions per mole of inactivated enzyme and retention of (1-/sup 14/C)trifluoroalanine label accompany inhibition, suggesting a monofluoro enzyme adduct. Partial denaturation (1 M guanidine) leads to rapid return of the initial 420-nm chromophore, followed by a slower (t1/2 approximately 30 min-1 h) loss of the fluoride ion and /sup 14/CO/sub 2/ release. At this point, reduction by NaB/sub 3/H/sub 4/ and tryptic digestion yield a single radiolabeled peptide. Purification and sequencing of the peptide reveals that lysine-38 is covalently attached to the PLP cofactor. A mechanism for enzyme inactivation by trifluoroalanine is proposed and contrasted with earlier results on monohaloalanines, in which nucleophilic attack of released aminoacrylate on the PLP aldimine leads to enzyme inactivation. For trifluoroalanine inactivation, nucleophilic attack of lysine-38 on the electrophilic beta-difluoro-alpha, beta-unsaturated imine provides an alternative mode of inhibition for these enzymes.

  6. 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.

  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. Beta decay of polarized neutrons

    SciTech Connect

    Bopp, P.; Dubbers, D.; Hornig, L.; Klemt, E.; Last, J.; Schuetze, H.; Freedman, S.J.; Schaerpf, O.

    1985-01-15

    Beta decay of polarized neutrons has been studied with the superconductive spectrometer PERKEO at the Institut Laue-Langevin. The energy spectrum of the ..beta..-decay asymmetry has been measured for the first time; from the absolute value of the asymmetry we obtain a new value for the ratio of weak coupling constants g/sub A//g/sub V/, which is compared to similar data from hyperon decays. The measurement of further weak interaction parameters from neutron decay is in progress.

  9. Beta-blockers for the treatment of problematic hemangiomas

    PubMed Central

    Sharma, Vishal K; Fraulin, Frankie OG; Dumestre, Danielle O; Walker, Lori; Harrop, A Robertson

    2013-01-01

    OBJECTIVE: To examine treatment indications, efficacy and side effects of oral beta-blockers for the treatment of problematic hemangiomas. METHODS: A retrospective review of patients with hemangiomas presenting to the Alberta Children’s Hospital Vascular Birthmark Clinic (Calgary, Alberta) between 2009 and 2011 was conducted. The subset of patients treated with oral beta-blockers was further characterized, investigating indication for treatment, response to treatment, time to resolution of indication, duration of treatment, occurrence of rebound growth and side effects of therapy. RESULTS: Between 2009 and 2011, 311 new patients with hemangiomas were seen, of whom 105 were treated with oral beta-blockers. Forty-five patients completed beta-blocker treatment while the remainder continue to receive therapy. Indications for treatment were either functional concerns (68.6%) or disfigurement (31.4%). Functional concerns included ulceration (29.5%), periocular location with potential for visual interference (28.6%), airway interference (4.8%), PHACES syndrome (3.8%), auditory interference (0.95%) and visceral location with congestive heart failure (0.95%). The median age at beta-blocker initiation was 3.3 months; median duration of therapy was 10.6 months; and median maximal treatment dose was 1.5 mg/kg/day for propranolol and 1.6 mg/kg/day for atenolol. Ninety-nine patients (94.3%) responded to therapy with size reduction, colour changes, softened texture and/or healing of ulceration. Rebound growth requiring an additional course of therapy was observed in 23 patients. Side effects from beta-blockers included cool extremities (26.7%), irritability (17.1%), lower gastrointestinal upset (14.3%), emesis (11.4%), hypotension (10.5%), poor feeding (7.6%), lethargy (4.8%), bronchospasm (0.95%) and rash (0.95%). Side effects did not result in complete discontinuation of beta-blocker treatment in any case; however, they prompted a switch to a different beta

  10. 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

  11. Individual Differences in Behavioural Despair Predict Brain GSK-3beta Expression in Mice: The Power of a Modified Swim Test.

    PubMed

    Strekalova, Tatyana; Markova, Nataliia; Shevtsova, Elena; Zubareva, Olga; Bakhmet, Anastassia; Steinbusch, Harry M; Bachurin, Sergey; Lesch, Klaus-Peter

    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

  12. 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

  13. Beta-lactamase stability of faropenem.

    PubMed

    Dalhoff, A; Nasu, T; Okamoto, K

    2003-09-01

    Faropenem (FAR) is an orally available member of the penem class unique among carbapenems and other available beta-lactams. This study compared FAR to cephalosporins and imipenem with respect to beta-lactamase (BLA) stability and emergence of resistance to Staphylococcus aureus and Escherichia coli. BLA stability was studied using enzyme preparations from sonicated/centrifuged 24-hour cultures of E. coli, Enterobacter cloacae, Proteus vulgaris, Providencia rettgeri, Klebsiella pneumoniae, S. aureus, and Bacteroides fragilis grown in the presence of 20 mg/l ampicillin or cephaloridine to induce penicillinase or cephalosporinase, respectively. Substrate hydrolysis was quantitated spectrophotometrically. Multistep acquisition of resistance was promoted by growing bacteria in broth containing 2-fold dilutions of antibiotic over 10 cycles. Aliquots from test tubes with visible growth provided the inoculum for the next series of dilutions. FAR as well as other cephalosporins tested were highly stable to penicillinase derived from S. aureus and E. coli. However, E. coli- and P. vulgaris-derived cephalosporinase hydrolyzed cephaloridine, cefaclor and cefotiam considerably, whereas FAR was highly stable. FAR was highly stable against hydrolysis by various BLAs prepared from four B. fragilis strains and the rate of FAR hydrolysis by metallo-BLA was 5 times lower than that for imipenem. Additionally, the acquisition of resistant S. aureus strains was less pronounced for FAR compared to other agents tested. MICs rose 8-fold after the 10th sub-MIC exposure, while MICs rose 16-, 31- and 512-fold for cefixime, cefazolin and cefaclor, respectively. E. coli shifts in MICs were moderate for all the agents tested. In conclusion, FAR is characterized by pronounced BLA stability compared to other cephalosporins and imipenem. Furthermore, a lower propensity for resistance development with FAR as compared to cephalosporins was observed. PMID:14504433

  14. Migration of neutrophils across endothelial monolayers is stimulated by treatment of the monolayers with beta-endorphin.

    PubMed

    Wiedermann, C J; Schratzberger, P; Kähler, C M

    1994-09-01

    To study the effects of the cytokine and neuroendocrine hormone beta-endorphin on the transendothelial migration of neutrophils, bovine pulmonary artery endothelial cells were grown to confluence on PVP-free polycarbonate filters coated with gelatin. Pretreatment of endothelial cell cultures with 1 to 10 mumol/liter of beta-endorphin for 60 min resulted in significantly stimulated migration of subsequently added neutrophils across the endothelial monolayer. The number of neutrophils that migrated across beta-endorphin-treated endothelial cells was similar to the number that traversed untreated monolayers in response to gradients of formylpeptide. Consistently, an additive effect was seen when migration was induced by both beta-endorphin pretreatment of the endothelial cells and a formylpeptide chemotactic gradient. When used at optimal concentration, beta-endorphin was equally effective in stimulating neutrophil migration as was tumor necrosis factor-alpha. In the absence of formylpeptide the effect of apical surface exposure of endothelial cells to beta-endorphin versus basal surface exposure was comparable. Stimulation of neutrophil transendothelial migration in this system appeared to be specific and mediated by opiate receptors, since excess concentration of naloxone completely abolished the effect of beta-endorphin but not of tumor necrosis factor-alpha. These results suggest that beta-endorphin, released during stress, may act upon the endothelium to promote emigration of neutrophils from the vasculature.

  15. 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,…

  16. Balancing needs and means: the dilemma of the beta-cell in the modern world.

    PubMed

    Leibowitz, G; Kaiser, N; Cerasi, E

    2009-11-01

    The insulin resistance of type 2 diabetes mellitus (T2DM), although important for its pathophysiology, is not sufficient to establish the disease unless major deficiency of beta-cell function coexists. This is demonstrated by the fact that near-physiological administration of insulin (CSII) achieved excellent blood glucose control with doses similar to those used in insulin-deficient type 1 diabetics. The normal beta-cell adapts well to the demands of insulin resistance. Also in hyperglycaemic states some degree of adaptation does exist and helps limit the severity of disease. We demonstrate here that the mammalian target of rapamycin (mTOR) system might play an important role in this adaptation, because blocking mTORC1 (complex 1) by rapamycin in the nutritional diabetes model Psammomys obesus caused severe impairment of beta-cell function, increased beta-cell apoptosis and progression of diabetes. On the other hand, under exposure to high glucose and FFA (gluco-lipotoxicity), blocking mTORC1 in vitro reduced endoplasmic reticulum (ER) stress and beta-cell death. Thus, according to the conditions of stress, mTOR may have beneficial or deleterious effects on the beta-cell. beta-Cell function in man can be reduced without T2DM/impaired glucose tolerance (IGT). Prospective studies have shown subjects with reduced insulin response to present, several decades later, an increased incidence of IGT/T2DM. From these and other studies we conclude that T2DM develops on the grounds of beta-cells whose adaptation capacity to increased nutrient intake and/or insulin resistance is in the lower end of the normal variation. Inborn and acquired factors that limit beta-cell function are diabetogenic only in a nutritional/metabolic environment that requires high functional capabilities from the beta-cell.

  17. Effects of alcohol on beta-endorphin and reproductive hormones in the male rat.

    PubMed

    Adams, M L; Cicero, T J

    1991-08-01

    In an attempt to examine the relationship between alcohol-induced alterations in immunoreactive beta-endorphin (i-beta E) levels in the hypothalamic-pituitary-gonadal axis and the synthesis and release of reproductive hormones, male rats were treated with either an acute intraperitoneal injection of alcohol or were chronically exposed to an alcohol-containing liquid diet. Hypothalamic, pituitary, serum, and testicular levels of immunoreactive beta-endorphin (i-beta E) and serum levels of luteinizing hormone (LH) and testosterone were measured at various times after initiation of these treatments. Testicular interstitial fluid (TIF) volumes and levels of TIF i-beta E and testosterone were also measured 4 hr after acute treatment as an index of testicular release of these substances. Acute alcohol decreased pituitary levels of i-beta E and increased serum levels of the peptide for up to 1 hr after its injection, but did not alter hypothalamic or testicular levels. Acute alcohol markedly increased TIF i-beta E and decreased TIF testosterone and TIF volume. Sharp decreases in serum LH and testosterone were observed in association with these acute changes in i-beta E levels in the pituitary, blood, and testes. During chronic alcohol exposure serum testosterone levels were substantially depressed, but tolerance appeared to develop quickly to the chronic effects of alcohol on serum LH. Similarly, tolerance to alcohol's effects on i-beta E levels in the pituitary and serum also appeared to develop during chronic alcohol administration. However, hypothalamic and testicular i-beta E levels were markedly suppressed by chronic alcohol administration in contrast to the lack of effect observed after acute alcohol administration.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. 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.

  19. 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.

  20. Predicted and observed early effects of combined alpha and beta lung irradiation

    SciTech Connect

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

    1990-12-01

    The nonstochastic radiobiological effects of combined alpha and beta irradiation of the lungs of rats from inhaled radionuclides were studied. Both respiratory functional morbidity at 18 mo and mortality from radiation pneumonitis within 18 mo after exposure were examined for rats exposed to the beta-emitter 147Pm, the alpha-emitter 238Pu, or both combined. The results were used to validate hazard-function models that were developed (1) for respiratory functional morbidity at 18 mo and (2) for lethality from radiation pneumonitis within 18 mo. Both models were found to adequately predict the experimental observations for chronic alpha plus beta irradiation of the lung. Based on this 18-mo study, a relative biological effectiveness of approximately seven was obtained for 238Pu alpha radiation compared to 147Pm beta radiation for both respiratory functional morbidity and lethality from radiation pneumonitis. However, the relative biological effectiveness for the alpha radiation is likely to increase with longer follow-up.

