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Sample records for 24-h exposure period

  1. Intrinsic near-24-h pacemaker period determines limits of circadian entrainment to a weak synchronizer in humans.

    PubMed

    Wright, K P; Hughes, R J; Kronauer, R E; Dijk, D J; Czeisler, C A

    2001-11-20

    Endogenous circadian clocks are robust regulators of physiology and behavior. Synchronization or entrainment of biological clocks to environmental time is adaptive and important for physiological homeostasis and for the proper timing of species-specific behaviors. We studied subjects in the laboratory for up to 55 days each to determine the ability to entrain the human clock to a weak circadian synchronizing stimulus [scheduled activity-rest cycle in very dim (approximately 1.5 lux in the angle of gaze) light-dark cycle] at three approximately 24-h periods: 23.5, 24.0, and 24.6 h. These studies allowed us to test two competing hypotheses as to whether the period of the human circadian pacemaker is near to or much longer than 24 h. We report here that imposition of a sleep-wake schedule with exposure to the equivalent of candle light during wakefulness and darkness during sleep is usually sufficient to maintain circadian entrainment to the 24-h day but not to a 23.5- or 24.6-h day. Our results demonstrate functionally that, in normally entrained sighted adults, the average intrinsic circadian period of the human biological clock is very close to 24 h. Either exposure to very dim light and/or the scheduled sleep-wake cycle itself can entrain this near-24-h intrinsic period of the human circadian pacemaker to the 24-h day. PMID:11717461

  2. Intrinsic near-24-h pacemaker period determines limits of circadian entrainment to a weak synchronizer in humans

    NASA Technical Reports Server (NTRS)

    Wright, K. P. Jr; Hughes, R. J.; Kronauer, R. E.; Dijk, D. J.; Czeisler, C. A.

    2001-01-01

    Endogenous circadian clocks are robust regulators of physiology and behavior. Synchronization or entrainment of biological clocks to environmental time is adaptive and important for physiological homeostasis and for the proper timing of species-specific behaviors. We studied subjects in the laboratory for up to 55 days each to determine the ability to entrain the human clock to a weak circadian synchronizing stimulus [scheduled activity-rest cycle in very dim (approximately 1.5 lux in the angle of gaze) light-dark cycle] at three approximately 24-h periods: 23.5, 24.0, and 24.6 h. These studies allowed us to test two competing hypotheses as to whether the period of the human circadian pacemaker is near to or much longer than 24 h. We report here that imposition of a sleep-wake schedule with exposure to the equivalent of candle light during wakefulness and darkness during sleep is usually sufficient to maintain circadian entrainment to the 24-h day but not to a 23.5- or 24.6-h day. Our results demonstrate functionally that, in normally entrained sighted adults, the average intrinsic circadian period of the human biological clock is very close to 24 h. Either exposure to very dim light and/or the scheduled sleep-wake cycle itself can entrain this near-24-h intrinsic period of the human circadian pacemaker to the 24-h day.

  3. Immune cell changes in response to a swimming training session during a 24-h recovery period.

    PubMed

    Morgado, José P; Monteiro, Cristina P; Teles, Júlia; Reis, Joana F; Matias, Catarina; Seixas, Maria T; Alvim, Marta G; Bourbon, Mafalda; Laires, Maria J; Alves, Francisco

    2016-05-01

    Understanding the impact of training sessions on the immune response is crucial for the adequate periodization of training, to prevent both a negative influence on health and a performance impairment of the athlete. This study evaluated acute systemic immune cell changes in response to an actual swimming session, during a 24-h recovery period, controlling for sex, menstrual cycle phases, maturity, and age group. Competitive swimmers (30 females, 15 ± 1.3 years old; and 35 males, 16.5 ± 2.1 years old) performed a high-intensity training session. Blood samples were collected before, immediately after, 2 h after, and 24 h after exercise. Standard procedures for the assessment of leukogram by automated counting (Coulter LH 750, Beckman) and lymphocytes subsets by flow cytometry (FACS Calibur BD, Biosciences) were used. Subjects were grouped according to competitive age groups and pubertal Tanner stages. Menstrual cycle phase was monitored. The training session induced neutrophilia, lymphopenia, and a low eosinophil count, lasting for at least 2 h, independent of sex and maturity. At 24 h postexercise, the acquired immunity of juniors (15-17 years old), expressed by total lymphocytes and total T lymphocytes (CD3(+)), was not fully recovered. This should be accounted for when planning a weekly training program. The observed lymphopenia suggests a lower immune surveillance at the end of the session that may depress the immunity of athletes, highlighting the need for extra care when athletes are exposed to aggressive environmental agents such as swimming pools. PMID:27028294

  4. Refined multiscale entropy: application to 24-h Holter recordings of heart period variability in healthy and aortic stenosis subjects.

    PubMed

    Valencia, José Fernando; Porta, Alberto; Vallverdú, Montserrat; Clarià, Francesc; Baranowski, Rafal; Orłowska-Baranowska, Ewa; Caminal, Pere

    2009-09-01

    Multiscale entropy (MSE) was proposed to characterize complexity as a function of the time-scale factor tau. Despite its broad use, this technique suffers from two limitations: 1) the artificial MSE reduction due to the coarse graining procedure and 2) the introduction of spurious MSE oscillations due to the suboptimal procedure for the elimination of the fast temporal scales. We propose a refined MSE (RMSE), and we apply it to simulations and to 24-h Holter recordings of heart rate variability (HRV) obtained from healthy and aortic stenosis (AS) groups. The study showed that the refinement relevant to the elimination of the fast temporal scales was more helpful at short scales (spanning the range of short-term HRV oscillations), while that relevant to the procedure of coarse graining was more useful at large scales. In healthy subjects, during daytime, RMSE was smaller at short scales (i.e., tau = 1-2) and larger at longer scales (i.e., tau = 4-20) than during nighttime. In AS population, RMSE was smaller during daytime both at short and long time scales (i.e., tau = 1 -11) than during nighttime. RMSE was larger in healthy group than in AS population during both daytime (i.e., tau = 2 -9) and nighttime (i.e., tau = 2). RMSE overcomes two limitations of MSE and confirms the complementary information that can be derived by observing complexity as a function of the temporal scale. PMID:19457745

  5. No effect of route of exposure (oral; subcutaneous injection) on plasma bisphenol A throughout 24h after administration in neonatal female mice.

    PubMed

    Taylor, Julia A; Welshons, Wade V; Vom Saal, Frederick S

    2008-02-01

    Route of administration of chemicals in adults is an important factor in pharmacokinetics of chemicals such as bisphenol A (BPA), the monomer with estrogenic activity used to make polycarbonate plastic products and to line food and beverage cans. Based on findings in adults it has been proposed (CERHR, 2007) that non-oral routes of administration in newborn rodents would also lead to high exposure relative to oral administration. However, in fetuses and neonates, the enzyme that conjugates BPA (UDP-glucuronosyltransferase) is expressed at low levels, suggesting that there may be no differences in pharmacokinetics between oral and non-oral dosing. We thus conducted an analysis of plasma concentrations of unconjugated 3H-BPA after HPLC separation in postnatal day 3 female mice throughout the 24h after administering 3H-BPA orally or via subcutaneous injection at doses above and below the current EPA reference dose. We found no significant difference in plasma BPA based on route of administration in neonatal mice at either dose. However, compared to data from other studies conducted with adults, there was a markedly higher plasma BPA level after oral administration of BPA in newborn mice. This finding sets aside the belief that non-oral administration of BPA renders data as not suitable for consideration of the hazard posed by low-dose exposure to BPA during neonatal life. Therefore the large numbers of BPA studies that used non-oral administration at very low doses during the neonatal period should not be dismissed by scientists or the regulatory community based on route of administration. PMID:18295446

  6. Estimation of the respiratory tract burden resulting from a prolonged inhalation exposure to aerosols of DU, based on the U in a 24-h urine sample taken years after exposure.

    PubMed

    Valdés, M

    2014-12-01

    A procedure is presented to estimate the respiratory tract burden from a prolonged inhalation exposure to particulate matter of depleted uranium, in cases where the rate of deposition is an unknown function. The precise range of possible values is identified. The calculations are based on the amount of depleted uranium measured in a single 24-h urine sample. In order to present an example, a simplified pharmacokinetical model is introduced. The results presented in this article are valid for any pharmacokinetical model represented by homogeneous linear differential equations with constant coefficients and non-zero initial values, and that clearly includes the International Commission on Radiological Protection model. In fact, they are applicable to any monitorable quantity measured over a short period of time, a monitorable quantity with a kinetic that can be described using a structurally similar system of differential equations to one describing these pharmacokinetical models. PMID:24682012

  7. Spatial learning and memory deficits following exposure to 24 h of sleep fragmentation or intermittent hypoxia in a rat model of obstructive sleep apnea.

    PubMed

    Ward, Christopher P; McCoy, John G; McKenna, James T; Connolly, Nina P; McCarley, Robert W; Strecker, Robert E

    2009-10-19

    Obstructive sleep apnea is primarily characterized by hypoxemia due to frequent apneic episodes and fragmentation of sleep due to the brief arousals that terminate the apneic episodes. Though neurobehavioral deficits frequently accompany sleep apnea, the relative roles of hypoxia versus sleep fragmentation are difficult to separate in apneic patients. Here, we assessed cognitive function as measured by water maze in the Fischer/Brown Norway (FBN) rat, comparing 24 h of sleep interruption (SI) to 24 h of intermittent hypoxia (IH), in order to dissociate their relative contributions to cognitive impairment. For SI, automated treadmills were used to induce brief ambulation in rats every 2 min, either prior to, or after, initial water maze acquisition training. IH was simulated by cycling environmental oxygen levels between 6% and 19% every 2 min, again either prior to, or after, acquisition. Twenty-four hours of IH exposure had no significant effect on either acquisition or retention, irrespective of whether IH occurred prior to, or after, acquisition. To replicate previous work, another group of rats, exposed to 3 days of IH (10 h/day) prior to acquisition, had impaired performance during acquisition. A comparison of the 24 h IH and 3 day IH findings suggests that a minimum amount of IH exposure is necessary to produce detectable spatial memory impairments. Although SI before acquisition had no effect on acquisition or later retention of the hidden platform location, SI after acquisition robustly impaired retention, indicating that spatial memory consolidation is more susceptible to the effects of sleep disruption than is the acquisition (learning) of spatial information. PMID:19643093

  8. Synchronous high-resolution phenotyping of leaf and root growth in Nicotiana tabacum over 24-h periods with GROWMAP-plant

    PubMed Central

    2013-01-01

    Background Root growth is highly responsive to temporal changes in the environment. On the contrary, diel (24 h) leaf expansion in dicot plants is governed by endogenous control and therefore its temporal pattern does not strictly follow diel changes in the environment. Nevertheless, root and shoot are connected with each other through resource partitioning and changing environments for one organ could affect growth of the other organ, and hence overall plant growth. Results We developed a new technique, GROWMAP-plant, to monitor growth processes synchronously in leaf and root of the same plant with a high resolution over the diel period. This allowed us to quantify treatment effects on the growth rates of the treated and non-treated organ and the possible interaction between them. We subjected the root system of Nicotiana tabacum seedlings to three different conditions: constant darkness at 22°C (control), constant darkness at 10°C (root cooling), and 12 h/12 h light–dark cycles at 22°C (root illumination). In all treatments the shoot was kept under the same 12 h/12 h light–dark cycles at 22°C. Root growth rates were found to be constant when the root-zone environment was kept constant, although the root cooling treatment significantly reduced root growth. Root velocity was decreased after light-on and light-off events of the root illumination treatment, resulting in diel root growth rhythmicity. Despite these changes in root growth, leaf growth was not affected substantially by the root-zone treatments, persistently showing up to three times higher nocturnal growth than diurnal growth. Conclusion GROWMAP-plant allows detailed synchronous growth phenotyping of leaf and root in the same plant. Root growth was very responsive to the root cooling and root illumination, while these treatments altered neither relative growth rate nor diel growth pattern in the seedling leaf. Our results that were obtained simultaneously in growing leaves and roots of the same

  9. 24-h Efficacy of Glaucoma Treatment Options.

    PubMed

    Konstas, Anastasios G P; Quaranta, Luciano; Bozkurt, Banu; Katsanos, Andreas; Garcia-Feijoo, Julian; Rossetti, Luca; Shaarawy, Tarek; Pfeiffer, Norbert; Miglior, Stefano

    2016-04-01

    Current management of glaucoma entails the medical, laser, or surgical reduction of intraocular pressure (IOP) to a predetermined level of target IOP, which is commensurate with either stability or delayed progression of visual loss. In the published literature, the hypothesis is often made that IOP control implies a single IOP measurement over time. Although the follow-up of glaucoma patients with single IOP measurements is quick and convenient, such measurements often do not adequately reflect the untreated IOP characteristics, or indeed the quality of treated IOP control during the 24-h cycle. Since glaucoma is a 24-h disease and the damaging effect of elevated IOP is continuous, it is logical that we should aim to understand the efficacy of all treatment options throughout the 24-h period. This article first reviews the concept and value of diurnal and 24-h IOP monitoring. It then critically evaluates selected available evidence on the 24-h efficacy of medical, laser and surgical therapy options. During the past decade several controlled trials have significantly enhanced our understanding on the 24-h efficacy of all glaucoma therapy options. Nevertheless, more long-term evidence is needed to better evaluate the 24-h efficacy of glaucoma therapy and the precise impact of IOP characteristics on glaucomatous progression and visual prognosis. PMID:26909513

  10. Enhanced vagal baroreflex response during 24 h after acute exercise

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.; Adams, W. C.

    1991-01-01

    We evaluated carotid-cardiac baroreflex responses in eight normotensive men (25-41 yr) on two different test days, each separated by at least 1 wk. On one day, baroreflex response was tested before and at 3, 6, 12, 18, and 24 h after graded supine cycle exercise to volitional exhaustion. On another day, this 24-h protocol was repeated with no exercise (control). Beat-to-beat R-R intervals were measured during external application of graded pressures to the carotid sinuses from 40 to -65 mmHg; changes of R-R intervals were plotted against carotid pressure (systolic pressure minus neck chamber pressure). The maximum slope of the response relationship increased (P less than 0.05) from preexercise to 12 h (3.7 +/- 0.4 to 7.1 +/- 0.7 ms/mmHg) and remained significantly elevated through 24 h. The range of the R-R response was also increased from 217 +/- 24 to 274 +/- 32 ms (P less than 0.05). No significant differences were observed during the control 24-h period. An acute bout of graded exercise designed to elicit exhaustion increases the sensitivity and range of the carotid-cardiac baroreflex response for 24 h and enhances its capacity to buffer against hypotension by increasing heart rate. These results may represent an underlying mechanism that contributes to blood pressure stability after intense exercise.

  11. Acute effect of ephedrine on 24-h energy balance

    NASA Technical Reports Server (NTRS)

    Shannon, J. R.; Gottesdiener, K.; Jordan, J.; Chen, K.; Flattery, S.; Larson, P. J.; Candelore, M. R.; Gertz, B.; Robertson, D.; Sun, M.

    1999-01-01

    Ephedrine is used to help achieve weight control. Data on its true efficacy and mechanisms in altering energy balance in human subjects are limited. We aimed to determine the acute effect of ephedrine on 24-h energy expenditure, mechanical work and urinary catecholamines in a double-blind, randomized, placebo-controlled, two-period crossover study. Ten healthy volunteers were given ephedrine (50 mg) or placebo thrice daily during each of two 24-h periods (ephedrine and placebo) in a whole-room indirect calorimeter, which accurately measures minute-by-minute energy expenditure and mechanical work. Measurements were taken of 24-h energy expenditure, mechanical work, urinary catecholamines and binding of (+/-)ephedrine in vitro to human beta1-, beta2- and beta3-adrenoreceptors. Twenty-four-hour energy expenditure was 3.6% greater (8965+/-1301 versus 8648+/-1347 kJ, P<0.05) with ephedrine than with placebo, but mechanical work was not different between the ephedrine and placebo periods. Noradrenaline excretion was lower with ephedrine (0.032+/-0.011 microg/mg creatinine) compared with placebo (0.044+/-0.012 microg/mg creatinine) (P<0.05). (+/-)Ephedrine is a relatively weak partial agonist of human beta1- and beta2-adrenoreceptors, and had no detectable activity at human beta3-adrenoreceptors. Ephedrine (50 mg thrice daily) modestly increases energy expenditure in normal human subjects. A lack of binding of ephedrine to beta3-adrenoreceptors and the observed decrease in urinary noradrenaline during ephedrine treatment suggest that the thermogenic effect of ephedrine results from direct beta1-/beta2-adrenoreceptor agonism. An indirect beta3-adrenergic effect through the release of noradrenaline seems unlikely as urinary noradrenaline decreased significantly with ephedrine.

  12. Health in a 24-h society.

    PubMed

    Rajaratnam, S M; Arendt, J

    2001-09-22

    With increasing economic and social demands, we are rapidly evolving into a 24-h society. In any urban economy, about 20% of the population are required to work outside the regular 0800-1700 h working day and this figure is likely to increase. Although the increase in shiftwork has led to greater flexibility in work schedules, the ability to provide goods and services throughout the day and night, and possibly greater employment opportunities, the negative effects of shiftwork and chronic sleep loss on health and productivity are now being appreciated. For example, sleepiness surpasses alcohol and drugs as the greatest identifiable and preventable cause of accidents in all modes of transport. Industrial accidents associated with night work are common, perhaps the most famous being Chernobyl, Three Mile Island, and Bhopal. PMID:11583769

  13. Ongoing exposure versus intense periodic exposure to military conflict and terror attacks in Israel.

    PubMed

    Lahad, Mooli; Leykin, Dmitry

    2010-12-01

    The manifestation of posttraumatic stress disorder (PTSD) symptoms in two clinical samples in Israel (N = 212) was examined. Individuals suffering ongoing exposure to shelling were compared with subjects exposed to intense periodic exposure. Elevated arousal and avoidance symptoms, but not intrusion were reported in the ongoing exposure group. When compared by age, young participants in the ongoing exposure group had significantly lower PTSD scores, whereas no differences were found between participants among the intense periodic exposure age groups. No gender differences in symptoms were found among participants from intense periodic exposure, whereas in the other ongoing group the difference was in avoidance. Results are discussed in light of past research on exposure to terrorism. PMID:21171129

  14. Comparison of INTAKE24 (an Online 24-h Dietary Recall Tool) with Interviewer-Led 24-h Recall in 11-24 Year-Old.

    PubMed

    Bradley, Jennifer; Simpson, Emma; Poliakov, Ivan; Matthews, John N S; Olivier, Patrick; Adamson, Ashley J; Foster, Emma

    2016-01-01

    Online dietary assessment tools offer a convenient, low cost alternative to traditional dietary assessment methods such as weighed records and face-to-face interviewer-led 24-h recalls. INTAKE24 is an online multiple pass 24-h recall tool developed for use with 11-24 year-old. The aim of the study was to undertake a comparison of INTAKE24 (the test method) with interviewer-led multiple pass 24-h recalls (the comparison method) in 180 people aged 11-24 years. Each participant completed both an INTAKE24 24-h recall and an interviewer-led 24-h recall on the same day on four occasions over a one-month period. The daily energy and nutrient intakes reported in INTAKE24 were compared to those reported in the interviewer-led recall. Mean intakes reported using INTAKE24 were similar to the intakes reported in the interviewer-led recall for energy and macronutrients. INTAKE24 was found to underestimate energy intake by 1% on average compared to the interviewer-led recall with the limits of agreement ranging from minus 49% to plus 93%. Mean intakes of all macronutrients and micronutrients (except non-milk extrinsic sugars) were within 4% of the interviewer-led recall. Dietary assessment that utilises technology may offer a viable alternative and be more engaging than paper based methods, particularly for children and young adults. PMID:27294952

  15. Comparison of INTAKE24 (an Online 24-h Dietary Recall Tool) with Interviewer-Led 24-h Recall in 11–24 Year-Old

    PubMed Central

    Bradley, Jennifer; Simpson, Emma; Poliakov, Ivan; Matthews, John N. S.; Olivier, Patrick; Adamson, Ashley J.; Foster, Emma

    2016-01-01

    Online dietary assessment tools offer a convenient, low cost alternative to traditional dietary assessment methods such as weighed records and face-to-face interviewer-led 24-h recalls. INTAKE24 is an online multiple pass 24-h recall tool developed for use with 11–24 year-old. The aim of the study was to undertake a comparison of INTAKE24 (the test method) with interviewer-led multiple pass 24-h recalls (the comparison method) in 180 people aged 11–24 years. Each participant completed both an INTAKE24 24-h recall and an interviewer-led 24-h recall on the same day on four occasions over a one-month period. The daily energy and nutrient intakes reported in INTAKE24 were compared to those reported in the interviewer-led recall. Mean intakes reported using INTAKE24 were similar to the intakes reported in the interviewer-led recall for energy and macronutrients. INTAKE24 was found to underestimate energy intake by 1% on average compared to the interviewer-led recall with the limits of agreement ranging from minus 49% to plus 93%. Mean intakes of all macronutrients and micronutrients (except non-milk extrinsic sugars) were within 4% of the interviewer-led recall. Dietary assessment that utilises technology may offer a viable alternative and be more engaging than paper based methods, particularly for children and young adults. PMID:27294952

  16. Prenatal Tobacco Exposure: Developmental Outcomes in the Neonatal Period

    PubMed Central

    Espy, Kimberly Andrews; Fang, Hua; Johnson, Craig; Stopp, Christian; Wiebe, Sandra A.; Respass, Jennifer

    2010-01-01

    Smoking during pregnancy is a persistent public health problem that has been linked to later adverse outcomes. The neonatal period, the first month of life, carries substantial developmental change in regulatory skills, and is the period when tobacco metabolites are cleared physiologically. Studies to date mostly have used cross-sectional designs that limit characterizing potential impacts of prenatal tobacco exposure on the development of key self-regulatory processes and cannot disentangle short-term withdrawal effects from residual exposure-related impacts. In this study, pregnant participants (N = 304) were recruited prospectively during pregnancy and smoking was measured at multiple time points, using both self report and biochemical measures. Neonatal attention, irritable reactivity, and stress dysregulation were examined longitudinally at three time points during the first month of life, and physical growth indices were measured at birth. Tobacco-exposed infants showed significantly poorer attention skills after birth, and the magnitude of the difference between exposed and non-exposed groups attenuated across the neonatal period. In contrast, exposure-related differences in irritable reactivity were not evident and stable across the first month of life, but differed only marginally at 4-weeks of age. Third trimester smoking was associated with pervasive, deleterious, dose-response impacts on physical growth measured at birth, whereas nearly all smoking indicators throughout pregnancy predicted level and growth rates of early attention. The observed neonatal pattern is consistent with the neurobiology of tobacco on the developing nervous system and fits with developmental vulnerabilities observed later in life. PMID:21038943

  17. Cardiovascular and thermoregulatory dysregulation over 24 h following acute heat stress in rats.

    PubMed

    Quinn, Carrie M; Audet, Gerald N; Charkoudian, Nisha; Leon, Lisa R

    2015-08-15

    The influences of severe heat stroke (HS) on cardiovascular function during recovery are incompletely understood. We hypothesized that HS would elicit a heart rate (HR) increase persisting through 24 h of recovery due to hemodynamic, thermoregulatory, and inflammatory events, necessitating tachycardia to support mean arterial pressure (MAP). Core temperature (Tc), HR, and MAP were measured via radiotelemetry in conscious male Fischer 344 rats (n = 22; 282.4 ± 3.5 g) during exposure to 37°C ambient temperature until a maximum Tc of 42.0°C, and during recovery at 20°C ambient temperature through 24 h. Rats were divided into Mild, Moderate, and Severe groups based on pathophysiology. HS rats exhibited hysteresis relative to Tc with HR higher for a given Tc during recovery compared with heating (P < 0.0001). "Reverse" hysteresis occurred in MAP with pressure during cooling lower than heating per degree Tc (P < 0.0001). Mild HS rats showed tachycardia [P < 0.01 vs. control (Con)] through 8 h of recovery, elevated MAP (P < 0.05 vs. Con) for the initial 5 h of recovery, with sustained hyperthermia (P < 0.05 vs. Con) through 24 h. Moderate HS rats showed significant tachycardia (P < 0.01 vs. Con), normal MAP (P > 0.05 vs. Con), and rebound hyperthermia from 4 to 24 h post-HS (P < 0.05 vs. Con). Severe HS rats showed tachycardia (P < 0.05 vs. Con), hypotension (P < 0.01 vs. Con), and hypothermia for 24 h (P < 0.05 vs. Con). Severe HS rats showed 14- and 12-fold increase in heart and liver inducible nitric oxide synthase expression, respectively. Hypotension and hypothermia in Severe HS rats was consistent with inducible nitric oxide synthase-mediated systemic vasodilation. These findings provide mechanistic insight into hemodynamic and thermoregulatory impairments during 24 h of HS recovery. PMID:26071550

  18. Extreme Meteorological Parameters During Space Shuttle Pad Exposure Periods

    NASA Technical Reports Server (NTRS)

    Roberts, Barry C.; Overbey, B. Glenn

    2004-01-01

    During the 113 missions of the Space Transportation System (STS), the Space Shuttle fleet has been exposed to the elements on the launch pad for a total of 4195 days. This paper provides a summary of the historical record of the meteorological extremes encountered by the Space Shuttle fleet during the pad exposure period. Parameters included are temperature, dew point, relative humidity, wind speed, sea level pressure and precipitation. All the data presented are archived by the Marshall Space Flight Center Environments Group, and were obtained from a combination of surface observations and meteorological towers at Kennedy Space Center (KSC), Florida. Data are provided from the first launch of the STS in 1981 through the launch of STS-107 in 2003.

  19. Parabens in 24 h urine samples of the German Environmental Specimen Bank from 1995 to 2012.

    PubMed

    Moos, Rebecca K; Koch, Holger M; Angerer, Jürgen; Apel, Petra; Schröter-Kermani, Christa; Brüning, Thomas; Kolossa-Gehring, Marike

    2015-10-01

    Parabens are widely used as antimicrobial preservatives in personal care and consumer products, food and pharmaceuticals. Due to their ubiquity, humans are constantly exposed to these chemicals. We assessed exposure to nine parabens (methyl-, ethyl-, n- and iso-propyl-, n- and iso-butyl-, benzyl-, pentyl- and heptyl paraben) in the German population from 1995 to 2012 based on 660 24h urine samples from the German Environmental Specimen Bank (ESB) using on-line HPLC coupled to isotope dilution tandem mass spectrometry. The limit of quantification (LOQ) was 0.5 μg/L for all parabens. We detected methyl-, ethyl- and n-propyl paraben in 79-99% of samples, followed by n-butyl paraben in 40% of samples. We infrequently detected iso-butyl-, iso-propyl- and benzyl paraben in 24%, 4% and 1.4% of samples, respectively. Urinary concentrations were highest for methyl paraben (median 39.8 μg/L; 95th percentile 319 μg/L) followed by n-propyl paraben (4.8 μg/L; 95th percentile 74.0 μg/L) and ethyl paraben (2.1 μg/L; 95th percentile 39.1 μg/L). Women had significantly higher urinary levels for all parabens than men, except for benzyl paraben. Samples from the ESB revealed that over the investigation period of nearly 20 years urinary paraben levels remained surprisingly constant; only methyl paraben had a significant increase, for both men and women. We found strong correlations between methyl- and n-propyl paraben and between n- and iso-butyl paraben. These results indicate that parabens are used in combination and arise from common sources of exposure. Urinary excretion factors are needed to extrapolate from individual urinary concentrations to actual doses. PMID:26253560

  20. Identification of 24 h Ixodes scapularis immunogenic tick saliva proteins

    PubMed Central

    Lewis, Lauren A.; Radulović, Željko M.; Kim, Tae K.; Porter, Lindsay M.; Mulenga, Albert

    2015-01-01

    Ixodes scapularis is arguably the most medically important tick species in the United States. This tick transmits 5 of the 14 human tick-borne disease (TBD) agents in the USA: Borrelia burgdorferi, Anaplasma phagocytophilum, B. miyamotoi, Babesia microti, and Powassan virus disease. Except for the Powassan virus disease, I. scapularis-vectored TBD agents require more than 24 h post attachment to be transmitted. This study describes identification of 24 h immunogenic I. scapularis tick saliva proteins, which could provide opportunities to develop strategies to stop tick feeding before transmission of the majority of pathogens. A 24 h fed female I. scapularis phage display cDNA expression library was biopanned using rabbit antibodies to 24 h fed I. scapularis female tick saliva proteins, subjected to next generation sequencing, de novo assembly, and bioinformatic analyses. A total of 182 contigs were assembled, of which ~19% (35/182) are novel and did not show identity to any known proteins in GenBank. The remaining ~81% (147/182) of contigs were provisionally identified based on matches in GenBank including ~18% (27/147) that matched protein sequences previously annotated as hypothetical and putative tick saliva proteins. Others include proteases and protease inhibitors (~3%, 5/147), transporters and/or ligand binding proteins (~6%, 9/147), immunogenic tick saliva housekeeping enzyme-like (17%, 25/147), ribosomal protein-like (~31%, 46/147), and those classified as miscellaneous (~24%, 35/147). Notable among the miscellaneous class include antimicrobial peptides (microplusin and ricinusin), myosin-like proteins that have been previously found in tick saliva, and heat shock tick saliva protein. Data in this study provides the foundation for in-depth analysis of I. scapularis feeding during the first 24 h, before the majority of TBD agents can be transmitted. PMID:25825233

  1. Oxidative fuel selection and shivering thermogenesis during a 12- and 24-h cold-survival simulation.

    PubMed

    Haman, François; Mantha, Olivier L; Cheung, Stephen S; DuCharme, Michel B; Taber, Michael; Blondin, Denis P; McGarr, Gregory W; Hartley, Geoffrey L; Hynes, Zach; Basset, Fabien A

    2016-03-15

    Because the majority of cold exposure studies are constrained to short-term durations of several hours, the long-term metabolic demands of cold exposure, such as during survival situations, remain largely unknown. The present study provides the first estimates of thermogenic rate, oxidative fuel selection, and muscle recruitment during a 24-h cold-survival simulation. Using combined indirect calorimetry and electrophysiological and isotopic methods, changes in muscle glycogen, total carbohydrate, lipid, protein oxidation, muscle recruitment, and whole body thermogenic rate were determined in underfed and noncold-acclimatized men during a simulated accidental exposure to 7.5 °C for 12 to 24 h. In noncold-acclimatized healthy men, cold exposure induced a decrease of ∼0.8 °C in core temperature and a decrease of ∼6.1 °C in mean skin temperature (range, 5.4-6.9 °C). Results showed that total heat production increased by approximately 1.3- to 1.5-fold in the cold and remained constant throughout cold exposure. Interestingly, this constant rise in Ḣprod and shivering intensity was accompanied by a large modification in fuel selection that occurred between 6 and 12 h; total carbohydrate oxidation decreased by 2.4-fold, and lipid oxidation doubled progressively from baseline to 24 h. Clearly, such changes in fuel selection dramatically reduces the utilization of limited muscle glycogen reserves, thus extending the predicted time to muscle glycogen depletion to as much as 15 days rather than the previous estimates of approximately 30-40 h. Further research is needed to determine whether this would also be the case under different nutritional and/or colder conditions. PMID:26718783

  2. ADOLESCENT ALCOHOL EXPOSURE: ARE THERE SEPARABLE VULNERABLE PERIODS WITHIN ADOLESCENCE?

    PubMed Central

    Spear, Linda Patia

    2015-01-01

    There are two key alcohol use patterns among human adolescents that confer increased vulnerability for later alcohol abuse/dependence, along with neurocognitive alterations: (a) early initiation of use during adolescence, and (b) high rates of binge drinking that are particularly prevalent late in adolescence. The central thesis of this review is that lasting neurobehavioral outcomes of these two adolescent exposure patterns may differ. Although it is difficult to disentangle consequences of early use from later binge drinking in human studies given the substantial overlap between groups, these two types of problematic adolescent use are differentially heritable and hence separable to some extent. Although few studies using animal models have manipulated alcohol exposure age, those studies that have have typically observed timing-specific exposure effects, with more marked (or at least different patterns of) lasting consequences evident after exposures during early-mid adolescence than late-adolescence/emerging adulthood, and effects often restricted to male rats in those few instances where sex differences have been explored. As one example, adult male rats exposed to ethanol during early-mid adolescence (postnatal days [P] 25-45) were found to be socially anxious and to retain adolescent-typical ethanol-induced social facilitation into adulthood, effects that were not evident after exposure during late-adolescence/emerging adulthood (P45-65); exposure at the later interval, however, induced lasting tolerance to ethanol's social inhibitory effects that was not evident after exposure early in adolescence. Females, in contrast, were little influenced by ethanol exposure at either interval. Exposure timing effects have likewise been reported following social isolation as well as after repeated exposure to other drugs such as nicotine (and cannabinoids), with effects often, although not always, more pronounced in males where studied. Consistent with these timing

  3. Adolescent alcohol exposure: Are there separable vulnerable periods within adolescence?

    PubMed

    Spear, Linda Patia

    2015-09-01

    There are two key alcohol use patterns among human adolescents that confer increased vulnerability for later alcohol abuse/dependence, along with neurocognitive alterations: (a) early initiation of use during adolescence, and (b) high rates of binge drinking that are particularly prevalent late in adolescence. The central thesis of this review is that lasting neurobehavioral outcomes of these two adolescent exposure patterns may differ. Although it is difficult to disentangle consequences of early use from later binge drinking in human studies given the substantial overlap between groups, these two types of problematic adolescent use are differentially heritable and hence separable to some extent. Although few studies using animal models have manipulated alcohol exposure age, those studies that have have typically observed timing-specific exposure effects, with more marked (or at least different patterns of) lasting consequences evident after exposures during early-mid adolescence than late-adolescence/emerging adulthood, and effects often restricted to male rats in those few instances where sex differences have been explored. As one example, adult male rats exposed to ethanol during early-mid adolescence (postnatal days [P] 25-45) were found to be socially anxious and to retain adolescent-typical ethanol-induced social facilitation into adulthood, effects that were not evident after exposure during late-adolescence/emerging adulthood (P45-65); exposure at the later interval, however, induced lasting tolerance to ethanol's social inhibitory effects that was not evident after exposure early in adolescence. Females, in contrast, were little influenced by ethanol exposure at either interval. Exposure timing effects have likewise been reported following social isolation as well as after repeated exposure to other drugs such as nicotine (and cannabinoids), with effects often, although not always, more pronounced in males where studied. Consistent with these timing

  4. Prenatal Tobacco Exposure: Developmental Outcomes in the Neonatal Period

    ERIC Educational Resources Information Center

    Espy, Kimberly Andrews; Fang, Hua; Johnson, Craig; Stopp, Christian; Wiebe, Sandra A.; Respass, Jennifer

    2011-01-01

    Smoking during pregnancy is a persistent public health problem that has been linked to later adverse outcomes. The neonatal period--the first month of life--carries substantial developmental change in regulatory skills and is the period when tobacco metabolites are cleared physiologically. Studies to date mostly have used cross-sectional designs…

  5. Dietary protein distribution positively influences 24-h muscle protein synthesis in healthy adults.

    PubMed

    Mamerow, Madonna M; Mettler, Joni A; English, Kirk L; Casperson, Shanon L; Arentson-Lantz, Emily; Sheffield-Moore, Melinda; Layman, Donald K; Paddon-Jones, Douglas

    2014-06-01

    The RDA for protein describes the quantity that should be consumed daily to meet population needs and to prevent deficiency. Protein consumption in many countries exceeds the RDA; however, intake is often skewed toward the evening meal, whereas breakfast is typically carbohydrate rich and low in protein. We examined the effects of protein distribution on 24-h skeletal muscle protein synthesis in healthy adult men and women (n = 8; age: 36.9 ± 3.1 y; BMI: 25.7 ± 0.8 kg/m2). By using a 7-d crossover feeding design with a 30-d washout period, we measured changes in muscle protein synthesis in response to isoenergetic and isonitrogenous diets with protein at breakfast, lunch, and dinner distributed evenly (EVEN; 31.5 ± 1.3, 29.9 ± 1.6, and 32.7 ± 1.6 g protein, respectively) or skewed (SKEW; 10.7 ± 0.8, 16.0 ± 0.5, and 63.4 ± 3.7 g protein, respectively). Over 24-h periods on days 1 and 7, venous blood samples and vastus lateralis muscle biopsy samples were obtained during primed (2.0 μmol/kg) constant infusion [0.06 μmol/(kg⋅min)] of l-[ring-(13)C6]phenylalanine. The 24-h mixed muscle protein fractional synthesis rate was 25% higher in the EVEN (0.075 ± 0.006%/h) vs. the SKEW (0.056 ± 0.006%/h) protein distribution groups (P = 0.003). This pattern was maintained after 7 d of habituation to each diet (EVEN vs. SKEW: 0.077 ± 0.006 vs. 0.056 ± 0.006%/h; P = 0.001). The consumption of a moderate amount of protein at each meal stimulated 24-h muscle protein synthesis more effectively than skewing protein intake toward the evening meal. PMID:24477298

  6. Temporal variability of pyrethroid metabolite levels in bedtime, morning, and 24-h urine samples for 50 adults in North Carolina.

    PubMed

    Morgan, Marsha K; Sobus, Jon R; Barr, Dana Boyd; Croghan, Carry W; Chen, Fu-Lin; Walker, Richard; Alston, Lillian; Andersen, Erik; Clifton, Matthew S

    2016-01-01

    Pyrethroid insecticides are widely used to control insects in both agricultural and residential settings worldwide. Few data are available on the temporal variability of pyrethroid metabolites in the urine of non-occupationally exposed adults. In this work, we describe the study design and sampling methodology for the Pilot Study to Estimate Human Exposures to Pyrethroids using an Exposure Reconstruction Approach (Ex-R study). Two major objectives were to quantify the concentrations of several pyrethroid metabolites in bedtime, first morning void (FMV), and 24-h urine samples as concentration (wet weight), specific-gravity (SG) corrected, creatinine (CR) corrected, and excretion rate values for 50 Ex-R adults over a six-week monitoring period and to determine if these correction approaches for urine dilution reduced the variability of the biomarker levels. The Ex-R study was conducted at the United States Environmental Protection Agency's Human Studies Facility in Chapel Hill, North Carolina USA and at participants' homes within a 40-mile radius of this facility. Recruitment of participants and field activities occurred between October 2009 and May 2011. Participants, ages 19-50 years old, provided daily food, activity, and pesticide-use diaries and collected their own urine samples (bedtime, FMV, and 24-h) during weeks 1, 2, and 6 of a six-week monitoring period. A total of 2503 urine samples were collected from the study participants. These samples were analyzed for the pyrethroid metabolites 3-phenoxybenzoic acid (3-PBA), cis/trans-3-(2,2-dichlorovinyl)-2,2-dimethyl-cyclopropane carboxylic acid (cis/trans-DCCA), and 2-methyl-3-phenylbenzoic acid (MPA) using high performance liquid chromatography/tandem mass spectrometry. Only 3-PBA was frequently detected (>50%) in the adult urine samples. Median urinary 3-PBA levels were 0.88 ng/mL, 0.96 ng/mL-SG, 1.04 ng/mg, and 1.04 ng/min for concentration, SG-corrected, CR-corrected, and excretion rate values, respectively

  7. Effects of Developmental Lead Exposure on the Hippocampal Transcriptome: Influences of Sex, Developmental Period, and Lead Exposure Level

    PubMed Central

    Schneider, Jay S

    2012-01-01

    Developmental lead (Pb) exposure has profound effects on cognition and behavior. Much is known about effects of Pb on hippocampal-mediated behaviors, but little is known about the molecular consequences of Pb exposure and the influences of developmental timing of exposure, level of exposure, and sex as effect modifiers of Pb exposure on the brain. The aim of this study was to examine the effects of different levels of Pb exposure (250 and 750 ppm Pb acetate) during perinatal (gestation/lactation) and postnatal (through postnatal day 45) periods on the hippocampal transcriptome in male and female Long Evans rats. Total RNA was extracted from hippocampus from four animals per experimental condition. RNA was hybridized to Affymetrix Rat Gene RNA Arrays using standard methods. Pb exposure per se influenced the expression of 717 transcripts (328 unique annotated genes), with many influenced in a sex-independent manner. Significant differences in gene expression patterns were also influenced by timing and level of exposure, with generally larger effects at the lower level of exposure across all groups. Statistically enriched biological functions included ion binding, regulation of RNA metabolic processes, and positive regulation of macromolecule biosynthetic processes. Processes of regulation of transcription and regulation of gene expression were preferentially enriched in males, regardless of timing or amount of Pb exposure. The effect on transcription factors and the diverse pathways or networks affected by Pb suggest a substantial effect of developmental Pb exposure on plasticity and adaptability, with these effects significantly modified by sex, developmental window of exposure, and level of Pb exposure. PMID:22641619

  8. 24h Urinary Sodium Excretion and Subsequent Change in Weight, Waist Circumference and Body Composition

    PubMed Central

    Larsen, Sofus C.; Ängquist, Lars; Sørensen, Thorkild I. A.; Heitmann, Berit L.

    2013-01-01

    Background In the same period as the increasing obesity epidemic, there has been an increased consumption of highly processed foods with a high salt content, and a few studies have suggested that a diet with a high salt content may be associated with obesity. Objective To investigate the association between 24 h urinary sodium excretion and subsequent change in body weight (BW), waist circumference (WC), body fat (BF) and fat free mass (FFM) among adults. Design A longitudinal population study based on the Danish part of the MONICA project, with examinations in 1987–1988 and 1993–1994. Complete information on 24 h urinary sodium excretion along with repeated measures of obesity, as well as on potential confounders, was obtained from 215 subjects. Linear regression was used to examine the association between sodium excretion, as a measure of salt consumption, and subsequent changes in BW, WC, BF and FFM, and further evaluated by restricted cubic splines. Stepwise adjustments were made for selected covariates. Results Neither the crude nor the adjusted models showed any statistically significant associations between sodium excretion and change in BW or WC. Likewise, we found no significant association between sodium excretion and change in BF and FFM in the unadjusted models. However, after adjusting for potential baseline confounders and the concurrent BW change, we found a significant increase in BF of 0.24 kg (P = 0.015, CI: 0.05 to 0.43) per 100 mmol increase in 24 h urinary sodium excretion (equivalent to 6 g of salt), during the 6-year study period. Moreover, during the same period, we found a significant association with FFM of −0.21 kg (P = 0.041, CI: −0.40 to −0.01). Conclusions These results suggest that a diet with a high salt content may have a negative influence on development in body composition by expanding BF and reducing FFM. PMID:23936079

  9. A new portable device for recording 24-h indirect blood pressure in hypertensive outpatients.

    PubMed

    Tochikubo, O; Kaneko, Y; Yokoi, H; Yukinari, Y

    1985-12-01

    To simplify 24-h blood pressure (BP) recording in hypertensive outpatients, we devised a new portable, automatic BP recorder and studied its accuracy and usefulness. The fully automatic recorder, measuring 5 x 16 x 18 cm with a cuff of usual size, weighs approximately 1 kg and is driven by a rechargeable battery. The cuff is inflated by a compact CO2 cartridge and two microphones are used to detect differentially the Korotkoff sounds in the upper arm. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) are automatically measured, displayed with the time of measurement, and recorded on a memory card at intervals of 15 min for 24 h. This equipment has high noise immunity and works very quietly. It predicts approximate BP during the period of increasing cuff pressure, and measures BP more quickly than the conventional method (the time required for each measurement was reduced by about half). Afterwards, mean values with standard deviations, trendgrams and histograms of BP and HR over a certain period of time can be displayed and recorded with an accessory analyser. The accuracy of the BP values recorded by this device were compared with those measured by the auscultatory method. The average differences were -0.6 +/- 2.1 (s.d.) mmHg for SBP and 0.2 +/- 3.0 mmHg for DBP (n = 152). The BP values by this method were also compared with those obtained directly from the brachial artery, the differences being -5.8 +/- 5.9/0.3 +/- 6.0 mmHg (n = 85). In 30 ambulatory hypertensive patients, 24-h BP was recorded using this recorder.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2856737

  10. Creatinine measurements in 24 h urine by liquid chromatography--tandem Mass Spectrometry.

    PubMed

    Park, Eun-Kee; Watanabe, Takaho; Gee, Shirley J; Schenker, Marc B; Hammock, Bruce D

    2008-01-23

    A simple, sensitive, and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determining urinary creatinine was developed and used to evaluate 24 h urine samples collected during an exposure study. Urine (1 microL) was diluted with methanol and then directly applied to LC-MS/MS. Under electrospray ionization (ESI) conditions, the transition molecules of creatinine and creatinine- d3 were observed at m/ z 114 > 44 and m/ z 117 > 47, respectively. The retention time of creatinine was 0.59 min. The linear range was 1-2000 ng/mL, with a detection limit in urine of 1 ng/mL. LC-MS/MS and colorimetric end-point methods were significantly associated ( R2 = 0.8785, p < 0.0001). The LC-MS/MS method to determine creatinine in 24 h urine samples had shorter retention times, was more sensitive, reliable, reproducible, simple, selective, and used a smaller sample size than other LC-MS/MS or commercial methods. PMID:18092755

  11. Identifying waking time in 24-h accelerometry data in adults using an automated algorithm.

    PubMed

    van der Berg, Julianne D; Willems, Paul J B; van der Velde, Jeroen H P M; Savelberg, Hans H C M; Schaper, Nicolaas C; Schram, Miranda T; Sep, Simone J S; Dagnelie, Pieter C; Bosma, Hans; Stehouwer, Coen D A; Koster, Annemarie

    2016-10-01

    As accelerometers are commonly used for 24-h measurements of daily activity, methods for separating waking from sleeping time are necessary for correct estimations of total daily activity levels accumulated during the waking period. Therefore, an algorithm to determine wake and bed times in 24-h accelerometry data was developed and the agreement of this algorithm with self-report was examined. One hundred seventy-seven participants (aged 40-75 years) of The Maastricht Study who completed a diary and who wore the activPAL3™ 24 h/day, on average 6 consecutive days were included. Intraclass correlation coefficient (ICC) was calculated and the Bland-Altman method was used to examine associations between the self-reported and algorithm-calculated waking hours. Mean self-reported waking hours was 15.8 h/day, which was significantly correlated with the algorithm-calculated waking hours (15.8 h/day, ICC = 0.79, P = < 0.001). The Bland-Altman plot indicated good agreement in waking hours as the mean difference was 0.02 h (95% limits of agreement (LoA) = -1.1 to 1.2 h). The median of the absolute difference was 15.6 min (Q1-Q3 = 7.6-33.2 min), and 71% of absolute differences was less than 30 min. The newly developed automated algorithm to determine wake and bed times was highly associated with self-reported times, and can therefore be used to identify waking time in 24-h accelerometry data in large-scale epidemiological studies. PMID:26837855

  12. Self-Reported Maternal Cigarette Smoke Exposure during the Periconceptional Period and the Risk for Omphalocoele

    PubMed Central

    Feldkamp, Marcia L.; Srisukhumbowornchai, Sivithee; Romitti, Paul A.; Olney, Richard S.; Richardson, Sandra D.; Botto, Lorenzo D.

    2015-01-01

    Background We investigated whether maternal exposure to cigarette smoke was associated with omphalocoele and whether periconceptional folic acid modified the association. Methods We analysed data from the National Birth Defects Prevention Study on omphalocoele case (n = 301) and control (n = 8135) mothers for infants born from 1997 through 2007. Mothers who reported active smoking or exposure to second-hand smoke during the periconceptional period (1 month before conception to 3 months after) were considered exposed. Those who reported use of folic acid supplements during the same period were considered supplement users. Odds ratios and 95% confidence intervals were estimated using multivariable logistic regression adjusted for alcohol use, preconception body mass index, and race/ethnicity. Results One hundred fifteen (38.2%) case and 2592 (31.9%) control mothers reported exposure to cigarette smoke during the periconceptional period. Adjusted odds ratios [95% confidence intervals] were 1.19 [0.94, 1.53] for any smoke exposure, 0.87 [0.54, 1.40] for active smoking, 1.38 [1.00, 1.90] for second-hand smoke exposure, and 1.16 [0.80, 1.67] for both exposures combined. No dose-response relationship was observed. Folic acid-containing supplements did not reduce the risk for omphalocoele among women with active or second-hand smoke exposure. Conclusions Self-reported active maternal smoking, with or without exposure to second-hand smoke, during the periconceptional period was not associated with omphalocoele. In contrast, there was a possible association with periconceptional exposure to second-hand smoke. PMID:24313669

  13. Enhancing speech learning by combining task practice with periods of stimulus exposure without practice.

    PubMed

    Wright, Beverly A; Baese-Berk, Melissa M; Marrone, Nicole; Bradlow, Ann R

    2015-08-01

    Language acquisition typically involves periods when the learner speaks and listens to the new language, and others when the learner is exposed to the language without consciously speaking or listening to it. Adaptation to variants of a native language occurs under similar conditions. Here, speech learning by adults was assessed following a training regimen that mimicked this common situation of language immersion without continuous active language processing. Experiment 1 focused on the acquisition of a novel phonetic category along the voice-onset-time continuum, while Experiment 2 focused on adaptation to foreign-accented speech. The critical training regimens of each experiment involved alternation between periods of practice with the task of phonetic classification (Experiment 1) or sentence recognition (Experiment 2) and periods of stimulus exposure without practice. These practice and exposure periods yielded little to no improvement separately, but alternation between them generated as much or more improvement as did practicing during every period. Practice appears to serve as a catalyst that enables stimulus exposures encountered both during and outside of the practice periods to contribute to quite distinct cases of speech learning. It follows that practice-plus-exposure combinations may tap a general learning mechanism that facilitates language acquisition and speech processing. PMID:26328708

  14. Enhancing speech learning by combining task practice with periods of stimulus exposure without practice

    PubMed Central

    Wright, Beverly A.; Baese-Berk, Melissa M.; Marrone, Nicole; Bradlow, Ann R.

    2015-01-01

    Language acquisition typically involves periods when the learner speaks and listens to the new language, and others when the learner is exposed to the language without consciously speaking or listening to it. Adaptation to variants of a native language occurs under similar conditions. Here, speech learning by adults was assessed following a training regimen that mimicked this common situation of language immersion without continuous active language processing. Experiment 1 focused on the acquisition of a novel phonetic category along the voice-onset-time continuum, while Experiment 2 focused on adaptation to foreign-accented speech. The critical training regimens of each experiment involved alternation between periods of practice with the task of phonetic classification (Experiment 1) or sentence recognition (Experiment 2) and periods of stimulus exposure without practice. These practice and exposure periods yielded little to no improvement separately, but alternation between them generated as much or more improvement as did practicing during every period. Practice appears to serve as a catalyst that enables stimulus exposures encountered both during and outside of the practice periods to contribute to quite distinct cases of speech learning. It follows that practice-plus-exposure combinations may tap a general learning mechanism that facilitates language acquisition and speech processing. PMID:26328708

  15. A 24 h investigation of the hydrogeochemistry of baseflow and stormwater in an urban area impacted by mining: Butte, Montana

    NASA Astrophysics Data System (ADS)

    Gammons, Christopher H.; Shope, Christopher L.; Duaime, Terence E.

    2005-09-01

    Changes in water quality during a storm event were continuously monitored over a 24 h period at a single location along an urban stormwater drain in Butte, Montana. The Butte Metro Storm Drain (MSD) collects groundwater baseflow and stormwater draining Butte Hill, a densely populated site that has been severely impacted by 130 years of mining, milling, and smelting of copper-rich, polymetallic mineral deposits. On the afternoon of 26 June 2002, a heavy thunderstorm caused streamflow in the MSD to increase 100-fold, from 0.2 ft3 s-1 to more than 20 ft3 s-1. Hourly discharge and water quality data were collected before, during, and following the storm. The most significant finding was that the calculated loads (grams per hour) of both dissolved and particulate copper passing down the MSD increased more than 100-fold in the first hour following the storm, and remained elevated over baseline conditions for the remainder of the study period. Other metals, such as zinc, cadmium, and manganese, showed a decrease in load from pre-storm to post-storm conditions. In addition to the large flush of copper, loads of soluble phosphorus increased during the storm, whereas dissolved oxygen dropped to low levels (<2 mg l-1). These results show that infrequent storm events in Butte have the potential to generate large volumes of runoff that exceed Montana water quality standards for acute exposure of aquatic life to copper, as well as depressed levels of dissolved oxygen. This study has important implications to ongoing reclamation activities in the upper Clark Fork Superfund site, particularly with respect to management of storm flow, and may be applicable to other watersheds impacted by mining activities.

  16. Impact of asthma, exposure period, and filters on human responses during exposures to ozone and its initiated chemistry products.

    PubMed

    Fadeyi, M O; Tham, K W; Wu, W Y

    2015-10-01

    The impact of asthma, exposure period, and filter condition downstream of the mixing box of air-conditioning system on building occupants' perceptual response, work performance, and salivary α-amylase secretion during exposures to ozone and its initiated chemistry products is studied. The experiments were conducted in a field environmental chamber (FEC) (240 m(3)) simulating an office environment. Experiments were conducted during periods when the air-handling system operated with new or used pleated panel filters at constant recirculation (7/h) and ventilation (1/h) rates. Average ozone and secondary organic aerosols (ozone-initiated chemistry products) measured during non-asthmatic and asthmatic subjects' 3-h exposures in the FEC were in the ranges approximately 20-37 ppb and approximately 1.6-3 μg/m(3), respectively. Asthmatic subjects' perceived odor intensity and sensory (eye, nose, and throat) irritation ratings were generally lower than those of non-asthmatic subjects, possibly explaining why asthmatic subjects accept perceived air quality more than non-asthmatic subjects. However, asthmatic subjects' perceived physiological-like symptom ratings (flu, chest tightness, and headache) and concentrations of secreted salivary α-amylase were generally higher than those of non-asthmatic subjects. Asthmatic subjects had significantly lower accuracy than non-asthmatic subjects in a task that required higher concentration although they had higher work speed. Filter condition did not make any significant difference for subjects' responses. PMID:25250543

  17. ADVERSE EFFECTS OF PRENATAL EXPOSURE TO ATRAZINE DURING A CRITICAL PERIOD OF MAMMARY GLAND GROWTH

    EPA Science Inventory

    Prenatal exposure to 100 mg/kg atrazine (ATR) was previously shown to delay mammary gland (MG) development in the female offspring of Long Evans (LE) rats. To determine if the fetal MG was most sensitive to ATR effects during specific periods of development, timed-pregnant dams ...

  18. Using multilevel path analysis in analyzing 24-h ambulatory physiological recordings applied to medically unexplained symptoms.

    PubMed

    Houtveen, Jan H; Hamaker, Ellen L; Van Doornen, Lorenz J P

    2010-05-01

    A non-clinical group high on heterogeneous medically unexplained symptoms (MUS; n=97) was compared with healthy controls (n=66) on the within-subject relationships between physiological measures using multilevel path analysis. Momentary experienced somatic complaints, mood (tension and depression), cardiac autonomic activity (inter-beat intervals, pre-ejection period (PEP), and respiratory sinus arrhythmia (RSA)) and respiration (rate and partial pressure of CO(2) at the end of a normal expiration) were monitored for 24 h using electronic diary and ambulatory devices. Relationships between measures were controlled for diurnal variation and individual means. Only subtle group differences were found in the diurnal rhythm and in the within-subject relationships between physiological measures. For participants high on MUS, within-subject changes in bodily symptoms were related to changes in mood, but only marginally to the physiological measures. Results of the current path analysis confirm the subordinate role of cardiac autonomic and respiratory parameters in MUS. PMID:20030762

  19. Nqrs Data for C24H44CuI2N [C24H44N·1/2(Cu2I4)] (Subst. No. 1588)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for C24H44CuI2N [C24H44N·1/2(Cu2I4)] (Subst. No. 1588)

  20. Adaptive response of poplar (Populus nigra L.) after prolonged Cd exposure period.

    PubMed

    Jakovljević, Tamara; Bubalo, Marina Cvjetko; Orlović, Sanja; Sedak, Marija; Bilandžić, Nina; Brozinčević, Iva; Redovniković, Ivana Radojčić

    2014-03-01

    An outdoor pot experiment was designed to study the changes of growth parameters, accumulation, and distribution of Cd in poplar (Populus nigra L.) during a prolonged exposure period (growing period of 17 months including three harvest points), allowing the consideration of time effects and prolonged adaptation to Cd stress. Simultaneously, changes to the antioxidant system in roots and leaves were monitored. It was demonstrated that poplar could adapt to the Cd-contaminated soils after prolonged exposure. Total Cd accumulation in the aerial parts of poplar, due to high biomass production and acceptable Cd accumulation parameters, implies that the tested poplar species could be a good candidate for Cd phytoextraction application as well as could be used as phytostabilizer of Cd in heavily polluted soil. Furthermore, the activity of the antioxidant machinery displays both a tissue- and exposure-specific response pattern to different Cd treatments, indicating that strict regulation of the antioxidant defense system is required for the adaptive response of poplar. In addition, this report highlights the importance of prolonged exposure studies of physiological responses of plants, especially for long-life-cycle woody species under heavy metal stress, since some misleading conclusions could be reached after shorter time periods. PMID:24288057

  1. Hippocampal cell fate regulation by chronic cocaine during periods of adolescent vulnerability: Consequences of cocaine exposure during adolescence on behavioral despair in adulthood.

    PubMed

    García-Cabrerizo, R; Keller, B; García-Fuster, M J

    2015-09-24

    Given that adolescence represents a critical moment for shaping adult behavior and may predispose to disease vulnerability later in life, the aim of this study was to find a vulnerable period during adolescence in which hippocampal cell fate regulation was altered by cocaine exposure, and to evaluate the long-term consequences of a cocaine experience during adolescence in affecting hippocampal plasticity and behavioral despair in adulthood. Study I: Male rats were treated with cocaine (15mg/kg, i.p.) or saline for 7 consecutive days during adolescence (early post-natal day (PND) 33-39, mid PND 40-46, late PND 47-53). Hippocampal plasticity (i.e., cell fate regulation, cell genesis) was evaluated 24h after the last treatment dose during the course of adolescence (PND 40, PND 47, PND 54). Study II: The consequences of cocaine exposure during adolescence (PND 33-39 or PND 33-46; 7 or 14days) were measured in adulthood at the behavioral (i.e., forced swim test, PND 62-63) and molecular (hippocampal cell markers, PND 64) levels. Chronic cocaine during early adolescence dysregulated FADD forms only in the hippocampus (HC), as compared to other brain regions, and during mid adolescence, impaired cell proliferation (Ki-67) and increased PARP-1 cleavage (a cell death maker) in the HC. Interestingly, chronic cocaine exposure during adolescence did not alter the time adult rats spent immobile in the forced swim test. These results suggest that this paradigm of chronic cocaine administration during adolescence did not contribute to the later manifestation of behavioral despair (i.e., one pro-depressive symptom) as measured by the forced swim test in adulthood. PMID:26215918

  2. THE EFFECT OF EXPOSURE PERIOD AND TEMPERATURE ON THE PHOTOSENSORY PROCESS IN CIONA.

    PubMed

    Hecht, S

    1926-01-01

    1. Experiments are presented which show that the latent period in the photosensory response of Ciona is inversely proportional to the duration of the exposure period to light. From this it is found that the velocity of the chemical reaction which determines the latent period is directly proportional to the concentration of photochemical products formed during the exposure period. This is interpreted as showing that the two processes form a coupled photochemical reaction, of which the secondary reaction proceeds only in the presence of products from the primary reaction. This coupling may be a catalysis or a direct chemical relation. 2. Further experiments show that the relation between temperature and the latent period is accurately described by the Arrhenius equation in which micro = 16,200. The precise numerical value of micro tentatively identifies the latent period process as an oxidation reaction which is catalyzed by iron. 3. The photocatalytic properties of certain iron compounds are used as a model for the coupled photochemical reaction suggested for the photosensory mechanism of Ciona and Mya. PMID:19872201

  3. Evaluation of neurobehavioral and neuroinflammatory end-points in the post-exposure period in rats sub-acutely exposed to manganese

    PubMed Central

    Santos, Dinamene; Batoreu, M. Camila; Tavares de Almeida, I.; Davis, Randall L.; Mateus, Luisa; Andrade, Vanda; Ramos, Ruben; Torres, Edite; Aschner, Michael.; Marreilha dos Santos, A.P.

    2013-01-01

    Manganese (Mn) can cause manganism, a neurological disorder similar to Parkinson's Disease (PD). The neurobehavioral and neuroinflammatory end-points in the Mn post exposure period have not been studied yet. Rats were injected on alternate days with 8 doses of MnCl2 (25 mg/Kg) or saline, then euthanized 1, 10, 30 or 70 days following the last dose. Whole-blood (WB) (p<0.05), urine (p<0.05) and brain cortical (p<0.0001) Mn levels were significantly increased 24h after the last dose. Decreases in the rats’ ambulation were noted 1, 10 and 30 days after the last Mn dose (p<0.001; p<0.05; p<0.001, respectively) and also in the rearing activity at the four time-points (p<0.05). Cortical glial fibrillary acid protein immunoreactivity (GFAP-ir) was significantly increased at 1, 10, 30 (p<0.0001) and 70 (p<0.001) days after the last Mn dose, as well as tumor necrosis α (TNF-α) levels (p<0.05) but just on day 1. Taken together, the results show that, during the 70-day clearance phase of Mn, the recovery is not immediate as behavioral alterations and neuroinflammation persist long after Mn is cleared from cortical brain compartment. PMID:24060432

  4. Transient energy deficit induced by exercise increases 24-h fat oxidation in young trained men.

    PubMed

    Iwayama, Kaito; Kawabuchi, Ryosuke; Park, Insung; Kurihara, Reiko; Kobayashi, Masashi; Hibi, Masanobu; Oishi, Sachiko; Yasunaga, Koichi; Ogata, Hitomi; Nabekura, Yoshiharu; Tokuyama, Kumpei

    2015-01-01

    Whole body fat oxidation increases during exercise. However, 24-h fat oxidation on a day with exercise often remains similar to that of sedentary day, when energy intake is increased to achieve an energy-balanced condition. The present study aimed to examine a possibility that time of the day when exercise is performed makes differences in 24-h fat oxidation. As a potential mechanism of exercise affecting 24-h fat oxidation, its relation to exercise-induced transient energy deficit was examined. Nine young male endurance athletes underwent three trials of indirect calorimetry using a metabolic chamber, in which they performed a session of 100 min of exercise before breakfast (AM), after lunch (PM), or two sessions of 50 min of exercise before breakfast and after lunch (AM/PM) at 65% of maximal oxygen uptake. Experimental meals were designed to achieve individual energy balance. Twenty-four-hour energy expenditure was similar among the trials, but 24-h fat oxidation was 1,142 ± 97, 809 ± 88, and 608 ± 46 kcal/24 h in descending order of its magnitude for AM, AM/PM, and PM, respectively (P < 0.05). Twenty-four-hour carbohydrate oxidation was 2,558 ± 110, 2,374 ± 114, and 2,062 ± 96 kcal/24 h for PM, AM/PM, and AM, respectively. In spite of energy-balanced condition over 24 h, exercise induced a transient energy deficit, the magnitude of which was negatively correlated with 24-h fat oxidation (r = -0.72, P < 0.01). Similarly, transient carbohydrate deficit after exercise was negatively correlated with 24-h fat oxidation (r = -0.40, P < 0.05). The time of the day when exercise is performed affects 24-h fat oxidation, and the transient energy/carbohydrate deficit after exercise is implied as a factor affecting 24-h fat oxidation. PMID:25554797

  5. Exposure to sucrose during periods of withdrawal does not reduce cocaine-seeking behavior in rats

    PubMed Central

    Nicolas, Céline; Lafay-Chebassier, Claire; Solinas, Marcello

    2016-01-01

    Concomitant access to drugs of abuse and alternative rewards such as sucrose has been shown to decrease addiction-related behaviors in animals. Here we investigated whether access to sucrose during abstinence in contexts that are temporally and physically distinct from drug-related contexts could reduce subsequent drug seeking. In addition, we investigated whether a history of cocaine self-administration would alter the rewarding effects of sucrose. Rats self-administered cocaine for ten sessions, while yoked-saline rats received only saline injections, and then we subjected them to a 30-day withdrawal period during which they had access to water and sucrose continuously or intermittently according to a schedule that induces binge-drinking behavior. At the end of the withdrawal period, rats were tested for cocaine seeking behavior during a single 6 h session. We found that exposure to cocaine increased sucrose consumption only when rats had intermittent access to sucrose, but exposure to sucrose did not alter drug seeking regardless of the schedule of access. These results suggest that exposure to cocaine cross-sensitizes to the rewarding effects of sucrose, but exposure to sucrose during abstinence, temporally and physically distinct from drug-related environments, does not to reduce drug seeking. PMID:26997496

  6. Association of food form with self-reported 24-h energy intake and meal patterns in US adults: NHANES 2003–2008123

    PubMed Central

    Kant, Ashima K; Graubard, Barry I; Mattes, Richard D

    2012-01-01

    Background: Laboratory studies suggest that food form (beverages compared with solid foods) evokes behavioral and physiologic responses that modify short-term appetite and food intake. Beverage energy may be less satiating and poorly compensated, which leads to higher energy intake. Objective: We examined associations between 24-h energy consumed in beverages and a variety of meal and dietary attributes to quantify the contribution of beverage consumption to the energy content of diets in free-living individuals consuming their self-selected diets. Design: We used dietary recall data for adults (n = 13,704) in NHANES 2003–2008 to examine the multiple covariate-adjusted associations between 24-h energy from beverages and nonbeverages and associations between beverage intake, eating behaviors, and the energy density of beverage and nonbeverage foods. Results: In the highest tertile of 24-h beverage energy intake, beverages provided >30% of energy. Total 24-h energy and nonbeverage energy consumption and energy density (kcal/g) of both beverage and nonbeverage foods increased with increasing energy from beverages (P < 0.0001). With increasing 24-h beverage energy consumption, the reported frequency of all, snack, and beverage-only ingestive episodes and length of the ingestive period increased, whereas the percentage of energy from main meals decreased (P < 0.0001). Conclusions: Higher 24-h beverage energy intake was related to higher energy intake from nonbeverage foods, quality of food selections, and distribution of 24-h energy into main meal and snack episodes. Moderation of beverage-only ingestive episodes and curtailing the length of the ingestion period may hold potential to lower uncompensated beverage energy consumption in the US population. PMID:23097271

  7. Validity and relative validity of a novel digital approach for 24-h dietary recall in athletes

    PubMed Central

    2014-01-01

    Background We developed a digital dietary analysis tool for athletes (DATA) using a modified 24-h recall method and an integrated, customized nutrient database. The purpose of this study was to assess DATA’s validity and relative validity by measuring its agreement with registered dietitians’ (RDs) direct observations (OBSERVATION) and 24-h dietary recall interviews using the USDA 5-step multiple-pass method (INTERVIEW), respectively. Methods Fifty-six athletes (14–20 y) completed DATA and INTERVIEW in randomized counter-balanced order. OBSERVATION (n = 26) consisted of RDs recording participants’ food/drink intake in a 24-h period and were completed the day prior to DATA and INTERVIEW. Agreement among methods was estimated using a repeated measures t-test and Bland-Altman analysis. Results The paired differences (with 95% confidence intervals) between DATA and OBSERVATION were not significant for carbohydrate (10.1%, -1.2–22.7%) and protein (14.1%, -3.2–34.5%) but was significant for energy (14.4%, 1.2–29.3%). There were no differences between DATA and INTERVIEW for energy (-1.1%, -9.1–7.7%), carbohydrate (0.2%, -7.1–8.0%) or protein (-2.7%, -11.3–6.7%). Bland-Altman analysis indicated significant positive correlations between absolute values of the differences and the means for OBSERVATION vs. DATA (r = 0.40 and r = 0.47 for energy and carbohydrate, respectively) and INTERVIEW vs. DATA (r = 0.52, r = 0.29, and r = 0.61 for energy, carbohydrate, and protein, respectively). There were also wide 95% limits of agreement (LOA) for most method comparisons. The mean bias ratio (with 95% LOA) for OBSERVATION vs. DATA was 0.874 (0.551-1.385) for energy, 0.906 (0.522-1.575) for carbohydrate, and 0.895(0.395-2.031) for protein. The mean bias ratio (with 95% LOA) for INTERVIEW vs. DATA was 1.016 (0.538-1.919) for energy, 0.995 (0.563-1.757) for carbohydrate, and 1.031 (0.514-2.068) for protein. Conclusion DATA has good relative

  8. Global crop exposure to critical high temperatures in the reproductive period: historical trends and future projections

    NASA Astrophysics Data System (ADS)

    Gourdji, Sharon M.; Sibley, Adam M.; Lobell, David B.

    2013-06-01

    Long-term warming trends across the globe have shifted the distribution of temperature variability, such that what was once classified as extreme heat relative to local mean conditions has become more common. This is also true for agricultural regions, where exposure to extreme heat, particularly during key growth phases such as the reproductive period, can severely damage crop production in ways that are not captured by most crop models. Here, we analyze exposure of crops to physiologically critical temperatures in the reproductive stage (Tcrit), across the global harvested areas of maize, rice, soybean and wheat. Trends for the 1980-2011 period show a relatively weak correspondence (r = 0.19) between mean growing season temperature and Tcrit exposure trends, emphasizing the importance of separate analyses for Tcrit. Increasing Tcrit exposure in the past few decades is apparent for wheat in Central and South Asia and South America, and for maize in many diverse locations across the globe. Maize had the highest percentage (15%) of global harvested area exposed to at least five reproductive days over Tcrit in the 2000s, although this value is somewhat sensitive to the exact temperature used for the threshold. While there was relatively little sustained exposure to reproductive days over Tcrit for the other crops in the past few decades, all show increases with future warming. Using projections from climate models we estimate that by the 2030s, 31, 16, and 11% respectively of maize, rice, and wheat global harvested area will be exposed to at least five reproductive days over Tcrit in a typical year, with soybean much less affected. Both maize and rice exhibit non-linear increases with time, with total area exposed for rice projected to grow from 8% in the 2000s to 27% by the 2050s, and maize from 15 to 44% over the same period. While faster development should lead to earlier flowering, which would reduce reproductive extreme heat exposure for wheat on a global basis

  9. 'Life in the age of screens': parent perspectives on a 24-h no screen-time challenge.

    PubMed

    Peláez, Sandra; Alexander, Stephanie; Roberge, Jean-Baptiste; Henderson, Melanie; Bigras, Jean-Luc; Barnett, Tracie A

    2016-08-01

    Screens have become ubiquitous in modern society. Their use frequently underlies sedentary behaviour, a well-established determinant of obesity. As part of a family oriented clinic offering a 2-year lifestyle program for obese children and youth, we explored parents' experiences with a 24-h no screen-time challenge, an intervention designed to raise awareness of screen-time habits and to help families develop strategies to limit their use. In total, 15 parents representing 13 families participated. A focus group with nine parents and six phone interviews with those who could not join in person were conducted. Interviews were transcribed verbatim and analysed qualitatively. Key elements to successful completion of the 24-h no screen-time challenge emerged, namely: clear rules about permitted activities during the 24-h period; togetherness, i.e. involving all family members in the challenge; and busyness, i.e. planning a full schedule in order to avoid idleness and preclude the temptation to use screens. Our findings suggest that practitioners aiming to increase awareness of screen-time or to limit their use may be more likely to succeed if they include all family members, offer concrete alternatives to screen-based activities and provide tailored strategies to manage discretionary time. PMID:27242271

  10. Time course of the MAPK and PI3-kinase response within 24 h of skeletal muscle overload

    NASA Technical Reports Server (NTRS)

    Carlson, C. J.; Fan, Z.; Gordon, S. E.; Booth, F. W.

    2001-01-01

    Knowledge of the molecular mechanisms by which skeletal muscle hypertrophies in response to increased mechanical loading may lead to the discovery of novel treatment strategies for muscle wasting and frailty. To gain insight into potential early signaling mechanisms associated with skeletal muscle hypertrophy, the temporal pattern of mitogen-activated protein kinase (MAPK) phosphorylation and phosphatidylinositol 3-kinase (PI3-kinase) activity during the first 24 h of muscle overload was determined in the rat slow-twitch soleus and fast-twitch plantaris muscles after ablation of the gastrocnemius muscle. p38alpha MAPK phosphorylation was elevated for the entire 24-h overload period in both muscles. In contrast, Erk 2 and p54 JNK phosphorylation were transiently increased by overload, returning to the levels of sham-operated controls by 24 h. PI3-kinase activity was increased by muscle overload only at 12 h of overload and only in the plantaris muscle. In summary, sustained elevation of p38alpha MAPK phosphorylation occurred early in response to muscle overload, identifying this pathway as a potential candidate for mediating early hypertrophic signals in response to skeletal muscle overload.

  11. Time-Based Measurement of Personal Mite Allergen Bioaerosol Exposure over 24 Hour Periods.

    PubMed

    Tovey, Euan R; Liu-Brennan, Damien; Garden, Frances L; Oliver, Brian G; Perzanowski, Matthew S; Marks, Guy B

    2016-01-01

    Allergic diseases such as asthma and rhinitis are common in many countries. Globally the most common allergen associated with symptoms is produced by house dust mites. Although the bed has often been cited as the main site of exposure to mite allergens, surprisingly this has not yet been directly established by measurement due to a lack of suitable methods. Here we report on the development of novel methods to determine the pattern of personal exposure to mite allergen bioaerosols over 24-hour periods and applied this in a small field study using 10 normal adults. Air was sampled using a miniature time-based air-sampler of in-house design located close to the breathing zone of the participants, co-located with a miniature time-lapse camera. Airborne particles, drawn into the sampler at 2L/min via a narrow slot, were impacted onto the peripheral surface of a disk mounted on the hour-hand of either a 12 or 24 hour clock motor. The impaction surface was either an electret cloth, or an adhesive film; both novel for these purposes. Following a review of the time-lapse images, disks were post-hoc cut into subsamples corresponding to eight predetermined categories of indoor or outdoor location, extracted and analysed for mite allergen Der p 1 by an amplified ELISA. Allergen was detected in 57.2% of the total of 353 subsamples collected during 20 days of sampling. Exposure patterns varied over time. Higher concentrations of airborne mite allergen were typically measured in samples collected from domestic locations in the day and evening. Indoor domestic Der p 1 exposures accounted for 59.5% of total exposure, whereas total in-bed-asleep exposure, which varied 80 fold between individuals, accounted overall for 9.85% of total exposure, suggesting beds are not often the main site of exposure. This study establishes the feasibility of novel methods for determining the time-geography of personal exposure to many bioaerosols and identifies new areas for future technical

  12. Time-Based Measurement of Personal Mite Allergen Bioaerosol Exposure over 24 Hour Periods

    PubMed Central

    Tovey, Euan R.; Liu-Brennan, Damien; Garden, Frances L.; Oliver, Brian G.; Perzanowski, Matthew S.; Marks, Guy B.

    2016-01-01

    Allergic diseases such as asthma and rhinitis are common in many countries. Globally the most common allergen associated with symptoms is produced by house dust mites. Although the bed has often been cited as the main site of exposure to mite allergens, surprisingly this has not yet been directly established by measurement due to a lack of suitable methods. Here we report on the development of novel methods to determine the pattern of personal exposure to mite allergen bioaerosols over 24-hour periods and applied this in a small field study using 10 normal adults. Air was sampled using a miniature time-based air-sampler of in-house design located close to the breathing zone of the participants, co-located with a miniature time-lapse camera. Airborne particles, drawn into the sampler at 2L/min via a narrow slot, were impacted onto the peripheral surface of a disk mounted on the hour-hand of either a 12 or 24 hour clock motor. The impaction surface was either an electret cloth, or an adhesive film; both novel for these purposes. Following a review of the time-lapse images, disks were post-hoc cut into subsamples corresponding to eight predetermined categories of indoor or outdoor location, extracted and analysed for mite allergen Der p 1 by an amplified ELISA. Allergen was detected in 57.2% of the total of 353 subsamples collected during 20 days of sampling. Exposure patterns varied over time. Higher concentrations of airborne mite allergen were typically measured in samples collected from domestic locations in the day and evening. Indoor domestic Der p 1 exposures accounted for 59.5% of total exposure, whereas total in-bed-asleep exposure, which varied 80 fold between individuals, accounted overall for 9.85% of total exposure, suggesting beds are not often the main site of exposure. This study establishes the feasibility of novel methods for determining the time-geography of personal exposure to many bioaerosols and identifies new areas for future technical

  13. The efficacy of periodic +Gz exposure in the prevention of bedrest induced orthostatic intolerance

    NASA Technical Reports Server (NTRS)

    Ludwig, D. A.; Vernikos, J.; Duvoisin, M. R; Stinn, J. L.

    1992-01-01

    What is the most efficient dosage of periodic exposure to positive 1G(z) during microgravity to maintain a functional upright position after returning to a positive 1G(z) environment? The answer has implications for the type of countermeasures astronauts will be required to perform during long term space flight. Methods: Nine males were subjected to four different positive 1G exposure protocols plus a control protocol ('zero G(z)') during four days of continuous bedrest. The four positive 1G(z) exposures consisted of periodic standing or walking, each for a total period of two or four hours. Each subject was returned for bedrest on five different occasions over a period of approximately one year to obtain data on each of the nine subjects across all four positive 1G(z) treatments and the control. A 30 min tilt test was used to measure orthostatic response during pre and post bedrest. Results: In terms of survival rate (percentage of subjects who did not faint after 30 sec of tilt), four hours of intermittent standing was the only protocol that maintained a rate comparable to pre bedrest levels (87.5 percent). Although the other three positive 1G(z) protocols performed better than the 'zero G(z) control (22.2 percent), only the four hour standing returned post bedrest survival rates to pre bedrest levels. Conclusions: The results will need to be evaluated with regards to a variety of other physiological systems which are known to decondition during microgravitry.

  14. Effects of dietary fatty acid composition on 24-h energy expenditure and chronic disease risk factors in men123

    PubMed Central

    Cooper, Jamie A; Watras, Abigail C; Adams, Alexandra K; Schoeller, Dale A

    2009-01-01

    Background: A high-fat (HF) diet and sedentary lifestyle are implicated in the development of obesity. Controlled feeding studies and measures of short-term resting energy expenditure (REE) have suggested that the type of dietary fat may alter energy expenditure (EE). Objective: The objective was to examine the effects of an HF diet rich in either monounsaturated or saturated fatty acids (FAs) and of exercise on EE and chronic disease risk factors. Design: Eight healthy men [age: 18–45 y; body mass index (in kg/m2): 22 ± 3] were randomly assigned in a 2 × 2 crossover design to 1 of 4 treatments: HF diet (50% of energy) with a high amount of saturated fat (22% of energy) plus exercise (SE) or a sedentary (SS) condition or a diet high in monounsaturated fat (30% of energy) plus exercise (UE) or a sedentary (US) condition. The subjects spent 5 d in a metabolic chamber and cycled at 45% of maximal oxygen uptake for 2 h each day during the exercise visits. Respiratory gases and urinary nitrogen were measured to determine 24-h EE. Resting metabolic rate was measured on days 2, 4, and 6. Results: Average 24-h EE was not different with respect to dietary FA composition (3202 ± 146, 3208 ± 151, 2240 ± 82, and 2270 ± 104 for SE, UE, SS, and US, respectively). Total and LDL cholesterol and blood pressure were significantly greater after the SE and SS treatments than after the UE and US treatments. Conclusion: Resting metabolic rate and 24-h EE were not significantly different after short-term exposure to an HF diet rich in monounsaturated FAs or after exposure to a diet rich in saturated FAs in healthy, nonobese men. PMID:19321562

  15. Personal Care Product Use in Pregnancy and the Postpartum Period: Implications for Exposure Assessment.

    PubMed

    Lang, Carly; Fisher, Mandy; Neisa, Angelica; MacKinnon, Leona; Kuchta, Sandra; MacPherson, Susan; Probert, Adam; Arbuckle, Tye E

    2016-01-01

    Concern regarding the potential for developmental health risks associated with certain chemicals (e.g., phthalates, antibacterials) used in personal care products is well documented; however, current exposure data for pregnant women are limited. The objective of this study was to describe the pattern of personal care product use in pregnancy and the post-partum period. Usage patterns of personal care products were collected at six different time points during pregnancy and once in the postpartum period for a cohort of 80 pregnant women in Ottawa, Canada. The pattern of use was then described and groups of personal care product groups commonly used together were identified using hierarchical cluster analysis. The results showed that product use varied by income and country of birth. General hygiene products were the most commonly used products and were consistently used over time while cosmetic product use declined with advancing pregnancy and post-delivery. Hand soaps and baby products were reported as used more frequently after birth. This study is the first to track personal care product use across pregnancy and into the postpartum period, and suggests that pregnant populations may be a unique group of personal care product users. This information will be useful for exposure assessments. PMID:26751460

  16. Personal Care Product Use in Pregnancy and the Postpartum Period: Implications for Exposure Assessment

    PubMed Central

    Lang, Carly; Fisher, Mandy; Neisa, Angelica; MacKinnon, Leona; Kuchta, Sandra; MacPherson, Susan; Probert, Adam; Arbuckle, Tye E.