  1. Urinary beta 2-microglobulin concentration and mortality in a cadmium-polluted area

    SciTech Connect

    Nakagawa, H.; Nishijo, M.; Morikawa, Y.; Tabata, M.; Senma, M.; Kitagawa, Y.; Kawano, S.; Ishizaki, M.; Sugita, N.; Nishi, M. )

    1993-11-01

    A 9-y follow-up study of 3,178 persons who lived in a cadmium-polluted area was conducted to assess the influence of environmental cadmium exposure on long-term outcome. The standardized mortality ratios of the urinary beta 2-microglobulin-positive subjects (> 1,000 micrograms/g creatinine) of both sexes were higher than those of the general Japanese population, whereas the cumulative survival curves were lower than those of the urinary beta 2-microglobulin-negative group. A significant association was also found between urinary beta 2-microglobulin and mortality, using a Cox's proportional hazards model. Moreover, mortality rates increased in proportion to increases in the amount of urinary beta 2-microglobulin excreted. These results suggest that the prognosis for cadmium-exposed subjects with proximal tubular dysfunction is unfavorable. The mortality rate tended to become higher as the severity of renal dysfunction progressed.

  2. 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.

  3. 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...

  4. 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. PMID:14620395

  5. Effects of temperature on Escherichia coli overproducing beta-lactamase or human epidermal growth factor.

    PubMed Central

    Chalmers, J J; Kim, E; Telford, J N; Wong, E Y; Tacon, W C; Shuler, M L; Wilson, D B

    1990-01-01

    The effects of temperature on strains of Escherichia coli which overproduce and excrete either beta-lactamase or human epidermal growth factor were investigated. E. coli RB791 cells containing plasmid pKN which has the tac promoter upstream of the gene for beta-lactamase were grown and induced with isopropyl-beta-D-thiogalactopyranoside in batch culture at 37, 30, 25, and 20 degrees C. The lower temperature greatly reduced the formation of periplasmic beta-lactamase inclusion bodies, increased significantly the total amount of beta-lactamase activity, and increased the purity of extracellular beta-lactamase from approximately 45 to 90%. Chemostat operation at 37 and 30 degrees C was difficult due to poor cell reproduction and beta-lactamase production. However, at 20 degrees C, continuous production and excretion of beta-lactamase were obtained for greater than 450 h (29 generations). When the same strain carried plasmid pCU encoding human epidermal growth factor, significant cell lysis was observed after induction at 31 and 37 degrees C, whereas little cell lysis was observed at 21 and 25 degrees C. Both total soluble and total human epidermal growth factor increased with decreasing temperature. These results indicate that some of the problems of instability of strains producing high levels of plasmid-encoded proteins can be mitigated by growth at lower temperatures. Further, lower temperatures can increase for at least some secreted proteins both total plasmid-encoded protein formed and the fraction that is soluble. Images PMID:2155574

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Genetics Home Reference: beta-ureidopropionase deficiency

    MedlinePlus

    ... eliminate beta-ureidopropionase enzyme activity. Loss of this enzyme function reduces the production of beta-aminoisobutyric acid and ... aminoisobutyric acid and beta-alanine may impair the function of these molecules in the ... in enzyme activity caused by a particular UPB1 gene mutation, ...

  11. 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.

  12. Evidence for increased cardiac compliance during exposure to simulated microgravity

    NASA Technical Reports Server (NTRS)

    Koenig, S. C.; Convertino, V. A.; Fanton, J. W.; Reister, C. A.; Gaffney, F. A.; Ludwig, D. A.; Krotov, V. P.; Trambovetsky, E. V.; Latham, R. D.

    1998-01-01

    We measured hemodynamic responses during 4 days of head-down tilt (HDT) and during graded lower body negative pressure (LBNP) in invasively instrumented rhesus monkeys to test the hypotheses that exposure to simulated microgravity increases cardiac compliance and that decreased stroke volume, cardiac output, and orthostatic tolerance are associated with reduced left ventricular peak dP/dt. Six monkeys underwent two 4-day (96 h) experimental conditions separated by 9 days of ambulatory activities in a crossover counterbalance design: 1) continuous exposure to 10 degrees HDT and 2) approximately 12-14 h per day of 80 degrees head-up tilt and 10-12 h supine (control condition). Each animal underwent measurements of central venous pressure (CVP), left ventricular and aortic pressures, stroke volume, esophageal pressure (EsP), plasma volume, alpha1- and beta1-adrenergic responsiveness, and tolerance to LBNP. HDT induced a hypovolemic and hypoadrenergic state with reduced LBNP tolerance compared with the control condition. Decreased LBNP tolerance with HDT was associated with reduced stroke volume, cardiac output, and peak dP/dt. Compared with the control condition, a 34% reduction in CVP (P = 0.010) and no change in left ventricular end-diastolic area during HDT was associated with increased ventricular compliance (P = 0.0053). Increased cardiac compliance could not be explained by reduced intrathoracic pressure since EsP was unaltered by HDT. Our data provide the first direct evidence that increased cardiac compliance was associated with headward fluid shifts similar to those induced by exposure to spaceflight and that reduced orthostatic tolerance was associated with lower cardiac contractility.

  13. Anionic ring-opening polymerization of beta-alkoxymethyl-substituted beta-lactones.

    PubMed

    Adamus, Grazyna; Kowalczuk, Marek

    2008-02-01

    We report on anionic ring-opening polymerization (ROP) of racemic beta-(methoxymethyl)-beta-propiolactone (MOMPL) and beta-(ethoxymethyl)-beta-propiolactone (EOMPL) initiated by supramolecular complex of potassium acetate and tetrabutylammonium acetate (Bu4N+ Ac) as well as by tetrabutylammonium hydroxide, respectively. Structure of the resulting polymers has been established at the molecular level by electrospray ionization multistage mass spectrometry (ESI-MS(n)) and has been confirmed by FT-IR, NMR, and GPC analyses. Similar behavior of MOMPL and EOMPL with respect to already-studied beta-alkyl-substituted beta-lactones, e.g., beta-butyrolactone (MPL), has been observed under the conditions of anionic ROP (including observed side reactions leading to unsaturated end groups) and the already-established mechanisms of anionic polymerization of beta-alkyl-substituted beta-lactones are extended on beta-alkoxymethyl-substituted ones. PMID:18179174

  14. A transforming growth factor. beta. (TGF-. beta. ) receptor from human placenta exhibits greater affinity for TGF-. beta. 2 than for TGF-. beta. 1

    SciTech Connect

    Mitchell, E.J.; O'Connor-McCourt, M.D. )

    1991-04-30

    Affinity-labeling techniques have been used to identify three types of high-affinity receptors for transforming growth factor {beta} (TGF-{beta}) on the surface of many cells in culture. Here the authors demonstrate that membrane preparations from tissue sources may also be used as an alternative system for studying the binding properties of TGF-{beta} receptors. Using a chemical cross-linking technique with {sup 125}I-TGF-{beta}1 and {sup 125}I-TGF-{beta}2 and bis(sulfosuccinimidyl)suberate (BS{sup 3}), they have identified and characterized two high-affinity binding components in membrane preparations derived from human term placenta. The larger species, which migrates as a diffuse band of molecular mass 250-350 kDa on sodium dodecyl sulfate-polyacrylamide electrophoresis gels, is characteristic of the TGF-{beta} receptor type III, a proteoglycan containing glycosaminoglycan (GAG) chains of chondroitin and heparan sulfate. The smaller species of molecular mass 140 kDa was identified as the core glycoprotein of this type III receptor by using the techniques of enzymatic deglycosylation and peptide mapping. Competition experiments, using {sup 125}I-TGF-{beta}1 or {sup 125}I-TGF-{beta}2 and varying amounts of competing unlabeled TGF-{beta}1 or TGF-{beta}2, revealed that both the placental type III proteoglycan and its core glycoprotein belong to a novel class of type III receptors that exhibit a greater affinity for TGF-{beta}2 than for TGF-{beta}1. This preferential binding of TGF-{beta}2 to placental type III receptors suggests differential roles for TGF-{beta}2 and TGF-{beta} 1 in placental function.

  15. Glycogen synthase kinase 3beta phosphorylates p21WAF1/CIP1 for proteasomal degradation after UV irradiation.

    PubMed

    Lee, Ji Young; Yu, Su Jin; Park, Yun Gyu; Kim, Joon; Sohn, Jeongwon

    2007-04-01

    UV irradiation has been reported to induce p21(WAF1/CIP1) protein degradation through a ubiquitin-proteasome pathway, but the underlying biochemical mechanism remains to be elucidated. Here, we show that ser-114 phosphorylation of p21 protein by glycogen synthase kinase 3beta (GSK-3beta) is required for its degradation in response to UV irradiation and that GSK-3beta activation is a downstream event in the ATR signaling pathway triggered by UV. UV transiently increased GSK-3beta activity, and this increase could be blocked by caffeine or by ATR small interfering RNA, indicating ATR-dependent activation of GSK-3beta. ser-114, located within the putative GSK-3beta target sequence, was phosphorylated by GSK-3beta upon UV exposure. The nonphosphorylatable S114A mutant of p21 was protected from UV-induced destabilization. Degradation of p21 protein by UV irradiation was independent of p53 status and prevented by proteasome inhibitors. In contrast to the previous report, the proteasomal degradation of p21 appeared to be ubiquitination independent. These data show that GSK-3beta is activated by UV irradiation through the ATR signaling pathway and phosphorylates p21 at ser-114 for its degradation by the proteasome. To our knowledge, this is the first demonstration of GSK-3beta as the missing link between UV-induced ATR activation and p21 degradation.

  16. Beta-carotene content of postharvest orange-fleshed muskmelon fruit: effect of cultivar, growing location and fruit size.

    PubMed

    Lester, G E; Eischen, F

    1996-04-01

    The influence of two growing locations (soil types), six fruit sizes, and two years on the postharvest Beta-carotene content of muskmelon (Cucumis melo L. var. reticulatus Naud.) fruit was studied with two different cultivars. Fully abscised commercial size fruit: 9, 12, 15, 18, 23, and 30 (fruit/0.04 M3 shipping box) had highly variable Beta-carotene contents (5.3 to 33.8 micrograms/g fresh weight) that varied by size class, soil type and cultivar. Beta-carotene content increased with fruit size up to a maximum, though fruit size continued to increase. Find sandy loam soil produced fruit with less Beta-carotene content than silty clay loam soil. The cultivar Primo contained higher Beta-carotene content levels than cultivar Cruiser. Mesocarp percent moisture content for both 'Cruiser' and 'Primo' at both locations by fruit size was not significantly correlated (r = 0.40) with Beta-carotene content. Indicating fruit cell dilution may not contribute to the differences in Beta-carotene content in different fruit size classes. Beta-carotene content of size class '18' fruit from six cultivars grown on the silty clay loam soil for two consecutive years, showed a year, and year by cultivar effect for some cultivars. Whereas, some cultivars did not differ in Beta-carotene content between the two years. This indicates a potential for controlling Beta-carotene content of muskmelon fruit at a constant, high level by careful selection of production cultivar.

  17. Characterization of the phase dependent pulmonary response following irritant inhalation exposure to nitrogen dioxide gas

    SciTech Connect

    Siegel, P.D.

    1988-01-01

    The present study utilized NO{sub 2} to fingerprint the biochemical reaction of the pulmonary compartment to oxidative damage and to correlate this with histopathology following acute and subacute exposures to NO{sub 2}. Acute exposure to NO{sub 2} produced dose-dependent immediate increases in the nonenzymatic parameters of pulmonary protein content, protease inhibitor activity and lung weight. The enzymatic activities of lactate dehydrogenase (LDH), choline kinase and beta-glucuronidase were elevated by two days following acute exposure. All of the above parameters were elevated following subacute exposure, however, nonenzymatic manifestations were attenuated with respect to enzymatic alterations. Hydroxyurea-induced granulocytopenia attenuated the increases in activities of LDH and beta-glucuronidase following acute, but not subacute exposures. Cycloheximide-induced protein synthesis inhibition decrease the LDH and beta-glucuronidase response to NO{sub 2} without altering the increases in protein content or protease inhibitor activity.

  18. 40 CFR 158.2260 - Applicator exposure.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Applicator exposure. 158.2260 Section 158.2260 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Antimicrobial Pesticide Data Requirements § 158.2260 Applicator exposure....

  19. 46 CFR 169.551 - Exposure suits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Exposure suits. 169.551 Section 169.551 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Lifesaving and Firefighting Equipment Additional Lifesaving Equipment § 169.551 Exposure suits. (a) This section applies to each vessel operating in exposed...

  20. Beta genus papillomaviruses and skin cancer.

    PubMed

    Howley, Peter M; Pfister, Herbert J

    2015-05-01

    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.

  1. 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.

  2. Reactions of fluoroalkyl-. beta. -ketoesters with ammonia

    SciTech Connect

    Pashkevich, K.I.; Saloutin, V.I.; Fomin, A.N.; Rudaya, M.N.; Egorova, L.G.

    1987-01-20

    It has been found that ..beta..-ketoesters containing highly fluorinated substituents (CF/sub 3/, or H(CF/sub 2/)/sub 4/) react with ammonia to give ..beta..-aminocrotonate esters, or under severe conditions, ..beta..-ketoamides. The latter react with a tenfold excess of ammonia to give ..beta..-aminocrotonamides together with acetamide and fluorocarboxamides. Acetoacetic and 4,4-difluoroacetoacetic esters react with ammonia, irrespective of the reaction conditions, to give ..beta..-aminocrotonate and 4,4-difluoro-..beta..-aminocrotonate esters. Using DNMR and dipole moments, it has been shown that rotation of the amino group around the C-N bond in fluorinated ..beta..-aminocrotonate esters is restricted (..delta..Gnumber approx. 50 kJ/mole).

  3. Triphenylmethane Dye Activation of Beta-Arrestin

    PubMed Central

    2013-01-01

    β-Arrestins regulate G protein-coupled receptor signaling as competitive inhibitors and protein adaptors. Low molecular weight biased ligands that bind receptors and discriminate between the G protein dependent arm and β-arrestin, clathrin-associated arm of receptor signaling are considered therapeutically valuable as a result of this distinctive pharmacological behavior. Other than receptor agonists, compounds that activate β-arrestins are not available. We show that within minutes of exposure to the cationic triphenylmethane dyes malachite green and brilliant green, tissue culture cells recruit β-arrestins to clathrin scaffolds in a receptor-activation independent manner. In the presence of these compounds, G protein signaling is inhibited, ERK and GSK3β signaling are preserved, and the recruitment of the beta2-adaptin, AP2 adaptor complex to clathrin as well as transferrin internalization is reduced. Moreover, malachite green binds β-arrestin2-GFP coated immunotrap beads relative to GFP only coated beads. Triphenylmethane dyes are FDA approved for topical use on newborns as components of triple-dye preparations and are not approved but used effectively as aqueous antibiotics in fish husbandry. As possible carcinogens, their chronic ingestion in food preparations, particularly through farmed fish, is discouraged in the U.S. and Europe. Our results indicate triphenylmethane dyes as a result of novel pharmacology may have additional roles as β-arrestin/clathrin pathway signaling modulators in both pharmacology research and clinical therapy. PMID:23865508

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. First neutrinoless double beta decay results from CUORE-0

    NASA Astrophysics Data System (ADS)

    Gironi, L.; Alduino, C.; Alfonso, K.; Artusa, D. R.; Avignone, F. T.; Azzolini, O.; Balata, M.; Banks, T. I.; Bari, G.; Beeman, J. W.; Bellini, F.; Bersani, A.; Biassoni, M.; Brofferio, C.; Bucci, C.; Camacho, A.; Caminata, A.; Canonica, L.; Cao, X. G.; Capelli, S.; Cappelli, L.; Carbone, L.; Cardani, L.; Carniti, P.; Casali, N.; Cassina, L.; Chiesa, D.; Chott, N.; Clemenza, M.; Copello, S.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Cushman, J. S.; Dafinei, I.; Dally, A.; Davis, C. J.; Dell'Oro, S.; Deninno, M. M.; Di Domizio, S.; Di Vacri, M. L.; Drobizhev, A.; Fang, D. Q.; Faverzani, M.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Franceschi, M. A.; Freedman, S. J.; Fujikawa, B. K.; Giachero, A.; Giuliani, A.; Gorla, P.; Gotti, C.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Hansen, E.; Heeger, K. M.; Hennings-Yeomans, R.; Hickerson, K. P.; Huang, H. Z.; Kadel, R.; Keppel, G.; Kolomensky, Yu. G.; Ligi, C.; Lim, K. E.; Liu, X.; Ma, Y. G.; Maino, M.; Martinez, M.; Maruyama, R. H.; Mei, Y.; Moggi, N.; Morganti, S.; Napolitano, T.; Nisi, S.; Nones, C.; Norman, E. B.; Nucciotti, A.; O'Donnell, T.; Orio, F.; Orlandi, D.; Ouellet, J. L.; Pagliarone, C. E.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pessina, G.; Pettinacci, V.; Piperno, G.; Pira, C.; Pirro, S.; Pozzi, S.; Previtali, E.; Rosenfeld, C.; Rusconi, C.; Sala, E.; Sangiorgio, S.; Santone, D.; Scielzo, N. D.; Sisti, M.; Smith, A. R.; Taffarello, L.; Tenconi, M.; Terranova, F.; Tomei, C.; Trentalange, S.; Ventura, G.; Vignati, M.; Wagaarachchi, S. L.; Wang, B. S.; Wang, H. W.; Wielgus, L.; Wilson, J.; Winslow, L. A.; Wise, T.; Woodcraft, A.; Zanotti, L.; Zarra, C.; Zhang, G. Q.; Zhu, B. X.; Zimmermann, S.; Zucchelli, S.

    2015-10-01

    The CUORE-0 experiment, a 52 bolometer array searching for neutrinoless double beta decay from 130Te, 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 130Te) 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 (T1/2 > 4.0 × 1024 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.

  9. 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.

  10. Continuing Liberal Education. Continuing Higher Education Series.

    ERIC Educational Resources Information Center

    House, David B.

    This book investigates the key areas of nontraditional education program planning and development by examining the ways that liberal arts programs at various institutions have been academically and administratively established, developed, and maintained. Areas examined are the following: (1) the history of continuing liberal education and the…

  11. The non-ligand binding beta-isoform of the human glucocorticoid receptor (hGR beta): tissue levels, mechanism of action, and potential physiologic role.

    PubMed Central

    de Castro, M.; Elliot, S.; Kino, T.; Bamberger, C.; Karl, M.; Webster, E.; Chrousos, G. P.

    1996-01-01

    BACKGROUND: Alternative splicing of the transcripts of the human glucocorticoid receptor gene results in two mutually exclusive products, the classic, ligand-binding glucocorticoid receptor (hGR alpha), and a dominant negative non-ligand-binding isoform, hGR beta. MATERIALS AND METHODS: We examined the existence of and quantified both hGR alpha and hGR beta isoforms in a panel of human tissues, as well as in intact and fractionated HeLa cells, using specific quantitative Western blots and/or immunocytochemistry. We studied the potential interactions of hGR beta with heat shock protein (hsp) 90 and/or hGR alpha using cross-immunoadsorption/precipitation procedures followed by Western blots. RESULTS: For the first time, we demonstrated the natural existence of the hGR beta protein, which was widely expressed in human tissues. The ratio of immunoreactive hGR alpha to hGR beta varied from 0.2 to 1.0 among different tissues, and was approximately 0.2 in HeLa cells. In the latter, both isoforms were distributed in the cytoplasm and nucleus in the absence of the hormonal ligand, and translocated into the nucleus after addition of dexamethasone. The cytosolic and nuclear hGR alpha-to-hGR beta ratio remained the same before and after dexamethasone exposure, suggesting that upon activation the two isoforms translocated into the nucleus in equal proportions. hGR alpha- and hGR beta-specific antibodies cross-adsorbed and precipitated cytosolic and nuclear glucocorticoid hGR alpha and hGR beta, respectively, as well as hsp90, suggesting that hGR alpha and hGR beta are in complex with hsp90 and/or each other. CONCLUSIONS: The hGR beta protein is widely expressed throughout the human body and present mostly in the cytoplasm of human cells, in complex with hsp90 and other proteins. In the presence of glucocorticoid, hGR beta probably heterodimerizes with ligand-bound hGR alpha and translocates into the nucleus to act as a dominant negative inhibitor of the classic receptor. Images

  12. 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.

  13. Electromagnetic gyrokinetic turbulence in high-beta helical plasmas

    NASA Astrophysics Data System (ADS)

    Ishizawa, Akihiro

    2013-10-01

    Gyrokinetic simulation of electromagnetic turbulence in finite-beta plasmas is important for predicting the performance of fusion reactors. Whereas in low-beta tokamaks the zonal flow shear acts to regulate ion temperature gradient (ITG) driven turbulence, it has often been observed that the kinetic ballooning mode (KBM) and, at moderate-beta, the ITG mode continue to grow without reaching a physically relevant level of saturation. The corresponding problem in helical high-beta plasmas, the identification of a saturation mechanism for microturbulence in regimes where zonal flow generation is too weak, is the subject of the present work. This problem has not been previously explored because of numerical difficulties associated with complex three-dimensional magnetic structures as well as multiple spatio-temporal scales related to electromagnetic ion and electron dynamics. The present study identifies a new saturation process of the KBM turbulence originating from the spatial structure of the KBM instabilities in a high-beta Large Helical Device (LHD) plasma. Specifically, the most unstable KBM in LHD has an inclined mode structure with respect to the mid-plane of a torus, i.e. it has finite radial wave-number in flux tube coordinates, in contrast to KBMs in tokamaks as well as ITG modes in tokamaks and helical systems. The simulations reveal that the growth of KBMs in LHD is saturated by nonlinear interactions of oppositely inclined convection cells through mutual shearing, rather than by the zonal flow shear. The mechanism is quantitatively evaluated by analysis of the nonlinear entropy transfer.

  14. New perspectives on beta-adrenergic mediation of innate and learned fear responses to predator odor.

    PubMed

    Do Monte, Fabrício H M; Canteras, Newton Sabino; Fernandes, Daniel; Assreuy, Jamil; Carobrez, Antonio P

    2008-12-01

    In the present study, we investigated the role of noradrenergic transmission in unconditioned and conditioned responses to predatory threats. First, we examined the effects of systemically injected beta-blockers on unconditioned and contextual conditioned response to cat odor. The centrally acting beta-blocker (propranolol) was able to impair unconditioned responses, as well as the acquisition of the contextual fear to cat odor; however, the peripherally acting (nadolol) was not effective. Next, we examined the neural substrate underlying the noradrenergic modulation of the defensive response to cat odor and focused on the dorsal premammillary nucleus (PMd), because it represents the hypothalamic site most responsive to predatory threats and, at the same time, presents a dense plexus of noradrenergic fibers. We were able to see that propranolol significantly reduced PMd-Fos expression in response to cat odor and that beta-adrenoceptor blockade in the PMd, before cat odor exposure, reduced defensive responses to the cat odor and to the cat odor-related environment. We have also shown that beta-adrenoceptor blockade in the PMd, before the exposure to cat odor-related context, impaired the contextual conditioned responses. Overall, the present results provide convincing evidence suggesting that central noradrenergic mediation is critical for the expression of unconditioned and contextual conditioned antipredatory responses. We have further shown that the PMd appears to be an important locus to mediate these beta-adrenoceptor effects. PMID:19052221

  15. Continuity of Care

    PubMed Central

    Alazri, Mohammed; Heywood, Philip; Neal, Richard D; Leese, Brenda

    2007-01-01

    Continuity of care is widely regarded as a core value of primary care. The objective of this article is to explore the literature about the concept of continuity of care focusing on factors that influence continuity; advantages and disadvantages of continuity and the effect of continuity on outcomes, hence on the quality of care. Electronic databases and other websites were searched for relevant literature. The results of this review showed that continuity of care is influenced by demographic factors, factors related to patients and healthcare professionals, patient-healthcare professional relationship, inter-professional factors, role of receptionists and organisational factors. Several advantages were found to be associated with most types of continuity in various medical disciplines preventive medicine, general health, maternity and child health, mental and psychosocial health, chronic diseases and costs of care.Various factors influenced different types of continuity. Most types of continuity were associated with good outcomes, hence indirectly affecting the quality of care. Health care professionals and policy makers should be aware of the effect of continuity on quality of care and of the factors that influence continuity if they wish to preserve it as a core value of primary care. PMID:21748104

  16. 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.