    2016-01-01

    Concern regarding the potential for developmental health risks associated with certain chemicals (e.g., phthalates, antibacterials) used in personal care products is well documented; however, current exposure data for pregnant women are limited. The objective of this study was to describe the pattern of personal care product use in pregnancy and the post-partum period. Usage patterns of personal care products were collected at six different time points during pregnancy and once in the postpartum period for a cohort of 80 pregnant women in Ottawa, Canada. The pattern of use was then described and groups of personal care product groups commonly used together were identified using hierarchical cluster analysis. The results showed that product use varied by income and country of birth. General hygiene products were the most commonly used products and were consistently used over time while cosmetic product use declined with advancing pregnancy and post-delivery. Hand soaps and baby products were reported as used more frequently after birth. This study is the first to track personal care product use across pregnancy and into the postpartum period, and suggests that pregnant populations may be a unique group of personal care product users. This information will be useful for exposure assessments. PMID:26751460

  17. Transient increase in alcohol self-administration following a period of chronic exposure to corticosterone.

    PubMed

    Besheer, Joyce; Fisher, Kristen R; Lindsay, Tessa G; Cannady, Reginald

    2013-09-01

    Stressful life events and chronic stressors have been associated with escalations in alcohol drinking. Stress exposure leads to the secretion of glucocorticoids (cortisol in the human; corticosterone (CORT) in the rodent). To model a period of heightened elevations in CORT, the present work assessed the effects of chronic exposure to the stress hormone CORT on alcohol self-administration. Male Long Evans rats were trained to self-administer a sweetened alcohol solution (2% sucrose/15% alcohol) resulting in moderate levels of daily alcohol intake (0.5-0.7 g/kg). Following stable baseline operant self-administration, rats received CORT in the drinking water for 7 days. A transient increase in alcohol self-administration was observed on the first self-administration session following CORT exposure, and behavior returned to control levels by the second session. Control experiments determined that this increase in alcohol self-administration was specific to alcohol, unrelated to general motor activation, and functionally dissociated from decreased CORT levels at the time of testing. These results indicate that repeated exposure to heightened levels of stress hormone (e.g., as may be experienced during stressful episodes) has the potential to lead to exacerbated alcohol intake in low to moderate drinkers. Given that maladaptive drinking patterns, such as escalated alcohol drinking following stressful episodes, have the potential to put an individual at risk for future drinking disorders, utilization of this model will be important for examination of neuroadaptations that occur as a consequence of CORT exposure in order to better understand escalated drinking following stressful episodes in nondependent individuals. PMID:23643750

  18. Association of left ventricular diastolic dysfunction with 24-h aortic ambulatory blood pressure: the SAFAR study.

    PubMed

    Zhang, Y; Kollias, G; Argyris, A A; Papaioannou, T G; Tountas, C; Konstantonis, G D; Achimastos, A; Blacher, J; Safar, M E; Sfikakis, P P; Protogerou, A D

    2015-07-01

    Aortic blood pressure (BP) and 24-h ambulatory BP are both better associated with target organ damage than office brachial BP. However, it remains unclear whether a combination of these two techniques would be the optimal methodology to evaluate patients' BP in terms of left ventricular diastolic dysfunction (LVDD) prevention. In 230 participants, office brachial and aortic BPs were measured by a validated BP monitor and a tonometry-based device, respectively. 24-h ambulatory brachial and aortic BPs were measured by a validated ambulatory BP monitor (Mobil-O-Graph, Germany). Systematic assessment of patients' LVDD was performed. After adjustment for age, gender, hypertension and antihypertensive treatment, septum and lateral E/Ea were significantly associated with office aortic systolic BP (SBP) and pulse pressure (PP) and 24-h brachial and aortic SBP and PP (P ⩽ 0.04), but not with office brachial BP (P ⩾ 0.09). Similarly, 1 standard deviation in SBP was significantly associated with 97.8 ± 20.9, 86.4 ± 22.9, 74.1 ± 23.3 and 51.3 ± 22.6 in septum E/Ea and 68.6 ± 2 0.1, 54.2 ± 21.9, 37.9 ± 22.4 and 23.1 ± 21.4 in lateral E/Ea, for office and 24-h aortic and brachial SBP, respectively. In qualitative analysis, except for office brachial BP, office aortic and 24-h brachial and aortic BPs were all significantly associated with LVDD (P ⩽ 0.03), with the highest odds ratio in 24-h aortic SBP. Furthermore, aortic BP, no matter in the office or 24-h ambulatory setting, showed the largest area under receiver operating characteristic curves (P ⩽ 0.02). In conclusion, 24-h aortic BP is superior to other BPs in the association with LVDD. PMID:25391758

  19. Stress exposure during the preimplantation period affects blastocyst lineages and offspring development.

    PubMed

    Burkuš, Ján; Kačmarová, Martina; Kubandová, Janka; Kokošová, Natália; Fabianová, Kamila; Fabian, Dušan; Koppel, Juraj; Čikoš, Štefan

    2015-01-01

    We found retardation of preimplantation embryo growth after exposure to maternal restraint stress during the preimplantation period in our previous study. In the present study, we evaluated the impact of preimplantation maternal restraint stress on the distribution of inner cell mass (ICM) and trophectoderm (TE) cells in mouse blastocysts, and its possible effect on physiological development of offspring. We exposed spontaneously ovulating female mice to restraint stress for 30 min three times a day during the preimplantation period, and this treatment caused a significant increase in blood serum corticosterone concentration. Microscopic evaluation of embryos showed that restraint stress significantly decreased cell counts per blastocyst. Comparing the effect of restraint stress on the two blastocyst cell lineages, we found that the reduction in TE cells was more substantial than the reduction in ICM cells, which resulted in an increased ICM/TE ratio in blastocysts isolated from stressed dams compared with controls. Restraint stress reduced the number of implantation sites in uteri, significantly delayed eye opening in delivered mice, and altered their behavior in terms of two parameters (scratching on the base of an open field test apparatus, time spent in central zone) as well. Moreover, prenatally stressed offspring had significantly lower body weights and in 5-week old females delivered from stressed dams, fat deposits were significantly lower. Our results indicate that exposure to stress during very early pregnancy can have a negative impact on embryonic development with consequences reaching into postnatal life. PMID:25985793

  20. Stress exposure during the preimplantation period affects blastocyst lineages and offspring development

    PubMed Central

    BURKUŠ, Ján; KAČMAROVÁ, Martina; KUBANDOVÁ, Janka; KOKOŠOVÁ, Natália; FABIANOVÁ, Kamila; FABIAN, Dušan; KOPPEL, Juraj; ČIKOŠ, Štefan

    2015-01-01

    We found retardation of preimplantation embryo growth after exposure to maternal restraint stress during the preimplantation period in our previous study. In the present study, we evaluated the impact of preimplantation maternal restraint stress on the distribution of inner cell mass (ICM) and trophectoderm (TE) cells in mouse blastocysts, and its possible effect on physiological development of offspring. We exposed spontaneously ovulating female mice to restraint stress for 30 min three times a day during the preimplantation period, and this treatment caused a significant increase in blood serum corticosterone concentration. Microscopic evaluation of embryos showed that restraint stress significantly decreased cell counts per blastocyst. Comparing the effect of restraint stress on the two blastocyst cell lineages, we found that the reduction in TE cells was more substantial than the reduction in ICM cells, which resulted in an increased ICM/TE ratio in blastocysts isolated from stressed dams compared with controls. Restraint stress reduced the number of implantation sites in uteri, significantly delayed eye opening in delivered mice, and altered their behavior in terms of two parameters (scratching on the base of an open field test apparatus, time spent in central zone) as well. Moreover, prenatally stressed offspring had significantly lower body weights and in 5-week old females delivered from stressed dams, fat deposits were significantly lower. Our results indicate that exposure to stress during very early pregnancy can have a negative impact on embryonic development with consequences reaching into postnatal life. PMID:25985793

  1. A Summary of Meteorological Parameters During Space Shuttle Pad Exposure Periods

    NASA Technical Reports Server (NTRS)

    Overbey, Glenn; Roberts, Barry C.

    2005-01-01

    During the 113 missions of the Space Transportation System (STS), the Space Shuffle fleet has been exposed to the elements on the launch pad for a total of 4195 days. The Natural Environments Branch at Marshall Space Flight Center archives atmospheric environments to which the Space Shuttle vehicles are exposed. This paper provides a summary of the historical record of the meteorological conditions encountered by the Space Shuttle fleet during the pad exposure period. Sources of the surface parameters, including temperature, dew point temperature, relative humidity, wind speed, wind direction, sea level pressure and precipitation are presented. Data is provided from the first launch of the STS in 1981 through the launch of STS-107 in 2003.

  2. Space Shuttle Pad Exposure Period Meteorological Parameters STS-1 Through STS-107

    NASA Technical Reports Server (NTRS)

    Overbey, B. G.; Roberts, B. C.

    2005-01-01

    During the 113 missions of the Space Transportation System (STS) to date, the Space Shuttle fleet has been exposed to the elements on the launch pad for approx. 4,195 days. The Natural Environments Branch at Marshall Space Flight Center archives atmospheric environments to which the Space Shuttle vehicles are exposed. This Technical Memorandum (TM) provides a summary of the historical record of the meteorological conditions encountered by the Space Shuttle fleet during the pad exposure period. Parameters included in this TM are temperature, relative humidity, wind speed, wind direction, sea level pressure, and precipitation. Extremes for each of these parameters for each mission are also summarized. Sources for the data include meteorological towers and hourly surface observations. Data are provided from the first launch of the STS in 1981 through the launch of STS-107 in 2003.

  3. Does an Adolescent’s Accuracy of Recall Improve with a Second 24-h Dietary Recall?

    PubMed Central

    Kerr, Deborah A.; Wright, Janine L.; Dhaliwal, Satvinder S.; Boushey, Carol J.

    2015-01-01

    The multiple-pass 24-h dietary recall is used in most national dietary surveys. Our purpose was to assess if adolescents’ accuracy of recall improved when a 5-step multiple-pass 24-h recall was repeated. Participants (n = 24), were Chinese-American youths aged between 11 and 15 years and lived in a supervised environment as part of a metabolic feeding study. The 24-h recalls were conducted on two occasions during the first five days of the study. The four steps (quick list; forgotten foods; time and eating occasion; detailed description of the food/beverage) of the 24-h recall were assessed for matches by category. Differences were observed in the matching for the time and occasion step (p < 0.01), detailed description (p < 0.05) and portion size matching (p < 0.05). Omission rates were higher for the second recall (p < 0.05 quick list; p < 0.01 forgotten foods). The adolescents over-estimated energy intake on the first (11.3% ± 22.5%; p < 0.05) and second recall (10.1% ± 20.8%) compared with the known food and beverage items. These results suggest that the adolescents’ accuracy to recall food items declined with a second 24-h recall when repeated over two non-consecutive days. PMID:25984743

  4. Does an Adolescent's Accuracy of Recall Improve with a Second 24-h Dietary Recall?

    PubMed

    Kerr, Deborah A; Wright, Janine L; Dhaliwal, Satvinder S; Boushey, Carol J

    2015-05-01

    The multiple-pass 24-h dietary recall is used in most national dietary surveys. Our purpose was to assess if adolescents' accuracy of recall improved when a 5-step multiple-pass 24-h recall was repeated. Participants (n = 24), were Chinese-American youths aged between 11 and 15 years and lived in a supervised environment as part of a metabolic feeding study. The 24-h recalls were conducted on two occasions during the first five days of the study. The four steps (quick list; forgotten foods; time and eating occasion; detailed description of the food/beverage) of the 24-h recall were assessed for matches by category. Differences were observed in the matching for the time and occasion step (p < 0.01), detailed description (p < 0.05) and portion size matching (p < 0.05). Omission rates were higher for the second recall (p < 0.05 quick list; p < 0.01 forgotten foods). The adolescents over-estimated energy intake on the first (11.3% ± 22.5%; p < 0.05) and second recall (10.1% ± 20.8%) compared with the known food and beverage items. These results suggest that the adolescents' accuracy to recall food items declined with a second 24-h recall when repeated over two non-consecutive days. PMID:25984743

  5. [Effect of diurnal distribution of food intake on 24-h profiles of plasma lipoproteins (author's transl)].

    PubMed

    Schneider, J; Tauber, H

    1981-02-16

    The lipid infiltration theory of atherogenesis accepted, 24 h lipoprotein profiles may be more relevant than preprandial morning samples. Such profiles were performed in 12 metabolically healthy volunteers during two dietetic regimes identical in total food content but differing in the distribution over the day: form A meant an evening meal of 15% of total caloric intake, form B of 40%. After one week of each form, 24 h lipoprotein profiles differed significantly in the time course of triglyceride rich lipoproteins and in the mean values over 24 h in VLDL and LDL phospholipids and HDL cholesterol. These findings are cautiously interpreted as possible signs of differences in the catabolism of triglyceride rich lipoproteins, remnants and intermediate lipoproteins. The difference in HDL cholesterol which was higher in form A is discussed in the context of recent epidemiologic evidence. PMID:7194945

  6. Postmortem redistribution of the heroin metabolites morphine and morphine-3-glucuronide in rabbits over 24 h.

    PubMed

    Maskell, Peter D; Albeishy, Mohammed; De Paoli, Giorgia; Wilson, Nathan E; Seetohul, L Nitin

    2016-03-01

    The interpretation of postmortem drug levels is complicated by changes in drug blood levels in the postmortem period, a phenomena known as postmortem drug redistribution. We investigated the postmortem redistribution of the heroin metabolites morphine and morphine-3-glucuronide in a rabbit model. Heroin (1 mg/kg) was injected into anesthetised rabbit; after 1 h, an auricular vein blood sample was taken and the rabbit was euthanised. Following death rabbits were placed in a supine position at room temperature and divided into three groups namely (1) immediate autopsy, (2) autopsy after 30 minutes and (3) autopsy 24 h after death. Various samples which included femoral blood, cardiac blood, lung, liver, kidney, vitreous humour, subcutaneous and abdominal fat, liver, bone marrow and skeletal muscle were taken. The samples were analysed with a validated LC-MS/MS method. It was observed that within minutes there was a significant increase in free morphine postmortem femoral blood concentration compared to the antemortem sample (0.01 ± 0.01 to 0.05 ± 0.02 mg/L).Various other changes in free morphine and metabolite concentrations were observed during the course of the experiment in various tissues. Principal component analysis was used to investigate possible correlations between free morphine in the various samples. Some correlations were observed but gave poor predictions (>20 % error) when back calculating. The results suggest that rabbits are a good model for further studies of postmortem redistribution but that further study and understanding of the phenomena is required before accurate predictions of the blood concentration at the time of death are possible. PMID:25863436

  7. Brain effects of manganese exposure in mice pups during prenatal and breastfeeding periods.

    PubMed

    Okada, Monica Akemi; Neto, Francisco Filipak; Noso, Cassio Hideo; Voigt, Carmen Lúcia; Campos, Sandro Xavier; Alberto de Oliveira Ribeiro, Ciro

    2016-07-01

    Manganese (Mn) is a trace element essential for brain development and functioning of the central nervous system. However, there is a lack of information concerning the neurotoxicity of Mn under realistic doses in early stages of development, though excess of Mn results in a progressive disorder of the nervous system called manganism. In the current study, adult mice were exposed to three doses of Mn for 60 days through daily gavages, while mice pups were exposed to the same Mn doses during developmental period (gestational and breast-feeding). From the latter group of mice, a group was exposed for more 60 days to the same Mn doses. Chemical analysis revealed a dose-dependent bioaccumulation of Mn in mice's brain. Biochemical parameters revealed that (1) Mn affects non-protein thiol levels, glutathione S-tranferase and acetylcholinesterase activities, as well as the levels of oxidized lipids and proteins in mice brain, though lipids and proteins alterations were found only after exposure to high and unrealistic doses; (2) Realistic doses of Mn affects the activity of brain AChE and finally; (3) Pups' brain were affected by Mn even whether only the parental females had been previously exposed. The current study shows evidences of chemical stress in mice exposed to Mn during the early period of development and an efficient mechanism of Mn elimination under higher doses. These findings open new lines of investigation regarding manganese toxicity in vertebrates mainly in the early stages of development. PMID:26972613

  8. Susceptible period of socio-emotional development affected by constant exposure to daylight.

    PubMed

    Koshiba, Mamiko; Senoo, Aya; Karino, Genta; Ozawa, Simpei; Tanaka, Ikuko; Honda, Yoshiko; Usui, Setsuo; Kodama, Tohru; Mimura, Koki; Nakamura, Shun; Kunikata, Tetsuya; Yamanouchi, Hideo; Tokuno, Hironobu

    2015-04-01

    As a diurnal experimental primate, the common marmoset (Callithrix jacchus) has recently contributed to numerous kinds of studies of neurobiological psychiatry as an essential pre-clinical model. The marmoset matures sexually within one or two years after birth. Thus, we can observe how the primate learns and develops psycho-cognitive functions through experiences in experimental environment for a much shorter period compared to that of humans. Longer daylight exposure may affect psychological development of children. In our research, we focus on raising marmosets under constant daylight from birth until various ages. In order to quantitatively evaluate the development of higher-ordered psychological functions, we designed a system of socio-behavioral tests and multivariate correlation analysis methods based on principal component analysis. With reference to the call and typical body movement expressed during a particular social context, we statistically inferred the emotional features of the subjects. In the current literature, we review our published results showing increased alert behaviors by constant light, and then, attempted to extend our additional analysis to seek age-dependent susceptibility to constant light. We then present the neurobiological mechanisms with reference to previous research reports. The current review suggests possible existence of a susceptible period earlier than three to five month-old in the environment-induced developmental disorder model, supposedly like attention deficit hyperactive disorders (ADHD) or oppositional defiant disorder (ODD). PMID:25305341

  9. Exposure to phytoestrogens in the perinatal period affects androgen secretion by testicular Leydig cells in the adult rat.

    PubMed

    Akingbemi, Benson T; Braden, Tim D; Kemppainen, Barbara W; Hancock, Karen D; Sherrill, Jessica D; Cook, Sarah J; He, Xiaoying; Supko, Jeffrey G

    2007-09-01

    The use of soy-based products in the diet of infants has raised concerns regarding the reproductive toxicity of genistein and daidzein, the predominant isoflavones in soybeans with estrogenic activity. Time-bred Long-Evans dams were fed diets containing 0, 5, 50, 500, or 1000 ppm of soy isoflavones from gestational d 12 until weaning at d 21 postpartum. Male rats in all groups were fed soy-free diets from postnatal d 21 until 90 d of age. The mean +/- SD concentration of unconjugated (i.e. biologically active) genistein and daidzein in serum from the group of dams maintained on the diet containing the highest amount of isoflavones (1000 ppm) were 17 +/- 27 and 56 +/- 30 nM, respectively, at d 21 postpartum. The concentrations were considerably greater in male offspring (genistein: 73 +/- 46 nM; daidzein: 106 +/- 53 nM). Although steroidogenesis was decreased in individual Leydig cells, male rats from the highest exposure group (1000 ppm diet) exhibited elevated serum levels of the sex steroid hormones androsterone at 21 d (control: 15 +/- 1.5 vs.28 +/- 3.5 ng/ml; P < 0.05) and testosterone at 90 d of age (control: 7.5 +/- 1 vs.17 +/- 2 ng/ml; P < 0.05). Testosterone secretion by immature Leydig cells, isolated from 35-d-old male rats, decreased on exposure to 0.1 nm genistein in vitro (control: 175 +/- 5 vs. 117 +/- 3 ng/10(6) cells per 24 h; P < 0.05), indicative of direct phytoestrogen action. Thus, phytoestrogens have the ability to regulate Leydig cells, and additional studies to assess potential adverse effects of dietary soy-based products on reproductive tract development in neonates are warranted. PMID:17569756

  10. NQRS Data for C24H20BCs (Subst. No. 1575)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for C24H20BCs (Subst. No. 1575)

  11. NQRS Data for C24H20BRb (Subst. No. 1578)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for C24H20BRb (Subst. No. 1578)

  12. NQRS Data for C24H24BN (Subst. No. 1583)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for C24H24BN (Subst. No. 1583)

  13. A "second window of protection" occurs 24 h after ischemic preconditioning in the rat heart.

    PubMed

    Yamashita, N; Hoshida, S; Taniguchi, N; Kuzuya, T; Hori, M

    1998-06-01

    We and others found that cardioprotection is acquired not only soon after, but also 24 h after ischemic preconditioning in canine and rabbit myocardial infarction models (second window of protection). However, a second window phenomenon against myocardial infarction was dependent on species limitations and has not been observed in porcine hearts. In this study, we examined whether the "second window of protection" against myocardial infarction is observed in the rat heart. In the ischemic preconditioning (IP) group, the left main coronary artery (LCA) of rats was occluded four times for 3 min. each separated by reperfusion for 10 min. After 0, 3, and 24 h, the rats were subjected to a 20-min LCA occlusion followed by 48-h reperfusion. At 0 and 24 h after IP, infarct size and the incidence of ventricular fibrillation (VF) during ischemia were significantly reduced compared with corresponding sham-operated groups without preconditioning. After 3 h of IP, there were no differences either in the incidence of VF during ischemia or in infarct size. Manganese superoxide dismutase (Mn-SOD) content in ischemic (LCA) region of myocardium significantly increased as compared with that of sham-operated rats 24 h after IP. Treatment with N-2-mercaptopropionyl glycine, an antioxidant and a hydroxyl radical scavenger, during IP abolished the early-phase (0 h after IP) and late-phase (24 h after IP) cardioprotection and the corresponding late increase in Mn-SOD content. These results indicate that a "second window of protection" against myocardial infarction also exists in rat hearts and the induction of an intrinsic scavenger, Mn-SOD, via free radical production during IP may be important in the second window of protection. PMID:9689592

  14. Human exposure to unconventional natural gas development: A public health demonstration of periodic high exposure to chemical mixtures in ambient air.

    PubMed

    Brown, David R; Lewis, Celia; Weinberger, Beth I

    2015-01-01

    Directional drilling and hydraulic fracturing of shale gas and oil bring industrial activity into close proximity to residences, schools, daycare centers and places where people spend their time. Multiple gas production sources can be sited near residences. Health care providers evaluating patient health need to know the chemicals present, the emissions from different sites and the intensity and frequency of the exposures. This research describes a hypothetical case study designed to provide a basic model that demonstrates the direct effect of weather on exposure patterns of particulate matter smaller than 2.5 microns (PM2.5) and volatile organic chemicals (VOCs). Because emissions from unconventional natural gas development (UNGD) sites are variable, a short term exposure profile is proposed that determines 6-hour assessments of emissions estimates, a time scale needed to assist physicians in the evaluation of individual exposures. The hypothetical case is based on observed conditions in shale gas development in Washington County, Pennsylvania, and on estimated emissions from facilities during gas development and production. An air exposure screening model was applied to determine the ambient concentration of VOCs and PM2.5 at different 6-hour periods of the day and night. Hourly wind speed, wind direction and cloud cover data from Pittsburgh International Airport were used to calculate the expected exposures. Fourteen months of daily observations were modeled. Higher than yearly average source terms were used to predict health impacts at periods when emissions are high. The frequency and intensity of exposures to PM2.5 and VOCs at a residence surrounded by three UNGD facilities was determined. The findings show that peak PM2.5 and VOC exposures occurred 83 times over the course of 14 months of well development. Among the stages of well development, the drilling, flaring and finishing, and gas production stages produced higher intensity exposures than the

  15. Clinical and Laboratory Responses of Cross-Country Skiing for a 24-H World Record: Case Report

    PubMed Central

    Niemelä, Markus; Juvonen, Jukka; Kangastupa, Päivikki; Niemelä, Onni; Juvonen, Tatu

    2015-01-01

    The physiological consequences of ultra-endurance cross-country skiing in cold conditions are poorly known. We report here clinical, echocardiographic and laboratory findings from a 41-y old male elite skier in a world record trial for 24-h skiing. The athlete completed a total of 406.8 km outdoors with the temperature ranging between -24°C and –5°C during the 24-h period. Post exercise, notable increases from baseline values were observed in myoglobin (50-fold), creatinine kinase (30-fold) and proBNP (6-fold), whereas troponin T or troponin I levels remained unchanged. At baseline, echocardiographic findings showed cardiac hypertrophy and after skiing, a 5% reduction of left-ventricular end-diastolic dimension. Increases in markers of kidney (creatinine) and liver function (alanine aminotransferase), serum uric acid, C-reactive protein and white blood cell counts were also noted. In addition, electrolyte disturbances including hyponatremia, hypophosphatemia and hypocalcaemia were noted during the follow-up. The data indicates that a prolonged period of high-intensity skiing leads to muscle, heart and kidney affection and activation of inflammation even in an experienced elite skier. The observed health effects underscore the need for strict medical surveillance of participants in extreme sports with long duration. Key points An elite athlete was able to ski over 400 km during 24 hours with an outdoor temperature ranging between –5 °C and –24 °C. Several postrace abnormalities occurred in biomarkers of muscle, heart, kidney, liver and inflammation status. Serum troponins, specific markers of myocardial cell damage, remained stable. The report supports careful medical surveillance of participants in extreme sports with long duration. PMID:26664265

  16. High-intensity interval exercise induces 24-h energy expenditure similar to traditional endurance exercise despite reduced time commitment.

    PubMed

    Skelly, Lauren E; Andrews, Patricia C; Gillen, Jenna B; Martin, Brian J; Percival, Michael E; Gibala, Martin J

    2014-07-01

    Subjects performed high-intensity interval training (HIIT) and continuous moderate-intensity training (END) to evaluate 24-h oxygen consumption. Oxygen consumption during HIIT was lower versus END; however, total oxygen consumption over 24 h was similar. These data demonstrate that HIIT and END induce similar 24-h energy expenditure, which may explain the comparable changes in body composition reported despite lower total training volume and time commitment. PMID:24773393

  17. Association Between Estimated 24-h Urinary Sodium Excretion and Metabolic Syndrome in Korean Adults

    PubMed Central

    Won, Jong Chul; Hong, Jae Won; Noh, Jung Hyun; Kim, Dong-Jun

    2016-01-01

    Abstract High sodium intake is 1 of the modifiable risk factors for cardiovascular disease, but in Korea, daily sodium intake is estimated to be double the level recommended by World Health Organization. We investigated the association between the estimated 24-h urinary sodium excretion (24hUNaE) and metabolic syndrome using nationwide population data. In total, 17,541 individuals (weighted n = 33,200,054; weighted men, 52.5% [95% confidence interval, CI = 51.8–53.3]; weighted age, 45.2 years [44.7–45.7]) who participated in the Korean Health and Nutrition Examination Survey 2009 to 2011 were investigated. NCEP-ATP III criteria for metabolic syndrome were used, and sodium intake was estimated by 24hUNaE using Tanaka equation with a spot urine sample. The weighted mean 24hUNaE values were 3964 mg/d (95% CI = 3885–4044) in men and 4736 mg/d (4654–4817) in women. The weighted age-adjusted prevalence of metabolic syndrome was 22.2% (21.4–23.0), and it increased with 24hUNaE quartile in both men and women (mean ± standard error of the mean; men: 22.5 ± 1.0%, 23.0 ± 1.0%, 26.0 ± 1.2%, and 26.0 ± 1.2%; P = 0.026; women: 19.4 ± 0.8%, 17.7 ± 0.8%, 19.8 ± 1.0%, and 23.0 ± 1.1%; P = 0.002, for quartiles 1–4, respectively). Even after adjustment for age, daily calorie intake, heavy alcohol drinking, regular exercise, college graduation, and antihypertensive medication, the weighted prevalence of metabolic syndrome increased with the increase in 24hUNaE in men and women. The weighted 24hUNaE was positively associated with the number of metabolic syndrome components after adjustment for confounding factors in men and women. In subjects without antihypertensive medication, the odds ratio for metabolic syndrome in quartile 4 of 24hUNaE compared with quartile 1 was 1.56 (1.33–1.84, P < 0.001) in the total population, 1.66 (1.34–2.06, P < 0.001) in men, and 1.94 (1.49–2.53, P < 0

  18. Risk factors for stillbirths and mortality during the first 24h of life on dairy farms in Hokkaido, Japan 2005-2009.

    PubMed

    Kayano, M; Kadohira, M; Stevenson, M A

    2016-05-01

    This was a retrospective cohort study using data from the insurance scheme provided by the Japanese Mutual Aid Association (NOSAI). The population of interest comprised all cattle born on NOSAI-client farms in the Japanese prefecture of Hokkaido, Japan for the period 1 April 2005-31 March 2009. The outcome of interest was whether or not at least one calf was stillborn, had died during delivery or died during the first 24 hours of life for a given calving event, termed first 24h mortality risk. A mixed-effects logistic regression model was developed to identify explanatory variables associated with first 24h mortality risk. The final data set comprised details of 1,281,737 calving events on a total of 5172 dairy herds from 19 NOSAI branches located throughout the prefecture of Hokkaido. Throughout the study period 7.68 (95% CI 7.64-7.73) of every 100 calving events had at least one calf that was either stillborn, dead at the time of delivery or dead during the first 24h of life. Factors that were positively associated with an increase in first 24h mortality risk included delivery during the colder months of the year (November-March), being of Wagyu breed, having a multipara dam, multiple (as opposed to single) birth deliveries, and delivery in larger herds. ​After adjusting for the fixed effects included in our multilevel model, 89% of the unexplained variation in first 24h mortality risk was at the calving event level. We propose that the data recording requirements of the NOSAI scheme are extended to include details of calving events (e.g. the presence or absence of dystocia) and details of the way in which calves are managed post delivery. This would allow more subtle risk factors for calf mortality to be identified which, in turn, will lead to refinement of recommendations for calf management during the first 24h of life in this area of Japan. PMID:27094140

  19. The alignment of immediate health effects of multi-hour exposure periods

    EPA Science Inventory

    Objective: Exposure to [me airborne particulate matter (PM2.5) has been associated with cardiovascular outcomes, including acute effects on endothelial dysfunction. With such immediate effects, the choice ofthe exposure timeframe may be a critical factor. This analysis compares t...

  20. DELAYED REPRODUCTIVE EFFECTS FOLLOWING EXPOSURE TO TOXIC CHEMICALS DURING CRITICAL DEVELOPMENTAL PERIODS

    EPA Science Inventory

    The studies presented in this review indicate that perinatal exposure of the fetal or neonatal rodent to a toxicant can adversely affect reproductive development, reduce fertility.and accelerate reproductive senescence. n rodents and humans exposure to DES, estrogens, androgens a...

  1. Nqrs Data for C24H20MnO4P (Subst. No. 1581)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for C24H20MnO4P (Subst. No. 1581)

  2. Association of estimated glomerular filtration rate with 24-h urinalysis and stone composition.

    PubMed

    Moreira, Daniel M; Friedlander, Justin I; Hartman, Christopher; Gershman, Boris; Smith, Arthur D; Okeke, Zeph

    2016-08-01

    The aim of this study is to determine the association of estimated glomerular filtration rate (eGFR) with 24-h urine analysis and stone composition. We performed a retrospective review of 1060 stone formers with 24-h urinalysis, of which 499 had stone composition analysis available. Comparisons of baseline patient characteristics and urinary abnormalities across eGFR groups (<60, 60-89.9, ≥90 mL/min/1.73 m(2)) were performed using Fisher's exact test for categorical data and analysis of variance for continuous variables. Analyses of 24-h urinalysis and stone composition across eGFR groups were performed using linear regression with eGFR groups as a continuous variable to evaluate trends. Of the 1060 patients in the study, 595 (56 %) were males. The mean age was 53.8 years. A total of 38 (4 %), 77 (7 %), and 945 (89 %) patients had eGFR <60, 60-89.9, and ≥90 mL/min/1.73 m(2), respectively. Lower eGFR was associated with older age, lower body-mass index, and female gender (all P < 0.05). Lower eGFR was also associated with lower urinary volume, calcium, citrate, uric acid, sodium, magnesium, phosphorus, sulfate, and creatinine on both univariable and multivariable analyses, adjusted for demographics, comorbidities and medication use (all P < 0.05). The prevalence of hypocitraturia and hypomagnesuria was associated with decreased eGFR, while hypercalciuria, hyperoxaluria, hyperuricosuria and hyperphosphaturia were associated with higher eGFR (all P < 0.05). Stone composition was similar across eGFR groups (all P > 0.05). In conclusion, lower eGFR was associated with lower excretion of urinary elements in a routine 24-h urinalysis, but similar stone composition. PMID:26573808

  3. Ovine platelet function is unaffected by extracorporeal membrane oxygenation within the first 24 h.

    PubMed

    Hayes, Rylan A; Foley, Samuel; Shekar, Kiran; Diab, Sara; Dunster, Kimble R; McDonald, Charles; Fraser, John F

    2015-10-01

    This study investigated platelet dysfunction during short-term extracorporeal membrane oxygenation (ECMO) and secondarily to determine if hyperoxaemia contributes to this dysfunction. Healthy sheep were anaesthetized and maintained on ECMO for either 2 or 24 h, with or without induction of smoke inhalation acute lung injury. A specialized animal-operating theatre was used to conduct the experimentation. Forty-three healthy female sheep were randomized into either a test or a control group. Following anaesthesia, test groups received ECMO ± smoke inhalation acute lung injury (SALI), whereas control groups were maintained with ventilation only ± SALI. Physiological, biochemical and coagulation data were obtained throughout via continuous monitoring and blood sampling. Platelet function was quantified through whole blood impedance aggregometry using Multiplate. Ovine platelet activity induced by adenosine diphosphate (ADP) and collagen was unaffected during the first 24 h of ECMO. However, progressive divergence of ADP-induced platelet activity was noted at cessation of the experiment. PaO2 was inversely related to ADP-dependent platelet activity in the ECMO groups--a relationship not identified in the control groups. ADP and collagen-dependent platelet activity are not significantly affected within the first 24 h of ECMO in sheep. However, dysfunction in ADP-dependent platelet activity may have continued to develop if observed beyond 24 h. Hyperoxaemia during ECMO does appear to affect how platelets react to ADP and may contribute to this developing dysfunction. Long-term animal models and investigation in clinical animals are warranted to fully investigate platelet function during ECMO. PMID:26196193

  4. Nqrs Data for C24H42Li2N4 (Subst. No. 1587)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for C24H42Li2N4 (Subst. No. 1587)

  5. Development of a UK Online 24-h Dietary Assessment Tool: myfood24

    PubMed Central

    Carter, Michelle C.; Albar, Salwa A.; Morris, Michelle A.; Mulla, Umme Z.; Hancock, Neil; Evans, Charlotte E.; Alwan, Nisreen A.; Greenwood, Darren C.; Hardie, Laura J.; Frost, Gary S.; Wark, Petra A.; Cade, Janet E.

    2015-01-01

    Assessment of diet in large epidemiological studies can be costly and time consuming. An automated dietary assessment system could potentially reduce researcher burden by automatically coding food records. myfood24 (Measure Your Food on One Day) an online 24-h dietary assessment tool (with the flexibility to be used for multiple 24 h-dietary recalls or as a food diary), has been developed for use in the UK population. Development of myfood24 was a multi-stage process. Focus groups conducted with three age groups, adolescents (11–18 years) (n = 28), adults (19–64 years) (n = 24) and older adults (≥65 years) (n = 5) informed the development of the tool, and usability testing was conducted with beta (adolescents n = 14, adults n = 8, older adults n = 1) and live (adolescents n = 70, adults n = 20, older adults n = 4) versions. Median system usability scale (SUS) scores (measured on a scale of 0–100) in adolescents and adults were marginal for the beta version (adolescents median SUS = 66, interquartile range (IQR) = 20; adults median SUS = 68, IQR = 40) and good for the live version (adolescents median SUS = 73, IQR = 22; adults median SUS = 80, IQR = 25). Myfood24 is the first online 24-h dietary recall tool for use with different age groups in the UK. Usability testing indicates that myfood24 is suitable for use in UK adolescents and adults. PMID:26024292

  6. Pulse Arrival Time Based Cuff-Less and 24-H Wearable Blood Pressure Monitoring and its Diagnostic Value in Hypertension.

    PubMed

    Zheng, Yali; Poon, Carmen C Y; Yan, Bryan P; Lau, James Y W

    2016-09-01

    Ambulatory blood pressure monitoring (ABPM) has become an essential tool in the diagnosis and management of hypertension. Current standard ABPM devices use an oscillometric cuff-based method which can cause physical discomfort to the patients with repeated inflations and deflations, especially during nighttime leading to sleep disturbance. The ability to measure ambulatory BP accurately and comfortably without a cuff would be attractive. This study validated the accuracy of a cuff-less approach for ABPM using pulse arrival time (PAT) measurements on both healthy and hypertensive subjects for potential use in hypertensive management, which is the first of its kind. The wearable cuff-less device was evaluated against a standard cuff-based device on 24 subjects of which 15 have known hypertension. BP measurements were taken from each subject over a 24-h period by the cuff-less and cuff-based devices every 15 to 30 minutes during daily activities. Mean BP of each subject during daytime, nighttime and over 24-h were calculated. Agreement between mean nighttime systolic BP (SBP) and diastolic (DBP) measured by the two devices evaluated using Bland-Altman plot were -1.4 ± 6.6 and 0.4 ± 6.7 mmHg, respectively. Receiver operator characteristics (ROC) statistics was used to assess the diagnostic accuracy of the cuff-less approach in the detection of BP above the hypertension threshold during nighttime (>120/70 mmHg). The area under ROC curves were 0.975/0.79 for nighttime. The results suggest that PAT-based approach is accurate and promising for ABPM without the issue of sleep disturbances associated with cuff-based devices. PMID:27447469

  7. The acceptability of repeat Internet-based hybrid diet assessment of previous 24-h dietary intake: administration of the Oxford WebQ in UK Biobank.

    PubMed

    Galante, Julieta; Adamska, Ligia; Young, Alan; Young, Heather; Littlejohns, Thomas J; Gallacher, John; Allen, Naomi

    2016-02-28

    Although dietary intake over a single 24-h period may be atypical of an individual's habitual pattern, multiple 24-h dietary assessments can be representative of habitual intake and help in assessing seasonal variation. Web-based questionnaires are convenient for the participant and result in automatic data capture for study investigators. This study reports on the acceptability of repeated web-based administration of the Oxford WebQ--a 24-h recall of frequency from a set food list suitable for self-completion from which energy and nutrient values can be automatically generated. As part of the UK Biobank study, four invitations to complete the Oxford WebQ were sent by email over a 16-month period. Overall, 176 012 (53% of those invited) participants completed the online version of the Oxford WebQ at least once and 66% completed it more than once, although only 16% completed it on all four occasions. The response rate for any one round of invitations varied between 34 and 26%. On most occasions, the Oxford WebQ was completed on the same day that they received the invitation, although this was less likely if sent on a weekend. Participants who completed the Oxford WebQ tended to be white, female, slightly older, less deprived and more educated, which is typical of health-conscious volunteer-based studies. These findings provide preliminary evidence to suggest that repeated 24-h dietary assessment via the Internet is acceptable to the public and a feasible strategy for large population-based studies. PMID:26652593

  8. Food Intake Recording Software System, version 4 (FIRSSt4): A self-completed 24-h dietary recall for children

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Food Intake Recording Software System, version 4 (FIRSSt4), is a web-based 24-h dietary recall (24 hdr) self-administered by children based on the Automated Self-Administered 24-h recall (ASA24) (a self-administered 24 hdr for adults). The food choices in FIRSSt4 are abbreviated to include only ...

  9. Antiretroviral drugs in meconium: detection for different gestational periods of exposure

    PubMed Central

    Himes, Sarah K.; Tassiopoulos, Katherine; Yogev, Ram; Huestis, Marilyn A.

    2015-01-01

    Objectives To determine whether antiretroviral (ARV) medications can be detected in meconium from 2nd or 3rd trimester, labor and delivery (L&D), or postnatal exposures. Study design Twenty ARV medications were quantified by LC-MS/MS in 598 meconium samples from uninfected infants born to pregnant women with HIV enrolled in the Pediatric HIV/AIDS Cohort Study. Results ARV detection in meconium following 3rd trimester exposure was 85.7–94.4% for all ARVs except stavudine (0%, n=2), likely due to low doses and a high limit for quantification. Of 107 samples with some 2nd trimester only ARV exposures, meconium was positive for only lopinavir, tenofovir, or efavirenz in 11.8–14.3% of exposed neonates; administration of these ARVs occurred between gestational weeks 25–28 in the positive samples. Days without lopinavir or tenofovir before delivery significantly correlated with decreasing concentrations of tenofovir and lamivudine in meconium. Concentrations significantly correlated with increasing gestational age among infants with continuous 2nd and 3rd trimester exposure. Zidovudine given during L&D or for neonatal prophylaxis was detected in 95.1% and 94.6% of meconium samples, respectively. Conclusions Changes in ARV treatments during pregnancy offered a unique opportunity to investigate ARV detection in meconium. ARVs in meconium primarily reflect 3rd trimester ARV exposures, although 6 of 107 2nd trimester only exposures were detected. Zidovudine administration during L&D was detected in meconium indicating potential urine contamination or rapid incorporation into meconium. These data will improve interpretation of meconium drug test results. PMID:26001315

  10. Studying cumulative ozone exposures in Europe during a 7-year period

    NASA Astrophysics Data System (ADS)

    Bastrup-Birk, Annemarie; Brandt, JøRgen; Zlatev, Zahari; Uria, Ignacio

    1997-10-01

    Ozone is one of the most harmful pollutants in the troposphere. High ozone concentrations can damage plants, animals and humans. The damaging effects depend on the magnitude of a critical level of a special parameter, the cumulative ozone exposure. This is why cumulative ozone exposures must be carefully studied. It is important to determine the relationships between relevant emissions (NOx emissions, human-made VOC emissions, and/or a combination of NOx emissions and human-made VOC emissions) and cumulative ozone exposures. All these issues are discussed in this paper. Meteorological data from seven consecutive years, from 1989 to 1995, have been used in the experiments with different scenarios for varying the emissions (the NOx emissions, the human-made VOC emissions, as well as both the NOx emissions and the human-made VOC emissions). The particular air pollution model used in this study is the Danish Eulerian Model. Several hundred runs with different input data (meteorological data and/or emission data) have been performed. Advanced visualization techniques are used to interpret the large amount of digital data collected in these runs and to show clearly different trends and relationships that are normally hidden behind millions and millions of numbers. The model results were compared with measurements taken at more than 80 stations located in different European countries. The experiments indicate that it is sufficient to carry out computations over 5 consecutive years in order to eliminate the influence of extreme meteorological conditions (very warm or very cold summer months) on the cumulative ozone exposures, while this effect is clearly seen if less than 5 years are used in the experiments. It is shown that the relationship between the emissions (NOx and/or human-made VOC emissions) and the cumulative ozone exposures is in general nonlinear. Finally, it is illustrated that the critical values for ozone exposures are exceeded in most of Europe (in many

  11. Local 24-h hyperglycemia does not affect endothelium-dependent or -independent vasoreactivity in humans.

    PubMed

    Houben, A J; Schaper, N C; de Haan, C H; Huvers, F C; Slaaf, D W; de Leeuw, P W; Nieuwenhuijzen Kruseman, C

    1996-06-01

    Hyperglycemia induces regional hemodynamic changes, as suggested by animal studies. These hemodynamic changes may play an initiating role in the pathogenesis of diabetic microangiopathy. The aim of the present study was to evaluate the effects of acute local hyperglycemia for 24 h on basal human forearm muscle and skin blood flow and endothelium-dependent and -independent vasoreactivity. Local hyperglycemia (approximately 15 mM) was induced by infusion of 5% glucose into the brachial artery of the nondominant arm. In control experiments, the same individual amount of glucose was infused intravenously in the dominant arm to correct for possible systemic effects of the infused glucose. Vasoreactivity of the forearm vasculature was evaluated by local infusion of acetylcholine (ACh), sodium nitroprusside (SNP), NG-monomethyl-L-arginine (L-NMMA), and norepinephrine (NE) into the brachial artery. Regional hemodynamic measurements were performed at baseline and after 6, 12, and 24 h of local hyperglycemia. Median (with interquartile range) basal forearm (muscle) blood flow (FBF) was not influenced by the 24-h local hyperglycemia [infused-to-contralateral arm FBF ratio for glucose 1.32 (1.16-1.64) vs. control 1.54 (1.34-1.69)]. Skin microcirculatory blood flow (laser Doppler flowmetry, LDF) was not influenced by the 24-h local hyperglycemia [LDF ratio for glucose 1.00 (0.62-1.56) vs control 0.80 (0.58-1.14)]. In addition, the vasoreactivity of both muscle and skin (not shown) vasculature to ACh [percent change in FBF ratio for glucose 167% (81-263) vs. control 148% (94-211)], SNP [for glucose 486% (178-586) vs. control 293% (196-454)], L-NMMA [for glucose -36% (-56 to -22) vs. control -41% (-51 to -24)], and NE [for glucose -48% (-72 to -41) vs. control -66% (-79 to -33)] was also not affected by the local hyperglycemia. Thus, in contrast to animal studies, our results suggest that a moderate-to-severe hyperglycemia does not affect the regulation of basal blood flow or

  12. Cytokine Profiling in Immigrants with Clinical Malaria after Extended Periods of Interrupted Exposure to Plasmodium falciparum

    PubMed Central

    Moncunill, Gemma; Mayor, Alfredo; Bardají, Azucena; Puyol, Laura; Nhabomba, Augusto; Barrios, Diana; Aguilar, Ruth; Pinazo, María-Jesús; Almirall, Mercè; Soler, Cristina; Muñoz, José; Gascón, Joaquim; Dobaño, Carlota

    2013-01-01

    Immunity to malaria is believed to wane with time in the absence of exposure to Plasmodium falciparum infection, but immunoepidemiological data on longevity of immunity remain controversial. We quantified serum cytokines and chemokines by suspension array technology as potential biomarkers for durability of immunity in immigrants with clinical malaria after years without parasite exposure. These were compared to serum/plasma profiles in naïve adults (travelers) and semi-immune adults under continuous exposure, with malaria, along with immigrant and traveler patients without malaria. Immigrants had higher levels of IL-2, IL-5 and IL-8 compared to semi-immune adults with malaria (P≤0.0200). Time since immigration correlated with increased IL-2 (rho=0.2738P=0.0495) and IFN-γ (rho=0.3044P=0.0282). However, immigrants did not show as high IFN-γ concentrations as travelers during a first malaria episode (P<0.0001). Immigrants and travelers with malaria had higher levels of IFN-γ, IL-6, and IL-10 (P<0.0100) than patients with other diseases, and IL-8 and IL-1β were elevated in immigrants with malaria (P<0.0500). Therefore, malaria patients had a characteristic strong pro-inflammatory/Th1 signature. Upon loss of exposure, control of pro-inflammatory responses and tolerance to P. falciparum appeared to be reduced. Understanding the mechanisms to maintain non-pathogenic effector responses is important to develop new malaria control strategies. PMID:23967342

  13. Exposure to hyperoxia in the neonatal period alters bone marrow function

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oxygen is often life saving in preterm infants, however, excessive exposure may lead to blood vessel and tissue injury in the lung and retina. Oxygen-treated neonates often exhibit bone marrow (BM) suppression requiring blood product transfusions. However, we do not know whether oxygen is directly t...

  14. Toxic effects upon exposure to polycyclic aromatic hydrocarbon (chrysene) in scallop Chlamys farreri during the reproduction period.

    PubMed

    Xiu, Meng; Pan, Luqing; Jin, Qian

    2016-06-01

    This study aims to investigate potential toxic effects of chrysene (CHR) on mature scallop Chlamys farreri during the reproduction period, using indicators of antioxidant defences and oxidative stress. Scallops were exposed to 0.2, 0.8 and 3.2μg/L waterborne CHR for 21 days, at day 10 scallops were induced to spawn. At days 1, 3, 6, 10, 11, 15 and 21, aryl hydrocarbon hydroxylase (AHH), 7-ethoxyresorufin-O-deethylase (EROD), glutathione-s-transferase (GST), glutathione (GSH), superoxide dismutase (SOD), lipid peroxidation (LPO), protein carbonyl (PC) and DNA strand breaks in digestive glands were examined by separately analysing male and female scallops. During the pre-spawn period, Levels of enzymatic activities and oxidative stress were all induced by the exposure to CHR for females and males. GST activity presented a good time- and dose-dependent relationship only in males, and GSH content showed a dose-dependent manner in both sexes. During the post-spawn period, different trends were observed, while PC contents maintained growth in time- and dose-dependent manner. Overall, males were more sensitive than females to CHR exposure in enzyme activities, and correspondingly, females suffered from more serious oxidative damages. Both GSH and PC contents seemed to be potential biomarkers for PAH exposure. These results will offer the information on toxicity of CHR in this species, and ensure the influence of gender and reproductive status on PAH detoxification metabolism. PMID:27131750

  15. Effect of intermittent chronic exposure to hypoxia on feeding behaviour of rats

    NASA Astrophysics Data System (ADS)

    Singh, S. B.; Selvamurthy, W.

    1993-12-01

    Healthy albino male rats were exposed to a simulated high altitude (HA) equivalent to 25000 ft (7620 m) for 6 h daily, continuously for 21 days to study the feeding behaviour. The 24-h food and water intake and body weight once in 3 days were recorded. Blood samples were drawn once a week from the retro-orbital venous plexus for blood sugar analysis. All the parameters were recorded before, during and after exposure to simulated HA. The results show a decrease in 24-h food and water intake and decreased gain in body weight during hypoxic exposure, which showed a tendency to come back to control during the post-exposure period. The blood sugar reflected a state of mild hyperglycaemia during exposure to HA.

  16. Time dependent effects of stress prior to encoding on event-related potentials and 24 h delayed retrieval.

    PubMed

    Quaedflieg, Conny W E M; Schwabe, Lars; Meyer, Thomas; Smeets, Tom

    2013-12-01

    Stress can exert profound effects on memory encoding. Here, we investigated whether (sub)cortical information processing during encoding and memory retrieval at a 24 h delayed test are affected by the temporal proximity between stress and memory encoding. Sixty-four participants engaged in the Maastricht Acute Stress Test (MAST) or a no-stress control condition either immediately before (i.e., proximate condition) or 30 min before (i.e., distant condition) a picture encoding task. In general, stress decreased the number of freely recalled and recognized pictures and increased the number of false alarms. However, timing of stress exposure did not differentially affect picture recall, recognition or selective attention processes (i.e., LPP). Nevertheless, stress-induced cortisol responses and correctly recognized neutral pictures were positively associated within the proximate stress condition but negatively associated within the distant stress condition. These findings suggest that the time at which a stressor is applied might differentially impact the association between stress-induced cortisol elevations and memory formation and indicate the need for a finer delineation of the time window during which glucocorticoids affect memory formation processes. PMID:24074803

  17. Nocturnal sleep-related variables from 24-h free-living waist-worn accelerometry: International Study of Childhood Obesity, Lifestyle and the Environment

    PubMed Central

    Tudor-Locke, C; Mire, E F; Barreira, T V; Schuna, J M; Chaput, J-P; Fogelholm, M; Hu, G; Kurpad, A; Kuriyan, R; Lambert, E V; Maher, C; Maia, J; Matsudo, V; Olds, T; Onywera, V; Sarmiento, O L; Standage, M; Tremblay, M S; Zhao, P; Church, T S; Katzmarzyk, P T

    2015-01-01

    Objectives: We describe the process of identifying and defining nocturnal sleep-related variables (for example, movement/non-movement indicators of sleep efficiency, waking episodes, midpoint and so on) using the unique 24-h waist-worn free-living accelerometer data collected in the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE). Methods: Seven consecutive days of 24-h waist-worn accelerometer (GT3X+, ActiGraph LLC) data were collected from over 500 children at each site. An expert subgroup of the research team with accelerometry expertize, frontline data collectors and data managers met on several occasions to categorize and operationally define nocturnal accelerometer signal data patterns. The iterative process was informed by the raw data drawn from a sub set of the US data, and culminated in a refined and replicable delineated definition for each identified nocturnal sleep-related variable. Ultimately based on 6318 participants from all 12 ISCOLE sites with valid total sleep episode time (TSET), we report average clock times for nocturnal sleep onset, offset and midpoint in addition to sleep period time, TSET and restful sleep efficiency (among other derived variables). Results: Nocturnal sleep onset occurred at 2218 hours and nocturnal sleep offset at 0707 hours. The mean midpoint was 0243 hours. The sleep period time of 529.6 min (8.8 h) was typically accumulated in a single episode, making the average TSET very similar in duration (529.0 min). The mean restful sleep efficiency ranged from 86.8% (based on absolute non-movement of 0 counts per minute) to 96.0% (based on relative non-movement of <100 counts per minute). Conclusions: These variables extend the potential of field-based 24-h waist-worn accelerometry to distinguish and categorize the underlying robust patterns of movement/non-movement signals conveying magnitude, duration, frequency and periodicity during the nocturnal sleep period. PMID:27152185

  18. Quantitative assessment of regulatory proteins in blood as markers of radiation effects in the late period after occupational exposure.

    PubMed

    Kirillova, Evgenia N; Zakharova, Maria L; Muksinova, Klara N; Drugova, Elena D; Pavlova, Olga S; Sokolova, Svetlana N

    2012-07-01

    The objective of this research was quantitative assessment of serum and membrane regulatory proteins in blood from nuclear workers as markers of radiation-induced alterations in immune homeostasis in the late period after protracted exposure of nuclear workers with different doses. The effector and regulatory lymphocytes were measured using a flow cytofluorometer in workers from the main facilities of the Mayak PA (aged ∼60 y up to 80 y) in the late period after combined exposure to external gamma-rays and internal alpha-radiation from incorporated 239Pu. The control group included non-occupationally exposed members of the Ozyorsk population matched by gender and age to the group of Mayak workers. Thirty serum proteins involved in regulation of immune homeostasis, such as growth factors, multifunctional interleukins, pro- and anti-inflammatory cytokines, and their receptors, were measured using ELISA in blood serum specimens from the Radiobiology Human Tissue Repository. The dosimetry estimates were obtained using Doses-2005. The correlation analysis revealed a statistically significant direct relationship of T-killers and plutonium body burden and a decreasing level of T-helpers with accumulated external dose in exposed individuals. There were differences in expression of membrane markers in young regulatory cells (double null T-lymphocytes, NKT-lymphocytes, regulatory T-cells, and an increase of activated forms of T-lymphocytes), which indicated an active role of regulatory cells in maintaining immune homeostasis in terms of protracted exposure. The assessment of regulatory proteins in blood indicated that growth factors (EGF, TGF-β1, PDGF), multifunctional interleukins (IL-17A, IL-18), and pro-inflammatory cytokines (IL-1β and INF-γ) could be potential markers of radiation-induced alterations in protein status. An imbalance of pro- and antiinflammatory proteins in blood and variations of protein profiles at the lower exposure levels (gamma-ray dose <1 Gy

  19. Validation and Assessment of Three Methods to Estimate 24-h Urinary Sodium Excretion from Spot Urine Samples in Chinese Adults.

    PubMed

    Peng, Yaguang; Li, Wei; Wang, Yang; Chen, Hui; Bo, Jian; Wang, Xingyu; Liu, Lisheng

    2016-01-01

    24-h urinary sodium excretion is the gold standard for evaluating dietary sodium intake, but it is often not feasible in large epidemiological studies due to high participant burden and cost. Three methods-Kawasaki, INTERSALT, and Tanaka-have been proposed to estimate 24-h urinary sodium excretion from a spot urine sample, but these methods have not been validated in the general Chinese population. This aim of this study was to assess the validity of three methods for estimating 24-h urinary sodium excretion using spot urine samples against measured 24-h urinary sodium excretion in a Chinese sample population. Data are from a substudy of the Prospective Urban Rural Epidemiology (PURE) study that enrolled 120 participants aged 35 to 70 years and collected their morning fasting urine and 24-h urine specimens. Bias calculations (estimated values minus measured values) and Bland-Altman plots were used to assess the validity of the three estimation methods. 116 participants were included in the final analysis. Mean bias for the Kawasaki method was -740 mg/day (95% CI: -1219, 262 mg/day), and was the lowest among the three methods. Mean bias for the Tanaka method was -2305 mg/day (95% CI: -2735, 1875 mg/day). Mean bias for the INTERSALT method was -2797 mg/day (95% CI: -3245, 2349 mg/day), and was the highest of the three methods. Bland-Altman plots indicated that all three methods underestimated 24-h urinary sodium excretion. The Kawasaki, INTERSALT and Tanaka methods for estimation of 24-h urinary sodium excretion using spot urines all underestimated true 24-h urinary sodium excretion in this sample of Chinese adults. Among the three methods, the Kawasaki method was least biased, but was still relatively inaccurate. A more accurate method is needed to estimate the 24-h urinary sodium excretion from spot urine for assessment of dietary sodium intake in China. PMID:26895296

  20. Validation and Assessment of Three Methods to Estimate 24-h Urinary Sodium Excretion from Spot Urine Samples in Chinese Adults

    PubMed Central

    Peng, Yaguang; Li, Wei; Wang, Yang; Chen, Hui; Bo, Jian; Wang, Xingyu; Liu, Lisheng

    2016-01-01

    24-h urinary sodium excretion is the gold standard for evaluating dietary sodium intake, but it is often not feasible in large epidemiological studies due to high participant burden and cost. Three methods—Kawasaki, INTERSALT, and Tanaka—have been proposed to estimate 24-h urinary sodium excretion from a spot urine sample, but these methods have not been validated in the general Chinese population. This aim of this study was to assess the validity of three methods for estimating 24-h urinary sodium excretion using spot urine samples against measured 24-h urinary sodium excretion in a Chinese sample population. Data are from a substudy of the Prospective Urban Rural Epidemiology (PURE) study that enrolled 120 participants aged 35 to 70 years and collected their morning fasting urine and 24-h urine specimens. Bias calculations (estimated values minus measured values) and Bland-Altman plots were used to assess the validity of the three estimation methods. 116 participants were included in the final analysis. Mean bias for the Kawasaki method was -740 mg/day (95% CI: -1219, 262 mg/day), and was the lowest among the three methods. Mean bias for the Tanaka method was -2305 mg/day (95% CI: -2735, 1875 mg/day). Mean bias for the INTERSALT method was -2797 mg/day (95% CI: -3245, 2349 mg/day), and was the highest of the three methods. Bland-Altman plots indicated that all three methods underestimated 24-h urinary sodium excretion. The Kawasaki, INTERSALT and Tanaka methods for estimation of 24-h urinary sodium excretion using spot urines all underestimated true 24-h urinary sodium excretion in this sample of Chinese adults. Among the three methods, the Kawasaki method was least biased, but was still relatively inaccurate. A more accurate method is needed to estimate the 24-h urinary sodium excretion from spot urine for assessment of dietary sodium intake in China. PMID:26895296

  1. Preliminary Estimation of Deoxynivalenol Excretion through a 24 h Pilot Study

    PubMed Central

    Rodríguez-Carrasco, Yelko; Mañes, Jordi; Berrada, Houda; Font, Guillermina

    2015-01-01

    A duplicate diet study was designed to explore the occurrence of 15 Fusarium mycotoxins in the 24 h-diet consumed by one volunteer as well as the levels of mycotoxins in his 24 h-collected urine. The employed methodology involved solvent extraction at high ionic strength followed by dispersive solid phase extraction and gas chromatography determination coupled to mass spectrometry in tandem. Satisfactory results in method performance were achieved. The method’s accuracy was in a range of 68%–108%, with intra-day relative standard deviation and inter-day relative standard deviation lower than 12% and 15%, respectively. The limits of quantitation ranged from 0.1 to 8 µg/Kg. The matrix effect was evaluated and matrix-matched calibrations were used for quantitation. Only deoxynivalenol (DON) was quantified in both food and urine samples. A total DON daily intake amounted to 49.2 ± 5.6 µg whereas DON daily excretion of 35.2 ± 4.3 µg was determined. DON daily intake represented 68.3% of the established DON provisional maximum tolerable daily intake (PMTDI). Valuable preliminary information was obtained as regards DON excretion and needs to be confirmed in large-scale monitoring studies. PMID:25723325

  2. BDNFval66met affects neural activation pattern during fear conditioning and 24 h delayed fear recall

    PubMed Central

    Golkar, Armita; Lindström, Kara M.; Haaker, Jan; Öhman, Arne; Schalling, Martin; Ingvar, Martin

    2015-01-01

    Brain-derived neurotrophic factor (BDNF), the most abundant neutrophin in the mammalian central nervous system, is critically involved in synaptic plasticity. In both rodents and humans, BDNF has been implicated in hippocampus- and amygdala-dependent learning and memory and has more recently been linked to fear extinction processes. Fifty-nine healthy participants, genotyped for the functional BDNFval66met polymorphism, underwent a fear conditioning and 24h-delayed extinction protocol while skin conductance and blood oxygenation level dependent (BOLD) responses (functional magnetic resonance imaging) were acquired. We present the first report of neural activation pattern during fear acquisition ‘and’ extinction for the BDNFval66met polymorphism using a differential conditioned stimulus (CS)+ > CS− comparison. During conditioning, we observed heightened allele dose-dependent responses in the amygdala and reduced responses in the subgenual anterior cingulate cortex in BDNFval66met met-carriers. During early extinction, 24h later, we again observed heightened responses in several regions ascribed to the fear network in met-carriers as opposed to val-carriers (insula, amygdala, hippocampus), which likely reflects fear memory recall. No differences were observed during late extinction, which likely reflects learned extinction. Our data thus support previous associations of the BDNFval66met polymorphism with neural activation in the fear and extinction network, but speak against a specific association with fear extinction processes. PMID:25103087

  3. The impact of a 24-h ultra-marathon on salivary antimicrobial protein responses.

    PubMed

    Gill, S K; Teixeira, A M; Rosado, F; Hankey, J; Wright, A; Marczak, S; Murray, A; Costa, R J S

    2014-10-01

    Depressed oral respiratory mucosal immunity and increased incidence of upper respiratory symptoms are commonly reported after bouts of prolonged exercise. The current study observed the impact of a 24-h continuous overnight ultra-marathon competition (distance range: 122-208 km; ambient temperature range: 0-20 °C) on salivary antimicrobial protein responses and incidence of upper respiratory symptoms. Body mass, unstimulated saliva and venous blood samples were taken from ultra-endurance runners (n=25) and controls (n=17), before and immediately after competition. Upper respiratory symptoms were assessed during and until 4-weeks after event completion. Samples were analyzed for salivary IgA, lysozyme, α-amylase and cortisol in addition to plasma osmolality. Decreased saliva flow rate (p<0.001), salivary IgA (p<0.001) and lysozyme (p=0.015) secretion rates, and increased salivary α-amylase secretion rate (p<0.001) and cortisol responses (p<0.001) were observed post-competition in runners, with no changes being observed in controls. No incidences of upper respiratory symptoms were reported by participants. A 24-h continuous overnight ultra-marathon resulted in the depression of some salivary antimicrobial protein responses, but no incidences of upper respiratory symptoms were evident during or following competition. Salivary antimicrobial protein synergism, effective management of non-infectious episodes, maintaining euhydration, and (or) favourable environmental influences could have accounted for the low prevalence of upper respiratory symptoms. PMID:24886918

  4. [Assessment of duodenogastric reflux 24h variability in subjects with functional dyspepsia].

    PubMed

    Romanowski, Marek; Chojnacki, Jan; Gil, Jerzy; Piotrowski, Wojciech

    2004-01-01

    Symptoms of functional dyspepsia demonstrate significant variability, among others dependently on the time of the day and on consumed meals. The aim of the study was to find out whether duodenogastric reflux is observed in subjects with nonulcer (NUD) and dysmotor dyspepsia (DD) and whether its intensification changes within 24 h. Investigations comprised 25 subjects with NUD and 25 with DD, aged 19-43 years after exclusion of other diseases and H. pylori infection. The gastric content of bilirubin was registered with Bilitec 2000 Synectics Medical. Duodenogastric reflux episodes were observed in both groups but their intensification and 24h dynamics were differentiated. In subjects with DD total reflux index was significantly higher than in those with NUD (mean=18.0+/-9.5% and mean=6.3+/-4.1%; p<0.05). These differences were particularly visible in after meal (mean=21.2+/-7.9% and mean=10.4+/-6.6%; p<0.01) and night time (mean=8.7+/-3.6% and mean=2.9+/-0.9%; p<0.01). The results of the study indicate that bilimetry may be useful in differentiation of the form of dyspepsia and in selection of rational therapy. PMID:15603369

  5. Preliminary estimation of deoxynivalenol excretion through a 24 h pilot study.

    PubMed

    Rodríguez-Carrasco, Yelko; Mañes, Jordi; Berrada, Houda; Font, Guillermina

    2015-03-01

    A duplicate diet study was designed to explore the occurrence of 15 Fusarium mycotoxins in the 24 h-diet consumed by one volunteer as well as the levels of mycotoxins in his 24 h-collected urine. The employed methodology involved solvent extraction at high ionic strength followed by dispersive solid phase extraction and gas chromatography determination coupled to mass spectrometry in tandem. Satisfactory results in method performance were achieved. The method's accuracy was in a range of 68%-108%, with intra-day relative standard deviation and inter-day relative standard deviation lower than 12% and 15%, respectively. The limits of quantitation ranged from 0.1 to 8 µg/Kg. The matrix effect was evaluated and matrix-matched calibrations were used for quantitation. Only deoxynivalenol (DON) was quantified in both food and urine samples. A total DON daily intake amounted to 49.2 ± 5.6 µg whereas DON daily excretion of 35.2 ± 4.3 µg was determined. DON daily intake represented 68.3% of the established DON provisional maximum tolerable daily intake (PMTDI). Valuable preliminary information was obtained as regards DON excretion and needs to be confirmed in large-scale monitoring studies. PMID:25723325

  6. Maternal cypermethrin exposure during the perinatal period impairs testicular development in C57BL male offspring.

    PubMed

    Huang, Chaobin; Li, Xiangdong

    2014-01-01

    Numerous studies have demonstrated that endocrine-disrupting compounds (EDC) are a possible cause of male reproductive organ malfunction and malformation. Cypermethrin (CYP) is a widely used synthetic pyrethroid and a potential EDC. This study aimed to examine the effects of perinatal exposure to low-dose CYP on the development and function of the offspring testes. Pregnant mice were intragastrically administered 0.12 to 12 mg/kg/day CYP from embryonic day 0.5 (E0.5) to weaning (PD21.5, postnatal day 21.5). Maternal exposure to 0.12, 1.2, and 12 mg/kg/day CYP affected the body and organ weight of the offspring. Exposure of CYP led to a dose-dependent decrease in the male-to-female sex ratio. A histopathological analysis revealed a thinner seminiferous epithelium layer at PD21.5, interstitial hyperplasia at PD45.5, and germ cell vacuolization at PD90.5 in the 12 mg/kg/day CYP group. The TUNEL assay results revealed increased germ cell apoptosis in the 12 mg/kg/day CYP group. The serum testosterone (T) level decreased, whereas the estradiol level increased with age in the 1.2 and 12 mg/kg/day CYP groups. The RT-PCR analysis demonstrated decreased expression of T production-related, mitosis-related, and meiosis-related genes in the 1.2 and 12 mg/kg/day CYP groups. The in vitro experimental results demonstrated reduced expression of steroidogenesis genes and decreased T levels. It is concluded that perinatal exposure to low-dose CYP affects testes development and function in adults. PMID:24810582

  7. Maternal Cypermethrin Exposure during the Perinatal Period Impairs Testicular Development in C57BL Male Offspring

    PubMed Central

    Huang, Chaobin; Li, Xiangdong

    2014-01-01

    Numerous studies have demonstrated that endocrine-disrupting compounds (EDC) are a possible cause of male reproductive organ malfunction and malformation. Cypermethrin (CYP) is a widely used synthetic pyrethroid and a potential EDC. This study aimed to examine the effects of perinatal exposure to low-dose CYP on the development and function of the offspring testes. Pregnant mice were intragastrically administered 0.12 to 12 mg/kg/day CYP from embryonic day 0.5 (E0.5) to weaning (PD21.5, postnatal day 21.5). Maternal exposure to 0.12, 1.2, and 12 mg/kg/day CYP affected the body and organ weight of the offspring. Exposure of CYP led to a dose-dependent decrease in the male-to-female sex ratio. A histopathological analysis revealed a thinner seminiferous epithelium layer at PD21.5, interstitial hyperplasia at PD45.5, and germ cell vacuolization at PD90.5 in the 12 mg/kg/day CYP group. The TUNEL assay results revealed increased germ cell apoptosis in the 12 mg/kg/day CYP group. The serum testosterone (T) level decreased, whereas the estradiol level increased with age in the 1.2 and 12 mg/kg/day CYP groups. The RT-PCR analysis demonstrated decreased expression of T production-related, mitosis-related, and meiosis-related genes in the 1.2 and 12 mg/kg/day CYP groups. The in vitro experimental results demonstrated reduced expression of steroidogenesis genes and decreased T levels. It is concluded that perinatal exposure to low-dose CYP affects testes development and function in adults. PMID:24810582

  8. Prenatal Alcohol Exposure is Associated with Regionally Thinner Cortex During the Preadolescent Period.

    PubMed

    Robertson, Frances C; Narr, Katherine L; Molteno, Christopher D; Jacobson, Joseph L; Jacobson, Sandra W; Meintjes, Ernesta M

    2016-07-01

    Children with fetal alcohol spectrum disorders (FASD) may exhibit craniofacial dysmorphology, neurobehavioral deficits, and reduced brain volume. Studies of cortical thickness in FASD have yielded contradictory findings, with 3 reporting thicker cerebral cortex in frontal and temporal brain regions and 2 showing thinner cortex across multiple regions. All 5 studies included subjects spanning a broad age range, and none have examined continuous measures of prenatal alcohol exposure. We investigated the relation of extent of in utero alcohol exposure to cortical thickness in 78 preadolescent children with FASD and controls within a narrow age range. A whole-brain analysis using FreeSurfer revealed no significant clusters where cortical thickness differed by FASD diagnostic group. However, alcohol dose/occasion during pregnancy was inversely related to cortical thickness in 3 regions-right cuneus/pericalcarine/superior parietal lobe, fusiform/lingual gyrus, and supramarginal/postcentral gyrus. The effect of prenatal alcohol exposure on IQ was mediated by cortical thickness in the right occipitotemporal region. It is noteworthy that a continuous measure of maternal alcohol consumption during pregnancy was more sensitive than FASD diagnosis and that the effect on cortical thickness was most evident in relation to a measure of maternal binge drinking. PMID:26088967

  9. Lead Exposure Impairs Hippocampus Related Learning and Memory by Altering Synaptic Plasticity and Morphology During Juvenile Period.

    PubMed

    Wang, Tao; Guan, Rui-Li; Liu, Ming-Chao; Shen, Xue-Feng; Chen, Jing Yuan; Zhao, Ming-Gao; Luo, Wen-Jing

    2016-08-01

    Lead (Pb) is an environmental neurotoxic metal. Pb exposure may cause neurobehavioral changes, such as learning and memory impairment, and adolescence violence among children. Previous animal models have largely focused on the effects of Pb exposure during early development (from gestation to lactation period) on neurobehavior. In this study, we exposed Sprague-Dawley rats during the juvenile stage (from juvenile period to adult period). We investigated the synaptic function and structural changes and the relationship of these changes to neurobehavioral deficits in adult rats. Our results showed that juvenile Pb exposure caused fear-conditioned memory impairment and anxiety-like behavior, but locomotion and pain behavior were indistinguishable from the controls. Electrophysiological studies showed that long-term potentiation induction was affected in Pb-exposed rats, and this was probably due to excitatory synaptic transmission impairment in Pb-exposed rats. We found that NMDA and AMPA receptor-mediated current was inhibited, whereas the GABA synaptic transmission was normal in Pb-exposed rats. NR2A and phosphorylated GluR1 expression decreased. Moreover, morphological studies showed that density of dendritic spines declined by about 20 % in the Pb-treated group. The spine showed an immature form in Pb-exposed rats, as indicated by spine size measurements. However, the length and arborization of dendrites were unchanged. Our results suggested that juvenile Pb exposure in rats is associated with alterations in the glutamate receptor, which caused synaptic functional and morphological changes in hippocampal CA1 pyramidal neurons, thereby leading to behavioral changes. PMID:26141123

  10. Addressing the recovery of feeding rates in post-exposure feeding bioassays: Cyathura carinata as a case study.

    PubMed

    Pais-Costa, Antonia Juliana; Acevedo, Pelayo; Marques, João Carlos; Martinez-Haro, Mónica

    2015-02-01

    Post-exposure bioassays are used in environmental assessment as a cost-effective tool, but the effects of organism's recovery after exposure to pollutant has not yet been addressed in detail. The recoveries of post-exposure feeding rates after being exposed to two sublethal concentrations of cadmium during two different exposure periods (48h and 96h) were evaluated under laboratory conditions using the estuarine isopod Cyathura carinata. Results showed that feeding depression was a stable endpoint up to 24h after cadmium exposure, which is useful for ecotoxicological bioassays. PMID:25576796

  11. Influence of exposure period on in vivo hippocampal glutamate and GABA release in rats chronically exposed to lead.

    PubMed

    Lasley, S M; Green, M C; Gilbert, M E

    1999-08-01

    Previous work has demonstrated that continual exposure to 0.2% lead (Pb) beginning at birth diminishes depolarization-induced hippocampal glutamate (GLU) and GABA release in vivo. The present study sought to extend these findings by examining Pb-induced changes as a function of exposure period. Rats were continually exposed to 0.2% Pb in the drinking water beginning at conception (Gestational-Life, GL) or two weeks after weaning (Wean-Life, WL), while exposure in a third group was begun at conception but terminated at weaning (Gestational-Wean, GW). Hippocampal transmitter release was induced in adult animals by perfusion of 150 mM K+ in the presence of Ca+2 (total release) through a microdialysis probe in one test session, followed by perfusion through a contralateral probe in the absence of Ca+2 (Ca+2-independent release) in the second session. Decreases in total GLU and GABA release were observed in the GL and WL groups compared to controls over the first 20-min after initiation of high K+, decrements that could be attributed to exposure-induced reductions in Ca+2-dependent release. The pattern of Pb-induced changes in the GL group is similar to that observed previously in a group continuously exposed from birth, indicating that gestational exposure did not further enhance the impact of Pb beginning at birth when exposure in both groups extends into adulthood. Similar responses were also found in the WL group, indicating that exposure during early development is not a requirement to induce changes in GLU and GABA release. Pb-induced decreases in response were also seen in the GW group: a decrease in Ca+2-dependent GLU release was observed, while decrements in total and Ca+2-dependent GABA release were similar to those in the GL and WL groups. Thus, exposure limited to early development is also sufficient to produce deficits in evoked transmitter release. In addition, the exposure-induced decreases in GLU responses correspond to Pb-induced impairments in long

  12. Impact of hypobaric hypoxia in pressurized cabins of simulated long-distance flights on the 24 h patterns of biological variables, fatigue, and clinical status.

    PubMed

    Coste, Olivier; Van Beers, Pascal; Touitou, Yvan

    2007-01-01

    Long-distance flights can cause a number of clinical problems in both passengers and crewmembers. Jet lag as well as mild hypoxia resulting from incomplete cabin pressurization could contribute to these problems. The objective of this study was to assess, using a chronobiological approach, the clinical impact of diurnal hypobaric, hypoxic exposure on fatigue and other common symptoms encountered during high-altitude exposure and to measure changes in blood chemistry (i.e., plasma creatinine, urea, uric acid, sodium, calcium, phosphorus, glycemia, and lipids). Fourteen healthy, diurnally active (from 07:00 to 23:00 h) male volunteers, aged 23 to 39 yrs, spent 8.5 h in a hypobaric chamber (08:00 to 16:30 h), at a simulated altitude of 8,000 ft (2,438 m). This was followed by an additional 8.5 h of study four weeks later at a simulated altitude of 12,000 ft (3,658 m). Clinical data were collected every 2 h between 08:00 and 18:00 h, and biological variables were assayed every 2 h over two (control and hypoxic-exposure) 24 h cycles. Clinical symptoms were more frequent with the 12,000 ft exposure. Wide interindividual variability was observed in the clinical tolerance to prolonged hypobaric hypoxia. The 24 h profiles of most biochemical variables were significantly altered at each altitude, with changes in mean plasma levels and a tendency toward phase delay, except for uric acid, which showed a phase advance. Changes in appetite mainly occurred with the simulated 12,000 ft exposure and may have been associated with changes in the postprandial glycemia profile. Finally, though the observed biochemical changes were significant, their clinical relevance must be clarified in studies involving actual long-distance flights. PMID:18075804

  13. Quantification of differences between occupancy and total monitoring periods for better assessment of exposure to particles in indoor environments

    NASA Astrophysics Data System (ADS)

    Wierzbicka, A.; Bohgard, M.; Pagels, J. H.; Dahl, A.; Löndahl, J.; Hussein, T.; Swietlicki, E.; Gudmundsson, A.

    2015-04-01

    For the assessment of personal exposure, information about the concentration of pollutants when people are in given indoor environments (occupancy time) are of prime importance. However this kind of data frequently is not reported. The aim of this study was to assess differences in particle characteristics between occupancy time and the total monitoring period, with the latter being the most frequently used averaging time in the published data. Seven indoor environments were selected in Sweden and Finland: an apartment, two houses, two schools, a supermarket, and a restaurant. They were assessed for particle number and mass concentrations and number size distributions. The measurements using a Scanning Mobility Particle Sizer and two photometers were conducted for seven consecutive days during winter in each location. Particle concentrations in residences and schools were, as expected, the highest during occupancy time. In the apartment average and median PM2.5 mass concentrations during the occupancy time were 29% and 17% higher, respectively compared to total monitoring period. In both schools, the average and medium values of the PM2.5 mass concentrations were on average higher during teaching hours compared to the total monitoring period by 16% and 32%, respectively. When it comes to particle number concentrations (PNC), in the apartment during occupancy, the average and median values were 33% and 58% higher, respectively than during the total monitoring period. In both houses and schools the average and median PNC were similar for the occupancy and total monitoring periods. General conclusions on the basis of measurements in the limited number of indoor environments cannot be drawn. However the results confirm a strong dependence on type and frequency of indoor activities that generate particles and site specificity. The results also indicate that the exclusion of data series during non-occupancy periods can improve the estimates of particle concentrations and

  14. Evaluation of wet tantalum capacitors after exposure to extended periods of ripple current, volume 2

    NASA Technical Reports Server (NTRS)

    Ward, C. M.

    1975-01-01

    The application of tantalum capacitors in the Viking Lander includes dc voltage and ripple current electrical stress, high temperature during nonoperating times (sterilization), and high vibration and shock loads. The capacitors must survive these severe environments without any degradation if reliable performance is to be achieved. A test program was established to evaluate both wet-slug tantalum and wet-foil capacitors under conditions accurately duplicating actual Viking applications. Test results of the electrical performance characteristics during extended periods of ripple current, the characteristics of the internal silver migration as a function of extended periods of ripple current, and the existence of any memory characteristics are presented.

  15. Evaluation of wet tantalum capacitors after exposure to extended periods of ripple current, volume 1

    NASA Technical Reports Server (NTRS)

    Watson, G. W.; Lasharr, J. C.; Shumaker, M. J.

    1974-01-01

    The application of tantalum capacitors in the Viking Lander includes both dc voltage and ripple current electrical stress, high temperature during nonoperating times (sterilization), and high vibration and shock loads. The capacitors must survive these severe environments without any degradation if reliable performance is to be achieved. A test program was established to evaluate both wet-slug tantalum and wet-foil capacitors under conditions accurately duplicating actual Viking applications. Test results of the electrical performance characteristics during extended periods of ripple current, the characteristics of the internal silver migration as a function for extended periods of ripple current, and the existence of any memory characteristics are presented.

  16. Differential gene expression analysis in Enchytraeus albidus exposed to natural and chemical stressors at different exposure periods.