  17. OAO-2 observations of beta Lyrae and a provisional interpretation

    NASA Technical Reports Server (NTRS)

    Kondo, Y.; Mccluskey, G. E., Jr.; Houck, T. E.

    1972-01-01

    Six-color ultraviolet photoelectric observations of beta Lyrae obtained with OAO-2 are presented. These observations, made at 1380, 1500, 1920, 2460, 2980 and 3330 A, represent the first truly continual coverage of the light changes of beta Lyrae during one orbital revolution and were obtained in November 1970. The photometric data are supplemented by spectral scans in the wavelength intervals 3800-1800 A and 2000-1050 A; the latter interval was scanned at 10 A resolution once during every OAO-2 orbit, i.e., about 100 minutes. Anomalous features, such as asymmetries and short and long term variations, are present in the light curves. A tentative discussion of solutions of the light curves is given.

  18. Continuous Liquid Interface Production (CLIP)

    NASA Astrophysics Data System (ADS)

    Tumbleston, John

    Continuous liquid interface production (CLIP) can rapidly produce 3D parts using a range of polymeric materials. A DLP-based form of additive manufacturing, CLIP proceeds via projecting a sequence of UV images through an oxygen-permeable, UV-transparent window below a liquid resin bath. A thin uncured liquid layer, or dead zone, is created above the window and maintains a liquid interface below the advancing part. Above the dead zone, the curing part is drawn out of the resin bath creating suction forces that renew reactive liquid resin. The dead zone is created due to oxygen inhibition of photopolymerization, a process that is traditionally a nuisance in other photopolymerization applications. However, for CLIP oxygen inhibition and creation of the dead zone allows for a continuous mode of printing where UV exposure, resin renewal, and part elevation are conducted simultaneously. This continual process is fundamentally different from traditional bottom-up stereolithography printers where these steps must be conducted in separate and discrete steps. Furthermore, the relatively gentle nature of CLIP due to the established dead zone enables the use of unique materials with a wide range of mechanical properties. This presentation will showcase the CLIP technology and provide a detailed picture of interactions between different resin and process parameters. New applications for 3D printing that span the micro- to macro-scale enabled by CLIP's combination of unique materials and part production speed will also be presented.

  19. Beta 1- and beta 2-adrenoceptor antagonist activities of ICI-215001, a putative beta 3-adrenoceptor agonist.

    PubMed Central

    Tesfamariam, B.; Allen, G. T.

    1994-01-01

    1. The present study was undertaken to characterize the beta 3-adrenoceptor agonist activity of ICI-215001 and to determine whether it exhibits additional activities on beta 1- and beta 2-adrenoceptors in isolated spontaneously beating atrium, trachea and ileum of guinea-pig. 2. In guinea-pig atrium, isoprenaline, a non-selective beta-adrenoceptor agonist, caused concentration-dependent, positive chronotropic effects that were inhibited by atenolol, a selective beta 1-antagonist. ICI-215001 also competitively antagonized the increase in heart rate caused by isoprenaline. 3. ICI-215001 exhibited low intrinsic activity at increasing the beating rate of atrium and no activity on resting or induced tone of tracheal strips. 4. In strips of guinea-pig trachea, contracted submaximally with carbachol, isoprenaline, caused concentration-dependent relaxations. Both ICI-118551, a selective beta 2-adrenoceptor antagonist, and ICI-215001 competitively inhibited the relaxations caused by isoprenaline. 5. In isolated strips of guinea-pig ileum longitudinal smooth muscle contracted with histamine, isoprenaline and ICI-215001 caused relaxations which were inhibited by alprenolol, a beta-adrenoceptor antagonist with modest affinity for beta 3-adrenoceptors, but were resistant to ICI-118551 and atenolol. 6. These results indicate that ICI-215001 exhibits beta 3-adrenoceptor agonist activity as demonstrated by relaxations mediated via atypical beta-adrenoceptors in the longitudinal smooth muscle of guinea-pig ileum. Further, the studies demonstrate that ICI-215001 can act as an antagonist at beta 1- and beta 2-adrenoceptors in situations where its intrinsic agonist activity is low. PMID:7913381

  20. 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/...

  1. 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.

  2. 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.

  3. Aerobic exercise and plasma beta endorphin levels in patients with migrainous headache without aura.

    PubMed

    Köseoglu, E; Akboyraz, A; Soyuer, A; Ersoy, A O

    2003-12-01

    This study aims to evaluate the effects of plasma beta endorphin level and exercise on migrainous headache. Forty patients with migrainous headache without aura (MWOA), firstly exercised on a treadmill and afterwards were asked to continue an aerobic home exercise program for six weeks. On evaluation, basal plasma beta endorphin level was negatively correlated with total duration of attacks in the last month period (P = 0.01). Exercise was found to have beneficial effects on all migraine parameters (P < 0.0001) and to increase beta endorphin levels after the treadmill practice (P < 0.0001) and after the home exercise program except four patients not regularly attended to the program (P < 0.0001). Any of the changes in headache parameters was not correlated with the change in beta endorphin level. However, pre-exercise beta endorphin level was found to be negatively correlated with the changes in the number of attacks (P < 0.05) and total duration of attacks (P = 0.01) and also with the change in beta endorphin level due to exercise (P < 0.0001). As a result, this study emphasizes the beneficial effect of exercise on migrainous headache, especially in patients with lower basal beta endorphin level. PMID:14984230

  4. 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. PMID:26900975

  5. Binding of transforming growth factor-beta (TGF-beta) to pregnancy zone protein (PZP). Comparison to the TGF-beta-alpha 2-macroglobulin interaction.

    PubMed

    Philip, A; Bostedt, L; Stigbrand, T; O'Connor-McCourt, M D

    1994-04-15

    Pregnancy zone protein (PZP) is quantitatively the most important pregnancy-associated plasma protein and it has strong similarity to alpha 2-macroglobulin. Since alpha 2-macroglobulin is a binding protein for transforming growth factors-beta (TGF-beta), it was of interest to test whether the related protein, PZP, also binds to these growth-regulatory proteins. Using affinity-labelling methods, we demonstrate that PZP binds both TGF-beta 1 and TGF-beta 2 and that the binding characteristics are similar to those of the TGF-beta-alpha 2-macroglobulin interaction. TGF-beta 2 and TGF-beta 1 bind to PZP in a predominantly noncovalent manner in vitro. TGF-beta 1 and TGF-beta 2 bind to both the dimeric and tetrameric forms of PZP. Our studies also indicate that PZP binds TGF-beta 2 with higher affinity than TGF-beta 1. Finally, we demonstrate that PZP inhibits the binding of TGF-beta 1 and TGF-beta 2 to their cell surface receptors. The increased level of PZP during pregnancy may affect the action of TGF-beta by regulating the distribution, clearance and/or general availability of TGF-beta. The preferential binding of TGF-beta 2 over TGF-beta 1 by PZP implies that PZP may differentially regulate the action of TGF-beta 1 and TGF-beta 2.

  6. Transforming growth factor-beta 1 (TGF-beta1) prevents the age-dependent decrease in bone formation in human osteoblast/implant cultures.

    PubMed

    Zhang, Hai; Aronow, Michael S; Gronowicz, Gloria A

    2005-10-01

    Titanium implants have been extensively used in orthopedic surgery and dentistry. Most of the patients who receive such implants are elderly with a compromised ability to heal and form new bone. By using an in vitro osteoblast/implant culture system, the potency of TGF-beta1 in enhancing mineralization of human osteoblast cultures from elderly subjects was investigated in this study. Primary human osteoblast (HOB) cells obtained from different age group human subjects [Young (Y), Middle (M), and Old (O)] were cultured on Ti alloy (Ti-6Al-4V) disks with or without continuous administration of 0.2 ng/mL TGF-beta1 in the medium for 2 or 4 weeks. TGF-beta1 significantly (p < 0.05) increased calcium content and the size of calcified nodules on implant disks in the O group, but had no effect on the Y or M groups. The number of calcified nodules was not different with or without TGF-beta1 in all age groups. As measured by Northern blot analysis and RT-PCR, TGF-beta1 significantly increased the expression of bone-specific extracellular matrix proteins, including alkaline phosphatase, Type I collagen, bone sialoprotein and osteocalcin, after both 2 and 4 weeks in the O group but not in the Y group. In conclusion, TGF-beta1 enhances mineralization on implant materials of osteoblast cultures from elderly human subjects.

  7. 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

  8. Presynaptic targeting of alpha4beta 2 nicotinic acetylcholine receptors is regulated by neurexin-1beta.

    PubMed

    Cheng, Shi-Bin; Amici, Stephanie A; Ren, Xiao-Qin; McKay, Susan B; Treuil, Magdalen W; Lindstrom, Jon M; Rao, Jayaraman; Anand, Rene

    2009-08-28

    The mechanisms involved in the targeting of neuronal nicotinic acetylcholine receptors (AChRs), critical for their functional organization at neuronal synapses, are not well understood. We have identified a novel functional association between alpha4beta2 AChRs and the presynaptic cell adhesion molecule, neurexin-1beta. In non-neuronal tsA 201 cells, recombinant neurexin-1beta and mature alpha4beta2 AChRs form complexes. alpha4beta2 AChRs and neurexin-1beta also coimmunoprecipitate from rat brain lysates. When exogenous alpha4beta2 AChRs and neurexin-1beta are coexpressed in hippocampal neurons, they are robustly targeted to hemi-synapses formed between these neurons and cocultured tsA 201 cells expressing neuroligin-1, a postsynaptic binding partner of neurexin-1beta. The extent of synaptic targeting is significantly reduced in similar experiments using a mutant neurexin-1beta lacking the extracellular domain. Additionally, when alpha4beta2 AChRs, alpha7 AChRs, and neurexin-1beta are coexpressed in the same neuron, only the alpha4beta2 AChR colocalizes with neurexin-1beta at presynaptic terminals. Collectively, these data suggest that neurexin-1beta targets alpha4beta2 AChRs to presynaptic terminals, which mature by trans-synaptic interactions between neurexins and neuroligins. Interestingly, human neurexin-1 gene dysfunctions have been implicated in nicotine dependence and in autism spectrum disorders. Our results provide novel insights as to possible mechanisms by which dysfunctional neurexins, through downstream effects on alpha4beta2 AChRs, may contribute to the etiology of these neurological disorders.

  9. beta-Galactosidase enzyme fragment complementation for the measurement of Wnt/beta-catenin signaling.

    PubMed

    Verkaar, Folkert; Blankesteijn, W Matthijs; Smits, Jos F M; Zaman, Guido J R

    2010-04-01

    Wnt/beta-catenin signaling is an important regulator of cell polarity, proliferation, and stem cell maintenance during development and adulthood. Wnt proteins induce the nuclear accumulation of beta-catenin, which regulates the expression of Wnt-responsive genes through association with TCF/LEF transcription factors. Aberrant Wnt/beta-catenin signaling has been implicated in a plethora of pathologies and, most notably, underlies initiation and expansion of several cancers. Here, we apply enzyme fragment complementation to measure the nuclear accumulation of beta-catenin. beta-Catenin was tagged with a peptide fragment of beta-galactosidase and transfected into cells expressing a corresponding deletion mutant of the enzyme exclusively in the nucleus. Stimulation of the cells with recombinant Wnt-3a restored beta-galactosidase activity in a dose-dependent manner with nanomolar potency. Using the assay, we confirmed that Wnt-5a represses beta-catenin-driven reporter gene activity downstream of nuclear entry of beta-catenin. In addition, we tested a library of >2000 synthetic chemical compounds for their ability to induce beta-catenin nuclear accumulation. The immunosuppressive protein kinase C inhibitor sotrastaurin (AEB-071) was identified as an activator of Wnt/beta-catenin signaling at micromolar concentrations. It was confirmed that the compound stabilizes endogenous beta-catenin protein and can induce TCF/LEF-dependent gene transcription. Subsequent biochemical profiling of >200 kinases revealed both isoforms of glycogen synthase kinase 3, as previously unappreciated targets of sotrastaurin. We show that the beta-catenin nuclear accumulation assay contributes to our knowledge of molecular interactions within the Wnt/beta-catenin pathway and can be used to find new therapeutics targeting Wnt/beta-catenin signaling.-Verkaar, F., Blankesteijn, W. M., Smits, J. F. M., Zaman, G. J. R. beta-Galactosidase enzyme fragment complementation for the measurement of Wnt/beta

  10. Evaluation of reproductive safety of beta-sitosterol on the American mink (Neovison vison).

    PubMed

    Nieminen, Petteri; Pölönen, Ilpo; Ikonen, Katja; Määttänen, Maija; Mustonen, Anne-Mari

    2008-03-01

    beta-Sitosterol is a weakly estrogenic phytosterol used extensively in functional foods to lower elevated serum cholesterol concentrations due to its inhibitory action on intestinal cholesterol absorption. It caused previously decreased sex steroid concentrations in fish and lowered sperm counts in rats. In the American mink (Neovison vison), litter size increased slightly due to dietary beta-sitosterol supplement. The aim of the present experiment was to conduct a dose-response study on the effects of beta-sitosterol on the reproduction of the American mink. Juvenile male and female mink (n=480) were exposed to 0, 5, 10 or 50 mg of peroral beta-sitosterol kg(-1)d(-1) for 10 months. After 3 months of exposure in November, 15 males per group were sacrificed and general biochemical variables reflecting overall health were determined. The beta-sitosterol-treated male mink had increased absolute and relative masses of intraabdominal fat and higher blood hemoglobin and serum high-density lipoprotein cholesterol concentrations. In spring, the top-rated male mink were mated with multiple females within each study group and reproductive success was assessed. No differences in the reproductive performance of the males (10-11 per group) or females (47-50 per group) could be detected in the exposed groups and the kits of all groups developed in a similar manner. The results suggest that dietary beta-sitosterol presents no significant risk to mammalian fertility. PMID:18035394

  11. Ionizing radiation alters beta-endorphin-like immunoreactivity in brain but not blood

    SciTech Connect

    Mickley, G.A.; Stevens, K.E.; Moore, G.H.; Deere, W.; White, G.A.; Gibbs, G.L.; Mueller, G.P.

    1983-12-01

    Previous behavioral and pharmacological studies have implicated endorphins in radiation-induced locomotor hyperactivity of the C57BL/6J mouse. However, the endogenous opiate(s) responsible for this behavioral change have not been identified. The present study measured beta-endorphin-like immunoreactivity (beta-END-LI) in brain, blood, and combined brain and pituitary samples from irradiated and sham-irradiated C57BL/6J mice. After radiation exposure, levels of beta-END-LI decreased significantly in the brain. A similar, but not statistically significant, decline was measured in combined brain and pituitary samples. Concentrations of blood beta-END-LI were not changed by irradiation. These radiogenic changes in beta-END-LI are in some ways similar to those observed after other stresses. However, radiation-induced locomotor hyperactivity may be mediated more by alterations of beta-END-LI in the brain than in the periphery. Other endogenous opiate systems may also contribute to this behavioral change in the C57BL/6J mouse.

  12. 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.

  13. Synthesis of polymorph A-enriched beta zeolites in a HF-concentrated system.

    PubMed

    Zhang, Guanqun; Wang, Bingchun; Zhang, Weiping; Li, Mingrun; Tian, Zhijian

    2016-04-21

    Polymorph A-enriched beta zeolites were synthesized by employing high HF concentrations in the synthesis medium. The polymorphic compositions of the synthesized beta zeolites were determined by the complementary characterization methods (19)F NMR analysis and PXRD simulation. With a variety of SDAs, a high HF concentration (HF/SDA > 1.0) in the synthesis medium results in the A-rich feature (55-65% A) of beta zeolites, while a moderate HF concentration only results in typical beta zeolites. A systematic study on the synthesis conditions reveals the existence of a buffered system of H(+) and F(-) formed in the highly HF-concentrated medium. This buffer results in a small but continuous supply of F(-) during zeolite crystallization, in contrast to the conventional fluoride route where all F(-) are discharged all-at-once at the initial stage. PMID:26974286

  14. Diffusional transport during the cyclic oxidation of gamma + beta, Ni-Cr-Al(Y, Zr) alloys

    NASA Technical Reports Server (NTRS)

    Nesbitt, J. A.; Heckel, R. W.

    1988-01-01

    The cyclic oxidation behavior of several cast gamma + beta, Ni-Cr-Al(Y, Zr) alloys and one low-pressure plasma spraying gamma + beta, Ni-Co-Cr-Al(Y) alloy was studied. Cyclic oxidation was found to result in a decreasing Al concentration at the oxide-metal interface due to a high rate of Al consumption coupled with oxide scale cracking and spalling. Diffusion paths plotted on the ternary phase diagram showed higher Ni concentrations with increasing cyclic oxidation exposures. The alloy with the highest rate of Al consumption and the highest Al content underwent breakaway oxidation following 500 1-hr cycles at 1200 C.

  15. 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.

  16. Regulation of transglutaminase type II by transforming growth factor-beta 1 in normal and transformed human epidermal keratinocytes.

    PubMed

    George, M D; Vollberg, T M; Floyd, E E; Stein, J P; Jetten, A M

    1990-07-01

    This study examines the effect of transforming growth factor-beta 1 (TGF-beta 1) on the expression of Type I and II transglutaminase in normal human epidermal keratinocytes (NHEK cells). Treatment of undifferentiated NHEK cells with 100 pM TGF-beta 1 caused a 10- to 15-fold increase in the activity of a soluble transglutaminase. Based on its cellular distribution and immunoreactivity this transglutaminase was identified as Type II (tissue) transglutaminase. TGF-beta 1 did not enhance the levels of the membrane-bound Type I (epidermal) transglutaminase activity which is induced during squamous cell differentiation and did not increase Type II transglutaminase activity in differentiated NHEK cells. Several SV40 large T antigen-immortalized NHEK cell lines also exhibited a dramatic increase in transglutaminase Type II activity after TGF-beta 1 treatment; however, TGF-beta 1 did not induce any significant change in transglutaminase activity in the carcinoma-derived cell lines SCC-13, SCC-15, and SQCC/Y1. Half-maximal stimulation of transglutaminase Type II activity in NHEK cells occurred at a dose of 15 pM TGF-beta 1. TGF-beta 2 was about equally effective. This enhancement in transglutaminase activity was related to an increase in the amount of transglutaminase Type II protein as indicated by immunoblot analysis. Northern blot analyses using a specific cDNA probe for Type II transglutaminase showed that exposure of NHEK cells to TGF-beta 1 caused a marked increase in the mRNA levels of this enzyme which could be observed as early as 4 h after the addition of TGF-beta 1. Maximal induction of transglutaminase Type II mRNA occurred between 18 and 24 h. The increase in Type II transglutaminase mRNA levels was blocked by the presence of cycloheximide, suggesting that this increase in mRNA by TGF-beta 1 is dependent on protein synthesis. PMID:1972706

  17. 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.

  18. First forbidden beta decay in light nuclei

    SciTech Connect

    Millener, D.J.; Warburton, E.K.

    1984-01-01

    Beta decay matrix elements for the operators sigma dot del and sigma dot r are calculated for eight J/sup +/ ..-->.. J/sup -/ or J/sup -/ ..-->.. J/sup +/ beta transitions. Results using harmonic oscillator wave functions differ markedly from those using more realistic Woods-Saxon wave functions. A substantial contribution to the sigma dot del matrix elements from pion exchange currents is required to reproduce the experimental beta decay rates. 15 references.

  19. 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

  20. Beta-blockers for treatment of hypertension.

    PubMed

    Basile, Jan N; Cohen, Jerome D

    2003-12-01

    Beta-blockers are an established class in the management of hypertension, and numerous randomized, controlled trials have shown that these drugs can prevent cardiovascular events in this population. However, beta-blockers are underutilized in managing the general hypertensive population. This phenomenon may stem in part from concerns about side effects. On the contrary, beta-blockers demonstrate comparable efficacy, safety, and tolerability compared with other classes of antihypertensive drugs. Because beta-blockers offer unique cardiovascular protection, they should be considered an integral part of the treatment regimen for patients with hypertension who are at risk for cardiovascular events.

  1. 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.

  2. Milk Intolerance, Beta-Casein and Lactose.

    PubMed

    Pal, Sebely; Woodford, Keith; Kukuljan, Sonja; Ho, Suleen

    2015-09-01

    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.

  3. Milk Intolerance, Beta-Casein and Lactose

    PubMed Central

    Pal, Sebely; Woodford, Keith; Kukuljan, Sonja; Ho, Suleen

    2015-01-01

    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. PMID:26404362

  4. Regulation of pancreatic beta-cell mass.

    PubMed

    Bouwens, Luc; Rooman, Ilse

    2005-10-01

    Beta-cell mass regulation represents a critical issue for understanding diabetes, a disease characterized by a near-absolute (type 1) or relative (type 2) deficiency in the number of pancreatic beta cells. The number of islet beta cells present at birth is mainly generated by the proliferation and differentiation of pancreatic progenitor cells, a process called neogenesis. Shortly after birth, beta-cell neogenesis stops and a small proportion of cycling beta cells can still expand the cell number to compensate for increased insulin demands, albeit at a slow rate. The low capacity for self-replication in the adult is too limited to result in a significant regeneration following extensive tissue injury. Likewise, chronically increased metabolic demands can lead to beta-cell failure to compensate. Neogenesis from progenitor cells inside or outside islets represents a more potent mechanism leading to robust expansion of the beta-cell mass, but it may require external stimuli. For therapeutic purposes, advantage could be taken from the surprising differentiation plasticity of adult pancreatic cells and possibly also from stem cells. Recent studies have demonstrated that it is feasible to regenerate and expand the beta-cell mass by the application of hormones and growth factors like glucagon-like peptide-1, gastrin, epidermal growth factor, and others. Treatment with these external stimuli can restore a functional beta-cell mass in diabetic animals, but further studies are required before it can be applied to humans. PMID:16183912

  5. Milk Intolerance, Beta-Casein and Lactose.

    PubMed

    Pal, Sebely; Woodford, Keith; Kukuljan, Sonja; Ho, Suleen

    2015-09-01

    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. PMID:26404362

  6. IN-SITU TRITIUM BETA DETECTOR

    SciTech Connect

    J.W. Berthold; L.A. Jeffers

    1998-04-15

    The objectives of this three-phase project were to design, develop, and demonstrate a monitoring system capable of detecting and quantifying tritium in situ in ground and surface waters, and in water from effluent lines prior to discharge into public waterways. The tritium detection system design is based on measurement of the low energy beta radiation from the radioactive decay of tritium using a special form of scintillating optical fiber directly in contact with the water to be measured. The system consists of the immersible sensor module containing the optical fiber, and an electronics package, connected by an umbilical cable. The system can be permanently installed for routine water monitoring in wells or process or effluent lines, or can be moved from one location to another for survey use. The electronics will read out tritium activity directly in units of pico Curies per liter, with straightforward calibration. In Phase 1 of the project, we characterized the sensitivity of fluor-doped plastic optical fiber to tritium beta radiation. In addition, we characterized the performance of photomultiplier tubes needed for the system. In parallel with this work, we defined the functional requirements, target specifications, and system configuration for an in situ tritium beta detector that would use the fluor-doped fibers as primary sensors of tritium concentration in water. The major conclusions from the characterization work are: A polystyrene optical fiber with fluor dopant concentration of 2% gave best performance. This fiber had the highest dopant concentration of any fibers tested. Stability may be a problem. The fibers exposed to a 22-day soak in 120 F water experienced a 10x reduction in sensitivity. It is not known whether this was due to the build up of a deposit (a potentially reversible effect) or an irreversible process such as leaching of the scintillating dye. Based on the results achieved, it is premature to initiate Phase 2 and commit to a prototype

  7. 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

  8. 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.