    PubMed

    Novais, Sara C; Howcroft, Clara F; Carreto, Laura; Pereira, Patrícia M; Santos, Manuel A S; De Coen, Wim; Soares, Amadeu M V M; Amorim, Mónica J B

    2012-01-01

    The soil oligochaete Enchytraeus albidus is a standard test organism used in biological testing for Environmental Risk Assessment (ERA). Although effects are known at acute and chronic level through survival, reproduction and avoidance behaviour endpoints, very little is known at the sub-cellular and molecular levels. In this study, the effects of soil properties (clay, organic matter and pH) and of the chemicals copper and phenmedipham were studied on E. albidus gene expression, during exposure periods of 2, 4 and 21 days, using DNA microarrays based on a normalised cDNA library for this test species (Amorim et al. 2011). The main objectives of this study were: (1) to assess changes in gene expression of E. albidus over time, and (2) to identify molecular markers for natural and chemical exposures. Results showed an influence of exposure time on gene expression. Transcriptional responses to phenmedipham were seen at 2 days while the responses to copper and the different soils were more pronounced at 4 days of exposure. Some genes were differentially expressed in a stress specific manner and, in general, the responses were related with effects in the energy metabolism and cell growth. PMID:21892792

  17. Trends in environmental lead exposure and troubled youth, 1960-1995: an age-period-cohort-characteristic analysis.

    PubMed

    McCall, Patricia L; Land, Kenneth C

    2004-06-01

    Beginning in the mid-1980s and extending into the early 1990s, the United States experienced a wave of increased youth violence and teenage pregnancy. Nevin (2000) proffers a cohort-based explanation that these trends can be attributed to corresponding trends in gasoline lead exposure during the youths' early years. He contends that the increased consumption of adversely impacted their intelligence levels (IQs). This decreased their intellectual ability, resulted in poor decisions made during their teen and young adult years, and in turn, led to disproportionally high level of criminal involvement and unwed pregnancies among this cohort. The present study evaluates Nevin's causal model by testing the connection between trends in lead exposure and youthful problem behavior with age-period-cohort-characteristic (APCC) models. Our research finds no support for this cohort explanation. PMID:15216841

  18. Boron uptake in tumors, cerebrum and blood from [10B]NA4B24H22S2

    DOEpatents

    Slatkin, Daniel N.; Micca, Peggy L.; Fairchild, Ralph G.

    1988-08-02

    A stable boronated (.sup.10 B-labeled) compound, sodium mercaptoundecahydrododecaborate is infused in the form of the disulfide dimer, [.sup.10 B]Na.sub.4 B.sub.24 H.sub.22 S.sub.2, at a dose of about 200 .mu.g .sup.10 B per gm body weight. The infusion is performed into the blood or peritoneal cavity of the patient slowly over a period of many days, perhaps one week or more, at the rate of roughly 1 .mu.g .sup.10 B per gm body weight per hour. Use of this particular boronated dimer in the manner or similarly to the manner so described permits radiotherapeutically effective amounts of boron to accumulate in tumors to be treated by boron neutron capture radiation therapy and also permits sufficient retention of boron in tumor after the cessation of the slow infusion, so as to allow the blood concentration of .sup.10 B to drop or to be reduced artificially to a radiotherapeutically effective level, less than one-half of the concentration of .sup.10 B in the tumor.

  19. Boron uptake in tumors, cerebrum and blood from [10B]NA4B24H22S2

    DOEpatents

    Slatkin, Daniel N.; Micca, Peggy L.; Fairchild, Ralph G.

    1988-01-01

    A stable boronated (.sup.10 B-labeled) compound, sodium mercaptoundecahydrododecaborate is infused in the form of the disulfide dimer, [.sup.10 B]Na.sub.4 B.sub.24 H.sub.22 S.sub.2, at a dose of about 200 .mu.g .sup.10 B per gm body weight. The infusion is performed into the blood or peritoneal cavity of the patient slowly over a period of many days, perhaps one week or more, at the rate of roughly 1 .mu.g .sup.10 B per gm body weight per hour. Use of this particular boronated dimer in the manner or similarly to the manner so described permits radiotherapeutically effective amounts of boron to accumulate in tumors to be treated by boron neutron capture radiation therapy and also permits sufficient retention of boron in tumor after the cessation of the slow infusion, so as to allow the blood concentration of .sup.10 B to drop or to be reduced artificially to a radiotherapeutically effective level, less than one-half of the concentration of .sup.10 B in the tumor.

  20. Sleep-like behavior and 24-h rhythm disruption in the Tc1 mouse model of Down syndrome

    PubMed Central

    Heise, I; Fisher, S P; Banks, G T; Wells, S; Peirson, S N; Foster, R G; Nolan, P M

    2015-01-01

    Down syndrome is a common disorder associated with intellectual disability in humans. Among a variety of severe health problems, patients with Down syndrome exhibit disrupted sleep and abnormal 24-h rest/activity patterns. The transchromosomic mouse model of Down syndrome, Tc1, is a trans-species mouse model for Down syndrome, carrying most of human chromosome 21 in addition to the normal complement of mouse chromosomes and expresses many of the phenotypes characteristic of Down syndrome. To date, however, sleep and circadian rhythms have not been characterized in Tc1 mice. Using both circadian wheel-running analysis and video-based sleep scoring, we showed that these mice exhibited fragmented patterns of sleep-like behaviour during the light phase of a 12:12-h light/dark (LD) cycle with an extended period of continuous wakefulness at the beginning of the dark phase. Moreover, an acute light pulse during night-time was less effective in inducing sleep-like behaviour in Tc1 animals than in wild-type controls. In wheel-running analysis, free running in constant light (LL) or constant darkness (DD) showed no changes in the circadian period of Tc1 animals although they did express subtle behavioural differences including a reduction in total distance travelled on the wheel and differences in the acrophase of activity in LD and in DD. Our data confirm that Tc1 mice express sleep-related phenotypes that are comparable with those seen in Down syndrome patients with moderate disruptions in rest/activity patterns and hyperactive episodes, while circadian period under constant lighting conditions is essentially unaffected. PMID:25558895

  1. A human calorimeter for the direct and indirect measurement of 24 h energy expenditure.

    PubMed

    Dauncey, M J; Murgatroyd, P R; Cole, T J

    1978-05-01

    1. A calorimeter for the continuous measurement of heat production and heat loss in the human subject, for at least 24 h, is described. The calorimeter operated on the heat-sink principle for direct calorimetry and an open-circuit system for indirect calorimetry. 2. Sensible heat loss was measured using a water-cooled heat exchanger, and the temperature of water entering the heat exchanger was controlled to maintain a mean temperature gradient of zero across the chamber walls. 3. Evaporative heat loss was determined from ingoing and outgoing wet-and-dry bulb temperatures and air flow-rates. 4. Problems associated with the calculation of evapoative heat loss and the estimation of the volume of incoming air in open-circuit systems are considered. 5. The calibration, limits of accuracy, sources of error and experiments with subjects are discussed. PMID:638125

  2. Master runners dominate 24-h ultramarathons worldwide—a retrospective data analysis from 1998 to 2011

    PubMed Central

    2013-01-01

    Background The aims of the present study were to examine (a) participation and performance trends and (b) the age of peak running performance in master athletes competing in 24-h ultra-marathons held worldwide between 1998 and 2011. Methods Changes in both running speed and the age of peak running speed in 24-h master ultra-marathoners (39,664 finishers, including 8,013 women and 31,651 men) were analyzed. Results The number of 24-h ultra-marathoners increased for both women and men across years (P < 0.01). The age of the annual fastest woman decreased from 48 years in 1998 to 35 years in 2011. The age of peaking running speed remained unchanged across time at 42.5 ± 5.2 years for the annual fastest men (P > 0.05). The age of the annual top ten women decreased from 42.6 ± 5.9 years (1998) to 40.1 ± 7.0 years (2011) (P < 0.01). For the annual top ten men, the age of peak running speed remained unchanged at 42 ± 2 years (P > 0.05). Running speed remained unchanged over time at 11.4 ± 0.4 km h-1 for the annual fastest men and 10.0 ± 0.2 km/h for the annual fastest women, respectively (P > 0.05). For the annual ten fastest women, running speed increased over time by 3.2% from 9.3 ± 0.3 to 9.6 ± 0.3 km/h (P < 0.01). Running speed of the annual top ten men remained unchanged at 10.8 ± 0.3 km/h (P > 0.05). Women in age groups 25–29 (r2 = 0.61, P < 0.01), 30–34 (r2 = 0.48, P < 0.01), 35–39 (r2 = 0.42, P = 0.01), 40–44 (r2 = 0.46, P < 0.01), 55–59 (r2 = 0.41, P = 0.03), and 60–64 (r2 = 0.57, P < 0.01) improved running speed; while women in age groups 45–49 and 50–54 maintained running speed (P > 0.05). Men improved running speed in age groups 25–29 (r2 = 0.48, P = 0.02), 45–49 (r2 = 0.34, P = 0.03), 50–54 (r2 = 0.50, P < 0.01), 55–59 (r2 = 0.70, P < 0.01), and 60–64 (r2 = 0.44, P = 0.03); while runners in age groups 30–34, 35–39, and 40–44 maintained running speed (P > 0.05). Conclusions Female and male age group runners improved

  3. Development of atopy and asthma: candidate environmental influences and important periods of exposure.

    PubMed Central

    Peden, D B

    2000-01-01

    Atopy is a major risk factor for the development of asthma. Immune processes that lead to the development of antigen-specific IgE are essential to the development of atopy. This review examines the immune processes that are candidate targets for modulation by environmental agents; environmental and lifestyle factors that have been suggested as modulators of the development of atopy; and the impact of known environmental agents on atopic processes in the airway. The most important periods of immune development with regard to expression of atopy are likely during gestation and early childhood. A better understanding of which environmental agents are important, as well as the period of life during which these agents may exert an important effect, is essential to devising rational environmental avoidance strategies for at-risk populations. PMID:10852847

  4. A new tool for radiation exposure calculations in aircraft flights during disturbed solar activity periods

    NASA Astrophysics Data System (ADS)

    Paschalis, Pavlos; Tezari, Anastasia; Gerontidou, Maria; Mavromichalaki, Helen

    2016-04-01

    Galactic cosmic rays and solar energetic particles can penetrate the Earth's atmosphere and interact with its molecules, which can cause atmospheric showers of secondary particles that are detected by ground based neutron monitor detectors. The cascades are of great importance for the study of the radiation exposure of aircraft crews. A new Geant4 software application is presented based on DYASTIMA (Dynamic Atmospheric Shower Tracking Interactive Model Application), which calculates the effective dose that aviators may receive in different flight scenarios characterized by different altitudes and different flight routes, during quiet and disturbed solar and cosmic ray activity. The concept is based on Monte Carlo simulations by using phantoms for the aircraft and the aviator and experimenting with different shielding materials.

  5. Neurodevelopmental and behavioral effects of nonylphenol exposure during gestational and breastfeeding period on F1 rats.

    PubMed

    Couderc, Mickaël; Gandar, Allison; Kamari, Abderrahmane; Allain, Yohann; Zalouk-Vergnoux, Aurore; Herrenknecht, Christine; Le Bizec, Bruno; Mouneyrac, Catherine; Poirier, Laurence

    2014-09-01

    Nonylphenols (NP) are endocrine-disruptors known to be widely present in our environment. This study evaluated the effects of 4-n-NP on neurobehavioral development and memory capacity after perinatal exposure on the offspring rats. Dams were gavaged with 4-n-NP (0, 50 and 200mg/kg/day) from gestational day 5 to postnatal day (PND) 21. Dams exposed to the higher dose lost weight during gestation and had a longer gestational duration. Juvenile female pups of the 200mg 4-n-NP/kg/day group were lighter. Their thyroid somatic index (TSI) was also affected. For male pups, a decrease of TSI at weaning for the 200mg 4-n-NP/kg/day group and an increase of GSI for the 50mg 4-n-NP/kg/day group were observed. Physical maturation (incisives and eyes) were likewise affected. In open field (OF) tests, females were more active than males. In the first OF (PND 36), a treatment effect was observed only for males, particularly for the high dose group, which became as active as females. The second OF (PND 71) showed few differences between groups (treated vs control), the gender difference whatever the dose was not abolished. In the Morris Water Maze test, the study of the first 30s showed that females (200mg/kg/day) were mainly affected. Their performances were improved by 4-n-NP. These effects were particularly important for the first short-term memory test and observed to a lesser extent in the second evaluation of the long-term memory (PND 69). These data showed that perinatal 4-n-NP exposure induced behavioral and neuro-developmental impairments from 50mg/kg/day. PMID:25058900

  6. 24-h activity rhythm and sleep in depressed outpatients.

    PubMed

    Hori, Hiroaki; Koga, Norie; Hidese, Shinsuke; Nagashima, Anna; Kim, Yoshiharu; Higuchi, Teruhiko; Kunugi, Hiroshi

    2016-06-01

    Disturbances in sleep and circadian rest-activity rhythms are key features of depression. Actigraphy, a non-invasive method for monitoring motor activity, can be used to objectively assess circadian rest-activity rhythms and sleep patterns. While recent studies have measured sleep and daytime activity of depressed patients using wrist-worn actigraphy, the actigraphic 24-h rest-activity rhythm in depression has not been well documented. We aimed to examine actigraphically measured sleep and circadian rest-activity rhythms in depressed outpatients. Twenty patients with DSM-IV major depressive episode and 20 age- and sex-matched healthy controls participated in this study. Participants completed 7 consecutive days of all-day actigraphic activity monitoring while engaging in usual activities. For sleep parameters, total sleep time, wake after sleep onset, and sleep fragmentation index were determined. Circadian rhythms were estimated by fitting individual actigraphy data to a cosine curve of a 24-h activity rhythm using the cosinor method, which generated three circadian activity rhythm parameters, i.e., MESOR (rhythm-adjusted mean), amplitude, and acrophase. Subjective sleep was also assessed using a sleep diary and the Pittsburgh Sleep Quality Index. Patients showed significantly lower MESOR and more dampened amplitude along with significant sleep disturbances. Logistic regression analysis revealed that lower MESOR and more fragmented sleep emerged as the significant predictors of depression. Correlations between subjectively and actigraphically measured parameters demonstrated the validity of actigraphic measurements. These results indicate marked disturbances in sleep and circadian rest-activity rhythms of depression. By simultaneously measuring sleep and rest-activity rhythm parameters, actigraphy might serve as an objective diagnostic aid for depression. PMID:26978182

  7. Variable day/night bias in 24-h non-invasive finger pressure against intrabrachial artery pressure is removed by waveform filtering and level correction.

    PubMed

    Westerhof, Berend E; Guelen, Ilja; Parati, Gianfranco; Groppelli, Antonella; van Montfrans, Gert A; Wieling, Wouter; Wesseling, Karel H; Bos, Willem Jan W

    2002-10-01

    BACKGROUND Twenty-four-hour finger arterial pressure (FAP) recordings show a negative bias against intrabrachial artery pressure (BAP) and the bias is greater during the night, thereby overestimating the nocturnal blood pressure dip. We have available a methodology with which to reconstruct BAP from FAP by waveform filtering (transfer function) and generalized level (bias) correction that reduces the bias for short-term blood pressure records. OBJECTIVE To investigate if this methodology also decreases the extra bias during the night, thereby yielding a better estimate of the nocturnal dip. METHODS Twenty-four-hour FAP and BAP blood pressure recordings were simultaneously obtained in eight healthy normotensive volunteers and 14 patients with hypertension (ages 19-60 years), during standardized scheduled activities. The data were analysed off-line, applying the brachial reconstruction technique (reBAP) consisting of a waveform filter and level correction. Simultaneous beats yielded systolic, diastolic and mean pressures that were averaged per 30 min, per day, per night, per activity, over the 24-h period, and for volunteers and patients separately. RESULTS Over the full 24 h, FAP systolic, diastolic and mean values for the total group differed from BAP by +1 +/- 10, -8 +/- 7 and -10 +/- 8 mmHg (mean +/- SD), respectively. Similarly, reBAPs differed by +1 +/- 11, -2 +/- 7 and -2 +/- 7 mmHg. BAPs dipped by 20 +/- 8, 13 +/- 6 and 15 +/- 6 mmHg, respectively, during the night. These dips were overestimated by +8, +4 and +4 mmHg by FAP, but not by reBAP: -1, +1 and +1 mmHg. The volunteer and the patient groups showed slight differences in results, but these were not statistically significant. CONCLUSIONS The generalized reconstruction technique to obtain near-brachial pressure from non-invasive FAP almost completely removed bias over the full 24-h day-night period and improved tracking of diurnal changes for all three blood pressure values. PMID:12359976

  8. A new page on the road book of inorganic mercury in fish body - tissue distribution and elimination following waterborne exposure and post-exposure periods.

    PubMed

    Pereira, Patrícia; Raimundo, Joana; Barata, Marisa; Araújo, Olinda; Pousão-Ferreira, Pedro; Canário, João; Almeida, Armando; Pacheco, Mário

    2015-03-01

    There are several aspects of inorganic mercury (iHg) toxicokinetics in fish that remain undeveloped despite its environmental ubiquity, bioaccumulation capacity and toxicity. Thus, this study presents new information on the uptake, distribution and accumulation of iHg following water contamination by adopting a novel set of body compartments (gills, eye wall, lens, blood, liver, brain and bile) of the white sea bream (Diplodus sargus) over 14 days of exposure. Realistic levels of iHg in water (2 μg L(-1)) were adopted in order to engender reliable conclusions in the assessment of fish health. A depuration phase of 28 days was also considered with the purpose of clarifying iHg elimination. It was found that iHg was accumulated faster in the gills (within 1 day), which also had the highest accumulated levels among all the target tissues/organs. Moreover, iHg increased gradually with exposure time in all the tissues/organs, except for the lens that showed relatively unaltered levels throughout the experiment. After 14 days of exposure, lower values of Hg were recorded in the brain/eye wall compared to the liver, which is probably related with the presence of blood-organ protection barriers, which limit iHg influx. iHg reached the brain earlier than the eye wall (3 and 7 days, respectively) and, hence, higher accumulated levels were recorded in the former. A depuration period of 28 days did not allow the total elimination of iHg in any of the tissues/organs. Despite this, iHg was substantially eliminated in the gills, blood and liver, whereas the brain and eye wall were not able to eliminate iHg within this timeframe. The brain and eye wall are more "refractory" structures with regard to iHg elimination, and this could represent a risk for wild fish populations. PMID:25677695

  9. [Neurological and psychopathological syndromes in the follow-up period after exposure to ionizing radiation].

    PubMed

    Loganovskiĭ, K N

    2000-01-01

    Neurologic, psychiatric and psychophysiologic (computed EEG) examinations were carried out in 100 Chernobyl accident's survivors who had got acute radiation sickness (ARS), in 100 Chernobyl liquidators who worked for 5 or more years in the zone (1986-1987) as well as in control groups: 20 normal age- and gender-matched adults and 50 veterans of the Afganistan war with consequences of the posttraumatic stress disorder (PTSD) and 50 veterans with both PTSD and mild closed head injury. Left-hemispheric cortical-limbic and diencephalic right-hemispheric syndromes were revealed. Left-hemispheric frontal-temporal-limbic dysfunction was associated with schizophrenia-like syndrome, while diencephalic right-hemispheric dysfunction--with the affective syndrome. Doses more than 0.3 Sv (including the ARS-patients) resulted more frequently in the left-hemispheric cortical-limbic and schizophrenia-like syndromes. Diencephalic right-hemispheric and affective syndromes were more frequently observed after the exposure to doses less [corrected] than 0.3 Sv. Development of schizophrenia spectrum disorders in the irradiated Chernobyl survivors could be due to radiation-induced left fronto-temporal-limbic dysfunction following irradiation doses more than 0.3 Sv (including the ARS-patients). The cerebral patterns of schizophrenia and postradiation brain damage are similar. Persons exposed fo 0.3 Sv and more could be classified as the group of higher risk of the development of schizophrenia spectrum disorders. The authors suggest that ionizing radiation may be an environmental trigger factor which can cause schizophrenia in the predisposed subjects. PMID:10812665

  10. Aircraft Crew Radiation Exposure in Aviation Altitudes During Quiet and Solar Storm Periods

    NASA Astrophysics Data System (ADS)

    Beck, Peter

    The European Commission Directorate General Transport and Energy published in 2004 a summary report of research on aircrew dosimetry carried out by the EURADOS working group WG5 (European Radiation Dosimetry Group, http://www.eurados.org/). The aim of the EURADOS working group WG5 was to bring together, in particular from European research groups, the available, preferably published, experimental data and results of calculations, together with detailed descriptions of the methods of measurement and calculation. The purpose is to provide a dataset for all European Union Member States for the assessment of individual doses and/or to assess the validity of different approaches, and to provide an input to technical recommendations by the experts and the European Commission. Furthermore EURADOS (European Radiation Dosimetry Group, http://www.eurados.org/) started to coordinate research activities in model improvements for dose assessment of solar particle events. Preliminary results related to the European research project CONRAD (Coordinated Network for Radiation Dosimetry) on complex mixed radiation fields at workplaces are presented. The major aim of this work is the validation of models for dose assessment of solar particle events, using data from neutron ground level monitors, in-flight measurement results obtained during a solar particle event and proton satellite data. The radiation protection quantity of interest is effective dose, E (ISO), but the comparison of measurement results obtained by different methods or groups, and comparison of measurement results and the results of calculations, is done in terms of the operational quantity ambient dose equivalent, H* (10). This paper gives an overview of aircrew radiation exposure measurements during quiet and solar storm conditions and focuses on dose results using the EURADOS In-Flight Radiation Data Base and published data on solar particle events

  11. Tuberculosis in hospitalized patients: clinical characteristics of patients receiving treatment within the first 24 h after admission*

    PubMed Central

    Silva, Denise Rossato; da Silva, Larissa Pozzebon; Dalcin, Paulo de Tarso Roth

    2014-01-01

    Objective: To evaluate clinical characteristics and outcomes in patients hospitalized for tuberculosis, comparing those in whom tuberculosis treatment was started within the first 24 h after admission with those who did not. Methods: This was a retrospective cohort study involving new tuberculosis cases in patients aged ≥ 18 years who were hospitalized after seeking treatment in the emergency room. Results: We included 305 hospitalized patients, of whom 67 (22.0%) received tuberculosis treatment within the first 24 h after admission ( ≤24h group) and 238 (88.0%) did not (>24h group). Initiation of tuberculosis treatment within the first 24 h after admission was associated with being female (OR = 1.99; 95% CI: 1.06-3.74; p = 0.032) and with an AFB-positive spontaneous sputum smear (OR = 4.19; 95% CI: 1.94-9.00; p < 0.001). In the ≤24h and >24h groups, respectively, the ICU admission rate was 22.4% and 15.5% (p = 0.258); mechanical ventilation was used in 22.4% and 13.9% (p = 0.133); in-hospital mortality was 22.4% and 14.7% (p = 0.189); and a cure was achieved in 44.8% and 52.5% (p = 0.326). Conclusions: Although tuberculosis treatment was initiated promptly in a considerable proportion of the inpatients evaluated, the rates of in-hospital mortality, ICU admission, and mechanical ventilation use remained high. Strategies for the control of tuberculosis in primary care should consider that patients who seek medical attention at hospitals arrive too late and with advanced disease. It is therefore necessary to implement active surveillance measures in the community for earlier diagnosis and treatment. PMID:25029651

  12. Low within- and between-day variability in exposure to new insulin glargine 300 U/ml

    PubMed Central

    Becker, R H A; Nowotny, I; Teichert, L; Bergmann, K; Kapitza, C

    2015-01-01

    Aims To characterize the variability in exposure and metabolic effect of insulin glargine 300 U/ml (Gla-300) at steady state in people with type 1 diabetes (T1DM). Methods A total of 50 participants with T1DM underwent two 24-h euglycaemic clamps in steady-state conditions after six once-daily administrations of 0.4 U/kg Gla-300 in a double-blind, randomized, two-treatment, two-period, crossover clamp study. Participants were randomized to receive Gla-300 as a standard cartridge formulation in the first treatment period, and as a formulation with enhanced stability through polysorbate-20 addition in the second treatment period, or vice versa. This design allowed the assessment of bioequivalence between formulations and, subsequently, within- and between-day variability. Results The cumulative exposure and effect of Gla-300 developed linearly over 24 h, and were evenly distributed across 6- and 12-h intervals. Diurnal fluctuation in exposure (within-day variability) was low; the peak-to-trough ratio of insulin concentration profiles was <2, and both the swing and peak-to-trough fluctuation were <1. Day-to-day reproducibility of exposure was high: the between-day within-subject coefficients of variation for total systemic exposure (area under the serum insulin glargine concentration time curve from time 0 to 24 h after dosing) and maximum insulin concentration were 17.4% [95% confidence interval (CI) 15–21] and 33.4% (95% CI 28–41), respectively. Reproducibility of the metabolic effect was lower than that of exposure. Conclusions Gla-300 provides predictable, evenly distributed 24-h coverage as a result of low fluctuation and high reproducibility in insulin exposure, and appears suitable for effective basal insulin use. PMID:25425394

  13. Baroreflex-mediated heart rate and vascular resistance responses 24 h after maximal exercise

    NASA Technical Reports Server (NTRS)

    Convertino, Victor A.

    2003-01-01

    INTRODUCTION: Plasma volume, heart rate (HR) variability, and stimulus-response relationships for baroreflex control of forearm vascular resistance (FVR) and HR were studied in eight healthy men after and without performing a bout of maximal exercise to test the hypotheses that acute expansion of plasma volume is associated with 1) reduction in baroreflex-mediated HR response, and 2) altered operational range for central venous pressure (CVP). METHODS: The relationship between stimulus (DeltaCVP) and vasoconstrictive reflex response (DeltaFVR) during unloading of cardiopulmonary baroreceptors was assessed with lower-body negative pressure (LBNP, 0, -5, -10, -15, -20 mm Hg). The relationship between stimulus (Deltamean arterial pressure (MAP)) and cardiac reflex response (DeltaHR) during loading of arterial baroreceptors was assessed with steady-state infusion of phenylephrine (PE) designed to increase MAP by 15 mm Hg alone and during application of LBNP (PE+LBNP) and neck pressure (PE+LBNP+NP). Measurements of vascular volume and autonomic baroreflex responses were conducted on two different test days, each separated by at least 1 wk. On one day, baroreflex response was tested 24 h after graded cycle exercise to volitional exhaustion. On another day, measurement of baroreflex response was repeated with no exercise (control). The order of exercise and control treatments was counterbalanced. RESULTS: Baseline CVP was elevated (P = 0.04) from a control value of 10.5 +/- 0.4 to 12.3 +/- 0.4 mm Hg 24 h after exercise. Average DeltaFVR/DeltaCVP during LBNP was not different (P = 0.942) between the exercise (-1.35 +/- 0.32 pru x mm Hg-1) and control (-1.32 +/- 0.36 pru x mm Hg-1) conditions. However, maximal exercise caused a shift along the reflex response relationship to a higher CVP and lower FVR. HR baroreflex response (DeltaHR/DeltaMAP) to PE+LBNP+NP was lower (P = 0.015) after maximal exercise (-0.43 +/- 0.15 beats x min-1 x mm Hg-1) compared with the control

  14. The friction coefficient of shoulder joints remains remarkably low over 24 h of loading.

    PubMed

    Jones, Brian K; Durney, Krista M; Hung, Clark T; Ateshian, Gerard A

    2015-11-01

    The frictional response of whole human joints over durations spanning activities of daily living has not been reported previously. This study measured the friction of human glenohumeral joints during 24 h of reciprocal loading in a pendulum testing device, at moderate (0.2 mm/s, 4320 cycles) and low (0.02 mm/s, 432 cycles) sliding speeds, under a 200 N load. The effect of joint congruence was also investigated by testing human humeral heads against significantly larger mature bovine glenoids. Eight human joints and six bovine joints were tested in four combinations: human joints tested at moderate (hHCMS, n=6) and low speed (hHCLS, n=3), human humeral heads tested against bovine glenoids at moderate speed (LCMS, n=3), and bovine joints tested at moderate speed (bHCMS, n=3). In the first half hour the mean±standard deviation of the friction coefficient was hHCMS: 0.0016±0.0011, hHCLS: 0.0012±0.0002, LCMS: 0.0008±0.0002 and bHCMS: 0.0024±0.0008; in the last four hours it was hHCMS: 0.0057±0.0025, hHCLS: 0.0047±0.0017, LCMS: 0.0012±0.0003 and bHCMS: 0.0056±0.0016. The initial value was lower than the final value (p<0.0001). The value in LCMS was significantly lower than in hHCMS and bHCMS (p<0.01). No visual damage was observed in any of the specimens. These are the first results to demonstrate that the friction coefficient of natural human shoulders remains remarkably low (averaging as little as 0.0015 and no greater than 0.006) for up to 24 h of continuous loading. The sustained low friction coefficients observed in incongruent joints (~0.001) likely represent rolling rather than sliding friction. PMID:26472306

  15. Ixodes scapularis Tick Saliva Proteins Sequentially Secreted Every 24 h during Blood Feeding.

    PubMed

    Kim, Tae Kwon; Tirloni, Lucas; Pinto, Antônio F M; Moresco, James; Yates, John R; da Silva Vaz, Itabajara; Mulenga, Albert

    2016-01-01

    Ixodes scapularis is the most medically important tick species and transmits five of the 14 reportable human tick borne disease (TBD) agents in the USA. This study describes LC-MS/MS identification of 582 tick- and 83 rabbit proteins in saliva of I. scapularis ticks that fed for 24, 48, 72, 96, and 120 h, as well as engorged but not detached (BD), and spontaneously detached (SD). The 582 tick proteins include proteases (5.7%), protease inhibitors (7.4%), unknown function proteins (22%), immunity/antimicrobial (2.6%), lipocalin (3.1%), heme/iron binding (2.6%), extracellular matrix/ cell adhesion (2.2%), oxidant metabolism/ detoxification (6%), transporter/ receptor related (3.2%), cytoskeletal (5.5%), and housekeeping-like (39.7%). Notable observations include: (i) tick saliva proteins of unknown function accounting for >33% of total protein content, (ii) 79% of proteases are metalloproteases, (iii) 13% (76/582) of proteins in this study were found in saliva of other tick species and, (iv) ticks apparently selectively inject functionally similar but unique proteins every 24 h, which we speculate is the tick's antigenic variation equivalent strategy to protect important tick feeding functions from host immune system. The host immune responses to proteins present in 24 h I. scapularis saliva will not be effective at later feeding stages. Rabbit proteins identified in our study suggest the tick's strategic use of host proteins to modulate the feeding site. Notably fibrinogen, which is central to blood clotting and wound healing, was detected in high abundance in BD and SD saliva, when the tick is preparing to terminate feeding and detach from the host. A remarkable tick adaptation is that the feeding lesion is completely healed when the tick detaches from the host. Does the tick concentrate fibrinogen at the feeding site to aide in promoting healing of the feeding lesion? Overall, these data provide broad insight into molecular mechanisms regulating different tick

  16. Ixodes scapularis Tick Saliva Proteins Sequentially Secreted Every 24 h during Blood Feeding

    PubMed Central

    Pinto, Antônio F. M.; Moresco, James; Yates, John R.; da Silva Vaz, Itabajara; Mulenga, Albert

    2016-01-01

    Ixodes scapularis is the most medically important tick species and transmits five of the 14 reportable human tick borne disease (TBD) agents in the USA. This study describes LC-MS/MS identification of 582 tick- and 83 rabbit proteins in saliva of I. scapularis ticks that fed for 24, 48, 72, 96, and 120 h, as well as engorged but not detached (BD), and spontaneously detached (SD). The 582 tick proteins include proteases (5.7%), protease inhibitors (7.4%), unknown function proteins (22%), immunity/antimicrobial (2.6%), lipocalin (3.1%), heme/iron binding (2.6%), extracellular matrix/ cell adhesion (2.2%), oxidant metabolism/ detoxification (6%), transporter/ receptor related (3.2%), cytoskeletal (5.5%), and housekeeping-like (39.7%). Notable observations include: (i) tick saliva proteins of unknown function accounting for >33% of total protein content, (ii) 79% of proteases are metalloproteases, (iii) 13% (76/582) of proteins in this study were found in saliva of other tick species and, (iv) ticks apparently selectively inject functionally similar but unique proteins every 24 h, which we speculate is the tick's antigenic variation equivalent strategy to protect important tick feeding functions from host immune system. The host immune responses to proteins present in 24 h I. scapularis saliva will not be effective at later feeding stages. Rabbit proteins identified in our study suggest the tick's strategic use of host proteins to modulate the feeding site. Notably fibrinogen, which is central to blood clotting and wound healing, was detected in high abundance in BD and SD saliva, when the tick is preparing to terminate feeding and detach from the host. A remarkable tick adaptation is that the feeding lesion is completely healed when the tick detaches from the host. Does the tick concentrate fibrinogen at the feeding site to aide in promoting healing of the feeding lesion? Overall, these data provide broad insight into molecular mechanisms regulating different tick

  17. Experimental sleep curtailment causes wake-dependent increases in 24-h energy expenditure as measured by whole-room indirect calorimetry1234

    PubMed Central

    Shechter, Ari; Rising, Russell; Albu, Jeanine B

    2013-01-01

    Background: Epidemiologic evidence has shown a link between short sleep and obesity. Clinical studies suggest a role of increased energy intake in this relation, whereas the contributions of energy expenditure (EE) and substrate utilization are less clearly defined. Objective: Our aim was to investigate the effects of sleep curtailment on 24-h EE and respiratory quotient (RQ) by using whole-room indirect calorimetry under fixed-meal conditions. Design: Ten females aged 22–43 y with a BMI (in kg/m2) of 23.4–27.5 completed a randomized, crossover study. Participants were studied under short- (4 h/night) and habitual- (8 h/night) sleep conditions for 3 d, with a 4-wk washout period between visits. Standardized weight-maintenance meals were served at 0800, 1200, and 1900 with a snack at 1600. Measures included EE and RQ during the sleep episode on day 2 and continuously over 23 h on day 3. Results: Short compared with habitual sleep resulted in significantly higher (±SEM) 24-h EE (1914.0 ± 62.4 compared with 1822.1 ± 43.8 kcal; P = 0.012). EE during the scheduled sleep episode (0100–0500 and 2300–0700 in short- and habitual-sleep conditions, respectively) and across the waking episode (0800–2300) were unaffected by sleep restriction. RQ was unaffected by sleep restriction. Conclusions: Short compared with habitual sleep is associated with an increased 24-h EE of ∼92 kcal (∼5%)—lower than the increased energy intake observed in prior sleep-curtailment studies. This finding supports the hypothesis that short sleep may predispose to weight gain as a result of an increase in energy intake that is beyond the modest energy costs associated with prolonged nocturnal wakefulness. This trial was registered at clinicaltrials.gov as NCT01751581. PMID:24088722

  18. Cerebral blood flow velocity in humans exposed to 24 h of head-down tilt

    NASA Technical Reports Server (NTRS)

    Kawai, Y.; Murthy, G.; Watenpaugh, D. E.; Breit, G. A.; Deroshia, C. W.; Hargens, A. R.

    1993-01-01

    This study investigates cerebral blood flow (CBF) velocity in humans before, during, and after 24 h of 6 deg head-down tilt (HDT), which is a currently accepted experimental model to simulate microgravity. CBF velocity was measured by use of the transcranial Doppler technique in the right middle cerebral artery of eight healthy male subjects. Mean CBF velocity increased from the pre-HDT upright seated baseline value of 55.5 +/- 3.7 (SE) cm/s to 61.5 +/- 3.3 cm/s at 0.5 h of HDT, reached a peak value of 63.2 +/- 4.1 cm/s at 3 h of HDT, and remained significantly above the pre-HDT baseline for over 6 h of HDT. During upright seated recovery, mean CBF velocity decreased to 87 percent of the pre-HDT baseline value. Mean CBF velocity correlated well with calculated intracranial arterial pressure (IAP). As analyzed by linear regression, mean CBF velocity = 29.6 + 0.32IAP. These results suggest that HDT increases CBF velocity by increasing IAP during several hours after the onset of microgravity. Importantly, the decrease in CBF velocity after HDT may be responsible, in part, for the increased risk of syncope observed in subjects after prolonged bed rest and also in astronauts returning to Earth.

  19. Gender differences in the impact of daily sadness on 24-h heart rate variability.

    PubMed

    Verkuil, Bart; Brosschot, Jos F; Marques, Andrea H; Kampschroer, Kevin; Sternberg, Esther M; Thayer, Julian F

    2015-12-01

    Reduced heart rate variability (HRV) is proposed to mediate the relation between depressive symptoms and cardiovascular health problems. Yet, several studies have found that in women depression is associated with higher HRV levels, whereas in men depression is associated with lower HRV levels. So far, these studies have only examined gender differences in HRV levels using a single assessment. This study aimed to test the interactive effects of gender and sadness on ambulatory-assessed HRV levels. A sample of 60 (41 women) employees participated in an ambulatory study. HRV levels (mean of successive differences; MSD) were continuously measured for 24 h. During the daytime, hourly assessments of sadness and other mood states were taken, while depressive symptoms were assessed with the Center for Epidemiologic Studies Depression scale (CES-D). Gender differences were observed when examining the impact of average daily sadness on MSD. In women, but not in men, the total amount of sadness experienced during the day was associated with higher circadian MSD levels. These findings suggest that researchers need to take gender differences into account when examining the relation between sadness, HRV, and cardiovascular problems. PMID:26338472

  20. Combined solar thermal and photovoltaic power plants - An approach to 24h solar electricity?

    NASA Astrophysics Data System (ADS)

    Platzer, Werner J.

    2016-05-01

    Solar thermal power plants have the advantage of being able to provide dispatchable renewable electricity even when the sun is not shining. Using thermal energy strorage (TES) they may increase the capacity factor (CF) considerably. However in order to increase the operating hours one has to increase both, thermal storage capacity and solar field size, because the additional solar field is needed to charge the storage. This increases investment cost, although levelised electricity cost (LEC) may decrease due to the higher generation. Photovoltaics as a fluctuating source on the other side has arrived at very low generation costs well below 10 ct/kWh even for Central Europe. Aiming at a capacity factor above 70% and at producing dispatchable power it is shown that by a suitable combination of CSP and PV we can arrive at lower costs than by increasing storage and solar field size in CSP plants alone. Although a complete baseload power plant with more than 90% full load hours may not be the most economic choice, power plants approaching a full 24h service in most days of the year seem to be possible at reasonably low tariffs.

  1. Fasting for 24 h improves nasal chemosensory performance and food palatability in a related manner.

    PubMed

    Cameron, Jameason D; Goldfield, Gary S; Doucet, Éric

    2012-06-01

    Changes in smell function can modify feeding behaviour but there is little evidence of how acute negative energy balance may impact olfaction and palatability. In a within-subjects repeated measures design, 15 subjects (nine male; six female) aged 28.6±4.5 years with initial body weight (BW) 74.7±4.9 kg and body mass index (BMI) 25.3±1.4 kg/m(2) were randomized and tested at baseline (FED) and Post Deprivation (FASTED) for nasal chemosensory performance (Sniffin' Sticks) and food palatability (visual analogue scale). Significant main effects for time indicated improvements in the FASTED session for odor threshold, odor discrimination, and total odor scores (TDI), and for increased palatability. There were significant positive correlations between initial BW and the change in odor threshold (r=.52) and TDI scores (r=.53). Positive correlations were also noted between delta identification score and delta palatability (r=.68). When the sample was split by sex, only for females were there significant correlations between delta palatability and: delta BW (r=.88); delta odor identification (r=.94); and delta TDI score (r=.85). Fasting for 24h improved smell function and this was related to increased palatability ratings and initial BW. Further studies should confirm the role of BW and sex in the context of olfaction, energy deprivation and palatability. PMID:22387713

  2. 24-h ambulatory blood pressure monitoring in healthy young adult Anglo, Hispanic, and African-American subjects.

    PubMed

    Chase, H P; Garg, S K; Icaza, G; Carmain, J A; Walravens, C F; Marshall, G

    1997-01-01

    The purpose of this study was to compare office and 24-h ambulatory blood pressure (ABP) values for adolescent and young adult males and females of Anglo, Hispanic, and African-American descent. One hundred and eighteen healthy subjects (62 females, 56 males) participated, with an ethnic distribution of 50 Anglo, 32 Hispanic, and 36 African-American subjects. All subjects came to the clinic for height, weight, sitting blood pressure (BP), and to begin 24-h ABP monitoring using the SpaceLabs model 90207 automatic noninvasive monitor. The monitor recorded readings every 0.5 h from 06:00 to 22:00 and every hour at night from 22:00 to 06:00. Office systolic and diastolic BP values were higher for all males compared to all females. Mean 24-h, nighttime, and daytime systolic ABP values were also significantly higher for males compared to females. The 24-h mean and daytime systolic ABP values were significantly different by ethnic groups. The African-American subjects always had the highest readings. Mean 24-h diastolic ABP was also significantly different by ethnic groups, with the African-American subjects being higher than the Anglos or the Hispanics. Diastolic ABP (24-h mean, daytime, and nighttime) values (for all subjects combined) increased gradually and varied significantly with age. This study provides preliminary normative data about ABP in an understudied population (ie, teenagers and young adults of different ethnic backgrounds). It also shows that higher blood pressures are present among males and among subjects of African-American descent in the teenage and young adult population. PMID:9008244

  3. [Complex pathogenetic treatment schemes of vascular dyscirculatory disorders in the remote period after exposure to low dose radiation].

    PubMed

    2013-01-01

    Complex studies including modern methods of investigation of structures and functions of nervous system: electroencephalograsphy (EEG), coherent analysis, neuropsychological study and methods of neuroimaging were performed in 517 participants in liquidation of consequences of the accident (LCA) at the Chernobyl NPP in 1986-1987. Dyscirculatory metabolic encephalopathy was revealed to be the main pathology with the etiological mechanism based on dyscirculatorhypoxic and metabolic disorders. Complexity of the revealed symptoms testified to an early organism aging in remote periods after exposure to low dose radiation. Pathogenetic schemes were developed for treatment of dyscirculatory encephalopathy in liquidators, which include drugs improving blood supply, antiaggregants, antioxidants and metabolites of the brains in various combinations. Taking into consideration that early appearance of vascular dyscirculatory disorders observed in liquidators is the sign of early aging of the organism, geroprotectors were added to treatment schemes. PMID:25507773

  4. [Complex pathogenetic treatment schemes of vascular dyscirculatory disorders in the remote period after exposure to low dose radiation].

    PubMed

    Holodova, N B; Zhavoronkova, L A; Ryzhov, B N

    2013-01-01

    Complex studies including modern methods of investigation of structures and functions of nervous system: electroencephalograsphy (EEG), coherent analysis, neuropsychological study and methods of neuroimaging were performed in 517 participants in liquidation of consequences of the accident (LCA) at the Chernobyl NPP in 1986-1987. Dyscirculatory metabolic encephalopathy was revealed to be the main pathology with the etiological mechanism based on dyscirculatorhypoxic and metabolic disorders. Complexity of the revealed symptoms testified to an early organism aging in remote periods after exposure to low dose radiation. Pathogenetic schemes were developed for treatment of dyscirculatory encephalopathy in liquidators, which include drugs improving blood supply, antiaggregants, antioxidants and metabolites of the brains in various combinations. Taking into consideration that early appearance of vascular dyscirculatory disorders observed in liquidators is the sign of early aging of the organism, geroprotectors were added to treatment schemes. PMID:25434175

  5. On the similarities and differences of non-traumatic sound exposure during the critical period and in adulthood

    PubMed Central

    Eggermont, Jos J.

    2013-01-01

    There is an almost dogmatic view of the different effects of moderate-level sound stimulation in neonatal vs. adult animals. It is often stated that exposure in neonates results in an expansion of the cortical area that responds to the frequencies present in the sound, being either pure tones or frequency modulated sounds. In contrast, recent findings on stimulating adult animals for a sufficiently long time with similar sounds show a contraction of the cortical region responding to those sounds. In this review I will suggest that most neonatal animal results have been wrongly interpreted (albeit generally not by the original authors) and that the changes caused in the critical period (CP) and in adulthood are very similar. Thus, the mechanisms leading to the cortical map changes appear to be similar in the CP and in adulthood. Despite this similarity, the changes induced in the CP are occurring faster and are generally permanent (unless extensive training paradigms to revert the changes are involved), whereas in adults the induction is slower and a slow recovery (months) to pre-exposure conditions takes place. PMID:23653598

  6. Effect of acute cold exposure on the mobilization of intramuscular glycogen and triglycerides in the rat.

    PubMed

    Górski, J; Kuryliszyn, A; Wereszczyńska, U

    1981-01-01

    Male Wistar rats, 300-360 g of body weight, were exposed to cold (1 degree) for 3 and 24 h. The levels of glycogen and triglycerides (TG) were estimated in "white" and "red" portions of the quadriceps muscle (FG and POG muscles respectively) in the soleus muscle (SO muscle), and in the heart muscle. It was found that 3 h cold exposure decreased significantly the glycogen level only in the heart muscle and had no effect in the other muscles examined. Exposure to cold for 24 h reduced the glycogen level in FG and FOG muscles, and lowered further the heart glycogen level. No change of glycogen level during cold exposure was observed in SO muscle. The level of TG in each examined muscle was significantly reduced already after 3 h of cold exposure. After 24 h it remained further unchanged in FG and FOG muscles whereas in SO and heart muscles a partial recovery of TG occurred. It is concluded that in warm-acclimatized rats the intramuscular TG play an important role as a local source of free fatty acids during the first period of acute exposure to cold. PMID:7348527

  7. Quality assurance of the international computerised 24 h dietary recall method (EPIC-Soft).

    PubMed

    Crispim, Sandra P; Nicolas, Genevieve; Casagrande, Corinne; Knaze, Viktoria; Illner, Anne-Kathrin; Huybrechts, Inge; Slimani, Nadia

    2014-02-01

    The interview-administered 24 h dietary recall (24-HDR) EPIC-Soft® has a series of controls to guarantee the quality of dietary data across countries. These comprise all steps that are part of fieldwork preparation, data collection and data management; however, a complete characterisation of these quality controls is still lacking. The present paper describes in detail the quality controls applied in EPIC-Soft, which are, to a large extent, built on the basis of the EPIC-Soft error model and are present in three phases: (1) before, (2) during and (3) after the 24-HDR interviews. Quality controls for consistency and harmonisation are implemented before the interviews while preparing the seventy databases constituting an EPIC-Soft version (e.g. pre-defined and coded foods and recipes). During the interviews, EPIC-Soft uses a cognitive approach by helping the respondent to recall the dietary intake information in a stepwise manner and includes controls for consistency (e.g. probing questions) as well as for completeness of the collected data (e.g. system calculation for some unknown amounts). After the interviews, a series of controls can be applied by dietitians and data managers to further guarantee data quality. For example, the interview-specific 'note files' that were created to track any problems or missing information during the interviews can be checked to clarify the information initially provided. Overall, the quality controls employed in the EPIC-Soft methodology are not always perceivable, but prove to be of assistance for its overall standardisation and possibly for the accuracy of the collected data. PMID:24001201

  8. Demographic, Dietary, and Urinary Factors and 24-h Urinary Calcium Excretion

    PubMed Central

    Curhan, Gary C.

    2009-01-01

    Background and objectives: Higher urinary calcium is a risk factor for nephrolithiasis. This study delineated associations between demographic, dietary, and urinary factors and 24-h urinary calcium. Design, setting, participants, & measurements: Cross-sectional studies were conducted of 2201 stone formers (SF) and 1167 nonstone formers (NSF) in the Health Professionals Follow-up Study (men) and Nurses' Health Studies I and II (older and younger women). Results: Median urinary calcium was 182 mg/d in men, 182 mg/d in older women, and 192 mg/d in younger women. Compared with NSF, urinary calcium as a fraction of calcium intake was 33 to 38% higher in SF (P values ≤0.01). In regression analyses, participants were combined because associations with urinary calcium were similar in each cohort and in SF and NSF. After multivariate adjustment, participants in the highest quartile of calcium intake excreted 18 mg/d more urinary calcium than those in the lowest (P trend =0.01). Caffeine and family history of nephrolithiasis were positively associated, whereas urinary potassium, thiazides, gout, and age were inversely associated, with urinary calcium. After multivariate adjustment, participants in the highest quartiles of urinary magnesium, sodium, sulfate, citrate, phosphorus, and volume excreted 71 mg/d, 37 mg/d, 44 mg/d, 61 mg/d, 37 mg/d, and 24 mg/d more urinary calcium, respectively, than participants in the lowest (P values trend ≤0.01). Conclusions: Intestinal calcium absorption and/or negative calcium balance is greater in SF than NSF. Higher calcium intakes at levels typically observed in free-living individuals are associated with only small increases in urinary calcium. PMID:19820135

  9. Cognitive Efficacy (SIB) of 13.3 Versus 4.6 mg/24 h Rivastigmine Patch in Severe Alzheimer's Disease.

    PubMed

    Isaacson, Richard S; Ferris, Steven; Velting, Drew M; Meng, Xiangyi

    2016-05-01

    Severe Impairment Battery (SIB) data from the 24-week, randomized, double-blind ACTivities of daily living and cognitION (ACTION) study suggest that patients with severe Alzheimer's disease (AD) benefit from treatment with 13.3 versus 4.6 mg/24 h rivastigmine patch. The objective of this retrospective analysis was to further examine the cognitive efficacy of 13.3 versus 4.6 mg/24 h rivastigmine patch on individual SIB items, and SIB domains derived using factor analysis of these items. Change from baseline at Week 24 on 9 new factor-defined domains and individual items was calculated and compared using effect sizes (Cohen's d). Numerically less decline was observed with 13.3 versus 4.6 mg/24 h patch on all domains and the majority of individual items. Largest least squares mean treatment differences were observed on "visuospatial reasoning," "object naming," "recognition," "design copying," "social agency," "ideational praxis," and "comprehension" domains. These findings suggest 13.3 mg/24 h rivastigmine patch demonstrates broad cognitive efficacy across a range of SIB items and domains in patients with severe AD. PMID:26371345

  10. [Use of customer relationship management to improve healthcare for citizens. The 24h Andalusian Health Service: Healthline].

    PubMed

    Quero, Manuel; Ramos, María Belén; López, Wilfredo; Cubillas, Juan José; González, José María; Castillo, José Luis

    2016-01-01

    Salud Responde (in English: Healthline) is a Health Service and Information Centre of the taxpayer-funded Andalusian Health System (AHS) that offers a Telephone Health Advisory Service called SA24h, among other services. The main objective of SA24h is to inform and advise citizens on health issues and the available health resources of the AHS. SA24h has a Customer Relationship Management information technology tool that organises information at various levels of specialization. Depending on the difficulty of the query, the citizen is attended by professionals with distinct profiles, providing a consensual response within the professionals working within Salud Responde or within other healthcare levels of the AHS. SA24h provided responses to 757,168 patient queries from late 2008 to the end of 01/12/2015. A total of 9.38% of the consultations were resolved by the non-health professionals working at Salud Responde. The remaining 84.07% were resolved by health staff. A total of 6.5% of users were referred to accident and emergency facilities while 88.77% did not need to attend their general practitioner within the next 24hours, thus avoiding unnecessary visits to health care facilities. PMID:26900101

  11. Association between Parent and Child Dietary Sodium and Potassium Intakes as Assessed by 24-h Urinary Excretion

    PubMed Central

    Service, Carrie; Grimes, Carley; Riddell, Lynn; He, Feng; Campbell, Karen; Nowson, Caryl

    2016-01-01

    The aim of this study was to assess the association between parent and child sodium (Na) and potassium (K) intake as assessed by 24-h urinary excretion (24hUE). Primary school children and their parent(s) provided one 24-h urine sample and information on cooking and children’s discretionary salt use. Valid urine samples were provided by 108 mothers (mean age 41.8 (5.1) (SD) years, Na 120 (45) mmol/day) (7.0 g/day salt equivalent) and 40 fathers (44.4 (4.9) years, Na 152 (49) mmol/day (8.9 g/day salt), and 168 offspring (51.8% male, age 9.1 (2.0) years, Na 101 (47) mmol/day (5.9 g/day salt). When adjusted for parental age, child age and gender a 17 mmol/day Na (1 g/day salt) increase in mother’s 24hUE was associated with a 3.4 mmol/day Na (0.2 g/day salt) increase in child’s salt 24hUE (p = 0.04) with no association observed between father and child. Sixty-seven percent of parents added salt during cooking and 37% of children added salt at the table. Children who reported adding table salt had higher urinary excretion than those who did not (p = 0.01). The association between mother and child Na intake may relate to the consumption of similar foods and highlights the importance of the home environment in influencing total dietary sodium intake. PMID:27043620

  12. Association between Parent and Child Dietary Sodium and Potassium Intakes as Assessed by 24-h Urinary Excretion.

    PubMed

    Service, Carrie; Grimes, Carley; Riddell, Lynn; He, Feng; Campbell, Karen; Nowson, Caryl

    2016-01-01

    The aim of this study was to assess the association between parent and child sodium (Na) and potassium (K) intake as assessed by 24-h urinary excretion (24hUE). Primary school children and their parent(s) provided one 24-h urine sample and information on cooking and children's discretionary salt use. Valid urine samples were provided by 108 mothers (mean age 41.8 (5.1) (SD) years, Na 120 (45) mmol/day) (7.0 g/day salt equivalent) and 40 fathers (44.4 (4.9) years, Na 152 (49) mmol/day (8.9 g/day salt), and 168 offspring (51.8% male, age 9.1 (2.0) years, Na 101 (47) mmol/day (5.9 g/day salt). When adjusted for parental age, child age and gender a 17 mmol/day Na (1 g/day salt) increase in mother's 24hUE was associated with a 3.4 mmol/day Na (0.2 g/day salt) increase in child's salt 24hUE (p = 0.04) with no association observed between father and child. Sixty-seven percent of parents added salt during cooking and 37% of children added salt at the table. Children who reported adding table salt had higher urinary excretion than those who did not (p = 0.01). The association between mother and child Na intake may relate to the consumption of similar foods and highlights the importance of the home environment in influencing total dietary sodium intake. PMID:27043620

  13. Prevalence and determinants of misreporting among European children in proxy-reported 24 h dietary recalls.

    PubMed

    Börnhorst, C; Huybrechts, I; Ahrens, W; Eiben, G; Michels, N; Pala, V; Molnár, D; Russo, P; Barba, G; Bel-Serrat, S; Moreno, L A; Papoutsou, S; Veidebaum, T; Loit, H-M; Lissner, L; Pigeot, I

    2013-04-14

    Dietary assessment is strongly affected by misreporting (both under- and over-reporting), which results in measurement error. Knowledge about misreporting is essential to correctly interpret potentially biased associations between diet and health outcomes. In young children, dietary data mainly rely on proxy respondents but little is known about determinants of misreporting here. The present analysis was conducted within the framework of the multi-centre IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) study and is based on 6101 children aged 2-9 years with 24 h dietary recall (24-HDR) and complete covariate information. Adapted Goldberg cut-offs were applied to classify the 24-HDR as 'over-report', 'plausible report' or 'under-report'. Backward elimination in the course of multi-level logistic regression analyses was conducted to identify factors significantly related to under- and over-reporting. Next to characteristics of the children and parents, social factors and parental concerns/perceptions concerning their child's weight status were considered. Further selective misreporting was addressed, investigating food group intakes commonly perceived as more or less socially desirable. Proportions of under-, plausible and over-reports were 8.0, 88.6 and 3.4 %, respectively. The risk of under-reporting increased with age (OR 1.19, 95 % CI 1.05, 1.83), BMI z-score of the child (OR 1.23, 95 % CI 1.10, 1.37) and household size (OR 1.12, 95 % CI 1.01, 1.25), and was higher in low/medium income groups (OR 1.45, 95 % CI 1.13, 1.86). Over-reporting was negatively associated with BMI z-scores of the child (OR 0.78, 95 % CI 0.69, 0.88) and higher in girls (OR 1.70, 95 % CI 1.27, 2.28). Further social desirability and parental concerns/perceptions seemed to influence the reporting behaviour. Future studies should involve these determinants of misreporting when investigating diet-disease relationships in children

  14. Exposure to a high fat diet during the perinatal period alters vagal motoneurone excitability, even in the absence of obesity

    PubMed Central

    Bhagat, Ruchi; Fortna, Samuel R; Browning, Kirsteen N

    2015-01-01

    The perinatal period is critically important to the development of autonomic neural circuits responsible for energy homeostasis. Vagal neurocircuits are vital to the regulation of upper gastrointestinal functions, including satiety. Diet-induced obesity modulates the excitability and responsiveness of both peripheral vagal afferents and central vagal efferents but less information is available regarding the effects of diet per se on vagal neurocircuit functions. The aims of this study were to investigate whether perinatal exposure to a high fat diet (HFD) dysregulated dorsal motor nucleus of the vagus (DMV) neurones, prior to the development of obesity. Whole cell patch clamp recordings were made from gastric-projecting DMV neurones in thin brainstem slices from rats that were exposed to either a control diet or HFD from pregnancy day 13. Our data demonstrate that following perinatal HFD: (i) DMV neurones had decreased excitability and input resistance with a reduced ability to fire action potentials; (ii) the proportion of DMV neurones excited by cholecystokinin (CCK) was unaltered but the proportion of neurones in which CCK increased excitatory glutamatergic synaptic inputs was reduced; (iii) the tonic activation of presynaptic group II metabotropic glutamate receptors on inhibitory nerve terminals was attenuated, allowing modulation of GABAergic synaptic transmission; and (iv) the size and dendritic arborization of gastric-projecting DMV neurones was increased. These results suggest that perinatal HFD exposure compromises the excitability and responsiveness of gastric-projecting DMV neurones, even in the absence of obesity, suggesting that attenuation of vago-vagal reflex signalling may precede the development of obesity. PMID:25556801

  15. Antioxidative stress responses in the floating macrophyte Lemna minor L. with cylindrospermopsin exposure.

    PubMed

    Flores-Rojas, Nelida Cecilia; Esterhuizen-Londt, Maranda; Pflugmacher, Stephan

    2015-12-01

    Cylindrospermopsin toxicity and oxidative stress have been examined in aquatic animals, however, only a few studies with aquatic plants have been conducted focusing on the potential for bioaccumulation of cylindrospermopsin. The oxidative stress effects caused by cylindrospermopsin on macrophytes have not yet been specifically studied. The oxidative stress response of Lemna minor L. with exposure to cylindrospermopsin, was therefore tested in this study. The hydrogen peroxide concentration together with the activities of the antioxidant enzymes (catalase, peroxidase, glutathione reductase and glutathione S-transferase) were determined after 24h (hours) of exposure to varying concentrations (0.025, 0.25, 2.5 and 25μg/L) of cylindrospermopsin. Responses with longer exposure periods (48, 96, 168h) were tested only with exposure to 2.5 and 25μg/L cylindrospermopsin. Additionally, the content of the carotenoids was determined as a possible non-enzymatic antioxidant defence mechanism against cylindrospermopsin. The levels of hydrogen peroxide increased after 24h even at the lowest cylindrospermopsin exposure concentrations. Catalase showed the most representative antioxidant response observed after 24h and maintained its activity throughout the experiment. Catalase activity corresponded with the contents of hydrogen peroxide at 2.5 and 25μg/L cylindrospermopsin. The data suggest that glutathione S-transferase, glutathione reductase and the carotenoid content act together with catalase but are more sensitive to higher concentrations of cylindrospermopsin and after a longer exposure period (168h). The results indicate that cylindrospermopsin promotes oxidative stress in L. minor at concentrations of 2.5 and 25μg/L. However, L. minor has sufficient defence mechanisms in place against this cyanobacterial toxin. Even though L. minor exhibits the potential to managing and control cylindrospermopsin contamination in aquatic systems, further studies in tolerance limits to

  16. Effects of exposure time, material type, and granular pesticide on glove contamination.

    PubMed

    Guo, C; Stone, J; Stahr, H M; Shelley, M

    2001-11-01

    Chemical-resistant gloves are recommended for pesticide applicators to reduce their exposure to agricultural chemicals. In this research, three chemical-resistant glove materials-nitrile, neoprene, and barrier laminate-were studied in relation to contamination with granular terbufos and tefluthrin. Surfaces of specimens backed with alpha cellulose were contaminated with 300 mg of either granular terbufos or tefluthrin for 1-, 2-, 4-, 8-, 16-, and 24-h time periods in petri dishes in the laboratory. Residues were extracted using ethyl acetate for terbufos and iso-octane for tefluthrin in test tubes for 24 h. Analysis of extracts by gas chromatograph and statistical analysis of the data showed that contamination levels varied with the time of exposure, material type, and pesticide used. Pesticide was not detected in the alpha cellulose even after 24 h contamination time. A linear relationship was found between contamination level and exposure time for terbufos in the three materials, with longer exposure times causing higher contamination levels. Contamination of nitrile was significantly less than neoprene or barrier laminate. Exposed glove materials contained higher levels of contamination of terbufos than tefluthrin. PMID:11598792

  17. Cardiorespiratory control and cytokine profile in response to heat stress, hypoxia, and lipopolysaccharide (LPS) exposure during early neonatal period.

    PubMed

    McDonald, Fiona B; Chandrasekharan, Kumaran; Wilson, Richard J A; Hasan, Shabih U

    2016-02-01

    Sudden infant death syndrome (SIDS) is one of the most common causes of postneonatal infant mortality in the developed world. An insufficient cardiorespiratory response to multiple environmental stressors (such as prone sleeping positioning, overwrapping, and infection), during a critical period of development in a vulnerable infant, may result in SIDS. However, the effect of multiple risk factors on cardiorespiratory responses has rarely been tested experimentally. Therefore, this study aimed to quantify the independent and possible interactive effects of infection, hyperthermia, and hypoxia on cardiorespiratory control in rats during the neonatal period. We hypothesized that lipopolysaccharide (LPS) administration will negatively impact cardiorespiratory responses to increased ambient temperature and hypoxia in neonatal rats. Sprague-Dawley neonatal rat pups were studied at postnatal day 6-8. Rats were examined at an ambient temperature of 33°C or 38°C. Within each group, rats were allocated to control, saline, or LPS (200 μg/kg) treatments. Cardiorespiratory and thermal responses were recorded and analyzed before, during, and after a hypoxic exposure (10% O2). Serum samples were taken at the end of each experiment to measure cytokine concentrations. LPS significantly increased cytokine concentrations (such as TNFα, IL-1β, MCP-1, and IL-10) compared to control. Our results do not support a three-way interaction between experimental factors on cardiorespiratory control. However, independently, heat stress decreased minute ventilation during normoxia and increased the hypoxic ventilatory response. Furthermore, LPS decreased hypoxia-induced tachycardia. Herein, we provide an extensive serum cytokine profile under various experimental conditions and new evidence that neonatal cardiorespiratory responses are adversely affected by dual interactions of environmental stress factors. PMID:26811056

  18. Addressing the recovery of feeding rates in post-exposure feeding bioassays: Cyathura carinata as a case study

    SciTech Connect

    Pais-Costa, Antonia Juliana; Acevedo, Pelayo; Marques, João Carlos; Martinez-Haro, Mónica

    2015-02-15

    Post-exposure bioassays are used in environmental assessment as a cost-effective tool, but the effects of organism's recovery after exposure to pollutant has not yet been addressed in detail. The recoveries of post-exposure feeding rates after being exposed to two sublethal concentrations of cadmium during two different exposure periods (48 h and 96 h) were evaluated under laboratory conditions using the estuarine isopod Cyathura carinata. Results showed that feeding depression was a stable endpoint up to 24 h after cadmium exposure, which is useful for ecotoxicological bioassays. - Highlights: • We studied recovery of post-exposure feeding rates 48–96 h after cadmium exposure. • The assay is based on the isopod Cyathura carinata. • Post-exposure feeding inhibition is a stable sublethal endpoint.

  19. Estimating individual-level exposure to airborne polycyclic aromatic hydrocarbons throughout the gestational period based on personal, indoor, and outdoor monitoring

    SciTech Connect

    Choi, H.; Perera, F.; Pac, A.; Wang, L.; Flak, E.; Mroz, E.; Jacek, R.; Chai-Onn, T.; Jedrychowski, W.; Masters, E.; Camann, D.; Spengler, J.

    2008-11-15

    Current understanding on health effects of long-term polycyclic aromatic hydrocarbon (PAH) exposure is limited by lack of data on time-varying nature of the pollutants at an individual level. In a cohort of pregnant women in Krakow, Poland, we examined the contribution of temporal, spatial, and behavioral factors to prenatal exposure to airborne PAHs within each trimester and developed a predictive model of PAH exposure over the entire gestational period. The observed personal, indoor, and outdoor B(a)P levels we observed in Krakow far exceed the recommended Swedish guideline value for B(a)P of 0.1 ng/m{sup 3}. Based on simultaneously monitored levels, the outdoor PAH level alone accounts for 93% of total variability in personal exposure during the heating season. Living near the Krakow bus depot, a crossroad, and the city, center and time spent outdoors or commuting were not associated with higher personal exposure. During the nonheating season only, a 1-hr increase in environmental tobacco smoke (ETS) exposure was associated with a 10-16% increase in personal exposure to the nine measured PAHs. A 1{degree}C decrease in ambient temperature was associated with a 3-5% increase in exposure to benz(a)anthracene, benzo(k)fluoranthene, and dibenz(a,h)anthracene, after accounting for the outdoor concentration. A random effects model demonstrated that mean personal exposure at a given gestational period depends on the season, residence location, and ETS. Considering that most women reported spending < 3 hr/day outdoors, most women in the study were exposed to outdoor-originating PAHs within the indoor setting. Cross-sectional, longitudinal monitoring supplemented with questionnaire data allowed development of a gestation-length model of individual-level exposure with high precision and validity.

  20. Environmental impact on crew of armoured vehicles: Effects of 24 h combat exercise in a hot desert

    NASA Astrophysics Data System (ADS)

    Singh, A. P.; Majumdar, D.; Bhatia, M. R.; Srivastava, K. K.; Selvamurthy, W.

    1995-06-01

    A field study was undertaken to investigate the effects of combined noise, vibration and heat stress on the physiological functions of the crew of armoured vehicles during prolonged combat exercise in a desert. The sound pressure level of noise was measured with a sound level meter and accelerations by vibration analyser. The thermal load on the crew was evaluated by calculating the wet bulb globe temperature index. The physiological responses of the subjects ( n=9), included significant increases in the heart rate, 24 h water intake and urinary catecholamine concentration. A significant decrease was recorded in body mass, peak expiratory flow rate and 24 h urinary output. The high heat load on the crew resulted in a hypohydration of 3% body mass and appeared to be the dominant factor in producing the physiological strain.

  1. Nqrs Data for C24H76BLiN12O4P4 (Subst. No. 1593)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for C24H76BLiN12O4P4 (Subst. No. 1593)

  2. Long-term blood pressure changes induced by the 2009 L'Aquila earthquake: assessment by 24 h ambulatory monitoring.

    PubMed

    Giorgini, Paolo; Striuli, Rinaldo; Petrarca, Marco; Petrazzi, Luisa; Pasqualetti, Paolo; Properzi, Giuliana; Desideri, Giovambattista; Omboni, Stefano; Parati, Gianfranco; Ferri, Claudio

    2013-09-01

    An increased rate of cardiovascular and cerebrovascular events has been described during and immediately after earthquakes. In this regard, few data are available on long-term blood pressure control in hypertensive outpatients after an earthquake. We evaluated the long-term effects of the April 2009 L'Aquila earthquake on blood pressure levels, as detected by 24 h ambulatory blood pressure monitoring. Before/after (mean±s.d. 6.9±4.5/14.2±5.1 months, respectively) the earthquake, the available 24 h ambulatory blood pressure monitoring data for the same patients were extracted from our database. Quake-related daily life discomforts were evaluated through interviews. We enrolled 47 patients (25 female, age 52±14 years), divided into three groups according to antihypertensive therapy changes after versus before the earthquake: unchanged therapy (n=24), increased therapy (n=17) and reduced therapy (n=6). Compared with before the quake, in the unchanged therapy group marked increases in 24 h (P=0.004), daytime (P=0.01) and nighttime (P=0.02) systolic blood pressure were observed after the quake. Corresponding changes in 24 h (P=0.005), daytime (P=0.01) and nighttime (P=0.009) diastolic blood pressure were observed. Daily life discomforts were reported more frequently in the unchanged therapy and increased therapy groups than the reduced therapy group (P=0.025 and P=0.018, respectively). In conclusion, this study shows that patients with unchanged therapy display marked blood pressure increments up to more than 1 year after an earthquake, as well as long-term quake-related discomfort. Our data suggest that particular attention to blood pressure levels and adequate therapy modifications should be considered after an earthquake, not only early after the event but also months later. PMID:23595046

  3. Nqrs Data for C24H46I2N6O2P2Sn (Subst. No. 1589)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for C24H46I2N6O2P2Sn (Subst. No. 1589)

  4. A pilot study on the effect of telmisartan & ramipril on 24 h blood pressure profile & dipping pattern in type 1 diabetes patients with nephropathy

    PubMed Central

    Anantharaman, R.; Bhansali, Anil; Bhadada, Sanjay K.; Kohli, Harbir S.; Walia, Rama; Shanmugasundar, G.; Jayaprakash, P.

    2011-01-01

    Background & objectives: Angiotensin converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) have been used to normalize the blood pressure and the dipping pattern in patients with type 1 diabetes mellitus (T1DM) and nephropathy. However, there are no data on the effect of the dual blockade on the dipping pattern in these subjects. We therefore, carried out this study to evaluate the effect of administrating an ACEI followed by ARB in the optimum doses in T1DM patients with nephropathy on 24 h blood pressure (BP) profile and nocturnal dipping pattern. Methods: An open label interventional pilot study was done during a one year period involving 30 consecutive patients who were treated with telmisartan 80 mg (0800-1000 h) for eight weeks followed by addition of ramipril 10 mg (1200-1400 h) for the next eight weeks. Ambulatory BP, dipping pattern and albumin excretion rate were studied after each phase. Twenty patients were hypertensive and 10 patients had macro- and 20 patients had microalbuminuria. Results: Telmisartan produced a fall in the clinic BP by 4/1.3 mm Hg (P<0.05 and P<0.362, respectively), 2/1.9 mm Hg in the mean 24 h BP, 1.4/1.1 mm Hg in the day BP and 3.7/3 mm Hg in the trough BP. Addition of ramipril to telmisartan produced a further reduction of 6.3/5.9 mm Hg in the clinic BP (P<0.001 for both), 4.3/4.2 mm Hg in the mean 24 h BP (P<0.01 and P<0.0001, respectively), 5.8/3.9 mm Hg in the day BP (P<0.01 for both), 4.2/2.5 mm Hg in the trough BP, with a reduction of clinic SBP and DBP of 10.3/7.2 mm Hg from the baseline. Telmisartan restored normal systolic dipping pattern in 33.3 per cent of the nondippers (P<0.01) but addition of ramipril was not complimentary. Hyperkalamia (>5.5 mmol/l) was observed only in 2 patients towards the end of the study. Interpretation & conclusions: The dual blockade with telmisartan and ramipril had complimentary effect on lowering of the BP, however, similar beneficial effect on the nocturnal dipping

  5. Ethanol exposure during peripubertal period increases the mast cell number and impairs meiotic and spermatic parameters in adult male rats.

    PubMed

    Paula Franco Punhagui, Ana; Rodrigues Vieira, Henrique; Eloisa Munhoz De Lion Siervo, Gláucia; da Rosa, Renata; Scantamburlo Alves Fernandes, Glaura

    2016-06-01

    Puberty is characterized by psychosomatic alterations, whereas chronic ethanol consumption is associated with morphophysiological changes in the male reproductive system. The purpose of this study was to show the toxic effects on testis and epididymal morphophysiology after ethanol administration during peripuberty. To this end, male Wistar rats were divided into two groups: ethanol (E) group: received a 2 g dose of ethanol/kg in 25% (v/v); and control (C) group: received the same volume of filtered water; both were treated by gavage for 54 days. On the 55th day of the experiment, epididymis, and testis were collected for sperm count, histopathology, mast cell count, and morphometry. The vas deferens was collected for sperm motility analysis. The femur and testicle were used for cytogenetic analysis. Ethanol exposure caused reduction in daily sperm production (DSP) and in sperm motility, multinucleated cells or those having no chromosomal content, and late chromosome migrations. No changes were observed in the number of chromosomes in the mitotic analysis. However, some alterations could be seen in meiocytes at different stages of cell division. Stereological analysis of the epididymis indicated reorganization of its component in the 2A and 5A/B regions. The epididymal cauda had greater recruitment, and both degranulated and full mast cells showed an increase in the initial segment, in the ethanol group. In conclusion, ethanol administration during the pubertal phase affects epididymis and testis in adult rats, as indicated mainly by our new findings related to mast cell number and meiotic impact. Microsc. Res. Tech. 79:541-549, 2016. © 2016 Wiley Periodicals, Inc. PMID:27058992

  6. Influence of different periods of exposure to hot environment on rumen function and diet digestibility in sheep

    NASA Astrophysics Data System (ADS)

    Bernabucci, U.; Lacetera, N.; Danieli, P. P.; Bani, P.; Nardone, A.; Ronchi, B.

    2009-09-01

    Effects of different periods of exposure to hot environments on rumen function, diet digestibility and digesta passage rate were studied in four adult not-pregnant Sardinian ewes housed in a climatic chamber. The ewes were kept in individual metabolic cages. The trial lasted 83 days; 17 days were spent under thermal comfort conditions (TC) [temperature-humidity index (THI) = 65.0 ± 2.0], followed by 49 days under elevated THI (ETHI: THI = 82.0 ± 2.5) and 17 days under thermal comfort (TC; THI = 65.0 ± 1.0). Five digestibility and passage rate trials were carried out during the 83 days. Trials 1 and 5 were carried out under TC; trials 2, 3 and 4 were carried out under ETHI. Values of rectal temperatures (39.7 ± 0.3°C) and respiratory rate (118.4 ± 31.8 breaths/min) indicated that sheep under ETHI were heat-stressed. Heat stress caused an increase ( P < 0.01) in water intake, and reductions ( P < 0.05) in dry matter intake, rumen pH, rumen cellulolytic and amylolytic bacteria count, rumen osmolarity, organic matter, dry matter, neutral detergent fibre, acid detergent fibre and non-structural carbohydrates digestibility coefficients, and a reduction of digesta passage rates. Under ETHI, diet digestibility and passage rate of digesta were reduced in a time-dependent fashion. Variation of diet digestibility under ETHI was not related to passage rate of digesta and feed intake. Reduction of cellulolytic and amylolytic bacteria and the adaptive response to hot environment seem to be related to alteration of digestibility observed in ewes chronically exposed to hot environment.

  7. Sensitive periods for 17β-estradiol exposure during immune system development in sea bass head kidney.

    PubMed

    Seemann, Frauke; Knigge, Thomas; Duflot, Aurélie; Marie, Sabine; Olivier, Stéphanie; Minier, Christophe; Monsinjon, Tiphaine

    2016-06-01

    An increasing body of evidence suggests that sex steroids play an important role in the development and regulation of vertebrate immune defense. Therefore, compounds with estrogenic activity may influence the immune system via receptor-mediated pathways. The presence of estrogen receptors in immune cells and organs during the early stages of development may indicate that female steroid hormones are involved in the maturation of the fish immune system. This is of particular importance, as some marine fish are probably exposed to sources of exogenous estrogens while they reside in their estuarine nursery grounds. In this study, the influence of 17β-estradiol (E2) on estrogen receptor and cytokine gene expression was assessed in juvenile sea bass (Dicentrarchus labrax) together with characterization of the head kidney leukocyte populations and corresponding phagocytic activity during organ regionalization from 98 to 239 dph. E2 exposure, beginning at 90 dph resulted in indirect and delayed modifications of interleukin 1β and estrogen receptor α gene expression, which may affect B-lymphocyte proliferation in the sea bass head kidney. The E2 treatment of 120 dph fish led to an increase in estrogen receptor β2 and a decrease in transforming growth factor β1 gene expression, which coincided with decreased phagocytic activity of head kidney lymphocytes and monocytes/macrophages. Additionally, these changes were observed during developmental periods described as critical phases for B-lymphocyte development in mammals. Consequently, exogenous estrogens have the potential to modify the innate immune response in juvenile sea bass and to exert detrimental effects on head kidney development. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26278277

  8. Exposure profiles and source identifications for workers exposed to crystalline silica during a municipal waste incinerator relining period.

    PubMed

    Shih, Tung-Sheng; Lu, Pao-Yin; Chen, Ching-Hwa; Soo, Jhy-Charm; Tsai, Ching-Lang; Tsai, Perng-Jy

    2008-06-15

    In this study, respirable crystalline silica exposures to furnace relining workers of 7 exposure groups were assessed by conducting personal respirable dust samplings. All possible pollutant sources were identified for each exposure group through field observations, and bulk samples were randomly collected from each identified pollutant source. All collected samples were analyzed for their tridymite, cristobalite, and quartz contents by using the X-ray diffraction method. Results show that quartz was the only detectable crystalline silica content. We found that the resultant respirable quartz exposure levels presented in sequence for the 7 exposure groups (sand blasting>bottom ash cleaning>wall demolishing>relining>others>grid repairing>scaffold establishing) were different from that of the corresponding respirable dust exposure levels (bottom ash cleaning>wall demolishing>sand blasting>relining>grid repairing>scaffold establishing>others). 87.3-100% of workers' respirable quartz exposures of the 7 exposure groups exceeded the TLV-TWA (0.025 mg m(-3)) indicating appropriate control strategies should be taken immediately. By comparing the fractions of quartz contained in personal respirable dust samples with that contained in all possible pollutant sources for each exposure group, this study identified main pollutant sources for each exposure group as: bottom ash cleaning and scaffold establishing: bottom ash; sand blasting: blasting sand; wall demolishing: refractory cement+wall ash; wall relining: refractory brick; grid repairing: wall ash+refractory cement; grid repairing: wall ash+refractory cement; others: blasting sand+bottom ash. Finally, effective control strategies were proposed for exposure reduction by using above information together with our field observations. PMID:18063296

  9. Rhythmic 24 h Variation of Core Body Temperature and Locomotor Activity in a Subterranean Rodent (Ctenomys aff. knighti), the Tuco-Tuco

    PubMed Central

    Tachinardi, Patricia; Bicudo, José Eduardo Wilken; Oda, Gisele Akemi; Valentinuzzi, Verónica Sandra

    2014-01-01

    The tuco-tuco Ctenomys aff. knighti is a subterranean rodent which inhabits a semi-arid area in Northwestern Argentina. Although they live in underground burrows where environmental cycles are attenuated, they display robust, 24 h locomotor activity rhythms that are synchronized by light/dark cycles, both in laboratory and field conditions. The underground environment also poses energetic challenges (e.g. high-energy demands of digging, hypoxia, high humidity, low food availability) that have motivated thermoregulation studies in several subterranean rodent species. By using chronobiological protocols, the present work aims to contribute towards these studies by exploring day-night variations of thermoregulatory functions in tuco-tucos, starting with body temperature and its temporal relationship to locomotor activity. Animals showed daily, 24 h body temperature rhythms that persisted even in constant darkness and temperature, synchronizing to a daily light/dark cycle, with highest values occurring during darkness hours. The range of oscillation of body temperature was slightly lower than those reported for similar-sized and dark-active rodents. Most rhythmic parameters, such as period and phase, did not change upon removal of the running wheel. Body temperature and locomotor activity rhythms were robustly associated in time. The former persisted even after removal of the acute effects of intense activity on body temperature by a statistical method. Finally, regression gradients between body temperature and activity were higher in the beginning of the night, suggesting day-night variation in thermal conductance and heat production. Consideration of these day-night variations in thermoregulatory processes is beneficial for further studies on thermoregulation and energetics of subterranean rodents. PMID:24454916

  10. Rhythmic 24 h variation of core body temperature and locomotor activity in a subterranean rodent (Ctenomys aff. knighti), the tuco-tuco.