  9. Low-dosage micronized 17 beta-estradiol prevents bone loss in postmenopausal women

    NASA Technical Reports Server (NTRS)

    Ettinger, B.; Genant, H. K.; Steiger, P.; Madvig, P.

    1992-01-01

    With the use of a double-blind, randomized, dose-ranging design, we tested during an 18-month period the degree of protection against postmenopausal bone loss afforded by micronized 17 beta-estradiol in dosages of 0.5, 1.0, and 2.0 mg. All subjects received supplementation to ensure a minimum of 1500 mg calcium daily. Fifty-one subjects completed at least 1 year of follow-up bone density measurements by quantitative computed tomography and by single- and dual-photon absorptiometry. In the placebo group spinal trabecular bone density decreased 4.9% annually (p less than 0.001), whereas in those taking micronized 17 beta-estradiol bone density tended to increase (annual increases of 0.3% in the 0.5 mg micronized 17 beta-estradiol group, 1.8% in the 1.0 mg micronized 17 beta-estradiol group, and 2.5% in the 2.0 mg micronized 17 beta-estradiol group). After completing the double-blind phase, 41 subjects completed an additional 18 months of follow-up while taking 1.0 mg micronized 17 beta-estradiol. During this time one third of the subjects were randomly assigned to discontinue calcium supplements. Among those who previously received placebo, trabecular bone density increased 4.3% annually, whereas among those who had used micronized 17 beta-estradiol, trabecular bone density response was inversely related to the dosage previously used. Additionally and independently, the level of calcium intake showed a statistically significant correlation with the change in spinal trabecular bone density (r = 0.37, p = 0.02). We conclude that micronized 17 beta-estradiol has a continuous skeletal dose-response effect in the range of 0.5 to 2.0 mg and that calcium intake positively modifies the skeletal response to 1.0 mg micronized 17 beta-estradiol.

  10. A Diet Containing Beta-Hydroxy-Beta-Methylbutyrate, L-Glutamine and L-Arginine Ameliorates Chemoradiation-Induced Gastrointestinal Injury in Rats.

    PubMed

    Alsan Cetin, Ilknur; Atasoy, Beste M; Cilaker, Serap; Alicikus, Lutfiye Zumre Arican; Karaman, Meral; Ersoy, Nevin; Demiral, Ayse Nur; Yilmaz, Osman

    2015-10-01

    The aim of this study was to investigate the effects of a specific diet, containing beta-hydroxy-beta-methylbutyrate, L-glutamine and L-arginine (HMB/Glu/Arg), on chemoradiation-induced injuries of the rat gastrointestinal mucosa. Wistar albino rats were divided into 4 groups: control (n = 5); radiation (n = 14); 5-fluorouracil treatment (5-FU; n = 14); and radiation and 5-FU treatment (n = 14). Rats were fed either a standard diet or a specific diet (SpD) containing HMB/Glu/Arg supplementation for 7 days prior to radiation exposure and/or 5-FU treatment. The irradiated groups were exposed to an 1 Gy dose of 6 MV x rays delivered to the who-abdominal. The animals receiving 5-FU treatment were given a 100 mg/kg dose of the drug. In the radiation and 5-FU treatment group, the 5-FU was administered 30 min prior to irradiation. After irradiation and/or 5-FU treatment, feeding with either the standard rat diet or specific diet continued as before. All animals were sacrificed on day 4 after irradiation and 5-FU treatment. Data collected included microbiological, histological and immunohistochemical end points. We found that bacterial colony counts in the ceca and mesenteric lymph nodes of irradiated rats treated with 5-FU were significantly lower in the specific diet (SpD) group than in the standard diet group (P = 0.002-0.05). Morphometrically, gastric, duodenal and colonic mucosal injuries were less severe in the irradiated animals fed the specific diet, as well as the 5-FU-treated animals fed the specific diet, compared to the similarly treated standard diet groups. Apoptosis, measured by TUNEL, revealed significantly lower numbers of TUNEL positive cells in irradiated animals fed the specific diet, and irradiated animals treated with 5-FU and fed the specific diet compared to irradiated animals fed the standard diet, and irradiated animals treated with 5-FU and fed the standard diet. In the 5-Fu-treated and SpD group, the extent of apoptosis was significantly lower

  11. Planning for Project Continuation.

    ERIC Educational Resources Information Center

    Berry, Grant, Jr.

    Designed to help colleges plan for the successful continuation of educational improvement projects beyond the end of their original funding period, this report presents a case study of Pennsylvania College of Technology's (PCT's) efforts to ensure the continuation of a Title III faculty development program. After describing the the Title III…

  12. Library of Continuation Algorithms

    2005-03-01

    LOCA (Library of Continuation Algorithms) is scientific software written in C++ that provides advanced analysis tools for nonlinear systems. In particular, it provides parameter continuation algorithms. bifurcation tracking algorithms, and drivers for linear stability analysis. The algorithms are aimed at large-scale applications that use Newton’s method for their nonlinear solve.

  13. 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…

  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. 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…

  16. Pin1 promotes production of Alzheimer's amyloid {beta} from {beta}-cleaved amyloid precursor protein

    SciTech Connect

    Akiyama, Hirotada; Shin, Ryong-Woon; Uchida, Chiyoko; Kitamoto, Tetsuyuki; Uchida, Takafumi . E-mail: uchidat@cir.tohoku.ac.jp

    2005-10-21

    Here we show that prolyl isomerase Pin1 is involved in the A{beta} production central to the pathogenesis of Alzheimer's disease. Enzyme immunoassay of brains of the Pin1-deficient mice revealed that production of A{beta}40 and A{beta}42 was lower than that of the wild-type mice, indicating that Pin1 promotes A{beta} production in the brain. GST-Pin1 pull-down and immunoprecipitation assay revealed that Pin1 binds phosphorylated Thr668-Pro of C99. In the Pin1 {sup -/-} MEF transfected with C99, Pin1 co-transfection enhanced the levels of A{beta}40 and A{beta}42 compared to that without Pin1 co-transfection. In COS7 cells transfected with C99, Pin1 co-transfection enhanced the generation of A{beta}40 and A{beta}42, and reduced the expression level of C99, facilitating the C99 turnover. Thus, Pin1 interacts with C99 and promotes its {gamma}-cleavage, generating A{beta}40 and A{beta}42. Further, GSK3 inhibitor lithium blocked Pin1 binding to C99 by decreasing Thr668 phosphorylation and attenuated A{beta} generation, explaining the inhibitory effect of lithium on A{beta} generation.

  17. Imperfect World of beta beta-decay Nuclear Data Sets

    SciTech Connect

    Pritychenko, B.

    2015-01-03

    The precision of double-beta ββ-decay experimental half lives and their uncertainties is reanalyzed. The method of Benford's distributions has been applied to nuclear reaction, structure and decay data sets. First-digit distribution trend for ββ-decay T2v1/2 is consistent with large nuclear reaction and structure data sets and provides validation of experimental half-lives. A complementary analysis of the decay uncertainties indicates deficiencies due to small size of statistical samples, and incomplete collection of experimental information. Further experimental and theoretical efforts would lead toward more precise values of-decay half-lives and nuclear matrix elements.

  18. Response of Panasonic dosimeters to submersion exposure by 133Xe.

    PubMed

    Hoffman, J M; Catchen, G L

    1990-01-01

    The dose response to 133Xe radiation of several types of Panasonic 800 series thermoluminescent dosimeters (TLD) were evaluated. The dosimeters were exposed by submersion in 133Xe gas. The relative sensitivities of the lithium borate and the calcium sulfate phosphors were determined for several configurations. The TLDs were exposed in the holders (as the devices came from the vendor) with various shields covering the elements, and they were exposed with the TLDs removed from the holders. Some dosimeters were exposed, both in holders and out of holders (TL insert only configuration), both in plastic bags and free in air. For the in-holder configuration, the responses of the heavily shielded (greater than 170 mg cm-2) elements were used to obtain the photon dose-rate component, and the responses of the lightly shielded (less than 13 mg cm-2) element were used to obtain the beta component. Similarly, for the insert-only configurations, the observed over-response of the calcium sulfate phosphors to low-energy photons could be used to separate the beta dose rate component. By using the calculated beta doses, correction factors were determined for the apparent under-responses of the elements to beta radiation. The results of both methods are consistent. These results also suggest that the beta component could be used in environmental monitoring as a more sensitive means to determine 133Xe activities in clouds and to separate some of the effects of submersion exposure from those of distant exposure.

  19. Beta-glucosidase I variants with improved properties

    DOEpatents

    Bott, Richard R.; Kaper, Thijs; Kelemen, Bradley; Goedegebuur, Frits; Hommes, Ronaldus Wilhelmus; Kralj, Slavko; Kruithof, Paulien; Nikolaev, Igor; Van Der Kley, Wilhelmus Antonious Hendricus; Van Lieshout, Johannes Franciscus Thomas; Van Stigt Thans, Sander

    2016-09-20

    The present disclosure is generally directed to enzymes and in particular beta-glucosidase variants. Also described are nucleic acids encoding beta-glucosidase variants, compositions comprising beta-glucosidase variants, methods of using beta-glucosidase variants, and methods of identifying additional useful beta-glucosidase variants.

  20. Comparative in vivo expression of beta(+)-thalassemia alleles.

    PubMed

    Marwan, M M; Scerri, C A; Zarroag, S O; Cao, A; Kyrri, A; Kalogirou, E; Kleanthous, M; Ioannou, P; Angastiniotis, M; Felice, A E

    1999-08-01

    Double heterozygotes who inherit one abnormal though stable beta-globin variant in association with a molecularly identified beta(+)-thalassaemia allele provide unique opportunities to quantify the in vivo expression of particular beta(+)-thalassemia alleles. The globin products of the two alleles can be separated, quantified and the output of the beta(+)-thalassaemia allele expressed as the MCH-beta(A) in pg beta(A)-globin/beta(+)-thalassemia allele/RBC = 0.5 MCH x Hb A%. In this communication we provide new quantitative data on the expression of five mutations as follows: the beta(+)-87 (C-->G) = 3.8 pg beta(A)-globin/beta(+)-thalassemia allele/RBC (n = 1); the beta(+) IVS-I-1 (G-->A) = 0.2 pg beta(A)-globin/beta(+)-thalassemia allele/RBC (n = 1); the beta(+) IVS-I-6 (T-->C) = 2.9 pg beta(A)-globin/beta(+)-thalassemia allele/RBC (n = 7); the beta(+) IVS-I-110 (G-->A) = 1.1 pg beta(A)-globin/beta(+)-thalassemia allele/RBC (n = 13), and the beta(+) IVS-II-745 (C-->G) = 1.74 pg beta(A)-globin/beta(+)-thalassemia allele/RBC (n = 2). The values obtained are compared with those of other beta(+)-thalassemia alleles from the literature. It can be seen that the MCH-beta(A) value may be a correct index of thalassemia severity useful for the correlation of genotype with phenotype, and for understanding the effects of mutations in beta-globin genes on pathophysiologically meaningful beta-globin gene expression. PMID:10490134

  1. Environmental hydrogen embrittlement of an alpha-beta titanium alloy - Effect of microstructure.

    NASA Technical Reports Server (NTRS)

    Nelson, H. G.; Williams, D. P.; Stein, J. E.

    1972-01-01

    Study of environmental hydrogen embrittlement of a Ti-6 Al-4 alloy as a function of test displacement rate and of variations in alpha-beta microstructure. Embrittlement in low-pressure (about 1 atm) gaseous hydrogen was inversely dependent on test displacement rate and strongly dependent on microstructure. At a given displacement rate, microstructures having a continuous alpha-phase matrix were less severely embrittled than those having a continuous beta-phase matrix. Further, brittle fracture occurred in the former microstructures by transgranular cleavage and in the latter microstructures by intergranular separation. These observations are consistent with previous studies made on slow strain-rate embrittlement of hydrogen-charged titanium alloys and are explained in terms of relative hydrogen transport rates within the alpha-phase and beta-phase titanium.