    PubMed

    Tachinardi, Patricia; Bicudo, José Eduardo Wilken; Oda, Gisele Akemi; Valentinuzzi, Verónica Sandra

    2014-01-01

    The tuco-tuco Ctenomys aff. knighti is a subterranean rodent which inhabits a semi-arid area in Northwestern Argentina. Although they live in underground burrows where environmental cycles are attenuated, they display robust, 24 h locomotor activity rhythms that are synchronized by light/dark cycles, both in laboratory and field conditions. The underground environment also poses energetic challenges (e.g. high-energy demands of digging, hypoxia, high humidity, low food availability) that have motivated thermoregulation studies in several subterranean rodent species. By using chronobiological protocols, the present work aims to contribute towards these studies by exploring day-night variations of thermoregulatory functions in tuco-tucos, starting with body temperature and its temporal relationship to locomotor activity. Animals showed daily, 24 h body temperature rhythms that persisted even in constant darkness and temperature, synchronizing to a daily light/dark cycle, with highest values occurring during darkness hours. The range of oscillation of body temperature was slightly lower than those reported for similar-sized and dark-active rodents. Most rhythmic parameters, such as period and phase, did not change upon removal of the running wheel. Body temperature and locomotor activity rhythms were robustly associated in time. The former persisted even after removal of the acute effects of intense activity on body temperature by a statistical method. Finally, regression gradients between body temperature and activity were higher in the beginning of the night, suggesting day-night variation in thermal conductance and heat production. Consideration of these day-night variations in thermoregulatory processes is beneficial for further studies on thermoregulation and energetics of subterranean rodents. PMID:24454916

  11. Manipulation of BDNF Signaling Modifies the Experience-Dependent Plasticity Induced by Pure Tone Exposure during the Critical Period in the Primary Auditory Cortex

    PubMed Central

    Anomal, Renata; de Villers-Sidani, Etienne; Merzenich, Michael M.; Panizzutti, Rogerio

    2013-01-01

    Sensory experience powerfully shapes cortical sensory representations during an early developmental “critical period” of plasticity. In the rat primary auditory cortex (A1), the experience-dependent plasticity is exemplified by significant, long-lasting distortions in frequency representation after mere exposure to repetitive frequencies during the second week of life. In the visual system, the normal unfolding of critical period plasticity is strongly dependent on the elaboration of brain-derived neurotrophic factor (BDNF), which promotes the establishment of inhibition. Here, we tested the hypothesis that BDNF signaling plays a role in the experience-dependent plasticity induced by pure tone exposure during the critical period in the primary auditory cortex. Elvax resin implants filled with either a blocking antibody against BDNF or the BDNF protein were placed on the A1 of rat pups throughout the critical period window. These pups were then exposed to 7 kHz pure tone for 7 consecutive days and their frequency representations were mapped. BDNF blockade completely prevented the shaping of cortical tuning by experience and resulted in poor overall frequency tuning in A1. By contrast, BDNF infusion on the developing A1 amplified the effect of 7 kHz tone exposure compared to control. These results indicate that BDNF signaling participates in the experience-dependent plasticity induced by pure tone exposure during the critical period in A1. PMID:23700463

  12. Sleep and cognitive function of crewmembers and mission controllers working 24-h shifts during a simulated 105-day spaceflight mission

    NASA Astrophysics Data System (ADS)

    Barger, Laura K.; Wright, Kenneth P.; Burke, Tina M.; Chinoy, Evan D.; Ronda, Joseph M.; Lockley, Steven W.; Czeisler, Charles A.

    2014-01-01

    The success of long-duration space missions depends on the ability of crewmembers and mission support specialists to be alert and maintain high levels of cognitive function while operating complex, technical equipment. We examined sleep, nocturnal melatonin levels and cognitive function of crewmembers and the sleep and cognitive function of mission controllers who participated in a high-fidelity 105-day simulated spaceflight mission at the Institute of Biomedical Problems (Moscow). Crewmembers were required to perform daily mission duties and work one 24-h extended duration work shift every sixth day. Mission controllers nominally worked 24-h extended duration shifts. Supplemental lighting was provided to crewmembers and mission controllers. Participants' sleep was estimated by wrist-actigraphy recordings. Overall, results show that crewmembers and mission controllers obtained inadequate sleep and exhibited impaired cognitive function, despite countermeasure use, while working extended duration shifts. Crewmembers averaged 7.04±0.92 h (mean±SD) and 6.94±1.08 h (mean±SD) in the two workdays prior to the extended duration shifts, 1.88±0.40 h (mean±SD) during the 24-h work shift, and then slept 10.18±0.96 h (mean±SD) the day after the night shift. Although supplemental light was provided, crewmembers' average nocturnal melatonin levels remained elevated during extended 24-h work shifts. Naps and caffeine use were reported by crewmembers during ˜86% and 45% of extended night work shifts, respectively. Even with reported use of wake-promoting countermeasures, significant impairments in cognitive function were observed. Mission controllers slept 5.63±0.95 h (mean±SD) the night prior to their extended duration work shift. On an average, 89% of night shifts included naps with mission controllers sleeping an average of 3.4±1.0 h (mean±SD) during the 24-h extended duration work shift. Mission controllers also showed impaired cognitive function during extended

  13. Acclimation of peanut (Arachis hypogaea L.) to water stress through exposure to differing periods of early season drought

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peanut (Arachis hypogaea L.) is able to withstand periods of water scarcity either in the early or late periods of the growing season, but suffers significant stress and yield loss during drought periods in mid-season, or the period coinciding with peak flower production and pod maturation. In fact...

  14. Association between 24h Urinary Sodium and Potassium Excretion and Estimated Glomerular Filtration Rate (eGFR) Decline or Death in Patients with Diabetes Mellitus and eGFR More than 30 ml/min/1.73m2

    PubMed Central

    Nagata, Takanobu; Hirakawa, Akihiro; Katsuno, Takayuki; Yasuda, Yoshinari; Matsuo, Seiichi; Tsuboi, Naotake; Maruyama, Shoichi

    2016-01-01

    Background Data regarding the association between 24h urinary sodium and potassium excretion with kidney outcomes in patients with diabetes mellitus is currently scarce. Methods We conducted a single-center, retrospective cohort study in which 1230 patients with diabetes who had undergone a 24h urinary sodium and potassium excretion test were analyzed. Patients with incomplete urine collection were excluded based on 24h urinary creatinine excretion. Outcomes were the composite of a 30% decline in eGFR or death. Multivariate cox regression analysis was used to investigate the association between urinary sodium and potassium excretion and outcomes. Results With a mean follow up period of 5.47 years, 130 patients reached the outcomes (30% decline in eGFR: 124, death: 6). Mean (SD) eGFR and 24h urinary sodium and potassium excretion at baseline were 78.6 (19.5) ml/min/1.73m2, 4.50 (1.64) g/day, and 2.14 (0.77) g/day. Compared with sodium excretion < 3.0 g/day, no significant change in risk of outcomes was observed with increased increments of 1.0 g/day. Compared with potassium excretion of < 1.5 g/day, 2.0–2.5 g/day, and 2.5–3.0 g/day were significantly associated with a lower risk of outcomes (hazard ratio [HR], 0.49 and 0.44; 95% confidence interval [CI], 0.28 to 0.84 and 0.22 to 0.87). Conclusions 24h urinary sodium excretion was not significantly associated with a risk of 30% decline in eGFR or death in patients with diabetes. However, an increased risk of 30% decline in eGFR or death was significantly associated with 24h urinary potassium excretion < 1.5 g/day than with 2.0–2.5 g/day and 2.5–3.0 g/day. PMID:27136292

  15. Alterations in amino acid concentrations in the plasma and muscle in human subjects during 24 h of simulated adventure racing.

    PubMed

    Borgenvik, Marcus; Nordin, Marie; Mikael Mattsson, C; Enqvist, Jonas K; Blomstrand, Eva; Ekblom, Björn

    2012-10-01

    This investigation was designed to evaluate changes in plasma and muscle levels of free amino acids during an ultra-endurance exercise and following recovery. Nine male ultra-endurance trained athletes participated in a 24-h standardized endurance trial with controlled energy intake. The participants performed 12 sessions of running, kayaking and cycling (4 × each discipline). Blood samples were collected before, during and after exercise, as well as after 28 h of recovery. Muscle biopsies were taken before the test and after exercise, as well as after 28 h of recovery. During the 24-h exercise, plasma levels of branched-chain (BCAA), essential amino acids (EAA) and glutamine fell 13, 14 and 19% (P < 0.05), respectively, whereas their concentrations in muscle were unaltered. Simultaneously, tyrosine and phenylalanine levels rose 38 and 50% (P < 0.05) in the plasma and 66 and 46% (P < 0.05) in muscle, respectively. After the 24-h exercise, plasma levels of BCAA were positively correlated with muscle levels of glycogen (r (2) = 0.73, P < 0.05), as was the combined concentrations of muscle tyrosine and phenylalanine with plasma creatine kinase (R (2) = 0.55, P < 0.05). Following 28-h of recovery, plasma and muscle levels of amino acids had either returned to their initial levels or were elevated. In conclusion, ultra-endurance exercise caused significant changes elevations in plasma and muscle levels of tyrosine and phenylalanine, which suggest an increase in net muscle protein breakdown during exercise. There was a reduction in plasma concentrations of EAA and glutamine during exercise, whereas no changes were detected in their muscle concentration after exercise. PMID:22350359

  16. Variations in 7-day/24-h circadian pattern of ambulatory blood pressure and heart rate of type 2 diabetes patients

    PubMed Central

    Bhardwaj, Shipra; Verma, Narsingh; Anjum, Baby; Bhardwaj, Kshitij

    2014-01-01

    Aims/Introduction Diabetes has profound consequences on the cardiovascular system leading to cardiovascular morbidity and mortality in diabetic patients. Blood pressure (BP) has a characteristic and reproducible circadian pattern, with high values during the day and low values at night. A 7-day timed analysis of BP through ambulatory blood pressure monitoring has been used not only to diagnose day and night dipping patterns of blood pressure, but also to measure day-to-day variability and the circadian hyper-amplitude-tension, a condition in which excessive circadian BP amplitude precedes the chronic established hypertension. Our objective was to assess the 7-day/24-h circadian pattern of BP and heart rate in diabetic patients, as it could be helpful in the diagnosis and prevention of cardiovascular morbidity. Materials and Methods A total of 50 diabetic patients with type 2 diabetes and 50 non-diabetic participants were recruited for the study. General health records were individually maintained, and 7-day/24-h ambulatory blood pressure monitoring using an ambulatory blood pressure monitor was carried out. Results The rhythmic parameters of systolic and diastolic BP, heart rate, double amplitude, acrophase and 3-h fractionated hyperbaric index were found to be significantly high in diabetic patients. A total of 12 participants were diagnosed with circadian hyper-amplitude-tension. These data suggest that diabetic patients have certain variations in the circadian pattern of blood pressure and heart rate, which can result in disturbed vascular events, and thus are at greater risk of cardiovascular morbidity. Conclusion Seven-day/24-h monitoring might be useful as an early predictive tool in assessing future cardiovascular risk, guiding treatment and management of these patients. PMID:25422775

  17. Restructuring and redistribution of actinides in Am-MOX fuel during the first 24 h of irradiation

    NASA Astrophysics Data System (ADS)

    Tanaka, Kosuke; Miwa, Shuhei; Sekine, Shin-ichi; Yoshimochi, Hiroshi; Obayashi, Hiroshi; Koyama, Shin-ichi

    2013-09-01

    In order to confirm the effect of minor actinide additions on the irradiation behavior of MOX fuel pellets, 3 wt.% and 5 wt.% americium-containing MOX (Am-MOX) fuels were irradiated for 10 min at 43 kW/m and for 24 h at 45 kW/m in the experimental fast reactor Joyo. Two nominal values of the fuel pellet oxygen-to-metal ratio (O/M), 1.95 and 1.98, were used as a test parameter. Emphasis was placed on the behavior of restructuring and redistribution of actinides which directly affect the fuel performance and the fuel design for fast reactors. Microstructural evolutions in the fuels were observed by optical microscopy and the redistribution of constituent elements was determined by EPMA using false color X-ray mapping and quantitative point analyses. The ceramography results showed that structural changes occurred quickly in the initial stage of irradiation. Restructuring of the fuel from middle to upper axial positions developed and was almost completed after the 24-h irradiation. No sign of fuel melting was found in any of the specimens. The EPMA results revealed that Am as well as Pu migrated radially up the temperature gradient to the center of the fuel pellet. The increase in Am concentration on approaching the edge of the central void and its maximum value were higher than those of Pu after the 10-min irradiation and the difference was more pronounced after the 24-h irradiation. The increment of the Am and Pu concentrations due to redistribution increased with increasing central void size. In all of the specimens examined, the extent of redistribution of Am and Pu was higher in the fuel of O/M ratio of 1.98 than in that of 1.95.

  18. Novelty-induced conditioned place preference, sucrose preference, and elevated plus maze behavior in adult rats after repeated exposure to methylphenidate during the preweanling period.

    PubMed

    Crawford, Cynthia A; Der-Ghazarian, Taleen; Britt, Cynthia E; Varela, Fausto A; Kozanian, Olga O

    2013-06-01

    Early treatment with methylphenidate has a persistent effect on the affective (i.e., anxiety- and depressive-like) behaviors of adult rats and mice. Interestingly, age at methylphenidate exposure appears to be a critical determinant influencing the expression of affective behaviors. In the present study, we exposed rats to methylphenidate during the preweanling period (i.e., PD 11-PD 20) because this ontogenetic period is analogous to early childhood in humans (an age associated with increasing methylphenidate usage). Rats were injected with methylphenidate (0, 2, or 5mg/kg) from PD 11 to PD 20 and reactivity to rewarding and aversive stimuli were measured in early adulthood. Specifically, novelty-induced CPP, sucrose preference, and elevated plus maze behavior were assessed on PD 60. Early treatment with 2 or 5mg/kg methylphenidate increased total time spent in the white compartment of the CPP chamber. This methylphenidate-induced effect occurred regardless of exposure condition. Performance on the elevated plus maze was also impacted by early methylphenidate exposure, because rats treated with 5mg/kg methylphenidate spent more time in the closed compartment of the elevated plus maze than vehicle controls. Early methylphenidate exposure did not alter sucrose preference. These data indicate that exposing rats to methylphenidate during the preweanling period differentially affects anxiety-like behavior depending on the type of anxiety-provoking stimulus. Specifically, early methylphenidate exposure decreased aversion to a bright white room when measured on a novelty-induced CPP task, whereas methylphenidate caused a long-term increase in anxiety when measured on the elevated plus maze. PMID:23466690

  19. Four to seven random casual urine specimens are sufficient to estimate 24-h urinary sodium/potassium ratio in individuals with high blood pressure.

    PubMed

    Iwahori, T; Ueshima, H; Torii, S; Saito, Y; Fujiyoshi, A; Ohkubo, T; Miura, K

    2016-05-01

    This study was done to clarify the optimal number and type of casual urine specimens required to estimate urinary sodium/potassium (Na/K) ratio in individuals with high blood pressure. A total of 74 individuals with high blood pressure, 43 treated and 31 untreated, were recruited from the Japanese general population. Urinary sodium, potassium and Na/K ratio were measured in both casual urine samples and 7-day 24-h urine samples and then analyzed by correlation and Bland-Altman analyses. Mean Na/K ratio from random casual urine samples on four or more days strongly correlated with the Na/K ratio of 7-day 24-h urine (r=0.80-0.87), which was similar to the correlation between 1 and 2-day 24-h urine and 7-day 24-h urine (r=0.75-0.89). The agreement quality for Na/K ratio of seven random casual urine for estimating the Na/K ratio of 7-day 24-h urine was good (bias: -0.26, limits of agreements: -1.53-1.01), and it was similar to that of 2-day 24-h urine for estimating 7-day 24-h values (bias: 0.07, limits of agreement: -1.03 to 1.18). Stratified analyses comparing individuals using antihypertensive medication and individuals not using antihypertensive medication showed similar results. Correlations of the means of casual urine sodium or potassium concentrations with 7-day 24-h sodium or potassium excretions were relatively weaker than those for Na/K ratio. The mean Na/K ratio of 4-7 random casual urine specimens on different days provides a good substitute for 1-2-day 24-h urinary Na/K ratio for individuals with high blood pressure. PMID:26310187

  20. Parallel assessment of nutrition and activity in athletes: validation against doubly labelled water, 24-h urea excretion, and indirect calorimetry.

    PubMed

    Koehler, Karsten; Braun, Hans; De Marees, Markus; Fusch, Gerhard; Fusch, Christoph; Mester, Joachim; Schaenzer, Wilhelm

    2010-11-01

    The assessment of nutrition and activity in athletes requires accurate and precise methods. The aim of this study was to validate a protocol for parallel assessment of diet and exercise against doubly labelled water, 24-h urea excretion, and respiratory gas exchange. The participants were 14 male triathletes under normal training conditions. Energy intake and doubly labelled water were weakly associated with each other (r = 0.69, standard error of estimate [SEE] = 304 kcal x day(-1)). Protein intake was strongly correlated with 24-h urea (r = 0.89) but showed considerable individual variation (SEE = 0.34 g kg(-1) x day(-1)). Total energy expenditure based on recorded activities was highly correlated with doubly labelled water (r = 0.95, SEE = 195 kcal x day(-1)) but was proportionally biased. During running and cycling, estimated exercise energy expenditure was highly correlated with gas exchange (running: r = 0.89, SEE = 1.6 kcal x min(-1); cycling: r = 0.95, SEE = 1.4 kcal x min(-1)). High exercise energy expenditure was slightly underestimated during running. For nutrition data, variations appear too large for precise measurements in individual athletes, which is a common problem of dietary assessment methods. Despite the high correlations of total energy expenditure and exercise energy expenditure with reference methods, a correction for systematic errors is necessary for the valid estimation of energetic requirements in individual athletes. PMID:20967672

  1. Effect of Androctonus bicolor scorpion venom on serum electrolytes in rats: A 24-h time-course study.

    PubMed

    Al-Asmari, A; Khan, H A; Manthiri, R A

    2016-03-01

    Black fat-tailed scorpion (Androctonus bicolor) belongs to the family Buthidae and is one of the most venomous scorpions in the world. The effects of A. bicolor venom on serum electrolytes were not known and therefore investigated in this study. Adult male Wistar rats were randomly divided into seven groups with five animals in each group. One of the groups served as control and received vehicle only. The animals in the remaining groups received a single subcutaneous injection of crude A. bicolor venom (200 μg/kg bodyweight) and were killed at different time intervals including 30 min, 1 h, 2 h, 4 h, 8 h, and 24 h after venom injection. The results showed that scorpion venom caused significant increase in serum sodium levels within 30 min after injection which slightly subsided after 1 h and then persisted over 24 h. Serum potassium levels continued to significantly increase until 4 h and then slightly subsided. There were significant decreases in serum magnesium (Mg(+)) levels following scorpion venom injection, at all the time points during the course of study. Serum calcium levels were significantly increased during the entire course of study, whereas serum chloride was significantly decreased. In conclusion, A. bicolor envenomation in rats caused severe and persistent hypomagnesemia with accompanied hypernatremia, hyperkalemia, and hypercalcemia. It is important to measure serum Mg(+) levels in victims of scorpion envenomation, and patients with severe Mg(+) deficiency should be treated accordingly. PMID:25964378

  2. Microdialysis in the Rat Striatum: Effects of 24 h Dexamethasone Retrodialysis on Evoked Dopamine Release and Penetration Injury

    PubMed Central

    2015-01-01

    The power of microdialysis for in vivo neurochemical monitoring is a result of intense efforts to enhance microdialysis procedures, the probes themselves, and the analytical systems used for the analysis of dialysate samples. Our goal is to refine microdialysis further by focusing attention on what happens when the probes are implanted into brain tissue. It is broadly acknowledged that some tissue damage occurs, such that the tissue nearest the probes is disrupted from its normal state. We hypothesize that mitigating such disruption would refine microdialysis. Herein, we show that the addition of dexamethasone, an anti-inflammatory drug, to the perfusion fluid protects evoked dopamine responses as measured by fast-scan cyclic voltammetry next to the probes after 24 h. We also show that dexamethasone stabilizes evoked dopamine responses measured at the probe outlet over a 4–24 h postimplantation interval. The effects of dexamethasone are attributable to its anti-inflammatory actions, as dexamethasone had no significant effect on two histochemical markers for dopamine terminals, tyrosine hydroxylase and the dopamine transporter. Using histochemical assays, we confirmed that the actions of dexamethasone are tightly confined to the immediate, local vicinity of the probe. PMID:25491242

  3. Schottky barrier height of Ni/TiO2/4H-SiC metal-insulator-semiconductor diodes

    NASA Astrophysics Data System (ADS)

    Kaufmann, Ivan R.; Pereira, Marcelo B.; Boudinov, Henri I.

    2015-12-01

    Ni/TiO2/4H-SiC diodes were analysed through measurements of current-voltage curves varying the temperature. The Schottky Barrier Height (SBH) which increased with temperature was studied by simulation of the Thermionic Emission Model, considering Ni/SiC Schottky structures with an insulator layer between the metal and semiconductor. This model shows that a new method of calculation should be applied to diodes that have a metal-insulator-semiconductor structure. Misleading results for SBH are obtained if the thin insulator layer is not considered. When applying the suggested method to the Ni/TiO2/4H-SiC diodes it was necessary to consider not only the deposited TiO2 layer, but also a second dielectric layer of native SiCxOy at the surface of SiC. By measuring I-V-T curves for two samples with different thicknesses of TiO2, the suggested method allows one to estimate the thicknesses of both dielectric layers: TiO2 and SiOxCy.

  4. The classification of oesophageal 24 h pH measurements using a Kohonen self-organizing feature map.

    PubMed

    Haylett, K R; Vales, P; McCloy, R F

    2004-06-01

    Analysis of 24 h oesophageal pH studies can be problematic with many patients asymptomatic during the investigation, despite observations of reflux. The aim of this study was to carry out a cluster analysis of ambulatory pH studies to determine any underlying patterns and classes within the data. The results of 900 24 h pH studies were investigated using the Kohonen self-organizing feature map (SOFM), a neural network that can be used to identify clusters within multidimensional data. The clinical features were presented to the network and the main classes identified. The SOFM-based analysis showed that patients clinically assessed as having symptomatic reflux during the study could be described by four major classifications. The results also showed that the probability of identifying a correlation between symptoms and reflux during an investigation varies from 0.49 to 0.78 for the classes identified. The developed network may be a useful tool in the classification of pH data. The cluster-based technique may offer an alternative to standard statistical techniques for high-dimensional gastrointestinal data and form the basis of an expert system for the automated analysis of pH data. PMID:15253122

  5. Temporally chimeric mice reveal flexibility of circadian period-setting in the suprachiasmatic nucleus

    PubMed Central

    Smyllie, Nicola J.; Chesham, Johanna E.; Hamnett, Ryan; Maywood, Elizabeth S.; Hastings, Michael H.

    2016-01-01

    The suprachiasmatic nucleus (SCN) is the master circadian clock controlling daily behavior in mammals. It consists of a heterogeneous network of neurons, in which cell-autonomous molecular feedback loops determine the period and amplitude of circadian oscillations of individual cells. In contrast, circuit-level properties of coherence, synchrony, and ensemble period are determined by intercellular signals and are embodied in a circadian wave of gene expression that progresses daily across the SCN. How cell-autonomous and circuit-level mechanisms interact in timekeeping is poorly understood. To explore this interaction, we used intersectional genetics to create temporally chimeric mice with SCN containing dopamine 1a receptor (Drd1a) cells with an intrinsic period of 24 h alongside non-Drd1a cells with 20-h clocks. Recording of circadian behavior in vivo alongside cellular molecular pacemaking in SCN slices in vitro demonstrated that such chimeric circuits form robust and resilient circadian clocks. It also showed that the computation of ensemble period is nonlinear. Moreover, the chimeric circuit sustained a wave of gene expression comparable to that of nonchimeric SCN, demonstrating that this circuit-level property is independent of differences in cell-intrinsic periods. The relative dominance of 24-h Drd1a and 20-h non-Drd1a neurons in setting ensemble period could be switched by exposure to resonant or nonresonant 24-h or 20-h lighting cycles. The chimeric circuit therefore reveals unanticipated principles of circuit-level operation underlying the emergent plasticity, resilience, and robustness of the SCN clock. The spontaneous and light-driven flexibility of period observed in chimeric mice provides a new perspective on the concept of SCN pacemaker cells. PMID:26966234

  6. Temporally chimeric mice reveal flexibility of circadian period-setting in the suprachiasmatic nucleus.

    PubMed

    Smyllie, Nicola J; Chesham, Johanna E; Hamnett, Ryan; Maywood, Elizabeth S; Hastings, Michael H

    2016-03-29

    The suprachiasmatic nucleus (SCN) is the master circadian clock controlling daily behavior in mammals. It consists of a heterogeneous network of neurons, in which cell-autonomous molecular feedback loops determine the period and amplitude of circadian oscillations of individual cells. In contrast, circuit-level properties of coherence, synchrony, and ensemble period are determined by intercellular signals and are embodied in a circadian wave of gene expression that progresses daily across the SCN. How cell-autonomous and circuit-level mechanisms interact in timekeeping is poorly understood. To explore this interaction, we used intersectional genetics to create temporally chimeric mice with SCN containing dopamine 1a receptor (Drd1a) cells with an intrinsic period of 24 h alongside non-Drd1a cells with 20-h clocks. Recording of circadian behavior in vivo alongside cellular molecular pacemaking in SCN slices in vitro demonstrated that such chimeric circuits form robust and resilient circadian clocks. It also showed that the computation of ensemble period is nonlinear. Moreover, the chimeric circuit sustained a wave of gene expression comparable to that of nonchimeric SCN, demonstrating that this circuit-level property is independent of differences in cell-intrinsic periods. The relative dominance of 24-h Drd1a and 20-h non-Drd1a neurons in setting ensemble period could be switched by exposure to resonant or nonresonant 24-h or 20-h lighting cycles. The chimeric circuit therefore reveals unanticipated principles of circuit-level operation underlying the emergent plasticity, resilience, and robustness of the SCN clock. The spontaneous and light-driven flexibility of period observed in chimeric mice provides a new perspective on the concept of SCN pacemaker cells. PMID:26966234

  7. Antigen exposure in the late light period induces severe symptoms of food allergy in an OVA-allergic mouse model

    PubMed Central

    Tanabe, Kana; Kitagawa, Eri; Wada, Misaki; Haraguchi, Atsushi; Orihara, Kanami; Tahara, Yu; Nakao, Atsuhito; Shibata, Shigenobu

    2015-01-01

    The mammalian circadian clock controls many physiological processes that include immune responses and allergic reactions. Several studies have investigated the circadian regulation of intestinal permeability and tight junctions known to be affected by cytokines. However, the contribution of circadian clock to food allergy symptoms remains unclear. Therefore, we investigated the role of the circadian clock in determining the severity of food allergies. We prepared an ovalbumin food allergy mouse model, and orally administered ovalbumin either late in the light or late in the dark period under light-dark cycle. The light period group showed higher allergic diarrhea and weight loss than the dark period group. The production of type 2 cytokines, IL-13 and IL-5, from the mesenteric lymph nodes and ovalbumin absorption was higher in the light period group than in the dark period group. Compared to the dark period group, the mRNA expression levels of the tight junction proteins were lower in the light period group. We have demonstrated that increased production of type 2 cytokines and intestinal permeability in the light period induced severe food allergy symptoms. Our results suggest that the time of food antigen intake might affect the determination of the severity of food allergy symptoms. PMID:26419283

  8. Exposure to altered gravity during specific developmental periods differentially affects growth, development, the cerebellum and motor functions in male and female rats

    NASA Astrophysics Data System (ADS)

    Nguon, K.; Ladd, B.; Sajdel-Sulkowska, E. M.

    2006-01-01

    We previously reported that perinatal exposure to hypergravity affects cerebellar structure and motor coordination in rat neonates. In the present study, we explored the hypothesis that neonatal cerebellar structure and motor coordination may be particularly vulnerable to the effects of hypergravity during specific developmental stages. To test this hypothesis, we compared neurodevelopment, motor behavior and cerebellar structure in rat neonates exposed to 1.65 G on a 24-ft centrifuge during discrete periods of time: the 2nd week of pregnancy [gestational day (G) 8 through G15; group A], the 3rd week of pregnancy (G15 through birth on G22/G23; group B), the 1st week of nursing [birth through postnatal day (P) 6; group C], the 2nd and 3rd weeks of nursing (P6 through P21; group D), the combined 2nd and 3rd weeks of pregnancy and nursing (G8 through P21; group E) and stationary control (SC) neonates (group F). Prenatal exposure to hypergravity resulted in intrauterine growth retardation as reflected by a decrease in the number of pups in a litter and lower average mass at birth. Exposure to hypergravity immediately after birth impaired the righting response on P3, while the startle response in both males and females was most affected by exposure during the 2nd and 3rd weeks after birth. Hypergravity exposure also impaired motor functions, as evidenced by poorer performance on a rotarod; while both males and females exposed to hypergravity during the 2nd and 3rd weeks after birth performed poorly on P21, male neonates were most dramatically affected by exposure to hypergravity during the second week of gestation, when the duration of their recorded stay on the rotarod was one half that of SC males. Cerebellar mass was most reduced by later postnatal exposure. Thus, for the developing rat cerebellum, the postnatal period that overlaps the brain growth spurt is the most vulnerable to hypergravity. However, male motor behavior is also affected by midpregnancy exposure to

  9. Long-term learning deficits and changes in unlearned behaviors following in utero exposure to multiple daily doses of cocaine during different exposure periods and maternal plasma cocaine concentrations.

    PubMed

    Vorhees, C V; Reed, T M; Acuff-Smith, K D; Schilling, M A; Cappon, G D; Fisher, J E; Pu, C

    1995-01-01

    Although the possible behavioral neurotoxic effects of in utero exposure to cocaine have been the subject of numerous experiments, only a limited number of different types of animal models of cocaine exposure, critical periods, or long-term effects of such exposures have been investigated. In the present experiment, the effects of multiple daily SC exposures to cocaine (20 mg/kg/dose x 5 doses per day) were investigated when administered to gravid Sprague-Dawley CD rats on embryonic days E7-12 or E13-18 compared to weight-matched, vehicle injected, pair-fed controls. Effects of exposure were assessed on general development, olfactory orientation behavior, early locomotion, startle reactivity, spontaneous motor activity, and learning on two different tasks (Morris and Cincinnati water mazes). The multiple cocaine dosing regimen produced maternal peak serum concentrations of cocaine 3 times higher than that of a single dose (approximately 1550 vs. approximately 550 ng/mL). Early-exposed cocaine offspring had lower olfactory orientation scores and reduced postweaning rearing and hole-poke motor activity, whereas late-exposed cocaine offspring had increased postweaning locomotor, rearing, and hole-poke activity. On the Morris hidden platform maze, the cocaine early-exposed females had longer latencies on acquisition than controls. On the Cincinnati multiple-T water maze, the early-exposed cocaine females and the late-exposed cocaine males had increased errors, whereas the early-exposed cocaine males had reduced errors. The effects on measures of learning, when taken together, and in light of their being in the early-exposed group, suggest that embryonic cocaine exposure may have subtle effects on cognition in the offspring as adults. Such effects represent a form of neurotoxicity not previously associated with prenatal cocaine exposure. PMID:7623735

  10. Personal power-frequency magnetic field exposure in women recruited at an infertility clinic: association with physical activity and temporal variability.

    PubMed

    Lewis, Ryan C; Hauser, Russ; Wang, Lu; Kavet, Robert; Meeker, John D

    2016-03-01

    Current epidemiologic approaches for studying exposure to power-frequency magnetic fields and the risk of miscarriage are potentially biased due to lack of attention to the relationship of exposure with physical activity and within-individual variability in exposures over time. This analysis examines these two issues using data from a longitudinal pilot study of 40 women recruited from an infertility clinic that contributed data for up to three 24-h periods separated by a median of 3.6 weeks. Physical activity was positively associated with peak exposure metrics. Higher physical activity within environments did not necessarily lead to higher peak exposures, suggesting that movement between and not within environments increases one's probability of encountering a high field source. Peak compared with central tendency metrics were more variable over time. Future epidemiology studies associated with peak exposure metrics should adjust for physical activity and collect more than 1 d of exposure measurement to reduce bias. PMID:26152565

  11. Short-term exposure to noise, fine particulate matter and nitrogen oxides on ambulatory blood pressure: A repeated-measure study.

    PubMed

    Chang, Li-Te; Chuang, Kai-Jen; Yang, Wei-Ting; Wang, Ven-Shing; Chuang, Hsiao-Chi; Bao, Bo-Ying; Liu, Chiu-Shong; Chang, Ta-Yuan

    2015-07-01

    Exposure to road traffic noise, fine particulate matter (aerodynamic diameter ≤2.5 μm; PM2.5) and nitrogen oxides (NOx) has been associated with transient changes in blood pressure, but whether an interaction exists remains unclear. This panel study investigated whether noise, PM2.5 and NOx exposure were independently associated with changes in 24-h ambulatory blood pressure. We recruited 33 males and 33 females aged 18-32 years as study subjects. Personal noise exposure and ambulatory blood pressure were monitored simultaneously in 2007. During the data collection periods, 24-h data on PM2.5 and NOx from five air-quality monitors within 6 km of participants' home addresses were used to estimate their individual exposures. Linear mixed-effects regression models were used to estimate single and combined effects on ambulatory blood pressure. Exposure to both noise and PM2.5 was significantly associated with increased systolic blood pressure (SBP) and diastolic blood pressure (DBP) over 24h; NOx exposure was only significantly related to elevated DBP. Twenty-four-hour ambulatory blood pressure increased with the current noise exposure of 5 A-weighted decibels (dBA) (SBP 1.44 [95% confidence interval: 1.16, 1.71] mmHg and DBP 1.40 [1.18, 1.61] mmHg) and PM2.5 exposure of 10-µg/m(3) (SBP 0.81 [0.19, 1.43] mmHg and DBP 0.63 [0.17, 1.10] mmHg), as well as the current NOx exposure of 10-ppb (DBP 0.54 [0.12, 0.97] mmHg) after simultaneous adjustment. These findings suggest that exposure to noise and air pollutants may independently increase ambulatory blood pressure and the risk of cardiovascular diseases. PMID:26073201

  12. Boron uptake in tumors, cerebrum and blood from (/sup 10/B)Na/sub 4/B/sub 24/H/sub 22/S/sub 2/

    DOEpatents

    Slatkin, D.N.; Micca, P.L.; Fairchild, R.G.

    1986-03-11

    A stable boronated (/sup 10/B-labeled) compound, sodium mercaptoundecahydrododecaborate is infused in the form of the disulfide dimer, (/sup 10/B)Na/sub 4/B/sub 24/H/sub 22/S/sub 2/, at a dose of about 200 ..mu..g /sup 10/B per gm body weight. The infusion is preformed into the blood or peritoneal cavity of the patient slowly over a period of many days, perhaps one week or more, at the rate of roughly 1 ..mu..g /sup 10/B per gm body weight per hour. Use of this particular boronated dimer in the manner or similarly to the manner so described permits radiotherapeutically effective amounts of boron to accumulate in tumors to be treated by boron neutron capture radiation therapy and also permits sufficient retention of boron in tumor after the cessation of the slow infusion, so as to allow the blood concentration of /sup 10/B to drop or to be reduced artificially to a radiotherapeutically effective level, less than one-half of the concentration of /sup 10/B in the tumor. 1 tab.

  13. Modelling personal exposure to particulate air pollution: an assessment of time-integrated activity modelling, Monte Carlo simulation & artificial neural network approaches.

    PubMed

    McCreddin, A; Alam, M S; McNabola, A

    2015-01-01

    An experimental assessment of personal exposure to PM10 in 59 office workers was carried out in Dublin, Ireland. 255 samples of 24-h personal exposure were collected in real time over a 28 month period. A series of modelling techniques were subsequently assessed for their ability to predict 24-h personal exposure to PM10. Artificial neural network modelling, Monte Carlo simulation and time-activity based models were developed and compared. The results of the investigation showed that using the Monte Carlo technique to randomly select concentrations from statistical distributions of exposure concentrations in typical microenvironments encountered by office workers produced the most accurate results, based on 3 statistical measures of model performance. The Monte Carlo simulation technique was also shown to have the greatest potential utility over the other techniques, in terms of predicting personal exposure without the need for further monitoring data. Over the 28 month period only a very weak correlation was found between background air quality and personal exposure measurements, highlighting the need for accurate models of personal exposure in epidemiological studies. PMID:25260856

  14. Hippuric acid in 24 h urine collections as a biomarker of fruits and vegetables intake in kidney stone formers.

    PubMed

    Guerra, Angela; Folesani, Giuseppina; Mena, Pedro; Ticinesi, Andrea; Allegri, Franca; Nouvenne, Antonio; Pinelli, Silvana; Del Rio, Daniele; Borghi, Loris; Meschi, Tiziana

    2014-12-01

    This work aimed to underline the prospects of hippuric acid, a product of the metabolism of polyphenols, as a new biomarker of fruits and vegetables intake associated with lithogenic risk. Biochemical parameters of lithogenic risk and hippuric acid were measured in the 24 h urine collections of a cohort of 696 Italian kidney stone formers divided into two subgroups according to their different dietary habits. The link between lithogenic risk parameters and hippuric acid was assessed and this compound was revealed as a valuable biomarker of fruits and vegetables intake in kidney stone formers. A cut-off value of urinary excretion of hippuric acid, 300 mg/24 h, was set as the threshold of discrimination between low and high intake of fruits and vegetables for these patients. These results highlight the importance of monitoring of the excretion hippuric acid in urine to address proper dietary guidelines for the management of stone former patients. PMID:25198158

  15. Nintendo® Wii Fit based sleepiness tester detects impairment of postural steadiness due to 24 h of wakefulness.

    PubMed

    Tietäväinen, Aino; Gates, Fred K; Meriläinen, Antti; Mandel, Jeff E; Hæggström, Edward

    2013-12-01

    A field-usable sleepiness tester could reduce sleepiness related accidents. 15 subjects' postural steadiness was measured with a Nintendo(®) Wii Fit balance board every hour for 24 h. Body sway was quantified with complexity index, CI, and the correlation between CI and alertness predicted by a three-process model of sleepiness was calculated. The CI group average was 8.9 ± 1.3 for alert and 7.9 ± 1.4 for sleep deprived subjects (p < 0.001, ρ = 0.94). The Wii Fit board detects the impairment of postural steadiness. This may allow large scale sleepiness testing outside the laboratory setting. PMID:24054980

  16. A Mobile Phone Based Method to Assess Energy and Food Intake in Young Children: A Validation Study against the Doubly Labelled Water Method and 24 h Dietary Recalls.

    PubMed

    Delisle Nyström, Christine; Forsum, Elisabet; Henriksson, Hanna; Trolle-Lagerros, Ylva; Larsson, Christel; Maddison, Ralph; Timpka, Toomas; Löf, Marie

    2016-01-01

    Mobile phones are becoming important instruments for assessing diet and energy intake. We developed the Tool for Energy Balance in Children (TECH), which uses a mobile phone to assess energy and food intake in pre-school children. The aims of this study were: (a) to compare energy intake (EI) using TECH with total energy expenditure (TEE) measured via doubly labelled water (DLW); and (b) to compare intakes of fruits, vegetables, fruit juice, sweetened beverages, candy, ice cream, and bakery products using TECH with intakes acquired by 24 h dietary recalls. Participants were 39 healthy, Swedish children (5.5 ± 0.5 years) within the ongoing Mobile-based Intervention Intended to Stop Obesity in Preschoolers (MINISTOP) obesity prevention trial. Energy and food intakes were assessed during four days using TECH and 24 h telephone dietary recalls. Mean EI (TECH) was not statistically different from TEE (DLW) (5820 ± 820 kJ/24 h and 6040 ± 680 kJ/24 h, respectively). No significant differences in the average food intakes using TECH and 24 h dietary recalls were found. All food intakes were correlated between TECH and the 24 h dietary recalls (ρ = 0.665-0.896, p < 0.001). In conclusion, TECH accurately estimated the average intakes of energy and selected foods and thus has the potential to be a useful tool for dietary studies in pre-school children, for example obesity prevention trials. PMID:26784226

  17. A Mobile Phone Based Method to Assess Energy and Food Intake in Young Children: A Validation Study against the Doubly Labelled Water Method and 24 h Dietary Recalls

    PubMed Central

    Delisle Nyström, Christine; Forsum, Elisabet; Henriksson, Hanna; Trolle-Lagerros, Ylva; Larsson, Christel; Maddison, Ralph; Timpka, Toomas; Löf, Marie

    2016-01-01

    Mobile phones are becoming important instruments for assessing diet and energy intake. We developed the Tool for Energy Balance in Children (TECH), which uses a mobile phone to assess energy and food intake in pre-school children. The aims of this study were: (a) to compare energy intake (EI) using TECH with total energy expenditure (TEE) measured via doubly labelled water (DLW); and (b) to compare intakes of fruits, vegetables, fruit juice, sweetened beverages, candy, ice cream, and bakery products using TECH with intakes acquired by 24 h dietary recalls. Participants were 39 healthy, Swedish children (5.5 ± 0.5 years) within the ongoing Mobile-based Intervention Intended to Stop Obesity in Preschoolers (MINISTOP) obesity prevention trial. Energy and food intakes were assessed during four days using TECH and 24 h telephone dietary recalls. Mean EI (TECH) was not statistically different from TEE (DLW) (5820 ± 820 kJ/24 h and 6040 ± 680kJ/24 h, respectively). No significant differences in the average food intakes using TECH and 24 h dietary recalls were found. All food intakes were correlated between TECH and the 24 h dietary recalls (ρ = 0.665–0.896, p < 0.001). In conclusion, TECH accurately estimated the average intakes of energy and selected foods and thus has the potential to be a useful tool for dietary studies in pre-school children, for example obesity prevention trials. PMID:26784226

  18. U.S. Gulf War Veterans: service periods in theater, differential exposures, and persistent unexplained illness. Portland Environmental Hazards Research Centre.

    PubMed

    Spencer, P S; McCauley, L A; Joos, S K; Lasarev, M R; Schuell, T; Bourdette, D; Barkhuizen, A; Johnston, W; Storzbach, D; Wynn, M; Grewenow, R

    1998-12-28

    Approximately 80,000 of the 697,000 American men and women who were stationed in SW Asia during the Gulf War (GW) report unexplained illness consisting of symptoms of persistent fatigue, cognitive difficulties, such as mild memory loss, diffuse muscle and joint pain, gastrointestinal symptoms, skin lesions, and respiratory problems, among others. Associations between major symptom groups and periods of deployment in the theater of operations have been sought in a population-based, clinical case-control study of GW veterans resident in the north-western region of the United States. No statistically significant differences were evident in the proportion of cases with unexplained fatigue, cognitive/psychological or musculoskeletal symptoms among veterans present in SW Asia in 3 specific time periods: (a) 8/1/1990-12/31/1990 (which includes Desert Shield), (b) the period surrounding Desert Storm (1/1/1991-3/31/1991), and (c) the (post-combat) period immediately following hostilities (4/1/1991-7/31/1991). There was a trend for all 3 case symptoms to be more common among GW veterans who served in the post-combat period. As numbers in these deployment groups were small, and power to detect differences low, the apparent absence of significant differences in the frequency of major symptom groups among these veterans requires confirmation in a larger study. Deployment for discrete periods in SW Asia is a method to separate distinct constellations of environmental factors; these are useful for analyses of associations among symptoms and exposures given the near-total absence of objective data on chemical and other possible exposures in the theater of operations. PMID:10022305

  19. Differential mRNA expression of neuroimmune markers in the hippocampus of infant mice following toluene exposure during brain developmental period.

    PubMed

    Win-Shwe, Tin-Tin; Kunugita, Naoki; Yoshida, Yasuhiro; Nakajima, Daisuke; Tsukahara, Shinji; Fujimaki, Hidekazu

    2012-02-01

    Toluene, a volatile organic compound with a wide range of industrial applications, can exert neurotoxic and immunotoxic effects. However, the effects of toluene exposure on developmental immunotoxicity in the brain have not yet been characterized. To investigate the susceptible window to toluene exposure during development and the effects of fetal and neonatal toluene exposure on the neuroimmune markers, gestational day (GD) 14 pregnant mice, postnatal day (PND) 2 and PND 8 male offspring were exposed to filtered air (control; 0 ppm), or 5 or 50 ppm toluene for 6 h per day for five consecutive days. The neuroimmune markers in the hippocampus of PND 21 were examined using a real-time RT-PCR and immunohistochemical analysis. Mice exposed to 50 ppm toluene on PND 2-6 showed significantly increased levels of nerve growth factor (NGF) and tumor necrosis factor (TNF)-α mRNAs. In contrast, NGF and brain-derived neurotrophic factor (BDNF) and proinflammatory cytokines TNF-α, CCL3, NF-κB, toll-like receptor (TLR)-4, astrocyte marker glial fibrillary acidic protein (GFAP), and microglia marker ionized calcium binding adapter molecule (Iba)-1 mRNAs were increased significantly in mice exposed to 5 ppm toluene on PND 8-12. These results indicate that low-level toluene exposure during the late postnatal period (PND 8-12) might induce neuroinflammatory mediators via TLR4-dependent NF-κB pathway in the hippocampus of PND 21 male mice. Among the three developmental phases, PND 8-12 seems to be most sensitive to toluene exposure. This is the first study to show developmental phase- and dose-specific changes in neuroimmune markers in infant mice following toluene exposure. PMID:21381054

  20. Exposure to hypergravity during specific developmental periods differentially affects metabolism and vestibular reactions in adult C57BL /6j mice.

    PubMed

    Bojados, Mickael; Jamon, Marc

    2011-12-01

    The development of the posturo-motor control of movement is conditioned by Earth's gravity. Missing or altered gravity during the critical periods of development delays development and induces durable changes in the vestibular, cerebellar, or muscular structures, but these are not consistently mirrored at a functional level. The differences in the time schedule of vestibular and motor development could contribute to this inconstancy. To investigate the influence of gravity on the development of vestibular and locomotor functions, we analysed the performance of adult mice subjected to hypergravity during the time covering either the vestibular or locomotor development. The mice were centrifuged at 2 g from embryonic day (E) 0 to postnatal day (P) 10 (PRE), from P10 to P30 (POST), from E0 to P30 (FULL), and from E7 to P21. Their muscular force, anxiety level, vestibular reactions, and aerobic capacity during treadmill training were then evaluated at the age of 2 and 6 months. The performance of young adults varied in relation to the period of exposure to hypergravity. The mice that acquired locomotion in hypergravity (POST and FULL) showed a lower forelimb force and delayed vestibular reactions. The mice centrifuged from conception to P10 (PRE) showed a higher aerobic capacity during treadmill training. The differences in muscular force and vestibular reactions regressed with age, but the metabolic changes persisted. These results confirmed that early exposure to hypergravity induces qualitative changes depending on the period of exposure. They validated, at a functional level, the existence of several critical periods for adaptation to gravity. PMID:22122506

  1. 24-h fluid kinetics and perception of sweat losses following a 1-h run in a temperate environment.

    PubMed

    O'Neal, Eric K; Caufield, Christina R; Lowe, Jordan B; Stevenson, Mary C; Davis, Brett A; Thigpen, Lauren K

    2014-01-01

    This study examined 24-h post-run hydration status and sweat loss estimation accuracy in college age runners (men=12, women=8) after completing a 1-h self-paced outdoor run (wet bulb globe temperature=19.9±3.0 °C). Sweat losses (1353±422 mL; 1.9%±0.5% of body mass) were significantly greater (p<0.001) than perceived losses (686±586 mL). Cumulative fluid consumption equaled 3876±1133 mL (218±178 mL during) with 37% of fluid ingested lost through urine voids (1450±678 mL). Fluid balance based on intake and urine production equaled +554±669 mL at 12 h and +1186±735 mL at 24 h. Most runners reported euhydrated (pre-run urine specific gravity (USG)=1.018±0.008) with no changes (p=0.33) at hours 12 or 24 when both genders were included. However, USG was higher (p=0.004) at 12 h post-run for men (1.025±0.0070 vs. 1.014±0.007), who consumed 171%±40% of sweat losses at 12 h vs. 268%±88% for women. Most runners do not need intervention concerning between bout hydration needs in temperate environments. However, repeated USG measurements were able to identify runners who greatly under or over consumed fluid during recovery. Practitioners can use multiple USG assessments as cheap method to detect runners who need to modify their hydration strategies and should promote assessment of sweat losses by change in body mass, as runners had poor perception of sweat losses. PMID:24451307

  2. The 24-h recall instrument for home nursing to measure the activity profile of home nurses: development and psychometric testing.

    PubMed

    De Vliegher, Kristel; Aertgeerts, Bert; Declercq, Anja; Gosset, Christiane; Heyden, Isabelle; Van Geert, Michel; Moons, Philip

    2015-01-01

    Home health care today is challenged by a shift from an acute to a chronic health-care model, moving the focus of care from the hospital to home-care setting. This increased focus on care at home emphasizes the need for an efficient, effective, and transparent management of home health care. However, it is not precisely known what home-care nurses do; what kind of care is received by patients; what the performance of home nurses is; and what the impact of the increasing need for home nursing is on the current and future role of home nurses. In this respect, it is necessary to gain a clear insight into the activity profile of home nurses, but there is no gold standard to measure their activities. This study reports on the development and psychometric testing of the '24-hour recall instrument for home nursing' to measure the activity profile of home nurses. Five home nurses in Belgium, simultaneously with the researcher, registered the performed activities in a total of 69 patients, using the 24-h recall instrument for home nursing. The validity and the interrater reliability of this instrument were high: the proportions that observed agreement were very high; the strength of kappa agreement was substantial to almost perfect; the prevalence index showed great variety; and the bias index was low. The findings in this study support the validity evidence based on test content and the interrater reliability of the 24-h recall instrument. This instrument can help to shape practice and policy by making the home nursing profession more transparent: a clear insight into the kind of care that is provided by home nurses and is received by the patients in primary care contributes to the development of a clear definition of the role of home nurses in health care. PMID:24479985

  3. Intracranial Pressure Elevation 24 h after Ischemic Stroke in Aged Rats Is Prevented by Early, Short Hypothermia Treatment

    PubMed Central

    Murtha, Lucy A.; Beard, Daniel J.; Bourke, Julia T.; Pepperall, Debbie; McLeod, Damian D.; Spratt, Neil J.

    2016-01-01

    Stroke is predominantly a senescent disease, yet most preclinical studies investigate treatment in young animals. We recently demonstrated that short-duration hypothermia-treatment completely prevented the dramatic intracranial pressure (ICP) rise seen post-stroke in young rats. Here, our aim was to investigate whether a similar ICP rise occurs in aged rats and to determine whether short-duration hypothermia is an effective treatment in aged animals. Experimental middle cerebral artery occlusion (MCAo-3 h occlusion) was performed on male Wistar rats aged 19–20 months. At 1 h after stroke-onset, rats were randomized to 2.5 h hypothermia-treatment (32.5°C) or normothermia (37°C). ICP was monitored at baseline, for 3.5 h post-occlusion, and at 24 h post-stroke. Infarct and edema volumes were calculated from histology. Baseline pre-stroke ICP was 11.2 ± 3.3 mmHg across all animals. Twenty-four hours post-stroke, ICP was significantly higher in normothermic animals compared to hypothermia-treated animals (27.4 ± 18.2 mmHg vs. 8.0 ± 5.0 mmHg, p = 0.03). Infarct and edema volumes were not significantly different between groups. These data demonstrate ICP may also increase 24 h post-stroke in aged rats, and that short-duration hypothermia treatment has a profound and sustained preventative effect. These findings may have important implications for the use of hypothermia in clinical trials of aged stroke patients. PMID:27303291

  4. 24-h urinary sodium excretion is associated with obesity in a cross-sectional sample of Australian schoolchildren.

    PubMed

    Grimes, Carley A; Riddell, Lynn J; Campbell, Karen J; He, Feng J; Nowson, Caryl A

    2016-03-28

    Emerging evidence indicates that dietary Na may be linked to obesity; however it is unclear whether this relationship is independent of energy intake (EI). The aim of this study was to assess the association between Na intake and measures of adiposity, including BMI z score, weight category and waist:height ratio (WHtR), in a sample of Australian schoolchildren. This was a cross-sectional study of schoolchildren aged 4-12 years. Na intake was assessed via one 24-h urine collection. BMI was converted to age- and sex-specific z scores, and WHtR was used to define abdominal obesity. In children aged ≥8 years, EI was determined via one 24-h dietary recall. Of the 666 children with valid urine samples 55 % were male (average age 9·3 (sd 1·8) years). In adjusted models an additional 17 mmol/d of Na was associated with a 0·10 higher BMI z score (95 % CI 0·07, 0·13), a 23 % (OR 1·23; 95 % CI 1·16, 1·31) greater risk of being overweight/obese and a 15 % (OR 1·15; 95 % CI 1·09, 1·23) greater risk of being centrally obese. In the subsample of 8-12-year-old children (n 458), adjustment for EI did not markedly alter the associations between Na and adiposity outcomes. Using a robust measure of daily Na intake we found a positive association between Na intake and obesity risk in Australian schoolchildren, which could not be explained by total energy consumption. To determine whether this is a causal relationship, longitudinal studies, with high-quality measures of Na and EI, are required. PMID:26810972

  5. 24-h Fluid Kinetics and Perception of Sweat Losses Following a 1-h Run in a Temperate Environment

    PubMed Central

    O’Neal, Eric K.; Caufield, Christina R.; Lowe, Jordan B.; Stevenson, Mary C.; Davis, Brett A.; Thigpen, Lauren K.

    2013-01-01

    This study examined 24-h post-run hydration status and sweat loss estimation accuracy in college age runners (men = 12, women = 8) after completing a 1-h self-paced outdoor run (wet bulb globe temperature = 19.9 ± 3.0 °C). Sweat losses (1353 ± 422 mL; 1.9% ± 0.5% of body mass) were significantly greater (p < 0.001) than perceived losses (686 ± 586 mL). Cumulative fluid consumption equaled 3876 ± 1133 mL (218 ± 178 mL during) with 37% of fluid ingested lost through urine voids (1450 ± 678 mL). Fluid balance based on intake and urine production equaled +554 ± 669 mL at 12 h and +1186 ± 735 mL at 24 h. Most runners reported euhydrated (pre-run urine specific gravity (USG) = 1.018 ± 0.008) with no changes (p = 0.33) at hours 12 or 24 when both genders were included. However, USG was higher (p = 0.004) at 12 h post-run for men (1.025 ± 0.0070 vs. 1.014 ± 0.007), who consumed 171% ± 40% of sweat losses at 12 h vs. 268% ± 88% for women. Most runners do not need intervention concerning between bout hydration needs in temperate environments. However, repeated USG measurements were able to identify runners who greatly under or over consumed fluid during recovery. Practitioners can use multiple USG assessments as cheap method to detect runners who need to modify their hydration strategies and should promote assessment of sweat losses by change in body mass, as runners had poor perception of sweat losses. PMID:24451307

  6. Genistein Exposure During the Early Postnatal Period Favors the Development of Obesity in Female, But Not Male Rats

    PubMed Central

    Helferich, William G.

    2014-01-01

    Genistein (Gen), the primary isoflavone in soy, has been shown to adversely affect various endocrine-mediated endpoints in rodents and humans. Soy formula intake by human infants has been associated with early age at menarche and decreased female-typical behavior in girls. Adipose deposition and expansion are also hormonally regulated and Gen has been shown to alter these processes. However, little is known about the impact of early-life soy intake on metabolic homeostasis in adulthood. The current study examined the impact of early-life Gen exposure on adulthood body composition (by magnetic resonance imaging) and the molecular signals mediating adipose expansion. From postnatal day (PND) 1 to 22, rat pups were daily orally dosed with 50mg/kg Gen to mimic blood Gen levels in human infants fed soy formula. Female but not male Gen-exposed rats had increased fat/lean mass ratio, fat mass, adipocyte size and number, and decreased muscle fiber perimeter. PND22 Gen-exposed females, but not males, had increased expression of adipogenic factors, including CCAAT/enhancer binding protein alpha (Cebpα), CCAAT/enhancer binding protein beta (Cebpβ), and peroxisome proliferator-activated receptor gamma (Pparγ). Furthermore, Wingless-related MMTV integration site 10b (Wnt10b), a critical regulator of adipogenic cell fate determination, was hypermethylated and had decreased expression in adipose of PND22 Gen-exposed females. These data suggest that developmental Gen exposure in rats has gender-specific effects on adiposity that closely parallel the effects of a postweaning high-fat diet and underscore the importance of considering timing of exposure and gender when establishing safety recommendations for early-life dietary Gen intake. PMID:24361872

  7. Holter monitor (24h)

    MedlinePlus

    ... be firmly attached to the chest so the machine gets an accurate recording of the heart's activity. While wearing the device, avoid: Electric blankets High-voltage areas Magnets Metal detectors Continue ...

  8. Holter monitor (24h)

    MedlinePlus

    ... heart medicine It may be used to diagnose: Atrial fibrillation or flutter Multifocal atrial tachycardia Palpitations Paroxysmal supraventricular ... Saunders Elsevier; 2011:chap 62. Read More Arrhythmias Atrial fibrillation or flutter Chest pain Electrocardiogram Fainting Heart attack ...

  9. Reduction in semen quality after mixed exposure to bisphenol A and isobutylparaben in utero and during lactation periods.

    PubMed

    Yang, Yun-Jung; Hong, Yeon-Pyo; Chae, Soo Ahn

    2016-08-01

    This study was performed to determine the effect of low-level exposure to a mixture of bisphenol A (BPA) and isobutylparaben (IBP) on male reproduction. Corn oil, BPA (0.05 mg/kg/day), IBP (2.5 mg/kg/day), and a BPA/IBP mixture (BPA 0.05 mg/kg/day and IBP 2.5 mg/kg/day) were administered once daily by oral gavage to female rats for 5 weeks from gestation day 6 to lactation day 21. Male pups were killed at postnatal day 70 and examined for developmental characteristics, body weight, testis and epididymis weight, steroid hormones, epididymal sperm count and motility, and histological changes in testis and epididymis. The BPA/IBP mixture produced a significant downregulation of epididymal sperm count and motility. BPA or IBP alone also reduced epididymal sperm count and motility compared to control. These results indicate that exposure to low-level BPA/IBP mixture, which showed no notable physiological response in early life stages, can decrease semen quality in adulthood. PMID:26519482

  10. Germination Response of MR 219 Rice Variety to Different Exposure Times and Periods of 2450 MHz Microwave Frequency

    PubMed Central

    Valdiani, Alireza; Maziah, Mahmood; Mohsenkhah, Mohammad

    2013-01-01

    Germination is a key process in plants' phenological cycles. Accelerating this process could lead to improvment of the seedling growth as well as the cultivation efficiency. To achieve this, the effect of microwave frequency on the germination of rice seeds was examined. The physiological feedbacks of the MR 219 rice variety in terms of seed germination rate (GR), germination percentage (GP), and mean germination time (MGT) were analyzed by exposing its seeds to 2450 MHz of microwave frequency for one, four, seven, and ten hours. It was revealed that exposing the seeds to the microwave frequency for 10 hours resulted in the highest GP. This treatment led to 100% of germination after three days with a mean germination time of 2.1 days. Although the other exposure times of microwave frequency caused the moderate effects on germination with a GPa3 ranged from 93% to 98%, they failed to reduce the MGTa3. The results showed that ten-hour exposure times of microwave frequency for six days significantly facilitated and improved the germination indices (primary shoot and root length). Therefore, the technique is expected to benefit the improvement of rice seed germination considering its simplicity and efficacy in increasing the germination percentage and rate as well as the primary shoot and root length without causing any environmental toxicity. PMID:24307869

  11. [Retrospective Cytogenetic Dose Evaluation. I. Chromosome Aberration Levels in Remote Periods after Acute External Exposure in Different Situations].

    PubMed

    Nugs, V Yu; Khvostunov, I K; Goloub, E V; Kozlova, M G; Nadejina, N M; Galstian, I A

    2015-01-01

    Cytogenetic analysis of peripheral blood lymphocyte cultures of 22 persons was performed in remote terms after acute external γ-, γ-β- or γ-neutron irradiation as a result of various accidents using the classical me- thod. The initial dose estimates were obtained using physical calculations, the method of measuring the EPR signal in tooth enamel, according to haematological and/or cytogenetic parameters. The purpose of this study was to obtain evidence about the state of the lymphocyte chromosome apparatus of people approxi- mately 17-50 years after an accidental radiation exposure. In general, elevated levels of chromosome aberra- tions were detected. An average correlation was observed between the atypical chromosome frequency and absorbed dose. It is proposed to use the obtained results in the future to explore the possibility of retrospective dose evaluation on the basis of a special computer program. PMID:26601536

  12. Ketogenic diet exposure during the juvenile period increases social behaviors and forebrain neural activation in adult Engrailed 2 null mice.

    PubMed

    Verpeut, Jessica L; DiCicco-Bloom, Emanuel; Bello, Nicholas T

    2016-07-01

    Prolonged consumption of ketogenic diets (KD) has reported neuroprotective benefits. Several studies suggest KD interventions could be useful in the management of neurological and developmental disorders. Alterations in the Engrailed (En) genes, specifically Engrailed 2 (En2), have neurodevelopmental consequences and produce autism-related behaviors. The following studies used En2 knockout (KO; En2(-/-)), and wild-type (WT; En2(+/+)), male mice fed either KD (80% fat, 0.1% carbohydrates) or control diet (CD; 10% fat, 70% carbohydrates). The objective was to determine whether a KD fed from weaning at postnatal day (PND) 21 to adulthood (PND 60) would alter brain monoamines concentrations, previously found dysregulated, and improve social outcomes. In WT animals, there was an increase in hypothalamic norepinephrine content in the KD-fed group. However, regional monoamines were not altered in KO mice in KD-fed compared with CD-fed group. In order to determine the effects of juvenile exposure to KD in mice with normal blood ketone levels, separate experiments were conducted in mice removed from the KD or CD and fed standard chow for 2days (PND 62). In a three-chamber social test with a novel mouse, KO mice previously exposed to the KD displayed similar social and self-grooming behaviors compared with the WT group. Groups previously exposed to a KD, regardless of genotype, had more c-Fos-positive cells in the cingulate cortex, lateral septal nuclei, and anterior bed nucleus of the stria terminalis. In the novel object condition, KO mice previously exposed to KD had similar behavioral responses and pattern of c-Fos immunoreactivity compared with the WT group. Thus, juvenile exposure to KD resulted in short-term consequences of improving social interactions and appropriate exploratory behaviors in a mouse model that displays autism-related behaviors. Such findings further our understanding of metabolic-based therapies for neurological and developmental disorders. PMID

  13. EROD activity and antioxidant defenses of sea bass (Dicentrarchus labrax) after an in vivo chronic hydrocarbon pollution followed by a post-exposure period.

    PubMed

    Danion, Morgane; Le Floch, Stéphane; Lamour, François; Quentel, Claire

    2014-12-01

    Chronic concentrations of polycyclic aromatic hydrocarbons (PAHs) have been commonly detected in international estuaries ecosystems. Reliable indicators still need to be found in order to properly assess the impact of PAHs in fish. After an in vivo chronic exposure to hydrocarbons, the enzymatic activity of 7-ethoxyresorufin O-deethylase (EROD) and the antioxidant defense system were assessed in sea bass, Dicentrarchus labrax. A total of 45 fish were exposed to the water-soluble fraction of Arabian crude oil, similar to a complex pollution by hydrocarbons chronically observed in situ, while 45 other control fish sustained the same experimental conditions in clean seawater. Fish samples were made after a 21-day exposure period and after a 15-day recovery period in clean fresh water. Throughout the experiment, liver EROD activity was significantly higher in contaminated fish than in control fish. In addition, nonenzymatic (total glutathione) and enzymatic (GPx, SOD, and CAT) antioxidant defense parameters measured in liver were not significantly different in fish. Furthermore, in gills, glutathione content had significantly increased while SOD activity had significantly decreased in contaminated fish compared to controls. On the other hand, CAT and GPx activities were not affected. Chronic exposure to PAHs disturbing the first step (SOD) and inhibiting the second step (GPx and CAT) could induce oxidative stress in tissues by the formation of oxygen radicals. After the postexposure period, there was no significant difference between control and contaminated fish in any of the antioxidant defense parameters measured in gills, attesting to the reversibility of the effects. PMID:24659404

  14. Spatial variation in inversion-focused vs 24-h integrated samples of PM2.5 and black carbon across Pittsburgh, PA

    PubMed Central

    Tunno, Brett J; Michanowicz, Drew R; Shmool, Jessie L C; Kinnee, Ellen; Cambal, Leah; Tripathy, Sheila; Gillooly, Sara; Roper, Courtney; Chubb, Lauren; Clougherty, Jane E

    2016-01-01

    A growing literature explores intra-urban variation in pollution concentrations. Few studies, however, have examined spatial variation during “peak” hours of the day (e.g., rush hours, inversion conditions), which may have strong bearing for source identification and epidemiological analyses. We aimed to capture “peak” spatial variation across a region of complex terrain, legacy industry, and frequent atmospheric inversions. We hypothesized stronger spatial contrast in concentrations during hours prone to atmospheric inversions and heavy traffic, and designed a 2-year monitoring campaign to capture spatial variation in fine particles (PM2.5) and black carbon (BC). Inversion-focused integrated monitoring (0600–1100 hours) was performed during year 1 (2011–2012) and compared with 1-week 24-h integrated results from year 2 (2012–2013). To allocate sampling sites, we explored spatial distributions in key sources (i.e., traffic, industry) and potential modifiers (i.e., elevation) in geographic information systems (GIS), and allocated 37 sites for spatial and source variability across the metropolitan domain (~388 km2). Land use regression (LUR) models were developed and compared by pollutant, season, and sampling method. As expected, we found stronger spatial contrasts in PM2.5 and BC using inversion-focused sampling, suggesting greater differences in peak exposures across urban areas than is captured by most integrated saturation campaigns. Temporal variability, commercial and industrial land use, PM2.5 emissions, and elevation were significant predictors, but did not more strongly predict concentrations during peak hours. PMID:25921079

  15. Spatial variation in inversion-focused vs 24-h integrated samples of PM2.5 and black carbon across Pittsburgh, PA.

    PubMed

    Tunno, Brett J; Michanowicz, Drew R; Shmool, Jessie L C; Kinnee, Ellen; Cambal, Leah; Tripathy, Sheila; Gillooly, Sara; Roper, Courtney; Chubb, Lauren; Clougherty, Jane E

    2016-06-01

    A growing literature explores intra-urban variation in pollution concentrations. Few studies, however, have examined spatial variation during "peak" hours of the day (e.g., rush hours, inversion conditions), which may have strong bearing for source identification and epidemiological analyses. We aimed to capture "peak" spatial variation across a region of complex terrain, legacy industry, and frequent atmospheric inversions. We hypothesized stronger spatial contrast in concentrations during hours prone to atmospheric inversions and heavy traffic, and designed a 2-year monitoring campaign to capture spatial variation in fine particles (PM2.5) and black carbon (BC). Inversion-focused integrated monitoring (0600-1100 hours) was performed during year 1 (2011-2012) and compared with 1-week 24-h integrated results from year 2 (2012-2013). To allocate sampling sites, we explored spatial distributions in key sources (i.e., traffic, industry) and potential modifiers (i.e., elevation) in geographic information systems (GIS), and allocated 37 sites for spatial and source variability across the metropolitan domain (~388 km(2)). Land use regression (LUR) models were developed and compared by pollutant, season, and sampling method. As expected, we found stronger spatial contrasts in PM2.5 and BC using inversion-focused sampling, suggesting greater differences in peak exposures across urban areas than is captured by most integrated saturation campaigns. Temporal variability, commercial and industrial land use, PM2.5 emissions, and elevation were significant predictors, but did not more strongly predict concentrations during peak hours. PMID:25921079

  16. Critical periods for chlorpyrifos-induced developmental neurotoxicity: alterations in adenylyl cyclase signaling in adult rat brain regions after gestational or neonatal exposure.

    PubMed Central

    Meyer, Armando; Seidler, Frederic J; Aldridge, Justin E; Tate, Charlotte A; Cousins, Mandy M; Slotkin, Theodore A

    2004-01-01

    Developmental exposure to chlorpyrifos (CPF) alters the function of a wide variety of neural systems. In the present study we evaluated the effects in adulthood of CPF exposure of rats during different developmental windows, using the adenylyl cyclase (AC) signaling cascade, which mediates the cellular responses to numerous neurotransmitters. Animals were exposed on gestational days (GD) 9-12 or 17-20 or on postnatal days (PN) 1-4 or 11-14 and assessed at PN60. In addition to basal AC activity, we evaluated the responses to direct AC stimulants (forskolin, Mn2+) and to isoproterenol, which activates signaling through ss-adrenoceptors coupled to stimulatory G-proteins. CPF exposure in any of the four periods elicited significant changes in AC signaling in a wide variety of brain regions in adulthood. In general, GD9-12 was the least sensitive stage, requiring doses above the threshold for impaired maternal weight gain, whereas effects were obtained at subtoxic doses for all other regimens. Most of the effects were heterologous, involving signaling elements downstream from the receptors, and thus shared by multiple stimulants; superimposed on this basic pattern, there were also selective alterations in receptor-mediated responses, in G-protein function, and in AC expression and subtypes. Exposures conducted at GD17-20 and later all produced sex-selective alterations. These results suggest that developmental exposure to CPF elicits long-lasting alterations in cell-signaling cascades that are shared by multiple neurotransmitter and hormonal inputs; the resultant abnormalities of synaptic communication are thus likely to occur in widespread neural circuits and their corresponding behaviors. PMID:14998743

  17. Glyphosate-based herbicide exposure causes antioxidant defence responses in the fruit fly Drosophila melanogaster.

    PubMed

    de Aguiar, Lais Mattos; Figueira, Fernanda Hernandes; Gottschalk, Marco Silva; da Rosa, Carlos Eduardo

    2016-01-01

    Glyphosate is a non-selective and post-emergent herbicide that affects plant growth. Animal exposure to this herbicide can lead to adverse effects, such as endocrine disruption, oxidative stress and behavioural disorders. Drosophilids have been utilized previously as an effective tool in toxicological tests. In the present study, the effects of a glyphosate-based herbicide (Roundup [Original]) were investigated regarding oxidative stress, the antioxidant defence system and acetylcholinesterase (AChE) activity in Drosophila melanogaster. Flies (of both genders) that were 1 to 3days old were exposed to different glyphosate concentrations (0.0mg/L=control, 1.0mg/L, 2.0mg/L, 5.0mg/L and 10.0mg/L) in the diet for 24h and 96h. After the exposure periods, reactive oxygen species (ROS) levels, antioxidant capacity against peroxyl radicals (ACAP) and lipid peroxidation (LPO) levels were quantified. In addition, the mRNA expression of antioxidant genes (i.e., keap1, sod, sod2, cat, irc, gclc, gclm, gss, trxt, trxr-1 and trxr-2) was evaluated via RT-PCR. Additionally, AChE activity was evaluated only after the 96h exposure period. The results indicated that Roundup exposure leads to a reduction in ROS levels in flies exposed for 96h. ACAP levels and gene expression of the antioxidant defence system exhibited an increase from 24h, while LPO did not show any significant alterations in both exposure periods. AChE activity was not affected following Roundup exposure. Our data suggest that Roundup exposure causes an early activation of the antioxidant defence system in D. melanogaster, and this can prevent subsequent damage caused by ROS. PMID:26980113

  18. Adenylyl cylases 1 and 8 mediate select striatal-dependent behaviors and sensitivity to ethanol stimulation in the adolescent period following acute neonatal ethanol exposure.

    PubMed

    Susick, Laura L; Lowing, Jennifer L; Bosse, Kelly E; Hildebrandt, Clara C; Chrumka, Alexandria C; Conti, Alana C

    2014-08-01

    maturational parameters examined in the current study may not be sensitive enough to detect effects of a single ethanol exposure during the brain growth spurt period. Genetic deletion of AC1/8 reveals a role for these cylases in attenuating ethanol-induced behavioral effects in the neonatally-exposed adolescent. PMID:24769171

  19. Leaching of cadmium, chromium, copper, lead, and zinc from two slag dumps with different environmental exposure periods under dynamic acidic condition.

    PubMed

    Jin, Zhisheng; Liu, Taoze; Yang, Yuangen; Jackson, Daniel

    2014-06-01

    Over the past few decades, zinc smelting activities in Guizhou, China have produced numerous slag dumps, which are often dispersed on roadsides and hill slopes throughout the region. During periods of acid rain, these exposed slags release heavy metals into surface water bodies. A column leaching study was designed to test the potential release of the heavy metals cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), and zinc (Zn) under simulated acid rain events. Two slags with varying environmental exposure periods were packed in columns and subjected to leaching solutions of pH 3.5, 5.5, or DI H2O at intervals of 1, 7, 14, 28, 56d. Pulse concentrations of Cd in leachate were found above 5μg/L, Cr, Pb, and Zn >10μg/L, whereas, Cu reached 10μg/L. After five leaching events, the leachability (percentage of cumulative heavy metal leached after five leaching events as in its respective total concentration in slags) of Cd was 0.05 percent and 0.035 percent from the old and young slag, respectively. Cr (0.035 percent and 0.05 percent) was greater than Cu (0.002 percent and 0.005 percent) and Zn (0.006 percent and 0.003 percent), while the lowest leachability was observed for Pb (0.0005 percent and 0.0002 percent) from the old and young slags, respectively. Reaction rates (release amount of heavy metals in certain period of leaching) of heavy metals in the leachates demonstrated the sequence of Zn>Cr>Cd, Cu>Pb. Leaching release of heavy metals was jointly affected by the pH of leaching solution and mineral composition of slags (including chemical forms of Cd, Cr, Cu, Pb, and Zn). Environmental exposure period of slags, resulting in the alteration of minerals, could affect the release process of heavy metals in leaching as well. PMID:24632122

  20. Cadmium uptake and distribution in mouse embryos following maternal exposure during the organogenic period: a scintillation and autoradiographic study

    SciTech Connect

    Christley, J.; Webster, W.S.

    1983-06-01

    Pregnant C57BL/6J mice were given a single intraperitoneal injection of either a teratogenic (2,400 micrograms Cd/kg) an intermediate (40 micrograms Cd/kg) or a trace dose (0.66 micrograms Cd/kg) of cadmium chloride (CdCl/sub 2/) on day 9 of gestation; each dose contained /sup 109/CdCl/sub 2/ (20 microCi). The mice were euthanized at various times after Cd exposure, and the amount of Cd in the embryos was determined in a gamma counter. For all three doses a low, but similar, percentage of the dose rapidly entered the embryos; levels then decreased during the next 11 hours, only to rise again by 24 hours and continue to rise for the remainder of the pregnancy. When the Cd content was related to embryonic weight the Cd concentration was at its highest level after 1 hour and then decreased rapidly and continued to decrease for the rest of pregnancy. Autoradiographic studies showed that the teratogenic dose of Cd entered all tissues of the embryos but was particularly localized in cells of the neural tube, limb buds, and gut. By 12 hours, cell damage was seen in the embryos but the affected cells were not necessarily the heavily labelled cells. In embryos exposed to the nonteratogenic dose the highest Cd accumulation was seen in the embryonic gut and limb bud ectoderm but all tissues showed a low level of labelling.

  1. Stability of continuously produced Fe(II)/Fe(III)/As(V) co-precipitates under periodic exposure to reducing agents.

    PubMed

    Doerfelt, Christoph; Feldmann, Thomas; Daenzer, Renaud; Demopoulos, George P

    2015-11-01

    Arsenic mobilized during ore processing necessitates its effective removal from process effluents and disposal in environmentally stable tailings. The most common method to accomplish this involves co-precipitation with excess ferric iron during lime neutralization. The precipitates produced are stable under oxic conditions. This may not be true, however, under sub-oxic or anoxic conditions. In this context, the potential stabilizing role of ferrous iron on arsenic removal/retention becomes important. As such, this work investigates the removal and redox stability of arsenic with ferrous, ferric and mixtures of both. The stability of produced solids is monitored in terms of arsenic release over time. It was found that ferrous was very effective for arsenic (V) removal with Fe(II)/As(V)=4, reducing its concentration down to <15 ppb via the apparent formation of ferrous arsenate. The presence of Fe(II) seemed to favor an oxidation path toward goethite (and possibly scorodite) formation in the aged bench-scale tailings. When pH and Eh were regularly adjusted with lime and sulfite or sulfide, slightly higher arsenic amounts were released (1-5 mg L(-1)); ferrous again was found to oxidize. Hence, it is concluded that Fe(II)/Fe(III)/As(V) co-precipitates are quite robust against incidental reducing agent exposure. PMID:26086809

  2. Pulmonary toxicity of multi-walled carbon nanotubes (Baytubes) relative to alpha-quartz following a single 6h inhalation exposure of rats and a 3 months post-exposure period.

    PubMed

    Ellinger-Ziegelbauer, Heidrun; Pauluhn, Jürgen

    2009-12-21

    Manufactured multi-walled carbon nanotubes (MWCNT) have attracted a great deal of attention due to their unique structural, chemical, and physical characteristics. This study utilized a 1x 6h inhalation exposure protocol followed by a 3 months post-exposure period. Wistar rats were nose-only exposed to 11 and 241 mg/m(3) MWCNT (Baytubes) of respirable, solid aerosol. MWCNT depleted of residual metals (depletion from 0.53% to 0.12% Co) were compared at 11 mg/m(3). Rats similarly exposed to air and alpha-quartz (248 mg/m(3)) served as negative and positive controls, respectively. Pulmonary response was characterized by bronchoalveolar lavage (BAL), lung histopathology, organ burden determinations, and gene expression analyses of lung homogenates with emphasis on extracellular matrix components. This acute inhalation exposure protocol was suitable to characterize and distinguish acute deposition-related effects from the long-term sequelae of retained MWCNT. Subtle differences in acute pulmonary toxic potency due to differences in metal contaminations could be revealed by this protocol. Consistent with the long retention halftime of poorly soluble particles, even short-term inhalation studies may require post-exposure periods of at least 3 months to reveal MWCNT-specific dispositional and toxicological characteristics relative to alpha-quartz. Distinct differences in the time course of pulmonary inflammation of MWCNT and alpha-quartz could be demonstrated. Transcriptomics proved to be a useful tool to analyze the etiopathology of collagen detected by BAL and histopathology. In summary, the pulmonary inflammogenicity following exposure to MWCNT was concentration-dependent with evidence of regression over time. Conversely, alpha-quartz resulted in progressive changes over time. The time course of pulmonary inflammation associated with retained MWCNT was independent on the concentration of residual cobalt. This supports the conclusion that the predominant response to

  3. Biochemical effects of low level exposure to soman vapour.

    PubMed

    Bajgar, J; Sevelová, L; Krejcová, G; Fusek, J; Vachek, J; Kassa, J; Herink, J; de Jong, L P A; Benschop, H

    2004-03-01

    The aim of this study was to demonstrate changes in acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities, tyrosine aminotransferase activity (TAT) and plasma corticosterone level, neuroexcitability and behavior following 24 hours and 4 weeks of soman sublethal inhalation exposure at low level. AChE activity in erythrocytes and BuChE activity in plasma was decreased (dependent on the concentration of soman) 24 h and 4 weeks after the exposure. Similar decrease in AChE activity in different brain parts was observed. One of stressogenic parameters (TAT) was changed after 24 h exposure only. 4 weeks after the exposure, these parameters (corticosterone and TAT) were in the range of normal values. Behaviour of experimental animals was changed 24 h after the exposure persisting 4 weeks after the exposure as well as neuroexcitability. PMID:15141961

  4. Periodic Exposure of Keratinocytes to Cold Physical Plasma: An In Vitro Model for Redox-Related Diseases of the Skin

    PubMed Central

    Schmidt, Anke; von Woedtke, Thomas; Bekeschus, Sander

    2016-01-01

    Oxidative stress illustrates an imbalance between radical formation and removal. Frequent redox stress is critically involved in many human pathologies including cancer, psoriasis, and chronic wounds. However, reactive species pursue a dual role being involved in signaling on the one hand and oxidative damage on the other. Using a HaCaT keratinocyte cell culture model, we investigated redox regulation and inflammation to periodic, low-dose oxidative stress after two, six, eight, ten, and twelve weeks. Chronic redox stress was generated by recurrent incubation with cold physical plasma-treated cell culture medium. Using transcriptome microarray technology, we identified both acute ROS-stress responses as well as numerous adaptions after several weeks of redox challenge. We determined a differential expression (2-fold, FDR < 0.01, p < 0.05) of 260 genes that function in inflammation and redox homeostasis, such as cytokines (e.g., IL-6, IL-8, and IL-10), growth factors (e.g., CSF2, FGF, and IGF-2), and antioxidant enzymes (e.g., HMOX, NQO1, GPX, and PRDX). Apoptotic signaling was affected rather modestly, especially in p53 downstream targets (e.g., BCL2, BBC3, and GADD45). Strikingly, the cell-protective heat shock protein HSP27 was strongly upregulated (p < 0.001). These results suggested cellular adaptions to frequent redox stress and may help to better understand the inflammatory responses in redox-related diseases. PMID:26966508

  5. Short-term tissue distribution, depuration and possible gene expression effects of [{sup 3}H]TCDD exposure in soft-shell clams (Mya arenaria)

    SciTech Connect

    Rhodes, L.D.; Beneden, R.J. van; Gardner, G.R.

    1997-09-01

    A short-term, waterborne exposure and depuration study of Mya arenaria to [{sup 3}H]tetrachlorodibenzo-p-dioxin ([{sup 3}H]TCDD) was performed. Gill, digestive gland, foot, and gonad were sampled up to 2 weeks after a 24-h exposure to a low dose (10 parts per trillion [pptr]) or high dose (2,000 pptr) of [{sup 3}H]TCDD in the water. In the gill, peak concentrations occurred at the beginning of depuration (406 and 8,658 pg/g wet weight, low- and high-dose groups, respectively), whereas peak concentrations in the digestive gland and foot were found 12 to 24 h after exposure. In contrast, tissue concentrations in the gonad increased through the post-exposure period; at 2 weeks after exposure, tissue concentrations were highest in the gonad. Examination of gill and gonad by differential display polymerase chain reaction identified potential alterations in expression of genes that may be associated with increased cell cycling or translation initiation. This study shows that M. arenaria can accumulate TCDD in the gonad from an acute exposure, and it identifies several M. arenaria genes whose expression may be altered by TCDD exposure.

  6. The 24-h Energy Intake of Obese Adolescents Is Spontaneously Reduced after Intensive Exercise: A Randomized Controlled Trial in Calorimetric Chambers

    PubMed Central

    Thivel, David; Isacco, Laurie; Montaurier, Christophe; Boirie, Yves

    2012-01-01

    Background Physical exercise can modify subsequent energy intake and appetite and may thus be of particular interest in terms of obesity treatment. However, it is still unclear whether an intensive bout of exercise can affect the energy consumption of obese children and adolescents. Objective To compare the impact of high vs. moderate intensity exercises on subsequent 24-h energy intake, macronutrient preferences, appetite sensations, energy expenditure and balance in obese adolescent. Design This randomized cross-over trial involves 15 obese adolescent boys who were asked to randomly complete three 24-h sessions in a metabolic chamber, each separated by at least 7 days: (1) sedentary (SED); (2) Low-Intensity Exercise (LIE) (40% maximal oxygen uptake, VO2max); (3) High-Intensity Exercise (HIE) (75%VO2max). Results Despite unchanged appetite sensations, 24-h total energy intake following HIE was 6–11% lower compared to LIE and SED (p<0.05), whereas no differences appeared between SED and LIE. Energy intake at lunch was 9.4% and 8.4% lower after HIE compared to SED and LIE, respectively (p<0.05). At dinner time, it was 20.5% and 19.7% lower after HIE compared to SED and LIE, respectively (p<0.01). 24-h energy expenditure was not significantly altered. Thus, the 24-h energy balance was significantly reduced during HIE compared to SED and LIE (p<0.01), whereas those of SED and LIE did not differ. Conclusions In obese adolescent boys, HIE has a beneficial impact on 24-h energy balance, mainly due to the spontaneous decrease in energy intake during lunch and dinner following the exercise bout. Prescribing high-intensity exercises to promote weight loss may therefore provide effective results without affecting appetite sensations and, as a result, food frustrations. Trial Registration ClinicalTrial.gov NCT01036360 PMID:22272251

  7. Effects of exposure period and nutrition on the developmental neurotoxicity of anticonvulsants in rats: short and long-term effects.

    PubMed

    Vorhees, C V; Rindler, J M; Minck, D R

    1990-01-01

    The results of three experiments on the functional neuroteratogenicity of anticonvulsants in rats are presented. Two of the experiments have been reported previously and are reviewed here, while the third experiment is presented here for the first time. The first experiment examined prenatal phenytoin (200 mg/kg), trimethadione (250 mg/kg), and phenobarbital (80 mg/kg) for critical period effects by exposing separate groups of rats to the drugs or to vehicle on embryonic (E) days 7-10, 11-14, or 15-18. Phenytoin produced effects in the E11-14 offspring, but few effects in the E15-18 offspring, and almost no effects in the E7-10 offspring. Phenytoin's E11-14 effects in the offspring were increased pivoting, delayed swimming ontogeny, hyperactivity, impaired water maze learning, and impaired passive avoidance retention. The second experiment looked for phenytoin's long-term effects. Phenytoin-exposed offspring administered 200 mg/kg on E7-18 exhibited numerous postnatal dysfunctions, including water maze learning deficits that persisted to beyond 501 days of age. The learning deficits were neither increased nor decreased in severity at this age compared to those seen in littermates tested at 50 days of age. The third experiment assessed the role of manganese in counteracting phenytoin-induced postnatal dysfunction and the possible confounding effects of maternal undernutrition associated with the drug's administration. The typical pattern of phenytoin-induced behavioral effects was observed in rat offspring. The results demonstrated that undernutrition was not a confound, since pair-feeding and pair-watering controls did not diminish the phenytoin-induced dysfunction in the offspring. Also, administration of a manganese supplementation (200 ppm in the drinking water) during gestation did not significantly alter the pattern of phenytoin-induced postnatal effects. PMID:2234544

  8. In ovo 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure in three avian species. 1. Effects on thyroid hormones and growth during the perinatal period.

    PubMed

    Janz, D M; Bellward, G D

    1996-08-01

    Thyroid hormones are important in the perinatal growth and development of avian species, and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds have been shown to cause alterations in these hormones in laboratory animals. Since the decreased reproductive success in certain fish-eating bird populations exposed to TCDD and related compounds is characterized by high embryo and hatchling mortality, we examined the effects of in ovo TCDD exposure on plasma thyroid hormone concentrations (total T3, total T4) and body and skeletal growth during the perinatal period in the domestic chicken (Gallus gallus), domestic pigeon (Columba livia), and great blue heron (Ardea herodias). Hepatic ethoxyresorufin O-deethylase (EROD) activity was also determined as an enzymatic marker of cytochrome P450IA induction by TCDD. [3H]TCDD was injected into the air cell of chicken eggs (21-day incubation period) on Embryonic Day 4.5 (0.1 microgram/kg egg), pigeon eggs (18-day incubation period) on Embryonic Day 3.5 (1 microgram/kg egg) and Embryonic Day 14 (3 microgram/kg egg), and heron eggs (28-day incubation period) at approximately the midpoint of incubation (2 microgram/kg egg). Chickens were euthanized on Embryonic Days 17 and 19, day of hatch (Embryonic Day 21), and Days 2 and 4 after hatch. Pigeons and herons were euthanized either at hatch (Embryonic Days 18 and 28, respectively), or fed an uncontaminated diet for 7 days prior to sacrifice. Although hepatic EROD activity was induced 13- to 43-fold above controls in chickens, there was no effect of TCDD exposure on hatchability, body growth, subcutaneous edema, or plasma thyroid hormone levels. In pigeons exposed to TCDD on Embryonic Day 3.5, EROD was induced 6- to 15-fold, hatchability was decreased, liver to body weight ratio was elevated, and body and skeletal growth were decreased (p < 0.01); however, there was no effect of TCDD exposure on plasma thyroid hormone levels. Similarly, in pigeons exposed to TCDD on

  9. Food intake during the previous 24 h as a percentage of usual intake: a marker of hypoxia in infants with bronchiolitis: an observational, prospective, multicenter study

    PubMed Central

    2013-01-01

    Background Hypoxia associated with bronchiolitis is not always easy to assess on clinical grounds alone. The aim of this study was to determine the value of food intake during the previous 24 hours (bottle and spoon feeding), as a percentage of usual intake (24h FI), as a marker of hypoxia, and to compare its diagnostic value with that of usual clinical signs. Methods In this observational, prospective, multicenter study, 18 community pediatricians, enrolled 171 infants, aged from 0 to 6 months, with bronchiolitis (rhinorrhea + dyspnea + cough + expiratory sounds). Infants with risk factors (history of prematurity, chronic heart or lung disorders), breast-fed infants, and infants having previously been treated for bronchial disorders were excluded. The 24h FI, subcostal, intercostal, supracostal retractions, nasal flaring, respiratory rate, pauses, cyanosis, rectal temperature and respiratory syncytial virus test results were noted. The highest stable value of transcutaneous oxygen saturation (SpO2) was recorded. Hypoxia was noted if SpO2 was below 95% and verified. Results 24h FI ≥ 50% was associated with a 96% likelihood of SpO2 ≥ 95% [95% CI, 91–99]. In univariate analysis, 24h FI < 50% had the highest odds ratio (13.8) for SpO2 < 95%, compared to other 24h FI values and other clinical signs, as well as providing one of the best compromises between specificity (90%) and sensitivity (60%) for identifying infants with hypoxia. In multivariate analysis with adjustment for age, SpO2 < 95% was related to the presence of intercostal retractions (OR = 9.1 [95% CI, 2.4-33.8%]) and 24h FI < 50% (OR = 10.9 [95% CI, 3.0-39.1%]). Hospitalization (17 infants) was strongly related to younger age, 24h FI and intercostal retractions. Conclusion In practice, the measure of 24 h FI may be useful in identifying hypoxia and deserves further study. PMID:23311899

  10. Neonatal exposure to whole body ionizing radiation induces adult neurobehavioural defects: Critical period, dose--response effects and strain and sex comparison.

    PubMed

    Eriksson, Per; Buratovic, Sonja; Fredriksson, Anders; Stenerlöw, Bo; Sundell-Bergman, Synnöve

    2016-05-01

    Development of the brain includes periods which can be critical for its normal maturation. The present study investigates specifically vulnerable peri-/postnatal periods in mice which are essential for understanding the etiology behind radiation induced neurotoxicity and functional defects, including evaluation of neurotoxicity between sexes or commonly used laboratory mouse strains following low/moderate doses of ionizing radiation (IR). Male Naval Medical Research Institute (NMRI) mice, whole body irradiated to a single 500 mGy IR dose, on postnatal day (PND) 3 or PND 10 showed an altered adult spontaneous behaviour and impaired habituation capacity, whereas irradiation on PND 19 did not have any impact on the studied variables. Both NMRI and C57bl/6 male and female mice showed an altered adult spontaneous behaviour and impaired habituation following a single whole body irradiation of 500 or 1000 mGy, but not after 20 or 100 mGy, on PND 10. The present study shows that exposure to low/moderate doses of IR during critical life stages might be involved in the induction of neurological/neurodegenerative disorder/disease. A specifically vulnerable period for radiation induced neurotoxicity seems to be around PND 3-10 in mice. Further studies are needed to investigate mechanisms involved in induction of developmental neurotoxicity following low-dose irradiation. PMID:26876140

  11. Captopril at 50 mg as well as at 100 mg once a day reduces blood pressure for up to 24 h: a double-blind randomized crossover study in mild to moderate hypertensives.

    PubMed

    Salvetti, A; Circo, A; Raciti, S; Gulizia, M; Cardillo, R; Miceli, S; Botta, G

    1988-12-01

    The extent and the duration of the antihypertensive effect of captopril, given once a day at a dose of 50 mg, compared with placebo and with the 100 mg once daily dose was studied in 30 mild or moderate uncomplicated essential hypertensives (mean +/- s.e.m. age 52.0 +/- 1.5 years), who responded (mean blood pressure decrease greater than 10%) to a single oral dose (12.5 mg) of captopril. According to a randomized, double-blind, crossover design, they were given 50 mg captopril four times a day, 100 mg captopril four times a day or matched placebo for 1 month. At the end of each treatment period blood pressure and heart rate were measured every 30 min from 3 h before to 2 h after the last dose. Although the heart rate did not change, mean blood pressure after the 50- and 100-mg doses of captopril was consistently significantly (P less than or equal to 0.05) lower than after placebo. The hypotensive effect peaked at the second hour and was still significant 24 h after dosing without any significant differences between the 50- and the 100-mg doses. These findings indicate that captopril, given chronically once a day at a dose of 50 mg to mild to moderate hypertensive responders, exerts its hypotensive effect up to 24 h and that doubling the dose does not increase either the extent or the duration of its action. PMID:3071596

  12. Estimation of the Exposure of the UK Population to the Bovine Spongiform Encephalopathy Agent through Dietary Intake During the Period 1980 to 1996

    PubMed Central

    Chen, Chu-Chih; Wang, Yin-Han

    2014-01-01

    Although the incidence of variant Creutzfeldt-Jakob disease (vCJD) has declined to 1 since 2012 in the UK, uncertainty remains regarding possible future cases and the size of the subclinical population that may cause secondary transmission of the disease through blood transfusion. Estimating the number of individuals who were exposed to the bovine spongiform encephalopathy (BSE) infectious agent and may be susceptible to vCJD will help to clarify related public health concerns and plan strategies. In this paper, we explore this estimate by describing the probability of potential exposure due to dietary intake throughout the BSE epidemic period from 1980 to 1996 as a stochastic Poisson process. We estimate the age- and gender-specific exposure intensities in food categories of beef and beef-containing dishes, burgers and kebabs, pies, and sausages, separating the two periods of 1980–1989 and 1990–1996 due to the specified bovine offal legislation of 1989. The estimated total number of (living) exposed individuals during each period is 5,089,027 (95% confidence interval [CI] 4,514,963–6,410,317), which was obtained by multiplying the population size of different birth cohorts by the probability of exposure via dietary intake and the probability of survival until the end of 2013. The estimated number is approximately doubled, assuming a contamination rate of . Among those individuals estimated, 31,855 (95% CI 26,849–42,541) are susceptible to infection. We also examined the threshold hypothesis by fitting an extreme-value distribution to the estimated infectious dose of the exposed individuals and obtained a threshold estimate of 13.7 bID50 (95% CI 6.6–26.2 bID50) (Weibull). The results provide useful information on potential carriers of prion disease who may pose a threat of infection via blood transfusion and thus provide insight into the likelihood of new incidents of vCJD occurring in the future. PMID:24736322

  13. Adapting a standardised international 24 h dietary recall methodology (GloboDiet software) for research and dietary surveillance in Korea.

    PubMed

    Park, Min Kyung; Park, Jin Young; Nicolas, Geneviève; Paik, Hee Young; Kim, Jeongseon; Slimani, Nadia

    2015-06-14

    During the past decades, a rapid nutritional transition has been observed along with economic growth in the Republic of Korea. Since this dramatic change in diet has been frequently associated with cancer and other non-communicable diseases, dietary monitoring is essential to understand the association. Benefiting from pre-existing standardised dietary methodologies, the present study aimed to evaluate the feasibility and describe the development of a Korean version of the international computerised 24 h dietary recall method (GloboDiet software) and its complementary tools, developed at the International Agency for Research on Cancer (IARC), WHO. Following established international Standard Operating Procedures and guidelines, about seventy common and country-specific databases on foods, recipes, dietary supplements, quantification methods and coefficients were customised and translated. The main results of the present study highlight the specific adaptations made to adapt the GloboDiet software for research and dietary surveillance in Korea. New (sub-) subgroups were added into the existing common food classification, and new descriptors were added to the facets to classify and describe specific Korean foods. Quantification methods were critically evaluated and adapted considering the foods and food packages available in the Korean market. Furthermore, a picture book of foods/dishes was prepared including new pictures and food portion sizes relevant to Korean diet. The development of the Korean version of GloboDiet demonstrated that it was possible to adapt the IARC-WHO international dietary tool to an Asian context without compromising its concept of standardisation and software structure. It, thus, confirms that this international dietary methodology, used so far only in Europe, is flexible and robust enough to be customised for other regions worldwide. PMID:25899045

  14. Dose-finding and 24-h monitoring for efficacy and safety of aerosolized Nacystelyn in cystic fibrosis.

    PubMed

    App, E M; Baran, D; Dab, I; Malfroot, A; Coffiner, M; Vanderbist, F; King, M

    2002-02-01

    The aim of the present studies was to investigate the tolerability and activity of a novel mucolytic drug, Nacystelyn (NAL), for the treatment of cystic fibrosis (CF) lung disease. In study 1, involving 10 CF patients, the main objective was to determine the tolerability and potential efficacy of a range of single doses of NAL in comparison to a placebo, in order to establish an optimal dose for further testing. On five consecutive scheduled treatment days, patients inhaled either from two (4 mg) to eight puffs (16 mg) of a single dose of NAL from the range, administered in an open-label fashion, or 12 puffs of active NAL (24 mg) versus 12 puffs of placebo, administered in a randomized double-blind fashion. Pulmonary function data were unaffected and clinically-adverse effects were limited to wheezing in some patients that inhaled 12 puffs of either placebo or active drug. Subsequent rheological analysis of their sputum showed a dose-dependent decrease in sputum viscoelasticity, accompanied by a decrease in sputum solids content and an increase in chloride and sodium concentrations. In study 2, involving 12 CF patients, the clinical safety and mucolytic activity of a single dose of NAL was monitored over 24 h. On different scheduled treatment days, 7 days apart, patients inhaled a single dose of 12 puffs of active NAL (24 mg) or 12 puffs of placebo drug in a randomized, double-blind sequence, with sputum samples taken at intervals before and after inhalation. Mucus rigidity decreased following NAL inhalation, with the maximum effect observed at 4 h; the 1-, 2- and 4-h NAL rheology results were significantly different from placebo. No adverse effects were observed. The drug was well tolerated in both studies. Sputum results were predictive of improved clearability by ciliary and cough transport mechanisms. PMID:11866009

  15. Mortality in the first 24h of very low birth weight preterm infants in the Northeast of Brazil

    PubMed Central

    de Castro, Eveline Campos Monteiro; Leite, Álvaro Jorge Madeiro; Guinsburg, Ruth

    2016-01-01

    Abstract Objective: To evaluate factors associated with neonatal death within 24 hours after birth in very low birth weight preterm newborns. Methods: Prospective cohort of live births with gestational age of 230/7–316/7 weeks, birth weight of 500–1499g without malformations, in 19 public maternity hospitals in nine capitals in northeastern Brazil from July to December 2007. The 19 hospitals were assessed in relation to physical resources, equipment, human resources and aiming at quality in care initiatives. Hospital, maternal and neonatal characteristics, neonatal morbidity, neonatal procedures and interventions were compared between preterm newborns that died or survived up to 24 hours of life. The variables associated with death within 24 hours after birth were determined by logistic regression. Results: Of the 627 newborns enrolled in the study, 179 (29%) died within 168 hours after birth, of which 59 (33%) up to 24 hours and 97 (54%) up to 48 hours after birth. The variables associated with death <24h were: weight <1000g (2.94; 1.32–6.53), 5th minute Apgar <7 (7.17; 3.46–14.88), male gender (2.99; 1.39–6.47). A better hospital structure was a protective factor for early neonatal death (odds ratio: 0.34; 95% confidence interval: 0.17–0.71). Conclusions: The high neonatal mortality on the first day of life in capital cities of Northeast Brazil is associated with biological variables such as weight and gender of the newborn, as well as low vitality at birth and a worse infrastructure of the hospital where the birth occurred. PMID:26726002

  16. Short-term blood pressure variability over 24 h and target organ damage in middle-aged men and women.

    PubMed

    Madden, J M; O'Flynn, A M; Dolan, E; Fitzgerald, A P; Kearney, P M

    2015-12-01

    Blood pressure variability (BPV) has been associated with cardiovascular events; however, the prognostic significance of short-term BPV remains uncertain. As uncertainty also remains as to which measure of variability most accurately describes short-term BPV, this study explores different indices and investigates their relationship with subclinical target organ damage (TOD). We used data from the Mitchelstown Study, a cross-sectional study of Irish adults aged 47-73 years (n=2047). A subsample (1207) underwent 24-h ambulatory BP monitoring (ABPM). As measures of short-term BPV, we estimated the s.d., weighted s.d. (wSD), coefficient of variation (CV) and average real variability (ARV). TOD was documented by microalbuminuria and electrocardiogram (ECG) left ventricular hypertrophy (LVH). There was no association found between any measure of BPV and LVH in both unadjusted and fully adjusted logistic regression models. Similar analysis found that ARV (24 h, day and night), s.d. (day and night) and wSD were all univariately associated with microalbuminuria and remained associated after adjustment for age, gender, smoking, body mass index (BMI), diabetes and antihypertensive treatment. However, when the models were further adjusted for the mean BP the association did not persist for all indices. Our findings illustrate choosing the appropriate summary measure, which accurately captures that short-term BPV is difficult. Despite discrepancies in values between the different measures, there was no association between any indexes of variability with TOD measures after adjustment for the mean BP. PMID:25787777

  17. The importance of bioimpedance (BIA) analysis and Cardio Tens (24-h ABPM and ECG) monitoring in the dialysis programme.

    PubMed

    Löcsey, L; Szlanka, B; Ménes, I; Kövér, A; Vitai, E; Malkócs, Z; Keresztes, P; Paragh, G

    1999-01-01

    The authors performed bioimpedance analysis and Cardio Tens (24-h ABPM and ECG) monitoring in 66 patients (28 males, 38 females) treated in the chronic haemodialysis programme. They investigated the correlations between the body weights before, during and after dialysis, the changes of the water compartments and fat body weight, and the recorded values of blood pressure and ECG alterations. On the basis of the measurements by this non-invasive method it is concluded that, as a result of dialysis and ultrafiltration, the total body weight and total body water are decreasing in a greater extent in men than in women. By gradually decreasing the body weight, the optimal dry weight could be attained, which resulted in the reduction of blood pressure or even normotension. In the course of dialysis the values of bioimpedance and bioreactance increase. The intradialytic hypotensive indispositions were accompanied by a significant reduction of bioreactance (n = 16). The BMI, total body weight and total body water hyperlipidaemic, hypalbuminic patients with treatment-resistant hypertension are considerably larger than those of the patients with normal blood pressure (p<0.01). During Cardio Tens monitoring 53% of the patients proved to be dippers, 47% of whom had ST depression, while in 73% of the non-dippers ischaemic alterations were encountered together with high hyperbaric impact values. The total body weights and total water compartments of patients returning to dialysis with an excess body weight of more than 3.5 kg were significantly larger than of patients who were cooperative and had no oedemas. In the last hour of dialysis and during the following few hours, arrhythmias and ST depressions of the cardiovascularly instable patients appeared more frequently. The total water compartments of these patients are significantly larger than normotensive, normolipaemic patients with appropriate serum albumin concentrations. The importance of the BIA and Cardio Tens monitoring

  18. Long-term invariant parameters obtained from 24-h Holter recordings: A comparison between different analysis techniques

    NASA Astrophysics Data System (ADS)

    Cerutti, Sergio; Esposti, Federico; Ferrario, Manuela; Sassi, Roberto; Signorini, Maria Gabriella

    2007-03-01

    Over the last two decades, a large number of different methods had been used to study the fractal-like behavior of the heart rate variability (HRV). In this paper some of the most used techniques were reviewed. In particular, the focus is set on those methods which characterize the long memory behavior of time series (in particular, periodogram, detrended fluctuation analysis, rescale range analysis, scaled window variance, Higuchi dimension, wavelet-transform modulus maxima, and generalized structure functions). The performances of the different techniques were tested on simulated self-similar noises (fBm and fGn) for values of α, the slope of the spectral density for very small frequency, ranging from -1 to 3 with a 0.05 step. The check was performed using the scaling relationships between the various indices. DFA and periodogram showed the smallest mean square error from the expected values in the range of interest for HRV. Building on the results obtained from these tests, the effective ability of the different methods in discriminating different populations of patients from RR series derived from Holter recordings, was assessed. To this extent, the Noltisalis database was used. It consists of a set of 30, 24-h Holter recordings collected from healthy subjects, patients suffering from congestive heart failure, and heart transplanted patients. All the methods, with the exception at most of rescale range analysis, were almost equivalent in distinguish between the three groups of patients. Finally, the scaling relationships, valid for fBm and fGn, when empirically used on HRV series, also approximately held.

  19. Twice Daily Melatonin Peaks in Siberian but not Syrian Hamsters under 24 h Light:Dark:Light:Dark Cycles

    PubMed Central

    Raiewski, Evan E.; Elliott, Jeffrey A.; Evans, Jennifer A.; Glickman, Gena L.; Gorman, Michael R.

    2016-01-01

    The daily pattern of blood borne melatonin varies seasonally under the control of a multi-oscillator circadian pacemaker. Here we examine patterns of melatonin secretion and locomotor activity in Siberian and Syrian hamsters entrained to bimodal LDLD8:4:8:4 and LD20:4 lighting schedules that facilitate novel temporal arrangements of component circadian oscillators. Under LDLD, both species robustly bifurcated wheel-running activity in distinct day scotophase (DS) and night scotophase (NS) bouts. Siberian hamsters displayed significant melatonin increases during each scotophase in LDLD, and in the single daily scotophase of LD20:4. The bimodal melatonin secretion pattern persisted in acutely extended 16 h scotophases. Syrian hamsters, in contrast, showed no significant increases in plasma melatonin during either scotophase of LDLD8:4:8:4 or in LD20:4. In this species, detectable levels were observed only when the day scotophase of LDLD was acutely extended to yield 16 h of darkness. Established species differences in the phase lag of nocturnal melatonin secretion relative to activity onset may underlie the above contrast: In non-bifurcated entrainment to 24 h LD cycles, Siberian hamsters show increased melatonin secretion within ~ 2 h after activity onset, whereas in Syrian hamsters, detectable melatonin secretion phase lags activity onset and the L/D transition by at least 4 h. The present results provide new evidence indicating multi-oscillator regulation of the waveform of melatonin secretion, specifically, the circadian control of the onset, offset, and duration of nocturnal secretion. PMID:23003567

  20. The Effects of Changing Attention and Context in an Awake Offline Processing Period on Visual Long-Term Memory

    PubMed Central

    Ellmore, Timothy M.; Feng, Anna; Ng, Kenneth; Dewan, Luthfunnahar; Root, James C.

    2016-01-01

    There is accumulating evidence that sleep as well as awake offline processing is important for the transformation of new experiences into long-term memory (LTM). Yet much remains to be understood about how various cognitive factors influence the efficiency of awake offline processing. In the present study we investigated how changes in attention and context in the immediate period after exposure to new visual information influences LTM consolidation. After presentation of multiple naturalistic scenes within a working memory paradigm, recognition was assessed 30 min and 24 h later in three groups of subjects. One group of subjects engaged in a focused attention task [the Revised Attentional Network Task (R-ANT)] in the 30 min after exposure to the scenes. Another group of subjects remained in the testing room during the 30 min after scene exposure and engaged in no goal- or task-directed activities. A third group of subjects left the testing room and returned 30 min later. A signal detection analysis revealed no significant differences among the three groups in hits, false alarms, or sensitivity on the 30-min recognition task. At the 24-h recognition test, the group that performed the R-ANT made significantly fewer hits compared to the group that left the testing room and did not perform the attention ask. The group that performed the R-ANT and the group that remained in the testing room during the 30-min post-exposure interval made significantly fewer false alarms on the 24-h recognition test compared to the group that left the testing room. The group that stayed in the testing room and engaged in no goal- or task-directed activities exhibited significantly higher sensitivity (d′) compared to the group that left the testing room and the group that performed the R-ANT task. Staying in the same context after exposure to new information and resting quietly with minimal engagement of attention results in the best ability to distinguish old from novel visual stimuli

  1. Measurement of personal exposure to volatile organic compounds and particle associated PAH in three UK regions.

    PubMed

    Saborit, Juana Mari Delgado; Aquilina, Noel J; Meddings, Claire; Baker, Stephen; Vardoulakis, Sotiris; Harrison, Roy M

    2009-06-15

    Personal exposures to 15 volatile organic compounds (VOC) and 16 polycyclic aromatic hydrocarbons (PAH) of 100 adult nonsmokers living in three UK areas, namely London, West Midlands, and rural South Wales, were measured using an actively pumped sampler carried around by the volunteers for 5/1 (VOC/PAH) consecutive 24-h periods, following their normal lifestyle. Results from personal exposure measurements categorized by geographical location, type of dwelling, and exposure to environmental tobacco smoke (ETS) are presented. The average personal exposure concentration to benzene, 1,3-butadiene, and benzo(a)pyrene representing the main carcinogenic components of the VOC and PAH mixture were 2.2 +/- 2.5 microg/m3, 0.4 +/- 0.7 microg/m3, and 0.3 +/- 0.7 ng/m3 respectively. The association of a number of generic factors with personal exposure concentrations was investigated, including first-line property, traffic, the presence of an integral garage, and ETS. Only living in houses with integral garages and being exposed to ETS were identified as unequivocal contributors to VOC personal exposure, while only ETS had a clear effect upon PAH personal exposures. The measurements of personal exposures were compared with health-based European and UK air quality guidelines, with some exceedences occurring. Activities contributing to high personal exposures included the use of a fireplace in the home, ETS exposure, DIY (i.e., construction and craftwork activities), and photocopying, among others. PMID:19603680

  2. Persistence of the acute effects of ozone exposure

    SciTech Connect

    Folinsbee, L.J.; Horvath, S.M.

    1986-12-01

    Reexposure to ozone 24 h after an initial exposure results in greater decreases in forced expiratory tests of lung function following the second exposure. The purpose of this study was to determine whether this hyperresponsiveness was present earlier than 24 h or persisted beyond 24 h. Four groups of subjects (n = 6,6,7,7) were exposed to 0.25 ppm ozone and then reexposed at 12, 24, 48, or 72 h, respectively. During the 1-h exposures (Ta = 20 degrees C, RH = 70%) all subjects exercised continuously at approximately 65% of their respective peak VO2; VE averaged 63 L X min-1. The decrease in FEV1.0 after the second ozone exposure was significantly larger than that after the first for subjects reexposed at 12 or 24 h; FEV1.0 dropped 12% and 19% in the 12 h group, and 20% and 35% in the 24 h group. Subjects reexposed at 48 or 72 h had FEV1.0 responses which were not significantly different from the first exposure. Delta FEV1.0 on the first and second exposures were significantly correlated (r = 0.59). Symptoms generally paralleled changes in function. We conclude that the hyperresponsiveness to ozone following exposure to 0.25 ppm ozone under the conditions of this study is apparent within 12 h and is not present at 72 h.

  3. Personal coarse particulate matter exposures in an adult cohort

    NASA Astrophysics Data System (ADS)

    Williams, Ron; Case, Martin; Yeatts, Karin; Chen, Fu-Lin; Scott, James; Svendsen, Erik; Devlin, Robert

    Volunteers associated with the North Carolina Adult Asthma and Environment Study (NCAAES) participated in an investigation of personal daily exposures to coarse and fine particulate matter size fractions (PM 10-2.5, PM 2.5). Data from these personal measurements were then compared to community-based measures that might typically represent surrogate measurements of exposure often used in epidemiological assessments. To determine personal exposures to various particulate matter (PM) size fractions, a recently evaluated personal PM monitor capable of direct PM 10-2.5 size fraction collection was used. Participants living in the central region of North Carolina and enrolled in the NCAAES were asked to wear the monitor attached to a supporting backpack for 24-h collection periods. These volunteers were monitored for 2 to 4 days with subsequent gravimetric analysis of their PM samples. Personal PM 10-2.5 mass concentrations were observed to be highly variable and ranged from 7.6 to 40.2 μg/m 3 over an 8-month period. The median for this measurement from all participants (50th percentile) was 13.7 μg/m 3. A coefficient of determination ( r2) of 0.02 was established for community-based PM 10-2.5 mass concentrations versus personal exposures. Similar coefficients established for PM 2.5 mass revealed only a modest improvement in agreement ( r2 = 0.12). Data from the exposure findings are reported here.

  4. Neonatal Benzo[a]pyrene Exposure Induces Oxidative Stress and DNA Damage Causing Neurobehavioural Changes during the Early Adolescence Period in Rats.

    PubMed

    Patel, Bhupesh; Das, Saroj Kumar; Patri, Manorama

    2016-01-01

    Humans are exposed to polycyclic aromatic hydrocarbons (PAHs) by ingestion of contaminated food and water. Prenatal exposure to benzo[a]pyrene (B[a]P) like PAHs through the placental barrier and neonatal exposure by breast milk and the environment may affect early brain development. In the present study, single intracisternal administration of B[a]P (0.2 and 2.0 µg/kg body weight) to male Wistar rat pups at postnatal day 5 (PND5) was carried out to study its specific effect on neonatal brain development and its consequences at PND30. B[a]P administration showed a significant increase in exploratory and anxiolytic-like behaviour with elevated hippocampal lipid peroxidation and protein oxidation at PND30. Further, DNA damage was estimated in vitro (Neuro2a and C6 cell lines) by the comet assay, and oxidative DNA damage of hippocampal sections was measured in vivo following exposure to B[a]P. DNA strand breaks (single and double) significantly increased due to B[a]P at PND30 in hippocampal neurons and increased the nuclear tail moment in Neuro2a cells. Hippocampal 8-oxo-2'-deoxyguanosine production was significantly elevated showing expression of more TUNEL-positive cells in both doses of B[a]P. Histological studies also revealed a significant reduction in mean area and perimeter of hippocampal neurons in rats treated with B[a]P 2.0 μg/kg, when compared to naïve and control rats. B[a]P significantly increased anxiolytic-like behaviour and oxidative DNA damage in the hippocampus causing apoptosis that may lead to neurodegeneration in adolescence. The findings of the present study address the potential role of B[a]P in inducing oxidative stress-mediated neurodegeneration in the hippocampus through oxidative DNA damage in the early adolescence period of rats. PMID:27271523

  5. Effect on the H19 gene methylation of sperm and organs of offspring after chlorpyrifos-methyl exposure during organogenesis period.

    PubMed

    Shin, Hyo-Sook; Seo, Jong-Hun; Jeong, Sang-Hee; Park, Sung-Won; Park, Young-Il; Son, Seong-Wan; Kang, Hwan-Goo; Kim, Jin Suk

    2015-12-01

    To elucidate the effect on the H19 gene methylation of sperm and organs in offspring by chlorpyrifos-methyl (CPM) exposure during organogenesis period, CPM was administered at doses of 4 (CPM4), 20 (CPM20), and 100 (CPM100) mg/kg bw/day from 7 days post coitum (d.p.c.) to 17 d.p.c. after mating CAST/Ei (♂) and B6 (♀). Anogenital distance (AGD) was measured at postnatal day (PND) 21. Clinical signs, body weights, feed and water consumption, organs weights, serum hormone values, and H19 methylation level of organ and sperm were measured at PND63. Body weights were significantly lower than control until PND6. AGD was significantly decreased in the CPM100 group in males and increased in the CPM20 group in females. The absolute weights of the thymus and epididymis were significantly increased for males in all of CPM treatment groups. In the CPM20 group, absolute weights of liver, kidney, heart, lung, spleen, prostate gland, and testes were significantly increased. Testosterone concentrations in serum were significantly increased by CPM treatment in males. H19 methylation level of liver and thymus showed decreased pattern in a dose-dependent manner in males. The levels of H19 methylation in sperm were 73.76 ± 7.16% (Control), 57.84 ± 12.94% (CPM4), 64.24 ± 3.79% (CPM20), and 64.24 ± 3.79% (CPM100). Conclusively, CPM exposure during organogenesis period can disrupt H19 methylation in sperm, liver, and thymus and disturb the early development of offspring. PMID:25782373

  6. Twelve weeks of moderate aerobic exercise without dietary intervention or weight loss does not affect 24-h energy expenditure in lean and obese adolescents.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exercise might have a persistent effect on energy expenditure and fat oxidation, resulting in increased fat loss. However, even without weight loss, exercise results in positive metabolic effects. The effect of an aerobic exercise program on 24-h total energy expenditure (TEE), and its components-ba...

  7. COMPARISON OF 24H AVERAGE VOC MONITORING RESULTS FOR RESIDENTIAL INDOOR AND OUTDOOR AIR USING CARBOPACK X-FILLED DIFFUSIVE SAMPLERS AND ACTIVE SAMPLING - A PILOT STUDY

    EPA Science Inventory

    Analytical results obtained by thermal desorption GC/MS for 24h diffusive sampling of 11 volatile organic compounds (VOCs) are compared with results of time-averaged active sampling at a known constant flow rate. Air samples were collected with co-located duplicate diffusive samp...

  8. Hyperinsulinaemia reduces the 24-h virological response to PEG-interferon therapy in patients with chronic hepatitis C and insulin resistance.

    PubMed

    Bortoletto, G; Scribano, L; Realdon, S; Marcolongo, M; Mirandola, S; Franceschini, L; Bonisegna, S; Noventa, F; Plebani, M; Martines, D; Alberti, A

    2010-07-01

    Insulin resistance (IR) reduces response to pegylated-interferon (PEG-IFN)/ribavirin in chronic hepatitis C (CHC), but the mechanisms are still undefined. We examined the relationship between baseline insulin levels, the main component affecting homeostasis model of assessment - insulin resistance (HOMA-IR) for assessment of IR in non-diabetic patients, and the 'acute' virological response to PEG-IFN measured 24 h after the first injection and taken as correlate of intracellular interferon signalling. In 62 patients treated with PEG-IFN/Ribavirin, serum insulin and HOMA-IR were assessed at baseline, while hepatitis C virus (HCV)-RNA was measured at baseline and 24 h, 1, 2, 4 and 12 weeks after treatment initiation. Sustained virological response was examined 24 weeks after therapy discontinuation. Mean baseline insulin was 11.52 +/- 8.51 U/L and mean HOMA-IR was 2.65 +/- 2.01 both being significantly higher with advanced liver fibrosis. Hepatitis C virus-RNA decay observed 24 h after the first injection of PEG-IFN was significantly lower (0.7 +/- 0.8 log) in patients with HOMA > or =3 compared with those with HOMA <3 (1.7 +/- 0.8, P = 0.001). A highly significant (r = -0.42) inverse correlation was observed between baseline insulin levels and the 24-h HCV-RNA decay. The difference in early viral kinetics between patients with HOMA > or =3 or <3 resulted in a significant difference in the percentage of patients achieving rapid (week 4) and sustained virological response. Multivariate analysis, inclusive of patient age, HCV genotype and fibrosis stage, identified baseline insulin levels as the main independent variable affecting the 24-h response to PEG-IFN. Hyperinsulinaemia reduces the cellular response to Pegylated-interferon in CHC with IR. Strategies to reduce insulin levels before initiation of treatment should be pursued to improve efficacy of anti-viral treatment. PMID:19878535

  9. Ultra-early microsurgical treatment within 24 h of SAH improves prognosis of poor-grade aneurysm combined with intracerebral hematoma

    PubMed Central

    CHEN, JUNHUI; ZHU, JUN; HE, JIANQING; WANG, YUHAI; CHEN, LEI; ZHANG, CHUNLEI; ZHOU, JINGXU; YANG, LIKUN

    2016-01-01

    Spontaneous subarachnoid hemorrhage (SAH) is the most common cerebrovascular disease. The conventional treatment for SAH is usually associated with high mortality. The present study aims to assess the prognosis of microsurgical treatment for patients with poor-grade aneurysm (Hunt and Hess grades IV–V) associated with intracerebral hematoma. A total of 18 consecutive patients who were diagnosed with poor-grade aneurysm accompanied with intracerebral hematoma were retrospectively recruited. All patients underwent microsurgical treatment between April 2010 and June 2013 at The 101st Hospital of Chinese People's Liberation Army (Wuxi, China). Among them, 15 cases underwent microsurgery within 24 h of SAH, and 3 cases underwent microsurgery 24 h following SAH. All 18 cases were examined by computed tomography angiography (CTA). The outcome was assessed during a follow-up time of 6–36 months. According to the Glasgow Outcome Scale, 4 patients experienced a good recovery, 6 were dissatisfied with the outcome, 4 were in vegetative state and 4 succumbed to disease. Poor outcome occurred in patients with an aneurysm diameter >10 mm, exhibited >50 ml volume of intracerebral hematoma or presented cerebral hernia prior to the surgical operation. The outcome of ultra-early surgery (within 24 h of SAH) was improved, compared with that of surgery following 24 h of SAH (P=0.005). Among 7 patients who accepted extraventricular drainage, good outcomes were achieved in 4 of them, whereas dissatisfaction and mortality occurred in 2 and 1 patients, respectively. Therefore, ultra-early microsurgery (within 24 h of SAH) combined with extraventricular drainage may improve the prognosis of patients with poor-grade aneurysm. PMID:27123084

  10. Perturbed energy balance and hydration status in ultra-endurance runners during a 24 h ultra-marathon.

    PubMed

    Costa, Ricardo J S; Gill, Samantha K; Hankey, Joanne; Wright, Alice; Marczak, Slawomir

    2014-08-14

    The present study aimed to assess the adequacy of energy, macronutrients and water intakes of ultra-endurance runners (UER) competing in a 24 h ultra-marathon (distance range: 122-208 km). The ad libitum food and fluid intakes of the UER (n 25) were recorded throughout the competition and analysed using dietary analysis software. Body mass (BM), urinary ketone presence, plasma osmolality (POsmol) and volume change were determined at pre- and post-competition time points. Data were analysed using appropriate t tests, with significance set at P <0·05. The total energy intake and expenditure of the UER were 20 (sd 12) and 55 (sd 11) MJ, respectively (control (CON) (n 17): 12 (sd 1) and 14 (sd 5) MJ, respectively). The protein, carbohydrate and fat intakes of the UER were 1·1 (sd 0·4), 11·3 (sd 7·0) and 1·5 (sd 0·7) g/kg BM, respectively. The rate of carbohydrate intake during the competition was 37 (sd 24) g/h. The total water intake of the UER was 9·1 (sd 4·0) litres (CON: 2·1 (sd 1·0) litres), while the rate of water intake was 378 (sd 164) ml/h. Significant BM loss occurred at pre- to post-competition time points (P =0·001) in the UER (1·6 (sd 2·0) %). No significant changes in POsmol values were observed at pre- (285 (sd 11) mOsmol/kg) to post-competition (287 (sd 10) mOsmol/kg) time points in the UER and were lower than those recorded in the CON group (P <0·05). However, plasma volume (PV) increased at post-competition time points in the UER (10·2 (sd 9·7) %; P <0·001). Urinary ketones were evident in the post-competition samples of 90 % of the UER. Energy deficit was observed in all the UER, with only one UER achieving the benchmark recommendations for carbohydrate intake during endurance exercise. Despite the relatively low water intake rates recorded in the UER, hypohydration does not appear to be an issue, considering increases in PV values observed in the majority (80 %) of the UER. Population-specific dietary recommendations may be

  11. Personal exposures to fine particulate matter and black carbon in households cooking with biomass fuels in rural Ghana

    PubMed Central

    Van Vliet, Eleanne D.S.; Asante, Kwakupoku; Jack, Darby W.; Kinney, Patrick L.; Whyatt, Robin M.; Chillrud, Steven N.; Abokyi, Livesy; Zandoh, Charles; Owusu-Agyei, Seth

    2014-01-01

    Objective To examine cooking practices and 24-h personal and kitchen area exposures to fine particulate matter (PM2.5) and black carbon in cooks using biomass in Ghana. Methods Researchers administered a detailed survey to 421 households. In a sub-sample of 36 households, researchers collected 24-h integrated PM2.5 samples (personal and kitchen area); in addition, the primary cook was monitored for real-time PM2.5. All filters were also analyzed for black carbon using a multi-wavelength reflectance method. Predictors of PM2.5 exposure were analyzed, including cooking behaviors, fuel, stove and kitchen type, weather, demographic factors and other smoke sources. Results The majority of households cooked outdoors (55%; 231/417), used biomass (wood or charcoal) as their primary fuel (99%; 412/413), and cooked on traditional fires (77%, 323/421). In the sub-sample of 29 households with complete, valid exposure monitoring data, the 24-h integrated concentrations of PM2.5 were substantially higher in the kitchen sample (mean 446.8 μg/m3) than in the personal air sample (mean 128.5 μg/m3). Black carbon concentrations followed the same pattern such that concentrations were higher in the kitchen sample (14.5 μg/m3) than in the personal air sample (8.8 μg/m3). Spikes in real-time personal concentrations of PM2.5 accounted for the majority of exposure; the most polluted 5%, or 72 min, of the 24-h monitoring period accounted for 75% of all exposure. Two variables that had some predictive power for personal PM2.5 exposures were primary fuel type and ethnicity, while reported kerosene lantern use was associated with increased personal and kitchen area concentrations of black carbon. Conclusion Personal concentrations of PM2.5 exhibited considerable inter-subject variability across kitchen types (enclosed, semi-enclosed, outdoor), and can be elevated even in outdoor cooking settings. Furthermore, personal concentrations of PM2.5 were not associated with kitchen type and were

  12. Comparative Efficacies of Human Simulated Exposures of Tedizolid and Linezolid against Staphylococcus aureus in the Murine Thigh Infection Model

    PubMed Central

    Keel, R. A.; Tessier, P. R.; Crandon, J. L.

    2012-01-01

    Tedizolid (formally torezolid) is an expanded-spectrum oxazolidinone with enhanced in vitro potency against Gram-positive pathogens, including methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA). The efficacies of human simulated exposures of tedizolid and linezolid against S. aureus in an immunocompetent mouse thigh model over 3 days were compared. Four strains of MRSA and one of MSSA with tedizolid and linezolid MICs ranging from 0.25 to 0.5 and from 2 to 4 μg/ml, respectively, were utilized. Tedizolid or linezolid was administered in a regimen simulating a human steady-state 24-h area under the free concentration-time curve of 200 mg every 24 h (Q24) or 600 mg Q12, respectively. Thighs were harvested after 4, 8, 12, 24, 36, 48, and 72 h, and efficacy was determined by the change in bacterial density. The mean bacterial density in control mice increased over the 3-day period. After 24 h of treatment, a reduction in bacterial density of ≥1 log CFU was observed for both the tedizolid and linezolid treatments. Antibacterial activity was enhanced for both agents with a reduction of ≥2.6 log CFU after 72 h of treatment. Any statistically significant differences (P ≤ 0.05) in efficacy between the agents were transient and did not persist throughout the 72-h treatment period. The tedizolid and linezolid regimens demonstrated similar in vivo efficacies against the S. aureus isolates tested. Both agents were bacteriostatic at 24 h and bactericidal on the third day of treatment. These data support the clinical utility of tedizolid for skin and skin structure infections caused by S. aureus, as well as the bactericidal activity of the oxazolidinones after 3 days of treatment. PMID:22687504

  13. Plasticity of the Intrinsic Period of the Human Circadian Timing System

    PubMed Central

    Scheer, Frank A.J.L.; Wright, Kenneth P.; Kronauer, Richard E.; Czeisler, Charles A.

    2007-01-01

    Human expeditions to Mars will require adaptation to the 24.65-h Martian solar day-night cycle (sol), which is outside the range of entrainment of the human circadian pacemaker under lighting intensities to which astronauts are typically exposed. Failure to entrain the circadian time-keeping system to the desired rest-activity cycle disturbs sleep and impairs cognitive function. Furthermore, differences between the intrinsic circadian period and Earth's 24-h light-dark cycle underlie human circadian rhythm sleep disorders, such as advanced sleep phase disorder and non-24-hour sleep-wake disorders. Therefore, first, we tested whether exposure to a model-based lighting regimen would entrain the human circadian pacemaker at a normal phase angle to the 24.65-h Martian sol and to the 23.5-h day length often required of astronauts during short duration space exploration. Second, we tested here whether such prior entrainment to non-24-h light-dark cycles would lead to subsequent modification of the intrinsic period of the human circadian timing system. Here we show that exposure to moderately bright light (∼450 lux; ∼1.2 W/m2) for the second or first half of the scheduled wake episode is effective for entraining individuals to the 24.65-h Martian sol and a 23.5-h day length, respectively. Estimations of the circadian periods of plasma melatonin, plasma cortisol, and core body temperature rhythms collected under forced desynchrony protocols revealed that the intrinsic circadian period of the human circadian pacemaker was significantly longer following entrainment to the Martian sol as compared to following entrainment to the 23.5-h day. The latter finding of after-effects of entrainment reveals for the first time plasticity of the period of the human circadian timing system. Both findings have important implications for the treatment of circadian rhythm sleep disorders and human space exploration. PMID:17684566

  14. Implications of pulsed chemical exposures for aquatic life criteria and wastewater permit limits.

    PubMed

    Diamond, Jerome M; Klaine, Stephen J; Butcher, Jonathan B

    2006-08-15

    Subacute effects of pulsed copper, zinc, or ammonia exposures were examined, including a range of pulse concentrations, durations, frequencies, and recovery times between pulses, using short-term chronic Pimephales promelas and 21-d Daphnia magna tests. Sublethal effects were rarely observed independent of mortality. Effects were observed only at concentrations near the species continuous exposure 48 h LC50 for each chemical. Daphnia often rebounded from temporary reproduction effects, meeting or exceeding control responses by the end of the test. Effects of 24 h ammonia or copper pulses were diminished soon after the pulse was removed, while 24 h zinc pulses caused continued effects for several days following removal of the pulse, indicating a slower uptake and/or depuration rate for zinc. D. magna exhibited less mortality as copper pulses were spaced further apart, while fish were equally or more affected with longer recovery times between copper pulses, indicative of different adaptation mechanisms between the two species. Responses were not predictable based on either average concentration or a combination of duration and concentration. Chronic water quality criteria and effluent permit limits, expressed as a 4- or 30-d average concentration, respectively, may not be appropriate for protecting against effects of pulsed exposures, depending on the frequency, magnitude, and duration of pulses, as well as the recovery period between events. PMID:16955918

  15. Effects of a quercetin-rich onion skin extract on 24 h ambulatory blood pressure and endothelial function in overweight-to-obese patients with (pre-)hypertension: a randomised double-blinded placebo-controlled cross-over trial.

    PubMed

    Brüll, Verena; Burak, Constanze; Stoffel-Wagner, Birgit; Wolffram, Siegfried; Nickenig, Georg; Müller, Cornelius; Langguth, Peter; Alteheld, Birgit; Fimmers, Rolf; Naaf, Stefanie; Zimmermann, Benno F; Stehle, Peter; Egert, Sarah

    2015-10-28

    The polyphenol quercetin may prevent CVD due to its antihypertensive and vasorelaxant properties. We investigated the effects of quercetin after regular intake on blood pressure (BP) in overweight-to-obese patients with pre-hypertension and stage I hypertension. In addition, the potential mechanisms responsible for the hypothesised effect of quercetin on BP were explored. Subjects (n 70) were randomised to receive 162 mg/d quercetin from onion skin extract powder or placebo in a double-blinded, placebo-controlled cross-over trial with 6-week treatment periods separated by a 6-week washout period. Before and after the intervention, ambulatory blood pressure (ABP) and office BP were measured; urine and blood samples were collected; and endothelial function was measured by EndoPAT technology. In the total group, quercetin did not significantly affect 24 h ABP parameters and office BP. In the subgroup of hypertensives, quercetin decreased 24 h systolic BP by -3·6 mmHg (P=0·022) when compared with placebo (mean treatment difference, -3·9 mmHg; P=0·049). In addition, quercetin significantly decreased day-time and night-time systolic BP in hypertensives, but without a significant effect in inter-group comparison. In the total group and also in the subgroup of hypertensives, vasoactive biomarkers including endothelin-1, soluble endothelial-derived adhesion molecules, asymmetric dimethylarginine, angiotensin-converting enzyme activity, endothelial function, parameters of oxidation, inflammation, lipid and glucose metabolism were not affected by quercetin. In conclusion, supplementation with 162 mg/d quercetin from onion skin extract lowers ABP in patients with hypertension, suggesting a cardioprotective effect of quercetin. The mechanisms responsible for the BP-lowering effect remain unclear. PMID:26328470

  16. Survey of construction workers repeatedly exposed to chlorine over a three to six month period in a pulpmill: I. Exposure and symptomatology.

    PubMed Central

    Courteau, J P; Cushman, R; Bouchard, F; Quévillon, M; Chartrand, A; Bhérer, L

    1994-01-01

    OBJECTIVE--The admission to hospital of three construction workers with acute respiratory distress caused by inhalation of chlorine gas prompted the inspection of a building site located in a kraft pulpmill. The accidental emissions had taken place in the bleach plant and the construction workers assigned there were surveyed to uncover possible large scale health effects. DESIGN AND PARTICIPANTS--A questionnaire was presented to 281 workers (participation rate = 97%); 257 workers reported an average of 24 exposure episodes to chlorine and derivatives over a three to six month period. The air monitoring data available from the pulpmill's industrial hygienist were not useful in linking specific events reported by the workers to environmental conditions in the bleach plant. RESULTS--Over 60% of the workers described a characteristic flu like syndrome that lasted for an average of 11 days and was exacerbated by new bouts of exposure. Irritation of the throat (78%) and eyes (77%), cough (67%), and headache (63%) were the most often reported symptoms. Shortness of breath was reported by 54% of the participants and was not associated with age, smoking state, or history of asthma or chronic bronchitis. First aid self referral was associated with significantly greater reporting of most symptoms, including dyspnoea and cough. A significantly greater proportion of workers in the dyspnoea group had gone at least once for first aid care after a gassing incident (64% as opposed to 48%, p = 0.008). Throat irritation and cough persisted for mean intervals of eight and 11 days respectively. A flu like syndrome lasted for an average of 20 days. Seventy one subjects were considered to be a moderate to high risk of having persisting respiratory symptoms. CONCLUSION--Throat and eye irritation as well as cough and flu like symptoms are frequent occurrences after repeated accidental inhalation of chlorine. Subjects who consulted first aid care stations after a gassing incident are more

  17. Utilization of potatoes for life support systems in space. III - Productivity at successive harvest dates under 12-h and 24-h photoperiods

    NASA Technical Reports Server (NTRS)

    Wheeler, Raymond M.; Tibbitts, Theodore W.

    1987-01-01

    Efficient crop production for controlled ecological life support systems requires near-optimal growing conditions with harvests taken when production per unit area per unit time is maximum. This maximum for potato was determined using data on Norland plants which were grown in walk-in growth rooms under 12-h and 24-h photoperiods at 16 C. Results show that high tuber production can be obtained from potatoes grown under a continuous light regime. The dry weights (dwt) of tuber and of the entire plants were found to increase under both photoperiods until the final harvest date (148 days), reaching 5732 g tuber dwt and 704 g total dwt under 12-h, and 791 g tuber dwt and 972 g total dwt under 24-h.

  18. Association Between Estimated 24-h Urinary Sodium Excretion and Metabolic Syndrome in Korean Adults: The 2009 to 2011 Korea National Health and Nutrition Examination Survey.

    PubMed

    Won, Jong Chul; Hong, Jae Won; Noh, Jung Hyun; Kim, Dong-Jun

    2016-04-01

    High sodium intake is 1 of the modifiable risk factors for cardiovascular disease, but in Korea, daily sodium intake is estimated to be double the level recommended by World Health Organization. We investigated the association between the estimated 24-h urinary sodium excretion (24hUNaE) and metabolic syndrome using nationwide population data.In total, 17,541 individuals (weighted n = 33,200,054; weighted men, 52.5% [95% confidence interval, CI = 51.8-53.3]; weighted age, 45.2 years [44.7-45.7]) who participated in the Korean Health and Nutrition Examination Survey 2009 to 2011 were investigated. NCEP-ATP III criteria for metabolic syndrome were used, and sodium intake was estimated by 24hUNaE using Tanaka equation with a spot urine sample.The weighted mean 24hUNaE values were 3964 mg/d (95% CI = 3885-4044) in men and 4736 mg/d (4654-4817) in women. The weighted age-adjusted prevalence of metabolic syndrome was 22.2% (21.4-23.0), and it increased with 24hUNaE quartile in both men and women (mean ± standard error of the mean; men: 22.5 ± 1.0%, 23.0 ± 1.0%, 26.0 ± 1.2%, and 26.0 ± 1.2%; P = 0.026; women: 19.4 ± 0.8%, 17.7 ± 0.8%, 19.8 ± 1.0%, and 23.0 ± 1.1%; P = 0.002, for quartiles 1-4, respectively). Even after adjustment for age, daily calorie intake, heavy alcohol drinking, regular exercise, college graduation, and antihypertensive medication, the weighted prevalence of metabolic syndrome increased with the increase in 24hUNaE in men and women. The weighted 24hUNaE was positively associated with the number of metabolic syndrome components after adjustment for confounding factors in men and women. In subjects without antihypertensive medication, the odds ratio for metabolic syndrome in quartile 4 of 24hUNaE compared with quartile 1 was 1.56 (1.33-1.84, P < 0.001) in the total population, 1.66 (1.34-2.06, P < 0.001) in men, and 1.94 (1.49-2.53, P < 0.001) in women.In this nationwide

  19. Evaluation of reduction of Fraser incubation by 24h in the EN ISO 11290-1 standard on detection and diversity of Listeria species.

    PubMed

    Gnanou Besse, Nathalie; Favret, Sandra; Desreumaux, Jennifer; Decourseulles Brasseur, Emilie; Kalmokoff, Martin

    2016-05-01

    The EN ISO 11290-1 method for the isolation of Listeria monocytogenes from food is carried out using a double enrichment in Fraser broths. While the method is effective it is also quite long requiring 4-7 days to process a contaminated food, and may be adversely affected by inter-strain and/or inter-species competition in samples containing mixed Listeria populations. Currently, we have little information on the impact of competition on food testing under routine conditions. Food samples (n=130) were analyzed using the standard method and the evolution of Listeria populations in 89 naturally contaminated samples followed over the entire enrichment process. In most instances, maximum increase in L. monocytogenes population occurred over the first 24h following sub-culture in Full Fraser broth and strain recovery was similar at both 24 and 48 h, indicating that the second enrichment step can be reduced by 24h without impacting the recovery of L. monocytogenes or affecting the sensitivity of the method. In approximately 6% of naturally contaminated samples the presence of competing Listeria species adversely impacted L. monocytogenes population levels. Moreover, these effects were more pronounced during the latter 24h of the Fraser enrichment, and potentially could affect or complicate the isolation of these strains. PMID:26913375

  20. Predictors of reported consumption of low-nutrient-density foods in a 24-h recall by 8-16 year old US children and adolescents.

    PubMed

    Kant, Ashima K; Graubard, Barry I

    2003-10-01

    The purpose of this study was to develop an explanatory model to predict the number of low-nutrient-density (LND) foods reported in a 24-h recall by US children and adolescents using data from the third National Health and Nutrition Examination Survey. The reported number of LND foods was estimated from 24-h dietary recall data for 8-16 year old respondents (n=4137; 2024 males and 2113 females). The LND foods included--baked and dairy desserts, sweeteners, salty snacks, visible/discretionary fat, and miscellaneous. The predictive ability of socio-demographic, family, weight/dieting related, life-style or food consumption related subject characteristics was determined using multiple linear regression analyses. The strongest independent negative predictor of the reported number of LND foods was the amount of nutrient-dense foods from the five major food groups. In addition, number of eating occasions reported was a significant independent positive predictor, and the weekly frequency of consuming a complete school lunch was a significant independent negative predictor of the reported number of LND foods. These models explained approximately 55% of the variance in LND food reporting in both males and females. Socio-demographic, family, body weight, or lifestyle characteristics contributed little to predicting the number of LND foods reported in a 24-h recall. PMID:14550315

  1. Hydra viridissima (green Hydra) rapidly recovers from multiple magnesium pulse exposures.

    PubMed

    Prouse, Andrea E; Hogan, Alicia C; Harford, Andrew J; van Dam, Rick A; Nugegoda, Dayanthi

    2015-08-01

    The time taken for organisms to recover from a pulsed toxicant exposure is an important consideration when water quality guidelines are applied to intermittent events in the environment. Organisms may appear to have recovered by standard toxicity testing methods but could carry residual toxicant or damage that may make them more sensitive to subsequent pulses. Such cumulative effects may render guidelines underprotective. The present study evaluated recovery of the freshwater cnidarian Hydra viridissima following multiple pulse exposure to magnesium (Mg). The H. viridissima were exposed to 4-h pulses of 790 mg/L and 1100 mg/L separated by 2-h, 10-h, 18-h, 24-h, 48-h, and 72-h recovery periods. Twenty-four-hour pulses of 570 mg/L, 910 mg/L, and 940 mg/L were separated by 24-h, 96-h, and 168-h recovery periods. All treatments showed similar or reduced sensitivity to the second pulse when compared with the single pulse, indicating that full recovery occurred prior to a second pulse-exposure. Five variations of equivalent time-weighted average concentrations were used to compare sensitivity of Hydra with various pulse scenarios. The sensitivity of the organisms to the multiple pulses was significantly lower than the time-weighted average continuous exposure response in 3 of the 4 scenarios tested, indicating that the Hydra benefited from interpulse recovery periods. The findings will be utilized alongside those from other species to inform the use of a site-specific, duration-based water quality guideline for Mg, and they provide an example of the use of empirical data in the regulation of toxicant pulses in the environment. PMID:25772150

  2. The Influence of User Characteristics and a Periodic Email Prompt on Exposure to an Internet-Delivered Computer-Tailored Lifestyle Program

    PubMed Central

    van Osch, Liesbeth; Schulz, Daniela N; Kremers, Stef PJ; de Vries, Hein

    2012-01-01

    Background The Internet is a promising medium in the field of health promotion for offering tailored and targeted lifestyle interventions applying computer-tailored (CT) techniques to the general public. Actual exposure to CT interventions is not living up to its high expectations, as only a (limited) proportion of the target group is actually using these programs. Objective To investigate exposure to an Internet-delivered, CT lifestyle intervention, targeting physical activity, fruit and vegetable intake, smoking behavior, and alcohol intake, we focused on three processes: first use, prolonged use, and sustained use. The first objectives were to identify user characteristics that predict initiation of an online CT lifestyle program (first use) and completion of this program (prolonged use). Furthermore, we studied the effect of using a proactive strategy, consisting of periodic email prompts, on program revisits (sustained use). Methods The research population for this study consisted of Dutch adults participating in the Adult Health Monitor, offered by the regional public health services. We used a randomized controlled trial design to assess predictors of first use, prolonged use, and sustained use. Demographics and behavioral characteristics, as well as the strategy used for revisiting, were included as predictors in the model. Results A total of 9169 participants indicated their interest in the new program and 5168 actually logged in to the program. Participants significantly more likely to initiate one of the CT modules were male, older, and employed, and had a lower income, higher body mass index, and relatively unhealthy lifestyle. Participants significantly more likely to complete one of the CT modules were older and had a higher income and a relatively healthier lifestyle. Finally, using a proactive strategy influenced sustained use, with people from the prompting condition being more likely to revisit the program (odds ratio 28.92, 95% confidence

  3. The physiological consequences of varied heat exposure events in adult Myzus persicae: a single prolonged exposure compared to repeated shorter exposures

    PubMed Central

    Andrew, Nigel R.

    2016-01-01

    The study of environmental stress tolerance in aphids has primarily been at low temperatures. In these cases, and in the rare cases of high temperature tolerance assessments, all exposures had been during a single stress event. In the present study, we examined the physiological consequences of repeated high temperature exposure with recovery periods between these stress events in Myzus persicae. We subjected individuals to either a single prolonged three hour heating event, or three one hour heating events with a recovery time of 24 h between bouts. Aphids exposed to repeated bouts of high temperatures had more glucose and higher expression of proteins and osmolyte compounds, such as glycerol, compared to the prolonged exposure group. However, aphids exposed to the repeated high temperature treatment had reduced sources of energy such as trehalose and triglyceride compounds than the prolonged exposure group. Recovery time had more physiological costs (based on production of more protein and consumption of more trehalose and triglyceride) and benefits (based on production of more osmolytes) in repeated high temperature treatments. As aphids are known to respond differently to constant versus ‘natural’ fluctuating temperature regimes, conclusions drawn from constant temperature data sets may be problematic. We suggest future experiments assessing insect responses to thermal stress incorporate a repeated stress and recovery pattern into their methodologies. PMID:27547583

  4. The physiological consequences of varied heat exposure events in adult Myzus persicae: a single prolonged exposure compared to repeated shorter exposures.

    PubMed

    Ghaedi, Behnaz; Andrew, Nigel R

    2016-01-01

    The study of environmental stress tolerance in aphids has primarily been at low temperatures. In these cases, and in the rare cases of high temperature tolerance assessments, all exposures had been during a single stress event. In the present study, we examined the physiological consequences of repeated high temperature exposure with recovery periods between these stress events in Myzus persicae. We subjected individuals to either a single prolonged three hour heating event, or three one hour heating events with a recovery time of 24 h between bouts. Aphids exposed to repeated bouts of high temperatures had more glucose and higher expression of proteins and osmolyte compounds, such as glycerol, compared to the prolonged exposure group. However, aphids exposed to the repeated high temperature treatment had reduced sources of energy such as trehalose and triglyceride compounds than the prolonged exposure group. Recovery time had more physiological costs (based on production of more protein and consumption of more trehalose and triglyceride) and benefits (based on production of more osmolytes) in repeated high temperature treatments. As aphids are known to respond differently to constant versus 'natural' fluctuating temperature regimes, conclusions drawn from constant temperature data sets may be problematic. We suggest future experiments assessing insect responses to thermal stress incorporate a repeated stress and recovery pattern into their methodologies. PMID:27547583

  5. What a Nostril Knows: Olfactory Nerve-Evoked AMPA Responses Increase while NMDA Responses Decrease at 24-h Post-Training for Lateralized Odor Preference Memory in Neonate Rat

    ERIC Educational Resources Information Center

    Yuan, Qi; Harley, Carolyn W.

    2012-01-01

    Increased AMPA signaling is proposed to mediate long-term memory. Rat neonates acquire odor preferences in a single olfactory bulb if one nostril is occluded at training. Memory testing here confirmed that only trained bulbs support increased odor preference at 24 h. Olfactory nerve field potentials were tested at 24 h in slices from trained and…

  6. Exposure and risk assessment of the Czech population to chlorinated pesticides and polychlorinated biphenyls using archived serum samples from the period 1970 to 1990.

    PubMed

    Černá, Milena; Krsková, Andrea; Šmíd, Jiří; Malý, Marek

    2016-07-01

    The serum samples from the years 1970-1990 archived at the temperature of -20°C in the biobank primarily intended for serological survey performed in the CR since 1960 were pooled and analyzed for DDT, its metabolites, HCB, HCHs, and indicator PCB congeners using up-to-date GC/MS/MS methods to retrospectively assess health risks according to current health guidelines. Samples were pooled based on the decade of sampling, age, gender, and three geographical areas; in adults, one pooled samples consisted of ten and in children of twenty individual samples. Altogether 233 pooled samples were analyzed. For all organochlorine pesticides (OCPs), significant downward trends were observed in the period 1970-1990 (p<0.001). The levels of HCB exceeded the Biomonitoring Equivalent (BE) value. The hazard quotient (HQ) in Prague and Ostrava during the 1970s and 1980s was about 40 and in the 1990s it had dropped to about five. In Uherské Hradiště, the HQ in 1975 was one order of magnitude higher (about 170), and had decreased to approximately 12 by 1987. For both HCB and the DDT sum, the BE-related carcinogenic risk of actual concentrations in the past exceeded significantly the individually accepted cancer risk level of 10(-4). The levels of the main PCB congeners in the 1970s through 1990s revealed an upward time trend in all analyzed strata. The highest concentrations were found in the serum of residents from the hot-spot area Uherské Hradiště. Critical PCB sum concentration levels (700ng/g lipid for vulnerable population groups and 1800ng/g lipid for other population groups) were substantially exceeded with an increasing time trend. PCB sum had exceeded HBM II values of 7μg/L of serum since 1980 in all age strata. In conclusion, the body burden of the Czech general population relative to persistent organic pollutants (POPs) in the period 1970 through 1990 significantly exceeded currently existing health based limit values. The past exposure might adversely affect the

  7. Antimicrobial resistance in commensal Escherichia coli from pigs during metaphylactic trimethoprim and sulfamethoxazole treatment and in the post-exposure period.

    PubMed

    Mazurek, Justyna; Bok, Ewa; Stosik, Michał; Baldy-Chudzik, Katarzyna

    2015-02-01

    The prevalence of trimethoprim (TMP) and sulfamethoxazole (SMX) resistance in commensal E. coli from pigs was tested in this study. E. coli was derived from three groups of piglets in successive stages of metaphylactic therapy and from two groups of sows 10 and 18 weeks after the treatment. MIC values of TMP and SMX were determined for a total of 352 strains. The presence of resistance genes (dfrA1, dfrA5, dfrA7, dfrA12, dfrA17, sul1, sul2, sul3) and class 1 and 2 integron-associated dfrA gene cassettes was tested. Resistance to TMP was very high during the administration of the antimicrobial (from 97 to 100%) and amounted to 86% and 69% in the post-exposure period; MIC > 32 mg/L. The isolates from all groups of pigs were resistant to sulfamethoxazole, with MIC > 1028 mg/L. The dfrA1 and sul1 genes (as part of integrons) dominated in E. coli from piglets, but the dfrA12 and sul1 genes were prevalent in E. coli from sows. Coexistence of the different dfrA genes was detected in 71 isolates from all groups of swine. Transcription analysis revealed that most of these genes were not transcribed, particularly gene cassettes of class 1 integrons. The research revealed a high level of resistance associated with the metaphylactic treatment, persistence and circulation of resistance in bacterial populations. Diverse genetic background with multiple and not transcribed resistance genes was observed. PMID:25689993

  8. Acute exposure to ultraviolet-B radiation modulates sex steroid hormones and receptor expression in the skin and may contribute to the sex bias of melanoma in a fish model.

    PubMed

    Mitchell, David L; Fernandez, André A; Garcia, Rachel; Paniker, Lakshmi; Lin, Kevin; Hanninen, Amanda; Zigelsky, Kyle; May, Matthew; Nuttall, Mark; Lo, Herng-Hsiang; Person, Maria D; Earley, Ryan

    2014-05-01

    Using the Xiphophorus fish melanoma model, we show a strong male bias for sunlight-induced malignant melanoma, consistent with that seen in the human population. To examine underlying factors, we exposed adult X. couchianus fish to a single, sublethal dose of UVB and measured circulating sex steroid hormones and expression of associated hormone receptor genes over a 24-h period. We found that a single exposure had profound effects on circulating levels of steroid hormones with significant decreases for all free sex steroids at 6 and 24 h and increases in conjugated 2-estradiol and 11-ketotestosterone at 6 and 24 h, respectively. Whereas ARα expression increased in male and female skin, neither ARβ nor either of the ERs showed significant responses to UVB in either sex. The rapid response of male androgens and their receptors in the skin after UVB irradiation implicates hormones in the male bias of skin cancer and suggests that the photoendocrine response immediately after UV exposure may be relevant to melanomagenesis. PMID:24406016

  9. Environmental exposure to air pollution and allergens and peak flow changes.

    PubMed

    Higgins, B G; Francis, H C; Yates, C; Warburton, C J; Fletcher, A M; Pickering, C A; Woodcock, A A

    2000-07-01

    Laboratory-based studies have shown that ozone and nitrogen dioxide can potentiate the effect of allergen in sensitized asthmatic subjects, but it is not known whether this interaction is important under natural exposure conditions. Thirty-five subjects with clinical diagnoses of asthma or chronic obstructive pulmonary disease and with a provocative dose causing a 20% fall in forced expiratory volume in one second methacholine <12.25 micromol (using the Yan method) kept peak expiratory flow (PEF) records for a 4-week period during late summer, with concurrent measurement of spore and pollen counts and pollution levels. Multiple regression analysis was then used to determine the effect on PEF of aeroallergen, and of the interaction between aeroallergen and pollutant levels. A statistically significant interaction was demonstrated between total spore count and ozone, but not nitrogen dioxide. Mean PEF fell in association with increasing spore count (same-day and 24-h lag level) and PEF variability increased with increasing spore count (24-h lag level only); both changes were greater the higher the prior ozone level. These results suggest that ozone can potentiate the effect of aeroallergens in subjects with bronchial hyperreactivity under natural exposure conditions. However, the effect was small, and the clinical significance of the interaction requires further study. PMID:10933086

  10. Blocking glucocorticoid receptors at adolescent age prevents enhanced freezing between repeated cue-exposures after conditioned fear in adult mice raised under chronic early life stress.

    PubMed

    Arp, J Marit; Ter Horst, Judith P; Loi, Manila; den Blaauwen, Jan; Bangert, Eline; Fernández, Guillén; Joëls, Marian; Oitzl, Melly S; Krugers, Harm J

    2016-09-01

    Early life adversity can have long-lasting impact on learning and memory processes and increase the risk to develop stress-related psychopathologies later in life. In this study we investigated (i) how chronic early life stress (ELS) - elicited by limited nesting and bedding material from postnatal day 2 to 9 - affects conditioned fear in adult mice and (ii) whether these effects can be prevented by blocking glucocorticoid receptors (GRs) at adolescent age. In adult male and female mice, ELS did not affect freezing behavior to the first tone 24h after training in an auditory fear-conditioning paradigm. Exposure to repeated tones 24h after training also resulted in comparable freezing behavior in ELS and control mice, both in males and females. However, male (but not female) ELS compared to control mice showed significantly more freezing behavior between the tone-exposures, i.e. during the cue-off periods. Intraperitoneal administration of the GR antagonist RU38486 during adolescence (on postnatal days 28-30) fully prevented enhanced freezing behavior during the cue-off period in adult ELS males. Western blot analysis revealed no effects of ELS on hippocampal expression of glucocorticoid receptors, neither at postnatal day 28 nor at adult age, when mice were behaviorally tested. We conclude that ELS enhances freezing behavior in adult mice in a potentially safe context after cue-exposure, which can be normalized by brief blockade of glucocorticoid receptors during the critical developmental window of adolescence. PMID:27246249

  11. AN EFFICIENT MULTIPLE-EXPOSURE ANALYSIS OF THE TOXICITY OF CRISNATOL, A DNA INTERCALATOR IN PHASE II CLINICAL TRIALS

    EPA Science Inventory

    To investigate how exposure conditions influence drug toxicity assessment, we used flow cytometry to analyze the cellular and nuclear parameters of murine erythroleukemia cells (MELC) exposed (4 h + recovery, 24 h) to several concentrations of crisnatol (CRS), an antitumor agent ...

  12. The Influence of Human and Environmental Exposure Factors on Personal NO2 Exposures

    EPA Science Inventory

    The US Environmental Protection Agency’s (US EPA) Detroit Exposure and Aerosol Research Study (DEARS) deployed a total of over 2000 nitrogen dioxide, NO2, passive monitors during 3 years of field data collections. These 24-h based personal, residential outdoor and comm...

  13. Light period regulation of carbohydrate partitioning

    NASA Technical Reports Server (NTRS)

    Janes, Harry W.

    1994-01-01

    We have shown that the photosynthetic period is important in regulating carbon partitioning. Even when the same amount of carbon is fixed over a 24h period considerably more is translocated out of the leaf under the longer photosynthetic period. This is extremely important when parts of the plant other than the leaves are to be sold. It is also important to notice the amount of carbon respired in the short photosynthetic period. The light period effect on carbohydrate fixation, dark respiration, and translocation is shown in this report.

  14. Concerns regarding 24-h sampling for formaldehyde, acetaldehyde, and acrolein using 2,4-dinitrophenylhydrazine (DNPH)-coated solid sorbents

    NASA Astrophysics Data System (ADS)

    Herrington, Jason S.; Hays, Michael D.

    2012-08-01

    There is high demand for accurate and reliable airborne carbonyl measurement methods due to the human and environmental health impacts of carbonyls and their effects on atmospheric chemistry. Standardized 2,4-dinitrophenylhydrazine (DNPH)-based sampling methods are frequently applied for measuring gaseous carbonyls in the atmospheric environment. However, there are multiple short-comings associated with these methods that detract from an accurate understanding of carbonyl-related exposure, health effects, and atmospheric chemistry. The purpose of this brief technical communication is to highlight these method challenges and their influence on national ambient monitoring networks, and to provide a logical path forward for accurate carbonyl measurement. This manuscript focuses on three specific carbonyl compounds of high toxicological interest—formaldehyde, acetaldehyde, and acrolein. Further method testing and development, the revision of standardized methods, and the plausibility of introducing novel technology for these carbonyls are considered elements of the path forward. The consolidation of this information is important because it seems clear that carbonyl data produced utilizing DNPH-based methods are being reported without acknowledgment of the method short-comings or how to best address them.

  15. Cardiovascular autonomic function analysis using approximate entropy from 24-h heart rate variability and its frequency components in patients with type 2 diabetes

    PubMed Central

    Li, Xia; Yu, Shuo; Chen, Hui; Lu, Cheng; Zhang, Kuan; Li, Fangjie

    2015-01-01

    Aims/Introduction The principal aim of the present study was to investigate the cardiovascular autonomic system status of diabetes patients using approximate entropy (ApEn) extracted from 24-h heart rate variability (HRV) and its frequency components. Materials and Methods A total of 29 healthy controls and 63 type 2 diabetes patients were included. Participants’ 24-h HRV signals were recorded, and decomposed and reconstructed into four frequency components: high, low, very low and ultra low. The total 24-h HRV and its four components were divided into 24 1-h segments. ApEn values were extracted and statistically analyzed. Four traditional HRV indices, namely standard deviation of the RR intervals, root mean square of successive differences, coefficient of variance of RR intervals and ratio of low to high power of HRV, were also calculated. Results The low-frequency component contained the most abundant non-linear information, so was potentially most suitable for studying the cardiovascular system status with non-linear methods. ApEn values extracted from low- and high-frequency components of healthy controls were higher than those of diabetes patients. Except for root mean square of successive differences, standard deviation of the RR intervals, low to high power of HRV and coefficient of variance of RR intervals of healthy controls were all higher than those of diabetes patients. Conclusions The results showed that ApEn contained information on disorders of autonomic system function of diabetes patients as traditional HRV indices in time and frequency domains. ApEn and three traditional indices showed accordance to some degree. Non-linear information in subcomponents of HRV was shown, which is potentially more effective for distinguishing healthy individuals and diabetes patients than that extracted from the total HRV. Compared with diabetes patients, the cardiovascular system of healthy controls showed information of higher complexity, and better regulation

  16. Utilization of potatoes for life support systems in space: III. Productivity at successive harvest dates under 12-h and 24-h photoperiods.

    PubMed

    Wheeler, R M; Tibbitts, T W

    1987-01-01

    Potatoes are among several crops under consideration for use in controlled ecological life support systems (CELSS) being proposed for space colonies. Efficient crop production for such life support systems will require near-optimal growing conditions with harvests taken when production per unit area per unit time is maximum. To determine this maximum for potato, cv. Norland plants were grown in walk-in growth rooms under 12-h and 24-h photoperiods at 16 C and harvested at 42, 63, 84, 105, 126 and 148 days from planting. At 42 days, plants were encaged in wire fence cylinders with a cross-sectional area of 0.2 m2. The dry weights (dwt) of tubers and of the entire plants increased under both photoperiods until the final harvest date (148 days), reaching 572 g tuber dwt and 704 g total dwt under 12-h, and 791 g tuber dwt and 972 g total dwt under 24-h. At a spacing of 0.2 m2 per plant, the 148-day tuber production from plants under continuous light would equate to nearly 40 t ha-1 dry matter (200 t fresh weight), approximately twice that of exceptionally high field yields. Tuber productivity (g m-2 day-1) under the 24-h photoperiod reached a maximum of 29.4 g dwt m-2 day-1 at 126 days, but continued to rise throughout the experiment under the 12-h photoperiod, reaching 19.5 g dwt m-2 day-1 at 14 days, approximately 25 m2 would continuously provide the daily dietary energy requirements for one human. PMID:11539685

  17. Isotope concentrations from 24-h urine and 3-h serum samples can be used to measure intestinal magnesium absorption in postmenopausal women.