  2. Latent transforming growth factor beta1 activation in situ: quantitative and functional evidence after low-dose gamma-irradiation

    NASA Technical Reports Server (NTRS)

    Ehrhart, E. J.; Segarini, P.; Tsang, M. L.; Carroll, A. G.; Barcellos-Hoff, M. H.; Chatterjee, A. (Principal Investigator)

    1997-01-01

    The biological activity of transforming growth factor beta1 (TGF-beta) is controlled by its secretion as a latent complex in which it is noncovalently associated with latency-associated peptide (LAP). Activation is the extracellular process in which TGF-beta is released from LAP, and is considered to be a primary regulatory control. We recently reported rapid and persistent changes in TGF-beta immunoreactivity in conjunction with extracellular matrix remodeling in gamma-irradiated mouse mammary gland. Our hypothesis is that these specific changes in immunoreactivity are indicative of latent TGF-beta activation. In the present study, we determined the radiation dose response and tested whether a functional relationship exists between radiation-induced TGF-beta and collagen type III remodeling. After radiation exposures as low as 0.1 Gy, we detected increased TGF-beta immunoreactivity in the mammary epithelium concomitant with decreased LAP immunostaining, which are events consistent with activation. Quantitative image analysis demonstrated a significant (P=0.0005) response at 0.1 Gy without an apparent threshold and a linear dose response to 5 Gy. However, in the adipose stroma, loss of LAP demonstrated a qualitative threshold at 0.5 Gy. Loss of LAP paralleled induction of collagen III immunoreactivity in this tissue compartment. We tested whether TGF-beta mediates collagen III expression by treating animals with TGF-beta panspecific monoclonal antibody, 1D11.16, administered i.p. shortly before irradiation. Radiation-induced collagen III staining in the adipose stroma was blocked in an antibody dose-dependent manner, which persisted through 7 days postirradiation. RNase protection assay revealed that radiation-induced elevation of total gland collagen III mRNA was also blocked by neutralizing antibody treatment. These data provide functional confirmation of the hypothesis that radiation exposure leads to latent TGF-beta activation, support our interpretation of the

  3. EUV sources for EUV lithography in alpha-, beta-, and high volume chip manufacturing: an update on GDPP and LPP technology

    NASA Astrophysics Data System (ADS)

    Stamm, U.; Kleinschmidt, J.; Gabel, K.; Hergenhan, G.; Ziener, C.; Schriever, G.; Ahmad, I.; Bolshukhin, D.; Brudermann, J.; de Bruijn, R.; Chin, T. D.; Geier, A.; Gotze, S.; Keller, A.; Korobotchko, V.; Mader, B.; Ringling, J.; Brauner, T.

    2005-05-01

    In the paper we report about the progress made at XTREME technologies in the development of EUV sources based on gas discharge produced plasma (GDPP) technologies and laser produced plasma (LPP) technologies. First prototype xenon GDPP sources of the type XTS 13-35 based on the Z-pinch principle with 35 W power in 2π sr have been integrated into micro-exposure tools from Exitech, UK. Specifications of the EUV sources and experience of integration as well as data about component and optics lifetime are presented. In the source development program for Beta exposure tools and high volume manufacturing exposure tools both tin and xenon have been investigated as fuel for the EUV sources. Development progress in porous metal cooling technology as well as pulsed power circuit design has led to GDPP sources with xenon fuel continuous operating with an output power of 200 W in 2π sr at 4500 Hz repetition rate. With tin fuel an output power of 400 W in 2π sr was obtained leaving all other conditions unaltered with respect to the xenon based source. The performance of the xenon fueled sources is sufficiently good to fulfill all requirements up to the beta tool level. For both the xenon and the tin GDPP sources detailed data about source performance are reported, including component lifetime and optics lifetime. The status of the integration of the sources with grazing incidence collector optics is discussed. Theoretical estimations of collection efficiencies are compared with experimental data to determine the loss mechanisms in the beam path. Specifically contamination issues related to tin as target material as well as debris mitigation in tin sources is addressed. As driver lasers for the LPP source research diode-pumped Nd:YAG lasers have been used to generate EUV emitting plasma. As target material xenon has been employed. Conversion efficiencies have been measured and currently the maximum conversion efficiency amounts to 1 %. The laser driver power of 1.2 kW is

  4. Method for converting sucrose to .beta.-D-glucose

    DOEpatents

    Simmons, Blake A.; Volponi, Joanne V.; Ingersoll, David; Walker, Andrew

    2009-07-07

    Disclosed is an apparatus and method for continuously converting sucrose to .beta.-D-glucose. The method comprises a three-stage enzymatic reactor in which an aqueous solution of sucrose is first converted into a solution of fructose and .alpha.-D-glucose by passing it through a porous, packed column containing an inert media on which invertase is immobilized. This solution is then sent through a second packed column containing glucose isomerase and finally a third packed column containing mutarotase. Solution temperature and pH are adjusted to maximize glucose output.

  5. Augmented mixed beta regression models for periodontal proportion data

    PubMed Central

    Galvis, Diana M.; Bandyopadhyay, Dipankar; Lachos, Victor H.

    2014-01-01

    Continuous (clustered) proportion data often arise in various domains of medicine and public health where the response variable of interest is a proportion (or percentage) quantifying disease status for the cluster units, ranging between zero and one. However, because of the presence of relatively disease-free as well as heavily diseased subjects in any study, the proportion values can lie in the interval [0, 1]. While beta regression can be adapted to assess covariate effects in these situations, its versatility is often challenged because of the presence/excess of zeros and ones because the beta support lies in the interval (0, 1). To circumvent this, we augment the probabilities of zero and one with the beta density, controlling for the clustering effect. Our approach is Bayesian with the ability to borrow information across various stages of the complex model hierarchy and produces a computationally convenient framework amenable to available freeware. The marginal likelihood is tractable and can be used to develop Bayesian case-deletion influence diagnostics based on q-divergence measures. Both simulation studies and application to a real dataset from a clinical periodontology study quantify the gain in model fit and parameter estimation over other ad hoc alternatives and provide quantitative insight into assessing the true covariate effects on the proportion responses. PMID:24764045

  6. Beta maritima: the Origin of Beets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Along the undisturbed shores, especially of the Mediterranean Sea and the European North Atlantic Ocean, is a widespread plant called Beta maritima (Beta vulgaris subspecies maritima) by the botanists, or more commonly sea beet. Nothing for the inexperienced observer's eye distinguishes it from surr...

  7. Expression of transforming growth factor beta (TGF beta) receptors and expression of TGF beta 1, TGF beta 2 and TGF beta 3 in human small cell lung cancer cell lines.

    PubMed Central

    Damstrup, L.; Rygaard, K.; Spang-Thomsen, M.; Skovgaard Poulsen, H.

    1993-01-01

    A panel of 21 small cell lung cancer cell (SCLC) lines were examined for the presence of Transforming growth factor beta receptors (TGF beta-r) and the expression of TGF beta mRNAs. By the radioreceptor assay we found high affinity receptors to be expressed in six cell lines. scatchard analysis of the binding data demonstrated that the cells bound between 4.5 and 27.5 fmol mg-1 protein with a KD ranging from 16 to 40 pM. TGF beta 1 binding to the receptors was confirmed by cross-linking TGF beta 1 to the TGF beta-r. Three classes of TGF beta-r were demonstrated, type I and type II receptors with M(r) = 65,000 and 90,000 and the betaglycan (type III) with M(r) = 280,000. Northern blotting showed expression of TGF beta 1 mRNA in ten, TGF beta 2 mRNA in two and TGF beta 3 mRNA in seven cell lines. Our results provide, for the first time, evidence that a large proportion of a broad panel of SCLC cell lines express TGF beta-receptors and also produce TGF beta mRNAs. Images Figure 3 Figure 4 PMID:8388229

  8. An integrated job exposure matrix for electrical exposures of utility workers.

    PubMed

    Bracken, T Dan; Kavet, Robert; Patterson, Robert M; Fordyce, Tiffani A

    2009-08-01

    Electric utility workers may be exposed to any combination of magnetic fields, electric fields, nuisance shocks (from spark discharges and continuous currents), imperceptible contact currents, and electrical injuries. Collectively these exposures are referred to as EMF Factors. Previous occupational exposure assessments have mainly characterized the magnetic field, with less attention to the electric field. Nuisance shocks and electrical injuries, though palpable, have received little to no attention. This article presents a prototype job exposure matrix that addresses exposure to all EMF Factors taking into account job category, work environment, and occupied environment. Exposures for all factors were classified into three ordinal levels for 22 job categories. Electric and magnetic field exposures were classified by the geometric mean of daily average of personal exposure measurements. Although relatively sparse, survey data on nuisance shocks were adequate for exposure assignment by job category and indicate that the frequency of these exposures has diminished over time. The least information was available for imperceptible contact currents that are associated with electric field exposures and small contact voltages. Data for electrical injuries by job category were derived from the Electric Power Research Institute Occupational Health Surveillance Database, with exposure assignments based on combined injury rates for flash burn and electric shock/electrocution. The highest exposures for all EMF Factors are essentially limited to four job categories that work on or close to electrical equipment: (1) cable splicers, (2) electricians, (3) line workers, and (4) substation operators.

  9. Observation of the acceleration by an electromagnetic field of nuclear beta decay

    NASA Astrophysics Data System (ADS)

    Reiss, H. R.

    2008-02-01

    Measurements are reported of the acceleration of the first-forbidden beta decay of 137Cs by exposure to intense, low-frequency electromagnetic fields. Two separate experiments were done: one in a coaxial cavity, and the other in a coaxial transmission line. The first showed an increase in the beta decay rate of (6.8±3.2)×10-4 relative to the natural rate, and the other resulted in an increase of (6.5±2.0)×10- 4. In addition, a Fourier analysis of the rate of 662 keV gamma emission following from the beta decay in the standing-wave experiment showed a clear indication of the frequency with which the external field was switched on and off. A simultaneously detected gamma emission from a placebo nucleus showed no such peak.

  10. PBX: the Princeton beta experiment

    SciTech Connect

    Bol, K.; Chance, M.; Dewar, R.

    1983-09-01

    A rearrangement of the divertor coils in PDX will enable a test in 1984 of the MHD stability properties of deeply indented bean-shaped plasmas. The goal is a beta of 10%. Indentation is expected to counter the deterioration of MHD stability against pressure driven modes that is occasioned by the larger aspect ratios typical of anticipated reactor oriented devices. Indeed, as shown by M. Chance et al., indentation may offer direct access to the second region of stability for ballooning modes, and numerical analyses with PEST show the internal kink to be stabilized completely with even relatively modest indentation. The internal kink is implicated in the loss of beam ions in PDX. In this report the theoretical basis for the forthcoming experiment, and the design considerations underlying the modification from PDX to PBX, are described in detail. Additional theoretical material, including an analysis of particle orbits in an indented tokamak plasma, is appended.

  11. The chromosphere of Beta Cassiopeiae

    NASA Technical Reports Server (NTRS)

    Teays, Terry J.; Schmidt, Edward G.; Pasinetti Fracassini, Laura E.; Fracassini, Massimo

    1989-01-01

    High-resolution, long-wavelength IUE observations and ground-based photometry of the Delta Scuti star Beta Cas is reported. The ground-based observations were used together with previous results of Antonello et al. (1986) to ensure that the IUE observations were correctly phased relative to the photometric variation. Fluxes for the emission core of the Mg II k 2796-A line were obtained from the UV spectra over several cycles in 1986 and 1987. It is found that there is an increase in the emission during part of the cycle, but it occurs near minimum light in contrast to another Delta Scuti star, Rho Pup, and the classical Cepheids (where it occurs near maximum light). The mean level of chromospheric activity is comparable to other early F dwarfs.