    PubMed

    Hansen, Karen E; Nabak, Andrea C; Johnson, Rachael Erin; Marvdashti, Sheeva; Keuler, Nicholas S; Shafer, Martin M; Abrams, Steven A

    2014-04-01

    Studies suggest a link between magnesium status and osteoporosis. One barrier to more conclusive research on the potential relation is measuring intestinal magnesium absorption (MgA), which requires the use of stable isotopes and a ≥6-d stool or 3-d urine collection. We evaluated alternative methods of measuring MgA. We administered 2 stable magnesium isotopes to 15 postmenopausal women (cohort 1) aged 62 ± 8 y with a dietary magnesium intake of 345 ± 72 mg/d. Participants fasted from 1200 h to 0700 h and then consumed breakfast with ∼23 mg of oral ²⁶Mg and ∼11 mg of i.v. ²⁵Mg. We measured magnesium isotope concentrations in 72-h urine, spot urine (36, 48, 60, and 72 h), and spot serum (1, 3, and 5 h) samples collected after isotope dosing. We calculated MgA using the dose-corrected fraction of isotope concentrations from the 72-h urine collection. We validated new methods in 10 postmenopausal women (cohort 2) aged 59 ± 5 y with a dietary magnesium intake of 325 ± 122 mg/d. In cohort 1, MgA based on the 72-h urine collection was 0.28 ± 0.08. The 72-h MgA correlated most highly with 0-24 h urine MgA value alone (ρ = 0.95, P < 0.001) or the mean of the 0-24 h urine and the 3-h (ρ = 0.93, P < 0.001) or 5-h (ρ = 0.96, P < 0.001) serum MgA values. In cohort 2, Bland-Altman bias was lowest (-0.003, P = 0.82) using means of the 0-24 h urine and 3-h serum MgA values. We conclude that means of 0-24 h urine and 3-h serum MgA provide a reasonable estimate of 72-h MgA. However, if researchers seek to identify small changes in MgA, we recommend a 3-d urine or extended stool collection. PMID:24500940

  18. Isotope Concentrations from 24-h Urine and 3-h Serum Samples Can Be Used to Measure Intestinal Magnesium Absorption in Postmenopausal Women123

    PubMed Central

    Hansen, Karen E.; Nabak, Andrea C.; Johnson, Rachael Erin; Marvdashti, Sheeva; Keuler, Nicholas S.; Shafer, Martin M.; Abrams, Steven A.

    2014-01-01

    Studies suggest a link between magnesium status and osteoporosis. One barrier to more conclusive research on the potential relation is measuring intestinal magnesium absorption (MgA), which requires the use of stable isotopes and a ≥6-d stool or 3-d urine collection. We evaluated alternative methods of measuring MgA. We administered 2 stable magnesium isotopes to 15 postmenopausal women (cohort 1) aged 62 ± 8 y with a dietary magnesium intake of 345 ± 72 mg/d. Participants fasted from 1200 h to 0700 h and then consumed breakfast with ∼23 mg of oral 26Mg and ∼11 mg of i.v. 25Mg. We measured magnesium isotope concentrations in 72-h urine, spot urine (36, 48, 60, and 72 h), and spot serum (1, 3, and 5 h) samples collected after isotope dosing. We calculated MgA using the dose-corrected fraction of isotope concentrations from the 72-h urine collection. We validated new methods in 10 postmenopausal women (cohort 2) aged 59 ± 5 y with a dietary magnesium intake of 325 ± 122 mg/d. In cohort 1, MgA based on the 72-h urine collection was 0.28 ± 0.08. The 72-h MgA correlated most highly with 0–24 h urine MgA value alone (ρ = 0.95, P < 0.001) or the mean of the 0–24 h urine and the 3-h (ρ = 0.93, P < 0.001) or 5-h (ρ = 0.96, P < 0.001) serum MgA values. In cohort 2, Bland-Altman bias was lowest (−0.003, P = 0.82) using means of the 0–24 h urine and 3-h serum MgA values. We conclude that means of 0–24 h urine and 3-h serum MgA provide a reasonable estimate of 72-h MgA. However, if researchers seek to identify small changes in MgA, we recommend a 3-d urine or extended stool collection. This trial was registered at clinicaltrials.gov as NCT01593501. PMID:24500940

  19. The circadian clock gene period extends healthspan in aging Drosophila melanogaster

    PubMed Central

    Krishnan, Natraj; Kretzschmar, Doris; Rakshit, Kuntol; Chow, Eileen; Giebultowicz, Jadwiga M.

    2009-01-01

    There is increasing evidence that aging is affected by biological (circadian) clocks - the internal mechanisms that coordinate daily changes in gene expression, physiological functions and behavior with external day/night cycles. Recent data suggest that disruption of the mammalian circadian clock results in accelerated aging and increased age-related pathologies such as cancer; however, the links between loss of daily rhythms and aging are not understood. We sought to determine whether disruption of the circadian clock affects lifespan and healthspan in the model organism Drosophila melanogaster. We examined effects of a null mutation in the circadian clock gene period (per01) on the fly healthspan by challenging aging flies with short-term oxidative stress (24h hyperoxia) and investigating their response in terms of mortality hazard, levels of oxidative damage, and functional senescence. Exposure to 24h hyperoxia during middle age significantly shortened the life expectancy in per01 but not in control flies. This homeostatic challenge also led to significantly higher accumulation of oxidative damage in per01 flies compared to controls. In addition, aging per01 flies showed accelerated functional decline, such as lower climbing ability and increased neuronal degeneration compared to age-matched controls. Together, these data suggest that impaired stress defense pathways may contribute to accelerated aging in the per mutant. In addition, we show that the expression of per gene declines in old wild type flies, suggesting that the circadian regulatory network becomes impaired with age. PMID:20157575

  20. Alterations in the striatal dopamine system during intravenous methamphetamine exposure: effects of contingent and noncontingent administration.

    PubMed

    Laćan, Goran; Hadamitzky, Martin; Kuczenski, Ronald; Melega, William P

    2013-08-01

    The continuing spread of methamphetamine (METH) abuse has stimulated research aimed at understanding consequences of its prolonged exposure. Alterations in nigrostriatal dopamine (DA) system parameters have been characterized in experimental studies after discontinuation of long-term METH but fewer studies have included similar assessments during METH exposure. Here, we report METH plasma pharmacokinetics and striatal DA system alterations in rat after noncontingent and contingent METH administration for 7.5 weeks. Escalating METH exposure was delivered by dynamic infusion (DI) that incorporated a "humanized" plasma METH half life or by intravenous self-administration (IVSA) that included binge intakes. Kinetic modeling of DI and IVSA for 24 h periods during the final week of METH exposure showed that plasma METH levels remained between 0.7 and 1.5 µM. Animals were sacrificed during their last METH administration for autoradiography assessment using [³H]ligands and D2 agonist-induced [³⁵S]GTPγS binding. DA transporter binding was decreased (DI, 34%; IVSA, 15%) while vesicular monoamine transporter binding and substantia nigra DA cell numbers were unchanged. Decreases were measured for D2 receptor (DI and IVSA, 15-20%) and [³⁵S]GTPγS binding (DI, 35%; IVSA, 18%). These similar patterns of DI and IVSA associated decreases in striatal DA markers reflect consequences of cumulative METH exposure and not the drug delivery method. For METH IVSA, individual differences were observed, yet each animal's total intake was similar within and across three 24-h binges. IVSA rodent models may be useful for identifying molecular mechanisms that are associated with METH binges in humans. PMID:23417852

  1. Alterations in the Striatal Dopamine System During Intravenous Methamphetamine Exposure: Effects of Contingent and Noncontingent Administration

    PubMed Central

    Laćan, Goran; Hadamitzky, Martin; Kuczenski, Ronald; Melega, William P.

    2014-01-01

    The continuing spread of methamphetamine (METH) abuse has stimulated research aimed at understanding consequences of its prolonged exposure. Alterations in nigrostriatal dopamine (DA) system parameters have been characterized in experimental studies after discontinuation of long term METH but fewer studies have included similar assessments during METH exposure. Here, we report METH plasma pharmacokinetics and striatal DA system alterations in rat after noncontingent and contingent METH administration for 7.5 weeks. Escalating METH exposure was delivered by dynamic infusion (DI) that incorporated a ‘humanized’ plasma METH half life, or by intravenous self-administration (IVSA) that included binge intakes. Kinetic modeling of DI and IVSA for 24 h periods during the final week of METH exposure showed that plasma METH levels remained between 0.7–1.5 μM. Animals were sacrificed during their last METH administration for autoradiography assessment using [3H]ligands and D2 agonist-induced [35S]GTPγS binding. DA transporter binding was decreased (DI, 34%; IVSA, 15%) while vesicular monoamine transporter binding and substantia nigra DA cell numbers were unchanged. Decreases were measured for D2 receptor (DI and IVSA, 15–20%) and [35S]GTPγS binding (DI, 35%; IVSA, 18%). These similar patterns of DI and IVSA associated decreases in striatal DA markers reflect consequences of cumulative METH exposure and not the drug delivery method. For METH IVSA, individual differences were observed, yet each animal’s total intake was similar within and across three 24 h binges. IVSA rodent models may be useful for identifying molecular mechanisms that are associated with METH binges in humans. PMID:23417852

  2. Nanoscale probing of the lateral homogeneity of donors concentration in nitridated SiO2/4H-SiC interfaces.

    PubMed

    Fiorenza, Patrick; Di Franco, Salvatore; Giannazzo, Filippo; Roccaforte, Fabrizio

    2016-08-01

    In this paper, nanoscale resolution scanning capacitance microscopy (SCM) and local capacitance-voltage measurements were used to probe the interfacial donor concentration in SiO2/4H-SiC systems annealed in N2O. Such nitrogen-based annealings are commonly employed to passivate SiO2/SiC interface traps, and result both in the incorporation of N-related donors in SiC and in the increase of the mobility in the inversion layer in 4H-SiC MOS-devices. From our SCM measurements, a spatially inhomogeneous donor distribution was observed in the SiO2/4H-SiC system subjected to N2O annealing. Hence, the effect of a phosphorus implantation before the oxide deposition and N2O annealing was also evaluated. In this case, besides an increased average donor concentration, an improvement of the lateral homogeneity of the active doping was also detected. The possible implications of such a pre-implantation doping of the near-interface region on 4H-SiC MOS-devices are discussed. PMID:27324844

  3. Eplerenone restores 24-h blood pressure circadian rhythm and reduces advanced glycation end-products in rhesus macaques with spontaneous hypertensive metabolic syndrome

    PubMed Central

    Zhang, Yan; Zheng, Wen; Liu, Yuli; Wang, Jue; Peng, Ying; Shang, Haibao; Hou, Ning; Hu, Xiaomin; Ding, Yi; Xiao, Yao; Wang, Can; Zeng, Fanxin; Mao, Jiaming; Zhang, Jun; Ma, Dongwei; Sun, Xueting; Li, Chuanyun; Xiao, Rui-Ping; Zhang, Xiuqin

    2016-01-01

    Hypertension is often associated with metabolic syndrome (MetS), and serves as a risk factor of MetS and its complications. Blood pressure circadian rhythm in hypertensive patients has been suggested to contribute to cardiovascular consequences and organ damage of hypertension. But circadian changes of BP and their response to drugs have not been clearly investigated in non-human primates (NHPs) of MetS with hypertension. Here, we identified 16 elderly, hypertensive MetS rhesus monkeys from our in-house cohort. With implanted telemetry, we investigate BP changes and its circadian rhythm, together with the effect of antihypertensive drugs on BP and its diurnal fluctuation. MetS hypertensive monkeys displayed higher BP, obesity, glucose intolerance, and dyslipidemia. We also confirmed impaired 24-h BP circadian rhythm in MetS hypertensive monkeys. Importantly, Eplerenone, a mineralocorticoid receptor blocker, exerts multiple beneficial effects in MetS hypertensive monkeys, including BP reduction, 24-h BP circadian rhythm restoration, and decreased plasma concentration of inflammation factors and advanced glycation end-products. In summary, we identified a naturally-developed hypertensive MetS NHP model, which is of great value in the studies on pathogenesis of MetS-associated hypertension and development of novel therapeutic strategies. We also provided multiple novel mechanistic insights of the beneficial effect of Eplerenone on MetS with hypertension. PMID:27032687

  4. Toxicity of two pulsed metal exposures to Daphnia magna: relative effects of pulsed duration-concentration and influence of interpulse period.

    PubMed

    Hoang, Tham C; Gallagher, Jeffrey S; Tomasso, Joseph R; Klaine, Stephen J

    2007-11-01

    Aquatic organisms living in surface waters experience fluctuating contaminant exposures that vary in concentration, duration, and frequency. This study characterized the role of pulsed concentration, pulsed duration, and the interval between pulses on the toxicity of four metals (Cu, Zn, Se, and As) to Daphnia magna. During 21-d toxicity tests, neonatal D. magna were exposed to single or double pulses. Pulsed concentrations and durations ranged from 32 to 6000 microg/L and 8 to 96 h, respectively. Intervals between two pulses ranged from 24 to 288 h. Mortality, growth, and reproduction were characterized for exposures. For single-pulse exposures of Cu and As, metal concentration had a stronger effect on survival of D. magna than did pulsed duration: pulses with 2X concentration and 1Y duration resulted in more mortality than did pulses with 1X concentration and 2Y duration. In contrast, effects of pulsed duration were stronger than metal concentration for Zn. However, the effects of duration and concentration were similar for Se. The relative effects of pulsed concentration and duration found in the present study revealed that the common method using area under the curve (AUC = concentration x duration) may not always accurately estimate environmental risk from metals (e.g., for Cu, Zn, As). In addition, the occurrence of delayed mortality in the present study revealed that using continuous exposure bioassays might underestimate metal toxicity to aquatic biota. For double-pulse exposures, the toxicity of the second pulse was influenced by the first pulse for all four metals. This influence was dependent on the pulsed concentration and duration and the interval between pulses. Further, toxicity caused by the second pulse decreased as the time between the exposures increased. For all four metals, there existed an interval great enough that the toxicity of the two pulses was independent. This would result in less toxicity for multiple exposures than continuous

  5. Simulations of light effects on the human circadian pacemaker: implications for assessment of intrinsic period

    NASA Technical Reports Server (NTRS)

    Klerman, E. B.; Dijk, D. J.; Kronauer, R. E.; Czeisler, C. A.

    1996-01-01

    The sensitivity of the human circadian system to light has been the subject of considerable debate. Using computer simulations of a recent quantitative model for the effects of light on the human circadian system, we investigated these effects of light during different experimental protocols. The results of the simulations indicate that the nonuniform distribution over the circadian cycle of exposure to ordinary room light seen in classical free-run studies, in which subjects select their exposure to light and darkness, can result in an observed period of approximately 25 h, even when the intrinsic period of the subject's endogenous circadian pacemaker is much closer to 24 h. Other simulation results suggest that accurate assessment of the true intrinsic period of the human circadian pacemaker requires low ambient light intensities (approximately 10-15 lx) during scheduled wake episodes, desynchrony of the imposed light-dark cycle from the endogenous circadian oscillator, and a study length of at least 20 days. Although these simulations await further experimental substantiation, they highlight the sensitivity to light of the human circadian system and the potential confounding influence of light on the assessment of the intrinsic period of the circadian pacemaker.

  6. Volatile organic compounds concentrations in residential indoor and outdoor and its personal exposure in Korea.

    PubMed

    Son, Busoon; Breysse, Patrick; Yang, Wonho

    2003-04-01

    To date, personal volatile organic compounds (VOCs) exposure and residential indoor and outdoor VOCs levels have not been characterized in Korea. In this study, residential indoor and outdoor VOCs concentrations were measured and compared simultaneously with the personal exposure for each of 30 participants in a medium city, Asan, and in a metropolitan city, Seoul. Factors that influence personal VOCs exposures were assessed in relation to house characteristics and time activity information. All VOC concentrations were measured using passive samplers during a 24-h period and analyzed using GC-MS. Ten target VOCs were benzene, trichloroethylene, toluene, o-xylene, p-xylene, ethylbenzene, MIBK, n-octane, styrene, and 1,2-dichlorobenzene. Residential indoor and outdoor VOCs concentrations measured in Seoul were significantly higher than those in Asan. Indoor/outdoor (I/O) ratios for all target compounds ranged from 0.94 to 1.51 and I/O ratios of Asan were a little higher than those of Seoul. Results indicate that time activity information can be used to predict personal exposures, although such predictions will result in an over estimation compared to measured exposures. Factors which influence the indoor VOCs level and its personal exposure in relation to house characteristics included house age, indoor smoking, and house type. PMID:12605940

  7. Exposure of arctic field scientists to ultraviolet radiation evaluated using personal dosimeters.

    PubMed

    Cockell, C S; Scherer, K; Horneck, G; Rettberg, P; Facius, R; Gugg-Helminger, A; Driscoll, C; Lee, P

    2001-10-01

    During July 2000 we used an electronic personal dosimeter (X-2000) and a biological dosimeter (Deutsches Zentrum für Luft- und Raumfahrt: Biofilm) to characterize the UV radiation exposure of arctic field scientists involved in biological and geological fieldwork. These personnel were working at the Haughton impact structure on Devon Island (75 degrees N) in the Canadian High Arctic under a 24 h photoperiod. During a typical day of field activities under a clear sky, the total daily erythemally weighted exposure, as measured by electronic dosimetry, was up to 5.8 standard erythemal dose (SED). Overcast skies (typically 7-8 okta of stratus) reduced exposures by a mean of 54%. We estimate that during a month of field activity in July a typical field scientist at this latitude could potentially receive approximately 80 SED to the face. Because of body movements the upper body was exposed to a UV regimen that often changed on second-to-second time-scales as assessed by electronic dosimetry. Over a typical 10 min period on vehicle traverse, we found that erythemal exposure could vary to up to 87% of the mean exposure. Time-integrated exposures showed that the type of outdoor field activities in the treeless expanse of the polar desert had little effect on the exposure received. Although absolute exposure changed in accordance with the time of day, the exposure ratio (dose received over horizontal dose) did not vary much over the day. Under clear skies the mean exposure ratio was 0.35 +/- 0.12 for individual activities at different times of the day assessed using electronic dosimetry. Biological dosimetry showed that the occupation was important in determining daily exposures. In our study, scientists in the field received an approximately two-fold higher dose than individuals, such as medics and computer scientists, who spent the majority of their time in tents. PMID:11683037

  8. A method for the long-term exposure of rabbits to environmental pollutant gases.

    PubMed

    Douglas, G J; Price, J F; Page, C P

    1994-08-01

    The aims of the present study were twofold. Firstly, we wanted to develop a system for the exposure of rabbits to pollutant gases that would monitor gas concentrations accurately, allow flexibility, be simple to operate, and could be constructed at relatively modest cost. Additionally, we wanted to determine whether the procedures necessary for the daily exposure of young rabbits had any detrimental effect on their development. Using the environmental exposure system that we developed, littermate New Zealand White rabbits, neonatally immunized to either Alternaria tenuis or house dust mite antigen were exposed 2 h daily, from within 24 h of birth until 3 months of age, to either 4 ppm nitrogen dioxide (NO2), or 5 ppm sulphur dioxide (SO2) or ambient air. The environmental exposure system consists of four sections; a stainless steel exposure chamber; an airflow monitoring and control system and gas delivery system; a gas detector and monitoring system; and an exhaust fan. Equilibration and wash-out times of gas were short and the gas mixing within the chamber atmosphere was uniform. Levels of gases were reliably maintained throughout the period of exposure within predetermined limits. The weights of the immunized, gas-exposed animals did not differ significantly from those of the immunized, air-exposed animals at any time throughout the 3 month period of exposure. At 3 months of age, the basal values for lung resistance and dynamic compliance did not differ between gas- and air-exposed rabbits. These values did not differ significantly from those obtained from naive animals of the same age. Our results suggest that we have developed a sensitive, reliable and simple environmental exposure and monitoring system. It is anticipated that the methodology described will allow the careful investigation of the effects of long-term exposure to pollutant gases from birth on the development of airways hyperresponsiveness. PMID:7957839

  9. Commuter exposure to ultrafine particles in different urban locations, transportation modes and routes

    NASA Astrophysics Data System (ADS)

    Ragettli, Martina S.; Corradi, Elisabetta; Braun-Fahrländer, Charlotte; Schindler, Christian; de Nazelle, Audrey; Jerrett, Michael; Ducret-Stich, Regina E.; Künzli, Nino; Phuleria, Harish C.

    2013-10-01

    A better understanding of ultrafine particle (UFP) exposure in different urban transport microenvironments is important for epidemiological exposure assessments and for policy making. Three sub-studies were performed to characterize personal exposure to UFP concentration and average particle size distribution diameters in frequently traveled commuter microenvironments in the city of Basel, Switzerland. First, the spatial variation of sidewalk UFP exposures within urban areas and transport-specific microenvironments was explored. Second, exposure to UFP concentration and average particle size were quantified for five modes of transportation (walking, bicycle, bus, tram, car) during different times of the day and week, along the same route. Finally, the contribution of bicycle commuting along two different routes (along main roads, away from main roads) to total daily exposures was assessed by 24-h personal measurements. In general, smaller average particle sizes and higher UFP levels were measured at places and for travel modes in close proximity to traffic. Average trip UFP concentrations were higher in car (31,784 particles cm-³) and on bicycle (22,660 particles cm-³) compared to walking (19,481 particles cm-³) and public transportation (14,055-18,818 particles cm-³). Concentrations were highest for all travel modes during weekday morning rush hours, compared to other time periods. UFP concentration was lowest in bus, regardless of time period. Bicycle travel along main streets between home and work place (24 min on average) contributed 21% and 5% to total daily UFP exposure in winter and summer, respectively. Contribution of bicycle commutes to total daily UFP exposure could be reduced by half if main roads are avoided. Our results show the importance of considering commuter behavior and route choice in exposure assessment studies.

  10. Survival of Phytophthora ramorum hyphae after exposure to temperature extremes and various humidities.

    PubMed

    Browning, Marsha; Englander, Larry; Tooley, Paul W; Berner, Dana

    2008-01-01

    We examined the effect of short-term exposure to high and low temperatures and a range of relative humidity (RH) on survival of Phytophthora ramorum hyphae. Spore-free hyphal colonies were grown on dialysis squares atop V8 medium. Colonies were transferred to water agar plates positioned at 27.5-50 C on a thermal gradient plate and incubated 2.5-480 min. For low temperature trials colonies were transferred to vials of distilled water and incubated in a water bath at -5 to -25 C for 1-24 h. In the relative humidity trials hyphal colonies were transferred to sealed humidity chambers containing various concentrations of glycerin for 1-8 h. Relative humidity was 41-93% at 20 C and 43-86% at 28 C. Survival in all trials was characterized by growth from dialysis squares into V8 medium. Temperatures of 37.5-40 C were lethal to P. ramorum hyphae within several hours, and temperatures of 42.5-50 C were lethal within minutes. Exposure to 32.5 and 35 C resulted in reduced survival over 8 h, while 30 C had no effect on three of four isolates. Hyphal colonies demonstrated considerable tolerance to cold, with all isolates surviving a 24 h exposure to -5 C. Survival diminished over time at lower temperatures, however a few colonies survived 24 h exposure to -25 C. Temperature also affected the ability of hyphal colonies to withstand reduced humidity. A RH of 41-43% was lethal in 2 h at 28 C compared to 8 h at 20 C. Three of four isolates were unaffected by an 8 h exposure to 81 and 95% RH at 20 C, and 73 and 86% RH at 28 C. Isolate differences were apparent in tolerance to freezing temperatures and reduced humidity. From these results it is apparent that the cold temperatures found in the northeastern USA are not likely to prevent the establishment of P. ramorum. There is also the potential for hyphae, and presumably spores, to survive periods of high humidity on the leaf surface in the absence of free water. PMID:18592898

  11. The relationship between serum albumin levels and 24-h ambulatory blood pressure monitoring recordings in non-diabetic essential hypertensive patients

    PubMed Central

    Ahbap, Elbis; Sakaci, Tamer; Kara, Ekrem; Sahutoglu, Tuncay; Koc, Yener; Basturk, Taner; Sevinc, Mustafa; Akgol, Cuneyt; Kayalar, Arzu O.; Ucar, Zuhal A.; Bayraktar, Feyza; Unsal, Abdulkadir

    2016-01-01

    OBJECTIVES: The goal of this study was to evaluate the relationship between serum albumin levels and 24-hour ambulatory blood pressure monitoring (24-h ABPM) recordings in non-diabetic essential hypertensive patients. METHODS: A total of 354 patients (mean [SD] age: 55.5 [14.3] years, 50% females) with essential hypertension and 24-h ABPM recordings were included. Patient 24-h nighttime and daytime ABPM values, systolic and diastolic dipping status and average nocturnal dipping were recorded. The correlations between serum albumin levels and nocturnal systolic and diastolic dipping were evaluated, and correlates of average nocturnal systolic dipping were determined via a linear regression model. RESULTS: Overall, 73.2% of patients were determined to be non-dippers. The mean (SD) levels of serum albumin (4.2 [0.3] g/dL vs. 4.4 [0.4] g/dL, p<0.001) and the average nocturnal systolic (15.2 [4.8] mmHg vs. 0.3 [6.6] mmHg, p<0.001) and diastolic dipping (4.2 [8.6] mmHgvs. 18.9 [7.0] mmHg, p<0.001) were significantly lower in non-dippers than in dippers. A significant positive correlation was noted between serum albumin levels and both systolic (r=0.297, p<0.001) and diastolic dipping (r=0.265, p<0.001). The linear regression analysis revealed that for each one-unit increase in serum albumin, the average nocturnal dip in systolic BP increased by 0.17 mmHg (p=0.033). CONCLUSION: Our findings indicate an association between serum albumin levels and the deterioration of circadian BP rhythm among essential hypertensive patients along with the identification of a non-dipper pattern in more than two-thirds of patients. Our findings emphasize the importance of serum albumin levels, rather than urinary albumin excretion, as an independent predictor of nocturnal systolic dipping, at least in non-diabetic essential hypertensive patients with moderate proteinuria. PMID:27276394

  12. LACK OF ALTERATIONS IN THYROID HORMONES FOLLOWING EXPOSURE TO POLYBROMINATED DIPHENYL ETHER 47 DURING A PERIOD OF RAPID BRAIN DEVELOPMENT IN MICE

    EPA Science Inventory

    Polybrominated diphenyl ether 47 (PBDE-47) is one of a class of commonly used flame retardants that are accumulating in the environment, including human tissues. There are reports of thyroid alterations following exposure to PBDE mixtures, and it is possible that disruptions in t...

  13. Effects of treadmill running exercise during the adolescent period of life on behavioral deficits in juvenile rats induced by prenatal morphine exposure.

    PubMed

    Ahmadalipour, Ali; Rashidy-Pour, Ali

    2015-02-01

    Prenatal exposure to morphine throughout pregnancy results in an array of prolonged or permanent neurochemical and behavioral deficits, including deficits in learning and memory in children of addicted mothers. This study investigated the effects of forced exercise on behavioral deficits of pups born to mothers addicted to morphine in rats. After mating and ensuring of pregnancy of female Wistar rats, they were divided into morphine or saline groups and in the second half of pregnancy (on days 11-18 of gestation) were injected subcutaneously with morphine or saline, respectively. Pups were weaned at postnatal day (PND) 21 and trained at mild intensity on a treadmill 20 days. On PND 41-47, the behavioral responses were studied. Light/dark (L/D) box and elevated plus maze (EPM) apparatus were used for investigation of anxiety, shuttle box and forced swimming tests were used to assess passive avoidance learning and memory and depression behavior, respectively. The results showed that prenatal morphine exposure caused reductions in time spent in light compartment of L/D box and EPM open arm, while postnatal exercise reversed these effects. We also found that prenatal morphine exposure caused a reduction in step through latency in passive avoidance memory test and exercise counteracted with this effect. Performance in the forced swimming test did not affected by prenatal morphine exposure or postnatal exercise. Exercise seems to be one of the strategies in reduction of behavioral deficits of children born to addicted mothers to morphine. PMID:25446212

  14. ALTERATION OF BEHAVIORAL SEX DIFFERENTIATION BY EXPOSURE TO ESTROGENIC COMPOUNDS DURING A CRITICAL NEONATAL PERIOD: EFFECTS OF ZEARALENONE, METHOXYCHLOR, AND ESTRADIOL IN HAMSTERS

    EPA Science Inventory

    The present study was designed to determine if neonatal exposure to the estrogenic mycotoxin zearalenone or the weakly estrogenic pesticide methoxychlor could masculinize and/or defeminize the behavior of female hamsters. Neonatal hamsters were given a single s.c. injection of ei...

  15. Household exposure models

    SciTech Connect

    McKone, T.E.

    1988-01-01

    Human exposure to volatile organic compounds (VOCs) in tap water is often assumed to be dominated by ingestion of drinking water. This paper addresses the relative importance of inhalation and dermal exposures in a typical household. A three-compartment model is used to simulate the 24-h concentration history of VOCs in the shower, bathroom, and remaining household volumes as a result of tap water use. Mass transfers from water to air are derived from measured data for radon and used to estimate mass-transfer properties for VOCs. The model is used to calculate a range of concentrations and human exposures in US dwellings. The estimated ratio of household- inhalation uptake to ingestion uptake is in the range of 1 to 6 for VOCs. We use a dermal absorption model to assess exposure across the skin boundary during baths and showers. The ratio of dermal exposure to ingestion exposure is in the range 0.6 to 1. 24 refs., 1 fig., 7 tabs.

  16. Fabrication of SiO{sub 2}/4H-SiC (0001) interface with nearly ideal capacitance-voltage characteristics by thermal oxidation

    SciTech Connect

    Kikuchi, Richard Heihachiro; Kita, Koji

    2014-07-21

    We fabricated SiO{sub 2}/4H-SiC (0001) metal-oxide-semiconductor capacitors with nearly ideal capacitance-voltage characteristics, simply by the control of thermal oxidation conditions which were selected based on thermodynamic and kinetic considerations of SiC oxidation. The interface with low interface defect state density <10{sup 11 }cm{sup −2} eV{sup −1} for the energy range of 0.1–0.4 eV below the conduction band of SiC was obtained by thermal oxidation at 1300 °C in a ramp-heating furnace with a short rise/fall time, followed by low temperature O{sub 2} anneal at 800 °C.

  17. Characterization and Conductivity Behavior of Magnetic Activated Carbon (MAC) from FeCl2.4H2O-Containing Carbon

    NASA Astrophysics Data System (ADS)

    Aripin, Department Of Physics, Faculty Of Mathematics; Natural Science, Haluoleo University, Kampus Bumi Tridharma Anduonohu Kendari 93232 Indonesia

    2007-05-01

    Activated carbons (AC) and magnetic-containing activated carbons (MAC) have been synthesized using coconut shells as carbon sources and FeCl2.4H2O as magnetic precursor. The samples were characterized by nitrogen sorption, XRD, and FTIR. The BET surface area and total pore volume of MAC increase as the temperature increased. AC has XRD peaks, which evidences an amorphous carbon framework and MAC shows that this material consists of an organized carbon with the nanocrystalline magnetite embedded in its structure. The FTIR spectrum of MAC shows that carboxyl groups decreased as the temperature increased. Absorption bands of MAC shows the stretching and torsional vibration modes of the magnetite Fe-O bond in tetrahedral and octahedral sites, respectively. The electrical conductivity studies showed that conductivity of MAC is more than the AC due to structural properties of carbons exists on a framework containing metal structures.

  18. Entropy, pattern entropy, and related methods for the analysis of data on the time intervals between heartbeats from 24-h electrocardiograms

    NASA Astrophysics Data System (ADS)

    Żebrowski, J. J.; Popławska, W.; Baranowski, R.

    1994-11-01

    Sequences of the time intervals between heartbeats-medically termed RR intervals-extracted from 24-h electrocardiogram recordings are examined as three-dimensional return map images. The recordings were made in humans by means of the medically widely used portable electrocardiograph (Holter system). A time window measured in the number of heartbeats is used and different types of behavior are classified. Bifurcations between the types of dynamics of the heart are noted and a form of intermittency is found. An alternative quantitative measure-a form pattern entropy of the return map image-is defined that characterizes the dynamics of the RR interval sequence. It is shown that this is a measure of the degree of ordering of the RR interval sequence and as such it is a good novel medical diagnostic tool for analyzing heart rate variability which distinguishes between illness and health where other diagnostics fail.

  19. Cathodoluminescence study of radiative interface defects in thermally grown SiO{sub 2}/4H-SiC(0001) structures

    SciTech Connect

    Fukushima, Yuta; Chanthaphan, Atthawut; Hosoi, Takuji; Shimura, Takayoshi; Watanabe, Heiji

    2015-06-29

    Radiative defects in thermally grown SiO{sub 2}/4H-SiC(0001) structures and their location in depth were investigated by means of cathodoluminescence spectroscopy. It was found that while luminescence peaks ascribed to oxygen vacancy and nonbridging oxygen hole centers were observed both from thermal oxides grown on (0001) Si-face and C-face surfaces as with thermal oxides on Si, intense yellow luminescence at a wavelength of around 600 nm was identified only from the oxide interface on the Si-face substrate regardless of the oxide thickness and dopant type. Possible physical origins of the radiative centers localized near an oxide interface of a few nm thick are discussed on the basis of visible light emission from Si backbone structures.

  20. New high proper motion stars with declinations between -5(deg) and -30(deg) , and right ascensions between 13h 30m and 24h

    NASA Astrophysics Data System (ADS)

    Wroblewski, H.; Costa, E.

    1999-10-01

    Proper motions, positions, finding charts and magnitudes are given for 293 newly discovered stars with proper motions larger than 0.15 arcsec/year. They are located between -5(deg) and -30(deg) in declination, and 13h 30m and 24h in right ascension. Their blue photographic magnitudes range from approximately 13.0 to 18.5. Six stars of the above sample have proper motions larger than 0.4 (0.401 to 0.534) arcsec/year. An estimated precision level between 7 and 13 mas/year was achieved for the proper motions. Table~2 is only available in electronic form at the CDS via anonymous ftp 130.79.128.5 or http://cdsweb.u-strasbg.fr/Abstract.html and figures~2 are available in the on-line edition of the journal at http://www.edpsciences.com

  1. Validation of web-based, multiple 24-h recalls combined with nutritional supplement intake questionnaires against nitrogen excretions to determine protein intake in Dutch elite athletes.

    PubMed

    Wardenaar, F C; Steennis, J; Ceelen, I J M; Mensink, M; Witkamp, R; de Vries, J H M

    2015-12-28

    Information on dietary composition is vitally important for elite athletes to optimise their performance and recovery, which requires valid tools. The aim of the present study was to investigate the validity of assessing protein intake using three web-based 24-h recalls and questionnaires, by comparing these with three urinary N excretions on the same day. A total of forty-seven Dutch elite top athletes, both disabled and non-disabled, aged between 18 and 35 years, with a BMI of 17·5-31 kg/m2, exercising >12 h/week were recruited. Estimated mean dietary protein intake was 109·6 (sd 33·0) g/d by recalls and questionnaires v. 141·3 (sd 38·2) g/d based on N excretions in urine; the difference was 25·5 (sd 21·3) % between the methods (P<0·05). We found a reasonably good association between methods for protein intake of 0·65 (95 % CI 0·45, 0·79). On an individual level, under-reporting was larger with higher protein intakes than with lower intakes. No significant differences were found in reporting absolute differences between subcategories (sex, under-reporting, BMI, collection of recalls within a certain amount of time and using protein supplements or not). In conclusion, combined, multiple, 24-h recalls and questionnaires underestimated protein intake in these young elite athletes more than that reported for non-athlete populations. The method proved to be suitable for ranking athletes according to their protein intake as needed in epidemiological studies. On an individual level, the magnitude of underestimation was about equal for all athletes except for those with very high protein intakes. PMID:26435534

  2. Agreement between an online dietary assessment tool (myfood24) and an interviewer-administered 24-h dietary recall in British adolescents aged 11-18 years.

    PubMed

    Albar, Salwa A; Alwan, Nisreen A; Evans, Charlotte E L; Greenwood, Darren C; Cade, Janet E

    2016-05-01

    myfood24 Is an online 24-h dietary assessment tool developed for use among British adolescents and adults. Limited information is available regarding the validity of using new technology in assessing nutritional intake among adolescents. Thus, a relative validation of myfood24 against a face-to-face interviewer-administered 24-h multiple-pass recall (MPR) was conducted among seventy-five British adolescents aged 11-18 years. Participants were asked to complete myfood24 and an interviewer-administered MPR on the same day for 2 non-consecutive days at school. Total energy intake (EI) and nutrients recorded by the two methods were compared using intraclass correlation coefficients (ICC), Bland-Altman plots (using between and within-individual information) and weighted κ to assess the agreement. Energy, macronutrients and other reported nutrients from myfood24 demonstrated strong agreement with the interview MPR data, and ICC ranged from 0·46 for Na to 0·88 for EI. There was no significant bias between the two methods for EI, macronutrients and most reported nutrients. The mean difference between myfood24 and the interviewer-administered MPR for EI was -230 kJ (-55 kcal) (95 % CI -490, 30 kJ (-117, 7 kcal); P=0·4) with limits of agreement ranging between 39 % (3336 kJ (-797 kcal)) lower and 34 % (2874 kJ (687 kcal)) higher than the interviewer-administered MPR. There was good agreement in terms of classifying adolescents into tertiles of EI (κ w =0·64). The agreement between day 1 and day 2 was as good for myfood24 as for the interviewer-administered MPR, reflecting the reliability of myfood24. myfood24 Has the potential to collect dietary data of comparable quality with that of an interviewer-administered MPR. PMID:26975650

  3. Mitomycin C with weekly 24-h infusion of high-dose 5-fluorouracil and leucovorin in patients with biliary tract and periampullar carcinomas.

    PubMed

    Chen, J S; Lin, Y C; Jan, Y Y; Liau, C T

    2001-04-01

    We have reported a 33% partial response rate with acceptable toxicity using weekly 24-h infusion of high-dose 5-fluorouracil (5-FU) and leucovorin (LV) in patients with far advanced biliary tract cancers (BTC). In this study, we added mitomycin (MMC) to 5-FU and LV in an attempt to improve the response rate and survival. From July 1997 to September 1999, 25 chemotherapy-naive patients with pathology-proven far advanced BTC and periampullar cancers were enrolled. The regimen consisted of MMC 10 mg/m(2) every 8 weeks combined with 5-FU 2600 mg/m(2) and LV 150 mg at a schedule of 24-h infusion weekly for 6 weeks followed by a 2 week break. There were 10 males and 15 females with a median age of 57 years (range 40-76). The sites of primary tumor were 15 intrahepatic cholangiocarcinomas (CC), one perihilar CCs, three distal BTC, three gallbladder cancers (GB) and three periampullar cancers. A total of 148 sessions of chemotherapy were given with a mean of 8 (range 2-18). Nineteen patients were evaluable for response. The response rate was: 26% (five of 19) partial response, 42% (eight of 19) stable disease and 32% (six of 19) progressive disease. All of the patients were evaluable for toxicity. Toxicities more than grade III-IV were thrombocytopenia 16% (four of 25), leukopenia 12% (three of 25) and vomiting 4% (one of 25). There were four treatment-related deaths. The median time to disease progression was 3 months. The median survival was 6 months. A combination of MMC with weekly high-dose 5-FU and LV in patients with BTC did not improve the response rate, but produced more toxicity than weekly high-dose 5-FU and LV alone. PMID:11335790

  4. Distribution and variability of the 24-h average air exchange rates and interzonal flow rates in 26 Japanese residences in 5 seasons

    NASA Astrophysics Data System (ADS)

    Shinohara, Naohide; Kataoka, Toshiyuki; Takamine, Koichi; Gamo, Masashi

    2011-07-01

    In this study, to evaluate the distribution of air exchange rates in Japan, daily, seasonal, and inter-residence variabilities were determined as well as the air exchange rate itself. In addition, airflows among multiple zones were also evaluated. For this purpose, the 24 h average air exchange rates and interzonal air flow rates were measured using a passive perfluorocarbon tracer (PFT) method with three kinds of tracer gases for 1 week in three rooms of 26 Japanese residences over five seasons: summer and autumn of 2005, and winter, spring, and summer of 2006. During these seasons, the weekly average air exchange rates were found to be 1.6 ± 1.7, 0.58 ± 0.94, 0.61 ± 0.93, 1.2 ± 2.5, and 1.7 ± 1.8 h -1, respectively. Two-way repeated measure analysis of variance (ANOVA) revealed that the air exchange rates differed significantly with respect to the seasons, residences, and interaction of seasons and residences ( p < 0.01). In addition, the air exchange rates in both summers and spring were statistically higher than those in autumn and winter (Sheffe test, p < 0.01). According to the ANOVA, the percentage contribution of inter-residence variability, seasonal variability, interaction of seasonal and inter-residence variabilities, and daily variability to the total variability of the 24 h average air exchange rates in the present survey was 51%, 44%, 3.7%, and 1.0%, respectively.

  5. Lack of effects for dietary exposure of bisphenol A during in utero and lactational periods on reproductive development in rat offspring.

    PubMed

    Kobayashi, Kenichi; Kubota, Hisayo; Ohtani, Katsumi; Hojo, Rieko; Miyagawa, Muneyuki

    2012-01-01

    The potential for health effects on humans with exposure to bisphenol A (BPA) has raised concerns, and the adverse effects of low-dose exposure to BPA on reproduction have been controversial. The purpose of the present study was to investigate the effects of low-dose exposure to BPA on reproductive development in F(1) rat offspring. Pregnant female Sprague-Dawley rats (F(0)) were fed a diet containing low doses of BPA (0, 0.33, 3.3, or 33 ppm) from gestational day (GD) 6 through postnatal day (PND) 21. The weanlings (F(1)) from all dose groups were fed a normal diet ad libitum after weaning and then were subjected to necropsy at 5 weeks or 3 months of age. No BPA-related changes were observed in body weight or weight of any of the major reproductive organs in F(1) males and females. Epididymis weight was significantly lower only in 3-month-old F(1) males exposed to 33 ppm BPA. Anogenital distance (AGD), the ratio of AGD to the cube root of body weight, and relative ovary weight were significantly lower in 5-week-old F(1) females exposed to 3.3 and 33 ppm BPA, but significant differences were not observed in 3-month-old females. There were no BPA-related effects on cauda epididymal sperm motility in 3-month-old F(1) males. Plasma reproductive steroid hormone concentrations were not altered among groups in either sex. These outcomes indicate that low-dose exposure to BPA in the diet does not adversely affect reproductive development in F(1) rat offspring. PMID:22687996

  6. [KINETICS OF PHOTO-INDUCED FREE RADICALS IN THE HUMAN HAIR CHESTNUT COLOR AFTER SHORT PERIODS OF RED, GREEN, BLUE AND WHITE LIGHT EXPOSURE].

    PubMed

    Tskhvediani, N; Chikvaidze, E; Tsibadze, A; Kvachadze, I; Gogoladze, T; Katsitadze, A

    2016-04-01

    The aim of the study was to investigate the kinetics of photo-induced free radicals in the human hair chestnut color with short-term exposure to visible light in different frequency ranges. Studies carried out on human volunteers aged 17-21 years (n=37). Hairs of volunteers of the study were not treated with dyes and other active cosmetic preparations. Hairs bundled in a bun had a length - 1.5 cm, weight - 40 mg. At the beginning background EPR-spectrum of a sample was measured and then hairs were irradiated with visible light (blue, green, red and white) of different wavelength subsequently; exposure duration - 60 minutes; after the exposure the kinetics of photo-induced free radicals was measured within 60 minutes. The radiation source was selected LED array of the four crystals that provides a nearly monochromatic radiation spectrum having no parasitic infrared and ultraviolet radiations. The studies give a reason to assume that the impact on hairs by visible electromagnetic rays a leading factor is their frequency characteristics: on the one hand - the proximity of the blue light to ultraviolet radiation, and on the other - the red light to the infrared range. PMID:27249443

  7. Exposure to a Highly Caloric Palatable Diet During Pregestational and Gestational Periods Affects Hypothalamic and Hippocampal Endocannabinoid Levels at Birth and Induces Adiposity and Anxiety-Like Behaviors in Male Rat Offspring

    PubMed Central

    Ramírez-López, María Teresa; Vázquez, Mariam; Bindila, Laura; Lomazzo, Ermelinda; Hofmann, Clementine; Blanco, Rosario Noemí; Alén, Francisco; Antón, María; Decara, Juan; Ouro, Daniel; Orio, Laura; Suarez, Juan; Lutz, Beat; Rodríguez de Fonseca, Fernando; Gómez de Heras, Raquel

    2016-01-01

    Exposure to unbalanced diets during pre-gestational and gestational periods may result in long-term alterations in metabolism and behavior. The contribution of the endocannabinoid system to these long-term adaptive responses is unknown. In the present study, we investigated the impact of female rat exposure to a hypercaloric-hypoproteic palatable diet during pre-gestational, gestational and lactational periods on the development of male offspring. In addition, the hypothalamic and hippocampal endocannabinoid contents at birth and the behavioral performance in adulthood were investigated. Exposure to a palatable diet resulted in low weight offspring who exhibited low hypothalamic contents of arachidonic acid and the two major endocannabinoids (anandamide and 2-arachidonoylglycerol) at birth. Palmitoylethanolamide, but not oleoylethanolamide, also decreased. Additionally, pups from palatable diet-fed dams displayed lower levels of anandamide and palmitoylethanolamide in the hippocampus. The low-weight male offspring, born from palatable diet exposed mothers, gained less weight during lactation and although they recovered weight during the post-weaning period, they developed abdominal adiposity in adulthood. These animals exhibited anxiety-like behavior in the elevated plus-maze and open field test and a low preference for a chocolate diet in a food preference test, indicating that maternal exposure to a hypercaloric diet induces long-term behavioral alterations in male offspring. These results suggest that maternal diet alterations in the function of the endogenous cannabinoid system can mediate the observed phenotype of the offspring, since both hypothalamic and hippocampal endocannabinoids regulate feeding, metabolic adaptions to caloric diets, learning, memory, and emotions. PMID:26778987

  8. Exposure to a Highly Caloric Palatable Diet During Pregestational and Gestational Periods Affects Hypothalamic and Hippocampal Endocannabinoid Levels at Birth and Induces Adiposity and Anxiety-Like Behaviors in Male Rat Offspring.

    PubMed

    Ramírez-López, María Teresa; Vázquez, Mariam; Bindila, Laura; Lomazzo, Ermelinda; Hofmann, Clementine; Blanco, Rosario Noemí; Alén, Francisco; Antón, María; Decara, Juan; Ouro, Daniel; Orio, Laura; Suarez, Juan; Lutz, Beat; Rodríguez de Fonseca, Fernando; Gómez de Heras, Raquel

    2015-01-01

    Exposure to unbalanced diets during pre-gestational and gestational periods may result in long-term alterations in metabolism and behavior. The contribution of the endocannabinoid system to these long-term adaptive responses is unknown. In the present study, we investigated the impact of female rat exposure to a hypercaloric-hypoproteic palatable diet during pre-gestational, gestational and lactational periods on the development of male offspring. In addition, the hypothalamic and hippocampal endocannabinoid contents at birth and the behavioral performance in adulthood were investigated. Exposure to a palatable diet resulted in low weight offspring who exhibited low hypothalamic contents of arachidonic acid and the two major endocannabinoids (anandamide and 2-arachidonoylglycerol) at birth. Palmitoylethanolamide, but not oleoylethanolamide, also decreased. Additionally, pups from palatable diet-fed dams displayed lower levels of anandamide and palmitoylethanolamide in the hippocampus. The low-weight male offspring, born from palatable diet exposed mothers, gained less weight during lactation and although they recovered weight during the post-weaning period, they developed abdominal adiposity in adulthood. These animals exhibited anxiety-like behavior in the elevated plus-maze and open field test and a low preference for a chocolate diet in a food preference test, indicating that maternal exposure to a hypercaloric diet induces long-term behavioral alterations in male offspring. These results suggest that maternal diet alterations in the function of the endogenous cannabinoid system can mediate the observed phenotype of the offspring, since both hypothalamic and hippocampal endocannabinoids regulate feeding, metabolic adaptions to caloric diets, learning, memory, and emotions. PMID:26778987

  9. Acute exposure to 2,4-dinitrophenol alters zebrafish swimming performance and whole body triglyceride levels.

    PubMed

    Marit, Jordan S; Weber, Lynn P

    2011-06-01

    While swimming endurance (critical swimming speed or U(crit)) and lipid stores have both been reported to acutely decrease after exposure to a variety of toxicants, the relationship between these endpoints has not been clearly established. In order to examine these relationships, adult zebrafish (Danio rerio) were aqueously exposed to solvent control (ethanol) or two nominal concentrations of 2,4-dinitrophenol (DNP), a mitochondrial electron transport chain uncoupler, for a 24-h period. Following exposure, fish were placed in a swim tunnel in clean water for swimming testing or euthanized immediately without testing, followed by analysis of whole body triglyceride levels. U(crit) decreased in both the 6 mg/L and 12 mg/L DNP groups, with 12 mg/L approaching the LC₅₀. A decrease in tail beat frequency was observed without a significant change in tail beat amplitude. In contrast, triglyceride levels were elevated in a concentration-dependent manner in the DNP exposure groups, but only in fish subjected to swimming tests. This increase in triglyceride stores may be due to a direct interference of DNP on lipid catabolism as well as increased triglyceride production when zebrafish were subjected to the co-stressors of swimming and toxicant exposure. Future studies should be directed at determining how acute DNP exposure combines with swimming to cause alterations in triglyceride accumulation. PMID:21406246

  10. Monitoring of troponin release from cardiomyocytes during exposure to toxic substances using surface plasmon resonance biosensing.

    PubMed

    Andersson, Henrik; Kågedal, Bertil; Mandenius, Carl-Fredrik

    2010-10-01

    Troponin T (TnT) is a useful biomarker for studying drug-induced toxicity effects on cardiac cells. We describe how a surface plasmon resonance (SPR) biosensor was applied to monitor the release of TnT from active HL-1 cardiomyocytes in vitro when exposed to cardiotoxic substances. Two monoclonal human TnT antibodies were compared in the SPR immunosensor to analyse the TnT release. The detection limit of TnT was determined to be 30 ng/ml in a direct assay set-up and to be 10 ng/ml in a sandwich assay format. Exposure of the cardiomyocytes to doxorubicin, troglitazone, quinidine and cobalt chloride for periods of 6 and 24 h gave significant SPR responses, whereas substances with low toxicity showed insignificant effects (ascorbic acid, methotrexate). The SPR results were verified with a validated immunochemiluminescence method which showed a correlation of r (2) = 0.790. PMID:20694813

  11. Problem Periods

    MedlinePlus

    ... gov/ Home Body Getting your period Problem periods Problem periods It’s common to have cramps or feel ... doctor Some common period problems Signs of period problems top One way to know if you may ...

  12. Late preconditioning against myocardial stunning. An endogenous protective mechanism that confers resistance to postischemic dysfunction 24 h after brief ischemia in conscious pigs.

    PubMed

    Sun, J Z; Tang, X L; Knowlton, A A; Park, S W; Qiu, Y; Bolli, R

    1995-01-01

    Conscious pigs underwent a sequence of 10 2-min coronary occlusions, each separated by 2 min of reperfusion, for three consecutive days (days 1, 2, and 3 of stage I). The recovery of systolic wall thickening (WTh) after the 10th reperfusion was markedly improved on days 2 and 3 compared with day 1, indicating that the myocardium had become preconditioned against "stunning." 10 d after stage I, pigs underwent again a sequence of 10 2-min coronary occlusions for two consecutive days (days 1 and 2 of stage II). On day 1 of stage II, the recovery of WTh after the 10th reperfusion was similar to that noted on day 1 of stage I; on day 2 of stage II, however, the recovery of WTh was again markedly improved compared with day 1. Blockade of adenosine receptors with 8-p-sulfophenyl theophylline failed to prevent the development of preconditioning against stunning. Northern blot analysis demonstrated an increase in heat stress protein (HSP) 70 mRNA 2 h after the preconditioning ischemia; at this same time point, immunohistochemical analysis revealed a concentration of HSP70 in the nucleus and an overall increase in staining for HSP70. 24 h after the preconditioning ischemia, Western dot blot analysis demonstrated an increase in HSP70. This study indicates the existence of a new, previously unrecognized cardioprotective phenomenon. The results demonstrate that a brief ischemic stress induces a powerful, long-lasting (at least 48 h) adaptive response that renders the myocardium relatively resistant to stunning 24 h later (late preconditioning against stunning). This adaptive response disappears within 10 d after the last ischemic stress but can be reinduced by another ischemic stress. Unlike early and late preconditioning against infarction, late preconditioning against stunning is not blocked by adenosine receptor antagonists, and therefore appears to involve a mechanism different from that of other forms of preconditioning currently known. The increase in myocardial HSP70 is

  13. Phase II study of weekly vinorelbine and 24-h infusion of high-dose 5-fluorouracil plus leucovorin as first-line treatment of advanced breast cancer

    PubMed Central

    Yeh, K H; Lu, Y S; Hsu, C H; Lin, J F; Chao, H J; Huang, T C; Chung, C Y; Chang, C S; Yang, C H; Cheng, A L

    2005-01-01

    We prospectively investigated the efficacy and safety of combining weekly vinorelbine (VNB) with weekly 24-h infusion of high-dose 5-fluorouracil (5-FU) and leucovorin (LV) in the treatment of patients with advanced breast cancer (ABC). Vinorelbine 25 mg m−2 30-min intravenous infusion, and high-dose 5-FU 2600 mg m−2 plus LV 300 mg m−2 24-h intravenous infusion (HDFL regimen) were given on days 1 and 8 every 3 weeks. Between June 1999 and April 2003, 40 patients with histologically confirmed recurrent or metastatic breast cancer were enrolled with a median age of 49 years (range: 36–68). A total of 25 patients had recurrent ABC, and 15 patients had primary metastatic diseases. The overall response rate for the intent-to-treat group was 70.0% (95% CI: 54–84%) with eight complete responses and 20 partial responses. All 40 patients were evaluated for survival and toxicities. Among a total of 316 cycles of VNB–HDFL given (average: 7.9: range: 4–14 cycles per patient), the main toxicity was Gr3/4 leucopenia and Gr3/4 neutropenia in 57 (18.0%) and 120 (38.0%) cycles, respectively. Gr1/2 infection and Gr1/2 stomatitis were noted in five (1.6%) and 59 (18.7%) cycles, respectively. None of the patients developed Gr3/4 stomatitis or Gr3/4 infection. Gr2/3 and Gr1 hand–foot syndrome was noted in two (5.0%) and 23 (57.5%) patients, respectively. Gr1 sensory neuropathy developed in three patients. The median time to progression was 8.0 months (range: 3–25.5 months), and the median overall survival was 25.0 months with a follow-up of 5.5 to 45+ months. This VNB–HDFL regimen is a highly active yet well-tolerated first-line treatment for ABC. PMID:15770209

  14. Personal exposure to PM 2.5 and element composition—A comparison between outdoor and indoor workers from two Mexican cities

    NASA Astrophysics Data System (ADS)

    Tovalin-Ahumada, Horacio; Whitehead, Lawrence; Blanco, Salvador

    Many individuals work outdoors in the formal and informal economy of the large urban areas in developing countries, where they are potentially exposed for long periods to high concentrations of ambient airborne particulate matter (PM). This study describes the personal exposures to PM of 2.5 μm aerodynamic diameter and smaller (PM 2.5) for a sample of outdoor and indoor workers in two cities, Mexico City and Puebla, in central Mexico. Thirty-six workers in Mexico City and 17 in Puebla were studied. Thirty were outdoor workers (i.e., taxi and bus drivers, street vendors, and vehicle inspectors) and 23 were indoor (office) workers. Their personal exposures to PM 2.5 were monitored for a mean 19-h period. In Mexico City, the street vendors and taxi drivers overall exposures were significantly higher than indoor workers were. In Puebla, bus drivers had a higher overall exposure than vehicle inspectors or indoor workers. Most of the exposures were above the 65 μg m -3 24-h Mexican standard. In Mexico City, exposures to Si, Ti, Cr, Mn, Fe, Ni, Cu, Mo and Cd were higher for outdoor than for indoor workers. In Puebla, exposures to Si, S, K, Ca, Ti, V, Mn, and Zn also were higher for outdoor workers. In Mexico City outdoor workers exposures to Cu, Pb, Cr, Se and Mo were 4 or more times higher than for Puebla outdoor workers, while Puebla outdoor workers' exposures to V, Si, Fe and Ca were 3 or more times higher than Mexico City outdoor workers. These results suggest that for these outdoor workers the elevated local ambient air PM concentrations and an extended period spent outside are more important contributors to total exposures than indoor concentrations. These workers could be at particular risk of increased morbidity and mortality associated with ambient PM.

  15. Neonatal exposure to benzo[a]pyrene induces oxidative stress causing altered hippocampal cytomorphometry and behavior during early adolescence period of male Wistar rats.

    PubMed

    Patel, Bhupesh; Das, Saroj Kumar; Das, Swagatika; Das, Lipsa; Patri, Manorama

    2016-05-01

    Environmental neurotoxicants like benzo[a]pyrene (B[a]P) have been well documented regarding their potential to induce oxidative stress. However, neonatal exposure to B[a]P and its subsequent effect on anti-oxidant defence system and hippocampal cytomorphometry leading to behavioral changes have not been fully elucidated. We investigated the effect of acute exposure of B[a]P on five days old male Wistar pups administered with single dose of B[a]P (0.2 μg/kg BW) through intracisternal mode. Control group was administered with vehicle i.e., DMSO and a separate group of rats without any treatment was taken as naive group. Behavioral analysis showed anxiolytic-like behavior with significant increase in time spent in open arm in elevated plus maze. Further, significant reduction in fall off time during rotarod test showing B[a]P induced locomotor hyperactivity and impaired motor co-ordination in adolescent rats. B[a]P induced behavioral changes were further associated with altered anti-oxidant defence system involving significant reduction in the total ATPase, Na(+) K(+) ATPase, Mg(2+) ATPase, GR and GPx activity with a significant elevation in the activity of catalase and GST as compared to naive and control groups. Cytomorphometry of hippocampus showed that the number of neurons and glia in B[a]P treated group were significantly reduced as compared to naive and control. Subsequent observation showed that the area and perimeter of hippocampus, hippocampal neurons and neuronal nucleus were significantly reduced in B[a]P treated group as compared to naive and control. The findings of the present study suggest that the alteration in hippocampal cytomorphometry and neuronal population associated with impaired antioxidant signaling and mood in B[a]P treated group could be an outcome of neuromorphological alteration leading to pyknotic cell death or impaired differential migration of neurons during early postnatal brain development. PMID:26946409

  16. Structural and electronic properties of the transition layer at the SiO{sub 2}/4H-SiC interface

    SciTech Connect

    Li, Wenbo; Wang, Dejun; Zhao, Jijun

    2015-01-15

    Using first-principles methods, we generate an amorphous SiO{sub 2}/4H-SiC interface with a transition layer. Based this interface model, we investigate the structural and electronic properties of the interfacial transition layer. The calculated Si 2p core-level shifts for this interface are comparable to the experimental data, indicating that various SiC{sub x}O{sub y} species should be present in this interface transition layer. The analysis of the electronic structures reveals that the tetrahedral SiC{sub x}O{sub y} structures cannot introduce any of the defect states at the interface. Interestingly, our transition layer also includes a C-C=C trimer and SiO{sub 5} configurations, which lead to the generation of interface states. The accurate positions of Kohn-Sham energy levels associated with these defects are further calculated within the hybrid functional scheme. The Kohn-Sham energy levels of the carbon trimer and SiO{sub 5} configurations are located near the conduction and valence band of bulk 4H-SiC, respectively. The result indicates that the carbon trimer occurred in the transition layer may be a possible origin of near interface traps. These findings provide novel insight into the structural and electronic properties of the realistic SiO{sub 2}/SiC interface.

  17. Safety and Efficacy of 24-h Closed-Loop Insulin Delivery in Well-Controlled Pregnant Women With Type 1 Diabetes

    PubMed Central

    Murphy, Helen R.; Kumareswaran, Kavita; Elleri, Daniela; Allen, Janet M.; Caldwell, Karen; Biagioni, Martina; Simmons, David; Dunger, David B.; Nodale, Marianna; Wilinska, Malgorzata E.; Amiel, Stephanie A.; Hovorka, Roman

    2011-01-01

    OBJECTIVE To evaluate the safety and efficacy of closed-loop insulin delivery in well-controlled pregnant women with type 1 diabetes treated with continuous subcutaneous insulin infusion (CSII). RESEARCH DESIGN AND METHODS A total of 12 women with type 1 diabetes (aged 32.9 years, diabetes duration 17.6 years, BMI 27.1 kg/m2, and HbA1c 6.4%) were randomly allocated to closed-loop or conventional CSII. They performed normal daily activities (standardized meals, snacks, and exercise) for 24 h on two occasions at 19 and 23 weeks’ gestation. Plasma glucose time in target (63–140 mg/dL) and time spent hypoglycemic were calculated. RESULTS Plasma glucose time in target was comparable for closed-loop and conventional CSII (median [interquartile range]: 81 [59–87] vs. 81% [54–90]; P = 0.75). Less time was spent hypoglycemic (<45 mg/dL [0.0 vs. 0.3%]; P = 0.04), with a lower low blood glucose index (2.4 [0.9–3.5] vs. 3.3 [1.9–5.1]; P = 0.03), during closed-loop insulin delivery. CONCLUSIONS Closed-loop insulin delivery was as effective as conventional CSII, with less time spent in extreme hypoglycemia. PMID:22011408

  18. Successful outcome after endovascular thrombolysis for acute ischemic stroke with basis on perfusion-diffusion mismatch after 24 h of symptoms onset

    PubMed Central

    Mattei, Tobias A.; Rehman, Azeem A.; Goulart, Carlos R.; Sória, Marília G.; Rizelio, Vanessa; Meneses, Murilo S.

    2016-01-01

    Background: Although intravenous thrombolysis is the Food and Drug Administration-approved treatment for acute ischemic stroke (AIS) within 3 h, combined intravenous and intra-arterial thrombolysis with endovascular techniques may be able to extend this traditional time window. Case Description: We present the clinical evolution of a 45-year-old male presenting with acute left hemiparesis. Magnetic resonance imaging revealed a small diffusion restriction at the right basal ganglia with perfusion compromise in the entire right middle cerebral artery (MCA) territory. Angiography revealed a complete occlusion of MCA at its M1 segment. The patient underwent endovascular mechanical thrombectomy with additional intra-arterial thrombolysis more than 24 hours after the onset of the initial symptoms and experienced complete vessel recanalization. At 1 year, the patient had global independence with minor residual motor impairment in the left arm. Conclusions: We report the case of a successful thrombolytic therapy following AIS performed more than 24 h after the initial symptoms based on the presence of a perfusion-diffusion mismatch. This report is expected to stimulate the development of future prospective studies with special focus on the role of perfusion-diffusion mismatch in patient selection for treatment of AIS, especially in those presenting outside the traditional time window. PMID:27313971

  19. Reproductive rates, birth weight, calving ease and 24-h calf survival in a four-breed diallel among Simmental, Limousin, Polled Hereford and Brahman beef cattle.

    PubMed

    Comerford, J W; Bertrand, J K; Benyshek, L L; Johnson, M H

    1987-01-01

    Calving and weaning rates, birth weight, calving ease, and 24-h calf survival were evaluated in a four-breed diallel of Simmental (S), Limousin (L), Polled Hereford (H) and Brahman (B) beef cattle in five calf crops. Limousin dams tended to have the highest calving and weaning rates because they were able to have heavier calves with less calving difficulty and higher survival rates. Brahman-sired calves were the heaviest at birth (P less than .05) and B dams produced the lightest calves (P less than .001). Lower birth weights tended to be the limiting factor on survival of these calves. A linear comparison among means to evaluate purebred, additive, maternal and specific combining ability effects showed most of the reduction in birth weight from B dams was due to maternal effects. Breed of dam accounted for a higher proportion of variation in calving ease than did sire breed. Simmental sires had significantly heavier calves at birth and S and H dams tended to have more calving difficulty and lower survival rates. Heterosis for these traits was generally not significant. Correlations were generally positive and significant for birth weight and calving ease, but were more variable for birth weight and survival. Linear regressions of calving ease on birth weight both within years and within dam-breed-year subclasses were very similar in that the association of these two traits was reduced as dam age increased. PMID:3818492

  20. Insights into ultraviolet-induced electrical degradation of thermally grown SiO{sub 2}/4H-SiC(0001) interface

    SciTech Connect

    Ikeguchi, Daisuke; Hosoi, Takuji; Shimura, Takayoshi; Watanabe, Heiji; Nakano, Yuki; Nakamura, Takashi

    2014-01-06

    The harmful impact of ultraviolet (UV) light irradiation on thermally grown SiO{sub 2}/4H-SiC structures was investigated by means of electrical measurements of metal-oxide-semiconductor (MOS) capacitors. Unlike Si-based MOS devices, significant electrical degradation, such as positive flatband voltage (V{sub FB}) shift and hysteresis in the capacitance-voltage (C-V) curves of SiC-MOS capacitors was induced by UV irradiation with a low-pressure mercury lamp. The interfacial fixed charge density increased with UV-irradiation (22.6 mW/cm{sup 2} for 16 h) to 1.7 × 10{sup 12} cm{sup −2}, which was an order of magnitude larger than that of the as-grown SiO{sub 2}/SiC interface. A detailed study based on single wavelength solid-state UV lasers revealed that there was a threshold photon energy at around 5 eV and a moderate dependence of UV-induced degradation on temperature. These experimental findings imply that pre-existing inactive defects accumulated at the thermally grown SiO{sub 2}/SiC interface were transformed to active carrier traps with high-energy UV irradiation through transparent SiO{sub 2} layers.

  1. Effects of sodium ions on trapping and transport of electrons at the SiO{sub 2}/4H-SiC interface

    SciTech Connect

    Basile, A. F. Mooney, P. M.; Ahyi, A. C.; Williams, J. R.; Feldman, L. C.

    2014-01-21

    Capacitance-voltage (C-V) and Deep-Level-Transient Spectroscopy (DLTS) measurements were performed on Metal-Oxide-Semiconductor (MOS) capacitors fabricated on 4H-SiC with the SiO{sub 2} layer grown by Sodium-Enhanced Oxidation. This technique has yielded 4H-SiC MOS transistors with record channel mobility, although with poor bias stability. The effects of the mobile positive charge on the C-V characteristics and DLTS spectra were investigated by applying a sequence of positive and negative bias-temperature stresses, which drifted the sodium ions toward and away from the SiO{sub 2}/4H-SiC interface, respectively. Analytical modeling of the C-V curves shows that the drift of sodium ions in the SiO{sub 2} layer during the voltage sweep can explain the temperature dependence of the C-V curves. The effects of lateral fluctuations of the surface potential (due to a non-uniform charge distribution) on the inversion layer mobility of MOS transistors are discussed within a two-dimensional percolation model.

  2. Dietary intake of radiocesium in adult residents in Fukushima prefecture and neighboring regions after the Fukushima nuclear power plant accident: 24-h food-duplicate survey in December 2011.

    PubMed

    Harada, Kouji H; Fujii, Yukiko; Adachi, Ayumu; Tsukidate, Ayako; Asai, Fumikazu; Koizumi, Akio

    2013-03-19

    Since the nuclear power plant accident in Fukushima in March 2011, the Japanese government has conducted screening and removal of contaminated foods from the market that exceed provisional regulation limits for radionuclides. This study aimed to provide an urgent estimate of the dietary exposure of adult residents recruited from three areas in Japan to cesium 134 ((134)Cs), cesium 137 ((137)Cs), and, for comparison, natural potassium 40 ((40)K) on December 4, 2011. Fifty-three sets of 24-h food-duplicate samples were collected in Fukushima Prefecture and neighboring regions. The (134)Cs, (137)Cs, and (40)K levels in the samples were measured using a germanium detector. Items in the food-duplicate samples were recorded and analyzed for radiocesium intake. Radiocesium was detected in 25 of 26 samples from Fukushima. The median dietary intake of radiocesium was 4.0 Bq/day (range <0.26-17 Bq/day). The estimated annual dose from radiocesium was calculated assuming that the daily intake of radiocesium was constant throughout the year. The median estimated dose level was 23 μSv/year (range <2.6-99 μSv/year). The estimated dose level of radiocesium was significantly higher in Fukushima than in the Kanto region and western Japan. Stepwise multiple linear regression analyses demonstrated that the intake of fruits and mushrooms produced in Fukushima were significant factors for the dietary intake of (137)Cs in the 26 participants from Fukushima. The average radioactivity (±SD) of locally produced persimmons and apples (n = 16) were 23 ± 28 and 30 ± 35 Bq/kg for (134)Cs and (137)Cs, respectively. The preliminary estimated dietary dose levels among Fukushima residents were much lower than the maximum permissible dose 1 mSv/year, based on new Japanese standard limits for radiocesium in foods (100 Bq/kg for general foods). In future studies, the exposure estimates should be refined by probability sampling to eliminate biases. PMID:23259847

  3. Sublethal exposure to azamethiphos causes neurotoxicity, altered energy allocation and high mortality during simulated live transport in American lobster.

    PubMed

    Couillard, C M; Burridge, L E

    2015-05-01

    In the Bay of Fundy, New Brunswick, sea lice outbreaks in caged salmon are treated with pesticides including Salmosan(®), applied as bath treatments and then released into the surrounding seawater. The effect of chronic exposure to low concentrations of this pesticide on neighboring lobster populations is a concern. Adult male lobsters were exposed to 61 ngL(-1) of azamethiphos (a.i. in Salmosan(®) formulation) continuously for 10 days. In addition to the direct effects of pesticide exposure, effects on the ability to cope with shipping conditions and the persistence of the effects after a 24h depuration period in clean seawater were assessed. Indicators of stress and hypoxia (serum total proteins, hemocyanin and lactate), oxidative damage (protein carbonyls in gills and serum) and altered energy allocation (hepatosomatic and gonadosomatic indices, hepatopancreas lipids) were assessed in addition to neurotoxicity (chlolinesterase activity in muscle). Directly after exposure, azamethiphos-treated lobsters had inhibition of muscle cholinesterase, reduced gonadosomatic index and enhanced hepatosomatic index and hepatopancreas lipid content. All these responses persisted after 24-h depuration, increasing the risk of cumulative impacts with further exposure to chemical or non-chemical stressors. In both control and treated lobsters exposed to simulated shipment conditions, concentrations of protein and lactate in serum, and protein carbonyls in gills increased. However, mortality rate was higher in azamethiphos-treated lobsters (33 ± 14%) than in controls (2.6 ± 4%). Shipment and azamethiphos had cumulative impacts on serum proteins. Both direct effects on neurological function and energy allocation and indirect effect on ability to cope with shipping stress could have significant impacts on lobster population and/or fisheries. PMID:25499691

  4. Constitutive heat shock protein 70 (HSC70) expression in rainbow trout hepatocytes: effect of heat shock and heavy metal exposure.

    PubMed

    Boone, Adrienne N; Vijayan, Mathilakath M

    2002-06-01

    The 70-kDa family of heat shock proteins plays an important role as molecular chaperones in unstressed and stressed cells. The constitutive member of the 70 family (hsc70) is crucial for the chaperoning function of unstressed cells, whereas the inducible form (hsp70) is important for allowing cells to cope with acute stressor insult, especially those affecting the protein machinery. In fish, the role of hsc70 in the cellular stress response process is less clear primarily because of the lack of a fish-specific antibody for hsc70 detection. In this study, we purified hsc70 to homogeneity from trout liver using a three-step purification protocol with differential centrifugation, ATP-agarose affinity chromatography and electroelution. Polyclonal antibodies to trout hsc70 generated in rabbits cross-reacted strongly with both purified trout hsc70 protein and also purified recombinant bovine hsc70. Two-dimensional electrophoresis followed by Western blotting confirmed that the isoelectric point of rainbow trout hsc70 was more acidic than hsp70. Using this antibody, we detected hsc70 content in the liver, heart, gill and skeletal muscle of unstressed rainbow trout. Primary cultures of trout hepatocytes subjected to a heat shock (+15 degrees C for 1 h) or exposed to either CuSO(4) (200 microM for 24 h), CdCl(2) (10 microM for 24 h) or NaAsO(2) (50 microM for 1 h) resulted in higher hsp70 accumulation over a 24-h period. However, hsc70 content showed no change with either heat shock or heavy metal exposure suggesting that hsc70 is not modulated by sublethal acute stressors in trout hepatocytes. Taken together, we have for the first time generated polyclonal antibodies specific to rainbow trout hsc70 and this antibody will allow for the characterization of the role of hsc70 in the cellular stress response process in fish. PMID:12106899

  5. Pulmonary functional and morphological changes induced by a 4-week exposure to 0. 7 ppm ozone followed by a 9-week recovery period

    SciTech Connect

    Gross, K.B.; White, H.J.

    1986-01-01

    Male Fischer-344 rats were subjected to pulmonary-function testing procedures, then exposed to 0.7 ppm ozone for 28 d, 20 h/d. Another group of animals was similarly treated, but at each test point one-third were sacrificed for microscopic evaluation. When percent changes from preexposure values were compared to controls at each time point, the ozone exposure produced obstructive changes in the lung, including significant decreases in forced expiratory flows, lung volumes, and DL/sub CO/; and a significant increase in functional residual capacity. The total lung capacity was not significantly changed by the ozone. Microscopic examination revealed characteristic lesions in the region of terminal bronchioles and central acinar alveoli marked by peribronchiolar edema, bronchiolization of alveolar duct epithelium, and type II cell proliferation in involved alveoli with increased numbers of macrophages and a few leucocytes. Clearly discernable was a focal interalveolar-alveolar duct reaction made up of fibroblasts, a few inflammatory cells, and conspicuous mast cells, all embedded in a loose metachromatic matrix. After 4 wk of recovery, all measurements of lung volume and DL/sub CO/ had returned to the values of the control group; however, even after 9 wk some of the measurements of lung flow remained significantly although less depressed. Histologically, after 4 wk recovery, there remained only a slight unevenly distributed inflammatory reaction. In these foci there was often a residual, narrower, more condensed band of eosinophilic material, presumably colagen, that sometimes contained interspersed mast cells. After 9 wk, this collagen accumulation within the thickened wall of the alveolar duct could occasionally still be noted.

  6. Human immunodeficiency virus postexposure prophylaxis for occupational exposure in a medical school hospital in Thailand.

    PubMed

    Hiransuthikul, N; Hiransuthikul, P; Kanasuk, Y

    2007-12-01

    This is a retrospective review of occupational exposure to human immunodeficiency virus (HIV) and subsequent postexposure prophylaxis (PEP) among healthcare workers (HCWs) in King Chulalongkorn Memorial Hospital (KCMH), Bangkok, Thailand. From January 2002 to December 2004, data were collected from incident reports, the hospital's infectious diseases unit and the emergency department. There were 315 reported episodes of occupational exposure among 306 HCWs. Nurses (34.0%) were the HCWs most frequently exposed and percutaneous injury (91.4%) was the most common type of exposure. One-third of the source patients tested were infected with HIV. PEP was initiated following 200 (63.5%) of the 315 exposures and was started within 24h in >95% of cases. The most commonly prescribed PEP regimen was zidovudine, lamivudine and nelfinavir. Fifty-six percent of HCWs given PEP completed a four-week course but the remainder discontinued PEP prematurely due to side-effects, or after negative results from the source, or following informed risk reassessment or from their own accord. No exposed HCW acquired HIV during the study period. Appropriate counselling and careful risk assessment are important in achieving effective HIV PEP among HCWs. PMID:18023920

  7. Reversible suppression of protein synthesis in concert with polysome disaggregation during anoxia exposure in Littorina littorea.

    PubMed

    Larade, Kevin; Storey, Kenneth B

    2002-03-01

    Many marine invertebrates can live without oxygen for long periods of time, a capacity that is facilitated by the ability to suppress metabolic rate in anoxia to a value that is typically less than 10% of the normal aerobic rate. The present study demonstrates that a reduction in the rate of protein synthesis is one factor in the overall anoxia-induced metabolic suppression in the marine snail, Littorina littorea. The rate of [3H]leucine incorporation into newly translated protein in hepatopancreas isolated from 48 h anoxic snails was determined to be 49% relative to normoxic controls. However, protein concentration in hepatopancreas did not change during anoxia, suggesting a coordinated suppression of net protein turnover. Analysis of hepatopancreas samples from snails exposed to 24-72 h anoxia showed a gradual disaggregation of polysomes into monosomes. A re-aggregation of monosomes into polysomes was observed after 3 h of aerobic recovery. Analysis of fractions from the ribosome profile using radiolabeled probe to detect alpha-tubulin transcripts confirmed a general decrease in protein translation during anoxia exposure (transcript association with polysomes decreased) with a reversal during aerobic recovery. Western blotting of hepatopancreas samples from normoxic, 24 h anoxic, and 1 h aerobic recovered snails demonstrated that eIF-2alpha is substantially phosphorylated during anoxia exposure and dephosphorylated during normoxia and aerobic recovery, suggesting a decrease in translation initiation during anoxia exposure. These results suggest that metabolic suppression during anoxia exposure in L. littorea involves a decrease in protein translation. PMID:12030368

  8. Developmental ethanol exposure-induced sleep fragmentation predicts adult cognitive impairment.

    PubMed

    Wilson, D A; Masiello, K; Lewin, M P; Hui, M; Smiley, J F; Saito, M

    2016-05-13

    Developmental ethanol (EtOH) exposure can lead to long-lasting cognitive impairment, hyperactivity, and emotional dysregulation among other problems. In healthy adults, sleep plays an important role in each of these behavioral manifestations. Here we explored circadian rhythms (activity, temperature) and slow-wave sleep (SWS) in adult mice that had received a single day of EtOH exposure on postnatal day 7 and saline littermate controls. We tested for correlations between slow-wave activity and both contextual fear conditioning and hyperactivity. Developmental EtOH resulted in adult hyperactivity within the home cage compared to controls but did not significantly modify circadian cycles in activity or temperature. It also resulted in reduced and fragmented SWS, including reduced slow-wave bout duration and increased slow-wave/fast-wave transitions over 24-h periods. In the same animals, developmental EtOH exposure also resulted in impaired contextual fear conditioning memory. The impairment in memory was significantly correlated with SWS fragmentation. Furthermore, EtOH-treated animals did not display a post-training modification in SWS which occurred in controls. In contrast to the memory impairment, sleep fragmentation was not correlated with the developmental EtOH-induced hyperactivity. Together these results suggest that disruption of SWS and its plasticity are a secondary contributor to a subset of developmental EtOH exposure's long-lasting consequences. PMID:26892295

  9. Faecal excretion dynamic during subacute oral exposure to different Pb species in Rattus norvegicus.

    PubMed

    Cadková, Zuzana; Száková, Jiřina; Miholová, Daniela; Válek, Petr; Pacáková, Zuzana; Vadlejch, Jaroslav; Langrová, Iva; Jankovská, Ivana

    2013-05-01

    Faecal excretion is a basic means of detoxification upon ingestion of Pb-contaminated feed. In order to determine a time course of Pb elimination after oral exposure to two different forms of this heavy metal (lead acetate vs. phyto-bound Pb), a feeding study was carried out in experimental rats using the Pb phyto-hyperaccumulator Pistia stratiotes as a model diet. The effect of starvation on Pb excretion was further studied in rats that were fed plant material. Twelve Pb doses (7 μg Pb/1 g BW) were administered orally over a 5-week period. Faeces samples were collected 24 and 72 h post-exposure. Inductively coupled plasma optical emission spectrometry and electrothermal absorption spectrometry methods were used for determination of heavy metal concentrations. Up to 53 % of ingested Pb was rapidly eliminated from the exposed rats via faeces within 24 h after exposure. Faecal excretion in exposed rats differed significantly when compared to that of the control group. Fasting before exposure reduced Pb excretion by up to 50 %. Faecal excretions of both examined Pb forms exhibited almost identical patterns. Considerable differences were revealed concerning total excretion levels; lead acetate was excreted in amount greater extent than those of phytobound Pb. Results of our study suggest that Pb forms occurring in the P. stratiotes tissues are absorbed through the gastrointestinal tract to a greater extent than Pb from lead acetate. Therefore, higher portions of ingested Pb can be available for potential accumulation in tissues of exposed subjects. PMID:23408261

  10. Synthesis and antiproliferative evaluation of novel 2-(4H-1,2,4-triazole-3-ylthio)acetamide derivatives as inducers of apoptosis in cancer cells.

    PubMed

    Kulabaş, Necla; Tatar, Esra; Bingöl Özakpınar, Özlem; Özsavcı, Derya; Pannecouque, Christophe; De Clercq, Erik; Küçükgüzel, İlkay

    2016-10-01

    In this study, a series of thiosemicarbazide derivatives 12-14, 1,2,4-triazol-3-thione derivatives 15-17 and compounds bearing 2-(4H-1,2,4-triazole-3-ylthio)acetamide structure 18-32 have been synthesized starting from phenolic compounds such as 2-naphthol, paracetamol and thymol. Structures and purity of the target compounds were confirmed by the use of their chromatographic and spectral data besides microanalysis. All of the synthesized new compounds 12-32 were evaluated for their anti-HIV activity. Among these compounds, three representatives 18, 19 and 25 were selected and evaluated by the National Cancer Institute (NCI) against the full panel of 60 human cancer cell lines derived from nine different cancer types. Antiproliferative effects of the selected compounds were demonstrated in human tumor cell lines K-562, A549 and PC-3. These compounds inhibited cell growth assessed by MTT assay. Compound 18, 19 and 25 exhibited anti-cancer activity with IC50 values of 5.96 μM (PC-3 cells), 7.90 μM (A549/ATCC cells) and 7.71 μM (K-562 cells), respectively. After the cell viability assay, caspase activation and Bcl-2 activity of the selected compounds were measured and the loss of mitochondrial membrane potential (MMP) was detected. Compounds 18, 19 and 25 showed a significant increase in caspase-3 activity in a dose-dependent manner. This was not observed for caspase-8 activity with compound 18 and 25, while compound 19 was significantly elevated only at the dose of 50 μM. In addition, all three compounds significantly decreased the mitochondrial membrane potential and expression of Bcl-2. PMID:27214512

  11. Two or 24 h of daily contact with sexually active males results in different profiles of LH secretion that both lead to ovulation in anestrous goats.

    PubMed

    Bedos, M; Duarte, G; Flores, J A; Fitz-Rodríguez, G; Hernández, H; Vielma, J; Fernández, I G; Chemineau, P; Keller, M; Delgadillo, J A

    2014-07-01

    Two experiments were conducted to (a) determine whether sexually active males are able to stimulate the sexual activity of anestrous female goats when duration of contact is reduced to an intermittent contact shorter than 4 daily hours and (b) compare the pattern of secretion of LH when anestrous goats are exposed either permanently or intermittently to males. In the first experiment, 4 groups of anovulatory goats were exposed to sexually active males for 24, 4, 2, or 1 h/d during 15 consecutive days, whereas control females remained isolated. More than 89% of females in the groups exposed to the sexually active bucks ovulated, whereas only 5% did so in the control group (P < 0.001). However, the proportion of females ovulating before day 4 was greater in the 2-, 4-, or 24-h contact groups than in the control, whereas it did not differ between the control group and the 1-h contact group (P = 0.02, <0.001, <0.001 and 0.23, respectively). In the second experiment, 3 groups of anovulatory goats were exposed permanently (24 h/d) or intermittently (2 h/d) to bucks during 5 d or remained isolated. We found that pulsatility of luteinizing hormone (LH) increased in the intermittent and permanent contact groups after males were introduced to females (P = 0.05); this pulsatility of LH remained elevated in the permanent-contact group, whereas it decreased in the intermittent-contact group, once the male was removed (P = 0.32 and 0.05, respectively). We conclude that 1 or 2 daily hours of contact with sexually active males is sufficient to stimulate ovulatory activity in anovulatory goats; however, ovulation is obtained through a different pattern of secretion of LH. PMID:24906934

  12. Effects of living at two ambient temperatures on 24-h blood pressure and neuroendocrine function among obese and non-obese humans: a pilot study

    NASA Astrophysics Data System (ADS)

    Kanikowska, Dominika; Sato, Maki; Iwase, Satoshi; Shimizu, Yuuki; Nishimura, Naoki; Inukai, Yoko; Sugenoya, Junichi

    2013-05-01

    The effects of environmental temperature on blood pressure and hormones in obese subjects in Japan were compared in two seasons: summer vs winter. Five obese (BMI, 32 ± 5 kg/m2) and five non-obese (BMI, 23 ±3 kg/m2) men participated in this experiment at latitude 35°10' N and longitude 136°57.9' E. The average environmental temperature was 29 ± 1 °C in summer and 3 ± 1 °C in winter. Blood samples were analyzed for leptin, ghrelin, catecholamines, thyroid stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), total cholesterol, triglycerides, insulin and glucose. Blood pressure was measured over the course of 24 h in summer and winter. A Japanese version of the Profile of Mood States (POMS) questionnaire was also administered each season. Systolic and diastolic blood pressures in obese men were significantly higher in winter (lower environmental temperatures) than in summer (higher environmental temperatures). Noradrenaline and dopamine concentrations were also significantly higher at lower environmental temperatures in obese subjects, but ghrelin, TSH, fT3, fT4, insulin and glucose were not significantly different in summer and winter between obese and non-obese subjects. Leptin, total cholesterol and triglyceride concentrations were significantly higher in winter in obese than non-obese men. Results from the POMS questionnaire showed a significant rise in Confusion at lower environmental temperatures (winter) in obese subjects. In this pilot study, increased blood pressure may have been due to increased secretion of noradrenaline in obese men in winter, and the results suggest that blood pressure control in obese men is particularly important in winter.

  13. The use of multiple imputation method for the validation of 24-h food recalls by part-time observation of dietary intake in school.

    PubMed

    Kupek, Emil; de Assis, Maria Alice A

    2016-09-01

    External validation of food recall over 24 h in schoolchildren is often restricted to eating events in schools and is based on direct observation as the reference method. The aim of this study was to estimate the dietary intake out of school, and consequently the bias in such research design based on only part-time validated food recall, using multiple imputation (MI) conditioned on the information on child age, sex, BMI, family income, parental education and the school attended. The previous-day, web-based questionnaire WebCAAFE, structured as six meals/snacks and thirty-two foods/beverage, was answered by a sample of 7-11-year-old Brazilian schoolchildren (n 602) from five public schools. Food/beverage intake recalled by children was compared with the records provided by trained observers during school meals. Sensitivity analysis was performed with artificial data emulating those recalled by children on WebCAAFE in order to evaluate the impact of both differential and non-differential bias. Estimated bias was within ±30 % interval for 84·4 % of the thirty-two foods/beverages evaluated in WebCAAFE, and half of the latter reached statistical significance (P<0·05). Rarely (<3 %) consumed dietary items were often under-reported (fish/seafood, vegetable soup, cheese bread, French fries), whereas some of those most frequently reported (meat, bread/biscuits, fruits) showed large overestimation. Compared with the analysis restricted to fully validated data, MI reduced differential bias in sensitivity analysis but the bias still remained large in most cases. MI provided a suitable statistical framework for part-time validation design of dietary intake over six daily eating events. PMID:27452779

  14. A microarray analysis of gnotobiotic mice indicating that microbial exposure during the neonatal period plays an essential role in immune system development

    PubMed Central

    2012-01-01

    Background Epidemiological studies have suggested that the encounter with commensal microorganisms during the neonatal period is essential for normal development of the host immune system. Basic research involving gnotobiotic mice has demonstrated that colonization at the age of 5 weeks is too late to reconstitute normal immune function. In this study, we examined the transcriptome profiles of the large intestine (LI), small intestine (SI), liver (LIV), and spleen (SPL) of 3 bacterial colonization models—specific pathogen-free mice (SPF), ex-germ-free mice with bacterial reconstitution at the time of delivery (0WexGF), and ex-germ-free mice with bacterial reconstitution at 5 weeks of age (5WexGF)—and compared them with those of germ-free (GF) mice. Results Hundreds of genes were affected in all tissues in each of the colonized models; however, a gene set enrichment analysis method, MetaGene Profiler (MGP), demonstrated that the specific changes of Gene Ontology (GO) categories occurred predominantly in 0WexGF LI, SPF SI, and 5WexGF SPL, respectively. MGP analysis on signal pathways revealed prominent changes in toll-like receptor (TLR)- and type 1 interferon (IFN)-signaling in LI of 0WexGF and SPF mice, but not 5WexGF mice, while 5WexGF mice showed specific changes in chemokine signaling. RT-PCR analysis of TLR-related genes showed that the expression of interferon regulatory factor 3 (Irf3), a crucial rate-limiting transcription factor in the induction of type 1 IFN, prominently decreased in 0WexGF and SPF mice but not in 5WexGF and GF mice. Conclusion The present study provides important new information regarding the molecular mechanisms of the so-called "hygiene hypothesis". PMID:22823934

  15. In ovo 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure in three avian species. 2. Effects on estrogen receptor and plasma sex steroid hormones during the perinatal period.

    PubMed

    Janz, D M; Bellward, G D

    1996-08-01

    As opposed to mammals, the heterogametic sex in birds is female, and sexual differentiation of the central nervous system away from the intrinsic male pattern is dependent on ovarian estrogen secretions during the perinatal period. The contamination of aquatic systems with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds has been suggested to be responsible for decreased reproductive success in certain wild fish-eating bird populations. Since TCDD has been shown to alter estrogenic status in laboratory animals, we determined the effects of in ovo TCDD exposure on hepatic estrogen receptor (ER) concentrations and affinities, and plasma estradiol concentrations during the perinatal period in the domestic chicken (Gallus gallus), domestic pigeon (Columba livia), and great blue heron (Ardea herodias). Plasma testosterone levels were also determined in herons as an indication of androgenic status. [3H]TCDD was injected into the air cell of chicken eggs on Embryonic Day 4.5 (0.1 microgram/kg egg), pigeon eggs on Embryonic Day 3.5 (1 microgram/kg egg) and Embryonic Day 14 (3 micrograms/kg egg), and heron eggs at approximately Embryonic Day 13 (2 micrograms/kg egg). Chickens were euthanized on Embryonic Days 17 and 19, hatch, and Days 2 and 4 after hatch. Pigeons and herons were either euthanized at hatch or fed an uncontaminated diet for 7 days prior to termination. Between 5 and 10% of the injected [3H]TCDD dose was measured in the liver of hatchlings. There was no effect of in ovo TCDD exposure on hepatic ER levels or plasma estradiol concentrations in female chickens and pigeons exposed early in incubation. In female pigeons exposed during the latter third part of incubation to a TCDD dose that would cause high embryo lethality if injected early in incubation, hepatic ER concentrations were elevated (p < 0.001) and plasma estradiol concentrations were decreased (p < 0.01) at hatch. There was no effect of TCDD exposure on plasma estradiol levels in male

  16. The number of 24 h dietary recalls using the U.S. Department of Agriculture's automated multiple-pass method required to estimate nutrient intake in overweight and obese adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA’s Automated Multiple Pass Method (AMPM) is a five-step, multiple-pass, interviewer-administered, computerized, 24-h dietary recall. The objective of the study was to quantify sources of variation such as day of the week, season, sequence of the diet interviews (training effect), diet interv...

  17. INTRODUCTION OF THE VITELLOGENIN GENE IN EARLY LIFE STAGE FATHEAD MINNOWS AS AN EFFECTIVE EXPOSURE INDICATOR FOR ESTROGENIC COMPOUNDS

    EPA Science Inventory

    Vitellogenin (Vg) gene expression in adult male fathead minnows (FHM) has previously been used successfully to detect exposures to estrogenic compounds in aquatic systems; however, sample volume(s)required for >24h exposure durations and the logistics of sampling pose some limita...

  18. Renal denervation in treatment-resistant essential hypertension. A randomized, SHAM-controlled, double-blinded 24-h blood pressure-based trial

    PubMed Central

    Mathiassen, Ole N.; Vase, Henrik; Bech, Jesper N.; Christensen, Kent L.; Buus, Niels H.; Schroeder, Anne P.; Lederballe, Ole; Rickers, Hans; Kampmann, Ulla; Poulsen, Per L.; Hansen, Klavs W.; B⊘tker, Hans E.; Peters, Christian D.; Engholm, Morten; Bertelsen, Jannik B.; Lassen, Jens F.; Langfeldt, Sten; Andersen, Gratien; Pedersen, Erling B.; Kaltoft, Anne

    2016-01-01

    Background: Renal denervation (RDN), treating resistant hypertension, has, in open trial design, been shown to lower blood pressure (BP) dramatically, but this was primarily with respect to office BP. Method: We conducted a SHAM-controlled, double-blind, randomized, single-center trial to establish efficacy data based on 24-h ambulatory BP measurements (ABPM). Inclusion criteria were daytime systolic ABPM at least 145 mmHg following 1 month of stable medication and 2 weeks of compliance registration. All RDN procedures were carried out by an experienced operator using the unipolar Medtronic Flex catheter (Medtronic, Santa Rosa, California, USA). Results: We randomized 69 patients with treatment-resistant hypertension to RDN (n = 36) or SHAM (n = 33). Groups were well balanced at baseline. Mean baseline daytime systolic ABPM was 159 ± 12 mmHg (RDN) and 159 ± 14 mmHg (SHAM). Groups had similar reductions in daytime systolic ABPM compared with baseline at 3 months [−6.2 ± 18.8 mmHg (RDN) vs. −6.0 ± 13.5 mmHg (SHAM)] and at 6 months [−6.1 ± 18.9 mmHg (RDN) vs. −4.3 ± 15.1 mmHg (SHAM)]. Mean usage of antihypertensive medication (daily defined doses) at 3 months was equal [6.8 ± 2.7 (RDN) vs. 7.0 ± 2.5 (SHAM)]. RDN performed at a single center and by a high-volume operator reduced ABPM to the same level as SHAM treatment and thus confirms the result of the HTN3 trial. Conclusion: Further, clinical use of RDN for treatment of resistant hypertension should await positive results from double-blinded, SHAM-controlled trials with multipolar ablation catheters or novel denervation techniques. PMID:27228432

  19. Survey of residential 50 Hz EMF exposure from transformer stations.

    PubMed

    Szabó, Judit; Jánossy, Gábor; Thuróczy, György

    2007-01-01

    In Hungary it is typical that 10/04 kV transformer stations are being installed in multistory residential and office buildings. Magnetic fields (MFs) up to several tens of microT have been measured in apartments close to transformers. The aim of the present study was to provide systematic assessment of MF exposure of residents living above transformer stations. Out of 41 addresses provided by the electricity supplier, current load of 21 transformers and MF in 21 apartments was measured. Spot MFs at 1 m height and time weighted average 24 h MF exposure at bed height was measured. All-day personal MF exposure was measured at waist and HOME exposure was calculated. BED exposure was measured at bed height. Participants kept a time-activity diary. The time-weighted average 24 h MF exposure (3.03 microT) exceeded the usual residential exposure (<0.2 microT). The mean HOME and BED personal exposure above transformers was 0.825 and 1.033 microT, respectively. Our study provides exposure assessment of a cohort with a wider exposure range, compared to power-line epidemiological studies. PMID:16988992

  20. Alteration in Pimephales promelas mucus production after exposure to nanosilver or silver nitrate.

    PubMed

    Hawkins, Adam D; Thornton, Cammi; Steevens, Jeffery A; Willett, Kristine L

    2014-12-01

    The fish gill's ability to produce mucus effectively is a critical part of the stress response and protection against xenobiotic toxicity. Adult fathead minnows were exposed to silver nitrate (0.82 µg/L or 13.2 µg/L), polyvinylpyrrolidone-coated silver nanoparticles (11.1 µg/L or 208 µg/L), and citrate-coated silver nanoparticles (10.1 µg/L or 175 µg/L) for 96 h. Mucus concentrations based on glucose as a surrogate were determined at 0 h, 1 h, 2 h, 3 h, 4 h and 24 h after re-dosing each day. Higher mucus production rates following silver treatment were observed at the beginning as compared to controls and compared to after 3 d of exposure. Control fish produced consistent mucus concentrations throughout the exposure (0.62 mg/L and 0.40 mg/L at 24 h and 96 h, respectively). Following 24 h of exposure, all silver treatment groups produced significantly more mucus than controls. Following 96 h of exposure, mucus concentrations in treatment groups were significantly reduced compared with each respective treatment at 24 h. Reduced mucus production following long-term silver exposure could prevent the gills from removing silver, and thus increase toxicity. PMID:25262928

  1. Acute exposure to ultraviolet-B radiation modulates sex steroid hormones and receptor expression in the skin and may contribute to the sex-bias of melanoma in a fish model

    PubMed Central

    Mitchell, David L.; Fernandez, André A.; Garcia, Rachel; Paniker, Lakshmi; Lin, Kevin; Hanninen, Amanda; Zigelsky, Kyle; May, Matthew; Nuttall, Mark; Lo, Herng-hsiang; Person, Maria D.; Earley, Ryan

    2014-01-01

    Using the Xiphophorus fish melanoma model we show a strong male bias for cutaneous malignant melanoma, consistent with that seen in the human population. To examine underlying factors, we exposed adult X. couchianus fish to a single, sub-lethal dose of UVB and measured circulating sex steroid hormones and expression of associated hormone receptor genes over a 24 hour period. We found that a single exposure had profound effects on circulating levels of steroid hormones with significant decreases for all free sex steroids at 6 and 24 h and increases in conjugated 2-estradiol and 11-ketotestosterone at 6 and 24 h, respectively. Whereas ARα expression increased in male and female skin, neither ARβ nor either of the ER’s showed significant responses to UVB in either sex. The rapid response of male androgens and their receptors in the skin after UVB irradiation implicates hormones in the male-bias of skin cancer and suggests that the photoendocrine response immediately after UV exposure may be relevant to melanomagenesis. PMID:24406016

  2. The protective effect of a 17°C holding time on boar sperm plasma membrane fluidity after exposure to 5°C.

    PubMed

    Casas, I; Althouse, G C

    2013-02-01

    The holding time (HT) is the period during which an ejaculate, either in a raw or diluted state, is held at 17°C before further processing for cold-storage. In boars, the HT positively influences select sperm quality parameters of semen cooled from 15 to 5°C, a range in temperature during which plasma membrane remodeling occurs. Objective insight into the effect of HT on plasma membrane organization remains unknown. Therefore, the present work sought to elucidate if HT contributes to minimizing alterations in boar sperm plasma membrane fluidity at the initial step of the cooling process in a cryopreservation practice (holding at 5°C) and in relation with select sperm quality parameters. Nineteen ejaculates from five boars were collected and processed according to different treatments: T1) Fresh diluted semen, 0h at 17°C; T2) Fresh diluted semen, 24h at 17°C (HT); T3) Sperm from T1 in a lactose-egg yolk (LEY) extender, 3h at 5°C; T4) Sperm from T2 in LEY, 3h at 5°C; T5) Sperm from T1 in LEY, 24h at 5°C; T6) Sperm from T2 in LEY, 24h at 5°C. Sperm motility was assessed using CASA, and sperm plasma membrane integrity and fluidity were evaluated by flow cytometry with dual labeling (M540/YO-PRO®-1). Results demonstrated that the lack of exposure to a HT (T5) results in reduced sample motility compared to those having a HT (T6), with sperm exposed to HT exhibiting less plasma membrane fluidity. Collectively, these results provide empirical evidence that incorporation of a HT in semen processing protects boar sperm against cold injury through maintenance of lipid architecture of the plasma membrane. PMID:23219919

  3. Toxicity, uptake kinetics and behavior assessment in zebrafish embryos following exposure to perfluorooctanesulphonicacid (PFOS)

    PubMed Central

    Huang, Haihua; Huang, Changjiang; Wang, Lijun; Ye, Xiaowei; Bai, Chenglian; Simonich, Michael T.; Tanguay, Robert L.; Dong, Qiaoxiang

    2014-01-01

    Perfluorooctanesulphonicacid (PFOS), a persistent organic contaminant, has been widely detected in the environment, wildlife and humans, but few studies have assessed its effect on aquatic organisms. The present study evaluated the effect of PFOS on zebrafish embryos. Zebrafish embryos exhibited bent spine and developmental toxicity after exposure to various PFOS concentrations (0.01-16.0 μM) from 6 to 120 hour post-fertilization (hpf). The LC50 at 120 hpf was 4.39 μM and the EC50 at 120 hpf was 2.23 μM. PFOS induced apoptosis at 24 hpf was consistently located in the brain, eye, and tail region of embryos. PFOS elevated the basal rate of swimming after 4 days of exposure, and larvae exposed to PFOS (0.5-8.0μM) for only 1 h at 6 dpf swam faster with increasing PFOS concentration. Larvae exposed to 16.0 μM PFOS for 24 h periods from 1 to 121 hpf showed the highest incidence of malformations in the 97-121 hpf window. Continuous exposure to PFOS from 1 to 121 hpf resulted in a steady accumulation with no evidence of elimination. Our results further the understanding of the health risks of PFOS to aquatic organisms and identify additional research needed on PFOS toxicology. PMID:20171748

  4. Calculation of the structural and NMR properties of the tridecameric AlO 4Al 12(OH) 24(H 2O) 127+ polycation

    NASA Astrophysics Data System (ADS)

    Tossell, J. A.

    2001-09-01

    The aluminum tridecameric polyoxocation, AlO 4Al 12(OH) 24(H 2O) 127+ is a major component in partially hydrolyzed Al +3(aq) solutions and has been extensively studied experimentally, mainly using NMR techniques. I have calculated the equilbrium geometry of this cation using the Hartree-Fock method and a polarized double-zeta effective core potential basis set, obtaining bond distances which agree well with X-ray crystallographic studies of selenate and sulfate salts of the polycation (Al[4]: 4 × 1.85 Å calc, 4 × 1.84 Å exp: Al[6]: 4 × 1.85, 2 × 2.05 Å calc, 2 × 1.84, 2 × 1.88, 1.91, 2.04 Å exp [where the numbers in brackets indicate the coordination numbers]). I have also calculated electric field gradients and NMR shielding constants at all the atoms using the standard 6-31G∗ basis set and Hartree-Fock and hybrid Hartree-Fock-density functional (B3LYP) techniques. Using the Hartree-Fock method, the central four-coordinate Al is calculated to be deshielded by ˜56 ppm, and the six-coordinate Al atoms by ˜16 ppm, vs. the Al(OH 2) 6+3 reference, compared to experimental shifts of 63 and 12 ppm, respectively. The central Al[4] is thus shielded by ˜20 ppm with respect to the tetrahedral monomer Al(OH) 4-1. Al-NMR shifts obtained from the B3LYP calculations are very similar. The calculated O-NMR shifts, vs. free gas-phase H 2O, are 17 ppm for the η-OH 2 groups, 30 ppm for the μ-OH and μOH' groups, and 55 ppm for the μ 4-O group, which match well with the experimentally assigned shifts of 20, 30, and 55 ppm, respectively (vs. liquid H 2O). The B3LYP method yields O shifts, which are systematically about 40 to 50% larger. It is not clear whether the discrepancies in the calculated O shifts vs. liquid water are a result of deficiencies in the model (neglect of the aqueous environment) or in the method (lack of correlation in the Hartree-Fock method). Studies on the Al 2(OH) 2(OH 2) 8+4 cation with small numbers of explicit waters hydrogen-bonded to it

  5. A randomized cross-over comparison of short-term exposure of once-daily extended release tacrolimus and twice-daily tacrolimus on renal function in healthy volunteers

    PubMed Central

    Zaltzman, Jeffrey S; Lai, Vesta; Schulz, Miklos Z; Moon, Kyung-Hee; Cherney, David Z

    2014-01-01

    Calcineurin inhibitor nephrotoxicity remains an issue for transplant recipients. The pharmacokinetic profile (PK) of the once-daily tacrolimus extended release (Tac-ER) includes equivalent exposure [AUC(0–24 h)] but lower Cmax versus twice-daily tacrolimus immediate release (Tac-IR). We hypothesized that the unique PK profiles would result in pharmacodynamic differences in renal function. Nineteen healthy male subjects were allocated to once-daily Tac-ER and twice-daily Tac-IR in a prospective, randomized, two period, cross-over study. Tacrolimus was titrated to achieve trough levels of 8–12 ng/ml. Twenty four hours ERPF and GFR estimated by para-aminohippurate and sinistrin clearance were performed at baseline and at the end of each 10-day dosing period. Mean Tac C0 was 11.0 ± 2.2 and 11.3 ± 1.8 ng/ml for Tac-ER and Tac-IR, respectively. The mean Effective 24 h renal plasma flow (ERPF) was significantly higher with Tac-ER compared with Tac-IR (658 ± 127 vs. 610 ± 93 ml/min/1.73 m2, P = 0.046). There was a trend to a greater mean GFR over 24 h for Tac-ER at 114.5 ± 13.6 ml/min/1.73 m2 compared with 108.9 ± 9.7 ml/min/1.73 m2 for Tac-IR, P = 0.116. Under controlled physiological conditions, ERPF was significantly improved with Tac-ER compared with Tac-IR, likely owing to the differing PKs of these tacrolimus preparations (ClinicalTrials.gov Identifier: NCT01681134). PMID:25160518

  6. Irregular Periods

    MedlinePlus

    ... number of days after the last one. The Menstrual Cycle Most girls get their first period between the ... to skip periods or to have an irregular menstrual cycle. Illness, rapid weight change, or stress can also ...

  7. Do Wild Great Tits Avoid Exposure to Light at Night?

    PubMed Central

    de Jong, Maaike; Ouyang, Jenny Q.; van Grunsven, Roy H. A.; Visser, Marcel E.; Spoelstra, Kamiel

    2016-01-01

    Studies of wild populations have provided important insights into the effects of artificial light at night on organisms, populations and ecosystems. However, in most studies the exact amount of light at night individuals are exposed to remains unknown. Individuals can potentially control their nighttime light exposure by seeking dark spots within illuminated areas. This uncertainty makes it difficult to attribute effects to a direct effect of light at night, or to indirect effects, e.g., via an effect of light at night on food availability. In this study, we aim to quantify the nocturnal light exposure of wild birds in a previously dark forest-edge habitat, experimentally illuminated with three different colors of street lighting, in comparison to a dark control. During two consecutive breeding seasons, we deployed male great tits (Parus major) with a light logger measuring light intensity every five minutes over a 24h period. We found that three males from pairs breeding in brightly illuminated nest boxes close to green and red lamp posts, were not exposed to more artificial light at night than males from pairs breeding further away. This suggests, based on our limited sample size, that these males could have been avoiding light at night by choosing a roosting place with a reduced light intensity. Therefore, effects of light at night previously reported for this species in our experimental set-up might be indirect. In contrast to urban areas where light is omnipresent, bird species in non-urban areas may evade exposure to nocturnal artificial light, thereby avoiding direct consequences of light at night. PMID:27355354

  8. Near interface traps in SiO2/4H-SiC metal-oxide-semiconductor field effect transistors monitored by temperature dependent gate current transient measurements

    NASA Astrophysics Data System (ADS)

    Fiorenza, Patrick; La Magna, Antonino; Vivona, Marilena; Roccaforte, Fabrizio

    2016-07-01

    This letter reports on the impact of gate oxide trapping states on the conduction mechanisms in SiO2/4H-SiC metal-oxide-semiconductor field effect transistors (MOSFETs). The phenomena were studied by gate current transient measurements, performed on n-channel MOSFETs operated in "gate-controlled-diode" configuration. The measurements revealed an anomalous non-steady conduction under negative bias (VG > |20 V|) through the SiO2/4H-SiC interface. The phenomenon was explained by the coexistence of a electron variable range hopping and a hole Fowler-Nordheim (FN) tunnelling. A semi-empirical modified FN model with a time-depended electric field is used to estimate the near interface traps in the gate oxide (Ntrap ˜ 2 × 1011 cm-2).

  9. Evaluation of the antihistamine effects of olopatadine and levocetirizine during a 24-h period: a double-blind, randomized, cross-over, placebo-controlled comparison in skin responses induced by histamine iontophoresis.

    PubMed

    Takeo, Tomohiro; Kasugai, Chikatoshi; Tanaka, Rui; Ando, Takashi; Ogawa, Akina; Akita, Yoichi; Watanabe, Daisuke

    2013-12-01

    The antihistamine effects of olopatadine and levocetirizine, in standard-dose application described in their information (5 mg twice a day for olopatadine; 5 mg once daily for levocetirizine), were examined from 11.5 to 24 h after application. The test was designed in a double-blind, randomized, cross-over, placebo-controlled study of 12 healthy volunteers on histamine-induced flare and wheal response using an iontophoresis technique. The suppressive effect of olopatadine on the wheals induced by a 0.1-mA histamine iontophoresis lasted for 24 h after dosing. Both drugs inhibited flare induced by histamine iontophoresis almost completely until 24 h after the first administration. Suppression of the 0.2-mA-induced wheal response by levocetirizine, taken once daily, decreased with time, although 0.1-mA-induced flare was almost completely suppressed by the drug. Olopatadine completely suppressed even the wheal response induced by a 0.2-mA histamine iontophoresis. Compared with the placebo, the two drugs significantly suppressed the subjective itching assessed by visual analog scale at all intervals. There were no significant differences in subjective drowsiness and objective cognitive function between drug- and placebo-treated subjects. These results demonstrate that olopatadine seems to be more potent than levocetirizine when administrated in a standard dose. In conclusion, mild to moderate urticaria could be controlled by standard application as described in their information. On the other hand, severe urticaria could be managed by a standard application of olopatadine, but levocetirizine may need an additional dose to control severe urticaria. PMID:24303975

  10. Susceptibility of channel catfish, Ictalurus punctatus, to Edwardsiella ictaluri challange following copper sulfate exposure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel catfish, Ictalurus punctatus (Rafinesque) with or without a preliminary 24h exposure to 2 mg copper sulfate L-1, were challenged with 7.5 X 106 colony forming units L-1 of Edwardsiella ictaluri to determine the effect of copper sulfate on disease resistance. Catfish previously exposed to co...

  11. Short-term exposure to testosterone propionate leads to rapid bill color and dominance changes in zebra finches.

    PubMed

    Ardia, Daniel R; Broughton, Deanna R; Gleicher, Michael J

    2010-08-01

    Testosterone (T) can influence both male-male competition and mate choice displays. In zebra finches, female mate choice is based in part on bill color, and bill color has been shown to be enhanced by long-term testosterone supplementation. However, it is not clear whether bill color plays a role in male-male interactions and how bill color responds to shorter-term changes in T. We tested whether a single injection of testosterone propionate (TP) would influence male-male dominance interactions and lead to rapid (over a three-day period) changes in bill color. In addition, we tested whether bill color predicted aggression and dominance. We allowed birds in triads to establish hierarchies and then injected either dominant or subordinate individuals with TP, in addition to establishing sham control triads. We found that red chroma, but not hue, predicted aggressiveness of males. Exposure to TP led both dominant and subordinate birds to increase dominance scores over three days, longer than the <24h period in which injected TP stays active. In addition, exposure to TP increased red chroma and hue in three days showing the dynamic nature of allocation of pigments to the bill. Our results suggest that zebra finches can modulate T and bill color levels over short time periods and these changes may occur through positive feedback between T-levels and dominance. PMID:20406643

  12. Formation of chlorinated lipids post-chlorine gas exposure.

    PubMed

    Ford, David A; Honavar, Jaideep; Albert, Carolyn J; Duerr, Mark A; Oh, Joo Yeun; Doran, Stephen; Matalon, Sadis; Patel, Rakesh P

    2016-08-01

    Exposure to chlorine (Cl2) gas can occur during accidents and intentional release scenarios. However, biomarkers that specifically indicate Cl2 exposure and Cl2-derived products that mediate postexposure toxicity remain unclear. We hypothesized that chlorinated lipids (Cl-lipids) formed by direct reactions between Cl2 gas and plasmalogens serve as both biomarkers and mediators of post-Cl2 gas exposure toxicities. The 2-chloropalmitaldehyde (2-Cl-Pald), 2-chlorostearaldehyde (2-Cl-Sald), and their oxidized products, free- and esterified 2-chloropalmitic acid (2-Cl-PA) and 2-chlorostearic acid were detected in the lungs and plasma of mouse and rat models of Cl2 gas exposure. Levels of Cl-lipids were highest immediately post-Cl2 gas exposure, and then declined over 72 h with levels remaining 20- to 30-fold higher at 24 h compared with baseline. Glutathione adducts of 2-Cl-Pald and 2-Cl-Sald also increased with levels peaking at 4 h in plasma. Notably, 3-chlorotyrosine also increased after Cl2 gas exposure, but returned to baseline within 24 h. Intranasal administration of 2-Cl-PA or 2-Cl-Pald at doses similar to those formed in the lung after Cl2 gas exposure led to increased distal lung permeability and inflammation and systemic endothelial dysfunction characterized by loss of eNOS-dependent vasodilation. These data suggest that Cl-lipids could serve as biomarkers and mediators for Cl2 gas exposure and toxicity. PMID:27324796

  13. FASTING FOR LESS THAN 24 H INDUCES CYTOCHROME P450 2E1 AND 2B1/2ACTIVITIES IN RATS

    EPA Science Inventory

    Cytochrome p450 (CYP) 2E1 activity is induced after 24hr of fasting but no information is available for shorter fasting periods. e investigated the induction of CYP 2E1 in rats during the first 24 hours of food deprivation by examining marker activities for CYP isozymes 2b 1/2 an...

  14. Periadolescent ethanol exposure reduces adult forebrain ChAT+IR neurons: correlation with behavioral pathology.

    PubMed

    Ehlers, C L; Criado, J R; Wills, D N; Liu, W; Crews, F T

    2011-12-29

    Substance abuse typically begins in adolescence; therefore, the impact of alcohol during this critical time in brain development is of particular importance. Epidemiological data indicate that excessive alcohol consumption is prevalent among adolescents and may have lasting neurobehavioral consequences. Loss of cholinergic input to the forebrain has been demonstrated following fetal alcohol exposure and in adults with Wernicke-Korsakoff syndrome. In the present study, immunohistochemistry for choline acetyltransferase (ChAT) was determined to assess forebrain cholinergic neurons (Ch1-4), and behavioral changes following periadolescent alcohol exposure. Wistar rats were exposed to intermittent ethanol vapor (14 h on/10 h off/day) for 35 days from postnatal day (PD) 22 to PD 57 (average blood alcohol concentration (BAC): 163 mg%). Rats were withdrawn from vapor and assessed for locomotor activity, startle response, conflict behavior in the open field, and immobility in the forced swim test, as adults. Rats were then sacrificed at day 71/72 and perfused for histochemical analyses. Ethanol vapor-exposed rats displayed: increased locomotor activity 8 h after the termination of vapor delivery for that 24 h period at day 10 and day 20 of alcohol vapor exposure, significant reductions in the amplitude of their responses to prepulse stimuli during the startle paradigm at 24 h withdrawal, and at 2 weeks following withdrawal, less anxiety-like and/or more "disinhibitory" behavior in the open field conflict, and more immobility in the forced swim test. Quantitative analyses of ChAT immunoreactivity revealed a significant reduction in cell counts in the Ch1-2 and Ch3-4 regions of the basal forebrain in ethanol vapor-exposed rats. This reduction in cell counts was significantly correlated with less anxiety-like and/or more "disinhibitory" behavior in the open field conflict test. These studies demonstrate that behavioral measures of arousal, affective state, disinhibitory

  15. Recovery of otoacoustic emissions after high-level noise exposure in the American bullfrog

    PubMed Central

    Simmons, Dwayne D.; Lohr, Rachel; Wotring, Helena; Burton, Miriam D.; Hooper, Rebecca A.; Baird, Richard A.

    2014-01-01

    The American bullfrog (Rana catesbeiana) has an amphibian papilla (AP) that senses airborne, low-frequency sound and generates distortion product otoacoustic emissions (DPOAEs) similar to other vertebrate species. Although ranid frogs are typically found in noisy environments, the effects of noise on the AP have not been studied. First, we determined the noise levels that diminished DPOAE at 2f1–f2 using an f2 stimulus level at 80 dB SPL and that also produced morphological damage of the sensory epithelium. Second, we compared DPOAE (2f1–f2) responses with histopathologic changes occurring in bullfrogs after noise exposure. Consistent morphological damage, such as fragmented hair cells and missing bundles, as well as elimination of DPOAE responses were seen only after very high-level (>150 dB SPL) sound exposures. The morphological response of hair cells to noise differed along the mediolateral AP axis: medial hair cells were sensitive to noise and lateral hair cells were relatively insensitive to noise. Renewed or repaired hair cells were not observed until 9 days post-exposure. Following noise exposure, DPOAE responses disappeared within 24 h and then recovered to normal pre-exposure levels within 3–4 days. Our results suggest that DPOAEs in the bullfrog are sensitive to the initial period of hair cell damage. After noise-induced damage, the bullfrog AP has functional recovery mechanisms that do not depend on substantial hair cell regeneration or repair. Thus, the bullfrog auditory system might serve as an interesting model for investigation of ways to prevent noise damage. PMID:24501139

  16. Periodized wavelets

    SciTech Connect

    Schlossnagle, G.; Restrepo, J.M.; Leaf, G.K.

    1993-12-01

    The properties of periodized Daubechies wavelets on [0,1] are detailed and contrasted against their counterparts which form a basis for L{sup 2}(R). Numerical examples illustrate the analytical estimates for convergence and demonstrate by comparison with Fourier spectral methods the superiority of wavelet projection methods for approximations. The analytical solution to inner products of periodized wavelets and their derivatives, which are known as connection coefficients, is presented, and several tabulated values are included.

  17. Developmental mercury exposure elicits acute hippocampal cell death, reductions in neurogenesis, and severe learning deficits during puberty.

    PubMed

    Falluel-Morel, Anthony; Sokolowski, Katie; Sisti, Helene M; Zhou, Xiaofeng; Shors, Tracey J; Dicicco-Bloom, Emanuel

    2007-12-01

    Normal brain development requires coordinated regulation of several processes including proliferation, differentiation, and cell death. Multiple factors from endogenous and exogenous sources interact to elicit positive as well as negative regulation of these processes. In particular, the perinatal rat brain is highly vulnerable to specific developmental insults that produce later cognitive abnormalities. We used this model to examine the developmental effects of an exogenous factor of great concern, methylmercury (MeHg). Seven-day-old rats received a single injection of MeHg (5 microg/gbw). MeHg inhibited DNA synthesis by 44% and reduced levels of cyclins D1, D3, and E at 24 h in the hippocampus, but not the cerebellum. Toxicity was associated acutely with caspase-dependent programmed cell death. MeHg exposure led to reductions in hippocampal size (21%) and cell numbers 2 weeks later, especially in the granule cell layer (16%) and hilus (50%) of the dentate gyrus defined stereologically, suggesting that neurons might be particularly vulnerable. Consistent with this, perinatal exposure led to profound deficits in juvenile hippocampal-dependent learning during training on a spatial navigation task. In aggregate, these studies indicate that exposure to one dose of MeHg during the perinatal period acutely induces apoptotic cell death, which results in later deficits in hippocampal structure and function. PMID:17760861

  18. Effects of the organophosphate paraoxon-methyl on survival and reproduction of Daphnia magna: importance of exposure duration and recovery.

    PubMed

    Duquesne, Sabine; Reynaldi, Sebastián; Liess, Matthias

    2006-05-01

    The aim of this study was to determine the influence of exposure duration (1 h, 24 h, continuous) to paraoxon-methyl on the magnitude of lethal and sublethal effects, the shape of the concentration-response relationships and the recovery processes in Daphnia magna. Survival was more severely reduced in the continuous than in the pulse exposure regimes. The lethal concentrations (3d median lethal concentration [LC50] values) were 233, 2.33, and 1.14 microg/L after 1-h, 24-h, and continuous exposure, respectively. The shapes of the concentration-response relationships for survival were significantly different after 1 h of exposure than after 24-h and continuous exposure. Indeed, the slopes of the curves defined by the ratios LC90/LC10 (ratio of 90 and 10% lethal concentrations) were 100, 1.74, and 1.97 for 1-h, 24-h, and continuous exposure, respectively. The large difference between 1 h and longer durations of exposure shows that the population is partially affected (10-90%) over a much broader range of concentrations when exposure is short. Negative effects on reproductive outputs occurred mostly at concentrations affecting partly the survival and therefore also over a broad range of concentrations after 1 h of exposure. However, these effects were only transient in the pulse exposure regimes as individual performances recovered. By contrast, reproductive outputs of survivors exposed continuously remained impaired. These results suggest that a refined risk assessment should consider exposure duration because it influences the magnitude of effects and recovery. PMID:16704048

  19. Ambient Air Pollution Exposure and Respiratory, Cardiovascular and Cerebrovascular Mortality in Cape Town, South Africa: 2001–2006

    PubMed Central

    Wichmann, Janine; Voyi, Kuku

    2012-01-01

    Little evidence is available on the strength of the association between ambient air pollution exposure and health effects in developing countries such as South Africa. The association between the 24-h average ambient PM10, SO2 and NO2 levels and daily respiratory (RD), cardiovascular (CVD) and cerebrovascular (CBD) mortality in Cape Town (2001–2006) was investigated with a case-crossover design. For models that included entire year data, an inter-quartile range (IQR) increase in PM10 (12 mg/m3) and NO2 (12 mg/m3) significantly increased CBD mortality by 4% and 8%, respectively. A significant increase of 3% in CVD mortality was observed per IQR increase in NO2 and SO2 (8 mg/m3). In the warm period, PM10 was significantly associated with RD and CVD mortality. NO2 had significant associations with CBD, RD and CVD mortality, whilst SO2 was associated with CVD mortality. None of the pollutants were associated with any of the three outcomes in the cold period. Susceptible groups depended on the cause-specific mortality and air pollutant. There is significant RD, CVD and CBD mortality risk associated with ambient air pollution exposure in South Africa, higher than reported in developed countries. PMID:23202828

  20. Long-term exposure of the isopod Porcellionides pruinosus to nickel: Costs in the energy budget and detoxification enzymes.

    PubMed

    Ferreira, Nuno G C; Cardoso, Diogo N; Morgado, Rui; Soares, Amadeu M V M; Loureiro, Susana

    2015-09-01

    Terrestrial isopods from the species Porcellionides pruinosus were exposed to the maximum allowed nickel concentration in the Canadian framework guideline (50 mg Ni/kg soil) and to 5× this concentration (250 mg Ni/kg soil). The exposure lasted for 28 days and was followed by a recovery period of 14 days where organisms were changed to clean soil. Organisms were sampled after 24 h, 48 h, 96 h, 7 days, 14 days, 21 days, and 28 days of exposure, and at days 35 and 42 during the recovery period. For each sampling time the acetylcholinesterase (AChE), glutathione-S-transferases (GST), catalase (CAT), lactate dehydrogenase (LDH) activities were determined as well as lipid peroxidation rate (LPO) along with lipids, carbohydrates, proteins content, energy available (Ea), energy consumption (Ec) and cellular energy allocation (CEA). The integrated biomarker response (IBR) was calculated for each sampling time as well as for each one of the above parameters. In addition, mortality was also recorded throughout the assay. The results obtained showed that nickel induced oxidative stress, evidenced by results on GST, GPx, CAT or LPO, but also on changes in the energy reserves content of these organisms. In addition, this study showed that these organisms possess a specific strategy to handle nickel toxicity. In this case, biomarkers were associated with costs in the energy budget, and the increase of energy reserves has a compensation for that cost. PMID:25985212

  1. Nqrs Data for C24H48I12O42S12Tl12 [C12H24O6·12(CH2IO3STl)] (Subst. No. 1591)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for C24H48I12O42S12Tl12 [C12H24O6·12(CH2IO3STl)] (Subst. No. 1591)

  2. Periodic cages.

    PubMed

    Diudea, Mircea V; Nagy, Csaba L; Silaghi-Dumitrescu, Ioan; Graovac, Ante; Janezic, Dusanka; Vikić-Topić, Drazen

    2005-01-01

    Various cages are constructed by using three types of caps: f-cap (derived from spherical fullerenes by deleting zones of various size), kf-cap (obtainable by cutting off the polar ring, of size k), and t-cap ("tubercule"-cap). Building ways are presented, some of them being possible isomerization routes in the real chemistry of fullerenes. Periodic cages with ((5,7)3) covering are modeled, and their constitutive typing enumeration is given. Spectral data revealed some electronic periodicity in fullerene clusters. Semiempirical and strain energy calculations complete their characterization. PMID:15807490

  3. CONTRIBUTION OF FINE PARTICLES OF OUTDOOR ORIGIN TO PERSONAL EXPOSURES: RESULTS OF A 37-PERSON PANEL STUDY IN NORTH CAROLINA

    EPA Science Inventory

    The US EPA carried out a study of personal exposures to PM2.5 for 37 persons with hypertension or cardiovascular disease in North Carolina. Personal, indoor (home) and outdoor (home and central site) 24-h samples were collected for 7 consecutive days in each of four seasons in...

  4. Sex difference in the near-24-hour intrinsic period of the human circadian timing system

    PubMed Central

    Duffy, Jeanne F.; Cain, Sean W.; Chang, Anne-Marie; Phillips, Andrew J. K.; Münch, Mirjam Y.; Gronfier, Claude; Wyatt, James K.; Dijk, Derk-Jan; Czeisler, Charles A.

    2011-01-01

    The circadian rhythms of melatonin and body temperature are set to an earlier hour in women than in men, even when the women and men maintain nearly identical and consistent bedtimes and wake times. Moreover, women tend to wake up earlier than men and exhibit a greater preference for morning activities than men. Although the neurobiological mechanism underlying this sex difference in circadian alignment is unknown, multiple studies in nonhuman animals have demonstrated a sex difference in circadian period that could account for such a difference in circadian alignment between women and men. Whether a sex difference in intrinsic circadian period in humans underlies the difference in circadian alignment between men and women is unknown. We analyzed precise estimates of intrinsic circadian period collected from 157 individuals (52 women, 105 men; aged 18–74 y) studied in a month-long inpatient protocol designed to minimize confounding influences on circadian period estimation. Overall, the average intrinsic period of the melatonin and temperature rhythms in this population was very close to 24 h [24.15 ± 0.2 h (24 h 9 min ± 12 min)]. We further found that the intrinsic circadian period was significantly shorter in women [24.09 ± 0.2 h (24 h 5 min ± 12 min)] than in men [24.19 ± 0.2 h (24 h 11 min ± 12 min); P < 0.01] and that a significantly greater proportion of women have intrinsic circadian periods shorter than 24.0 h (35% vs. 14%; P < 0.01). The shorter average intrinsic circadian period observed in women may have implications for understanding sex differences in habitual sleep duration and insomnia prevalence. PMID:21536890

  5. The effects of intermittent exposure to low pH and oxygen conditions on survival and growth of juvenile red abalone

    NASA Astrophysics Data System (ADS)

    Kim, T. W.; Barry, J. P.; Micheli, F.

    2013-02-01

    Exposure of nearshore animals to hypoxic, low pH waters upwelled from below the continental shelf and advected near the coast may be stressful to marine organisms and lead to impaired physiological performance. We mimicked upwelling conditions in the laboratory and tested the effect of fluctuating exposure to water with low pH and/or low oxygen levels on the mortality and growth of juvenile red abalone (Haliotis rufescens, shell length 5-10 mm). Mortality rates of juvenile abalone exposed to low pH (7.5, total scale) and low O2 (40% saturation, 5 mg L-1) conditions for periods of 3 to 6 h every 3-5 days over 2 weeks did not differ from those exposed to control conditions (O2: 100% saturation, 12 mg L-1; pH 8.0). However, when exposure was extended to 24 h repeated twice over a 15 day period, juveniles experienced higher mortality in the low oxygen treatments compared to control conditions, regardless of pH levels (pH 7.5 vs. 8.0). Growth rates were reduced significantly when juveniles were exposed to low pH or low oxygen treatments and the growth was lowest when low pH exposure was combined with low O2. Furthermore, individual variation of growth rate increased when they were exposed to low pH and low O2 conditions. These results indicate that prolonged exposure to low oxygen levels is detrimental for the survival of red abalone, whereas both pH and oxygen is a crucial factor for their growth. However, given the higher individual variation in growth rate, they may have an ability to adapt to extended exposure to upwelling conditions.

  6. Concomitant efavirenz reduces pharmacokinetic exposure to the antimalarial drug artemether-lumefantrine in healthy volunteers

    PubMed Central

    Huang, Liusheng; Parikh, Sunil; Rosenthal, Philip J.; Lizak, Patricia; Marzan, Florence; Dorsey, Grant; Havlir, Diane; Aweeka, Francesca T.

    2012-01-01

    Background The antiretroviral drug efavirenz (EFV) and the antimalarial artemisinin-based combination therapy (ACT) artemether-lumefantrine (AL) are commonly co-administered to treat HIV and malaria. EFV is a known inducer of cytochrome P450 3A4, which converts artemether to dihydroartemisinin (DHA) that is also active and metabolizes longer acting lumefantrine (LR). A study in healthy volunteers was completed to address the concern that EFV impacts AL pharmacokinetics (PK). Methods Adults received AL (80/480 mg BID) for 3-days prior to and during EFV co-administration (600 mg daily for 26-days) with intensive PK for artemether, DHA, and LR conducted after the last AL dose for each period. EFV PK was evaluated with and without AL. PK parameters were estimated using non-compartmental methods. Results Twelve subjects completed the two-period study. PK exposure for artemether, DHA, and LR [as estimated by the area under the concentration time curve (AUClast)] decreased or trended toward decrease with EFV, compared to when administered alone [−51% (p=0.084), −46% (p=0.005), and −21% (p=0.102), respectively]. Day 7 LR levels, previously deemed predictive of treatment success, were 46% lower (p=0.002) with EFV, but the LR half-life was unchanged. EFV PK exposure was minimally altered following AL co-administration [AUC0–24h decreased by 17% (p=0.034)]. Conclusions Exposure to DHA, but not LR, was significantly lower during EFV-AL co-administration compared to that during administration of AL alone. These findings may have implications for the treatment efficacy of AL, particularly in children. However, the observed modest changes probably do not warrant dosage adjustment during co-administration of AL with EFV. PMID:22918158

  7. Cytotoxicity of aluminium oxide nanoparticles towards fresh water algal isolate at low exposure concentrations.

    PubMed

    Pakrashi, Sunandan; Dalai, Swayamprava; T C, Prathna; Trivedi, Shruti; Myneni, Radhika; Raichur, Ashok M; Chandrasekaran, N; Mukherjee, Amitava

    2013-05-15

    The growing commercial applications had brought aluminium oxide nanoparticles under toxicologists' purview. In the present study, the cytotoxicity of two different sized aluminium oxide nanoparticles (ANP(1), mean hydrodynamic diameter 82.6±22nm and ANP(2), mean hydrodynamic diameter 246.9±39nm) towards freshwater algal isolate Chlorella ellipsoids at low exposure levels (≤1μg/mL) using sterile lake water as the test medium was assessed. The dissolution of alumina nanoparticles and consequent contribution towards toxicity remained largely unexplored owing to its presumed insoluble nature. Herein, the leached Al(3+) ion mediated toxicity has been studied along with direct particulate toxicity to bring out the dynamics of toxicity through colloidal stability, biochemical, spectroscopic and microscopic analyses. The mean hydrodynamic diameter increased with time both for ANP(1) [82.6±22nm (0h) to 246.3±59nm (24h), to 1204±140nm (72h)] and ANP(2) [246.9±39nm (0h) to 368.28±48nm (24h), to 1225.96±186nm (72h)] signifying decreased relative abundance of submicron sized particles (<1000nm). The detailed cytotoxicity assays showed a significant reduction in the viability dependent on dose and exposure. A significant increase in ROS and LDH levels were noted for both ANPs at 1μg/mL concentration. The zeta potential and FT-IR analyses suggested surface chemical interaction between nanoparticles and algal cells. The substantial morphological changes and cell wall damage were confirmed through microscopic analyses (SEM, TEM, and CLSM). At 72h, significant Al(3+) ion release in the test medium [0.092μg/mL for ANP(1), and 0.19μg/mL for ANP(2)] was noted, and the resulting suspension containing leached ions caused significant cytotoxicity, revealing a substantial ionic contribution. This study indicates that both the nano-size and ionic dissolution play a significant role in the cytotoxicity of ANPs towards freshwater algae, and the exposure period largely determines

  8. Association between 24 h urinary sodium and potassium excretion and the metabolic syndrome in Chinese adults: the Shandong and Ministry of Health Action on Salt and Hypertension (SMASH) study.

    PubMed

    Ge, Zeng; Guo, Xiaolei; Chen, Xiaorong; Tang, Junli; Yan, Liuxia; Ren, Jie; Zhang, Jiyu; Lu, Zilong; Dong, Jing; Xu, Jianwei; Cai, Xiaoning; Liang, Hao; Ma, Jixiang

    2015-03-28

    The association of 24 h urinary Na and potassium excretion with the risk of the metabolic syndrome (MetS) has not been studied in China. The aim of the present study was to examine this association by analysing the data from 1906 study participants living in north China. To this end, 24 h urine samples were collected. Of the 1906 participants, 471 (24·7 %) had the MetS. The mean urinary Na and K excretion was 228·7 and 40·8 mmol/d, respectively. After multivariate adjustment, the odds of the MetS significantly increased across the increasing tertiles of urinary Na excretion (1·00, 1·40 and 1·54, respectively). For the components of the MetS, the odds of central obesity, elevated blood pressure and elevated TAG, but not the odds of low HDL-cholesterol and elevated fasting glucose, significantly increased with the successive tertiles of urinary Na excretion. Furthermore, for every 100 mmol/d increase in urinary Na excretion, the odds of the MetS, central obesity, elevated blood pressure and elevated TAG was significantly increased by 29, 63, 22 and 21 %, respectively. However, urinary K excretion was not significantly associated with the risk of the MetS. These findings suggest that high Na intake might be an important risk factor for the MetS in Chinese adults. PMID:25743698

  9. Effects of luseogliflozin, a sodium-glucose co-transporter 2 inhibitor, on 24-h glucose variability assessed by continuous glucose monitoring in Japanese patients with type 2 diabetes mellitus: a randomized, double-blind, placebo-controlled, crossover study.

    PubMed

    Nishimura, R; Osonoi, T; Kanada, S; Jinnouchi, H; Sugio, K; Omiya, H; Ubukata, M; Sakai, S; Samukawa, Y

    2015-08-01

    The aim of the present study was to determine the effects of luseogliflozin on 24-h glucose levels, assessed by continuous glucose monitoring, and on pharmacodynamic variables measured throughout the day. In this double-blind, placebo-controlled, crossover study, 37 patients with type 2 diabetes mellitus inadequately controlled with diet and exercise were randomized into two groups. Patients in each group first received luseogliflozin then placebo for 7 days each, or vice versa. After 7 days of treatment, the mean 24-h glucose level was significantly lower with luseogliflozin than with placebo [mean (95% confidence interval) 145.9 (134.4-157.5) mg/dl vs 168.5 (156.9-180.0) mg/dl; p < 0.001]. The proportion of time spent with glucose levels ≥70 to ≤180 mg/dl was significantly greater with luseogliflozin than with placebo [median (interquartile range) 83.2 (67.7-96.5)% vs 71.9 (46.9-83.3)%; p < 0.001] without inducing hypoglycaemia. The decrease in glucose levels was accompanied by reductions in serum insulin levels throughout the day. PMID:25930989

  10. Electrical and physical characterizations of the effects of oxynitridation and wet oxidation at the interface of SiO2/4H-SiC(0001) and (000\\bar{1})

    NASA Astrophysics Data System (ADS)

    Shiomi, Hiromu; Kitai, Hidenori; Tsujimura, Masatoshi; Kiuchi, Yuji; Nakata, Daisuke; Ono, Shuichi; Kojima, Kazutoshi; Fukuda, Kenji; Sakamoto, Kunihiro; Yamasaki, Kimiyohi; Okumura, Hajime

    2016-04-01

    The effects of oxynitridation and wet oxidation at the interface of SiO2/4H-SiC(0001) and (000\\bar{1}) were investigated using both electrical and physical characterization methods. Hall measurements and split capacitance-voltage (C-V) measurements revealed that the difference in field-effect mobility between wet oxide and dry oxynitride interfaces was mainly attributed to the ratio of the mobile electron density to the total induced electron density. The surface states close to the conduction band edge causing a significant trapping of inversion carriers were also evaluated. High-resolution Rutherford backscattering spectroscopy (HR-RBS) analysis and high-resolution elastic recoil detection analysis (HR-ERDA) were employed to show the nanometer-scale compositional profile of the SiC-MOS interfaces for the first time. These analyses, together with cathode luminescence (CL) spectroscopy and transmission electron microscopy (TEM), suggested that the deviations of stoichiometry and roughness at the interface defined the effects of oxynitridation and wet oxidation at the interface of SiO2/4H-SiC(0001) and (000\\bar{1}).

  11. Periodic Polymers

    NASA Astrophysics Data System (ADS)

    Thomas, Edwin

    2013-03-01

    Periodic polymers can be made by self assembly, directed self assembly and by photolithography. Such materials provide a versatile platform for 1, 2 and 3D periodic nano-micro scale composites with either dielectric or impedance contrast or both, and these can serve for example, as photonic and or phononic crystals for electromagnetic and elastic waves as well as mechanical frames/trusses. Compared to electromagnetic waves, elastic waves are both less complex (longitudinal modes in fluids) and more complex (longitudinal, transverse in-plane and transverse out-of-plane modes in solids). Engineering of the dispersion relation between wave frequency w and wave vector, k enables the opening of band gaps in the density of modes and detailed shaping of w(k). Band gaps can be opened by Bragg scattering, anti-crossing of bands and discrete shape resonances. Current interest is in our group focuses using design - modeling, fabrication and measurement of polymer-based periodic materials for applications as tunable optics and control of phonon flow. Several examples will be described including the design of structures for multispectral band gaps for elastic waves to alter the phonon density of states, the creation of block polymer and bicontinuous metal-carbon nanoframes for structures that are robust against ballistic projectiles and quasi-crystalline solid/fluid structures that can steer shock waves.

  12. Methane and carbon dioxide emissions from dairy cows in full lactation monitored over a six-month period.

    PubMed

    Kinsman, R; Sauer, F D; Jackson, H A; Wolynetz, M S

    1995-12-01

    Methane and CO2 emissions from a herd of 118 lactating cows were measured directly by continuous monitoring with an infrared gas analyzer from 24 gas sampling locations. A total of 112 d of gas output was recorded between June 1993 and November 1993. Recordings were integrated at .5-h intervals, so that there were 48 data points for each 24-h period. The mean 24-h CH4 emission per cow was 587 +/- 61.3 L; the range was 436 to 721 L. The mean 24-h CO2 emission per cow was 6137 +/- 505 L, and the range was 5032 to 7427 L. These values were not corrected for gas emissions from stored manure, which contributed 5.8 and 6.1%, respectively, to CH4 and CO2 output under conditions of this experiment. PMID:8675759

  13. Repeated blast exposures cause brain DNA fragmentation in mice.

    PubMed

    Wang, Ying; Arun, Peethambaran; Wei, Yanling; Oguntayo, Samuel; Gharavi, Robert; Valiyaveettil, Manojkumar; Nambiar, Madhusoodana P; Long, Joseph B

    2014-03-01

    The pathophysiology of blast-induced traumatic brain injury (TBI) and subsequent behavioral deficits are not well understood. Unraveling the mechanisms of injury is critical to derive effective countermeasures against this form of neurotrauma. Preservation of the integrity of cellular DNA is crucial for the function and survival of cells. We evaluated the effect of repeated blast exposures on the integrity of brain DNA and tested the utility of cell-free DNA (CFD) in plasma as a biomarker for the diagnosis and prognosis of blast-induced polytrauma. The results revealed time-dependent breakdown in cellular DNA in different brain regions, with the maximum damage at 24 h post-blast exposures. CFD levels in plasma showed a significant transient increase, which was largely independent of the timing and severity of brain DNA damage; maximum levels were recorded at 2 h after repeated blast exposure and returned to baseline at 24 h. A positive correlation was observed between the righting reflex time and CFD level in plasma at 2 h after blast exposure. Brain DNA damage subsequent to repeated blast was associated with decreased mitochondrial membrane potential, increased release of cytochrome C, and up-regulation of caspase-3, all of which are indicative of cellular apoptosis. Shock-wave-induced DNA damage and initiation of mitochondrial-driven cellular apoptosis in the brain after repeated blast exposures indicate that therapeutic strategies directed toward inhibition of DNA damage or instigation of DNA repair may be effective countermeasures. PMID:24074345

  14. Daily personal exposure to black carbon: A pilot study

    NASA Astrophysics Data System (ADS)

    Williams, Ryan D.; Knibbs, Luke D.

    2016-05-01

    Continuous personal monitoring is the benchmark for air pollution exposure assessment. Black carbon (BC) is a strong marker of primary combustion like vehicle and biomass emissions. There have been few studies that quantified daily personal BC exposure and the contribution that different microenvironments make to it. In this pilot study, we used a portable aethalometer to measure BC concentrations in an individual's breathing zone at 30-s intervals while he performed his usual daily activities. We used a GPS and time-activity diary to track where he spent his time. We performed twenty 24-h measurements, and observed an arithmetic mean daily exposure concentration of 603 ng/m3. We estimated that changing commute modes from bus to train reduced the 24-h mean BC exposure concentration by 29%. Switching from open windows to closed windows and recirculated air in a car led to a reduction of 32%. Living in a home without a wood-fired heater caused a reduction of 50% compared with a wood-heated home. Our preliminary findings highlight the potential utility of simple approaches to reduce a person's daily BC exposure.

  15. Daily personal exposure to black carbon: A pilot study

    NASA Astrophysics Data System (ADS)

    Williams, Ryan D.; Knibbs, Luke D.

    2016-05-01

    Continuous personal monitoring is the benchmark for air pollution exposure assessment. Black carbon (BC) is a strong marker of primary combustion like vehicle and biomass emissions. There have been few studies that quantified daily personal BC exposure and the contribution that different microenvironments make to it. In this pilot study, we used a portable aethalometer to measure BC concentrations in an individual's breathing zone at 30-s intervals while he performed his usual daily activities. We used a GPS and time-activity diary to track where he spent his time. We performed twenty 24-h measurements, and observed an arithmetic mean daily exposure concentration of 603 ng/m3. We estimated that changing commute modes from bus to train reduced the 24-h mean BC exposure concentration by 29%. Switching from open windows to closed windows and recirculated air in a car led to a reduction of 32%. Living in a home without a wood-fired heater caused a reduction of 50% compared with a wood-heated home. Our preliminary findings highlight the potential utility of simple approaches to reduce a person's daily BC exposure.

  16. Thermal exposure effects on the in vitro degradation and mechanical properties of Mg-Sr and Mg-Ca-Sr biodegradable implant alloys and the role of the microstructure.

    PubMed

    Bornapour, M; Celikin, M; Pekguleryuz, M

    2015-01-01

    Magnesium is an attractive biodegradable material for medical applications due to its non-toxicity, low density and good mechanical properties. The fast degradation rate of magnesium can be tailored using alloy design. The combined addition of Sr and Ca results in a good combination of mechanical and corrosion properties; the alloy compositions with the best performance are Mg-0.5Sr and Mg-0.3Sr-0.3Ca. In this study, we investigated an important effect, namely thermal treatment (at 400 °C), on alloy properties. The bio-corrosion of the alloys was analyzed via in vitro corrosion tests in simulated body fluid (SBF); the mechanical properties were studied through tensile, compression and three-point bending tests in two alloy conditions, as-cast and heat-treated. We showed that 8h of heat treatment increases the corrosion rate of Mg-0.5Sr very rapidly and decreases its mechanical strength. The same treatment does not significantly change the properties of Mg-0.3Sr-0.3Ca. An in-depth microstructural investigation via transmission electron microscopy, scanning electron microscopy, electron probe micro-analysis and X-ray diffraction elucidated the effects of the thermal exposure. Microstructural characterization revealed that Mg-0.3Sr-0.3Ca has a new intermetallic phase that is stable after 8h of thermal treatment. Longer thermal exposure (24h) leads to the dissolution of this phase and to its gradual transformation to the equilibrium phase Mg17Sr2, as well as to a loss of mechanical and corrosion properties. The ternary alloy shows better thermal stability than the binary alloy, but the manufacturing processes should aim to not exceed exposure to high temperatures (400 °C) for prolonged periods (over 24 h). PMID:25491955

  17. Periodic peristalsis releasing constrained water in high solids enzymatic hydrolysis of steam exploded corn stover.

    PubMed

    Liu, Zhi-Hua; Chen, Hong-Zhang

    2016-04-01

    Periodic peristalsis was used to release water constraint and increase high solids enzymatic hydrolysis efficiency. Glucan and xylan conversion in periodic peristalsis enzymatic hydrolysis (PPEH) at 21% solid loading increased by 5.2-6.4% and 6.8-8.8% compared with that in incubator shaker enzymatic hydrolysis (ISEH), respectively. Hydrolysis kinetics suggested that sugars conversion significantly increased within 24h in PPEH compared with ISEH. The peak height of main water pool increased by 7.7-43.1% within 24h in PPEH compared with ISEH. The increases in peak height of main water pool were consistent with the increases in glucan conversion. Submicroscopic particulates and macro granule residues contributed greatly to water constraint compared with glucose, xylose, ethanol, and Tween 80. Smaller particle size and longer residence time resulted in lower water constraint and facilitated the enzymatic hydrolysis performance. Periodic peristalsis was an effective method to reduce water constraint and increase high solids enzymatic hydrolysis efficiency. PMID:26826953

  18. 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 ...

  19. Stress-based aftershock forecasts made within 24 h postmain shock: Expected north San Francisco Bay area seismicity changes after the 2014 M = 6.0 West Napa earthquake

    NASA Astrophysics Data System (ADS)

    Parsons, Tom; Segou, Margaret; Sevilgen, Volkan; Milner, Kevin; Field, Edward; Toda, Shinji; Stein, Ross S.

    2014-12-01

    We calculate stress changes resulting from the M = 6.0 West Napa earthquake on north San Francisco Bay area faults. The earthquake ruptured within a series of long faults that pose significant hazard to the Bay area, and we are thus concerned with potential increases in the probability of a large earthquake through stress transfer. We conduct this exercise as a prospective test because the skill of stress-based aftershock forecasting methodology is inconclusive. We apply three methods: (1) generalized mapping of regional Coulomb stress change, (2) stress changes resolved on Uniform California Earthquake Rupture Forecast faults, and (3) a mapped rate/state aftershock forecast. All calculations were completed within 24 h after the main shock and were made without benefit of known aftershocks, which will be used to evaluative the prospective forecast. All methods suggest that we should expect heightened seismicity on parts of the southern Rodgers Creek, northern Hayward, and Green Valley faults.

  20. Stress-based aftershock forecasts made within 24h post mainshock: Expected north San Francisco Bay area seismicity changes after the 2014M=6.0 West Napa earthquake

    USGS Publications Warehouse

    Parsons, Thomas E.; Segou, Margaret; Sevilgen, Volkan; Milner, Kevin; Field, Ned; Toda, Shinji; Stein, Ross S.

    2014-01-01

    We calculate stress changes resulting from the M= 6.0 West Napa earthquake on north San Francisco Bay area faults. The earthquake ruptured within a series of long faults that pose significant hazard to the Bay area, and we are thus concerned with potential increases in the probability of a large earthquake through stress transfer. We conduct this exercise as a prospective test because the skill of stress-based aftershock forecasting methodology is inconclusive. We apply three methods: (1) generalized mapping of regional Coulomb stress change, (2) stress changes resolved on Uniform California Earthquake Rupture Forecast faults, and (3) a mapped rate/state aftershock forecast. All calculations were completed within 24 h after the main shock and were made without benefit of known aftershocks, which will be used to evaluative the prospective forecast. All methods suggest that we should expect heightened seismicity on parts of the southern Rodgers Creek, northern Hayward, and Green Valley faults.

  1. Surface photovoltage and Auger electron spectromicroscopy studies of HfO2/SiO2/4H-SiC and HfO2/Al2O3/4H-SiC structures

    NASA Astrophysics Data System (ADS)

    Domanowska, A.; Miczek, M.; Ucka, R.; Matys, M.; Adamowicz, B.; Żywicki, J.; Taube, A.; Korwin-Mikke, K.; Gierałtowska, S.; Sochacki, M.

    2012-08-01

    The electronic and chemical properties of the interface region in the structures obtained by the passivation of epitaxial n-type 4H-SiC layers with bilayers consisting of a 5 nm-thick SiO2 or Al2O3 buffer film and high-κ HfO2 layer were investigated. The main aim was to estimate the influence of the passivation approach on the interface effective charge density (Qeff) from the surface photovoltage (SPV) method and, in addition to determine the in-depth element distribution in the interface region from the Auger electron spectroscopy (AES) combined with Ar+ ion profiling. The structure HfO2/SiO2/4H-SiC exhibited slightly superior electronic properties in terms of Qeff (in the range of -1011 q cm-2).

  2. Lactotripeptides effect on office and 24-h ambulatory blood pressure, blood pressure stress response, pulse wave velocity and cardiac output in patients with high-normal blood pressure or first-degree hypertension: a randomized double-blind clinical trial.

    PubMed

    Cicero, Arrigo F G; Rosticci, Martina; Gerocarni, Beatrice; Bacchelli, Stefano; Veronesi, Maddalena; Strocchi, Enrico; Borghi, Claudio

    2011-09-01

    Contrasting data partially support a certain antihypertensive efficacy of lactotripeptides (LTPs) derived from enzymatic treatment of casein hydrolysate. Our aim was to evaluate this effect on a large number of hemodynamic parameters. We conducted a prospective double-blind randomized clinical trial, which included 52 patients affected by high-normal blood pressure (BP) or first-degree hypertension. We investigated the effect of a 6-week treatment with the LTPs isoleucine-proline-proline and valine-proline-proline at 3 mg per day, assumed to be functional food, on office BP, 24-h ambulatory BP monitoring (ABPM) values, stress-induced BP increase and cardiac output-related parameters. In the LTP-treated subjects, we observed a significant reduction in office systolic BP (SBP; -5±8 mm Hg, P=0.013) and a significant improvement in pulse wave velocity (PWV; -0.66±0.81 m s(-1), P=0.001; an instrumental biomarker of vascular rigidity). No effect on 24-h ABPM parameters and BP reaction to stress was observed from treatment with the combined LTPs. LTPs, but not placebo, were associated with a mild but significant change in the stroke volume (SV), SV index (markers of cardiac flow), the acceleration index (ACI) and velocity index (VI) (markers of cardiac contractility). No effect was observed on parameters related to fluid dynamics or vascular resistance. LTPs positively influenced the office SBP, PWV, SV, SV index, ACI and VI in patients with high-normal BP or first-degree hypertension. PMID:21753776

  3. Effects of exposure duration of herbicides on natural stream periphyton communities and recovery.

    PubMed

    Gustavson, K; Møhlenberg, F; Schlüter, L

    2003-07-01

    To improve risk estimates for herbicides in streams, the sensitivity of natural periphyton communities to four herbicides (metribuzin, hexazinone, isoproturon, and pendimethalin) was examined in experiments including varying exposure duration and a recovery phase. Effect parameters included assimilation of 14C and concentration of diagnostic pigments as proxies for photosynthetic activity and algal group composition, respectively. The results indicated that isoproturon, metribuzin, and hexazinone affected the photosynthetic activity of periphyton at distinctly lower concentrations than the effect concentrations published for standard single-species growth-tests with phytoplankton species. Pendimethalin did not show effects on the photosynthetic activity of periphyton at the concentrations tested. The effect concentration (EC50) of isoproturon and metribuzin decreased by one to two orders of magnitude when the duration of exposure increased from 1 h to 24 h, while hexazinone had a stimulating effect on the photosynthetic activity of periphyton after 1 h exposure and inhibiting effect after 24 h exposure. The photosynthetic activity after exposure to metribuzin for 1, 2, 6, 18, 23, or 48 h recovered almost completely after 48 h in herbicide-free water. However, different periphyton groups responded differently to metribuzin exposure: Chlorophytes were severely affected by exposure and did not recover, whereas diatoms and especially cyanobacteria recovered well. Overall the study showed that the effects of herbicides on periphyton are strongly affected by the duration of exposure, and even short-term exposure may have distinct effects on the periphyton community. PMID:12948172

  4. Attentional Modulation of the Mere Exposure Effect

    ERIC Educational Resources Information Center

    Yagi, Yoshihiko; Ikoma, Shinobu; Kikuchi, Tadashi

    2009-01-01

    The "mere exposure effect" refers to the phenomenon where previous exposures to stimuli increase participants' subsequent affective preference for those stimuli. This study explored the effect of selective attention on the mere exposure effect. The experiments manipulated the to-be-attended drawings in the exposure period (either red or green…

  5. Effects of zinc against mercury toxicity in female rats 12 and 48 hours after HgCl2 exposure

    PubMed Central

    Mesquita, Mariana; Pedroso, Taíse F.; Oliveira, Cláudia S.; Oliveira, Vitor A.; do Santos, Rafael Francisco; Bizzi, Cezar Augusto; Pereira, Maria Ester

    2016-01-01

    This work investigated the toxicity of inorganic mercury and zinc preventive effects in female rats sacrificed 12 or 48 h after HgCl2 exposure. Female Wistar rats were subcutaneously injected with ZnCl2 (27 mg/kg) or saline (0.9 %), and 24 h later they were exposed to HgCl2 (5 mg/kg) or saline (0.9 %). Rats sacrificed 12 hours after Hg administration presented an increase in kidney weight and a decrease in renal ascorbic acid levels. Zinc pretreatment prevented the renal weight increase. Rats sacrificed 48 h after Hg exposure presented a decrease in body weight gain, an increase in renal weight, a decrease in renal δ-aminolevulinic acid dehydratase activity, an increase in serum creatinine and urea levels, and a decrease in kidney total thiol levels. Zinc pretreatment partly prevented the decrease in body weight gain and increase in creatinine levels, in addition to totally preventing renal δ-aminolevulinic acid dehydratase inhibition. Mercury accumulation in the kidney and liver in both periods was observed after Hg administration. These results show the different Hg effects along the time of intoxication, and a considerably preventive effect of zinc against Hg toxicity. PMID:27330529

  6. Enhanced eryptosis following gramicidin exposure.

    PubMed

    Malik, Abaid; Bissinger, Rosi; Liu, Guoxing; Liu, Guilai; Lang, Florian

    2015-05-01

    The peptide antibiotic and ionophore gramicidin has previously been shown to trigger apoptosis of nucleated cells. In analogy to apoptosis, the suicidal death of erythrocytes or eryptosis involves cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include oxidative stress, increase of cytosolic Ca2+ activity ([Ca2+]i), and ceramide. The present study explored, whether gramicidin triggers eryptosis. To this end phosphatidylserine exposure at the cell surface was estimated from annexin V binding, cell volume from forward scatter, red blood cell distribution width (RDW) from electronic particle counting, reactive oxidant species (ROS) from 2',7'-dichlorodihydrofluorescein diacetate (DCFDA) fluorescence, [Ca2+]i from Fluo3- and Fluo4 fluorescence, and ceramide abundance from binding of specific antibodies. As a result, a 24 h exposure of human erythrocytes to gramicidin significantly increased the percentage of annexin-V-binding cells (≥1 µg/mL), forward scatter (≥0.5 µg/mL) and hemolysis. Gramicidin enhanced ROS activity, [Ca2+]i and ceramide abundance at the erythrocyte surface. The stimulation of annexin-V-binding by gramicidin was significantly blunted but not abolished by removal of extracellular Ca2+. In conclusion, gramicidin stimulates phospholipid scrambling of the erythrocyte cell membrane, an effect at least partially due to induction of oxidative stress, increase of [Ca2+]i and up-regulation of ceramide abundance. Despite increase of [Ca2+]i, gramicidin increases cell volume and slightly reduces RWD. PMID:25915718

  7. Enhanced Eryptosis Following Gramicidin Exposure

    PubMed Central

    Malik, Abaid; Bissinger, Rosi; Liu, Guoxing; Liu, Guilai; Lang, Florian

    2015-01-01

    The peptide antibiotic and ionophore gramicidin has previously been shown to trigger apoptosis of nucleated cells. In analogy to apoptosis, the suicidal death of erythrocytes or eryptosis involves cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include oxidative stress, increase of cytosolic Ca2+ activity ([Ca2+]i), and ceramide. The present study explored, whether gramicidin triggers eryptosis. To this end phosphatidylserine exposure at the cell surface was estimated from annexin V binding, cell volume from forward scatter, red blood cell distribution width (RDW) from electronic particle counting, reactive oxidant species (ROS) from 2',7'-dichlorodihydrofluorescein diacetate (DCFDA) fluorescence, [Ca2+]i from Fluo3- and Fluo4 fluorescence, and ceramide abundance from binding of specific antibodies. As a result, a 24 h exposure of human erythrocytes to gramicidin significantly increased the percentage of annexin-V-binding cells (≥1 µg/mL), forward scatter (≥0.5 µg/mL) and hemolysis. Gramicidin enhanced ROS activity, [Ca2+]i and ceramide abundance at the erythrocyte surface. The stimulation of annexin-V-binding by gramicidin was significantly blunted but not abolished by removal of extracellular Ca2+. In conclusion, gramicidin stimulates phospholipid scrambling of the erythrocyte cell membrane, an effect at least partially due to induction of oxidative stress, increase of [Ca2+]i and up-regulation of ceramide abundance. Despite increase of [Ca2+]i, gramicidin increases cell volume and slightly reduces RWD. PMID:25915718

  8. Morphological and Physiological Changes in Mature In Vitro Neuronal Networks towards Exposure to Short-, Middle- or Long-Term Simulated Microgravity

    PubMed Central

    Pani, Giuseppe; Samari, Nada; Quintens, Roel; de Saint-Georges, Louis; Meloni, MariAntonia; Baatout, Sarah; Van Oostveldt, Patrick; Benotmane, Mohammed Abderrafi

    2013-01-01

    One of the objectives of the current international space programmes is to investigate the possible effects of the space environment on the crew health. The aim of this work was to assess the particular effects of simulated microgravity on mature primary neuronal networks and specially their plasticity and connectivity. For this purpose, primary mouse neurons were first grown for 10 days as a dense network before being placed in the Random Positioning Machine (RPM), simulating microgravity. These cultures were then used to investigate the impact of short- (1 h), middle- (24 h) and long-term (10 days) exposure to microgravity at the level of neurite network density, cell morphology and motility as well as cytoskeleton properties in established two-dimensional mature neuronal networks. Image processing analysis of dense neuronal networks exposed to simulated microgravity and their subsequent recovery under ground conditions revealed different neuronal responses depending on the duration period of exposure. After short- and middle-term exposures to simulated microgravity, changes in neurite network, neuron morphology and viability were observed with significant alterations followed by fast recovery processes. Long exposure to simulated microgravity revealed a high adaptation of single neurons to the new gravity conditions as well as a partial adaptation of neuronal networks. This latter was concomitant to an increase of apoptosis. However, neurons and neuronal networks exposed for long-term to simulated microgravity required longer recovery time to re-adapt to the ground gravity. In conclusion, a clear modulation in neuronal plasticity was evidenced through morphological and physiological changes in primary neuronal cultures during and after simulated microgravity exposure. These changes were dependent on the duration of exposure to microgravity. PMID:24066080

  9. Genistein exposure inhibits growth and alters steroidogenesis in adult mouse antral follicles.

    PubMed

    Patel, Shreya; Peretz, Jackye; Pan, Yuan-Xiang; Helferich, William G; Flaws, Jodi A

    2016-02-15

    Genistein is a naturally occurring isoflavone phytoestrogen commonly found in plant products such as soybeans, lentils, and chickpeas. Genistein, like other phytoestrogens, has the potential to mimic, enhance, or impair the estradiol biosynthesis pathway, thereby potentially altering ovarian follicle growth. Previous studies have inconsistently indicated that genistein exposure may alter granulosa cell proliferation and hormone production, but no studies have examined the effects of genistein on intact antral follicles. Thus, this study was designed to test the hypothesis that genistein exposure inhibits follicle growth and steroidogenesis in intact antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice were cultured with vehicle (dimethyl sulfoxide; DMSO) or genistein (6.0 and 36μM) for 18-96h. Every 24h, follicle diameters were measured to assess growth. At the end of each culture period, the media were pooled to measure hormone levels, and the cultured follicles were collected to measure expression of cell cycle regulators and steroidogenic enzymes. The results indicate that genistein (36μM) inhibits growth of mouse antral follicles. Additionally, genistein (6.0 and 36μM) increases progesterone, testosterone, and dehydroepiandrosterone (DHEA) levels, but decreases estrone and estradiol levels. The results also indicate that genistein alters the expression of steroidogenic enzymes at 24, 72 and 96h, and the expression of cell cycle regulators at 18h. These data indicate that genistein exposure inhibits antral follicle growth by inhibiting the cell cycle, alters sex steroid hormone levels, and dysregulates steroidogenic enzymes in cultured mouse antral follicles. PMID:26792615

  10. Combined Exposure to Simulated Microgravity and Acute or Chronic Radiation Reduces Neuronal Network Integrity and Survival

    PubMed Central

    Quintens, Roel; Samari, Nada; de Saint-Georges, Louis; van Oostveldt, Patrick; Baatout, Sarah; Benotmane, Mohammed Abderrafi

    2016-01-01

    During orbital or interplanetary space flights, astronauts are exposed to cosmic radiations and microgravity. However, most earth-based studies on the potential health risks of space conditions have investigated the effects of these two conditions separately. This study aimed at assessing the combined effect of radiation exposure and microgravity on neuronal morphology and survival in vitro. In particular, we investigated the effects of simulated microgravity after acute (X-rays) or during chronic (Californium-252) exposure to ionizing radiation using mouse mature neuron cultures. Acute exposure to low (0.1 Gy) doses of X-rays caused a delay in neurite outgrowth and a reduction in soma size, while only the high dose impaired neuronal survival. Of interest, the strongest effect on neuronal morphology and survival was evident in cells exposed to microgravity and in particular in cells exposed to both microgravity and radiation. Removal of neurons from simulated microgravity for a period of 24 h was not sufficient to recover neurite length, whereas the soma size showed a clear re-adaptation to normal ground conditions. Genome-wide gene expression analysis confirmed a modulation of genes involved in neurite extension, cell survival and synaptic communication, suggesting that these changes might be responsible for the observed morphological effects. In general, the observed synergistic changes in neuronal network integrity and cell survival induced by simulated space conditions might help to better evaluate the astronaut's health risks and underline the importance of investigating the central nervous system and long-term cognition during and after a space flight. PMID:27203085

  11. Combined Exposure to Simulated Microgravity and Acute or Chronic Radiation Reduces Neuronal Network Integrity and Survival.