  12. Bovine beta-mannosidase deficiency.

    PubMed

    Bryan, L; Schmutz, S; Hodges, S D; Snyder, F F

    1990-12-14

    A fatal inherited glycoprotein storage disorder is described in Salers cattle which affects both sexes. Affected calves are unable to stand at birth, have a marked intention tremor, markedly enlarged kidneys, decreased white matter in all areas of the brain, and cytoplasmic vacuolation in multiple cell types of multiple tissues with nervous, renal, lymphoid and thyroid tissues most severely affected. Affected calves were grossly deficient in lymphocyte and brain beta-mannosidase activity and had markedly reduced but not deficient activity in liver and kidney. A test mating of obligate carriers produced three genotypes: affected, carrier, non-carrier in essentially the expected ratio of 1:2:1, consistent with autosomal recessive inheritance. PMID:2260963

  13. Peripheral beta-endorphin and pain modulation.

    PubMed

    Hartwig, A C

    1991-01-01

    Beta-endorphin is a peptide with morphine-like effects produced primarily in the anterior lobe of the pituitary gland. After its cleavage from the parent molecule, proopiomelanocortin, beta-endorphin is circulated via the blood stream to interact with specific opioid receptors located throughout the body. The peptide produces analgesia by inhibiting the firing of peripheral somatosensory fibers. It also affects other senses, such as vision, hearing, and smell. Whereas the ability to increase beta-endorphin secretion during times of surgical stress is positively correlated with amelioration of pain, the administration of exogenous opioids, such as fentanyl, reduces plasma beta-endorphin. Decreased beta-endorphin concentrations may play a role in trigeminal neuralgia, migraine headache, and rheumatoid arthritis. PMID:1814247

  14. Gamma-ray blind beta particle probe

    DOEpatents

    Weisenberger, Andrew G.

    2001-01-01

    An intra-operative beta particle probe is provided by placing a suitable photomultiplier tube (PMT), micro channel plate (MCP) or other electron multiplier device within a vacuum housing equipped with: 1) an appropriate beta particle permeable window; and 2) electron detection circuitry. Beta particles emitted in the immediate vicinity of the probe window will be received by the electron multiplier device and amplified to produce a detectable signal. Such a device is useful as a gamma insensitive, intra-operative, beta particle probe in surgeries where the patient has been injected with a beta emitting radiopharmaceutical. The method of use of such a device is also described, as is a position sensitive such device.

  15. Peripheral beta-endorphin and pain modulation.

    PubMed

    Hartwig, A C

    1991-01-01

    Beta-endorphin is a peptide with morphine-like effects produced primarily in the anterior lobe of the pituitary gland. After its cleavage from the parent molecule, proopiomelanocortin, beta-endorphin is circulated via the blood stream to interact with specific opioid receptors located throughout the body. The peptide produces analgesia by inhibiting the firing of peripheral somatosensory fibers. It also affects other senses, such as vision, hearing, and smell. Whereas the ability to increase beta-endorphin secretion during times of surgical stress is positively correlated with amelioration of pain, the administration of exogenous opioids, such as fentanyl, reduces plasma beta-endorphin. Decreased beta-endorphin concentrations may play a role in trigeminal neuralgia, migraine headache, and rheumatoid arthritis.

  16. Beta Pictoris planet finally imaged?

    NASA Astrophysics Data System (ADS)

    2008-11-01

    A team of French astronomers using ESO's Very Large Telescope have discovered an object located very close to the star Beta Pictoris, and which apparently lies inside its disc. With a projected distance from the star of only 8 times the Earth-Sun distance, this object is most likely the giant planet suspected from the peculiar shape of the disc and the previously observed infall of comets onto the star. It would then be the first image of a planet that is as close to its host star as Saturn is to the Sun. Sharpening Up Jupiter ESO PR Photo 42a/08 Beta Pictoris as seen in infrared light The hot star Beta Pictoris is one of the best-known examples of stars surrounded by a dusty 'debris' disc. Debris discs are composed of dust resulting from collisions among larger bodies like planetary embryos or asteroids. They are a bigger version of the zodiacal dust in our Solar System. Its disc was the first to be imaged -- as early as 1984 -- and remains the best-studied system. Earlier observations showed a warp of the disc, a secondary inclined disc and infalling comets onto the star. "These are indirect, but tell-tale signs that strongly suggest the presence of a massive planet lying between 5 and 10 times the mean Earth-Sun distance from its host star," says team leader Anne-Marie Lagrange. "However, probing the very inner region of the disc, so close to the glowing star, is a most challenging task." In 2003, the French team used the NAOS-CONICA instrument (or NACO [1]), mounted on one of the 8.2 m Unit Telescopes of ESO's Very Large Telescope (VLT), to benefit from both the high image quality provided by the Adaptive Optics system at infrared wavelengths and the good dynamics offered by the detector, in order to study the immediate surroundings of Beta Pictoris. Recently, a member of the team re-analysed the data in a different way to seek the trace of a companion to the star. Infrared wavelengths are indeed very well suited for such searches. "For this, the real challenge

  17. Continuing Appropriations Act, 2012

    THOMAS, 112th Congress

    Rep. Aderholt, Robert B. [R-AL-4

    2011-05-26

    09/30/2011 Became Public Law No: 112-33. (TXT | PDF) (All Actions) Notes: Continuing appropriations through 10/4/2011. Tracker: This bill has the status Became LawHere are the steps for Status of Legislation:

  18. Continuing Appropriations Act, 2012

    THOMAS, 112th Congress

    Rep. Graves, Sam [R-MO-6

    2011-07-21

    10/05/2011 Became Public Law No: 112-36. (TXT | PDF) (All Actions) Notes: Continuing appropriations through 11/18/2011. Tracker: This bill has the status Became LawHere are the steps for Status of Legislation:

  19. Locating Continuing Education Programs.

    ERIC Educational Resources Information Center

    Mason, Robert C.

    1986-01-01

    Emphasizes program location as an important component of the marketing plan for continuing education. Also discusses relations among program location and quality, costs, supportive services, and economies of scale. (CH)

  20. Continuing Appropriations Act, 2011

    THOMAS, 111th Congress

    Rep. Lowey, Nita M. [D-NY-18

    2009-06-26

    09/30/2010 Became Public Law No: 111-242. (TXT | PDF) (All Actions) Notes: Continuing appropriations through 12/3/2010. Tracker: This bill has the status Became LawHere are the steps for Status of Legislation:

  1. Continual improvement plan

    NASA Technical Reports Server (NTRS)

    1994-01-01

    NASA's approach to continual improvement (CI) is a systems-oriented, agency-wide approach that builds on the past accomplishments of NASA Headquarters and its field installations and helps achieve NASA's vision, mission, and values. The NASA of the future will fully use the principles of continual improvement in every aspect of its operations. This NASA CI plan defines a systematic approach and a model for continual improvement throughout NASA, stressing systems integration and optimization. It demonstrates NASA's constancy of purpose for improvement - a consistent vision of NASA as a worldwide leader in top-quality science, technology, and management practices. The CI plan provides the rationale, structures, methods, and steps, and it defines NASA's short term (1-year) objectives for improvement. The CI plan presents the deployment strategies necessary for cascading the goals and objectives throughout the agency. It also provides guidance on implementing continual improvement with participation from top leadership and all levels of employees.

  2. Continuing Appropriations Resolution, 2015

    THOMAS, 113th Congress

    Rep. Rogers, Harold [R-KY-5

    2014-09-09

    09/19/2014 Became Public Law No: 113-164. (TXT | PDF) (All Actions) Notes: Continuing appropriations through 12/11/2014. Tracker: This bill has the status Became LawHere are the steps for Status of Legislation:

  3. 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

  4. 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. PMID:20159912

  5. 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.

  6. Genetics Home Reference: mucolipidosis III alpha/beta

    MedlinePlus

    ... Health Conditions mucolipidosis III alpha/beta mucolipidosis III alpha/beta Enable Javascript to view the expand/collapse ... PDF Open All Close All Description Mucolipidosis III alpha/beta is a slowly progressive disorder that affects ...

  7. Genetics Home Reference: mucolipidosis II alpha/beta

    MedlinePlus

    ... Health Conditions mucolipidosis II alpha/beta mucolipidosis II alpha/beta Enable Javascript to view the expand/collapse ... PDF Open All Close All Description Mucolipidosis II alpha/beta (also known as I-cell disease) is ...

  8. 21 CFR 866.5160 - Beta-globulin immunolog-ical test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Beta-globulin immunolog-ical test system. 866.5160 Section 866.5160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems § 866.5160...

  9. 21 CFR 866.5630 - Beta-2-microglobulin immunological test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Beta-2-microglobulin immunological test system. 866.5630 Section 866.5630 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems §...

  10. 21 CFR 866.5630 - Beta-2-microglobulin immunological test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Beta-2-microglobulin immunological test system. 866.5630 Section 866.5630 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems §...

  11. 21 CFR 866.5430 - Beta-2-glycoprotein I immunological test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Beta-2-glycoprotein I immunological test system. 866.5430 Section 866.5430 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems §...

  12. 21 CFR 866.5440 - Beta-2-glycoprotein III immunological test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Beta-2-glycoprotein III immunological test system. 866.5440 Section 866.5440 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems §...

  13. 21 CFR 866.5630 - Beta-2-microglobulin immunological test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Beta-2-microglobulin immunological test system. 866.5630 Section 866.5630 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems §...

  14. 21 CFR 866.5160 - Beta-globulin immunolog-ical test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Beta-globulin immunolog-ical test system. 866.5160 Section 866.5160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems § 866.5160...

  15. 21 CFR 866.5630 - Beta-2-microglobulin immunological test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Beta-2-microglobulin immunological test system. 866.5630 Section 866.5630 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems §...

  16. 21 CFR 866.5440 - Beta-2-glycoprotein III immunological test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Beta-2-glycoprotein III immunological test system. 866.5440 Section 866.5440 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems §...

  17. 21 CFR 866.5430 - Beta-2-glycoprotein I immunological test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Beta-2-glycoprotein I immunological test system. 866.5430 Section 866.5430 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems §...

  18. 21 CFR 866.5160 - Beta-globulin immunolog-ical test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Beta-globulin immunolog-ical test system. 866.5160 Section 866.5160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems § 866.5160...

  19. Adaptive continuous twisting algorithm

    NASA Astrophysics Data System (ADS)

    Moreno, Jaime A.; Negrete, Daniel Y.; Torres-González, Victor; Fridman, Leonid

    2016-09-01

    In this paper, an adaptive continuous twisting algorithm (ACTA) is presented. For double integrator, ACTA produces a continuous control signal ensuring finite time convergence of the states to zero. Moreover, the control signal generated by ACTA compensates the Lipschitz perturbation in finite time, i.e. its value converges to the opposite value of the perturbation. ACTA also keeps its convergence properties, even in the case that the upper bound of the derivative of the perturbation exists, but it is unknown.

  20. Cluster observes formation of high-beta plasma blobs

    NASA Astrophysics Data System (ADS)

    Haerendel, G.; Georgescu, E.; Glassmeier, K. H.; Klecker, B.; Bogdanova, J.; Reme, H.; Frey, H. U.; Vaivads, A.

    2003-04-01

    Late in a sequence of four moderate substorms an 26 July 2001, Cluster observed periods of a few minutes durations of high-beta plasma events (B < 10nT, beta = 2 - 30), connected with dipolarizations of the magnetic field. Cluster was located near 02:45 MLT, at R = 19 Re and at about 5 degrees N GSM. These events began late in the recovery phase of the second and about 5 minutes before onset of the third substorm and lasted for three hours, way beyond the recovery phase of the fourth substorm. The most remarkable observation is that the onset coincided with the arrival of energetic (E ~ 7 keV) O+ ions from the ionosphere, which tended to dominate the plasma composition throughout the remaining time. The magnetic flux and the transverse plasma transport is continuously directed equator- and earthward with oscillatory east-west movements superposed. Periods of order 5 - 10 minutes and strong correlations between the magnetic elevation angle and log(beta) (correlation coefficient 0.78) are highly reminiscent of the high-beta plasma blobs discovered with Equator-S and Geotail between 9 and 11 Re in the late night/early morning sector [Haerendel et al. 1999]. Another feature in common with the Equator-S and Geotail observations is the plasma flow towards low latitudes during the magnetic field recovery. We conclude that Cluster observed the plasma blob formation in the tail plasma sheet, which seems to occur dominantly in the recovery and post-recovery phase of substorms. This is consistent with the finding of Equator-S and Geotail. The origin is a pulsed earthward plasma transport with velocity amplitudes of only several tens of km/s. It needs to be investigated whether the preceeding injection of ionospheric O+ ions into the plasma sheet plays a causal role in the process.