    PubMed

    Pani, Giuseppe; Verslegers, Mieke; Quintens, Roel; Samari, Nada; de Saint-Georges, Louis; van Oostveldt, Patrick; Baatout, Sarah; Benotmane, Mohammed Abderrafi

    2016-01-01

    During orbital or interplanetary space flights, astronauts are exposed to cosmic radiations and microgravity. However, most earth-based studies on the potential health risks of space conditions have investigated the effects of these two conditions separately. This study aimed at assessing the combined effect of radiation exposure and microgravity on neuronal morphology and survival in vitro. In particular, we investigated the effects of simulated microgravity after acute (X-rays) or during chronic (Californium-252) exposure to ionizing radiation using mouse mature neuron cultures. Acute exposure to low (0.1 Gy) doses of X-rays caused a delay in neurite outgrowth and a reduction in soma size, while only the high dose impaired neuronal survival. Of interest, the strongest effect on neuronal morphology and survival was evident in cells exposed to microgravity and in particular in cells exposed to both microgravity and radiation. Removal of neurons from simulated microgravity for a period of 24 h was not sufficient to recover neurite length, whereas the soma size showed a clear re-adaptation to normal ground conditions. Genome-wide gene expression analysis confirmed a modulation of genes involved in neurite extension, cell survival and synaptic communication, suggesting that these changes might be responsible for the observed morphological effects. In general, the observed synergistic changes in neuronal network integrity and cell survival induced by simulated space conditions might help to better evaluate the astronaut's health risks and underline the importance of investigating the central nervous system and long-term cognition during and after a space flight. PMID:27203085

  12. Developmental exposure to a complex PAH mixture causes persistent behavioral effects in naive Fundulus heteroclitus (killifish) but not in a population of PAH-adapted killifish.

    PubMed

    Brown, D R; Bailey, J M; Oliveri, A N; Levin, E D; Di Giulio, R T

    2016-01-01

    Acute exposures to some individual polycyclic aromatic hydrocarbons (PAHs) and complex PAH mixtures are known to cause cardiac malformations and edema in the developing fish embryo. However, the heart is not the only organ impacted by developmental PAH exposure. The developing brain is also affected, resulting in lasting behavioral dysfunction. While acute exposures to some PAHs are teratogenically lethal in fish, little is known about the later life consequences of early life, lower dose subteratogenic PAH exposures. We sought to determine and characterize the long-term behavioral consequences of subteratogenic developmental PAH mixture exposure in both naive killifish and PAH-adapted killifish using sediment pore water derived from the Atlantic Wood Industries Superfund Site. Killifish offspring were embryonically treated with two low-level PAH mixture dilutions of Elizabeth River sediment extract (ERSE) (TPAH 5.04 μg/L and 50.4 μg/L) at 24h post fertilization. Following exposure, killifish were raised to larval, juvenile, and adult life stages and subjected to a series of behavioral tests including: a locomotor activity test (4 days post-hatch), a sensorimotor response tap/habituation test (3 months post hatch), and a novel tank diving and exploration test (3months post hatch). Killifish were also monitored for survival at 1, 2, and 5 months over 5-month rearing period. Developmental PAH exposure caused short-term as well as persistent behavioral impairments in naive killifish. In contrast, the PAH-adapted killifish did not show behavioral alterations following PAH exposure. PAH mixture exposure caused increased mortality in reference killifish over time; yet, the PAH-adapted killifish, while demonstrating long-term rearing mortality, had no significant changes in mortality associated with ERSE exposure. This study demonstrated that early embryonic exposure to PAH-contaminated sediment pore water caused long-term locomotor and behavioral alterations in

  13. Selenium and trace element mobility affected by periodic displacement of stratification in the Great Salt Lake, Utah

    USGS Publications Warehouse

    Beisner, K.; Naftz, D.L.; Johnson, W.P.; Diaz, X.

    2009-01-01

    The Great Salt Lake (GSL) is a unique ecosystem in which trace element activity cannot be characterized by standard geochemical parameters due to the high salinity. Movement of selenium and other trace elements present in the lake bed sediments of GSL may occur due to periodic stratification displacement events or lake bed exposure. The water column of GSL is complicated by the presence of a chemocline persistent over annual to decadal time scales. The water below the chemocline is referred to as the deep brine layer (DBL), has a high salinity (16.5 to 22.9%) and is anoxic. The upper brine layer (UBL) resides above the chemocline, has lower salinity (12.6 to 14.7%) and is oxic. Displacement of the DBL may involve trace element movement within the water column due to changes in redox potential. Evidence of stratification displacement in the water column has been observed at two fixed stations on the lake by monitoring vertical water temperature profiles with horizontal and vertical velocity profiles. Stratification displacement events occur over periods of 12 to 24 h and are associated with strong wind events that can produce seiches within the water column. In addition to displacement events, the DBL shrinks and expands in response to changes in the lake surface area over a period of months. Laboratory tests simulating the observed sediment re-suspension were conducted over daily, weekly and monthly time scales to understand the effect of placing anoxic bottom sediments in contact with oxic water, and the associated effect of trace element desorption and (or) dissolution. Results from the laboratory simulations indicate that a small percentage (1%) of selenium associated with anoxic bottom sediments is periodically solubilized into the UBL where it potentially can be incorporated into the biota utilizing the oxic part of GSL.

  14. Serum Amyloid A as a Biomarker for Radiation Exposure

    PubMed Central

    Sproull, Mary; Kramp, Tamalee; Tandle, Anita; Shankavaram, Uma; Camphausen, Kevin

    2016-01-01

    There is a need for minimally invasive biomarkers that can accurately and quickly quantify radiation exposure. Radiation-responsive proteins have applications in clinical medicine and for mass population screenings after a nuclear or radiological incident where the level of radiation exposure and exposure pattern complicate medical triage for first responders. In this study, we evaluated the efficacy of the acute phase protein serum amyloid A (SAA) as a biomarker for radiation exposure using plasma from irradiated mice. Ten-week-old female C57BL6 mice received a 1–8 Gy single whole-body or partial-body dose from a Pantak X-ray source at a dose rate of 2.28 Gy/min. Plasma was collected by mandibular or cardiac puncture at 6, 24, 48 and 72 h or 1–3 weeks postirradiation. SAA levels were determined using a commercially available ELISA assay. Data was pooled to generate SAA μg/ml threshold values correlating plasma SAA levels with radiation dose. SAA levels were statistically significant over control at all exposures between 2 and 8 Gy at 24 h postirradiation but not at 6, 48 and 72 h or 1–3 weeks postirradiation. SAA levels at 1 Gy were not significantly elevated over control at all time points. Total-body-irradiated (TBI) SAA levels at 24 h were used to generate a dose prediction model that successfully differentiated TBI mice into dose received cohorts of control/1 Gy and ≥2 Gy groups with a high degree of accuracy in a blind study. Dose prediction of partial-body exposures based on the TBI model correlated increasing predictive accuracy with percentage of body exposure to radiation. Our findings indicate that plasma SAA levels might be a useful biomarker for radiation exposure in a variety of total- and partial-body irradiation settings. PMID:26114330

  15. Mechanical property of different corn stover morphological fractions and its correlations with high solids enzymatic hydrolysis by periodic peristalsis.

    PubMed

    Liu, Zhi-Hua; Chen, Hong-Zhang

    2016-08-01

    Selective structure fractionation combined with periodic peristalsis was exploited to improve the conversion performance of corn stover. The increase of glucan and lignin content and the decrease of xylan content in stem pith were highest after SE, whereas they were lowest in stem node. Glucan conversion increased in this order: steam nodeperiodic peristalsis increased by 10-17% before 24h compared with that using incubator shaker. Stem pith, leaf sheath, leaf, and WCS showed lower hardness and total work in texture profile analysis, resulting in higher glucan conversion compared with stem node and stem rind. Periodic peristalsis reduced hardness and total work before 24h, which was consistent with increased glucan conversion. Periodic peristalsis was an effective strategy to increase high solids enzymatic hydrolysis efficiency of different corn stover morphological fractions. PMID:27140819

  16. Evaluating alternative exposure indices in epidemiologic studies on extremely low-frequency magnetic fields

    SciTech Connect

    Juutilainen, J.; Hatfield, T.; Laeaerae, E.

    1996-05-01

    Choosing the right exposure index for epidemiological studies on 50--60 Hz magnetic fields is difficult due to the lack of knowledge about critical exposure parameters for the biological effects of magnetic fields. This paper uses data from a previously published epidemiological investigation on early pregnancy loss (EPL) to study the methods of evaluating the exposure-response relationship of 50 Hz magnetic fields. Two approaches were used. The first approach was to apply generalized additive modeling to suggest the functional form of the relationship between EPL data with eight alternative exposure indices: the 24 h average of magnetic field strength, three indices measuring the proportion of time above specified thresholds, and four indices measuring the proportion of time within specified intensity windows. Because the original exposure data included only spot measurements, estimates for the selected exposure indices were calculated indirectly form the spot measurements using empirical nonlinear equations derived from 24 h recording in 60 residences. The results did not support intensity windows, and a threshold-type dependence on field strength appeared to be more plausible than a linear relationship. In addition, the study produced data suggesting that spot measurements may be used as surrogates for other exposure indices besides the time average field strength. No final conclusions should be drawn from this study alone, but the authors hope that this exercise stimulates evaluation of alternative exposure indices in other planned and ongoing epidemiological studies.

  17. Periodic properties of the histaminergic system of the mouse brain.

    PubMed

    Rozov, Stanislav V; Zant, Janneke C; Karlstedt, Kaj; Porkka-Heiskanen, Tarja; Panula, Pertti

    2014-01-01

    Brain histamine is involved in the regulation of the sleep-wake cycle and alertness. Despite the widespread use of the mouse as an experimental model, the periodic properties of major markers of the mouse histaminergic system have not been comprehensively characterized. We analysed the daily levels of histamine and its first metabolite, 1-methylhistamine, in different brain structures of C57BL/6J and CBA/J mouse strains, and the mRNA level and activity of histidine decarboxylase and histamine-N-methyltransferase in C57BL/6J mice. In the C57BL/6J strain, histamine release, assessed by in vivo microdialysis, underwent prominent periodic changes. The main period was 24 h peaking during the activity period. Additional 8 h periods were also observed. The release was highly positively correlated with active wakefulness, as shown by electroencephalography. In both mouse strains, tissue histamine levels remained steady for 24 h in all structures except for the hypothalamus of CBA/J mice, where 24-h periodicity was observed. Brain tissue 1-methylhistamine levels in both strains reached their maxima in the periods of activity. The mRNA level of histidine decarboxylase in the tuberomamillary nucleus and the activities of histidine decarboxylase and histamine-N-methyltransferase in the striatum and cortex did not show a 24-h rhythm, whereas in the hypothalamus the activities of both enzymes had a 12-h periodicity. These results show that the activities of histamine-metabolizing enzymes are not under simple direct circadian regulation. The complex and non-uniform temporal patterns of the histaminergic system of the mouse brain suggest that histamine is strongly involved in the maintenance of active wakefulness. PMID:24438489

  18. Mechanical properties of Haynes Alloy 188 after exposure to LiF-22CaF2, air, and vacuum at 1093 K for periods up to 10,000 hours

    SciTech Connect

    Whittenberger, J.D. )

    1992-08-01

    As part of a program to provide reassurance that the cobalt-base superalloy Haynes Alloy 188 can adequately contain a LiF-CaF2 eutectic thermal energy storage salt, 4900- and 10,000-hr exposures of Haynes Alloy 188 to LiF-22CaF2, its vapor, vacuum, and air at 1093 K have been undertaken. Following such exposures, the microstructure has been characterized and the 77 to 1200 K tensile properties measured. In addition, 1050 K vacuum creep-rupture testing of as-received and molten salt- and vacuum-exposed samples has been undertaken. Although slight degradation of the mechanical properties of Haynes Alloy 188 due to prior exposure was observed, basically none of the losses could be ascribed to a particular environment. Hence, observed decreases in properties are due to thermal aging effects, not corrosive attack. In view of these findings, Haynes Alloy 188 is still deemed to be suitable for containment of the eutectic LiF-CaF2 thermal energy storage media. 8 refs.

  19. Mechanical properties of Haynes Alloy 188 after exposure to LiF-22CaF2, air, and vacuum at 1093 K for periods up to 10,000 hours

    NASA Technical Reports Server (NTRS)

    Whittenberger, J. D.

    1992-01-01

    As part of a program to provide reassurance that the cobalt-base superalloy Haynes Alloy 188 can adequately contain a LiF-CaF2 eutectic thermal energy storage salt, 4900- and 10,000-hr exposures of Haynes Alloy 188 to LiF-22CaF2, its vapor, vacuum, and air at 1093 K have been undertaken. Following such exposures, the microstructure has been characterized and the 77 to 1200 K tensile properties measured. In addition, 1050 K vacuum creep-rupture testing of as-received and molten salt- and vacuum-exposed samples has been undertaken. Although slight degradation of the mechanical properties of Haynes Alloy 188 due to prior exposure was observed, basically none of the losses could be ascribed to a particular environment. Hence, observed decreases in properties are due to thermal aging effects, not corrosive attack. In view of these findings, Haynes Alloy 188 is still deemed to be suitable for containment of the eutectic LiF-CaF2 thermal energy storage media.

  20. Strategies to assess systemic exposure of chemicals in subchronic/chronic diet and drinking water studies

    SciTech Connect

    Saghir, Shakil A. . E-mail: ssaghir@dow.com; Mendrala, Alan L.; Bartels, Michael J.; Day, Sue J.; Hansen, Steve C.; Sushynski, Jacob M.; Bus, James S.

    2006-03-15

    Strategies were developed for the estimation of systemically available daily doses of chemicals, diurnal variations in blood levels, and rough elimination rates in subchronic feeding/drinking water studies, utilizing a minimal number of blood samples. Systemic bioavailability of chemicals was determined by calculating area under the plasma concentration curve over 24 h (AUC-24 h) using complete sets of data ({>=}5 data points) and also three, two, and one selected time points. The best predictions of AUC-24 h were made when three time points were used, corresponding to C {sub max}, a mid-morning sample, and C {sub min}. These values were found to be 103 {+-} 10% of the original AUC-24 h, with 13 out of 17 values ranging between 96 and 105% of the original. Calculation of AUC-24 h from two samples (C {sub max} and C {sub min}) or one mid-morning sample afforded slightly larger variations in the calculated AUC-24 h (69-136% of the actual). Following drinking water exposure, prediction of AUC-24 h using 3 time points (C {sub max}, mid-morning, and C {sub min}) was very close to actual values (80-100%) among mice, while values for rats were only 63% of the original due to less frequent drinking behavior of rats during the light cycle. Collection and analysis of 1-3 blood samples per dose may provide insight into dose-proportional or non-dose-proportional differences in systemic bioavailability, pointing towards saturation of absorption or elimination or some other phenomenon warranting further investigation. In addition, collection of the terminal blood samples from rats, which is usually conducted after 18 h of fasting, will be helpful in rough estimation of blood/plasma half-life of the compound. The amount of chemical(s) and/or metabolite(s) in excreta and their possible use as biomarkers in predicting the daily systemic exposure levels are also discussed. Determining these parameters in the early stages of testing will provide critical information to improve the

  1. Measurement of DNA damage and apoptosis in Molt-4 cells after in vitro exposure to radiofrequency radiation.

    PubMed

    Hook, Graham J; Zhang, Peng; Lagroye, I; Li, Li; Higashikubo, Ryuji; Moros, Eduardo G; Straube, William L; Pickard, William F; Baty, Jack D; Roti Roti, Joseph L

    2004-02-01

    To determine whether exposure to radiofrequency (RF) radiation can induce DNA damage or apoptosis, Molt-4 T lymphoblastoid cells were exposed with RF fields at frequencies and modulations of the type used by wireless communication devices. Four types of frequency/modulation forms were studied: 847.74 MHz code-division multiple-access (CDMA), 835.62 MHz frequency-division multiple-access (FDMA), 813.56 MHz iDEN(R) (iDEN), and 836.55 MHz time-division multiple-access (TDMA). Exponentially growing cells were exposed to RF radiation for periods up to 24 h using a radial transmission line (RTL) exposure system. The specific absorption rates used were 3.2 W/kg for CDMA and FDMA, 2.4 or 24 mW/kg for iDEN, and 2.6 or 26 mW/kg for TDMA. The temperature in the RTLs was maintained at 37 degrees C +/- 0.3 degrees C. DNA damage was measured using the single-cell gel electrophoresis assay. The annexin V affinity assay was used to detect apoptosis. No statistically significant difference in the level of DNA damage or apoptosis was observed between sham-treated cells and cells exposed to RF radiation for any frequency, modulation or exposure time. Our results show that exposure of Molt-4 cells to CDMA, FDMA, iDEN or TDMA modulated RF radiation does not induce alterations in level of DNA damage or induce apoptosis. PMID:14731070

  2. Biological monitoring of isocyanates and related amines. IV. 2,4- and 2,6-toluenediamine in hydrolysed plasma and urine after test-chamber exposure of humans to 2,4- and 2,6-toluene diisocyanate.

    PubMed

    Brorson, T; Skarping, G; Sangö, C

    1991-01-01

    Two men were exposed to toluene diisocyanate (TDI) atmospheres at three different air concentrations (ca. 25, 50 and 70 micrograms/m3). The TDI atmospheres were generated by a gas-phase permeation method, and the exposures were performed in an 8-m3 stainless-steel test chamber. The effective exposure period was 4 h. The isomeric composition of the air in the test chamber was 30% 2,4-TDI and 70% 2,6-TDI. The concentration of TDI in air of the test chamber was determined by an HPLC method using the 9-(N-methyl-amino-methyl)-anthracene reagent and by a continuous-monitoring filter-tape instrument. Following the hydrolysis of plasma and urine, the related amines, 2,4-toluenediamine (2,4-TDA) and 2,6-toluenediamine (2,6-TDA), were determined as pentafluoropropionic anhydride (PFPA) derivatives by capillary gas chromatography using selected ion monitoring (SIM) in the electron-impact mode. In plasma, 2,4- and 2,6-TDA showed a rapid-phase elimination half-time of ca. 2-5 h, and that for the slow phase was greater than 6 days. A connection was observed between concentrations of 2,4- and 2,6-TDI in air and the levels of 2,4- and 2,6-TDA in plasma. The cumulated amount of 2,4-TDA excreted in the urine over 24 h was ca. 15%-19% of the estimated inhaled dose of 2,4-TDI, and that of 2,6-TDA was ca. 17%-23% of the inhaled dose of 2,6-TDI. A connection was found between the cumulated (24-h) urinary excretion of 2,4- and 2,6-TDA and the air concentration of 2,4- and 2,6-TDI in the test chamber.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1660449

  3. Global Molecular and Morphological Effects of 24-Hour Chromium(VI) Exposure on Shewanella oneidensis MR-1

    PubMed Central

    Chourey, Karuna; Thompson, Melissa R.; Morrell-Falvey, Jennifer; VerBerkmoes, Nathan C.; Brown, Steven D.; Shah, Manesh; Zhou, Jizhong; Doktycz, Mitchel; Hettich, Robert L.; Thompson, Dorothea K.

    2006-01-01

    The biological impact of 24-h (“chronic”) chromium(VI) [Cr(VI) or chromate] exposure on Shewanella oneidensis MR-1 was assessed by analyzing cellular morphology as well as genome-wide differential gene and protein expression profiles. Cells challenged aerobically with an initial chromate concentration of 0.3 mM in complex growth medium were compared to untreated control cells grown in the absence of chromate. At the 24-h time point at which cells were harvested for transcriptome and proteome analyses, no residual Cr(VI) was detected in the culture supernatant, thus suggesting the complete uptake and/or reduction of this metal by cells. In contrast to the untreated control cells, Cr(VI)-exposed cells formed apparently aseptate, nonmotile filaments that tended to aggregate. Transcriptome profiling and mass spectrometry-based proteomic characterization revealed that the principal molecular response to 24-h Cr(VI) exposure was the induction of prophage-related genes and their encoded products as well as a number of functionally undefined hypothetical genes that were located within the integrated phage regions of the MR-1 genome. In addition, genes with annotated functions in DNA metabolism, cell division, biosynthesis and degradation of the murein (peptidoglycan) sacculus, membrane response, and general environmental stress protection were upregulated, while genes encoding chemotaxis, motility, and transport/binding proteins were largely repressed under conditions of 24-h chromate treatment. PMID:16957260

  4. Global Molecular and Morphological Effects of 24-Hour Chromium(VI)Exposure on Shewanella oneidensis MR-1

    SciTech Connect

    Chourey, Karuna; Thompson, Melissa R; Morrell-Falvey, Jennifer L; Verberkmoes, Nathan C; Brown, Steven D; Shah, Manesh B; Zhou, Jizhong; Doktycz, Mitchel John; Hettich, Robert {Bob} L; Thompson, Dorothea K

    2006-01-01

    The biological impact of 24-h ("chronic") chromium(VI) [Cr(VI) or chromate] exposure on ShewanellaoneidensisMR-1 was assessed by analyzing cellular morphology as well as genome-wide differential gene and protein expression profiles. Cells challenged aerobically with an initial chromate concentration of 0.3 mM in complex growth medium were compared to untreated control cells grown in the absence of chromate. At the 24-h time point at which cells were harvested for transcriptome and proteome analyses, no residual Cr(VI) was detected in the culture supernatant, thus suggesting the complete uptake and/or reduction of this metal by cells. In contrast to the untreated control cells, Cr(VI)-exposed cells formed apparently aseptate, nonmotile filaments that tended to aggregate. Transcriptome profiling and mass spectrometry-based proteomic charac terization revealed that the principal molecular response to 24-h Cr(VI) exposure was the induction of prophage-related genes and their encoded products as well as a number of functionally undefined hypothetical genes that were located within the integrated phage regions of the MR-1 genome. In addition, genes with annotated functions in DNA metabolism, cell division, biosynthesis and degradation of the murein (pepti doglycan) sacculus, membrane response, and general environmental stress protection were upregulated, while genes encoding chemotaxis, motility, and transport/binding proteins were largely repressed under conditions of 24-h chromate treatment.

  5. The effects of intermittent exposure to low-pH and low-oxygen conditions on survival and growth of juvenile red abalone

    NASA Astrophysics Data System (ADS)

    Kim, T. W.; Barry, J. P.; Micheli, F.

    2013-11-01

    Exposure of nearshore animals to hypoxic, low-pH waters upwelled from below the continental shelf and advected near the coast may be stressful to marine organisms and lead to impaired physiological performance. We mimicked upwelling conditions in the laboratory and tested the effect of fluctuating exposure to water with low-pH and/or low-oxygen levels on the mortality and growth of juvenile red abalone (Haliotis rufescens, shell length 5-10 mm). Mortality rates of juvenile abalone exposed to low-pH (7.5, total scale) and low-O2 (40% saturation, mg L-1) conditions for periods of 3 to 6 h every 3-5 days over 2 weeks did not differ from those exposed to control conditions (O2: 100% saturation, 12 mg L-1; pH 8.0). However, when exposure was extended to 24 h, twice over a 15-day period, juveniles experienced 5-20% higher mortality in the low-oxygen treatments compared to control conditions. Growth rates were reduced significantly when juveniles were exposed to low-oxygen and low-pH treatments. Furthermore, individual variation of growth rate increased when juveniles were exposed simultaneously to low-pH and low-O2 conditions. These results indicate that prolonged exposure to low-oxygen levels is detrimental for the survival of red abalone, whereas pH is a crucial factor for their growth. However, the high individual variation in growth rate under low levels of both pH and oxygen suggests that cryptic phenotypic plasticity may promote resistance to prolonged upwelling conditions by a portion of the population.

  6. Contrasting low-dimensional magnetism in the 3D metal-organic frameworks [Cu(VF6)(pyz)2]4H2O and [Cu(HF2)(pyz)2]SbF6 (pyz = pyrazine)

    NASA Astrophysics Data System (ADS)

    Manson, Jamie; Schlueter, John; Goddard, Paul; Singleton, John; McDonald, Ross; Ayala-Valenzuela, Oscar; Lancaster, Tom; Blundell, Stephen

    2012-02-01

    [Cu(VF6)(pyz)2]4H2O (1) and [Cu(HF2)(pyz)2]SbF6 (2) form tetragonal frameworks that consist of 2D [Cu(pyz)2]^2+ square lattices that are linked in 3D by bridging VF6^2- (1) or HF2^- (2) anions. Magnetic susceptibility data shows apparent paramagnetism, although not simple Curie-Weiss behavior, in 1. For 2, a broad maximum in χ(T) at 12.5 K and a sharp kink at 4.3 K indicate short- (SRO) and long-range (LRO) magnetic ordering, respectively. Additional experimental data for 1 (e.g., heat capacity and μ^+SR) however, indicate that a LRO state occurs below 3.6 K whereas pulsed-field magnetization data suggest a superposition of AFM Cu^2+ layers and fluctuating V^4+ moments. The structural and magnetic behavior of 1 and 2 will be described as well as possible new directions.

  7. Estimation and interpretation of fermentation in the gut: coupling results from a 24 h batch in vitro system with fecal measurements from a human intervention feeding study using fructo-oligosaccharides, inulin, gum acacia, and pea fiber.

    PubMed

    Koecher, Katie J; Noack, Jackie A; Timm, Derek A; Klosterbuer, Abby S; Thomas, William; Slavin, Joanne L

    2014-02-12

    Gut bacteria ferment fiber at different rates to primarily short chain fatty acids (SCFA) and gas while proteins are metabolized to SCFA, branched chain fatty acids (BCFA), gas, and undesirable metabolites. Large volumes of gas produced in vivo may contribute to bloating and flatulence in an individual. The objectives of this trial were to (1) compare the in vitro fermentation profiles of fructo-oligosaccharides (FOS), inulin, gum acacia, and pea fiber alone or blended using a 24 h batch model and (2) relate these findings to a human study that fed enteral formula fortified with fiber blend (FB) or no fiber (FF). The in vitro fermentation of the fiber blend resulted in a delayed pH decrease and gas and SCFA production compared to the FOS and inulin. Human samples had higher SCFA on FB compared to FF (p = 0.029). BCFA were not different between formulas. By using a blend of fibers, we observed a slower fermentation in vitro but still increased fecal SCFA when fed to human subjects. PMID:24446899

  8. Analysis of Latvian familial melanoma patients shows novel variants in the noncoding regions of CDKN2A and that the CDK4 mutation R24H is a founder mutation.

    PubMed

    Veinalde, Rūta; Ozola, Aija; Azarjana, Kristīne; Molven, Anders; Akslen, Lars A; Doniņa, Simona; Proboka, Guna; Cēma, Ingrīda; Baginskis, Ainārs; Pjanova, Dace

    2013-06-01

    Hereditary cutaneous melanoma is associated with mutations in the high-risk CDKN2A gene in about 40% of melanoma-prone families. Mutations in the CDK4 gene are the cause in only a few pedigrees. In this study, we analyzed 20 Latvian familial melanoma probands and carried out a comprehensive analysis of CDKN2A including sequencing of its promoter/intronic regions and deletion screening. We also analyzed the critical second exon of the CDK4 gene. One novel intronic variant (IVS2+82C>T) of the CDKN2A gene and a small deletion (c.-20677_-20682delGTACGC) in its promoter region were found. Genotyping of the novel variants in larger melanoma and control groups indicated that the deletion increases the risk of melanoma (odds ratio=6.353, 95% confidence interval: 1.34-30.22, P=0.0168). The CDK4 gene analysis showed a Latvian melanoma family with the mutation R24H carried on the same haplotype as in two previously described Latvian CDK4-positive families. Our study suggests that the main risk gene in Latvian families with a strong family history of melanoma is CDK4 and that most of the other cases analyzed could be sporadic or associated with low-penetrance risk genes. PMID:23546221

  9. Relationship between pulmonary and systemic markers of exposure to multiple types of welding particulate matter.

    PubMed

    Erdely, Aaron; Salmen-Muniz, Rebecca; Liston, Angie; Hulderman, Tracy; Zeidler-Erdely, Patti C; Antonini, James M; Simeonova, Petia P

    2011-09-01

    Welding results in a unique and complex occupational exposure. Recent epidemiological studies have shown an increased risk of cardiovascular disease following welding fume exposure. In this study, we compared the induction of pulmonary and systemic inflammation following exposure to multiple types of welding fumes. Mice were exposed to 340μg of manual metal arc stainless steel (MMA-SS), gas metal arc-SS (GMA-SS) or GMA-mild steel (GMA-MS) by pharyngeal aspiration. Mice were sacrificed at 4 and 24h post-exposure to evaluate various parameters of pulmonary and systemic inflammation. Alterations in pulmonary gene expression by a custom designed TaqMan array showed minimal differences between the fumes at 4h. Conversely at 24h, gene expression changes were further increased by SS but not GMA-MS exposure. These findings were associated with the surrogate marker of systemic inflammation, liver acute phase gene induction. Interestingly, stress response genes in cardiovascular tissues were only increased following MMA-SS exposure. These effects were related to the initial level of pulmonary cytotoxicity, as measured by lactate dehydrogenase activity, which was greatest following MMA-SS exposure. In conclusion, varying types of welding fumes elicit quantitatively different systemic inflammatory and/or stress responses. PMID:21708214

  10. Co-exposure to aluminum and acrylamide disturbs expression of metallothionein, proinflammatory cytokines and induces genotoxicity: Biochemical and histopathological changes in the kidney of adult rats.

    PubMed

    Ghorbel, Imen; Maktouf, Sameh; Fendri, Nesrine; Jamoussi, Kamel; Ellouze Chaabouni, Semia; Boudawara, Tahia; Zeghal, Najiba

    2016-09-01

    The individual toxic effects of aluminum and acrylamide are known but there is no data on their combined effects. The present study investigates the toxic effects after combined exposure to these toxicants on: (i) oxidative stress during combined chronic exposure to aluminum and acrylamide on kidney function (ii) correlation of oxidative stress with metallothionein (MT) and inflammatory cytokines expression, DNA damage, and histopathological changes. Rats were exposed to aluminum (50 mg/kg body weight) in drinking water and acrylamide (20 mg/kg body weight) by gavage either individually or in combination for 3 weeks. Exposure rats to aluminum chloride or acrylamide alone and in combination induced nephrotoxicity, as evidenced by a decrease in the 24-h urine volume and uric acid levels in plasma and an increase of plasma creatinine, urea, and blood urea nitrogen levels. Nephrotoxicity was objectified by a significant increase in malondialdehyde level, advanced oxidation protein, and protein carbonyl contents, whereas reduced glutathione, nonprotein thiol, vitamin C levels, catalase, and glutathione peroxidase activities showed a significant decline. Superoxide dismutase activity and its gene expression were increased. Aluminum and acrylamide co-exposure exhibited synergism in various biochemical variables and also in DNA damage. Kidney total MT levels and genes expression of MT1, MT2, and proinflammatory cytokines were increased. All these changes were supported by histopathological observations. Co-exposure to aluminum and acrylamide exhibited synergism and more pronounced toxic effects compared with their individual effects based on various biochemical variables, genotoxic, and histopathological changes. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1044-1058, 2016. PMID:25858877

  11. The management of varicella-zoster virus exposure and infection in pregnancy and the newborn period. Australasian Subgroup in Paediatric Infectious Diseases of the Australasian Society for Infectious Diseases.

    PubMed

    Heuchan, A M; Isaacs, D

    2001-03-19

    Zoster immunoglobulin (ZIG) should be offered to pregnant, varicella-seronegative women with significant exposure to varicella-zoster virus (VZV) (chickenpox) infection. Oral aciclovir prophylaxis should be considered for susceptible pregnant women exposed to VZV who did not receive ZIG or have risk factors for severe disease. Intravenous aciclovir should be given to pregnant women who develop complicated varicella at any stage of pregnancy. Counselling on the risk of congenital varicella syndrome is recommended for pregnant women who develop chickenpox. ZIG should be given to a baby whose mother develops chickenpox up to 7 days before delivery or up to 28 days after delivery. Intravenous aciclovir should be given to babies presenting unwell with chickenpox, whether or not they received ZIG. Breastfeeding of babies infected with or exposed to VZV is encouraged. A mother with chickenpox or zoster does not need to be isolated from her own baby. If siblings at home have chickenpox, a newborn baby should be given ZIG if its mother is seronegative. The newborn baby does not need to be isolated from its siblings with chickenpox, whether or not the baby was given ZIG. After significant nursery exposure to VZV, ZIG should be given to seronegative babies and to all babies born before 28 weeks' gestation. PMID:11297117

  12. Murine strain differences and the effects of zinc on cadmium concentrations in tissues after acute cadmium exposure.

    PubMed

    King, L M; Anderson, M B; Sikka, S C; George, W J

    1998-10-01

    The role of strain differences in cadmium tissue distribution was studied using sensitive (129/J) and resistant (A/J) mice. These murine strains have previously been shown to differ in their susceptibility to cadmium-induced testicular toxicity. Cadmium concentration was measured in testis, epididymis, seminal vesicle, liver, and kidney at 24 h after cadmium chloride exposure (4, 10, and 20 micromol/kg CdCl2). The 129/J mice exhibited a significant increase in cadmium concentration in testis, epididymis, and seminal vesicle at all cadmium doses used, compared to A/J mice. However, cadmium concentrations in liver and kidney were not different between the strains, at any dose, indicating that cadmium uptake is similar in these organs at 24 h. These murine strains demonstrate similar hepatic and renal cadmium uptake but significantly different cadmium accumulation in the reproductive organs at 24 h. The mechanism of the protective effect of zinc on cadmium toxicity was studied by assessing the impact of zinc acetate (ZnAc) treatment on cadmium concentrations in 129/J mice after 24 h. Zinc pretreatment (250 micromol/kg ZnAc), given 24 h prior to 20 micromol/kg CdCl2 administration, significantly decreased the amount of cadmium in the testis, epididymis, and seminal vesicle of 129/J mice, and significantly increased the cadmium content of the liver after 24 h. Cadmium levels in the kidney were unaffected at this time. Zinc pretreatment also prevented the cadmium-induced decrease in testicular sperm concentration and epididymal sperm motility seen in 129/J mice. These findings suggest that the differences in the two murine strains may be attributed partly to the differential accumulation of cadmium in murine gonads. This may be caused by strain differences in the specificity of cadmium transport mechanisms. The protective role of zinc in cadmium-induced testicular toxicity in the sensitive strain may be due to an interference in the cadmium uptake by susceptible

  13. Transcriptional responses of the nerve agent-sensitive brain regions amygdala, hippocampus, piriform cortex, septum, and thalamus following exposure to the organophosphonate anticholinesterase sarin

    PubMed Central

    2011-01-01

    Background Although the acute toxicity of organophosphorus nerve agents is known to result from acetylcholinesterase inhibition, the molecular mechanisms involved in the development of neuropathology following nerve agent-induced seizure are not well understood. To help determine these pathways, we previously used microarray analysis to identify gene expression changes in the rat piriform cortex, a region of the rat brain sensitive to nerve agent exposure, over a 24-h time period following sarin-induced seizure. We found significant differences in gene expression profiles and identified secondary responses that potentially lead to brain injury and cell death. To advance our understanding of the molecular mechanisms involved in sarin-induced toxicity, we analyzed gene expression changes in four other areas of the rat brain known to be affected by nerve agent-induced seizure (amygdala, hippocampus, septum, and thalamus). Methods We compared the transcriptional response of these four brain regions to sarin-induced seizure with the response previously characterized in the piriform cortex. In this study, rats were challenged with 1.0 × LD50 sarin and subsequently treated with atropine sulfate, 2-pyridine aldoxime methylchloride, and diazepam. The four brain regions were collected at 0.25, 1, 3, 6, and 24 h after seizure onset, and total RNA was processed for microarray analysis. Results Principal component analysis identified brain region and time following seizure onset as major sources of variability within the dataset. Analysis of variance identified genes significantly changed following sarin-induced seizure, and gene ontology analysis identified biological pathways, functions, and networks of genes significantly affected by sarin-induced seizure over the 24-h time course. Many of the molecular functions and pathways identified as being most significant across all of the brain regions were indicative of an inflammatory response. There were also a number of

  14. Pacer cell response to periodic Zeitgebers

    NASA Astrophysics Data System (ADS)

    Beersma, D. G. M.; Broer, H. W.; Efstathiou, K.; Gargar, K. A.; Hoveijn, I.

    2011-09-01

    Almost all organisms show some kind of time periodicity in their behavior. In mammals, the neurons of the suprachiasmatic nucleus form a biological clock regulating the activity-inactivity cycle of the animal. The main question is how this clock is able to entrain to the natural 24 h light-dark cycle by which it is stimulated. Such a system is usually modeled as a collection of mutually coupled two-state (active-inactive) phase oscillators with an external stimulus (Zeitgeber). In this article however, we investigate the entrainment of a single pacer cell to the ensemble of other pacer cells. Moreover the stimulus of the ensemble is taken to be periodic. The pacer cell interacts with its environment by phase delay at the end of its activity interval and phase advance at the end of its inactivity interval. We develop a mathematical model for this system, naturally leading to a circle map depending on parameters like the intrinsic period and phase delay and advance. The existence of resonance tongues in a circle map shows that an individual pacer cell is able to synchronize with the ensemble. We furthermore show how the parameters in the model can be related to biological observable quantities. Finally we give several directions of further research.

  15. Long-term signal of population disturbance after pulse exposure to an insecticide: rapid recovery of abundance, persistent alteration of structure.

    PubMed

    Liess, Matthias; Pieters, Barry Johan; Duquesne, Sabine

    2006-05-01

    Little is known about the effect of pulse exposure to toxicants on populations when density regulation is present. Yet, for a more realistic risk assessment, it is necessary to include effect and recovery at the population level. Here, we investigate the long-term and delayed effects as well as the subsequent recovery of populations of Daphnia magna. A 24-h pulse of the pyrethroid fenvalerate reduced the abundance at a concentration of 1.0 microg/L and higher. However, abundance recovered and reached control levels after one to two generation times (GTs) following reproduction of surviving individuals (GT = 8 d, from birth until first reproduction). At high concentrations above the acute median lethal concentration (3.2 micorg/L), abundance initially decreased even more strongly but was then elevated compared to control values for an extended period of time. Population structure (size distribution) was affected at lower concentrations than abundance (> 0.8 microg/L). In addition, the alteration of population structure lasted for a long time, so that control levels were approached only after approximately six or seven GTs. Our results show that pulse exposure to toxicants may lead to a long-term alteration of population structure even at sublethal concentrations. Possible mechanisms that sustain the effects of toxicants may be delayed life-history effects on the individual level and elevated competition because of altered population structure on the population level. PMID:16704065

  16. Impacts of the phenylpyrazole insecticide fipronil on larval fish: time-series gene transcription responses in fathead minnow (Pimephales promelas) following short-term exposure.

    PubMed

    Beggel, Sebastian; Werner, Inge; Connon, Richard E; Geist, Juergen P

    2012-06-01

    The utilization of molecular endpoints in ecotoxicology can provide rapid and valuable information on immediate organismal responses to chemical stressors and is increasingly used for mechanistic interpretation of effects at higher levels of biological organization. This study contributes knowledge on the sublethal effects of a commonly used insecticide, the phenylpyrazole fipronil, on larval fathead minnow (Pimephales promelas), utilizing a quantitative transcriptomic approach. Immediately after 24h of exposure to fipronil concentrations of ≥31 μg.L(-1), highly significant changes in gene transcription were observed for aspartoacylase, metallothionein, glucocorticoid receptor, cytochrome P450 3A126 and vitellogenin. Different mechanisms of toxicity were apparent over the course of the experiment, with short-term responses indicating neurotoxic effects. After 6 days of recovery, endocrine effects were observed with vitellogenin being up-regulated 90-fold at 61 μg.L(-1) fipronil. Principal component analysis demonstrated a significant increase in gene transcription changes over time and during the recovery period. In conclusion, multiple mechanisms of action were observed in response to fipronil exposure, and unknown delayed effects would have been missed if transcriptomic responses had only been measured at a single time-point. These challenges can be overcome by the inclusion of multiple endpoints and delayed effects in experimental designs. PMID:22542256

  17. Repeated systemic administration of the nutraceutical alpha-linolenic acid exerts neuroprotective efficacy, an antidepressant effect and improves cognitive performance when given after soman exposure.

    PubMed

    Pan, Hongna; Piermartiri, Tetsade C B; Chen, Jun; McDonough, John; Oppel, Craig; Driwech, Wafae; Winter, Kristin; McFarland, Emylee; Black, Katelyn; Figueiredo, Taiza; Grunberg, Neil; Marini, Ann M

    2015-12-01

    Exposure to nerve agents results in severe seizures or status epilepticus caused by the inhibition of acetylcholinesterase, a critical enzyme that breaks down acetylcholine to terminate neurotransmission. Prolonged seizures cause brain damage and can lead to long-term consequences. Current countermeasures are only modestly effective against the brain damage supporting interest in the evaluation of new and efficacious therapies. The nutraceutical alpha-linolenic acid (LIN) is an essential omega-3 polyunsaturated fatty acid that has a wide safety margin. Previous work showed that a single intravenous injection of alpha-linolenic acid (500 nmol/kg) administered before or after soman significantly protected against soman-induced brain damage when analyzed 24h after exposure. Here, we show that administration of three intravenous injections of alpha-linolenic acid over a 7 day period after soman significantly improved motor performance on the rotarod, enhanced memory retention, exerted an anti-depressant-like activity and increased animal survival. This dosing schedule significantly reduced soman-induced neuronal degeneration in four major vulnerable brain regions up to 21 days. Taken together, alpha-linolenic acid reduces the profound behavioral deficits induced by soman possibly by decreasing neuronal cell death, and increases animal survival. PMID:26386148

  18. Chloroform: exposure estimation, hazard characterization, and exposure-response analysis.

    PubMed

    Meek, M E; Beauchamp, R; Long, G; Moir, D; Turner, L; Walker, M

    2002-01-01

    Chloroform has been assessed as a Priority Substance under the Canadian Environmental Protection Act. The general population in Canada is exposed to chloroform principally through inhalation of indoor air, particularly during showering, and through ingestion of tap water. Data on concentrations of chloroform in various media were sufficient to serve as the basis for development of deterministic and probabilistic estimates of exposure for the general population in Canada. On the basis of data acquired principally in studies in experimental animals, chloroform causes hepatic and renal tumors in mice and renal tumors in rats. The weight of evidence indicates that chloroform is likely carcinogenic only at concentrations that induce the obligatory precursor lesions of cytotoxicity and proliferative regenerative response. Since this cytotoxicity is primarily related to rates of formation of reactive, oxidative metabolites, dose response has been characterized in the context of rates of formation of reactive metabolites in the target tissue. Results presented here are from a "hybrid" physiologically based pharmacokinetic (PBPK) animal model that was revised to permit its extension to humans. The relevant measure of exposure response, namely, the mean rate of metabolism in humans associated with a 5% increase in tumor risk (TC05), was estimated on the basis of this PBPK model and compared with tissue dose measures resulting from 24-h multimedia exposure scenarios for Canadians based on midpoint and 95th percentiles for concentrations in outdoor air, indoor air, air in the shower compartment, air in the bathroom after showering, tap water, and food. Nonneoplastic effects observed most consistently at lowest concentrations or doses following repeated exposures of rats and mice to chloroform are cytotoxicity and regenerative proliferation. As for cancer, target organs are the liver and kidney. In addition, chloroform has induced nasal lesions in rats and mice exposed by both

  19. Use of lanthanum to detect changes in the permeability barrier of rat skin after dermal exposure to organic chemicals

    SciTech Connect

    Mattie, D.R.; McDougal, J.N.; Chase, M.R.; Hixson, C.J.

    1987-01-01

    Occupational dermal exposures to organic solvents are of importance due to local effects in the skin and systematic toxicity if penetration occurs through the skin. Repeated or prolonged contact with organic solvents have been shown to penetrate the skin; little information is available however, concerning effects on the barrier properties of skin after dermal exposure to solvents. This investigation examines the ultrastructural changes in rat skin after exposure of 3 organic chemicals and to correlate changes with the location of an electron-dense tracer, lanthanum, which is normally excluded by the permeability barrier in the stratum corneum. Male rats were exposed for 24 h to sterile saline, trichloroethylene (TCE), perchloroethylene (PERC), or toluene using dermal-exposure cells developed in this laboratory. Rat skin exposed to saline for 24 h appeared normal. Rat skin exposed to neat TCE, PERC or toluene for 24 h caused acute, coagulative necrosis of the epidermis and upper 1/2 to 1/3 of the dermis.

  20. Transcriptional analysis of rat piriform cortex following exposure to the organophosphonate anticholinesterase sarin and induction of seizures

    PubMed Central

    2011-01-01

    Background Organophosphorus nerve agents irreversibly inhibit acetylcholinesterase, causing a toxic buildup of acetylcholine at muscarinic and nicotinic receptors. Current medical countermeasures to nerve agent intoxication increase survival if administered within a short period of time following exposure but may not fully prevent neurological damage. Therefore, there is a need to discover drug treatments that are effective when administered after the onset of seizures and secondary responses that lead to brain injury. Methods To determine potential therapeutic targets for such treatments, we analyzed gene expression changes in the rat piriform cortex following sarin (O-isopropyl methylphosphonofluoridate)-induced seizure. Male Sprague-Dawley rats were challenged with 1 × LD50 sarin and subsequently treated with atropine sulfate, 2-pyridine aldoxime methylchloride (2-PAM), and the anticonvulsant diazepam. Control animals received an equivalent volume of vehicle and drug treatments. The piriform cortex, a brain region particularly sensitive to neural damage from sarin-induced seizures, was extracted at 0.25, 1, 3, 6, and 24 h after seizure onset, and total RNA was processed for microarray analysis. Principal component analysis identified sarin-induced seizure occurrence and time point following seizure onset as major sources of variability within the dataset. Based on these variables, the dataset was filtered and analysis of variance was used to determine genes significantly changed in seizing animals at each time point. The calculated p-value and geometric fold change for each probeset identifier were subsequently used for gene ontology analysis to identify canonical pathways, biological functions, and networks of genes significantly affected by sarin-induced seizure over the 24-h time course. Results A multitude of biological functions and pathways were identified as being significantly altered following sarin-induced seizure. Inflammatory response and signaling

  1. Investigation of Leakage Current Mechanisms in La2O3/SiO2/4H-SiC MOS Capacitors with Varied SiO2 Thickness

    NASA Astrophysics Data System (ADS)

    Wang, Yucheng; Jia, Renxu; Zhao, Yanli; Li, Chengzhan; Zhang, Yuming

    2016-07-01

    In this study, the material and electrical properties of La2O3/SiO2/4H-SiC metal-oxide-semiconductor (MOS) capacitors are systematically characterized. Thermal oxidization SiO2 with varying thickness (0 nm, 3.36 nm, 5 nm, 8 nm, and 30 nm) were coated with La2O3 using atomic layer deposition on n-type 4H-SiC. The stacking oxides were measured using atomic force microscopy, transmission electron microscopy, and x-ray photoelectron spectroscopy, and the MOS capacitors were measured by capacitance-voltage and current-voltage measurements. The results demonstrate that the main gate current leakage mechanisms are dependent on the thickness of the SiO2 oxide under the applied electric field. The primary mechanism for current leakage from the La2O3/4H-SiC MOS capacitor follows the Schottky emission mechanism due to its low conduction band offset. In contrast, the current leakage mechanism for the capacitor with a 3.36 nm SiO2 layer follows the Poole-Frenkel emission mechanism on account of its high trap charge density in the gate dielectric and at the interface. When the thickness of the SiO2 layer increases to 8 nm, lower leakage current is observed by reason of the low trap charge density and high conduction band offset when E ≤ 5 MV/cm. As the electric field strength increases to 5 MV/cm and 5.88 MV/cm (30 nm SiO2: 4.8 MV/cm), the main current leakage mechanism changes to the Fowler-Nordheim tunneling mechanism, which indicates that the La2O3/SiO2 stacking structure can improve the properties of MOS capacitors.

  2. Children's school-breakfast reports and school-lunch reports (in 24-h dietary recalls): conventional and reporting-error-sensitive measures show inconsistent accuracy results for retention interval and breakfast location.

    PubMed

    Baxter, Suzanne D; Guinn, Caroline H; Smith, Albert F; Hitchcock, David B; Royer, Julie A; Puryear, Megan P; Collins, Kathleen L; Smith, Alyssa L

    2016-04-14

    Validation-study data were analysed to investigate retention interval (RI) and prompt effects on the accuracy of fourth-grade children's reports of school-breakfast and school-lunch (in 24-h recalls), and the accuracy of school-breakfast reports by breakfast location (classroom; cafeteria). Randomly selected fourth-grade children at ten schools in four districts were observed eating school-provided breakfast and lunch, and were interviewed under one of eight conditions created by crossing two RIs ('short'--prior-24-hour recall obtained in the afternoon and 'long'--previous-day recall obtained in the morning) with four prompts ('forward'--distant to recent, 'meal name'--breakfast, etc., 'open'--no instructions, and 'reverse'--recent to distant). Each condition had sixty children (half were girls). Of 480 children, 355 and 409 reported meals satisfying criteria for reports of school-breakfast and school-lunch, respectively. For breakfast and lunch separately, a conventional measure--report rate--and reporting-error-sensitive measures--correspondence rate and inflation ratio--were calculated for energy per meal-reporting child. Correspondence rate and inflation ratio--but not report rate--showed better accuracy for school-breakfast and school-lunch reports with the short RI than with the long RI; this pattern was not found for some prompts for each sex. Correspondence rate and inflation ratio showed better school-breakfast report accuracy for the classroom than for cafeteria location for each prompt, but report rate showed the opposite. For each RI, correspondence rate and inflation ratio showed better accuracy for lunch than for breakfast, but report rate showed the opposite. When choosing RI and prompts for recalls, researchers and practitioners should select a short RI to maximise accuracy. Recommendations for prompt selections are less clear. As report rates distort validation-study accuracy conclusions, reporting-error-sensitive measures are recommended. PMID

  3. Predicting survival time for cold exposure

    NASA Astrophysics Data System (ADS)

    Tikuisis, Peter

    1995-06-01

    The prediction of survival time (ST) for cold exposure is speculative as reliable controlled data of deep hypothermia are unavailable. At best, guidance can be obtained from case histories of accidental exposure. This study describes the development of a mathematical model for the prediction of ST under sedentary conditions in the cold. The model is based on steady-state heat conduction in a single cylinder comprised of a core and two concentric annular shells representing the fat plus skin and the clothing plus still boundary layer, respectively. The ambient condition can be either air or water; the distinction is made by assigning different values of insulation to the still boundary layer. Metabolic heat production ( M) is comprised of resting and shivering components with the latter predicted by temperature signals from the core and skin. Where the cold exposure is too severe for M to balance heat loss, ST is largely determined by the rate of heat loss from the body. Where a balance occurs, ST is governed by the endurance time for shivering. End of survival is marked by the deep core temperature reaching a value of 30° C. The model was calibrated against survival data of cold water (0 to 20° C) immersion and then applied to cold air exposure. A sampling of ST predictions for the nude exposure of an average healthy male in relatively calm air (1 km/h wind speed) are the following: 1.8, 2.5, 4.1, 9.0, and >24 h for -30, -20, -10, 0, and 10° C, respectively. With two layers of loose clothing (average thickness of 1 mm each) in a 5 km/h wind, STs are 4.0, 5.6, 8.6, 15.4, and >24 h for -50, -40, -30, -20, and -10° C. The predicted STs must be weighted against the extrapolative nature of the model. At present, it would be prudent to use the predictions in a relative sense, that is, to compare or rank-order predicted STs for various combinations of ambient conditions and clothing protection.

  4. SOURCES AND PATHWAYS OF LEAD EXPOSURE

    EPA Science Inventory

    Exposure is defined here as the amount of a substance that comes into contact with an absorbing surface during a specified period of time. The normal units of exposure are expressed as micrograms per day. The two components of exposure are the concentration of the substance in ...

  5. Changes in peak oxygen uptake and plasma volume in fit and unfit subjects following exposure to a simulation of microgravity

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.

    1998-01-01

    To test the hypothesis that the magnitude of reduction in plasma volume and work capacity following exposure to simulated microgravity is dependent on the initial level of aerobic fitness, peak oxygen uptake (VO2peak) was measured in a group of physically fit subjects and compared with VO2peak in a group of relatively unfit subjects before and after 10 days of continuous 6 degrees head-down tilt (HDT). Ten fit subjects (40 +/- 2 year) with mean +/- SE VO2peak = 48.9 +/- 1.7 mL kg-1 min-1 were matched for age, height, and lean body weight with 10 unfit subjects (VO2peak = 37.7 +/- 1.6 mL kg-1 min-1). Before and after HDT, plasma, blood, and red cell volumes and body composition were measured and all subjects underwent a graded supine cycle ergometer test to determine VO2peak period needed. Reduced VO2peak in fit subjects (-16.2%) was greater than that of unfit subjects (-6.1%). Similarly, reductions in plasma (-18.3%) and blood volumes (-16.0%) in fit subjects were larger than those of unfit subjects (blood volume = -5.6%; plasma volume = -6.6%). Reduced plasma volume was associated with greater negative body fluid balance during the initial 24 h of HDT in the fit group (912 +/- 154 mL) compared with unfit subjects (453 +/- 200 mL). The percentage change for VO2peak correlated with percentage change in plasma volume (r = +0.79). Following exposure to simulated microgravity, fit subjects demonstrated larger reductions in VO2peak than unfit subjects which was associated with larger reductions in plasma and blood volume. These data suggest that the magnitude of physical deconditioning induced by exposure to microgravity without intervention of countermeasures was influenced by the initial fitness of the subjects.

  6. The Influence of Red Light Exposure at Night on Circadian Metabolism and Physiology in Sprague–Dawley Rats

    PubMed Central

    Dauchy, Robert T; Wren, Melissa A; Dauchy, Erin M; Hoffman, Aaron E; Hanifin, John P; Warfield, Benjamin; Jablonski, Michael R; Brainard, George C; Hill, Steven M; Mao, Lulu; Dobek, Georgina L; Dupepe, Lynell M; Blask, David E

    2015-01-01

    Early studies on rodents showed that short-term exposure to high-intensity light (> 70 lx) above 600 nm (red-appearing) influences circadian neuroendocrine and metabolic physiology. Here we addressed the hypothesis that long-term, low-intensity red light exposure at night (rLEN) from a ‘safelight’ emitting no light below approximately 620 nm disrupts the nocturnal circadian melatonin signal as well as circadian rhythms in circulating metabolites, related regulatory hormones, and physiologic parameters. Male Sprague–Dawley rats (n = 12 per group) were maintained on control 12:12-h light:dark (300 lx; lights on, 0600) or experimental 12:12 rLEN (8.1 lx) lighting regimens. After 1 wk, rats underwent 6 low-volume blood draws via cardiocentesis (0400, 0800, 1200, 1600, 2000, and 2400) over a 4-wk period to assess arterial plasma melatonin, total fatty acid, glucose, lactic acid, pO2, pCO2, insulin, leptin and corticosterone concentrations. Results revealed plasma melatonin levels (mean ± 1 SD) were high in the dark phase (197.5 ± 4.6 pg/mL) and low in the light phase (2.6 ± 1.2 pg/mL) of control conditions and significantly lower than controls under experimental conditions throughout the 24-h period (P < 0.001). Prominent circadian rhythms of plasma levels of total fatty acid, glucose, lactic acid, pO2, pCO2, insulin, leptin, and corticosterone were significantly (P < 0.05) disrupted under experimental conditions as compared with the corresponding entrained rhythms under control conditions. Therefore, chronic use of low-intensity rLEN from a common safelight disrupts the circadian organization of neuroendocrine, metabolic, and physiologic parameters indicative of animal health and wellbeing. PMID:25651090

  7. Captan exposure and evaluation of a pesticide exposure algorithm among orchard pesticide applicators in the Agricultural Health Study.

    PubMed

    Hines, Cynthia J; Deddens, James A; Jaycox, Larry B; Andrews, Ronnee N; Striley, Cynthia A F; Alavanja, Michael C R

    2008-04-01

    Pesticide exposure assessment in the Agricultural Health Study (AHS) has relied upon two exposure metrics: lifetime exposure days and intensity-weighted lifetime exposure days, the latter incorporating an intensity score computed from a questionnaire-based algorithm. We evaluated this algorithm using actual fungicide exposure measurements from AHS private orchard applicators. Captan was selected as a marker of fungicide exposure. Seventy-four applicators from North Carolina and Iowa growing apples and/or peaches were sampled on 2 days they applied captan in 2002 and 2003. Personal air, hand rinse, 10 dermal patches, a pre-application first-morning urine and a subsequent 24-h urine sample were collected from each applicator per day. Environmental samples were analyzed for captan, and urine samples were analyzed for cis-1,2,3,6-tetrahydrophthalimide (THPI). Task and personal protective equipment information needed to compute an individual's algorithm score was also collected. Differences in analyte detection frequency were tested in a repeated logistic regression model. Mixed-effects models using maximum-likelihood estimation were employed to estimate geometric mean exposures and to evaluate the measured exposure data against the algorithm. In general, captan and THPI were detected significantly more frequently in environmental and urine samples collected from applicators who used air blast sprayers as compared to those who hand sprayed. The AHS pesticide exposure intensity algorithm, while significantly or marginally predictive of thigh and forearm captan exposure, respectively, did not predict air, hand rinse or urinary THPI exposures. The algorithm's lack of fit with some exposure measures among orchard fungicide applicators may be due in part to the assignment of equal exposure weights to air blast and hand spray application methods in the current algorithm. Some modification of the algorithm is suggested by these results. PMID:18326518

  8. Proteomic Analysis of Cellular Response Induced by Multi-Walled Carbon Nanotubes Exposure in A549 Cells

    PubMed Central

    Zhang, Xing; Jia, Zhenyu; Gao, Xiangjing; Jiang, Ying; Yan, Chunlan; Duerksen-Hughes, Penelope J.; Chen, Fanqing Frank; Li, Hongjuan; Zhu, Xinqiang; Yang, Jun

    2014-01-01

    The wide application of multi-walled carbon nanotubes (MWCNT) has raised serious concerns about their safety on human health and the environment. However, the potential harmful effects of MWCNT remain unclear and contradictory. To clarify the potentially toxic effects of MWCNT and to elucidate the associated underlying mechanisms, the effects of MWCNT on human lung adenocarcinoma A549 cells were examined at both the cellular and the protein level. Cytotoxicity and genotoxicity were examined, followed by a proteomic analysis (2-DE coupled with LC-MS/MS) of the cellular response to MWCNT. Our results demonstrate that MWCNT induces cytotoxicity in A549 cells only at relatively high concentrations and longer exposure time. Within a relatively low dosage range (30 µg/ml) and short time period (24 h), MWCNT treatment does not induce significant cytotoxicity, cell cycle changes, apoptosis, or DNA damage. However, at these low doses and times, MWCNT treatment causes significant changes in protein expression. A total of 106 proteins show altered expression at various time points and dosages, and of these, 52 proteins were further identified by MS. Identified proteins are involved in several cellular processes including proliferation, stress, and cellular skeleton organization. In particular, MWCNT treatment causes increases in actin expression. This increase has the potential to contribute to increased migration capacity and may be mediated by reactive oxygen species (ROS). PMID:24454774

  9. Measurement of DNA damage after exposure to electromagnetic radiation in the cellular phone communication frequency band (835.62 and 847.74 MHz).

    PubMed

    Malyapa, R S; Ahern, E W; Straube, W L; Moros, E G; Pickard, W F; Roti Roti, J L

    1997-12-01

    Mouse C3H 10T1/2 fibroblasts and human glioblastoma U87MG cells were exposed to cellular phone communication frequency radiations to investigate whether such exposure produces DNA damage in in vitro cultures. Two types of frequency modulations were studied: frequency-modulated continuous-wave (FMCW), with a carrier frequency of 835.62 MHz, and code-division multiple-access (CDMA) centered on 847.74 MHz. Exponentially growing (U87MG and C3H 10T1/2 cells) and plateau-phase (C3H 10T1/2 cells) cultures were exposed to either FMCW or CDMA radiation for varying periods up to 24 h in specially designed radial transmission lines (RTLs) that provided relatively uniform exposure with a specific absorption rate (SAR) of 0.6 W/kg. Temperatures in the RTLs were monitored continuously and maintained at 37 +/- 0.3 degrees C. Sham exposure of cultures in an RTL (negative control) and 137Cs gamma-irradiated samples (positive control) were included with every experiment. The alkaline comet assay as described by Olive et al. (Exp. Cell Res. 198, 259-269, 1992) was used to measure DNA damage. No significant differences were observed between the test group exposed to FMCW or CDMA radiation and the sham-treated negative controls. Our results indicate that exposure of cultured mammalian cells to cellular phone communication frequencies under these conditions at an SAR of 0.6 W/kg does not cause DNA damage as measured by the alkaline comet assay. PMID:9399708

  10. Exposure to medium and high ambient levels of ozone causes adverse systemic inflammatory and cardiac autonomic effects.

    PubMed

    Arjomandi, Mehrdad; Wong, Hofer; Donde, Aneesh; Frelinger, Jessica; Dalton, Sarah; Ching, Wendy; Power, Karron; Balmes, John R

    2015-06-15

    Epidemiological evidence suggests that exposure to ozone increases cardiovascular morbidity. However, the specific biological mechanisms mediating ozone-associated cardiovascular effects are unknown. To determine whether short-term exposure to ambient levels of ozone causes changes in biomarkers of cardiovascular disease including heart rate variability (HRV), systemic inflammation, and coagulability, 26 subjects were exposed to 0, 100, and 200 ppb ozone in random order for 4 h with intermittent exercise. HRV was measured and blood samples were obtained immediately before (0 h), immediately after (4 h), and 20 h after (24 h) each exposure. Bronchoscopy with bronchoalveolar lavage (BAL) was performed 20 h after exposure. Regression modeling was used to examine dose-response trends between the endpoints and ozone exposure. Inhalation of ozone induced dose-dependent adverse changes in the frequency domains of HRV across exposures consistent with increased sympathetic tone [increase of (parameter estimate ± SE) 0.4 ± 0.2 and 0.3 ± 0.1 in low- to high-frequency domain HRV ratio per 100 ppb increase in ozone at 4 h and 24 h, respectively (P = 0.02 and P = 0.01)] and a dose-dependent increase in serum C-reactive protein (CRP) across exposures at 24 h [increase of 0.61 ± 0.24 mg/l in CRP per 100 ppb increase in ozone (P = 0.01)]. Changes in HRV and CRP did not correlate with ozone-induced local lung inflammatory responses (BAL granulocytes, IL-6, or IL-8), but changes in HRV and CRP were associated with each other after adjustment for age and ozone level. Inhalation of ozone causes adverse systemic inflammatory and cardiac autonomic effects that may contribute to the cardiovascular mortality associated with short-term exposure. PMID:25862833

  11. Pulmonary function and clearance after prolonged sulfuric acid aerosol exposure

    SciTech Connect

    Ives, P.J. ); Gerrity, T.R.; DeWitt, P.; Folinsbee, L.J. )

    1991-03-15

    The authors studied pulmonary function and clearance responses after a 4 H exposure to 75-100 {mu}g/m{sup 3} sulfuric acid aerosol (SAA). Healthy subjects, who exercised for 30 min/H at ventilation of about 25 L/min, were exposed once to clean air and once to SAA. Oral hygiene and acidic juice gargle were used to minimize oral ammonia. Lung function tests, including spirometry, plethysmography, and partial flow-volume (PEFV) curves were performed before and after exposure. Clearance of 99m-Technetium labeled iron oxide was assessed after each exposure. The first moment of fractional tracheobronchial retention (M1TBR), after correcting for 24 H retention and normalizing to time zero, was used as an index of clearance. There were no significant changes in lung volumes, airways resistance, or maximum expiratory flows after SAA exposure. Flow at 40% of total lung capacity on PEFV curves decreased 17% (NS) after SAA exposure. Tracheobronchial clearance was accelerated after a single exposure to SAA; M1TBR decreased from 73 {plus minus} 5 min (air) to 69 {plus minus} 5 min (SAA). These results suggest that acute prolonged exposure to low levels of SAA has minimal effects on lung mechanics in healthy subjects but does produce a modest acceleration of particle clearance.

  12. Impact of Dilution and Polymerization on Cytotoxicity of Dentin Adhesives to Human Gingival Fibroblasts: Early Exposure Time

    PubMed Central

    Banava, Sepideh; Najibfard, Kaveh; Garcia-Godoy, Franklin; Saghiri, Mohammad Ali; Ghahremani, Mohammad Hossein; Ostad, Naser

    2015-01-01

    Background and aims. The aim of this study was to evaluate the effect of dilution and curing methods of an etch-and-rinse adhesive and a self-etching primer from the same manufacturer at early exposure time on cytotoxicity of primary human gingival fibroblasts. Materials and methods. Primary human gingival fibroblasts were exposed to different dilutions of Adper Single Bond (ASB) and Adper Prompt L-Pop (APL) (3M ESPE, USA). They were evaluated in unpolymerized mode for 20 s, 5 min and 24 h and in polymerized mode for 24 h and 48 h. Cytotoxicity was evaluated using three cytotoxic tests (MTT, cell counting and DNA condensation). Data was analyzed by a one-way ANOVA and Post Hoc Tukey HSD test. Results. Cytotoxicity tests revealed that unpolymerized APL was more cytotoxic compared to ASB after 20 s (P<0.05). By increasing the time to 5 min and 24 h, ASB was more cytotoxic than APL with lower dilutions. Polymerized ASB was more toxic than APL. Conclusion. Both adhesives were cytotoxic in different dilutions, times and curing modes. Cytotoxicity of the unpolymerized self-etching primer (APL) was more than etch-and-rinse adhesive (ASB) in 20 s, which is important clinically and dentists should be aware of the harmful effects and try to minimize it by curing and rinsing soon after composite resin insertion. ASB was more cytotoxic at 5 min and 24h. PMID:26697147

  13. Effects of flame made zinc oxide particles in human lung cells - a comparison of aerosol and suspension exposures

    PubMed Central

    2012-01-01

    Background Predominantly, studies of nanoparticle (NPs) toxicology in vitro are based upon the exposure of submerged cell cultures to particle suspensions. Such an approach however, does not reflect particle inhalation. As a more realistic simulation of such a scenario, efforts were made towards direct delivery of aerosols to air-liquid-interface cultivated cell cultures by the use of aerosol exposure systems. This study aims to provide a direct comparison of the effects of zinc oxide (ZnO) NPs when delivered as either an aerosol, or in suspension to a triple cell co-culture model of the epithelial airway barrier. To ensure dose–equivalence, ZnO-deposition was determined in each exposure scenario by atomic absorption spectroscopy. Biological endpoints being investigated after 4 or 24h incubation include cytotoxicity, total reduced glutathione, induction of antioxidative genes such as heme-oxygenase 1 (HO–1) as well as the release of the (pro)-inflammatory cytokine TNFα. Results Off-gases released as by-product of flame ZnO synthesis caused a significant decrease of total reduced GSH and induced further the release of the cytokine TNFα, demonstrating the influence of the gas phase on aerosol toxicology. No direct effects could be attributed to ZnO particles. By performing suspension exposure to avoid the factor “flame-gases”, particle specific effects become apparent. Other parameters such as LDH and HO–1 were not influenced by gaseous compounds: Following aerosol exposure, LDH levels appeared elevated at both timepoints and the HO–1 transcript correlated positively with deposited ZnO-dose. Under submerged conditions, the HO–1 induction scheme deviated for 4 and 24h and increased extracellular LDH was found following 24h exposure. Conclusion In the current study, aerosol and suspension-exposure has been compared by exposing cell cultures to equivalent amounts of ZnO. Both exposure strategies differ fundamentally in their dose–response pattern

  14. Criminal exposure.

    PubMed

    1999-08-01

    A 39-year-old man who had sex with a 16-year-old boy, was sentenced to five years in prison. The defendant pleaded guilty to statutory rape and criminal exposure to HIV. The boy discovered that the man was taking HIV medications, and the man subsequently disclosed his treatment after being arrested. PMID:11367003

  15. 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 ...

  16. 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

  17. A Role for the PERIOD:PERIOD Homodimer in the Drosophila Circadian Clock

    PubMed Central

    Wolf, Eva; Stanewsky, Ralf

    2009-01-01

    Circadian clocks in eukaryotes rely on transcriptional feedback loops, in which clock genes repress their own transcription resulting in molecular oscillations with a period of ∼24 h. In Drosophila, the clock proteins Period (PER) and Timeless (TIM) operate in such a feedback loop, whereby they first accumulate in the cytoplasm of clock cells as a heterodimer. Nuclear translocation of the complex or the individual PER and TIM proteins is followed by repression of per and tim transcription, whereby PER seems to act as the prime repressor. We found that in addition to PER:TIM complexes, functional PER:PER homodimers exist in flies. Specific disruption of PER homodimers results in drastically impaired behavioral and molecular rhythmicity, pointing the biological importance of this clock protein complex. Analysis of PER subcellular distribution and repressor competence in the PER dimer mutant revealed defects in PER nuclear translocation and a disruption of rhythmic period transcription. The striking similarity of these phenotypes with that of reduced CKII activity suggests that the formation or function of the PER dimer is closely linked to this kinase. Our results confirm a previous structural model for PER and provide strong evidence that PER homodimers are important for circadian clock function. PMID:19402744

  18. Neonatal endotoxin exposure changes neuroendocrine, cardiovascular function and mortality during polymicrobial sepsis in adult rats.

    PubMed

    Saia, Rafael Simone; Oliveira-Pelegrin, Gabriela Ravanelli; da Silva, Maria Emília Nadaletto Bonifácio; Aguila, Fábio Alves; Antunes-Rodrigues, José; Rocha, Maria José Alves; Cárnio, Evelin Capellari

    2011-08-01

    Our aim was to investigate whether neonatal LPS challenge may improve hormonal, cardiovascular response and mortality, this being a beneficial adaptation when adult rats are submitted to polymicrobial sepsis by cecal ligation and puncture (CLP). Fourteen days after birth, pups received an intraperitoneal injection of lipopolysaccharide (LPS; 100μg/kg) or saline. After 8-12 weeks, they were submitted to CLP, decapitated 4, 6 or 24h after surgery and blood was collected for vasopressin (AVP), corticosterone and nitrate measurement, while AVP contents were measured in neurohypophysis, supra-optic (SON) and paraventricular (PVN) nuclei. Moreover, rats had their mean arterial pressure (MAP) and heart rate (HR) evaluated, and mortality and bacteremia were determined at 24h. Septic animals with neonatal LPS exposure had higher plasma AVP and corticosterone levels, and higher c-Fos expression in SON and PVN at 24h after surgery when compared to saline treated rats. The LPS pretreated group showed increased AVP content in SON and PVN at 6h, while we did not observe any change in neurohypophyseal AVP content. The nitrate levels were significantly reduced in plasma at 6 and 24h after surgery, and in both hypothalamic nuclei only at 6h. Septic animals with neonatal LPS exposure showed increase in MAP during the initial phase of sepsis, but HR was not different from the neonatal saline group. Furthermore, neonatally LPS exposed rats showed a significant decrease in mortality rate as well as in bacteremia. These data suggest that neonatal LPS challenge is able to promote beneficial effects on neuroendocrine and cardiovascular responses to polymicrobial sepsis in adulthood. PMID:21549159

  19. A residue-based toxicokinetic model for pulse-exposure toxicity in aquatic systems

    SciTech Connect

    Hickie, B.E.; McCarty, L.S.; Dixon, D.G.

    1995-12-01

    This pulse-exposure model (PULSETOX) is based on the simple one-compartment first-order kinetics (1CFOK) equation. It tracks the accumulation of waterborne organic chemicals by fish and predicts acute toxicity by means of previously established relationships between whole-body residues and lethality. The predictive capabilities of the model were tested with a data set of 27 acute pulse-exposure lethality tests with larval fathead minnows (Pimephales promelas) exposed to pentachlorophenol (PCP). Tests included eight single exposures (2 to 96 h) and 19 multiple exposures, which varied in the number (2 to 15) and duration (2 to 24 h) of pulses, and time interval between pulses (6 to 24 h). Experimental work included determination of 1CFOK kinetics parameters from [{sup 14}C]PCP uptake and clearance, and from time-toxicity curves. Lethality was expected in any exposure regime where the fish reaches or exceeds the critical body residue (CBR) of 0.30 mmol PCP/kg fish (SD, {+-} 0.02; n = 11). Using the CBR endpoint, the model accounted for between 90 and 93% of variability in the observed lethality data, depending on the toxicokinetic parameters employed. Predictive power of the model was optimized by using kinetics parameters derived from the toxicity curve for pulse-toxicity tests as shown by the regression: predicted LC50 = 1.04 {center_dot} (observed LC50) + 0.01 (p < 0.001, r{sup 2} = 0.94, n = 27).

  20. Tadpole swimming performance and activity affected by acute exposure to sublethal levels of carbaryl

    USGS Publications Warehouse

    Bridges, C.M.

    1997-01-01

    General activity and swimming performance (i.e., sprint speed and distance) of plains leopard frog tadpoles (Rana blairi) were examined after acute exposure to three sublethal concentrations of carbaryl (3.5, 5.0, and 7.2 mg/L). Both swimming performance and spontaneous swimming activity are important for carrying out life history functions (e.g., growth and development) and for escaping from predators. Measured tadpole activity diminished by nearly 90% at 3.5 mg/L carbaryl and completely ceased at 7.2 mg/L. Sprint speed and sprint distance also decreased significantly following exposure. Carbaryl affected both swimming performance and activity after just 24 h, suggesting that 24 h may be an adequate length of exposure to determine behavioral effects on tadpoles. Slight recovery of activity levels was noted at 24 and 48 h post-exposure; no recovery of swimming performance was observed. Reduction in activity and swimming performance may result in increased predation rates and, because activity is closely associated with feeding, may result in slowed growth leading to a failure to emerge before pond drying or an indirect reduction in adult fitness. Acute exposure to sublethal toxicants such as carbaryl may not only affect immediate survival of tadpoles but also impact critical life history functions and generate changes at the local population level.

  1. Occupational exposure of hairdressers to [14C]-para-phenylenediamine-containing oxidative hair dyes: a mass balance study.

    PubMed

    Hueber-Becker, Frédérique; Nohynek, Gerhard J; Dufour, Eric K; Meuling, Wim J A; de Bie, Albertus Th H J; Toutain, Herve; Bolt, Hermann M

    2007-01-01

    We monitored the exposure of hairdressers to oxidative hair dyes for 6 working days under controlled conditions. Eighteen professional hairdressers (3/day) coloured hairdresser's training heads bearing natural human hair (hair length: approximately 30 cm) for 6 h/working day with a dark-shade oxidative hair dye containing 2% [14C]-para-phenylenediamine (PPD). Three separate phases of hair dyeing were monitored: (A) dye preparation/hair dyeing, (B) rinsing/shampooing/conditioning and (C) cutting/drying/styling. Ambient air and personal monitoring samples (vapours and particles), nasal and hand rinses were collected during all study phases. Urine (pre-exposure, quantitative samples for the 0-12, 12-24, 24-48 h periods after start of exposure) and blood samples (blank, 4, 8 or 24 h) were collected from all exposed subjects. Radioactivity was determined in all biological samples and study materials, tools and washing liquids, and a [14C]-mass balance was performed daily. No adverse events were noted during the study. Waste, equipment, gloves and coveralls contained 0.41+/-0.16%, dye mixing bowls 2.88+/-0.54%, hair wash 45.47+/-2.95%, hair+scalp 53.46+/-4.06% of the applied radioactivity, respectively. Plasma levels were below the limit of quantification (10 ng PPDeq/mL). Total urinary 0-48 h excretion of [14C] levels ranged from a total of <2-18 microg PPDeq and was similar in subjects exposed during the different phases of hair dyeing. Minimal air levels at or slightly above the limit of quantification were found in a few personal air monitoring samples during the phases of hair dyeing and hair cutting, but not during the rinsing phase. Air area monitoring samples or nasal rinses contained no measurable radioactivity. Hand residues ranged from 0.006 to 0.15 microg PPDeq/cm2, and were found predominantly after the cutting/drying phase. The mean mass balance of [14C] across the six study days was 102.50+/-2.20%. Overall, the mean, total systemic exposure of hairdressers

  2. In utero exposure to benzene increases embryonic c-Myb and Pim-1 protein levels in CD-1 mice

    SciTech Connect

    Wan, Joanne; Winn, Louise M.

    2008-05-01

    Benzene is a known human leukemogen, but its role as an in utero leukemogen remains controversial. Epidemiological studies have correlated parental exposure to benzene with an increased incidence of childhood leukemias. We hypothesize that in utero exposure to benzene may cause leukemogenesis by affecting the embryonic c-Myb/Pim-1 signaling pathway and that this is mediated by oxidative stress. To investigate this hypothesis, pregnant CD-1 mice were treated with either 800 mg/kg of benzene or corn oil (i.p.) on days 10 and 11 of gestation and in some cases pretreated with 25 kU/kg of PEG-catalase. Phosphorylated and total embryonic c-Myb and Pim-1 protein levels were assessed using Western blotting and maternal and embryonic oxidative stress were assessed by measuring reduced to oxidized glutathione ratios. Our results show increased oxidative stress at 4 and 24 h after exposure, increased phosphorylated Pim-1 protein levels 4 h after benzene exposure, and increased Pim-1 levels at 24 and 48 h after benzene exposure. Embryonic c-Myb levels were elevated at 24 h after exposure. PEG-catalase pretreatment prevented benzene-mediated increases in embryonic c-Myb and Pim-1 protein levels, and benzene-induced oxidative stress. These results support a role for ROS in c-Myb and Pim-1 alterations after in utero benzene exposure.

  3. Evolution of periodicity in periodical cicadas

    PubMed Central

    Ito, Hiromu; Kakishima, Satoshi; Uehara, Takashi; Morita, Satoru; Koyama, Takuya; Sota, Teiji; Cooley, John R.; Yoshimura, Jin

    2015-01-01

    Periodical cicadas (Magicicada spp.) in the USA are famous for their unique prime-numbered life cycles of 13 and 17 years and their nearly perfectly synchronized mass emergences. Because almost all known species of cicada are non-periodical, periodicity is assumed to be a derived state. A leading hypothesis for the evolution of periodicity in Magicicada implicates the decline in average temperature during glacial periods. During the evolution of periodicity, the determinant of maturation in ancestral cicadas is hypothesized to have switched from size dependence to time (period) dependence. The selection for the prime-numbered cycles should have taken place only after the fixation of periodicity. Here, we build an individual-based model of cicadas under conditions of climatic cooling to explore the fixation of periodicity. In our model, under cold environments, extremely long juvenile stages lead to extremely low adult densities, limiting mating opportunities and favouring the evolution of synchronized emergence. Our results indicate that these changes, which were triggered by glacial cooling, could have led to the fixation of periodicity in the non-periodical ancestors. PMID:26365061

  4. Effect of light exposure on in vitro germination and germ tube growth of eight species of rust fungi.

    PubMed

    Buck, James W; Dong, Weibo; Mueller, Daren S

    2010-01-01

    The effects of light on urediniospore germination and germ tube elongation was studied with eight species of rust fungi that infect ornamental plants or row crops. Exposure of six species of fungi to cool